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Sample records for ysgg laser estudo

  1. A Pilot Study of Skin Resurfacing Using the 2,790-nm Erbium:YSGG Laser System.

    Science.gov (United States)

    Rhie, Jong Won; Shim, Jeong Su; Choi, Won Seok

    2015-01-01

    The erbium:yttrium scandium gallium garnet (Er:YSGG) laser differs from other laser techniques by having a faster and higher cure rate. Since the Er:YSGG laser causes an appropriate proportion of ablation and coagulation, it has advantages over the conventional carbon dioxide (CO2) laser and the erbium-doped yttrium aluminum garnet (Er:YAG) laser, including heating tendencies and explosive vaporization. This research was conducted to explore the effects and safety of the Er:YSGG laser. Twenty patients participated in the pilot study of a resurfacing system using a 2,790-nm Er:YSGG laser. All patients received facial treatment by the 2,790-nm Er:YSGG laser system (Cutera) twice with a 4-week interval. Wrinkle reduction, reduction in pigment inhomogeneity, and improvement in tone and texture were measured. Study subjects included 15 women and five men. Re-epithelization occurred in all subjects 3 to 4 days after treatment, and wrinkle reduction, reduction in pigment inhomogeneity, and improvement in tone and texture within 6 months of treatment. The 2,790-nm YSGG laser technique had fewer complications and was effective in the improvement of scars, pores, wrinkles, and skin tone and color with one or two treatments. We expect this method to be effective for people with acne scars, pore scars, deep wrinkles, and uneven skin texture and color.

  2. A Pilot Study of Skin Resurfacing Using the 2,790-nm Erbium:YSGG Laser System

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    Jong Won Rhie

    2015-01-01

    Full Text Available BackgroundThe erbium:yttrium scandium gallium garnet (Er:YSGG laser differs from other laser techniques by having a faster and higher cure rate. Since the Er:YSGG laser causes an appropriate proportion of ablation and coagulation, it has advantages over the conventional carbon dioxide (CO2 laser and the erbium-doped yttrium aluminum garnet (Er:YAG laser, including heating tendencies and explosive vaporization. This research was conducted to explore the effects and safety of the Er:YSGG laser.MethodsTwenty patients participated in the pilot study of a resurfacing system using a 2,790-nm Er:YSGG laser. All patients received facial treatment by the 2,790-nm Er:YSGG laser system (Cutera twice with a 4-week interval. Wrinkle reduction, reduction in pigment inhomogeneity, and improvement in tone and texture were measured.ResultsStudy subjects included 15 women and five men. Re-epithelization occurred in all subjects 3 to 4 days after treatment, and wrinkle reduction, reduction in pigment inhomogeneity, and improvement in tone and texture within 6 months of treatment.ConclusionsThe 2,790-nm YSGG laser technique had fewer complications and was effective in the improvement of scars, pores, wrinkles, and skin tone and color with one or two treatments. We expect this method to be effective for people with acne scars, pore scars, deep wrinkles, and uneven skin texture and color.

  3. Root canal preparation with Er:YSGG laser

    Science.gov (United States)

    Benthin, Hartmut; Ertl, Thomas P.; Onal, B.; Schruender, Stephan; Mueller, Gerhard J.

    1994-12-01

    The high level of efficiency of hard tissue ablation with Er:YAG and Er:YSGG lasers is well known. Of these lasers it is possible only to transmit Er:YSGG laser radiation with OH reduced quartz fibers. Most of the fibers we use in this study were prepared as hemispherical fiber tips. Fifty single rooted teeth were divided into ten groups (n equals 5). After conventional opening of the pulp chamber, root canal preparation was performed in five groups under water only using the laser. In the other five groups preparation with K-files to size 35 was performed before treatment with laser radiation. All teeth were axially separated with direct access to the root canal and examined in SEM investigations. The groups were compared by measuring the areas with patent dentin tubules. Representative areas were examined by TEM. The temperature at the root surface was measured during laser irradiation with thermocouples positioned at several points. The in-vitro study of the effect of the high delivered energy (50 - 100 mJ per pulse) in the root canal showed a good ablation effect. Most of the dentin tubules were opened. The increase in temperature at the root surface was tolerable.

  4. Bonding performance of universal adhesives to er,cr:YSGG laser-irradiated enamel.

    Science.gov (United States)

    Ayar, Muhammet Kerim; Erdemir, Fatih

    2017-04-01

    Universal adhesives have been recently introduced for use as self-etch or etch-and-rinse adhesives depending on the dental substrate and clinical condition. However, their bonding effectiveness to laser-irradiated enamel is still not well-known. Thus, the aim of this study was to compare the shear bond strength (SBS) of universal adhesives (Single Bond Universal; Nova Compo-B Plus) applied to Er,Cr:YSGG laser-irradiated enamel with SBS of the same adhesives applied in self-etch and acid-etching modes, respectively. Crown segments of sixty bovine incisors were embedded into standardized acrylic blocks. Flattened enamel surfaces were prepared. Specimens were divided into six groups according to universal adhesives and application modes randomly (n = 10), as follows: Single Bond Universal/acid-etching mode; Nova Compo-B Plus/acid-etching mode; Single Bond Universal/self-etching mode; Nova Compo-B Plus/self-etching mode; and Single Bond Universal/Er,Cr:YSGG Laser-etching mode; Nova Compo-B Plus/Er,Cr:YSGG Laser-etching mode. After surface treatments, universal adhesives were applied onto surfaces. SBS was determined after storage in water for 24 h using a universal testing machine with a crosshead speed of 0.5 mm min -1 . Failure modes were evaluated using a stereomicroscope. Data was analyzed using two-way of analyses of variances (ANOVA) (p = 0.05). Two-way ANOVA revealed that adhesive had no effect on SBS (p = 0.88), but application mode significantly influenced SBS (p = 0.00). Acid-etching significantly increased SBS, whereas there are no significant differences between self-etch mode and laser-etching for both adhesives. The bond strength of universal adhesives may depend on application mode. Acid etching may significantly increase bond strength, while laser etching may provide similar bond strength when compared to self-etch mode. © 2016 Wiley Periodicals, Inc.

  5. Effect of Er,Cr:YSGG laser irradiation on bovine enamel surface during in-office tooth bleaching ex vivo.

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    Dionysopoulos, Dimitrios; Strakas, Dimitrios; Koliniotou-Koumpia, Eugenia; Koumpia, Effimia

    2017-07-01

    The aim of this in vitro study was to evaluate the effect of using Er,Cr:YSGG laser during in-office tooth bleaching on bovine enamel surface to evaluate the safety of this therapy on tooth tissues. Thirty-six enamel specimens were prepared from bovine incisors and divided into three groups: Group 1 specimens (control) received no bleaching treatment; Group 2 received a conventional in-office bleaching treatment (40 % H 2 O 2 ); Group 3 received laser-assisted bleaching procedure (40 % H 2 O 2 ) utilizing an Er,Cr:YSGG laser. The specimens were stored for 10 days after the bleaching treatment in artificial saliva. Vickers hardness was determined using a microhardness tester, and measurements for surface roughness were done using a VSI microscope. Three specimens for each experimental group were examined under SEM and mineral composition of the specimens was evaluated using EDS. Data were statistically analyzed using one-way ANOVA, Tukey's post hoc, Wilcoxon signed rank and Kruskal-Wallis tests (a = 0.05). The Vickers hardness of the enamel was reduced after in-office bleaching procedures (p  0.05), and no changes in mineral composition of the enamel were detected after in-office bleaching procedures (p > 0.05). The laser-assisted bleaching treatment with Er,Cr:YSGG laser did not influence the enamel surface compared to the conventional bleaching technique. The safety of the use of Er,Cr:YSGG laser during in-office tooth bleaching regarding the surface properties of the enamel was confirmed under in vitro conditions.

  6. Er,Cr:YSGG Laser as a Novel Method for Rebonding Failed Ceramic Brackets.

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    Sohrabi, Aydin; Jafari, Sanaz; Kimyai, Soodabeh; Rikhtehgaran, Sahand

    2016-10-01

    Since there is no standard method for rebonding loose ceramic brackets, the aim of this study was to evaluate the possibility of using Er,Cr:YSGG laser to eliminate the remaining composite materials from the base of ceramic brackets and to compare the bond strength of rebonded brackets with the new ones. Sixty-two extracted human premolars were mounted in acrylic cylinders. Thirty-one ceramic brackets were bonded, and shear bond strength was tested using Hounsfield testing machine. The remnants of the bonding material were removed from the bases of brackets using Er,Cr:YSGG laser. These brackets were rebonded to 31 fresh teeth and again shear bond strength was measured. Pattern of debonding was assessed in both cases under a stereomicroscope and graded according to ARI index. Data were analyzed with independent t-test and Fisher's exact test. Mean shear bond strength of the bond and rebond groups was 12.29 ± 5.46 and 10.58 ± 5.16 MPa, respectively. There were no significant differences between the two groups (p = 0.21). Pattern of bond failure was not statistically different between the two groups. Er,Cr:YSGG laser was effective in removing the remnants of bonding material from the base of ceramic brackets without any interference with the ceramic base itself, demonstrating that it might be a suitable method for rebonding ceramic brackets.

  7. Effects of an Er, Cr:YSGG laser on canine oral hard tissues

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    Rizoiu, Ioana-Mihaela; Kimmel, Andrew I.; Eversole, Lewis R.

    1996-12-01

    Beagle dogs were utilized to assess the biologic effects of an Er, Cr:YSGG hard tissue cutting laser and results were compared with conventional mechanical preparations of enamel and dentin. Intraoperative pulpal temperature fluctuations were recorded with thermocouples. The laser cuts failed to induce inflammation in the pulps except in teeth with intentional pulp exposures for both methods. No increase in temperature was detected with the laser. It is concluded that this laser system may be safely employed for tooth preparations without causing adverse pulpal effects.

  8. FT-Raman spectroscopic analysis of Nd:YAG and Er,Cr:YSGG laser irradiated enamel for preventive purposes

    Science.gov (United States)

    Ana, P. A.; Kauffmann, C. M. F.; Bachmann, L.; Soares, L. E. S.; Martin, A. A.; Gomes, A. S. L.; Zezell, D. M.

    2014-03-01

    This study evaluated the effect of combining laser irradiation with fluoride on an enamel microstructure and demineralization by FT-Raman spectroscopy (FTRS). Eighty human enamel slabs were divided into eight groups: (G1) untreated; (G2) acidulated phosphate fluoride application (APF—1.23% F- for 4 min) (G3) Nd:YAG irradiation (84.9 J cm-2, 60 mJ/pulse) (G4) Nd:YAG + APF; (G5) APF + Nd:YAG; (G6) Er,Cr:YSGG irradiation (2.8 J cm-2, 12.5 mJ/pulse) (G7) Er,Cr:YSGG + APF; and (G8) APF + Er,Cr:YSGG. After treatment, the samples were submitted to a ten-day pH-cycling model. Chemical changes were determined on the slabs before and after treatment, and also after pH-cycling, by FTRS in the range 400-4000 cm-1. The inorganic bands at 440, 590, 870, 960, 1100 cm-1, and the organic bands at 1270, 1450, 1670, 2945 cm-1 were considered. Demineralization promoted reduction in organic contents; Nd:YAG laser irradiation promoted loss of carbonate and organic content, while Er,Cr:YSGG did not produce significant changes in the relative band intensities of organic and inorganic contents of the enamel. In lased samples, no effects caused by pH-cycling on enamel were observed. In conclusion, laser treatment and its association with fluoride can somehow interfere with the demineralization dynamics, reducing its effects over the enamel.

  9. Comparing the efficiency of Er,Cr:YSGG laser and diode laser on human β-defensin-1 and IL-1β levels during the treatment of generalized aggressive periodontitis and chronic periodontitis.

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    Ertugrul, Abdullah Seckin; Tekin, Yasin; Talmac, Ahmet Cemil

    2017-11-01

    The aim of this study is to determine the suitability of the Er,Cr:YSGG and 940 ± 15-nm diode laser for the treatment of generalized aggressive periodontitis and chronic periodontitis by measuring the levels of human β-defensin-1 and IL-1β. A total of 26 patients were included in this study. The study was designed as a "split-mouth" experiment. We performed scaling and root planing in the right maxillary quadrant, scaling and root planning + Er,Cr:YSGG laser in the left maxillary quadrant, scaling and root planning + 940 ± 15-nm diode laser in the left mandibular quadrant, and only scaling and root planing in the right mandibular quadrant. The presence of human β-defensin-1 and IL-1β was analyzed with an ELISA. When the baseline and post-treatment human β-defensin-1 levels and IL-1β levels of the study groups were evaluated, a decrease in human β-defensin-1 and IL-1β were observed in the quadrant where the Er,Cr:YSGG laser was applied in both the generalized aggressive periodontitis group and the chronic periodontitis group. The use of the Er,Cr:YSGG laser at non-surgical periodontal treatment decreased both IL-1β and human β-defensin-1 levels. It is likely that Er,Cr:YSGG laser is more suitable for the treatment of generalized aggressive periodontitis and chronic periodontitis.

  10. Short-term clinical outcomes of laser supported periodontal treatment concept using Er,Cr:YSGG (2780nm) and diode (940 nm): a pilot study

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    Odor, Alin A.; Violant, Deborah; Badea, Victoria; Gutknecht, Norbert

    2016-03-01

    Backgrounds: Er,Cr:YSGG (2780nm) and diode (940 nm) lasers can be used adjacent to the conventional periodontal treatment as minimally invasive non-surgical devices. Aim: To describe the short-term clinical outcomes by combining Er,Cr:YSGG (2780nm) and diode 940 nm lasers in non-surgical periodontal treatment. Materials and methods: A total of 10 patients with periodontal disease (mild, moderate, severe) - 233 teeth and 677 periodontal pockets ranging from 4 mm to 12 mm - were treated with Er,Cr:YSGG (2780nm) and diode (940 nm) lasers in adjunct to manual and piezoelectric scaling and root planning (SRP). Periodontal parameters such as mean probing depth (PD), mean clinical attachment level (CAL) and mean bleeding on probing (BOP) were evaluated at baseline and 6 months after the laser treatment using an electronic periodontal chart. Results: At baseline, the mean PD was 4.06 ± 1.06 mm, mean CAL was 4.56 ± 1.43 mm, and mean BOP was 43.8 ± 23.84 %. At 6 months after the laser supported periodontal treatments the mean PD was 2.6 ± 0.58 mm (p laser wavelengths in adjunct to SRP offers significant improvements of periodontal clinical parameters such as PD, CAL and BOP. Keywords: Laser supported periodontal treatment concept, Er,Cr:YSGG and diode 940nm lasers, Scaling and root planning, Minimally invasive non-surgical device

  11. FT-Raman spectroscopic analysis of Nd:YAG and Er,Cr:YSGG laser irradiated enamel for preventive purposes

    International Nuclear Information System (INIS)

    Ana, P A; Kauffmann, C M F; Gomes, A S L; Bachmann, L; Soares, L E S; Martin, A A; Zezell, D M

    2014-01-01

    This study evaluated the effect of combining laser irradiation with fluoride on an enamel microstructure and demineralization by FT-Raman spectroscopy (FTRS). Eighty human enamel slabs were divided into eight groups: (G1) untreated; (G2) acidulated phosphate fluoride application (APF—1.23% F − for 4 min); (G3) Nd:YAG irradiation (84.9 J cm −2 , 60 mJ/pulse); (G4) Nd:YAG + APF; (G5) APF + Nd:YAG; (G6) Er,Cr:YSGG irradiation (2.8 J cm −2 , 12.5 mJ/pulse); (G7) Er,Cr:YSGG + APF; and (G8) APF + Er,Cr:YSGG. After treatment, the samples were submitted to a ten-day pH-cycling model. Chemical changes were determined on the slabs before and after treatment, and also after pH-cycling, by FTRS in the range 400−4000 cm −1 . The inorganic bands at 440, 590, 870, 960, 1100 cm −1 , and the organic bands at 1270, 1450, 1670, 2945 cm −1 were considered. Demineralization promoted reduction in organic contents; Nd:YAG laser irradiation promoted loss of carbonate and organic content, while Er,Cr:YSGG did not produce significant changes in the relative band intensities of organic and inorganic contents of the enamel. In lased samples, no effects caused by pH-cycling on enamel were observed. In conclusion, laser treatment and its association with fluoride can somehow interfere with the demineralization dynamics, reducing its effects over the enamel. (paper)

  12. Influence of Er,Cr:YSGG Laser Surface Treatments on Micro Push-Out Bond Strength of Fiber Posts to Composite Resin Core Materials

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    Mehrsima Ghavami-Lahiji

    2018-03-01

    Full Text Available Statement of problem: The bonding of fiber post to resin core or root dentin is challenged by limited penetration of resin material to the polymeric matrix of fiber posts. Objectives: The purpose of this study was to investigate the effect of Er,Cr:YSGG on micro push-out bond strength of glass fiber posts to resin core material. Materials and Methods: We used 2 commercially available fiber posts, Exacto (Angelus and White Post DC (FGM, which had similar coronal diameters. Specimens of each fiber post (n=36 were randomly divided into three subgroups (n=12 posts per group according to different surface treatment methods: control (no surface treatment, irradiation by 1W Er,Cr:YSGG, and irradiation by 1.5W Er,Cr:YSGG. A cylindrical plastic tube was placed around the post. Resin core material was filled into the tube and cured. Coronal portions of the posts were sectioned into 1-mm-thick slices. Then, the specimens were subjected to a thermocyling device for 3000 cycles. The micro push-out test was carried out using a Universal Testing Machine. Data were analyzed using one-way ANOVA followed by Tukey’s HSD post hoc test to investigate the effect of different surface treatments on each type of fiber post. Results: The 1.5W Er,Cr:YSGG laser statistically reduced micro push-out bond strength values in the Exacto groups (P0.05. Mode of failure analysis showed that mixed failure was the predominant failure type for all surface treatment groups. Conclusions: The beneficial effect of Er,Cr:YSGG laser application could not be confirmed based on the results of this in vitro study. Er,Cr:YSGG laser could not significantly enhance the bond strength values. However, the 1.5W laser statistically decreased micro push-out bond strength in the Exacto fiber posts.

  13. Laser Supported Reduction of Specific Microorganisms in the Periodontal Pocket with the Aid of an Er,Cr:YSGG Laser: A Pilot Study

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    N. Gutknecht

    2015-01-01

    Full Text Available Objective. The aim of this study was to evaluate the effectiveness of a radial firing tip of an Er,Cr:YSGG laser as an adjunct to a nonsurgical periodontal treatment. Methods. Twelve patients with chronic or aggressive periodontitis were treated by conventional periodontal treatment using ultrasonic devices and hand instruments and, additionally, in two quadrants with an Er,Cr:YSGG laser. A new radial firing tip (RFPT 14-5, Biolase was used with 1.5 W, 30 Hz, 11% air, 20% water, and pulse duration 140 μs. Microbiological smears were taken before treatment, one day after lasing, and three and six months after lasing. Pocket depths of all periodontal sites were measured before and six months after treatment. Results. The total bacterial load of Prevotella intermedia, Tannerella forsythia, Treponema denticola, Fusobacterium nucleatum, Porphyromonas gingivalis, and Aggregatibacter actinomycetemcomitans inside the pocket was reduced significantly throughout the whole examination time. Greater pocket depth reductions were observed in all groups. There was a slight higher reduction of pocket depth in the lased group after six months. Conclusions. These results support the thesis that Er,Cr:YSGG laser supported periodontal treatment leads to a significant reduction of periopathogenes and thereby helps the maintenance of periodontal health.

  14. Investigation of Coronal Leakage of Root Fillings after Smear Layer Removal with EDTA or Er,Cr:YSGG Laser through Capillary Flow Porometry

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    Tom Edgard Maria Vergauwen

    2014-01-01

    Full Text Available No studies have been performed evaluating the marginal seal of root fillings after direct exposure of root canal (RC walls to Er,Cr:YSGG laser irradiation. Therefore, 75 root filled teeth (5 × 15–cold lateral condensation were analyzed for through-and-through leakage (TTL using capillary flow porometry (CFP. The cleaning protocol determined the experimental groups: (1 irrigation with NaOCl 2.5% and EDTA 17% or standard protocol (SP, (2 SP + Er,Cr:YSGG lasing (dried RC, (3 NaOCl 2.5% + Er,Cr:YSGG lasing (dried RC, (4 SP + Er,Cr:YSGG lasing (wet RC, and (5 NaOCl 2.5% + Er,Cr:YSGG lasing (wet RC. Groups 6 to 10 consisted of the same filled teeth with resected apices. Resection was performed after the first CFP measurement. CFP was used to assess minimum, mean flow, and maximum pore diameters after 48 h. Statistics were performed using nonparametric tests (P>0.05. Additional three roots per group were submitted to SEM of the RC walls. TTL was observed in all groups without statistically significant differences between the different groups for minimum, mean, and maximum pore diameter (P>0.05. In this study, the use of EDTA and/or Er,Cr:YSGG laser did not reduce through-and-through leakage in nonresected and resected roots.

  15. The combined use of Er,Cr:YSGG laser and fluoride to prevent root dentin demineralization

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    Vinícius Rangel GERALDO-MARTINS

    2014-10-01

    Full Text Available The use of erbium lasers to prevent caries in enamel has shown positive results. However, it is not known if Er,Cr:YSGG laser can also be used to increase acid resistance of root dentine, which is another dental tissue susceptible to the action of cariogenic bacteria. Objective: To analyze the effects of the Er,Cr:YSGG laser (λ=2.78 μm, 20 Hz irradiation associated with 2% neutral sodium fluoride (NaF to prevent root dentin demineralization. Material and Methods: One hundred human root dentin samples were divided into 10 groups (G and treated as follows: G1: no treatment; G2: NaF; G3: laser (4.64 J/cm2 with water cooling (WC=5.4 mL/min; G4: laser (4.64 J/cm2 without WC; G5: laser (8.92 J/cm2 with WC; G6: laser (8.92 J/cm2 without WC; G7: laser (4.64 J/cm2 with WC and NaF; G8: laser (4.64 J/cm2 without WC and NaF; G9: laser (8.92 J/cm2 with WC and NaF; G10: laser (8.92 J/cm2 without WC and NaF. The NaF gel was applied alone or after 4 min of irradiation. After 14 days of acid challenge, the samples were sectioned and the Knoop microhardness (KHN test was done at different depths (30, 60, 90 and 120 μm from the outer dentin surface. Data were analyzed by one-way ANOVA and Fisher’s test (α=5%. Results: The results showed that G8 and G10 presented higher KHN than the G1 for the depths of 30 and 60 μm, indicating an increase of the acid resistance of the dentin in up to 35% (p<0.05. Conclusions: The use of Er,Cr:YSGG laser irradiation at 4.64 J/ cm2 and 8.92 J/cm2 without water cooling and associated with 2% NaF can increase the acid resistance of human root dentin.

  16. The effect of an Er,Cr:YSGG laser on external adaptation of healthy and decayed cavities

    International Nuclear Information System (INIS)

    Kabbach, William; Tonetto, Mateus Rodrigues; Campos, Edson Alves; Andrade, Marcelo Ferrarezi; Frizzera, Fausto; Zezéll, Denise Maria; Bandéca, Matheus Coelho; Borges, Alvaro Henrique

    2014-01-01

    The aim of this study was to evaluate the influence of chlorhexidine and Er,Cr:YSGG laser irradiation on the bond strength and external adaptation in mixed healthy and caries-affected class V cavities before and after thermal cycling. Thirty-six cavity preparations were made in mixed class V buccal human molars, half of them being artificially caries-induced. Any remaining affected dentin was removed from the cavity with a round burr at low speed. The teeth were divided into six groups, according to cleaning agent for both healthy and caries-induced dentin: no treatment, chlorhexidine and erbium, chromium-doped: yttrium, scandium, gallium, garnet (Er,Cr:YSGG) laser irradiation. A Filtek P90 (3M ESPE, St Paul, MN, USA) silorane adhesive restorative system was used. The specimens were subjected to 5000 thermal cycles (5–55 °C 60 min). Epoxy replicas were obtained to characterize the external adaptation under scanning electron microscopy. The average percentages of non-continuous margins were 5.41% and 6.49% in enamel dentin before thermal cycling and 25% and 33.7% after thermal cycling, respectively. The caries-affected and laser irradiated cavities showed higher non-continuous margins. Thermal cycling was able to raise the percentage of non-continuous margin for all groups. Chlorhexidine did not affect the marginal adaptation results, and the Er,Cr: YSGG laser irradiation showed significantly worse results compared with the control group. (paper)

  17. Spectrophotometric analysis of the effectiveness of a novel in-office laser-assisted tooth bleaching method using Er,Cr:YSGG laser.

    Science.gov (United States)

    Dionysopoulos, Dimitrios; Strakas, Dimitrios; Tolidis, Kosmas; Tsitrou, Effrosyni; Koumpia, Effimia; Koliniotou-Koumpia, Eugenia

    2017-11-01

    The purpose of this in vitro study was to compare the effectiveness of a novel Er,Cr:YSGG laser-assisted in-office tooth bleaching method with a conventional method by spectrophotometric analysis of the tooth color change. Furthermore, the influence of the application time of the bleaching gel on the effectiveness of the methods and the maintenance of the results 7 days and 1 month after the treatments were also evaluated. Twenty-four bovine incisors were stained and randomly distributed into four groups. Group 1 specimens received an in-office bleaching treatment with 35% H 2 O 2 for 2 × 15 min. Group 2 specimens received the same treatment but with extended application time (2 × 20 min). In Group 3, the same in-office bleaching procedure (2 × 15 min) was carried out as that in Group 1, using Er,Cr:YSGG laser irradiation for 2 × 15 s on each specimen to catalyze the reaction of H 2 O 2 breakdown. Group 4 specimens received the same bleaching treatment as Group 3 but with extended application time (2 × 20 min). Er,Cr:YSGG laser-assisted tooth bleaching treatment is more effective than the conventional treatment regarding color change of the teeth. Application time of the bleaching agent may influence the effectiveness of the methods. The color change of the tested treatments decreases after 7 days and 1 month. The clinical relevance of this study is that this novel laser-assisted bleaching treatment may be more advantageous in color change and application time compared to the conventional bleaching treatment.

  18. Er,Cr:YSGG Laser Energy Delivery: Pulse and Power Effects on Enamel Surface and Erosive Resistance.

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    de Oliveira, Renan Mota; de Souza, Vinicius Matsuzaki; Esteves, Camila Machado; de Oliveira Lima-Arsati, Ynara Bosco; Cassoni, Alessandra; Rodrigues, José Augusto; Brugnera Junior, Aldo

    2017-11-01

    High power lasers have been suggested as a useful tool for dental caries and erosion prevention due to the increase of enamel acid resistance. to evaluate the effect of Er,Cr:YSGG (erbium,chromium:yttrium, scandium, gallium, garnet) laser irradiation pulse frequency and power on enamel surface and acid erosion resistance. By combining pulse frequency (5-75 Hz) and power settings (0.10-1.00 W), 20 irradiated groups and one nonirradiated control group were tested. A total of 63 bovine enamel blocks (n = 3/group) were prepared for surface hardness and roughness evaluation, performed in three phases: baseline, after irradiation, and after erosive challenge. Enamel blocks were irradiated with Er,Cr:YSGG laser with MZ8 tip (iPlus; Waterlase, Biolase, CA) for 30 sec according to experimental group and submitted. Erosive challenge consisted of four cycles alternating immersion in 0.01 M HCl (5 mL/mm 2 ; 2 min; at 37°C) and immersion in artificial saliva for 3 h. Analysis of variance (three-way ANOVA), Tukey's test, and Pearson correlation were performed for the statistical analysis (p hardness. After erosive challenge, 5 and 75 W groups showed increase in surface hardness; 0.25, 0.5, 0.75, and 1 W groups showed minor alterations in surface roughness. the irradiation of Er,Cr:YSGG laser with different parameters of power and pulse frequency settings may alter enamel surface and erosive resistance differently. Pulse frequency of 30 Hz and power of 0.50 W was considered the best parameter to prevent enamel acid erosion.

  19. Effects of Er, Cr:YSGG laser irradiation on external adaptation of restorations in caries-affected cavities

    International Nuclear Information System (INIS)

    Tonetto, Mateus Rodrigues; Saad, José Roberto Cury; Campos, Edson Alves de; Neto, Sizenando de Toledo Porto; De Andrade, Marcelo Ferrarezi; Bandéca, Matheus Coelho; Borges, Alvaro Henrique; Pinto, Shelon Cristina Souza

    2013-01-01

    This study evaluated the effect of Er,Cr:YSGG laser irradiation on the external adaptation of composite resin restorations in caries-affected cavities. Mixed class V cavity preparations were performed in 36 intact human third molars, in half of which caries was artificially induced. Both healthy and carious dentin were etched with 35% phosphoric acid (Ultradent Products Inc., South Jordan, Utah, USA), and the teeth were divided into three groups, i.e., (a) untreated etched dentin, (b) application of the Er, Cr:YSGG laser and (c) use of chlorhexidine as an adjunct in the bonding process. Restorations were fabricated with Z350 XT FiltekTM composite resin (3M ESPE) and subsequently the specimens were subjected to thermocycling to simulate artificial ageing. Quantitative analysis of external adaptation was performed by scanning electron microscopy in both healthy and affected dentin using epoxy resin replicas. It was concluded that the application of laser and chlorhexidine did not affect the percentages of marginal adaptation of class V restorations. Furthermore, thermocycling may influence adaptation values. (letter)

  20. Biocompatibility of Er:YSGG laser radiated root surfaces

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    Benthin, Hartmut; Ertl, Thomas P.; Schmidt, Dirk; Purucker, Peter; Bernimoulin, J.-P.; Mueller, Gerhard J.

    1996-01-01

    Pulsed Er:YAG and Er:YSGG lasers are well known to be effective instruments for the ablation of dental hard tissues. Developments in the last years made it possible to transmit the laser radiation at these wavelengths with flexible fibers. Therefore the application in the periodontal pocket may be possible. The aim of this study was to evaluate the in-vitro conditions to generate a bioacceptable root surface. Twenty extracted human teeth, stored in an antibiotic solution, were conventionally scaled, root planed and axially separated into two halves. Two main groups were determined. With the first group laser radiation was carried out without and in the second group with spray cooling. The laser beam was scanned about root surface areas. Laser parameters were varied in a selected range. The biocompatibility was measured with the attachment of human gingival fibroblasts and directly compared to conventionally treated areas of the root surfaces. The fibroblasts were qualified and counted in SEM investigations. On conventionally treated areas gingival fibroblasts show the typical uniform cover. In dependance on the root roughness after laser treatment the fibroblasts loose the typical parallel alignment to the root surface. With spray cooling a better in-vitro attachment could be obtained. Without spray cooling the higher increase in temperature conducted to less bioacceptance by the human gingival fibroblasts to the root surface. These results show the possibility of producing bioacceptable root surfaces with pulsed laser radiation in the range of very high water absorption near 3 micrometer.

  1. Effect of Er, Cr: YSGG laser combined with oral basic treatment on inflammatory injury and apoptosis in patients with periodontitis

    Directory of Open Access Journals (Sweden)

    Wei-Xing Jin

    2017-09-01

    Full Text Available Objective: To study the effect of Er, Cr: YSGG laser combined with oral basic treatment on inflammatory injury and apoptosis in patients with periodontitis. Methods: Patients with chronic periodontitis who were treated in dental clinic of our hospital between February 2015 and March 2017 were selected as the research subjects and randomly divided into the group A who accepted ultrasonic dental cleaning, hand scaling combined with Er, Cr: YSGG laser treatment and the group B who received ultrasonic dental cleaning and hand scaling treatment. The contents of inflammatory response cytokines, protease molecules and apoptosis molecules in gingival crevicular fluid were detected before treatment and 1 week after treatment. Results: TNF-α, hs-CRP, IL-1β, IL-6, IL-8, EMMPRIN, CyPA, MMP2, MMP9, Smac, Bax, Fas and FasL contents in gingival crevicular fluid of both groups of patients 1 week after treatment were significantly lower than those before treatment, and TNF-α, hs-CRP, IL-1β, IL-6, IL-8, EMMPRIN, CyPA, MMP2, MMP9, Smac, Bax, Fas and FasL contents of group A 1 week after treatment were significantly lower than those of group B. Conclusion: Er, Cr: YSGG laser combined with oral basic treatment can inhibit the inflammatory injury and apoptosis in periodontal tissue of patients with periodontitis.

  2. Evaluation of enamel mineral loss around cavities prepared by the Er,Cr:YSGG laser and restored with different materials

    Science.gov (United States)

    Navarro, Ricardo Scarparo; Lago, Andréa. Dias Neves; Bonifácio, Clarissa Calil; Mendes, Fausto Medeiros; de Freitas, Patrícia Moreira; Baptista, Alessandra; Nunez, Silvia Cristina; Matos, Adriana Bona; Imparato, José Carlos P.

    2018-02-01

    The aim of this study was to evaluate the enamel demineralization around cavities prepared by Er,Cr:YSGG laser (2780 nm) and restored with different materials after an acid challenge. The human dental enamel samples were randomly divided in 12 groups (n=10): G1- high-speed drill (HD); G2- Er,Cr:YSGG laser L (3 W, 20 Hz, 53.05 J/cm2)(air 65% - water 55%); G3- L (4 W, 20 Hz, 70.74 J/cm2); G4- L (5 W, 20 Hz, 88.43 J/cm2). Each group was divided in subgroups: 1- glass ionomer cement (GIC), 2- resin modified GIC (RMGIC), 3- composite resin (C). Samples were submitted to an acid challenge (4.8 pH) for7 days. The calcium ion contend (ppm/mm2) from demineralizing solutions were analyzed by atomic emission spectrometry. ANOVA and LSD tests were performed (α=5%). The significant lower average values of calcium loss were observed on G2 + GIC, G2 + RMGIC, G1 + RMGIC (penamel demineralization. The findings of this in vitro study suggest that the Er,Cr:YSGG lased cavities restored with GIC or RMGIC or conventional drill cavities with RMGIC were effective on reducing the demineralization around restorations, showing an important potential in preventing secondary caries.

  3. Effect of Er,Cr:YSGG laser on the microtensile bond strength of two different adhesives to the sound and caries-affected dentin.

    Science.gov (United States)

    Ergücü, Z; Celik, E U; Unlü, N; Türkün, M; Ozer, F

    2009-01-01

    This study examined the effect of Er,Cr:YSGG laser irradiation on the microtensile bond strength (microTBS) of a three-step etch-and-rinse and a two-step self-etch adhesive to sound and caries-affected dentin. Sixteen freshly extracted human molars with occlusal dentin caries were used. The caries lesion was removed by one of the following methods: conventional treatment with burs or Er,Cr:YSGG laser (Waterlase MD, Biolase). The adhesive systems (AdheSE, Ivoclar Vivadent and Scotchbond Multi Purpose, 3M ESPE) were applied to the entire tooth surface according to the manufacturers' instructions. Resin composites were applied to the adhesive-treated dentin surfaces and light-cured. Each tooth was sectioned into multiple beams with the "non-trimming" version of the microtensile test. The specimens were subjected to microtensile forces (BISCO Microtensile Tester, BISCO). The data was analyzed by three-way ANOVA and independent t-tests (p=0.05). Er,Cr:YSGG laser irradiation exhibited similar microTBS values compared to that of conventional bur treatment, regardless of the adhesive system and type of treated dentin. The self-etch system revealed lower microTBS values, both with conventional and laser treatment techniques, compared to the etch-and-rinse adhesive in sound and caries-affected dentin (padhesive systems to sound and caries-affected dentin.

  4. Effect of Surface Treatment on Enamel Cracks After Orthodontic Bracket Debonding: Er,Cr:YSGG Laser-Etching Versus Acid-Etching

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    Ghaffari, Hassanali; Mirhashemi, Amirhossein; Baherimoghadam, Tahereh; Azmi, Amir

    2017-01-01

    Objectives: This study sought to compare enamel cracks after orthodontic bracket debonding in the surfaces prepared with erbium, chromium: yttrium-scandium-galliumgarnet (Er,Cr:YSGG) laser and the conventional acid-etching technique. Materials and Methods: This in-vitro experimental study was conducted on 60 sound human premolars extracted for orthodontic purposes. The teeth were randomly divided into two groups (n=30). The teeth in group A were etched with 37% phosphoric acid gel, while the teeth in group B were subjected to Er,Cr:YSGG laser irradiation (gold handpiece, MZ8 tip, 50Hz, 4.5W, 60μs, 80% water and 60% air). Orthodontic brackets were bonded to the enamel surfaces and were then debonded in both groups. The samples were inspected under a stereomicroscope at ×38 magnification to assess the number and length of enamel cracks before bonding and after debonding. Independent-samples t-test was used to compare the frequency of enamel cracks in the two groups. Levene’s test was applied to assess the equality of variances. Results: No significant difference was noted in the frequency or length of enamel cracks between the two groups after debonding (P>0.05). Conclusions: Despite the same results of the frequency and length of enamel cracks in the two groups and by considering the side effects of acid-etching (demineralization and formation of white spot lesions), Er,Cr:YSGG laser may be used as an alternative to acid-etching for enamel surface preparation prior to bracket bonding. PMID:29296111

  5. In Vitro Comparison Of Fluoride Gel Alone and in Combination With Er,Cr:YSGG Laser on Reducing White Spot Lesions in Primary Teeth.

    Science.gov (United States)

    Molaasadollah, Fatemeh; Asnaashari, Mohammad; Mashhadi Abbas, Fatemeh; Jafary, Maral

    2017-01-01

    Introduction: Laser therapy has been suggested as a method for caries-prevention, and ErCr:YSGG laser is increasingly used in dentistry. This study aimed to compare the efficacy of fluoride gel alone and in conjunction with Er,Cr:YSGG laser for remineralization of white spot lesions (WSLs) in primary teeth. Methods: This study was conducted on 20 primary teeth with WSLs extracted for orthodontic reasons. Three sections were made of each tooth at the site of WSLs. The surface area of WSLs was measured under a stereomicroscope at ×25 magnification. Samples were assigned to 3 groups of control (group 1), exposure to 1.23% APF gel for 4 minutes (group 2) and Er,Cr:YSGG laser (0.5 W power, 20 Hz frequency, 60% water, 40% air, pulse duration of 5±1 seconds) plus fluoride (group 3). All samples were stored in artificial saliva for 10 days and then the surface area of the WSLs was measured again under a stereomicroscope. Data were analyzed using the Kruskal-Wallis, MannWhitney and Wilcoxon signed rank tests. Results: The reduction in surface area of the WSLs was significantly different between the control and fluoride ( P laser plus fluoride groups ( P laser plus fluoride groups was not significant ( P =0.265). Comparison of the surface area of WSLs before and after the intervention showed no significant difference in group one ( P =0.737) while this difference in groups 2 ( P laser irradiation plus 1.23% APF gel was not significantly different from the application of fluoride gel alone in enhancing the remineralization of WSLs.

  6. Influence of Er,Cr: YSGG laser on bond strength of self-adhesive resin cement

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    Matheus Coelho Bandéca

    2012-08-01

    Full Text Available The purpose of this study was to investigate the bond strength of fiber post previously laser treated root canals. Forty single-rooted bovine teeth were endodontically treated, randomly and equally divided into two main groups according to the type of pretreatment: G1: 2.5% NaOCl (control group; and G2: Er,Cr:YSGG laser. Each group was further subdivided into 2 groups based on the category of adhesive systems/ luting materials used: a: an etch-and-rinse resin cement (Single Bond/RelyX ARC; 3M ESPE, and b: a self-adhesive resin cement (Rely X Unicem; 3M ESPE. Three 1.5 mm thick slabs were obtained per root and the push-out test was performed at a crosshead speed of 0.5 mm/min until post dislodgement occurred. Data were analyzed by ANOVA and post-hoc Tukey's test at a pre-set alpha of 0.05. Analysis of variance showed no statistically significant difference (p > 0.05 among the groups G1a (25.44 ± 2.35 and G1b (23.62 ± 3.48, G2a (11.77 ± 2.67 and G2b (9.93 ± 3.37. Fractures were observed at the interface between the dentin and the resin in all groups. The Er,Cr:YSGG laser irradiation did not influence on the bond strength of the resin cements and the etch-and-rinse resin cement had better results on bond strength than self-adhesive resin cement.

  7. Study in vitro of Er,Cr:YSGG laser effects in bone tissue by ATR-FTIR spectroscopy

    International Nuclear Information System (INIS)

    Benetti, Carolina

    2010-01-01

    Laser proves to be, more and more, an effective tool for helping health professionals, being intensively used in ophthalmological and odontological procedures. In particular, high-density, infrared emitting lasers have great potential in cutting mineralized biological hard tissues, given their high absorption by hydroxyapatite and water, these tissues' main components. In comparison to mechanical instruments, laser presents a series of advantages, namely, smaller damage to the remaining tissue and promotion of homeostatic effect, apart from making it possible to execute procedures in areas with difficult access. However, for an efficient and safe use of this technique, it is necessary to know the effects of the laser irradiation on the tissue. The Fourier transform infrared (FTIR) technique is heavily used in the study of organic materials, because apart from making it possible to identify the materials' components, it also allows to prepare a semi quantitative analysis. This work aims to establish the ATR-FTIR technique in the characterization of natural and irradiated osseous tissue, and to verify the possible chemical and structural changes caused by irradiation. Firstly, the best conditions for the obtainment of bone sample spectra were determined. Then, bone samples, irradiated with the Er,Cr:YSGG (2,78 μm) infrared emitting laser (adjusted with different energy densities) were analyzed alongside with natural bone samples. It has been verified that the technique is effective in the bone tissue characterization, and that it is possible to observe the chemical changes caused by the temperature rise due to laser irradiation. It has been observed a gradual organic material loss as the energy density goes up. These results are the first steps in testing the Er,Cr:YSGG laser efficacy as a cutting tool, a pivotal aspect of its consolidation in clinical procedures. (author)

  8. Management of Retrograde Peri-Implantitis Using an Air-Abrasive Device, Er,Cr:YSGG Laser, and Guided Bone Regeneration

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    Nikolaos Soldatos

    2018-01-01

    Full Text Available Background. The placement of an implant in a previously infected site is an important etiologic factor contributing to implant failure. The aim of this case report is to present the management of retrograde peri-implantitis (RPI in a first maxillary molar site, 2 years after the implant placement. The RPI was treated using an air-abrasive device, Er,Cr:YSGG laser, and guided bone regeneration (GBR. Case Description. A 65-year-old Caucasian male presented with a draining fistula associated with an implant at tooth #3. Tooth #3 revealed periapical radiolucency two years before the implant placement. Tooth #3 was extracted, and a ridge preservation procedure was performed followed by implant rehabilitation. A periapical radiograph (PA showed lack of bone density around the implant apex. The site was decontaminated with an air-abrasive device and Er,Cr:YSGG laser, and GBR was performed. The patient was seen every two weeks until suture removal, followed by monthly visits for 12 months. The periapical X-rays, from 6 to 13 months postoperatively, showed increased bone density around the implant apex, with no signs of residual clinical or radiographic pathology and probing depths ≤4 mm. Conclusions. The etiology of RPI in this case was the placement of an implant in a previously infected site. The use of an air-abrasive device, Er,Cr:YSGG, and GBR was utilized to treat this case of RPI. The site was monitored for 13 months, and increased radiographic bone density was noted.

  9. Shear bond strength of composite bonded with three adhesives to Er,Cr:YSGG laser-prepared enamel.

    Science.gov (United States)

    Türkmen, Cafer; Sazak-Oveçoğlu, Hesna; Günday, Mahir; Güngör, Gülşad; Durkan, Meral; Oksüz, Mustafa

    2010-06-01

    To assess in vitro the shear bond strength of a nanohybrid composite resin bonded with three adhesive systems to enamel surfaces prepared with acid and Er,Cr:YSGG laser etching. Sixty extracted caries- and restoration-free human maxillary central incisors were used. The teeth were sectioned 2 mm below the cementoenamel junction. The crowns were embedded in autopolymerizing acrylic resin with the labial surfaces facing up. The labial surfaces were prepared with 0.5-mm reduction to receive composite veneers. Thirty specimens were etched with Er,Cr:YSGG laser. This group was also divided into three subgroups, and the following three bonding systems were then applied on the laser groups and the other three unlased groups: (1) 37% phosphoric acid etch + Bond 1 primer/adhesive (Pentron); (2) Nano-bond self-etch primer (Pentron) + Nano-bond adhesive (Pentron); and (3) all-in-one adhesive-single dose (Futurabond NR, Voco). All of the groups were restored with a nanohybrid composite resin (Smile, Pentron). Shear bond strength was measured with a Zwick universal test device with a knife-edge loading head. The data were analyzed with two-factor ANOVA. There were no significant differences in shear bond strength between self-etch primer + adhesive and all-in-one adhesive systems for nonetched and laser-etched enamel groups (P > .05). However, bond strength values for the laser-etched + Bond 1 primer/adhesive group (48.00 +/- 13.86 MPa) were significantly higher than the 37% phosphoric acid + Bond 1 primer/adhesive group (38.95 +/- 20.07 MPa) (P enamel surface more effectively than 37% phosphoric acid for subsequent attachment of composite material.

  10. Comparison of gingival depigmentation with Er,Cr:YSGG laser and surgical stripping, a 12-month follow-up.

    Science.gov (United States)

    Gholami, Leila; Moghaddam, Somayeh Ansari; Rigi Ladiz, Mohammad Ayoub; Molai Manesh, Zohreh; Hashemzehi, Hadi; Fallah, Alireza; Gutknecht, Norbert

    2018-04-13

    Gingival melanin hyperpigmentation is an esthetic concern for many individuals. In this study, we compared the standard surgical removal method with two different Er,Cr:YSGG laser settings in order to find the best treatment method. In 33 dental arches, the following three treatment groups were comparatively evaluated: (1) surgical stripping, (2) removal with laser setting 1 (4.5 W, 50 Hz, 100% water, 80% air, 60 μs, 800 μm Tip; MZ8), and (3) laser setting 2 (2.5 W, 50 Hz, 20% water, 40% air, 700 μs, 800 μm Tip; MZ8). We comparatively evaluated pain, patient satisfaction and wound healing, treatment time, and the amount of bleeding. Re-pigmentation was evaluated after 1 and 12 months by Hedin and Dummet pigmentation scores. Laser setting 1 had the best results regarding pain and patient satisfaction, although not statistically significant (P > 0.05). Wound healing results were better using lasers compared to surgical stripping (P Laser setting 1 was a faster procedure with mild amounts of bleeding. The least amount of bleeding was seen with laser setting 2. After 1 month, only two cases of the laser setting 2-treated areas showed an isolated pigmented area in the papilla; at 12 months, the mean Hedin indexes were still less than 2 and mean Dummett index less than 1 in all treatment techniques, with the lowest scores seen in the laser setting 1 sites. Based on our results, Er,Cr:YSGG laser can be more convenient for gingival depigmentation compared to surgical blade. Although not statistically significant, laser setting 1 with shorter pulse duration and higher water spray showed better overall results. However, laser setting 2, with longer pulse duration and less water spray, resulted in better coagulative effects and can be used to control bleeding wherever necessary in clinical practice.

  11. The influence of a novel in-office tooth whitening procedure using an Er,Cr:YSGG laser on enamel surface morphology.

    Science.gov (United States)

    Dionysopoulos, Dimitrios; Strakas, Dimitrios; Koliniotou-Koumpia, Eugenia

    2015-08-01

    The purpose of this in vitro study was to evaluate the influence of a novel in-office tooth whitening procedure using Er,Cr:YSGG laser radiation on bovine enamel. Forty-eight enamel specimens were prepared from bovine canines and divided into four groups: Group 1 specimens (control) received no whitening treatment; Group 2 received whitening treatment with an at-home whitening agent (22% carbamide peroxide) for 7 days; Group 3 received whitening treatment with a novel in-office whitening agent (35% H(2)O(2)); Group 4 received the same in-office whitening therapy with Group 3 using Er,Cr:YSGG laser in order to accelerate the whitening procedure. The specimens were stored for 10 days after the whitening treatment in artificial saliva. Vickers hardness was determined using a microhardness tester and surface roughness was evaluated using a VSI microscope. Three specimens of each experimental group were examined under SEM and the mineral composition of the specimens was evaluated using EDS. Data were statistically analyzed using one-way ANOVA, Tukey's post-hoc test, Wilcoxon signed rank and Kruskal-Wallis tests (a = 0.05). The surface microhardness of the enamel was reduced after the in-office whitening treatments (Pwhitening treatment (P> 0.05). Moreover, the surface roughness was not significantly changed after tooth whitening. EDS analysis did not show alterations in the enamel mineral composition, while SEM observations indicated changes in the surface morphology, especially after in-office tooth whitening (Pwhitening treatment with Er,Cr:YSGG laser did not affect the alterations in enamel surface compared with the conventional in-office whitening technique. © 2015 Wiley Periodicals, Inc.

  12. SEM Evaluation of Enamel Surface Changes and Enamel Microhardness around Orthodontic Brackets after Application of CO2 Laser, Er,Cr:YSGG Laser and Fluoride Varnish: An In vivo Study.

    Science.gov (United States)

    Kaur, Tarundeep; Tripathi, Tulika; Rai, Priyank; Kanase, Anup

    2017-09-01

    One of the most undesirable consequences of orthodontic treatment is occurrence of enamel demineralization around orthodontic brackets. Numerous in vitro studies have reported the prevention of enamel demineralization by surface treatment with lasers and fluoride varnish. To evaluate the changes on the enamel surface and microhardness around orthodontic brackets after surface treatment by CO 2 laser, Er, Cr:YSGG laser and fluoride varnish in vivo. A double blind interventional study was carried out on 100 premolars which were equally divided into five groups, out of which one was the control group (Group 0). The intervention groups (Group I to IV) comprised of patients requiring fixed orthodontic treatment with all 4 first premolars extraction. Brackets were bonded on all 80 premolars which were to be extracted. Enamel surface treatment of Groups I, II and III was done by CO 2 laser, Er, Cr:YSGG laser and 5% sodium fluoride varnish respectively and Group IV did not receive any surface treatment. A modified T-loop was ligated to the bracket and after two months, the premolars were extracted. Surface changes were evaluated by Scanning Electron Microscopic (SEM) and microhardness testing. Comparison of mean microhardness between all the groups was assessed using post-hoc test with Bonferroni correction. Group I showed a melted enamel appearance with fine cracks and fissures while Group II showed a glossy, homogenous enamel surface with well coalesced enamel rods. Group III showed slight areas of erosions and Group IV presented areas of stripped enamel. Significant difference was observed between the mean microhardness (VHN) of Group I, Group II, Group III, Group IV and Group 0 with p<0.001. A significant difference of p<0.001 was observed while comparing Group I vs II,III,IV,0 and Group II vs III,IV,0. However, difference while comparing Group III vs IV was p=0.005 and difference between the mean microhardness of Group 0 vs Group III was non significant. Surface

  13. Management of denture-induced epulis fissuratum with Er,Cr:YSGG laser: a case report

    Science.gov (United States)

    Koli, Dheeraj Kumar; Gupta, Manak; Verma, Mahesh; Lamba, Arundeep Kaur; Chawla, Kirti

    2012-01-01

    Epulis fissuratum refers to tissue growth into the oral cavity, located over the alveolar ridges or the soft tissues of the vestibular sulcus. Trauma and irritation are important aetiological factors for epulis fissuratum and lesions arise in areas of persistent mucosal injury. This report presents a case of a 68-year old male patient with two soft tissue hyperplastic growths seen in the buccal vestibule in the lower anterior region. These lesions were removed using an Er,Cr:YSGG laser. The healing was uneventful and no suture or analgesic was required. The histopathological report confirmed the presurgical diagnosis. No relapse was observed till one year after surgery.

  14. Sub-ablative Er,Cr:YSGG laser irradiation under all-ceramic restorations: effects on demineralization and shear bond strength.

    Science.gov (United States)

    Bağlar, Serdar

    2018-01-01

    This study evaluated the caries resistant effects of sub-ablative Er,Cr:YSGG laser irradiation alone and combined with fluoride in comparison with fluoride application alone on enamel prepared for veneer restorations. And also, evaluated these treatments' effects on the shear bond strength of all-ceramic veneer restorations. One hundred and thirty-five human maxillary central teeth were assigned to groups of 1a-control, 1b-laser treated, 1c-fluoride treated, 1d-laser + fluoride treated for shear bond testing and to groups of 2a-positive control(non-demineralised), 2b-laser treated, 2c-fluoride treated, 2d-laser + fluoride treated, 2e-negative control (demineralised) for microhardness testing (n = 15, N = 135). Demineralisation solutions of microhardness measurements were used for the ICP-OES elemental analysis. The parameters for laser irradiation were as follows: power output, 0.25 W; total energy density, 62.5 J/cm 2 and energy density per pulse, 4.48 J/cm 2 with an irradiation time of 20 s and with no water cooling. Five percent NaF varnish was used as fluoride preparate. ANOVA and Tukey HSD tests were performed (α = 5%). Surface treatments showed no significant effects on shear bond strength values (p = 0.579). However, significant differences were found in microhardness measurements and in elemental analysis of Ca and P amounts (p < 0.01). Surface-treated groups showed significantly high VNH values and significantly low ICP-OES values when compared with non-treated (-control) group while there were no significance among surface-treated groups regarding VHN and ICP-OES values. Sub-ablative Er,Cr:YSGG treatment alone or combined with fluoride is as an effective method as at least fluoride alone for preventing the prepared enamel to demineralization with no negative effect on shear bond strength.

  15. Evaluation of microshear bond strength of resin composites to enamel of dental adhesive systems associated with Er,Cr:YSGG laser

    Science.gov (United States)

    Cassimiro-Silva, Patricia F.; Zezell, Denise M.; Monteiro, Gabriela Q. d. M.; Benetti, Carolina; de Paula Eduardo, Carlos; Gomes, Anderson S. L.

    2016-02-01

    The aim of this in vitro study was to evaluate the microshear bond strength (μSBS) of resin composite to enamel etching by Er,Cr:YSGG laser with the use of two differents adhesives systems. Fifty freshly extracted human molars halves were embedded in acrylic resin before preparation for the study, making a total of up to 100 available samples. The specimens were randomly assigned into six groups (η=10) according to substrate pre-treatment and adhesive system on the enamel. A two-step self-etching primer system (Clearfil SE Bond) and a universal adhesive used as an etch-andrinse adhesive (Adper Single Bond Universal) were applied to the nonirradiated enamel surface according to manufacturer's instructions, as control groups (Control CF and Control SB, respectively). For the other groups, enamel surfaces were previously irradiated with the Er,Cr:YSGG laser with 0.5 W, 75 mJ and 66 J/cm2 (CF 5 Hz and SB 5 Hz) and 1.25 W, 50 mJ and 44 J/cm2 (CF 15 Hz and SB 15 Hz). Irradiation was performed under air (50%) and water (50%) cooling. An independent t-test was performed to compare the adhesive systems. Mean μSBS ± sd (MPa) for each group was 16.857 +/- 2.61, 17.87 +/- 5.83, 12.23 +/- 2.02, 9.88 +/- 2.26, 15.94 +/- 1.98, 17.62 +/- 2.10, respectively. The control groups and the 50 mJ laser groups showed no statistically significant differences, regardless of the adhesive system used. The results obtained lead us to affirm that the bonding interaction of adhesives to enamel depends not only on the morphological aspects of the dental surface, but also on the characteristics of the adhesive employed and the parameters of the laser.

  16. In vitro study of demineralization resistance and fluoride retention in dental enamel irradiated with Er,Cr: YSGG laser; Estudo in vitro da resistencia a desmineralizacao e da retencao de fluor em esmalte dental irradiado com laser de Er, Cr: YSGG

    Energy Technology Data Exchange (ETDEWEB)

    Ana, Patricia Aparecida da. E-mail: patriciadaana@yahoo.com.br

    2007-07-01

    This study aimed to establish irradiation conditions of Er,Cr:YSGG laser ({lambda} of 2.79 {mu}m) which could propitiate changes on human dental enamel and increase its resistance to demineralization, when associated or not with topical application of acidulated phosphate fluoride (APF). Fluences of 2,8 J/cm{sup 2}, 5,6 J/cm{sup 2} e 8,5 J/cm{sup 2} were selected; they were associated or not with previous application of a photo absorber (coal paste) and then APF was applied or not after laser irradiation. In a first step, the morphological findings, the surface temperatures, and the pupal temperatures were evaluated during laser irradiation. After that, the treated samples were submitted to a a ten-day pH-cycling model. After producing the incipient white-spots lesions, the following aspects were evaluated: the mineral loss, the loosely bound fluoride and the firmly bound fluoride. All the demineralizing and remineralizing pH-cycling solutions were evaluated with respect to their calcium (Ca), inorganic phosphorous (Pi) and fluoride (F{sup -}) concentrations. The data had their normality and homogeneity distribution statistically evaluated, and it was chosen an appropriated statistical test for each performed analysis according to the obtained results, considering 5% significant level. The fluences selected for this study created ablated surfaces; the fluences of 5.6 J/cm{sup 2} and 8.5 J/cm{sup 2} promoted increments in surface temperature above 110 deg C. The intrapupal temperature changes revealed that laser irradiation did not increase the pulpal temperatures above the critical threshold for induction of pulpitis. The coal paste did not promote any changes on surface morphology or in the intrapulpal temperature changes; however, this paste increased the surface temperatures during laser irradiation. Only laser irradiation at 8.5 J/cm{sup 2} was able to decrease the mineral loss when compared to the no-treatment group; although the association of coal paste

  17. Evaluation of the bond strength of resin cements used to lute ceramics on laser-etched dentin.

    Science.gov (United States)

    Giray, Figen Eren; Duzdar, Lale; Oksuz, Mustafa; Tanboga, Ilknur

    2014-07-01

    The purpose of this study was to investigate the shear bond strength (SBS) of two different adhesive resin cements used to lute ceramics on laser-etched dentin. Erbium, chromium: yttrium, scandium, gallium, garnet (Er,Cr:YSGG) laser irradiation has been claimed to improve the adhesive properties of dentin, but results to date have been controversial, and its compatibility with existing adhesive resin cements has not been conclusively determined. Two adhesive cements, one "etch-and-rinse" [Variolink II (V)] and one "self-etch" [Clearfil Esthetic Cement (C)] luting cement, were used to lute ceramic blocks (Vita Celay Blanks, Vita) onto dentin surfaces. In total, 80 dentin specimens were distributed randomly into eight experimental groups according to the dentin surface-etching technique used Er,Cr:YSGG laser and Er:YAG laser: (1) 37% orthophosphoric acid+V (control group), (2) Er,Cr:YSGG laser+V, (3) Er,Cr:YSGG laser+acid+V, (4) Er:YAG laser+V, (5) Er:YAG laser+acid+V, (6) C, (7) Er,Cr:YSGG laser+C, and (8) Er:YAG laser+C. Following these applications, the ceramic discs were bonded to prepared surfaces and were shear loaded in a universal testing machine until fracture. SBS was recorded for each group in MPa. Shear test values were evaluated statistically using the Mann-Whitney U test. No statistically significant differences were evident between the control group and the other groups (p>0.05). The Er,Cr:YSGG laser+A+V group demonstrated significantly higher SBS than did the Er,Cr:YSGG laser+V group (p=0.034). The Er,Cr:YSGG laser+C and Er:YAG laser+C groups demonstrated significantly lower SBS than did the C group (pceramic bond strengths, depending upon the adhesive cement used.

  18. Biophysical evaluation of fractional laser skin resurfacing with an Er:YSGG laser device in Japanese skin.

    Science.gov (United States)

    Kimura, Utako; Kinoshita, Ayako; Osawa, Aki; Negi, Osamu; Haruna, Kunitaka; Mizuno, Yuki; Suga, Yasushi

    2012-05-01

    Ablative fractional laser skin resurfacing (FLSR) has recently been used for the amelioration of acne scars, and previous studies have shown clinical effectiveness. Despite its extensive use, few studies have focused on the associated changes in biophysical properties of the epidermis. Herein, we evaluate transepidermal water loss, sebum levels, skin hydration, and skin elasticity, following FLSR treatments with an Er:YSGG laser device (Pearl FractionalTM, Cutera Inc., Brisbane, CA), employing non-invasive measurements. Five Japanese patients with facial acne scars underwent one FLSR session. Some acne scars appeared to become less obvious as a consequence of the treatment. All patients were aware of a feeling of skin tightness in treated areas. Objective measurements on the lower lateral angle of the eye and on the inner cheeks were evaluated at baseline and at 3 days, 1 week, and 4 weeks after FLSR. Transepidermal water loss showed a significant two-fold (100%) increase at day 3, but had returned to almost the baseline level at week 4 in both areas. Sebum secretion showed a 50% increase at day 3, but had returned to the baseline level after day 7. Skin hydration showed a significant decrease at day 3, but had returned to the baseline level by day 7, and showed significant improvement at the end of the study. Skin elasticity (R2) was still at baseline on day 3, but showed some improvement--an increase of at least 30%--at the end of the study. Based on our findings, we believe that FLSR should be performed no more than once a month to allow sufficient time for the damaged skin to recover its barrier function in most areas of the face.

  19. A laser-powered hydrokinetic system for caries removal and cavity preparation.

    Science.gov (United States)

    Hadley, J; Young, D A; Eversole, L R; Gornbein, J A

    2000-06-01

    Laser systems have been developed for the cutting of dental hard tissues. The erbium, chromium:yttrium-scandium-gallium-garnet, or Er,Cr:YSGG, laser system used in conjunction with an air-water spray has been shown to be efficacious in vitro for cavity preparation. The authors randomly selected subjects for cavity preparation with conventional air turbine/bur dental surgery or an Er,Cr:YSGG laser-powered system using a split-mouth design. They prepared Class I, III and V cavities, placed resin restorations and evaluated subjects on the day of the procedure and 30 days and six months postoperatively for pulp vitality, recurrent caries, pain and discomfort, and restoration retention. Sixty-seven subjects completed the study. There were no statistical differences between the two treatment groups for the parameters measured with one exception; there was a statistically significant decrease in discomfort levels for the laser system at the time of cavity preparation for subjects who declined to receive local anesthetic. The Er,Cr:YSGG laser system is effective for preparation of Class I, III and V cavities and resin restorations are retained by lased tooth surfaces. Hard-tissue cutting lasers are being introduced for use in operative dentistry. In this study, an Er,Cr:YSGG laser has been shown to be effective for cavity preparation and restoration replacement.

  20. Morphology of resin-dentin interfaces after Er,Cr:YSGG laser and acid etching preparation and application of different bonding systems.

    Science.gov (United States)

    Beer, Franziska; Buchmair, Alfred; Körpert, Wolfram; Marvastian, Leila; Wernisch, Johann; Moritz, Andreas

    2012-07-01

    The goal of this study was to show the modifications in the ultrastructure of the dentin surface morphology following different surface treatments. The stability of the adhesive compound with dentin after laser preparation compared with conventional preparation using different bonding agents was evaluated. An Er,Cr:YSGG laser and 36% phosphoric acid in combination with various bonding systems were used. A total of 100 caries-free human third molars were used in this study. Immediately after surgical removal teeth were cut using a band saw and 1-mm thick dentin slices were created starting at a distance of 4 mm from the cusp plane to ensure complete removal of the enamel. The discs were polished with silicon carbide paper into rectangular shapes to a size of 6 × 4 mm (±0,2 mm).The discs as well as the remaining teeth stumps were stored in 0.9% NaCl at room temperature. The specimens were divided into three main groups (group I laser group, group II etch group, group III laser and etch group) and each group was subdivided into three subgroups which were allocated to the different bonding systems (subgroup A Excite, subgroup B Scotchbond, subgroup C Syntac). Each disc and the corresponding tooth stump were treated in the same way. After preparation the bonding composite material was applied according to the manufacturers' guidelines in a hollow tube of 2 mm diameter to the disc as well as to the corresponding tooth stump. Shear bond strength testing and environmental scanning electron microscopy were used to assess the morphology and stability of the resin-dentin interface. The self-etching bonding system showed the highest and the most constant shear values in all three main groups, thus enabling etching with phosphoric acid after laser preparation to be avoided. Thus we conclude that laser preparation creates a surface texture that allows prediction of the quality of the restoration without the risk of negative influences during the following treatment steps. This

  1. The effect of erbium family laser on tensile bond strength of composite to dentin in comparison with conventional method.

    Science.gov (United States)

    Shahabi, Sima; Chiniforush, Nasim; Bahramian, Hoda; Monzavi, Abbas; Baghalian, Ali; Kharazifard, Mohammad Javad

    2013-01-01

    The purpose of this study was to evaluate the effect of Er:YAG and Er,Cr:YSGG laser on tensile bond strength of composite resin to dentine in comparison with bur-prepared cavities. Fifteen extracted caries-free human third molars were selected. The teeth were cut at a level below the occlusal pit and fissure plan and randomly divided into three groups. Five cavities were prepared by diamond bur, five cavities prepared by Er:YAG laser, and the other group prepared by Er,Cr:YSGG laser. Then, all the cavities were restored by composite resin. The teeth were sectioned longitudinally with Isomet and the specimens prepared in dumbbelled shape (n = 36). The samples were attached to special jigs, and the tensile bond strength of the three groups was measured by universal testing machine at a speed of 0.5 mm/min. The results of the three groups were analyzed with one-way ANOVA and Tamhane test. The means and standard deviations of tensile bond strength of bur-cut, Er:YAG laser-ablated, and Er,Cr:YSGG laser-ablated dentine were 5.04 ± 0.93, 13.37 ± 3.87, and 4.85 ± 0.93 MPa, respectively. There is little difference in tensile bond strength of composite resin in Er,Cr:YSGG lased-prepared cavities in comparison with bur-prepared cavities, but the Er:YAG laser group showed higher bond strength than the other groups.

  2. In vitro study of demineralization resistance and fluoride retention in dental enamel irradiated with Er,Cr: YSGG laser

    International Nuclear Information System (INIS)

    Ana, Patricia Aparecida da.

    2007-01-01

    This study aimed to establish irradiation conditions of Er,Cr:YSGG laser (λ of 2.79 μm) which could propitiate changes on human dental enamel and increase its resistance to demineralization, when associated or not with topical application of acidulated phosphate fluoride (APF). Fluences of 2,8 J/cm 2 , 5,6 J/cm 2 e 8,5 J/cm 2 were selected; they were associated or not with previous application of a photo absorber (coal paste) and then APF was applied or not after laser irradiation. In a first step, the morphological findings, the surface temperatures, and the pupal temperatures were evaluated during laser irradiation. After that, the treated samples were submitted to a a ten-day pH-cycling model. After producing the incipient white-spots lesions, the following aspects were evaluated: the mineral loss, the loosely bound fluoride and the firmly bound fluoride. All the demineralizing and remineralizing pH-cycling solutions were evaluated with respect to their calcium (Ca), inorganic phosphorous (Pi) and fluoride (F - ) concentrations. The data had their normality and homogeneity distribution statistically evaluated, and it was chosen an appropriated statistical test for each performed analysis according to the obtained results, considering 5% significant level. The fluences selected for this study created ablated surfaces; the fluences of 5.6 J/cm 2 and 8.5 J/cm 2 promoted increments in surface temperature above 110 deg C. The intrapupal temperature changes revealed that laser irradiation did not increase the pulpal temperatures above the critical threshold for induction of pulpitis. The coal paste did not promote any changes on surface morphology or in the intrapulpal temperature changes; however, this paste increased the surface temperatures during laser irradiation. Only laser irradiation at 8.5 J/cm 2 was able to decrease the mineral loss when compared to the no-treatment group; although the association of coal paste + laser at 2.8 J/cm 2 + APF application

  3. Evaluation of Root-End Resections Performed by Er, Cr: YSGG Laser with and without Placement of a Root-End Filling Material

    Directory of Open Access Journals (Sweden)

    John Sullivan

    2009-01-01

    Full Text Available Microleakage following root-end resections has a direct influence on the outcome of surgical endodontic procedures. This study compared the microleakage after root-end resections performed by the Er, Cr: YSGG laser or carbide burs with or without the placement of MTA, and evaluated the presence of microcracks and gaps at the interface of GP/MTA and the canal walls. Ninety single-rooted teeth were instrumented, obturated with GP and AH-Plus sealer, and divided into 3 experimental groups: (I root-end resections were performed with the laser and G6 tips (parameters: 4.5 w, 30 pps, 20% water and 50% air; (II Lindeman burs were used, without the placement of MTA; (III the burs were used followed by root-end fillings with MTA, and one control (IV of five unobturated roots resected with the burs. The samples were prepared for microleakage (=20 and SEM (=10 analysis. They were immersed in 1% methylene blue, decalcified, cleared, and evaluated for dye penetration (mm2 with the ImageJ software. Epoxy-resin replicas of the root-ends were analyzed by SEM for gaps (m2 and microcracks. Microleakage results were 0.518±1.059, 0.172±0.223, and 0.158±0.253, for the laser (I, no root-end filling (II, and MTA (III samples, respectively, (ANOVA =.02. The laser (7831.7±2329.2 and no root-end filling (7137.3±1400.7 samples presented gaps. Whereas, none was found in the MTA (ANOVA =.002. Microcracks were not observed. The MTA group demonstrated statistically less leakage and better adaptation to the canal walls when compared to the other groups. There was no correlation between the size of the gaps and the degree of microleakage.

  4. Thermal effects from modified endodontic laser tips used in the apical third of root canals with erbium-doped yttrium aluminium garnet and erbium, chromium-doped yttrium scandium gallium garnet lasers.

    Science.gov (United States)

    George, Roy; Walsh, Laurence J

    2010-04-01

    To evaluate the temperature changes occurring on the apical third of root surfaces when erbium-doped yttrium aluminium garnet (Er:YAG) and erbium, chromium-doped yttrium scandium gallium garnet (Er,Cr:YSGG) laser energy was delivered with a tube etched, laterally emitting conical tip and a conventional bare design optical fiber tip. Thermal effects of root canal laser treatments on periodontal ligament cells and alveolar bone are of concern in terms of safety. A total of 64 single-rooted extracted teeth were prepared 1 mm short of the working length using rotary nickel-titanium Pro-Taper files to an apical size corresponding to a F5 Pro-Taper instrument. A thermocouple located 2 mm from the apex was used to record temperature changes arising from delivery of laser energy through laterally emitting conical tips or plain tips, using an Er:YAG or Er,Cr:YSGG laser. For the Er:YAG and Er,Cr:YSGG systems, conical fibers showed greater lateral emissions (452 + 69% and 443 + 64%) and corresponding lower forward emissions (48 + 5% and 49 + 5%) than conventional plain-fiber tips. All four combinations of laser system and fiber design elicited temperature increases less than 2.5 degrees C during lasing. The use of water irrigation attenuated completely the thermal effects of individual lasing cycles. Laterally emitting conical fiber tips can be used safely under defined conditions for intracanal irradiation without harmful thermal effects on the periodontal apparatus.

  5. Comparative evaluation of surface topography of tooth prepared using erbium, chromium: Yttrium, scandium, gallium, garnet laser and bur and its clinical implications

    Directory of Open Access Journals (Sweden)

    Mahesh Verma

    2015-01-01

    Conclusions: Er, Cr: YSGG laser can be used for preparing tooth and bond strength value achieved by laser preparation alone without surface treatment procedure lies in the range of clinical acceptability.

  6. Temperature dependence of the absorption coefficient of water for midinfrared laser radiation

    NARCIS (Netherlands)

    Jansen, E. D.; van Leeuwen, T. G.; Motamedi, M.; Borst, C.; Welch, A. J.

    1994-01-01

    The dynamics of the water absorption peak around 1.94 microns was examined. This peak is important for the absorption of holmium and thulium laser radiation. To examine the effect of temperature on the absorption coefficient, the transmission of pulsed Ho:YAG, Ho:YAG, Ho:YSGG, and Tm:YAG laser

  7. Comparative evaluation of surface topography of tooth prepared using erbium, chromium: Yttrium, scandium, gallium, garnet laser and bur and its clinical implications.

    Science.gov (United States)

    Verma, Mahesh; Kumari, Pooja; Gupta, Rekha; Gill, Shubhra; Gupta, Ankur

    2015-01-01

    Erbium, chromium: Yttrium, scandium, gallium, garnet (Er, Cr: YSGG) laser has been successfully used in the ablation of dental hard and soft tissues. It has been reported that this system is also useful for preparing tooth surfaces and etching, but no consensus exist in the literature regarding the advantage of lasers over conventional tooth preparation technique. Labial surfaces of 25 extracted human maxillary central incisors were divided into two halves. Right half was prepared with diamond bur and left half with Er, Cr; YSGG laser and a reduction of 0.3-0.5 mm was carried out. Topography of prepared surfaces of five teeth were examined under scanning electron microscope (SEM). The remaining samples were divided into 4 groups of 10 specimens each based on the surface treatment received: One group was acid etched and other was nonetched. Composite resin cylinders were bonded on prepared surfaces and shear bond strength was assessed using a universal testing machine. The SEM observation revealed that the laser prepared surfaces were clean, highly irregular and devoid of a smear layer. Bur prepared surfaces were relatively smooth but covered with smear layer. Highest bond strength was shown by laser prepared acid etched group, followed by bur prepared the acid etched group. The bur prepared nonacid etched group showed least bond strength. Er, Cr: YSGG laser can be used for preparing tooth and bond strength value achieved by laser preparation alone without surface treatment procedure lies in the range of clinical acceptability.

