WorldWideScience

Sample records for cavity preparation efeitos

  1. Access cavity preparation.

    Science.gov (United States)

    Adams, N; Tomson, P L

    2014-03-01

    Each stage of root canal treatment should be carried out to the highest possible standard. The access cavity is arguably the most important technical stage, as subsequent preparation of the root canal(s) can be severely comprised if this is not well executed. Inadequate access can lead to canals being left untreated, poorly disinfected, difficult to shape and obturate, and may ultimately lead to the failure of the treatment. This paper highlights common features in root canal anatomy and outlines basic principles for locating root canals and producing a good access cavity. It also explores each phase of the preparation in detail and offers suggestions of instruments that have been specifically designed to overcome potential difficulties in the process. Good access design and preparation will result in an operative environment which will facilitate cleaning, shaping and obturation of the root canal system in order to maximise success.

  2. Dissipative preparation of entanglement in optical cavities

    DEFF Research Database (Denmark)

    Kastoryano, Michael James; Reiter, Florentin; Sørensen, Anders Søndberg

    2011-01-01

    We propose a novel scheme for the preparation of a maximally entangled state of two atoms in an optical cavity. Starting from an arbitrary initial state, a singlet state is prepared as the unique fixed point of a dissipative quantum dynamical process. In our scheme, cavity decay is no longer...

  3. 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)

  4. Cavity preparation machine for the standardization of in vitro preparations.

    Science.gov (United States)

    Soares, Carlos José; Fonseca, Rodrigo Borges; Gomide, Henner Alberto; Correr-Sobrinho, Lourenço

    2008-01-01

    Several in vitro studies employ the confection of cavity preparations that are difficult to standardize by means of manual high speed handpieces. This study presents the development of a cavity preparation machine designed to standardize in vitro cavity preparations. A metal base of 25 mm x 25 mm x 4 mm (length x width x height) was coupled to a small mobile table which was designed to be able to move by means of two precision micrometers (0.01-mm accuracy) in the horizontal directions (right-left, and back-front). A high speed handpiece was coupled to a metallic connecting rod which had an accurate dial indicator enabling control of the vertical movement. The high speed handpiece is also able to move 180 degrees around its longitudinal axis and 360 degrees around its transversal axis. The suggested cavity preparation machine precisely helps in the standardization of cavity preparations for in vitro studies. PMID:18949317

  5. Cavity preparation machine for the standardization of in vitro preparations

    Directory of Open Access Journals (Sweden)

    Carlos José Soares

    2008-09-01

    Full Text Available Several in vitro studies employ the confection of cavity preparations that are difficult to standardize by means of manual high speed handpieces. This study presents the development of a cavity preparation machine designed to standardize in vitro cavity preparations. A metal base of 25 mm x 25 mm x 4 mm (length x width x height was coupled to a small mobile table which was designed to be able to move by means of two precision micrometers (0.01-mm accuracy in the horizontal directions (right-left, and back-front. A high speed handpiece was coupled to a metallic connecting rod which had an accurate dial indicator enabling control of the vertical movement. The high speed handpiece is also able to move 180° around its longitudinal axis and 360° around its transversal axis. The suggested cavity preparation machine precisely helps in the standardization of cavity preparations for in vitro studies.

  6. Cavity preparation machine for the standardization of in vitro preparations.

    Science.gov (United States)

    Soares, Carlos José; Fonseca, Rodrigo Borges; Gomide, Henner Alberto; Correr-Sobrinho, Lourenço

    2008-01-01

    Several in vitro studies employ the confection of cavity preparations that are difficult to standardize by means of manual high speed handpieces. This study presents the development of a cavity preparation machine designed to standardize in vitro cavity preparations. A metal base of 25 mm x 25 mm x 4 mm (length x width x height) was coupled to a small mobile table which was designed to be able to move by means of two precision micrometers (0.01-mm accuracy) in the horizontal directions (right-left, and back-front). A high speed handpiece was coupled to a metallic connecting rod which had an accurate dial indicator enabling control of the vertical movement. The high speed handpiece is also able to move 180 degrees around its longitudinal axis and 360 degrees around its transversal axis. The suggested cavity preparation machine precisely helps in the standardization of cavity preparations for in vitro studies.

  7. Preparation of the W state via cavity QED

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jin; YE Liu

    2004-01-01

    A scheme for preparation of the tripartite W state via cavity quantum electrodynamics is presented in this paper. And the scheme can be generalized to prepare the n-atom W states. The second part of this paper shows how to prepare n-cavity W states. All cavities involved are initially in the vacuum states, thus the requirement on the quality factor of the cavities is greatly loosened.

  8. Abrasão a ar: efeito no preparo cavitário e na microinfiltração em dentes decíduos = Air Abrasion: effect on cavity preparation and on microleakage in primary teeth

    Directory of Open Access Journals (Sweden)

    Antunes, Lívia Azeredo Alves

    2014-01-01

    Full Text Available Objetivo: Comparar os efeitos da abrasão a ar e ponta diamantada de alta rotação sobre a topografia de preparos cavitários e a microinfiltração em dentes decíduos. Métodos: Neste estudo in vitro, as cavidades foram preparadas nas superfícies de 60 dentes, utilizando ambas as técnicas em cada dente. Vinte dentes foram escolhidos aleatoriamente para uma análise descritiva da topografia. Metade dos dentes restantes (20 foram tratados com um sistema adesivo de condicionamento total e a outra metade tratada com um sistema adesivo auto-condicionante e todas as amostras foram restauradas com resina. Depois disso, as amostras foram preparadas para os testes de microinfiltração e avaliadas por dezenas. Os dados estatísticos foram avaliados e um nível de significância de 5 % foi adotado para todos os testes. Resultados: A técnica de abrasão a ar produziu topografia diferenciada e aumentou a formação da camada de smear layer (Test qui-quadrado Stuart -Maxwell, p=0,03. Infiltração não foi influenciada por qualquer um dos sistemas de adesivos usados para preparações de cavidade (teste de Wilcoxon, p=0,08. No entanto, a ponta diamantada de alta rotação proporcionou mais infiltração independente do adesivo utilizado (Mann-Whitney, p=0,04; p=0,01. Conclusão: A técnica de abrasão a ar demonstrou ser uma boa alternativa para a prevenção de infiltração durante a preparação da cavidade em dentes decíduos

  9. Ultrasonic Abrasion: An Alternative for Cavity Preparation

    Directory of Open Access Journals (Sweden)

    Áurea Simone Barrôso VIEIRA

    2007-05-01

    Full Text Available Introduction: Restorative dentistry aims to repair damages caused by caries disease. Along the years, researchers have developed effective and less invasive methods with the goal of preserving the teeth from caries destruction. Therefore, the improvement of scientific knowledge, auxiliary diagnostic systems, dental materials, and new instruments has changed the approaches and treatments in this field. In addition to conservative removal of carious tissue, patient’s comfort has also become a concern in modern dentistry.Purpose: Considering that ultrasonic abrasion has attracted great interest of dental professionals, this article discusses an alternative technique for cavity preparation by literature review, addressing its indications, contra-indications, advantages and limitations compared to the conventional high-speed method.Conclusion: There are not many studies on this subject. The available studies have demonstrated several qualities of the ultrasonic abrasion system, but some aspects remain unclear. Therefore, it is important to highlight that laboratorial and clinical studies in primary/permanent teeth should be conducted to elucidate questionable issues, such as time of cavity preparation, topography, presence of smear layer and microleakage, in order to offer safety to the extensive use of this new technology for both the professional and the patient. In this context, the dentist should always be attentive to innovations referring to minimally invasive techniques.

  10. Preparation of W state in resonant bimodal cavity quantum electrodynamics

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A scheme is proposed for generating entangled W states with four cavity modes. In this scheme, we send a Ⅴ-type three-level atom through two identical two-mode cavities in succession. After the atom exits from the second cavity,the four cavity modes are prepared in the W state. On the other hand we can obtain three-atom W states by sending three Ⅴ-type three-level atoms through a two-mode cavity in turn. The present scheme does not require conditional measurement, and it is easily generalized to preparing 2n-mode W states and n-atom W states.

  11. Effects of low-intensity GaAlAs laser radiation ({lambda}=660 nm) on dentine-pulp interface after class I cavity preparation; Efeitos da radiacao laser GaAlAs ({lambda}=660 nm) em baixa intensidade na interface dentina-polpa pos-preparo cavitario classe 1

    Energy Technology Data Exchange (ETDEWEB)

    Godoy, Bruno Miranda

    2003-07-01

    The aim of this study was to investigate the effects of low-intensity irradiation with GaAlAs laser (red emission) on the ultrastructure of dentine-pulp interface after conventionally prepared class I cavity preparation. Two patients with 8 premolars for extraction indicated for orthodontic reasons. Class I cavities were prepared in these teeth that were then divided into two groups. The first group received a treatment with laser with continuous emission, {lambda}=660 nm, with maximum power output of 30 mW. The dosimetry applied was of approximately 2J/cm{sup 2}, directly and perpendicularly into the cavity in only one section. After the irradiation, the cavities were filled with composite resin. The second group received the same treatment, except by the laser therapy. Twenty-eight days after the preparation, the teeth were extracted and were processed for transmission electron microscopy analysis. Two sound teeth, without any preparation, were also studied. The irradiated group presented odontoblastic processes in higher contact with the extracellular matrix and the collagen fibers appeared more aggregated and organized than those of control group. These results were also observed in the healthy-teeth. Thus, we suggest that laser irradiation accelerates the recovery of the dental structures involved in the cavity preparation at the pre-dentine level. (author)

  12. Preparation of cluster state in large detuned cavity

    Institute of Scientific and Technical Information of China (English)

    Zou Chang-Lin; Gao Guo-Jun; Lu Yan; Li Da-Chuang; Yang Ming; Cao Zhuo-Liang

    2008-01-01

    An experimentally realizable physical scheme for preparing multiqubit cluster states from a large detuned atomcavity interaction is proposed. The scheme is free of any type of measurement and insensitive to the cavity decay, and the cavity field is only virtually excited so that there is no information exchanging between atom and cavity. The time required for the gate operations is very short, which is important for decoherence. We also discuss the experimental feasibility of our scheme.

  13. Strong-Driving-Assisted Probabilistic State Preparation in Cavity QED

    Institute of Scientific and Technical Information of China (English)

    YANG Zhen-Biao

    2006-01-01

    An alternative scheme is proposed for preparing the superpositions of coherent states with controllable weighting factors along a straight line for a cavity field. The scheme is based on the interaction of a single-mode cavity field with a resonant two-level atom driven by a strong classical field. It is in contrast to the previous methods used in cavity QED of injecting a coherent state into a cavity via a microwave source. In the scheme, the interaction between the cavity mode and atoms is fully resonant, thus the required interaction time is greatly shortened. Moreover, the present scheme requires smaller numbers of operations. In view of decoherence, a reduction of interaction time and numbers of operations for the state preparation is very important for experimental implementation of quantum state engineering.

  14. Preparation of Macroscopic Quantum Superposition States of Cavity Modes Using rf-SQUIDs in a Cavity

    Institute of Scientific and Technical Information of China (English)

    WANG Bo

    2008-01-01

    We propose a potential scheme of preparing Schrodinger-cat state of the cavity mode by placing an rf-superconducting quantum interference device (rf-SQUID) in a single-mode microwave cavity. By properly adjusting the detuning and the strength regarding the radiation fields, we show how to generate single-mode Schrodinger-eat state. Generalizing this method we discuss the generation of the engtangled coherent states. The experimental feasibility of our scheme is discussed under consideration of the cavity decay.

  15. A virtual system for cavity preparation in endodontics.

    Science.gov (United States)

    Marras, Ioannis; Nikolaidis, Nikolaos; Mikrogeorgis, Georgios; Lyroudia, Kleoniki; Pitas, Ioannis

    2008-04-01

    This article presents a novel virtual teeth drilling system designed to aid dentists, dental students, and researchers in getting acquainted with teeth anatomy, the handling of drilling instruments, and the challenges associated with drilling procedures during endodontic therapy. The system is designed to be used for educational and research purposes in dental schools. The application features a 3D face and oral cavity model constructed using anatomical data that can be adapted to the characteristics of a specific patient using either facial photographs or 3D data. Animation of the models is also feasible. Virtual drilling using a Phantom Desktop (Sensable Technologies Inc., Woburn, MA) force feedback haptic device is performed within the oral cavity on 3D volumetric and surface models of teeth, obtained from serial cross sections of natural teeth. Final results and intermediate steps of the drilling procedure can be saved on a file for future use. The application has the potential to be a very promising educational and research tool that allows the user to practice virtual teeth drilling for endodontic cavity preparation or other related procedures on high-detail teeth models placed within an adaptable and animated 3D face and oral cavity model.

  16. Pulpal responses to cavity preparation in aged rat molars.

    Science.gov (United States)

    Kawagishi, Eriko; Nakakura-Ohshima, Kuniko; Nomura, Shuichi; Ohshima, Hayato

    2006-10-01

    The dentin-pulp complex is capable of repair after tooth injuries including dental procedures. However, few data are available concerning aged changes in pulpal reactions to such injuries. The present study aimed to clarify the capability of defense in aged pulp by investigating the responses of odontoblasts and cells positive for class II major histocompatibility complex (MHC) to cavity preparation in aged rat molars (300-360 days) and by comparing the results with those in young adult rats (100 days). In untreated control teeth, immunoreactivity for intense heat-shock protein (HSP)-25 and nestin was found in odontoblasts, whereas class-II-MHC-positive cells were densely distributed in the periphery of the pulp. Cavity preparation caused two types of pulpal reactions based on the different extent of damage in the aged rats. In the case of severe damage, destruction of the odontoblast layer was conspicuous at the affected site. By 12 h after cavity preparation, numerous class-II-MHC-positive cells appeared along the pulp-dentin border but subsequently disappeared together with HSP-25-immunopositive cells, and finally newly differentiated odontoblast-like cells took the place of the degenerated odontoblasts and acquired immunoreactivity for HSP-25 and nestin by postoperative day 3. In the case of mild damage, no remarkable changes occurred in odontoblasts after operation, and some survived through the experimental stages. These findings indicate that aged pulp tissue still possesses a defense capacity, and that a variety of reactions can occur depending on the difference in the status of dentinal tubules and/or odontoblast processes in individuals.

  17. A Scheme for Preparation of W-Type Entangled Coherent State of Three-Cavity Fields

    Institute of Scientific and Technical Information of China (English)

    YUAN Chun-Hua; OU Yong-Cheng; ZHANG Zhi-Ming

    2006-01-01

    @@ We present an experimental scheme to prepare the three-cavity W-type entangled coherent state in the context of dispersive cavity quantum electrodynamics. The discussion of our scheme indicates that it can be realized by current technology.

  18. A method to minimize complications in endodontic access cavity preparation.

    Science.gov (United States)

    Zelikow, Robert; Cozzarelli-Moldauer, Gina; Keiner, Steven; Hardigan, Patrick C

    2008-06-01

    This article presents a method of avoiding some operative errors in endodontic-access cavity preparation. Utilizing the radiograph, a line representing the coronal extension of the image of the coronal two-thirds of the root canal(s) is drawn on the facial surface of the crown (Fig. 1). This line determines the proper angulation of the bur to facilitate entry into the pulp chamber in proper mesio-distal orientation, thereby reducing the likelihood of mesial and distal gouging and perforating. Marking the tooth to be treated prior to rubber-dam placement help in preventing treatment of an incorrect tooth. Two studies utilizing Nova Southeastern University College of Dental Medicine (NSUCDM) second-year dental students (D-2), one utilizing University of Florida, College of Dentistry (UFCD) second year dental students (D2) and one utilizing NSUCDM Advanced Education in General Dentistry (AEGD) faculty and students were undertaken to evaluate the method. Evaluation was by endodontic teachers. Results indicate use of the line-drawing method may facilitate more ideal access cavities than those prepared without the method. Welch's t-test, chi-square test and estimating equations were employed. One study showed significant difference between control and test groups (p less than 045). All studies indicated a difference. Further testing of the method is indicated. This valuable tool should be considered for use in teaching and practice.

  19. Preparation of Genuinely Entangled Six-Atom State via Cavity Quantum Electrodynamics

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wen; LIU Yi-Min; YIN Xiao-Feng; ZHANG Zhan-Jun

    2011-01-01

    A cavity quantum electrodynamics scheme for preparing a genuinely entangled state [A. Borras, et al., J. Phys. A 40 (2007) 13407] on six two-level atoms is proposed. In the scheme, the atom-cavity detuning is much bigger than the atom-cavity coupling strength and the necessary preparation time is much shorter than the Rydberg-atom lifespan. Hence the scheme has two distinct features, i.e., insensitive to the cavity decay and the atom radiation.

  20. The effect of cavity preparation on substance P expression in human dental pulp.

    Science.gov (United States)

    Caviedes-Bucheli, Javier; Correa-Ortíz, José Antonio; García, Leydy Viviana; López-Torres, Rocío; Lombana, Nelson; Muñoz, Hugo Roberto

    2005-12-01

    Substance P (SP) plays an important role during neurogenic inflammation of dental pulp. The purpose of this study was to use a radioimmunoassay for determining the effect of cavity preparation on SP expression in healthy human dental pulp. Ten pulp samples were obtained from healthy premolars where extraction was indicated for orthodontic reasons. Deep cavity preparation (cavity preparation had been performed compared to control values (p cavity preparation) and its expression may have an important clinical significance in terms of experiencing inflammation and pain.

  1. Effectiveness of Er:YAG laser in cavity preparation for retrograde filling--in vitro study.

    Science.gov (United States)

    Karlović, Zoran; Grgurević, Lovro; Verzak, Zeljko; Modrić, Vesna-Erika; Sorić, Pjetra; Grgurević, Josko

    2014-06-01

    The purpose of this study was to determine the sealing quality of Super EBA cement in laser prepared root-end cavities in comparison with root-end cavities classically prepared with steel burrs. Two groups of three millimeter root sections were prepared. The first group was prepared with the Er:YAG laser and the second group with a steel burr mounted on a surgical handpiece. The sections were filled with Super EBA cement and tested for leakage with fluid transport techniques. The sealing quality of Super EBA cement in the classically prepared root-end cavities was better, but there was no statistically significant difference between the two preparation techniques. The possible reason for greater leakage in the laser prepared root-end cavities was probably the irregular shape of the root-end cavity.

  2. Unconditional preparation of entanglement between atoms in cascaded optical cavities

    CERN Document Server

    Clark, S; Gu, M; Parkins, S; Clark, Stephen; Peng, Amy; Gu, Mile; Parkins, Scott

    2003-01-01

    We propose a scheme to unconditionally entangle the internal states of atoms trapped in separate high finesse optical cavities. The scheme uses the technique of quantum reservoir engineering in a cascaded cavity QED setting, and for ideal (lossless) coupling between the cavities generates an entangled pure state. Highly entangled states are also shown to be possible for realizable cavity QED parameters and with nonideal coupling.

  3. Teleportation of Atomic States via Cavity QED for a Cavity Prepared in a Superposition of Zero and One Fock States

    CERN Document Server

    Guerra, E S

    2004-01-01

    In this article we discuss two schemes of teleportation of atomic states. In the first scheme we consider atoms in a three-level cascade configuration and in the second scheme we consider atoms in a three-level lambda configuration. The experimental realization proposed makes use of cavity Quatum Electrodynamics involving the interaction of Rydberg atoms with a micromaser cavity prepared in a state $|\\psi >_{C}=(|0> +|1>)/\\sqrt{2}$

  4. Fracture strength of the remaining dental structure after different cavity preparation designs.

    Science.gov (United States)

    Teixeira, Evisabel Siqueira Simões; Rizzante, Fabio Antonio Piola; Ishikiriama, Sérgio Kiyoshi; Mondelli, José; Furuse, Adilson Yoshio; Mondelli, Rafael Francisco Lia; Bombonatti, Juliana Fraga Soares

    2016-01-01

    The aim of this in vitro study was to evaluate the loss of tooth structure after cavity preparation for direct (retentive) and indirect (nonretentive) restorations and its relationship to the fracture strength of the prepared tooth. Sound human third molars (60 maxillary and 60 mandibular) were randomly assigned into 12 groups (n = 10) according to the type of cavity preparation and the respective buccolingual width. Class II mesio-occlusodistal cavity preparations, for both indirect inlay and direct resin restorations, were prepared with standardized dimensions of one-half, one-third, or one-quarter of the occlusal intercuspal distance. Fracture resistance was lower and weight loss was greater for all nonretentive preparations. Greater losses in weight and fracture resistance occurred when the buccolingual width for both types of cavities increased, except for the weight loss of the one-quarter and one-third indirect cavity preparations in the mandibular molars, and the fracture resistance of the one-half and one-third direct cavity preparations in maxillary molars. Higher tooth structure loss and lower fracture strength were recorded after preparation of the inlay cavities.

  5. Patient's perception of location, form and size in case of cavity preparation.

    Science.gov (United States)

    Isoya, Kazuhiro; Sasaki, Yoshiyuki; Mataki, Shiro

    2004-06-01

    The aim of the present study was to clarify the difference between the imagination of patients and the reality in regard to the location, the form and the size of the cavity in case of cavity preparation for dental restoration. Firstly, we manufactured the dummy dentition for simulated cavity preparation and the operator intra-orally prepared a cavity on the dummy dentition in subject to confirm its validity. Then, 5 operators intra-orally prepared prescribed cavities at the both sides of maxillary first molars on the dummy dentition in every one of 5 subjects with masking. We compared the location, the form and the area of these prepared cavities with those imagined by subjects, respectively. In 58% of cases, the subjects could accurately recognize the location of prepared teeth. And 34% of cases also determined the Class of cavity form. The imagined area was larger than the actual area and the difference was statistically significant (p cavity preparation and patients tended to overestimate amounts of removed tooth substance.

  6. Laser-assisted cavity preparation and adhesion to erbium-lased tooth structure: part 1. Laser-assisted cavity preparation.

    Science.gov (United States)

    De Moor, Roeland Jozef Gentil; Delmé, Katleen Ilse Maria

    2009-12-01

    The use of the ruby laser (693.4 nm) was first described in 1960, and it was applied for hard tissue ablation in 1964. Different wavelengths [Nd:YAG (1.065 microm), CO2 (9.6 microm), Ho:YAG (2.12 microm)] were consequently explored. Due to massive thermal side effects, these wavelengths caused increased temperature in dental pulp, as well as microcracks and carbonization. The use of this laser for dental hard tissue preparation was eventually abandoned. At the end of the 1980s, excimer lasers (ultraviolet) and the erbium laser (infrared) were developed, with the advantages of improved temperature control and smaller penetration depths. With the development of smaller devices and improved knowledge of how to limit damage to the surrounding tissues, new ablation techniques were established in the 1990s. There is still contradiction in the current literature, however, in that different wavelengths are advocated for hard tissue removal, and heterogeneity in laser parameters and power densities remain. In this review, the effects of the wavelengths presently used for cavity preparation are evaluated. We conclude that erbium lasers (Er:YAG and Er,Cr:YSGG) are most efficient and, with the right parameters, the thermal side effects are small. There is a substantial need for "gold standards", although this is difficult to establish in practice owing to different laser parameters (including pulse repetition rate, amount of cooling, energy delivered per pulse, and types of pulses) and target specificity (tissue interaction with sound or decayed enamel or dentin, and the extent of (de)mineralization) which influence tissue interaction.

  7. A practical guide to endodontic access cavity preparation in molar teeth.

    Science.gov (United States)

    Patel, S; Rhodes, J

    2007-08-11

    The main objective of access cavity preparation is to identify the root canal entrances for subsequent preparation and obturation of the root canal system. Access cavity preparation can be one of the most challenging and frustrating aspects of endodontic treatment, but it is the key to successful treatment. Inadequate access cavity preparation may result in difficulty locating or negotiating the root canals. This may result in inadequate cleaning, shaping and filling of the root canal system. It may also contribute to instrument separation and aberrations of canal shape. These factors may ultimately lead to failure of treatment. Good access cavity design and preparation is therefore imperative for quality endodontic treatment, prevention of iatrogenic problems, and prevention of endodontic failure.

  8. A Cavity Preparation Evaluation System in the Skill Assessment of Dental Students.

    Science.gov (United States)

    Zou, Huiru; Jin, Shufeng; Sun, Jianping; Dai, Yanmei

    2016-08-01

    The aim of this study was to compare a computerized, laser-scanning Cavity Preparation Skill Evaluation System (CPSES) with conventional teachers' eye-hand grading assessment of dental students' Class I cavity preparation evaluations. Thirty-eight cavity preparations of lower left first molars made by junior dental students at a dental school in China were tested from September 2013 to November 2014. The outline and retention form, smoothness, depth, wall angulation, and cavity margin index of the preparations were evaluated by CPSES and then by teachers' eye-hand grading. The mean difference in scores for each method was considered, as was the variability of scores within each method. Compared with the teachers' eye-hand grading method, CPSES provided objective evaluation results that had statistically significant differences (pcavity preparation skills and encourage students in their self-paced learning and independent practice.

  9. Interactions between cavity preparation and restoration events and their effects on pulp vitality.

    Science.gov (United States)

    Wisithphrom, Kessiri; Murray, Peter E; About, Imad; Windsor, L Jack

    2006-12-01

    The purpose of this study was to investigate the precise effect and rank the importance of cavity preparation and restoration variables on human pulp vitality. Fifty-three Class V unexposed cavities were prepared and restored with calcium hydroxide/amalgam, resin-modified glass ionomer, zinc oxide-eugenol, resin composite, or zinc polycarboxylate materials. Pulp vitality was reduced by the remaining dentin thickness of the cavity preparations, whereas the other variables, including the type of restorative material, had little effect. Restorative materials cause minimal pulp damage in isolation; it is more important to minimize the removal of intact dentin to maintain the vitality of teeth.

  10. Evaluation of ultrasonic and ErCr:YSGG laser retrograde cavity preparation.

    Science.gov (United States)

    Batista de Faria-Junior, Norberto; Tanomaru-Filho, Mário; Guerreiro-Tanomaru, Juliane Maria; de Toledo Leonardo, Renato; Camargo Villela Berbert, Fábio Luiz

    2009-05-01

    Root end cavity preparation techniques aim to create a clean and properly shaped cavity in a short time. Although the use of ultrasonics has been widely recommended, a laser can also be used. This study evaluated the time required and quality of retrograde cavity preparations using ultrasonics or ErCr:YSGG laser. Thirty single-rooted teeth were instrumented, root filled, submitted to apicectomies, and grouped. Root end cavities were prepared by using the following: group 1 (G1): CVD (6.1107-6) ultrasonic retrotips (CVD-Vale, São José dos Campos, Brazil); group 2 (G2): EMS (DT-060/Berutti) ultrasonic retrotips (EMS, LeSentier, Switzerland); and group 3 (G3): ErCr:YSGG (G6/Waterlase; Biolase Technology, San Clemente, CA) laser tips. The time taken to complete the preparation was recorded. Epoxy resin replicas of the root apices were examined under a scanning electron microscope. The parameters for evaluation were the presence of fractures, and the quality of the preparations. The Waterlase showed the highest mean time for preparation of the root end cavities (p 0.05). Fractures in the cavosurface angle occurred only in G2. G1 and G2 showed better scores for quality of preparation than G3 (p < 0.05). These results suggest that root end cavities should be prepared by ultrasonic tips.

  11. Efficient scheme for preparation of the multi-atom W state via cavity quantum electrodynamics

    Institute of Scientific and Technical Information of China (English)

    Zhang Jin; Ye Liu

    2004-01-01

    We present an efficient scheme for preparation of the multi-atom W state via cavity quantum electrodynamics.Involved in this scheme are n identical two-level atoms and a single-mode cavity field. Discussion indicates that this scheme can be realized easily by current technologies.

  12. Production of Artificial Lesions for Teaching Cavity Preparation in the Phantom Head.

    Science.gov (United States)

    Treasure, Patrick

    1990-01-01

    To teach the modern concepts of cavity preparation, it is desirable to have a supply of natural teeth exhibiting suitable carious lesions. This paper describes a simple method for producing consistent artificial lesions in extracted natural teeth. (MLW)

  13. Cavity-based single atom preparation and high-fidelity hyperfine state readout

    OpenAIRE

    Gehr R.; Volz J.; Dubois G.; Steinmetz T.; Colombe Y.; Lev B.L.; Long R.; Esteve J.; Reichel J.

    2010-01-01

    We prepare and detect the hyperfine state of a single 87Rb atom coupled to a fiber-based high finesse cavity on an atom chip. The atom is extracted from a Bose-Einstein condensate and trapped at the maximum of the cavity field, resulting in a reproducibly strong atom-cavity coupling. We use the cavity reflection and transmission signal to infer the atomic hyperfine state with a fidelity exceeding 99.92% in a read-out time of 100 microseconds. The atom is still trapped after detection.

  14. Preparation and Testing of the SRF Cavities for the CEBAF 12 GeV Upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Reilly, A. V.; Bass, T.; Burrill, A.; Davis, G. K.; Marhauser, F.; Reece, C. E.; Stirbet, M.

    2011-07-01

    Eighty new 7-cell, low-loss cell-shaped cavities are required for the CEBAF 12 GeV Upgrade project. In addition to ten pre-production units fabricated at JLab, the full set of commercially-produced cavities have been delivered. An efficient processing routine, which includes a controlled 30 micron electropolish, has been established to transform these cavities into qualified 8-cavity strings. This work began in 2010 and will run through the end of 2011. The realized cavity performance consistently exceeds project requirements and also the maximum useful gradient in CEBAF: 25 MV/m. We will describe the cavity processing and preparation protocols and summarize test results obtained to date.

  15. Cavities

    Science.gov (United States)

    ... the bacteria produce acids that cause decay. Tooth pain occurs after decay reaches the inside of the tooth. Dentists can detect cavities by examining the teeth and taking x-rays periodically. Good oral hygiene and regular dental care plus a healthy diet can help prevent cavities. ...

  16. Times required for cavity preparation using ultrasonic tips

    NARCIS (Netherlands)

    Özcan, Mutlu; Nergiz, Ibrahim; Pfeiffer, Peter; Tütüncü, Rengin

    1999-01-01

    Poster for: Date/Event/Venue: 10.03.99-13.03.99 77th General Session & Exhibition of the IADR Vancouver The purpose of this study was to evaluate the required time for opening the proximal cavities using three ultrasonic tips of different sizes and fine diamond inlay bur followed by ultrasonic tip.