  8. Application of lasers in endodontics

    Science.gov (United States)

    Ertl, Thomas P.; Benthin, Hartmut; Majaron, Boris; Mueller, Gerhard J.

    1997-12-01

    Root canal treatment is still a problem in dentistry. Very often the conventional treatment fails and several treatment sessions are necessary to save the tooth from root resection or extraction. Application of lasers may help in this situation. Bacteria reduction has been demonstrated both in vitro and clinically and is either based on laser induced thermal effects or by using an ultraviolet light source. Root canal cleansing is possible by Er:YAG/YSGG-Lasers, using the hydrodynamic motion of a fluid filled in the canals. However root canal shaping using lasers is still a problem. Via falsas and fiber breakage are points of research.

  9. Efficiency of Lasers and a Desensitizer Agent on Dentin ...

    African Journals Online (AJOL)

    2018-02-23

    Feb 23, 2018 ... Department of Prosthodontic, Faculty of Dentistry, Bezmialem. Vakif University, Vatan .... were as follows: (1) good general health with no known allergies to ..... reported that local anesthesia may be facilitated by. Ee,Cr:YSGG ... Jacobson B, Berger J, Kravitz R, Patel P. Laser pediatric crowns performed ...

  10. Effect of different power settings of Er,Cr:YSGG laser before or after tribosilicatization on the microshear bond strength between zirconia and two types of cements.

    Science.gov (United States)

    Zeidan, Leonardo C; Esteves, Camila M; Oliveira, Juliana A; Brugnera, Aldo; Cassoni, Alessandra; Rodrigues, José Augusto

    2018-02-01

    The aim of this study was to evaluate the effect of different output powers of Er,Cr:YSGG laser and the association with tribochemical silica coating on the bond strength between zirconia ceramic and two resin cements. One hundred ninety-two zirconia ceramic bars (IPS e-max ZirCAD Ivoclar Vivadent-) were sectioned (6 × 6 × 4 mm), sintered, and randomly divided into 12 groups for each cement system according to the surface treatment (n = 8): C-without treatment (control); R-tribochemical coating + resin cement (control); 2L-laser (2.0 W) + resin cement; 2LR-laser (2.0 W) + tribochemical coating + resin cement; R2L-tribochemical coating + laser (2.0 W) + resin cement; 2.5L-laser (2.5 W) + resin cement; 2.5LR-laser (2.5 W) + tribochemical coating + resin cement; R2.5L-tribochemical coating + laser (2.5 W) + resin cement; 3L-laser (3.0 W) + resin cement; 3LR-laser (3.0 W) + tribochemical coating + resin cement, R3L-tribochemical coating + laser (3.0 W) + resin cement; and RPHO-tribochemical + resin cement + photoactivation (control). After the surface treatment, the respective primers were applied, and resin cements, Multilink N, Ivoclar Vivadent (M), and Panavia F 2.0, Kuraray Medical Inc. (P), were inserted into Tygon molds which were bonded to the zirconia bars. Each specimen received two cements bars. After 24 h of storage in a relative humidity (100%) at 37 °C, they were evaluated by the microshear test speed of 1 mm/min. The microshear values were analyzed by one-way ANOVA and Tukey's test (α = 0.05). ANOVA showed statistically significant differences among the evaluated groups. The highest bond strength was observed in RPHO, which statistically differed from all groups. The lowest bond strength was observed in M2.5L (Multilink N) and in P3LR (Panavia F 2.0). It can be concluded that the lowest power output tested was suitable and showed bond strength values similar to tribochemical silica deposition. The light curing is important to

  11. Repair bond strength of composite resin to sandblasted and laser irradiated Y-TZP ceramic surfaces.

    Science.gov (United States)

    Kirmali, Omer; Barutcigil, Çağatay; Ozarslan, Mehmet Mustafa; Barutcigil, Kubilay; Harorlı, Osman Tolga

    2015-01-01

    This study investigated the effects of different surface treatments on the repair bond strength of yttrium-stabilized tetragonal zirconia polycrystalline ceramic (Y-TZP) zirconia to a composite resin. Sixty Y-TZP zirconia specimens were prepared and randomly divided into six groups (n = 10) as follows: Group 1, surface grinding with Cimara grinding bur (control); Group 2, sandblasted with 30 µm silica-coated alumina particles; Group 3, Nd:YAG laser irradiation; Group 4, Er,Cr:YSGG laser irradiation; Group 5, sandblasted + Nd:YAG laser irradiation; and Group 6, sandblasted + Er,Cr:YSGG laser irradiation. After surface treatments, the Cimara(®) System was selected for the repair method and applied to all specimens. A composite resin was built-up on each zirconia surface using a cylindrical mold (5 × 3 mm) and incrementally filled. The repair bond strength was measured with a universal test machine. Data were analyzed using a one-way ANOVA and a Tukey HSD test (p = 0.05). Surface topography after treatments were evaluated by a scanning electron microscope (SEM). Shear bond strength mean values ranged from 15.896 to 18.875 MPa. There was a statistically significant difference between group 3 and the control group (p < 0.05). Also, a significant increase in bond strength values was noted in group 6 (p < 0.05). All surface treatment methods enhanced the repair bond strength of the composite to zirconia; however, there were no significant differences between treatment methods. The results revealed that Nd:YAG laser irradiation along with the combination of sandblasting and Er,Cr:YSGG laser irradiation provided a significant increase in bond strength between the zirconia and composite resin. © Wiley Periodicals, Inc.

  12. Effects of erbium‑and chromium‑doped yttrium scandium gallium ...

    African Journals Online (AJOL)

    2014-08-21

    Aug 21, 2014 ... The Er, Cr: YSGG laser also caused deep defects on composite, compomer, and RMGIC ... In amalgam samples, neither laser left significant harmful effects at the ..... The Er, Cr: YSGG laser left shallow irradiation markings.

  13. Influence of Laser Activated Irrigation with Erbium Lasers on Bond Strength of Inidividually Formed Fiber Reinforced Composite Posts to Root Canal Dentin

    Directory of Open Access Journals (Sweden)

    Ivana Miletić

    2016-01-01

    Full Text Available Objective: The aim of this in vitro study was to investigate the effect of laser activated irrigation (LAI using two erbium lasers on bond strength of individually formed fiber-reinforced composite (FRC posts to root canal dentin. Materials and methods: Twenty-seven single-rooted human teeth were endodontically treated and after post space preparation divided into three groups (n=9 per group, according to the pre-treatment of post space preparation: 1 Conventional syringe irrigation (CSI and saline; 2 Er.YAG photon-induced photoacoustic streaming (PIPS technique and saline; 3 Er,Cr:YSGG activated irrigation with RFT2 tip. Two specimens from each group were used for SEM analysis. The remaining specimens (n=7 per group received individually formed FRC post, everStick POST, luted with self-adhesive cement, G-CEM LinkAce. After cementation, the roots were perpendicularly sectioned into 1 mm thin sections and a push-out test was carried out (0.5 mm/min. The data were calculated as megapascals and were log transformed and statistically analysed using one-way ANOVA at the level of significance set at 5%. Results: In the control group, the smear layer was still present. In the Er:YAG group, the smear layer was removed. In the Er,Cr:YSGG group, the smear layer was partially removed. The Er,Cr:YSGG group achieved the highest bond strength values, followed by the control group and then the Er:YAG group, but no statistically significant difference was found in bond strength values in the tested group of post space pretreatment (p=0.564. Conclusions: LAI using two erbium lasers, with PIPS or RFT2 tip, did not affect the bond strength of individually formed FRC posts to root canal dentin.

  14. Laser induced explosive vapor and cavitation resulting in effective irrigation of the root canal. Part 1: a visualization study.

    Science.gov (United States)

    Blanken, Jan; De Moor, Roeland Jozef Gentil; Meire, Maarten; Verdaasdonk, Rudolf

    2009-09-01

    Limited information exists regarding the induction of explosive vapor and cavitation bubbles in an endodontic rinsing solution. It is also not clear whether a fiber has to be moved in the irrigation solution or can be kept stationary. No information is available on safe power settings for the use of cavitation in the root canal. This study investigates the fluid movements and the mechanism of action caused by an Er,Cr:YSGG laser in a transparent root model. Glass models with an artificial root canal (15 mm long, with a 0.06 taper and apical diameter of 400 microm) were used for visualization and registration with a high-speed imaging technique (resolution in the microsecond range) of the creation of explosive vapor bubbles with an Er,Cr:YSGG laser at pulse energies of 75, 125, and 250 mJ at 20 Hz using a 200 microm fiber (Z2 Endolase). Fluid movement was investigated by means of dyes and visualization of the explosive vapor bubbles, and as a function of pulse energy and distance of the fiber tip to the apex. The recordings in the glass model show the creation of expanding and imploding vapor bubbles with secondary cavitation effects. Dye is flushed out of the canal and replaced by surrounding fluid. It seems not necessary to move the fiber close to the apex. Imaging suggests that the working mechanism of an Er,Cr:YSGG laser in root canal treatment in an irrigation solution can be attributed to cavitation effects inducing high-speed fluid motion into and out the canal.

  15. Nanostructured synthetic hydroxyapatite and dental enamel heated and irradiated by ER,CR:YSGG: characterized by FTIR and XRD; Hidroxiapatita sintetica nanoestruturada e esmalte dental aquecidos e irradiados por laser de Er,Cr:YSGG: caracterizacao por FTIR e por DRX

    Energy Technology Data Exchange (ETDEWEB)

    Rabelo Neto, Jose da Silva

    2009-07-01

    The study evaluate the physical changes and/or chemical that occurs in synthetic hydroxyapatite (HAP) and in enamel under action of thermal heating in oven or laser irradiation of Er,Cr:YSGG that may cause changes in its structure to make them more resistant to demineralization aiming the formation of dental caries. The synthetic HAP was produced by reaction of solutions of Ca(NO{sub 3}) and (NH{sub 4}){sub 2}HPO{sub 4} with controlled temperature and pH. The enamel powder was collected from the bovine teeth. Samples of powder enamel and synthetic HAP were subjected to thermal heating in oven at temperatures of 200 deg C, 400 deg C, 600 deg C, 800 deg C and 1000 deg C. For the laser irradiation of materials, were made with 5,79 J/cm{sup 2} of irradiation, 7,65 J/cm{sup 2}, 10,55 J/cm{sup 2} and 13,84 J/cm{sup 2} for synthetic HAP and 7,53 J/cm{sup 2}, 10,95 J/cm{sup 2}, and 13,74 J/cm{sup 2} for the enamel. The samples were evaluated by X-ray diffraction (XRD) for analysis of crystallographic phases and analysis by the Rietveld method, to determine their respective proportions in the material, as well as results of changes of the lattice unit cell parameters (axis-a, axis-c and volume), crystallites sizes and the occupation rate of sites of Ca and P atoms. The samples were analyzed by Fourier transform infrared spectroscopy (FTIR), which should compositional changes due to treatment related to carbonate, phosphate, adsorbed water and hydroxyl radicals content. The infrared was used to measure the surface temperature generated by the laser beam in the solid samples of enamel. Besides the major hydroxyapatite crystallographic phases, there was formations of octa calcium phosphate (OCP) and phase {beta} of tricalcium phosphate ({beta}-TCP ) in enamel heated at 800 deg C. There was reduction of the axis-a, volume and size of crystallites to the temperatures between 400 degree C and 600 deg C and also on laser irradiated samples. Above the temperature of 600 degree C it

  16. Comparative study of the shear bond strength of composite resin bonded to enamel treated with acid etchant and erbium, chromium: Yttrium, scandium, gallium, garnet laser

    Directory of Open Access Journals (Sweden)

    Adel Sulaiman Alagl

    2016-01-01

    Full Text Available Aim: The purpose of this investigation is in vitro comparison of the shear bond strength (SBS of composite resin bonded to enamel pretreated with an acid etchant against enamel etched with erbium, chromium: yttrium, scandium, gallium, garnet (Er, Cr:YSGG laser. Materials and Methods: Sixty premolars were sectioned mesiodistally and these 120 specimens were separated into two groups of 60 each (Groups A and B. In Group A (buccal surfaces, enamel surface was etched using 37% phosphoric acid for 15 s. In Group B (lingual surfaces, enamel was laser-etched at 2W for 10 s by Er, Cr:YSGG laser operational at 2780 nm with pulse duration of 140 μs and a frequency of 20 Hz. After application of bonding agent on all test samples, a transparent plastic cylinder of 1.5 mm × 3 mm was loaded with composite and bonded by light curing for 20 s. All the samples were subjected to SBS analysis using Instron Universal testing machine. Failure modes were observed under light microscope and grouped as adhesive, cohesive, and mixed. Failure mode distributions were compared using the Chi-square test. Results: SBS values obtained for acid-etched enamel were in the range of 7.12–28.36 megapascals (MPa and for laser-etched enamel were in the range of 6.23–23.35 MPa. Mean SBS for acid-etched enamel was 15.77 ± 4.38 MPa, which was considerably greater (P < 0.01 than laser-etched enamel 11.24 ± 3.76 MPa. The Chi-square test revealed that the groups showed no statistically significant differences in bond failure modes. Conclusions: We concluded that the mean SBS of composite with acid etching is significantly higher as compared to Er, Cr: YSGG (operated at 2W for 10 s laser-etched enamel.

  17. Excision of oral mucocele by different wavelength lasers

    Directory of Open Access Journals (Sweden)

    Umberto Romeo

    2013-01-01

    Full Text Available Background: Mucocele is a common benign neoplasm of oral soft tissues and the most common after fibroma. It generally occurs in the lower lip and its treatment includes excision of cyst and the responsible salivary gland, in order to prevent recurrences. Aims: To evaluate the capability of three different lasers in performing the excision of labial mucocele with two different techniques. Materials and Methods: In the presented cases, excision was performed using two different techniques (circumferential incision technique and mucosal preservation technique and three different laser wavelengths (Er,Cr:YSGG 2780 nm, diode 808 nm, and KTP 532 nm. Results: All the tested lasers, regardless of wavelength, showed many advantages (bloodless surgical field, no postoperative pain, relative speed, and easy execution. The most useful surgical technique depends on clinical features of the lesion. Conclusion: Tested lasers, with both techniques, are helpful in the management of labial mucocele.

  18. Evaluation of Mechanical Properties of Glass Fiber Posts Subjected to Laser Surface Treatments.

    Science.gov (United States)

    Barbosa Siqueira, Carolina; Spadini de Faria, Natália; Raucci-Neto, Walter; Colucci, Vivian; Alves Gomes, Erica

    2016-10-01

    The aim of this study was to evaluate the influence of laser irradiation on flexural strength, elastic modulus, and surface roughness and morphology of glass fiber posts (GFPs). Laser treatment of GFPs has been introduced to improve its adhesion properties. A total of 40 GFPs were divided into 4 groups according to the irradiation protocol: GC-no irradiation, GYAG-irradiation with erbium:yttrium-aluminum-garnet [Er:YAG], GCR-irradiation with erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG), and GDI-irradiation with diode laser. The GFP roughness and morphology were evaluated through laser confocal microscopy before and after surface treatment. Three-point bending flexural test measured flexural strength and elastic modulus. Data about elastic modulus and flexural strength were subjected to one-way ANOVA and Bonferroni test (p properties of GFPs.

  19. Compact erbium lasers in the IR photorefractive keratectomy (PRK)

    Science.gov (United States)

    Liu, Baining; Eichler, Hans J.; Sperlich, O.; Holschbach, A.; Kayser, M.

    1996-09-01

    Erbium lasers deliver laser radiation near 3 micrometers and are a promising alternative to excimer laser photorefractive keratectomy (UV-PRK). In addition to easier handling due to all solid state technology, especially when operated in the fundamental mode, IR-PRK eliminates the potential of mutagenic side effects associated with UV-PRK. However, a successful IR-PRK for the clinic treatment in the near future demands both technological development of erbium lasers in different operation modes and clinical investigation of interaction between 3 micrometers radiation and human corneas. The excellent cooperation between university, company and hospital makes this possible. Uncoated thin plates made from infrared materials were found to be effective etalon reflectors with high damage threshold as high as 1 GW/cm2 for erbium lasers. Four kinds of such reflectors were successfully tested in Q-switched Er:YAG-laser at 2.94 micrometers and Er:Cr:YSGG-laser at 2.80 micrometers. Very stable operation of our erbium lasers with high output energy both in free-running and Q-switched modes is realized. First infrared photorefractive keratectomy (IR-PRK) for myopic correction in human corneas by a free-running erbium laser based on our new construction concepts was achieved.

  20. Cutting and skin-ablative properties of pulsed mid-infrared laser surgery.

    Science.gov (United States)

    Kaufmann, R; Hartmann, A; Hibst, R

    1994-02-01

    Pulsed mid-infrared lasers allow a precise removal of soft tissues with only minimal thermal damage. To study the potential dermatosurgical usefulness of currently available systems at different wavelengths (2010-nm Thulium:YAG laser, 2100-nm Holmium:YAG laser, 2790-nm Erbium:YSGG laser, and 2940-nm Erbium:YAG laser) in vivo on pig skin. Immediate effects and wound healing of superficial laser-abrasions and incisions were compared with those of identical control lesions produced by dermabrasion, scalpel incisions, or laser surgery performed by a 1060-nm Nd:YAG and a 1060-nm CO2 laser (continuous and superpulsed mode). Best efficiency and least thermal injury was found for the pulsed Erbium:YAG laser, leading to ablative and incisional lesions comparable to those obtained by dermabrasion or superficial scalpel incisions, respectively. In contrast to other mid-infrared lasers tested, the 2940-nm Erbium:YAG laser thus provides a potential instrument for future applications in skin surgery, especially when aiming at a careful ablative removal of delicate superficial lesions with maximum sparing of adjacent tissue structures. However, in the purely incisional application mode pulsed mid-infrared lasers, though of potential usefulness in microsurgical indications (eg, surgery of the cornea), do not offer a suggestive alternative to simple scalpel surgery of the skin.

  1. Gingival melanin depigmentation by Er:YAG laser: A literature review.

    Science.gov (United States)

    Pavlic, Verica; Brkic, Zlata; Marin, Sasa; Cicmil, Smiljka; Gojkov-Vukelic, Mirjana; Aoki, Akira

    2018-04-01

    Laser ablation is recently suggested as a most effective and reliable technique for depigmentation of melanin hyperpigmented gingiva. To date, different lasers have been used for gingival depigmentation (CO 2 , diode, Nd:YAG, Er:YAG and Er,Cr:YSGG lasers). The use of Er:YAG laser for depigmentation of melanin hyperpigmented gingiva has gained increasing importance in recent years. The purpose of this study was to report removal of gingival melanin pigmentation using an Er:YAG laser in a literature review. The main outcomes, such as improvement of signs (clinical parameters of bleeding, erythema, swelling and wound healing), symptoms (pain) and melanin recurrence/repigmentation were measured. The literature demonstrated that depigmentation of gingival melanin pigmentation can be performed safely and effectively by Er:YAG laser resulting in healing and an esthetically significant improvement of gingival discoloration. Thus, Er:YAG laser seems to be safe and useful in melanin depigmentation procedure. However, the main issue in giving the final conclusion of the optimal Er:YAG laser use in melanin depigmentation is that, to date, studies are offering completely discrepant Er:YAG laser procedure protocols (complex settings of laser parameters), and different criteria for the assessment of depigmentation and repigmentation (recurrence), thus hampering the comparison of the results. Therefore, further studies are necessary to give an optimal recommendation on the use of Er:YAG laser in gingival melanin hyperpigmentation.

  2. The Use of Lasers in Disinfection and Cleaning of Root Canals: a Review

    Directory of Open Access Journals (Sweden)

    Ivica Anić

    2014-01-01

    Full Text Available The outcome of root canal treatment is based on efficient disinfection of the root canal system and prevention of reinfection. Current chemomechanical cleaning methods do not always achieve these goals, and insufficient root canal disinfection is the main reason for endodontic failure. Due to high energy content and specific characteristics of laser light, laser treatment has been proposed for cleaning and disinfecting the root canal system. This paper reviews the literature covering the effect of Er:YAG, Er,Cr:YSGG, Nd:YAG and diode laser on the root canal wall in the removal of smear layer and against intracanal bacteria. Recently, the use of laser energy to induce cavitation and acoustic streaming of intracanal irrigants has been investigated. Based on recent literature, it can be concluded that lasers have bactericidal effects. However, they still cannot replace sodium hypochlorite and should be considered as an adjunct to the current chemical root canal disinfection protocols. Certain lasers can help in removing the smear layer and debris and can modify the morphology of the root canal wall. Unfortunately, there have not been enough randomized clinical studies evaluating endodontic treatment outcome following the use of laser.

  3. Efetividade da fluorescência a laser no diagnóstico de lesões de cárie. Estudos in vitro e in vivo

    OpenAIRE

    Diniz, Michele Baffi [UNESP

    2006-01-01

    O objetivo do presente estudo foi avaliar a efetividade da fluorescência a laser (KaVo DIAGNOdent) para a determinação da severidade de lesões de cárie oclusal em dentes permanentes in vivo e para determinação da remineralização in vitro de lesões de cárie induzidas artificialmente em esmalte de dentes bovinos. No estudo in vitro, 78 blocos de esmalte com lesões de cárie artificial (mancha branca) com valores de dureza Vickers de 38,48 l 0,85 foram submetidos ao tratamento com dentifrício flu...

  4. Nanostructured synthetic hydroxyapatite and dental enamel heated and irradiated by ER,CR:YSGG: characterized by FTIR and XRD

    International Nuclear Information System (INIS)

    Rabelo Neto, Jose da Silva

    2009-01-01

    The study evaluate the physical changes and/or chemical that occurs in synthetic hydroxyapatite (HAP) and in enamel under action of thermal heating in oven or laser irradiation of Er,Cr:YSGG that may cause changes in its structure to make them more resistant to demineralization aiming the formation of dental caries. The synthetic HAP was produced by reaction of solutions of Ca(NO 3 ) and (NH 4 ) 2 HPO 4 with controlled temperature and pH. The enamel powder was collected from the bovine teeth. Samples of powder enamel and synthetic HAP were subjected to thermal heating in oven at temperatures of 200 deg C, 400 deg C, 600 deg C, 800 deg C and 1000 deg C. For the laser irradiation of materials, were made with 5,79 J/cm 2 of irradiation, 7,65 J/cm 2 , 10,55 J/cm 2 and 13,84 J/cm 2 for synthetic HAP and 7,53 J/cm 2 , 10,95 J/cm 2 , and 13,74 J/cm 2 for the enamel. The samples were evaluated by X-ray diffraction (XRD) for analysis of crystallographic phases and analysis by the Rietveld method, to determine their respective proportions in the material, as well as results of changes of the lattice unit cell parameters (axis-a, axis-c and volume), crystallites sizes and the occupation rate of sites of Ca and P atoms. The samples were analyzed by Fourier transform infrared spectroscopy (FTIR), which should compositional changes due to treatment related to carbonate, phosphate, adsorbed water and hydroxyl radicals content. The infrared was used to measure the surface temperature generated by the laser beam in the solid samples of enamel. Besides the major hydroxyapatite crystallographic phases, there was formations of octa calcium phosphate (OCP) and phase β of tricalcium phosphate (β-TCP ) in enamel heated at 800 deg C. There was reduction of the axis-a, volume and size of crystallites to the temperatures between 400 degree C and 600 deg C and also on laser irradiated samples. Above the temperature of 600 degree C it is observed the effect in the lattice parameters. The Ca

  5. Estudo comparativo entre blefaropeeling e laser fracionado de CO2 no tratamento do rejuvenescimento periorbital

    Directory of Open Access Journals (Sweden)

    Elisangela dos Santos Boeno

    2010-06-01

    Full Text Available Introdução: A queixa de rugas e flacidez na região periocular é freqüente.O blefaropeelingutilizando a fórmula de Baker-Gordon e a aplicação de laser fracionado ablativo de CO2 fracionado são consideradas opções efetivas para o tratamento dessa região. Objetivo: Comparar as técnicas, a recuperação e os resultados finais das duas modalidades terapêuticas. Material e Métodos: Estudo comparativo de hemi-faces em pacientes com dermatocálase e rítides moderadas. Realizou-se no lado direito blefaropeeling e, no esquerdo, laser fracionado de CO2, cujos resultados foram avaliados por fotografia, medidas do sulco palpebral superior e melhora clínica. Resultados: Foram incluídas 11 pacientes no protocolo.Verificou-se melhora clínica efotográfica com ambos os métodos. O tempo de recuperação foi maior com o peeling de fenol. As medidas do sulco palpebral superior não mostraram diferenças significativas. Conclusões: Ambas as modalidades terapêuticas são efetivas no tratamento do envelhecimento periorbital. O processo de recuperação o blefaropeeling foi mais demorado. Clinicamente a melhora da flacidez palpebral foi superior com o blefaropeeling.

  6. A EFICÁCIA DO LASER NA CICATRIZAÇÃO DE ÚLCERA DE DECÚBITO EM PACIENTE DIABÉTICO: ESTUDO DE CASO

    Directory of Open Access Journals (Sweden)

    Luiz Armando Vidal Ramos

    2014-08-01

    Full Text Available A úlcera de decúbito tornou-se um dos principais problemas de saúde pública devido o maior tempo de internação em hospitais, alcançando índices preocupantes e mortes evitáveis. Desta forma, o estudo tem como objetivo verificar os efeitos da laserterapia de baixa potência como coadjuvante no tratamento de paciente diabético com úlcera de decúbito. Foi investigada e acompanhada uma paciente diabética do Tipo II portadora de úlcera de decúbito, sendo esta idosa, do gênero feminino, idade 83 anos. Essa paciente foi submetida à aplicação de laser tipo Hélio Neônio (Hene, com comprimento de onda de 670 nm, modo pulsado, método pontual, densidade de energia de 6 J/cm2, com duração de 5 minutos em cada ponto, a qual o procedimento ocorreu durante 5 vezes por semana, no período de 6 semanas. A paciente foi avaliada por meio de registros fotográficos e por mensuração da ferida com uma régua milimétrica, em que delimitou a área da úlcera em cm². Observou-se melhora e redução da úlcera de decúbito a partir da terceira sessão. Com base nos resultados deste estudo o laser tipo Hene foi eficaz no tratamento da úlcera de decúbito em paciente diabético no aspecto cicatrização. Palavras-chave: Laser; Úlcera de Decúbito; Diabetes Mellitus; Cicatrização. DOI: http://dx.doi.org/10.18561/2179-5746/biotaamazonia.v4n2p74-79

  7. Experimental investigation and crystal-field modeling of Er{sup 3+} energy levels in GSGG crystal

    Energy Technology Data Exchange (ETDEWEB)

    Gao, J.Y., E-mail: jygao1985@sina.com [Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei 230031 (China); Sun, D.L.; Zhang, Q.L. [Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei 230031 (China); Wang, X.F. [Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei 230031 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100049 (China); Liu, W.P.; Luo, J.Q.; Sun, G.H.; Yin, S.T. [Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei 230031 (China)

    2016-06-25

    The Er{sup 3+}-doped Gd{sub 3}Sc{sub 2}Ga{sub 3}O{sub 12} (Er{sup 3+}:GSGG) single crystal, a excellent medium of the mid-infrared and anti-radiation solid state laser pumped by laser diode, was grown by Czochralski method successfully. The absorption spectra were measured and analyzed in a wider spectral wavelength range of 350–1700 nm at different temperatures of 7.6, 77, 200 and 300 K. The free-ions and crystal-field parameters were fitted to the experimental energy levels with the root mean square deviation of 9.86 cm{sup −1}. According to the crystal-field calculations, 124 degenerate energy levels of Er{sup 3+} in GSGG host crystals were assigned. The fitting results of free-ions and crystal-field parameters were compared with those already reported of Er{sup 3+}:YSGG. The results indicated that the free-ions parameters for Er{sup 3+} in GSGG host are similar to those in YSGG host crystals, and the crystal-field interaction of GSGG is weaker than that of YSGG, which may result in the better laser characterization of Er{sup 3+}:GSGG crystal. - Highlights: • The efficient diode-end-pumped laser crystal Er:GSGG has been grown successfully. • The absorption spectra of Er:GSGG have been measured in range of 350–1700 nm. • The fitting result is very well for the root mean square deviation is 9.86 cm{sup −1}. • The 124 levels of Er:GSGG have been assigned from the crystal-field calculations.

  8. Cavitation and shock waves emission on the rigid boundary of water under mid-IR nanosecond laser pulse excitation

    Science.gov (United States)

    Pushkin, A. V.; Bychkov, A. S.; Karabutov, A. A.; Potemkin, F. V.

    2018-06-01

    The processes of conversion of light energy into mechanical energy under mid-IR nanosecond laser excitation on a rigid boundary of water are investigated. Strong water absorption of Q-switched Cr:Yb:Ho:YSGG (2.85 µm, 6 mJ, 45 ns) laser radiation provides rapid energy deposition of ~8 kJ cm‑3 accompanied with strong mechanical transients. The evolution of shock waves and cavitation bubbles is studied using the technique of shadowgraphy and acoustic measurements, and the conversion efficiency into these energy channels for various laser fluence (0.75–2.0 J cm‑2) is calculated. For 6 mJ laser pulse with fluence of 2.0 J cm‑2, the conversion into shock wave energy reaches 67%. The major part of the shock wave energy (92%) is dissipated when the shock front travels the first 250 µm, and the remaining 8% is transferred to the acoustic far field. The calculated pressure in the vicinity of water-silicon interface is 0.9 GPa. Cavitation efficiency is significantly less and reaches up to 5% of the light energy. The results of the current study could be used in laser parameters optimization for micromachining and biological tissue ablation.

  9. Evaluation of microtensile and tensile bond strength tests ...

    African Journals Online (AJOL)

    2015-11-03

    Nov 3, 2015 ... Bond strength tests and Er,Cr:YSGG laser frequency. 586 ... power, 90% air pressure, 75% water pressure, 45 s irradiation ..... geometry on the measurement of the tensile bond strength to dentin. J Dent ... Bur‑cut enamel and.

  10. Analysis of peripheral thermal damage after laser irradiation of dentin using polarized light microscopy and synchrotron radiation infrared spectromicroscopy

    Science.gov (United States)

    Dela Rosa, Alfredo; Sarma, Anupama V.; Le, Charles Q.; Jones, Robert S.; Fried, Daniel

    2004-05-01

    It is necessary to minimize peripheral thermal damage during laser irradiation, since thermal damage to collagen and mineral compromises the bond strength to restorative materials in dentin and inhibits healing and osteointegration in bone. The overall objective of this study was to test the hypothesis that lasers resonant to the specific absorption of water, collagen, and hydroxyapatite with pulse durations less than the thermal relaxation times at each respective laser wavelength will efficiently remove dentin with minimal peripheral thermal damage. Precise incisions were produced in 3 x 3 mm2 blocks of human dentin using CO2 (9.6 μm), Er:YSGG (2.79 μm), and Nd:YAG (355 nm) lasers with and without a computer controlled water spray. Polarization-sensitive optical coherence tomography was used to obtain optical cross-sections of each incision to determine the rate and efficiency of ablation. The peripheral thermal damage zone around each incision was analyzed using polarized light microscopy (PLM) and Synchrotron-Radiation Fourier Transform Infrared Spectro-microscopy (SR-FTIR). Thermally induced chemical changes to both mineral and the collagen matrix was observed with SR-FTIR with a 10-μm spatial resolution and those changes were correlated with optical changes observed with PLM. Minimal (alveolar bone.

  11. Residual heat deposition in dental enamel during IR laser ablation at 2.79, 2.94, 9.6, and 10.6 microm.

    Science.gov (United States)

    Fried, D; Ragadio, J; Champion, A

    2001-01-01

    The principal factor limiting the rate of laser ablation of dental hard tissue is the risk of excessive heat accumulation in the tooth. Excessive heat deposition or accumulation may result in unacceptable damage to the pulp. The objective of this study was to measure the residual heat deposition during the laser ablation of dental enamel at those IR laser wavelengths well suited for the removal of dental caries. Optimal laser ablation systems minimize the residual heat deposition in the tooth by efficiently transferring the deposited laser energy to kinetic and internal energy of ejected tissue components. The residual heat deposition in dental enamel was measured at laser wavelengths of 2.79, 2.94, 9.6, and 10.6 microm and pulse widths of 150 nsec -150 microsec using bovine block "calorimeters." Water droplets were applied to the surface before ablation with 150 microsec Er:YAG laser pulses to determine the influence of an optically thick water layer on reducing heat deposition. The residual heat was at a minimum for fluences well above the ablation threshold where measured values ranged from 25-70% depending on pulse duration and wavelength for the systems investigated. The lowest values of the residual heat were measured for short (heat deposition during ablation with 150 microsec Er:YAG laser pulses. Residual heat deposition can be markedly reduced by using CO(2) laser pulses of less than 20 microsec duration and shorter Q-switched Er:YAG and Er:YSGG laser pulses for enamel ablation. Copyright 2001 Wiley-Liss, Inc.

  12. LASERTERAPIA EM AFECÇÕES LOCOMOTORAS: REVISÃO SISTEMÁTICA DE ESTUDOS EXPERIMENTAIS

    Directory of Open Access Journals (Sweden)

    Maria Verônica de Souza

    2016-02-01

    Full Text Available RESUMO Introdução: Ao longo dos anos a fisioterapia tem contribuído para o tratamento das lesões musculotendíneas e osteoarticulares pela utilização de diversos recursos eletrotermofototerapêuticos como, por exemplo, o laser de baixa potência. Objetivo: A finalidade desse estudo foi identificar mediante revisão sistemática, o efeito da laserterapia de baixa potência em afecções do sistema locomotor de ratos, com destaque para a dose de energia e o comprimento de onda utilizado, assim como para a resposta ao tratamento. Métodos: Foram consultadas as bases de dados Medline, Lilacs, PEDro e SciELO, entre janeiro de 2005 a maio de 2013, utilizando os termos "tendinopathy", "laser therapy", "rats", "tendon", "muscle", "bone", "low-level laser therapy", assim como "tendinopatia", "laserterapia", "ratos", "tendão", "músculo", "osso" e "laser de baixa potência". Apenas foram incluídos estudos experimentais publicados nos idiomas português e inglês, que induziram lesão em tendões, músculos, ossos e/ou articulação, tratada com laserterapia, associada ou não a outros tratamentos. Resultados: Foi encontrado um total de 30 estudos experimentais nas bases de dados consultadas, dos quais 15 (50% foram realizados em tendão, 10 (33,33% em músculo e cinco (16,66% em osso e/ou articulação. As doses de energia mais comumente utilizadas foram de 3 J (26,66% e 1 J (16,66%. Já os comprimentos de onda foram de 904 nm (21,21% e 830 nm (21,21%. Conclusão: A informação mais expressiva obtida com a terapia foi a diminuição da resposta inflamatória (36,66% em lesões ortopédicas agudas.

  13. Evaluation of microtensile and tensile bond strength tests ...

    African Journals Online (AJOL)

    Objectives: The aim of the present study was to compare two different bond strength test methods (tensile and microtensile) in investing the influence of erbium, chromium: yttrium‑scandium‑gallium‑garnet (Er, Cr: YSGG) laser pulse frequency on resin‑enamel bonding. Materials and Methods: One‑hundred and twenty‑five ...

  14. Cicatrização da membrana timpânica na timpanocentese com laser de argônio comparado à técnica com microlanceta: estudo experimental em ratos Tympanic membrane healing in myringotomies performed with argon laser or microknife: an experimental study in rats

    Directory of Open Access Journals (Sweden)

    Lucio Almeida Castagno

    2006-12-01

    Full Text Available Otite média secretora (OMS e otite média aguda recorrente (OMAR podem necessitar tratamento cirúrgico para adequada ventilação da orelha média. A abertura clássica do tímpano (timpanocentese requer incisão por microlanceta sob controle de microscópio cirúrgico e mantém-se patente por alguns dias. Estudos recentes sugerem que a timpanocentese feita por diferentes lasers pode permanecer permeável por maior tempo, o que possibilitaria a normalização da otite média. MATERIAL E MÉTODOS: Neste estudo experimental 34 ratos linhagem Wistar, albinos, machos adultos pesando cerca de 300g, foram anestesiados com cetamina 27 mg/kg e xilazina 2,7 mg/kg. A seguir, foram submetidos à timpanocentese incisional com microlanceta no ouvido direito (ML-OD, e à timpanocentese mediada por laser de argônio no ouvido esquerdo (LA-OE. RESULTADOS: Não houve diferença significativa no tempo de cicatrização das timpanocenteses feitas com laser de argônio ou microlanceta. Todas as timpanocenteses cicatrizaram em 10 dias. CONCLUSÃO: A timpanocentese com laser de argônio apresentou patência e cicatrização semelhantes à técnica clássica com microlanceta realizada em ratos Wistar sem enfermidades de orelha média.Secretory otitis media (SOM and recurrent acute otitis media (RAOM may require surgical treatment to proper ventilate the middle ear. Incisional myringotomy is usually done under microscopy with a micro-knife , but it remains patent for just a few days. Recent research indicates that laser assisted myringotomies remain open much longer, allowing middle ear ventilation and healing. MATERIAL AND METHODS: In this experimental study 34 white, male, adult, Wistar rats, without middle ear disease were submited to anesthesia with ketamine 27 mg/kg and xylazine 2,7 mg/kg. Incisional myringotomy was done on the right ear, while laser myringotomy was done on the left. Myringotomies were evaluated periodically until healing. RESULTS: The healing

  15. Estudo comparativo das alterações histológicas imediatas causadas pelo uso do laser de CO2 e do laser de erbium na pele de ratos wistar Comparative study of histopathological abnormalities induced by CO2 and erbium laser on the skin of wistar rats

    Directory of Open Access Journals (Sweden)

    Lúcia de Noronha

    2001-01-01

    Full Text Available O presente estudo tem como objetivo analisar, do ponto de vista anatomopatológico, os efeitos térmicos encontrados na pele de ratos wistar após a aplicação do laser de CO2 e do laser erbium. Utilizaram-se oito ratos submetidos a tricotomia em toda a região toracodorsal. Selecionaram-se duas áreas separadas, as quais receberam a aplicação do laser. Na primeira foram realizadas duas passadas do laser de CO2 e na segunda, duas passadas do laser erbium. A área-controle correspondeu àquela imediatamente adjacente à área submetida ao laser. A análise microscópica da lesão causada pelo laser de CO2 revela lesão em forma de U, com ablação completa da epiderme em toda a sua extensão. A derme superficial apresenta degeneração do colágeno, correspondendo ao dano térmico residual, e a transição deste para a derme normal é bem demarcada. Na pele lesada com laser erbium observa-se também extensa área de pele lesada em forma de platô, com algumas pequenas áreas de pele não-lesada. Pode-se observar, ainda, dano do colágeno na derme superficial, porém mais discreto que aquele causado pelo CO2.The aim of this paper is to analyses the histopathology of the termal effects on the skin of Wistar rats after the application of CO2 and erbium laser. Eight rats had their flanks shaved and two areas were selected for the use of the laser. The first area received two applications of CO2 laser, and the second area two applications of the erbium laser. The skin adjacent to the laser application site was used as a control area. The microscopic analysis of the injury caused by CO2 laser revealed a complete ablation of epidermis and an injury that looked like an "U" in shape. The superficial dermis presented a degeneration of the collagen that corresponded to the residual thermal injury, to normal dermis was sharply demarcated. The injury caused by erbium laser was observed as a plateau injured area with a few small normal areas. The collagen

  16. Estudo experimental da aplicação retiniana do laser infravermelho via transescleral sob condições de baixa visibilidade Transscleral infrared laser retinal photocoagulation experimental study under low visibility conditions

    Directory of Open Access Journals (Sweden)

    Dario Grechi Goulart

    2008-06-01

    Full Text Available OBJETIVOS: Pesquisa experimental, com laser de diodo infravermelho, para estimar a segurança, a reprodutibilidade e a permeabilidade da parede ocular à sua atuação clínica, quando aplicado via transescleral, em condições de baixa visibilidade. MÉTODOS: Submetemos olhos de coelhos pigmentados da raça Nova Zelândia à fotocoagulação retiniana por laser de diodo infravermelho. No olho direito, realizamos fotocoagulação via transescleral sob parâmetros de potência e tempo pré-determinados clinicamente. No olho esquerdo, foram repetidos os mesmos valores da potência e tempo usados no olho direito, desta vez, via transpupilar. Imediatamente e após 2 meses, estudos clínicos baseados na retinografia e histopatológicos foram realizados. RESULTADOS: A permeabilidade da parede ocular, quando da aplicação do laser de diodo infravermelho via transescleral, variou entre 58,95 e 63,87%. A média da permeabilidade da parede ocular a 300 mW (63,14% mostrou-se significativamente superior àquela da permeabilidade da parede ocular encontrada a 500 mW (59,11%, (PPURPOSE: Retinal photocoagulation under poor visualization condition is often required. Transscleral infrared laser can be used as an alternative to regular transpupillary treatment. Based upon retinographic measurements, we proposed to estimate the reproducibility as well as ocular wall permeability rate for this treatment. Our primary goal was to evaluate whether this technique can deliver adequate photocoagulation at predetermined parameters without direct retinal visualization. METHODS: In New Zealand pigmented rabbits, optimal transscleral infrared diode laser settings were administered to the right eye. With the same parameters, transpupillary photocoagulation was repeated in the left eye. Retinographic and clinical examinations were performed immediately and two months later. RESULTS: Ocular wall permeability rate varied between 58.95 and 63.87%. Average permeability using a

  17. Micro-fractional ablative skin resurfacing with two novel erbium laser systems.

    Science.gov (United States)

    Dierickx, Christine C; Khatri, Khalil A; Tannous, Zeina S; Childs, James J; Cohen, Richard H; Erofeev, Andrei; Tabatadze, David; Yaroslavsky, Ilya V; Altshuler, Gregory B

    2008-02-01

    Fractional ablation offers the potential benefits of full-surface ablative skin resurfacing while minimizing adverse effects. The purpose of this study was to evaluate the safety, damage profile, and efficacy of erbium fractional lasers. Histology from animal and human skin as well as clinical evaluations were conducted with erbium YAG (2,940 nm) and erbium YSGG (2,790 nm) fractional lasers varying pulse width, microbeam (microb) energy, number of passes, and stacking of pulses. Single-pulse treatment parameters from 1 to 12 mJ per 50-70 microm diameter microbeam and 0.25-5 milliseconds pulse widths produced microcolumns of ablation with border coagulation of up to 100 microm width and 450 microm depth. Stacking of pulses generated deeper microcolumns. Clinical observations and in vivo histology demonstrate rapid re-epithelization and limited adverse side effects. Facial treatments were performed in the periorbital and perioral areas using 1-8 passes of single and stacked pulses. Treatments were well-tolerated and subjects could resume their normal routine in 4 days. A statistically significant reduction in wrinkle scores at 3 months was observed for both periorbital and perioral wrinkles using blinded grading. For periorbital treatments of four passes or more, over 90% had > or =1 score wrinkle reduction (0-9 scale) and 42% had > or =2. For perioral wrinkles, over 50% had substantial improvements (> or =2). The clinical observations and histology findings demonstrate that micro-fractional ablative treatment with 2,790 and 2,940 nm erbium lasers resulted in safe and effective wrinkle reduction with minimal patient downtime. The depth and width of the ablated microcolumns and varying extent of surrounding coagulation can be controlled and used to design new treatment procedures targeted for specific indications and areas such as moderate to severe rhytides and photodamaged skin.

  18. In vitro evaluation of repair bond strength of composite: Effect of surface treatments with bur and laser and application of universal adhesive.

    Science.gov (United States)

    Kiomarsi, Nazanin; Espahbodi, Melika; Chiniforush, Nasim; Karazifard, Mohammad Javd; Kamangar, Sedighe Sadat Hashemi

    2017-09-30

    This study aimed to assess the effect of surface treatment by bur and laser and application of universal adhesive on repair bond strength of composite resin. A total of 120 composite blocks measuring 6×4×4 mm were fabricated of Filtek Z250 composite. All samples were subjected to 5,000 thermal cycles and divided into two groups for surface preparation by bur and by Er,Cr:YSGG laser (n = 60). The surfaces were then etched with orthophosphoric acid, rinsed with water and divided into three groups (silane, silane plus Single Bond and silane plus Single Bond Universal). Repair composite was then bonded to aged composite. Half of the samples in each group were stored in distilled water at 37°C for 24 hours and the other half underwent 5000 thermal cycles. All samples were then subjected to shear bond strength testing using a universal testing machine at a crosshead speed of 1 mm/minute. The data were analyzed using one-way ANOVA and Tukey's HSD test. Mode of failure was determined using a stereomicroscope. Bur preparation plus universal adhesive yielded the highest bond strength (30.16 µ 2.26 MPa). Laser plus silane yielded the lowest bond strength (5.63 µ 2.43 MPa). Bur preparation yielded significantly higher bond strength than laser (P composite by bur and application of universal adhesive can improve the repair bond strength of composite. Application of silane (without adhesive) in the process of repair cannot provide adequately high repair bond strength.

  19. Hard tissue ablation with a spray-assisted mid-IR laser

    International Nuclear Information System (INIS)

    Kang, H W; Rizoiu, I; Welch, A J

    2007-01-01

    The objective of this study was to understand the dominant mechanism(s) for dental enamel ablation with the application of water spray. A free-running Er,Cr:YSGG (yttrium, scandium, gallium, garnet) laser was used to ablate human enamel tissue at various radiant exposures. During dental ablation, distilled water was sprayed on the sample surface, and these results were compared to ablation without a spray (dry ablation). In order to identify dominant ablation mechanisms, transient acoustic waves were compared to ablation thresholds and the volume of material removed. The ablation profile and depth were measured using optical coherence tomography (OCT). Irregular surface modification, charring and peripheral cracks were associated with dry ablation, whereas craters for spray samples were relatively clean without thermal damage. In spite of a 60% higher ablation threshold for spray associated irradiations owing to water absorption, acoustic peak pressures were six times higher and ablation volume was up to a factor of 2 larger compared to dry ablation. The enhanced pressure and ablation performance of the spray-assisted process was the result of rapid water vaporization, material ejection with recoil stress, interstitial water explosion and possibly liquid-jet formation. With water cooling and abrasive/disruptive mechanical effects, the spray ablation can be a safe and efficient modality for dental treatment

  20. Hard tissue ablation with a spray-assisted mid-IR laser

    Science.gov (United States)

    Kang, H. W.; Rizoiu, I.; Welch, A. J.

    2007-12-01

    The objective of this study was to understand the dominant mechanism(s) for dental enamel ablation with the application of water spray. A free-running Er,Cr:YSGG (yttrium, scandium, gallium, garnet) laser was used to ablate human enamel tissue at various radiant exposures. During dental ablation, distilled water was sprayed on the sample surface, and these results were compared to ablation without a spray (dry ablation). In order to identify dominant ablation mechanisms, transient acoustic waves were compared to ablation thresholds and the volume of material removed. The ablation profile and depth were measured using optical coherence tomography (OCT). Irregular surface modification, charring and peripheral cracks were associated with dry ablation, whereas craters for spray samples were relatively clean without thermal damage. In spite of a 60% higher ablation threshold for spray associated irradiations owing to water absorption, acoustic peak pressures were six times higher and ablation volume was up to a factor of 2 larger compared to dry ablation. The enhanced pressure and ablation performance of the spray-assisted process was the result of rapid water vaporization, material ejection with recoil stress, interstitial water explosion and possibly liquid-jet formation. With water cooling and abrasive/disruptive mechanical effects, the spray ablation can be a safe and efficient modality for dental treatment.

  1. Shear bond strength of a self‑etched resin cement to an indirect ...

    African Journals Online (AJOL)

    2014-11-15

    Nov 15, 2014 ... was used to analyze the bond strength values of different groups. .... was 10 Hz, 3W, 300 mJ, at a distance of 10 mm from the .... gallium-garnet (Er,Cr:YSGG) group, (e) 2 W Er,Cr:YSGG group, (f) 3 W Er,Cr:YSGG group d c b f.

  2. The Effect of Laser Irradiation on Shear Bond Strength of GI to Dentin After CPP-ACP Treatment

    Directory of Open Access Journals (Sweden)

    Moezizadeh

    2016-02-01

    Full Text Available Background Dentin sensitivity is one of the most important problems in dentistry. Enamel loss due to root exposure is serious issue and common exposure is one of the reasons for dentin hypersensitivity. There are different methods for solving this problem. One of the most conservative and least expensive methods is use of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP paste. Objectives The aim of this study was to evaluate shear bond strength of GIC to dentin, with or without laser, CPP-ACP paste and polyacrylic acid treatments. Materials and Methods Fifty sound human third molars were bisected in a mesiodistal direction using a diamond disk. Using 400, 600 and 800 grit silicon carbide paper, dentin surfaces were exposed. The teeth were divided into five groups. In groups A, B, D and H, CPP-ACP (GC tooth mousse Itabashi-Ku, Tokyo, Japan was applied for one hour the first day and repeated at the same time of day for a total of five days. In groups B, C, D and E, the specimens were subjected to laser for 10 seconds using Er, Cr: YSGG laser. In groups B, C, H and G, specimens were treated with 10% polyacrylic acid for 20 seconds. A plastic tube containing GI was positioned over the tooth. Samples were loaded in shear bond using a Universal Testing Machine (Zwick/Roell, Germany, at a 0.5 mm/minute crosshead speed. Results Despite the failing of groups A and D, group analysis showed that there were no significant differences between the groups. The predominant type of fracture in all groups was adhesive. Conclusions Application of CPP-ACP, without preconditioning with polyacrylic acid, can decrease shear bond strength. Laser irradiation has no effect on shear bond strength of GIC to dentin in this condition.

  3. Estudo morfométrico e morfológico da cicatrização após uso do laser erbium: YAG em tecidos cutâneos de ratos Morphometrical and morphological study of cicatricial effects caused by application of laser erbium: YAG on the skin of rats

    Directory of Open Access Journals (Sweden)

    Lúcia de Noronha

    2004-02-01

    Full Text Available Este trabalho analisa o efeito da reparação cutânea do laser erbium:yttrium aluminunn garnet (YAG (Er:YAG em pele de ratos através de estudo histológico e morfométrico. Tatuaram-se duas figuras no dorso de cada animal (n = 35, denominadas controle e experimento. Na figura experimento, aplicaram-se três passadas de laser Er:YAG com parâmetros padronizados. Cinco animais foram eutanasiados nos dias 0, 7, 14, 28, 56, 84 e 112 de pós-operatório. O estudo histológico demonstrou no dia 0 dano de ablação médio de 215,24 micrômetros (mm, sendo homogêneo com vaporização da epiderme e porções superficiais da derme. O dano térmico residual foi pequeno (média de 41,45mm, observando-se áreas onde estava praticamente ausente. A fibroplasia cicatricial já estava presente no dia 7 (média de 55,58mm, aumentando rapidamente até o dia 28 (média de 209,49mm, quando atingiu um platô e se manteve até o dia 112. Não houve sinais de processo inflamatório agudo no dia 7 e a reepitelização já estava completa. Concluiu-se que a aplicação de laser na pele de ratos induz reparação cutânea ao longo de 112 dias nas condições do experimento.This study analyses the skin contracture effect of the erbium:YAG (Er:YAG laser on the skin of rats by light microscopic histological and morphometrical evaluations. Two squares of back skin were precision tattooed on each of the animals (n = 35, that were termed control and experimental skin. The experimental skin was treated with three passes of the Er:YAG laser with standardized parameters. Five animals were killed and skin specimens were analyzed at 00, 07, 14, 28, 56, 84 and 112 days. Histologic examination demonstrated a mean of 215.24 micrometers ablative damage that was homogeneous with complete vaporization of the epidermis and superficial dermis. The residual thermal damage was small (mean of 41.45 micrometers observing areas where it was absent. The cicatritial fibroplasy was present at

  4. Effect of adhesive system application for cavities prepared with erbium, chromium: yttrium scandium gallium garnet laser on rat dental pulp tissue.

    Science.gov (United States)

    Takada, Mayo; Suzuki, Masaya; Haga-Tsujimura, Maiko; Shinkai, Koichi

    2017-07-01

    We examined the effects of adhesive systems under study applied for a laser-cut cavity using an Er,Cr:YSGG laser on rat dental pulp at 24 h and 14 days postoperatively. Group 1, laser-cut cavities were treated with a self-etching-primer and bonding agent; group 2, pretreated with a phosphoric-acid, and then treated with a self-etching-primer and bonding agent; group 3, pretreated with a phosphoric-acid and sodium-hypochlorite, and then treated with a self-etching-primer and bonding agent; and group 4, treated with an all-in-one adhesive. A flowable resin composite was used as filling material for each cavity treated with each group. A glass-ionomer-cement was used as a control. The following items were evaluated: pulp-tissue-disorganization (PTD), inflammatory-cell-infiltration (ICI), tertiary-dentin-formation (TDF), and bacterial-penetration (BP). The results were statistically analyzed using the Kruskal-Wallis test and Mann-Whitney U test. No significant differences were observed among the experimental groups for all parameters after 24 h and 14 days (P > 0.05). The majority of the specimens showed PTD with edema formation after 24 h; however, all the specimens demonstrated pulpal healing with TDF after 14 days. On the parameter of TDF, all groups showed significant differences between the two postoperative periods (P < 0.01). On the parameter of ICI, a significant difference was found between the two postoperative periods in group 4 (P < 0.05). No specimens showed BP. The pretreatment on the cavity prepared with the laser using phosphoric-acid or sodium-hypochlorite did not affect the dental pulp healing of rat tooth.

  5. A efetividade do laser de HeNe 632,8 nm no reestabelecimento da integridade dos tecidos cutâneos em animais experimentais: revisão sistemática Effectiveness of HeNe 632.8 nm laser on skin tissue integrity repair in experimental animals: a systematic review

    Directory of Open Access Journals (Sweden)

    Clarissa Tôrres Leal

    2012-09-01

    Full Text Available O objetivo desta revisão sistemática foi analisar o efeito do laser de HeNe na cicatrização de feridas em ratos. Foram selecionados estudos experimentais que adotaram o laser HeNe para o tratamento de feridas agudas em ratos adultos saudáveis, com lesões induzidas por bisturi, nas bases de dados PubMed/MEDLINE, LILACS e SciELO. Foram utilizados os seguintes descritores: cicatrização de feridas e colágeno, de acordo com o MeSH e o DeCS, além dos unitermos laser HeNe e reparação da pele e seus equivalentes em inglês e espanhol. Três estudos foram incluídos na revisão sistemática, não sendo possível a realização de metanálise, devido à impossibilidade de comparação entre as metodologias dos estudos selecionados. Todos os estudos realizaram análise por meio de cortes histológicos das cicatrizes. A presença de falhas metodológicas nos três artigos dificultou a interpretação fidedigna dos dados encontrados. Os estudos destacaram uma redução na intensidade da resposta inflamatória e uma melhor organização das fibras colágenas no grupo irradiado. A terapia com laser HeNe mostrou boa resposta no reparo tecidual. No entanto, tais resultados devem ser analisados de modo criterioso, uma vez que há presença de heterogeneidade, principalmente em relação aos parâmetros adotados.The aim of this systematic review was to analyze the effect of HeNe laser on wound healing in rats. Experimental studies that adopted HeNe laser as a treatment of acute lesions in healthy adult rats were selected, with scalpel-induced lesions, at PubMed/MEDLINE, LILACS, and SciELO databases. The following keywords were used: wound healing and collagen, according to MeSH and DeCS, besides the terms HeNe laser and skin repair, and their equivalent in Portuguese and Spanish. Three studies were included in this systematic review, but it was not possible to perform a metanalysis, due to impossibility to compare methods of the selected studies. All

  6. Efeitos da radiação laser de dióxido de carbono em tecido ósseo: estudo macroscópico em ratos Effect of carbon dioxide laser radiation on osseous tissue: macroscopic study in rats

    Directory of Open Access Journals (Sweden)

    Walter NICCOLI-FILHO

    2001-06-01

    Full Text Available O laser de dióxido de carbono (CO2, pelas suas propriedades intrínsecas, tem se tornado um instrumento cirúrgico importante; entre estas podemos citar: hemostasia, redução do edema e da dor pós-operatória e esterilização do campo cirúrgico. Seu uso em tecido ósseo para realização de osteotomias ainda é questionável, principalmente devido à possibilidade de iatrogenias causadas pelo aumento da temperatura tecidual, bem como destes efeitos na área paraincisional. O propósito deste estudo foi proporcionar a confecção de um plano piloto visando analisar macroscopicamente os efeitos da radiação laser de CO2 em tíbia de rato a fim de estabelecerem-se parâmetros de segurança quanto a potência. Foram utilizados 12 ratos. Após anestesia, os ossos foram submetidos a radiação com potência de 1, 3 e 5 watts. Os animais foram sacrificados nos tempos imediatamente após, 3, 7 e 14 dias após a irradiação, visando à remoção do osso tratado. Os espécimes obtidos foram observados através de lupa estereoscópica com aumentos de 14, 25 e 40 vezes e fotografados para posterior análise. Os resultados permitiram concluir que a potência de 1 watt proporciona uma melhor qualidade de resposta à reparação e que as potências de 3 e 5 watts provocaram o atraso na cronologia de reparo.The use of CO2 laser in osseous tissue to execute osteotomies is still questionable, mainly due to the increase of temperature in the site of irradiation. The purpose of this research was to carry out a pilot study in order to analyze macroscopically the effect of CO2 laser irradiation on rat tibia and to establish security parameters regarding power. Twelve rats were submitted to irradiation with 1, 3 and 5 watts of power and were examined immediately, 3, 7 and 14 days after irradiation. The results showed better healing when irradiation was carried out with the power of 1 watt; the 3- and 5-watt powers caused delay in the chronology of healing.

  7. Fotocoagulação a laser em pacientes portadores de descolamento de retina regmatogênico periférico

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    Paulo Escarião

    2013-08-01

    Full Text Available OBJETIVO: Relatar uma série de casos de descolamento de retina sem envolvimento macular tratados com fotocoagulação a laser. MÉTODOS: Estudo tipo série de casos envolvendo 14 olhos de 12 pacientes com descolamento de retina regmatogênico sem envolvimento macular, retrospectivo, de intervenção. Olhos com procedimentos cirúrgicos prévios foram excluídos. A fotocoagulação a laser foi aplicada com três fileiras confluentes de spot de 300μm, posterior ao descolamento de retina, se extendendo até a ora serrata. A melhor acuidade visual corrigida pré e pós-operatória e a progressão do descolamento de retina foram registrados durante o estudo. RESULTADOS: Treze olhos necessitaram de apenas uma sessão de laser para conter o descolamento de retina. Apenas um olho necessitou de intervenção adicional por causa da evolução do descolamento de retina. Miopia foi encontrada em 7 olhos. Todos os pacientes mantiveram acuidade visual corrigida igual ou melhor que 20/30. CONCLUSÃO:Em casos bem selecionados, a fotocoagulação a laser pode ser considerada para o tratamento de descolamento de retina regmatogênico.

  8. Bonding Strength of Universal Adhesives To Er,Cr:YSGG Laser ...

    African Journals Online (AJOL)

    2018-02-07

    Feb 7, 2018 ... E-mail: kerimayar@biruni.edu.tr smear layer ... increased, owing to their greater aesthetic properties and the potential ... produced by the selective ablation of the intertubular dentin ... 2.780 nm, power of 1.5 W, frequency of 20 Hz, pulse duration ..... Lopes RM, Trevelin LT, da Cunha SRB, de Oliveira RF, de.

  9. Estudo comparativo das extensões das lesões causadas por duas e quatro passadas de laser Erbium em ratos Wistar com 0% de sobreposição dos spots Comparative study of alterations found in 2 and 4 Erbium: YAG laser passes in Wistar rats with 0% overlap of spots

    Directory of Open Access Journals (Sweden)

    Lúcia de Noronha

    2001-06-01

    Full Text Available Lasers de CO2 tem sido apresentados com a finalidade de rejuvenecer a face através do resurfacing. Embora cada sistema de laser tenha o mesmo princípio básico, há significativa diferença entre os lasers que pode resultar em variações no efeito tecidual clínico e histológico. O laser Erbium:YAG que tem como característica o comprimento de onda com 10 vezes mais afinidade pela água que o laser de CO2. O propósito deste estudo experimental foi comparar as alterações morfométricas encontradas em 2 e 4 passadas com laser Erbium:YAG com sobreposição de 0% dos spots. Foi avaliada a homogeneidade da ablaçãoem comprimento e usou-se a pele do dorso de 3 ratos in vivo. Foi selecionada uma área de pele controle de cada rato. Finalmente, num período máximo de 3 horas, a pele foi ressecada e encaminhada à histopatologia para as avaliações propostas. Como resultados com 4 passadas houve mais homogeneidade da extensão da ablação do que em 2 passadas. Conclui-se que a extensão e homogeneidade de ablação foi maior com 4 passadas. A utilização de 0% de sobreposição dos spots não garante homogeneidade de ablação.CO2 lasers has been presented with the purpose of rejuvenating the face by means of resurfacing. Though each laser systems has the same base principle, there is a significant difference among lasers which could result in variations in the clinical and histological effects of the tissue. The Erbium:YAG laser has the characteristic of having the wavelength with 10 times more affinity for water than the CO2 laser. The purpose of this experimental study was to compare the morphometric alterations found in 2 and 4 Erbium:YAG laser passes with 0% overlap of spots. It was evaluated the homogeneity of ablation in length and was used the dorsal skin of 3 living mice. It was selected a control area in each mouse. Finally, in the maximum period of three hours, the skin was resected and sent to histopathology for evaluations

  10. Neocolagenização induzida pelo resurfacing com laser erbium:YAG isolado e associado a lifting cutâneo: estudo morfométrico comparativo em ratos Comparison of single erbium:YAG laser resurfacing to a combination with cutaneous lifting: a morphometric study of neocollagenization in rats

    Directory of Open Access Journals (Sweden)

    Lucia Noronha

    2005-10-01

    Full Text Available INTRODUÇÃO: Diferente do lifting, cuja tração mecânica é a responsável pelo efeito clínico de rejuvenescimento sobre rugas profundas, a fibroplasia (ou neocolagenização é a responsável direta pelo resultado final da ação do laser sobre a pele com rugas superficiais, conferindo-lhe aparência mais jovem. O uso combinado dessas duas técnicas pode ser vantajoso, pois permite um resultado estético melhor com um único procedimento anestésico e cirúrgico em um curto período de recuperação. OBJETIVOS: O presente estudo morfométrico se propõe a avaliar se ocorre alguma alteração na espessura da fibroplasia induzida pelo resurfacing a laser erbium:YAG quando este se associa ao lifting cutâneo. MÉTODO: Foram utilizados 50 ratos da linhagem Wistar, divididos em dois grupos de 25, sendo que o primeiro grupo foi submetido à aplicação exclusiva de laser erbium:YAG no dorso de cada animal e o outro sofreu a aplicação de laser Erbium: YAG combinada ao lifting, o qual foi representado, no animal de experimentação, por retalho cutâneo dorsal pediculado. A fibroplasia foi avaliada nos dois grupos com medidas morfométricas lineares realizadas após o sacrifício dos animais nos dias 14, 28, 56, 84 e 112 do pós-operatório. RESULTADO: Foi observado aumento da fibroplasia em ambos os grupos estudados, porém o crescimento do colágeno foi superior no grupo submetido à terapia isolada com laser Erbium: YAG. CONCLUSÃO: A espessura da fibroplasia induzida pelo resurfacing a laser Erbium: YAG foi influenciada pela associação de um segundo procedimento cirúrgico no mesmo tempo operatório, neste caso, o lifting cutâneo.INTRODUCTION: The fibroplasia is the responsible for the final aesthetic results induced by laser resurfacing upon skin with superficial wrinkles. On the other hand, the lifting is responsible for the deeper wrinkles removal, produced by mechanic results. The use of the combination of these two rejuvenation

  11. Estudos de atmosfera

    Directory of Open Access Journals (Sweden)

    Carlos Eduardo Riccioppo

    2016-11-01

    Full Text Available Joker e Estudos de balística possuíam formas distintas dos cadernos ou livros quando foram exibidos pela primeira vez, na mostra Dual Overdrive. De algum modo, o flagrante das imagens dos cartazes da campanha política parisiense e daquelas cusparadas sobre o asfalto era preservado no modo como eram mostrados os trabalhos, que repunham não apenas a orientação espacial dos objetos fotografados, mas, igualmente, sua escala: Joker apresentava-se na parede, em dimensões relativamente próximas às dos cartazes lambe-lambe que retratavam; e Estudos de balística, no chão da galeria, também com ampliação suficiente para que se tivesse a impressão de que se tratava de imagens “em tamanho real”.

  12. Effect of the application of surface treatments before and after sintering on the flexural strength, phase transformation and surface topography of zirconia.

    Science.gov (United States)

    Kurtulmus-Yilmaz, Sevcan; Aktore, Huseyin

    2018-05-01

    To evaluate the effects of airborne-particle abrasion (APA) and Er,Cr:YSGG laser irradiation on 4-point-flexural strength, phase transformation and morphologic changes of zirconia ceramics treated at pre-sintered or post-sintered stage. Three hundred and forty-two bar shaped zirconia specimens were milled with different sizes according to the flexural strength test (n = 10), X-ray diffraction (XRD) (n = 4) and field emission scanning electron microscope (FE-SEM) (n = 4) analyses. For each test protocol, specimens were divided into 4 main groups whether the surface treatments applied before or after sintering and whether the specimens received heat treatment or not as pre-sintered, post-sintered no-heat and post-sintered heat-treated groups, and a group was served as control. Main groups were further divided into 6 equal subgroups according to surface treatment method applied (2 W-, 3 W-, 4 W-, 5 W-, 6 W-laser irradiations and APA). Surface treatments were applied to pre-sintered groups before sintering and to post-sintered groups after sintering. Post-sintered heat-treated groups were subjected to veneer ceramic firing simulation after surface treatments. Flexural strength and flexural modulus values were statistically analysed and monoclinic phase content was calculated. Weibull analysis was used to evaluate strength reliability and fractographic analysis was conducted. Highest flexural strength values were detected at post-sintered no-heat APA and 4W-laser groups (P SEM images pre-sintered groups. Application of surface treatments at pre-sintered stage may be detrimental for zirconia ceramics in terms of flexural strength. Treating the surface of zirconia ceramic before sintering process is not recommended due to significant decrease in flexural strength values. 2 W-4 W Er,Cr:YSGG laser irradiations can be regarded as alternative surface treatment methods when zirconia restoration would be subjected to veneer ceramic firing procedures

  13. ESTUDOS ESTILÍSTICOS NO BRASIL

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    Carlos Eduardo Falcão Uchôa

    2013-06-01

    Full Text Available Este artigo objetiva mostrar os inícios e a progressão dos estudos estilísticos no Brasil. Após uma introdução sobre o surgimento, na Europa, da Estilística como disciplina de pesquisa no campo da linguagem, detém-se, sucessivamente, nas contribuições de filólogos, linguistas, teóricos da literatura e gramáticos para o estudo dos mais variados recursos estilísticos ocorrentes sobretudo em autores brasileiros.

  14. O desamparo aprendido revisitado: estudos com animais

    Directory of Open Access Journals (Sweden)

    Maria Helena Leite Hunziker

    Full Text Available O desamparo aprendido tem sido definido como a dificuldade de aprendizagem apresentada por indivíduos que tiveram experiência prévia com estímulos aversivos incontroláveis. O objetivo deste trabalho é fazer uma revisão crítica dos estudos sobre o desamparo aprendido, com animais. Nessa análise, são considerados aspectos conceituais e metodológicos dos estudos em questão e as interpretações teóricas sobre esse efeito comportamental. Aborda-se a evolução histórica desses estudos, bem como alguns aspectos controversos das publicações que se acumularam ao longo de quatro décadas de pesquisa. A associação do desamparo aprendido com a depressão clínica é analisada criticamente, destacando-se a necessidade de maior rigor metodológico e conceitual nos estudos da área.

  15. Transscleral diode laser retinopexy in retinal reattachment surgery Retinopexia com laser de diodo transescleral na cirurgia de descolamento de retina

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    João Carlos de Miranda Gonçalves

    2004-02-01

    Full Text Available PURPOSE: Transscleral diode retinal photocoagulation (diopexy is becoming an accepted technique in the treatment of selected retinal diseases. The objective of this study is to evaluate diopexy technique in the production of adhesive chorioretinal lesions during the surgical treatment of the rhegmatogenous retinal detachment. METHODS: 25 patients with rhegmatogenous retinal detachment were enrolled in a prospective clinical-surgical study to evaluate the technique of transscleral diode laser photocoagulation to obtain adhesive chorioretinal lesions during retinal reattachment surgery. The surgery consisted of the placement of an exoplant silicon to produce a buckle effect combined with a drainage of subretinal fluid in most cases. RESULTS: By a mean follow-up of 10 months, 21 of 25 eyes had their retinas reattached after only one surgery with diopexy used in all cases. CONCLUSION: Transscleral diode laser photocoagulation was a technically easy, controlled, effective, reproducible and safe means of obtaining chorioretinal adhesion in retinal reattachment surgery.OBJETIVO: Fotocoagulação transescleral com laser de diodo (diopexia está se tornando técnica utilizada no tratamento de algumas doenças retinianas. O objetivo deste estudo é avaliar a técnica de diopexia na produção de lesões coriorretinianas aderentes durante o tratamento cirúrgico do descolamento de retina regmatogênico. MÉTODOS: Vinte e cinco pacientes com descolamento de retina regmatogênico participaram deste estudo clínico-cirúrgico prospectivo para avaliar a técnica de fotocoagulação com laser de diodo transescleral para obter lesões coriorretinianas aderentes durante a cirurgia de descolamento de retina. A cirurgia consistiu de colocação de explante de silicone para produzir efeito de introflexão escleral combinado com drenagem do líquido subretiniano na maioria dos casos. RESULTADOS: Após um período médio de seguimento de 10 meses, em 21 dos 25 olhos

  16. Practical considerations on frenectomy

    Science.gov (United States)

    Moldoveanu, Lucia; Badea, Florin Ciprian; Odor, Alin A.

    2014-01-01

    Besides surgically classical frenectomy, modern dentistry currently allows its approach by dental laser. Materials and Method: We proposed clinical observation of the results obtained by frenectomy with/without frenoplasty made by laser Er,Cr:YSGG 2780 nm. Results: The patients reported no pain, bleeding, swelling or major discomfort during the postoperative control of the following day. In terms of psycho-emotional reactions, both patients well behave well, the calm being given by no pain, bleeding, suture or edema. Discussions: The accuracy of this method, as well as the use of additional means of healing, allow satisfactory results both for patient and physician. Working parameters depend on the type of laser that is used, in our case Biolase Waterlase MD Turbo, regularly used in Toldimed Clinic in Constanta. Conclusions: Our study reveals that the possibilities regarding the surgical modeling of the lower lip frenulum are higher due to laser than the classical surgical approach. Moreover, a major role in the prevention of relapse by inappropriate healing is represented by the approach of frenectomy accompanied by frenuloplasty.

  17. In vitro study of temperature changes in root during Er:YAG laser application; Estudo in vitro da alteracao da temperatura durante a aplicacao do Er:YAG laser intracanal

    Energy Technology Data Exchange (ETDEWEB)

    Brandao, Redson Vilela

    2001-07-01

    The temperature increase in root dentine irradiated by Er:YAG laser beam was analyzed, for different dentine thickness and different energy and frequency conditions, aiming the evaluation of Er:YAG laser in endodontic therapy, without causing any damages to close tissues. Twenty four human teeth were separated in four groups with six teeth each, and longitudinally sectioned in thickness of 0.5 mm (first group), 1,0 mm (second group), 1,5 mm (third group) and 2,0 mm (fourth group). Those samples were irradiated with the Er:YAG laser, emitting at the wavelength of 2.94{mu}m, by using a sapphire optic fiber with diameter of 0.375 mm, and forming an angle of 5 deg with the irradiated dentine surface. Three different laser energies were used in this study, 180 mJ, 160 mJ and 140 mJ, with frequencies of 10 Hz and 15 Hz. The temperature data were collected in a digital-analog system and sent to a computer for analysis. It was verified that the time for temperature increases of 5 deg in the external root walls varies according to the laser energy, repetition rate and dentine root thickness. Thus, in this work we could obtain laser parameters to avoid thermal damages in periodontal tissues. (author)

  18. Uma ferramenta para planejamento de estudos para concursos

    Directory of Open Access Journals (Sweden)

    Leonardo Pimentel

    2015-11-01

    Full Text Available De acordo com a constituição brasileira, a única forma de se tornar um empregado do governo é passar em um concurso público. O exame de conhecimento do cargo é um dos componentes mais importantes de um concurso. Estudar para esse exame é uma tarefa que requer planejamento. Um meio de obter um bom planejamento é construir uma grade de horários que relacione as matérias a serem estudadas com os respectivos horários disponíveis para o estudo. Esse tipo de problema se assemelha bastante à gerência de projetos, em que se procura estabelecer a distribuição das atividades ao longo do tempo disponível. Assim, torna-se interessante explorar a dinâmica de estudos para concursos como um projeto. O presente trabalho apresenta a ferramenta de apoio ao estudos - Passe-me, baseada no ciclo PDCA (do inglês, Plan-Do-Check-Act. Por se tratar de uma ferramenta web, o tempo de resposta para produzir uma grade de estudos é fundamental. A ferramenta faz uso de algoritmo genético para calcular a grade de horários priorizando a velocidade de resposta. A ferramenta foi avaliada em diferentes cenários de uso e obteve desempenho satisfatório durante a produção da grade de estudos.

  19. Debates críticos: os Estudos de Segurança e o futuro dos Estudos da Paz e dos Conflitos 10.5102/uri.v11i2.2526

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    André Barrinha

    2013-11-01

    Full Text Available Irremediavelmente ligados pela proximidade dos respetivos objetos de estudo, Estudos de Segurança e Estudos da Paz e dos Conflitos constituíram-se e evoluíram ao longo da Guerra Fria como disciplinas antagónicas. Essa divisão operou-se sobretudo na Europa, onde Galtung e seus discípulos encaminharam o estudo das questões da guerra e da paz para uma agenda claramente normativa e crítica, enquanto o estudo das questões de segurança se centrava numa abordagem orientada para o policy-making. Como é defendido neste artigo, o final do conflito bipolar correspondeu, até certo ponto, a uma inversão de papéis, com os Estudos da Paz e dos Conflitos acomodados a um empirismo desprovido de normatividade e os Estudos de Segurança, pelo menos na Europa, a abrirem-se a novas abordagens de cariz mais crítico. É aqui sugerido que esta inversão contém, em si, importantes lições para os Estudos da Paz e da Segurança, nomeadamente sobre a centralidade da teoria na definição de uma nova agenda crítica que permita uma aproximação entre as duas disciplinas.

  20. Pensamento, Teoria e Estudos Latino-americanos

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    Jacques de Novion

    2014-12-01

    Full Text Available RESUMO O presente trabalho configura como artigo inicial do Dossiê Especial – Pensamento, Teoria e Estudos Latino-americanos, organizado conjuntamente por nós, a pedido da Revista de Estudos e Pesquisas sobre as Américas (CEPPAC, do Instituto de Ciências Sociais (ICS, da Universidade de Brasília (UnB. De forma breve, este artigo apresenta a importância alcançada pelo Pensamento, pela Teoria, e, sobre tudo, pelos Estudos Latino-americanos nas últimas décadas. Em seguida, o artigo apresenta os quatorze trabalhos e uma resenha que compõem este Dossiê, resultado da contribuição de diferentes pesquisadores de distintas localidades da região, organizados em três blocos: Ciências Sociais Latino-americanas, Pensamento e Estudos. PALAVRAS CHAVE: Ciências Sociais Latino-americanas; Pensamento Latino-americanos; Teoria Latino-americana; Estudos Latino-americanos. --- RESUMEN El presente trabajo configura como articulo inicial del Dossier Especial – Pensamiento Teoría y Estudios Latinoamericanos, organizado conjuntamente por nosotros, a pedido de la Revista de Estudos e Pesquisas sobre as Américas (CEPPAC, del Instituto de Ciências Sociais (ICS, de la Universidade de Brasília (UnB. De forma breve, este articulo presenta la importancia alcanzada por el Pensamiento, por la Teoría, y, sobre todo, por los Estudios Latinoamericanos en las últimas décadas. En seguida, el articulo presenta los catorce trabajos e una reseña que componen este Dossier, resultado de la contribución de diferentes investigadores de distintas localidades de la región, organizados en tres bloques: Ciencias Sociales Latinoamericanas, Pensamiento y Estudios. PALABRAS CLAVE: Ciencias Sociales Latinoamericanas; Pensamiento Latinoamericano; Teoría Latinoamericana; Estudios Latinoamericanos. --- ABSTRACT This paper is set up as the initial article of this Special Dossier - Thought, Theory and Latin American Studies, which we organized collectively, at the request

  1. Influence of the incidence angle on the morphology of enamel and dentin under Er:YAG laser irradiation; Estudo da influencia da angulacao do feixe laser na morfologia de esmalte e dentina irradiados com laser de Er:YAG

    Energy Technology Data Exchange (ETDEWEB)

    Junqueira Junior, Duilio Naves

    2002-07-01

    The purpose of this study is to make an in vitro evaluation, using scanning electron microscopy, of the influence of the laser beam irradiation angle on the enamel and dentin morphology. These tissues were both irradiated by Er:YAG Laser, with the same energy parameter. Twenty-four incisive bovine teeth were used, separated in eight groups, four of enamel, and four of dentin, with three specimens in each group. Each specimen was submitted to three laser applications, varying the incidence angle, between the laser and the tooth surface, at 90, 50 and 20 degrees. The applied frequency was 2 Hz, with 20 pulses in each application. The KaVo Key Laser 3 was employed, wavelength at 2940 nm, adjustable energy from 40 to 600 mJ and repetition rate from 1 to 25 Hz. The groups were distributed according to the energy parameter as follows - enamel: 250 mJ; 300 mJ; 350 mJ and 400 mJ; dentin: 200 mJ; 250 mJ; 300 mJ and 350 mJ. The results evidenced the Laser incidence angle importance; it is an essential parameter in the protocol of utilization and it should not be disregarded. The observations of this study allow to conclude that the Laser incidence angle has direct influence on the morphological aspect of the alterations produced in enamel and dentin. (author)

  2. Desafios dos Estudos Gays, Lésbicos e Transgêneros

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    Denilson Lopes

    2008-09-01

    Full Text Available Resumo: Este ensaio introduz algumas questões relativas aos estudos feministas, gays, lésbicos, transgênecos e teoria queer na busca de contribuições teórico-metodológicas na análise da cultura contemporânea. Palavras-chave: Estudos gays e lésbicos, estudos transgêneros, teoria queer, cultura. Abstrat: This essay introduces some issues related tofeminist studies, gay and lesbian studies, transgender studies and queer theory in the search of theoretical and methodological contributions in the analysis of contemporary culture. Key-words: Gay and Lesbian Studies, transgender studies, queer theory, culture

  3. Sintomas depressivos em crianças: estudos com duas versões do CDI

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    Miriam Cruvinel

    Full Text Available O objetivo deste estudo foi identificar o número de crianças com sintomas depressivos em duas amostras de estudantes da cidade de campinas. Utilizou-se, no estudo 1, a versão brasileira do Inventário de Depressão Infantil (CDI e, no estudo 2, a versão original. Do estudo 1, realizado em 2001, participaram 169 estudantes de 3ª, 4ª e 5ª séries, e, do estudo 2, conduzido em 2005, 157 alunos de 3ª e 4ª séries. A prevalência de sintomatologia depressiva no estudo 1 foi de 3,55%, e, no estudo 2, de 17%. Em ambos os estudos, não foram encontradas diferenças significativas entre a média no CDI em relação às variáveis demográficas. conclui-se pela necessidade de mais estudos nacionais de prevalência no ensino fundamental e de esforços direcionados não só para a identificação dos fatores de risco, de proteção e das variáveis associadas mas também do refinamento dos instrumentos de medidas da depressão infantil.

  4. TOPOGRAFIA DE TÚNEIS COM LASER SCANNER TERRESTRE: ESTUDO DE CASO

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    Jorge Pimentel Cintra

    Full Text Available Apresenta-se a aplicação da tecnologia Laser Scanner 3D terrestre ao levantamento do túnel de adutora, escavado em rocha. Depois de apresentar o local, é descrito o problema, que consiste no levantamento preciso do túnel para identificar e coletar dados para quantificar alterações na sua secção transversal com relação à secção prevista em projeto, para a posterior correção desses defeitos. São resumidos os principais métodos possíveis de levantamento, listando prós e contras de cada um. A seguir mostram-se os fundamentos dessa tecnologia de levantamento bem como a metodologia dos trabalhos de campo e de escritório, incluindo o cálculo das coordenadas dos pontos do túnel. Finaliza-se com o controle de qualidade e uma avaliação do método, indicando seus pontos fortes comparado com outras metodologias.

  5. estudo comparativo

    OpenAIRE

    Álvaro, Rocha

    2005-01-01

    O sítio web é um importante meio de comunicação e competitividade das universidades. Há diferentes razões para acreditar que os sítios possam variar entre universidades, mas contudo há certeza da existência de requisitos de qualidade comuns e transversais a todas. Este estudo visou avaliar, de forma quantitativa e objectiva, o cumprimento de requisitos de qualidade pelos sítios web das Universidades Portuguesas, com base nas características de alto nível da norma ISO 9126-1 que interessam aos...

  6. Study of the mechanisms involved in the laser superficial hardening process of metallic alloys; Estudo dos mecanismos envolvidos no processo de endurecimento superficial a laser de ligas metalicas

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Edmara Marques Rodrigues da

    2001-07-01

    The laser superficial hardening process of a ferrous alloy (gray cast iron) and of an aluminum-silicon alloy was investigated in this work. These metallic alloys are used in the automobile industry for manufacturing cylinders and pistons, respectively. By application of individual pulses and single tracks, the involved mechanisms during the processing were studied. Variables such as energy density, power density, temporal width, beam diameter on the sample surface, atmosphere of the processing region, overlapping and scanning velocity. The hardened surface was characterized by optical and scanning electronic microscopy, dispersive energy microanalysis, X-ray mapping, X-ray diffraction, and measurements of roughness and Vickers microhardness. Depending on the processing parameters, it is possible to obtain different microstructures. The affected area of gray cast iron, can be hardened by remelting or transformation hardening (total or partial) if the reached temperature is higher or not that of melting temperature. Laser treatment originated new structures such as retained austenite, martensite and, occasionally, eutectic of cellular dendritic structure. Aluminum-silicon alloy does not have phase transformation in solid state, it can be hardened only by remelting. The increase of hardness is a function of the precipitation hardening process, which makes the silicon particles smaller and more disperse in the matrix. Maximal values of microhardness (700-1000 HV) were reached with the laser treatment in gray cast iron samples. The initial microhardness is of 242 HV. For aluminum-silicon alloy, the laser remelting increases the initial microhardness of 128 HV to the range of 160-320 HV. The found results give a new perspective for using the CLA/IPEN's laser in the heat treatment area. Besides providing a higher absorptivity to the materials, compared with the CO{sub 2} laser, and optical fiber access, the superficial hardening with Nd:YAG laser, depending on the

  7. He-Ne laser effects on blood microcirculation. An in vivo study through laser doppler flowmetry; Efeito do laser de helio neonio sobre a microcirculacao sanguinea durante a reparacao tecidual. Estudo in vivo por meio de fluxometria laser doppler

    Energy Technology Data Exchange (ETDEWEB)

    Nunez, Silvia Cristina

    2002-07-01

    Blood microcirculation performs an important function in tissue repair process, as well as in pain control, allowing for greater oxygenation of the tissues and the accelerated expulsion of metabolic products, that may be contributing to pain. Low Intensity Laser Therapy (LILT) is widely used to promote healing, and there is an assumption that it is mechanism of action may be due to an enhancement of blood supply. The purpose of this study was to evaluate, using laser Doppler flowmetry (LDF), the stated effects caused by radiation emitted by a He-Ne laser ({lambda}=632.8 nm) on blood microcirculation during tissue repair. To this end, 15 male mice were selected and received a liquid nitrogen provoked lesion, above the dorsal region, and blood flow was measured periodically, during 21 days. Due to radiation emission by the LDF equipment, a control group was established to evaluate possible effects caused by this radiation on microcirculation. To evaluate the He-Ne laser effects, a 1.15 J/cm{sup 2} dose was utilized, with an intensity of 6 mW/cm{sup 2}. The results obtained demonstrate flow alterations, provoked by the lesion, and subsequent inflammatory response. There was no statistical difference between the studied groups. As per the analysis of the results there is no immediate effect due the radiation emitted by a He Ne laser on microcirculation, although a percentage increase was observed in day 7 on medium blood flow rate in irradiated specimens. New studies are necessary to validate the use of this wavelength, in order to promote beneficial alterations in blood supply in radiated areas. (author)

  8. Estudos transcriptômicos no contexto da conectividade perturbada em esquizofrenia Transcriptome studies in the context of disturbed connectivity in schizophrenia

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    Andrea Schmitt

    2013-01-01

    Full Text Available Esquizofrenia é uma severa doença neurobiológica com fatores genéticos e ambientais desempenhando um papel na fisiopatologia. Diversas regiões cerebrais têm sido implicadas no processo da doença e estão conectadas em complexos circuitos neuronais. Nos níveis molecular e celular, a conectividade afetada entre essas regiões, envolvendo mielinização disfuncional dos axônios neuronais, bem como as alterações no nível sináptico e metabolismo energético levando a distúrbios na plasticidade sináptica, são os maiores achados em estudos post-mortem. Estudos de microarranjos investigando a expressão gênica contribuíram para os achados de alterações em vias complexas em regiões cerebrais relevantes na esquizofrenia. Além disso, estudos utilizando microdissecção e captura a laser permitiram a investigação da expressão gênica em grupos específicos de neurônios. Entretanto, deve ser mantido em mente que em estudos post-mortem, confusos efeitos de medicação, qualidade de RNAm, bem como capacidade de mecanismos regenerativos neuroplásticos do cérebro em indivíduos com história de vida de esquizofrenia, podem influenciar o complexo padrão de alterações no nível molecular. Apesar dessas limitações, estudos transcriptômicos livres de hipóteses em tecido cerebral de pacientes esquizofrênicos oferecem uma possibilidade única para aprender mais sobre os mecanismos subjacentes, levando a novas ópticas da fisiopatologia da doença.Schizophrenia is a severe neurobiological disease with genetic and environmental factors playing a role in the pathophysiology. Several brain regions have been implicated in the disease process and are connected in complex neuronal circuits. On the cellular and molecular level, affected connectivity between these regions, involving dysfunctional myelination of neuronal axons, as well as alterations on the synaptic level and energy metabolism of neurons leading to disturbances in synaptic

  9. Estudos transcriptômicos no contexto da conectividade perturbada em esquizofrenia Transcriptome studies in the context of disturbed connectivity in schizophrenia

    Directory of Open Access Journals (Sweden)

    Andrea Schmitt

    2012-01-01

    Full Text Available Esquizofrenia é uma severa doença neurobiológica com fatores genéticos e ambientais desempenhando um papel na fisiopatologia. Diversas regiões cerebrais têm sido implicadas no processo da doença e estão conectadas em complexos circuitos neuronais. Nos níveis molecular e celular, a conectividade afetada entre essas regiões, envolvendo mielinização disfuncional dos axônios neuronais, bem como as alterações no nível sináptico e metabolismo energético levando a distúrbios na plasticidade sináptica, são os maiores achados em estudos post-mortem. Estudos de microarranjos investigando a expressão gênica contribuíram para os achados de alterações em vias complexas em regiões cerebrais relevantes na esquizofrenia. Além disso, estudos utilizando microdissecção e captura a laser permitiram a investigação da expressão gênica em grupos específicos de neurônios. Entretanto, deve ser mantido em mente que em estudos post-mortem, confusos efeitos de medicação, qualidade de RNAm, bem como capacidade de mecanismos regenerativos neuroplásticos do cérebro em indivíduos com história de vida de esquizofrenia, podem influenciar o complexo padrão de alterações no nível molecular. Apesar dessas limitações, estudos transcriptômicos livres de hipóteses em tecido cerebral de pacientes esquizofrênicos oferecem uma possibilidade única para aprender mais sobre os mecanismos subjacentes, levando a novas ópticas da fisiopatologia da doença.Schizophrenia is a severe neurobiological disease with genetic and environmental factors playing a role in the pathophysiology. Several brain regions have been implicated in the disease process and are connected in complex neuronal circuits. On the cellular and molecular level, affected connectivity between these regions, involving dysfunctional myelination of neuronal axons, as well as alterations on the synaptic level and energy metabolism of neurons leading to disturbances in synaptic

  10. ACREDITAÇÃO HOSPITALAR: UM ESTUDO DE CASO

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    Felipe Antunes

    2005-06-01

    Full Text Available Este artigo aborda a qualidade e acreditação hospitalar através do Manual das Organizações Prestadoras de Serviços Hospitalares, desenvolvido pela Organização Nacional de Acreditação (ONA. O objetivo geral deste trabalho é avaliar o processo de acreditação, identificando dificuldades e benefícios advindos da implantação deste  Manual. Após a realização de uma revisão bibliográfica sobre qualidade em hospitais e normas da qualidade aplicáveis a hospitais, é feita uma análise crítica teórica do Manual das Organizações Prestadoras de Serviços Hospitalares. Tal análise crítica inclui um estudo comparativo entre os requisitos do Manual e da norma NBR ISO 9001/2000. A seguir, a análise teórica é complementada através de um estudo de caso contemplando a implantação do Manual junto a um hospital de grande porte. Finalmente, são apresentadas as conclusões, baseadas tanto no estudo teórico como no estudo prático.

  11. Marketing do mercado de luxo: Estudo de caso Victoria's Secret

    OpenAIRE

    Ana Francisca Giuliani

    2013-01-01

    Este artigo teve por objetivo identificar quais são as estratégias de marketing utilizadas pela empresa varejista Victoria’s Secret para a fidelização do consumidor de luxo em nível global. O estudo caracterizou-se como uma pesquisa qualitativa, utilizando-se como estratégia de campo o estudo de caso de caráter ilustrativo. Para o alcance do objetivo proposto, dividiu-se o estudo em duas fases. Na primeira, denominada exploratória, buscou-se em dados secundários o embasamento para a construçã...

  12. Pragmatismo e os pragmáticos nos estudos organizacionais

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    Francis Kanashiro Meneghetti

    Full Text Available O objetivo central deste ensaio teórico é avaliar as contribuições do pragmatismo nos Estudos Organizacionais e, os específicos, avaliar se as contribuições teóricas de Charles Peirce e John Dewey possibilitam afirmar o pragmatismo como senso comum, ciência ou teoria do conhecimento; analisar as contribuições - possibilidadese limites - do pragmatismo como conhecimento científico; compreender os percursos do pragmatismo nos Estudos Organizacionais. Chaga-se a conclusão de que ser pragmático é diferente de conceber estudos articulados no campo epistemológico do pragmatismo. O sujeito pragmático vê na sua utilidade e na necessidade deação, o ponto de tensão que coloca em dúvida a veracidade dos pressupostos do pragmatismo como ciência. O que ocorre nos Estudos Organizacionais éa conversão do pragmatismo como conhecimento científico emsubordinação irracional à utilidade e à ação prática, sobretudo, no campo da economia, da política, da ciência, da cultura, da educação, e assim por diante.

  13. Efeito da Convecção no Humor Vítreo Sobre o Dano Térmico de um Melonoma de Coroide Durante Teremoterapia Transpupilar a Laser

    OpenAIRE

    Garcia, Olga Pinheira

    2015-01-01

    O estudo da distribuição de temperaturas no olho humano é capaz de fornecer subsídios para tratamentos hipertérmicos e para o cálculo dos danos causados pela exposição à radiação de uma fonte de laser. Um exemplo é a termoterapia transpupilar a laser (TTT), aplicada no tratamento de um melanoma de coroide. Neste trabalho, foi desenvolvido, através do software comercial SolidWorks®, um modelo tridimensional do olho humano portador de um melanoma de coroide, utilizado para simula...

  14. A Teoria Queer e os Estudos Organizacionais: Revisando Conceitos sobre Identidade

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    Eloisio Moulin de Souza

    2017-05-01

    Full Text Available A teoria queer desenvolveu-se incialmente na década de noventa, nas ciências sociais e humanas, principalmente nos estudos literários e linguísticos, sendo posteriormente incorporada aos estudos organizacionais. Entretanto, apesar de sua aplicação aos estudos organizacionais, ainda existe uma lacuna acerca do debate sobre seus conceitos e significados. Por isso, este artigo objetiva aprofundar e revisar o debate sobre os aspectos desenvolvidos por essa teoria, focando-se nos conceitos relacionados à produção identitária e subjetiva. Para cumprir este intento, as ideias queer sobre identidade, sujeito, performatividade, performance e identificação são apresentadas e debatidas. Defende-se que a teoria queer é um verbo (ação ao invés de um substantivo (identidade e a aplicação de seus conceitos não se restringe somente aos estudos sobre gênero, sexualidade e minorias. Por fim, discute-se a expansão da utilização dos conceitos queer no estudo de outras formas hegemônicas de categorias identitárias presentes no mundo corporativo.

  15. The influence of low-level laser therapy on biomodulation of collagen and elastic fibers A influência da terapia a laser de baixa densidade de energia na biomodulação das fibras colágenas e elásticas

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    Lívia Souza Pugliese

    2003-12-01

    Full Text Available The study of low-level laser therapy upon extracellular matrix elements is important to understand the wound healing process under this agent. However, little is known about the interference of laser light in relation to collagen and elastic fibers. Cutaneous wounds were performed on the back of 72 Wistar rats and a Ga-Al-As low-level laser was punctually applied with different energy densities. The animals were killed after 24, 48, 72 hours and 5, 7 and 14 days. Tissues were stained with hematoxilin-eosin, sirius red fast green and orcein and then analyzed. It was observed that the treated group exhibited larger reduction of edema and inflammatory infiltrate. The treated animals presented a larger expression of collagen and elastic fibers, although without statistical significance (p > 0.05. Treatment with a dosage of 4 J/cm² exhibited more expressive results than that with 8 J/cm². In this study, the authors concluded that low-level laser therapy contributed to a larger expression of collagen and elastic fibers during the early phases of the wound healing process.O estudo da terapia a laser de baixa densidade de energia sobre os diversos constituintes da matriz extracelular é crucial para o entendimento do processo cicatricial sob esse agente. Todavia, pouco se sabe sobre a interferência do laser em relação às fibras colágenas e elásticas. Realizaram-se ferimentos cutâneos padronizados no dorso de setenta e dois ratos Wistar e, em seguida, aplicação pontual do raio laser de baixa potência do tipo Arseneto de Gálio-Alumínio (Ga-Al-As com diferentes densidades de energia. Os animais foram sacrificados com 24, 48 e 72 horas e aos 5, 7 e 14 dias. Procedeu-se à análise das secções teciduais coradas por hematoxilina-eosina, sírius vermelho e orceína. Observou-se, que nos grupos submetidos à terapia a laser, houve maior redução do edema e infiltrado inflamatório. Os animais tratados apresentaram uma maior expressão de fibras

  16. Estudos de atmosfera

    OpenAIRE

    Carlos Eduardo Riccioppo

    2016-01-01

    Joker e Estudos de balística possuíam formas distintas dos cadernos ou livros quando foram exibidos pela primeira vez, na mostra Dual Overdrive. De algum modo, o flagrante das imagens dos cartazes da campanha política parisiense e daquelas cusparadas sobre o asfalto era preservado no modo como eram mostrados os trabalhos, que repunham não apenas a orientação espacial dos objetos fotografados, mas, igualmente, sua escala: Joker apresentava-se na parede, em dimensões relativamente próximas às d...

  17. EFICÁCIA CLÍNICA DO LASER ACUPUNTURAL NO TRATAMENTO DA DESORDEM TEMPOROMANDIBULAR

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    Diego Rodrigues Pessoa

    2016-12-01

    Full Text Available A disfunção temporomandibular (DTM é a condição mais frequente de dor orofacial crônica. A DTM é caracterizada pela a presença de sinais e sintomas na região orofacial. A acupuntura e Terapia a laser de baixa intensidade (TLBI vêm sendo empregadas no tratamento da DTM. A acupuntura consiste na inserção de agulhas em acupontos específicos do corpo para promover efeitos terapêuticos. A TLBI é uma modalidade de tratamento não invasiva, que vem sendo utilizada com frequência na prática clínica para o tratamento das DTM. Diante do exposto, o objetivo deste estudo foi realizar revisão de literatura, acerca da eficácia clinica do laser acupuntural em pacientes com a DTM. O emprego do laseracupuntural no tratamento das DTM favorece o controle antálgico, miorrelaxante e anti-inflamatório, no entanto, são necessárias novas pesquisas acerca do tema para determinar a eficácia do laser acupuntural em longo prazo para o tratamento de desordens temporomandibulares.

  18. Estudo multicasos sobre atividades inovativas

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    Sonia Regina Hierro Parolin

    2013-09-01

    Full Text Available Em estudos sobre competitividade argumenta-se que as empresas necessitam de estratégias baseadas em inovações e de capacidades internas em constantes e intensas transformações, não somente nos padrões tecnológicos, mas também no encadeamento do processo de gestão das atividades inovativas, como processos dinâmicos, não lineares e diversificados, em função de múltiplos fatores dos ambientes interno e externo. Para contribuir com essas discussões, neste artigo apresenta-se um estudo multicasos em quatro indústrias de médio e grande portes, de segmentos, densidades tecnológicas e históricos com inovações diferentes entre si. Como principais resultados, salientam-se o encadeamento das atividades inovativas como parte de uma estratégia organizacional para obter resultados com inovação e a afluência de todas as pessoas, e não somente as alocadas em pesquisa e desenvolvimento, para o cumprimento dessa estratégia.

  19. Discriminação entre olhos normais e glaucomatosos mediante polarimetria de varredura a laser

    OpenAIRE

    Magacho,Leopoldo; Marcondes,Ana Maria; Costa,Vital Paulino

    2004-01-01

    OBJETIVOS: Avaliar a capacidade da polarimetria de varredura a laser de discriminar entre olhos normais e glaucomatosos. MÉTODOS: Cento e doze pacientes com glaucoma primário de ângulo aberto e 88 indivíduos normais foram incluídos no estudo. Todos os indivíduos foram submetidos a exame oftalmológico completo, perimetria computadorizada (Humphrey 24-2, full threshold), avaliando-se Mean Deviation (MD) e Correct Pattern Standard Deviation (CPSD) e exame com GDx. Curvas ROC foram criadas e novo...

  20. Estudos organizacionais, (descolonialidade e estudos da dependência: as contribuições da Cepal

    Directory of Open Access Journals (Sweden)

    Sergio Wanderley

    Full Text Available O objetivo deste artigo é (revisitar o conceito de dependência como categoria de investigação da (e a partir da América Latina, por meio de uma perspectiva histórica crítica descolonial, a fim de ampliar o espaço de debates em estudos organizacionais e promover alternativas à ordem neoliberal. Este ensaio terá como foco os estudos da dependência realizados pela Comissão Econômica para a América Latina e o Caribe (Cepal durante a década de 1950 e o início dos anos 1960. A perspectiva descolonial é um constructo teórico de autores latino-americanos que se consideram herdeiros da longa tradição do pensamento social crítico da região, na qual a teoria da dependência está inserida. As propostas dos autores da dependência confrontaram as principais teorias ortodoxas do Norte produzidas à época. A partir do conceito de centro-periferia, da denúncia de assimetrias nas relações entre essas regiões, do reconhecimento da interdependência entre desenvolvimento e subdesenvolvimento, o conceito de dependência foi sendo (reelaborado nas décadas de 1950 e 1960 por diversos autores latino-americanos como uma categoria de investigação da realidade da (e a partir da região. Essas investigações tinham por objetivo não somente elaborar constructos teóricos, mas, também, transformar a realidade por meio da criação de diversas organizações e instituições que deveriam servir ao propósito de superar o subdesenvolvimento. A denúncia da historicidade da situação de subdesenvolvimento desnudou o caráter de neutralidade do economicismo das teorias produzidas no Norte e promoveu um encontro teórico entre economia e política que muito tem a contribuir com a área dos estudos organizacionais.

  1. 'In vitro' study of the efficacy of diode laser and LED irradiation during dental bleaching; Estudo 'in vitro' da acao do LED e laser de diodo no clareamento dental

    Energy Technology Data Exchange (ETDEWEB)

    Barroso, Marcia Cristina da Silva

    2003-07-01

    This in vitro study evaluated the efficacy of LED and laser diode irradiation during the dental bleaching procedure, using two bleaching agents (Opalescence X-tra and HP Whiteness). The diode laser and the LED were operated in the continuous mode, with wavelength of 808 nm and 470 nm, respectively. The results of the irradiations were characterized with the CIELAB system calculating the L{sup *}a{sup *}b{sup *} values for the darkened and the bleached teeth (60 bovine incisors). This is to our knowledge the first time that light sources laser and LED are compared with respect to their whitening capability when applied to different agents. Significant differences in the chroma value are obtained for the two whitening agents and for the different light sources, too. Also, in terms of luminance, the combination of laser/ Whiteness HP showed significantly better results than when the same agent was used alone or in combination with LED. Best overall results are obtained with the combination of Whiteness HP and laser. (author)

  2. EFEITOS DA TERAPIA LASER DE BAIXA INTENSIDADE EM MODELO EXPERIMENTAL DE TENDINOPATIA EM RATOS: REVISÃO DE LITERATURA

    Directory of Open Access Journals (Sweden)

    Diego Rodrigues Pessoa

    2017-12-01

    Full Text Available Tendinopatia é o termo utilizado para descrever lesões que afetam os tendões (tendinites e tendinoses, caracterizada pela presença de inflamação e degeneração tecidual, associada à sobrecarga mecânica e a movimentos repetitivos. Diversas modalidades terapêuticas têm sido estudadas no tratamento das tendinopatias, entre elas, destaca-se a terapia a laser de baixa intensidade (TLBI que visa acelerar o processo regenerativo, diminuir a inflamação e reduzir a dor.  Diante do exposto, este trabalho teve como objetivo realizar revisão de literatura, de artigos científicos com foco nos efeitos da terapia a laser de baixa intensidade (TLBI, em modelo experimental de tendinopatia em ratos. O estudo baseou-se na investigação de publicações entre janeiro de 2011 a outubro de 2016, em bases de dados eletrônicas com o emprego dos descritores “tendinopatia”, “laserterapia”, “ratos”, “tendão” e “terapia a laser de baixa intensidade”, combinados aos descritores booleanos. Foram selecionados sete artigos que apontam que a TLBI possibilitou a redução de importantes marcadores pró-inflamatórios, tais como IL-6 e TNF-α, bem como a proliferação aumentada de tenócitos, independentemente da dosagem aplicada. Os estudos científicos selecionados nesta revisão sistemática sinalizaram efeitos positivos da TLBI, principalmente na modulação da resposta inflamatória aguda ou crônica após a indução da tendinopatia.

  3. Estudo sobre reciclagem de lâmpadas fluorescentes

    OpenAIRE

    Bacila,Danniele Miranda; Fischer,Klaus; Kolicheski,Mônica Beatriz

    2014-01-01

    Lâmpadas fluorescentes (LF) contêm mercúrio em sua composição, um metal pesado que pode causar danos à saúde e ao meio ambiente. As LF são amplamente consumidas no Brasil, porém o descarte correto de LF usadas não é amplamente divulgado e os índices de reciclagem são baixos. O objetivo deste estudo foi demonstrar a relevância do descarte adequado, avaliar as tecnologias de reciclagem e a destinação dos materiais, por meio de estudo comparativo entre Brasil e Alemanha. Através de visitas a rec...

  4. Os estudos brasileiros e os 'brazilianists'

    Directory of Open Access Journals (Sweden)

    José Honório Rodrigues

    1976-09-01

    Full Text Available (primeiro parágrafo do artigo Quando, em 1943-1944, estive nos Estados Unidos, estudando e pesquisando, conheci muitas bibliotecas públicas e universitárias, e o grande Arquivo Nacional dos Estados Unidos. Nas Universidades já se ofereciam cursos de estudos latino-americanos, centralizados sobretudo no estudo da língua espanhola, portuguesa em menor escala, estenografía em espanhol, e raras propunham o ensino da literatura comparativa, antropologia, economia, geografia, política e história latino-americana, sempre em conjunto; raríssimas, como a Columbia, ofereciam aulas de história social e econômica do Brasil, e tambem do México e da América Central, e ainda da Argentina, Uruguai e Paraguai. Havia pouca especialização por paises e áreas, e se via predominantemente a América Latina como um bloco uno e uniforme.

  5. Efeito do laser Nd:YAG no selamento de fóssulas e fissuras: estudo in vivo = Nd:yag laser effect on pit and fissures sealing: an in vivo study

    Directory of Open Access Journals (Sweden)

    Firoozmand, Leily Macedo

    2007-01-01

    Full Text Available O objetivo desta pesquisa foi o de avaliar o comportamento clínico do laser Nd: YAG em comparação ao de um selante com carga, durante o período de 12 meses, observando; a pigmentação do sulco, incidência de cárie e fratura ou perda do selante. Foram selecionados 62 primeiros e segundos premolares hígidos de pacientes na faixa etária de 12 a 15 anos, de uma escola da rede pública de São José dos Campos. Nos 31 primeiros premolares foi aplicado o laser Nd: YAG, Pulse Máster 600 IQ em toda a extensão do sulco oclusal por 30 segundos utilizando 60 mJ, 10 HZ, 0,6W. Nos 31 segundos premolares foi realizado o selamento dos sulcos oclusais com o selante Fluorshield. Após 6 meses observou-se que dos casos selados com Fluorshield 19,35% apresentaram perda e/ou fratura do selante e em 16,66% os sulcos apresentaram cárie incipiente. Já nos casos em que foi aplicado o laser Nd: YAG 6,45% apresentaram início de lesão de cárie. Com 12 meses de avaliação tanto com selante Fluorshield como com o laser Nd: YAG observou-se o aparecimento de sulcos pigmentados em 12, 90% dos casos e uma incidência de 9,67% de lesões incipientes de cárie. Utilizando-se o selante Fluorshield houve queda do material em 25,80% e fratura em 3,22% dos casos. Concluímos que após 12 meses de avaliação o laser Nd: YAG e o selante Fluorshield apresentaram comportamento clínico semelhante, diante das mesmas condições bucais, sendo que a porcentagem de aparecimento de lesão inicial de cárie foi igual para os dois métodos de prevenção utilizados

  6. ESTUDOS NACIONAIS SOBRE O ENSINO PARA CEGOS: UMA REVISÃO BIBLIOGRÁFICA

    Directory of Open Access Journals (Sweden)

    Rosana Mendes Éleres de FIGUEIREDO

    2015-12-01

    Full Text Available RESUMO O presente artigo tem como objetivo apresentar uma revisão bibliográfica dos estudos nacionais acerca do ensino curricular para cegos. Foi realizada uma busca sistemática em três bases de dados: Google Acadêmico, Scielo e Lilacs, de estudos publicados no período de 2004 a 2014, que tivessem em seu título um dos seguintes descritores: alunos cegos; alunos deficientes visuais; crianças cegas; crianças deficientes visuais. Foram localizados 188 estudos e 56 selecionados dentro dos critérios estabelecidos. Fez-se a leitura integral desses e definiram-se cinco categorias de análise: tipo de estudo; participantes; tipo de abordagem; tipo de discussão e matrizes curriculares. Para cada categoria, foram estabelecidas subcategorias. Ao total 26 subcategorias foram descritas. Os resultados indicam que o Google Acadêmico é a base de dados com maior número de títulos encontrados (188/156; a Scielo apresenta melhor eficiência na relação encontrado x selecionado (12/10. Nas subcategorias de análise, as maiores frequências são identificadas nos estudos empíricos (22; junto a crianças (19; de análises qualitativas (21; na matriz curricular de Educação Física (sete e na subcategoria relacionamento social (16. Contudo, os estudos são convergentes em apontar que as principais dificuldades no ensino às pessoas cegas se referem a deficiências na formação de professores, onde, normalmente, não são discutidos métodos de ensino e produção de material para trabalhar com essa população específica. Em conclusão, além de realizar um mapeamento dos estudos que têm sido conduzidos junto a alunos cegos nos últimos dez anos, este artigo aponta para lacunas na literatura e direciona futuras investigações na área.

  7. Assessment of the bacteria reduction in the infected root canal irradiated with diode laser; Avaliacao da reducao bacteriana em conduto radicular infectado e irradiado com laser de diodo. Estudo in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Radaelli, Claudia Amaral Rabello de Mello

    2002-07-01

    High success rates are achieved in conventional endodontic treatment of vital pulp teeth. However, in cases of non-vital pulp, a decrease in the rate of success occurs due to difficulties in achieving a complete disinfection of the root canals system. Some bacteria, such as Enterococcus faecalis, are frequently found in cases of endodontic treatment failure due to their high resistance to the conventional endodontic treatment. The aim of this study was to evaluate the efficiency of a high power diode laser irradiation in bacterial reduction of contaminated canals associated with dressing compose by calcium hydroxide paste propylene glycol and camphorated paramonochlorophenol. Eighty-two root canals were infected in vitro with Enterococcus faecalis in a concentration of 1x10{sup 8} CFU/ml. Specimens were high intensity irradiated with a diode laser model Opus 10, at a wavelength of 830 nm. Two different parameters were employed in continuous mode: 3 W and 2,5 W with a 360 {mu}m optical fiber at an angle of approximately 5 degrees respect to the dentine surface during 5 seconds, in 4 applications, with 20 seconds intervals among them. After these proceedings specimens were vortexed in peptone water and dilutions performed. Aliquots of the dilution were plated on m-Enterococcus agar, incubated, and the Colonies Forming Units (CFU) of ali groups was counted. The results showed a significant reduction of bacteria on ali groups after laser irradiation. A high reduction rate was achieved: 98.5% immediately after the laser irradiation; 48 hours after, the reduction was of 96,73% and, finally, a 100% reduction was achieved through the combination of laser irradiation and a long lasting dressing of calcium hydroxide paste, propylene glycol and camphorated paramonochlorophenol. High rates of bacteria reduction were achieved using the parameter of 3 W in continuous mode with the power of 2,9473 KW/cm{sup 2}. The temperature was monitored with a K-pipe thermocouple placed at

  8. Caso de estudo: a entrada do azeite Gallo no mercado chinês

    OpenAIRE

    Costa, Miguel Maria Portugal Martins

    2014-01-01

    Mestrado em Gestão 7 Classificação JEL: M16; F23 A elaboração desta dissertação consiste na criação de um caso de estudo pedagógico com o objectivo de tirar ilações sobre a entrada da marca “Azeite Gallo” no mercado Chinês. Optamos por desenvolver este caso de estudo através de um estudo qualitativo, suportado por um referencial teórico. O intuito do projecto é de documentar um exemplo paradigmático de um produto consumível de marca portuguesa que sucedeu em ultrapassar as barreiras ...

  9. Effects of low intensity laser radiation on osteointegration mechanism of implants: study 'in vivo'; Efeitos da radiacao laser em baixa intensidade no mecanismo de osseointegracao de implantes: estudo 'in vivo'

    Energy Technology Data Exchange (ETDEWEB)

    Blay, Alberto

    2001-07-01

    The purpose of this study is to determine whether the process of bone integration of implants placed in rabbit tibia is changed in any way if the region is radiated with laser, as compared to the time required for the bone integration process without radiation. Thirty adult male white New Zealand rabbits were submitted to implant surgery, for subsequent evaluation of the removal torque and resonance frequency. Each animal received two implants of pure titanium, one in each proximal metaphysics of the tibia, which were inserted with a 40 Ncm torque, and their initial stability was also monitored by means of a resonance frequency analyzer. The rabbits were then divided into 3 groups: one control group and two laser groups. The groups were evaluated in regard to removal torque and resonance frequency of the implants, after 3 and 6 weeks. One of the laser groups was radiated with a laser beam of a wavelength in the infrared range (830 nm) and the other group was radiated with a laser beam emitted in the visible range (680 nm). Ten radiation sessions were performed, 48 hours apart, the first of them during the immediate post-operation period. Radiation energy density was 4 J/cm{sup 2} per point, and there were two points at each side of the tibia. Results of the statistical analysis of the resonance frequency indicated that for both laser groups there was a significant difference between frequency values at the time of implant and the values obtained after 3 and 6 weeks. Furthermore, the results obtained for the removal torque of the three groups showed a statistically significant difference after a period of 6 weeks; removal torque values for the laser groups were, in the average, much greater than those of the control group. From these results it is possible to conclude that implants in rabbit tibia, that were exposed to laser radiation with wavelengths of 680 nm and 830 nm, had a better degree of bone integration than the control group.(author)

  10. IMPACTOS MICROCLIMÁTICOS DO DESENHO URBANO: ESTUDOS REALIZADOS EM CURITIBA

    Directory of Open Access Journals (Sweden)

    Eduardo KRUGER

    2011-04-01

    Full Text Available O artigo busca compreender as relações entre atributos da geometria urbana e alterações no microclima. São apresentados dois estudos distintos conduzidos na mesma área central de Curitiba, PR, a partir de medições de campo realizadas em 2009 e de simulações de clima urbano no software ENVI-met. Os estudos, embora utilizem a mesma campanha de coleta de dados, possuem objetivos e metodologias diferentes. O primeiro estudo foca no impacto da geometria urbana, na temperatura ambiente e nos níveis de conforto em ruas de pedestre no período diurno, sendo o fator de visão do céu utilizado como indicador da complexa geometria urbana. O segundo estudo trata do impacto da orientação das vias em relação ao vento dominante, quanto às taxas de ventilação resultantes (velocidade do ar e distribuição espacial, visando à dispersão de poluentes gerados pelo tráfego, no contexto urbano. Os resultados auferidos evidenciam a influência da forma urbana para a determinação do conforto térmico em ruas de pedestres, restringindo-se a um período diurno específico, e para a criação de cenários de poluição.

  11. New solid laser: Ceramic laser. From ultra stable laser to ultra high output laser

    International Nuclear Information System (INIS)

    Ueda, Kenichi

    2006-01-01

    An epoch-making solid laser is developed. It is ceramic laser, polycrystal, which is produced as same as glass and shows ultra high output. Ti 3+ :Al 2 O 3 laser crystal and the CPA (chirped pulse amplification) technique realized new ultra high output lasers. Japan has developed various kinds of ceramic lasers, from 10 -2 to 67 x 10 3 w average output, since 1995. These ceramic lasers were studied by gravitational radiation astronomy. The scattering coefficient of ceramic laser is smaller than single crystals. The new fast ignition method is proposed by Institute of Laser Engineering of Osaka University, Japan. Ultra-intense short pulse laser can inject the required energy to the high-density imploded core plasma within the core disassembling time. Ti 3+ :Al 2 O 3 crystal for laser, ceramic YAG of large caliber for 100 kW, transparent laser ceramic from nano-crystals, crystal grain and boundary layer between grains, the scattering coefficient of single crystal and ceramic, and the derived release cross section of Yb:YAG ceramic are described. (S.Y.)

  12. um estudo de caso

    OpenAIRE

    Costa, Cátia Filipa Pereira da

    2011-01-01

    Dissertação apresentada à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Psicologia Jurídica As situações de abuso sexual de crianças nas quais o perpetrador pertence ao sexo feminino obtiveram ao longo dos últimos anos um acrescido reconhecimento por parte da comunidade científica, evidenciado pelo significativo incremento das investigações no âmbito desta temática consistindo na sua maioria estudos de caso. Um conjunto de particularidades encont...

  13. Aprendizagem Organizacional, Teoria Ator-Rede e Estudos Foucaultianos: Tempo, Espaço e Poder

    OpenAIRE

    Bruno Luiz Américo

    2016-01-01

    Esse trabalho baseia-se no mapeamento de lacunas encontradas nos desenvolvimentos dos estudos organizacionais de conhecimento e aprendizagem, e busca contribuir para a consolidação da aprendizagem organizacional como uma teoria do movimento organizacional/social. Para isso, propõe diálogo entre a Perspectiva Social-Política da Aprendizagem social, a Teoria Ator-Rede e os estudos foucaultianos. O trabalho conclui destacando o potencial da teoria ator-rede e dos estudos foucaultianos para anali...

  14. Estudo de ligas de ouro por XRF e SEM-EDS

    OpenAIRE

    Coxito, Afonso Maria Teixeira

    2016-01-01

    Serve o presente estudo para testar uma metodologia para análise de ligas metálicas, em particular ligas de ouro, utilizando as técnicas de fluorescência de raios-X e microscopia electrónica de varrimento. No contexto do presente estudo, foi identificada a composição das folhas de ouro utilizadas em obras de arte. As técnicas laboratoriais utilizadas foram: Microscopia óptica; Espectroscopia de fluorescência de raios-X com dispersão de energia (EDXRF); Microscopi...

  15. EMPREENDEDORISMO E VALORES HUMANOS: UM ESTUDO CONCEITUAL

    Directory of Open Access Journals (Sweden)

    Luciano Vignochi

    2013-09-01

    Full Text Available O objetivo principal deste artigo foi identificar conceitos de valores humanos em publicações científicas sobre empreendedorismo. Não há um único conceito de valores humanos, gerando diversas abordagens e aplicações do termo em estudos sobre empreendedorismo. Para identificar diferenças conceituais e aplicações práticas, optou-se por realizar uma análise de conteúdo em um portfólio de artigos selecionados em bases de dados. O principal critério de seleção das publicações foi aderência ao tema. Os resultados mostram que valores podem ser definidos como: critérios de julgamento da realidade; aspectos abstratos, cognitivos e afetivos ou características determinantes da personalidade e do comportamento de empreendedores. Valores influenciam a sobrevivência do indivíduo, o crescimento do empreendimento e podem nivelar a congruência do empreendedor e seu propósito de empreendimento com os critérios de convivência social. Ainda foram discriminados resultados de estudos aplicados com vistas a destacar evidências de contribuições práticas de pesquisas sobre valores humanos em empreendedorismo. Futuras investigações para aprofundar e replicar as análises realizadas neste estudo podem contribuir com a formação de empreendedores, a realização de diagnóstico empresarial e com avanços para a consolidação um modelo de desenvolvimento de empresas baseado em valores humanos.

  16. In vitro study of morphological and chemical modification threshold of bovine dental enamel irradiated by the holmium laser; Estudo in vitro das alteracoes morfologicas e quimicas do esmalte dental bovino irradiado pelo laser de holmio

    Energy Technology Data Exchange (ETDEWEB)

    Eduardo, Patricia Lerro de Paula

    2001-07-01

    The aim of this study is to investigate the Ho:YLF laser effects on the dental enamel surface with regards to its morphology, thermal variations during its irradiation in the pulp chamber and its increased resistance to demineralization through quantitative analysis of calcium and phosphorous atoms reactive concentrations in samples. Twenty samples of bovine enamel were used and divided in four groups: control - acidulated phosphate fluoride (APF) application followed by demineralization treatment with lactic acid; irradiation with Ho:YLF laser (100 J/cm{sup 2}) followed by APF topic application and demineralization treatment with lactic acid; irradiation with Ho:YLF laser (350 J/cm{sup 2}) followed by APF topic application and demineralization treatment with lactic acid: and irradiation with Ho:YLF laser ( 450 J/cm{sup 2}) followed by APF topic application and demineralization treatment with lactic acid. Ali samples were quantified according to their calcium and phosphorous atoms relative concentrations before and after the treatments above. X-Ray fluorescence spectrochemical analysis and scanning electron microscopy were carried out. It was observed an increase on the calcium and phosphorous atoms concentration ratio and therefore the enamel demineralization reduction as a result of the lactic acid treatment in the samples irradiated with the holmium laser followed by the APF application. In order to evaluate the feasibility of this study for clinical purposes, morphological changes caused by the holmium laser irradiation were analyzed. Such modifications were characterized by melted and re-solidified regions of the enamel with consequent changes on its permeability and solubility. Temperature changes of ten human pre-molars teeth irradiated with 350 J/cm{sup 2} and 450 J/cm{sup 2} were also monitored in the pulp chamber in real time. Temperature increases over 4,20 C did not occur. The results obtained from this study along with the results from previous

  17. ESTUDO DE ETNOECODESIGN DE IMAGENS SACRAS EM GESSO DANIFICADAS E DESCARTADAS PELO USUÁRIO. ESTUDO DE MODELO SUSTENTÁVEL DE NICHO DE DESCARTE.

    Directory of Open Access Journals (Sweden)

    Paulo Sergio de Sena

    2016-10-01

    Full Text Available O Etnoecodesingn trata-se de um estudo interdisciplinar onde o dialogo envolve os critérios culturais, sociais e ambientais. Os componentes etnoecológicos do estudo das Imagens Sacras de Gesso se materializam no grupo de artesãos tradicionais locais (mais de 100 anos de exploração da técnica e recurso natural gesso. Na produção de imagens sacras, como souvenir, em Aparecida- SP, que agrega processos e materiais que contribuem significativamente para contaminação do ambiente, durante a pré-produção, produção, pós-produção e descarte, principalmente quando houve constatação, no projeto anterior, de matéria prima contaminada por metais pesados. Este trabalho trata dos possíveis impactos causados pelo descarte das imagens, uma vez danificadas, diretamente no ambiente por conta de uma prática cultural denominada de “Santa Cruz” e vem contribuir para o estudo comparado dos atuais modelos de nicho de descarte e a proposta de um modelo mais sustentável para a Santa Cruz.

  18. Festivais musicais : um estudo sob a ótica do turismo

    OpenAIRE

    Ruas, Rayane

    2014-01-01

    Este trabalho trata-se de uma pesquisa de caráter qualitativo, baseada no método hipotético-dedutivo, que busca analisar os festivais de música enquanto encontros que permitem a ruptura do cotidiano proporcionando uma experiência do turismo. Primeiramente foi realizada uma pesquisa exploratória explicativa acerca do tema o que delimitou o seu objeto de estudo. O recorte do objeto de estudo foram os festivais de música desde o Festival de Monterey em 1967 até os dias atuais. Durante a pesquisa...

  19. Clinical study on the removal of gingival melanin pigmentation: comparison between Nd:YAG laser ablation and mechanical abrasion; Estudo clinico comparativo entre as tecnicas de despigmentacao melanica gengival: laser neodimio (1064 nm) e gengivoabrasao

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, Luis Mario de Melo

    2002-07-01

    Melanin pigmentation occurs as a result of excessive deposition of melanin, produced by the melanocytes present in the basal layer of the epithelium. This study compares clinical parameters such as inflammation and/or hemorrhage, healing process and re-pigmentation, caused by the Nd:YAG laser ablation and the mechanical abrasion of the melanin, by means of photographic images, taken during the first 30 days after the treatment. The patients comfort was monitored during the first ten days after the treatment using the method of the Visual Analog Scale to measure the pain. Six patients with gingival melanin pigmentation were selected. The left upper gingival quadrant was treated with the Nd:YAG laser using 125 mJ per pulse and 20 Hz, the right upper gingival quadrant received mechanical abrasion and the lower quadrants served for control. Both techniques did not result in inflammation and/or hemorrhage. The healing process was slower with the laser. Using mechanical abrasion, ali patients showed remaining pigmentation or re-pigmentation of varying intensity after a period of 30 days. With the laser 50 % of the patients did not show any re-pigmentation after this period. The pain analysis showed that the pain sensed 24 hours after the treatment with the laser is higher than using mechanical abrasion. (author)

  20. Colestase neonatal prolongada: estudo prospectivo

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    PRADO Elizabeth Teixeira Mendes Livramento

    1999-01-01

    Full Text Available Em razão da urgência de se decidir por um tratamento clínico ou por uma intervenção cirúrgica imediata, o estudo da colestase neonatal prolongada envolve dois objetivos básicos: o diagnóstico diferencial entre atresia biliar e hepatite neonatal e a pesquisa dos agentes etiológicos associados. Desta maneira, através de estudo prospectivo desenvolvido na década de 1970, foram avaliadas 77 crianças portadoras de colestase neonatal prolongada para estabelecer o diagnóstico diferencial entre atresia biliar e hepatite neonatal e, numa segunda fase, 108 crianças, visando esclarecer a etiopatogenia da colestase neonatal prolongada. Os resultados do diagnóstico diferencial revelaram que, dos 18 atributos avaliados, apenas oito mostraram-se bons indicadores de atresia biliar, em ordem decrescente: ductos proliferados (espaço-porta, fibrose (espaço-porta, colestase (espaço-porta, cor das fezes -- acolia, hepatomegalia, colestase canalicular (lóbulo, infiltrado (espaço-porta, células gigantes (lóbulo. Estes oito atributos foram então compostos, mediante uma ponderação, em um único indicador de grande poder discriminativo, capaz de decidir o diagnóstico diferencial em 99% dos casos. Quanto à etiopatogenia, registrou-se: vírus rubéola 0%, vírus herpes simples 0%, listeriose 0%, citomegalovirose 2,2%, vírus hepatite B 2,4%, toxoplasmose 2,8%, deficiência de alfa-1-antitripsina 13,1%, sífilis 21,1 %, auto-anticorpos hepáticos 58,4%. O trabalho desenvolvido mostra que as 8 variáveis mais decisivas, como indicadoras diferenciais entre atresia biliar e hepatite neonatal, permanecem como índices fundamentais, auxiliando, em conjunto com novos métodos diagnósticos, na composição de uma estratégia multifatorial cada vez menos invasiva e mais precisa. O estudo da etiopatogenia, dependente das condições epidemiológicas locais e da época, com a introdução de novos métodos diagnósticos, torna-se atualmente cada vez mais

  1. Novas tecnologias no estudo de ondas sonoras

    Directory of Open Access Journals (Sweden)

    Marisa Almeida Cavalcante

    2013-10-01

    Full Text Available http://dx.doi.org/10.5007/2175-7941.2013v30n3p579 O presente trabalho propõe a construção de um Tubo de Kundt adaptado às novas tecnologias disponíveis para o ensino de física. Tem como principal objetivo utilizar a placa Arduino em experimentos didáticos envolvendo o estudo de ondas sonoras. O Arduino é uma placa de controle I/O baseada no micro-controlador Atmega (Atmel e foi projetado inicialmente para fins didáticos. O fato da linguagem de programação utilizada e hardware serem do tipo open source (código aberto possibilitou sua ampla difusão em diversas áreas. Uma das intenções deste projeto é difundir o uso deste recurso para fins educacionais e particularmente no estudo de ondas sonoras estacionarias em tubos, contribuindo com a melhora na abordagem deste conteúdo no ensino e aprendizagem de Física.

  2. Ana Carolina Escosteguy: Cenários dos estudos culturais

    Directory of Open Access Journals (Sweden)

    Thaisa Cristina Bueno

    2015-12-01

    Full Text Available Autora do livro “Cartografia dos Estudos Culturais”, “Comunicação e recepção” (em coautoria com Nilda Jacks, “Leituras em comunicação, cultura e tecnologia”, além de coautora e organizadora em outras obras de referência sobre o tema cultura e comunicação no Brasil, Ana Carolina Escosteguy é hoje um dos nomes mais importantes quando se pensa em Estudos Culturais no país. Doutora em Ciências da Comunicação pela Universidade de São Paulo (2000, com pós-doutorado no CAMRI (Communication and Media Research Institute, associado ao Department of Journalism and Mass Communication da School of Media, Art and Design da University of Westminster (UK, Ana Carolina Escosteguy é professora titular da Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS e bolsista produtividade em pesquisa do CNPq, desde março 2001. Nesta entrevista ela discute pontos sensíveis da área, entre eles o pouco destaque das pesquisas desse campo têm tido no Jornalismo, o fato de a base teórica ser bem mais ampla que os tradicionais estudos de recepção a que são comumente aproximados, não se nega a tratar das confusões com a folkcomunicação, bem como as próprios limites e intersecções desse campo de estudos. Durante esta conversa, aproveita para apontar as obras que considera essenciais para adentrar na área e mostra coragem e segurança para se colocar como uma pesquisadora que busca entender o tempo atual, as tecnologias e as rupturas a partir da perspectiva do usuário. Confiram:

  3. Morphological change study on root surfaces treated with curettes, sonic instruments or Er:YAG laser; Estudo in vitro da alteracao morfologica em superficie radicular tratada com curetas, aparelho ultrasonico ou com laser de Er:YAG

    Energy Technology Data Exchange (ETDEWEB)

    Guimaraes Filho, Arlindo Lopes

    2004-07-01

    Periodontal disease is caused by dental plaque and dental calculus on roots surfaces, specially on cervical areas. As dental plaque is the main cause and dental calculus a secondary one, it is practically impossible to separate one factor to the other one. In order to get periodontal tissue health it is necessary to eliminate dental plaque and calculus from root surfaces. In this sense, Er:YAG laser comes in as an excellent way to control periodontal disease, not only, by removing calculus and dental plaque but also for its bacteria reduction. The aim of this study is to compare, by S.E.M., root surfaces changing when they are treated with curettes and ultrasonic scaling or Er:YAG laser irradiation with two different energy levels of 60 mJ/pulse and 100 mJ/pulse and repetition tax of 10 Hz (in the display). It is also objective of this study to check a possible thermic damage to pulp tissue when the roots surfaces are irradiated with Er:YAG laser. We used for this study, five human dental roots, each one of them were cut into four samples, giving us a total of twenty samples, which were divided in five groups of four samples each one. The control group, we did not indicated any kind of treatment. The first group, the roots samples were scaled and planned with Gracey curettes 5/6 and 7/8. The second group, the roots samples were treated with ultrasonic instruments. The third group was irradiated with Er:YAG laser using 60 mJ/pulse , 10 Hz and energy density of 4 J/cm{sup 2} (approximated). The fourth group was irradiated with Er:YAG laser using 100 mJ/pulse, 10 Hz and energy density of 7 J/cm{sup 2} (approximated). The results analysis showed that roots scaling either with Gracey curettes or with ultrasonic instruments created smear layer covering roots surfaces; roots surfaces irradiated with Er:YAG laser showed few roughness in the third group; roots surfaces irradiated with Er:YAG laser showed no smear layer and the Er:YAG laser irradiation did not bring any

  4. In vitro study of the diode laser effect on artificial demineralized surface of human dental enamel; Estudo in vitro do efeito do laser diodo sobre a superficie de esmalte dental humano desmineralizado artificialmente

    Energy Technology Data Exchange (ETDEWEB)

    Ebel, Patricia

    2003-07-01

    In scientific literature there are many reports about fusion and resolidification of dental enamel after laser irradiation and their capability to generate surfaces with increased resistance to demineralization compared to non-irradiated areas. The use of high power diode laser on demineralized surfaces of human dental enamel is presented as a good alternative in caries prevention. The purpose of this study is to investigate the morphological changes produced by the use of one high power diode laser on human dental enamel surface after demineralization treatment with lactic acid, under chosen parameters. Fifteen samples of human dental molars were used and divided in four groups: control - demineralization treatment with lactic acid and no irradiation, and demineralization treatment with lactic acid followed of irradiation with 212,20 mJ/cm{sup 2}, 282,84 mJ/cm{sup 2} and 325,38 mJ/cm{sup 2}, respectively. The samples were irradiated with high power diode laser (808 nm) with a 300 {mu}m diameter fiber optics. Black ink was used on enamel surface to enhance the superficial absorption. The samples were studied by optical microscopy and scanning electron microscopy. Modifications on the enamel surfaces were observed. Such modifications were characterized by melted and re-solidified region of the enamel. According with our results the best parameter was 2.0 W, presenting the most uniform surface. The use of high power diode laser as demonstrated in this study is able to promote melting and re-solidification on human dental enamel. (author)

  5. Benchmarking e a indústria do conhecimento: um estudo de caso

    OpenAIRE

    Maciel Filho, Adalberto Rego; Aquino, Miriam Cunha de; Sales, Nayade Kennedy

    2016-01-01

    Resumo Estudo de caso das Bibliotecas Indústria do Conhecimento (IDCs) do sistema do Serviço Social da Indústria-Sesi localizadas em Alagoas (25), Paraíba (10),Pernambuco (18), Rio Grande do Norte (10), especificamente as IDCs Públicas, objetivando analisar o seu desempenho e apresentar oportunidades para incremento de frequência utilizando benchmarking. Inclui revisão de literatura de projetos nacionais de uso de benchmarking, bem como estudos e considerações sobre esse processo. Para anális...

  6. O adolescer como portadora de HIV/AIDS : um estudo com adolescentes e suas cuidadoras-familiares

    OpenAIRE

    Ana Amélia Antunes Lima

    2006-01-01

    Trata-se de um estudo exploratório com abordagem qualitativa que aborda a questão do adolescer com HIV/AIDS. Os objetivos do estudo foram: conhecer como ocorre o processo de adolescer para as adolescentes portadoras de HIV/AIDS por transmissão materno-infantil e conhecer como os cuidadores-familiares dessas adolescentes percebem o processo de adolescer com HIV/AIDS. Participaram do estudo sete sujeitos, sendo quatro adolescentes portadoras de HIV/AIDS e três cuidadoras, residentes em Porto Al...

  7. Balancing work, study and home: a research with master’s students in a Brazilian University / Equilibrando trabalho, estudo e lar: um estudo com mestrandos em uma universidade brasileira

    Directory of Open Access Journals (Sweden)

    Amanda Magri Eller

    2016-06-01

    Full Text Available Purpose: Understand the tactics that nontraditional students use to manage the boundaries between work, home and study. Originality/gap/relevance/implications: The originality of this study relies on transfer of the focus from the conflict to the balance between work, home and study. It also breaks new ground by directing attention to the micro level of individual action, in contrast to a literature that traditionally studied organizational actions. Finally, it performs an innovative reading of the interface between work, home and study domains from the perspective of the boundary theory. Key methodological aspects: This qualitative study was held from 18 interviews that were recorded, transcribed and content analyzed, which revealed a list of individual tactics employed by respondents to reconcile the demands of work, home and study. Summary of key results: The analysis allowed us to identify 18 tactics that our respondents employ to negotiate the level of permeability between the boundaries between work, school and home. These tactics were classified as behavioral, communicative, physical and temporal. Key considerations/conclusions: The study revealed that students develop an active role by interpreting the expectations of the social actors from the home and work domains and from the institution where they study and adopt boundaries with degrees of permeability that enable a state of greater balance between these domains Objetivo: Compreender as táticas que estudantes não tradicionais utilizam para gerenciar as fronteiras entre trabalho, lar e estudo. Originalidade/Lacuna/Relevância/Implicações: O estudo se mostra original ao transferir o foco do conflito para o equilíbrio entre trabalho, lar e estudos. Além disso, também inova ao direcionar a atenção para o nível micro da ação individual, contrastando com uma literatura que tradicionalmente estuda ações organizacionais. Por fim, realiza uma leitura inovadora do fenômeno da

  8. Análise clínica do efeito da fotobiomodulação laser (GaAs - 904 nm sobre a disfunção temporomandibular Clinical analysis of the effect of laser photobiomodulation (GaAs - 904 nm on temporomandibular joint dysfunction

    Directory of Open Access Journals (Sweden)

    JC Frare

    2008-02-01

    Full Text Available INTRODUÇÃO: Nos últimos anos, tem sido notado grande interesse no estudo de novas modalidades para o tratamento das disfunções temporomandibulares (DTM. A dor descrita como dor facial, cefaléia ou dor de ouvido, comumente exacerbada pela função da mandíbula, é, em geral, a principal queixa do paciente. A fotobiomodulação laser vem sendo utilizada no tratamento da dor em DTM. OBJETIVO: O objetivo deste estudo foi verificar o nível de dor de pacientes com DTM tratados com fotobiomodulação laser. MATERIAIS E MÉTODOS: Foram estudados 18 pacientes do sexo feminino, com idade média de 27 anos (± 7, com diagnóstico de DTM, os quais foram separados aleatoriamente em dois grupos: Placebo (Controle e Tratado. O Grupo Tratado (n= 10 recebeu atendimento duas vezes por semana, por quatro semanas consecutivas (totalizando oito aplicações. Utilizou-se o laser de GaAs (904 nm, 6 J/cm², 0,38 mW/cm², área do feixe de 0,039 cm², com modo de emissão contínua. Realizou-se a aplicação do laser em quatro pontos pré-auriculares e um em meato acústico externo. O Grupo Placebo (n= 8 foi manipulado como o tratado, porém com o laser desligado. Para análise do nível de dor dos pacientes, empregou-se a Escala Visual Analógica (EVA de dor, antes e após a terapia. Para a análise dos dados, empregou-se o teste t de Student, com nível de significância de 5% (pINTRODUCTION: Over the last few years, there has been great interest in studying new methods for treating temporomandibular joint dysfunction (TMD. Pain, described as facial pain, headache or earache, usually exacerbated by jaw use, is generally the patients' main complaint. Laser photobiomodulation has been used for treating pain in cases of TMD. OBJECTIVE: The aim of this study was to investigate the pain levels in TMD patients treated with laser photobiomodulation. MATERIAL AND METHODS: Eighteen female patients of mean age was 27 years (± 7, with a diagnosis of TMD, were studied

  9. Estudo de ligações em estruturas mistas de concreto-madeira

    OpenAIRE

    Elias Antonio Nicolas

    2001-01-01

    Resumo: Esta pesquisa se refere ao estudo do comportamento mecânico de conectores empregados em estruturas mistas de concreto e madeira, estruturas estas normalmente utilizadas em construções civis tais como pontes, pisos e coberturas residenciais. Neste sentido, foi realizado um estudo teórico-experimental sobre os conectores onde se determinou o valor do módulo de deslizamento (K) através de curvas cargas x deslizamentos obtidas a partir ensaios de laboratório. Os corpos-de-prova foram mold...

  10. Laser-diode pumped Nd:YAG lasers; Laser diode reiki Nd:YAG lasear

    Energy Technology Data Exchange (ETDEWEB)

    Yuasa, H.; Akiyama, Y.; Nakayama, M. [Toshiba Corp., Tokyo (Japan)

    2000-04-01

    Laser-diode pumped Nd:YAG lasers are expected to be applied to laser processing fields such as welding, cutting, drilling, and marking due to their potential for high efficiency and compactness. We are designing and developing laser-diode pumped Nd:YAG lasers using numerical analysis simulation techniques such as ray tracing and thermal analysis. We have succeeded in achieving a laser power of more than 3 kW with 20% efficiency, which is the best ever obtained. In addition, we have developed a laser-diode pumped green laser by second harmonic generation, for precision machining on silicon wafers. (author)

  11. In vitro study of hydroxy apatite and enamel powder fused in human enamel by Nd:YAG laser; Estudo in vitro da fusao de hidroxiapatita e esmalte em superficies de esmalte humano pelo laser de Nd:YAg

    Energy Technology Data Exchange (ETDEWEB)

    Ferrreira, Marcus Vinicius Lucas

    2000-07-01

    The aim of this study was to evaluate the effects of pulsed Nd:YAG (1064 nm) laser irradiation on hydroxyapatite and enamel powder fusion. This laser beam is not well absorbed by this two compounds for this reason they were mixed with vegetal coal to increase the absorption of the laser beam. Fifteen enamel flat surfaces and six occlusal enamel surfaces were prepared with three different substances: hydroxyapatite mixed with vegetal coal (3:1 in weigh); enamel powder mixed with vegetal coal (3:1 in weigh); vegetal coal. The occlusal surfaces were utilized to determine if the compounds could seal pits and fissures. Flat surfaces were utilized to determine fusion of hydroxyapatite and enamel powder. All samples were irradiated with Nd:YAG laser with the parameters: 80 mJ, 15 Hz, 1,2 W, 100 {mu}s pulse-width, 131,1 J/cm{sup 2}. Laser beam was delivered to the samples with a 300 {mu}m diameter fiber optic. Morphology of the irradiated surfaces were examined by scanning electron microscopy (SEM). The compounds with hydroxyapatite and enamel powder were fused to enamel surfaces. Only partial pits and fissures sealing could be observed. (author)

  12. EFEITO AGUDO DO LASER DE BAIXA POTÊNCIA NA FADIGA DO BÍCEPS BRAQUIAL DE ATLETAS DE VOLEIBOL

    Directory of Open Access Journals (Sweden)

    Juliana Lôbo Froio

    Full Text Available RESUMO Introdução: A laserterapia de baixa potência tem entre seus propósitos auxiliar a recuperação de tecidos biológicos, atenuando os efeitos da fadiga muscular e contribuindo com a melhora do desempenho em atletas. Aspectos metodológicos ainda limitam as conclusões do efeito agudo da laserterapia sobre o desempenho muscular. Objetivo: Verificar o efeito agudo do laser terapêutico de baixa potência na fadiga induzida do bíceps braquial de atletas de voleibol. Métodos: Este foi um estudo randomizado e duplo-cego, aprovado pelo Comitê de Ética da UNESP de Marília. Participaram do estudo 19 atletas de voleibol de ambos os sexos. Realizou-se coleta de dados eletromiográficos do músculo bíceps braquial no exercício isométrico de flexão de cotovelo antes e após a aplicação do laser terapêutico. Um haltere com 75% do pico de força, obtido por uma célula de carga, foi utilizado para o protocolo de fadiga. Em seguida, os voluntários foram submetidos à aplicação do laser (ativo ou placebo em seis pontos do músculo bíceps braquial. Os dados eletromiográficos foram analisados no domínio da frequência, utilizando-se o software Myosystem®. Verificou-se a distribuição de normalidade dos dados pelo teste de Shapiro-Wilk, e utilizou-se Anova (split plot de medidas repetidas a fim de testar a interação entre tempo e grupo. Resultados: Para nenhuma das variáveis analisadas foi observada interação significativa entre grupo e tempo, indicando que o grupo irradiado não apresentou vantagens com relação ao grupo placebo. Conclusão: Após o protocolo de fadiga proposto, uma única aplicação de laser de baixa potência não foi suficiente para produzir efeitos positivos no desempenho de força e no sinal eletromiográfico do músculo bíceps braquial de atletas de voleibol.

  13. Auditoria interna de sistema de gestão ambiental: estudo de caso no Verdegreen Hotel

    OpenAIRE

    Adriano Lucena da Silva; Isaiane Vieira de Melo; Diego Rodrigues de Lucena

    2017-01-01

    Esta pesquisa analisa as contribuições e os desafios associados às auditorias internas no Verdegreen Hotel, empreendimento hoteleiro de grande destaque na cidade de João Pessoa-PB, selecionado como unidade de estudo por dispor de um Sistema de Gestão Ambiental (SGA) ISO 14001 implantado e certificado. Este estudo trata de uma pesquisa descritiva, baseada em um estudo de caso qualitativo. As técnicas utilizadas na metodologia foram: levantamento bibliográfico sobre as normas ISO que abordam as...

  14. Marketing do mercado de luxo: Estudo de caso Victoria's Secret

    Directory of Open Access Journals (Sweden)

    Ana Francisca Giuliani

    2013-12-01

    Full Text Available Este artigo teve por objetivo identificar quais são as estratégias de marketing utilizadas pela empresa varejista Victoria’s Secret para a fidelização do consumidor de luxo em nível global. O estudo caracterizou-se como uma pesquisa qualitativa, utilizando-se como estratégia de campo o estudo de caso de caráter ilustrativo. Para o alcance do objetivo proposto, dividiu-se o estudo em duas fases. Na primeira, denominada exploratória, buscou-se em dados secundários o embasamento para a construção do referencial teórico. Na segunda, adotou-se a técnica de pesquisa por observação, utilizando-se os sites da Victoria’s Secret, e analisou-se o composto de marketing aplicado ao mercado de luxo com base no modelo proposto por Nahás (2009. Concluiu-se que as estratégias da referida empresa se baseiam no luxo acessível, de modo que, além de conquistar o consumidor, a Victoria’s Secret consegue manter sua fidelidade por apresentar estratégias de forte apelo emocional.

  15. Casos de Estudo em Estratégia e Marketing - Promovendo o Debate Empresarial

    OpenAIRE

    Au-Yong Oliveira, Manuel; Gonçalves, Ramiro; Martins, José; Moreira, Fernando; Branco, Frederico

    2016-01-01

    Os casos de estudo sobre organizações e empresas são um veículo de comunicação de excelência na área da gestão. Este livro reúne uma série de casos de estudo que abordam a inovação e a diferenciação, a internacionalização, o marketing, a evolução estratégica, os modelos de negócio (e como são afetados pela tecnologia), as aquisições de empresas, e tem ainda um caso de estudo sobre a responsabilidade social (área de crescente importância para todo o tipo de organizações). A estratégia e o mark...

  16. Casos de estudo em estratégia e marketing: promovendo o debate empresarial

    OpenAIRE

    Oliveira, Manuel Au-Yong; Gonçalves, Ramiro; Martins, José; Moreira, Fernando; Branco, Frederico

    2016-01-01

    Os casos de estudo sobre organizações e empresas são um veículo de comunicação de excelência na área da gestão. Este livro reúne uma série de casos de estudo que abordam a inovação e a diferenciação, a internacionalização, o marketing, a evolução estratégica, os modelos de negócio (e como são afetados pela tecnologia), as aquisições de empresas, e tem ainda um caso de estudo sobre a responsabilidade social (área de crescente importância para todo o tipo de organizações). A estratégia e o mark...

  17. Mobbing: assédio moral em contexto de enfermagem - estudo preliminar

    OpenAIRE

    Carvalho, Guilhermina

    2007-01-01

    A temática abordada neste estudo refere-se a um fenómeno que não é recente, contudo pouco estudado em Portugal: o Mobbing. Após uma pesquisa bibliográfica, verificou-se uma prevalência significativa de mobbing em contexto de trabalho em todo o mundo, nomeadamente na profissão de enfermagem. Este estudo pretende validar uma escala sobre as estratégias de mobbing: o LIPT - 60 (Leymann Inventory of Psychological Terrorization) a uma população portuguesa de enfermeiros, assim como, avaliar a ...