  17. Preparation and handling of surfaces for superconducting radio frequency cavities

    International Nuclear Information System (INIS)

    Fortunately, surface treatment for s.c. cavities knows only one simple rule. If one observes this rule strictly one will be successful, if not, one will fail! The rule is CLEANLINESS. This means: clean material (high purity niobium without inclusions), clean (analytical grade) polishing chemicals and solvents, ultraclean (semiconductor grade) rinsing water, ultraclean (class 100) assembly environment. In general, if one applies the same working practice as the semiconductor industry, one will produce surfaces that are less clean than silicon wafers, due to the shape of the cavity (an inner surface is much more difficult to clean than a flat wafer); due to its size and due to the material (niobium is hydrophilic which makes the water with all the dirt in it stick to the surface). 9 references

  18. Evaluation of new injection and cavity preparation model in local anesthesia teaching

    NARCIS (Netherlands)

    S.S. Yekta; F. Lampert; S. Kazemi; R. Kazemi; H.S. Brand; J.A. Baart; M. Mazandarani

    2013-01-01

    The aim of this study was to evaluate a recently developed preclinical injection and cavity preparation model in local anesthesia. Thirty-three dental students administered an inferior alveolar nerve block injection in the model, followed by preparation on a tooth. The injection was evaluated by thr

  19. [The effectiveness of cavity preparation training using a virtual reality simulation system with or without feedback].

    Science.gov (United States)

    Yasukawa, Yuriko

    2009-06-01

    The aims of this research were to examine the effectiveness of feedback (FB) study of cavity preparation using a virtual reality system (VRS) and to discuss the evidence from an educational standpoint Thirty-nine dental undergraduate students of the fifth grade of Tokyo Medical and Dental University were randomly divided into the FR group and no-FR group (FB group n=21, no-FR group n=18). All subjects of each group performed cavity preparation of class II on the lower left first molar using VRS (DentSim) four times every week (EXO-3). At session EXO, all subjects performed a pre-test to assess their basic skill leve. At sessions EX1 and EX2, the FR group received feedback from the instructor based on a computer-assessment system. The no-FR group practiced their self-judgment without any feedback. At the last session, EX3, the preparation test was administered. All cavity preparations were graded by the VRS. The results showed that the FR group obtained significantly higher scores than the no-FR group, such as total score, outline shape, outline centralization, outline smoothness, wall incline, wall smoothness, proximal clearance, and box width. By session EX2, the FR group tended to spend longer preparation time than the no-FR group, however, at session EX3, there was no difference between both groups. These resdlts confirmed the effectiveness of cavity preparation with feedback study using VRS. It is suggested that this method of learning cavity preparation techniques is suitable for novice undergraduate dental students at the initial stage of cavity preparation practice.

  20. Implementation of quantum controlled phase gate and preparation of multiparticle entanglement in cavity QED

    Institute of Scientific and Technical Information of China (English)

    Wu Xi; Chen Zhi-Hua; Zhang Yong; Chen Yue-Hua; Ye Ming-Yong; Lin Xiu-Min

    2011-01-01

    Schemes are presented for realizing quantum controlled phase gate and preparing an N-qubit W-like state, which are based on the large-detuned interaction among three-state atoms, dual-mode cavity and a classical pulse. In particular, a class of W states that can be used for perfect teleportation and superdense coding is generated by only one step.Compared with the previous schemes, cavity decay is largely suppressed because the cavity is only virtually excited and always in the vacuum state and the atomic spontaneous emission is strongly restrained due to a large atom-field detuning.

  1. Preparation of Multi—Atom Entangled States with a Single Cavity in a Thermal State

    Institute of Scientific and Technical Information of China (English)

    ZHENGShi-Biao

    2002-01-01

    A scheme is suggested for the generation of multi-atom maximally entangled states with a cavity in a thermal state,In this scheme several appropriately prepared two-level atoms are simultaneously sent through the nonresonant cavity.We divide the whole atom-cavity interaction time into two equal parts.At the end of the first part a π pulse is applied to the atome using a classical field.Then the photon-number-dependent shifts on the atomic states are cancelled and the atomic system finally evoloves to a maximally entangled state.

  2. Preparation of a New Type of Multiqubit Entangled States in Cavity QED*

    Institute of Scientific and Technical Information of China (English)

    XIONG Wen-Yuan; WANG Xin-Wen; XIA Li-Xin

    2008-01-01

    Recently Yang,Chu,and Plan [Phys.Rev.A 70 (2004) 022329] presented a new type of multipartite entangled states for implementing efficient many-party controlled teleportation of multiqubit quantum information.Here we propose a simple scheme for preparing such a type of multi-atom entangled states in cavity quantum electrodynamics (QED).The scheme involves atom-cavity interaction with large detuning,and is immune to the cavity decay and the thermal field states.Some practical analyses show its availability with the present technology.

  3. Influence of the power level of an ultra-sonic system on dental cavity preparation.

    Science.gov (United States)

    Josgrilberg, Erika Botelho; Guimarães, Murilo de Sousa; Pansani, Cyneu Aguiar; Cordeiro, Rita de Cássia Loiola

    2007-01-01

    The aim of this study was to evaluate the shape of dental cavities made with the CVDentus system using different ultrasound power levels. One standard cavity was made on the buccal aspect of 15 bovine incisors with a CVDentus cylindrical bur (82142). The sample was divided into three groups: G1-ultrasound with power II; G2-ultrasound with power III; and G3-ultrasound with power IV. A standardizing device was used to obtain standardized preparations and ultrasound was applied during one minute in each dental preparation. The cavities were sectioned in the middle, allowing observation of the cavity's profile with a magnifying glass, and width and depth measurement using the Leica Qwin program. The Kruskal-Wallis (p<0.05) and Dunn statistical analyses demonstrated differences between the dental cavity shapes when powers III and IV were used. However, the cavities that were made with power III presented dimensions similar to those of the bur used for preparation. We concluded that the power recommended by the manufacturer (III) is the most adequate for use with the CVDentus system.

  4. Microleakage of composite resin restoration in cavities prepared by Er,Cr:YSGG laser irradiation and etched bur cavities in primary teeth.

    Science.gov (United States)

    Hossain, Mozammal; Nakamura, Yukio; Yamada, Yoshishige; Murakami, Yoshiko; Matsumoto, Koukichi

    2002-01-01

    In this in vitro study, the surface alterations of enamel and dentin in cavities prepared by Er,Cr:YSGG laser irradiation was investigated by scanning electron microscopy and compared to the microleakage degree after composite resin restoration with etched bur cavities in human primary teeth. The results confirmed that laser cavity surface facilitated a good adhesion with the restorative materials; the acid etch step can be easily avoided with the laser treatment.

  5. Sealing ability of retrofilling materials following various root-end cavity preparation techniques.

    Science.gov (United States)

    Koçak, Mustafa Murat; Koçak, Sibel; Aktuna, Serkan; Görücü, Jale; Yaman, Sis Darendeliler

    2011-07-01

    The aim of this study is to compare the sealing efficacy of the retrograde cavity preparations prepared and filled with different equipment and materials. In the study, low speed burs, ultrasonic or Er, Cr:YSGG laser devices were used for cavity preparations and ProRoot MTA and MTA-Angelus as filling materials. Seventy-eight single-rooted teeth were instrumented, root filled, and grouped. Root-end cavities were prepared and filled by using the following: Group 1: Low-speed carbide bur + ProRoot MTA; Group 2: Low-speed bur + MTA-Angelus; Group 3: Ultrasonic retrotips + ProRoot MTA; Group 4: Ultrasonic retrotips + MTA-Angelus; Group 5: Er, Cr:YSGG laser tips + ProRoot MTA; Group 6: Er, Cr:YSGG laser tips + MTA-Angelus. Microleakage was measured using a fluid filtration technique. Differences in the fluid movement among groups were analyzed with a two-way analysis of variance (ANOVA) and LSD test. The results showed a significant difference between the groups prepared with laser and carbide bur (p  0.05). According to the results of the study, the cavities prepared with Er, Cr:YSGG laser demonstrated significantly lower microleakage in all the filling materials considered.

  6. Preparation of Entanglement of Atoms and of Photons via Cavity Input-Output Process

    Institute of Scientific and Technical Information of China (English)

    ZHOU Yan-Li; YANG Li-Jia; DAI Hong-Yi; LI Cheng-Zu

    2009-01-01

    We propose a method to prepare multipartite entangled states such as cluster states and graph states based on the cavity input-output process and single photon measurement.Two quantum gates,a controlled phase gate and a fusion gate between two atoms trapped in respective cavities,are proposed to prepare atomic cluster states and graph states with one and two dimensions.We also introduce a scheme that can generate an arbitrary multipartite photon cluster state which uses two coherent states as a qubit basis.

  7. Clinical dental application of Er:YAG laser for Class V cavity preparation.

    Science.gov (United States)

    Matsumoto, K; Nakamura, Y; Mazeki, K; Kimura, Y

    1996-06-01

    Following the development of the ruby laser by Maiman in 1960, the Nd:YAG laser, the CO2 laser, the semiconductor laser, the He-Ne laser, excimer lasers, the argon laser, and finally the Er:YAG laser capable of cutting hard tissue easily were developed and have come to be applied clinically. In the present study, the Er:YAG laser emitting at a wavelength of 2.94 microns developed by Luxar was used for the clinical preparation of class V cavities. Parameters of 8 Hz and approx. 250 mJ/pulse maximum output were used for irradiation. Sixty teeth of 40 patients were used in this clinical study. The Er:YAG laser used in this study was found to be a system suitable for clinical application. No adverse reaction was observed in any of the cases. Class V cavity preparation was performed without inducing any pain in 48/60 cases (80%). All of the 12 cases that complained of mild or severe intraoperative pain had previously complained of cervical dentin hypersensibility during the preoperative examination. Cavity preparation was completed with this laser system in 58/60 cases (91.7%). No treatment-related clinical problems were observed during the follow-up period of approx. 30 days after cavity preparation and resin filling. Cavity preparation took between approx. 10 sec and 3 min and was related more or less to cavity size and depth. Overall clinical evaluation showed no safety problem with very good rating in 49 cases (81.7%). PMID:9484088

  8. Microleakage in conservative cavities varying the preparation method and surface treatment

    Directory of Open Access Journals (Sweden)

    Juliana Abdallah Atoui

    2010-08-01

    Full Text Available OBJECTIVE: To assess microleakage in conservative class V cavities prepared with aluminum-oxide air abrasion or turbine and restored with self-etching or etch-and-rinse adhesive systems. Materials and Methods: Forty premolars were randomly assigned to 4 groups (I and II: air abrasion; III and IV: turbine and class V cavities were prepared on the buccal surfaces. Conditioning approaches were: groups I/III - 37% phosphoric acid; groups II/IV - self-priming etchant (Tyrian-SPE. Cavities were restored with One Step Plus/Filtek Z250. After finishing, specimens were thermocycled, immersed in 50% silver nitrate, and serially sectioned. Microleakage at the occlusal and cervical interfaces was measured in mm and calculated by a software. Data were subjected to ANOVA and Tukey's test (α=0.05. RESULTS: Marginal seal provided by air abrasion was similar to high-speed handpiece, except for group I. There was SIGNIFICANT difference between enamel and dentin/cementum margins for to group I and II: air abrasion. The etch-and-rinse adhesive system promoted a better marginal seal. At enamel and dentin/cementum margins, the highest microleakage values were found in cavities treated with the self-etching adhesive system. At dentin/cementum margins, high-speed handpiece preparations associated with etch-and-rinse system provided the least dye penetration. CONCLUSION: Marginal seal of cavities prepared with aluminum-oxide air abrasion was different from that of conventionally prepared cavities, and the etch-and-rinse system promoted higher marginal seal at both enamel and dentin margins.

  9. Assessing microleakage of composite restorations in class V cavities prepared by Er:YAG laser irradiation or diamond bur

    Directory of Open Access Journals (Sweden)

    Sakineh Arami

    2014-01-01

    Full Text Available Introduction: The aim of this study was to make a comparison between microleakage of conventionally restored class V cavities using bur and acid etchant and, the ones prepared and conditioned by Er:YAG laser. Materials and Methods: 30 recently extracted intact caries and filling free human permanent molars were used for this study. Then, Cold cure acrylic resin was used to seal the apices. The samples were randomly assigned to 5 groups of six each. Class V cavities were prepared one on buccal and one on lingual surface of each sample. Group 1: cavity preparation by diamond bur and turbine + acid etch, Group 2: cavity preparation by Er:YAG laser + acid etch, Group 3: cavity preparation by Er:YAG laser + Laser etching, Group 4: cavity preparation by diamond bur and turbine + laser etching, Group 5: cavity preparation by Er:YAG laser with no conditioning procedure. The cavities restored with restorative composite resin. Samples were then immersed in 2% methylene blue solution for 24 hours. The data were then analyzed using Wilcoxon signed ranks test and Kruskal-Wallis statistical tests. Results: The Kruskal Wallis test showed a significant difference (P < 0.05 between enamel and cementum margin microleakage, while the higher microleakage was related to the cementum margin of restorations. Conclusion: There was no significant difference in evaluating microleakeage degree of cavities prepared by Er:YAG laser and diamond bur.

  10. The quality of root fillings remaining in mandibular incisors after root-end cavity preparation

    NARCIS (Netherlands)

    Wu, MK; de Schwartz, FBC; van der Sluis, LWM; Wesselink, PR

    2001-01-01

    Aim The aim of this study was to determine the quality of root fillings remaining in mandibular incisors after root-end resection and root-end cavity preparation. Methodology Roots of 40 mandibular incisors. 12 mm in length. were divided into two groups and instrumented using a balanced force techni

  11. [Cavity preparation using an Er:YAG laser in the adult dentition].

    Science.gov (United States)

    Delmé, K; Meire, M; De Bruyne, M; Nammour, S; De Moor, R

    2009-01-01

    Many lasers (i.e., different wavelengths) are available today for clinical applications. Not all lasers are to be used for cavity preparation and removal of carious tissues. Erbiumlasers (Er:YAG and Er,Cr:YSGG) are suitable for these purposes (the wavelengths coincide with the highest absorption peaks of water and hydroxyapatite). The advantages during cavity preparation and caries removal are smear layer free cavity walls, selective and localised removal of tooth substance, a restricted need or the absence of anaesthesia, and cavity walls with a higher acid resistance resulting in a better protection against secondary decay. Possible side effects of erbium lasers with water cooling and used with respect for correct power setting are minimal and can be compared with those of rotary instruments. Erbium laser tooth preparation is now one of the options in the minimal invasive approach. The needs for acid etching has been debated for long. At present it has become clear that acid etching is mandatory to obtain a good adhesion and retention with resin composites.

  12. Preparation of Multi-Atom Entangled States with a Single Cavity in a Thermal State

    Institute of Scientific and Technical Information of China (English)

    ZHENG Shi-Biao

    2002-01-01

    A scheme is suggested for the generation of multi-atom maximally entangled states with a cavity in a thermalstate. In this scheme several appropriately prepared two-level atoms are simultaneously sent through the nonresonantcavity. We divide the whole atom-cavity interaction time into two equal parts. At the end of the first part a π pulse isapplied to the atoms using a classical field. Then the photon-number-dependent shifts on the atomic states are cancelledand the atomic system finally evolves to a maximally entangled state.

  13. Mutans streptococci strains prevalence before and after cavity preparation during Atraumatic Restorative Treatment.

    Science.gov (United States)

    Toi, C S; Bönecker, M; Cleaton-Jones, P E

    2003-06-01

    Critics argue that all carious dentine is not removed from the hand-prepared cavity during the Atraumatic Restorative Treatment (ART) procedure, and that the caries process is soon resumed. The aim of this study was to determine the effectiveness of ART in removing carious tissue, by investigating the numbers of mutans streptococci and lactobacilli, with emphasis on the prevalence of Streptococcus mutans and Streptococcus sobrinus strains before, and after ART treatment of dental caries. Two microbiology samples were collected. The first sample was removed from the centre of the carious lesion at the enamel-dentine junction, and the second was collected from the centre of the hard cavity wall above the pulp, after the soft infected dentine had been manually removed. A total of 71 mutans streptococci isolates from 31 children and 40 carious teeth were subcultured, biochemically characterised and genotyped by the arbitrarily primed polymerase chain reaction (AP-PCR). Results showed a significant decrease in TVC (Ppreparation. AP-PCR identified S. mutans strains that were undetectable during biotyping, and divided clinical isolates into two main clusters. In all, 63% (45/71) of isolates from the carious lesions comprised S. mutans strains. After cavity preparation, this was reduced to 35% (25/71), of which 30% (21/71) were S. mutans and the remaining 6% (4/71) S. sobrinus strains. The number of mutans streptococci strains was below detectable levels in 19 of the prepared cavities. The significant decrease in bacteria after manual cavity preparation demonstrates the reliability of a standardized ART technique, yet the presence of S. mutans strains shows that the effectiveness of the ART procedure can vary during treatment and between dental practitioners.

  14. Conditioning effects of cavities prepared with an Er,Cr:YSGG laser and an air-turbine.

    Science.gov (United States)

    Kato, Chikage; Taira, Yoshihisa; Suzuki, Masaya; Shinkai, Koichi; Katoh, Yoshiroh

    2012-07-01

    The purpose of this study was to examine, morphologically and histochemically, five types of conditioning effects on cavities prepared with an Er,Cr:YSGG laser and an air-turbine. Cavities were prepared using a Waterlase(®) MD turbo handpiece (W) and an air-turbine (AT) on human extracted molars. The cavity conditionings used were non-conditioned (G1), K-etchant Gel (G2), K-etchant Gel + AD Gel (G3), Clearfil SE Bond primer (G4) and Clearfil S(3) Bond (G5). On naked eye observations, enamel of G1, G2 and G3 in the W cavities and etched enamel of G2 and G3 in the AT cavities were observed as rough and dull in appearance. G4 and G5 in W and AT cavities were observed as shiny surfaces. On SEM observations, no smeared layer was observed in W cavities, while a smeared layer and bur-scratches were observed in AT cavities. In W cavities, rough surfaces were observed on enamel. That is, cracks and minute rough surfaces were observed. In contrast, equally etched scale-shaped enamel rods were observed in AT cavities. Widely opened dentinal tubules and protruding peritubular matrices of dentin were observed in W cavities. A few remaining smeared plugs could be observed at the AT cavities. On LM observations, 13-16 μm layers of the dentin in G1, G2, G4 and G5 of W cavities were stained red in color by the Azan staining method, while redness was not observed in G3. No groups were stained red in AT cavities. It was considered that layers stained red in color were thermal degeneration layers of dentin induced by W. Namely 30 s etching of 40% phosphoric acid gel followed by 90 s treatment of 10% NaClO gel should be recommended for use when combined with an Er,Cr:YSGG laser for cavity preparation.

  15. DIAGNOdent measurements and correlation with the depth and volume of minimally invasive cavity preparations.

    Science.gov (United States)

    Hamilton, James C; Gregory, William A; Valentine, John B

    2006-01-01

    In this clinical study, DIAGNOdent (KaVo) was used to assess previously diagnosed carious lesions in the pits and fissures of first and second molars. The measurements from this device were correlated with the depth and volume of the cavity preparations that resulted from minimal intervention to remove occlusal carious lesions. Twenty-five patients, 18 years of age and older, who were previously scheduled for an occlusal restoration due to caries, were recruited and enrolled in this clinical study. These patients had 48 qualifying teeth without previous restorations, sealants or other carious lesions. The occlusal surface of each study tooth was cleaned utilizing ProphyFlex2 (KaVo). Two dentists separately traced the pit and fissure system of each tooth using DIAGNOdent for two 15-second periods each. The peak reading of each of the four measurements was recorded. An impression of the occlusal surface of each tooth was recorded with a polyvinyl siloxane bite registration material. The carious lesions were removed with an air abrasion unit employing a 0.015-inch nozzle opening utilizing minimal operative intervention. A low viscosity polyvinyl siloxane was used to take an impression of the cavity preparation impression, using the bite registration impression to form the occlusal surface of the preparation impression. The preparation impression volume was calculated from its weight, using the known density of the impression material. The greatest depth of the preparation was measured. The Pearson correlation coefficient was used to investigate any relationship between depth or volume of the preparation impression and the DIAGNOdent measurements. The correlation for preparation volume and maximum DIAGNOdent measurement was 0.191 (p = 0.189). Other logical subsets of cases also did not result in any statistically significant correlations between the DIAGNOdent readings and the depth or volume of the final cavity preparations.

  16. Effect of cavity preparation on the flexural strengths of acrylic resin repairs

    Directory of Open Access Journals (Sweden)

    Safa Salim Elhadiry

    2010-12-01

    Full Text Available OBJECTIVE: To investigate the effect of cavity preparation on the flexural strength of heat-curing denture resin when repaired with an auto-curing resin. MATERIAL AND METHODS: Ninety-six rectangular specimens (64x10x2.5 mm prepared from heat-curing denture base resin (Meliodent were randomly divided into four groups before repair. One group was left intact as control. Each repair specimen was sectioned into two; one group was repaired using the conventional repair method (Group 1. Two groups had an additional transverse cavity (2x3.5x21.5 mm prepared prior to the repair; one repaired with (Group 2 and one without glass-fiber reinforcement (Group 3. A three-point flexural bending test according to the ISO 1567:1999 specification8 for denture base polymers was carried out on all groups after 1, 7 and 30 days of water immersion. Statistical analysis was carried out using two-way ANOVA, Kruskal Wallis and post-hoc Mann Whitney tests. RESULTS: The highest flexural strength was observed in the control group. Control and conventional repairs group (Group 1 showed reduction in the flexural strength 30 days after water immersion. No significant change in the strength was observed for Groups 2 and 3 where the repair joints were similarly prepared with additional transverse cavity. CONCLUSION: Repaired specimens showed lower flexural strength values than intact heat-curing resin. Cavity preparation had no significant effect on the flexural strength of repair with water immersion.

  17. Temperature variation on root surface with three root-end cavity preparation techniques

    Directory of Open Access Journals (Sweden)

    Bodrumlu Emre

    2013-01-01

    Full Text Available Introduction. Thermal changes can occur on the external root surface when root-end cavity preparation is performed, which may damage periodontal ligament cells and alveolar bone. Objective. The purpose of this study was to evaluate the temperature changes during preparation of the root-end cavities at 1 and 3 mm to the sectioned apical root surfaces when either tungsten carbide round bur, diamond round bur or ultrasonic diamond tip was used. Methods. Root-end resection was performed at 90° to the long axis of the root, 3 mm from the apex. Specimens were randomly divided into three groups of 12 teeth each for three different root-end cavity preparation techniques to be used, i.e. tungsten carbide bur, diamond bur and ultrasonic diamond retro tip. Thermocouples were used to measure temperature changes at 1 mm (T1 and 3 mm (T2 to the cutting plane during the preparations. Results. For T1, the lowest and the highest mean temperature increases of 3.53°C and 4.34°C were recorded for the carbide and diamond burs, respectively. For T2, the lowest and the highest mean temperature increases of 2.62°C and 4.39°C where recorded for the carbide and diamond burs, respectively. The mean temperatures with the ultrasonic tip were 3.68 and 3.04 ºC at T1 and T2 region, respectively. For root-end preparation, the ultrasonic preparation technique took the shortest preparation time (10.25 sec and the diamond bur took the longest time (28.17 sec. Conclusion. Ultrasonic retro tips and burs caused temperature to rise from 2.62° to 4.39°C, and these rises were within safety levels.

  18. Scheme for implementing perfect remote state preparation with W-class state in cavity QED

    Institute of Scientific and Technical Information of China (English)

    Wang Xue-Wen; Peng Zhao-Hui

    2008-01-01

    In this paper we present a remote state preparation scheme with a three-qubit W-class state in cavity QED. It has been shown that a special single-qubit state and a special two-qubit entangled state can be remotely prepared perfectly. Furthermore, the classical information cost in this scheme is less than that in the corresponding teleportation scheme and only a single-qubit projective measurement is made by the sender. We also generalize this idea to the multiqubit W-class state.

  19. Microleakage of composite resin restoration in cavities prepared by Er:YAG laser irradiation in primary teeth.

    Science.gov (United States)

    Yamada, Y; Hossain, M; Nakamura, Y; Murakami, Y; Matsumoto, K

    2002-03-01

    AIM: The purposes of this study were to investigate the surface morphology of cavities prepared by Er:YAG laser irradiation and to compare the microleakage degree after composite resin restoration with etched bur cavities in primary teeth, in vitro. MATERIALS AND METHODS: On the buccal (facial) and lingual (palatal) surfaces of 25 primary teeth, a round cavity was prepared with the Er:YAG laser system and with a high-speed diamond bur, respectively. Five cavities from each group were investigated by scanning electron microscopy (SEM). The remaining cavities were filled with a composite resin and subjected to a microleakage test (0.6% rodamine B solution) under thermocycling. Only bur cavities were acid-etched before filling. Statistical analysis was performed using the Mann-Whitney's U test; a value of p adhesion between the restorative material and dental hard tissues; there was also no gap at the interface. DISCUSSION: The highly irregular surface or the removal of the debris-like smear layer after laser irradiation may facilitate good adhesion of composite resin with enamel or dentine, and these surfaces might play a major role in decreasing microleakage of laser cavities. CONCLUSION: It can be concluded that cavities prepared by Er:YAG laser are capable of decreasing microleakage of composite resin restorations in primary teeth, and the efficiency is similar to etched bur cavities.

  20. Preparation and characterization of novel fast disintegrating capsules (Fastcaps) for administration in the oral cavity.

    Science.gov (United States)

    Ciper, Mesut; Bodmeier, Roland

    2005-10-13

    The objective of this study was to prepare novel capsule-based fast disintegrating dosage forms for the oral cavity (Fastcaps). First, cast films were prepared from various additive-containing gelatin solutions and evaluated with respect to disintegration time and mechanical properties in order to identify suitable formulations for the capsule preparation. The disintegration time of films decreased with decreasing bloom strength and could be further decreased by the addition of sugars or PEGs. Fast disintegrating capsules were successfully prepared by a dipping process, whereby parameters such as the viscosity and temperature of the dipping solution and the dipping velocity of the steel pins were optimized. The required viscosity range of the dipping solution for Fastcap manufacturing was 500-600 cP. The addition of the hydrophilic additives (xylitol, sorbitol or PEG 1500) did not significantly affect the viscosity and gelation temperature of the dipping solution. The in vitro disintegration of Fastcaps (30-45 s) was twice as rapid as the one of regular hard gelatin capsules. In vivo, Fastcaps disintegrated rapidly (9-13 s) and their content was spread throughout the oral cavity within seconds. Lactose and/or microcrystalline cellulose were suitable fillers for Fastcaps. The mechanical properties of Fastcaps were similar to commercially available gelatin capsules, which assures good processability and handling.

  1. Efeitos do sulfato de bário na cavidade pleural de ratos Effects of barium sulphate in rats pleural cavity

    Directory of Open Access Journals (Sweden)

    Giovanni Antonio Marsico

    2001-10-01

    Full Text Available OBJETIVO: Avaliar os efeitos do sulfato de bário na cavidade pleural de ratos. MÉTODO: Foram avaliados, experimentalmente, os efeitos do sulfato de bário a 100% na cavidade pleural de 43 ratos. Sob anestesia inalatória com éter, foi realizada injeção de contraste radiológico (1ml na cavidade pleural direita após punção com agulha romba pela via subxifóide. Os ratos, divididos em três grupos, foram mortos em câmara fechada com éter, após 24h (13 ratos, 48h (16 ratos e 21 dias (14 ratos, respectivamente. Através de esternotomia longitudinal e laparotomia alta, foram retiradas a pleura parietal e visceral, juntas com o gradil costal e o pulmão direito. No grupo-controle, de 22 ratos, foi injetado 1ml de soro fisiológico a 0,9% na cavidade pleural direita. RESULTADOS: Não houve mortes entre os 43 ratos em que foi injetado sulfato de bário e no grupo-controle. As alterações encontradas na cavidade pleural dos grupos injetados com sulfato de bário e mortos com 24h e 48h foram semelhantes: leve e difusa hiperemia na pleura parietal, sulfato de bário livre, derrame pleural inflamatório com predomínio de polimorfonucleares; macrófagos na pleura fagocitando sulfato de bário e pleura com infiltrado predominantemente polimorfonuclear. Com 21 dias, o sulfato de bário estava localizado e bloqueado na região retroesternal e havia formação de sínfises pleurais intensas. No exame histopatológico das pleuras havia grande quantidade de macrófagos repletos de sulfato de bário, raros pigmentos de sulfato de bário no meio extracelular, importante proliferação fibroblástica em 13/14 (92% casos e não ocorreu formação de granulomas. No grupo-controle (22 ratos, o exame histopatológico foi normal em todas as fases do experimento. CONCLUSÕES: a o sulfato de bário causou derrame pleural inflamatório em todos os casos; b com 21 dias ocorreu formação de sínfises pleurais em 100% dos casos; c não houve formação de

  2. SEM evaluation of the hybrid layer after cavity preparation with Er:YAG laser.

    Science.gov (United States)

    de Barceleiro, Marcos Oliveira; Dias, Kátia Regina Hostílio Cervantes; Sales, Helena Xavier; Silva, Bárbara Carvalho; Barceleiro, Cristiane Gomes

    2008-01-01

    This study compared the thickness of the hybrid layer formed using Scotchbond Multi-Purpose Plus, Single Bond 2, Prime & Bond 2.1 and Xeno III on a dentin surface prepared with a diamond bur in a high speed handpiece or prepared with an Er:YAG laser used with two parameters of pulse energy (200 and 400 mJ) and two parameters of frequency (4 and 6 Hz). Flat dentin surfaces obtained from 20 human third molars were treated with the two methods and were then prepared with the dentin adhesive systems according to the manufacturers' instructions. After a layer of composite was applied, the specimens were sectioned, flattened, polished and prepared for Scanning Electronic Microscopy observation. Five different measurements of the hybrid layer thickness were obtained along the bonded surface in each specimen. The results were statistically analyzed using Analysis of Variance and Student-Newman-Keuls tests (p cavity preparation method, four groups were formed: Group I (diamond bur) > Group II (Laser 200 mJ/4 Hz) = Group III (Laser 200 mJ/6 Hz) > Group IV (Laser 400 mJ/4 Hz) > Group V (Laser 400 mJ/6 Hz). When comparing the dentin adhesive systems, there were no statistically significant differences. These results showed that the four tested dentin adhesive systems produced a 2.90 +/- 1.71 microm hybrid layer in dentin prepared with a diamond bur. This hybrid layer was regular and routinely found. In the laser groups, the dentin adhesive systems produced hybrid layers ranging from 0.41 +/- 1.00 microm to 2.06 +/- 2.49 microm, which were very irregular and not routinely found. It was also concluded that the Er:YAG laser, with the parameters used in this experiment, has a negative influence on the formation of a hybrid layer and cavity preparation methods influence formation of the hybrid layer.

  3. Ultrasonic cavity preparation using CVD coated diamond bur: A case report.

    Science.gov (United States)

    de Vasconcellos, Beatriz Tholt; Thompson, Jeffrey Y; de Paula Macedo, Manoel Roberto; de Oliveira Maia, Janaína Monalisa; Oda, Margareth; Garone-Netto, Narciso

    2013-01-01

    Before any restorative procedure can be undertaken a proper cavity preparation is required. This clinical step is the mechanical alteration of the tooth to receive a restorative material with which a satisfactory form, function and the esthetics of the tooth will be established. In recent years improvements in materials and techniques have been devised and new technologies are now available for this purpose. The aim of the present study is to report two clinical cases in which a CVD coated diamond bur coupled to an ultrasonic handpiece is used in dental preparation. This technique provides an accurate and conservative tooth preparation with ideal access and visibility and because of enhanced efficiency can also play a role in eliminating some of the patient discomfort of the dental treatment.