  18. Estilos educativos parentais, valores e autoconceito de adolescentes : um estudo transcultural

    OpenAIRE

    Iglesia, Yara Rodrigues de la

    2017-01-01

    Tese de doutoramento, Educação (Psicologia da Educação), Universidade de Lisboa, Instituto de Educação, 2017 O presente estudo teve como objetivo principal investigar, a partir de uma perspectiva transcultural, como se caracterizam os estilos educativos parentais, o autoconceito e os valores na adolescência, como se relacionam estas variáveis entre si e como se diferenciam, em função de variáveis específicas. Em relação à metodologia, foi realizado um estudo quantitativo, de tipo transvers...

  19. A sociologia funcionalista nos estudos organizacionais: foco em Durkheim

    Directory of Open Access Journals (Sweden)

    Augusto Cabral

    Full Text Available O tema que estrutura este ensaio é o da sociologia funcionalista, particularmente em termos de sua influência nos estudos organizacionais. O seu foco de análise é duplo. Em um primeiro momento, as obras de Durkheim. Em um segundo momento, o impacto e a supremacia dos enfoques funcionalistas nos estudos organizacionais. Embora seus segmentos estejam inter-relacionados, ele é composto de quatro partes. Na primeira, é feita uma análise histórica da emergência e sistematização das ciências sociais, de modo a traçar sua evolução até o surgimento dos trabalhos de Durkheim. Na segunda, tomando como referencial a obra de Burrell e Morgan (1979, é estudado o paradigma funcionalista em termos de sua origem e expoentes, com destaque para Comte e Spencer, visando chegar a uma compreensão inicial do pensamento de Durkheim e de sua sociologia. Na terceira, a vida e as principais obras de Durkheim são sumariadas e discutidas. Por fim, o status atual dos estudos organizacionais -vistos como um conjunto impreciso, elástico e eclético de teorias e pesquisas sociais voltados para os problemas das organizações -é analisado em termos de seus pressupostos epistemológicos e ontológicos subjacentes, como meio de explicitar a supremacia dos enfoques positivistas-funcionalistas.

  20. Lasers '89

    International Nuclear Information System (INIS)

    Harris, D.G.; Shay, T.M.

    1990-01-01

    This book covers the following topics: XUV, X-Ray and Gamma-Ray Lasers, excimer lasers, chemical lasers, nuclear pumped lasers, high power gas lasers, solid state lasers, laser spectroscopy. The paper presented include: Development of KrF lasers for fusion and Nuclear driven solid-state lasers

  1. O estudo das fontes estrangeiras na obra de Machado de Assis e o caso italiano

    Directory of Open Access Journals (Sweden)

    Eugênio Vinci de Moraes

    2008-04-01

    Full Text Available Os estudos das fontes italianas na obra de Machado de Assis ainda são uma esquecida árvore no meio da floresta dos estudos machadianos. Três aspectos explicam talvez a posição marginal dessas pesquisas: primeiro, o número menor de refer~encias italianas perante as inglesas e francesas, por exemplo; segundo, a ausência de estudos de maior fôlego; por último, por essa fonte não tocar nas questões centrais da obra de Machado. Neste artigo pretende-se mostrar de que forma trabalhar com as fontes em Machado, com base em três modelos de análise, e também de que forma esses estudos podem tocar, sim, em pontos fundamentais da obra de Machado, desde que não se desdenhe a já alentada e qualificada fortuna crítica do escritor fluminense.

  2. Laser safety at high profile laser facilities

    International Nuclear Information System (INIS)

    Barat, K.

    2010-01-01

    Complete text of publication follows. Laser safety has been an active concern of laser users since the invention of the laser. Formal standards were developed in the early 1970's and still continue to be developed and refined. The goal of these standards is to give users guidance on the use of laser and consistent safety guidance and requirements for laser manufacturers. Laser safety in the typical research setting (government laboratory or university) is the greatest challenge to the laser user and laser safety officer. This is due to two factors. First, the very nature of research can put the user at risk; consider active manipulation of laser optics and beam paths, and user work with energized systems. Second, a laser safety culture that seems to accept laser injuries as part of the graduate student educational process. The fact is, laser safety at research settings, laboratories and universities still has long way to go. Major laser facilities have taken a more rigid and serious view of laser safety, its controls and procedures. Part of the rationale for this is that these facilities draw users from all around the world presenting the facility with a work force of users coming from a wide mix of laser safety cultures. Another factor is funding sources do not like bad publicity which can come from laser accidents and a poor safety record. The fact is that injuries, equipment damage and lost staff time slow down progress. Hence high profile/large laser projects need to adapt a higher safety regimen both from an engineering and administrative point of view. This presentation will discuss all these points and present examples. Acknowledgement. This work has been supported by the University of California, Director, Office of Science.

  3. Marginal microleakage in vitro study on class V cavities prepared with Er:YAG laser and etched with acid or etched with Er:YAG laser and acid; Estudo in vitro da microinfiltracao marginal em cavidades classe V preparadas com laser de Er:YAG e condicionadas com acido ou com laser de Er:YAG e acido

    Energy Technology Data Exchange (ETDEWEB)

    Tavares, Henrique Dutra Simoes

    2001-07-01

    Microleakage at the interface between the teeth and the restorative materials remains a problem with composite resin restorations. Microleakage at the gingival margins of class V cavities restorations still challenge as they are usually placed in dentin and/or cementum. Previous studies have shown that the cavity preparation with Er:YAG laser is possible. It has been reported that Er:YAG laser has ability to create irregular surface providing micromechanical retention for adhesive dental restorative materials and to improve marginal sealing. The purpose of this in vitro study was to evaluate the marginal microleakage on class V cavities prepared with Er:YAG laser and etched with acid or with Er:YAG laser and acid, in compared to those prepared and etched conventionally. Thirty human molars were divided into three groups, namely: group I - prepared with Er:YAG laser (KaVo KEY Laser II - Germany) and etched with 37% phosphoric acid; group II - prepared with Er:YAG laser and etched with Er:YAG laser and 37% phosphoric acid; group III (control group) - prepared with high speed drill and etched with 37% phosphoric acid. All cavities were treated with same adhesive system (Single Bond - 3M) and restored with the composite resin (Z100 - 3M), according to the manufacturer's instructions. The specimens were stored at 37 deg C in water for 24 hours, polished with Sof-Lex discs (3M), thermally stressed, sealed with a nail polish coating except for the area of the restoration and 1 mm around it, and immersed in a 50% aqueous solution of silver nitrate for 24 hours. After that, the specimens were rinsed in water, soaked in a photodeveloping solution and exposed to a fluorescent light for 8 hours. The teeth were embedded in an autopolymerizing resin and sectioned longitudinally using a diamond saw microtome under running water. The sections were photographed. The microleakage at the occlusal cavity and at the gingival margins of each specimen was evaluated with scores (0-3) by

  4. Marginal microleakage in vitro study on class V cavities prepared with Er:YAG laser and etched with acid or etched with Er:YAG laser and acid; Estudo in vitro da microinfiltracao marginal em cavidades classe V preparadas com laser de Er:YAG e condicionadas com acido ou com laser de Er:YAG e acido

    Energy Technology Data Exchange (ETDEWEB)

    Tavares, Henrique Dutra Simoes

    2001-07-01

    Microleakage at the interface between the teeth and the restorative materials remains a problem with composite resin restorations. Microleakage at the gingival margins of class V cavities restorations still challenge as they are usually placed in dentin and/or cementum. Previous studies have shown that the cavity preparation with Er:YAG laser is possible. It has been reported that Er:YAG laser has ability to create irregular surface providing micromechanical retention for adhesive dental restorative materials and to improve marginal sealing. The purpose of this in vitro study was to evaluate the marginal microleakage on class V cavities prepared with Er:YAG laser and etched with acid or with Er:YAG laser and acid, in compared to those prepared and etched conventionally. Thirty human molars were divided into three groups, namely: group I - prepared with Er:YAG laser (KaVo KEY Laser II - Germany) and etched with 37% phosphoric acid; group II - prepared with Er:YAG laser and etched with Er:YAG laser and 37% phosphoric acid; group III (control group) - prepared with high speed drill and etched with 37% phosphoric acid. All cavities were treated with same adhesive system (Single Bond - 3M) and restored with the composite resin (Z100 - 3M), according to the manufacturer's instructions. The specimens were stored at 37 deg C in water for 24 hours, polished with Sof-Lex discs (3M), thermally stressed, sealed with a nail polish coating except for the area of the restoration and 1 mm around it, and immersed in a 50% aqueous solution of silver nitrate for 24 hours. After that, the specimens were rinsed in water, soaked in a photodeveloping solution and exposed to a fluorescent light for 8 hours. The teeth were embedded in an autopolymerizing resin and sectioned longitudinally using a diamond saw microtome under running water. The sections were photographed. The microleakage at the occlusal cavity and at the gingival margins of each specimen was evaluated with scores (0

  5. Eficácia da laserterapia nas disfunções têmporo-mandibulares: estudo controle Lasertherapy efficacy in temporomandibular disorders: control study

    Directory of Open Access Journals (Sweden)

    Thiago de Santana Santos

    2010-06-01

    Full Text Available A disfunção têmporo-mandibular é caracterizada pela presença de sintomatologia dolorosa articular/muscular na região da face. A principal justificativa do uso do laser da laserterapia na disfunção é seu efeito analgésico, fato observado na maioria dos estudos encontrados na literatura. OBJETIVO: Foi avaliar a eficácia da laserterapia no tratamento das disfunções têmporo-mandibulares. MATERIAL E MÉTODO: 50 voluntários com disfunção têmporo-mandibular foram divididos em dois grupos (controle e experimental tiveram as amplitudes dos movimentos de abertura bucal, lateralidade direita e esquerda registrados, antes e após aplicação do laser. Foi registrada, também, a nota de dor do indivíduo através da escala analógica visual de dor e, através do exame físico, os pontos álgicos. Utilizou-se o laser de AsGaAl com potência de 40mW, com 80J/cm², por 16 segundos, em quatro pontos selecionados por apenas uma sessão com reavaliação após uma semana. Desenho Científico Utilizado: Clínico. RESULTADOS: Notou-se que a laserterapia promoveu aumento da média de amplitude dos movimentos mandibulares (p=0,0317 e houve redução significativa (43,6% da intensidade de dor dos pacientes medida através da escala analógica visual de dor. CONCLUSÕES: A laserterapia promove redução da sintomatologia dolorosa do paciente após a aplicação por ação analgésica e/ou por um efeito placebo.Temporomandibular dysfunction is characterized by the presence of painful joint/muscular symptoms muscle in the face. The main justification for the use of lasers in laser therapy dysfunction is its analgesic effect, which was observed in most studies in the literature. AIM: We evaluated the effectiveness of laser therapy in the treatment of temporomandibular disorders. METHODS: 50 volunteers with temporomandibular disorders were divided into two groups (control and experimental had amplitudes of movements of mouth opening, right and left

  6. Coleta Seletiva – Um estudo comparativo em contextos turísticos

    OpenAIRE

    Silva, Ana Flávia da

    2015-01-01

    Anais do IV Encontro de Iniciação Científica da Unila - “UNILA 5 anos: Integração em Ciência, Tecnologia e Cultura na Tríplice Fronteira” - 05 e 06 de novembro de 2015 – Sessão Ciência Política, Sociologia, Filosofia e Antropologia O projeto Coleta Seletiva- um estudo comparativo, traz um debate sobre a eficácia da coleta seletiva em Foz. Propõe, principalmente realizar um estudo etnográfico na cidade de Foz do Iguaçu, com a intenção de identificar aspectos do trabalho na reciclagem ...

  7. A revista Saúde em Debate como fonte e objeto de estudo

    Directory of Open Access Journals (Sweden)

    Daniela Carvalho Sophia

    2013-11-01

    Full Text Available A presente nota de pesquisa busca divulgar estudo sobre o Centro Brasileiro de Estudos da Saúde e o movimento de reforma sanitária desenvolvido no âmbito do Programa de História das Ciências e da Saúde Pública da Casa de Oswaldo Cruz. Atém-se à revista Saúde em Debate , periódico do Centro, devido à relevância que teve na área ao longo dos dez anos de publicação. A utilização da revista na pesquisa deu visibilidade a questões pertinentes à participação de seus membros na reforma sanitária. Enfatiza-se o fato de que a utilização do periódico como fonte e objeto de estudo para fomentar a produção de pesquisa na área da saúde merece investigação mais ampla.

  8. Unidade de estudos de mastites em pequenos ruminantes: estudos em ovinos de regime extensivo Small ruminant mastitis unity: studies on grazing ewes

    Directory of Open Access Journals (Sweden)

    M.C. Queiroga

    2007-01-01

    Full Text Available A “Unidade de Estudo de Mastites em Pequenos Ruminantes”, formalmente constituída no âmbito do Programa Nacional de Re-equipamento Científico, da Fundação para a Ciência e a Tecnologia, vem dar corpo ao trabalho de colaboração de diversas equipas de investigação que se têm debruçado sobre a problemática das infecções intramamárias em pequenos ruminantes, nos seus aspectos de saúde animal, saúde pública veterinária e qualidade e segurança alimentar. Tem como principal objectivo criar condições para o desenvolvimento de trabalhos de investigação e divulgação científica que contribuam para reduzir a prevalência de mastites em pequenos ruminantes e assim melhorar a produção e a qualidade do leite, favorecendo produtores de leite, produtores de queijo e consumidores. Entre os trabalhos já realizados pela equipa científica, destacam-se o isolamento e identificação de agentes etiológicos de mastite em ovelhas, o estudo de factores de virulência nas bactérias mais relevantes, o estudo dos mecanismos de infecção e a resposta imunológica local e sistémica do hospedeiro e outros estudos na área da epidemiologia. O estudo da etiologia e da fisiopatologia da mastite ovina, com o objectivo de compreender a modulação da resposta imunitária da glândula mamária, poderá contribuir para o desenvolvimento de métodos de controlo com base na estimulação da resposta imunitária, alternativos ao uso de antibióticos.The “Small Ruminant Mastitis Unit”, formally constituted in the scope of the Programa Nacional de Re-equipamento Científico, Science and Technology Foundation, gathers the collaborative work of several research groups that have been addressing the issue of small ruminants intramammary infections, related to animal health, veterinary public health and food safety and quality. Its main purpose is to generate an adequate environment for research and scientific communication that may contribute to

  9. Laser in urology. Laser i urologien

    Energy Technology Data Exchange (ETDEWEB)

    Breisland, H.O. (Aker Sykehus, Oslo (Norway))

    1991-09-01

    The neodymium YAG laser is particularly suited for endoscopic urologic surgery because the YAG laser light can be conducted in flexible fibers. Superficial bladder tumours can be treated under local anaesthesia in the outpatient department. The frequency of local recurrences is low, significantly lower than after electrosection or electrocoagulation. Selected cases of T2-muscle invasive bladder tumours can be cured with laser coagulation applied subsequently to transurethral resection. Combined treatment with electrosection and laser coagulation of localized prostatic cancer is a promising method which compares favourably with results obtained by other treatment modalities. Tumours in the upper urinary tract can be laser-treated through ureteroscopes or nephroscopes, but the treatment should be limited to low stage, low grade tumours. Laser is the treatment of choice for intraurethral condylomatas. Laser treatment of penil carcinoma gives excellent cosmetic and functional results and few local recurrences. Laser lithotripsy is a new technique for treatment of ureteric stones and photodynamic laser therapy is a promising tecnique for treatment of carcinoma in situ in the bladder empithelium. However, neither of these techniques are available for clinical use in Norway as yet. 17 refs., 3 figs., 1 tabs.

  10. Forest structure and stem volume assessment based on airborne laser scanning / Avaliação da estrutura florestal e do volume de madeira a partir de laser aerotransportado

    Directory of Open Access Journals (Sweden)

    Markus Hollaus

    2012-10-01

    Full Text Available This paper presents a methodology for the derivation of structural parameters and stem volume in forests based on Airborne Laser Scanning (ALS data. We describe three different measures of horizontal and vertical canopy structure: (1 tree crown segmentation, (2 compactness of vegetation patches, and (3 vertical layering of vegetation patches and canopy cover. An empirical regression model for the derivation of stem volume from the ALS and forest inventory sample plot data is described and its results are validated with extensive reference data. Different study areas in Austria were used to illustrate the workflows. The presented study demonstrates the applicability of the proposed methods on study sites and ALS data of differing characteristics, as well as it points out the suitability of ALS as a tool for reliable wide area assessment of structural parameters and stem volume for forested areas.ResumoEsse artigo apresenta uma metodologia para derivação de parâmetros estruturais e de volume de madeira em florestas baseado em dados de Laser Scanner Aerotransportado (ALS. Nós descrevemos três diferentes medidas da estrutura horizontal e vertical da copa: (1 segmentação da copa da árvore, (2 compacidade das manchas de vegetação, (3 estratificação vertical das manchas de vegetação e cobertura do dossel. Um modelo empírico de regressão para derivar o volume de madeira fazendo uso de dados ALS e dados amostrais obtidos em inventário florestal é descrito e seus resultados são validados com extensivos dados de referência. Diferentes áreas na Áustria foram utilizadas para ilustrar o fluxo de trabalho. O estudo apresentado demonstra a aplicabilidade dos métodos propostos nas áreas de estudo e dos dados ALS de diferentes características, bem como aponta a adequação do ALS como ferramenta confiável para avaliação de parâmetros de estrutura e de volume de madeira de amplas áreas florestais.

  11. CULTURA ORGANIZACIONAL: UM ESTUDO DE CASO NA EMPRESA MGO

    Directory of Open Access Journals (Sweden)

    Vagner Luís Wentz

    2012-07-01

    Full Text Available O tema cultura tem sido objeto de estudo há muitos anos, e as literaturas existentes apontam uma grande diversidade de conceitos, o que torna as organizações grandes fontes de pesquisa. A MGO, uma multinacional fabricante de produtos agrícolas, convive constantemente com mudanças de seus procedimentos, de suas tarefas do cotidiano e de comportamentos por parte de seus colaboradores, uma relação entre “novatos” e “veteranos” que, em alguns casos, é geradora de conflitos, o que pode vir a prejudicar a imagem da companhia. Diante disso, este estudo tem como objetivo geral analisar a cultura organizacional a partir da percepção das lideranças de uma unidade da empresa MGO situada em Montenegro/RS. Esta pesquisa se classifica, quanto aos procedimentos, como bibliográfica e estudo de caso; quanto aos objetivos, como descritiva; e quanto ao problema, esta pesquisa é classificada como qualitativa. A partir da análise dos dados coletados através de entrevistas semiestruturadas com as lideranças de departamentos diferentes, análise de documentos, observação participante e aplicação do teste para identificação da tipologia de cultura, pode-se identificar a cultura da organização e sugerir algumas melhorias que podem ajudar na harmonia do clima da organização. Palavras-chave: Cultura. Clima. Organização.

  12. Análise de Estudos sobre Atenção Publicados em Periódicos Brasileiros

    Directory of Open Access Journals (Sweden)

    Patrícia Maria Uchôa Simões

    Full Text Available A atenção esteve presente nos estudos da Psicologia desde os introspeccionistas até a atualidade. Com a hegemonia do behaviorismo os estudos sobre atenção foram abandonados, e só no final da década de 50 e início de 60 houve uma retomada dessas questões, com o surgimento das ciências cognitivas. O presente estudo realizou uma pesquisa bibliográfica sobre o tema em periódicos brasileiros publicados entre 1999 e 2008, encontrados na base de dados do SCIELO. Foram analisados 96 artigos identificados a partir do descritor atenção para palavras-chave. A análise incidiu sobre os aspectos: ano da publicação, área do periódico e palavras-chave. Os resultados mostraram um maior número de artigos na área da Saúde, com foco na hiperatividade infantil. A análise desses resultados propõe uma discussão sobre o papel que a atenção vem ocupando nos estudos em Psicologia e sugere uma agenda de pesquisas que supere a fragmentação das análises nos estudos.

  13. Unidade de Estudos de Mastites em Pequenos Ruminantes - estudos em ovinos de regime extensivo

    OpenAIRE

    Queiroga, Cristina; Potes, Maria Eduarda; Duarte, Elsa Maria; Marinho, Artur; Bettencourt, Carlos Manuel; Matos, Claudino; Belo, Carlos Carmona; Ribeiro, José Manuel; Vilela, Cristina Lobo

    2007-01-01

    A “Unidade de Estudo de Mastites em Pequenos Ruminantes”, formalmente constituída no âmbito do Programa Nacional de Re-equipamento Científico, da Fundação para a Ciência e a Tecnologia, vem dar corpo ao trabalho de colaboração de diversas equipas de investigação que se têm debruçado sobre a problemática das infecções intramamárias em pequenos ruminantes, nos seus aspectos de saúde animal, saúde pública veterinária e qualidade e segurança alimentar. Tem como principal objectivo criar condições...

  14. Laser system using ultra-short laser pulses

    Science.gov (United States)

    Dantus, Marcos [Okemos, MI; Lozovoy, Vadim V [Okemos, MI; Comstock, Matthew [Milford, MI

    2009-10-27

    A laser system using ultrashort laser pulses is provided. In another aspect of the present invention, the system includes a laser, pulse shaper and detection device. A further aspect of the present invention employs a femtosecond laser and binary pulse shaping (BPS). Still another aspect of the present invention uses a laser beam pulse, a pulse shaper and a SHG crystal.

  15. Application of Various Lasers to Laser Trimming Resistance System

    Institute of Scientific and Technical Information of China (English)

    SUN Ji-feng

    2007-01-01

    Though the laser trimming resistance has been an old laser machining industry for over 30 years, the development of technology brings new alternative lasers which can be used for the traditional machining. The paper describes application of various lasers to laser trimming resistance system including early traditional krypton arc lamp pumped Nd:YAG to laser, modern popular diode pumped solid state laser and the present advanced harmonic diode pumped solid state laser. Using the new alternative lasers in the laser trimming resistance system can dramatically improve the yields and equipment performance.

  16. Os estudos acadêmicos de literatura: uma experiência constitutiva

    Directory of Open Access Journals (Sweden)

    Eunice T. Piazza Gai

    2015-07-01

    Full Text Available O artigo apresenta uma reflexão sobre o tema dos estudos acadêmicos de literatura. Embasa-se na leitura de diversos autores, tais como Platão, Vygotsky, Compagnon, Palmer, Bruner, Secchieri, entre outros. Defende a ideia de que é necessário rever as práticas acadêmicas que consideram os textos literários de um ponto de vista exógeno. Em contrapartida, seria preferível que os estudos de literatura se voltassem para as questões da sua natureza intrínseca, ou seja, que ocorressem, a partir da reflexão sobre a especificidade do conhecimento por ela veiculado e sobre as possibilidades de constituição de sentido propiciadas pelo trabalho hermenêutico.

  17. Afetividade, ensino e aprendizagem: um estudo no GT20 da ANPEd

    Directory of Open Access Journals (Sweden)

    Elvira Cristina Martins Tassoni

    Full Text Available Este artigo traz um levantamento bibliográfico dos trabalhos apresentados no GT20 - Psicologia da Educação da ANPEd (Associação Nacional de Pós-Graduação e Pesquisa em Educação no período de 2000 a 2010. O objetivo foi rastrear as produções científicas mais recentes que discutem a afetividade e sua relação com os processos de ensino e aprendizagem. Apresenta as perspectivas teóricas em que os estudos sobre a afetividade foram abordados e em que medida tais estudos discutem as influências entre os aspectos afetivos e os processos de ensino e aprendizagem. Os trabalhos foram selecionados segundo os procedimentos metodológicos da análise de conteúdo fundamentada em Bardin (1977. Os resultados permitiram a construção de um panorama a respeito dos estudos sobre afetividade, apontando tendências, períodos em que as discussões sobre o tema foram mais intensas e, sobretudo, demonstrando que tal temática vem marcando presença constante nas discussões das Reuniões Anuais da ANPEd.

  18. Interfaces entre a Pedagogia do Teatro e os Estudos da Performance

    Directory of Open Access Journals (Sweden)

    Luciana Hartmann

    2014-11-01

    Full Text Available http://dx.doi.org/10.5902/1984644413816Este texto propõe o debate sobre pontos de contato entre a nova terminologia utilizada nos processos de ensino-aprendizagem em teatro, a Pedagogia do Teatro, e os Estudos da Performance. Partindo de uma análise dos Parâmetros Curriculares Nacionais (PCN Arte I e II e das perspectivas histórico-críticas trazidas por alguns dos principais pesquisadores brasileiros que tem se dedicado ao tema, busca-se, ao longo do texto, refletir sobre as contribuições que os Estudos da Performance podem trazer para o desenvolvimento do campo da Pedagogia do Teatro.

  19. Effects of the low-intensity red laser radiation on the fluoride uptake in enamel. A clinical trial; Avaliacao dos efeitos da radiacao laser de emissao vermelha em baixa intensidade na incorporacao de fluor no esmalte. Estudo clinico

    Energy Technology Data Exchange (ETDEWEB)

    Nakasone, Regina Keiko

    2004-07-01

    Fluoride has been the most important preventive method on development of the caries. This in vivo study evaluated the effects of low-intensity red laser radiation on the fluoride uptake in enamel. Ten healthy participants were recruited for this study. The two maxillary central incisors of each volunteer to be biopsied were used and divided into 4 groups: group G{sub C} (control, which was untreated; group G{sub F} (fluoride), which received topical acidulated phosphate fluoride (APF) 1,23% treatment for 4 minutes; group G{sub LF} (laser + fluoride), which was irradiated with a low-intensity diode laser ({lambda}= 660 nm and dose= 6 J/cm{sup 2}) with APF application after irradiation and group G{sub FL} (fluoride + laser), which received APF before irradiation using the same parameters as G{sub LF}. The determination of fluoride was performed using a fluoride ion electrode after an acid-etch enamel biopsy. The results show a significant increase of the fluoride uptake in enamel for groups G{sub F}, G{sub LF} and G{sub FL} when compared to control group. Although a percentage increase of 57% was observed for G{sub LF} with respect to G{sub F}, there were no statistical differences among treated groups. These findings suggest that low-intensity laser radiation used before APF could be employed in the clinical practice to prevent dental caries. (author)

  20. Laser optically pumped by laser-produced plasma

    International Nuclear Information System (INIS)

    Silfvast, W.T.; Wood, O.R. II.

    1975-01-01

    Laser solids, liquids and gases are pumped by a new technique in which the output from an efficient molecular laser, such as a CO 2 laser, ionizes a medium, such as xenon, into a generally cylindrical plasma volume, in proximity to the pumped laser body. Breakdown yields a visible and ultraviolet-radiation-emitting plasma in that volume to pump the laser body. The spectral radiance of the plasma is significantly higher than that produced by a dc-discharge-heated plasma at nearly all wavelengths in the plasma spectrum. The risetime of radiation from the laser-produced plasma can also be significantly shorter than that of a dc heated plasma. A further advantage resides in the fact that in some applications the attenuating walls needed by flashlamps may be eliminated with the result that laser threshold is more readily reached. Traveling wave excitation may be provided by oblique incidence of the pumping laser beam through the ionizable medium to create sequential ionization of portions of that medium along the length of the pumped laser body. (auth)

  1. Diode laser-pumped Ho:YLF laser

    International Nuclear Information System (INIS)

    Hemmati, H.

    1987-01-01

    The author reports laser action in Ho:YLF at 2.06 μm following optical pumping with a cw diode laser array. Diode laser-pumped Nd-YAG and Ho:YAG have been reported recently. Lasers with a wavelength of 2 μm have medical and optical communication applications. The diode laser light is focused with a 60-mm focal length lens onto the YLF crystal. A high-reflectivity mirror with 100-mm radius of curvature was used as the output coupler. The lasing threshold was at 5 mWof incident power. This is higher than expected considering that a high reflector was used as the output coupler. However, a more uniform cooling of the crystal is expected to lower the lasing threshold. With 100 mW of pump power coupled into the crystal, --20 mW of 2-μm radiation was observed from this unoptimized setup. The 2-μm laser output is highly sensitive to output coupler alignment, YLF crystal temperature, and pump laser wavelength. The 20% optical conversion efficiency achieved in his preliminary measurements is expected to be improved by better crystal cooling, proper matching of laser wavelength to crystal absorption, variations in the concentration of Ho and sensitizers and use of a proper output coupler. A study of the parameters mentioned above and the effect of crystal temperature on the laser output is under way

  2. Lasers for the SILVA laser isotope separation process

    International Nuclear Information System (INIS)

    Lapierre, Y.

    1997-01-01

    The main principles of the laser isotope separation process for the production of enriched uranium at lower cost, are reviewed and the corresponding optimal laser characteristics are described. The development of the SILVA laser isotope separation process involved researches in the various domains of pump lasers, dye lasers, laser and optics systems and two test facilities for the feasibility studies which are expected for 1997

  3. In vitro studies of morphological changes in enamel surface after Er:YAG and Nd:YAG laser irradiation, by SEM; Estudo in vitro do efeito do laser Nd:YAG e Er:YAG sobre o esmalte dental humano atraves de microscopia eletronica de varredura

    Energy Technology Data Exchange (ETDEWEB)

    Verlangieri, Eleonora Jaeger

    2001-07-01

    The caries prevention by using laser irradiation has been investigated by many authors using various lasers with different irradiations conditions. The purpose of this study was to investigated the morphological changes in enamel surface after Er:YAG and Nd:YAG laser irradiation, in vitro, by SEM. Fifteen freshly extracted, intact, caries-free, human third molars, were used in this study. The coronary portions were sectioned, from buccal to lingual direction, in two half-parts. Each one was irradiated by a different laser. The first one was irradiated with water-air spray, by a Nd:YAG laser, at 1.084 nm wave length, at 10 W, 10 Hz, 100 mJ for 60 sec., with an optical fiber in contact mode (0,32 mm of diameter); and the other half, with water-air spray by an Er:YAG laser at 2,94 micrometers wave length at the parameters of 4 Hz, 80 mJ, 24.95 J/cm{sup 2} for 60 sec. The results of this study suggested that both lasers promoted morphological changes in the enamel surface enhancing resistance and can be an alternative clinical method for caries preventions. (author)

  4. Development of frequency tunable Ti:sapphire laser and dye laser pumped by a pulsed Nd:YAG laser

    International Nuclear Information System (INIS)

    Yi, Jong Hoon; Horn, Roland; Wendt, K.

    2001-01-01

    We investigated lasing characteristics of two kinds of tunable laser, liquid dye laser and solid Ti:sapphire crystal laser, pumped by high pulse repetition rate Nd:YAG laser. Dye laser showed drastically reduced pulsewidth compared with that of pump laser and it also contained large amount of amplified spontaneous emission. Ti:sapphire laser showed also reduced pulsewidth. But, the laser conversion pump laser and Ti:sapphire laser pulse, we used a Brewster-cut Pockel's cell for Q-switching. The laser was frequency doubled by a type I BBO crystal outside of the cavity.

  5. Margem crítica e legitimação nos estudos para a paz

    Directory of Open Access Journals (Sweden)

    José Manuel Pureza

    2012-10-01

    Full Text Available Os Estudos para a Paz, constituídos historicamente como conhecimento crítico e, portanto, alternativo à ciência normal em Relações Internacionais, vieram, nos anos noventa, a ser cooptados pelas estruturas de regulação do sistema internacional como fundamento de muitas das opções postas em prática sobretudo no quadro dos processos de reconstrução pós-bélica. Neste contexto, o resgate da linhagem crítica dos Estudos para a Paz implica hoje duas opções radicais. A primeira é a da qualificação da paz pretendida como paz sustentável. A segunda é a da descolonização epistemológica dos Estudos para a Paz.

  6. Uso do conceito de aprendizagem em estudos relacionados ao trabalho e organizações

    Directory of Open Access Journals (Sweden)

    Francisco Antonio Coelho Junior

    2008-01-01

    Full Text Available A literatura em comportamento organizacional apresenta diversos estudos referenciando o conceito aprendizagem aplicado no âmbito das organizações. Porém, verifica-se o uso pouco crítico ou sistemático deste conceito. O objetivo do presente artigo consiste em realizar uma análise conceitual do termo aprendizagem, justificando sua transposição para estudos organizacionais. Aplicaram-se técnicas de análise conceitual propostas por Ryle. Como resultado, verificou-se que a natureza multifacetada do conceito de aprendizagem favorece o advento das diversas definições associadas a ele. Espera-se que haja maior sistematicidade acerca do uso do termo aprendizagem aplicado em estudos organizacionais, considerando seus níveis de análise e as dimensões presentemente discutidas.

  7. Pancreatic capillary blood flow during caerulein-induced pancreatitis evaluated by a laser-doppler flowmeter in rats Estudo das alterações do fluxo capilar pancreático após infusão de ceruleína avaliado por laser-Doppler em ratos

    Directory of Open Access Journals (Sweden)

    Roberto Ferreira Meirelles Jr.

    2003-01-01

    Full Text Available PURPOSE: The pancreatic capillary blood flow (PCBF was studied to determine its alterations during caerulein-induced pancreatitis in rats. METHODS: Twenty rats were divided in groups: control and caerulein. A laser-Doppler flowmeter to measure PCBF continuously was used. Blood pressure (BP and heart rate (HR were monitored. Serum biochemistry analyses were determined. Histopathological study was performed. RESULTS: The PCBF measured a mean of 109.08 ± 14.54% and 68.24 ± 10.47% in control group and caerulein group, respectively. Caerulein group had a mean decrease of 31.75 ± 16.79%. The serum amylase was 1323.70 ± 239.10U.I-1 and 2184.60 ± 700.46U.I-1 in control and caerulein groups, respectively. There was a significant difference in the PCBF (pOBJETIVO: O fluxo capilar pancreático (FCP foi estudado para determinar suas alterações durante a pancreatite aguda induzida por ceruleína, em ratos. MÉTODOS: Vinte ratos foram divididos em grupo controle e grupo ceruleína. Um laser-Doppler fluxímetro foi empregado para determinar, continuamente, o FCP durante 120 minutos. A pressão arterial média (PAM e a freqüência cardíaca (FC foram determinadas, durante o experimento. Análise bioquímica sérica e estudo histopatológico, por microscopia ótica, do tecido pancreático foram realizados, ao final do experimento. RESULTADOS: O FCP foi em média 109,08 ± 2,17% e 68,24 ± 16,79% nos grupos controle e ceruleína , respectivamente. No grupo ceruleína, houve uma diminuição média de 31,75 ± 16,79%. Os níveis de amilase sérica foram de 1323,70 ± 239,10U.I-1 e 2184,60 ± 700,46U.I-1 nos grupos controle e ceruleína, respectivamente. Houve diferença significante (p<0,05 no FCP e na amilasemia, quando comparado o grupo controle com o grupo ceruleína. Embora micro e macrovacuolização estivessem presentes no grupo ceruleína, não houve diferença histológica entre os grupos. CONCLUSÃO: A diminuição do FCP parece um evento precoce

  8. Photonic bandgap fiber lasers and multicore fiber lasers for next generation high power lasers

    DEFF Research Database (Denmark)

    Shirakawa, A.; Chen, M.; Suzuki, Y.

    2014-01-01

    Photonic bandgap fiber lasers are realizing new laser spectra and nonlinearity mitigation that a conventional fiber laser cannot. Multicore fiber lasers are a promising tool for power scaling by coherent beam combination. © 2014 OSA....

  9. Estudos quantitativos em educação Quantitative studies in education

    Directory of Open Access Journals (Sweden)

    Bernardete A. Gatti

    2004-04-01

    Full Text Available O artigo trata de estudos em educação, realizados no Brasil nas últimas três décadas, utilizando abordagens quantitativas. Para a seleção dos trabalhos a serem tratados fez-se um levantamento em todos os números publicados de 1970 para cá dos seguintes periódicos: Revista Brasileira de Estudos Pedagógicos (Inep/MEC, Cadernos de Pesquisa (Fundação Carlos Chagas, Educação e Realidade (UFRS, Educação e Sociedade (Cedes/Unicamp, Revista Brasileira de Educação (ANPEd, Estudos em Avaliação Educacional (Fundação Carlos Chagas, Ensaio (Fundação Cesgranrio. Algumas fontes bibliográficas foram consultadas na busca de outros estudos. Ressalta-se a importância de perspectivas teóricas para o delineamento e desenvolvimento dos estudos, que devem ser colocados no contexto de uma reflexão educacional e de problematização, bem como, assinala a necessidade de adequação das escolhas dos tipos de análise a serem empregados. Discute a pouca tradição de realização de trabalhos em educação com as metodologias quantitativas no Brasil e o possível papel da quantificação na pesquisa educacional. Mostra algumas contribuições desses trabalhos à reflexão no campo da Educação, bem como para a fundamentação de algumas perspectivas críticas. Essas contribuições foram tratadas por temas, a saber: analfabetismo, percurso escolar e fracasso escolar; fluxo escolar/análise de coortes; letramento; políticas e educação básica; financiamento da educação/municipalização; fatores sociais e educação; jovens e educação; avaliação educacional; temas variados.The article refers to studies in education carried out in Brazil during the last three decades using quantitative approaches. The selection of the works to be examined was based on a survey of all issues published since 1970 by the following journals: Revista Brasileira de Estudos Pedagógicos (Inep/MEC, Cadernos de Pesquisa (Fundação Carlos Chagas, Educação e

  10. Mosaico da linguagem das crianças bilíngues bimodais: estudos experimentais

    Directory of Open Access Journals (Sweden)

    Ronice Müller de Quadros

    2016-03-01

    Full Text Available Resumo: O presente trabalho apresenta a metodologia utilizada no estudo experimental que investiga o desenvolvimento bilíngue bimodal de crianças surdas com implante coclear (IC e crianças ouvintes filhas de pais surdos (Kodas2, com faixa etária entre 4 e 8 anos. Além desses dois grupos de crianças, participaram da pesquisa crianças surdas filhas de pais surdos ou filhas de pais ouvintes, e adultos ouvintes filhos de pais surdos, com o intuito de constituírem os grupos de controle. Inicialmente, descrevemos o estudo experimental desenvolvido e apresentamos como organizamos as feiras para coleta de dados. E, em seguida, apresentamos os testes utilizados no estudo, que contemplam os aspectos linguísticos da Língua de Sinais Brasileira (Libras e do Português Brasileiro (PB e formam o mosaico da linguagem dessas crianças. Concluímos com os resultados gerais das investigações realizadas até o momento.

  11. Treinamento auditivo nas alterações do processamento auditivo: estudo de caso

    OpenAIRE

    Stroiek,Susan; Quevedo,Lenita da Silva; Kieling,Carla Hernandez; Battezini,Ana Carolina Lago

    2015-01-01

    O objetivo deste estudo é verificar a eficácia de um programa de Treinamento Auditivo comparando o desempenho inicial, nos testes de avaliação do processamento auditivo, com o desempenho após o treinamento auditivo. Para este estudo de caso, desenvolvido na clínica de Fonoaudiologia da Universidade de Passo Fundo, foi selecionado um indivíduo que apresentava alterações de linguagem, queixas compatíveis com alterações de processamento auditivo, avaliação audiológica básica normal e avaliação d...

  12. Estudo de mercado: "A satisfação dos franchisados em Portugal"

    OpenAIRE

    Fialho, Maria Cristina Grilo

    2013-01-01

    Este relatório de estágio foi realizado no âmbito do Mestrado em Matemática e Aplicações, com especialização em Estatística e Investigação Operacional, da Universidade de Aveiro, e o estágio foi realizado no GEMEO (Gabinete de Estudos de Mercado e Opinião do IPAM). Foram desenvolvidas várias atividades relacionadas com os Estudos de Mercado, e uma dessas atividades é sobre o Franchising, onde se pretende avaliar o perfil e satisfação do Franchisado em Portugal. Para isso, fo...

  13. UM ESTUDO BIBLIOMÉTRICO SOBRE ALIANÇAS, INOVAÇÃO E DESEMPENHO

    OpenAIRE

    Fábio de Oliveira Paula; Luiz Fernando de Paris Caldas; Jorge Ferreira da Silva

    2016-01-01

    O objetivo deste artigo é analisar os trabalhos mais relevantes para o estudo do impacto das alianças para inovação no desempenho das firmas e identificar os temas mais relevantes que formam o arcabouço teórico dessa área. A pesquisa analisou, a partir de um corte longitudinal compreendendo três períodos de seis anos entre 1997 e 2014, a evolução dos temas e trabalhos, identificando os que mantiveram relevância e em torno de quais temas os estudos convergiram. A pesquisa foi realizada aplican...

  14. Hardwares e sistemas multiagente: um estudo sobre arquiteturas híbridas

    Directory of Open Access Journals (Sweden)

    Rafhael Rodrigues Cunha

    2015-05-01

    Full Text Available Este artigo apresenta três estudos de caso sobre a aplicabilidade de arquiteturas de hardware reconfiguráveis, como FPGA, voltadas à utilização em sistemas multiagentes. Feita uma análise visando à elucidação dos resultados e das contribuições que os estudos proporcionaram aos autores, observa-se que o desenvolvimento de sistemas inteligentes depende cada vez mais de uma programação que explore o hardware ao máximo. Esse desfecho torna o uso de hardwares reconfiguráveis o mais aconselhável quando problemas computacionais complexos demandam respostas rápidas e eficientes, como nos casos estudados.

  15. Laser power sources and laser technology for accelerators

    International Nuclear Information System (INIS)

    Lowenthal, D.

    1986-01-01

    The requirements on laser power sources for advanced accelerator concepts are formidable. These requirements are driven by the need to deliver 5 TeV particles at luminosities of 10/sup 33/ - 10/sup 34/ cm/sup -2/ sec/sup -1/. Given that optical power can be transferred efficiently to the particles these accelerator parameters translate into single pulse laser output energies of several kilojoules and rep rates of 1-10 kHz. The average laser output power is then 10-20 MW. Larger average powers will be needed if efficient transfer proves not to be possible. A laser plant of this magnitude underscores the importance of high wall plug efficiency and reasonable cost in $/Watt. The interface between the laser output pulse format and the accelerator structure is another area that drives the laser requirements. Laser accelerators break up into two general architectures depending on the strength of the laser coupling. For strong coupling mechanisms, the architecture requires many ''small'' lasers powering the accelerator in a staged arrangement. For the weak coupling mechanisms, the architecture must feature a single large laser system whose power must be transported along the entire accelerator length. Both of these arrangements have demanding optical constraints in terms of phase matching sequential stages, beam combining arrays of laser outputs and optimizing coupling of laser power in a single accelerating stage

  16. OS SISTEMAS AGROFLORESTAIS COMO ALTERNATIVA ECONÔMICA EM PEQUENAS PROPRIEDADES RURAIS: ESTUDO DE CASO

    Directory of Open Access Journals (Sweden)

    Mário Jorge Campos dos Santos

    2002-05-01

    Full Text Available Os Sistemas Agroflorestais (SAFs constituem-se em uma alternativa de uso da terra para aliar a estabilidade do ecossistema visando à eficiência e otimização de recursos naturais na produção de forma integrada e sustentada. O objetivo deste estudo de caso foi avaliar a viabilidade econômica de um sistema agroflorestal localizado na região do Pontal do Paranapanema. O SAF em estudo é formada por espécies agrícolas: milho (Zea maiz, feijão guandu (Cajanus cajan, carioquinha, (Vigna unguiculata, preto (Phaseolus vulgaris e mandioca (Manihot esculenta com espécies florestais: Eucalyptus citriodora e Eucalyptus camaldulensis. A rentabilidade econômica do sistema foi mensurada, utilizando Valor Presente Líquido (VPL, Razão Benefício/Custo (RB/C para as culturas agrícolas anuais e Valor Esperado da terra (VET para os componentes madeireiros. Para tais cálculos foi escolhida uma taxa de desconto de 6%. O estudo demonstrou que o sistema agroflorestal apresentou rentabilidade econômica positiva, e que podem ser adotados por pequenos produtores. Assim, pode-se concluir que os sistemas agroflorestais são economicamente viáveis para pequenos produtores rurais trabalhando nas mesmas condições apresentadas neste estudo.

  17. Laser pumped lasers for isotope separation

    International Nuclear Information System (INIS)

    Fry, S.M.

    1976-01-01

    A study of the isotope separation laser requirements reveals that high pressure polyatomic molecular gas laser pumped lasers can attain the necessary characteristics including tunability, energy output, pulse width, and repetition rate. The results of a search, made for molecules meeting the appropriate requirements for one of several pump schemes utilizing a CO 2 laser and with output in the 12 μm or 16μm wavelength range, are presented. Several methods of pumping are reviewed and two novel pump schemes are presented. A laser pumped laser device design is given, and operation of this device and associated diagnostic equipment is confirmed by repeating experiments in OCS and NH 3 . The results of OCS laser experiments show that an improvement in pump rate and output per unit length is obtained with the device, using a wedged transverse pumping scheme. A new multi-line laser system in NH 3 pumped by a TEA CO 2 laser is reported. More than forty transitions spanning the wavelength range of 9.2 to 13.8 μm are observed and identified. A strong output at 12.08 μm is one of the closest lines yet found to the required laser isotope separation wavelength. Far infrared emission near 65 μm is observed and is responsible for populating levels which lase in pure ammonia near 12.3 μm. Buffer gas (e.g., N 2 or He) pressures of approximately 40--800 torr cause energy transfer by collision-induced rotationaltransitions from the pumped antisymmetric to the lasing symmetric levels in the nu 2 = 1 band of ammonia. Most of the observed lines are aP(J,K) transitions which originate from the nu 2 /sup s/ band. Measurements of the pressure dependence of the laser output shows that some lines lase at pressures greater than one atmosphere. Transient behavior of the 12.08 μm line is calculated from a simplified analytic model and these calculations are compared to the experimental results

  18. Future prospects of laser diodes and fiber lasers

    International Nuclear Information System (INIS)

    Ueda, Ken-ichi

    2000-01-01

    For the next century we should develop new concepts for coherent control of light generation and propagation. Owing to the recent development of ultra fine structures in semiconductor lasers, fiber lasers, and various kinds of waveguide structure, we can make optical devices which control the light propagation artificially. But, the phase locking and phase control of multiple laser oscillators are one of the most important directions of laser science and technology. The coherent summation has been a dream of laser since 1960. Is it possible to solve this old and quite challenging problem for laser science? This is also a very basic concept because the laser action based on the stimulated emission is the process of coherent summation of huge number of photons emitted from individual atoms. In this paper, I discuss the fundamental direction of laser research in the next ten or twenty years. The active optics and laser technology should be combined intrinsically in near future. (author)

  19. Estudo bibliométrico do descritor “Ergonomia” na base LISA

    Directory of Open Access Journals (Sweden)

    Eliana Maria dos Santos Bahia

    2011-03-01

    Full Text Available Objetivo: O estudo analisa a produção científica sobre ergonomia utilizando a base de dados Library and Information Science Abstracts (LISA. A base de dados LISA, iniciada em 1969, mantém sua cobertura temática na área de Biblioteconomia e Ciência da Informação.Método: No estudo utilizou-se o método da bibliometria aplicada para verificar a produção científica indexada.Resultados: Entre os resultados da busca de termos indexados na base de dados LISA, encontraram-se 503 artigos com o termo “Ergonomic”; 352 artigos, com a expressão “Design”; 111 artigos com o descritor “Systems”; 110 artigos com o termo “Work”; e , 98 artigos com o termo “Evaluation”. Dentre os 34 títulos de periódicos, 4 títulos cobrem 79% dos artigos que tratam sobre Ergonomia na base LISA. Os demais 30 títulos de periódicos cobrem 21% dos artigos indexados sob essa temática.Conclusões: O presente estudo bibliométrico oferece possibilita um panorama de como a ergonomia é percebida na área da Biblioteconomia e Ciência da Informação.

  20. Morphologic analysis, by means of scanning electron microscopy, of the effect of Er: YAG laser on root surfaces submitted to scaling and root planing Análise morfológica, através de microscopia eletrônica de varredura, da ação do laser de Er: YAG em superfícies radiculares submetidas à raspagem e aplainamento radicular

    Directory of Open Access Journals (Sweden)

    Letícia Helena Theodoro

    2002-12-01

    Full Text Available The purpose of this study was to morphologically evaluate, by means of scanning electron microscopy, the effects of Er:YAG laser on the treatment of root surfaces submitted to scaling and root planing with conventional periodontal instruments. Eighteen root surfaces (n = 18, which had been previously scaled and planed, were assigned to 3 groups (n = 6. The control Group (G1 received no further treatment; Group 2 (G2 was irradiated with Er:YAG laser (2.94 mum, with 47 mJ/10 Hz, in a focused mode with air/water spray during 15 s and with 0.57 J/cm² of fluency per pulse; Group 3 (G 3 was irradiated with Er:YAG laser (2.94 mum, with 83 mJ/10 Hz, in a focused mode with air/water spray during 15 s and with 1.03 J/cm² of fluency per pulse. We concluded that the parameters adopted for Group 3 removed the smear layer from the root surface, exposing the dentinal tubules. Although no fissures, cracks or carbonized areas were observed, an irregular surface was produced by Er:YAG laser irradiation. Thus, the biocompatibility of the irradiated root surface, within the periodontal healing process, must be assessed.O objetivo do presente estudo foi analisar morfologicamente, através de microscopia eletrônica de varredura, os efeitos do laser de Er:YAG no tratamento de superfícies radiculares submetidas à raspagem e aplainamento radicular com instrumentos manuais. Foram utilizados 18 espécimes (n = 18 de superfícies radiculares que após ser submetidos à raspagem e aplainamento radicular foram divididos em 3 grupos (n = 6. O grupo controle (G1 não sofreu nenhum tratamento; Grupo 2 (G2 foi irradiado com laser de Er:YAG (2,94 mim 47 mJ/10 Hz, focalizado,com refrigeração à água durante 15 s e fluência de pulso de 0,57 J/cm²; Grupo 3 (G3 foi irradiado com laser de Er:YAG (2,94 mim, 83 mJ/10 Hz, focalizado, com refrigeração à agua durante 15 s e fluência de pulso de 1,03 J/cm². Através da análise dos resultados podemos concluir que o laser de

  1. YCOB lasers

    International Nuclear Information System (INIS)

    Richardson, Martin; Hammons, Dennis; Eichenholz, Jason; Chai, Bruce; Ye, Qing; Jang, Won; Shah, Lawrence

    1999-01-01

    We review new developments with a new laser host material, YCa 4 O(BO 3 ) 3 or YCOB. Lasers based on this host material will open new opportunities for the development of compact, high-power, frequency-agile visible and near IR laser sources, as well as sources for ultrashort pulses. Efficient diode-pumped laser action with both Nd-doped and Yb-doped YCOB has already been demonstrated. Moreover, since these materials are biaxial, and have high nonlinear optical coefficients, they have become the first laser materials available as efficient self-frequency-doubled lasers, capable of providing tunable laser emission in several regions of the visible spectrum. Self-frequency doubling eliminates the need for inclusion of a nonlinear optical element within or external to the laser resonator. These laser materials possess excellent thermal and optical properties, have high laser-damage thresholds, and can be grown to large sizes. In addition they are non-hygroscopic. They therefore possess all the characteristics necessary for laser materials required in rugged, compact systems. Here we summarize the rapid progress made in the development of this new class of lasers, and review their potential for a number of applications. (author)

  2. Parameters in fractional laser assisted delivery of topical anesthetics: Role of laser type and laser settings.

    Science.gov (United States)

    Meesters, Arne A; Nieboer, Marilin J; Kezic, Sanja; de Rie, Menno A; Wolkerstorfer, Albert

    2018-05-07

    Efficacy of topical anesthetics can be enhanced by pretreatment of the skin with ablative fractional lasers. However, little is known about the role of parameters such as laser modality and laser density settings in this technique. Aims of this study were to compare the efficacy of pretreatment with two different ablative fractional laser modalities, a CO 2 laser and an Er:YAG laser, and to assess the role of laser density in ablative fractional laser assisted topical anesthesia. In each of 15 healthy subjects, four 10 × 10 mm test regions on the back were randomized to pretreatment (70-75 μm ablation depth) with CO 2 laser at 5% density, CO 2 laser at 15% density, Er:YAG laser at 5% density or Er:YAG laser at 15% density. Articaine hydrochloride 40 mg/ml + epinephrine 10 μg/ml solution was applied under occlusion to all four test regions. After 15 minutes, a pass with the CO 2 laser (1,500 μm ablation depth) was administered as pain stimulus to each test region. A reference pain stimulus was given on unanesthetized skin. The main outcome parameter, pain, was scored on a 0-10 visual analogue scale (VAS) after each pain stimulus. Median VAS scores were 1.50 [CO 2 5%], 0.50 [CO 2 15%], 1.50 [Er:YAG 5%], 0.43 [Er:YAG 15%], and 4.50 [unanesthetized reference]. VAS scores for all pretreated test regions were significantly lower compared to the untreated reference region (P laser pretreated regions. However, VAS scores were significantly lower at 15% density compared to 5% density for both for the CO 2 laser (P laser (P laser was considered slightly more painful than pretreatment with Er:YAG laser by the subjects. Fractional laser assisted topical anesthesia is effective even with very low energy settings and an occlusion time of only 15 minutes. Both the CO 2 laser and the Er:YAG laser can be used to assist topical anesthesia although the CO 2 laser pretreatment is experienced as more painful. In our study settings, using articaine

  3. Laser beam cutting method. Laser ko ni yoru kaitai koho

    Energy Technology Data Exchange (ETDEWEB)

    Kutsumizu, A. (Obayashi Corp., Osaka (Japan))

    1991-07-01

    In this special issue paper concerning the demolition of concrete structures, was introduced a demolition of concrete structures using laser, of which practical application is expected due to the remarkable progress of generating power and efficiency of laser radiator. The characteristics of laser beam which can give a temperature of one million centigrade at the irradiated spot, the laser radiator consisting of laser medium, laser resonator and pumping apparatus, and the laser kinds for working, such as CO{sub 2} laser, YAG laser and CO laser, were described. The basic constitution of laser cutting equipment consisting of large generating power radiator, beam transmitter, beam condenser, and nozzle for working was also illustrated. Furthermore, strong and weak points in the laser cutting for concrete and reinforcement were enumerated. Applications of laser to cutting of reinforced and unreinforced concrete constructions were shown, and the concept and safety measure for application of laser to practical demolition was discussed. 5 refs., 8 figs.

  4. Effect of diode laser irradiation on the apical sealing of MTA retrofillings Efeito da irradiação de laser de diodo no selamento apical em retrobturações com MTA

    Directory of Open Access Journals (Sweden)

    Eliana Barbosa de Souza

    2006-09-01

    Full Text Available Apical sealing is essential for the success of paraendodontic surgery, so any procedure that may favor an adequate sealing of the apical remainder should be performed. The purpose of this study was to evaluate the influence of diode laser irradiation on the apical sealing of root-end cavities with MTA retrofillings. Root canals in twenty extracted human teeth were shaped with K-files and filled with gutta-percha. The apexes were cut off and root-end preparations were performed. The roots were divided randomly in 2 groups. Group 1 (ten specimens was retrofilled with MTA. Group 2 was irradiated with diode laser, with 1 W for 20 seconds, on the apical surface and root end cavity before retrofilling with MTA. The specimens had their external surfaces impermeabilized with cyanoacrylate, except for the apical surface, and were then immersed in 1% rhodamine B dye for 72 h and placed in plaster stone. After that, the specimens were submitted to longitudinal abrasion until half of the root remained. The linear dye leakage was observed in these mid-roots between the root canal wall and retrofilling. The linear dye leakage was measured with Image Lab software, and the results were statistically analyzed with Student's t test. There were no statistically significant differences between the two groups (p > 0.05. The diode laser irradiation did not improve the apical sealing of MTA retrofillings under the conditions of this in vitro study.O selamento apical é fundamental para o sucesso da cirurgia parendodôntica. Assim, procedimentos que melhorem o selamento do remanescente apical devem ser utilizados. O objetivo deste estudo foi verificar se a irradiação de laser de diodo poderia aumentar o selamento apical em cavidades retrógradas obturadas com MTA. Foram utilizadas 20 raízes de dentes humanos extraídos que, após preparo com lima tipo K, tiveram seus canais obturados com guta-percha. Os ápices foram cortados e sofreram preparo de cavidades retr

  5. Ultrashort pulse laser technology laser sources and applications

    CERN Document Server

    Schrempel, Frank; Dausinger, Friedrich

    2016-01-01

    Ultrashort laser pulses with durations in the femtosecond range up to a few picoseconds provide a unique method for precise materials processing or medical applications. Paired with the recent developments in ultrashort pulse lasers, this technology is finding its way into various application fields. The book gives a comprehensive overview of the principles and applications of ultrashort pulse lasers, especially applied to medicine and production technology. Recent advances in laser technology are discussed in detail. This covers the development of reliable and cheap low power laser sources as well as high average power ultrashort pulse lasers for large scale manufacturing. The fundamentals of laser-matter-interaction as well as processing strategies and the required system technology are discussed for these laser sources with respect to precise materials processing. Finally, different applications within medicine, measurement technology or materials processing are highlighted.

  6. Studies of the mechanisms involved in the laser surface hardening process of aluminum base alloys; Estudos dos mecanismos envolvidos em processos de endurecimento superficial a laser de ligas a base de aluminio

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Luciana Ventavele da

    2011-07-01

    The Al-Si alloys are widely used in industry to replace the steel and gray cast iron in high-tech sectors. The commercial importance of these alloys is mainly due to its low weight, excellent wear (abrasion) and corrosion resistance, high resistance at elevated temperatures, low coefficient of thermal expansion and lesser fuel consumption that provide considerable reduction of emission of pollutants. In this work, Al-Si alloy used in the automotive industry to manufacture pistons of internal combustion engines, was undergone to surface treatments using LASER remelting (Nd:YAG, {lambda} = 1.06 {mu}m, pulsed mode). The LASER enables various energy concentrations with accurate transfer to the material without physical contact. The intense energy transfer causes the occurrence of structural changes in the superficial layer of the material. Experiments with single pulses and trails were conducted under various conditions of LASER processing in order to analyze microstructural changes resulting from treatments and their effects on the hardness. For the characterization of hardened layer was utilized the following techniques: optical microscopy, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), x-ray mapping, Vickers microhardness and maximum roughness tests. The high cooling rate caused a change in the alloy structure due to the refinement of the primary eutectic silicon particles, resulting in increase of the mechanical properties (hardness) of the Al-Si alloy. (author)

  7. Avaliação da eficácia do laser de baixa intensidade no tratamento das disfunções têmporo-mandibular: estudo clínico randomizado

    Directory of Open Access Journals (Sweden)

    Maria Helena Chaves de Vasconcelos Catão

    2013-12-01

    Full Text Available OBEJTIVO: avaliar a eficácia do laser de baixa intensidade no tratamento da dor em pacientes com desordens temporomandibulares. MÉTODO:consistiu de um ensaio clínico randomizado divididos em dois grupos: Grupo 1: laser AsGaAl, Grupo 2: laser InGaAlP, do qual participaram 20 pacientes entre 19 e 35 anos de idade, com diagnóstico de sinais e sintomas de DTM. Os pacientes tinham a amplitude de movimento para abertura máxima da boca e lateralidade registados no início e no final do tratamento a laser. O Laser foi aplicado em quatro pontos pré-auriculares, totalizando 12 sessões três vezes por semana, durante um mês. Dor dos pacientes foi registrado com base na utilização da escala analógica visual (EAV e também por exame físico dos pontos álgicos. RESULTADOS: observou-se redução significante (p<0,028 do nível de dor em ambos os grupos, porém no G1 a significância foi maior. A evolução do limiar de sensibilidade muscular evidenciou diferença estatisticamente significante (p<0,05 para G1 e G2. A laserterapia no Grupo 1 melhorou a abertura bucal em média de 4,643 mm, enquanto no Grupo 2, a média foi de 3,71 mm por paciente. CONCLUSÃO: houve eficácia em ambos os lasers no controle da dor e abertura bucal dos pacientes.

  8. Estudo das características da oclusão na dentição decídua e na mista e fatores associados

    OpenAIRE

    Costa, Catiara Terra da

    2013-01-01

    Conhecer as características oclusais das dentições decídua e mista, seu desenvolvimento, alterações e possíveis fatores influentes é importante para a prevenção e interceptação das maloclusões, tornando-se de grande valor epidemiológico. Para isto, estudos longitudinais são apropriados, pois observam a mesma população em momentos temporais diferentes. Este estudo foi constituído de duas partes: estudo transversal e estudo longitudinal. O estudo transversal investigou a influência dos fatores ...

  9. Laser beam diagnostics for kilowatt power pulsed YAG laser

    International Nuclear Information System (INIS)

    Liu, Yi; Leong, Keng H.

    1992-01-01

    There is a growing need for high power YAG laser beam diagnostics with the recent introduction of such lasers in laser material processing. In this paper, we will describe the use of a commercially available laser beam analyzer (Prometec) to profile the laser beam from a 1600 W pulsed Nd:YAG laser that has a 1 mm fiber optic beam delivery system. The selection of laser pulse frequency and pulse width for the measurement is discussed. Laser beam propagation parameters by various optical components such as fibers and lenses can be determined from measurements using this device. The importance of such measurements will be discussed

  10. Laser materials processing with diode lasers

    OpenAIRE

    Li, Lin; Lawrence, Jonathan; Spencer, Julian T.

    1996-01-01

    Laser materials processing is currently dominated by CO2, Nd-YAG and Excimer lasers. Continuous advances in semiconductor laser technology over the last decade have increased the average power output of the devices annualy by two fold, resulting in the commercial availability of the diode lasers today with delivery output powers in excess of 60W in CW mode and 5kW in qasi-CW mode. The advantages of compactness, high reliability, high efficiency and potential low cost, due to the mass producti...

  11. Enfermeiros e clientela com bulimia e anorexia: estudo de caso

    Directory of Open Access Journals (Sweden)

    Claudia Regina Carvalho Martins

    2012-06-01

    Full Text Available Investigação que objetivou identificar a interação de enfermeiros e clientes portadores de bulimia e anorexia. Utilizamos o estudo de caso como recurso, para o qual coletamos dados de prontuários e fizemos entrevistas com oito de quatorze enfermeiros, que foram nossos sujeitos-objeto. De acordo com os enfermeiros, os clientes se isolavam do mundo, vivendo num mundo sem fome e de espelhos que refletiam um corpo sempre acima do "peso ideal"; eram pessoas solitárias, que perderam o brilho pessoal, emitindo sinais de que podiam extinguir a vida deles a qualquer momento. Com o estudo, foi possível identificar a maneira pela qual os enfermeiros interagiam e percebiam os clientes e, em decorrência disso, explicitamos uma prática de cuidar peculiar na enfermagem.

  12. Transurethral vaporesection of prostate: diode laser or thulium laser?

    Science.gov (United States)

    Tan, Xinji; Zhang, Xiaobo; Li, Dongjie; Chen, Xiong; Dai, Yuanqing; Gu, Jie; Chen, Mingquan; Hu, Sheng; Bai, Yao; Ning, Yu

    2018-05-01

    This study compared the safety and effectiveness of the diode laser and thulium laser during prostate transurethral vaporesection for treating benign prostate hyperplasia (BPH). We retrospectively analyzed 205 patients with BPH who underwent a diode laser or thulium laser technique for prostate transurethral vaporesection from June 2016 to June 2017 and who were followed up for 3 months. Baseline characteristics of the patients, perioperative data, postoperative outcomes, and complications were compared. We also assessed the International Prostate Symptom Score (IPSS), quality of life (QoL), maximum flow rate (Q max ), average flow rate (AFR), and postvoid residual volume (PVR) at 1 and 3 months postoperatively to evaluate the functional improvement of each group. There were no significant differences between the diode laser and thulium laser groups related to age, prostate volume, operative time, postoperative hospital stays, hospitalization costs, or perioperative data. The catheterization time was 3.5 ± 0.8 days for the diode laser group and 4.7 ± 1.8 days for the thulium laser group (p diode laser and thulium laser contributes to safe, effective transurethral vaporesection in patients with symptomatic BPH. Diode laser, however, is better than thulium laser for prostate transurethral vaporesection because of its shorter catheterization time. The choice of surgical approach is more important than the choice of laser types during clinical decision making for transurethral laser prostatectomy.

  13. MAPEAMENTO GEOLITERÁRIO: UMA PROPOSTA METODOLÓGICA PARA OS ESTUDOS GEOGRÁFICOS

    Directory of Open Access Journals (Sweden)

    Walter Luiz Jardim Rodrigues

    2016-06-01

    Full Text Available Os romances são produções literárias que abrigam em suas páginas, variadas possibilidades de estudos. Embora pouco explorados neste sentido, seus estudos podem ser muito úteis não somente para linha de pesquisa da Geografia e Literatura, mas para diversos ramos do conhecimento como a percepção ambiental, urbanismo, história, economia e entre outros. Neste sentido, procura-se contribuir com uma abordagem metodológica para apreensão do espaço geográfico através de obras literárias, e nesse estudo, a análise do espaço geográfico da cidade de Belém do Pará da década de 1920, descrita no romance “Belém do Grão-Pará” de Dalcídio Jurandir. E assim comparar com a atual organização espacial da cidade a partir do uso das geotecnologias para espacializar, identificar, analisar e representar o espaço através de mapas temáticos gerados a partir do mapeamento geoliterário.

  14. Laser de baixa intensidade em deiscência aguda de safenectomia: proposta terapêutica Low level laser therapy in acute dehiscence saphenectomy: therapeutic proposal

    Directory of Open Access Journals (Sweden)

    Nathali Cordeiro Pinto

    2009-03-01

    Full Text Available Deiscência é uma complicação temida em cirurgias de grande porte. Paciente submetida a revascularização miocárdica evoluiu com deiscência de safenectomia em membro inferior, edema e dor no 15º dia pós-operatório (PO, tendo sido realizado inicialmente o tratamento convencional no ambulatório sem melhora clínica. No 30º PO, aplicou-se somente Laser de Baixa Intensidade (LBI ao redor da borda da ferida, pontualmente. A lesão respondeu com tecido de granulação, diminuição do processo inflamatório e analgesia desde a primeira aplicação. Neste estudo piloto, a laserterapia mostrou ter um papel importante como agente facilitador de cicatrização, por meio de uma terapia nãoinvasiva, eficaz e segura.Dehiscence is a feared complication after major surgeries. Patient who had undergone coronary artery bypass grafting developed saphenectomy's dehiscence on lower limb with edema and pain on the 15th postoperative day. Conventional treatment had been initially performed without clinical improvement. On the 30th postoperative day only Low Level Laser Therapy (LLLT was applied punctually around surgical wounds edge. The results revealed granulated tissue, reduction of inflammatory process and analgesic effect since the first application. In this pilot study, LLLT has shown a considerable role as a wound healing agent, through a new proposal for efficient, safe and noninvasive therapy.

  15. Qualidade de vida em pacientes com endometriose: um estudo de revisão

    Directory of Open Access Journals (Sweden)

    Maria Paula Custódio Silva

    2014-09-01

    Full Text Available Objetivo: O presente estudo teve como objetivo mostrar os principais resultados dos estudos que avaliaram qualidade de vida (QV em mulheres com endometriose. Também são apresentadas estratégias para promoção da saúde, visando demonstrar as pacientes com essa condição ginecológica que é possível viver bem mesmo sendo portadora de uma doença crônica. Métodos: Para isso, foi realizada uma pesquisa bibliográfica no PubMed utilizando os descritores quality of life and endometriosis e os seguintes filtros: artigos com abstract disponível, com data de publicação dos últimos 10 anos, em humanos do sexo feminino, idioma inglês/português e cujos termos constavam no título/abstract. A busca foi realizada em dezembro de 2013, resultou em 147 artigos e de acordo com os critérios de inclusão, 12 foram selecionados para leitura. Resultados: Todos os artigos evidenciaram que as mulheres com endometriose apresentaram uma redução na QV e cinco estudos associaram nível socioeconômico, intensidade da dor e hábitos saudáveis como fatores que influenciam a QV dessa população. No entanto, nenhum dos estudos propõe as pacientes com a doença estratégias para a melhora da QV. O presente estudo mostra os benefícios da prática regular de atividade física em elevar a QV e, portanto, estimula sua realização como uma maneira de minimizar os sintomas da endometriose, em especial a dor e os sintomas psicológicos. Conclusão: Considerando que a endometriose é uma doença complexa e prevalente, o ideal seria o fornecimento de um atendimento holístico as pacientes, executado por uma equipe multidisciplinar que atuaria de modo integrado na orientação, acompanhamento e tratamento das mulheres com endometriose.

  16. Reverse spontaneous laser line sweeping in ytterbium fiber laser

    Czech Academy of Sciences Publication Activity Database

    Navrátil, Petr; Peterka, Pavel; Honzátko, Pavel; Kubeček, V.

    2017-01-01

    Roč. 14, č. 3 (2017), č. článku 035102. ISSN 1612-2011 R&D Projects: GA ČR(CZ) GA16-13306S Institutional support: RVO:67985882 ; RVO:68378271 Keywords : laser line sweeping * ytterbium * fiber lasers Subject RIV: BH - Optics, Masers, Lasers; BH - Optics, Masers, Lasers (FZU-D) OBOR OECD: Optics (including laser optics and quantum optics); Optics (including laser optics and quantum optics) (FZU-D) Impact factor: 2.537, year: 2016

  17. Tendências dos estudos com idosos mais velhos na comunidade: uma revisão sistemática (internacional

    Directory of Open Access Journals (Sweden)

    Idiane Rosset

    2011-03-01

    Full Text Available O estudo objetivou identificar e analisar as tendências e tipos de estudos, publicados no país e no exterior, envolvendo idosos >80 anos residentes na comunidade. Realizou-se uma revisão sistemática da literatura nacional nas bases de dados LILACS e SciELO e internacional nas bases PUBMED e EMBASE, nas duas últimas décadas. Selecionaram-se 162 referências internacionais e 12 nacionais. Predominou a área das ciências biológicas, tanto no nível nacional (50% quanto internacional (74,1%. Todos os trabalhos nacionais foram observacionais, sendo 91,7% de estudos transversais. Dentre os internacionais, 93,3% foram observacionais. Destes, 48,1% de estudos transversais e 37,6% de estudos de corte. Os Estados Unidos foram responsáveis por 41,4% do total de publicações internacionais. O Brasil e a China foram os únicos países em desenvolvimento a apresentar produções internacionais. Apesar do significativo aumento no número de produções científicas internacionais a partir de 2005, o mesmo ainda não foi constatado em nível nacional.

  18. APRENDIZAGEM INDIVIDUAL, SUPORTE ORGANIZACIONAL E DESEMPENHO PERCEBIDO: UM ESTUDO COM DOCENTES UNIVERSITÁRIOS

    Directory of Open Access Journals (Sweden)

    Pérola Cavalcante Dourado

    2018-03-01

    Full Text Available Resumo: O estudo analisou as relações entre a percepção de aprendizagem de competências e de desempenho de docentes de nível superior. Além disso, testou o papel moderador do suporte organizacional na relação entre a aprendizagem individual e desempenho docente. Participaram do estudo 275 docentes de uma universidade pública federal, que responderam ao inventário de percepção de aprendizagem de competências, suporte à transferência e desempenho docente (ASOD. Foram realizadas análises confirmatórias e testados os modelos de predição e moderação. Uma das conclusões do estudo foi que a aprendizagem docente nas atividades de ensino, pesquisa, extensão e gestão predizem a percepção de desempenho em cada uma das atividades respectivamente. Não foram encontradas evidências de que o suporte modera as relações entre as aprendizagens e a percepção de desempenho docente.

  19. Welding shape memory alloys with NdYAG lasers Soldadura de ligas de memória de forma com laser Nd-YAG

    Directory of Open Access Journals (Sweden)

    Luisa Quintino

    2012-09-01

    os materias base têm propriedades diferentes com consquentes diferenças no escoamento térmico, movimentação de fuido e distribuição de tensões residuais. A composição química varia ao longo do banho de fusão e formam-se compostos intermetálicos. É essencial realizar-se investigação sobre estes efeitos do processamento laser de NiTi para ultrapassar este desafio. O presente estudo visa analisar os efeitos da soldadura a laser na forma do cordão de soldadura em juntas similares e dissimilares de NiTi com aço inoxidável e ligas de titâneo.

  20. Gestão em Alimentos e Bebidas: Indicadores para um Novo Campo de Estudos no Brasil

    Directory of Open Access Journals (Sweden)

    Carlos Eduardo de Mattos

    2016-10-01

    Full Text Available A partir de dezembro de 2015 a CAPES reconheceu formalmente a proposta de abertura de um novo curso em Mestrado Profissional em Administração com foco na Gestão em Alimentos e Bebidas. Ainda que no exterior este campo de pesquisa (Food and Beverage Management já esteja consolidado, no Brasil ele é formalmente inédito. Este estudo tem o propósito de identificar, por meio de pesquisa bibliográfica nas bases de dados EBSCO e Food and Beverage Management Commons, as áreas de estudo de alimentos e bebidas no campo da administração de empresas. A pesquisa também possui o objetivo de quantificar, de forma longitudinal, o número de estudos por área. Os resultados identificaram 18 áreas da administração de empresas em que existem pesquisas sobre alimentos e bebidas. Os resultados, também, quantificaram o número de publicações e demonstraram, ao longo do tempo, a partir da década de 1960, o progresso e os turns (períodos de grandes evoluções na produção dos estudos em alimentos e bebidas em cada década. Este artigo contribuiu, de forma seminal, para mapear a área e fornecer indicadores de sua produção científica. O estudo contribuiu, também, para direcionar investigações futuras.

  1. High-energy molecular lasers self-controlled volume-discharge lasers and applications

    CERN Document Server

    Apollonov, V V

    2016-01-01

    This book displays the physics and design of high-power molecular lasers. The lasers described are self-controlled volume-discharge lasers. The book explains self-sustained discharge lasers, self-initiated discharge lasers and technical approaches to laser design. Important topics discussed are laser efficiency, laser beam quality and electric field homogeneity. The book contains many new innovative applications.

  2. Novas Modulações do Controle Organizacional: um Estudo de Caso

    Directory of Open Access Journals (Sweden)

    Cláudia Maria Perrone

    Full Text Available Resumo O poder nas organizações não se manifesta apenas por vias coercitivas na atualidade. Ele atua por meio de dispositivos de poder, nos quais são incluídos os métodos disciplinares, que operam diretamente na subjetividade do sujeito. Esses mecanismos tornam os trabalhadores reconhecíveis, identificáveis e comparáveis entre si. Este estudo objetivou explicitar parte dos resultados de uma pesquisa sobre controle organizacional e subjetividade no contemporâneo. A pesquisa referida investigou a lógica pós-disciplinar presente nos mecanismos de controle organizacional por meio da problematização do nexo entre tecnologia e subjetivação. Os resultados apresentados neste trabalho são relativos a uma parte da amostra total, composta de trinta sujeitos. Foi escolhido o caso de uma mulher, funcionária de uma instituição financeira transnacional, configurando este artigo como um estudo de caso. Os resultados do estudo de caso apontaram que a lógica vigente da organização do trabalho obriga que o trabalhador assuma para si as flutuações da demanda, bem como a responsabilidade dos resultados. Dessa forma, há indicativos que as novas formas de organização do trabalho possibilitam a autorresponsabilização do sujeito.

  3. Laser safety considerations for a mobile laser program

    Science.gov (United States)

    Flor, Mary

    1997-05-01

    An increased demand for advanced laser technology, especially in the area of cutaneous and cosmetic procedures has prompted physicians to use mobile laser services. Utilization of a mobile laser service allows physicians to provide the latest treatments for their patients while minimizing overhead costs. The high capital expense of laser systems is often beyond the financial means of individual clinicians, group practices, free-standing clinics and smaller community hospitals. Historically rapid technology turnover with laser technology places additional risk which is unacceptable to many institutions. In addition, health care reform is mandating consolidation of equipment within health care groups to keep costs at a minimum. In 1994, Abbott Northwestern Hospital organized an in-house mobile laser technology service which employs a group of experienced laser specialists to deliver and support laser treatments for hospital outreach and other regional physicians and health care facilities. Many of the hospital's internal safety standards and policies are applicable to the mobile environment. A significant challenge is client compliance because of the delicate balance of managing risk while avoiding being viewed as a regulator. The clinics and hospitals are assessed prior to service to assure minimum laser safety standards for both the patient and the staff. A major component in assessing new sites is to inform them of applicable regulatory standards and their obligations to assure optimum laser safety. In service training is provided and hospital and procedures are freely shared to assist the client in establishing a safe laser environment. Physician and nursing preceptor programs are also made available.

  4. Dermatological laser treatment

    International Nuclear Information System (INIS)

    Moerk, N.J.; Austad, J.; Helland, S.; Thune, P.; Volden, G.; Falk, E.

    1991-01-01

    The article reviews the different lasers used in dermatology. Special emphasis is placed on the treatment of naevus flammeus (''portwine stain'') where lasers are the treatment of choice. Argon laser and pulsed dye laser are the main lasers used in vascular skin diseases, and the article focuses on these two types. Copper-vapour laser, neodymium-YAG laser and CO 2 laser are also presented. Information is provided about the availability of laser technology in the different health regions in Norway. 5 refs., 2 figs

  5. Laser Ablation of Biological Tissue Using Pulsed CO2 Laser

    International Nuclear Information System (INIS)

    Hashishin, Yuichi; Sano, Shu; Nakayama, Takeyoshi

    2010-01-01

    Laser scalpels are currently used as a form of laser treatment. However, their ablation mechanism has not been clarified because laser excision of biological tissue occurs over a short time scale. Biological tissue ablation generates sound (laser-induced sound). This study seeks to clarify the ablation mechanism. The state of the gelatin ablation was determined using a high-speed video camera and the power reduction of a He-Ne laser beam. The aim of this study was to clarify the laser ablation mechanism by observing laser excision using the high-speed video camera and monitoring the power reduction of the He-Ne laser beam. We simulated laser excision of a biological tissue by irradiating gelatin (10 wt%) with radiation from a pulsed CO 2 laser (wavelength: 10.6 μm; pulse width: 80 ns). In addition, a microphone was used to measure the laser-induced sound. The first pulse caused ablation particles to be emitted in all directions; these particles were subsequently damped so that they formed a mushroom cloud. Furthermore, water was initially evaporated by laser irradiation and then tissue was ejected.

  6. Laser applications in nanotechnology: nanofabrication using laser ablation and laser nanolithography

    International Nuclear Information System (INIS)

    Makarov, G N

    2013-01-01

    The fact that nanoparticles and nanomaterials have fundamental properties different both from their constituent atoms or molecules and from their bulk counterparts has stimulated great interest, both theoretical and practical, in nanoparticles and nanoparticle-based assemblies (functional materials), with the result that these structures have become the subject of explosive research over the last twenty years or so. A great deal of progress in this field has relied on the use of lasers. In this paper, the directions followed and results obtained in laser nanotechnology research are reviewed. The parameters, properties, and applications of nanoparticles are discussed, along with the physical and chemical methods for their fabrication and investigation. Nanofabrication applications of and fundamental physical principles behind laser ablation and laser nanolithography are discussed in detail. The applications of laser radiation are shown to range from fabricating, melting, and evaporating nanoparticles to changing their shape, structure, size, and size distribution, through studying their dynamics and forming them into periodic arrays and various structures and assemblies. The historical development of research on nanoparticles and nanomaterials and the application of laser nanotechnology in various fields are briefly reviewed. (reviews of topical problems)

  7. Laser spectroscopy and laser isotope separation of atomic gadolinium

    International Nuclear Information System (INIS)

    Chen, Y. W.; Yamanaka, C.; Nomaru, K.; Kou, K.; Niki, H.; Izawa, Y.; Nakai, S.

    1994-01-01

    Atomic vapor laser isotope separation (AVLIS) is a process which uses intense pulsed lasers to selectively photoionize one isotopic species of a chemical element, after which these ions are extracted electromagnetically. The AVLIS has several advantages over the traditional methods based on the mass difference, such as high selectivity, low energy consumption, short starting time and versatility to any atoms. The efforts for atomic vapor laser isotope separation at ILT and ILE, Osaka University have been concentrated into the following items: 1) studies on laser spectroscopy and laser isotope separation of atomic gadolinium, 2) studies on interaction processes including coherent dynamics, propagation effects and atom-ion collision in AVLIS system, 3) development of laser systems for AVLIS. In this paper, we present experimental results on the laser spectroscopy and laser isotope separation of atomic gadolinium.

  8. The Newest Laser Processing

    International Nuclear Information System (INIS)

    Lee, Baek Yeon

    2007-01-01

    This book mentions laser processing with laser principle, laser history, laser beam property, laser kinds, foundation of laser processing such as laser oscillation, characteristic of laser processing, laser for processing and its characteristic, processing of laser hole including conception of processing of laser hole and each material, and hole processing of metal material, cut of laser, reality of cut, laser welding, laser surface hardening, application case of special processing and safety measurement of laser.

  9. A study of low power laser on the regenerative process of Girardia tigrina (Girard,1850 (Turbellaria; Tricladida; Dugesiidae Um estudo de laser de baixa potência no processo regenerativo de Girardia tigrina (Girard,1850 (Turbellaria; Tricladida; Dugesiidae

    Directory of Open Access Journals (Sweden)

    KAR. Lopes

    2009-05-01

    Full Text Available The mechanism of regeneration does not start to restore the wound until its corresponding epimorphic phase. A bioestimulation of tissues and cells by laser radiation depends on the wavelength, on the dose, and on the intensity of the light. The goal of this work was to verify the effect of the low power laser at 660 nm on the regenerative process of Girardia tigrina. The specimens were maintained in the laboratory under a temperature ranging from 19° up to 24 °C for 21 days. The planarians were anesthetized by placing them on ice and then cut them with a scalpel. The three treatments were as following: animals individually irradiated with 14 sessions with 1 minute duration (treatment 1, 14 sessions with 3 minutes duration (treatment 2, and without irradiation (control. The planarians were amputated and divided in three study treatments: a control group (without radiation, and two other treatments: irradiated for 1 minute, and irradiated for 3 minutes. The animals were irradiated with diode laser (660 nm with 3.3 ± 0.3 mW of power, using 0.94 mW.mm-2 power density for each irradiation procedure. During the experiment, 14 irradiation sessions were undertaken. The specimens were fixed in Bouin, and stained with hematoxyline and eosin. From observation and histological analysis, it was possible to assess the effects of interaction between laser and tissue. The head fragment after 1 minute of irradiation presented a better organized tissue scheme, when compared with the other treatments. Aspects of the body fragments submitted to 3 minutes of light treatment were very similar to fragments that had not been injured. It can be concluded that there are changes in the quality of regeneration when treated with low power laser under the conditions mentioned above.O mecanismo de regeneração não restaura a ferida até sua fase epimórfica correspondente. A bioestimulação de tecidos e células por radiação laser depende do comprimento de onda, da

  10. Mensuração de alturas de árvores individuais a partir de dados laser terrestre / Individual tree height mensuration with laser terrestrial data

    Directory of Open Access Journals (Sweden)

    Christel Lingnau

    2008-09-01

    Full Text Available O presente estudo tem como principal objetivo a obtenção de variáveis dendrométricas de árvores em um povoamento de Pinus sp a partir de dados laser scanner terrestre. O povoamento de pinus possui quarenta anos de idade, já sofreu desbastes, e apresenta uma densidade de cerca de 890 arv./ha. A metodologia iniciou-se com a coleta de dados de forma tradicional e com o equipamento ILRIS-3D (OPTECH. Com o auxilio de GPS geodésico e estação total determinou-se coordenadas de alvos na fl oresta que serviram de base para georreferenciamento do scanner. A varredura foi realizada em um giro de 360 graus com resoluções de 10 mm e 50 mm a 50 metros em dois pontos distintos do povoamento. Os dados da varredura foram processados com o intuito de isolar efiltrar uma árvore. Como resultado, chegou-se a um bom isolamento de árvores e fi ltragem de pontos, obteve-se ainda a altura total de 31,93 metros e alturas parciais em intervalos de 1 metro relativas a uma árvore do povoamento. A tecnologia laser scanner terrestre apresenta potencial promissor para área florestal abrangendo a aplicação em inventáriosflorestais, planejamento de manejo, produção e colheita florestal.

  11. Estudo de filmes de Langmuir e Langmuir-Blodgett de aminas anfifílicas utilizando a espectroscopia SFG

    OpenAIRE

    Thiers Massami Uehara

    2010-01-01

    O estudo da interação de moléculas orgânicas com a água é de grande importância para diversas áreas das ciências, como por exemplo, na compreensão de sistemas biológicos. Uma elevada diversidade de estudos nesta área já foram realizados, no entanto, alguns aspectos do estudo de filmes finos de aminas anfifílicas não foram satisfatoriamente esclarecidos. Este trabalho aborda filmes de Langmuir de octadecilamina em função do pH e da força iônica de subfases aquosas, investigando a estrutura d...

  12. GESTÃO DO VOLUNTARIADO: Um Panorama dos Estudos Realizados no Brasil.

    Directory of Open Access Journals (Sweden)

    Sheila Patrícia Ramos

    2016-08-01

    Full Text Available Um novo padrão de voluntariado iniciou a partir de 1990 no Brasil, foram criados centros de referência que tinham por objetivo organizar, capacitar e direcionar o trabalho voluntário. A presente pesquisa tem como objetivo analisar os estudos publicados no Brasil sobre o tema gestão do voluntariado e com isso pretende-se mapear estudos teóricos e empíricos nacionais. Para tanto, foi realizada uma pesquisa bibliométrica, de caráter exploratório-descritiva, em dados secundários. Os resultados foram dispostos em forma de tabela. A amostra foi composta por quinze estudos, sendo artigos científicos publicados em revistas e eventos. A média de autores identificados nos artigos foram de 2,4. Predominam as pesquisas práticas e qualitativas com uso da técnica de entrevista apoiado pelo uso de documentos e/ou observação.  80% das pesquisas são qualitativas e 20% de natureza quali/quanti. 80% dos estudos identificados são práticos, 60% foram publicados em fontes classificadas pela CAPES como “B” e 40% “A”.    A new voluntary standard started from 1990 in Brazil, the reference centers have been created that aimed to organize, train and direct volunteer work. This research aims to analyze the studies published in Brazil the problem of volunteer management and aims to map theoretical and empirical national. For this, a bibliometric, descriptive and exploratory research was conducted on secondary data. The results were arranged in a table. The sample consisted of fifteen scientific studies and articles published in magazines and events. The average number of authors identified in Articles 2.4. Predominance of practice and qualitative research using the interview technique with the support of the use of documents and / or observation. 80% of research is qualitative and 20% qualitative / quantitative nature. 80% of the identified studies are practical, 60% were published in classified by CAPES as "B" and 40% "A" sources.

  13. Os sistemas agroflorestais como alternativa econômica em pequenas propriedades rurais: estudo de caso.

    Directory of Open Access Journals (Sweden)

    Mário Jorge Campos dos Santos

    2010-08-01

    Full Text Available Os Sistemas Agroflorestais (SAFs constituem-se em uma alternativa de uso da terra para aliar a estabilidade do ecossistema visando à eficiência e otimização de recursos naturais na produção de forma integrada e sustentada. O objetivo deste estudo de caso foi avaliar a viabilidade econômica de um sistema agroflorestal localizado na região do Pontal do Paranapanema. O SAF em estudo é formada por espécies agrícolas: milho (Zea maiz, feijão guandu (Cajanus cajan, carioquinha, (Vigna unguiculata, preto (Phaseolus vulgaris e mandioca (Manihot esculenta com espécies florestais: Eucalyptus citriodora e Eucalyptus camaldulensis. A rentabilidade econômica do sistema foi mensurada, utilizando Valor Presente Líquido (VPL, Razão Benefício/Custo (RB/C para as culturas agrícolas anuais e Valor Esperado da terra (VET para os componentes madeireiros. Para tais cálculos foi escolhida uma taxa de desconto de 6%. O estudo demonstrou que o sistema agroflorestal apresentou rentabilidade econômica positiva, e que podem ser adotados por pequenos produtores. Assim, pode-se concluir que os sistemas agroflorestais são economicamente viáveis para pequenos produtores rurais trabalhando nas mesmas condições apresentadas neste estudo.

  14. Aplicação do laser 808nm na dor articular crônica de ratos Wistar Aplication of 808nm laser in chronic joint pain in Wistar rats

    Directory of Open Access Journals (Sweden)

    Gladson Ricardo Flor Bertolini

    2009-08-01

    Full Text Available Durante o processo inflamatório, alguns tipos de células predominam e estão envolvidos com a produção de dor. O laser de baixa potência mostra-se útil no controle de mediadores inflamatórios, mas a ampla divergência nos parâmetros dosimétricos, conduz a variações nos resultados positivos. O objetivo deste estudo foi analisar o uso do laser 808nm, na dor articular crônica e edema de ratos Wistar submetidos a sinovite. Foram utilizados 10 ratos Wistar, divididos em dois grupos: GC - indução de sinovite em joelho direito e tratamento placebo; GT - indução de sinovite e irradiado com laser 10J/cm². Para a produção de sinovite foram injetados 100µl de formalina a 5%, no espaço articular tibiofemoral direito. A avaliação da dor ocorreu pelo tempo de elevação da pata (TEP. No 10º dia após a indução de sinovite, iniciou-se o tratamento com laser sobre a face articular medial do joelho, procedimento mantido no decorrer de 10 dias. Os resultados mostraram que o laser apresentou efeitos analgésicos, visto que, para o grupo tratado, houve redução significativa nos valores de TEP, indicando redução da dor, quando comparados os valores pós-tratamento com os pré-tratamento, o que não ocorreu para o grupo que recebeu tratamento placebo; para o edema, o laser também mostrou redução significativa do mesmo. Concluiu-se que o laser 808nm, com 10J/cm², é eficaz na redução da dor articular crônica e edema, em animais submetidos a sinovite experimental.During the inflammatory process some kinds of cells are predominant and are involved with pain production. Low power laser seems to be useful in the control of inflammatory mediators, but wide divergence in the dosemetric parameters leads to variations in its positive results. The aim of this study was to assess the use of the 808nm laser in the chronic joint pain and edema of Wistar rats submitted to synovitis. Sample was composed of 10 Wistar rats divided in two groups

  15. Electrodeless excimer laser; Laser a eccimeri senza elettrodi

    Energy Technology Data Exchange (ETDEWEB)

    Lisi, N. [ENEA, Divisione Nuovi Materiali, Centro Ricerche Casaccia, Rome (Italy)

    2001-07-01

    In this paper it is proposed how to build an excimer laser based on an electrodeless discharge (or Dielectric Barrier Discharge). Such laser could operate with a low energy per pulse (<100 mJ) and a high repetition rate (<100 kHz). The most relevant advantage an electrodeless DBD laser is the much longer gas mixture lifetime. This feature could allow the operation of a sealed laser emitting higher average power with respect to commercially available excimer lasers. Such discharge scheme could be advantageous in order to excite the F{sub 2} excimer molecule, whose emission wavelength in the VUV range (157 nm) at high reprate is particularly interesting in the micro-lithography field. [Italian] In questo documento viene proposto come costruire un laser a eccimeri basato su una scarica priva di elettrodi, o Dielectric Barrier Discharge. Tale laser puo' funzionare con una bassa energia per impulso (<100 mJ) ad alta frequenza di ripetizione (<100 kHz). Il vantaggio fondamentale di un laser a DBD e quindi privo di elettrodi e' la vita media della miscela gassosa molto piu' alta che potrebbe permettere alla camera laser di operare sigillata ad una potenza media superiore a quella dei laser a eccimeri attuali. Tale schema di pompaggio potrebbe essere particolarmente vantaggioso per eccitare la molecola eccimero F{sub 2} la cui lunghezza di emissione nel VUV (157 nm) ad elevata frequenza di ripetizione presenta un notevole interesse nel campo della produzione di microcircuiti.

  16. Laser technologies for laser accelerators. Annual report

    International Nuclear Information System (INIS)

    1985-01-01

    The primary result of the work reported is the determination of laser system architectures that satsify the requirements of high luminosity, high energy (about 1 TeV), electron accelerators. It has been found that high laser efficiency is a very hard driver for these accelerators as the total average laser output optical power is likely to fall above 10 MW. The luminosity requires rep rates in the kHz range, and individual pulse lengths in the 1-10 psec range are required to satisfy acceleration gradient goals. CO 2 and KrF lasers were chosen for study because of their potential to simultaneously satisfy the given requirements. Accelerator luminosity is reviewed, and requirements on laser system average power and rep rate are determined as a function of electron beam bunch parameters. Laser technologies are reviewed, including CO 2 , excimers, solid state, and free electron lasers. The proposed accelerator mechanisms are summarized briefly. Work on optical transport geometries for near and far field accelerators are presented. Possible exploitation of the CO 2 and DrF laser technology to generate the required pulse lengths, rep rates, and projected efficiencies is illustrated and needed development work is suggested. Initial efforts at developing a 50 GeV benchmark conceptual design and a 100 MeV demonstration experiment conceptual design are presented

  17. A educação matemática e os estudos históricos comparativos A educação matemática e os estudos históricos comparativos Mathematics education and comparative historical studies

    Directory of Open Access Journals (Sweden)

    Wagner RODRIGUES VALENTE

    2013-07-01

    Full Text Available Este texto tem por objetivos: caracterizar a área de pesquisa denominada «história da educação matemática» e defender a idéia de que a educação matemática constitui tema privilegiado de pesquisa no âmbito dos estudos históricos comparativos. Utiliza-se para isso uma revisão da literatura sobre estudos comparativos, a análise de dois momentos fundamentais ocorridos no século XX onde intenta-se internacionalizar um currículo de matemática para as escolas de diferentes países e um estudo de caso trazido por projeto de cooperação internacional entre Brasil e Portugal.Este texto tem por objetivos: caracterizar a área de pesquisa denominada «história da educação matemática» e defender a idéia de que a educação matemática constitui tema privilegiado de pesquisa no âmbito dos estudos históricos comparativos. Utiliza-se para isso uma revisão da literatura sobre estudos comparativos, a análise de dois momentos fundamentais ocorridos no século XX onde intenta-se internacionalizar um currículo de matemática para as escolas de diferentes países e um estudo de caso trazido por projeto de cooperação internacional entre Brasil e Portugal.This paper has as its aims: to characterize the area of research «history of mathematics education» and to defend the idea that mathematics education has constituted a privileged research theme within the field of comparative historical studies. To achieve these aims, the text includes references to a review of the literature concerning comparative studies, the analysis of two fundamental moments focused on attempts to internationalize the mathematics curriculum, both of which occurred during the 20th century, and, to end, a case study emanating from an international cooperation between researchers in Brazil and Portugal.

  18. Laser ion sources

    Energy Technology Data Exchange (ETDEWEB)

    Bykovskij, Yu

    1979-02-01

    The characteristics a laser source of multiply-ionized ions are described with regard to the interaction of laser radiation and matter, ion energy spectrum, angular ion distribution. The amount of multiple-ionization ions is evaluated. Out of laser source applications a laser injector of multiple-ionization ions and nuclei, laser mass spectrometry, laser X-ray microradiography, and a laser neutron generators are described.

  19. Laser Physics and Physics with Lasers - Recent Advances

    International Nuclear Information System (INIS)

    Marowsky, G.

    2008-01-01

    This contribution reviews the development as well as recent technological advances in the field of optics with lasers and laser-related applications. Topics ranging from 'attoscience' to 'zero-modes' shall be dealt with in this presentation. Further reading in the following references is suggested: Springer Handbook of Lasers and Optics (F. Trager, ed.), 2007, ISBN-13: 978-0-387-95579-7; Chapter 11.7, Part C: Ultraviolet Lasers: Excimers, Fluorine (F2), Nitrogen (N2), pp. 764-776; Excimer Laser Technology (D. Basting, G. Marowsky, eds.) 2005, Springer, ISBN-13 978-3-540-20056-7

  20. LASER PROCESSING ON SINGLE CRYSTALS BY UV PULSE LASER

    OpenAIRE

    龍見, 雅美; 佐々木, 徹; 高山, 恭宜

    2009-01-01

    Laser processing by using UV pulsed laser was carried out on single crystal such as sapphire and diamond in order to understand the fundamental laser processing on single crystal. The absorption edges of diamond and sapphire are longer and shorter than the wave length of UV laser, respectively. The processed regions by laser with near threshold power of processing show quite different state in each crystal.

  1. Design windows of laser fusion power plants and conceptual design of laser-diode pumped slab laser

    International Nuclear Information System (INIS)

    Kozaki, Y.; Eguchi, T.; Izawa, Y.

    1999-01-01

    An analysis of the design space available to laser fusion power plants has been carried out, in terms of design key parameters such as target gain, laser energy and laser repetition rate, the number of fusion react ion chambers, and plant size. The design windows of economically attractive laser fusion plants is identified with the constraints of key design parameters and the cost conditions. Especially, for achieving high repetition rate lasers, we have proposed and designed a diode-pumped solid-state laser driver which consists of water-cooled zig-zag path slab amplifiers. (author)

  2. Estudos de avaliação do conhecimento nutricional de adultos: uma revisão sistemática

    Directory of Open Access Journals (Sweden)

    Lídia Bezerra Barbosa

    2016-02-01

    Full Text Available Resumo O objetivo deste estudo é revisar de forma sistematizada a literatura relativa a estudos que avaliaram o nível de conhecimento em nutrição de indivíduos adultos, com ênfase aos aspectos metodológicos e de conteúdo. Foi realizada busca de artigos na base de dados Medline, Lilacs e Scielo. Limitou-se a busca aos limites de espécie “humanos”, aos idiomas inglês, português e espanhol e idade (19 acima. Os critérios de inclusão foram: estudos transversais, com indivíduos >18 anos e que avaliaram o nível de conhecimento sobre nutrição em aspectos gerais. A qualidade metodológica dos artigos foi avaliada usando-se o Strengthening the Reporting of Observational Studies in Epidemiology (STROBE. Foram encontrados 3.623 artigos na busca inicial. Após leitura de títulos, resumos e aplicação de critérios de exclusão, 25 artigos selecionados. Os resultados mostraram que o conhecimento nutricional na maioria dos estudos esteve associado a variáveis socioeconômicas e ao comportamento alimentar. A maioria dos estudos pertenciam à classe B (92%, na qual atendiam 50% a 80% dos critérios do STROBE. Os estudos revelaram a existência de uma maior tendência de avaliar a relação do conhecimento em nutrição com variáveis sociodemográficas e econômicas.

  3. Lasers

    CERN Document Server

    Milonni, Peter W

    1988-01-01

    A comprehensive introduction to the operating principles and applications of lasers. Explains basic principles, including the necessary elements of classical and quantum physics. Provides concise discussions of various laser types including gas, solid state, semiconductor, and free electron lasers, as well as of laser resonators, diffraction, optical coherence, and many applications including holography, phase conjugation, wave mixing, and nonlinear optics. Incorporates many intuitive explanations and practical examples. Discussions are self-contained in a consistent notation and in a style that should appeal to physicists, chemists, optical scientists and engineers.

  4. Development of laser materials processing and laser metrology techniques

    International Nuclear Information System (INIS)

    Kim, Cheol Jung; Chung, Chin Man; Kim, Jeong Mook; Kim, Min Suk; Kim, Kwang Suk; Baik, Sung Hoon; Kim, Seong Ouk; Park, Seung Kyu

    1997-09-01

    The applications of remote laser materials processing and metrology have been investigated in nuclear industry from the beginning of laser invention because they can reduce the risks of workers in the hostile environment by remote operation. The objective of this project is the development of laser material processing and metrology techniques for repairing and inspection to improve the safety of nuclear power plants. As to repairing, we developed our own laser sleeve welding head and innovative optical laser weld monitoring techniques to control the sleeve welding process. Furthermore, we designed and fabricated a 800 W Nd:YAG and a 150 W Excimer laser systems for high power laser materials processing in nuclear industry such as cladding and decontamination. As to inspection, we developed an ESPI and a laser triangulation 3-D profile measurement system for defect detection which can complement ECT and UT inspections. We also developed a scanning laser vibrometer for remote vibration measurement of large structures and tested its performance. (author). 58 refs., 16 tabs., 137 figs

  5. Tratamento cirúrgico da laringomalácia grave: estudo retrospectivo de 11 casos

    Directory of Open Access Journals (Sweden)

    José Antonio Pinto

    2013-10-01

    Full Text Available A laringomalácia é a anomalia congênita da laringe mais frequente, sendo responsável por cerca de 60% a 75% dos casos de estridor congênito. Apesar de seu curso benigno e autolimitado, 10% dos casos necessitam de intervenção. Atualmente, as supraglotoplastias são consideradas o tratamento padrão da laringomalácia grave. OBJETIVO: Descrever a experiência adquirida pelos autores no tratamento cirúrgico dos pacientes com laringomalácia grave. Metodologia: Estudo retrospectivo. MÉTODO: Os prontuários de 11 casos consecutivos de laringomalácia grave, submetidos ao tratamento cirúrgico entre 2003 e 2012, foram analisados quanto à idade, gênero, sintomas, doenças associadas, técnica cirúrgica adotada, tempo de extubação, complicações cirúrgicas, tempo de internação e evolução clínica. RESULTADOS: Dos 11 casos de laringomalácia grave, seis pacientes (54,5% foram operados com o uso do laser de CO2 e em cinco pacientes (45,5% foram realizadas a técnica a frio. Apenas um paciente (9,1% necessitou reabordagem cirúrgica. Não foram observados casos de complicações cirúrgicas. Todos os pacientes apresentaram melhora clínica importante. CONCLUSÃO: A supraglotoplastia mostrou-se um procedimento eficaz e seguro no tratamento da laringomalácia grave.

  6. Development of short pulse laser pumped x-ray lasers

    International Nuclear Information System (INIS)

    Dunn, J; Osterheld, A L; Hunter, J R; Shlyaptsev, V N

    2000-01-01

    X-ray lasers have been extensively studied around the world since the first laboratory demonstration on the Novette laser at LLNL in 1984 [l]. The characteristic properties of short wavelength, high monochromaticity, collimation and coherence make x-ray lasers useful for various applications. These include demonstrations of biological imaging within the water window, interferometry of laser plasmas and radiography of laser-heated surfaces. One of the critical issues has been the high power pump required to produce the inversion. The power scaling as a function of x-ray laser wavelength follows a -k4 to law. The shortest x-ray laser wavelength of ∼ 35 (angstrom) demonstrated for Ni-like All was at the limit of Nova laser capabilities. By requiring large, high power lasers such as Nova, the shot rate and total number of shots available have limited the rapid development of x-ray lasers and applications. In fact over the last fifteen years the main thrust has been to develop more efficient, higher repetition rate x-ray lasers that can be readily scaled to shorter wavelengths. The recent state of progress in the field can be found in references. The objective of the project was to develop a soft x-ray laser (XRL) pumped by a short pulse laser of a few joules. In effect to demonstrate a robust, worlung tabletop x-ray laser at LLNL for the first time. The transient collisional scheme as proposed by Shlyaptsev et al [8, 9] was the candidate x-ray laser for study. The successful endeavour of any scientific investigation is often based upon prudent early decisions and the choice of this scheme was both sound and fruitful. It had been demonstrated very recently for Ne-like Ti at 326 A using a small tabletop laser [10] but had not yet reached its full potential. We chose this scheme for several reasons: (a) it was a collisional-type x-ray laser which has been historically the most robust; (b) it had the promise of high efficiency and low energy threshold for lasing; (c) the

  7. Laser-supported detonation waves and pulsed laser propulsion

    International Nuclear Information System (INIS)

    Kare, J.

    1990-01-01

    A laser thermal rocket uses the energy of a large remote laser, possibly ground-based, to heat an inert propellant and generate thrust. Use of a pulsed laser allows the design of extremely simple thrusters with very high performance compared to chemical rockets. The temperatures, pressures, and fluxes involved in such thrusters (10 4 K, 10 2 atmospheres, 10 7 w/cm 2 ) typically result in the creation of laser-supported detonation (LSD) waves. The thrust cycle thus involves a complex set of transient shock phenomena, including laser-surface interactions in the ignition of the LSD wave, laser-plasma interactions in the LSD wave itself, and high-temperature nonequilibrium chemistry behind the LSD wave. The SDIO Laser Propulsion Program is investigating these phenomena as part of an overall effort to develop the technology for a low-cost Earth-to-orbit laser launch system. We will summarize the Program's approach to developing a high performance thruster, the double-pulse planar thruster, and present an overview of some results obtained to date, along with a discussion of the many research question still outstanding in this area

  8. ND:GLASS LASER DESIGN FOR LASER ICF FISSION ENERGY (LIFE)

    International Nuclear Information System (INIS)

    Caird, J.A.; Agrawal, V.; Bayramian, A.; Beach, R.; Britten, J.; Chen, D.; Cross, R.; Ebbers, C.; Erlandson, A.; Feit, M.; Freitas, B.; Ghosh, C.; Haefner, C.; Homoelle, D.; Ladran, T.; Latkowski, J.; Molander, W.; Murray, J.; Rubenchik, S.; Schaffers, K.; Siders, C.W.; Stappaerts, E.; Sutton, S.; Telford, S.; Trenholme, J.; Barty, C.J.

    2008-01-01

    We have developed preliminary conceptual laser system designs for the Laser ICF (Inertial Confinement Fusion) Fission Energy (LIFE) application. Our approach leverages experience in high-energy Nd:glass laser technology developed for the National Ignition Facility (NIF), along with high-energy-class diode-pumped solid-state laser (HEC-DPSSL) technology developed for the DOE's High Average Power Laser (HAPL) Program and embodied in LLNL's Mercury laser system. We present laser system designs suitable for both indirect-drive, hot spot ignition and indirect-drive, fast ignition targets. Main amplifiers for both systems use laser-diode-pumped Nd:glass slabs oriented at Brewster's angle, as in NIF, but the slabs are much thinner to allow for cooling by high-velocity helium gas as in the Mercury laser system. We also describe a plan to mass-produce pump-diode lasers to bring diode costs down to the order of $0.01 per Watt of peak output power, as needed to make the LIFE application economically attractive

  9. O uso da eletroglotografia, eletromiografia, espectografia e ultrassom nos estudos de fala - revisão teórica

    Directory of Open Access Journals (Sweden)

    Fernanda Wiethan

    2015-03-01

    Full Text Available O emprego de novas tecnologias na avaliação e terapia de fala a partir de uma revisão de artigos publicados nos últimos 5 anos é o tema deste estudo, que tem por objetivo realizar uma revisão bibliográfica dos estudos nacionais e internacionais que utilizaram os recursos: eletroglotografia, espectrografia, ultrassonografia e eletromiografia na avaliação e terapia das alterações de fala. Existe um crescente interesse da inserção desses recursos nos estudos de fala, contudo, os trabalhos existentes que os correlacionam ainda são escassos.

  10. Laser fusion

    International Nuclear Information System (INIS)

    Eliezer, S.

    1982-02-01

    In this paper, the physics of laser fusion is described on an elementary level. The irradiated matter consists of a dense inner core surrounded by a less dense plasma corona. The laser radiation is mainly absorbed in the outer periphery of the plasma. The absorbed energy is transported inward to the ablation surface where plasma flow is created. Due to this plasma flow, a sequence of inward going shock waves and heat waves are created, resulting in the compression and heating of the core to high density and temperature. The interaction physics between laser and matter leading to thermonuclear burn is summarized by the following sequence of events: Laser absorption → Energy transport → Compression → Nuclear Fusion. This scenario is shown in particular for a Nd:laser with a wavelength of 1 μm. The wavelength scaling of the physical processes is also discussed. In addition to the laser-plasma physics, the Nd high power pulsed laser is described. We give a very brief description of the oscillator, the amplifiers, the spatial filters, the isolators and the diagnostics involved. Last, but not least, the concept of reactors for laser fusion and the necessary laser system are discussed. (author)

  11. Laser 830nm na viabilidade do retalho cutâneo de ratos submetidos à nicotina Laser 830nm on the viability of skin flaps in rats submitted of nicotine

    Directory of Open Access Journals (Sweden)

    Lais Mara Siqueira das Neves

    2011-01-01

    Full Text Available OBJETIVO: Investigar os possíveis efeitos da laserterapia com laser diodo 830nm ao se contrapor a ação da nicotina na viabilidade do retalho cutâneo em ratos. MÉTODOS: Foram utilizados 16 ratos Wistar, distribuídos em 2 grupos de 8: Grupo 1- submetido à técnica cirúrgica, para obtenção dos retalhos cutâneos randômicos de base cranial, com injeção subcutânea de nicotina em uma dose de 2mg/Kg/dia, uma semana antes e uma semana após o procedimento cirúrgico e simulação da radiação laser; Grupo 2- similar ao grupo 1, cujos retalhos cutâneos randômicos de base cranial foram submetidos à irradiação do laser imediatamente após a cirurgia e nos 4 dias subsequentes. Após a eutanásia, as áreas de necrose e de tecido viável foram examinadas através do método de pesagem do Gabarito de Papel e pelo método semi-automático de análise de imagens (Mini-Mop®. RESULTADOS: Os resultados foram analisados estatisticamente através do teste ANOVA. Os valores de porcentagem de área de necrose através do método de análise mostraram uma diminuição da área de necrose no grupo 2 onde foi aplicado laser. CONCLUSÃO: O laser 830nm foi eficaz na melhora da viabilidade do retalho cutâneo em ratos submetido à ação da nicotina. Nível de evidência II: Estudos terapêuticos - Investigação dos resultados do tratamento.OBJECTIVE: To investigate the possible effects of laser diode 830nm counter to the action of nicotine on the viability of the skin flap in rats. METHODS: 24 Wistar-albino rats were used, divided into 3 groups of 8: Group 1 - subject to the surgical technique to obtain the random skin flap in cranial base, subcutaneous injection of nicotine of 2mg/Kg/dia a week before and one week after surgery and simulation of laser. Group 2 - similar to group 1, the random skin flap in the cranial base were subjected to laser irradiation immediately after surgery and on thesubsequent 4 days. After euthanasia, areas of necrosis and

  12. New power lasers

    International Nuclear Information System (INIS)

    Yamanaka, Masanobu; Daido, Hiroyuki; Imasaki, Kazuo.

    1989-01-01

    As the new power lasers which are expected to exert large extending effect to the fields of advanced science and technology including precision engineering as well as laser nuclear fusion, LD-excited solid laser, X-ray laser and free electron laser are taken up and outlined. Recently, the solid laser using high power output, high efficiency semiconductor laser as the exciting beam source has been developed. This is called laser diode (LD)-excited solid laser, and the heightening of power output and efficiency and the extension of life are planned. Its present status and application to medical use, laser machining, laser soldering and so on are described. In 1960, the laser in visible region appeared, however in 1985, the result of observing induced emission beam by electron collision exciting method was reported in USA. In the wavelength range of 200 A, holography and contact X-ray microscope applications were verified. The various types of soft X-ray laser and the perspective hereafter are shown. The principle of free electron laser is explained. In the free electron laser, wavelength can be changed by varying electron beam energy, the period of wiggler magnetic field and the intensity of magnetic field. Further, high efficiency and large power output are possible. Its present status, application and the perspective hereafter are reported. (K.I.)

  13. An application of the theory of laser to nitrogen laser pumped dye laser

    International Nuclear Information System (INIS)

    Osman, Fatima Ahmed

    1998-03-01

    In this thesis we gave a general discussion on lasers, reviewing some of their properties, types and application. We also conducted an experiment where we obtained a dye laser pumped by nitrogen laser with a wave length of 337.1 nm and a power of 5 Mw.It was noticed that the produced radiation possesses characteristics different from those of other types of laser. This characteristics determine the tunability i.e the possibility of choosing the appropriately required wave-length of radiation for various applications.(Author)

  14. Laser propulsion for orbit transfer - Laser technology issues

    Science.gov (United States)

    Horvath, J. C.; Frisbee, R. H.

    1985-01-01

    Using reasonable near-term mission traffic models (1991-2000 being the assumed operational time of the system) and the most current unclassified laser and laser thruster information available, it was found that space-based laser propulsion orbit transfer vehicles (OTVs) can outperform the aerobraked chemical OTV over a 10-year life-cycle. The conservative traffic models used resulted in an optimum laser power of about 1 MW per laser. This is significantly lower than the power levels considered in other studies. Trip time was taken into account only to the extent that the system was sized to accomplish the mission schedule.

  15. Fractional resurfacing in the Asian patient: Current state of the art.

    Science.gov (United States)

    Wat, Heidi; Wu, Douglas C; Chan, Henry Hin Lee

    2017-01-01

    Fractionated photothermolysis (FP) has revolutionized modern laser technology. By creating selective columns of microthermal damage, fractionated devices allows for greater treatment depths to be achieved without the prolonged downtime and risk of complications seen in traditional fully ablative laser resurfacing. Fractional resurfacing is a proven method to treat a variety of cutaneous conditions. In the Caucasian patient, a wide range of devices and treatment settings can be utilized safely and effectively. However, ethnic skin requires special consideration due to its unique pigmentary characteristics and clinical presentations. In this review article, we detail the current indications and strategies to optimize results and mitigate complications when utilizing fractional resurfacing for the Asian patient. A review of the MEDLINE English literature was conducted on fractionated laser devices studied in the Asian population. Articles included describe non-ablative devices including fractionated erbium glass, thulium fiber, diode, and radiofrequency devices; and ablative devices including fractionated carbon dioxide (CO 2 ) laser, erbium yttrium aluminum garnet and yttrium scandium gallium garnet (YSGG) laser. These data were integrated with the expert opinion of the authors. Taking into account the unique characteristics and cosmetic concerns of the Asian population, fractional resurfacing can be considered a safe and effective option for the treatment of atrophic and hypertrophic scarring, and photorejuvenation in ethnic skin types. Select cases of melasma may be treated with fractionated non-ablative devices, but utilized with caution. The predominant complication associated with fractional resurfacing for these conditions is post-inflammatory hyperpigmentation (PIH) and rebound worsening of melasma. A greater number of treatments at lower density settings and wider treatment intervals typically produce the lowest risks of PIH without compromising treatment

  16. Efficiencies of laser dyes for atomic vapor laser isotope separation

    International Nuclear Information System (INIS)

    Maeda, Mitsuo; Oki, Yuji; Uchiumi, Michihiro; Takao, Takayuki; Igarashi, Kaoru; Shimamoto, Kojiro.

    1995-01-01

    Efficiencies of 30 laser dyes for the atomic vapor laser isotope separation (AVLIS) are experimentally evaluated with a dye laser pumped by a frequency-doubled Nd:YAG laser. On the other hand, a simulation code is developed to describe the laser action of Rhodamine 6G, and the dependence of the laser efficiency on the pump wavelength is calculated. Following conclusions are obtained by these considerations:space: 1) Pyrromethene 567 showed 16% higher laser efficiency than Rhodamine 6G by 532 nm pumping, and Pyrromethene 556 has an ability to provide better efficiency by green light pumping with a Cu vapor laser; 2) Kiton red 620 and Rhodamine 640, whose efficiencies were almost the same as Rhodamine 6G by 532 nm pumping, will show better efficiencies by two-wavelength pumping with a Cu vapor laser. (author)

  17. A VISUALIDADE URBANA CONTEMPORÂNEA COMO CAMPO DE ESTUDOS INTERDISCIPLINARES

    Directory of Open Access Journals (Sweden)

    Francisco Antônio Zorzo

    2017-02-01

    Full Text Available O artigo traz uma discussão sobre o estudo da visualidade urbana segundo uma abordagem interdisciplinar. Segundo a proposta aqui indicada, parece útil entender os fenômenos urbanos sob um outro olhar. Torna-se muito conveniente considerar a interação entre tecnologia, arte e ciência na constituição dos estudos sobre o ambiente urbano e sobre a produção da imagen. Tendo em mente tal concepção, pode-se partir de uma referência mais concreta para estudar a cidade e a visualidade, como um campo de múltiplas produções em abordagem interdisciplinar. Para isso foi selecionada a produção do grafite nas metrópoles brasileiras. Nos muros de Salvador há uma série de grafites que merecem a reflexão e um acolhimento crítico por tratarem exatamente de problematizar o olho e o olhar no ambiente da cidade.

  18. Clinical evaluation of the immediate effectiveness of GaAIAs laser on the therapy of dentin hypersensitivity Avaliação clínica da eficácia imediata do laser de GaAIAs na terapia da sensibilidade dentinária

    Directory of Open Access Journals (Sweden)

    Márcia Sepúlveda Noya

    2004-12-01

    Full Text Available The aim of the present study was to determine the effectiveness of GaAlAs laser therapy with lambda670nm laser on the treatment of dentin hypersensitivity. Thirty-two intact human teeth were evaluated, the sensitivity of which to thermal (cold water, mechanical (probe and evaporative (air stimuli was recorded before and immediately after irradiation. Whenever desensitization was not observed after the first application, the patient was scheduled for a maximum of three further applications at 4-day intervals. The results demonstrated that laser therapy yielded a statistically significant reduction (pO objetivo deste trabalho foi realizar um estudo clinico para avaliar a eficácia da laserterapia com laser de lambda670nm no tratamento da sensibilidade dentinária. Foram avaliados 32 dentes íntegros cuja sensibilidade a estímulo térmico, tátil e evaporativo foi registrada antes e após irradiação. Quando não era evidenciada dessensibilização após a primeira sessão de irradiação, o paciente era agendado para novas aplicações, máximo de três sessões, sempre com intervalos de quatro dias. De acordo com os resultados a laserterapia promoveu uma redução estatisticamente significante (p< 0,05 da sensibilidade dentinária para os três estímulos analisados. De acordo com os resultados obtidos com a utilização do laser de GaAlAs foi necessária apenas uma sessão terapêutica para os estímulos sonda e térmico, embora tenham sido necessárias duas sessões para conseguir-se redução da sensibilidade ao estímulo evaporativo.

  19. Laser frequency modulator for modulating a laser cavity

    Science.gov (United States)

    Erbert, Gaylen V.

    1992-01-01

    The present invention relates to a laser frequency modulator for modulating a laser cavity. It is known in the prior art to utilize a PZT (piezoelectric transducer) element in combination with a mirror to change the cavity length of a laser cavity (which changes the laser frequency). Using a PZT element to drive the mirror directly is adequate at frequencies below 10 kHz. However, in high frequency applications (100 kHz and higher) PZT elements alone do not provide a sufficient change in the cavity length. The present invention utilizes an ultrasonic concentrator with a PZT element and mirror to provide modulation of the laser cavity. With an ultrasonic concentrator, the mirror element at the end of a laser cavity can move at larger amplitudes and higher frequencies.

  20. Laserterapia de baixa intensidade na expressão de colágeno após lesão muscular cirúrgica Low-level laser therapy in the expression of collagen after muscular surgical injury

    Directory of Open Access Journals (Sweden)

    Flávia Fonseca Moreira

    2011-03-01

    Full Text Available A laserterapia é um procedimento utilizado em larga escala nas lesões musculoesqueléticas, devido as suas diversas propriedades, antiinflamatórias, cicatrizantes entre outras. Além disso, há tipos distintos de aparelhos de laser. Mesmo com os diversos modelos experimentais existentes na literatura, não há um consenso sobre a faixa de utilização, bem como o tipo de laser que promove melhor reparo no tecido muscular. Este estudo visa analisar os efeitos da laserterapia de baixa intensidade na expressão de colágeno após lesão muscular. Camundongos Swiss albinos (n=18 foram submetidos à lesão muscular cirúrgica e divididos em dois grupos, controle (C e teste (T. Os animais foram submetidos a uma irradiação diária de 5 J/cm² pelos lasers AsGaAl 830 nm e AsGa 904 nm e, em diferentes tempos de sacrifício (7 e 14 dias. Os resultados não demonstraram diferença estatística significativa na expressão de colágeno em ambos os grupos analisados. Contudo, os dados apontam que a dose de 5 J/cm² do laser AsGa 904 nm promoveu maior deposição de fibras colágenas após 14 dias de tratamento, sugerindo que a terapia seja efetiva na síntese de colágeno. Outros estudos experimentais, em humanos, devem ser propostos para maiores inferências sobre os resultados do laser no tratamento da lesão muscular.The laser therapy is a procedure utilized at long scale in the musculoskeletal injuries, due its anti-inflammatory and reparatory proprieties and others. Besides, there are differents types of laser equipments. Despites with the many experimental models at literature, there is no consensus about the range of application as well as the type of laser that promove of the best repair in muscular tissue. The aim of this study is to analyze the effects of the low level laser therapy in the expression of collagen after muscular injury. Mice Swiss albinos (n=18 were subjected to the muscular surgical injury and separated in two groups, control (C

  1. Prevalência dos sintomas otológicos na desordem temperomandibular: estudo de 126 casos

    OpenAIRE

    Pascoal Maria I. N.; Rapoport Abrão; Chagas José F. S.; Pascoal Maria B.N.; Costa Claudiney C.; Magna Luis Antonio

    2001-01-01

    Introdução: A presença de sintomas otológicos associados à desordem temporomandibular (DTM) é discutida há seis décadas; entretanto, sua etiologia ainda permanece obscura. Forma de estudo: Prospectivo clínico randomizado. Objetivo: Neste estudo foram avaliadas a prevalência de sintomas otológicos na DTM, sua correlação com a dor muscular e a ausência de dentes posteriores. Material e Método: Foram avaliados 126 pacientes portadores de DTM, através de questionário subjetivo dos sintomas, palpa...

  2. Estudo da sintomatologia depressiva e ansiosa em crianças com e sem obesidade

    OpenAIRE

    Morgado, Joana Alexandra da Silva

    2013-01-01

    A obesidade infantil constitui um problema de saúde pública, o que motivou a sua classificação pela WHO como “epidemia do seculo XXI”. Como se não bastasse, surge sempre associada ao aumento quer da mortalidade, quer da morbilidade. Este estudo procura perceber em que medida as crianças com obesidade infantil diferem das crianças sem obesidade em termos de sintomatologia depressiva e ansiosa. O desenho do estudo é de natureza transversal e comparativa. A amostra é composta por 85 crianças, co...

  3. Psicoterapia de grupo de criança : aspectos clinicos de um estudo de caso

    OpenAIRE

    Regina Celia Ciriano Calil

    2001-01-01

    Resumo: Essa tese de doutorado tem o objetivo de efetuar um estudo de caso referente ao atendimento de um grupo de psicoterapia realizado com crianças em idade escolar, no contexto institucional do Ambulatório de Saúde Mental Infantil do Hospital das Clínicas da Unicamp. Para o atendimento do grupo estudado, utilizou-se a técnica de psicoterapia infantil de abordagem psicodinâmica, adaptada à condição de trabalho grupal e às circunstâncias institucionais. Nesse estudo de caso, foram analisad...

  4. Revista Estudos Feministas Is Ten Years Old - A Brief History of Feminism in Brazil

    Directory of Open Access Journals (Sweden)

    Mirian Pillar Grossi

    2004-01-01

    Full Text Available This article is a report on the activities of Revista Estudos Feministas during its first phase at UFSC (1999-2002. It is divided into three parts: the first presents a brief review of literature about feminism and gender studies in Brazil; the second covers the move of Estudos Feministas from Rio de Janeiro to Santa Catarina, and the third presents some considerations on the role of this periodical in relation to the movement and to the field of gender, feminist and women’s studies in Brazil.

  5. Clinical effect of ablative fractional laser-assisted topical anesthesia on human skin%点阵Er:YAG激光辅助外用麻醉药物传输的临床观察

    Institute of Scientific and Technical Information of China (English)

    罗瑶佳; 吴严; 高兴华; 何春涤; 陈洪铎; 李远宏

    2011-01-01

    Objective Most topically used medications need a long time to be absorbed into the skin owing to the stratum corneum(SC) barrier. The fractional Erbium:yttrium-aluminum-garnet (Er:YAG) laser,creating vertical channels to disrupt the SC,might assist the delivery of topically applied drug to penetrate into the skin. This study was intended to determine whether pretreatment with fractional Er:YAG laser could assist transdermal delivery of topical anesthesia. Methods Thirty-one subjects were enrolled in this study. Three neighboring 4cm×3cm regions were marked on their left forearm with the interference of Er:YAG laser plus topical anesthesia (laser +anesthesia +pain stimuli), anesthesia control (anesthesia + pain stimuli) and blank control (moisture + pain stimuli) respectively. Then each region was treated with YSGG laser to evaluate the pain sensation using the visual analogue scale (VAS) as a way to scale the transdermal absorption of topical anesthesia. Results The pain scores for Er:YAG laser plus topical anesthesia, anesthesia control and blank control regions are 2.84±0.66, 3.91 ±0.79 and 4.59±0.87 respectively. The pain score for Er:YAG laser plus topical anesthesia region is significantly lower than the anesthesia control (P=0.042) and blank control (P=0.003). Conclusion This proved the laser assistance of transdermal absorption for topical anesthesia medication.%目的:由于角质层的屏障作用,外用药物很难经皮吸收.铒:钇铝石榴石(Er:YAG)点阵激光通过点状剥脱的模式穿透角质层,破坏了角质层的完整性,可以加速外用药物经皮吸收的速度.本实验旨在验证外用表面麻醉药之前用点阵Er:YAG激光破坏角质层,可以促进表面麻醉药的吸收速度.方法:在31名受试者的左前臂上划出三块相邻的4cm×3cm区域,分别予以Er:YAG激光加表面麻醉药("点阵+麻药+疼痛"),

  6. Revisão da Maytenus ilicifolia Mart. ex Reissek, Celastraceae. Contribuição ao estudo das propriedades farmacológicas

    Directory of Open Access Journals (Sweden)

    Ralph Santos-Oliveira

    Full Text Available A Maytenus ilicifolia Mart. ex Reissek, Celastraceae, vem sendo utilizada à muitos anos na terapêutica clínica, contudo suas propriedades farmacológicas continuam sob estudo. O objetivo desse trabalho é fornecer subsídios teóricos para o aprimoramento dos estudos, em especial os estudos clínicos, e assim estabelecer definitivamente as propriedades reais da Maytenus ilicifolia.

  7. A propósito da “síntese brasileira” nos estudos de gêneros

    Directory of Open Access Journals (Sweden)

    Benedito Gomes Bezerra

    2016-03-01

    Full Text Available Em publicações recentes, pesquisadores estrangeiros têm mencionado a existência de uma “síntese brasileira” nos estudos de gêneros (textuais/discursivos, a qual teria sido impulsionada pelos Parâmetros Curriculares Nacionais (PCN e pelo Simpósio Internacional de Estudos de Gêneros Textuais (SIGET, configurando-se como um modelo teórico alternativo, uma quarta ou quinta grande tendência mundial de estudos de gêneros, capaz de conciliar abordagens linguísticas, retóricas, sociológicas e pedagógicas. O aludido modelo brasileiro encontraria suas bases teóricas e metodológicas na Escola de Genebra e no interacionismo sociodiscursivo. Este trabalho tem como objetivo discutir o estatuto da “síntese brasileira” conforme defendida principalmente por Bawarshi e Reiff ([2010] 2013, mas também por Swales (2012, a partir de um levantamento panorâmico das abordagens teóricas correntes no país, incluindo uma discussão das principais influências que marcam a pesquisa brasileira no campo dos gêneros. Para isso, uma atenção especial é dedicada a estudos que buscam mapear abordagens teóricas, bem como combinações entre abordagens, nos trabalhos de pesquisadores brasileiros, além de se realizar um exame crítico de publicações que contribuíram para a divulgação dos estudos brasileiros de gêneros no exterior e fundamentaram a hipótese da síntese. Os resultados indicam a existência de uma significativa complexidade e ecletismo nas abordagens de gêneros por autores brasileiros, ao lado da adesão a perspectivas específicas e diferenciadas, o que problematiza em muito a possibilidade de uma síntese entendida como uma perspectiva única e unificada.

  8. Estudo de vocábulos para avaliação de crianças com deficiência sem linguagem oral

    Directory of Open Access Journals (Sweden)

    Andréa Carla Paura

    2014-03-01

    Full Text Available Pesquisadores da área de comunicação suplementar e alternativa consideram a falta de instrumentos para avaliar crianças e jovens com necessidade complexa de comunicação. Este trabalho objetivou selecionar vocábulos para um instrumento de avaliação do repertório de vocabulário de crianças não-oralizadas com idade de dois a 11 anos e 11 meses. Para a seleção dos vocábulos foram realizados três estudos. O primeiro estudo identificou e descreveu instrumentos disponíveis para avaliação do vocabulário receptivo e suas listas de vocábulos. O segundo estudo identificou e descreveu pesquisas que apresentaram inventários ou listas de vocábulos empregados por crianças e seus parceiros de comunicação. O terceiro estudo identificou o vocabulário relatado por pais e professores. Os vocábulos identificados nos três estudos foram analisados de acordo com: o número de ocorrência dos vocábulos; a classificação do sistema Picture Communication Symbols e uma classificação semântica e sintática. A partir dos estudos foram estabelecidos como critérios para a seleção dos vocábulos: os 45 vocábulos presentes nos três estudos; os vocábulos que tiveram ocorrência maior ou igual a cinco, considerando os três estudos, representando 167 (14,14% vocábulos; os vocábulos que estiveram presentes no estudo 1 ou 2, mas que foram citados pelas famílias, 183 (19,37% de 945 vocábulos ou pelas professoras 108 (11,43% de 945 vocábulos. A lista de vocábulos apresentou 269 itens, classificadas em 18 temas semânticos e sintático e representa um instrumento inicial para profissionais da saúde e educação estabelecerem metas para a avaliação inicial de crianças e jovens usuários de sistemas de comunicação suplementar e alternativa.

  9. Estudos sobre a toxicologia da ε-caprolactama

    Directory of Open Access Journals (Sweden)

    Marcus Vinicius Justo Bomfim

    2009-03-01

    Full Text Available A ε-caprolactama (CAP é um monômero precursor de polímeros denominados nylon 6. Esses polímeros destinam-se à produção de tapetes, vestuário e materiais plásticos tais como equipamentos, sistemas e componentes automotivos, conectores, além de embalagens plásticas. Resíduos de CAP podem migrar de embalagens plásticas de nylon 6 para os alimentos. Diante disso, foi de interesse realizar uma revisão dos efeitos relativos à exposição à CAP e o seu impacto sobre a saúde humana. Estudos epidemiológicos indicam a possibilidade da CAP causar inflamações oculares e cutâneas, além de irritações no sistema respiratório. Pode ocorrer ainda hipotensão, taquicardia, palpitações, rinorréia, ressecamento nasal, efeitos geniturinários e sobre a reprodução como distúrbios nas funções menstrual e ovariana, e complicações no parto; além de problemas neurológicos e hematológicos. Estudos com animais são consistentes com tais relatos. Os estudos de genotoxicidade in vitro e in vivo por via oral e intraperitoneal mostram em sua grande maioria, resultados negativos, bem como ausência de efeitos carcinogênicos em ratos e camundongos e sobre o desenvolvimento e reprodução em ratos e coelhos.ε -Caprolactam (CAP is a precursor monomer of nylon 6 polymers. Nylon 6 is used in the manufacture of carpets, clothes and plastic materials, such as equipment, systems and automotive components, connectors and plastic packaging. CAP residues can migrate from nylon 6 plastic packaging to foods. Given this fact, this review was realized concerning the effects of CAP exposure and its impact on human health. Epidemiological studies indicate that CAP could cause ocular, cutaneous and respiratory irritations, as well as hypotension, tachycardia, palpitations, rhinorrhea, nose dryness, neurological and blood problems, and genitourinary and reproductive effects, such as alterations in ovarian-menstrual functions and pregnancy

  10. Laser Technology.

    Science.gov (United States)

    Gauger, Robert

    1993-01-01

    Describes lasers and indicates that learning about laser technology and creating laser technology activities are among the teacher enhancement processes needed to strengthen technology education. (JOW)

  11. O estudo da cultura organizacional por meio das práticas: uma proposta à luz do legado de Bourdieu

    OpenAIRE

    Souza, Eda Castro Lucas de; Fenili, Renato Ribeiro

    2016-01-01

    Resumo O objetivo deste artigo é propor o estudo da cultura organizacional por meio das práticas de gestão, à luz do quadro teórico de Bourdieu. Para tanto, apresenta-se como objetivo secundário analisar o estado da arte dos estudos organizacionais que empregam esse quadro teórico. Inicialmente, é apresentada uma categorização das tendências predominantes no estudo da cultura e discorre-se sobre esse conceito, salientando sua abordagem como diretamente relacionada às práticas. O foco do estud...

  12. RELAÇÕES DE GÊNERO NO COMPORTAMENTO DE COMPRA PELA INTERNET: ESTUDO DAS DIMENSÕES DO RISCO PERCEBIDO

    OpenAIRE

    Carvalho, Juliana Del Secchi Dias de; Silva, Wesley Vieira da; Del Corso, Jansen Maia; Tortato, Ubiratã

    2012-01-01

    O risco percebido é considerado como um dos grandes entraves para o crescimento da Internet como canal de compras. A inovação que este artigo propõe para os estudos desta temática é a avaliação do risco percebido nas compras pela Internet sob uma perspectiva de gênero, motivada por estudos precedentes que revelaram uma significativa maior adesão a este comércio por parte dos homens, que seriam também mais propensos a assumir riscos. Para tanto, foi realizado uma estudo quantitativo, com corte...

  13. ND:GLASS LASER DESIGN FOR LASER ICF FISSION ENERGY (LIFE)

    Energy Technology Data Exchange (ETDEWEB)

    Caird, J A; Agrawal, V; Bayramian, A; Beach, R; Britten, J; Chen, D; Cross, R; Ebbers, C; Erlandson, A; Feit, M; Freitas, B; Ghosh, C; Haefner, C; Homoelle, D; Ladran, T; Latkowski, J; Molander, W; Murray, J; Rubenchik, S; Schaffers, K; Siders, C W; Stappaerts, E; Sutton, S; Telford, S; Trenholme, J; Barty, C J

    2008-10-28

    We have developed preliminary conceptual laser system designs for the Laser ICF (Inertial Confinement Fusion) Fission Energy (LIFE) application. Our approach leverages experience in high-energy Nd:glass laser technology developed for the National Ignition Facility (NIF), along with high-energy-class diode-pumped solid-state laser (HEC-DPSSL) technology developed for the DOE's High Average Power Laser (HAPL) Program and embodied in LLNL's Mercury laser system. We present laser system designs suitable for both indirect-drive, hot spot ignition and indirect-drive, fast ignition targets. Main amplifiers for both systems use laser-diode-pumped Nd:glass slabs oriented at Brewster's angle, as in NIF, but the slabs are much thinner to allow for cooling by high-velocity helium gas as in the Mercury laser system. We also describe a plan to mass-produce pump-diode lasers to bring diode costs down to the order of $0.01 per Watt of peak output power, as needed to make the LIFE application economically attractive.

  14. Estado nutricional de pré-escolares de creche pública: um estudo longitudinal

    OpenAIRE

    Pereira,Alessandra da Silva; Peixoto,Natasha Gabrielle de Araújo; Nogueira Neto,José Firmino; Lanzillotti,Haydée Serrão; Soares,Eliane de Abreu

    2013-01-01

    O objetivo do estudo foi monitorar o estado nutricional de pré-escolares de uma creche pública. Trata-se de um estudo longitudinal, antes (t0) e depois (t1), com 51 crianças de 2 a 4 anos de idade. Os procedimentos foram: avaliação antropométrica (P/I, P/E e E/I - OMS 2006, classificação SISVAN-2008); avaliação bioquímica (colesterol total, HDLc, LDLc, triglicerídeos e glicose); avaliação hematológica (hemoglobina); avaliação dietética (pesagem direta dos alimentos e registro alimentar). Para...

  15. The influence of laser-particle interaction in laser induced breakdown spectroscopy and laser ablation inductively coupled plasma spectrometry

    International Nuclear Information System (INIS)

    Lindner, Helmut; Loper, Kristofer H.; Hahn, David W.; Niemax, Kay

    2011-01-01

    Particles produced by previous laser shots may have significant influence on the analytical signal in laser-induced breakdown spectroscopy (LIBS) and laser ablation inductively coupled plasma (LA-ICP) spectrometry if they remain close to the position of laser sampling. The effects of these particles on the laser-induced breakdown event are demonstrated in several ways. LIBS-experiments were conducted in an ablation cell at atmospheric conditions in argon or air applying a dual-pulse arrangement with orthogonal pre-pulse, i.e., plasma breakdown in a gas generated by a focussed laser beam parallel and close to the sample surface followed by a delayed crossing laser pulse in orthogonal direction which actually ablates material from the sample and produces the LIBS plasma. The optical emission of the LIBS plasma as well as the absorption of the pre-pulse laser was measured. In the presence of particles in the focus of the pre-pulse laser, the plasma breakdown is affected and more energy of the pre-pulse laser is absorbed than without particles. As a result, the analyte line emission from the LIBS plasma of the second laser is enhanced. It is assumed that the enhancement is not only due to an increase of mass ablated by the second laser but also to better atomization and excitation conditions favored by a reduced gas density in the pre-pulse plasma. Higher laser pulse frequencies increase the probability of particle-laser interaction and, therefore, reduce the shot-to-shot line intensity variation as compared to lower particle loadings in the cell. Additional experiments using an aerosol chamber were performed to further quantify the laser absorption by the plasma in dependence on time both with and without the presence of particles. The overall implication of laser-particle interactions for LIBS and LA-ICP-MS/OES are discussed.

  16. The influence of laser-particle interaction in laser induced breakdown spectroscopy and laser ablation inductively coupled plasma spectrometry

    Science.gov (United States)

    Lindner, Helmut; Loper, Kristofer H.; Hahn, David W.; Niemax, Kay

    2011-02-01

    Particles produced by previous laser shots may have significant influence on the analytical signal in laser-induced breakdown spectroscopy (LIBS) and laser ablation inductively coupled plasma (LA-ICP) spectrometry if they remain close to the position of laser sampling. The effects of these particles on the laser-induced breakdown event are demonstrated in several ways. LIBS-experiments were conducted in an ablation cell at atmospheric conditions in argon or air applying a dual-pulse arrangement with orthogonal pre-pulse, i.e., plasma breakdown in a gas generated by a focussed laser beam parallel and close to the sample surface followed by a delayed crossing laser pulse in orthogonal direction which actually ablates material from the sample and produces the LIBS plasma. The optical emission of the LIBS plasma as well as the absorption of the pre-pulse laser was measured. In the presence of particles in the focus of the pre-pulse laser, the plasma breakdown is affected and more energy of the pre-pulse laser is absorbed than without particles. As a result, the analyte line emission from the LIBS plasma of the second laser is enhanced. It is assumed that the enhancement is not only due to an increase of mass ablated by the second laser but also to better atomization and excitation conditions favored by a reduced gas density in the pre-pulse plasma. Higher laser pulse frequencies increase the probability of particle-laser interaction and, therefore, reduce the shot-to-shot line intensity variation as compared to lower particle loadings in the cell. Additional experiments using an aerosol chamber were performed to further quantify the laser absorption by the plasma in dependence on time both with and without the presence of particles. The overall implication of laser-particle interactions for LIBS and LA-ICP-MS/OES are discussed.

  17. Excimer Laser Technology

    CERN Document Server

    Basting, Dirk

    2005-01-01

    This comprehensive survey on Excimer Lasers investigates the current range of the technology, applications and devices of this commonly used laser source, as well as the future of new technologies, such as F2 laser technology. Additional chapters on optics, devices and laser systems complete this compact handbook. A must read for laser technology students, process application researchers, engineers or anyone interested in excimer laser technology. An effective and understandable introduction to the current and future status of excimer laser technology.

  18. Laser systems for on-line laser ion sources

    International Nuclear Information System (INIS)

    Geppert, Christopher

    2008-01-01

    Since its initiation in the middle of the 1980s, the resonant ionization laser ion source has been established as a reliable and efficient on-line ion source for radioactive ion beams. In comparison to other on-line ion sources it comprises the advantages of high versatility for the elements to be ionized and of high selectivity and purity for the ion beam generated by resonant laser radiation. Dye laser systems have been the predominant and pioneering working horses for laser ion source applications up to recently, but the development of all-solid-state titanium:sapphire laser systems has nowadays initiated a significant evolution within this field. In this paper an overview of the ongoing developments will be given, which have contributed to the establishment of a number of new laser ion source facilities worldwide during the last five years.

  19. APLICAÇÃO DA FERRAMENTA FMEA: ESTUDO DE CASO EM UMA EMPRESA DO SETOR DE

    Directory of Open Access Journals (Sweden)

    Leandro Cantorski da Rosa

    2007-06-01

    Full Text Available Este trabalho apresenta um estudo de caso em que se implantou a ferramenta Failure Modes and Effects Analysis (FMEA emuma empresa atuante no segmento de transporte terrestre e aéreo de passageiros e cargas. O objetivo deste estudo de caso foideterminar, com a ferramenta FMEA, ações que minimizem ou eliminem modos de falha em potencial em um dos desdobramentos deserviços prestados pela empresa. O ponto específico onde se implantou a ferramenta foi na gestão dos pneus dos veículos de transporteterrestre de passageiros, pois falhas relacionadas a este componente aumentam os custos de manutenção da empresa e tendem a gerarinsatisfações aos clientes. Também foram utilizadas, incorporadas à ferramenta FMEA, outras ferramentas da qualidade como oBrainstorming, Diagrama de Ishikawa e Gráfico de Pareto. Os resultados do trabalho foram alcançados ao se determinar ações quetrazem consigo o objetivo principal deste estudo, isto é, o aumento de confiabilidade e qualidade do serviço prestado. Deste modo, arealização do presente estudo de caso proporcionou um maior entendimento acerca da temática proposta, além de mostrar aimportância da gestão da qualidade nos dias atuais e frente as crescentes exigências dos clientes.

  20. Auditoria interna de sistema de gestão ambiental: estudo de caso no Verdegreen Hotel

    Directory of Open Access Journals (Sweden)

    Adriano Lucena da Silva

    2017-06-01

    Full Text Available Esta pesquisa analisa as contribuições e os desafios associados às auditorias internas no Verdegreen Hotel, empreendimento hoteleiro de grande destaque na cidade de João Pessoa-PB, selecionado como unidade de estudo por dispor de um Sistema de Gestão Ambiental (SGA ISO 14001 implantado e certificado. Este estudo trata de uma pesquisa descritiva, baseada em um estudo de caso qualitativo. As técnicas utilizadas na metodologia foram: levantamento bibliográfico sobre as normas ISO que abordam as temáticas SGA e auditoria; questionários aplicados aos membros do comitê verde; e análise documental do manual do SGA. Para este estudo, três categorias foram selecionadas: i instrumentos, ii procedimentos e iii recursos humanos. A partir da análise de conteúdo das respostas dos questionários aplicados e do manual do SGA, foi constatado que as auditorias internas do Verdegreen Hotel ocorrem baseadas em métodos bem definidos de coleta e tratamento de informações e que o hotel mantém programas de capacitação para seus colaboradores. Com base nos resultados da pesquisa, tornou-se possível compreender como as questões relacionadas à aplicação da auditoria interna são oportunidades de aprimoramento do SGA implantado.

  1. Estudo da microcirculação na hanseníase virchowiana com o uso da microscopia de luz ortogonal polarizada e com laser-doppler fluxometria

    OpenAIRE

    Curt Mafra Treu

    2010-01-01

    A hanseníase é uma doença infecciosa com características únicas, dentre elas o fato de atingir intensamente a inervação da pele e seus anexos. Entremeando estes anexos, está a microcirculação cutânea, que a principio também tem sua inervação comprometida. Vários artigos apontam para alterações de disautonomia microcirculatória, citando como exemplo as alterações no reflexo vasomotor. O presente estudo se propõe a avaliar a microcirculação cutânea na hanseníase virchowiana, tanto em sua morfol...