  4. Influence of cavity design on the biomechanics of direct composite resin restorations in Class IV preparations.

    Science.gov (United States)

    Xu, Haiping; Jiang, Zhe; Xiao, Ximei; Fu, Jing; Su, Qin

    2012-04-01

    This study evaluated the effect of cavity design on stress distribution and fracture resistance of direct composite resin restorations in Class IV preparations. A finite element analysis (FEA) model of the maxillary central incisor with a Class IV cavity was established. Five model variations were studied: (i) a 1-mm bevel (ii) a 2-mm bevel, (iii) a plain chamfer, (iv) a stair-step chamfer, and (v) butt joints (a control configuration). All FEA variations modeled a tooth restored with composite resin loaded under 100 N at an angle of 45° to the longitudinal axis. The interfacial von Mises stress was evaluated. The FEA was complemented with an in vitro assessment. Fracture resistance of direct composite resin restorations was tested with a universal testing machine and fracture patterns were observed. Finite element analysis showed that stress in chamfer and stair-step chamfer models was more homogenously distributed, while stress in bevel models was relatively concentrated at lingual regions. Fracture resistance of a 1-mm bevel preparation was lower than for the 2-mm bevel, plain chamfer, and stair-step chamfer preparations, but was higher than for butt joints. The stair-step chamfer group presented the most favorable failure pattern. Considering biomechanics and esthetics, the present study indicates that the stair-step chamfer and 2-mm bevel should be recommended for clinical restoration. PMID:22409223

  5. Comparing and studying crack formation during apical cavity preparation using ultrasonic instruments

    Directory of Open Access Journals (Sweden)

    Zarrabian M.

    1999-07-01

    Full Text Available One of the major goals of periradicular surgery is to create a good apical sea! at the apex. This"nis done by sectioning of 2 to 3mm from the apex, preparation of a class I cavity and filling with a"nbiocompatible material."nThe purpose of this in vitro study was to determine whether ultrasonic units used for root end"npreparations could change the surface & structure of resected root ends, as competed to common"nmethods of retropreparation. Eighty-five extracted single rooted teeth were divided into five similar"ngroups. Then instrumented and filled with lateral condensation method. Then three millimeter of apex"nwas resected, retropreparaiions in two groups were done with low speed handpiece and round V ^ur"nand cavities in two other groups prepared with the highest power of dentspiay ultrasonic unit with TFI-"n10 tip and in one other group prepared with the highest power of neo sonic ultrasonic unit with diamond"ncoated CT-1 retro tip."nFollowing root resection and retropreparation the surface of resected root ends were examined for the"npresence of any cracks or structural changes on the surface of resected root ends with stereo microscope"n50x."nThe results of this study showed thai high power settings of ultrasonic units can increase the potential of"ncrack formation on resected root surfaces. In conclusion it is better to use low power setting of ultrasonic"nfor retropreparation.

  6. Comparison of two tooth-saving preparation techniques for one-surface cavities.

    Science.gov (United States)

    Rahimtoola, Salim; van Amerongen, Evert

    2002-01-01

    The atraumatic restorative treatment technique (ART) is based on removing infected tooth material using only hand instruments and filling the subsequently cleaned cavity with adhesive material such as glass ionomer. As its name suggests, the ART technique should be atraumatic during treatment, as well as for the tooth itself as for the patient. It was primarily developed for treating people living in underserved areas of the world where resources and facilities such as electricity and trained manpower are limited. Many studies have evaluated the ART technique and the results have supported its application. However, a very limited number of studies have compared ART with more conventional techniques. For that reason, a study was conducted in Pakistan, to compare the ART technique with another more conventional treatment technique. The results of this study show that the preparations with hand instruments resulted in smaller sized cavities and therefore may be less traumatic to the tooth. It was also associated with less pain reactions compared to the more conventional technique. Although preparations with hand instruments required more time, this did not seem to affect the survival of restorations. The survival of glass ionomer cement restorations made with hand instruments was comparable with single surface amalgam restorations made with a more conventional technique. Recurrent caries was not associated with any glass ionomer cement restorations made with hand instruments. The retention rate of glass ionomer sealants was low, however one dentist had a sealant retention rate of 81.5 percent that suggests that this procedure can be performed satisfactorily in conjunction with a glass ionomer cement restoration. Operator variances did seem to affect the restorations. Survival of glass ionomer restorations made with both hand and rotary instruments varied for different operators. Similarly, the retention of fissure sealant also varied amongst operators. Operator

  7. Odontoblast response to cavity preparation with Er:YAG laser in rat molars: an immunohistochemical study.

    Science.gov (United States)

    Shigetani, Yoshimi; Suzuki, Hironobu; Ohshima, Hayato; Yoshiba, Kunihiko; Yoshiba, Nagako; Okiji, Takashi

    2013-07-01

    This study aimed to examine the dynamics of odontoblast-lineage cells following cavity preparation with erbium:yttrium-aluminum-garnet (Er:YAG) laser in rat molars. Cavity preparation was made with Er:YAG laser in the mesial surface of the maxillary left first molar of 8-week-old Wistar rats. Contralateral first molar served as unirradiated control. Immediately, 6 and 12 h and 1, 2, 3, 5 and 7 days after the lasing (n = 5, each), specimens were collected and processed for immunohistochemistry for heat-shock protein (HSP)-25 and nestin as markers for odontoblast-lineage cells. Cell proliferation assay using bromodeoxyuridine (BrdU) labeling was also performed. Unirradiated teeth showed HSP-25- and nestin-immunoreactivity in odontoblasts. At 6-12 h after irradiation, the odontoblastic layer was disorganized and some of odontoblasts lost the immunoreactivity to HSP-25 and nestin. At 1-2 days, however, HSP-25- and nestin-immunoreactivities in the odontoblast layer showed a noticeable recovery, resulting in the rearrangement of odontoblast-like cells intensely immunoreactive to HSP-25 and nestin at 3-7 days. BrdU-positive cells showed a significant increase at 2 days (P cavity preparation with Er:YAG laser induced mild and reversible damage to odontoblasts. The reparative process was characterized by the rearrangement of HSP-25- and nestin-immunoreactive odontoblast-like cells, which took place subsequent to the odontoblastic layer disorganization with partial loss of these immunoreactivities.

  8. Cell dynamics in the pulpal healing process following cavity preparation in rat molars.

    Science.gov (United States)

    Harada, Masahiro; Kenmotsu, Shin-Ichi; Nakasone, Naohiro; Nakakura-Ohshima, Kuniko; Ohshima, Hayato

    2008-10-01

    Odontoblast-lineage cells acquire heat-shock protein (HSP)-25-immunoreactivity (IR) after they complete their cell division, suggesting that this protein acts as a switch between cell proliferation and differentiation during tooth development. However, there are few available data concerning the relationship between cell proliferation and differentiation following cavity preparation. The present study aims to clarify the expression of HSP-25 in the odontoblast-lineage cells with their proliferative activity after cavity preparation by immunocytochemistry for HSP-25 and cell proliferation assay using 5-bromo-2'-deoxyuridine (BrdU) labeling. In untreated control teeth, intense HSP-25-IR was found in odontoblasts and some subodontoblastic mesenchymal cells. Cavity preparation caused the destruction of odontoblasts and the disappearance of HSP-25-IR was conspicuous at the affected site, although some cells retained HSP-25-IR and subsequently most of them disappeared from the pulp-dentin border by postoperative day 1. Contrary, some subodontoblastic mesenchymal cells with weak HSP-25-IR began to take the place of degenerated cells, although no proliferative activity was recognizable in the dental pulp. Interestingly, proliferative cells in the dental pulp significantly increased in number on day 2 when the newly differentiating cells already arranged along the pulp-dentin border, and continued their proliferative activity in the wide range of the pulp tissue until day 5. These findings indicate that progenitor cells equipped in the subodontoblastic layer firstly migrate and differentiate into new odontoblast-like cells to compensate for the loss of the odontoblast layer, and subsequently the reorganization of dental pulp was completed by active proliferation of the mesenchymal cells occurring in a wide range of pulp tissue.

  9. Patient preference: conventional rotary handpieces or air abrasion for cavity preparation.

    Science.gov (United States)

    Malmström, Hans S; Chaves, Yvette; Moss, Mark E

    2003-01-01

    It has been suggested that patients should accept the use of the air abrasion technique over the conventional handpiece due to the reduced need for anesthesia. Technologies for both air abrasion and the conventional rotary handpiece have, in recent decades, seen major improvements, but there are no recent scientific publications that evaluate the patient's preference for these two technologies when performing a cavity preparation. This study determined the patient's preference for air abrasion or the rotary handpiece for removing occlusal fissure carious lesions in mandibular premolars. Ten healthy subjects 18 years of age or older were recruited from the General Dentistry Clinic of the University of Rochester Eastman Dental Center, with fissure caries at a DEJ depth of similar size (determined by radiographs and clinical examination) in any two mandibular premolars in opposite quadrants. Within each subject, the two methods of caries removal were randomly assigned. In one premolar, air abrasion was used for cavity preparation, and in the other premolar, a conventional rotary handpiece was used. At each visit prior to treatment, the patients were instructed to complete the Emotional Status (ES) questionnaire (SUNY University at Buffalo Craniofacial Pain Clinic) to assess differences in their emotional status between appointments. At each appointment, when the restorative treatment was completed, patients were instructed to rate their pain on the Visual Analogue Scale (VAS). A technique preference questionnaire was given after the second appointment. The subjects rated the perception of pain as significantly lower (p cavity preparation when removing fissural caries in mandibular premolars and most subjects did not experience any pain when air abrasion was used.

  10. Comparison of Dentin Permeability After Tooth Cavity Preparation with Diamond Bur and Er:YAG Laser

    OpenAIRE

    Hasani Tabatabaei, Masoumeh; Shirmohammadi, Sara; Yasini, Esmaeil; Mirzaei, Mansoureh; Arami, Sakineh; Kermanshah, Hamid; Ranjbar Omrani, Ladan; Alimi, Azar; Chiniforush, Nasim; Nakhostin, Afrooz; Abbasi, Mahdi

    2015-01-01

    Objectives: The aim of this study was to compare the permeability of dentin after using diamond bur and Er:YAG laser. Materials and Methods: Seventy-two recently extracted, intact, and restoration-free human permanent molars were used in this study. The samples were randomly divided into three groups of 24 each and class I cavities were prepared as follows. Group 1: High speed diamond bur with air and water spray. Group 2: Er:YAG laser. Group 3: Er:YAG laser followed by additional sub-ablativ...

  11. Dissipative preparation of a tripartite singlet state in coupled arrays of cavities via quantum feedback control

    Science.gov (United States)

    Shao, X. Q.; Wang, Z. H.; Liu, H. D.; Yi, X. X.

    2016-09-01

    We propose an experimentally feasible scheme for dissipative preparation of a tripartite entangled state with atoms separately trapped in an array of three coupled cavities. The combination of coherent driving fields and quantum-jump-based feedback control will drive the system into a nonequilibrium steady state, which has a nearly perfect overlap with the genuine three-atom singlet state. Different control strategies are investigated and the corresponding optimal parameters are confirmed. Moreover, the fidelity of the target state is insensitive to detection inefficiencies, and it exceeds 90% for a wide range of decoherence parameters as long as the single-atom cooperativity parameter C ≡g2/(γ κ ) >350 .

  12. Scanning electron microscopy study of cavity preparation in deciduous teeth using the Er:YAG laser with different powers.

    Science.gov (United States)

    Zhang, Sun; Chen, Tao; Ge, Li-hong

    2012-01-01

    Using scanning electron microscopy (SEM) we evaluated the morphology of cavity surfaces in deciduous teeth prepared in vitro with the Er:YAG laser with different power parameters. Eight extracted cavity-free deciduous teeth with an intact crown were prepared using a traditional handpiece or an Er:YAG laser with different parameters (10 Hz/200 mJ, 10 Hz/300 mJ and 10 Hz/400 mJ). Samples were then processed and cavity surface morphology was evaluated by SEM to detect open dentinal tubules, or melting or cracking of the dentin. SEM showed that laser cavity preparation in deciduous teeth using different parameters left no smear layer and the dentinal tubules were clear. Dentin melting was not seen after cavity preparation at 200 mJ or 300 mJ, while visible dentin melting and cracks were detected at 400 mJ. The use of the laser at 10 Hz/200 mJ and 10 Hz/300 mJ for cavity preparation in deciduous teeth is safe and effective, but higher powers may damage the dentin.

  13. Temperature rise during Er:YAG cavity preparation of primary enamel.

    Science.gov (United States)

    Contente, Marta Maria Martins Giamatei; de Lima, Fabrício Augusto; Galo, Rodrigo; Pécora, Jesus Djalma; Bachmann, Luciano; Palma-Dibb, Regina Guenka; Borsatto, Maria Cristina

    2012-01-01

    This study aimed to assess in vitro thermal alterations taking place during the Er:YAG laser cavity preparation of primary tooth enamel at different energies and pulse repetition rates. Forty healthy human primary molars were bisected in a mesio-distal direction, thus providing 80 fragments. Two small orifices were made on the dentin surface to which type K thermocouples were attached. The fragments were individually fixed with wax in a cylindrical Plexiglass® abutment and randomly assigned to eight groups, according to the laser parameters (n = 10): G1 - 250 mJ/ 3 Hz, G2 - 250 mJ/ 4 Hz, G3 - 250 mJ/ 6 Hz, G4 - 250 mJ/10 Hz, G5 - 250 mJ/ 15 Hz, G6 - 300 mJ/ 3 Hz, G7 - 300 mJ/ 4 Hz and G8 - 300 mJ/ 6 Hz. An area of 4 mm(2) was delimited. Cavities were done (2 mm long × 2 mm wide × 1 mm thick) using non-contact (12 mm) and focused mode. Temperature values were registered from the start of laser irradiation until the end of cavity preparation. Data were analyzed by one-way ANOVA and Tukey test (p ≤ 0.05). Groups G1, G2, G6, and G7 were statistically similar and furnished the lowest mean values of temperature rise. The set 250 mJ/10 and 15 Hz yielded the highest temperature values. The sets 250 and 300 mJ and 6 Hz provided temperatures with mean values below the acceptable critical value, suggesting that these parameters ablate the primary tooth enamel. Moreover, the temperature elevation was directly related to the increase in the employed pulse repetition rates. In addition, there was no direct correlation between temperature rise and energy density. Therefore, it is important to use a lower pulse frequency, such as 300 mJ and 6 Hz, during cavity preparation in pediatric patients.

  14. Realization of GHZ States and the GHZ Test via Cavity QED for a Cavity Prepared in a Superposition of Zero and One Fock States

    CERN Document Server

    Guerra, E S

    2004-01-01

    In this article we discuss the realization of atomic GHZ states involving three-level atoms in a cascade and in a lambda configuration and we show explicitly how to use this state to perform the GHZ test in which it is possible to decide between local realism theories and quantum mechanics. The experimental realizations proposed makes use the interaction of Rydberg atoms with a cavity prepared in a state which is a superposition of zero and one Fock states.

  15. Evaluation of Er:YAG laser radiation cavity preparation under transmitted and polarized light and by electron microanalyser

    Science.gov (United States)

    Dostalova, Tatjana; Krejsa, Otakar; Rokytova, Kveta; Jelinkova, Helena; Hamal, Karel

    1993-12-01

    The results of evaluation of Er:YAG radiation cavity preparation under transmitted and polarized light and by the electron microanalyzer are presented. We examined the longitudinal sections of intact teeth, teeth with early dental caries, teeth with laser preparation in enamel and teeth with Er:YAG laser preparation in enamel and dentine class I and V. We examined intact teeth and laser prepared teeth for the variation of mineralization. Phosphorus and calcium were regularly distributed. The margins of cavities had no necrosis zones. The defects of mineralization in caries depend on demineralization of hard tissues. In the structures was irregular loss of calcium and phosphorus. Thus, Er:YAG laser irradiation with water cooling has been found to be a non-invasive preparation technique.

  16. The dimensional accuracy of preparation of femoral cavity in cementless total hip arthroplasty

    Institute of Scientific and Technical Information of China (English)

    WU Li-dong (吴立东); HAHNE H.J.; HASSENPFLUG J.

    2004-01-01

    Objective: To observe the accuracy of femoral preparation and the position of the cementless prosthesis in femoral cavity, and to compare the results between the computer-assisted surgical group (CASPAR) and the conventional group. Methods: Ten femoral components were implanted either manually or by CASPAR in cadaver femurs. The specimens were cut to 3 mm thick slices. Microradiograms of every slice were sent to a computer for analysis with special software (IDL). The gaps and the medullary cavities between component and bone, the direct bone contact area of the implant surface,the gap width and the percentage of gap and bone contact area were measured in every slice. Results: In the proximal implant coated with HA of the CASPAR group, the average percentage of bone contact reached 93.2% (ranging from 87.6% to 99.7%); the average gap percentage was 2.9% (ranging from 0.3% to 7.8%); the maximum gap width was 0.81 mm and the average gap width was only 0.20 mm. While in the conventional group, the average percentage of bone contact reached 60.1% (ranging from 49.2% to 70.4%); the average gap percentage was 32.8% (ranging from 25.1% to 39.9%); the maximum gap width was 2.97 mm and the average gap width was 0.77 mm. The average gap around the implant in the CASPAR group was only 9% of that in the manual group; the maximum and average gap widths were only about 26% of those in the manual group. On the other hand, the CASPAR group showed 33% higher bone contact than the manual group. Conclusion: With the use of robotics-assisted system, significant progress can be achieved for femoral preparation in total hip arthroplasty.

  17. The dimensional accuracy of preparation of femoral cavity in cementless total hip arthroplasty

    Institute of Scientific and Technical Information of China (English)

    吴立东; HAHNEH.J.; HASSENPFLUGJ.

    2004-01-01

    Objective: To observe the accuracy of femoral preparation and the position of the cementless prosthesis in femoral cavity, and to compare the results between the computer-assisted surgical group (CASPAR) and the conventional group. Methods: Ten femoral components were implanted either manually or by CASPAR in cadaver femurs. The specimens were cut to 3mm thick slices. Microradiograms of every slice were sent to a computer for analysis with special software (IDL). The gaps and the medullary cavities between component and bone, the direct bone contact area of the implant surface, the gap width and the percentage of gap and bone contact area were measured in every slice. Results: In the proximal implant coated with HA of the CASPAR group, the average percentage of bone contact reached 93.2% (ranging from 87.6% to 99.7%); the average gap percentage was 2.9% (ranging from 0.3% to 7.8%); the maximum gap width was 0.81mm and the average gap width was only 0.20mm. While in the conventional group, the average percentage of bone contact reached 60.1% (ranging from 49.2% to 70.4%); the average gap percentage was 32.8% (ranging from 25.1% to 39.9%); the maximum gap width was 2.97mm and the average gap width was 0.77mm. The average gap around the implant in the CASPAR group was only 9% of that in the manual group; the maximum and average gap widths were only about 26% of those in the manual group. On the other hand, the CASPAR group showed 33% higher bone contact than the manual group. Conclusion: With the use of robotics-assisted system, significant progress can be achieved for femoral preparation in total hip arthroplasty.

  18. Preparation of genuine Yeo-Chua entangled state and teleportation of two-atom state via cavity QED

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    We first propose a scheme for preparing the genuine Yeo-Chua 4-qubit entangled state via cavity QED. Using the genuine Yeo-Chua atomic state, we further propose a cavity QED scheme for teleporting an arbitrary two-atom state. In two schemes the large-detuning is chosen and the necessary time is designed to be much shorter than Rydberg-atom’s lifespan. Both schemes share the distinct advantage that cavity decay and atom decay can be neglected. As for the interaction manipulation, our preparation scheme is more feasible than a recent similar one. Compared with the Yeo and Chua’s scheme, our teleportation scheme has significantly reduced the measuring difficulty.

  19. The use of Erbium: Yttrium-aluminum-garnet laser in cavity preparation and surface treatment: 3-year follow-up.

    Science.gov (United States)

    Buyukhatipoglu, Isil; Secilmis, Asli

    2015-01-01

    From the currently available choices, esthetic restorative materials for posterior teeth are limited to composite and ceramic restoration. Ceramic inlays/onlays are reliable solutions for both of these treatments. For successful treatment planning, usable ceramic and adhesive systems should be chosen by the dentist. Since the Federal Drug Administration approval of the erbium: Yttrium-aluminum-garnet (Er:YAG) laser-for caries removal, cavity preparation and the conditioning of tooth substance-in 1997, there have been many reports on the use of this technique in combination with composite resins. In addition, cavity pretreatment with the Er:YAG laser (laser etching) has been proposed as an alternative to acid etching of enamel and dentin. This case report presents the use of the Er:YAG in cavity preparation for composite resin restoration and surface treatment for ceramic onlay restoration of adjacent permanent molars. PMID:26038665

  20. The use of Erbium: Yttrium-aluminum-garnet laser in cavity preparation and surface treatment: 3-year follow-up.

    Science.gov (United States)

    Buyukhatipoglu, Isil; Secilmis, Asli

    2015-01-01

    From the currently available choices, esthetic restorative materials for posterior teeth are limited to composite and ceramic restoration. Ceramic inlays/onlays are reliable solutions for both of these treatments. For successful treatment planning, usable ceramic and adhesive systems should be chosen by the dentist. Since the Federal Drug Administration approval of the erbium: Yttrium-aluminum-garnet (Er:YAG) laser-for caries removal, cavity preparation and the conditioning of tooth substance-in 1997, there have been many reports on the use of this technique in combination with composite resins. In addition, cavity pretreatment with the Er:YAG laser (laser etching) has been proposed as an alternative to acid etching of enamel and dentin. This case report presents the use of the Er:YAG in cavity preparation for composite resin restoration and surface treatment for ceramic onlay restoration of adjacent permanent molars.

  1. The use of Erbium: Yttrium-aluminum-garnet laser in cavity preparation and surface treatment: 3-year follow-up

    Science.gov (United States)

    Buyukhatipoglu, Isil; Secilmis, Asli

    2015-01-01

    From the currently available choices, esthetic restorative materials for posterior teeth are limited to composite and ceramic restoration. Ceramic inlays/onlays are reliable solutions for both of these treatments. For successful treatment planning, usable ceramic and adhesive systems should be chosen by the dentist. Since the Federal Drug Administration approval of the erbium: Yttrium-aluminum-garnet (Er:YAG) laser-for caries removal, cavity preparation and the conditioning of tooth substance-in 1997, there have been many reports on the use of this technique in combination with composite resins. In addition, cavity pretreatment with the Er:YAG laser (laser etching) has been proposed as an alternative to acid etching of enamel and dentin. This case report presents the use of the Er:YAG in cavity preparation for composite resin restoration and surface treatment for ceramic onlay restoration of adjacent permanent molars. PMID:26038665

  2. Evaluation of new injection and cavity preparation model in local anesthesia teaching.

    Science.gov (United States)

    Said Yekta, Sareh; Lampert, Friedrich; Kazemi, Saeid; Kazemi, Reza; Brand, Henk S; Baart, Jacques A; Mazandarani, Mina

    2013-01-01

    The aim of this study was to evaluate a recently developed preclinical injection and cavity preparation model in local anesthesia. Thirty-three dental students administered an inferior alveolar nerve block injection in the model, followed by preparation on a tooth. The injection was evaluated by three observers, and the feedback from the model was registered. After completion of the practical session, the opinion of the dental students was explored with a ten-item questionnaire. Thirty dental students (91 percent) performed the injection correctly according to the feedback of the model, and twenty-eight students (85 percent) did so according to the expert opinion. The agreement between feedback from the training model and the expert opinion was high. The students were very satisfied with the opportunity to practice with the training model, as indicated by the high scores on each item of the questionnaire. These results suggest that use of this preclinical training model in anesthesia teaching may have beneficial effects on the administration of local anesthetics by dental students.

  3. Efeitos do sulfato de bário na cavidade pleural de ratos Effects of barium sulphate in rats pleural cavity

    OpenAIRE

    Giovanni Antonio Marsico; Rui Haddad; Carlos Eduardo de Souza Carvalho; Patrícia Gioia de Assis; Ivam Martinelli Júnior; Maria Das Graças Martins

    2001-01-01

    OBJETIVO: Avaliar os efeitos do sulfato de bário na cavidade pleural de ratos. MÉTODO: Foram avaliados, experimentalmente, os efeitos do sulfato de bário a 100% na cavidade pleural de 43 ratos. Sob anestesia inalatória com éter, foi realizada injeção de contraste radiológico (1ml) na cavidade pleural direita após punção com agulha romba pela via subxifóide. Os ratos, divididos em três grupos, foram mortos em câmara fechada com éter, após 24h (13 ratos), 48h (16 ratos) e 21 dias (14 ratos), re...

  4. Scanning electron microscopy evaluation of the interaction pattern between dentin and resin after cavity preparation using Er:YAG laser

    International Nuclear Information System (INIS)

    The aim of this study was to describe the interaction pattern formed between dentin and resin on cavities prepared with an erbium laser (Er:YAG). The morphological aspect of the irradiated dentin after acid etching was also observed. Ten dentin disks were obtained from fresh extracted third molars. Each disk received two cavities, one prepared with a conventional high-speed drill, while the other cavity was obtained by the use of an Er:YAG laser (KaVo KEY Laser, KaVo Co.). The laser treatment was performed with 250 mJ/pulse, 4 Hz, non contact mode, focused beam, and a fine water mist was used. Five disks were prepared for morphological analysis of the acid etched dentin. The other five disks had their cavities restored with Single Bond (3M) followed by Z100 resin (3M). The specimens were observed under scanning electron microscopy after dentin-resin interface demineralization and deproteinization. It was observed that the morphological characteristics of the acid-etched irradiated dentin were not favorable to the diffusion of monomers through the collagen network. The dentin resin interfacial aspect of irradiated dentin, after acid etching, showed thin tags and scarce hybridization zones, which agreed with the morphology of the irradiated and acid-etched dentin substrate observed. (author)

  5. Cavity Preparation/assembly Techniques and Impact on Q, Realistic Q - Factors in a Module, Review of Modules

    Energy Technology Data Exchange (ETDEWEB)

    Peter Kneisel

    2005-03-19

    This contribution summarizes the surface preparation procedures for niobium cavities presently used both in laboratory experiments and for modules, such as buffered chemical polishing (BCP), electropolishing (EP), high pressure ultrapure water rinsing (HPR), CO{sub 2} snow cleaning and high temperature heat treatments for hydrogen degassing or postpurification. The impact of surface treatments and the degree of cleanliness during assembly procedures on cavity performance (Q - value and accelerating gradient E{sub acc}) will be discussed. In addition, an attempt will be made to summarize the experiences made in module assemblies in different labs/projects such as DESY(TTF), Jlab (Upgrade) and SNS.

  6. Cavity preparation/assembly techniques and impact on Q, realistic Q-factors in a module, review of modules

    Science.gov (United States)

    Kneisel, Peter

    2006-02-01

    This contribution summarizes the surface preparation procedures for niobium cavities presently used both in laboratory experiments and for modules, such as buffered chemical polishing (BCP), electropolishing (EP), high pressure ultrapure water rinsing (HPR), CO 2 snow cleaning and high temperature heat treatments for hydrogen degassing or post-purification. The impact of surface treatments and the degree of cleanliness during assembly procedures on cavity performance ( Q-value and accelerating gradient Eacc) will be discussed. In addition, an attempt will be made to summarize the experiences made in module assemblies in different labs/projects such as DESY (TTF), Jlab (Upgrade) and SNS.

  7. Comparing high speed dental turbine and endoscopic device in crack formation following cavity preparation in periapical surgeries in Cat teeth

    Directory of Open Access Journals (Sweden)

    H. Razmi

    1998-05-01

    Full Text Available   In Present research study, 44 canine teeth of with completely formed apex was selected in 11 cats. Jaw bones were removed while teeth were kept intra alveolar sockets and routine root canal therapy was performed on each root. Afterwards, 3mm of each root were cut apically. 20 teeth underwent cavity preparation via high speed dental turbine and round diamond bur, 20 via endosonic device and 4 (10% of all remained untreated as control group. Then, the cavity walls were assessed with stereomicroscope while the teeth were still kept in their alveolar sockets in order to detect cracks.

  8. Cavity preparation/assembly techniques and impact on Q, realistic Q-factors in a module, review of modules

    Energy Technology Data Exchange (ETDEWEB)

    Kneisel, Peter [Jefferson Laboratory, 12000 Jefferson Avenue, Newport News, VA 23606 (United States)]. E-mail: kneisel@jlab.org

    2006-02-01

    This contribution summarizes the surface preparation procedures for niobium cavities presently used both in laboratory experiments and for modules, such as buffered chemical polishing (BCP), electropolishing (EP), high pressure ultrapure water rinsing (HPR), CO{sub 2} snow cleaning and high temperature heat treatments for hydrogen degassing or post-purification. The impact of surface treatments and the degree of cleanliness during assembly procedures on cavity performance (Q-value and accelerating gradient E {sub acc}) will be discussed. In addition, an attempt will be made to summarize the experiences made in module assemblies in different labs/projects such as DESY (TTF), Jlab (Upgrade) and SNS.

  9. A self-designed instrument to evaluate cavosurface angle for class I amalgam cavity preparation: A learning aid.

    Science.gov (United States)

    Arora, Ankit; Acharya, Shashi Rashmi; Ballal, Vasudev; Sharma, Padmaja

    2012-07-01

    Fighting the controversies, amalgam, as a posterior restorative material has survived till date. The fate of amalgam restoration is determined by geometry of the cavity preparation and cavosurface angle is one integral part of the cavity, which decides the marginal characteristics of the restoration and health of the tooth. Low edge strength of amalgam highlights the importance of cavosurface angle. However, at the same time conservation of the tooth also should be considered. This article presents a self-designed instrument to evaluate and obtain a cavosurface angle close to 110°. The design of the instrument also helps in evaluating parameters, such as depth of the cavity, undercut angle, and allows finishing of the buccal or lingual walls.

  10. Evidence-based concepts and procedures for bonded inlays and onlays. Part II. Guidelines for cavity preparation and restoration fabrication.

    Science.gov (United States)

    Rocca, Giovanni Tommaso; Rizcalla, Nicolas; Krejci, Ivo; Dietschi, Didier

    2015-01-01

    The second part of this article series presents an evidence-based update of clinical protocols and procedures for cavity preparation and restoration selection for bonded inlays and onlays. More than ever, tissue conservation dictates preparation concepts, even though some minimal dimensions still have to be considered for all restorative materials. In cases of severe bruxism or tooth fragilization, CAD/CAM composite resins or pressed CAD/CAM lithium disilicate glass ceramics are often recommended, although this choice relies mainly on scarce in vitro research as there is still a lack of medium- to long-term clinical evidence. The decision about whether or not to cover a cusp can only be made after a multifactorial analysis, which includes cavity dimensions and the resulting tooth biomechanical status, as well as occlusal and esthetic factors. The clinical impact of the modern treatment concepts that were outlined in the previous article - Dual Bonding (DB)/Immediate Dentin Sealing (IDS), Cavity Design Optimization (CDO), and Cervical Margins Relocation (CMR) - are described in detail in this article and discussed in light of existing clinical and scientific evidence for simpler, more predictable, and more durable results. Despite the wide choice of restorative materials (composite resin or ceramic) and techniques (classical or CAD/CAM), the cavity for an indirect restoration should meet five objective criteria before the impression. PMID:26171443

  11. Evidence-based concepts and procedures for bonded inlays and onlays. Part II. Guidelines for cavity preparation and restoration fabrication.