  2. Histologic evaluation of laser lipolysis: pulsed 1064-nm Nd:YAG laser versus cw 980-nm diode laser.

    Science.gov (United States)

    Mordon, Serge; Eymard-Maurin, Anne Françoise; Wassmer, Benjamin; Ringot, Jean

    2007-01-01

    The use of the laser as an auxiliary tool has refined the traditional technique for lipoplasty. During laser lipolysis, the interaction between the laser and the fat produced direct cellular destruction before the suction, reduced bleeding, and promoted skin tightening. This study sought to perform a comparative histologic evaluation of laser lipolysis with the pulsed 1064-nm Nd:YAG laser versus a continuous 980-nm diode laser. A pulsed 1064-nm Nd:YAG (Smart-Lipo; Deka, Italy) and a CW 980-nm diode laser (Pharaon, Osyris, France) were evaluated at different energy settings for lipolysis on the thighs of a fresh cadaver. The lasers were coupled to a 600-microm optical fiber inserted in a 1-mm diameter cannula. Biopsy specimens were taken on irradiated and non-irradiated areas. Hematoxylin-erythrosin-safran staining and immunostaining (anti-PS100 polyclonal antibody) were performed to identify fat tissue damage. In the absence of laser exposures (control specimens), cavities created by cannulation were seen; adipocytes were round in appearance and not deflated. At low energy settings, tumescent adipocytes were observed. At higher energy settings, cytoplasmic retraction, disruption of membranes, and heat-coagulated collagen fibers were noted; coagulated blood cells were also present. For the highest energy settings, carbonization of fat tissue involving fibers and membranes was clearly seen. For equivalent energy settings, 1064-nm and 980-nm wavelengths gave similar histologic results. Laser lipolysis is a relatively new technique that is still under development. Our histologic findings suggest several positive benefits of the laser, including skin retraction and a reduction in intraoperative bleeding. The interaction of the laser with the tissue is similar at 980 nm and 1064 nm with the same energy settings. Because higher volumes of fat are removed with higher total energy, a high-power 980-nm diode laser could offer an interesting alternative to the 1064-nm Nd

  3. An in vitro study of the Nd-YAG laser in the permeability of the cervical dentin; Estudo in vitro do uso do laser Nd-YAG na permeabilidade dentinaria cervical

    Energy Technology Data Exchange (ETDEWEB)

    Magalhaes, Manoelita Figueiredo de

    2001-07-01

    The purpose of this in vitro study was to verify the efficacy of the Nd:YAG pulse laser, with 1064 nm emission, in sealing the dentinal tubules for the treatment of dentin hypersensitivity, a very frequent complaint in the dental office. In spite of the existence of many articles over this subject, no fast, efficient and long lasting treatments for this problem were found yet. The obliteration of the opening of the dentinal tubules stops its inner fluid displacement and the consequent painful response (BRAENNSTROEM' S Hydrodynamics Theory). Twenty freshly and healthy extracted human teeth were used as samples, kept in saline solution. The cervical cement was removed with a 57FG Carbide bur in order to expose the dentin in an area of approximately 4 mm{sup 2}, two of which were in the buccal aspect: Groups A and S, and one in the lingual: Group C (control). A thickness plier was used to measure, directly in each sample, the thickness of the remaining dentin that was standardized, and only the samples with dentinal thickness between 1 and 1,5 mm were selected. The irradiation parameters were: 30 mJ energy per pulse; O,21 W power (Group A) and 40 mJ; O,28 W (Group B); 7 Hz frequency in both groups, in two applications of 43 seconds each with a 10 seconds interval between them. Subsequently, 10 of the samples were submitted to SEM (Screening Electronic Microscopy) examination, where it was detected a melting of the superficial dentin and a sealing of the dentinal tubules opening, besides the recrystallization of the dentin. It was then concluded that the use of the Nd:YAG laser was shown to be a very effective measure in melting and sealing the dentinal tubules and can use in treating dentin hypersensitivity, with the right parameters. The other 10 samples were cleaved in the center of the irradiated area in order to investigate the laser penetration depth in the dentin (SEM), with an approximate variation of up to 5Jlm in the center of the samples irradiated with

  4. An in vitro study of the Nd-YAG laser in the permeability of the cervical dentin; Estudo in vitro do uso do laser Nd-YAG na permeabilidade dentinaria cervical

    Energy Technology Data Exchange (ETDEWEB)

    Magalhaes, Manoelita Figueiredo de

    2001-07-01

    The purpose of this in vitro study was to verify the efficacy of the Nd:YAG pulse laser, with 1064 nm emission, in sealing the dentinal tubules for the treatment of dentin hypersensitivity, a very frequent complaint in the dental office. In spite of the existence of many articles over this subject, no fast, efficient and long lasting treatments for this problem were found yet. The obliteration of the opening of the dentinal tubules stops its inner fluid displacement and the consequent painful response (BRAENNSTROEM' S Hydrodynamics Theory). Twenty freshly and healthy extracted human teeth were used as samples, kept in saline solution. The cervical cement was removed with a 57FG Carbide bur in order to expose the dentin in an area of approximately 4 mm{sup 2}, two of which were in the buccal aspect: Groups A and S, and one in the lingual: Group C (control). A thickness plier was used to measure, directly in each sample, the thickness of the remaining dentin that was standardized, and only the samples with dentinal thickness between 1 and 1,5 mm were selected. The irradiation parameters were: 30 mJ energy per pulse; O,21 W power (Group A) and 40 mJ; O,28 W (Group B); 7 Hz frequency in both groups, in two applications of 43 seconds each with a 10 seconds interval between them. Subsequently, 10 of the samples were submitted to SEM (Screening Electronic Microscopy) examination, where it was detected a melting of the superficial dentin and a sealing of the dentinal tubules opening, besides the recrystallization of the dentin. It was then concluded that the use of the Nd:YAG laser was shown to be a very effective measure in melting and sealing the dentinal tubules and can use in treating dentin hypersensitivity, with the right parameters. The other 10 samples were cleaved in the center of the irradiated area in order to investigate the laser penetration depth in the dentin (SEM), with an approximate variation of up to 5Jlm in the center of the samples irradiated with the

  5. Tapered diode laser pumped 946 nm Nd:YAG laser

    DEFF Research Database (Denmark)

    Cheng, Haynes Pak Hay; Jensen, Ole Bjarlin; Petersen, Paul Michael

    2009-01-01

    We successfully implemented a 946 nm Nd:YAG laser based on a 808 nm tapered diode pump laser. The tapered diode is developed at the Ferdinand-Braun-Institute fur Hochstfrequenztechnik in Germany. Figure 2 shows the experimental setup and results of each pump source coupled into a 1.5 mm crystal...... laser, we show that tapered diode laser pumping potentially increase the power of 946 nm lasers by a factor of two and reduce the threshold by a factor of three....

  6. Bone repair of the periapical lesions treated or not with low intensity laser ({lambda} = 904 nm).(An X-ray study in human); Reparacao ossea de lesoes perirradiculares tratadas ou nao com lasers em baixa intensidade ({lambda}=904 nm). Estudo radiografico em humanos

    Energy Technology Data Exchange (ETDEWEB)

    Sousa, Gerdal Roberto de

    2001-07-01

    The purpose of this study was to evaluate the influence of low intensity laser on the bone repair over periapical lesions of dental elements. Fifteen patients with a total of eighteen periapical lesions were selected and divided into two groups. Lesions of the control group were submitted to endodontic treatment and/or periapical surgery and the lesions of the experimental laser group, were submitted to the same procedures of the first group but also irradiated by low intensity laser. It was used a 904 nm wavelength laser GaAs, employing 11 mW of power delivered by a fiber optic system, irradiation continuos and contact mode, using a fluency of 9 J/cm{sup 2}. The mentioned treatment was repeated for 10 sessions with intervals of 72 hours between each session. Bone repair was evaluated through lesion measurements, which were accessed from the X ray pictures using a time and then, were also statistically analyzed. Results showed a significant difference between lased and control groups (p<0,10), emphasizing that for the laser group presented a significant reduction of the lesions area, confirmed by X ray. (author)

  7. Antecedentes do Conflito Intragrupal: Um Estudo Comparativo

    OpenAIRE

    XAVIER, Tércio Antonio de Souza

    2002-01-01

    No campo do comportamento organizacional vem crescendo a importância dos grupos para as organizações, também têm crescido os problemas relacionados à motivação, à coordenação e aos conflitos. Nesse sentido, este estudo visa estudar e entender o conflito intragrupal em situações de trabalho e seus antecedentes na ótica dos funcionários. Buscam-se os prováveis determinantes das diferenças significativas nos graus de conflito de unidades organizacionais, a fim de subsidiar program...

  8. Habilidades auditivas e afasia: um estudo comparativo

    OpenAIRE

    Nascimento, Maria da Soledade Rolim do

    2012-01-01

    A compreensão da informação recebida pela modalidade auditiva é um requisito importante para a efetividade da comunicação, especialmente na linguagem expressiva. Este trabalho teve como objetivo avaliar a relação das habilidades auditivas com o processo de compreensão da linguagem em pacientes com afasia. Trata-se de um estudo descritivo, transversal, comparativo, com 32 sujeitos, distribuídos em dois grupos: Grupo com afasia (n=16) e Grupo controle (n=16). Os indivíduos foram ...

  9. Análise da eficácia do laser de baixa potência no tratamento da dor tendínea em ratos imunossuprimidos Analysis of low-level laser therapy efficacy on tendon pain treatment in immunosuppressed rats

    Directory of Open Access Journals (Sweden)

    Fernanda de Oliveira Busarello

    2011-12-01

    Full Text Available O comprometimento do sistema imune, que pode ser apresentado por indivíduos com doenças crônicas, leva à baixa resposta imunológica. Um dos tratamentos utilizados para lesões agudas em tendões é o laser de baixa potência, contudo há uma lacuna em relação ao seu uso em imunodepressão. O objetivo do presente estudo foi analisar se o laser de baixa potência é eficaz para o tratamento da dor em ratos imunodeprimidos submetidos a trauma tendíneo. Foram utilizados 23 ratos, machos, da linhagem Wistar, divididos aleatoriamente em três grupos: grupo controle, placebo e laser. Os animais foram imunodeprimidos (por administração de Ciclosporina A e submetidos à lesão no tendão calcâneo direito, com impacto de cerca de 0,40 J. Para o tratamento, utilizou-se laser de baixa potência, 670 nm, 30 mW e dose de 2 J/cm², durante 3 dias. A avaliação da dor foi realizada pelo teste de incapacidade funcional e por filamento de Von Frey digital. Os resultados apresentaram valores significativos para o grupo laser, com diminuição de dor funcional e da dor à pressão na superfície plantar e no local lesionado (tendão calcâneo direito. Portanto, concluiu-se que o laser de baixa potência é eficaz para reduzir a dor em ratos imunodeprimidos submetidos a trauma tendíneo.The commitment of immune system, which may be presented by individuals with chronic diseases, leading to a low immune response. One of the treatments used for acute injuries in tendons is the low-power laser, however there is a gap in relation to its use in immunosuppression. The objective of this study was to analyze if low-level laser therapy is effective for the treatment of pain in immunosuppressed rats subjected to trauma tendon. We used 23 male rats of Wistar strain, divided randomly in three groups: control group, placebo and laser. The animals were immunosuppressed (by administration of Cyclosporin A and underwent right Achilles tendon injury, with impact of about

  10. High power lasers & systems

    OpenAIRE

    Chatwin, Chris; Young, Rupert; Birch, Philip

    2015-01-01

    Some laser history;\\ud Airborne Laser Testbed & Chemical Oxygen Iodine Laser (COIL);\\ud Laser modes and beam propagation;\\ud Fibre lasers and applications;\\ud US Navy Laser system – NRL 33kW fibre laser;\\ud Lockheed Martin 30kW fibre laser;\\ud Conclusions

  11. A identidade profissional do professor: um estudo de revisão sistemática

    Directory of Open Access Journals (Sweden)

    Patrícia Maria Silva Gomes

    2013-06-01

    Full Text Available O presente estudo é uma revisão sistemática da literatura cujo objetivo foi cartografar a tipologia de estudos empíricos realizados acerca da Identidade Profissional do professor. A pesquisa foi efetuada nas bases de dados eletrônicas ISI Web of Knowledge, ERIC, SPORTDiscus e SCOPUS entre 2001 e 2012. As equações de pesquisa foram "Professional Identity" AND "Teacher", no campo título e "Professional Identity" AND "Teacher" AND "Physical Education", no campo "Abstract", tendo sido integrados 42 artigos. A análise de conteúdo, com categorias definidas "a priori", foi a técnica utilizada: a foco do estudo; b ano e local de publicação; c objetivos; d participantes; e instrumentos e f principais conclusões. Os resultados evidenciaram um aumento da pesquisa na área e nas metodologias qualitativas. Estas colocam o desenvolvimento profissional como elemento central no processo de (reconstrução da Identidade Profissional, sendo que ao nível do professor de Educação Física a pesquisa ainda é escassa.

  12. Spectroscopic and imaging diagnostics of pulsed laser deposition laser plasmas

    International Nuclear Information System (INIS)

    Thareja, Raj K.

    2002-01-01

    An overview of laser spectroscopic techniques used in the diagnostics of laser ablated plumes used for thin film deposition is given. An emerging laser spectroscopic imaging technique for the laser ablation material processing is discussed. (author)

  13. Laser-diode pumped 40-W Yb:YAG ceramic laser.

    Science.gov (United States)

    Hao, Qiang; Li, Wenxue; Pan, Haifeng; Zhang, Xiaoyi; Jiang, Benxue; Pan, Yubai; Zeng, Heping

    2009-09-28

    We demonstrated a high-power continuous-wave (CW) polycrystalline Yb:YAG ceramic laser pumped by fiber-pigtailed laser diode at 968 nm with 400 mum fiber core. The Yb:YAG ceramic laser performance was compared for different Yb(3+) ion concentrations in the ceramics by using a conventional end-pump laser cavity consisting of two flat mirrors with output couplers of different transmissions. A CW laser output of 40 W average power with M(2) factor of 5.8 was obtained with 5 mol% Yb concentration under 120 W incident pump power. This is to the best of our knowledge the highest output power in end-pumped bulk Yb:YAG ceramic laser.

  14. Ceramic Laser Materials

    Directory of Open Access Journals (Sweden)

    Guillermo Villalobos

    2012-02-01

    Full Text Available Ceramic laser materials have come a long way since the first demonstration of lasing in 1964. Improvements in powder synthesis and ceramic sintering as well as novel ideas have led to notable achievements. These include the first Nd:yttrium aluminum garnet (YAG ceramic laser in 1995, breaking the 1 KW mark in 2002 and then the remarkable demonstration of more than 100 KW output power from a YAG ceramic laser system in 2009. Additional developments have included highly doped microchip lasers, ultrashort pulse lasers, novel materials such as sesquioxides, fluoride ceramic lasers, selenide ceramic lasers in the 2 to 3 μm region, composite ceramic lasers for better thermal management, and single crystal lasers derived from polycrystalline ceramics. This paper highlights some of these notable achievements.

  15. Infrared laser system

    International Nuclear Information System (INIS)

    Cantrell, C.D.; Carbone, R.J.

    1977-01-01

    An infrared laser system and method for isotope separation may comprise a molecular gas laser oscillator to produce a laser beam at a first wavelength, Raman spin flip means for shifting the laser to a second wavelength, a molecular gas laser amplifier to amplify said second wavelength laser beam to high power, and optical means for directing the second wavelength, high power laser beam against a desired isotope for selective excitation thereof in a mixture with other isotopes. The optical means may include a medium which shifts the second wavelength high power laser beam to a third wavelength, high power laser beam at a wavelength coincidental with a corresponding vibrational state of said isotope and which is different from vibrational states of other isotopes in the gas mixture

  16. Ceramic Laser Materials

    Science.gov (United States)

    Sanghera, Jasbinder; Kim, Woohong; Villalobos, Guillermo; Shaw, Brandon; Baker, Colin; Frantz, Jesse; Sadowski, Bryan; Aggarwal, Ishwar

    2012-01-01

    Ceramic laser materials have come a long way since the first demonstration of lasing in 1964. Improvements in powder synthesis and ceramic sintering as well as novel ideas have led to notable achievements. These include the first Nd:yttrium aluminum garnet (YAG) ceramic laser in 1995, breaking the 1 KW mark in 2002 and then the remarkable demonstration of more than 100 KW output power from a YAG ceramic laser system in 2009. Additional developments have included highly doped microchip lasers, ultrashort pulse lasers, novel materials such as sesquioxides, fluoride ceramic lasers, selenide ceramic lasers in the 2 to 3 μm region, composite ceramic lasers for better thermal management, and single crystal lasers derived from polycrystalline ceramics. This paper highlights some of these notable achievements. PMID:28817044

  17. Laser cutting: industrial relevance, process optimization, and laser safety

    Science.gov (United States)

    Haferkamp, Heinz; Goede, Martin; von Busse, Alexander; Thuerk, Oliver

    1998-09-01

    Compared to other technological relevant laser machining processes, up to now laser cutting is the application most frequently used. With respect to the large amount of possible fields of application and the variety of different materials that can be machined, this technology has reached a stable position within the world market of material processing. Reachable machining quality for laser beam cutting is influenced by various laser and process parameters. Process integrated quality techniques have to be applied to ensure high-quality products and a cost effective use of the laser manufacturing plant. Therefore, rugged and versatile online process monitoring techniques at an affordable price would be desirable. Methods for the characterization of single plant components (e.g. laser source and optical path) have to be substituted by an omnivalent control system, capable of process data acquisition and analysis as well as the automatic adaptation of machining and laser parameters to changes in process and ambient conditions. At the Laser Zentrum Hannover eV, locally highly resolved thermographic measurements of the temperature distribution within the processing zone using cost effective measuring devices are performed. Characteristic values for cutting quality and plunge control as well as for the optimization of the surface roughness at the cutting edges can be deducted from the spatial distribution of the temperature field and the measured temperature gradients. Main influencing parameters on the temperature characteristic within the cutting zone are the laser beam intensity and pulse duration in pulse operation mode. For continuous operation mode, the temperature distribution is mainly determined by the laser output power related to the cutting velocity. With higher cutting velocities temperatures at the cutting front increase, reaching their maximum at the optimum cutting velocity. Here absorption of the incident laser radiation is drastically increased due to

  18. Laser wakefield acceleration with high-power, few-cycle mid-IR lasers

    OpenAIRE

    Papp, Daniel; Wood, Jonathan C.; Gruson, Vincent; Bionta, Mina; Gruse, Jan-Niclas; Cormier, Eric; Najmudin, Zulfikar; Légaré, François; Kamperidis, Christos

    2018-01-01

    The study of laser wakefield electron acceleration (LWFA) using mid-IR laser drivers is a promising path for future laser driven electronaccelerators, when compared to traditional near-IR laser drivers uperating at 0.8-1 {\\mu}m central wavelength ({\\lambda}laser), as the necessary vector potential a_0 for electron injection can be achieved with smaller laser powers due to the linear dependence on {\\lambda}laser. In this work, we perform 2D PIC simulations on LWFA using few-cycle high power (5...

  19. Laser requirements for a laser fusion energy power plant

    Institute of Scientific and Technical Information of China (English)

    Stephen; E.Bodner; Andrew; J.Schmitt; John; D.Sethian

    2013-01-01

    We will review some of the requirements for a laser that would be used with a laser fusion energy power plant, including frequency, spatial beam smoothing, bandwidth, temporal pulse shaping, efficiency, repetition rate, and reliability. The lowest risk and optimum approach uses a krypton fluoride gas laser. A diode-pumped solid-state laser is a possible contender.

  20. Percurso histórico-epistemológico dos estudos de citação no Brasil

    Directory of Open Access Journals (Sweden)

    Murilo Artur Araújo da SILVEIRA

    Full Text Available Resumo Este artigo apresenta a trajetória histórica e epistemológica dos estudos de citação no Brasil por meio dos artigos de periódicos nacionais. Tem como justificativa a ausência de pesquisas que apontem o estado da arte dos estudos de citação no Brasil, bem como a importância dos seus resultados para a compreensão da dinâmica dos contextos de produção e comunicação da ciência. O objetivo da pesquisa é identificar e discutir os elementos que configuram a trajetória histórica e epistemológica dos estudos de citação no Brasil presentes nos artigos indexados na Base de Dados Referencial de Artigos de Periódicos em Ciência da Informação, de 1972 a 2014. A pesquisa, de natureza descritiva, utilizou a técnica de análise de conteúdo para sistematização temporal e teórico-metodológica dos elementos constantes dos artigos publicados ao longo de quarenta anos. Discute as características e as configurações dos estudos de citação com base: (a nos dois períodos: embrionário e emergente; e (b nos enfoques teóricos: normativo, construtivista e sociocultural. Sinaliza o estágio do percurso histórico e epistemológico dos estudos de citação e lança perspectivas para os próximos trabalhos relacionados à temática.

  1. LaserFest Celebration

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Alan Chodos; Elizabeth A. Rogan

    2011-08-25

    LaserFest was the yearlong celebration, during 2010, of the 50th anniversary of the demonstration of the first working laser. The goals of LaserFest were: to highlight the impact of the laser in its manifold commercial, industrial and medical applications, and as a tool for ongoing scientific research; to use the laser as one example that illustrates, more generally, the route from scientific innovation to technological application; to use the laser as a vehicle for outreach, to stimulate interest among students and the public in aspects of physical science; to recognize and honor the pioneers who developed the laser and its many applications; to increase awareness among policymakers of the importance of R&D funding as evidenced by such technology as lasers. One way in which LaserFest sought to meet its goals was to encourage relevant activities at a local level all across the country -- and also abroad -- that would be identified with the larger purposes of the celebration and would carry the LaserFest name. Organizers were encouraged to record and advertise these events through a continually updated web-based calendar. Four projects were explicitly detailed in the proposals: 1) LaserFest on the Road; 2) Videos; 3) Educational material; and 4) Laser Days.

  2. Development of high-power CO2 lasers and laser material processing

    Science.gov (United States)

    Nath, Ashish K.; Choudhary, Praveen; Kumar, Manoj; Kaul, R.

    2000-02-01

    Scaling laws to determine the physical dimensions of the active medium and optical resonator parameters for designing convective cooled CO2 lasers have been established. High power CW CO2 lasers upto 5 kW output power and a high repetition rate TEA CO2 laser of 500 Hz and 500 W average power incorporated with a novel scheme for uniform UV pre- ionization have been developed for material processing applications. Technical viability of laser processing of several engineering components, for example laser surface hardening of fine teeth of files, laser welding of martensitic steel shroud and titanium alloy under-strap of turbine, laser cladding of Ni super-alloy with stellite for refurbishing turbine blades were established using these lasers. Laser alloying of pre-placed SiC coating on different types of aluminum alloy, commercially pure titanium and Ti-6Al-4V alloy, and laser curing of thermosetting powder coating have been also studied. Development of these lasers and results of some of the processing studies are briefly presented here.

  3. ABORDAGENS SOCIOTÉCNICAS E OS ESTUDOS EM TECNOLOGIA SOCIAL

    Directory of Open Access Journals (Sweden)

    José de Arimatéia Dias Valadão

    2014-05-01

    Full Text Available Este ensaio procura discutir as perspectivas sociotécnicas como base para o desenvolvimento teórico em tecnologia social (TS. Para subsidiar essa discussão foram analisadas a abordagem dos sistemas sociotécnicos elaborada inicialmente por Trist, Emery e colaboradores do Instituto Tavistock; a abordagem da adequação sociotécnica oriunda da perspectiva construtivista da tecnologia e a abordagem dos híbridos sociotécnicos proposta por Latour. O argumento central é que o desenvolvimento de TS deve considerar as tramas de relações, em que tanto os aspectos sociais como técnicos estão imbricados nas organizações, evitando as ênfases de cada corrente e considerando a mediação sociotécnica como principal unidade de análise nos estudos em TS. A motivação dessa discussão é que a aplicação das abordagens sociotécnicas, sem o equilíbrio aparente das mediações sociotécnicas, parece fazer das TS somente mais uma dentre muitas outras abordagens “alternativas”, como os próprios estudos na área têm criticado.

  4. Laser plasma instability experiments with KrF lasers

    International Nuclear Information System (INIS)

    Weaver, J. L.; Karasik, M.; Serlin, V.; Obenschain, S.; Chan, L-Y.; Kehne, D.; Schmitt, A. J.; Colombant, D.; Velikovich, A.; Oh, J.; Lehmberg, R. H.; Afeyan, B.; Phillips, L.; Seely, J.; Brown, C.; Feldman, U.; Aglitskiy, Y.; Mostovych, A. N.; Holland, G.

    2007-01-01

    Deleterious effects of laser-plasma instability (LPI) may limit the maximum laser irradiation that can be used for inertial confinement fusion. The short wavelength (248 nm), large bandwidth, and very uniform illumination available with krypton-fluoride (KrF) lasers should increase the maximum usable intensity by suppressing LPI. The concomitant increase in ablation pressure would allow implosion of low-aspect-ratio pellets to ignition with substantial gain (>20) at much reduced laser energy. The proposed KrF-laser-based Fusion Test Facility (FTF) would exploit this strategy to achieve significant fusion power (150 MW) with a rep-rate system that has a per pulse laser energy well below 1 MJ. Measurements of LPI using the Nike KrF laser are presented at and above intensities needed for the FTF (I∼2x10 15 W/cm 2 ). The results to date indicate that LPI is indeed suppressed. With overlapped beam intensity above the planar, single beam intensity threshold for the two-plasmon decay instability, no evidence of instability was observed via measurements of (3/2)ω o and (1/2)ω o harmonic emissions

  5. Physics of laser fusion. Volume III. High-power pulsed lasers

    International Nuclear Information System (INIS)

    Holzrichter, J.F.; Eimerl, D.; George, E.V.; Trenholme, J.B.; Simmons, W.W.; Hunt, J.T.

    1982-09-01

    High-power pulsed lasers can deliver sufficient energy on inertial-confinement fusion (ICF) time scales (0.1 to 10 ns) to heat and compress deuterium-tritium fuel to fusion-reaction conditions. Several laser systems have been examined, including Nd:glass, CO 2 , KrF, and I 2 , for their ICF applicability. A great deal of developmental effort has been applied to the Nd:glass laser and the CO 2 gas laser systems; these systems now deliver > 10 4 J and 20 x 10 12 W to ICF targets. We are constructing the Nova Nd:glass laser at LLNL to provide > 100 kJ and > 100 x 10 12 W of 1-μm radiation for fusion experimentation in the mid-1980s. For ICF target gain > 100 times the laser input, we expect that the laser driver must deliver approx. 3 to 5 MJ of energy on a time scale of 10 to 20 ns. In this paper we review the technological status of fusion-laser systems and outline approaches to constructing high-power pulsed laser drivers

  6. Efficacy and safety of green laser photocoagulation for threshold retinopathy of prematurity Eficácia e segurança da fotocoagulação com laser verde na retinopatia da prematuridade limiar

    Directory of Open Access Journals (Sweden)

    Rodrigo Pessoa Cavalcanti Lira

    2008-02-01

    Universidade Federal de Pernambuco, entre janeiro 2004 e janeiro 2006. Tratamento foi realizado com anestesia tópica, sob monitorização de neonatologistas. Foi utilizado laser verde de estado sólido com diodo de freqüência dobrada de 532 nm. Presença de túnica vasculosa lentis ou catarata foi excluída antes do tratamento. Foram obtidos os seguintes dados pré-operatórios: idade, peso ao nascer e estágio da ROP. Dados pós-operatórios incluíram complicações associadas com o tratamento, estágio da ROP e avaliação da necessidade de cirurgia por falha do tratamento com fotocoagulação. RESULTADOS: Vinte e dois neonatos foram submetidos à fotocoagulação com laser verde para ROP limiar. Um total de 31 olhos foi incluído no estudo. A idade gestacional média foi de 30 ± 3 semanas e a média do peso ao nascer foi de 1120 ± 490 g. Regressão da doença após terapia com laser foi observada em 30 olhos (96,7%. Apesar do tratamento um olho evoluiu para estágio 4A. Apenas 7 olhos precisaram de mais uma sessão de laser. Não houve efeitos adversos na câmara anterior como queimaduras ou sangramentos. Também não foram observados efeitos colaterais no segmento posterior. Formação de catarata não foi observada até o final do acompanhamento. CONCLUSÕES: A fotocoagulação com laser verde é uma alternativa efetiva e segura à fotocoagulação com laser vermelho e à crioterapia para o tratamento da ROP limiar.

  7. Prêmio de liquidez de ações : um estudo para o mercado brasileiro

    OpenAIRE

    Chiara, Marco

    2014-01-01

    Existe uma divergência nos estudos de mercados emergentes sobre a relação entre retorno e liquidez. Enquanto nos mercados desenvolvidos é consenso que o retorno cresce com a falta de liquidez, em mercados como o Brasil concorda-se com a sua influência, mas não é unânime o crescimento da rentabilidade diante da iliquidez. Assim, este estudo busca definir as variáveis que representam o conceito de liquidez e se elas possuem influência no retorno das ações brasileiras, além de entender se existe...

  8. A comparative study of the effect of low laser radiation on mast cells in inflammatory fibrous hyperplasia colored and not colored by the toluidine blue; Estudo comparativo do efeito da radiacao laser em baixa intensidade sobre mastocitos de hiperplasias fibrosas inflamatorias coradas e nao coradas por azul de toluidina

    Energy Technology Data Exchange (ETDEWEB)

    Sawazaki, Iris

    2001-07-01

    THIS STUDY SHOWS A COMPARATIVE ANALYSIS OF THE EFFECTS OF THE LASER RADIATION IN LOW INTENSITY ON THE MAST CELL DEGRANULATION IN INFLAMMATORY FIBROUS HYPERPLASIA WHEN THEY ARE COLORED OR NOT BY THE TOLUIDINE BLUE. THE DYE WAS USED IN ORDER TO INCREASE THE ABSORPTION OF THE LASER LIGHT BY THE TISSUE. THE INJURE WAS DIVIDED IN THREE EQUAL PARTS, AND EACH PART RECEIVED A DIFFERENT KIND OF TREATMENT. ONE OF THEM WAS REMOVED TO BE THE CONTROL, THE SECOND PART WAS LASER TREATED AND THEN IMMEDIATELY REMOVED AND THE LAST ONE, AFTER BEING SUPERFICIALLY COLORED, WAS LASER TREATED AND THEN IMMEDIATELY REMOVED . THE ORDER OF THE STAGES WAS RANDOMLY CHANGED , THEN THE TIME BETWEEN THE STAGES WOULD NOT INTERFERE IN THE STATISTICAL ANALYSIS OF THE MAST CELL DEGRANULATION RATES. IT WAS FOUND THAT THE MAST CELL DEGRANULATION RATES WERE 49% FOR THE CONTROL GROUP, 87% FOR THE LASER GROUP AND 88% FOR THE COLORED/LASER GROUP. THERE WAS NO SIGNIFICANT STATISTICAL DIFFERENCES BETWEEN THE GROUP LASER TREATED AND THE ONE COLORED/LASER TREATED. HOWEVER, THERE WAS A SIGNIFICANT DIFFERENCE BETWEEN THE CONTROL AND THE TREATED GROUP (PS {<=} 0,01). (AUTHOR)

  9. Action of diode laser (830 nm) on cutaneous wound healing process: biometrical and histological study in rats; Acao do diodo laser emitindo em 830 nm, sobre o processo de cicatrizacao de lesoes cutaneas: estudo biometrico e histologico em ratos

    Energy Technology Data Exchange (ETDEWEB)

    Rezende, Sandra Bastos

    2001-07-01

    In this research, it was analyzed the acceleration of the healing process of cutaneous lesions in mice, using a diode laser emitting in 830 nm. The 64 selected animals in this study were randomically divided into four groups of 16 animals each (G1, G2, G3 and G4). Biometric and histological comparisons were accomplished in the following periods: 3, 7 and 14 days after the surgery and laser application. Three laser irradiation configurations were used: a punctual contact (G2) and two non-contact and uniform (G3 and G4). For group G2, the laser intensity was 428 mW/cm{sup 2} , and for groups G3 and G4 it was 53 mW/cm{sup 2}. The total doses were D = 3 J/cm{sup 2} for groups G2 and G4, and D = 1,3 J/cm{sup 2} for G3. The first group, G1, was considered control and thus not submitted to any treatment after the surgery. All irradiated lesions presented acceleration of the healing process with regard to the control group. However, our results clearly indicate that the smaller laser intensity (uniform irradiation) leaded to the best results. On the other hand, the smaller used dose also leaded to the more significant and expressive results. The combination of the intensity value of 53 mW/cm{sup 2} and the dose of 1,3 J/cm{sup 2} leaded to optimal results, regarding the Biometric and histological analysis, presenting faster lesion contraction, quicker neoformation of epithelial and conjunctive tissue (with more collagen fibers ). (author)

  10. Hiperglicinemia não cetótica: estudo de um caso

    Directory of Open Access Journals (Sweden)

    M.V. Moura-Ribeiro

    1987-03-01

    Full Text Available A hiperglicinemia não cetótica é erro inato do metabolismo que se manifesta por crises epilépticas de difícil controle desde os primeiros dias de vida, em recém-nascido hipotônico. A falta do enzima que catalisa a conversão de glicina em ácido hidroximetiltetra-hidrofólico, dióxido de carbono e amônia, no fígado e no cérebro, resulta em aumento da concentração de glicina no sangue. Neste estudo é relatado caso de hiperglicinemia diagnosticado no período neonatal e caracterizado por hipotonia e múltiplas convulsões não controláveis. Os achados clínicos e eletrencefalográficos, aspectos do tratamento e do estudo anátomo-patológico são comentados.

  11. A resposta broncodilatadora em doentes com DPOC (dados do estudo UPLIFT

    Directory of Open Access Journals (Sweden)

    D. Tashkin

    2008-07-01

    Full Text Available Resumo: No início do estudo, foi realizada espirometria antes e depois de 80 μg de ipratrópio e 400 μg de salbutamol, administrados 90 e 30 minutos antes, respectivamente. A administração de dois broncodilatadores e a sua temporalidade teve como objectivo atingir a broncodilatação máxima ou quase máxima. O FEV1 basal após esta broncodilatação, no estudo UPLIFT, permitiu: - examinar a resposta broncodilatadora aguda numa grande coorte de doentes com DPOC moderada a muito grave; - determinar o que pode ser considerado critério de resposta usando vários critérios de reversibilidade; - avaliar as características dos doentes com e sem reversibilidade.

  12. Raman fiber lasers

    CERN Document Server

    2017-01-01

    This book serves as a comprehensive, up-to-date reference about this cutting-edge laser technology and its many new and interesting developments. Various aspects and trends of Raman fiber lasers are described in detail by experts in their fields. Raman fiber lasers have progressed quickly in the past decade, and have emerged as a versatile laser technology for generating high power light sources covering a spectral range from visible to mid-infrared. The technology is already being applied in the fields of telecommunication, astronomy, cold atom physics, laser spectroscopy, environmental sensing, and laser medicine. This book covers various topics relating to Raman fiber laser research, including power scaling, cladding and diode pumping, cascade Raman shifting, single frequency operation and power amplification, mid-infrared laser generation, specialty optical fibers, and random distributed feedback Raman fiber lasers. The book will appeal to scientists, students, and technicians seeking to understand the re...

  13. Effect of laser spot size on energy balance in laser induced plasmas

    International Nuclear Information System (INIS)

    Pant, H.C.; Sharma, S.; Bhawalkar, D.D.

    1980-01-01

    The effect of the laser spot size on laser light absorption in laser induced plasmas from solid targets was studied. It was found that at a constant laser intensity on the target, reduction in the laser spot size enhances the net laser energy absorption. It was also observed that the laser light reflection from the target becomes more diffused when the focal spot size is reduced

  14. Influence of laser parameters on laser ultrasonic efficiency

    CSIR Research Space (South Africa)

    Forbes, A

    2007-01-01

    Full Text Available , TEA CO2 lasers, laser chemistry, short pulses 1. INTRODUCTION Polymer-matrix composites are increasingly used in the aerospace industry, particularly in the manufacture of modern fighter planes1-3. The number and complexity of such composites... efficiency can be improved by utilising short pulses in the 3–4 µm and 10 µm spectral regions1. Short pulse 10 µm radiation can be produced by transversely excited, atmospheric CO2 (TEA CO2) lasers. Due to the technological maturity of these lasers...

  15. Estudos de Comunidade e ciências sociais no Brasil

    Directory of Open Access Journals (Sweden)

    Nemuel da Silva Oliveira

    2011-12-01

    Full Text Available O objetivo deste artigo é fazer um balanço da literatura sobre os Estudos de Comunidade (EC no Brasil, destacando o contexto intelectual em que foram produzidos e os debates que suscitaram, especialmente entre as décadas de 1940 e 1960. Método de pesquisa em comunidades, oriundo da Antropologia, em investigações sobre o processo de mudança social, os EC estiveram em voga nos Estados Unidos entre os anos 1920 e 1950, tendo papel fundamental na institucionalização das Ciências Sociais no Brasil. Destacamos três aspectos na produção desses estudos no país, iniciando com uma abordagem conceitual: definições, origem e sua relação com temáticas marcantes nos anos 1950. Em seguida, privilegiamos os aspectos relacionados ao papel dos EC na história das Ciências Sociais no Brasil, com destaque para o processo de institucionalização das Ciências Sociais. Por fim, revisitamos os debates que tais estudos geraram entre os cientistas sociais quanto ao padrão de trabalho sociológico a ser desenvolvido naquele momento.The purpose of this article is to examine the literature about Community Studies(CS in Brazil, highlighting their intellectual context of production and the debates evoked by them, especially between the 1940's and 1960's. As a research method arising from Anthropology on communities in social change process, CS was used in United States between 1920's and 1950's, and played a fundamental role in the institutionalization of Social Sciences in Brazil. Three aspects are highlighted on CS production: first, in a conceptual approach, we discuss their definitions, origins and relation to main topics in the 1950's. The second aspect is related to the role of CS in the history of Social Sciences, especially their institutionalization process. By the end, we revisit the debates between social scientists about the sociological work standard to be developed at that time.

  16. Improving the laser brightness of a commercial laser system

    Science.gov (United States)

    Naidoo, Darryl; Litvin, Igor; Forbes, Andrew

    2016-02-01

    We investigate the selection of a flat-top beam and a Gaussian beam inside a laser cavity on opposing mirrors. The concept is tested external to the laser cavity in a single pass and double pass regime where the latter mimics a single round trip in the laser. We implement this intra-cavity selection through the use of two 16 level diffractive optical elements. We consider a solid-state diode side-pumped laser resonator in a typical commercial laser configuration that consists of two planar mirrors where the DOEs are positioned at the mirrors. We out couple the Gaussian and flat-top distributions and we show that we improve the brightness of the laser with active mode control. We also demonstrate that the quality of the beam transformations determine the brightness improvement.

  17. Estudo bacteriológico de lesões periapicais

    Directory of Open Access Journals (Sweden)

    ROCHA Márcia Maria de Negreiros Pinto

    1998-01-01

    Full Text Available O tecido perirradicular de 30 casos cirúrgicos foi submetido a exame microbiológico e histopatológico. Foram isoladas 137 cepas bacterianas das 30 lesões periapicais estudadas. Do total de bactérias isoladas, 90 (65,7% foram caracterizadas como anaeróbias estritas, 40 (29,2% como anaeróbias facultativas e 7 (5,1% como aeróbias estritas. Fusobacterium nucleatum, bacilos Gram-negativos pigmentados anaeróbios estritos, Peptostreptococcus sp, Streptococcus mitis e bacilos Gram-positivos não esporulados anaeróbios estritos foram, em ordem decrescente de freqüência, as bactérias mais comumente isoladas das lesões periapicais. A análise histopatológica demonstrou prevalência de granuloma periapical. O estudo de sensibilidade a antimicrobianos foi realizado em 16 cepas de Fusobacterium nucleatum. Os antimicrobianos utilizados foram penicilina, cefoxitina, eritromicina, metronidazol e tetraciclina. Todas as amostras apresentaram suscetibilidade à cefoxitina, tetraciclina e metronidazol; os percentuais de resistência à penicilina e à eritromicina foram 12,5 e 68,8, respectivamente. Os percentuais de resistência de Fusobacterium nucleatum, uma espécie bacteriana importante na patogênese das lesões periapicais, à penicilina e à eritromicina, enfatizam a necessidade de outros estudos de resistência a antimicrobianos de bactérias isoladas em infecções odontogênicas.

  18. Navigated Pattern Laser System versus Single-Spot Laser System for Postoperative 360-Degree Laser Retinopexy.

    Science.gov (United States)

    Kulikov, Alexei N; Maltsev, Dmitrii S; Boiko, Ernest V

    2016-01-01

    Purpose . To compare three 360°-laser retinopexy (LRP) approaches (using navigated pattern laser system, single-spot slit-lamp (SL) laser delivery, and single-spot indirect ophthalmoscope (IO) laser delivery) in regard to procedure duration, procedural pain score, technical difficulties, and the ability to achieve surgical goals. Material and Methods . Eighty-six rhegmatogenous retinal detachment patients (86 eyes) were included in this prospective randomized study. The mean procedural time, procedural pain score (using 4-point Verbal Rating Scale), number of laser burns, and achievement of the surgical goals were compared between three groups (pattern LRP (Navilas® laser system), 36 patients; SL-LRP, 28 patients; and IO-LRP, 22 patients). Results . In the pattern LRP group, the amount of time needed for LRP and pain level were statistically significantly lower, whereas the number of applied laser burns was higher compared to those in the SL-LRP group and in the IO-LRP group. In the pattern LRP, SL-LRP, and IO-LRP groups, surgical goals were fully achieved in 28 (77.8%), 17 (60.7%), and 13 patients (59.1%), respectively ( p > 0.05). Conclusion . The navigated pattern approach allows improving the treatment time and pain in postoperative 360° LRP. Moreover, 360° pattern LRP is at least as effective in achieving the surgical goal as the conventional (slit-lamp or indirect ophthalmoscope) approaches with a single-spot laser.

  19. Practical laser safety

    International Nuclear Information System (INIS)

    Winburn, D.C.

    1985-01-01

    This book includes discussions of the following topics: characteristics of lasers; eye components; skin damage thresholds; classification of lasers by ANSI Z136.1; selecting laser-protective eyewear; hazards associated with lasers; and, an index

  20. Lasers technology

    International Nuclear Information System (INIS)

    2014-01-01

    The Laser Technology Program of IPEN is developed by the Center for Lasers and Applications (CLA) and is committed to the development of new lasers based on the research of new optical materials and new resonator technologies. Laser applications and research occur within several areas such as Nuclear, Medicine, Dentistry, Industry, Environment and Advanced Research. Additional goals of the Program are human resource development and innovation, in association with Brazilian Universities and commercial partners

  1. LASERS: A cryogenic slab CO laser

    Science.gov (United States)

    Ionin, Andrei A.; Kozlov, A. Yu; Seleznev, L. V.; Sinitsyn, D. V.

    2009-03-01

    A compact capacitive transverse RF-discharge-pumped slab CO laser with cryogenically cooled electrodes, which operates both in the cw and repetitively pulsed regimes, is fabricated. The laser operation is studied in the free running multifrequency regime at the vibrational - rotational transitions of the fundamental (V + 1 → V) vibrational bands of the CO molecule in the spectral region from 5.1 to 5.4 μm. Optimal operation conditions (gas mixture composition and pressure, RF pump parameters) are determined. It is shown that only gas mixtures with a high content of oxygen (up to 20% with respect to the concentration of CO molecules) can be used as an active medium of this laser. It is demonstrated that repetitively pulsed pumping is more efficient compared to cw pumping. In this case, quasi-cw lasing regime can be obtained. The maximum average output power of ~12 W was obtained for this laser operating on fundamental bands and its efficiency achieved ~14 %. The frequency-selective operation regime of the slab RF-discharge-pumped CO laser was realised at ~ 100 laser lines in the spectral region from 5.0 to 6.5 μm with the average output power of up to several tens of milliwatts in each line. Lasing at the transitions of the first vibrational overtone (V + 2 → V) of the CO molecule is obtained in the spectral region from 2.5 to 3.9 μm. The average output power of the overtone laser achieved 0.3 W. All the results were obtained without the forced gas mixture exchange in the discharge chamber. Under fixed experimental conditions, repetitively pulsed lasing (with fluctuations of the output characteristics no more than ±10 %) was stable for more than an hour.

  2. Gestão de marcas por meio das redes sociais: um estudo sobre a utilização do facebook

    OpenAIRE

    Flávia Preuss Siqueira Batista

    2011-01-01

    Este estudo aborda a utilização das mídias sociais como ferramenta para gestão de marcas. O tema se demonstra relevante por tratar de três assuntos considerados importantes na atualidade: gestão de marcas, marketing de relacionamento e redes sociais no ambiente virtual. A proposta do estudo é explorar se as organizações estão estabelecendo um relacionamento com seus clientes de forma que este promova o brand equity por meio do uso das redes sociais. Para se atingir os objetivos do estudo, foi...

  3. Laser Stabilization with Laser Cooled Strontium

    DEFF Research Database (Denmark)

    Christensen, Bjarke Takashi Røjle

    The frequency stability of current state-of-the-art stabilized clock lasers are limited by thermal fluctuations of the ultra-stable optical reference cavities used for their frequency stabilization. In this work, we study the possibilities for surpassing this thermal limit by exploiting the nonli......The frequency stability of current state-of-the-art stabilized clock lasers are limited by thermal fluctuations of the ultra-stable optical reference cavities used for their frequency stabilization. In this work, we study the possibilities for surpassing this thermal limit by exploiting...... the nonlinear effects from coupling of an optical cavity to laser cooled atoms having a narrow transition linewidth. Here, we have realized such a system where a thermal sample of laser cooled strontium-88 atoms are coupled to an optical cavity. The strontium-88 atoms were probed on the narrow 1S0-3P1 inter......-combination line at 689 nm in a strongly saturated regime. The dynamics of the atomic induced phase shift and absorption of the probe light were experimentally studied in details with the purpose of applications to laser stabilization. The atomic sample temperature was in the mK range which brought this system out...

  4. Construindo pontes: a prática da interdisciplinaridade. Estudo PopTrans: um estudo com travestis e mulheres transexuais em Salvador, Bahia, Brasil

    Directory of Open Access Journals (Sweden)

    Ines Dourado

    Full Text Available Resumo: Pessoas trans, incluindo travestis, mulheres transexuais, apresentam taxas desproporcionalmente elevadas de HIV/AIDS em comparação com o restante da população. Entretanto, são poucos os estudos quantitativos/qualitativos com pessoas trans no Brasil. Assim, uma equipe de pesquisadores de diferentes áreas desenvolve um projeto de pesquisa interdisciplinar com o objetivo de conhecer as condições e os modos de vida, e ao mesmo tempo investigar fatores determinantes da infecção pelo HIV, sífilis e hepatites B e C entre travestis e mulheres transexuais. Neste artigo, pretende-se descrever a experiência de implantação e desenvolvimento do estudo com uma abordagem etnoepidemiológica em Salvador, Bahia, Brasil. O mapeamento da população começou com uma pesquisa formativa que foi crucial para orientar o inquérito epidemiológico. A produção de dados etnoepidemiológicos é um desafio cotidiano para os pesquisadores, produzindo uma série de reflexões sobre os limites de nossos conceitos e categorias para traduzir a diversidade de práticas e experiências das participantes da pesquisa.

  5. Measurements of laser parameters for the Shiva laser fusion facility

    International Nuclear Information System (INIS)

    Ozarski, R.G.

    1979-01-01

    Large laser systems require numerous laser diagnostics to provide configuration, performance and maintenance data to permit efficient operation. The following diagnostics for a large laser system named Shiva are discussed: (1) description of Shiva laser system, (2) what measurements are desired and or required and why, (3) what measurement techniques and packages are employed and a brief description of the operating principles of the sensors employed, and (4) the laser diagnostic data acquisition and display system

  6. O artista e sua arte: um estudo fenomenológico

    Directory of Open Access Journals (Sweden)

    Giuliana Gnatos Lima Bilbao

    2006-04-01

    Full Text Available Este estudo tem por objetivo apreender a estrutura do vivido do artista e sua arte e as decorrências para a Psicologia. Foram gravados 9 (nove depoimentos de artistas de diferentes áreas, posteriormente submetidos aos passos do método fenomenológico, incluindo leitura inicial para apreensão do todo, releituras para apreensão de unidades de significado, compreensão psicológica das unidades de significado, síntese específica de cada depoimento e, por fim, síntese geral dos depoimentos. A síntese geral, abarcando as vivências de todos os participantes, delineou aspectos positivos da arte: auto-conhecimento; integração da personalidade; transformação de valores e afetos; transcendência da realidade cotidiana. Os resultados apontam para uma consideração da criatividade como componente da saúde e da prática de uma atividade artística como facilitadora do desenvolvimento psicológico, abrindo perspectivas para novos estudos sobre arte, que vem sendo associada a processos psicoterapêuticos na atualidade.

  7. Laser beam-plasma plume interaction during laser welding

    Science.gov (United States)

    Hoffman, Jacek; Moscicki, Tomasz; Szymanski, Zygmunt

    2003-10-01

    Laser welding process is unstable because the keyhole wall performs oscillations which results in the oscillations of plasma plume over the keyhole mouth. The characteristic frequencies are equal to 0.5-4 kHz. Since plasma plume absorbs and refracts laser radiation, plasma oscillations modulate the laser beam before it reaches the workpiece. In this work temporary electron densities and temperatures are determined in the peaks of plasma bursts during welding with a continuous wave CO2 laser. It has been found that during strong bursts the plasma plume over the keyhole consists of metal vapour only, being not diluted by the shielding gas. As expected the values of electron density are about two times higher in peaks than their time-averaged values. Since the plasma absorption coefficient scales as ~N2e/T3/2 (for CO2 laser radiation) the results show that the power of the laser beam reaching the metal surface is modulated by the plasma plume oscillations. The attenuation factor equals 4-6% of the laser power but it is expected that it is doubled by the refraction effect. The results, together with the analysis of the colour pictures from streak camera, allow also interpretation of the dynamics of the plasma plume.

  8. Para-hydrogen raman laser and its application to laser induced chemistry

    International Nuclear Information System (INIS)

    Tashiro, Hideo

    1988-01-01

    The report outlines the mechanism of the para-hydrogen Raman laser as a infrared light source, and its application to laser induced chemistry. The Stoke's wave number after a Raman shift is equal to the difference between the wave number of the CO 2 laser used for excitation and the rotation Raman wave number of the hydrogen molecule. A Raman laser can serve as an infrared source. CO 2 laser oscillation beam in the range of 9∼11 micrometers is selected and the frequency of infrared beam is varied by changing the wave number of the CO 2 laser beam. A problem with the Raman laser is that the Raman scatterring gain is small due to a large wavelength. In developing equipment, a special mechanism is required to solve this problem. A Raman laser comprises a CO 2 laser for excitation and multi-pulse Raman cells. The combination of a TEA oscillator and amplifiers gives CO 2 pulses with a peak power of about several tens of MW. Many heavy metal compounds including fluorides, carbonyl compounds and other organic compounds, absorb light with wavelengths in the same range as those of the Raman laser. Such compounds can be dissociated directly by applying Raman laser beams. The laser will be helpful for separation of isotopes, etc. (Nogami, K.)

  9. Laser material processing

    CERN Document Server

    Steen, William

    2010-01-01

    This text moves from the basics of laser physics to detailed treatments of all major materials processing techniques for which lasers are now essential. New chapters cover laser physics, drilling, micro- and nanomanufacturing and biomedical laser processing.

  10. Revisão sistemática e meta-análise de estudos observacionais em Psicologia

    Directory of Open Access Journals (Sweden)

    Gabriela Andrade da Silva

    2015-04-01

    Full Text Available O objetivo do presente trabalho foi levantar e sumarizar informações sobre metodologias para a realização de revisões sistemáticas e meta-análises de estudos observacionais, com considerações sobre o seu emprego e relevância na área da Psicologia. Revisão sistemática é uma revisão de literatura com base em uma pergunta de pesquisa, que usa métodos sistemáticos para a busca, seleção e avaliação crítica de estudos, resultando em uma sumarização. Meta-análise é um conjunto de técnicas estatísticas para combinar e sintetizar os resultados de dois ou mais estudos realizados de forma independente e selecionados em uma revisão sistemática. Essas metodologias têm elevada relevância na construção do conhecimento, por sintetizar informações de estudos publicados em diferentes fontes; diminuir o atraso entre as descobertas científicas e suas aplicações à prática profissional; e permitir testar novas hipóteses a partir dos dados já coletados. Foram descritas as etapas para realização de revisão sistemática. Os desafios específicos relacionados com a inclusão de estudos observacionais, bem como a aplicação desta técnica para o campo da Psicologia, foram abordados a fim de orientar os pesquisadores interessados em realizar revisões sistemáticas e meta-análises, bem como psicólogos, outros profissionais de saúde e gestores que buscam informações em evidências científicas para apoiar as suas práticas.

  11. Propriedades dos estudos de teoria da contabilidade em um periódico científico brasileiro

    Directory of Open Access Journals (Sweden)

    Sidnei Celerino da Silva

    2014-09-01

    Full Text Available Este estudo bibliométrico tem como objetivo avaliar a produção científica na área de teoria da Contabilidade, publicada na Revista de Contabilidade e Finanças (RCF, da Faculdade de Economia e Administração da Universidade de São Paulo (FEA/USP, no período de 2001 a 2010. Por meio de uma pesquisa descritiva com delineamento documental, foram identificados e analisados 27 artigos relacionados à área selecionada. O estudo analisou as características das autorias e formação de redes de pesquisa, predominando autoria e redes vinculadas a FEA/USP. Em relação ao enfoque, abordagem e tipologia metodológica, o estudo identificou que a maioria dos artigos adotou o enfoque da racionalidade econômica. Cresceram a quantidade de artigos com abordagem positiva nos últimos anos, mas prevalecem estudos normativos no período. Constatou ainda, que os autores privilegiaram os estudos empíricos, com uso acentuado de ferramental estatístico e prevalece a discussão do tema conservadorismo. Ademais, os autores privilegiaram a consulta aos periódicos internacionais, livros nacionais e internacionais e pesquisas em dissertações e teses nacionais, sendo que James Ohlson e Eliseu Martins foram os autores mais citados. Por fim, constatou-se que é imprescindível a vinculação dos autores da área a pesquisadores de instituições internacionais e de outras áreas do conhecimento para mitigar a endogenia da produção científica, o viés contábil e aprimorar a reflexão sobre o direcionamento da pesquisa contábil na área.

  12. Fobia específica: um estudo transversal com 103 pacientes tratados em ambulatório

    OpenAIRE

    Terra,Mauro Barbosa; Garcez,Joana Presser; Noll,Betina

    2007-01-01

    OBJETIVOS: Este estudo tem por objetivo investigar a presença de fobia específica (FE) entre pacientes atendidos em um ambulatório de psiquiatria. MÉTODOS: Foi realizado um estudo transversal, no qual foi aplicado o SCID-I em 103 pacientes, para se examinar a ocorrência de fobia específica. Os dados foram analisados por meio de medidas descritivas e mediante os testes de independência baseados na estatística qui-quadrado de Pearson ou no teste exato de Fisher. RESULTADOS: Foi verificada FE em...

  13. Lasers in space

    Science.gov (United States)

    Michaelis, M. M.; Forbes, A.; Bingham, R.; Kellett, B. J.; Mathye, A.

    2008-05-01

    A variety of laser applications in space, past, present, future and far future are reviewed together with the contributions of some of the scientists and engineers involved, especially those that happen to have South African connections. Historically, two of the earliest laser applications in space, were atmospheric LIDAR and lunar ranging. These applications involved atmospheric physicists, several astronauts and many of the staff recruited into the Soviet and North American lunar exploration programmes. There is a strong interest in South Africa in both LIDAR and lunar ranging. Shortly after the birth of the laser (and even just prior) theoretical work on photonic propulsion and space propulsion by laser ablation was initiated by Georgii Marx, Arthur Kantrowitz and Eugen Saenger. Present or near future experimental programs are developing in the following fields: laser ablation propulsion, possibly coupled with rail gun or gas gun propulsion; interplanetary laser transmission; laser altimetry; gravity wave detection by space based Michelson interferometry; the de-orbiting of space debris by high power lasers; atom laser interferometry in space. Far future applications of laser-photonic space-propulsion were also pioneered by Carl Sagan and Robert Forward. They envisaged means of putting Saenger's ideas into practice. Forward also invented a laser based method for manufacturing solid antimatter or SANTIM, well before the ongoing experiments at CERN with anti-hydrogen production and laser-trapping. SANTIM would be an ideal propellant for interstellar missions if it could be manufactured in sufficient quantities. It would be equally useful as a power source for the transmission of information over light year distances. We briefly mention military lasers. Last but not least, we address naturally occurring lasers in space and pose the question: "did the Big Bang lase?"

  14. Craniostenose em gêmeos: estudo genético

    Directory of Open Access Journals (Sweden)

    Walter Carlos Pereira

    1968-09-01

    Full Text Available É relatada a ocorrência de formas clínicas diversas de craniostenose em gêmeos de sexo diferente. A menina apresentava obliteração completa da sutura coronaria e dos dois terços anteriores da sutura sagital; no menino a sutura sagital era a única afetada. O estudo genético mostrou que a craniostenose independe de aberrações cromossômicas, indicando ser transmitida por gens recessivos raros de natureza autossômica.

  15. Frequency-doubled diode laser for direct pumping of Ti:sapphire lasers

    DEFF Research Database (Denmark)

    Müller, André; Jensen, Ole Bjarlin; Unterhuber, Angelika

    2012-01-01

    . However, the superior electro-optical efficiency of the diode laser improves the overall efficiency of the Ti:sapphire laser by a factor > 2. The optical spectrum emitted by the Ti:sapphire laser shows a spectral width of 112 nm (FWHM). Based on autocorrelation measurements, pulse widths of less than 20...... fs are measured. These results open the opportunity of establishing diode laser pumped Ti:sapphire lasers for e.g. biophotonic applications like retinal optical coherence tomography or pumping of photonic crystal fibers for CARS microscopy.......A single-pass frequency doubled high-power tapered diode laser emitting nearly 1.3 W of green light suitable for direct pumping of Ti:sapphire lasers generating ultrashort pulses is demonstrated. The pump efficiencies reached 75 % of the values achieved with a commercial solid-state pump laser...

  16. Literacia fiscal : um estudo empírico

    OpenAIRE

    Pereira, Ana Isabel Teixeira Duarte

    2014-01-01

    O objetivo desta dissertação prende-se com o estudo da literacia fiscal numa zona rural de Portugal. Aqui se aborda a importância da perceção fiscal que o contribuinte deveria possuir para uma melhor atuação perante situações fiscais com que se depara no seu quotidiano, em seu benefício. O presente trabalho versa também sobre fatores que influenciam o (in)cumprimento fiscal por parte do cidadão contribuinte. A educação fiscal tem impacto no cumprimento fiscal no sentido de que transmite o ...

  17. Inteligência emocional: estudo exploratório

    OpenAIRE

    Seabra, Diana Catarina Lopes

    2013-01-01

    A presente dissertação tem como objetivo esclarecer e refletir sobre a inteligência emocional e explorar se existe uma influência entre a atividade que o grupo exerce, o tempo de pertença e o tempo de vida do mesmo, ao nível da inteligência emocional grupal e das suas dimensões. Para tal, foi desenvolvido um estudo exploratório. A recolha dos dados realizou-se através do Questionário de Inteligência Emocional Grupal traduzido e adaptado por Correia (2010) do Group Emotional Intelligence Quest...

  18. Excimer laser applications

    International Nuclear Information System (INIS)

    Fantoni, R.

    1988-01-01

    This lecture deals with laser induced material photoprocessing, especially concerning those processes which are initiated by u.v. lasers (mostly excimer laser). Advantages of using the u.v. radiation emitted by excimer lasers, both in photophysical and photochemical processes of different materials, are discussed in detail. Applications concerning microelectronics are stressed with respect to other applications in different fields (organic chemistry, medicine). As further applications of excimer lasers, main spectroscopic techniques for ''on line'' diagnostics which employ excimer pumped dye lasers, emitting tunable radiation in the visible and near u.v. are reviewed

  19. Technological laser application

    International Nuclear Information System (INIS)

    Shia, D.O.; Kollen, R.; Rods, U.

    1980-01-01

    Problems of the technological applications of lasers are stated in the popular form. Main requirements to a technological laser as well as problems arising in designing any system using lasers have been considered. Areas of the laser applications are described generally: laser treatment of materials, thermal treatment, welding, broach and drilling of holes, scribing, microtreatment and adjustment of resistors, material cutting, investigations into controlled thermonuclear fussion

  20. Effects of laser fluence on silicon modification by four-beam laser interference

    International Nuclear Information System (INIS)

    Zhao, Le; Li, Dayou; Wang, Zuobin; Yue, Yong; Zhang, Jinjin; Yu, Miao; Li, Siwei

    2015-01-01

    This paper discusses the effects of laser fluence on silicon modification by four-beam laser interference. In this work, four-beam laser interference was used to pattern single crystal silicon wafers for the fabrication of surface structures, and the number of laser pulses was applied to the process in air. By controlling the parameters of laser irradiation, different shapes of silicon structures were fabricated. The results were obtained with the single laser fluence of 354 mJ/cm 2 , 495 mJ/cm 2 , and 637 mJ/cm 2 , the pulse repetition rate of 10 Hz, the laser exposure pulses of 30, 100, and 300, the laser wavelength of 1064 nm, and the pulse duration of 7–9 ns. The effects of the heat transfer and the radiation of laser interference plasma on silicon wafer surfaces were investigated. The equations of heat flow and radiation effects of laser plasma of interfering patterns in a four-beam laser interference distribution were proposed to describe their impacts on silicon wafer surfaces. The experimental results have shown that the laser fluence has to be properly selected for the fabrication of well-defined surface structures in a four-beam laser interference process. Laser interference patterns can directly fabricate different shape structures for their corresponding applications

  1. Laser innovated manufacturing technology; Laser ga seisan gijutsu wo kakushinshita

    Energy Technology Data Exchange (ETDEWEB)

    Maruyama, I. [Honda Motor Co. Ltd., Tokyo (Japan)

    1996-11-01

    This paper looks back the history of applications of laser processing in the automobile industry, and introduces contents of some particularly unique applications from among them. The CO2 laser and YAG laser that are used mainly have increased their outputs with the times, and 50-kW CO2 laser and 4-kW YAG laser have now become available commercially. The laser processing has become used widely for cutting purpose in Japan, which is in contrast with their high application to welding in Europe and America. Cutting thick plates has been developed recently, which is applicable to plates as thick as about 25 mm. A flexible system in which YAG laser is combined with an optical fiber/articulated robot is operating for three-dimensional shape processing. Automobile makers are adopting laser processing for welding in place of the electron beam welding that has been used conventionally. The process is used also for a number of other applications including surface reformation, such as surface quenching for cylinder liner, and valve seat padding. 8 refs., 8 figs.

  2. A resposta broncodilatadora em doentes com DPOC (dados do estudo UPLIFT

    Directory of Open Access Journals (Sweden)

    D. Tashkin

    2008-07-01

    Full Text Available Resumo: No início do estudo, foi realizada espirometria antes e depois de 80 μg de ipratrópio e 400 μg de salbutamol, administrados 90 e 30 minutos antes, respectivamente. A administração de dois broncodilatadores e a sua temporalidade teve como objectivo atingir a broncodilatação máxima ou quase máxima. O FEV1 basal após esta broncodilatação, no estudo UPLIFT, permitiu: – examinar a resposta broncodilatadora aguda numa grande coorte de doentes com DPOC moderada a muito grave; – determinar o que pode ser considerado critério de resposta usando vários critérios de reversibilidade; – avaliar as características dos doentes com e sem reversibilidade.

  3. Validação do teste Need For Cognition: um estudo em contabilidade comportamental

    OpenAIRE

    Lima Filho, Raimundo Nonato; Bruni, Adriano Leal; Menezes, Igor Gomes

    2013-01-01

    Este estudo teve como objetivo validar a escala Need For Cognition (NFC) em estudos em Contabilidade comportamental. Ademais, buscou-se medir possíveis correlações entre o nível de necessidade de cognição e a existência de vieses cognitivos em decisões contábeis e financeiras. Para efetivar o processo de validação completo, foram realizadas duas validações - critério e construto. A análise foi feita mediante a apreciação de uma amostra formada por 128 estudantes de pós-graduação. A técnica es...

  4. Clinical comparative study between the use of lasers and conventional methods of diagnosis and treatment in deciduous teeth with presence of carious lesion; Estudo clinico comparativo entre o uso de lasers e metodos convencionais de diagnostico e tratamento em dentes deciduos da presenca de lesao cariosa

    Energy Technology Data Exchange (ETDEWEB)

    Pulga, Fabiane Galvao

    2001-07-01

    The aim of this work was to evaluate the efficiency of deciduous tooth cavity preparation by the Er:YAG laser in comparison with the conventional burr rotary instrument. Besides, we have used the laser fluorescence technique (DIAGNOdent equipment) for diagnosis and compared it to the usual tactile and visual examination as well as X-ray diagnosis. For this purpose, 20 chronic occlusal carious deciduous molar teeth from children with the ages between 5 to 10 years old were selected. Selection was ma de according to visual inspection, X-ray periapical image and measures of the DIAGNOdent. For treatment the teeth were divided in two groups, 10 to be treated by the Er:YAG laser and 10 with conventional burr. For enamel, the laser energy used was in the interval from 200 to 300 mJ; for the dentine the range was from 100 mJ to 200 mJ. In both cases, the laser frequency was in the range from 2 to 4 Hz. The results have shown that the laser treatment was more accepted by the children than the conventional burro Clinical evaluation of the cavity preparation indicates that the Er:YAG laser treatment is recommend. The DIAGNOdent evaluation method was very effective for diagnosis of carious tissue for initial detection. After successful removal of the carious tissue, confirmed by visual inspection, the DIAGNOdent evaluation method was only effective for the treatment with conventional burro For evaluation of the tooth after cavity preparation with the Er:YAG laser, the measurements oscillate covering the full range of the equipment. Therefore, the use of the DIAGNOdent equipment is indicated only for initial caries diagnosis. (author)

  5. The Mercury Laser Advances Laser Technology for Power Generation

    Energy Technology Data Exchange (ETDEWEB)

    Ebbers, C A; Caird, J; Moses, E

    2009-01-21

    The National Ignition Facility (NIF) at Lawrence Livermore Laboratory is on target to demonstrate 'breakeven' - creating as much fusion-energy output as laser-energy input. NIF will compress a tiny sphere of hydrogen isotopes with 1.8 MJ of laser light in a 20-ns pulse, packing the isotopes so tightly that they fuse together, producing helium nuclei and releasing energy in the form of energetic particles. The achievement of breakeven will culminate an enormous effort by thousands of scientists and engineers, not only at Livermore but around the world, during the past several decades. But what about the day after NIF achieves breakeven? NIF is a world-class engineering research facility, but if laser fusion is ever to generate power for civilian consumption, the laser will have to deliver pulses nearly 100,000 times faster than NIF - a rate of perhaps 10 shots per second as opposed to NIF's several shots a day. The Mercury laser (named after the Roman messenger god) is intended to lead the way to a 10-shots-per-second, electrically-efficient, driver laser for commercial laser fusion. While the Mercury laser will generate only a small fraction of the peak power of NIF (1/30,000), Mercury operates at higher average power. The design of Mercury takes full advantage of the technology advances manifest in its behemoth cousin (Table 1). One significant difference is that, unlike the flashlamp-pumped NIF, Mercury is pumped by highly efficient laser diodes. Mercury is a prototype laser capable of scaling in aperture and energy to a NIF-like beamline, with greater electrical efficiency, while still running at a repetition rate 100,000 times greater.

  6. Vivências de pais diante da Unidade de Terapia Intensiva Neonatal: um estudo de caso

    Directory of Open Access Journals (Sweden)

    Suzane Pereira Busatta

    2011-01-01

    Full Text Available http://dx.doi.org/10.5007/2178-4582.2011v45n1p135 O presente estudo buscou investigar a percepção dos pais sobre a internação de um filho internado em Unidade de Terapia Intensiva Neonatal (UTIN. Foi utilizada a metodologia qualitativa, por meio de um estudo de caso e como instrumento de coleta de dados a entrevista semi-estruturada com um pai e uma mãe de um bebê prematuro internado em UTIN. O conteúdo das entrevistas foi analisado por meio da metodologia de análise de conteúdo, constituindo duas categorias e quatro subcategorias, que possibilitaram a compreensão de que o casal deste estudo vivenciou momentos de ambiva- lência de sentimentos, de uma rotina modificada pela hospitalização, bem como a busca de apoio para enfrentar estas situações. Percebeu-se a impor- tância do psicólogo no sentido de auxiliar os pais neste momento de sofri- mento psicológico.

  7. Laser program overview

    International Nuclear Information System (INIS)

    Storm, E.; Coleman, L.W.

    1985-01-01

    The objectives of the Lawrence Livermore National Laboratory Laser Fusion program are to understand and develop the science and technology of inertial confinement fusion (ICF), and to utilize ICF in short- and long-term military applications, and, in the long-term, as a candidate for central-station civilian power generation. In 1984, using the Novette laser system, the authors completed experiments showing the very favorable scaling of laser-plama interactions with short-wavelength laser light. Their Novette experiments have unequivocally shown that short laser wavelength, i.e., less than 1 μm, is required to provide the drive necessary for efficient compression, ignition, and burn of DT fusion fuel. In other experiments with Novette, the authors made the first unambiguous observation of amplified spontaneous emission in the soft x-ray regime. The authors also conducted military applications and weapons physics experiments, which they discuss in detail in the classified volume of our Laser Program Annual Report. In the second thrust, advanced laser studies, they develop and test the concepts, components, and materials for present and future laser systems. Over the years, this has meant providing the technology base and scientific advances necessary to construct and operate a succession of six evermore-powerful laser systems. The latest of these, Nova, a 100-TW/100-kJ-class laser system, was completed in 1984. The Nd:glass laser continues to be the most effective and versatile tool for ICF and weapons physics because of its scalability in energy, the ability to efficiently convert its 1=μm output to shorter wavelengths, its ability to provide flexible, controlled pulse shaping, and its capability to adapt to a variety of irradiation and focusing geometries. For these reasons, many of our advanced laser studies are in areas appropriate to solid state laser technologies

  8. MODOS DE SER JOVEM NA ESCOLA: um estudo de caso etnográfico

    Directory of Open Access Journals (Sweden)

    Livian Lino Netto

    2016-08-01

    Full Text Available O artigo apresenta um recorte de pesquisa realizada com estudantes do Instituto Federal Sul-rio-grandense, que teve por objetivo descrever imagens da juventude com foco na percepção que os jovens têm sobre si mesmos na escola. A partir de princípios qualitativos, o estudo caracterizou-se como estudo de caso de inspiração etnográfica. A coleta foi realizada através da filmagem de documentários pelos estudantes sobre o que é ser jovem na escola e qual o sentido da mesma em suas vidas. Como resultado, afirma-se que o principal sentido atribuído pelos jovens à escola é o estar junto com o outro.

  9. Power balancing of multibeam laser fusion lasers

    International Nuclear Information System (INIS)

    Seka, W.; Morse, S.; Letzring, S.; Kremens, R.; Kessler, T.J.; Jaanimagi, P.; Keck, R.; Verdon, C.; Brown, D.

    1989-01-01

    The success of laser fusion depends to a good degree on the ability to compress the target to very high densities of ≥1000 times liquid DT. To achieve such compressions require that the irradiation nonuniformity must not exceed ∼1% rms over the whole time of the compression, particularly during the early phases of irradiation. The stringent requirements for the irradiation uniformity for laser fusion have been known for quite some time but until recently the energy balance was mistakenly equated to power balance. The authors describe their effort on energy balance and irradiation patterns on the target. They significantly improved the laser performance with respect to overall intensity distributions on target including the implementation of distributed (random) phase plates in each high power beam. However, the slightly varying performance of the third harmonic conversion crystals in the twenty-four beams of their laser system was generally compensated for by appropriately adjusted 1.054μm input laser energy. Computational analysis of the results of the recent high density campaign are shown

  10. Biocavity Lasers

    Energy Technology Data Exchange (ETDEWEB)

    Gourley, P.L.; Gourley, M.F.

    2000-10-05

    Laser technology has advanced dramatically and is an integral part of today's healthcare delivery system. Lasers are used in the laboratory analysis of human blood samples and serve as surgical tools that kill, burn or cut tissue. Recent semiconductor microtechnology has reduced the size o f a laser to the size of a biological cell or even a virus particle. By integrating these ultra small lasers with biological systems, it is possible to create micro-electrical mechanical systems that may revolutionize health care delivery.

  11. An overview of the laser ranging method of space laser altimeter

    Science.gov (United States)

    Zhou, Hui; Chen, Yuwei; Hyyppä, Juha; Li, Song

    2017-11-01

    Space laser altimeter is an active remote sensing instrument to measure topographic map of Earth, Moon and planetary. The space laser altimeter determines the range between the instrument and laser footprint by measuring round trip time of laser pulse. The return pulse reflected from ground surface is gathered by the receiver of space laser altimeter, the pulsewidth and amplitude of which are changeable with the variability of the ground relief. Meantime, several kinds of noise overlapped on the return pulse signal affect its signal-to-noise ratio. To eliminate the influence of these factors that cause range walk and range uncertainty, the reliable laser ranging methods need to be implemented to obtain high-precision range results. Based on typical space laser altimeters in the past few decades, various ranging methods are expounded in detail according to the operational principle of instruments and timing method. By illustrating the concrete procedure of determining time of flight of laser pulse, this overview provides the comparison of the employed technologies in previous and undergoing research programs and prospect innovative technology for space laser altimeters in future.

  12. Novel laterally pumped by prism laser configuration for compact solid-state lasers

    International Nuclear Information System (INIS)

    Dascalu, T; Salamu, G; Sandu, O; Voicu, F; Pavel, N

    2013-01-01

    We propose a new laser configuration in which the pump radiation is coupled into the laser crystal through a prism. The laser medium is square shaped and the prism is attached on one of its lateral sides, near one of the crystal extremities. The diode-laser fiber end is placed close to the prism hypotenuse, the pump radiation is coupled into the laser crystal through the opposite surface of the prism and propagates into the crystal through total internal reflections. This laser geometry is simple to align and permits the realization of compact diode-pumped laser systems, as well as power scaling. A diode-pumped Nd:YAG laser yielding pulses of 2.1 mJ energy under a pump with pulses of 9.9 mJ is demonstrated. The laser slope efficiency is 0.22. Furthermore, this geometry enables one to obtain passively Q-switched lasers with the saturable absorber crystal placed between the resonator high-reflectivity mirror and the laser crystal. A Nd:YAG laser, passively Q-switched by a Cr 4+ :YAG crystal with initial transmission T 0 = 0.90, delivering laser output with a pulsed energy of 93 μJ, a duration of 26 ns and a pump threshold of 1.9 mJ, is realized in order to prove the concept. (letter)

  13. Relação universidade-empresa: um estudo no setor de T.I. do Estado do Rio Grande do Sul

    OpenAIRE

    Zanluchi, João Batista

    2015-01-01

    A relação Universidade-Empresa é um tema em constante debate na esfera nacional, sendo que vários estudos buscam avaliar esta relação sob diversos ângulos e focos de pesquisa. O referencial teórico sobre o tema apresenta uma carência de estudos com foco na empresa. Com base nesta premissa este estudo investigou a relação Universidade-Empresa no setor de T.I. do Estado do Rio Grande do Sul com o objetivo de avaliar como é o relacionamento das empresas com as universidades. A metodologia adotad...

  14. A Laser Technology Test Facility for Laser Inertial Fusion Energy (LIFE)

    International Nuclear Information System (INIS)

    Bayramian, A.J.; Campbell, R.W.; Ebbers, C.A.; Freitas, B.L.; Latkowski, J.; Molander, W.A.; Sutton, S.B.; Telford, S.; Caird, J.A.

    2010-01-01

    A LIFE laser driver needs to be designed and operated which meets the rigorous requirements of the NIF laser system while operating at high average power, and operate for a lifetime of >30 years. Ignition on NIF will serve to demonstrate laser driver functionality, operation of the Mercury laser system at LLNL demonstrates the ability of a diode-pumped solid-state laser to run at high average power, but the operational lifetime >30 yrs remains to be proven. A Laser Technology test Facility (LTF) has been designed to specifically address this issue. The LTF is a 100-Hz diode-pumped solid-state laser system intended for accelerated testing of the diodes, gain media, optics, frequency converters and final optics, providing system statistics for billion shot class tests. These statistics will be utilized for material and technology development as well as economic and reliability models for LIFE laser drivers.

  15. Perspectivas psicossociais para o estudo do cotidiano de trabalho

    Directory of Open Access Journals (Sweden)

    Fábio de Oliveira

    2014-04-01

    Full Text Available Este estudo teve por objetivo analisar o debate e o aprofundamento teórico e metodológico desenvolvido nos estudos sobre a vida cotidiana no trabalho. A investigação partiu do diálogo interdisciplinar entre a antropologia do trabalho, a ergologia e a psicologia social do trabalho e sistematizou as contribuições mútuas entre esses campos científicos, suas aproximações e seus afastamentos da tematização e da apropriação da atividade humana no trabalho sob a perspectiva do cotidiano. A análise comparativa destacou eixos que diferenciam as formas de aproximação ao objeto, que se referem às relações estabelecidas entre saberes práticos e técnico-científicos e aos modos de intervenção sobre as situações de trabalho. As abordagens comparativas compartilham o interesse em conhecer o trabalho real, o valor conferido aos conhecimentos dos trabalhadores e a sensibilidade às dimensões micropolíticas do cotidiano. Conclui-se que a localização em cada um desses eixos depende da maior ou menor filiação às tradições da antropologia ou da ergonomia.

  16. GESTÃO DE MARCAS: UM ESTUDO SOBRE A UNIMED

    Directory of Open Access Journals (Sweden)

    Hellen Taís Zanóbio

    2018-03-01

    Full Text Available O crescimento da demanda por serviços de saúde suplementar somado às mudanças da relação marca versus consumidor tornam esse mercado cada vez mais competitivo. Esses fatores implicam na movimentação das prestadoras deste tipo de serviço em relação à necessidade de identificar e implantar a melhor forma de gestão de marca, com o objetivo de torná-la conhecida e diferenciada. A empresa estudada foi a Unimed, a maior Cooperativa de Trabalho Médico do Brasil, onde se aplica o seguinte problema de pesquisa: quais as estratégias utilizadas pela Unimed na gestão de sua marca? Este estudo tem o objetivo de estudar as estratégias aplicadas pela Unimed em estudos que as exploram utilizando a metodologia de pesquisa de Revisão Bibliográfica. Os resultados obtidos foram o destaque da importância dada pela Unimed à gestão de sua marca onde a centraliza como diferencial competitivo, e o sucesso do uso das estratégias de gestão de marca como a identidade, imagem, personalidade, arquitetura e valor, tornando-a uma marca forte e consolidada no mercado.

  17. Robot-laser system

    International Nuclear Information System (INIS)

    Akeel, H.A.

    1987-01-01

    A robot-laser system is described for providing a laser beam at a desired location, the system comprising: a laser beam source; a robot including a plurality of movable parts including a hollow robot arm having a central axis along which the laser source directs the laser beam; at least one mirror for reflecting the laser beam from the source to the desired location, the mirror being mounted within the robot arm to move therewith and relative thereto to about a transverse axis that extends angularly to the central axis of the robot arm; and an automatic programmable control system for automatically moving the mirror about the transverse axis relative to and in synchronization with movement of the robot arm to thereby direct the laser beam to the desired location as the arm is moved

  18. Development of a compact vertical-cavity surface-emitting laser end-pumped actively Q-switched laser for laser-induced breakdown spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Li, Shuo; Chen, Rongzhang; Nelsen, Bryan; Chen, Kevin, E-mail: pec9@pitt.edu [Department of Electrical and Computer Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15260 (United States); Liu, Lei; Huang, Xi; Lu, Yongfeng [Department of Electrical and Computer Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588 (United States)

    2016-03-15

    This paper reports the development of a compact and portable actively Q-switched Nd:YAG laser and its applications in laser-induced breakdown spectroscopy (LIBS). The laser was end-pumped by a vertical-cavity surface-emitting laser (VCSEL). The cavity lases at a wavelength of 1064 nm and produced pulses of 16 ns with a maximum pulse energy of 12.9 mJ. The laser exhibits a reliable performance in terms of pulse-to-pulse stability and timing jitter. The LIBS experiments were carried out using this laser on NIST standard alloy samples. Shot-to-shot LIBS signal stability, crater profile, time evolution of emission spectra, plasma electron density and temperature, and limits of detection were studied and reported in this paper. The test results demonstrate that the VCSEL-pumped solid-state laser is an effective and compact laser tool for laser remote sensing applications.

  19. Estudo de caso controle para avaliar o impacto do abuso sexual infantil nos transtornos alimentares

    Directory of Open Access Journals (Sweden)

    Felipe Paraventi

    2011-01-01

    Full Text Available CONTEXTO: O objetivo deste estudo foi investigar se antecedente de abuso sexual na infância (ASI está associado com transtornos alimentares na vida adulta. MÉTODOS: Realizou-se um estudo de caso controle (N = 120 comparando mulheres com transtornos alimentares tratadas em ambulatório universitário especializado com um grupo controle de pacientes de clínica não psiquiátrica (ambulatório de oftalmologia. RESULTADOS: Este estudo encontrou maior prevalência de ASI na anorexia nervosa (AN comparada ao grupo controle (50% versus 14,8%; OR = 5,8 IC 95% = 1,3-25,6; p < 0,05, entretanto não identificou diferença estatística entre os grupos comparando com casos de bulimia nervosa (BN (26,7% versus 27% no grupo controle; OR = 0,99; IC 95% = 0,24-4,1 e com transtorno de compulsão alimentar periódica (TCAP, apesar da maior prevalência de ASI observada neste último em relação ao grupo controle (43,7% versus 27,3%; OR = 2,1 IC 95% = 0,5- 8,1. Considerando-se a presença de dois ou mais episódios de ASI, observou-se também maior prevalência em AN (35,7% versus 3,7% nos controles; OR = 14,4 IC 95% = 1,5-140,8; p < 0,05. CONCLUSÃO: Este estudo mostrou forte associação da anorexia nervosa com antecedentes de abuso sexual na infância.

  20. Contribuições das teorias institucionais para o estudo de subsidiárias de corporações multinacionais

    Directory of Open Access Journals (Sweden)

    Takeyoshi Imasato

    Full Text Available Este ensaio destaca, inicialmente, as contribuições dos Estudos Organizacionais para o entendimento das corporações multinacionais. Em decorrência da capacidade de influenciar os demais atores nos âmbitos local, nacional, regional, internacional e transnacional, as multinacionais desafiam as abordagens tradicionais de estudos organizacionais seguidas por pesquisadores da área de Gestão Internacional. A seguir, o ensaio explora as possibilidades e os limites das abordagens de teoria institucional para o entendimento das subsidiárias de corporações multinacionais. Esse aporte teórico pode auxiliar tanto no estudo dessas empresas quanto da natureza das diferenças entre as instituições nos diversos países de operação, por possibilitarem a análise simultânea de múltiplos contextos institucionais simultaneamente. Como resultado, o ensaio contribui para o desenvolvimento teórico das interfaces entre as áreas de Estudos Organizacionais e de Gestão Internacional, principalmente, no que se refere às investigações que enfatizem o papel estratégico das subsidiárias.

  1. Laser in urology

    International Nuclear Information System (INIS)

    Breisland, H.O.

    1991-01-01

    The neodymium YAG laser is particularly suited for endoscopic urologic surgery because the YAG laser light can be conducted in flexible fibers. Superficial bladder tumours can be treated under local anaesthesia in the outpatient department. The frequency of local recurrences is low, significantly lower than after electrosection or electrocoagulation. Selected cases of T2-muscle invasive bladder tumours can be cured with laser coagulation applied subsequently to transurethral resection. Combined treatment with electrosection and laser coagulation of localized prostatic cancer is a promising method which compares favourably with results obtained by other treatment modalities. Tumours in the upper urinary tract can be laser-treated through ureteroscopes or nephroscopes, but the treatment should be limited to low stage, low grade tumours. Laser is the treatment of choice for intraurethral condylomatas. Laser treatment of penil carcinoma gives excellent cosmetic and functional results and few local recurrences. Laser lithotripsy is a new technique for treatment of ureteric stones and photodynamic laser therapy is a promising tecnique for treatment of carcinoma in situ in the bladder empithelium. However, neither of these techniques are available for clinical use in Norway as yet. 17 refs., 3 figs., 1 tabs

  2. Laser-induced interactions

    International Nuclear Information System (INIS)

    Green, W.R.

    1979-01-01

    This dissertation discusses some of the new ways that lasers can be used to control the energy flow in a medium. Experimental and theoretical considerations of the laser-induced collision are discussed. The laser-induced collision is a process in which a laser is used to selectively transfer energy from a state in one atomic or molecular species to another state in a different species. The first experimental demonstration of this process is described, along with later experiments in which lasers were used to create collisional cross sections as large as 10 - 13 cm 2 . Laser-induced collisions utilizing both a dipole-dipole interaction and dipole-quadrupole interaction have been experimentally demonstrated. The theoretical aspects of other related processes such as laser-induced spin-exchange, collision induced Raman emission, and laser-induced charge transfer are discussed. Experimental systems that could be used to demonstrate these various processes are presented. An experiment which produced an inversion of the resonance line of an ion by optical pumping of the neutral atom is described. This type of scheme has been proposed as a possible method for constructing VUV and x-ray lasers

  3. Multimegajoule laser project: new compact multipass laser design

    International Nuclear Information System (INIS)

    Holzrichter, J.F.

    1985-01-01

    A simple laser design that has the fewest laser components of all fusion systems that the authors have studied and that packs closely, thus minimizing space requirements is shown. The Advanced Laser Program objectives are determined by the requirements of the subsystems. The requirements consists of the following elements: high damage thresholds on reflectors; AR layers and dichroic coatings; high-efficiency amplifiers; low-cost production of laser glass, pulse power, and optical elements; and special optical elements, such as an effective phase conjugator and isolator. The combination of a compact architecture and lower-cost, higher-performance components can lead to significant reduction in overall system cost

  4. Laser Propulsion - Quo Vadis

    International Nuclear Information System (INIS)

    Bohn, Willy L.

    2008-01-01

    First, an introductory overview of the different types of laser propulsion techniques will be given and illustrated by some historical examples. Second, laser devices available for basic experiments will be reviewed ranging from low power lasers sources to inertial confinement laser facilities. Subsequently, a status of work will show the impasse in which the laser propulsion community is currently engaged. Revisiting the basic relations leads to new avenues in ablative and direct laser propulsion for ground based and space based applications. Hereby, special attention will be devoted to the impact of emerging ultra-short pulse lasers on the coupling coefficient and specific impulse. In particular, laser sources and laser propulsion techniques will be tested in microgravity environment. A novel approach to debris removal will be discussed with respect to the Satellite Laser Ranging (SRL) facilities. Finally, some non technical issues will be raised aimed at the future prospects of laser propulsion in the international community

  5. Distributed feedback dye laser pumped with copper-vapor laser emission

    Energy Technology Data Exchange (ETDEWEB)

    Mirza, S Yu; Soldatov, A N; Sukhanov, V B

    1983-10-01

    The power-spectrum characteristics of the emission of a distributed feedback dye laser pumped with a copper vapor laser have been studied. Laser action has been observed in five dyes over a tuning range of 530-723 nm with an efficiency of 12.4%. The specfic features of the distributed feedback dye laser operating at pulse repetition rates of 4 kHz are discussed.

  6. Influence of the laser pulse duration on laser-produced plasma properties

    International Nuclear Information System (INIS)

    Drogoff, B Le; Margot, J; Vidal, F; Laville, S; Chaker, M; Sabsabi, M; Johnston, T W; Barthelemy, O

    2004-01-01

    In the framework of laser-induced plasma spectroscopy (LIPS) applications, time-resolved characteristics of laser-produced aluminium plasmas in air at atmospheric pressure are investigated for laser pulse durations ranging from 100 fs to 270 ps. Measurements show that for delays after the laser pulse longer than ∼100 ns, the plasma temperature increases slightly with the laser pulse duration, while the electron density is independent of it. In addition, as the pulse duration increases, the plasma radiation emission lasts longer and the spectral lines arise later from the continuum emission. The time dependence of the continuum emission appears to be similar whatever the duration of the laser pulse is, while the temporal evolution of the line emission seems to be affected mainly by the plasma temperature. Finally, as far as spectrochemical applications (such as LIPS) of laser-produced plasmas are concerned, this study highlights the importance of the choice of appropriate temporal gating parameters for each laser pulse duration

  7. PERCEÇÕES SOBRE AS ABORDAGENS À APRENDIZAGEM – ESTUDO DE VARIÁVEIS PSICOLÓGICAS

    OpenAIRE

    Lourenço, Abílio Afonso; Nogueira, Carla Maria Leite

    2014-01-01

    Esta investigação, realizada numa escola básica no norte de Portugal, tem como objetivo analisar as perceções que os alunos apresentam sobre algumas variáveis relativas à forma como desenvolvem a sua aprendizagem, nomeadamente: a autorregulação para a aprendizagem; os processos de estudo utilizados; o controlo volitivo; a planificação da gestão do tempo; e a procrastinação. Outra finalidade deste estudo éverificar se existe uma relação significativa entre estas variáveis e a perceção de autoe...

  8. Estudo paramétrico para um muro de gravidade submetido a carregamentos sísmicos.

    OpenAIRE

    Tatiana Galvão Kurz

    2014-01-01

    A presente dissertação apresenta um estudo do comportamento de um muro de gravidade flexível submetido a carregamentos sísmicos. A influência do carregamento sísmico, e mais precisamente da variação da aceleração horizontal de pico é avaliada num estudo paramétrico, através da análise dos resultados obtidos para os deslocamentos e acelerações horizontais que ocorreram no paramento do muro de gravidade. Optou-se pela análise ao longo do tempo, introduzindo o carregamento sísmico ao modelo numé...

  9. Sindrome de Landau Kleffner aspectos clinicos, eletrencefalograficos e psicossociais : estudo de seguimento a longo prazo

    OpenAIRE

    Marcos Henrique Coelho Duran

    2008-01-01

    Resumo: Objetivos: A Síndrome de Landau-Kleffner (SLK) é uma entidade rara, caracterizada por epilepsia e afasia. Ocorre em crianças com aquisição normal da linguagem, geralmente, entre 3 e 7 anos de idade. A evolução a longo prazo é controversa e pouco estudada. O presente estudo tem como objetivo verificar a evolução em uma série de sujeitos com diagnóstico de SLK, enfocando os aspectos clínicos, eletrencefalográficos, psicossociais e da qualidade de vida. Métodos: Trata-se de um estudo tra...

  10. Síndrome icterícia em gatos: revisão de literatura e estudo retrospectivo

    OpenAIRE

    OLIVEIRA, Roberta Alencar de; DANIEL, Alexandre Gonçalves Teixeira; RECHE JUNIOR, Archivaldo

    2008-01-01

    Icterícia é uma alteração clínica comumente encontrada nos felinos, causada por níveis excessivos de bilirrubina na circulação e nos tecidos, indicando hemólise grave ou doença hepatobiliar. Este trabalho é composto por uma revisão da literatura e um estudo retrospectivo sobre a síndrome icterícia em felinos e suas principais causas: lipidose hepática, colângio-hepatite, tríade felina e micoplasmose felina. O estudo retrospectivo foi realizado utilizando-se das informações contidas nos prontu...

  11. História e oralidade nos estudos comunicacionais

    Directory of Open Access Journals (Sweden)

    Juniele Rabêlo Almeida

    2016-05-01

    Full Text Available Concepções, métodos e formas do conhecimento histórico são expressos em diversos estudos na área de comunicação social. Buscamos analisar, na interface história e narrativa oral, aspectos da chamada mediação cultural, na qual a comunicação está para além da condição de canal. Acreditamos que os estudos comunicacionais não recaem, necessariamente, sobre especificidades técnicas, mas sobre a posição que a comunicação assume no campo histórico-cultural. Interações, expressas nos trabalhos de história oral, se configuram (e resultam em processos comunicacionais que indicam construções sócio históricas e diferentes referenciais de pertencimento. Palavras-chave: Estudos comunicacionais, História, Narrativas Orais.   Abstract: Conceptions, methods and historical knowledge forms are expressed in several studies in the area of social communication. We analyze, history and oral narrative interface, called aspects of cultural mediation, in which the communication is in addition to the channel condition. We believe that communication studies do not fall necessarily on technicalities, but on the position that the communication is in the historical-cultural field. Interactions, expressed in the works of oral history, are configured (and result in communication processes that indicate historical social constructions and different frames of belonging. Keywords: communication Studies, History, Oral Narratives.   Resumen: Conceptos, métodos y formas de conocimiento histórico se expresan en varios estudios en el área de la comunicación social. Analizamos, la historia y la interfaz de la narrativa oral, llamados aspectos de mediación cultural, en el que la comunicación es, además de la condición de canal. Creemos que los estudios de comunicación no caen necesariamente en técnicos, sino a la posición de que la comunicación es en el campo histórico-cultural. Interacciones, expresados en las obras de la historia oral, est

  12. Laser cleaning of pulsed laser deposited rhodium films for fusion diagnostic mirrors

    International Nuclear Information System (INIS)

    Uccello, A.; Maffini, A.; Dellasega, D.; Passoni, M.

    2013-01-01

    Highlights: ► Pulsed laser deposition is exploited to produce Rh films for first mirrors. ► Pulsed laser deposition is exploited to produce tokamak-like C contaminants. ► Rh laser damage threshold has been evaluated for infrared pulses. ► Laser cleaning of C contaminated Rh films gives promising results. -- Abstract: In this paper an experimental investigation on the laser cleaning process of rhodium films, potentially candidates to be used as tokamak first mirrors (FMs), from redeposited carbon contaminants is presented. A relevant issue that lowers mirror's performance during tokamak operations is the redeposition of sputtered material from the first wall on their surface. Among all the possible techniques, laser cleaning, in which a train of laser pulses is launched to the surface that has to be treated, is a method to potentially mitigate this problem. The same laser system (Q-switched Nd:YAG laser with a fundamental wavelength of 1064-nm and 7-ns pulses) has been employed with three aims: (i) production by pulsed laser deposition (PLD) of Rh film mirrors, (ii) production by PLD of C deposits with controlled morphology, and (iii) investigation of the laser cleaning method onto C contaminated Rh samples. The evaluation of Rh films laser damage threshold, as a function of fluence and number of pulses, is discussed. Then, the C/Rh films have been cleaned by the laser beam. The exposed zones have been characterized by visual inspection and scanning electron microscopy (SEM), showing promising results

  13. Attenuation of laser power of a focused Gaussian beam during interaction between a laser and powder in coaxial laser cladding

    International Nuclear Information System (INIS)

    Liu Jichang; Li Lijun; Zhang Yuanzhong; Xie Xiaozhu

    2005-01-01

    The power of a focused laser beam with a Gaussian intensity profile attenuated by powder in coaxial laser cladding is investigated experimentally and theoretically, and its resolution model is developed. With some assumptions, it is concluded that the attenuation of laser power is an exponential function and is determined by the powder feed rate, particle moving speed, spraying angles and waist positions and diameters of the laser beam and powder flow, grain diameter and run of the laser beam through the powder flow. The attenuation of laser power increases with powder feed rate or run of laser beam through the powder flow. In the experiment presented, 300 W laser power from a focused Gaussian beam is attenuated by a coaxial powder flow. The experimental results agree well with the values calculated with the developed model

  14. Estra: um corpus para o estudo do estilo da tradução

    Directory of Open Access Journals (Sweden)

    Célia Magalhães

    2014-12-01

    Full Text Available Este artigo apresenta a evolução e as contribuições da pesquisa em estudos da tradução orientados para corpora no Brasil. Faz-se uma revisão dos trabalhos iniciais desenvolvidos no Laboratório Experimental de Tradução (LETRA, mostrando que a maioria deles adotava uma abordagem de linguística contrastiva da tradução e que as pesquisas, gradualmente, foram evoluindo para uma preocupação com a estilística tradutória e o estilo do tradutor literário. Também se relata a compilação de um corpus para o estudo do estilo da tradução, o ESTRA, projetado exclusivamente para esse fim. Mostra-se como a pesquisa de corpora do ESTRA promove a interdisciplinaridade nos estudos da tradução e introduz a triangulação de resultados de análises realizadas com procedimentos metodológicos das diferentes abordagens usadas para estudar o estilo. Descrevem-se procedimentos metodológicos novos, em especial a etiquetagem do corpus para algumas das categorias de estilo. Termina-se o artigo com uma visão crítica sobre o que tem sido feito até o presente, apresentando perspectivas futuras de pesquisa em estilística tradutória no LETRA.

  15. Tunable laser applications

    CERN Document Server

    Duarte, FJ

    2008-01-01

    Introduction F. J. Duarte Spectroscopic Applications of Tunable Optical Parametric Oscillators B. J. Orr, R. T. White, and Y. He Solid-State Dye Lasers Costela, I. García-Moreno, and R. Sastre Tunable Lasers Based on Dye-Doped Polymer Gain Media Incorporating Homogeneous Distributions of Functional Nanoparticles F. J. Duarte and R. O. James Broadly Tunable External-Cavity Semiconductor Lasers F. J. Duarte Tunable Fiber Lasers T. M. Shay and F. J. Duarte Fiber Laser Overview and Medical Applications

  16. Estudo sobre reciclagem de lâmpadas fluorescentes

    Directory of Open Access Journals (Sweden)

    Danniele Miranda Bacila

    2014-01-01

    Full Text Available Lâmpadas fluorescentes (LF contêm mercúrio em sua composição, um metal pesado que pode causar danos à saúde e ao meio ambiente. As LF são amplamente consumidas no Brasil, porém o descarte correto de LF usadas não é amplamente divulgado e os índices de reciclagem são baixos. O objetivo deste estudo foi demonstrar a relevância do descarte adequado, avaliar as tecnologias de reciclagem e a destinação dos materiais, por meio de estudo comparativo entre Brasil e Alemanha. Através de visitas a recicladoras e análise das tecnologias adotadas nos dois países, foi verificado que no Brasil o vidro é destinado à indústria de cerâmica, enquanto que na Alemanha é destinado à fabricação de tubos para LF. Além disso, foi observado que o mercúrio apresenta diversas possibilidades de uso. Um ponto a ser explorado nos dois países, e de grande potencial para reciclagem, é a recuperação de terras raras do pó fosfórico presente nas LF. Tanto Brasil como Alemanha possuem oportunidades de melhoria na logística reversa de LF, por meio da qual se torna possível elevar os índices de reciclagem e reduzir os impactos ambientais causados pelo descarte inadequado de LF usadas.

  17. Greco Laser-matter interaction

    International Nuclear Information System (INIS)

    1986-01-01

    Research program in 1985 at GRECO ILM (Group of Coordinated Research: Interaction Laser Matter) continued with its principal direction in fundamental physics of laser inertial confinement; also researches on X-ray lasers hare been undergone and new high power laser application fields with particle acceleration, material processing and X-ray sources. A six beam laser was operated. Wavelength effects were studied. Atomic physics was deeply stressed as dense medium diagnostics from multicharged ions. Research development in ultra-dense medium was also important X-ray laser research gave outstanding results. New research fields were developed this year: laser acceleration of particles by wave beating or Raman instability; dense laser produced plasma use as X-ray source; material processing by laser shocks [fr

  18. Laser applications in materials processing

    International Nuclear Information System (INIS)

    Ready, J.F.

    1980-01-01

    The seminar focused on laser annealing of semiconductors, laser processing of semiconductor devices and formation of coatings and powders, surface modification with lasers, and specialized laser processing methods. Papers were presented on the theoretical analysis of thermal and mass transport during laser annealing, applications of scanning continuous-wave and pulsed lasers in silicon technology, laser techniques in photovoltaic applications, and the synthesis of ceramic powders from laser-heated gas-phase reactants. Other papers included: reflectance changes of metals during laser irradiation, surface-alloying using high-power continuous lasers, laser growth of silicon ribbon, and commercial laser-shock processes

  19. HF laser

    International Nuclear Information System (INIS)

    Suzuki, Kazuya; Iwasaki, Matae

    1977-01-01

    A review is made of the research and development of HF chemical laser and its related work. Many gaseous compounds are used as laser media successfully; reaction kinetics and technological problems are described. The hybrid chemical laser of HF-CO 2 system and the topics related to the isotope separation are also included. (auth.)

  20. Effects of the infrared diode low intensity laser therapy for oral mucositis: a clinical trial; Estudo clinico dos efeitos do laser diodo de baixa intensidade de emissao infravermelha para casos de mucosite bucal

    Energy Technology Data Exchange (ETDEWEB)

    Freire, Maria do Rosario Santos

    2004-07-01

    Chemotherapy associated or not with radiotherapy and surgery may be used for treating patients presenting some pathogenies such as cancer. Many side effects are visibly in the mouth in several forms as a consequence of this treatment and oral mucositis is the most common, with great prevalence, causing degrees of morbidity and even death. This research is about improving the quality of life for these patients by using of laser radiation through a GaAlAs active medium, in a continuous manner, with a low power ( 60 mW), the diode laser acting at 780 nm wavelength infrared, with a energy density 7,5 J/cm{sup 2} and 6,0 J/cm{sup 2}, for the therapeutic and preventive groups respectively, and a third control group without radiation. Two protocols were studied in patients during 5-fluorouracil chemotherapic regime and combinations, because nowadays polychemotherapy is used, an associations of drugs, for a neoadjuvant treatment, adjuvant, potentionalize or palliative means, for the chemotherapy treatment. In a context of 60 patients, 16 patients had received the laser irradiations doses, 10 days for the therapeutic protocols and 11 days for the preventive irradiations. The therapeutic group presented a 50% of the total healing process and significant decrease in symptoms of pain (VAS=0 with p =0,01). For the preventive irradiations (D-5, D, D+5), that means the day of the QT, 5 days before the chemotherapy regime starts until 5 days later, only 1 patient had some kind of ulceration during more than four months of control. Results of the present study showed to be effective and promising for both employed protocols, therapeutic and preventive. Further studies must be developed in order to improve the present results. (author)

  1. Multibeam Fibre Laser Cutting

    DEFF Research Database (Denmark)

    Olsen, Flemming Ove

    The appearance of the high power high brilliance fibre laser has opened for new possibilities in laser materials processing. In laser cutting this laser has demonstrated high cutting performance compared to the dominating cutting laser, the CO2-laser. However, quality problems in fibre......-laser cutting have until now limited its application in metal cutting. In this paper the first results of proof-of-principle studies applying a new approach (patent pending) for laser cutting with high brightness short wavelength lasers will be presented. In the approach, multi beam patterns are applied...... to control the melt flow out of the cut kerf resulting in improved cut quality in metal cutting. The beam patterns in this study are created by splitting up beams from 2 single mode fibre lasers and combining these beams into a pattern in the cut kerf. The results are obtained with a total of 550 W of single...

  2. Multibeam fiber laser cutting

    DEFF Research Database (Denmark)

    Olsen, Flemming Ove; Hansen, Klaus Schütt; Nielsen, Jakob Skov

    2009-01-01

    The appearance of the high power high brilliance fiber laser has opened for new possibilities in laser materials processing. In laser cutting this laser has demonstrated high cutting performance compared to the dominating Cutting laser, the CO2 laser. However, quality problems in fiber......-laser cutting have until now limited its application to metal cutting. In this paper the first results of proof-of-principle Studies applying a new approach (patent pending) for laser cutting with high brightness and short wavelength lasers will be presented. In the approach, multibeam patterns are applied...... to control the melt flow out of the cut kerf resulting in improved cut quality in metal cutting. The beam patterns in this study are created by splitting up beams from two single mode fiber lasers and combining these beams into a pattern in the cut kerf. The results are obtained with a total of 550 W...

  3. Caracterização geoecológica como subsídio para estudos ambientais em RPPNs: estudos de casos no Paraná

    Directory of Open Access Journals (Sweden)

    Maristela Moresco Mezzomo

    2014-10-01

    Full Text Available A caracterização do meio físico de unidades de conservação apresenta-se como importante aspecto para o planejamento de ações de gestão ambiental, devendo, inclusive, constar no plano de manejo. Porém, muitas unidades de conservação não contam com esse plano. Nessa perspectiva, este artigo apresenta a técnica de caracterização geoecológica, por meio da construção de perfis geoecológicos, como método para o levantamento e reconhecimento do meio físico de unidade de conservação, em especial para Reservas Particulares do Patrimônio Natural (RPPNs. Este estudo foi aplicado nas RPPNs Artur Cesar Vigilato/Fazenda Santa Terezinha e Artur Cesar Vigilato/Fazenda Mangueira, localizadas, respectivamente, nos Municípios de Luiziana e Campo Mourão, Estado do Paraná. Os resultados possibilitaram reconhecer como é a organização vertical e horizontal dos elementos da paisagem das áreas, os quais foram representados visualmente nos perfis geoecológicos. Além disso, foi possível compreender a dinâmica das RPPNs, no que tange aos riscos ambientais, possibilitando a organização de informações e dados que poderão subsidiar outros estudos ambientais.

  4. Lasers in periodontics.

    Science.gov (United States)

    Elavarasu, Sugumari; Naveen, Devisree; Thangavelu, Arthiie

    2012-08-01

    Laser is one of the most captivating technologies in dental practice since Theodore Maiman in 1960 invented the ruby laser. Lasers in dentistry have revolutionized several areas of treatment in the last three and a half decades of the 20(th) century. Introduced as an alternative to mechanical cutting device, laser has now become an instrument of choice in many dental applications. Evidence suggests its use in initial periodontal therapy, surgery, and more recently, its utility in salvaging implant opens up a wide range of applications. More research with better designs are a necessity before lasers can become a part of dental armamentarium. This paper gives an insight to laser in periodontics.

  5. Laser-driven ion acceleration with hollow laser beams

    International Nuclear Information System (INIS)

    Brabetz, C.; Kester, O.; Busold, S.; Bagnoud, V.; Cowan, T.; Deppert, O.; Jahn, D.; Roth, M.; Schumacher, D.

    2015-01-01

    The laser-driven acceleration of protons from thin foils irradiated by hollow high-intensity laser beams in the regime of target normal sheath acceleration (TNSA) is reported for the first time. The use of hollow beams aims at reducing the initial emission solid angle of the TNSA source, due to a flattening of the electron sheath at the target rear side. The experiments were conducted at the PHELIX laser facility at the GSI Helmholtzzentrum für Schwerionenforschung GmbH with laser intensities in the range from 10 18  W cm −2 to 10 20  W cm −2 . We observed an average reduction of the half opening angle by (3.07±0.42)° or (13.2±2.0)% when the targets have a thickness between 12 μm and 14 μm. In addition, the highest proton energies were achieved with the hollow laser beam in comparison to the typical Gaussian focal spot

  6. Laser-driven ion acceleration with hollow laser beams

    Energy Technology Data Exchange (ETDEWEB)

    Brabetz, C., E-mail: c.brabetz@gsi.de; Kester, O. [Goethe-Universität Frankfurt am Main, 60323 Frankfurt (Germany); GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt (Germany); Busold, S.; Bagnoud, V. [GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt (Germany); Helmholtz-Institut Jena, 07743 Jena (Germany); Cowan, T. [Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden (Germany); Technische Universität Dresden, 01069 Dresden (Germany); Deppert, O.; Jahn, D.; Roth, M. [Technische Universität Darmstadt, 64277 Darmstadt (Germany); Schumacher, D. [GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt (Germany)

    2015-01-15

    The laser-driven acceleration of protons from thin foils irradiated by hollow high-intensity laser beams in the regime of target normal sheath acceleration (TNSA) is reported for the first time. The use of hollow beams aims at reducing the initial emission solid angle of the TNSA source, due to a flattening of the electron sheath at the target rear side. The experiments were conducted at the PHELIX laser facility at the GSI Helmholtzzentrum für Schwerionenforschung GmbH with laser intensities in the range from 10{sup 18} W cm{sup −2} to 10{sup 20} W cm{sup −2}. We observed an average reduction of the half opening angle by (3.07±0.42)° or (13.2±2.0)% when the targets have a thickness between 12 μm and 14 μm. In addition, the highest proton energies were achieved with the hollow laser beam in comparison to the typical Gaussian focal spot.

  7. High-power pulsed lasers

    International Nuclear Information System (INIS)

    Holzrichter, J.F.

    1980-01-01

    The ideas that led to the successful construction and operation of large multibeam fusion lasers at the Lawrence Livermore Laboratory are reviewed. These lasers are based on the use of Nd:glass laser materials. However, most of the concepts are applicable to any laser being designed for fusion experimentation. This report is a summary of lectures given by the author at the 20th Scottish University Summer School in Physics, on Laser Plasma Interaction. This report includes basic concepts of the laser plasma system, a discussion of lasers that are useful for short-pulse, high-power operation, laser design constraints, optical diagnostics, and system organization

  8. ESTRESSE NO TRABALHO: ESTUDO COM GESTORES PÚBLICOS DO ESTADO DE MINAS GERAIS

    Directory of Open Access Journals (Sweden)

    Lyovan Neves Maffia

    Full Text Available O objetivo deste trabalho consistiu em analisar o estresse no trabalho de gestores públicos que atuam nas secretarias de estado de Minas Gerais. A base teórica relacionada ao estresse ocupacional foi fundamentada em Zille (2005, Chanlat (2005, Cooper et al. (2002, 1988, Couto (1987 e Selye (1959. Em relação à gestão, baseou-se em OCDE (2010, Bresser-Pereira (2009, Madureira e Rodrigues (2006 e Davel e Melo (2005; Rezende (2002 e Marini (2002. Este trabalho pode ser classificado como um estudo descritivo, com abordagem quantitativa. Foram analisados 181 gestores das secretarias de estado de Minas Gerais, sendo que o Modelo Teórico de Explicação do Estresse Ocupacional em Gerentes (MTEG, desenvolvido por Zille (2005, foi a referência principal. Os softwares Excel e SPSS - Statistical Package for the Social Sciences foram utilizados para a análise dos dados. Os resultados evidenciaram que 26,0% dos gestores pesquisados apresentaram ausência de estresse ocupacional; 26,0%, nível de estresse leve a moderado; 43,0%, nível de estresse intenso; e 5,0% nível de estresse muito intenso. Foram identificadas as principais fontes de tensão excessivas existentes no ambiente de trabalho, os mecanismos de regulação mais utilizados pelos gestores públicos estaduais para enfrentar as situações tensionantes e os indicadores de impacto do estresse na produtividade dos gestores. Este estudo mostrou-se oportuno uma vez que há estudos sobre o estresse ocupacional em gestores da iniciativa privada, mas pouco se sabe sobre o impacto das reformas administrativas do serviço público na saúde laboral dos gestores. Os resultados deste trabalho apresentaram relação direta com outros estudos e espera-se que possa contribuir com o balizamento de projetos institucionais do estado de Minas Gerais para redução ou controle dos níveis de estresse ocupacional dos gestores.

  9. Encefalopatia hepática: estudo de 50 casos

    Directory of Open Access Journals (Sweden)

    Luiz Antonio de Lima Resende

    1984-12-01

    Full Text Available Os autores apresentam estudo retrospectivo de 50 pacientes com encefalopatia hepática atendidos no Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto a partir de 1959 e discutem os aspectos clínicos, laboratoriais e anátomo-patológicos. Expõem os diagnósticos das hepatopatias, os fatores precipitantes dos episódios de coma e pré-coma hepático e enfatizam o papel da gasometria arterial no estabelecimento do diagnóstico.

  10. Bruxas da Serra: Estudo numa comunidade beirã

    OpenAIRE

    Carvalho, Clara

    1984-01-01

    O tema deste trabalho é o estudo das manifestações do discurso da bruxaria numa pequena comunidade beirã situada nas faldas da serra do Caramulo. Nesta aldeia trabalham como "bruxas" cinco dos seus habitantes. Com este trabalho pretendi descrever os métodos utilizados por essas cinco pessoas e os mecanismos que levam a restante população a utilizar esse discurso. Não se trata aqui de um levantamento e análise das diversas figuras designadas pelo termo "bruxa" , tal como foi realizado por Lisó...

  11. Advanced lasers for fusion

    International Nuclear Information System (INIS)

    Krupke, W.F.; George, E.V.; Haas, R.A.

    1979-01-01

    Laser drive systems' performance requirements for fusion reactors are developed following a review of the principles of inertial confinement fusion and of the technical status of fusion research lasers (Nd:glass; CO 2 , iodine). These requirements are analyzed in the context of energy-storing laser media with respect to laser systems design issues: optical damage and breakdown, medium excitation, parasitics and superfluorescence depumping, energy extraction physics, medium optical quality, and gas flow. Three types of energy-storing laser media of potential utility are identified and singled out for detailed review: (1) Group VI atomic lasers, (2) rare earth solid state hybrid lasers, and (3) rare earth molecular vapor lasers. The use of highly-radiative laser media, particularly the rare-gas monohalide excimers, are discussed in the context of short pulse fusion applications. The concept of backward wave Raman pulse compression is considered as an attractive technique for this purpose. The basic physics and device parameters of these four laser systems are reviewed and conceptual designs for high energy laser systems are presented. Preliminary estimates for systems efficiencies are given. (Auth.)

  12. OS ESTUDOS SOBRE A CULTURA DA ESCOLA: FORMA, TRADIÇÕES, COMUNIDADE, CLIMA, PARTICIPAÇÃO, PODER

    Directory of Open Access Journals (Sweden)

    Ana Maria Falsarella

    2018-04-01

    Full Text Available RESUMO: Este trabalho versa sobre temas relacionados à cultura de instituições escolares em seu funcionamento cotidiano: tradição escolar, clima organizacional, participação e partilha do poder, conceito de comunidade. Trata-se de uma exploração teórica, sem pretensão de esgotar a literatura a respeito dos assuntos. Situa-se no campo de estudos da Sociologia da Educação. Visa contribuir para clarear conceitos significativos relacionados aos estudos sobre a escola, levantar pontos para reflexão e sugerir subsídios para análises de pesquisas empíricas desenvolvidas na área da educação. Destaca que estudar a escola em seu funcionamento cotidiano é desafio difícil para o pesquisador, mas que traz ricas contribuições para a escola e para os estudos acadêmicos.

  13. Effects of 960 nm diode laser irradiation on dental enamel in vitro: temperature and morphological analysis and evaluation of enamel demineralization; Estudo in vitro dos efeitos promovidos pelo laser de diodo em 960 nm no esmalte dental humano: analise de temperatura, analise morfologica e avaliacao da resistencia a desmineralizacao

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Ilka Tiemy

    2004-07-01

    The aim of this study is to determine the effects of diode laser irradiation on enamel demineralization. To achieve this goal appropriate photon absorbing substances for the laser radiation, safe laser parameters and adequate temperature measuring apparatus had to be determined. Next, the effects of diode laser and acidulated phosphate fluoride on enamel demineralization by calcium content analysis were evaluated with inductively coupled plasma atomic emission spectrometry (ICP-AES). In the first part of the study, five dyes consisting of vegetable coal diluted in five different liquids were analyzed and vegetable coal diluted in physiological solution was chosen for use as absorber. Methodologies to measure pulp chamber temperature were evaluated and modeling clay was chosen as fixture for the enamel samples held at body temperature. In the second part of the study, different energy density parameters (1.8 J/cm{sup 2}, 3.7 J/cm{sup 2}, 5.6 J/cm{sup 2}, 7.4 J/cm{sup 2} and 9.3 J/cm{sup 2}) exposure times (10, 15, 20, 25 e 30 seconds) and time intervals between dye application and laser irradiation (5, 30, 60, 90 e 120 seconds) were evaluated with respect to temperature changes in the pulp chamber. The enamel morphology was analyzed by scanning electron microscopy. Acid resistance was measured using seventy five enamel specimens, divided in five groups (control, fluoride, laser, laser + fluoride and fluoride + laser). The amount of calcium lost during demineralization in lactic acid was measured by ICP-AES. The results obtained in this experiment permit the conclusion that diode laser irradiation did not increase acid resistance. When associated with fluoride, the acid resistance did not differ from the results obtained with fluoride alone. (author)

  14. Only lasers can be used for low level laser therapy.

    Science.gov (United States)

    Moskvin, Sergey Vladimirovich

    2017-12-01

    The question of lasers' exclusivity, as well as the degree of influence of special properties of low-intensity laser illumination (LILI), such as coherence, polarity and monochromaticity, on the effectiveness of low level laser therapy (LLLT) continues to cause arguments. The study analyzes publications from 1973 to 2016, in which laser and conventional light sources are compared, and the following conclusions are drawn. First, there are a lot of publications with incorrect comparison or unfounded statements. Secondly, other sources of light are often meant by LILI without any justification. Thirdly, all studies, in which the comparison is carried out correctly and close parameters of the impact and the model are used, have a firm conclusion that laser light is much more effective. Fourthly, it is uniquely identified that the most important parameter that determines the efficiency of lasers is monochromaticity, i.e., a much narrower spectral width than for all other light sources. Only laser light sources can be used for LLLT! © Author(s) 2017. This article is published with open access by China Medical University.

  15. Laser Research Lab

    Data.gov (United States)

    Federal Laboratory Consortium — The Laser Research lab is thecenter for the development of new laser sources, nonlinear optical materials, frequency conversion processes and laser-based sensors for...

  16. Laser Cutting of Thick Diamond Films Using Low-Power Laser

    Energy Technology Data Exchange (ETDEWEB)

    Park, Y.J.; Baik, Y.J. [Korea Institute of Science and Technology, Seoul (Korea)

    2000-02-01

    Laser cutting of thick diamond films is studied rising a low-power(10 W) copper vapor laser. Due to the existence of the saturation depth in laser cutting, thick diamond films are not easily cut by low-power lasers. In this study, we have adopted a low thermal- conductivity underlayer of alumina and a heating stage (up to 500 deg. C in air) to prevent the laser energy from consuming-out and, in turn, enhance the cutting efficiency. Aspect ratio increases twice from 3.5 to 7 when the alumina underlayer used. Adopting a heating stage also increases aspect ratio and more than 10 is obtained at higher temperatures than 400 deg. C. These results show that thick diamond films can be cut, with low-power lasers, simply by modifying the thermal property of underlayer. (author). 13 refs., 5 figs.

  17. Estudo da aderência de arames da armadura de tração em conectores de dutos flexíveis

    OpenAIRE

    Marcelo Badini Daflon

    2010-01-01

    Este projeto tem o objetivo de apresentar o estudo dos arames da armadura de tração que são empregados no transporte de óleo, gás e umbilicais hidráulicos na indústria petrolífera. Este estudo foi desenvolvido sob a necessidade de melhor ancoragem dos arames da armadura de tração de modo a garantir que, mesmo após a ruptura do arame dentro do conector não haverá o escorregamento do mesmo provocando a queda do duto flexível. Assim sendo, foi estabelecido o estudo de aderência da interface dos ...

  18. Laser solenoid: an alternate use of lasers in fusion power

    International Nuclear Information System (INIS)

    Rose, P.H.

    1977-01-01

    A unique laser assisted fusion approach is under development at Mathematical Sciences Northwest, Inc. (MSNW). This approach captures one of the most developed aspects of high energy laser technology, the efficient, large, scalable, pulsed electron beam initiated, electric discharge, CO 2 infrared laser. This advanced technology is then combined with the simple geometry of a linear magnetic confinement system. The laser solenoid concept will be described, current work and experimental progress will be discussed, and the technological problems of building such a system will be assessed. Finally a comparison will be made of the technology and economics for the laser solenoid and alternative fusion approaches

  19. Organic solid-state lasers

    CERN Document Server

    Forget, Sébastien

    2013-01-01

    Organic lasers are broadly tunable coherent sources, potentially compact, convenient and manufactured at low-costs. Appeared in the mid 60’s as solid-state alternatives for liquid dye lasers, they recently gained a new dimension after the demonstration of organic semiconductor lasers in the 90's. More recently, new perspectives appeared at the nanoscale, with organic polariton and surface plasmon lasers. After a brief reminder to laser physics, a first chapter exposes what makes organic solid-state organic lasers specific. The laser architectures used in organic lasers are then reviewed, with a state-of-the-art review of the performances of devices with regard to output power, threshold, lifetime, beam quality etc. A survey of the recent trends in the field is given, highlighting the latest developments with a special focus on the challenges remaining for achieving direct electrical pumping of organic semiconductor lasers. A last chapter covers the applications of organic solid-state lasers.

  20. Quantum well lasers

    CERN Document Server

    Zory, Jr, Peter S; Kelley, Paul

    1993-01-01

    This book provides the information necessary for the reader to achieve a thorough understanding of all aspects of QW lasers - from the basic mechanism of optical gain, through the current technolgoical state of the art, to the future technologies of quantum wires and quantum dots. In view of the growing importance of QW lasers, this book should be read by all those with an active interest in laser science and technology, from the advanced student to the experienced laser scientist.* The first comprehensive book-length treatment of quantum well lasers* Provides a detailed treatment

  1. Lasers in space.

    CSIR Research Space (South Africa)

    Michaelis, MM

    2008-04-01

    Full Text Available cube, laser beam reflectors, placed on the Moon half a century ago. These early achievements will soon be followed by a plethora of experiments involving lasers in low earth orbit (LEO) or at Lagrange points. And not much later, laser communications... will stretch out as far as Mars and beyond. One important low Earth orbit (LEO) application is the removal of space debris by Earth based or LEO relayed lasers as promoted by Phipps et al.3. Another is military communication. The prominent L1 laser space...

  2. Bleaching Dengan Teknologi Laser

    OpenAIRE

    Eliwaty

    2008-01-01

    Penulisan tentang bleaching dengan laser dimaksudkan untuk menambah wawasan serta pengetahuan dari pembaca di bidang kedokteran gigi. Macam-macam laser yang dipergunakan dalam bleaching yaitu argon, CO2 serta dioda laser. Contoh merek produk laser yaitu Blulaze, Dentcure untuk argonlaser, Novapulse untuk C02 serta Opus 5 untuk dioda laser. Laser bleaching hasilnya dapat dicapai dalam satu kunjungan saja, cepat, efisien namun biayanya relatif mahal, dapat menimbulkan burn, sensitivitas se...

  3. Marketing interno e cultura organizacional: um estudo de caso em empresa de multi marcas.

    Directory of Open Access Journals (Sweden)

    Antonio Carlos Giuliani

    2005-04-01

    Full Text Available Não há planejamento que sobreviva, dentro das organizações, a um organismo social sem espírito de equipe, iniciativa, ou atuando sem a definição de valores por seus dirigentes. Em suma, sem diretrizes que componham a sua cultura organizacional. A análise da cultura organizacional permite a identificação de disfunção nos fatores culturais que estão interferindo no clima organizacional e, por conseqüência, no relacionamento entre as pessoas, prejudicando sua produtividade e o bom andamento dos trabalhos. Este estudo objetivou examinar a contribuição da cultura organizacional ao desenvolvimento de programas de marketing interno, filosofia empresarial da área de marketing, buscando o comprometimento dos funcionários com as metas da organização. Como referencial da prática, baseou-se em estudo de caso realizado na Comercial Importadora Ltda., empresa de multimarcas, com 35 funcionários, localizada em Piracicaba – São Paulo. Como resultados, o estudo possibilitou uma análise de como a cultura organizacional contribui para o uso de técnicas de marketing interno, mostrando a aplicabilidade prática dos dois conceitos.

  4. Diode-pumped solid state laser. (Part V). ; Short pulse laser oscillation. Handotai laser reiki kotai laser. 5. ; Tan pulse hasshin

    Energy Technology Data Exchange (ETDEWEB)

    Kuwabara, M.; Bando, N. (Asahi Glass Co. Ltd., Tokyo (Japan))

    1991-12-25

    A semiconductor laser (LD) excited solid state laser using an LD as an excited light source is under discussion for its practical applications to measurements, processing, communications, office automation, and medical areas. This paper describes the discussions given on the short pulse transmission using AOQ switching elements in the LD excited solid state laser with a long wave length band (1.3{mu}m), which is expected of its application in the communications and measurements area. Based on a possibility of raising a measurements resolution by making the pluses in the LD excited solid state laser, and experiments were performed using Nd:YLF as a laser host. as a results, it was found that the smaller the effective mode volume V {sub eff},the smaller the pulse width, and that the ratio of number of initial inversion distribution (N{sub i}/N{sub t}), an important parameter to determine pulse widths, can be obtained from the ratio of the LD exciting light to the input power (P{sub in}/P{sub t}). 7 refs., 14 figs., 2 tabs.

  5. Wavelength sweepable laser source

    DEFF Research Database (Denmark)

    2014-01-01

    Wavelength sweepable laser source is disclosed, wherein the laser source is a semiconductor laser source adapted for generating laser light at a lasing wavelength. The laser source comprises a substrate, a first reflector, and a second reflector. The first and second reflector together defines...... and having a rest position, the second reflector and suspension together defining a microelectromechanical MEMS oscillator. The MEMS oscillator has a resonance frequency and is adapted for oscillating the second reflector on either side of the rest position.; The laser source further comprises electrical...... connections adapted for applying an electric field to the MEMS oscillator. Furthermore, a laser source system and a method of use of the laser source are disclosed....

  6. Mathematical modeling of a photovoltaic-laser energy converter for iodine laser radiation

    Science.gov (United States)

    Walker, Gilbert H.; Heinbockel, John H.

    1987-01-01

    Space-based laser power systems will require converters to change laser radiation into electricity. Vertical junction photovoltaic converters are promising devices for this use. A promising laser for the laser power station is the t-C4F9I laser which emits radiation at a wavelength of 1.315 microns. This paper describes the results of mathematical modeling of a photovoltaic-laser energy converter for use with this laser. The material for this photovoltaic converter is Ga(53)In(47)As which has a bandgap energy of 0.94 eV, slightly below the energy of the laser photons (0.943 eV). Results of a study optimizing the converter parameters are presented. Calculated efficiency for a 1000 vertical junction converter is 42.5 percent at a power density of 1 x 10 to the 3d power w/sq cm.

  7. Laser Materials and Laser Spectroscopy - A Satellite Meeting of IQEC '88

    Science.gov (United States)

    Wang, Zhijiang; Zhang, Zhiming

    1989-03-01

    The Table of Contents for the book is as follows: * Laser Materials * Laser Site Spectroscopy of Transition Metal Ions in Glass * Spectroscopy of Chromium Doped Tunable Laser Materials * Spectroscopic Properties of Nd3+ Ions in LaMgAl11O19 Crystal * Spectral Study and 2.938 μm Laser Emission of Er3+ in the Y3Al5O12 Crystal * Raman-infrared Spectra and Radiationless Relaxation of Laser Crystal NdAl3(BO3)4 * A Study on HB and FLN in BaFCl0.5Br0.5:Sm2+ at 77K * Pair-pumped Upconversion Solid State Lasers * CW Upconversion Laser Action in Neodymium and Erbium doped Solids * Ultra-high Sensitive Upconversion Fluorescence of YbF3 Doped with Trace Tm3+ and Er3+ * The Growth and Properties of NYAB and EYAB Multifunctional Crystal * Study on Fluorescence and Laser Light of Er3+ in Glass * Growth and Properties of Single Crystal Fibers for Laser Materials * A Study on the Quality of Sapphire, Ruby and Ti3+ Doped Sapphire Grown by Temperature Gradient Technique (TGT) and Czochralski Technique (CZ) * The Measurement of Output Property of Ti3+ Al2O3 Laser Crystal * An Xα Study of the Laser Crystal MgF2 : V2+ * Q-switched NAB Laser * Miniature YAG Lasers * Study of High Efficiency {LiF}:{F}^-_2 Color Center Crystals * Study on the Formation Conditions and Optical Properties of (F2+)H Color Center in NaCl:OH- Crystals * Novel Spectroscopic Properties of {LiF}:{F}^+_3 - {F}_2 Mixed Color Centers Laser Crystals * Terraced Substrate Visible GaAlAs Semiconductor Lasers with a Large Optical Cavity * The Temperature Dependence of Gain Spectra, Threshold Current and Auger Recombination in InGaAsP-InP Double Heterojunction Laser diode * Time-resolved Photoluminescence and Energy Transfer of Bound Excitons in GaP:N Crystals * Optical Limiting with Semiconductors * A Critical Review of High-efficiency Crystals for Tunable Lasers * Parametric Scattering in β - BaB2O4 Crystal Induced by Picosecond Pulses * Generation of Picosecond Pulses at 193 nm by Frequency Mixing in β - BaB2O4

  8. Ultraviolet laser transverse profile shaping for improving x-ray free electron laser performance

    International Nuclear Information System (INIS)

    Li, S.; Alverson, S.; Bohler, D.; Egger, A.; Fry, A.

    2017-01-01

    The photocathode rf gun is one of the most critical components in x-ray free electron lasers. The drive laser strikes the photocathode surface, which emits electrons with properties that depend on the shape of the drive laser. Most free electron lasers use photocathodes with work function in the ultraviolet, a wavelength where direct laser manipulation becomes challenging. In this paper, we present a novel application of a digital micromirror device (DMD) for the 253 nm drive laser at the Linear Coherent Light Source. Laser profile shaping is accomplished through an iterative algorithm that takes into account shaping error and efficiency. Next, we use laser shaping to control the X-ray laser output via an online optimizer, which shows improvement in FEL pulse energy. Lastly, as a preparation for electron beam shaping, we use the DMD to measure the photocathode quantum efficiency across cathode surface with an averaged laser rms spot size of 59 μm. In conclusion, our experiments demonstrate promising outlook of using DMD to shape ultraviolet lasers for photocathode rf guns with various applications.

  9. Ultraviolet laser transverse profile shaping for improving x-ray free electron laser performance

    Science.gov (United States)

    Li, S.; Alverson, S.; Bohler, D.; Egger, A.; Fry, A.; Gilevich, S.; Huang, Z.; Miahnahri, A.; Ratner, D.; Robinson, J.; Zhou, F.

    2017-08-01

    The photocathode rf gun is one of the most critical components in x-ray free electron lasers. The drive laser strikes the photocathode surface, which emits electrons with properties that depend on the shape of the drive laser. Most free electron lasers use photocathodes with work function in the ultraviolet, a wavelength where direct laser manipulation becomes challenging. In this paper, we present a novel application of a digital micromirror device (DMD) for the 253 nm drive laser at the Linear Coherent Light Source. Laser profile shaping is accomplished through an iterative algorithm that takes into account shaping error and efficiency. Next, we use laser shaping to control the X-ray laser output via an online optimizer, which shows improvement in FEL pulse energy. Lastly, as a preparation for electron beam shaping, we use the DMD to measure the photocathode quantum efficiency across cathode surface with an averaged laser rms spot size of 59 μ m . Our experiments demonstrate promising outlook of using DMD to shape ultraviolet lasers for photocathode rf guns with various applications.

  10. Laser sampling

    International Nuclear Information System (INIS)

    Gorbatenko, A A; Revina, E I

    2015-01-01

    The review is devoted to the major advances in laser sampling. The advantages and drawbacks of the technique are considered. Specific features of combinations of laser sampling with various instrumental analytical methods, primarily inductively coupled plasma mass spectrometry, are discussed. Examples of practical implementation of hybrid methods involving laser sampling as well as corresponding analytical characteristics are presented. The bibliography includes 78 references

  11. Studies on corrosion protection of laser hybrid welded AISI 316 by laser remelting

    DEFF Research Database (Denmark)

    Olsen, Flemming Ove; Ambat, Rajan; Rasmussen, A.J.

    2005-01-01

    laser surface melting on microstructure and corrosion behaviour of AISI 316L welds. Welding and laser treatment parameters were varied. General corrosion behaviour of the weld and laser treated surface was characterised using a gel visualization test. The local electrochemistry of the weld and laser......Unlike in autogenous laser welding, hybrid laser welding of stainless steel could introduce grain boundary carbides due to low cooling rates. Formation of grain boundary carbides leads to reduced corrosion properties. Studies have initially been carried out on hybrid laser welding and subsequent...... treated surface was investigated using a novel micro electrochemical technique with a tip resolution of ~1 mm. Results show that hybrid laser welding of 316L has increased corrosion susceptibility probably as a result of grain boundary carbide formation. However a suitable post laser treatment could...

  12. Excimer laser decontamination

    Science.gov (United States)

    Sentis, Marc L.; Delaporte, Philippe C.; Marine, Wladimir; Uteza, Olivier P.

    2000-04-01

    The application of excimer laser ablation process to the decontamination of radioactive surfaces is discussed. This technology is very attractive because it allows to efficiently remove the contaminated particles without secondary waste production. To demonstrate the capability of such technology to efficiently decontaminate large area, we studied and developed a prototype which include a XeCl laser, an optical fiber delivery system and an ablated particles collection cell. The main physical processes taking place during UV laser ablation will be explained. The influence of laser wavelength, pulse duration and absorption coefficient of material will be discussed. Special studies have been performed to understand the processes which limit the transmission of high average power excimer laser through optical fiber, and to determine the laser conditions to optimize the value of this transmission. An in-situ spectroscopic analysis of laser ablation plasma allows the real time control of the decontamination. The results obtained for painting or metallic oxides removal from stainless steel surfaces will be presented.

  13. Efficient Ho:YLF laser pumped by a Tm:fiber laser

    CSIR Research Space (South Africa)

    Koen, W

    2013-10-01

    Full Text Available A thulium fiber laser pumped Ho:YLF laser delivering 45.1 W in a near diffraction limited beam when pumped with 84.7 W is demonstrated. The optical-to-optical efficiency of 53 % compares favorably with similar Ho:YAG lasers....

  14. Laser Safety Evaluation of the MILES and Mini MILES Laser Emitting Components; TOPICAL

    International Nuclear Information System (INIS)

    AUGUSTONI, ARNOLD L.

    2002-01-01

    Laser safety evaluation and output emission measurements were performed (during October and November 2001) on SNL MILES and Mini MILES laser emitting components. The purpose, to verify that these components, not only meet the Class 1 (eye safe) laser hazard criteria of the CDRH Compliance Guide for Laser Products and 21 CFR 1040 Laser Product Performance Standard; but also meet the more stringent ANSI Std. z136.1-2000 Safe Use of Lasers conditions for Class 1 lasers that govern SNL laser operations. The results of these measurements confirmed that all of the Small Arms Laser Transmitters, as currently set (''as is''), meet the Class 1 criteria. Several of the Mini MILES Small Arms Transmitters did not. These were modified and re-tested and now meet the Class 1 laser hazard criteria. All but one System Controllers (hand held and rifle stock) met class 1 criteria for single trigger pulls and all presented Class 3a laser hazard levels if the trigger is held (continuous emission) for more than 5 seconds on a single point target. All units were Class 3a for ''aided'' viewing. These units were modified and re-tested and now meet the Class 1 hazard criteria for both ''aided'' as well as ''unaided'' viewing. All the Claymore Mine laser emitters tested are laser hazard Class 1 for both ''aided'' as well as ''unaided'' viewing

  15. Laser ablation principles and applications

    CERN Document Server

    1994-01-01

    Laser Ablation provides a broad picture of the current understanding of laser ablation and its many applications, from the views of key contributors to the field. Discussed are in detail the electronic processes in laser ablation of semiconductors and insulators, the post-ionization of laser-desorbed biomolecules, Fourier-transform mass spectroscopy, the interaction of laser radiation with organic polymers, laser ablation and optical surface damage, laser desorption/ablation with laser detection, and laser ablation of superconducting thin films.

  16. CO2-laser fusion

    International Nuclear Information System (INIS)

    Stark, E.E. Jr.

    1978-01-01

    The basic concept of laser fusion is described, with a set of requirements on the laser system. Systems and applications concepts are presented and discussed. The CO 2 laser's characteristics and advantages for laser fusion are described. Finally, technological issues in the development of CO 2 laser systems for fusion applications are discussed

  17. Laser dynamics of asynchronous rational harmonic mode-locked fiber soliton lasers

    International Nuclear Information System (INIS)

    Jyu, Siao-Shan; Jiang, Guo-Hao; Lai, Yinchieh

    2013-01-01

    Laser dynamics of asynchronous rational harmonic mode-locked (ARHM) fiber soliton lasers are investigated in detail. In particular, based on the unique laser dynamics of asynchronous mode-locking, we have developed a new method for determining the effective active modulation strength in situ for ARHM lasers. By measuring the magnitudes of the slowly oscillating pulse timing position and central frequency, the effective phase modulation strength at the multiplication frequency of rational harmonic mode-locking can be accurately inferred. The method can be a very useful tool for developing ARHM fiber lasers. (paper)

  18. Scanning laser polarimetry in glaucomatous and nonglaucomatous Brazilian subjects Polarimetria de varredura a laser em grupos de brasileiros glaucomatosos e não glaucomatosos

    Directory of Open Access Journals (Sweden)

    Christiane Rolim de Moura

    2003-12-01

    Full Text Available PURPOSE: To compare the results of scanning laser polarimetry of the retinal nerve fiber layer obtained by using the GDx Scanning Laser System® in primary open angle glaucoma (POAG and nonglaucomatous Brazilian subjects over 40 years, also analyzing the differences between the data obtained from right and left eyes. METHODS: Forty-six POAG patients and 44 normal subjects were enrolled in this study. Retardation data were assessed by the GDx Scanning Laser System®. The medians of the parameters printed in the result were compared in these two groups, separately in the right and left eyes, using Mann-Whitney's test. Also the frequencies of outside normal parameters and quadrants of deviation from normal graph were compared in these two groups, using chi-square or Fisher's exact test. RESULTS: All parameters obtained by GDx differed in a statistically significant way between the two groups, except symmetry for left eyes. The frequency of inferior quadrant with pOBJETIVOS: Comparar os resultados da polarimetria de varredura a laser da camada de fibras nervosas obtidas por meio do GDx Scanning Laser System® em brasileiros portadores de glaucoma primário de ângulo aberto e indivíduos não glaucomatosos acima de 40 anos, analisando também as diferenças obtidas entre olhos direitos e esquerdos. MÉTODOS: Foram incluídos neste estudo 46 pacientes portadores de glaucoma primário de ângulo aberto e 44 pacientes normais. Os dados de retardo polarimétrico foram obtidos por meio do GDx Scanning Laser System®. As medianas dos parâmetros impressos no resultado foram comparadas nesses dois grupos, separadamente para olhos direitos e esquerdos, usando o teste de Mann-Whitney. A freqüência de parâmetros impressa como fora da normalidade e quadrantes estatisticamente alterados do gráfico "deviation from normal" foram comparados nesses dois grupos usando chi-quadrado e o teste exato de Fischer. RESULTADOS: Todos os parâmetros obtidos pelo GDx

  19. IMPLEMENTAÇÃO DO PLANEJAMENTO ESTRÁTEGICO FUNCIONAL: ESTUDO DE CASO EM UMA INDÚSTRIA DE BEBIDAS

    OpenAIRE

    Breno Antonio Jacobi

    2006-01-01

    Este trabalho visa, através de um estudo de caso, em uma indústria de bebidas de Santa Maria-RS, analisar e integrar o Planejamento Estratégico Corporativo ao nível tático e operacional. A empresa, objeto deste estudo, CVI Refrigerantes Ltda, fabricante do sistema Coca-Cola Brasil, fabrica bebidas carbonatadas e revende bebidas não carbonatadas e alcoólicas. Apresenta, em seu organograma, seis departamentos distintos: Sistemas, Marketing, Administrativo-Financeiro, Comercial, Industrial...

  20. Radiological protection against lasers

    Energy Technology Data Exchange (ETDEWEB)

    Ballereau, P

    1974-04-01

    A brief description of the biological effects of laser beams is followed by a review of the factors involved in eye and skin damage (factors linked with the nature of lasers and those linked with the organ affected) and a discussion of the problems involved in the determination of threshold exposure levels. Preventive measures are recommended, according to the type of laser (high-energy pulse laser, continuous laser, gas laser). No legislation on the subject exists in France or in Europe. Types of lasers marketed, threshold exposure levels for eye and skin, variations of admissible exposure levels according to wavelength, etc. are presented in tabular form. Nomogram for determination of safe distance for direct vision of a laser is included.

  1. Laser-tissue interaction in tattoo removal by q-switched lasers.

    Science.gov (United States)

    Barua, Shyamanta

    2015-01-01

    Q-switched (QS) lasers are widely considered the gold standard for tattoo removal, with excellent clinical results, impressive predictability, and a good safety profile. The generation of giant pulses by the method of Q-switching is responsible for the unique laser-tissue interaction that is seen in tattoo removal by QS lasers. The QS lasers work by impaction and dissolution of the tattoo pigments. Mechanical fragmentation of the tattoo pigments encased in intracellular lamellated organelles followed by their phagocytosis by macrophages is thought to be the major event in the clearance of pigments by QS lasers. A few novel techniques have been tried in recent times to hasten the clearance of tattoo pigments.

  2. Traveling-wave laser-produced-plasma energy source for photoionization laser pumping and lasers incorporating said

    Science.gov (United States)

    Sher, Mark H.; Macklin, John J.; Harris, Stephen E.

    1989-09-26

    A traveling-wave, laser-produced-plasma, energy source used to obtain single-pass gain saturation of a photoionization pumped laser. A cylindrical lens is used to focus a pump laser beam to a long line on a target. Grooves are cut in the target to present a surface near normal to the incident beam and to reduce the area, and hence increase the intensity and efficiency, of plasma formation.

  3. A evolução da teoria institucional nos estudos organizacionais: um campo de pesquisa a ser explorado

    Directory of Open Access Journals (Sweden)

    Fernando Antonio de Melo Pereira

    2012-11-01

    Full Text Available A teoria institucional vem sendo aplicada nas organizações como elemento central na criação e perpetuação de grupos sociais duradouros no ambiente de trabalho. Nesse sentido, o objetivo deste trabalho é identificar nos principais periódicos internacionais as pesquisas mais relevantes no período de 2006 a 2012 no âmbito de formas inovadoras da abordagem institucionalista. A pesquisa é baseada em um estudo bibliometrico. O artigo apresenta um mapeamento dos estudos em teoria institucional focando nos elementos: caracterização geral dos trabalhos, avaliação do conteúdo e avaliação de referências. Os resultados indicam que a teoria institucional vem sendo estudada no âmbito teórico e prático e, vem sendo utilizada em diversos contextos organizacionais, demonstrando que as organizações sentem a necessidade de padronizar comportamentos e de disseminar a identidade organizacional entre os funcionários. Esses resultados podem ser generalizados para toda a comunidade cientifica. O estudo oferece um guia de avaliação e identificação de tendências de estudos futuros sobre o tema no cenário mundial. 

  4. 5W intracavity frequency-doubled green laser for laser projection

    Science.gov (United States)

    Yan, Boxia; Bi, Yong; Li, Shu; Wang, Dongdong; Wang, Dongzhou; Qi, Yan; Fang, Tao

    2014-11-01

    High power green laser has many applications such as high brightness laser projection and large screen laser theater. A compact and high power green-light source has been developed in diode-pumped solid-state laser based on MgO doped periodically poled LiNbO3 (MgO:PPLN). 5W fiber coupled green laser is achieved by dual path Nd:YVO4/MgO:PPLN intra-cacity frequency-doubled. Single green laser maximum power 2.8W at 532nm is obtained by a 5.5W LD pumped, MgO:PPLN dimensions is 5mm(width)×1mm(thickness)×2mm(length), and the optical to optical conversion efficiency is 51%. The second LD series connected with the one LD, the second path green laser is obtained using the same method. Then the second path light overlap with the first path by the reflection mirrors, then couple into the fiber with a focus mirror. Dual of LD, Nd:YVO4, MgO:PPLN are placed on the same heat sink using a TEC cooling, the operating temperature bandwidth is about 12°C and the stablity is 5% in 96h. A 50×50×17mm3 laser module which generated continuous-wave 5 W green light with high efficiency and width temperature range is demonstrated.

  5. Estudo de Caso: Análise de um Relatório de Controle Ambiental (RCA Referente à Atividade de Levantamento Sísmico

    Directory of Open Access Journals (Sweden)

    Igor Leonardo Morais Nascimento

    2010-01-01

    Full Text Available Este trabalho aborda a análise de um Relatório de Controle Ambiental (RCA, da atividade de sísmica, submetido à obtenção de licenciamento ambiental junto ao Instituto de Defesa do Meio Ambiente – IDEMA. Realiza uma comparação dos itens exigidos no Termo de Referência (TR do IDEMA com o Estudo ambiental citado, a fim de identificar se todos os itens exigidos legalmente foram contemplados no RCA e se os mesmos estão em conformidade com o Termo. Utiliza a técnica de estudo de impacto ambiental baseado em um contexto legal que estabelece requisitos a serem observados e procedimentos a serem cumpridos, tal técnica é a análise formal da qualidade de um estudo ambiental. Verifica, também, a repetição ou não das principais deficiências apontadas no elemento Mitigação e compensação de impactos com base no estudo do Ministério Público Federal - MPF, a partir da técnica de análise de conteúdo de estudo ambiental.

  6. Estudo sobre o trabalho do policial e suas implicações na saúde mental

    OpenAIRE

    Joana Helena Rodrigues da Silva

    2009-01-01

    Sendo a violência e a preocupação com a segurança temas amplamente discutidos atualmente, seja por meio da imprensa ou de produção científica, a atuação profissional de policiais militares torna-se fator de preocupação e estudo, quer no âmbito da prevenção e repressão aos crimes, quer pelos desdobramentos que suas ações são capazes de provocar. Dentro deste contexto, de violência e risco, o presente estudo pretende traçar algumas considerações acerca da atuação do policial militar, que desemp...

  7. Designing of Raman laser

    International Nuclear Information System (INIS)

    Zidan, M. D.; Al-Awad, F.; Alsous, M. B.

    2005-01-01

    In this work, we describe the design of the Raman laser pumped by Frequency doubled Nd-YAG laser (λ=532 nm) to generate new laser wavelengths by shifting the frequency of the Nd-YAG laser to Stokes region (λ 1 =683 nm, λ 2 =953.6 nm, λ 3 =1579.5 nm) and Antistokes region (λ ' 1 =435 nm, λ ' 2 =369.9 nm, λ ' 3=319.8 nm). Laser resonator has been designed to increase the laser gain. It consists of two mirrors, the back mirror transmits the pump laser beam (λ=532 nm) through the Raman tube and reflects all other generated Raman laser lines. Four special front mirrors were made to be used for the four laser lines λ 1 =683 nm, λ 2 =953.6 nm and λ ' 1 = 435 nm, λ ' 2 =369.9 nm. The output energy for the lines υ 1 s, υ 2 s, υ 1 as,υ 2 as was measured. The output energy of the Raman laser was characterized for different H 2 pressure inside the tube. (Author)

  8. Development of Cr,Nd:GSGG laser as a pumping source of Ti:sapphire laser

    International Nuclear Information System (INIS)

    Tamura, Koji; Arisawa, Takashi

    1999-08-01

    Since efficiency of Cr,Nd doped gadolinium scandium gallium garnet (GSGG) laser is in principle higher than that of Nd:YAG laser, it can be a highly efficient pumping source for Ti:sapphire laser. We have made GSGG laser, and measured its oscillation properties. It was two times more efficient than Nd:YAG laser at free running mode operation. At Q-switched mode operation, fundamental output of 50 mJ and second harmonics output of 8 mJ were obtained. The developed laser had appropriate spatial profile, temporal duration, long time stability for solid laser pumping. Ti:sapphire laser oscillation was achieved by the second harmonics of GSGG laser. (author)

  9. Soft x-ray lasers

    International Nuclear Information System (INIS)

    Matthews, D.L.; Rosen, M.D.