    Science.gov (United States)

    Rocca, Giovanni Tommaso; Rizcalla, Nicolas; Krejci, Ivo; Dietschi, Didier

    2015-01-01

    The second part of this article series presents an evidence-based update of clinical protocols and procedures for cavity preparation and restoration selection for bonded inlays and onlays. More than ever, tissue conservation dictates preparation concepts, even though some minimal dimensions still have to be considered for all restorative materials. In cases of severe bruxism or tooth fragilization, CAD/CAM composite resins or pressed CAD/CAM lithium disilicate glass ceramics are often recommended, although this choice relies mainly on scarce in vitro research as there is still a lack of medium- to long-term clinical evidence. The decision about whether or not to cover a cusp can only be made after a multifactorial analysis, which includes cavity dimensions and the resulting tooth biomechanical status, as well as occlusal and esthetic factors. The clinical impact of the modern treatment concepts that were outlined in the previous article - Dual Bonding (DB)/Immediate Dentin Sealing (IDS), Cavity Design Optimization (CDO), and Cervical Margins Relocation (CMR) - are described in detail in this article and discussed in light of existing clinical and scientific evidence for simpler, more predictable, and more durable results. Despite the wide choice of restorative materials (composite resin or ceramic) and techniques (classical or CAD/CAM), the cavity for an indirect restoration should meet five objective criteria before the impression.

  12. Pulpal regeneration after cavity preparation, with special reference to close spatio-relationships between odontoblasts and immunocompetent cells.

    Science.gov (United States)

    Ohshima, Hayato; Nakakura-Ohshima, Kuniko; Takeuchi, Kiichi; Hoshino, Masaaki; Takano, Yoshiro; Maeda, Takeyasu

    2003-04-01

    The regeneration process of the odontoblast cell layer incident to tooth injury, especially its relationship with immunocompetent cells in pulp healing, has not been fully understood. The purpose of the present study was to clarify this relationship between odontoblasts and immunocompetent cells in the process of pulp regeneration following cavity preparation in rat molars by immunocytochemistry for heat shock protein (Hsp) 25 as well as class II major histocompatibility complex (MHC) molecules. In untreated control teeth, intense Hsp 25-immunoreactivity was found in the cell bodies of odontoblasts and their processes within the predentin, whereas class II MHC-positive cells were predominantly located beneath the odontoblast cell layer. Cavity preparation caused the destruction of the odontoblast layer to form an edematous lesion and the shift of class II MHC-positive cells with the injured odontoblasts toward the pulp core at the affected site. Some damaged odontoblasts without apparent cytoplasmic processes, round in profile, retained the immunoreactivity for Hsp25, suggesting the survival of a part of the odontoblasts against artificial external stimuli. Twelve hours after cavity preparation, numerous class II MHC-positive cells appeared along the pulp-dentin border and extended their processes deep into the exposed dentinal tubules. By postoperative 72 hours, newly differentiated odontoblasts with Hsp 25-immunoreactivity were arranged at the pulp-dentin border, but the class II MHC-positive cells moved from the pulp-dentin border to the subodontoblastic layer. These findings indicate that the time course of changes in the expression of Hsp 25-immunoreactivity reflects the regeneration process of odontoblasts. The functional roles of Hsp 25-positive odontoblasts and immunocompetent cells such as class II MHC-positive cells in the process of pulp regeneration after cavity preparation are discussed in conjunction with our previous experimental data.

  13. Sympathetic nerve fibers sprout into rat odontoblast layer, but not into dentinal tubules, in response to cavity preparation.

    Science.gov (United States)

    Shimeno, Yoichi; Sugawara, Yumiko; Iikubo, Masahiro; Shoji, Noriaki; Sasano, Takashi

    2008-04-11

    This study was designed to determine if sympathetic nerve fibers exist in dentinal tubules in rat normal dental pulp, and if they sprout into the dentinal tubules in response to artificial cavity preparation in dentin. Sympathetic nerve fibers in rat molar dental pulp were labeled using an anterograde axonal transport technique involving injection of wheat germ agglutinin-horseradish peroxidase (WGA-HRP) into the superior cervical ganglion (SCG). They were then observed using light and electron microscopes. In normal dental pulp (control), scattered WGA-HRP reaction products were observed in unmyelinated nerve endings in the odontoblast layer and subodontoblastic region. In injured pulp 3 weeks after cavity preparation, reaction products were about 1.8-times more plentiful in the above areas (versus control pulp). However, no labeled nerve fibers were observed in the dentinal tubules in either control or injured dental pulp. These results indicate that although sympathetic nerve fibers do indeed sprout in rat dental pulp in response to cavity preparation, they do not penetrate into the dentinal tubules in which postganglionic nerve endings derived from the SCG were not originally present.

  14. Preparation and Decoherence of Two-Atom Entangled States in a Dissipative Cavity

    Institute of Scientific and Technical Information of China (English)

    XIANG Shao-Hua; SONG Ke-Hui

    2006-01-01

    @@ We present a scheme for generating four pairs of two-atom Einstein-Podolsky-Rosen (EPR) states using the simultaneous interaction of the two atoms with a single-mode cavity field under a large detuning condition.

  15. [Cavity preparation and restorative therapy in articles, published by the Fogorvosi Szemle in the last hundred years].

    Science.gov (United States)

    Nemes, Júlia; Duhaj, Szilvia; Nyárasdy, Ida

    2009-04-01

    The aim of this review is to overview the development achieved in restorative therapy based on the publications in Fogorvosi Szemle during the past hundred years. The top quality of the restorative therapy was, and still has been the inlay, but nowadays the esthetic inlay -- fixed with adhesive material -- has priority over the gold inlay. The quality of amalgam fillings has been recently improved by using high-copper containing amalgam alloys. The development on the field of adhesive material and methods made it possible to give up the routine use of any conventional base material. The place of gingival wall of the cavity moved from subgingival position into supragingival position. The macro retention has been replaced by micro retention, and nowadays the cavity preparation prefers minimal-invasive techniques.

  16. Cluster-state preparation in thermal cavities without single-qubit operation

    Institute of Scientific and Technical Information of China (English)

    Zhang Xiao-Long; Feng Mang; Gao Ke-Lin

    2008-01-01

    A potential scheme is proposed for generating cluster states of many atoms in cavity quantum electradynamics We show how to create the cluster states by performing a two-step but no single-qubit operation.Discussion is also carried out on the experimental feasibility of our scheme.

  17. PAIN PERCEPTION OF PEDIATRIC PATIENTS DURING CAVITY PREPARATION WITH Er:YAG LASER AND CONVENTIONAL ROTARY INSTRUMENTS.

    Directory of Open Access Journals (Sweden)

    Ani Belcheva

    2014-11-01

    Full Text Available Aim: The aim of the present study is to evaluate and compare the pain perception of pediatric patients during cavity preparation with the use of Erbium:YAG laser 2940 nm and conventional rotary instruments. Methods and materials: A group of ninety 6-12-years-old patients with matched carious lesions (D3 threshold, WHO system was divided into two equal treatment groups and treated without anaesthesia. In the intervention group the cavities were prepared with Erbium:YAG laser 2940nm and in the control group with conventional rotary instruments. At the end of the treatment each patient was asked to point the degree of its pain on the universal pain assessment tool. Results: Participants in the laser treatment group reported significantly lower pain scores compared to participants in the control group (p<0.005. The analysis of pain indicated that in the intervention group the scores obtained from the majority of cases (71.1% were low and only one patient reported severe pain perception. In the conventional treatment group the results showed approximately equal frequency for low (40% and moderate (42.2% pain level. Conclusions: The Erbium:YAG lasers produce less pain compared to the conventional mechanical preparation. They offer new and useful possibilities in restorative dentistry in pediatric dentistry and are good treatment options.

  18. An X-ray microtomography study on the mineral concentration of carious dentine removed during cavity preparation in deciduous molars.

    Science.gov (United States)

    Willmott, N S; Wong, F S L; Davis, G R

    2007-01-01

    Dentists use a number of criteria in order to assess when a cavity is caries free, amongst which hardness is probably the most widely used. However, the judgement is subjective. X-ray microtomography (XMT) is a non-destructive microscopic technique that allows in vitro specimens to be scanned, manipulated and then rescanned. In this study, a high-definition XMT scanner was used to determine the mineral distribution of carious dentine in 10 deciduous molars, and the extent of dentine removed by an experienced clinician was investigated. For each tooth, after an initial XMT scan, caries was removed using a steel bur in a slow hand-piece. The tooth was then repositioned and rescanned. Mineral concentrations were calculated from the linear attenuation coefficients assuming the mineral phase to be hydroxyapatite and the organic phase to be collagen. The volume of dentine tissues removed was calculated by subtracting data of the second scan from the first. The results showed that the mean modal mineral concentration for the 10 teeth was 1.42 g x cm(-3) for sound dentine. Because of uncertainty about collagen concentration in carious dentine, the mean modal mineral concentration for the carious dentine had a range of 0.37-0.5 g x cm(-3). It was found that the subjective criteria used by the operator could lead to inconsistency of cavity preparation. The cavities could be overprepared by 8.5-44.3% in volume. However, the overpreparation was not uniform throughout the cavity: residual demineralised dentine could still be detected in the postoperative scan in isolated regions.

  19. Effects of low-intensity GaAlAs laser radiation (λ=660 nm) on dentine-pulp interface after class I cavity preparation

    International Nuclear Information System (INIS)

    The aim of this study was to investigate the effects of low-intensity irradiation with GaAlAs laser (red emission) on the ultrastructure of dentine-pulp interface after conventionally prepared class I cavity preparation. Two patients with 8 premolars for extraction indicated for orthodontic reasons. Class I cavities were prepared in these teeth that were then divided into two groups. The first group received a treatment with laser with continuous emission, λ=660 nm, with maximum power output of 30 mW. The dosimetry applied was of approximately 2J/cm2, directly and perpendicularly into the cavity in only one section. After the irradiation, the cavities were filled with composite resin. The second group received the same treatment, except by the laser therapy. Twenty-eight days after the preparation, the teeth were extracted and were processed for transmission electron microscopy analysis. Two sound teeth, without any preparation, were also studied. The irradiated group presented odontoblastic processes in higher contact with the extracellular matrix and the collagen fibers appeared more aggregated and organized than those of control group. These results were also observed in the healthy-teeth. Thus, we suggest that laser irradiation accelerates the recovery of the dental structures involved in the cavity preparation at the pre-dentine level. (author)

  20. Evolução dos preparos das cavidades de classe II Developments in preparation of class II cavities

    Directory of Open Access Journals (Sweden)

    Mary Miyuki ONO

    1997-01-01

    Full Text Available A evolução dos preparos de classe II com a introdução de novos materiais e a conscientização da importância da preservação de estrutura dental sadia são abordadas nos preparos do tipo Almqvist, Roggenkamp e túnel, em que se observa a necessidade de menor desgaste da estrutura dentária, com aumento da resistência à fratura, melhor estética e melhor retençãoDevelopments in preparation of class II cavities with the introduction of new materials and awareness of the importance of preservation of a sound dental structure are broached in preparations of the type Almqvist, Roggenkamp and tunnel, where the need for less wear of the dental structure was observed with an increase in fracture strength, better aesthetics, and better retention

  1. The influence of the cavity preparation design on marginal accuracy of laboratory-processed resin composite restorations.

    Science.gov (United States)

    Fonseca, Rodrigo Borges; Correr-Sobrinho, Lourenço; Fernandes-Neto, Alfredo Júlio; Quagliatto, Paulo Sérgio; Soares, Carlos José

    2008-03-01

    The aim of this study was to evaluate the influence of different cavity preparation designs on marginal accuracy of laboratory-processed resin composite restored teeth. Eighty mandibular human third molars were selected. There were two experimental factors, occlusal isthmus width (narrow vs wide) and cuspal coverage (inlay, one-cusp onlay, two-cusp onlay, and all-cusp onlay), resulting on eight groups (N = 10). Indirect composite restorations (SR Adoro, Ivoclar-Vivadent) were manufactured and positioned over each respective preparation. Marginal accuracy evaluation was accomplished using a stereomicroscope at three points on buccal, lingual, mesial, and distal regions with 40x magnification. The results showed significant differences (P = 0.00) with wide inlay showing the best overall marginal accuracy and narrow inlay the worst one. Two-way analysis of variance (ANOVA) showed significant differences when considering the factor occlusal isthmus width (P = 0.00). In general, preparations with wide occlusal isthmus presented better results than narrow ones, except for wide all-cusp onlays; however, the test failed to show differences when considering the cuspal coverage (P = 0.42) or the interaction between both factors (P = 0.30). The effect of occlusal width extension on marginal accuracy of indirect composite resin restorations is significant, with lower values of gaps width in wide preparations, but since in a clinical situation this would mean greater removal of sound tooth structure, less-aggressive preparations combined with other restorative procedures seem to be more feasible.

  2. Hybrid layer thickness and morphology: Influence of cavity preparation with air abrasion.

    Science.gov (United States)

    Barceleiro, Marcos Oliveira; de Mello, Jose Benedicto; Porto, Celso Luis de Angelis; Dias, Katia Regina Hostilio Cervantes; de Miranda, Mauro Sayao

    2011-01-01

    Dentinal surfaces prepared with air abrasion have considerably different characteristics from those prepared with conventional instruments. Different hybrid layer morphology and thickness occur, which can result in differences in the quality of restorations placed on dentinal surfaces prepared with a diamond bur compared to surfaces prepared using air abrasion. The objective of this study was to compare the hybrid layer thickness and morphology formed utilizing Scotchbond Multi-Purpose Plus (SBMP) on dentin prepared with a diamond bur in a high-speed handpiece and on dentin prepared using air abrasion. Flat dentin surfaces obtained from five human teeth were prepared using each method, then treated with the dentin adhesive system according to manufacturer's instructions. After a layer of composite was applied, specimens were sectioned, flattened, polished, and prepared for scanning electron microscopy. Ten different measurements of hybrid layer thickness were obtained along the bonded surface in each specimen. SBMP produced a 3.43 ± 0.75 µm hybrid layer in dentin prepared with diamond bur. This hybrid layer was regular and found consistently. In the air abrasion group, SBMP produced a 4.94 ± 1.28 µm hybrid layer, which was regular and found consistently. Statistical ANOVA (P = 0.05) indicated that there was a statistically significant difference between the groups. These data indicate that the air abrasion, within the parameters used in this study, provides a thick hybrid layer formation.

  3. Femtosecond laser for cavity preparation in enamel and dentin: ablation efficiency related factors

    Science.gov (United States)

    Chen, H.; Li, H.; Sun, Yc.; Wang, Y.; Lü, Pj.

    2016-02-01

    To study the effects of laser fluence (laser energy density), scanning line spacing and ablation depth on the efficiency of a femtosecond laser for three-dimensional ablation of enamel and dentin. A diode-pumped, thin-disk femtosecond laser (wavelength 1025 nm, pulse width 400 fs) was used for the ablation of enamel and dentin. The laser spot was guided in a series of overlapping parallel lines on enamel and dentin surfaces to form a three-dimensional cavity. The depth and volume of the ablated cavity was then measured under a 3D measurement microscope to determine the ablation efficiency. Different values of fluence, scanning line spacing and ablation depth were used to assess the effects of each variable on ablation efficiency. Ablation efficiencies for enamel and dentin were maximized at different laser fluences and number of scanning lines and decreased with increases in laser fluence or with increases in scanning line spacing beyond spot diameter or with increases in ablation depth. Laser fluence, scanning line spacing and ablation depth all significantly affected femtosecond laser ablation efficiency. Use of a reasonable control for each of these parameters will improve future clinical application.

  4. SUBJECTIVE ACCEPTANCE OF PEDIATRIC PATIENTS DURING CAVITY PREPARATION WITH Er:YAG LASER AND CONVENTIONAL ROTARY INSTRUMENTS.

    Directory of Open Access Journals (Sweden)

    Ani Belcheva

    2014-11-01

    Full Text Available Aim: The aim of the present study is to evaluate and compare the subjective acceptance in children during hard dental tissue therapy using Er:YAG laser 2940nm and conventional rotary instruments. Methods and materials: The study included ninety 6-12-years-old children with matched carious lesions (D3 threshold, WHO system, divided into two equal treatment groups. In the intervention group the cavities were prepared with Erbium:YAG laser 2940nm and in the control group with conventional rotary instruments, without anaesthesia. After cavity preparation patient’s subjective acceptance was assessed by a questionnaire concerning primary stress triggers. Results: The annoyance factor (vibration was found as a stress trigger in the majority of control children (86.7%, while in the intervention group it was found in 2.2% of cases. The most anxiety provoking items in the intervention group were smell (67.7% and taste (42.2%. The sound was found to be a stress trigger in more than half of control children (62.2% and less than one-fifth of the children in the intervention group (15.6%. The study results showed significant difference in these items between two groups (p< 0.001. Conclusions: The Erbium:YAG lasers reduce three of four stress triggers in `4S` principle - vibration, sight and sound. They are a good treatment option for fearful children since they have acceptable efficiency in treatment of pediatric anxiety disorders compared to the mechanical preparation.

  5. Comparison of the effect of Er, Cr-YSGG laser and ultrasonic retrograde root-end cavity preparation on the integrity of root apices.

    Science.gov (United States)

    Rahimi, Saeed; Yavari, Hamid R; Shahi, Shahriar; Zand, Vahid; Shakoui, Sahar; Reyhani, Mohammad F; Pirzadeh, Ahmad

    2010-03-01

    The aim of this study was to compare the effect of Waterlase laser and ultrasonic root end cavity preparation on the integrity of root end in extracted human teeth. The canals of 60 extracted maxillary central incisors were cleaned, shaped, obturated and 3 mm of the root end was resected and examined for the presence of any cracks. Class I root-end cavities were then prepared using an ultrasonic unit or Waterlase laser. In the ultrasonic group, KIS 2D tip and medium intensity and in the laser group, 600 mum laser tips and an output power setting of 4 W with 55% water and 65% air were used to prepare the cavity which was studied for the presence of any cracks or chippings. One crack was found in the ultrasonic group, while no cracks were observed in the laser group. There was no significant difference between the two groups (P > 0.05). As for the chipping effect, seven cases (23%) had chipping after cavity preparation in the ultrasonic group but no chipping was found in the specimens of the laser group and the difference was statistically significant (P < 0.05). According to the results of this in vitro study, laser preserves the integrity of root-end cavities better than ultrasonic devices from the standpoint of producing chipping.

  6. Morphological evaluation of cavity preparation surface after duraphat and Er:YAG laser treatment by scanning electronic microscopy

    International Nuclear Information System (INIS)

    The treatment of dental surface using different lasers to prevent dental caries has been studied for several on last years. The purpose of this in vitro study was to evaluate the morphological changes on dentin surface from pulpal wall of cavity preparations performed by high-speed drill, treated with 2,26% fluoride varnish (Duraphat) and Er:YAG laser, and then submitted after receiving or not to EDTA 15% treatment. Twenty Class V cavities were performed on ten humans molars. The specimens were randomly divided in to 4 groups: group 1- treatment with Duraphat followed by Er:YAG laser irradiation (120 mJ/ 4 Hz); group 2: Er:YAG laser irradiation, same parameters, followed by Duraphat treatment; group 3- same group 1 followed by immersion in EDTA (5 min); group 4 - same as group 2 followed by immersion in EDTA (5 min). The specimens were processed for SEM analysis. The micrographs showed that Duraphat treatment promoted morphological changes on dentin, closing dentinal tubules; the specimens treated by Duraphat and Er:YAG laser and immersed in EDTA (group 3) showed homogeneous surface, closed and protected dentinal tubules, maintenance of the fluoride varnish on the dentin surface and around the dentinal tubules, showing feasible and efficiency of these therapies the feasibility.(author)

  7. Effect of the erbium:yttrium-aluminum-garnet laser or diamond bur cavity preparation on the marginal microleakage of class V cavities restored with different adhesives and composite systems.

    Science.gov (United States)

    Yaman, Batu Can; Guray, Begum Efes; Dorter, Can; Gomeç, Yavuz; Yazıcıoglu, Oktay; Erdilek, Dina

    2012-07-01

    The aim of this in vitro study was to compare the microleakage of Er:YAG laser and diamond bur on different bonding systems in class V restorations. Class V cavities were prepared with Er:YAG laser or diamond bur on 80 intact human molars. Teeth were randomly distributed into ten groups and cavities were restored with CeramX duo (DENTSPLY) or Filtek Silorane (3M/ESPE) using different bonding materials (One Coat 7.0 (Coltène), XP Bond (DENTSPLY), Clearfil Protect Bond (Kuraray), AdperSE (3M/ESPE), and Silorane System Adhesive (3M/ESPE). All specimens were subjected to thermocycling and load cycling. After being immersed in silver nitrate dye, the specimens were sectioned. Microleakage was evaluated by stereomicroscope and SEM. Data were statistically analyzed by one-way ANOVA, Kruskal-Wallis, and Mann-Whitney tests. Statistically differences were found between groups (p > 0.05) and cavities prepared with the Er:YAG laser showed higher microleakage than diamond bur. The microleakage of different bonding systems was influenced by the choice of diamond bur or Er:YAG laser for class V composite cavity preparation.

  8. Pulpal response to cavity preparation by an erbium, chromium:YSGG laser-powered hydrokinetic system.

    Science.gov (United States)

    Eversole, L R; Rizoiu, I; Kimmel, A I

    1997-08-01

    The near red-pulsed erbium, chromium:yttrium-scandium-gallium-garnet laser hydrokinetic system, or Er,Cr:YSGG laser HKS, is effective in cutting dental hard tissues. In this longitudinal study, the authors studied the continuously erupting open-apex incisors of New Zealand albino rabbits and the constricted apex teeth of beagles to determine the effects of HKS-produced lesions at various energy levels and of preparations produced by a tapered fissure bur on dental pulp. No pulpal inflammatory responses could be identified either immediately or 30 days after surgery in HKS preparations that removed enamel and dentin without pulp exposure. PMID:9260419

  9. Relationships between tissue properties and operational parameters of a dental handpiece during simulated cavity preparation.

    Science.gov (United States)

    Sun, Hongyan; Lau, Andrew; Heo, Young C; Lin, Lianshan; Delong, Ralph; Fok, Alex

    2013-01-01

    A preliminary study was conducted on the development of an intelligent dental handpiece with functionality to detect subtle changes in mechanical properties of tooth tissue during milling. Such equipment would be able to adopt changes in cutting parameters and make real-time measurements to avoid tooth tissue damage caused by overexertion and overextension of the cutting tool. A modified dental handpiece, instrumented with strain gauges, microphone, displacement sensor, and air pressure sensor, was mounted to a linear movement table and used to mill three to four cavities in >50 bovine teeth. Extracted sound frequency and density were analyzed along with force, air pressure, and displacement for correlations and trends. Experimental results showed a high correlation (coefficient close to 0.7) between the feed force, the rotational frequency, and the averaged gray scale. These results could form the basis of a feedback control system to improve the safety of dental cutting procedures. This article is written in memory of Dr Hongyan Sun, who passed away in 2011 at a young age of 37.

  10. Accuracy of navigated control concepts using an Er: Yag-laser for cavity preparation.

    Science.gov (United States)

    Wolff, Regine; Weitz, Jochen; Poitzsch, Luise; Hohlweg-Majert, Bettina; Deppe, Herbert; Lueth, Tim C

    2011-01-01

    This paper describes a method for measuring the shape accuracy of a cylindrical hole which is created by means of an automatically power-controlled laser system using navigated control. In dental surgery, drills or mills are used for bone treatment. For most patients the use of these instruments is very inconvenient. Furthermore, the bone treatment with rotating instruments can lead to thermal necrosis. Using a laser system could be a good alternative for the patient. The utilization of a laser system could also facilitate bone treatment without any severe thermal damage. An optical navigation system can be used for a safer handling of a laser system. The position and the orientation of the laser handpiece relative to the patient can be calculated. Thereby, the laser can be automatically switched off, if the end of the laser beam does not hit the preoperative planned area. In order to measure the accuracy of such a laser system, we created several cavities in a phantom with a manually guided, automatically power-controlled laser. Afterwards, the deviation between the planned shape and the shape created by manually guided automatically power-controlled laser treatment has been measured. The application of this system showed, that the required accuracy of <1 mm for dental implantology applications, could not be reached.

  11. 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

    International Nuclear Information System (INIS)

    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

  12. Effect of surface roughness of cavity preparations on the microleakage of Class V resin composite restorations.

    Science.gov (United States)

    Shook, Larry W; Turner, Edgar W; Ross, Judith; Scarbecz, Mark

    2003-01-01

    This study determined whether surface roughness of the internal walls of a Class V resin composite preparation, using a carbide bur, a medium-grit diamond bur and a fine-grit diamond bur, affected the degree of microleakage of the restoration. The facial and lingual surfaces of 45 non-carious extracted human molars provided 90 samples for evaluation. The specimen surfaces were assigned randomly in equal numbers to one of three groups (n = 30). Conservative Class V composite preparations were made using one of three different burs: a 330-carbide bur, a 330 fine-grit diamond bur or a 330 medium-grit diamond bur (Brasseler USA). After acid etching, PQ1 (Ultradent Products Inc) primer/bonding resin and Vitalescence (Ultradent Products Inc) were applied and cured following the manufacturers' instructions. After minor finishing, the apices of all root surfaces were sealed with Vitrebond (3M), and the unprepared external surfaces were sealed with nail polish to within 1 mm of the restoration margins. The specimens were stored in distilled water at room temperature for 24 hours, then subjected to 1,200 thermocycles at 5 degrees C and 55 degrees C with a 30-second dwell time. After cycling, the teeth were immersed in a 5% solution of methylene blue dye for 12 hours. The molars were invested in clear acrylic casting resin, labeled, then sectioned once vertically approximately midway through the facial and lingual surfaces using a diamond coated saw blade. Microleakage was evaluated using a 10x microscope for the enamel and cementum surfaces and blindly scored by two independent examiners. In all cases, regardless of the examiner, at both the enamel and the dentin margins, the analysis revealed no statistically significant differences in microleakage across bur types. Further results show that dentin margins leaked significantly more than enamel margins for all bur types.

  13. Comparison of the Er,Cr:YSGG laser with a chemical vapour deposition bur and conventional techniques for cavity preparation: a microleakage study.

    Science.gov (United States)

    Yazici, A Rüya; Yıldırım, Zeren; Antonson, Sibel A; Kilinc, Evren; Koch, Daniele; Antonson, Donald E; Dayangaç, Berrin; Ozgünaltay, Gül

    2012-01-01

    The aim of this study was to compare the effects of the Er,Cr:YSGG laser using chemical vapour deposition (CVD) bur cavity preparation with conventional preparation methods including a diamond bur and a carbide bur on the microleakage with two different adhesive systems. A total of 40 extracted human premolars were randomly assigned to four experimental groups according to the cavity preparation technique: group I diamond bur (Diatech); group II carbide bur (Diatech); group III Er,Cr:YSGG laser (Biolase Millennium II); and group IV CVD bur (CVDentUS). Using the different preparation techniques, Class V standardized preparations were performed on the buccal and lingual surfaces with gingival margins on the dentin and occlusal margins on the enamel. Each preparation group was randomly assigned to two subgroups (five teeth, ten preparations) according to the type of adhesive: an etch-and-rinse adhesive (Adper Single Bond), and a single-step self-etch adhesive (AdheSE One). All preparations were restored with a nanohybrid composite resin in a single increment. Following thermocycling (×500; 5-55°C), the teeth were immersed in basic fuchsin and sectioned in the orovestibular direction. Dye penetration was evaluated under a light microscope by two blinded examiners. Data were statistically analysed with the Kruskal-Wallis and Wilcoxon tests (p0.05). Comparing the enamel and dentin leakage scores within each group, no statistically significant differences were found (p>0.05). The Er,Cr:YSGG laser cavity preparation did not differ from preparation with CVD, diamond or carbide bur in terms of microleakage with the different adhesive systems.

  14. Effect of cavity preparation method on microtensile bond strength of a self-etching primer vs phosphoric acid etchant to enamel.

    Science.gov (United States)

    de Souza-Zaroni, Wanessa Christine; Delfino, Carina Sinclér; Ciccone-Nogueira, Juliane Cristina; Palma-Dibb, Regina Guenka; Corona, Silmara Aparecida Milori

    2007-10-01

    This study evaluated the effect of cavity preparation using air abrasion or carbide bur on bond strength to enamel treated with a self-etching primer (Tyrian SPE) or a phosphoric acid etchant. Twenty-four molars were divided into three groups: high-speed; standard handpiece (ST air abrasion) or supersonic handpiece (SP air abrasion) of the same air-abrasive system. The enamel surfaces were treated with one of the two etchants and the same adhesive agent One Step Plus, and then composite buildups were done with Filtek Z250. After 24 h at 37 degrees C, beams (0.8 mm2) were obtained and subjected to tensile stress in a universal testing machine (0.5 mm/min). The data were submitted to analysis of variance and Tukey's test (P cavity preparation method was dependent on the conditioning system used, only when using carbide-bur preparation technique.

  15. A Comparative Study on Micro Hardness and Structural Changes of Dentin Floor Cavity Prepared by Er: YAG Laser Irradiation and Mechanical Bur

    Directory of Open Access Journals (Sweden)

    Arbabzadeh F.

    2013-06-01

    Full Text Available Statement of Problem: Laser irradiation makes structural and chemical changes on the dental hard tissues. These changes alter the level of solubility and permeability of dentin. Purpose: The aim of this study was to compare the microhardness and the structural changes in the dentin cavity floor prepared with Er: YAG laser and bur.Material and Methods: In this experimental study, fifteen intact human molars were selected. Two square cavities were prepared on the buccal and lingual surfaces of each tooth. One side was randomly prepared by Er:YAG laser and the other side by bur. The specimens were divided into two halves. Consequently, there were 30 samples in every group. One half was assigned for the Vickers’s hardness test and the other one, for determination of Ca and P percentage and atomic elements analysis. The data were analyzed by Paired T-tests through SPSS16 (α≤o.o5.Results: The means and the standard deviation of the microhardness were 69.77±25.62 and 51.33±9.31 Kg/mm2 in the laser and bur groups, respectively. Statistical analysis showed significant differences between the two groups (p=0.017. Weight percentage of calcium in the laser cavity (65.5 was less than the bur cavities (68.21 and the difference was significant (p= 0.037.Conclusion: The hardness of dentin in laser group was higher than the bur group because of the higher mineral content of the dentin. The hardness and the mineral content of dentin are important factors in the bonding effectiveness of the dental materials so with laser cavity preparation, good mineral substrate are available for a better bonding.

  16. In-vitro evaluation of Er:YAG laser irradiation in apicoectomy and retrofilling cavity preparation compared to two other techniques

    Science.gov (United States)

    Camargo, Selma C. C.; Gavini, Giulio; Eduardo, Carlos d. P.; Aun, Carlos E.; Coil, Jeffrey M.

    1998-04-01

    The aim of this research was to evaluate under SEM observation, the apical cut surface and retrofilling cavity prepared with Er:YAG laser and two other conventional techniques. Thirty extracted human teeth were divided into two groups of 15 teeth each. For Group 1 apicoectomy was performed using high speed handpiece and diamond burs. For Group 2 Er:YAG* laser irradiation (wavelength of 2.94 micrometer, pulse width of 250 - 500 microseconds) was used in 400 mJ of energy, frequency of 6 Hz, on focus mode under destiled water refrigeration. Each group was divided into 3 subgroups. For groups G1A and G2A, retrofilling cavity preparations were performed using low speed handpiece and burs, for groups G1B and G2B Enac technique was indicated. Groups G1C and G2C Er:YAG laser irradiation was used under same energy level previously described. All specimens were prepared for SEM observations. Pictures were taken under 30x and 600x magnification. Two different observers analyzed the smoothness and morphological appearance of those preparations. Data's were collected showing a smoothness surface, no debries or smear layer on group 2 (Laser irradiation) compared to group 1. Differences were also noted when retrofiling cavities were analyzed.

  17. Comparative histopathological analysis of human pulps after class I cavity preparation with a high-speed air-turbine handpiece or Er:YAG laser

    Science.gov (United States)

    Kina, J. F.; Benitez, P. C.; Lizarelli, R. F. Z.; Bagnato, V. S.; Martinez, T. C.; Oliveira, C. F.; Hebling, J.; Costa, C. A. S.

    2008-12-01

    The purpose of this study was to comparatively evaluate the response of human pulps after cavity preparation with different devices. Deep class I cavities were prepared in sound mandibular premolars using either a high-speed air-turbine handpiece (Group 1) or an Er:YAG laser (Group 2). Following total acid etching and the application of an adhesive system, all cavities were restored with composite resin. Fifteen days after the clinical procedure, the teeth were extracted and processed for analysis under optical microscopy. In Group 1 in which the average for the remaining dentin thickness (RDT) between the cavity floor and the coronal pulp was 909.5 μm, a discrete inflammatory response occurred in only one specimen with an RDT of 214 μm. However, tissue disorganization occurred in most specimens. In Group 2 (average RDT = 935.2 μm), the discrete inflammatory pulp response was observed in only one specimen (average RDT = 413 μm). It may be concluded that the high-speed air-turbine handpiece caused greater structural alterations in the pulp, although without inducing inflammatory processes.

  18. Comparative study of the influence of cavity preparation with high-speed rotation or Er:YAG laser on infiltration of aesthetic restorations

    Science.gov (United States)

    Costa, D. P. T. S.; Beatrice, L. C. S.; Guerra, L. S. C.; Ribeiro, M. A.; Zanin, F. A. A.; Queiroga, A. S.; Limeira Júnior, F. A.; Gerbi, M. E. M. M.

    2010-04-01

    The aim of the present study was to compare marginal infiltration in Class V cavities prepared on extracted human premolars with either high-speed rotation or a Er:YAG laser. Class V cavities were executed on the vestibular and lingual faces of twelve premolars, with high-speed rotation or a Er:YAG laser (300 mJ, 4 Hz, and 3 W), and cavity surfaces were conditioned with 37% phosphoric acid combined with laser treatment (80 mJ, 5 Hz, 3 W) or without laser treatment in the following manner: G1—high-speed rotation + conditioning with phosphoric acid; G2—high-speed rotation + conditioning with laser and phosphoric acid; G3—laser + conditioning with phosphoric acid; and G4—laser + conditioning with laser and phosphoric acid. Specimens were restored with the composite resin, thermocycled and immersed in 0.5% basic fuchsin for 24 h. Specimens were then cross-cut and analyzed using a stereoscopic magnifying glass. Evaluations were submitted to the Kruskall-Wallis statistical test. No significant differences were found between the averages of the groups ( p > 0.05). High-speed rotation and Er:YAG laser for the confection of cavity preparation exhibited a similar performance with regard to marginal infiltration.

  19. Photonic crystal cavity embedded barium strontium titanate thin-film rib waveguide prepared by focused ion beam etching

    International Nuclear Information System (INIS)

    A photonic crystal (PC) cavity embedded Ba0.7Sr0.3TiO3 (barium strontium titanate, or BST) rib waveguide, which functions as an optical filter at λ = 1550 nm, is designed using finite-difference time-domain (FDTD) simulation. The PC cavity is composed of two 5-row photonic crystal mirrors, which are formed by air holes (radii 250 nm) arranged in triangular lattice (periodicity 625 nm) in the BST matrix. Calculations suggested that the required cavity length should be 800 nm for the resonant peak to be situated at 1550 nm. Based on this design, PC cavities were fabricated on BST thin-film rib waveguides by focused ion beam etching with satisfactory results. The transmission spectra of the BST thin-film rib waveguides with PC cavities have been measured. The results agreed well with the FDTD simulation.

  20. 窝洞预备技能评价系统用于牙体预备质量评估的探讨%Exploration of the application of cavity preparation skill evaluation system in pre-clinical dental cavity preparation assessment

    Institute of Scientific and Technical Information of China (English)

    邹慧儒; 靳淑凤; 孙建萍; 王雅楠; 林欣; 戴艳梅

    2014-01-01

    Objective To analyze the effects of Cavity Preparation Skill Evaluation System (CPSES) in pre-clinical dental cavity preparation assessment.Methods Twenty one dental undergraduates in Medical School of Nankai University were chosen in this study.After cavity preparation training,students' cavity preparation skills were evaluated systematically.The outline form and depth of 21 left mandibular first molar class Ⅰ cavity preparation made by students were evaluated by CPSES system and evaluators' visual assessment.The evaluation results were analyzed using GraphPad InStat statistical software(V3.1) with paired t test (test level α=0.05) and correlation analysis to study the application effects of the CPSES system.Results The evaluation results generated from CPSES system and evaluators' visual assessment for class Ⅰ dental cavity preparation skill evaluation showed significant difference(two tailed P value 0.0050,t=3.156) and certain correlation on cavity preparation assessment(two tailed P value 0.0837,r=0.386 2).Conclusion Application of cavity preparation skill evaluation system in undergraduate endodontic teaching can deepen and strengthen the students' understanding of cavity preparation requirements and help students master cavity preparation knowledge and skills better.%目的 分析窝洞预备技能评价系统(cavity preparation skill evaluation system,CPSES)应用于牙体窝洞预备质量评估的教学效果.方法 选择南开大学医学院口腔临床医学专业本科四年级学生21人为研究对象,经窝洞预备培训后,集中考核窝洞预备技能掌握情况.根据恒磨牙Ⅰ类洞窝洞预备要求,由21名本科学生对左下第一恒磨牙标准模型牙进行Ⅰ类洞窝洞预备.之后依据窝洞外形轮廓、洞深等预备标准,分别采用CPSES和教师目测评估两种方法,对学生预备的21颗标准模型牙Ⅰ类洞窝洞进行评分.两种方法获取的评估结果采用GraphPad InStat统计软件(V3.1)

  1. Teleportation of Cavity Field States via Cavity QED

    CERN Document Server

    Guerra, E S

    2004-01-01

    In this article we discuss two schemes of teleportation of cavity field states. In the first scheme we consider cavities prepared in a coherent state and in the second scheme we consider cavities prepared in a superposition of zero and one Fock states.

  2. Preparation of Entanglement and Schrodinger Cat States of Superconducting Quantum Interference Devices Qubits via Coupling to a Microwave Cavity

    Institute of Scientific and Technical Information of China (English)

    LI Sheng-Chang; YANG Wen-Xing; DUAN Wen-Shan

    2008-01-01

    An alternative scheme is proposed for the generation of n-qubit W states of superconducting quantum interference devices (SQUID) in cavity QED. In this scheme, Raman coupling of two lower flux states of SQUID system is achieved via a microwave pulse and the cavity mode. Conditioned on no photon leakage from the cavity, the n-qubit W state can be generated whether the effective coupling parameters of the SQUID to cavity mode and classical microwave fields are the same or different. Our strictly numerical simulations of the time evolution of the system including decay show that the success probability of our scheme is almost unity and the interaction time is on the order of 10-9 s. The scheme can also be used to generate the Schrfdinger cat states of multi-SQUID.

  3. Effect of irradiation mode and filling technique on resin/dentin bonding strength in class I cavities Efeito do modo de ativação e da técnica restauradora na resistência de união entre compósito e dentina em cavidades classe I

    Directory of Open Access Journals (Sweden)

    Alex José Souza dos Santos

    2004-09-01

    Full Text Available Factors such as light-curing mode, filling technique and cavity configuration may affect the bonding strength to dentin. This study evaluated the effect of irradiation mode and filling technique on resin/dentin bonding strength on the buccal wall of class I cavities in human teeth. Occlusal enamel was removed to expose a flat dentin surface. Occlusal cavities (4 x 3 x 3 mm were prepared in dentin. The adhesive Single Bond was applied according to the manufacturer's instructions and TPH Spectrum composite resin was placed using the following: oblique incremental, horizontal incremental or bulk filling techniques. The composite resin was light-cured either by continuous (600 mW/cm² for 40 s or Soft-Start (250 mW/cm² for 10 s + 600 mW/cm² for 30 s modes. Specimens of the control group were obtained by bonding the material to the flat exposed buccal wall of the cavity (C-factor = 1. The teeth were stored in water at 37ºC for 24 h and prepared for microtensile testing. Bonded beams of approximately 0.8 mm² were obtained from the buccal wall and tested with a tension of 0.5 mm/min. Results were analyzed by two-way ANOVA, Tukey's test and Dunnett's test (alpha = 0.05. Incremental placement techniques with both irradiation modes produced higher bonding strength values than the bulk technique (p Fatores como o modo de ativação, a técnica restauradora e a configuração cavitária podem afetar a resistência adesiva à dentina. Este estudo avaliou os efeitos dos modos de ativação e das técnicas restauradoras na resistência de união compósito/dentina na parede vestibular de restaurações classe I. O esmalte oclusal dos dentes foi removido para expor uma superfície dentinária planificada. Cavidades oclusais (4 x 3 x 3 mm foram preparadas em dentina. O adesivo Single Bond foi aplicado de acordo com as instruções do fabricante, e o compósito TPH Spectrum, inserido através de três diferentes técnicas: oblíqua incremental, horizontal

  4. Efeito de diferentes métodos de preparo na germinação de sementes de tomate Effects of different methods of seed preparation on the germination of tomato seeds

    Directory of Open Access Journals (Sweden)

    Antônio Augusto do Lago

    1976-01-01

    Full Text Available Sementes de tomate, extraídas mecanicamente dos frutos e após diferentes métodos de preparo, tiveram seu poder germinativo determinado após 0, 4 e 12 meses de armazenagem. Ao todo, foram estudados os efeitos de 30 métodos de preparo conseguidos com a combinação de cinco tipos de fermentação, dois de desinfecção e três de secagem. O poder germinativo das sementes diminuiu com o aumento do tempo de fermentação e, principalmente, quando se utilizou ácido acético glacial na massa de fermentação. A desinfecção das sementes com sublimado corrosivo proporcionou melhores resultados, o mesmo ocorrendo quando da secagem das sementes à sombra. Os efeitos de interações entre as variáveis foram também analisados.Tomato seeds mechanically extracted from the fruits were subjected to different methods of preparation, i.e., five types of fermentation, two of desinfection, and three of drying. Viability of such seeds was determined after 0, 4, and 12 months of storage. Germination of tomato seeds decreased with the increase of time of fermentation, and, mostly when acetic acid was added to the mass being fermented. The best product for seed desinfection was HgCl2, and shade-drying was the most adequate for tomato seeds.

  5. Entanglement Preparation and Quantum Information Processing with Atoms Trapped in Separated Cavities Through a Single Resonant Atom-Field Interaction

    Science.gov (United States)

    Lin, Li-Hua

    2014-01-01

    In this paper, a scheme is presented for generation of W-type entangled states for n atoms trapped in separated cavities connected by optical fibers. The scheme only requires a single atom-cavity-fiber interaction and no classical field is needed. Due to these features, the scheme is simpler and more robust against decoherence than the previous ones. The scheme can also be used to realize quantum state transfer and controlled phase gates between qubits located at distant nodes of a quantum network.

  6. Laser-assisted cavity preparation and adhesion to erbium-lased tooth structure: part 2. present-day adhesion to erbium-lased tooth structure in permanent teeth.

    Science.gov (United States)

    De Moor, Roeland Jozef Gentil; Delme, Katleen Ilse Maria

    2010-04-01

    With the introduction of the Er:YAG laser, it has become possible to remove enamel and dentin more effectively and efficiently than with other lasers. Thermal damage is reduced, especially in conjunction with water spray. Since FDA (Federal Drug Administration) approval of the Er:YAG laser in 1997--for caries removal, cavity preparation and conditioning of tooth substance - there have been many reports on the use of this technique in combination with composite resins. Moreover, cavity pretreatment with Er:YAG laser (laser etching) has been proposed as an alternative to acid etching of enamel and dentin. Reports evaluating the adhesion of glass-ionomer cements to Er:YAG-lased tooth substance are scarce. This article reviews the literature regarding adhesion and sealing efficacy using different (pre)treatment protocols in association with Er:YAG laser preparation. Recent research has shown that lasing of enamel and dentin may result in surface and subsurface alterations that have negative effects on both adhesion and seal. It is concluded that at present, it is advisable to respect the conventional pretreatment procedures as needed for the respective adhesive materials. Although the majority of present day reports show that microleakage and bond strength are negatively influenced by laser (pre)treatment (compared with conventional preparation), there is ongoing discussion of how adhesion is best achieved on Er:YAG-lased surfaces.

  7. Frequency of Iatrogenic damage to adjacent tooth during class II cavity preparation among dental students at Tehran University of Medical Sciences in 2010

    Directory of Open Access Journals (Sweden)

    Reza Yazdani

    2013-08-01

    Full Text Available   Background and Aims: Iatrogenic damage to adjacent tooth during proximal cavity preparation is one of the most common side effects in operative dentistry. The aim of this study was to determine prevalence of iatrogenic damages to adjacent tooth during the preparation of proximal Class II cavities among undergraduate students at dental faculty of Tehran University of Medical Sciences in 2010 .   Materials and Methods: 106 posterior permanent teeth which had Class II decay with sound proximal surfaces of adjacent teeth were selected and restored by dental students awarding the aims of the present study. After finishing restoration, proximal surfaces were completely dried by air and evaluated with dental chair light. In doubtful cases, surfaces were evaluated with × 3 magnification. Damages were classified into 2 groups; abrasion and groove. Data were analyzed using Fishers exact and Pearson chi square tests .   Results: The frequency of adjacent surfaces damage were 57.5%, with 31.1% damages as abrasion and 26.4% as groove. Students who used matrix band and wedge in proximal area as preventive instruments showed 53.4% damages and other students showed 57.3% damages (P>0.05. A significantly higher number of females and students at restorative course level (3 used wedge and matrix band than males and students at restorative course level (4 for protecting adjacent teeth (P<0.05.   Conclusion: According to the high percentage of iatrogenic damages on adjacent sound teeth in class II cavity preparation, teaching of preventive methods and using proper techniques is necessary for dental students as future dentists.

  8. Influence of different composite materials and cavity preparation designs on the fracture resistance of mesio-occluso-distal inlay restoration.

    Science.gov (United States)

    Tekçe, Neslihan; Pala, Kansad; Demirci, Mustafa; Tuncer, Safa

    2016-01-01

    The aim of the study to evaluate the fracture resistance of a computer-aided design/computer-aided manufacturing (CAD/CAM) and three indirect composite materials for three different mesio-occluso-distal (MOD) inlay cavity designs. A total of 120 mandibular third molar were divided into three groups: (G1) non-proximal box, (G2) 2-mm proximal box, and (G3) 4-mm proximal box. Each cavity design received four composite materials: Estenia, Epricord (Kuraray, Japan), Tescera (Bisco, USA), and Cerasmart CAD/CAM blocks (GC, USA). The specimens were subjected to a compressive load at a crosshead speed of 1 mm/min. The data was analyzed using the two-way analysis of variance and Bonferroni post hoc test (prestoration. PMID:27252011

  9. Influence of different composite materials and cavity preparation designs on the fracture resistance of mesio-occluso-distal inlay restoration.

    Science.gov (United States)

    Tekçe, Neslihan; Pala, Kansad; Demirci, Mustafa; Tuncer, Safa

    2016-01-01

    The aim of the study to evaluate the fracture resistance of a computer-aided design/computer-aided manufacturing (CAD/CAM) and three indirect composite materials for three different mesio-occluso-distal (MOD) inlay cavity designs. A total of 120 mandibular third molar were divided into three groups: (G1) non-proximal box, (G2) 2-mm proximal box, and (G3) 4-mm proximal box. Each cavity design received four composite materials: Estenia, Epricord (Kuraray, Japan), Tescera (Bisco, USA), and Cerasmart CAD/CAM blocks (GC, USA). The specimens were subjected to a compressive load at a crosshead speed of 1 mm/min. The data was analyzed using the two-way analysis of variance and Bonferroni post hoc test (p<0.05). Estenia exhibited significantly higher fracture strength than Epricord and Cerasmart in G1. In G2 and G3, there was no significant difference among the four materials. Using a non-proximal box design for the cavity can improve the fracture resistance of the inlay restoration.

  10. Association of Er:YAG and Nd:YAG irradiation for apicoectomy and retrofilling cavity preparation compared to conventional technique: a permeability study

    Science.gov (United States)

    Camargo, Selma C. C.; Gavini, Giulio; Eduardo, Carlos d. P.; Aun, Carlos E.; Ribeiro, Luciano W.; Coil, Jeffrey M.

    1999-05-01

    The aim of this research was to evaluate dentin permeability effects at the apical cut surface prepared with Er:YAG laser and irradiated with Nd:YAG laser compared to conventional techniques. 62 extracted human teeth were divided into four groups of 7 teeth each. For Group 1 apicoectomy was performed using high speed handpiece and diamond burs. Group 2 was prepared as group 1 and lased with Nd:YAG (1W,15Hz of energy before retrograde cavity filling). For group 3 Er:YAG* laser irradiation (wavelength of 2.94μm, pulse width of 250-500μs)was used in 400mJ of energy, frequency of 6Hz, on focus mode under distilled water refrigeration and group 4 was performed as group 3 and lased with Nd:YAG (1W, 15Hz of energy before retrograde cavity filling). Permeability was evaluated by the extent of methylene blue dye penetration into the tubules. There were statistically significant differences in permeability between groups. Nd:YAG laser irradiation significantly reduced apical dentin permeability when compared to unlased groups. Er:YAG laser by itself showed higher percentage of dye penetration.

  11. Frequency Tuning for a DQW Crab Cavity

    CERN Document Server

    Verdú-Andrés, Silvia; Ben-Zvi, Ilan; Calaga, Rama; Capatina, Ofelia; Leuxe, Raphael; Skaritka, John; Wu, Qiong; Xiao, Binping; Zanoni, Carlo

    2016-01-01

    The nominal operating frequency for the HL-LHC crab cavities is 400.79 MHz within a bandwidth of ±60kHz. Attaining the required cavity tune implies a good understanding of all the processes that influence the cavity frequency from the moment when the cavity parts are being fabricated until the cavity is installed and under operation. Different tuning options will be available for the DQW crab cavity of LHC. This paper details the different steps in the cavity fabrication and preparation that may introduce a shift in the cavity frequency and introduces the different tuning methods foreseen to bring the cavity frequency to meet the specifications.

  12. An immunocytochemical study of pulpal responses to cavity preparation by laser ablation in rat molars by using antibodies to heat shock protein (Hsp) 25 and class II MHC antigen.

    Science.gov (United States)

    Suzuki, Takeshi; Nomura, Shuichi; Maeda, Takeyasu; Ohshima, Hayato

    2004-03-01

    Initial responses of odontoblasts and immunocompetent cells to cavity preparation by laser ablation were investigated in rat molars. In untreated control teeth, intense heat shock protein (Hsp) 25 immunoreactivity was found in the cell bodies of odontoblasts, whereas cells immunopositive for the class II major histocompatibility complex (MHC) antigen were predominantly located beneath the odontoblast layer in the dental pulp. Cavity preparation caused the destruction of the odontoblast layer and the shift of most class-II-MHC-positive cells from the pulp-dentin border toward the pulp core at the affected site. Twelve hours after cavity preparation, numerous class-II-MHC-positive cells appeared along the pulp-dentin border and extended their processes deep into the exposed dentinal tubules, but subsequently disappeared from the pulp-dentin border together with Hsp-25-immunopositive cells by 24 h after the operation. By 3-5 days postoperation, distinct abscess formation consisting of polymorphonuclear leukocytes was found in the dental pulp. The penetration of masses of oral bacteria was recognizable in the dentinal tubules beneath the prepared cavity. These findings indicate that cavity preparation by laser ablation induces remarkable inflammation by continuous bacterial infections via dentinal tubules in this experimental model, thereby delaying pulpal regeneration.

  13. Changeability of Oral Cavity Environment

    OpenAIRE

    Surdacka, Anna; Strzyka³a, Krystyna; Rydzewska, Anna

    2007-01-01

    Objectives In dentistry, the results of in vivo studies on drugs, dental fillings or prostheses are routinely evaluated based on selected oral cavity environment parameters at specific time points. Such evaluation may be confounded by ongoing changes in the oral cavity environment induced by diet, drug use, stress and other factors. The study aimed to confirm oral cavity environment changeability. Methods 24 healthy individuals aged 20–30 had their oral cavity environment prepared by having p...

  14. Guided access cavity preparation using cone-beam computed tomography and optical surface scans - an ex vivo study

    DEFF Research Database (Denmark)

    Buchgreitz, J; Buchgreitz, M; Mortensen, D;

    2016-01-01

    AIM: To evaluate ex vivo, the accuracy of a preparation procedure planned for teeth with pulp canal obliteration (PCO) using a guide rail concept based on a cone-beam computed tomography (CBCT) scan merged with an optical surface scan. METHODOLOGY: A total of 48 teeth were mounted in acrylic bloc...

  15. Seamless/bonded niobium cavities

    Science.gov (United States)

    Singer, W.

    2006-07-01

    Technological aspects and performance of seamless cavities produced by hydroforming are presented. Problems related to the fabrication of seamless cavities from bulk niobium are mainly solved thanks to the progress of the last years. The highest achieved accelerating gradients are comparable for both seamless and welded versions (ca. 40 MV/m) Nevertheless further development of seamless cavities is desirable in order to avoid the careful preparation of parts for welding and get reliable statistic. Fabrication of NbCu clad cavities from bimetallic tubes is an interesting option that gives new opportunity to the seamless technique. On the one hand it allows reducing the niobium costs contribution; on the other hand it increases the thermal stability of the cavity. The highest accelerating gradient achieved on seamless NbCu clad single cell cavities (ca. 40 MV/m) is comparable to the one reached on bulk Nb cavities. Fabrication of multi-cell NbCu cavities by hydroforming was recently proven.

  16. PREPARATION OF MANY-ATOM ENTANGLED STATE VIA THE QUANTIZED CAVITY FIELD RESONANT INTERACTION WITH ATOM%利用原子-腔场共振相互作用制备多原子缠结态(英)

    Institute of Scientific and Technical Information of China (English)

    陈昌永

    2002-01-01

    A scheme for preparation of the many-atom entangled state via the resonant interaction of quantized cavity with atom is presented.It is injected an two-level atom initially prepared in the superposition of the ground state and excited state through the cavity prepared in the vacuum state.The atom passing through the cavity creates atom-field entanglement.The other two-level atoms prepared in the ground states are injected into the cavity at different angles,respectively.After the interaction with the cavity field,the many-atom entangled state is produced and the cavity field is still in the vacuum state.Comparing with the existing schemes,ours is easier to realize experimently.%提出了一个利用量子腔场与原子的共振相互作用制备多原子缠结态的方案.首先将一个初态制备在基态和激发态的叠加态的二能级原子注入一个真空态腔场中.原子通过腔时产生原子-场缠结.制备于基态的其它二能级原子分别以不同角度注入腔场,在与腔场相互作用时可制得多原子缠结态,而空腔仍然保持在真空态.与现存的方案比较,该方案在实验上更容易实现.

  17. Influence of the power level of an ultra-sonic system on dental cavity preparation Influência do nível de potência de um sistema de ultra-som em preparos cavitários

    OpenAIRE

    Érika Botelho Josgrilberg; Murilo de Sousa Guimarães; Cyneu Aguiar Pansani; Rita de Cássia Loiola Cordeiro

    2007-01-01

    The aim of this study was to evaluate the shape of dental cavities made with the CVDentus® system using different ultrasound power levels. One standard cavity was made on the buccal aspect of 15 bovine incisors with a CVDentus® cylindrical bur (82142). The sample was divided into three groups: G1 - ultrasound with power II; G2 - ultrasound with power III; and G3 - ultrasound with power IV. A standardizing device was used to obtain standardized preparations and ultrasound was applied during on...

  18. Effects of ultrasonic root-end cavity preparation with different surgical-tips and at different power-settings on glucose-leakage of root-end filling material

    Directory of Open Access Journals (Sweden)

    Betul Gunes

    2014-01-01

    Full Text Available Aim: The aim of this in vitro study was to evaluate the effects of different ultrasonic surgical-tips and power-settings on micro-leakage of root-end filling material. Materials and Methods: The root canals were instrumented using rotary-files and were filled with tapered gutta-percha and root canal sealer using a single-cone technique. The apical 3 mm of each root was resected and the roots were divided into six experimental groups; negative and positive control groups. Root-end cavities were prepared with diamond-coated, zirconum-nitride-coated and stainless-steel ultrasonic retro-tips at half-power and high-power settings. The time required to prepare the root-end cavities for each group was recorded. Root-end cavities were filled with Super-EBA. Leakage values of all samples evaluated with glucose penetration method on 7, 14, 21 and 28 th days. The results were statistically analyzed with Kruskal-Wallis and Hollander-Wolfe tests. Results: The mean time required to prepare retro cavities using diamond-coated surgical tip at high-power setting was significantly less than other groups (P 0.01. Diamond-coated surgical tip showed the least leakage at high-power setting at 3 rd and 4 th weeks (P < 0.01. Conclusions: Under the conditions of this study, cavity preparation time was the shortest and the leakage of the root-end filling was the least when diamond-coated retro-tip used at high-power setting.

  19. Superconducting cavity model for LEP

    CERN Multimedia

    1979-01-01

    A superconducting cavity model is being prepared for testing in a vertical cryostat.At the top of the assembly jig is H.Preis while A.Scharding adjusts some diagnostic equipment to the cavity. See also photo 7912501X.

  20. The AppIication Study of UItrasonic DentaI ScaIer on Cavity Preparation of Deciduous Teeth%超声洁牙机在乳牙窝洞预备上的实验研究

    Institute of Scientific and Technical Information of China (English)

    姚军; 苏盟盟; 谢莉; 叶晓昂; 卢兆杰

    2015-01-01

    目的:探讨超声洁牙机在乳牙窝洞预备上的应用。方法采用快速涡轮机、低速涡轮机以及超声洁牙机分别在离体乳牙上进行窝洞预备,然后在洞形处片切。电镜下观察、对比3种方法预备后洞壁牙面的粗糙程度以及在分体式测振仪上观察3种器械在备洞时的振动频率。结果电镜显示,快速涡轮机预备后的牙面较光滑,低速涡轮机预备后的牙面较粗糙,超声洁牙机介于上述两者之间;而在振动频率方面,超声洁牙机的平均振动频率介于快速涡轮机与低速涡轮机之间。结论超声洁牙机对乳牙的窝洞预备后牙面粗糙度适中,可保证充填材料与牙面接触的表面积和粘着强度,窝洞预备后的牙面不会影响充填材料的粘结固位。%Objective To evaluate the feasibility of ultrasonic dental scaler applied in cavity prepa-ration of deciduous teeth . Methods Rapid turbine ,slow speed turbine and ultrasonic scaler are used to prepare cavities in deciduous teeth respectively ,then cavities are cut into slices to observe the roughness of the surface of teeth after cavity preparation under electron microscope and to gauge vibration frequency in the frequency indicator . ResuIts Under electron microscope ,the surface of teeth prepared by the rapid turbine is smoother than that prepared by slow speed turbine ,w hile the surface of teeth prepared by ultra-sonic dental scaler is in between smoothness and roughness . The vibration frequency of ultrasonic dental scaler lies between those of two other instruments too . ConcIusions Ultrasonic dental scaler can be ap-plied in preparing caries cavity of deciduous teeth ,and the roughness of teeth surface prepared by it is moderate . Rougher surface can increase the contact area of filling material and tooth surface ,thus en-hance bonding strength .

  1. Influence of cavity preparation, light-curing units, and composite filling on intrapulpal temperature increase in an in vitro tooth model.

    Science.gov (United States)

    Choi, S H; Roulet, J F; Heintze, S D; Park, S H

    2014-01-01

    This study examined the effect of both the tooth substance and restorative filling materials on the increase in pulp chamber temperature when using light-curing units with different power densities. The tip of a temperature sensor was positioned on the pulpal dentinal wall of the buccal side of a maxillary premolar. Metal tubes were inserted in the palatal and buccal root of the tooth, one for water inflow and the other for water outflow. Polyethylene tubes were connected from the metal tubes to a pump to control the flow rate. For the unprepared tooth group (group 1), the tooth was light-cured from the buccal side using two light-curing units (three curing modes): the VIP Junior (QTH, BISCO, Schaumburg, IL, USA) and the Bluephase LED light-curing units (two modes: LEDlow and LEDhigh; Ivoclar Vivadent, Schaan, Liechtenstein). The power densities of each light-curing unit for the LEDlow, QTH, and LEDhigh modes were 785 mW/cm(2), 891 mW/cm(2), and 1447 mW/cm(2), respectively. All light-curing units were activated for 60 seconds. For the prepared tooth group (group 2), a Class V cavity, 4.0 mm in width by 4.0 mm in height by 1.8 mm in depth in size, was prepared on the buccal surface of the same tooth for the temperature measurement. The light-curing and temperature measurements were performed using the same methods used in group 1. The cavity prepared in group 2 was filled with a resin composite (Tetric N Ceram A3 shade, Ivoclar Vivadent) (group 3) or a flowable composite (Tetric N Flow with A3 shade, Ivoclar Vivadent) (group 4). The light-curing and temperature measurements were performed for these groups using the same methods used for the other groups. The highest intrapulpal temperature (TMAX) was measured, and a comparison was conducted between the groups using two-way analysis of variance with a post hoc Tukey test at the 95% confidence level. The TMAX values were as follows: 38.4°C (group 1), 39.0°C (group 2), 39.8°C (group 3), and 40.3°C (group 4) for the

  2. Cavity magnomechanics.

    Science.gov (United States)

    Zhang, Xufeng; Zou, Chang-Ling; Jiang, Liang; Tang, Hong X

    2016-03-01

    A dielectric body couples with electromagnetic fields through radiation pressure and electrostrictive forces, which mediate phonon-photon coupling in cavity optomechanics. In a magnetic medium, according to the Korteweg-Helmholtz formula, which describes the electromagnetic force density acting on a medium, magneostrictive forces should arise and lead to phonon-magnon interaction. We report such a coupled phonon-magnon system based on ferrimagnetic spheres, which we term as cavity magnomechanics, by analogy to cavity optomechanics. Coherent phonon-magnon interactions, including electromagnetically induced transparency and absorption, are demonstrated. Because of the strong hybridization of magnon and microwave photon modes and their high tunability, our platform exhibits new features including parametric amplification of magnons and phonons, triple-resonant photon-magnon-phonon coupling, and phonon lasing. Our work demonstrates the fundamental principle of cavity magnomechanics and its application as a new information transduction platform based on coherent coupling between photons, phonons, and magnons. PMID:27034983

  3. Dental cavities

    Science.gov (United States)

    ... leading to cavities. Treatment may involve: Fillings Crowns Root canals Dentists fill teeth by removing the decayed tooth ... gold, porcelain, or porcelain attached to metal. A root canal is recommended if the nerve in a tooth ...