    1988-01-01

    One of the elusive dreams of laser physicists has been the development of an x-ray laser. After 25 years of waiting, the x-ray laser has at last entered the scientific scene, although those now in operation are still laboratory prototypes. They produce soft x rays down to about five nanometers. X-ray lasers retain the usual characteristics of their optical counterparts: a very tight beam, spatial and temporal coherence, and extreme brightness. Present x-ray lasers are nearly 100 times brighter that the next most powerful x-ray source in the world: the electron synchrotron. Although Lawrence Livermore National Laboratory (LLNL) is widely known for its hard-x-ray laser program which has potential applications in the Strategic Defense Initiative, the soft x-ray lasers have no direct military applications. These lasers, and the scientific tools that result from their development, may one day have a place in the design and diagnosis of both laser fusion and hard x-ray lasers. The soft x-ray lasers now in operation at the LLNL have shown great promise but are still in the primitive state. Once x-ray lasers become reliable, efficient, and economical, they will have several important applications. Chief among them might be the creation of holograms of microscopic biological structures too small to be investigated with visible light. 5 figs

  10. History and principle of lasers

    International Nuclear Information System (INIS)

    Townes, Ch.H.; Schwob, C.; Julien, J.; Forget, S.; Robert-Philip, I.; Balcou, Ph.

    2010-01-01

    In the first article C.H. Townes, the inventor of the maser, describes the work and ideas that led to the invention of the laser. The second article explains how a laser operate and the third article reviews the main different types of laser: solid lasers, gas lasers, diode lasers and dye lasers

  11. Laser Safety and Hazard Analysis for the Trailer (B70) Based AURA Laser System

    International Nuclear Information System (INIS)

    AUGUSTONI, ARNOLD L.

    2003-01-01

    A laser safety and hazard analysis was performed for the AURA laser system based on the 2000 version of the American National Standards Institute's (ANSI) Standard Z136.1, for ''Safe Use of Lasers'' and the 2000 version of the ANSI Standard Z136.6, for ''Safe Use of Lasers Outdoors''. The trailer based AURA laser system is a mobile platform, which is used to perform laser interaction experiments and tests at various national test sites. The trailer (B70) based AURA laser system is generally operated on the United State Air Force Starfire Optical Range (SOR) at Kirtland Air Force Base (KAFB), New Mexico. The laser is used to perform laser interaction testing inside the laser trailer as well as outside the trailer at target sites located at various distances from the exit telescope. In order to protect personnel, who work inside the Nominal Hazard Zone (NHZ), from hazardous laser emission exposures it was necessary to determine the Maximum Permissible Exposure (MPE) for each laser wavelength (wavelength bands) and calculate the appropriate minimum Optical Density (OD min ) of the laser safety eyewear used by authorized personnel and the Nominal Ocular Hazard Distance (NOHD) to protect unauthorized personnel who may have violated the boundaries of the control area and enter into the laser's NHZ

  12. On-Chip Laser-Power Delivery System for Dielectric Laser Accelerators

    Science.gov (United States)

    Hughes, Tyler W.; Tan, Si; Zhao, Zhexin; Sapra, Neil V.; Leedle, Kenneth J.; Deng, Huiyang; Miao, Yu; Black, Dylan S.; Solgaard, Olav; Harris, James S.; Vuckovic, Jelena; Byer, Robert L.; Fan, Shanhui; England, R. Joel; Lee, Yun Jo; Qi, Minghao

    2018-05-01

    We propose an on-chip optical-power delivery system for dielectric laser accelerators based on a fractal "tree-network" dielectric waveguide geometry. This system replaces experimentally demanding free-space manipulations of the driving laser beam with chip-integrated techniques based on precise nanofabrication, enabling access to orders-of-magnitude increases in the interaction length and total energy gain for these miniature accelerators. Based on computational modeling, in the relativistic regime, our laser delivery system is estimated to provide 21 keV of energy gain over an acceleration length of 192 μ m with a single laser input, corresponding to a 108-MV/m acceleration gradient. The system may achieve 1 MeV of energy gain over a distance of less than 1 cm by sequentially illuminating 49 identical structures. These findings are verified by detailed numerical simulation and modeling of the subcomponents, and we provide a discussion of the main constraints, challenges, and relevant parameters with regard to on-chip laser coupling for dielectric laser accelerators.

  13. Laser therapy for cancer

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000905.htm Laser therapy for cancer To use the sharing features ... Lasers are also used on the skin. How Laser Therapy is Used Laser therapy can be used ...

  14. Lasers in Cancer Treatment

    Science.gov (United States)

    ... the advantages of laser therapy? What are the disadvantages of laser therapy? What does the future hold ... therapy is appropriate for them. What are the disadvantages of laser therapy? Laser therapy also has several ...

  15. Laser therapy (image)

    Science.gov (United States)

    A laser is used for many medical purposes. Because the laser beam is so small and precise, it enables ... without injuring surrounding tissue. Some uses of the laser are retinal surgery, excision of lesions, and cauterization ...

  16. Tunable laser optics

    CERN Document Server

    Duarte, FJ

    2015-01-01

    This Second Edition of a bestselling book describes the optics and optical principles needed to build lasers. It also highlights the optics instrumentation necessary to characterize laser emissions and focuses on laser-based optical instrumentation. The book emphasizes practical and utilitarian aspects of relevant optics including the essential theory. This revised, expanded, and improved edition contains new material on tunable lasers and discusses relevant topics in quantum optics.

  17. Laser cutting system

    Science.gov (United States)

    Dougherty, Thomas J

    2015-03-03

    A workpiece cutting apparatus includes a laser source, a first suction system, and a first finger configured to guide a workpiece as it moves past the laser source. The first finger includes a first end provided adjacent a point where a laser from the laser source cuts the workpiece, and the first end of the first finger includes an aperture in fluid communication with the first suction system.

  18. O efeito do laser de baixa energia no crescimento bacteriano "in vitro" Low level laser effect in "in vitro" bacterial growth

    Directory of Open Access Journals (Sweden)

    Fernando Coutinho

    2007-08-01

    Full Text Available OBJETIVO: Avaliar, por meio de estudo bacteriológico in vitro, o efeito de dois tipos de laser de baixa energia (LBE sobre diferentes populações bacterianas habitualmente presentes em feridas pós-traumáticas. MÉTODOS: Foram colhidos swabs diretamente do sítio de infecção de pacientes internados com osteomielite pós-traumática crônica. As bactérias isoladas foram Acinetobacter baumanii complex, Escherichia coli, Haemophilus influenzae, Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonela sp, Serratia sp e Staphylococcus aureus. O material coletado foi semeado em meio ágar-sangue, através de alça estéril, utilizando-se 30 placas de Petri para cada germe. Foram utilizados dois aparelhos de LBE: Ibramed Laser Pulse #01189, com 15W/904nm por 200 segundos, e Phisiolux dual Bioset #9909001, com 20W/904nm por 230 segundos. Nos grupos I (n = 10 e II (n = 10, as bactérias sofreram irradiação pelo laser. O grupo III (n = 10 serviu de controle, não sendo irradiado. As bactérias dos grupos I e II foram irradiadas em câmara de fluxo laminar, previamente esterilizada por raio ultravioleta. O laser foi administrado de forma direta, central e perpendicularmente à superfície de cultivo das bactérias, com distância-padrão de 1cm, através de orifício confeccionado na tampa das placas. O crescimento bacteriano foi analisado após 12 e 24 horas da irradiação. Os resultados foram processados estatisticamente, utilizando-se o teste não-paramétrico de Kruskall-Wallis, com nível de significância p OBJECTIVE: To perform an in vitro bacteriologic study to evaluate the effect of two types of low level laser (LLL on different bacterial populations usually present in post-traumatic wounds. METHODS: Swabs were prepared directly at the infection site of patients hospitalized with chronic post-traumatic osteomyelitis. Isolated bacteria were Acinetobacter baumanii complex, Escherichia coli, Haemophilus influenzae, Klebsiella pneumoniae

  19. Laser cooling of solids

    CERN Document Server

    Petrushkin, S V

    2009-01-01

    Laser cooling is an important emerging technology in such areas as the cooling of semiconductors. The book examines and suggests solutions for a range of problems in the development of miniature solid-state laser refrigerators, self-cooling solid-state lasers and optical echo-processors. It begins by looking at the basic theory of laser cooling before considering such topics as self-cooling of active elements of solid-state lasers, laser cooling of solid-state information media of optical echo-processors, and problems of cooling solid-state quantum processors. Laser Cooling of Solids is an important contribution to the development of compact laser-powered cryogenic refrigerators, both for the academic community and those in the microelectronics and other industries. Provides a timely review of this promising field of research and discusses the fundamentals and theory of laser cooling Particular attention is given to the physics of cooling processes and the mathematical description of these processes Reviews p...

  20. Estudos de associação genética no transtorno obsessivo-compulsivo

    Directory of Open Access Journals (Sweden)

    Aline Santos Sampaio

    2013-01-01

    Full Text Available INTRODUÇÃO: O caráter familial do transtorno obsessivo-compulsivo (TOC já é bem estabelecido. Ele segue o modelo complexo de transmissão genética que envolve a influência de diversos genes de pequeno efeito em interação com o ambiente. MÉTODOS: Foi realizada uma revisão sistemática de estudos de associação genética com o TOC por meio de busca de artigos publicados até 2012 nas bases de dados: PubMed, Embase e SciELO, usando os termos MeSH, seus associados ou sinônimos para "obsessive-compulsive disorder", "gene" e "genetic association studies". RESULTADOS: Foram selecionados 105 artigos cujos principais resultados foram agrupados em grupos de genes relacionados a serotonina, dopamina, glutamato, GABA, substância branca, hormônios, sistema imune e outros genes (MAO-A, BNDF, COMT. CONCLUSÃO: Há grande variabilidade nos achados de estudos de associação entre os diversos genes candidatos estudados e o TOC. Genes relacionados às vias glutamatérgicas são candidatos promissores, porém não há associação conclusiva entre nenhum dos genes candidatos estudados e o TOC. Estudos de associação com grande tamanho amostral, avaliação de subgrupos mais homogêneos do fenótipo e metanálises ainda são necessários.

  1. Síndrome de BURNOUT: Um estudo com professores da rede pública

    Directory of Open Access Journals (Sweden)

    Graziela Nascimento da Silva

    Full Text Available O objetivo deste estudo foi analisar se o gênero estabelece diferenças significativas nos níveis e no processo da Síndrome de Burnout em professores de escolas da rede pública. Também procurou identificar associações das dimensões de burnout com variáveis demográficas, laborais e comportamentais. Foi utilizado como instrumento de pesquisa o MBI- Maslach Burnout Inventory e um questionário elaborado especificamente para este estudo para as demais variáveis. A amostra, do tipo de conveniência, foi composta de 31 homens e 30 mulheres. Os resultados obtidos indicam não existir diferença estatisticamente significativa entre os grupos nas dimensões e níveis de Burnout; no entanto, verifica-se a ocorrência de associação diferenciada nos dois grupos entre as dimensões de Burnout e determinadas variáveis demográficas, profissionais e comportamentais.

  2. Auto cuidado no tratamento pelo método de Ilizarov: um estudo de caso

    Directory of Open Access Journals (Sweden)

    Marisa Toshiko Ono Tashiro

    1995-03-01

    Full Text Available As autoras realizaram um estudo de caso com aplicação do modelo de auto cuidado de Dorothea Orem, no tratamento pelo método de Ilizarov, utilizando cuidados e orientações específicas para a recuperação e prevenção de complicações. A operacionalização do estudo constou de procedimentos relativos às demandasdecuida dos universais e terapêuticos, durante a hospitalização. As demandas foram detectadas no pré-operatório e os cuidados desenvolvidos no pós-operatório, facilitando ao paciente o aprendizado e a realização dos procedimentos necessários a dar continuidade dos mesmos no seu domicílio.

  3. Estudo epidemiológico de pacientes com queimaduras por eletricidade atendidos em unidade de queimados em Recife – PE

    Directory of Open Access Journals (Sweden)

    Ana Claudia Siqueira Torquato

    2015-09-01

    Full Text Available Objetivo: verificar a frequência das queimaduras por eletricidade e perfil clínico-epidemiológico de pacientes atendidos na Unidade de Queimados em Recife-PE. Métodos: estudo retrospectivo, transversal e descritivo de pacientes com queimaduras por eletricidade atendidos na Unidade de Queimados do Hospital da Restauração (HR em Recife-PE, no período de janeiro 2007 a dezembro de 2008. Resultados: foram atendidos 115 pacientes com queimaduras por eletricidade no período de realização do estudo (média de 57,5 pacientes/ano, correspondendo a quase 8% de todas as queimaduras atendidas no serviço. Quanto ao sexo, 83,5% eram do sexo masculino e 16,5% eram do sexo feminino. A idade média foi de 27 anos. Ocorreu predominância do Médio queimado (70%. O acidente doméstico foi mais encontrado. Quanto ao tempo de hospitalização, aproximadamente 90% dos pacientes receberam alta com menos de dois meses de internação. Durante a evolução, 42,6% dos pacientes necessitaram de enxerto e 13% sofreram amputação. Nenhum óbito foi notificado no período de realização do estudo. Conclusões: a frequência de queimaduras por eletricidade em nosso estudo foi maior que as relatadas em outras séries. O perfil clínico- epidemiológico encontrado no presente estudo foi similar ao descrito na literatura.

  4. (Sem saber e (com poder nos estudos organizacionais

    Directory of Open Access Journals (Sweden)

    José Henrique de Faria

    Full Text Available Bacon afirma que saber é poder. Tragtenberg contesta. Essa discussão, na contemporaneidade, faz-se mais importante do que se possa imaginar. Por isso, o objetivo central deste artigo é verificar as relações entre saber e poder, na atualidade, levando em consideração o papel da ciência e dos elementos imediatos a ela relacionados. Quanto aos objetivos específicos deste estudo, destacam-se: · compreender o sentido da filosofia e da ciência e suas relações com a ideologia; · verificar como o discurso da neutralidade axiológica da ciência se apresenta como mito da modernidade e como se dá a presença da "fé" na filosofia e na ciência, na contemporaneidade; · refletir sobre a consolidação da ciência como força produtiva e/ou como mercadoria no atual sistema econômico; · destacar a importância do complexo industrial militar como financiador de grande parte dos atuais estudos científicos; · entender o processo de racionalização, avaliando a importância do pragmatismo e da burocracia universitária como afirmação da ciência na atualidade. O texto conclui que tanto é possível a existência de saber como poder (Bacon como a de não saber, mas com poder (Tragtenberg para compreendermos a relação entre saber e poder.

  5. Aspectos históricos dos estudos caso-controle

    Directory of Open Access Journals (Sweden)

    Rêgo Marco Antônio Vasconcelos

    2001-01-01

    Full Text Available Este texto apresenta um relato da evolução dos estudos de caso-controle (ECC até o final dos anos 80. A comparação de dois grupos quanto à exposição a um fator de risco é verificada desde o século XVII. A segunda metade do século XIX significou o declínio da Epidemiologia das "populações", e os primeiros ECC só foram realizados na década de 20. O avanço do método ocorreu na segunda metade do século, com destaque para as investigações sobre câncer de pulmão e hábito de fumar. As principais contribuições dos estudiosos do método foram o uso da odds ratio como estimativa do risco relativo; a definição dos aspectos estatísticos da análise de dados de estudos retrospectivos; o cálculo do risco atribuível e da fração etiológica para ECC; e a discussão da essência dos ECC. Os críticos referiam as fragilidades do método e a susceptibilidade aos bias. Conclui-se que os ECC tiveram aplicação crescente nas últimas décadas, sendo utilizados em diversas áreas da epidemiologia, constituindo-se em um importante instrumento para as ações de Saúde Pública.

  6. Laser physics and a review of laser applications in dentistry for children.

    Science.gov (United States)

    Martens, L C

    2011-04-01

    The aim of this introduction to this special laser issue is to describe some basic laser physics and to delineate the potential of laser-assisted dentistry in children. A brief review of the available laser literature was performed within the scope of paediatric dentistry. Attention was paid to soft tissue surgery, caries prevention and diagnosis, cavity preparation, comfort of the patient, effect on bacteria, long term pulpal vitality, endodontics in primary teeth, dental traumatology and low level laser therapy. Although there is a lack of sufficient evidence taking into account the highest standards for evidence-based dentistry, it is clear that laser application in a number of different aetiologies for soft tissue surgery in children has proven to be successful. Lasers provide a refined diagnosis of caries combined with the appropriate preventive adhesive dentistry after cavity preparation. This will further lead to a new wave of micro-dentistry based on 'filling without drilling'. It has become clear from a review of the literature that specific laser applications in paediatric dentistry have gained increasing importance. It can be concluded that children should be considered as amongst the first patients for receiving laser-assisted dentistry.

  7. Doença Pulmonar Obstrutiva Crónica em Portugal: estudo Pneumobil (1995 e estudo de prevalência de 2002 revisitados

    Directory of Open Access Journals (Sweden)

    J. Cardoso

    2013-05-01

    Full Text Available Resumo: Introdução: A doença pulmonar obstrutiva crónica (DPOC tem sido, ao longo dos anos, uma importante causa de morbilidade e mortalidade no mundo. Em 1995, a implementação de um rastreio da função respiratória pareceu a forma mais adequada para alertar para os sintomas respiratórios negligenciados e sensibilizar para os rastreios espirométricos. Em 2002, foram criadas novas normas consensuais de diagnóstico e o reconhecimento de que a prevalência da DPOC depende dos critérios de definição de obstrução das vias aéreas. O objetivo deste estudo foi revisitar estes 2 estudos e publicar alguns dos resultados e respetivas metodologias. Métodos: Dos 12 684 indivíduos que constavam da base de dados do Pneumobil, apenas os indivíduos com 40 e mais anos (n = 9061 foram considerados para esta análise. No estudo de 2002 foi incluída uma amostra aleatorizada e representativa de 1384 indivíduos, com idades entre os 35 e os 69 anos. Resultados: A prevalência da DPOC foi de 8,96% no estudo Pneumobil e de 5,34% no estudo de 2002. Em ambos os estudos, a presença da DPOC foi superior no sexo masculino, tendo-se verificado uma associação positiva entre a presença da DPOC e os grupos etários mais velhos. Nos fumadores e ex-fumadores encontrou-se maior proporção de casos com DPOC. Conclusões: A prevalência em Portugal é mais baixa do que noutros países europeus, o que pode estar relacionado com uma menor prevalência de tabagismo. De um modo geral, os fatores de risco mais importantes que mostraram a associação com a DPOC foram a idade maior do que 60 anos, o sexo masculino e a exposição tabágica. Todos os aspetos e as limitações que se referem a diferentes critérios de definição e a metodologias de recrutamento realçam a necessidade de métodos padronizados para determinar a prevalência da DPOC e os

  8. Monossialogangliosídeo transdérmico com laser no tratamento de lesão medular espinal de ratos Transdermal monosialoganglioside with laser in the treatment of spinal cord lesion in rats

    Directory of Open Access Journals (Sweden)

    Fabiano Inácio de Souza

    2013-04-01

    Full Text Available OBJETIVOS: Avaliar os efeitos de monossialogangliosídeos (GM1 administrados com laser por via transdérmica na recuperação da lesão da medula espinal de ratos. MÉTODOS: Quarenta ratos Wistar machos foram submetidos a contusão da medula espinal usando NYU Impactor. No Grupo 1, os ratos receberam 0,2 ml de solução salina diária por via intraperitoneal; no Grupo 2, GM1 foi administrada intraperitonealmente em concentração de 30 mg/kg por dia; no Grupo 3, os ratos foram tratados diariamente com o laser a baixa temperatura sobre a pele, e no Grupo 4, a sessão de laser diária também continha GM1. Todos os grupos foram tratados durante 42 dias. Os animais foram avaliados pela escala funcional de Basso, Baettie e Bresnahan (BBB nos dias 7, 14, 21, 28, 35 e 42 após a lesão, e por histopatologia e potencial motor evocado 42 dias depois da lesão. RESULTADOS: Os animais do Grupo 4 apresentaram escores BBB mais elevados em comparação com os outros grupos. Não houve diferenças entre os grupos ou nas comparações ao longo do tempo. A avaliação histológica não mostrou diferenças, e tampouco foram encontradas diferenças significativas no potencial evocado. CONCLUSÃO: A GM1 associada ao uso de laser a baixa temperatura não mostra resultados superiores no tratamento de lesões da medula espinal de ratos. Nível de Evidência I, Experimental, Estudo Controlado de Animais.OBJECTIVES: to evaluate the effects of monosialoganglioside (gm1 administered transdermally with laser in the recovery of spinal cord injury in rats. METHODS: forty male wistar rats underwent spinal cord contusion using the nyu impactor. in group 1, the rats received 0,2 ml of saline intraperitoneally daily; in group 2, gm1 was administered intraperitoneally at a concentration of 30 mg/kg per day; in group 3, rats were treated daily with laser at low temperature on the skin, and in group 4, the daily laser session also contained gm1. all the groups were treated for 42

  9. Femtosecond laser inscribed cladding waveguide lasers in Nd:LiYF4 crystals

    Science.gov (United States)

    Li, Shi-Ling; Huang, Ze-Ping; Ye, Yong-Kai; Wang, Hai-Long

    2018-06-01

    Depressed circular cladding, buried waveguides were fabricated in Nd:LiYF4 crystals with an ultrafast Yb-doped fiber master-oscillator power amplifier laser. Waveguides were optimized by varying the laser writing conditions, such as pulse energy, focus depth, femtosecond laser polarization and scanning velocity. Under optical pump at 799 nm, cladding waveguides showed continuous-wave laser oscillation at 1047 nm. Single- and multi-transverse modes waveguide laser were realized by varying the waveguide diameter. The maximum output power in the 40 μm waveguide is ∼195 mW with a slope efficiency of 34.3%. The waveguide lasers with hexagonal and cubic cladding geometry were also realized.

  10. Advanced Laser Architecture for Two-Step Laser Tandem Mass Spectrometer

    Science.gov (United States)

    Fahey, Molly E.; Li, Steven X.; Yu, Anthony W.; Getty, Stephanie A.

    2016-01-01

    Future astrobiology missions will focus on planets with significant astrochemical or potential astrobiological features, such as small, primitive bodies and the icy moons of the outer planets that may host diverse organic compounds. These missions require advanced instrument techniques to fully and unambiguously characterize the composition of surface and dust materials. Laser desorptionionization mass spectrometry (LDMS) is an emerging instrument technology for in situ mass analysis of non-volatile sample composition. A recent Goddard LDMS advancement is the two-step laser tandem mass spectrometer (L2MS) instrument to address the need for future flight instrumentation to deconvolve complex organic signatures. The L2MS prototype uses a resonance enhanced multi-photon laser ionization mechanism to selectively detect aromatic species from a more complex sample. By neglecting the aliphatic and inorganic mineral signatures in the two-step mass spectrum, the L2MS approach can provide both mass assignments and clues to structural information for an in situ investigation of non-volatile sample composition. In this paper we will describe our development effort on a new laser architecture that is based on the previously flown Lunar Orbiter Laser Altimeter (LOLA) laser transmitter for the L2MS instrument. The laser provides two discrete midinfrared wavelengths (2.8 m and 3.4 m) using monolithic optical parametric oscillators and ultraviolet (UV) wavelength (266 nm) on a single laser bench with a straightforward development path toward flight readiness.

  11. Laser in operative dentistry

    Directory of Open Access Journals (Sweden)

    E. Yasini

    1994-06-01

    Full Text Available Today laser has a lot of usage in medicine and dentistry. In the field of dentistry, laser is used in soft tissue surgery, sterilization of canals (in root canal therapy and in restorative dentistry laser is used for cavity preparation, caries removal, sealing the grooves (in preventive dentistry, etching enamel and dentin, composite polymerization and removal of tooth sensitivity. The use of Co2 lasers and Nd: YAG for cavity preparation, due to creating high heat causes darkness and cracks around the region of laser radiation. Also due to high temperature of these lasers, pulp damage is inevitable. So today, by using the Excimer laser especially the argon floride type with a wavelength of 193 nm, the problem of heat stress have been solved, but the use of lasers in dentistry, especially for cavity preparation needs more researches and evaluations.

  12. Flexible Laser Metal Cutting

    DEFF Research Database (Denmark)

    Villumsen, Sigurd; Jørgensen, Steffen Nordahl; Kristiansen, Morten

    2014-01-01

    This paper describes a new flexible and fast approach to laser cutting called ROBOCUT. Combined with CAD/CAM technology, laser cutting of metal provides the flexibility to perform one-of-a-kind cutting and hereby realises mass production of customised products. Today’s laser cutting techniques...... possess, despite their wide use in industry, limitations regarding speed and geometry. Research trends point towards remote laser cutting techniques which can improve speed and geometrical freedom and hereby the competitiveness of laser cutting compared to fixed-tool-based cutting technology...... such as punching. This paper presents the concepts and preliminary test results of the ROBOCUT laser cutting technology, a technology which potentially can revolutionise laser cutting....

  13. Questionário de estilos parentais para pais (PAQ-P) - Estudos de validação

    OpenAIRE

    Pires, Mónica; Jesus, Saul Neves de; Hipólito, João

    2011-01-01

    Após a adaptação e dos procedimentos de tradução do Parental Authority Questionnaire (Buri, 1991), para a língua portuguesa e para a resposta a pais, e dos estudos iniciais de adaptação e pré-validação (Pires, Hipólito & Jesus, 2010), procedeu-se à validação final do Questionário de Estilos Parentais para Pais (PAQ-P), permitindo avaliar as suas qualidades psicométricas e respectiva comparação com estudos exploratórios anteriores (Pires, 2008; Pires, Hipólito & Jesus, 2010) ...

  14. Estudo fitoquímico e ensaios biológicos de Davilla Kunthii A. St. Hil (Dilleniaceae)

    OpenAIRE

    Leandro da Silva Nascimento

    2014-01-01

    O uso de plantas ou extratos de plantas para propósitos medicinais tem sido realizado a milhares de anos. O estudo químico e biológico de plantas constitui numa estratégia alternativa na procura de novos agentes terapêuticos para a identificação de compostos bioativos. A espécie Davilla kunthii A. St. Hil, pertencente à família Dilleniaceae, é conhecida popularmente como cipódefogo e podem ser encontradas em regiões de savana. Este trabalho teve como objetivo realizar o estudo fitoquímico e e...

  15. Determinação de amlodipina atraves da tecnica LC-MS-MS em estudo de bioequivalencia

    OpenAIRE

    Andreia Maria Lopes Guermani Orives

    2004-01-01

    Resumo: O objetivo deste estudo foi avaliar a bioequivalência de duas formulações de amlodipina em comprimidos ( Amlodipina® 5 mg comprimidos, Laboratório Teuto Brasileiro Ltda., formulação teste e Norvasc ® 5 mg, Laboratórios Pfizer Ltda., como referência ) após administração oral a 24 voluntários adultos sadios de ambos os sexos. O estudo foi aberto, randomizado com duas fases, onde os voluntários receberam uma dose única de besilato de amlodipina 5 mg. As amostras de plasma foram obtidas e...

  16. Demanda de informação pelo setor industrial: dois estudos no intervalo de 25 anos

    OpenAIRE

    Araujo, Vania M. R. Hermes de; Freire, Isa Maria; Mendes, Teresa Cristina M.

    1997-01-01

    Os estudos sobre a demanda de informação dos usuários do setor produtivo industrial tornam-se cada vez mais necessários, à medida que a informação se estabelece como fator/insumo de produção. Neste trabalho, são analisados, comparativamente, dois estudos em nível nacional, separados por um intervalo de tempo de 25 anos. Neles, pode-se observar semelhanças e diferenças, sendo possível distinguir quais os tipos de informação mais relevantes para o setor industrial, nas respectivas etapas histór...

  17. Estudo clínico comparativo entre diferentes sistemas de clareamento de uso em consultório

    OpenAIRE

    Flávio Henrique Umeda Gentil

    2015-01-01

    Objetivos: Estudos clínicos longitudinais que acompanham os pacientes por longos períodos não são muito comuns na literatura, ainda mais quando associados a grandes amostras (veio do fim do resumo). Por isso, o objetivo do trabalho foi determinar a eficiência, estabilidade de cor e sensibilidade dental, trans e pós operatória, dentro de um período de 365 dias, de quatro protocolos de clareamento em consultório. Material e Métodos: Foi realizado um estudo clínico randomizado, cego (para os pac...

  18. Measurement of the emission spectrum of a semiconductor laser using laser-feedback interferometry.

    Science.gov (United States)

    Keeley, James; Freeman, Joshua; Bertling, Karl; Lim, Yah L; Mohandas, Reshma A; Taimre, Thomas; Li, Lianhe H; Indjin, Dragan; Rakić, Aleksandar D; Linfield, Edmund H; Davies, A Giles; Dean, Paul

    2017-08-03

    The effects of optical feedback (OF) in lasers have been observed since the early days of laser development. While OF can result in undesirable and unpredictable operation in laser systems, it can also cause measurable perturbations to the operating parameters, which can be harnessed for metrological purposes. In this work we exploit this 'self-mixing' effect to infer the emission spectrum of a semiconductor laser using a laser-feedback interferometer, in which the terminal voltage of the laser is used to coherently sample the reinjected field. We demonstrate this approach using a terahertz frequency quantum cascade laser operating in both single- and multiple-longitudinal mode regimes, and are able to resolve spectral features not reliably resolved using traditional Fourier transform spectroscopy. We also investigate quantitatively the frequency perturbation of individual laser modes under OF, and find excellent agreement with predictions of the excess phase equation central to the theory of lasers under OF.

  19. Uso do laser, 670 nm, no quadro álgico de ratos submetidos à modelo experimental de ciatalgia Use of laser, 670 nm, in painful episodes of rats submitted to experimental model of sciatica

    Directory of Open Access Journals (Sweden)

    Núbia Broetto Cunha

    2008-04-01

    Full Text Available A ciatalgia deve-se a compressão do nervo isquiático em algum ponto de seu trajeto, e seu tratamento consiste em solucionar a causa da compressão nervosa, seja por tratamento cirúrgico ou conservador. Alguns recursos fisioterapêuticos atuam basicamente na redução dos sintomas ocasionados por este distúrbio. O objetivo deste estudo foi verificar a eficácia do laser 670 nm, em duas diferentes densidades de energia, na redução do quadro álgico, em ratos submetidos a modelo experimental de ciatalgia. Foram utilizados 18 ratos, divididos em 3 grupos: G1 (n=6 submetidos à ciatalgia e simulado o tratamento (grupo placebo, G2 (n=6 submetido à ciatalgia e tratados com laser 2 J/cm², G3 (n=6 submetidos à ciatalgia e irradiados com laser 4 J/cm². O nervo isquiático do membro posterior direito dos animais foi exposto e compressão com fio catgut em 4 pontos ao redor do nervo foi realizada. No 3° dia pós-operatório, iniciou-se o tratamento com laser na região do procedimento cirúrgico do membro posterior direito durante 10 dias consecutivos. Verificou-se por meio da marcha, o tempo em que o membro permanecia no ar nos períodos: anterior à ciatalgia, pré e pós-tratamento. Os resultados demonstraram que o laser não foi eficaz na redução do quadro álgico, porém com 4 J/cm² houve efeito positivo, sem restabelecimento completo da funcionalidade.Sciatica is caused by the sciatic nerve compression in some point of its course, and its treatment consists of solving the nervous compression cause, either by surgical or conservative treatment. Some physiotherapeutic resources act basically in the reduction of the symptoms caused by this disturbance. The aim of this study was to verify the effectiveness of the laser 670 nm, in two different energy densities, in the pain reduction, in rats submitted to a sciatica experimental model. Eighteen rats, divided in 3 groups were used: G1 (n=6 submitted to sciatica and simulated treatment (placebo

  20. Lasers in chemical processing

    International Nuclear Information System (INIS)

    Davis, J.I.

    1982-01-01

    The high cost of laser energy is the crucial issue in any potential laser-processing application. It is expensive relative to other forms of energy and to most bulk chemicals. We show those factors that have previously frustrated attempts to find commercially viable laser-induced processes for the production of materials. Having identified the general criteria to be satisfied by an economically successful laser process and shown how these imply the laser-system requirements, we present a status report on the uranium laser isotope separation (LIS) program at the Lawrence Livermore National Laboratory

  1. Laser power supply

    International Nuclear Information System (INIS)

    Bernstein, D.

    1975-01-01

    The laser power supply includes a regulator which has a high voltage control loop based on a linear approximation of a laser tube negative resistance characteristic. The regulator has independent control loops for laser current and power supply high voltage

  2. Lasers in endodontics: an overview

    Science.gov (United States)

    Frentzen, Matthias; Braun, Andreas; Koort, Hans J.

    2002-06-01

    The interest in endodontic use of dental laser systems is increasing. Developing laser technology and a better understanding of laser effects widened the spectrum of possible endodontic indications. Various laser systems including excimer-, argon+-, diode-, Nd:YAG-, Er:YAG- and CO2-lasers are used in pulp diagnosis, treatment of hypersensitivity, pulp capping, sterilization of root canals, root canal shaping and obturation or apicoectomy. With the development of new delivery systems - thin and flexible fibers - for many different wavelengths laser applications in endodontics may increase. Since laser devices are still relatively costly, access to them is limited. Most of the clinical applications are laser assisted procedures such as the removing of pulp remnants and debris or disinfection of infected root canals. The essential question is whether a laser can provide improved treatment over conventional care. To perform laser therapy in endodontics today different laser types with adopted wavelengths and pulse widths are needed, each specific to a particular application. Looking into the future we will need endodontic laser equipment providing optimal laser parameters for different treatment modalities. Nevertheless, the quantity of research reports from the last decade promises a genuine future for lasers in endodontics.

  3. Cutting using the CO laser. Trennen mit dem CO-Laser

    Energy Technology Data Exchange (ETDEWEB)

    Maisenhaelder, F.; Stoehr, M. (DLR, Inst. fuer Technische Physik, Stuttgart (Germany))

    1991-02-01

    Several cutting experiments were performed to investigate the maximum cutting speed when using CO or CO{sub 2} laser radiation. The material which was used for these experiments was mild steel (St 37) and stainless steel (V2A; X5CrNi 189), the material thickness varied from 0.5 mm to 4 mm. The cutting parameters, especially the focal power density and the focal diameter, were equal for both laser wavelengths. The experimental result shows an increased cutting speed with CO laser beams in comparison to CO{sub 2} laser beams.

  4. Morphometric and ultrastructural studies of the effect of infrared laser on rabbit temporo-mandibular joint fibroblasts

    Directory of Open Access Journals (Sweden)

    Ricardo Cornejo Uribe

    2009-06-01

    articulação temporo-mandibular de coelhos que foram irradiados com raio laser e de outras não irradiadas que foram consideradas como controle normal. As doses diarias de irradiação foram de 2 Joules /cm² durante 10 dias. As amostras foram tratadas para microscopia eletrônica de transmissão. Dos fibroblastos normais e irradiados obtiveram-se microfotografias eletrônicas de transmissão com aumentos finais de 11.500 X, realizando-se estudos morfometricos com propósito de quantificar as frações volumétricas dos componentes celulares pertencentes aos tipos celulares assinalados. Das células indicadas avaliaram-se frações volumétricas correspondentes ao núcleo, citoplasma, retículo endoplásmico rugoso, eucromatina e heterocromatina. Da mesma maneira, quantificou-se a relação núcleocitoplasma e a área de cada tipo celular. Os resultados originados do estudo morfométrico comparativo entre fibroblastos normais e irradiados, indicaram que existem diferencas significativas nas frações volumétricas de eucromatina e heterocromatina e fundamentalmente nas áreas celulares de ambos os tipos. Os outros parâmetros quantificados mantiveram-se constantes. A conclusão é que a função celular traduzida em síntese e secreção de colágeno é constante em ambos os tipos celulares, contudo, produto das estimulações com raio laser infravermelho este fibroblasto tem tendência devido a sua percentagem de eucromatina transcripcionalmente ativa a uma sintese imediata e facilitada de proteinas.

  5. Estudo de estabilidade do antibiótico meropenem

    OpenAIRE

    Andreas Sebastian Loureiro Mendez

    2007-01-01

    A estabilidade de medicamentos constitui um tema atual e de grande importância no meio científico. Tem sido constantemente abordada em estudos direcionados à avaliação da qualidade das preparações farmacêuticas. O meropenem, um antibiótico carbapenêmico de amplo espectro de ação, é utilizado como um importante recurso terapêutico para o tratamento de infecções graves. Por ser um agente antimicrobiano ativo e eficaz, de uso clínico em muitos países, tornase necessária a pesquisa mais aprofunda...

  6. Laser marking method and device

    International Nuclear Information System (INIS)

    Okazaki, Yuki; Aoki, Nobutada; Mukai, Narihiko; Sano, Yuji; Yamamoto, Seiji.

    1997-01-01

    An object is disposed in laser beam permeating liquid or gaseous medium. Laser beams such as CW laser or pulse laser oscillated from a laser device are emitted to the object to apply laser markings with less degradation of identification and excellent corrosion resistance on the surface of the object simply and easily. Upon applying the laser markings, a liquid or gas as a laser beam permeating medium is blown onto the surface of the object, or the liquid or gas in the vicinity of the object is sucked, the laser beam-irradiated portion on the surface can be cooled positively. Accordingly, the laser marking can be formed on the surface of the object with less heat affection to the object. In addition, if the content of a nitrogen gas in the laser beam permeating liquid medium is reduced by degassing to lower than a predetermined value, or the laser beam permeating gaseous medium is formed by an inert gas, a laser marking having high corrosion resistance and reliability can be formed on the surface of the objective member. (N.H.)

  7. CO laser angioplasty system: efficacy of manipulatable laser angioscope catheter

    Science.gov (United States)

    Arai, Tsunenori; Kikuchi, Makoto; Mizuno, Kyoichi; Sakurada, Masami; Miyamoto, Akira; Arakawa, Koh; Kurita, Akira; Nakamura, Haruo; Takeuchi, Kiyoshi; Utsumi, Atsushi; Akai, Yoshiro

    1992-08-01

    A percutaneous transluminal coronary angioplasty system using a unique combination of CO laser (5 micrometers ) and As-S infrared glass fiber under the guidance of a manipulatable laser angioscope catheter is described. The ablation and guidance functions of this system are evaluated. The angioplasty treatment procedure under angioscope guidance was studied by in vitro model experiment and in vivo animal experiment. The whole angioplasty system is newly developed. That is, a transportable compact medical CO laser device which can emit up to 10 W, a 5 F manipulatable laser angioscope catheter, a thin CO laser cable of which the diameter is 0.6 mm, an angioscope imaging system for laser ablation guidance, and a system controller were developed. Anesthetized adult mongrel dogs (n equals 5) with an artificial complete occlusion in the femoral artery and an artificial human vessel model including occluded or stenotic coronary artery were used. The manipulatability of the catheter was drastically improved (both rotation and bending), therefore, precise control of ablation to expand stenosis was obtained. A 90% artificial stenosis made of human yellow plaque in 4.0 mm diameter in the vessel was expanded to 70% stenosis by repetitive CO laser ablations of which total energy was 220 J. All procedures were performed and controlled under angioscope visualization.

  8. Histopathological study of the effects of low-intensity laser irradiation ({lambda}=650 nm) on dental pulp tissue after cavity preparation; Estudo histopatologico dos efeitos da irradiacao laser em baixa intensidade ({lambda}=650nm) em tecido pulpar apos preparo cavitario

    Energy Technology Data Exchange (ETDEWEB)

    Bertella, Claudio

    2001-07-01

    The purpose of this study was to evaluate (in vivo) the effects of low-intensity Arsenide Gallium Aluminium laser application post-cavity preparation class 1. Six patients with bilateral pre-molars and molars indicated to extraction for orthodontics aim were selected. Four samples of these teeth underwent cavity preparation with deep from medium to high and two samples underwent cavity preparation from high to pulp expositions. The samples were constituted of two teeth of the same patient and received different treatments. One of the teeth underwent laser exposition and the other one was maintained as control, before restorative procedure with polycarboxylate cement. A diode laser ({lambda}=650 nm), output power 30 mW and fluencies of 1,8 J/cm{sup 2} and 2,7 J/cm{sup 2} in pre-molars and molars, respectively, was used for irradiation with repetition rate of 18 Hz in interrupted continuous wave mode. After seven days, the teeth were extracted and processed histologically with HE to verify morphological changes in the pulpy tissue. The four samples, which cavity preparation and restorative material were not in contact with the pulp, did not show histological differences between irradiated and non-irradiated teeth. Both of them presented the same characteristics of normality. The two samples with exposed pulpy tissue showed different results. The irradiated teeth presented no or slight inflammatory signs when compared to the control samples, which showed abscess in the coronary pulp interior and intense inflammatory infiltrated. These results suggest that the laser irradiation can be used as a therapeutic modality in clinical trials, in the conditions employed in this study. (author)

  9. Otomycosis: a retrospective study Otomicoses: um estudo retrospectivo

    Directory of Open Access Journals (Sweden)

    Zélia Braz Vieira da Silva Pontes

    2009-06-01

    Full Text Available Otomycosis is a fungal infection of the external ear canal with only a few studies about its real frequence in Brazil. AIM: to evaluate otomycosis frequence and characteristics in patients with clinical suspicion of external otitis. STUDY DESIGN: Retrospective study with transversal cohort (2000-2006. MATERIALS AND METHODS:103 patients were assigned to mycological diagnosis (direct microscopic examination and culture. RESULTS: Otomycosis was diagnosed in 19.4% of the patients. Patient age varied from 2 to 66 years (an average of 23.5 years of age, and 60% of otomycosis cases were seen in women between 2 to 20 years of age. Chronic otitis, previous antibiotic therapy and the lack of cerumen were predisposing factors; itching, otalgia, otorrhea and hypoacusis were the symptoms reported by the patients. The most frequently isolated species were C. albicans (30%, C. parapsilosis (20%, A. niger (20%, A. flavus (10%, A. fumigatus (5%, C. tropicalis (5%, Trichosporon asahii (5% and Scedosporium apiospermum (5%. CONCLUSIONS: Otomycosis is endemic in João Pessoa-PB. Clinical exam and mycological studies are important for diagnostic purposes because otomycosis symptoms are not specific.Otomicose é uma infecção fúngica do conduto auditivo externo com poucos estudos sobre sua real frequência no Brasil. OBJETIVO: Avaliar a frequência e características das otomicoses em pacientes com suspeita clínica de otite externa. DESENHO DO ESTUDO: Estudo retrospectivo com corte transversal (2000-2006. MATERIAL E MÉTODOS: 103 pacientes foram atendidos para diagnóstico micológico (exame microscópico direto e cultivo. RESULTADOS: Otomicoses foram diagnosticadas em 19,4% dos pacientes. A idade desses pacientes variou de 2 a 66 anos (média de 23,5 anos e 60% das otomicoses foram observadas em mulheres entre 2 a 20 anos de idade. Otite crônica, antibioticoterapia prévia e ausência de cerume foram os fatores predisponentes e prurido otológico, otalgia

  10. Laser welding engineering

    International Nuclear Information System (INIS)

    Bhieh, N. M.; El Eesawi, M. E.; Hashkel, A. E.

    2007-01-01

    Laser welding was in its early life used mainly for unusual applications where no other welding process would be suitable that was twenty five years ago. Today, laser welding is a fully developed part of the metal working industry, routinely producing welds for common items such as cigarette lighters, which springs, motor/transformer lamination, hermetic seals, battery and pacemaker cans and hybrid circuit packages. Yet very few manufacturing engineering have seriously considers employing lasers in their own operations. Why? There are many reasons, but a main one must be not acquainted with the operation and capabilities of a laser system. Other reasons, such as a relatively high initial cost and a concern about using lasers in the manufacturing environment, also are frequently cited, and the complexity of the component and flexibility of the light delivery system. Laser welding could be used in place of many different standard processes, such as resistance (spot or seam), submerged arc, RF induction, high-frequency resistance, ultrasonic and electronic and electron-beam. while each of these techniques has established an independent function in the manufacturing world, the flexible laser welding approach will operate efficiently and economically in many different applications. Its flexibility will even permit the welding system to be used for other machining function, such as drilling, scribing, sealing and serializing. In this article, we will look at how laser welding works and what benefits it can offer to manufacturing engineers. Some industry observers state that there are already 2,000 laser machine tools being used for cutting, welding and drilling and that the number could reach 30,000 over the next 15 years as manufacturing engineers become more aware of the capabilities of lasers [1). While most laser applications are dedicated to one product or process that involves high-volume, long-run manufacturing, the flexibility of a laser to supply energy to hard

  11. GOVERNANÇA NA EMPRESA FAMILIAR: ESTUDO DE CASO SOBRE GESTÃO, PROFISSIONALIZAÇÃO E SUCESSÃO

    Directory of Open Access Journals (Sweden)

    Anderson Felipe Klein

    2010-01-01

    Full Text Available Os estudos abordando a temática de empresas familiares mostram-se cada vez mais necessários, devido ao crescente número de organizações que se caracterizam com esse perfil de administração e ao poder que essas entidades exercem sobre a economia local. Este trabalho tem como objetivo conhecer as práticas de gestão utilizadas pelos dirigentes na empresa Latina Haus, buscando embasamento teórico, para apoiar os resultados e a análise em autores especialistas no assunto, como, por exemplo: Lodi (1987, 1993, Bernhoeft (1987, 1991, Bornholdt (2005 e Gersick et al. (1997. Os procedimentos metodológicos utilizados para este estudo caracterizam-se como exploratório, utilizando como procedimentos a pesquisa bibliográfica, o estudo de caso e a pesquisa participante. Utilizou-se de abordagem qualitativa para o problema de pesquisa. A coleta de dados deu-se sob a forma de entrevistas semiestruturadas, com os dirigentes da Latina Haus, e pela observação participante dos autores. Os resultados do estudo sugerem que a empresa procure profissionalizar sua gestão, no sentido de facilitar um futuro processo de sucessão, para melhor controle e organização das atividades administrativas, visando a distinguir assuntos de interesse familiar em relação aos que envolvem negócios familiares. Palavras-chave: Empresa Familiar. Governança. Profissionalização. Sucessão. Cultura Organizacional.

  12. Teradiode's high brightness semiconductor lasers

    Science.gov (United States)

    Huang, Robin K.; Chann, Bien; Burgess, James; Lochman, Bryan; Zhou, Wang; Cruz, Mike; Cook, Rob; Dugmore, Dan; Shattuck, Jeff; Tayebati, Parviz

    2016-03-01

    TeraDiode is manufacturing multi-kW-class ultra-high brightness fiber-coupled direct diode lasers for industrial applications. A fiber-coupled direct diode laser with a power level of 4,680 W from a 100 μm core diameter, BPP) of 3.5 mm-mrad and is the lowest BPP multi-kW-class direct diode laser yet reported. This laser is suitable for industrial materials processing applications, including sheet metal cutting and welding. This 4-kW fiber-coupled direct diode laser has comparable brightness to that of industrial fiber lasers and CO2 lasers, and is over 10x brighter than state-of-the-art direct diode lasers. We have also demonstrated novel high peak power lasers and high brightness Mid-Infrared Lasers.

  13. Color speckle in laser displays

    Science.gov (United States)

    Kuroda, Kazuo

    2015-07-01

    At the beginning of this century, lighting technology has been shifted from discharge lamps, fluorescent lamps and electric bulbs to solid-state lighting. Current solid-state lighting is based on the light emitting diodes (LED) technology, but the laser lighting technology is developing rapidly, such as, laser cinema projectors, laser TVs, laser head-up displays, laser head mounted displays, and laser headlamps for motor vehicles. One of the main issues of laser displays is the reduction of speckle noise1). For the monochromatic laser light, speckle is random interference pattern on the image plane (retina for human observer). For laser displays, RGB (red-green-blue) lasers form speckle patterns independently, which results in random distribution of chromaticity, called color speckle2).

  14. Recent laser experiments on the Aurora KrF/ICF laser system

    International Nuclear Information System (INIS)

    Turner, T.P.; Jones, J.E.; Czuchlewski, S.J.; Watt, R.G.; Thomas, S.J.; Kang, M.; Tallman, C.R.; Mack, J.M.; Figueira, J.F.

    1990-01-01

    The Aurora KrF/ICF Laser Facility at Los Alamos is operational at the kilojoule-level for both laser and target experiments. We report on recent laser experiments on the system and resulting system improvements. 3 refs., 4 figs

  15. Laser for fusion energy

    International Nuclear Information System (INIS)

    Holzrichter, J.F.

    1995-01-01

    Solid state lasers have proven to be very versatile tools for the study and demonstration of inertial confinement fusion principles. When lasers were first contemplated to be used for the compression of fusion fuel in the late 1950s, the laser output energy levels were nominally one joule and the power levels were 10 3 watts (pulse duration's of 10 -3 sec). During the last 25 years, lasers optimized for fusion research have been increased in power to typically 100,000 joules with power levels approaching 10 14 watts. As a result of experiments with such lasers at many locations, DT target performance has been shown to be consistent with high gain target output. However, the demonstration of ignition and gain requires laser energies of several megajoules. Laser technology improvements demonstrated over the past decade appear to make possible the construction of such multimegajoule lasers at affordable costs. (author)

  16. Laser Processing and Chemistry

    CERN Document Server

    Bäuerle, Dieter

    2011-01-01

    This book gives an overview of the fundamentals and applications of laser-matter interactions, in particular with regard to laser material processing. Special attention is given to laser-induced physical and chemical processes at gas-solid, liquid-solid, and solid-solid interfaces. Starting with the background physics, the book proceeds to examine applications of lasers in “standard” laser machining and laser chemical processing (LCP), including the patterning, coating, and modification of material surfaces. This fourth edition has been enlarged to cover the rapid advances in the understanding of the dynamics of materials under the action of ultrashort laser pulses, and to include a number of new topics, in particular the increasing importance of lasers in various different fields of surface functionalizations and nanotechnology. In two additional chapters, recent developments in biotechnology, medicine, art conservation and restoration are summarized. Graduate students, physicists, chemists, engineers, a...

  17. Laser applications for energy. Fifty years since advent of laser and next thirty years

    International Nuclear Information System (INIS)

    Nakai, Sadao

    2011-01-01

    The utilization of light has been changed since the advent of lasers about fifty years ago. Now in the twenty first century, laser science is being applied in every industry as the fundamental technology. In the recent years, remarkable progresses have been made in the semiconductor lasers of high power and wide wavelength region. The amazing developments of ceramics laser materials like YAG and nonlinear optics materials of organic crystals have been achieved as well as the big progress in the fiber lasers. It is also to be pointed out that very high power ultra short laser pulses have become available. In the field of power photonics, which is based on the power semiconductor lasers, fiber lasers and new laser materials, various industrial applications are expected to be constructed further in civil engineering, manufacturing technology, agricultural and biological applications, medical utilization and space sciences. It is expected, by the development of ultra short pulse and ultra high mean power lasers, that particle accelerations, ultra high density sciences, nuclear fusion neutron sources and laser fusion power reactors are to be advanced drastically. Recent development and future prospects of high power lasers are illustrated. Lasers are now regarded as one of the key technologies in line with the national policy toward the creation of innovative industries. Realization of the laser fusion reactor is the most challenging target in the coming thirty years. (S. Funahashi)

  18. Disk laser: a new generation of industrial lasers

    Science.gov (United States)

    Brockmann, Rüdiger; Havrilla, David

    2009-02-01

    The disk laser concept aggregates high efficiency, excellent beam quality, high average and peak power with moderate cost and high reliability. Therefore it became one major technology in industrial laser material processing. In several large scale installations in the automotive industry, high power cw- systems make already use of the high brightness and high efficiency of disk lasers, e.g. in remote welding [1,2]. Other applications including cutting, drilling, deep welding and hybrid welding are arising. This report highlights the latest results in cw disk laser development. A 1.5 kW source with a beam parameter product (BPP) of 2 mm mrad is described as well as the demonstration of a 14 kW system out of three disks with a BPP of 8 mm mrad. The future prospects regarding increased power and even further improved productivity and economics are presented. A new industrial disk laser series with output powers up to 16 kW and a beam parameter product of 8 mm*mrad will enable both, new applications in the thick sheet area and very cost efficient high productive applications like welding and cutting of thin sheets.

  19. Laser development for laser fusion applications. Research progress report, October 1979-September 1980

    International Nuclear Information System (INIS)

    1981-04-01

    Research conducted during this period is reported on the following: (1) rare-gas-halogen lasers, (2) XeCl laser at excitation rates of 1.7 to 4.7 MW/cm 3 , (3) rare gas halogen laser modeling, (4) three-body ion recombination coefficients, (5) electron beam accelerators, (6) power conditioning studies for accelerators, (7) chemically pumped iodine lasers, (8) hydrogen fluoride lasers, and (9) supporting research

  20. A low-cost, tunable laser lock without laser frequency modulation

    Science.gov (United States)

    Shea, Margaret E.; Baker, Paul M.; Gauthier, Daniel J.

    2015-05-01

    Many experiments in optical physics require laser frequency stabilization. This can be achieved by locking to an atomic reference using saturated absorption spectroscopy. Often, the laser frequency is modulated and phase sensitive detection used. This method, while well-proven and robust, relies on expensive components, can introduce an undesirable frequency modulation into the laser, and is not easily frequency tuned. Here, we report a simple locking scheme similar to those implemented previously. We modulate the atomic resonances in a saturated absorption setup with an AC magnetic field created by a single solenoid. The same coil applies a DC field that allows tuning of the lock point. We use an auto-balanced detector to make our scheme more robust against laser power fluctuations and stray magnetic fields. The coil, its driver, and the detector are home-built with simple, cheap components. Our technique is low-cost, simple to setup, tunable, introduces no laser frequency modulation, and only requires one laser. We gratefully acknowledge the financial support of the NSF through Grant # PHY-1206040.

  1. Epilepsias com focos projetados na linha média: estudo com EEG quantitativo e topográfico (mapeamento cerebral

    Directory of Open Access Journals (Sweden)

    ANGHINAH RENATO

    1998-01-01

    Full Text Available Estudamos com EEG quantitativo e topográfico (mapeamento cerebral quatro pacientes com exames pregressos de EEG convencional mostrando foco de linha média. O estudo quantitativo revelou-se mais preciso na definição do foco, localizando o seu hemisfério de origem e definindo a atividade focal como parassagital. Estes achados deverão ser validados em estudos futuros com amostragem maior.

  2. CO2 laser pulse shortening by laser ablation of a metal target

    International Nuclear Information System (INIS)

    Donnelly, T.; Mazoyer, M.; Lynch, A.; O'Sullivan, G.; O'Reilly, F.; Dunne, P.; Cummins, T.

    2012-01-01

    A repeatable and flexible technique for pulse shortening of laser pulses has been applied to transversely excited atmospheric (TEA) CO 2 laser pulses. The technique involves focusing the laser output onto a highly reflective metal target so that plasma is formed, which then operates as a shutter due to strong laser absorption and scattering. Precise control of the focused laser intensity allows for timing of the shutter so that different temporal portions of the pulse can be reflected from the target surface before plasma formation occurs. This type of shutter enables one to reduce the pulse duration down to ∼2 ns and to remove the low power, long duration tails that are present in TEA CO 2 pulses. The transmitted energy is reduced as the pulse duration is decreased but the reflected power is ∼10 MW for all pulse durations. A simple laser heating model verifies that the pulse shortening depends directly on the plasma formation time, which in turn is dependent on the applied laser intensity. It is envisaged that this plasma shutter will be used as a tool for pulse shaping in the search for laser pulse conditions to optimize conversion efficiency from laser energy to useable extreme ultraviolet (EUV) radiation for EUV source development.

  3. Laser safety tools and training

    CERN Document Server

    Barat, Ken

    2008-01-01

    Lasers perform many unique functions in a plethora of applications, but there are many inherent risks with this continually burgeoning technology. Laser Safety: Tools and Training presents simple, effective ways for users in a variety of facilities to evaluate the hazards of any laser procedure and ensure they are following documented laser safety standards.Designed for use as either a stand-alone volume or a supplement to Laser Safety Management, this text includes fundamental laser and laser safety information and critical laser use information rarely found in a single source. The first lase

  4. Injection-controlled laser resonator

    Science.gov (United States)

    Chang, J.J.

    1995-07-18

    A new injection-controlled laser resonator incorporates self-filtering and self-imaging characteristics with an efficient injection scheme. A low-divergence laser signal is injected into the resonator, which enables the injection signal to be converted to the desired resonator modes before the main laser pulse starts. This injection technique and resonator design enable the laser cavity to improve the quality of the injection signal through self-filtering before the main laser pulse starts. The self-imaging property of the present resonator reduces the cavity induced diffraction effects and, in turn, improves the laser beam quality. 5 figs.

  5. Estudo da associação entre hipertonia do complexo esfincteriano anal e dispareunia em mulheres adultas

    OpenAIRE

    Fernandes, Samantha Figueiredo Frota

    2012-01-01

    Existem várias associações entre causas orgânicas e dispareunia, no entanto há poucos estudos que examinam sua relação com a hipertonia da musculatura do assoalho pélvico. Portanto, mulheres com hipertonia neste grupo muscular caracterizam uma amostra relevante para investigar a ocorrência de dispareunia. Objetivo: Estudar a possível associação entre hipertonia do complexo esfincteriano anal e dispareunia em mulheres adultas. Método: Participaram do estudo 57 mulheres, com idade de 18 a 51 an...

  6. High power laser research and development at the Laboratory for Laser Energetics

    International Nuclear Information System (INIS)

    Soures, J.M.; McCrory, R.L.; Cerqua, K.A.

    1986-01-01

    As part of its research mission - to investigate the interaction of intense radiation with matter - the Laboratory for Laser Energetics (LLE) of the University of Rochester is developing a number of high-peak power and high-average-power laser systems. In this paper we highlight some of the LLE work on solid-state laser research, development and applications. Specifically, we discuss the performance and operating characteristics of Omega, a twenty-four beam, 4000 Joule, Nd:glass laser system which is frequently tripled using the polarization mismatch scheme. We also discuss progress in efforts to develop high-average-power solid-state laser systems with active-mirror and slab geometries and to implement liquid-crystal devices in high-power Nd:glass lasers. Finally we present results from a program to develop a compact, ultrahigh-peak-power solid-state laser using the concept of frequency chirped pulse amplification

  7. Verification of a characterization method of the laser-induced selective activation based on industrial lasers

    DEFF Research Database (Denmark)

    Zhang, Yang; Hansen, Hans Nørgaard; Tang, Peter T.

    2013-01-01

    In this article, laser-induced selective activation (LISA) for subsequent autocatalytic copper plating is performed by several types of industrial scale lasers, including a Nd:YAG laser, a UV laser, a fiber laser, a green laser, and a short pulsed laser. Based on analysis of all the laser......-machined surfaces, normalized bearing area curves and parameters are used to characterize the surface quantitatively. The range of normalized bearing area curve parameters for plate-able surface is suggested. PBT/PET with 40 % glass fiber was used as the substrate material. For all of the studied lasers......, the parameters were varied in a relatively large range, and matrixes of the laser-machined surface were obtained. The topography of those laser-machined surfaces was examined by scanning electronic microscope (SEM). For each sample examined by SEM, there was an identical workpiece plated by for 90 min...

  8. Dependence of Parameters of Laser-Produced Au Plasmas on the Incident Laser Energy of Sub-Nanosecond and Picosecond Laser Pulses

    International Nuclear Information System (INIS)

    Woryna, E.; Badziak, J.; Makowski, J.; Parys, P.; Vankov, A.B.; Wolowski, J.; Krasa, J.; Laska, L.; Rohlena, K.

    2001-01-01

    The parameters of Au plasma as functions of laser energy for ps pulses are presented and compared with the ones for sub-ns pulses at nearly the same densities of laser energy. The experiments were performed at the IPPLM with the use of CPA (chirped pulse amplification) Nd:glass laser system. Thick Au foil targets were irradiated by normally incident focused laser beams with maximum intensities of 8x10 16 and 2x10 14 W/cm 2 for ps and sub-ns laser pulses, respectively. The characteristics of ion streams were investigated with the use of ion diagnostics methods based on the time-of flight technique. In these experiments the laser energies were changed in the range from 90 to 700 mJ and the measurements were performed at a given focus position FP = 0 and along the target normal for both the laser pulses. The charge carried by the ions, the maximum ion velocities of fast and thermal ion groups, the maximum ion current density as well as the area of photopeak in dependence on the incident laser energy for sub-ns and ps pulses were investigated and discussed. (author)

  9. PESQUISA ACADÊMICA EM SECRETARIADO EXECUTIVO: UM ESTUDO DE CASO NA REVISTA EXPECTATIVA

    Directory of Open Access Journals (Sweden)

    Rodrigo Müller

    2014-09-01

    Full Text Available A evolução nos estudos e pesquisas em secretariado, contemplando desde campos de atuação ao perfil profissional, se apresenta como uma forma de reafirmação das capacidades e habilidades interdisciplinares dos secretários executivos. No intuito de comprovar essa situação, esta pesquisa desenvolveu-se sob um estudo de caso junto à Revista Expectativa, elaborada e mantida pelo curso de Secretariado Executivo da Universidade Estadual do Oeste do Paraná – Unioeste Campus de Toledo, analisando o perfil dos trabalhos científicos publicados no periódico desde 2001 até 2012. Dessa forma, este estudo objetiva, de forma geral, investigar a produção científica em secretariado executivo na Revista Expectativa. Para tanto, os seguintes objetivos específicos foram delimitados: a analisar os artigos publicados no periódico científico entre o período de 2001 a 2012; e b identificar as principais expressões utilizadas como palavras-chave desses artigos. O estudo será embasado na literatura da área de pesquisa acadêmica em secretariado executivo. Em termos metodológicos, a pesquisa apresenta abordagem de métodos mistos, de natureza descritiva, sendo que os principais procedimentos de investigação se deram a partir de pesquisa bibliográfica e análise de conteúdos. Os dados coletados demonstram que o perfil dos trabalhos publicados passou a ser mais generalista, englobando as áreas de administração, empreendedorismo, comunicação organizacional, dentre outras, além dos temas inerentes à profissão, evidenciando o fato de o profissional de secretariado possuir perfil interdisciplinar e capacidades e habilidades variadas, podendo atuar em vários setores dentro das organizações e atender a variadas demandas sociais. Atualmente, o preparo e capacitação concernentes aos secretários executivos vão além das funções secretariais e de assessoria e cada vez mais ao encontro das demandas organizacionais, oferecendo ao mercado

  10. Active-passively mode-locked dye laser for diagnosis of laser-produced plasmas

    International Nuclear Information System (INIS)

    Teng, Y.L.; Fedosejevs, R.; Sigel, R.

    1981-03-01

    In this report an active-passively mode-locked, flashlamp-pumped dye laser for diagnosis of laser-produced plasmas is described. This dye laser system used as a pulsed light source for high-speed photography of laser-target experiments was synchronized to the ASTERIX III iodine laser pulse with better than 100 ps accuracy. The single pulse energy was 10 μJ, pulse duration less than 10 ps. In 111 shots clear shadowgrams were obtained during a total of 151 target shots, i.e. the system worked well in 74% of the shots. (orig.)

  11. Solar pumped laser

    Science.gov (United States)

    Lee, J. H.; Hohl, F.; Weaver, W. R. (Inventor)

    1984-01-01

    A solar pumped laser is described in which the lasant is a gas that will photodissociate and lase when subjected to sunrays. Sunrays are collected and directed onto the gas lasant to cause it to lase. Applications to laser propulsion and laser power transmission are discussed.

  12. Diode lasers optimized in brightness for fiber laser pumping

    Science.gov (United States)

    Kelemen, M.; Gilly, J.; Friedmann, P.; Hilzensauer, S.; Ogrodowski, L.; Kissel, H.; Biesenbach, J.

    2018-02-01

    In diode laser applications for fiber laser pumping and fiber-coupled direct diode laser systems high brightness becomes essential in the last years. Fiber coupled modules benefit from continuous improvements of high-power diode lasers on chip level regarding output power, efficiency and beam characteristics resulting in record highbrightness values and increased pump power. To gain high brightness not only output power must be increased, but also near field widths and far field angles have to be below a certain value for higher power levels because brightness is proportional to output power divided by beam quality. While fast axis far fields typically show a current independent behaviour, for broadarea lasers far-fields in the slow axis suffer from a strong current and temperature dependence, limiting the brightness and therefore their use in fibre coupled modules. These limitations can be overcome by carefully optimizing chip temperature, thermal lensing and lateral mode structure by epitaxial and lateral resonator designs and processing. We present our latest results for InGaAs/AlGaAs broad-area single emitters with resonator lengths of 4mm emitting at 976nm and illustrate the improvements in beam quality over the last years. By optimizing the diode laser design a record value of the brightness for broad-area lasers with 4mm resonator length of 126 MW/cm2sr has been demonstrated with a maximum wall-plug efficiency of more than 70%. From these design also pump modules based on 9 mini-bars consisting of 5 emitters each have been realized with 360W pump power.

  13. Longitudinally excited CO2 laser with multiple laser tubes

    Science.gov (United States)

    Uno, Kazuyuki; Akitsu, Tetsuya; Jitsuno, Takahisa

    2016-11-01

    We developed a longitudinally excited CO2 laser system that was constituted of two or three laser tubes and a single driving circuit. The multiple laser tubes simultaneously produced almost the same short laser pulses with a spike pulse width of about 164 ns and a pulse tail length of about 74 μs with a single driving circuit. The double-tube system was constituted of two 30 cm-long laser tubes with inner diameters of 13 mm and 16 mm and a single driving circuit with an input energy of 2.18 J. The output energy of the 13 mm-tube was 23.3 mJ, and that of the 16 mm-tube was 21.9 mJ at a gas pressure of 4.2 kPa (CO2:N2:He = 1:1:2). The triple-tube system was constituted of three 30 cm-long laser tubes with inner diameters of 9 mm, 13 mm, and 16 mm and a single driving circuit with an input energy of 2.18 J. The output energy of the 9 mm tube was 15.9 mJ, that of the 13 mm tube was 24.1 mJ, and that of the 16 mm tube was 19.2 mJ at a gas pressure of 4.2 kPa. With the same driving circuit and the same input energy, the total output energies of the multitube laser systems were higher than the output energy of a single-tube system.

  14. Technology of discharge and laser resonators for high power CO2 lasers. Koshutsuryoku CO2 laser ni tsukawareru hoden reiki laser kyoshinki gijutsu

    Energy Technology Data Exchange (ETDEWEB)

    Takenaka, Y.; Kuzumoto, M. (Mitsubishi Electric Corp., Tokyo (Japan))

    1994-03-20

    This paper describes discharge excitation technology and resonator technology as basic technologies for high power CO2 lasers. As a result of progress in high-frequency power element techniques, the discharge excitation technology now generally uses laser excitation using AC discharge of capacity coupling type. Its representative example is silent discharge (SD) excitation. This is a system to excite laser by applying high voltages with as high frequency as 100 kHz to 1 MHz across a pair of electrodes covered with a dielectric material. The system maintains stability in discharge even if power supply voltage amplitude is modulated, and easily provides pulse outputs. Discharge excitation for diffusion cooled type CO2 laser generates a discharge in a gap with a gap length of about 2 mm, and can perform gas cooling by means of thermal conduction of gas, whereas a compact resonator can be fabricated. A resonator for the diffusion cooled type CO2 laser eliminates gas circulation and cooling systems, hence the device can be made more compact. A report has been given that several of these compact resonators were combined, from which a laser output of 85W was obtained by using RF discharge of 2kW. 43 refs., 21 figs.

  15. Nuclear-pumped lasers

    CERN Document Server

    Prelas, Mark

    2016-01-01

    This book focuses on Nuclear-Pumped Laser (NPL) technology and provides the reader with a fundamental understanding of NPLs, a review of research in the field, and exploration of large scale NPL system design and applications. Early chapters look at the fundamental properties of lasers, nuclear-pumping and nuclear reactions that may be used as drivers for nuclear-pumped lasers. The book goes on to explore the efficient transport of energy from the ionizing radiation to the laser medium and then the operational characteristics of existing nuclear-pumped lasers. Models based on Mathematica, explanations and a tutorial all assist the reader’s understanding of this technology. Later chapters consider the integration of the various systems involved in NPLs and the ways in which they can be used, including beyond the military agenda. As readers will discover, there are significant humanitarian applications for high energy/power lasers, such as deflecting asteroids, space propulsion, power transmission and mining....

  16. Atomic iodine laser

    International Nuclear Information System (INIS)

    Fisk, G.A.; Gusinow, M.A.; Hays, A.K.; Padrick, T.D.; Palmer, R.E.; Rice, J.K.; Truby, F.K.; Riley, M.E.

    1978-05-01

    The atomic iodine photodissociation laser has been under intensive study for a number of years. The physics associated with this system is now well understood and it is possible to produce a 0.1 nsec (or longer) near-diffraction-limited laser pulse which can be amplified with negligible temporal distortion and little spatial deformation. The output of either a saturated or unsaturated amplifier consists of a high-fidelity near-diffraction-limited, energetic laser pulse. The report is divided into three chapters. Chapter 1 is a survey of the important areas affecting efficient laser operation and summarizes the findings of Chap. 2. Chapter 2 presents detailed discussions and evaluations pertinent to pumps, chemical regeneration, and other elements in the overall laser system. Chapter 3 briefly discusses those areas that require further work and the nature of the work required to complete the full-scale evaluation of the applicability of the iodine photodissociation laser to the inertial confinement program

  17. Principles of Lasers

    CERN Document Server

    Svelto, Orazio

    2010-01-01

    This new Fifth Edition of Principles of Lasers incorporates corrections to the previous edition. The text’s essential mission remains the same: to provide a wide-ranging yet unified description of laser behavior, physics, technology, and current applications. Dr. Svelto emphasizes the physical rather than the mathematical aspects of lasers, and presents the subject in the simplest terms compatible with a correct physical understanding. Praise for earlier editions: "Professor Svelto is himself a longtime laser pioneer and his text shows the breadth of his broad acquaintance with all aspects of the field … Anyone mastering the contents of this book will be well prepared to understand advanced treatises and research papers in laser science and technology." (Arthur L. Schawlow, 1981 Nobel Laureate in Physics) "Already well established as a self-contained introduction to the physics and technology of lasers … Professor Svelto’s book, in this lucid translation by David Hanna, can be strongly recommended for...

  18. Improvements of the ruby laser oscillator system for laser scattering

    International Nuclear Information System (INIS)

    Yamauchi, Toshihiko; Kumagai, Katsuaki; Kawakami, Tomohide; Matoba, Tohru; Funahashi, Akimasa

    1978-10-01

    A ruby laser oscillator system is used to measure electron temperatures of the Tokamak plasmas(JFT-2 and JFT-2a). Improvements have been made of the laser oscillator to obtain the correct values. Described are the improvements and the damages of a ruby rod and a KD*P crystal for Q-switching by laser beam. Improvement are the linear Xe lamp replaced by a helical Xe lamp and in the electrical circuit for Q-switching. The damage of an optical component by a laser beam should be clarified from the damage data; the cause is not found yet. (author)

  19. Características pessoais de filhos de alcoolistas: um estudo na perspectiva da resiliência

    Directory of Open Access Journals (Sweden)

    Priscila Arruda da Silva

    2013-07-01

    Full Text Available Objetivo: Este estudo objetivou identificar e analisar as características pessoais que segundo o ponto de vista de filhos de alcoolistas os ajudaram no enfrentamento das experiências negativas que vivenciaram em decorrência do alcoolismo dos pais, ao longo da infância e da adolescência. Metodologia: Trata-se de um estudo qualitativo, desenvolvido com cinco famílias selecionadas entre a população em geral, cujos dados foram coletados entre novembro/2010 e janeiro/2011 através de entrevista semiestruturada. Resultados e discussão: Os resultados desse estudo foram agrupados em quatro categorias. A primeira trata-se das características pessoais do ponto de vista dos filhos participantes, ou seja, como eles se percebem. Além das características pessoais apontam outras três categorias assim denominadas: capacidade de estabelecer distanciamento com relação às vivências críticas; capacidade de se perceber e viver diferente dos pais e capacidade de se ver no futuro. Conclusão: Destaca-se a importância do trabalho de enfermagem no cuidado dessas famílias, especialmente dos filhos que convivem com o alcoolismo dos pais.

  20. Direct pumping of ultrashort Ti:sapphire lasers by a frequency doubled diode laser

    DEFF Research Database (Denmark)

    Müller, André; Jensen, Ole Bjarlin; Unterhuber, Angelika

    2011-01-01

    electro-optical efficiency of the diode laser. Autocorrelation measurements show that pulse widths of less than 20 fs can be expected with an average power of 52 mW when using our laser. These results indicate the high potential of direct diode laser pumped Ti: sapphire lasers to be used in applications....... When using our diode laser system, the optical conversion efficiencies from green to near-infrared light reduces to 75 % of the values achieved with the commercial pump laser. Despite this reduction the overall efficiency of the Ti: sapphire laser is still increased by a factor > 2 due to the superior...... like retinal optical coherence tomography (OCT) or pumping of photonic crystal fibers for CARS (coherent anti-stokes Raman spectroscopy) microscopy....