  4. radiofrequency cavity

    CERN Multimedia

    1988-01-01

    The pulse of a particle accelerator. 128 of these radio frequency cavities were positioned around CERN's 27-kilometre LEP ring to accelerate electrons and positrons. The acceleration was produced by microwave electric oscillations at 352 MHz. The electrons and positrons were grouped into bunches, like beads on a string, and the copper sphere at the top stored the microwave energy between the passage of individual bunches. This made for valuable energy savings as it reduced the heat generated in the cavity.

  5. Effect of Er:YAG laser using for cavity preparation on the expression of substance P in dental pulp%Er:YAG激光备洞对牙髓P物质表达的影响

    Institute of Scientific and Technical Information of China (English)

    李涛; 杨冬茹; 董福生; 杨运田; 徐彦彬; 李春年

    2012-01-01

    Objective To study the biological effect on dental pulp tissue after cavity preparation with Er:YAG laser. Methods Sixty-six male SD rats were randomly divided into experimental group and control group. Cavities on each experimental rat's upper left first molar were prepared by high-speed drill and cavities on the upper right first molar were prepared by EnYAG laser. Molars of the rats in control group were without any treatment. The rats were killed in batches at the scheduled time. The specimen was stained by hematoxylin and eosin, and was observed for histopathologieal change of dental pulp. Expression of substance P (SP) was observed by immunohistochemical method. Results It look less time for the pathological change of the dental pulp and the change of expression of SP to restore to normal after cavity preparation with EnYAG laser than high-speed drill. Conclusion EnYAG laser for cavity preparation results in less stimulation to the dental pulp.%目的 探讨Er:YAG激光备洞对牙髓的生物学效应.方法 雄性SD大鼠66只随机分为实验组与对照组,实验组大鼠左上第一磨牙用高速牙钻备洞,右上第一磨牙用Er:YAG激光备洞,对照组大鼠磨牙不作任何处理.于不同时段分批处死大鼠,取标本做HE染色进行牙髓组织病理学观察,免疫组化法观察P物质(substance P,SP)的表达情况.结果 Er:YAG激光备洞后牙髓组织病理学改变及P物质的表达改变恢复正常要快于高速牙钻备洞.结论 Er:YAG激光备洞对牙髓的刺激小.

  6. Tooth structure and fracture strength of cavities

    DEFF Research Database (Denmark)

    Mondelli, José; Sene, Fábio; Ramos, Renata Pereira;

    2007-01-01

    This study evaluated, in vitro, the loss of tooth substance after cavity preparation for direct and indirect restorations and its relationship with fracture strength of the prepared teeth. Sixty sound human maxillary first premolars were assigned to 6 groups (n=10). MOD direct composite cavities......) or 1/2 (Groups III and VI) of the intercuspal distance. Teeth were weighed (digital balance accurate to 0.001 g) before and after preparation to record tooth substance mass lost during cavity preparation. The prepared teeth were submitted to occlusal loading to determine their fracture strength using...

  7. accelerating cavity

    CERN Multimedia

    On the inside of the cavitytThere is a layer of niobium. Operating at 4.2 degrees above absolute zero, the niobium is superconducting and carries an accelerating field of 6 million volts per metre with negligible losses. Each cavity has a surface of 6 m2. The niobium layer is only 1.2 microns thick, ten times thinner than a hair. Such a large area had never been coated to such a high accuracy. A speck of dust could ruin the performance of the whole cavity so the work had to be done in an extremely clean environment.

  8. Preparation ofβ-cyclodextrin cavity-based high oil absorbents%环糊精基高吸油树脂的制备

    Institute of Scientific and Technical Information of China (English)

    李倩; 杨项项; 朱靖; 徐龙宇; 何娟; 魏宏亮; 楚晖娟

    2015-01-01

    将单取代烯烃引入到β-环糊精(β-CD)外腔,使之成为空腔内外均具亲油性、且含有可聚合双键的活性大单体(β-CD-A);选取软单体丙烯酸十六酯(HDA)、硬单体苯乙烯与β-CD-A 配伍,经悬浮共聚制备出了含环糊精基三元共聚高吸油树脂—PCDHS.论文探讨了β-CD-A 用量、软硬单体配比、交联剂用量等对树脂吸油性能的影响,并确定了最佳工艺.结果表明,PCDHS 高吸油树脂对汽油、甲苯、氯仿和四氯化碳的吸油倍数分别达到25.6,37.2,45.3和54.6 g/g,保油率高达90%以上.%Introducing the mono substituted olefin to the external cavity,theβ-cyclodextrin derivative became a lipophilic active macromerβ-CD-A containing polymerizable bounds.Selection of soft monomer hexadecyl acry-late (HDA),and hard monomer styrene andβ-CD-A,the suspension copolymerization prepared copolymer high oil absorption resin PCDHS with cyclodextrin based three component copolymer.The impact ofβ-CD-A dosage, the ratio of soft/hard monomer,crosslinking agent on the properties of resins,and determine the best process. Were discussed in this paper.The results showed that the oil absorption ratio of PCDHS,the high oil absorbing resin on gasoline,toluene,chloroform and CCl4 were respectively 25.6,37.2,45.3 and 54.6 g/g,the oil reten-tion rate is as high as 90%.

  9. The effect of insertion and photopolymerization techniques on microleakage of Class V cavities: a quantitative evaluation Efeito de diferentes técnicas de inserção e fotopolimerização na microinfiltração de cavidades Classe V: avaliação quantitativa

    Directory of Open Access Journals (Sweden)

    Fabiana Mantovani Gomes França

    2005-03-01

    Full Text Available The aim of this in vitro study was to evaluate by spectrophotometry the influence of the incremental technique and progressive light curing in the microleakage of Class V cavities. Forty samples were prepared with class V cylindrical cavities on the buccal root surface of bovine incisive teeth and filled with composite resin (Z250. The samples were divided into four groups: I: cavity was bulk filled and the composite was light cured for 40 seconds; Group II: cavity was bulk filled and a "soft-start" polymerization was used; Group III: cavity was filled with the incremental technique in two coats and light cured for 40 seconds; Group IV: cavity was filled with the incremental technique in two coats and light cured with "soft-start" polymerization. After the restoration, the specimens were thermally stressed for 3,000 cycles in bath at 5 ± 2°C and 55 ± 2°C, protected with nail enamel, colored with 2% methylene blue and cut into sections. These sections were triturated and the dye was recovered with PA ethanol and the supernatant was evaluated. The data were submitted to ANOVA and the results showed the following averages: bulk filled and conventional photopolymerization (I 0.06075 µg/ml; bulk filled and progressive photopolymerization (II 0.04030 µg/ml; incremental insertion and conventional photopolymerization (III 0.04648 µg/ml; incremental insertion and progressive photopolymerization (IV 0.04339 µg/ml. No significant statistic differences were observed among the mean values. The Degulux "soft-start" equipment probably emits too high initial light intensity to promote progressive photopolymerization.O objetivo deste estudo in vitro foi avaliar através de espectrofotometria a influência das técnicas de inserção incremental e de fotopolimerização progressiva na microinfiltração de cavidades Classe V. Foram preparadas 40 cavidades cilíndricas na superfície radicular vestibular de incisivos bovinos e preenchidas com resina

  10. 窝洞预备技能评价系统在牙体牙髓病学实验教学中的应用%Application of cavity preparation skill evaluation system in undergraduate endodontic teaching

    Institute of Scientific and Technical Information of China (English)

    邹慧儒; 靳淑凤; 孙建萍; 王雅楠; 林欣; 戴艳梅

    2014-01-01

    Objective To evaluate the effects of a cavity preparation skill evaluation system (CPSES) in undergraduate endodontic teaching. Methods CPSES, a system software which scans, evaluates, and scores the form of prepared cavities, was used in 2010 grade undergraduates in Dental School of Nankai University. The average scores of 2010 grade undergraduates were calculated and compared with the ones from 2009 grade students. A questionnaire survey was designed and conducted in 2010 grade undergraduate students. Results CPSES system can consistently and reliably compare the student's tooth preparation result with the (faculty-determined) standardized preparation. Most of students felt that the CPSES system help them to understand the basic knowledge and practice skills of cavity preparation. This system provides objective evaluation results and accurate assessment of student work and accurate feedback, which can help students learn and develop cavity preparation skills more efficiently and in a shorter period of time. Conclusion Application of cavity preparation skill evaluation system in undergraduate endodontic teaching can helps students to understand cavity preparation skills and enhance the quality of undergraduate education.%目的:研究窝洞预备技能评价系统(CPSES)用于牙体牙髓病学窝洞预备实验教学的教学效果。方法针对2009级口腔本科学生,在牙体牙髓病学窝洞预备实验教学中采用传统授课及教师目测方法评估学生预备窝洞技能,针对2010级口腔本科学生应用CPSES系统软件评估。统计2010级口腔本科学生窝洞预备实验课理论与操作考核成绩,与2009级口腔本科学生的窝洞预备实验课理论与操作考核成绩进行比较,并对2010级学生进行问卷调查,以评价该系统应用效果。结果窝洞预备实验课考核成绩分析显示,2010级学生窝洞预备知识点掌握情况较好,问卷调查结果可见学生对窝洞预备技能评价系统的应

  11. Er:YAG激光备洞对牙髓降钙素基因相关肽表达的影响%Effect of Er:YAG laser using for cavity preparation on the expression of CGRP in dental pulp

    Institute of Scientific and Technical Information of China (English)

    李涛; 杨冬茹; 董福生; 马哲; 徐彦彬; 刘莉

    2012-01-01

    目的 探讨Er:YAG激光备洞对牙髓的生物学效应.方法 雄性SD大鼠66只随机分为实验组与对照组,实验组大鼠左上第一磨牙用高速牙钻备洞,右上第一磨牙用Er:YAG激光备洞,对照组大鼠磨牙不作任何处理.于不同时段分批处死大鼠,取标本做HE染色进行牙髓组织病理学观察,免疫组化染色法观察牙髓内降钙素基因相关肽(calcitonin cene-related peptide,CGRP)的表达.结果 Er:YAG激光备洞后牙髓组织病理学改变及降钙素基因相关肽的表达改变恢复正常要快于高速牙钻备洞.结论 Er:YAG激光备洞对牙髓的刺激小.%Objective To explore the biological effect of EnYAG laser using for cavity preparation. Methods Sixty-six SD male rats were randomly divided into experimental group and control group. Cavities on each experimental rat's upper left first molar were prepared by high-speed drill and cavities on the upper right first molar were prepared by EnYAG laser. Rats in control group were without any treatment. The animals were sacrificed at the scheduled time. Pathological changes in the dental pulp were observed by HE staining and the expression of CGRP were assayed by immunohistochemistry. Results Compared with those in high-speed drill group, it took less time to restore to normal for the expression of CGRP and the pathological appearance in the dental pulp in EnYAG laser group. Conclusion EnYAG laser for cavity preparation results in less stimulation to the dental pulp.

  12. Research on 3D Model Reconstruction for Cavity Preparation Based on Laser Triangulation%义齿窝洞预备体三维重构关键技术研究

    Institute of Scientific and Technical Information of China (English)

    刘宝龙; 孙萍; 陈桦; 王秀斋

    2016-01-01

    Digtal evaluation of cavity preparation is still a gap in China.The products of this class are still monopolized by forerign companies.The 3D model reconstruction for cavity preparation based on laser triangulation took the dental cavity preparation as the object.The original data of dental surface were obtained by non?contact 3D scanning.The corresponding points in ICP algorithm were selected by using K?D tree searching policy,and the results were divided into four sections with each radial direction kept.The 3D model reconstruction was completed through denoising,triangular meshes techniques.The testing results show that the proposed method can present the 3D model of cavity preparation.Compared with other techniqnes abroad,the new method improves the efficiency of the system.%义齿窝洞预备体的数字化评估目前在我国还是空白,该类产品主要由国外垄断。基于激光三角测量法的义齿窝洞预备体三维重构技术以制备的窝洞预备体为测量对象,利用非接触式三角测量技术获取预备体表面形态的数据信息,采用 K?D(K?Dimension,K?D)树搜索策略实现 ICP(Iterative Closest Point,ICP)算法中对应点的选取,将 ICP 拼接后的数据分为四个块,保留每个相机径向上的部分,在此基础上通过去噪、消差、三角面法等技术实现被测预备体的三维重构。结果表明,本分提出的解决方案能够客观的呈现窝洞预备体的三维形貌。与国外同类技术比较,在保证三维点集配准精确度的情况下,有效提高了系统的整体运算速度。

  13. [Marginal leakage in composite resin restorations in posterior teeth. Effect of material, cavity preparation and enamel conditioning at the cervical level].

    Science.gov (United States)

    Marotta Araujo, R; da Silva Filho, F P; Dias Mendes, A J

    1990-01-01

    The purpose of this "in vitro" study was to investigate the cervical marginal leakage in class II restorations with chemically cured resin (P10) and light-cured resin (P30) in two types of cavities: conventional and adhesive. The effect of acid-etching in this area was also observed. Dentine adhesive Scotchbond was used in all experimental groups. Leakage was evidenced by Rodamina B dye penetration after thermocycling procedure between 10 degrees C and 50 degrees C temperature and analysed by using Zeiss Stereoscopic Magnifying Glass (10 X). According to the results obtained marginal leakage occurred in all experimental groups, with lower percentage for adhesives cavities when enamel acid-etching and light-cured resin P30 was used.

  14. 21 CFR 872.3250 - Calcium hydroxide cavity liner.

    Science.gov (United States)

    2010-04-01

    ... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3250 Calcium hydroxide cavity liner. (a... prepared cavity before insertion of restorative material, such as amalgam, to protect the pulp of a...

  15. Teleportation of Atomic States via Cavity Quantum Electrodynamics

    CERN Document Server

    Guerra, E S

    2004-01-01

    In this article we discuss a scheme of teleportation of atomic states. The experimental realization proposed makes use of cavity Quatum Electrodynamics involving the interaction of Rydberg atoms with a micromaser cavity prepared in a coherent state. We start presenting a scheme to prepare atomic Bell states via the interaction of atoms with a cavity. In our scheme the cavity and some atoms play the role of auxiliary systems used to achieve the teleportation.

  16. CHECHIA cavity driving with FPGA controller

    Energy Technology Data Exchange (ETDEWEB)

    Czarski, T.; Koprek, W.; Pozniak, K.T.; Romaniuk, R.S. [Technical Univ. Warsaw (Poland). ELHEP Laboratory, ISE; Simrock, S. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). TESLA

    2005-07-01

    The initial control of the superconductive cavity has recently been performed by applying the FPGA (Field Programmable Gate Array) technology system in DESY Hamburg. This first experiment turned attention to the general recognition of the cavity features and projected control methods. The electrical model of the cavity is taken as a consideration origin. The calibration of the signal channel is considered as a key preparation for an efficient cavity driving. The cavity parameters identification is confirmed as a proper approach for the required performance: driving on resonance during filling and field stabilization during flattop time with reasonable power consumption. The feed-forward and feedback modes were applied successfully for the CHECHIA cavity driving. Representative results of experiments are presented for different levels of the cavity field gradient. (orig.)

  17. Cavity magnomechanics

    Science.gov (United States)

    Zou, Chang-Ling; Zhang, Xufeng; Jiang, Liang; Tang, Hong

    2016-05-01

    Recently, cavity magnonics has attracted much attention for potential applications of coherent information transduction and hybrid quantum devices. The magnon is a collective spin wave excitation in ferromagnetic material. It is magnetically tunability, with long coherence time and non-reciprocical interaction with electro-magnetic fields. We report the coherent coupling between magnon, microwave photon and phonon. First, we demonstrate strong coupling and ultrastrong coupling between the magnon in YIG sphere and microwave photon in three-dimensional cavity. Then, based on the hybridized magnon-photon modes, we observe the triply resonant magnon-mcirowave photon-phonon coupling, where the ultrahigh-Q mechanical vibration of YIG sphere is dispersively coupled with the magnon via magnetostrictive interaction. We observe interesting phenomena, including electromagnetically induced transparency/absorption and parametric amplification. In particular, benefit from the large tunability of the magnon, we demonstrate a tunable microwave amplifier with gain as high as 30 dB. The single crystal YIG also has excellent optical properties, and thus provide a unique platform bridging MHz, GHz and THz information carriers. Finally, we present the latest progress towards coherent magnon to optical photon conversion.

  18. O efeito facilitatório do óxido nítrico sobre a transmissão neuromuscular de preparações nervo frênico- diafragma isolado de ratos é Ca++ dependente - DOI: 10.4025/actascibiolsci.v26i4.1528 NO- induced neuromuscular facilitation in the phrenic nerve diaphragm preparation of rats is Ca++ dependent - DOI: 10.4025/actascibiolsci.v26i4.1528

    Directory of Open Access Journals (Sweden)

    Heraldo Esheveria Borges

    2004-04-01

    Full Text Available A pesquisa foi conduzida para verificar se os efeitos neuromusculares induzidos por óxido nítrico (NO poderiam depender dos níveis extracelulares de Ca++. O doador de NO, nitroprussiato de sódio (NPS, e o análogo de GMPc, 8-Br-cGMP, aumentaram a amplitude das contrações musculares (ACM em preparações indiretamente estimuladas a 0.2 Hz, mas não produziram efeitos quando a solução nutriente (Krebs normal foi trocada por Krebs com baixo Ca++/ alto Mg++. NPS e 8-Br-cGMP reduziram a ACM quando as preparações foram diretamente estimuladas, mas tal efeito não foi observado com o uso de Krebs com baixo Ca++/ alto Mg++. Dados sugerem que os efeitos neuromusculares induzidos por NO dependem dos níveis extracelulares de Ca++The research was carried out to verify whether the neuromuscular effects induced by nitric oxide (NO might depend on extracellular level of Ca++. The donor of NO, sodium nitroprusside (SNP, and the analogue of cGMP, 8-Br-cGMP, increased the muscular contraction amplitude (MCA in preparations indirectly stimulated at 0.2 Hz, but did not produce any effect when the nutrient solution was exchanged by Krebs buffer low Ca++/ high Mg++. SNP and 8-Br-cGMP reduced the MCA in preparations directly stimulated. Such effect was not recorded in Krebs buffer low Ca++/ high Mg++. Data suggest that the neuromuscular effects induced by NO or cGMP depend on extracellular level of Ca++

  19. Agent for roentgenocontrast examination of cavities

    International Nuclear Information System (INIS)

    The water-soluble agent, additionaly containing starch, agar, water, is suggested to increase accuracy of injured cavity diagnostics. The method for roentgenocontrast agent preparation on the base of starch-agar gel is described. Advantages of the agent suggested in comparison with those of roentgenologic cavity investigation used are shown

  20. Generation of Cluster States in Cavity QED

    Institute of Scientific and Technical Information of China (English)

    ZHOU Yan-Li; YANG Li-Jia; DAI Hong-Yi

    2007-01-01

    We propose two schemes for the generation of cluster states in the context of cavity quantum electrodynamics (QED).In the first scheme,we prepare multi-cavity cluster states with information encoded in the coherent states.The second scheme is to generate multi-atom cluster states,where qubits are represented by the states of cascade Rydberg atoms.Both the schemes are based on the atom-cavity interaction and the atomic spontaneous radiation can be effciently reduced since the cavity frequency is largely detuned from the atomic transition frequency.

  1. Cavity magnomechanics

    Science.gov (United States)

    Zhang, Xufeng; Zou, Changling; Jiang, Liang; Tang, Hong X.

    Mechanical oscillators have been recently widely utilized to couple with optical and microwave photons in a variety of hybrid quantum systems, but they all lack the tunability. The magnetostrictive force provides an alternative mechanism to allow phonon to couple with a different type of information carrier-magnon, the collective excitation of magnetization whose frequency can be tuned by a bias magnetic field. Here, we demonstrate an intriguing hybrid system that consists of a magnonic, a mechanical, and a microwave resonator. The magnon-phonon interaction results in hallmark coherent phenomena such as magnomechanically induced transparency/absorption and magnomechanical parametric amplification. The magnetic field dependence of magnon provides our system with unprecedented tunability. Moreover, the great flexibility of our system allows us to achieve triple resonance among magnon, phonon and photon, which drastically enhances the magnomechanical interaction. Our work demonstrates the fundamental principle of cavity magnetomechanics, opening up great opportunities in various applications, such as tunable microwave filter and amplifier, long-lifetime quantum memories, microwave-to-optics conversion.

  2. Evaluation of tooth preparations for Class II cavities using magnification loupes among dental interns and final year BDS students in preclinical laboratory

    Directory of Open Access Journals (Sweden)

    Khyati Narula

    2015-01-01

    Conclusions: Magnifying loupes help the dental students to have better vision, thus improved dexterity with hands while preparing the tooth for restoration. However, dental students have to get adapted to the loupes for the ease of using loupes. Using loupes frequently may help them to get adapted to the loupes.

  3. Influence of the power level of an ultra-sonic system on dental cavity preparation Influência do nível de potência de um sistema de ultra-som em preparos cavitários

    Directory of Open Access Journals (Sweden)

    Érika Botelho Josgrilberg

    2007-12-01

    Full Text Available The aim of this study was to evaluate the shape of dental cavities made with the CVDentus® system using different ultrasound power levels. One standard cavity was made on the buccal aspect of 15 bovine incisors with a CVDentus® cylindrical bur (82142. The sample was divided into three groups: G1 - ultrasound with power II; G2 - ultrasound with power III; and G3 - ultrasound with power IV. A standardizing device was used to obtain standardized preparations and ultrasound was applied during one minute in each dental preparation. The cavities were sectioned in the middle, allowing observation of the cavity’s profile with a magnifying glass, and width and depth measurement using the Leica Qwin program. The Kruskal-Wallis (p O objetivo deste estudo foi avaliar o formato dos preparos cavitários realizados com o sistema CVDentus® utilizando potências variadas do ultra-som. Uma cavidade padronizada foi realizada na face vestibular de 15 incisivos bovinos utilizando as pontas cilíndricas CVDentus® (82142. A amostra foi dividida em 3 grupos: G1 - ultra-som com potência II; G2 - ultra-som com potência III; e G3 - ultra-som com potência IV. Foi utilizada uma máquina padronizadora de preparos cavitários e o ultra-som foi aplicado durante 1 minuto em cada preparo. As cavidades foram seccionadas no centro, permitindo a visualização do perfil cavitário em uma lupa estereoscópica, e esse foi medido em largura e profundidade por meio do programa Leica Qwin. O teste estatístico Kruskal-Wallis (p < 0,05 e o método de Dunn demonstraram diferenças entre os formatos das cavidades produzidas com as potências III e IV. Entretanto, as cavidades realizadas com a potência III apresentaram dimensões semelhantes às da ponta utilizada. Concluiu-se que a potência indicada pelo fabricante (III é a mais adequada para uso do sistema CVDentus®.

  4. Observation of dressed intra-cavity dark states

    OpenAIRE

    Wang, Yanhua; Zhang, Jiepeng; Zhu, Yifu

    2011-01-01

    Cavity electromagnetically induced transparency in a coherently prepared cavity-atom system is manifested as a narrow transmission peak of a weak probe laser coupled into the cavity mode. We show that with a resonant pump laser coupling the cavity-confined four-level atoms from free space, the narrow transmission peak of the cavity EIT is split into two peaks. The two peaks represent the dressed intra-cavity dark states and have a frequency separation approximately equal to the Rabi frequency...

  5. 1.3 GHz superconducting RF cavity program at Fermilab

    Energy Technology Data Exchange (ETDEWEB)

    Ginsburg, C.M.; Arkan, T.; Barbanotti, S.; Carter, H.; Champion, M.; Cooley, L.; Cooper, C.; Foley, M.; Ge, M.; Grimm, C.; Harms, E.; /Fermilab

    2011-03-01

    At Fermilab, 9-cell 1.3 GHz superconducting RF (SRF) cavities are prepared, qualified, and assembled into cryomodules (CMs) for Project X, an International Linear Collider (ILC), or other future projects. The 1.3 GHz SRF cavity program includes targeted R&D on 1-cell 1.3 GHz cavities for cavity performance improvement. Production cavity qualification includes cavity inspection, surface processing, clean assembly, and one or more cryogenic low-power CW qualification tests which typically include performance diagnostics. Qualified cavities are welded into helium vessels and are cryogenically tested with pulsed high-power. Well performing cavities are assembled into cryomodules for pulsed high-power testing in a cryomodule test facility, and possible installation into a beamline. The overall goals of the 1.3 GHz SRF cavity program, supporting facilities, and accomplishments are described.

  6. 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

  7. Crab Cavity Development

    CERN Document Server

    Calaga, R; Burt, G; Ratti, A

    2015-01-01

    The HL-LHC upgrade will use deflecting (or crab) cavities to compensate for geometric luminosity loss at low β* and non-zero crossing angle. A local scheme with crab cavity pairs across the IPs is used employing compact crab cavities at 400 MHz. Design of the cavities, the cryomodules and the RF system is well advanced. The LHC crab cavities will be validated initially with proton beam in the SPS.

  8. TESLA cavity driving with FPGA controller

    Science.gov (United States)

    Czarski, Tomasz; Pozniak, Krzysztof; Romaniuk, Ryszard; Simrock, Stefan

    2005-09-01

    The digital control of the TESLA (TeV-Energy Superconducting Linear Accelerator) resonator is presented. The laboratory setup of the CHECHIA cavity in DESY-Hamburg has been driven by the FPGA (Field Programmable Gate Array) technology system. This experiment focused attention to the general recognition of the cavity features and projected control methods. The electrical model of the resonator is taken as a consideration origin. The calibration of the signal channel is considered as a key preparation for an efficient cavity driving. The identification of the resonator parameters is confirmed as a proper approach for the required performance: driving on resonance during filling and field stabilization during flattop time with reasonable power consumption. The feed-forward and feedback modes were applied successfully for the CHECHIA cavity driving. Representative results of experiments are presented for different levels of the cavity field gradient.

  9. Niobium Cavity Electropolishing Modelling and Optimisation

    CERN Document Server

    Ferreira, L M A; Forel, S; Shirra, J A

    2013-01-01

    It’s widely accepted that electropolishing (EP) is the most suitable surface finishing process to achieve high performance bulk Nb accelerating cavities. At CERN and in preparation for the processing of the 704 MHz high-beta Superconducting Proton Linac (SPL) cavities a new vertical electropolishing facility has been assembled and a study is on-going for the modelling of electropolishing on cavities with COMSOL® software. In a first phase, the electrochemical parameters were taken into account for a fixed process temperature and flow rate, and are presented in this poster as well as the results obtained on a real SPL single cell cavity. The procedure to acquire the data used as input for the simulation is presented. The modelling procedure adopted to optimise the cathode geometry, aimed at a uniform current density distribution in the cavity cell for the minimum working potential and total current is explained. Some preliminary results on fluid dynamics is also briefly described.

  10. Scanning electron microscopy evaluation of the interaction pattern between dentin and resin after cavity preparation using Er:YAG laser; Avaliacao, atraves de microscopia eletronica de varredura, do padrao de interacao dentina-resina em cavidades preparadas com laser de Er:YAG

    Energy Technology Data Exchange (ETDEWEB)

    Schein, Marcelo Thome

    2001-07-01

    The aim of this study was to describe the interaction pattern formed between dentin and resin on cavities prepared with an erbium laser (Er:YAG). The morphological aspect of the irradiated dentin after acid etching was also observed. Ten dentin disks were obtained from fresh extracted third molars. Each disk received two cavities, one prepared with a conventional high-speed drill, while the other cavity was obtained by the use of an Er:YAG laser (KaVo KEY Laser, KaVo Co.). The laser treatment was performed with 250 mJ/pulse, 4 Hz, non contact mode, focused beam, and a fine water mist was used. Five disks were prepared for morphological analysis of the acid etched dentin. The other five disks had their cavities restored with Single Bond (3M) followed by Z100 resin (3M). The specimens were observed under scanning electron microscopy after dentin-resin interface demineralization and deproteinization. It was observed that the morphological characteristics of the acid-etched irradiated dentin were not favorable to the diffusion of monomers through the collagen network. The dentin resin interfacial aspect of irradiated dentin, after acid etching, showed thin tags and scarce hybridization zones, which agreed with the morphology of the irradiated and acid-etched dentin substrate observed. (author)

  11. RF Cavity Design

    CERN Document Server

    Jensen, E

    2014-01-01

    After a short overview of a general approach to cavity design, we sketch the derivation of waveguide modes from plane waves and of cavity fields from waveguide modes. The characteristic parameters describing cavities and their performance are defined and explained. An equivalent circuit is introduced and extended to explain beam loading and higher order modes. Finally travelling- and standing-wave multi-gap cavities are introduced using the Brillouin diagram.

  12. Dawn of Cavity Spintronics

    OpenAIRE

    Hu, Can-Ming

    2015-01-01

    Merging the progress of spintronics with the advancement in cavity quantum electrodynamics and cavity polaritons, a new field of Cavity Spintronics is forming, which connects some of the most exciting modern physics, such as quantum information and quantum optics, with one of the oldest science on the earth, the magnetism.

  13. Scheme for Generation of Entanglement among Bimodal Cavities

    Institute of Scientific and Technical Information of China (English)

    SONG Xin-Guo; FENG Xun-Li

    2004-01-01

    @@ We present a scheme for generation of an entangled state in many spatially separated bimodal cavity modes via cavity quantum electrodynamics. A V-type three-level atom, initially prepared in a coherent superposition of its excited states, successively passes through both the bimodal cavities. If the atom is measured in its ground state after leaving the last cavity, an entangled state of many cavity modes can be generated. The conditions to generate the maximally entangled state with unity probability are worked out.

  14. Preparação e caracterização de membranas assimétricas de poli (fluoreto de vinilideno suportadas em poliéster - I: efeito do tratamento térmico nas propriedades das membranas Preparation and characterization of asymmetric membranes of poly (vinylidene fluoride supported in polyester - I: effect of heat treatment in the properties of membranes

    Directory of Open Access Journals (Sweden)

    Mônica B. Thürmer

    2010-09-01

    Full Text Available O poli(fluoreto de vinilideno (PVDF é um polímero semicristalino contendo uma fase amorfa e uma cristalina. Essa característica é importante para o preparo de membranas assimétricas, pois a fase cristalina tem grande influência na formação da estrutura da membrana e a fase amorfa na porosidade. Membranas de PVDF foram preparadas pelo processo de inversão de fases e avaliadas quanto à permeabilidade e morfologia, bem como o efeito do tratamento térmico. Foram comparadas as seguintes membranas: membrana sem tratamento térmico, membrana com tratamento térmico e membrana comercial. Ensaios de resistência química, fluxo permeado de água a várias pressões, difusão de íons, Microscopia Eletrônica de Varredura (MEV, Calorimetria Exploratória Diferencial (DSC e Análise Termogravimétrica (TGA foram realizados para verificar o comportamento das membranas.Poly(Vinylidene Fluoride (PVDF is a semicrystalline polymer containing an amorphous and a crystalline phase. This characteristic is important for the preparation of asymmetric membranes, because the crystalline phase has great influence on the membranes structure, while the amorphous phase affects the porosity. PVDF membranes were prepared by the phase inversion process, which were then evaluated with regard to permeability and morphology, as well as the thermal treatment effect. The following membranes were compared: without thermal treatment, with thermal treatment and commercially-available membrane. The analysis of chemical resistance, water permeability flux to different pressures and diffusion of ions, in addition to studies with Scanning Electron Microscopy (SEM, Differential Scanning Calorimetry (DSC and Thermogravimetric Analysis (TGA, were performed to investigate the membranes properties.

  15. Efeito das condições de preparação na condutividade elétrica de blendas de poli(fluoreto de vinilideno e poli(o-metoxianilina Effect of preparation conditions on the electrical conductivity of blends of poly (vinylidene fluoride and poly(o-methoxyaniline

    Directory of Open Access Journals (Sweden)

    Luiz Francisco Malmonge

    1998-01-01

    Full Text Available Neste trabalho estudou-se o efeito das condições de preparação na condutividade elétrica de blendas condutoras de poli(fluoreto de vinilideno (PVDF com poli(o-metoxianilina (POMA. A condutividade elétrica e a qualidade dos filmes produzidos dependem significativamente do solvente, dopante e das condições de preparação das blendas. Filmes flexíveis e auto-sustentáveis da blenda PVDF/POMA dopada com o ácido p-tolueno sulfônico (TSA foram obtidos em condições otimizadas. Estes apresentam condutividade elétrica em uma larga faixa (10-12 - 10-2 S/cm, onde para baixos teores de POMA-TSA (In this work, the effect of preparation conditions on the properties of conductive blends of poly (vinylidene fluoride (PVDF and poly(o-methoxyaniline (POMA was studied. The quality and conductivity of the films produced depend significantly on the solvent, dopant and preparation conditions of the blends. Flexible, free-standing films of PVDF/POMA blends doped with p-toluene sulfonic acid (TSA were obtained in optimized conditions. These blends can exhibit electrical conductivity in a wide range (10-12 - 10-2 S/cm. Furthermore, relatively high conductivity values (10-7 S/cm are reached starting from low contents of POMA-TSA (<2,0% weight without definition of a percolation threshold.

  16. Improved surface treatment of the superconducting TESLA cavities

    Energy Technology Data Exchange (ETDEWEB)

    Lilje, L. E-mail: lutz.lilje@desy.de; Antoine, C.; Benvenuti, C.; Bloess, D.; Charrier, J.-P.; Chiaveri, E.; Ferreira, L.; Losito, R.; Matheisen, A.; Preis, H.; Proch, D.; Reschke, D.; Safa, H.; Schmueser, P.; Trines, D.; Visentin, B.; Wenninger, H

    2004-01-11

    The proposed linear electron-positron collider TESLA is based on 1.3 GHz superconducting niobium cavities for particle acceleration. For a centre-of-mass energy of 500 GeV, an accelerating field of 23.4 MV/m is required which is reliably achieved with a niobium surface preparation by chemical etching. An upgrade of the collider to 800 GeV requires an improved cavity preparation technique. In this paper, results are presented on single-cell cavities which demonstrate that fields of up to 40 MV/m are accessible by electrolytic polishing of the inner surface of the cavity.

  17. Improved surface treatment of the superconducting TESLA cavities

    Science.gov (United States)

    Lilje, L.; Antoine, C.; Benvenuti, C.; Bloess, D.; Charrier, J.-P.; Chiaveri, E.; Ferreira, L.; Losito, R.; Matheisen, A.; Preis, H.; Proch, D.; Reschke, D.; Safa, H.; Schmüser, P.; Trines, D.; Visentin, B.; Wenninger, H.

    2004-01-01

    The proposed linear electron-positron collider TESLA is based on 1.3 GHz superconducting niobium cavities for particle acceleration. For a centre-of-mass energy of 500 GeV, an accelerating field of 23.4 MV/m is required which is reliably achieved with a niobium surface preparation by chemical etching. An upgrade of the collider to 800 GeV requires an improved cavity preparation technique. In this paper, results are presented on single-cell cavities which demonstrate that fields of up to 40 MV/m are accessible by electrolytic polishing of the inner surface of the cavity.

  18. Improved surface treatment of the superconducting TESLA cavities

    Energy Technology Data Exchange (ETDEWEB)

    Lilje, L.; Matheisen, A.; Proch, D.; Reschke, D.; Trines, D.; Antoine, C.; Charrier, J.P.; Safa, H.; Visentin, B. [CEA Saclay, DAPHNIA, Gif-sur-Yvette (France); Benvenuti, C.; Bloess, D.; Chiaveri, E.; Ferreira, L.; Losito, R.; Preis, H.; Wenninger, H. [CERN, Geneva (Switzerland); Schmueser, P. [Hamburg Univ. (Germany)

    2004-01-01

    The proposed linear electron-positron collider TESLA is based on 1.3 GHz superconducting niobium cavities for particle acceleration. For a center-of-mass energy of 500 GeV an accelerating field of 23.4 MV/m is required which is reliably achieved with a niobium surface preparation by chemical etching. An upgrade of the collider to 800 GeV requires an improved cavity preparation technique. In this paper results are presented on single-cell cavities which demonstrate that fields of up to 40 MV/m are accessible by electrolytic polishing of the inner surface of the cavity. (orig.)

  19. Beam cavity interaction

    CERN Document Server

    Gamp, A

    2011-01-01

    We begin by giving a description of the rf generator-cavity-beam coupled system in terms of basic quantities. Taking beam loading and cavity detuning into account, expressions for the cavity impedance as seen by the generator and as seen by the beam are derived. Subsequently methods of beam-loading compensation by cavity detuning, rf feedback, and feed-forward are described. Examples of digital rf phase and amplitude control for the special case of superconducting cavities are also given. Finally, a dedicated phase loop for damping synchrotron oscillations is discussed.

  20. Supersonic flows over cavities

    Institute of Scientific and Technical Information of China (English)

    Tianwen FANG; Meng DING; Jin ZHOU

    2008-01-01

    The characteristics of supersonic cold flows over cavities were investigated experimentally and numer-ically, and the effects of cavities of different sizes on super-sonic flow field were analyzed. The results indicate that the ratio of length to depth L/D within the range of 5-9 has little relevance to integral structures of cavity flow. The bevel angle of the rear wall does not alter the overall structure of the cavity flow within the range of 30°-60°, but it can exert obvious effect on the evolvement of shear layer and vortexes in cavities.

  1. Cavity turnover and equilibrium cavity densities in a cottonwood bottomland

    Science.gov (United States)

    Sedgwick, James A.; Knopf, Fritz L.

    1992-01-01

    A fundamental factor regulating the numbers of secondary cavity nesting (SCN) birds is the number of extant cavities available for nesting. The number of available cavities may be thought of as being in an approximate equilibrium maintained by a very rough balance between recruitment and loss of cavities. Based on estimates of cavity recruitment and loss, we ascertained equilibrium cavity densities in a mature plains cottonwood (Populus sargentii) bottomland along the South Platte River in northeastern Colorado. Annual cavity recruitment, derived from density estimates of primary cavity nesting (PCN) birds and cavity excavation rates, was estimated to be 71-86 new cavities excavated/100 ha. Of 180 active cavities of 11 species of cavity-nesting birds found in 1985 and 1986, 83 were no longer usable by 1990, giving an average instantaneous rate of cavity loss of r = -0.230. From these values of cavity recruitment and cavity loss, equilibrium cavity density along the South Platte is 238-289 cavities/100 ha. This range of equilibrium cavity density is only slightly above the minimum of 205 cavities/100 ha required by SCN's and suggests that cavity availability may be limiting SCN densities along the South Platte River. We submit that snag management alone does not adequately address SCN habitat needs, and that cavity management, expressed in terms of cavity turnover and cavity densities, may be more useful.

  2. Methyl biodiesel from Dipteryx lacunifera: preparation, characterization and effect of antioxidant on the oxidation stability; Biodiesel metilico de Dipteryx lacunifera: preparacao, caracterizacao e efeito de antioxidantes na estabilidade a oxidacao

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Francisca Diana da Silva; Moura, Carla Veronica Rodarte de; Chaves, Mariana H., E-mail: mariana@ufpi.edu.b [Universidade Federal do Piaui (UFPI), Teresina, PI (Brazil). Dept. de Quimica

    2010-07-01

    The objective of this work was to study the potentialities of Dipteryx lacunifera Ducke seeds oil for biodiesel production. The yield in oil was of 46.11 {+-} 0.37%. Methyl biodiesel was prepared by base catalyzed transesterification yielding 88.13% and percentage conversion of triglycerides to corresponding methyl ester of 89.1%. The addition of the tertiary butylhydroquinone (TBHQ, 50 ppm), butylated hydroxytoluene (BHT, 50 ppm) and cashew nut shell liquid (CNSL, 2000 ppm) antioxidants in the biodiesel contributed to the increase of the induction period of 2.97 h for 8.08; 6.06 and 6.02 h, respectively. (author)

  3. 根管显微镜在开髓术及髓腔预备操作教学中的应用%Study of Root Canal Microscope Used in Open Experiment on Pulp and Pulp Cavity Preparation in Teaching

    Institute of Scientific and Technical Information of China (English)

    宋建玲; 董茜茜; 侯铁舟; 刘忠奇; 邓晓红; 刘青

    2014-01-01

    Objective The research of the application of root canal microscope aims at examining the ad‐vantages of improving the opening pulp and pulp cavity preparation technology in teaching ,and explo‐ring the root canal microscope application prospect in experimental teaching of dental pulp disease . Method The research object is thirty students and were randomly divided into three groups ,no‐micro‐scope group ,microscope teaching group and microscope operation group ,recording pith and pith cavi‐ty preparation operation time with self‐made‘open pith and pith cavity preparation skills score table’ and‘attitude of students evaluation form’ ,to quantitatively evaluate student mastery of the skills and learning attitude .Result There were no significant differences between the three groups in operation time (P>0 .05) .No microscopic group and microscopy teaching groups and no microscopic group and microscope operating group’s operation skill score have significant difference(P<0 .05) ,microscope teaching group and microscope operating group scores are higher than the group without microscope . Between group and microscope operation microscope group and teaching group and the microscope op‐eration between groups ,attitude of students test scores have the difference of statistics P<0 .05 ,mi‐croscope operation group scoring higher than those without microscope group and microscope teaching group .Conclusion The application of root canal microscope can effectively be improved in the teaching quality of this technology in the open pulp and pulp cavity preparation teaching ,helping to improve the students’ interest in learning the technique .Recommendations can develop application root canal microscope in teaching in conditional units .%目的:通过应用根管显微镜对提高开髓术和髓腔预备技术的教学效果探讨,探索其在根管治疗术实验教学中的应用前景。方法将西安交大口腔医学五、七年制学生30

  4. Retention proposal in complex cavities.

    Directory of Open Access Journals (Sweden)

    Pedro Alvarez Rodríguez

    2003-12-01

    Full Text Available Background: Dental Operatory is the main structure in which Odontology lies. It is not an easy discipline that gives enjoyable results with little effort due to the difficulties that a correct reconstruction of a destroyed dental element offers.The frequency with which pulpar injury occurs while anchoring additional retainers in complex cavities, the technical difficulties the lack of these devices cause and the need to simplify dental procedures lead this study to show the advantages to substitute additional retainers for a retainer surcus. Method: An observational descriptive study was applied to 53 patients(42% of the universe , sample which was selected by means of a simple randomized sample . From a proximal-occlusal cavity, the preparations were extended in a box-like shape towards the bucal or lingual region and the additional retainers were substituted for a surcus which was performed in the gingival wall of the preparation. Calcium Hydroxide of rapid dryness was used as a cavity cover and Policarboxilate cement as a base; then the amalgam restoration was performed. The number of restorations were studied taking into account the patient´s age and the failures due to fractures of amalgam, loss of vitality and periapical changes were assessed taking into consideration the patient´s age and a one- year follow up. Results: Most of the amalgam restorations were performed in patients aged from 35 to 59 years and the relative frequencies due to fractures of amalgam, loss of vitality and periapical changes were very low. Conclusion: The substitution of additional retainers for a retainer surcus in complex cavities of vital molars showed to be advantageous because it guarantees a less degree of pulpar damage and less pulpar damage.

  5. Superconducting cavity driving with FPGA controller

    International Nuclear Information System (INIS)

    The digital control of several superconducting cavities for a linear accelerator is presented. The laboratory setup of the CHECHIA cavity and ACC1 module of the VU-FEL TTF in DESY-Hamburg have both been driven by a Field Programmable Gate Array (FPGA) based system. Additionally, a single 9-cell TESLA Superconducting cavity of the FNPL Photo Injector at FERMILAB has been remotely controlled from WUT-ISE laboratory with the support of the DESY team using the same FPGA control system. These experiments focused attention on the general recognition of the cavity features and projected control methods. An electrical model of the resonator was taken as a starting point. Calibration of the signal path is considered key in preparation for the efficient driving of a cavity. Identification of the resonator parameters has been proven to be a successful approach in achieving required performance; i.e. driving on resonance during filling and field stabilization during flattop time while requiring reasonable levels of power consumption. Feed-forward and feedback modes were successfully applied in operating the cavities. Representative results of the experiments are presented for different levels of the cavity field gradient. (orig.)

  6. 牙科电子麻醉在窝洞制备和开髓治疗中的应用%The analgesic effect of electronic dental anesthesia in cavity preparation and pulp treatment

    Institute of Scientific and Technical Information of China (English)

    兰俊; 赵俊

    2001-01-01

    的:评价牙科电子麻醉在窝洞制备和开髓过程中的镇痛效果。 方法:对60例窝洞制备患者和15例开髓患者应用电子麻醉进行局部镇痛,另对60例窝洞制备患者和15例开髓患者应用传统局部麻醉作为对照,计算有效率,并对所得数值进行统计学处理(χ2检验)。 结果:窝洞制备组中,电子麻醉有效率为93.33%,局部麻醉有效率为98.33%,二者差异不显著(P>0.05);开髓治疗组中,电子麻醉有效率为26.67%,局部麻醉有效率为93.33%,二者差异显著(P0.05).For patients with pulpitis in need of pulp treatment ,the effective rates in EDA group and LA group were 26.7% and 93.33% respectively(P<0.01). Conclusions: EDA can be an effective analgesic method for cavity preparation, but not for pulp treatment.

  7. Plasma Treatment of Niobium SRF Cavity Surfaces

    Energy Technology Data Exchange (ETDEWEB)

    J. Upadhyay, M. Raskovic, L. Vuskovic, S. Popovic, A.-M. Valente-Feliciano, L. Phillips

    2010-05-01

    Plasma based surface modification provides an excellent opportunity to eliminate non- superconductive pollutants in the penetration depth region of the SRF cavity surface and to remove mechanically damaged surface layer improving surface roughness. We have demonstrated on flat samples that plasma etching in Ar / Cl2 of bulk Nb is a viable alternative surface preparation technique to BCP and EP methods, with comparable etching rates. The geometry of SRF cavities made of bulk Nb defines the use of asymmetric RF discharge configuration for plasma etching. In a specially designed single cell cavity with sample holders, discharge parameters are combined with etched surface diagnostics to obtain optimum combination of etching rates, roughness and homogeneity in a variety of discharge types, conditions, and sequences. The optimized experimental conditions will ultimately be applied to single cell SRF cavities.

  8. Electromagnetic SCRF Cavity Tuner

    Energy Technology Data Exchange (ETDEWEB)

    Kashikhin, V.; Borissov, E.; Foster, G.W.; Makulski, A.; Pischalnikov, Y.; Khabiboulline, T.; /Fermilab

    2009-05-01

    A novel prototype of SCRF cavity tuner is being designed and tested at Fermilab. This is a superconducting C-type iron dominated magnet having a 10 mm gap, axial symmetry, and a 1 Tesla field. Inside the gap is mounted a superconducting coil capable of moving {+-} 1 mm and producing a longitudinal force up to {+-} 1.5 kN. The static force applied to the RF cavity flanges provides a long-term cavity geometry tuning to a nominal frequency. The same coil powered by fast AC current pulse delivers mechanical perturbation for fast cavity tuning. This fast mechanical perturbation could be used to compensate a dynamic RF cavity detuning caused by cavity Lorentz forces and microphonics. A special configuration of magnet system was designed and tested.

  9. LEP copper accelerating cavities

    CERN Multimedia

    Laurent Guiraud

    1999-01-01

    These copper cavities were used to generate the radio frequency electric field that was used to accelerate electrons and positrons around the 27-km Large Electron-Positron (LEP) collider at CERN, which ran from 1989 to 2000. The copper cavities were gradually replaced from 1996 with new superconducting cavities allowing the collision energy to rise from 90 GeV to 200 GeV by mid-1999.

  10. 以修复为中心的简易种植模板指导下三种备洞方法的精度比较%Comparison of precision among three methods of cavity preparation directed by simple template of dental implant centered on repair

    Institute of Scientific and Technical Information of China (English)

    夏蕊; 戎志静; 丁明会; 崔晓光; 李枢安; 韩克难

    2016-01-01

    Objective To analyze and compare the precision among three methods of cavity preparation. Methods The dental im⁃plant on the resin patterns based on the bilateral posterior teeth loss was located by employing the simple template of dental implant cen⁃tered on repair. Then the traditional method of preparing cavity by using twist drill step by step, the Brånemark method of cavity prepa⁃ration and the method of preparing cavity by using multistep drill separately were applied to simulate an external cavity preparation for implant on the epoxy patterns. Lastly, the angle and deviation value between plant holes and templates after applying three methods were measured. Results The deviation value existed in all the methods, among which the traditional method of preparing cavity by u⁃sing twist drill step by step showed the most significant one (7.06°±0.37°), followed by the method of preparing cavity by using multi⁃step drill (4.84°±0.75°) and then the Brånemark method of cavity preparation (2.68°±0.77°). Conclusion Directed by simple tem⁃plate of dental implant centered on repair, Brånemark method demonstrates the highest precision, so it is the most suitable method of performing the operation with template.%目的:分析比较3种种植备洞方法的精度。方法利用以修复为中心的简易种植模板在双侧后牙缺失的树脂模型上进行种植定位,分别用传统麻花钻逐级备洞法、Brånemark备洞法和阶梯式钻逐级备洞法对环氧树脂模型进行体外模拟种植备洞,最后测量三种方法备洞后种植窝与模板植入道之间的角度及偏差值。结果不同备洞方法均存在一定偏差值,其中传统麻花钻备洞法的偏差最大(7.06°±0.37°),阶梯钻备洞法次之(4.84°±0.75°),Brånemark备洞法最小(2.68°±0.77°)。结论在以修复为中心的简易种植模板引导下,Brånemark备洞法精度最高,最适

  11. Two interacting atoms in a cavity: Entanglement vs decoherence

    CERN Document Server

    Torres, J M; Seligman, T H

    2009-01-01

    We address the problem of two interacting atoms of different species inside a cavity and find the explicit solutions of the corresponding eigenvalue problem. Closed expressions for concurrence and purity as a function of time when the cavity is prepared in a number state are found. The behavior in the concurrence-purity plane is discussed.

  12. Cavity spin optodynamics

    CERN Document Server

    Brahms, N

    2010-01-01

    The dynamics of a large quantum spin coupled parametrically to an optical resonator is treated in analogy with the motion of a cantilever in cavity optomechanics. New spin optodynamic phenonmena are predicted, such as cavity-spin bistability, optodynamic spin-precession frequency shifts, coherent amplification and damping of spin, and the spin optodynamic squeezing of light.

  13. Superconducting cavities for LEP

    CERN Multimedia

    1983-01-01

    Above: a 350 MHz superconducting accelerating cavity in niobium of the type envisaged for accelerating electrons and positrons in later phases of LEP. Below: a small 1 GHz cavity used for investigating the surface problems of superconducting niobium. Albert Insomby stays on the right. See Annual Report 1983 p. 51.

  14. SPS accelerating cavity

    CERN Multimedia

    1980-01-01

    One of the SPS acceleration cavities (200 MHz, travelling wave structure). On the ceiling one sees the coaxial transmission line which feeds the power from the amplifier, located in a surface building above, to the upstream end of the cavity. See 7603195 for more details, 7411032 for the travelling wave structure, and also 8104138, 8302397.

  15. Superconducting RF cavities

    CERN Document Server

    Bernard, Philippe

    1999-01-01

    It was 20 years ago when the research and development programme for LEP superconducting cavities was initiated. It lasted about 10 years. Today, my aim is not to tell you in great detail about the many innovations made thanks to our research, but I would like to point out some milestones in the development of superconducting cavities where Emilio's influence was particularly important.

  16. SPS accelerating cavity

    CERN Multimedia

    CERN PhotoLab

    1981-01-01

    One of the SPS accelerating cavities (200 MHz, travelling wave structure). The power that is fed into the upstream end of the cavity is extracted at the downstream end and sent into a dump load. See 7603195 for more details, 7411032 for the travelling wave structure, and also 8011289, 8302397.

  17. Ferrite loaded rf cavity

    International Nuclear Information System (INIS)

    The mechanism of a ferrite-loaded rf cavity is explained from the point of view of its operation. Then, an analysis of the automatic cavity-tuning system is presented using the transfer function; and a systematic analysis of a beam-feedback system using transfer functions is also presented. (author)

  18. Marginal microleakage of cavities prepared with Er:YAG laser on primary teeth in vitro%乳牙应用 Er:YAG 激光备洞充填微渗漏效果的离体研究

    Institute of Scientific and Technical Information of China (English)

    谢窈; 张笋; 葛立宏

    2014-01-01

    Objective:To investigate the marginal microleakage after cavity preparation by Er:YAG la-ser and conventional bur applying different adhesive systems , conditioning surface with acid etching or not.Methods:In the study, 50 primary teeth were divided into 5 groups.(1) Bur+etch-and-rinse sys-tem, (2) Bur+self-etching system, (3) Er:YAG laser+etch-and-rinse system, (4) Er:YAG laser+self-etching system, (5) Er:YAG laser+none-etched.The class V cavities were all filled with composite resin.The microleakage tests were performed , observed and scored under stereomicroscope .Results:Bur+etch-and-rinse group had higher microleakage than Er:YAG laser +etch-and-rinse group , and Bur+self-etching group had higher microleakage than Er:YAG laser +self-etching group ( P<0 .05 ) . There was no difference between Er:YAG laser+etch-and-rinse group and Er:YAG laser+self-etching group, while they had significantly lower microleakage than that of Er:YAG+none-etched group.Con-clusion:Composite resin restoration showed less marginal microleakage when all-in-one self-etch system was used after irradiation by Er:YAG laser on primary teeth .%目的:Er:YAG激光备洞和传统的涡轮钻针备洞,使用不同粘接系统和界面处理方式,对乳牙树脂充填的微渗漏效果进行研究。方法:50颗乳牙随机分为5组,第1组:涡轮钻针预备+全酸蚀粘接充填;第2组:涡轮钻针预备+自酸蚀粘接充填;第3组:Er:YAG激光预备+全酸蚀粘接充填;第4组:Er:YAG激光预备+自酸蚀粘接充填;第5组:Er:YAG激光预备后不酸蚀+配合全酸蚀粘接剂充填,对不同组进行微渗漏体视显微镜检查。结果:涡轮钻针+全酸蚀组和涡轮钻针+自酸蚀组的微渗漏分别高于Er:YAG激光+全酸蚀组和Er:YAG激光+自酸蚀组(P<0.05);涡轮钻针+全酸蚀组与Er:YAG激光+不酸蚀组的微渗漏差异无统计学意义。 Er:YAG激光预备的3个组中,全

  19. Passivated niobium cavities

    Science.gov (United States)

    Myneni, Ganapati Rao; Hjorvarsson, Bjorgvin; Ciovati, Gianluigi

    2006-12-19

    A niobium cavity exhibiting high quality factors at high gradients is provided by treating a niobium cavity through a process comprising: 1) removing surface oxides by plasma etching or a similar process; 2) removing hydrogen or other gases absorbed in the bulk niobium by high temperature treatment of the cavity under ultra high vacuum to achieve hydrogen outgassing; and 3) assuring the long term chemical stability of the niobium cavity by applying a passivating layer of a superconducting material having a superconducting transition temperature higher than niobium thereby reducing losses from electron (cooper pair) scattering in the near surface region of the interior of the niobium cavity. According to a preferred embodiment, the passivating layer comprises niobium nitride (NbN) applied by reactive sputtering.

  20. SPS RF Cavity

    CERN Multimedia

    1975-01-01

    The picture shows one of the two initially installed cavities. The main RF-system of the SPS comprises four cavities: two of 20 m length and two of 16.5 m length. They are all installed in one long straight section (LSS 3). These cavities are of the travelling-wave type operating at a centre frequency of 200.2 MHz. They are wideband, filling time about 700 ns and untuned. The power amplifiers, using tetrodes are installed in a surface building 200 m from the cavities. Initially only two cavities were installed, a third cavity was installed in 1978 and a forth one in 1979. The number of power amplifiers was also gradually increased: by end 1980 there were 8 500 kW units combined in pairs to feed each of the 4 cavities with up to about 1 MW RF power, resulting in a total accelerating voltage of about 8 MV. See also 7412017X, 7411048X, 7505074.

  1. SPS RF Accelerating Cavity

    CERN Multimedia

    1979-01-01

    This picture shows one of the 2 new cavities installed in 1978-1979. The main RF-system of the SPS comprises four cavities: two of 20 m length and two of 16.5 m length. They are all installed in one long straight section (LSS 3). These cavities are of the travelling-wave type operating at a centre frequency of 200.2 MHz. They are wideband, filling time about 700 ns and untuned. The power amplifiers, using tetrodes are installed in a surface building 200 m from the cavities. Initially only two cavities were installed, a third cavity was installed in 1978 and a forth one in 1979. The number of power amplifiers was also increased: to the first 2 MW plant a second 2 MW plant was added and by end 1979 there were 8 500 kW units combined in pairs to feed each of the 4 cavities with up to about 1 MW RF power, resulting in a total accelerating voltage of about 8 MV. See also 7412016X, 7412017X, 7411048X

  2. In vivo microbiological evaluation of the effect of biomechanical preparation of root canals using different irrigating solutions Avaliação microbiológica in vivo do efeito do preparo biomecânico dos canais radiculares utilizando diferentes soluções irrigadoras

    Directory of Open Access Journals (Sweden)

    Mário Tanomaru Filho

    2006-04-01

    Full Text Available The aim of this study was to evaluate the antimicrobial effect of biomechanical preparation using different irrigating solutions. Seventy-eight root canals from premolars of four dogs were used. After experimental induction of periapical lesions, the root canals were prepared using the following solutions for irrigation: Group 1 2.5% sodium hypochlorite (NaOCl; Group 2 2% chlorhexidine (CHX; Group 3 saline solution and Group 4 control group with no biomechanical preparation. The microbiological evaluation of the root canals was performed by counting the colony forming units (CFUs using different culture mediums. Two absorbent paper cones were used in each root canal in order to collect the microbiological samples before, and thirty days after the biomechanical preparation. The culture plates were incubated in aerobic, anaerobic and microaerophilic environment. Statistical evaluation was carried out using analysis of variance, Tukey and Student tests. The results demonstrated that there was reduction in the number of microorganisms in the NaOCl and CHX groups (pO objetivo deste estudo foi avaliar o efeito antimicrobiano do preparo biomecânico com diferentes soluções irrigadoras. Foram utilizados 78 canais radiculares de pré-molares de 4 cães. Após indução experimental das lesões periapicais, os canais radiculares foram preparados utilizando as seguintes soluções irrigadoras: grupo 1 hipoclorito de sódio a 2,5% (NaOCl; grupo 2 clorexidina a 2% (CHX; grupo 3 soro fisiológico. No grupo 4 (controle não foi realizado preparo biomecânico. A avaliação microbiológica do canal radicular foi realizada pela contagem de unidades formadoras de colônia, em ufc, nos diferentes meios de cultura. Foram utilizados 2 cones de papel absorvente em cada canal radicular para a realização da colheita microbiológica antes e 30 dias após o preparo biomecânico. As placas de cultura foram incubadas em ambiente de aerobiose, anaerobiose e

  3. Hydroforming of elliptical cavities

    Science.gov (United States)

    Singer, W.; Singer, X.; Jelezov, I.; Kneisel, P.

    2015-02-01

    Activities of the past several years in developing the technique of forming seamless (weldless) cavity cells by hydroforming are summarized. An overview of the technique developed at DESY for the fabrication of single cells and multicells of the TESLA cavity shape is given and the major rf results are presented. The forming is performed by expanding a seamless tube with internal water pressure while simultaneously swaging it axially. Prior to the expansion the tube is necked at the iris area and at the ends. Tube radii and axial displacements are computer controlled during the forming process in accordance with results of finite element method simulations for necking and expansion using the experimentally obtained strain-stress relationship of tube material. In cooperation with industry different methods of niobium seamless tube production have been explored. The most appropriate and successful method is a combination of spinning or deep drawing with flow forming. Several single-cell niobium cavities of the 1.3 GHz TESLA shape were produced by hydroforming. They reached accelerating gradients Eacc up to 35 MV /m after buffered chemical polishing (BCP) and up to 42 MV /m after electropolishing (EP). More recent work concentrated on fabrication and testing of multicell and nine-cell cavities. Several seamless two- and three-cell units were explored. Accelerating gradients Eacc of 30 - 35 MV /m were measured after BCP and Eacc up to 40 MV /m were reached after EP. Nine-cell niobium cavities combining three three-cell units were completed at the company E. Zanon. These cavities reached accelerating gradients of Eacc=30 - 35 MV /m . One cavity is successfully integrated in an XFEL cryomodule and is used in the operation of the FLASH linear accelerator at DESY. Additionally the fabrication of bimetallic single-cell and multicell NbCu cavities by hydroforming was successfully developed. Several NbCu clad single-cell and double-cell cavities of the TESLA shape have been

  4. Cavity-enhanced spectroscopies

    CERN Document Server

    van Zee, Roger

    2003-01-01

    ""Cavity-Enhanced Spectroscopy"" discusses the use of optical resonators and lasers to make sensitive spectroscopic measurements. This volume is written by the researcchers who pioneered these methods. The book reviews both the theory and practice behind these spectroscopic tools and discusses the scientific discoveries uncovered by these techniques. It begins with a chapter on the use of optical resonators for frequency stabilization of lasers, which is followed by in-depth chapters discussing cavity ring-down spectroscopy, frequency-modulated, cavity-enhanced spectroscopy, intracavity spectr

  5. RF BREAKDOWN STUDIES USING PRESSURIZED CAVITIES

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Rolland

    2014-09-21

    Many present and future particle accelerators are limited by the maximum electric gradient and peak surface fields that can be realized in RF cavities. Despite considerable effort, a comprehensive theory of RF breakdown has not been achieved and mitigation techniques to improve practical maximum accelerating gradients have had only limited success. Part of the problem is that RF breakdown in an evacuated cavity involves a complex mixture of effects, which include the geometry, metallurgy, and surface preparation of the accelerating structures and the make-up and pressure of the residual gas in which plasmas form. Studies showed that high gradients can be achieved quickly in 805 MHz RF cavities pressurized with dense hydrogen gas, as needed for muon cooling channels, without the need for long conditioning times, even in the presence of strong external magnetic fields. This positive result was expected because the dense gas can practically eliminate dark currents and multipacting. In this project we used this high pressure technique to suppress effects of residual vacuum and geometry that are found in evacuated cavities in order to isolate and study the role of the metallic surfaces in RF cavity breakdown as a function of magnetic field, frequency, and surface preparation. One of the interesting and useful outcomes of this project was the unanticipated collaborations with LANL and Fermilab that led to new insights as to the operation of evacuated normal-conducting RF cavities in high external magnetic fields. Other accomplishments included: (1) RF breakdown experiments to test the effects of SF6 dopant in H2 and He gases with Sn, Al, and Cu electrodes were carried out in an 805 MHz cavity and compared to calculations and computer simulations. The heavy corrosion caused by the SF6 components led to the suggestion that a small admixture of oxygen, instead of SF6, to the hydrogen would allow the same advantages without the corrosion in a practical muon beam line. (2) A

  6. The ``Q disease'' in Superconducting Niobium RF Cavities

    Science.gov (United States)

    Knobloch, J.

    2003-07-01

    Superconducting niobium cavities can achieve quality (Q0) factors of 1010-1011, more than six orders of magnitude higher than conventional copper cavities. However, to maintain this performance at high accelerating gradient (20 MV/m) the radio-frequency (rf) surface must be damage and dust free. Cavity preparation techniques therefore routinely include a chemical etch or electropolishing. Under certain conditions, these (and other) treatments can contaminate the niobium with hydrogen. Hydrides may then form when the cavity is cooled through 150 K, even if only a few atomic percent hydrogen are present. If hydrides are formed, the cavity quality can degrade substantially (Q disease). A rapid cooldown often inhibits the hydride formation. Other "cures" include degassing cavities at 900 °C to eliminate the hydrogen. A historical review of the Q disease is provided here, with the emphasis being placed on its discovery, symptoms, mechanism, and cures.

  7. SPS accelerating cavity

    CERN Multimedia

    1983-01-01

    See photo 8202397: View towards the downstream end of one of the SPS accelerating cavities (200 MHz, travelling wave structure). See 7603195 and 8011289 for more details, 7411032 for the travelling wave structure, and also 8104138.

  8. SPS accelerating cavity

    CERN Multimedia

    1983-01-01

    View towards the downstream end of one of the SPS accelerating cavities (200 MHz, travelling wave structure). See 7603195 and 8011289 for more details, 7411032 for the travelling wave structure, and also 8104138.

  9. Moving Detectors in Cavities

    CERN Document Server

    Obadia, N

    2007-01-01

    We consider two-level detectors, coupled to a quantum scalar field, moving inside cavities. We highlight some pathological resonant effects due to abrupt boundaries, and decide to describe the cavity by switching smoothly the interaction by a time-dependent gate-like function. Considering uniformly accelerated trajectories, we show that some specific choices of non-adiabatic switching have led to hazardous interpretations about the enhancement of the Unruh effect in cavities. More specifically, we show that the emission/absorption ratio takes arbitrary high values according to the emitted quanta properties and to the transients undergone at the entrance and the exit of the cavity, {\\it independently of the acceleration}. An explicit example is provided where we show that inertial and uniformly accelerated world-lines can even lead to the same ``pseudo-temperature''.

  10. accelerating cavity from LEP

    CERN Multimedia

    This is an accelerating cavity from LEP, with a layer of niobium on the inside. Operating at 4.2 degrees above absolute zero, the niobium is superconducting and carries an accelerating field of 6 million volts per metre with negligible losses. Each cavity has a surface of 6 m2. The niobium layer is only 1.2 microns thick, ten times thinner than a hair. Such a large area had never been coated to such a high accuracy. A speck of dust could ruin the performance of the whole cavity so the work had to be done in an extremely clean environment. These challenging requirements pushed European industry to new achievements. 256 of these cavities are now used in LEP to double the energy of the particle beams.

  11. SPS accelerating cavity

    CERN Multimedia

    1976-01-01

    The SPS started up with 2 accelerating cavities (each consisting of 5 tank sections) in LSS3. They have a 200 MHz travelling wave structure (see 7411032 and 7802190) and 750 kW of power is fed to each of the cavities from a 1 MW tetrode power amplifier, located in a surface building above, via a coaxial transmission line. Clemens Zettler, builder of the SPS RF system, is standing at the side of one of the cavities. In 1978 and 1979 another 2 cavities were added and entered service in 1980. These were part of the intensity improvement programme and served well for the new role of the SPS as proton-antiproton collider. See also 7411032, 8011289, 8104138, 8302397.

  12. Hydroforming of Elliptical Cavities

    OpenAIRE

    W. Singer; Singer, X.; Jelezov, I.; Kneisel, P.

    2015-01-01

    Activities of the past several years in developing the technique of forming seamless (weldless) cavity cells by hydroforming are summarized. An overview of the technique developed at DESY for the fabrication of single cells and multicells of the TESLA cavity shape is given and the major rf results are presented. The forming is performed by expanding a seamless tube with internal water pressure while simultaneously swaging it axially. Prior to the expansion the tube is necked at the iris area ...

  13. Hybrid vertical cavity laser

    DEFF Research Database (Denmark)

    Chung, Il-Sug; Mørk, Jesper

    2010-01-01

    A new hybrid vertical cavity laser structure for silicon photonics is suggested and numerically investigated. It incorporates a silicon subwavelength grating as a mirror and a lateral output coupler to a silicon ridge waveguide.......A new hybrid vertical cavity laser structure for silicon photonics is suggested and numerically investigated. It incorporates a silicon subwavelength grating as a mirror and a lateral output coupler to a silicon ridge waveguide....

  14. REFRIGERAÇÃO UTILIZANDO PASTILHAS DE EFEITO PELTIER

    OpenAIRE

    Antonio Luiz P. S. Campos; Aécio Vinícius Amorim Farias; Jainne Daniele F. S. Fernandes; Alailson de Freitas Braz; Ludmila Sayonara S. X. Machado; Edfranklin de Souza Pimentel

    2010-01-01

    Pastilhas de Peltier são dispositivos baseados no efeito Peltier e são aplicadas para produzir efeito refrigerador ou aquecedor. Este trabalho aborda conceitos envolvidos na fabricação e funcionamento desses dispositivos tais como: histórico do efeito Peltier e desenvolvimento de placas de efeito Peltier. É feito um estudo de eficiência da refrigeração de água utilizando uma placa de efeito Peltier existente no Campus Natal – Zona Norte. Para isso, é implementada uma estrutura de refrigeração...

  15. Cavity Optomechanics at Millikelvin Temperatures

    Science.gov (United States)

    Meenehan, Sean Michael

    The field of cavity optomechanics, which concerns the coupling of a mechanical object's motion to the electromagnetic field of a high finesse cavity, allows for exquisitely sensitive measurements of mechanical motion, from large-scale gravitational wave detection to microscale accelerometers. Moreover, it provides a potential means to control and engineer the state of a macroscopic mechanical object at the quantum level, provided one can realize sufficiently strong interaction strengths relative to the ambient thermal noise. Recent experiments utilizing the optomechanical interaction to cool mechanical resonators to their motional quantum ground state allow for a variety of quantum engineering applications, including preparation of non-classical mechanical states and coherent optical to microwave conversion. Optomechanical crystals (OMCs), in which bandgaps for both optical and mechanical waves can be introduced through patterning of a material, provide one particularly attractive means for realizing strong interactions between high-frequency mechanical resonators and near-infrared light. Beyond the usual paradigm of cavity optomechanics involving isolated single mechanical elements, OMCs can also be fashioned into planar circuits for photons and phonons, and arrays of optomechanical elements can be interconnected via optical and acoustic waveguides. Such coupled OMC arrays have been proposed as a way to realize quantum optomechanical memories, nanomechanical circuits for continuous variable quantum information processing and phononic quantum networks, and as a platform for engineering and studying quantum many-body physics of optomechanical meta-materials. However, while ground state occupancies (that is, average phonon occupancies less than one) have been achieved in OMC cavities utilizing laser cooling techniques, parasitic absorption and the concomitant degradation of the mechanical quality factor fundamentally limit this approach. On the other hand, the high

  16. Research on Field Emission and Dark Current in ILC Cavities

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Kexin; Li, Yongming; Palczewski, Ari; Geng, Rongli

    2013-09-01

    Field emission and dark current are issues of concern for SRF cavity performance and SRF linac operation. Complete understanding and reliable control of the issue are still needed, especially in full-scale multi-cell cavities. Our work aims at developing a generic procedure for finding an active field emitter in a multi-cell cavity and benchmarking the procedure through cavity vertical test. Our ultimate goal is to provide feedback to cavity preparation and cavity string assembly in order to reduce or eliminate filed emission in SRF cavities. Systematic analysis of behaviors of field emitted electrons is obtained by ACE3P developed by SLAC. Experimental benchmark of the procedure was carried out in a 9-cell cavity vertical test at JLab. The energy spectrum of Bremsstrahlung X-rays is measured using a NaI(Tl) detector. The end-point energy in the X-ray energy spectrum is taken as the highest kinetic electron energy to predict longitudinal position of the active field emitter. Angular location of the field emitter is determined by an array of silicon diodes around irises of the cavity. High-resolution optical inspection was conducted at the predicted field emitter location.

  17. Metasurface external cavity laser

    Science.gov (United States)

    Xu, Luyao; Curwen, Christopher A.; Hon, Philip W. C.; Chen, Qi-Sheng; Itoh, Tatsuo; Williams, Benjamin S.

    2015-11-01

    A vertical-external-cavity surface-emitting-laser is demonstrated in the terahertz range, which is based upon an amplifying metasurface reflector composed of a sub-wavelength array of antenna-coupled quantum-cascade sub-cavities. Lasing is possible when the metasurface reflector is placed into a low-loss external cavity such that the external cavity—not the sub-cavities—determines the beam properties. A near-Gaussian beam of 4.3° × 5.1° divergence is observed and an output power level >5 mW is achieved. The polarized response of the metasurface allows the use of a wire-grid polarizer as an output coupler that is continuously tunable.

  18. Metasurface external cavity laser

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Luyao, E-mail: luyaoxu.ee@ucla.edu; Curwen, Christopher A.; Williams, Benjamin S. [Department of Electrical Engineering, University of California, Los Angeles, California 90095 (United States); California NanoSystems Institute, University of California, Los Angeles, California 90095 (United States); Hon, Philip W. C.; Itoh, Tatsuo [Department of Electrical Engineering, University of California, Los Angeles, California 90095 (United States); Chen, Qi-Sheng [Northrop Grumman Aerospace Systems, Redondo Beach, California 90278 (United States)

    2015-11-30

    A vertical-external-cavity surface-emitting-laser is demonstrated in the terahertz range, which is based upon an amplifying metasurface reflector composed of a sub-wavelength array of antenna-coupled quantum-cascade sub-cavities. Lasing is possible when the metasurface reflector is placed into a low-loss external cavity such that the external cavity—not the sub-cavities—determines the beam properties. A near-Gaussian beam of 4.3° × 5.1° divergence is observed and an output power level >5 mW is achieved. The polarized response of the metasurface allows the use of a wire-grid polarizer as an output coupler that is continuously tunable.

  19. Experimental investigation of cavity flows

    Energy Technology Data Exchange (ETDEWEB)

    Loeland, Tore

    1998-12-31

    This thesis uses LDV (Laser Doppler Velocimetry), PIV (Particle Image Velocimetry) and Laser Sheet flow Visualisation to study flow inside three different cavity configurations. For sloping cavities, the vortex structure inside the cavities is found to depend upon the flow direction past the cavity. The shape of the downstream corner is a key factor in destroying the boundary layer flow entering the cavity. The experimental results agree well with numerical simulations of the same geometrical configurations. The results of the investigations are used to find the influence of the cavity flow on the accuracy of the ultrasonic flowmeter. A method to compensate for the cavity velocities is suggested. It is found that the relative deviation caused by the cavity velocities depend linearly on the pipe flow. It appears that the flow inside the cavities should not be neglected as done in the draft for the ISO technical report on ultrasonic flowmeters. 58 refs., 147 figs., 2 tabs.

  20. LEP superconducting cavity

    CERN Document Server

    1995-01-01

    Engineers work in a clean room on one of the superconducting cavities for the upgrade to the LEP accelerator, known as LEP-2. The use of superconductors allow higher electric fields to be produced so that higher beam energies can be reached.

  1. Melatonin and oral cavity.

    Science.gov (United States)

    Cengiz, Murat İnanç; Cengiz, Seda; Wang, Hom-Lay

    2012-01-01

    While initially the oral cavity was considered to be mainly a source of various bacteria, their toxins and antigens, recent studies showed that it may also be a location of oxidative stress and periodontal inflammation. Accordingly, this paper focuses on the involvement of melatonin in oxidative stress diseases of oral cavity as well as on potential therapeutic implications of melatonin in dental disorders. Melatonin has immunomodulatory and antioxidant activities, stimulates the proliferation of collagen and osseous tissue, and acts as a protector against cellular degeneration associated with aging and toxin exposure. Arising out of its antioxidant actions, melatonin protects against inflammatory processes and cellular damage caused by the toxic derivates of oxygen. As a result of these actions, melatonin may be useful as a coadjuvant in the treatment of certain conditions of the oral cavity. However, the most important effect of melatonin seems to result from its potent antioxidant, immunomodulatory, protective, and anticancer properties. Thus, melatonin could be used therapeutically for instance, locally, in the oral cavity damage of mechanical, bacterial, fungal, or viral origin, in postsurgical wounds caused by tooth extractions and other oral surgeries. Additionally, it can help bone formation in various autoimmunological disorders such as Sjorgen syndrome, in periodontal diseases, in toxic effects of dental materials, in dental implants, and in oral cancers.

  2. Melatonin and Oral Cavity

    Directory of Open Access Journals (Sweden)

    Murat İnanç Cengiz

    2012-01-01

    Full Text Available While initially the oral cavity was considered to be mainly a source of various bacteria, their toxins and antigens, recent studies showed that it may also be a location of oxidative stress and periodontal inflammation. Accordingly, this paper focuses on the involvement of melatonin in oxidative stress diseases of oral cavity as well as on potential therapeutic implications of melatonin in dental disorders. Melatonin has immunomodulatory and antioxidant activities, stimulates the proliferation of collagen and osseous tissue, and acts as a protector against cellular degeneration associated with aging and toxin exposure. Arising out of its antioxidant actions, melatonin protects against inflammatory processes and cellular damage caused by the toxic derivates of oxygen. As a result of these actions, melatonin may be useful as a coadjuvant in the treatment of certain conditions of the oral cavity. However, the most important effect of melatonin seems to result from its potent antioxidant, immunomodulatory, protective, and anticancer properties. Thus, melatonin could be used therapeutically for instance, locally, in the oral cavity damage of mechanical, bacterial, fungal, or viral origin, in postsurgical wounds caused by tooth extractions and other oral surgeries. Additionally, it can help bone formation in various autoimmunological disorders such as Sjorgen syndrome, in periodontal diseases, in toxic effects of dental materials, in dental implants, and in oral cancers.

  3. SPS accelerating cavity

    CERN Multimedia

    1983-01-01

    See photo 8302397: View from the downstream end of one of the SPS accelerating cavities (200 MHz, travelling wave structure). See 7603195 and 8011289 for more details, 7411032 for the travelling wave structure, and also 8104138. Giacomo Primadei stands on the left.

  4. Statistical electromagnetics: Complex cavities

    NARCIS (Netherlands)

    Naus, H.W.L.

    2008-01-01

    A selection of the literature on the statistical description of electromagnetic fields and complex cavities is concisely reviewed. Some essential concepts, for example, the application of the central limit theorem and the maximum entropy principle, are scrutinized. Implicit assumptions, biased choic

  5. Laser cavity modelling

    OpenAIRE

    Damakoa, I.; Audounet, J.; Bouyssou, G.; Vassilieff, G.

    1993-01-01

    Two approachs of modelling nonhomogeneous cavity laser are presented. They are based on the beam propagation method which allows the use of fast Fourier transform (FFT). The resulting procedures provide selfconsistent solutions to the Maxwell and diffusion equations. Results are given to illustrate the two methods.


  6. Niobium superconducting cavity

    CERN Multimedia

    1980-01-01

    This 5-cell superconducting cavity, made from bulk-Nb, stems from the period of general studies, not all directed towards direct use at LEP. This one is dimensioned for 1.5 GHz, the frequency used at CEBAF and also studied at Saclay (LEP RF was 352.2 MHz). See also 7908227, 8007354, 8209255, 8210054, 8312339.

  7. Implosion of the small cavity and large cavity cannonball targets

    International Nuclear Information System (INIS)

    Recent results of cannonball target implosion research are briefly reviewed with theoretical predictions for GEKKO XII experiments. The cannonball targets are classified into two types according to the cavity size ; small cavity and large cavity. The compression mechanisms of the two types are discussed. (author)

  8. Sensitivity of Niobium Superconducting RF Cavities to Magnetic Field

    CERN Document Server

    Gonnella, Dan

    2015-01-01

    Future particle accelerators such as the the SLAC "Linac Coherent Light Source-II" (LCLS-II) and the proposed Cornell Energy Recovery Linac (ERL) require hundreds of superconducting RF (SRF) cavities operating in continuous wave (CW) mode. In order to achieve economic feasibility of projects such as these, the cavities must achieve a very high intrinsic quality factor (Q0). In order to reach these high Q0's in the case of LCLS-II, nitrogen-doping has been proposed as a cavity preparation technique. When dealing with Q0's greater than 1x10^10, the effects of ambient magnetic field on Q0 become significant. Here we show that the sensitivity that a cavity has to ambient magnetic field is highly dependent on the cavity preparation. Specifically, standard electropolished and 120C baked cavities show a sensitivity of ~0.8 and ~0.6 nOhm/mG trapped, respectively, while nitrogen-doped cavities show a sensitivity of ~2 to 5 nOhm/mG trapped. Less doping results in weaker sensitivity. This difference in sensitivities is ...

  9. Open Microwave Cavity for use in a Purcell Enhancement Cooling Scheme

    CERN Document Server

    Evetts, N; Bizzotto, D; Longuevergne, D; Hardy, W N

    2016-01-01

    A microwave cavity is described which can be used to cool lepton plasmas for potential use in synthesis of antihydrogen. The cooling scheme is an incarnation of the Purcell Effect: when plasmas are coupled to a microwave cavity, the plasma cooling rate is resonantly enhanced through increased spontaneous emission of cyclotron radiation. The cavity forms a three electrode section of a Penning-Malmberg trap and has a bulged cylindrical geometry with open ends aligned with the magnetic trapping axis. This allows plasmas to be injected and removed from the cavity without the need for moving parts while maintaining high quality factors for resonant modes. The cavity includes unique surface preparations for adjusting the cavity quality factor and achieving anti-static shielding using thin layers of nichrome and colloidal graphite respectively. Geometric design considerations for a cavity with strong cooling power and low equilibrium plasma temperatures are discussed. Cavities of this weak-bulge design will be appli...

  10. Expression of HSP70 in rabbit dental pulp after cavity preparation with Er,Cr:YSGG laser%Er,Cr:YSGG激光备洞对兔牙髓组织热休克蛋白70表达的影响

    Institute of Scientific and Technical Information of China (English)

    杨超; 贾兴亚; 安欣; 王抒智; 钟鸣

    2012-01-01

    目的 观察Er,Cr:YSGG激光用于牙体窝洞制备后兔牙髓的形态学变化及热休克蛋白70 (heat shock protein70 HSP70)的表达情况.方法 用Er,Cr:YSGG激光在家兔前牙制备V类洞并常规充填,普通高速牙钻备洞作对照,分别于术后4h、24h处死实验动物,组织切片经HE染色及免疫组化染色,镜下观察.结果 Er,Cr:YSGG激光备洞后牙髓轻到中度炎症反应,与牙钻对照组无明显差异.备洞后24h,激光组成牙本质细胞HSP70中到强阳性表达,成纤维细胞、血管内皮细胞中度阳性表达.牙钻组成牙本质细胞及相邻成纤维细胞强阳性表达,血管内皮细胞强阳性表达,对照组HSP70表达高于Er,Cr:YSGG激光实验组,差别有统计学意义(P<0.05).结论 Er,Cr:YSGG激光备洞对牙髓刺激小,有很好的临床使用价值.%Objective To observe the dental pulpal morphological changes and the expression of HSP70 to cavity preparation in rabbit incisors by the Er,Cr:YSGG laser. Methods A total of thirtyt-wo incisors of eight healthy rabbits were divided into two groups: Er,Cr:YSGG laser and conventional bur group.after the cavities preparation by the laser and the conventional bur in rabbit incisors, the cavities, were filled by normal way .The teeth were extracted 4 and 24 hours after operation respectively, after HE and immunohistochemical staining, the tissue sections were observed by microscopy. Results The histological examination showed that there was no appreciable difference in the manner in which dental pulp tissue responds to cavity preparation with either Er,Cr:YSGG laser or a conventional bur. 24h after the operation, the Er,Cr:YSGG laser group have a moderate to strong expression of HSP70 in Odontoblasts,and moderate expression in Fibroblast and endothelial cells.the expression of HSP70 in the control group was higher than that in the Er, Cr:YSGG laser group (P<0.05). Conclusion Cavity preparation by Er,Cr:YSGG laser causes no noticeable pulpal damage

  11. Engineering three-dimensional maximally entangled states for two modes in a bimodal cavity

    Institute of Scientific and Technical Information of China (English)

    Yang Zhen-Biao; Su Wan-Jun

    2007-01-01

    An alternative scheme is proposed for engineering three-dimensional maximally entangled states for two modes of a superconducting microwave cavity. In this scheme, an appropriately prepared four-level atom is sent through a bimodal cavity. During its passing through the cavity, the atom is coupled resonantly with two cavity modes simultaneously and addressed by a classical microwave pulse tuned to the required transition. Then the atomic states are detected to collapse two modes onto a three-dimensional maximally entangled state. The scheme is different from the previous one in which two nonlocal cavities are used. A comparison between them is also made.

  12. Efficient scheme of quantum SWAP gate and multi-atom cluster state via cavity QED

    Institute of Scientific and Technical Information of China (English)

    Jiang Chun-Lei; Fang Mao-Fa; Hu Yao-Hua

    2008-01-01

    In this paper,we propose a physical scheme to realize quantum SWAP gate by using a large-detuned single-mode cavity field and two identical Rydberg atoms.It is shown that the scheme can also be used to create multi-atom cluster state.During the interaction between atom and cavity,the cavity is only virtually excited and thus the scheme is insensitive to the cavity field states and cavity decay.With the help of our scheme it is very simple to prepare the N-atom cluster state with perfect fidelity and probability.The practical feasibility of this method is also discussed.

  13. Colloquium: cavity optomechanics

    CERN Multimedia

    2011-01-01

    Monday 14 November 2011, 17:00 Ecole de Physique, Auditoire Stueckelberg Université de Genève Cavity optomechanics: controlling micro mechanical oscillators with laser light Prof. Tobias Kippenberg EPFL, Lausanne Laser light can be used to cool and to control trapped ions, atoms and molecules at the quantum level. This has lead to spectacular advances such as the most precise atomic clocks. An outstanding frontier is the control with lasers of nano- and micro-mechancial systems. Recent advances in cavity optomechanics have allowed such elementary control for the first time, enabling mechanical systems to be ground state cooled leading to readout with quantum limited sensitivity and permitting to explore new device concepts resulting from radiation pressure.  

  14. RF superconducting cavities

    CERN Document Server

    Kojima, Y

    1980-01-01

    The history and present activity in research on RF superconducting cavities in various countries are reviewed. The program of the July 1980 Karlsruhe workshop is reproduced and research activity in this field at Stanford HEPL and SLAC, Cornell, Oregon, Brookhaven, KEK (Japan), Weismann (Israel), Genoa, CERN and Karlsruhe (KfK) listed. The theoretical basis of surface resistance and intracavity magnetic field, multipacing and non-resonant electron loading are outlined. (20 refs).

  15. Crab Cavities for Linear Colliders

    Energy Technology Data Exchange (ETDEWEB)

    Burt, G.; Ambattu, P.; Carter, R.; Dexter, A.; Tahir, I.; /Cockcroft Inst. Accel. Sci. Tech. /Lancaster U.; Beard, C.; Dykes, M.; Goudket, P.; Kalinin, A.; Ma, L.; McIntosh, P.; /Daresbury; Shulte, D.; /CERN; Jones, Roger M.; /Cockcroft Inst. Accel. Sci. Tech. /Manchester U.; Bellantoni, L.; Chase, B.; Church, M.; Khabouline, T.; Latina, A.; /Fermilab; Adolphsen, C.; Li, Z.; Seryi, Andrei; /SLAC

    2011-11-08

    Crab cavities have been proposed for a wide number of accelerators and interest in crab cavities has recently increased after the successful operation of a pair of crab cavities in KEK-B. In particular crab cavities are required for both the ILC and CLIC linear colliders for bunch alignment. Consideration of bunch structure and size constraints favour a 3.9 GHz superconducting, multi-cell cavity as the solution for ILC, whilst bunch structure and beam-loading considerations suggest an X-band copper travelling wave structure for CLIC. These two cavity solutions are very different in design but share complex design issues. Phase stabilisation, beam loading, wakefields and mode damping are fundamental issues for these crab cavities. Requirements and potential design solutions will be discussed for both colliders.

  16. Crab cavities for linear colliders

    CERN Document Server

    Burt, G; Carter, R; Dexter, A; Tahir, I; Beard, C; Dykes, M; Goudket, P; Kalinin, A; Ma, L; McIntosh, P; Shulte, D; Jones, Roger M; Bellantoni, L; Chase, B; Church, M; Khabouline, T; Latina, A; Adolphsen, C; Li, Z; Seryi, Andrei; Xiao, L

    2008-01-01

    Crab cavities have been proposed for a wide number of accelerators and interest in crab cavities has recently increased after the successful operation of a pair of crab cavities in KEK-B. In particular crab cavities are required for both the ILC and CLIC linear colliders for bunch alignment. Consideration of bunch structure and size constraints favour a 3.9 GHz superconducting, multi-cell cavity as the solution for ILC, whilst bunch structure and beam-loading considerations suggest an X-band copper travelling wave structure for CLIC. These two cavity solutions are very different in design but share complex design issues. Phase stabilisation, beam loading, wakefields and mode damping are fundamental issues for these crab cavities. Requirements and potential design solutions will be discussed for both colliders.

  17. Electro Polishing of Niobium Cavities at DESY

    CERN Document Server

    Matheisen, A; Morales, H; Petersen, B; Schmoekel, M; Steinhau-Kühl, N

    2004-01-01

    At DESY a facility for electro polishing (EP) of the super conducting (s.c.) TESLA/TTF cavities have been built and is operational since summer 2003. The EP infrastructure is capable to handle single-cell structures and the standard TESLA/ TTF nine-cell cavities. Several electro polishing processes have been made since and acceleration voltage up to 40 MV/m have been reached in nine cell structures. We report on measurements and experiences gained since 2003 as well as on handling procedures developed for the preparation of electro polished resonators. Specific data like heat production, variation of current density and bath aging will be presented. Another important point for reproducible results is the quality control of the electro polishing process. First quality control steps to be implanted in the EP procedure for large-scale production will be described.

  18. Measurement-induced macroscopic superposition states in cavity optomechanics

    CERN Document Server

    Hoff, Ulrich B; Neergaard-Nielsen, Jonas S; Andersen, Ulrik L

    2016-01-01

    We present a novel proposal for generating quantum superpositions of macroscopically distinct states of a bulk mechanical oscillator, compatible with existing optomechanical devices operating in the readily achievable bad-cavity limit. The scheme is based on a pulsed cavity optomechanical quantum non-demolition (QND) interaction, driven by displaced non-Gaussian states, and measurement-induced feedback, avoiding the need for strong single-photon optomechanical coupling. Furthermore, we show that single-quadrature cooling of the mechanical oscillator is sufficient for efficient state preparation, and we outline a three-pulse protocol comprising a sequence of QND interactions for squeezing-enhanced cooling, state preparation, and tomography.

  19. Morphological evaluation of cavity preparation surface after duraphat and Er:YAG laser treatment by scanning electronic microscopy; Avaliacao das alteracoes morfologicas da superficie do preparo cavitario apos condicionamento com verniz fluoretado a 2,26 % e laser de Er:YAG atraves de microscopia eletronica de varredura

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Luciane Borelli

    2002-07-01

    The treatment of dental surface using different lasers to prevent dental caries has been studied for several on last years. The purpose of this in vitro study was to evaluate the morphological changes on dentin surface from pulpal wall of cavity preparations performed by high-speed drill, treated with 2,26% fluoride varnish (Duraphat) and Er:YAG laser, and then submitted after receiving or not to EDTA 15% treatment. Twenty Class V cavities were performed on ten humans molars. The specimens were randomly divided in to 4 groups: group 1- treatment with Duraphat followed by Er:YAG laser irradiation (120 mJ/ 4 Hz); group 2: Er:YAG laser irradiation, same parameters, followed by Duraphat treatment; group 3- same group 1 followed by immersion in EDTA (5 min); group 4 - same as group 2 followed by immersion in EDTA (5 min). The specimens were processed for SEM analysis. The micrographs showed that Duraphat treatment promoted morphological changes on dentin, closing dentinal tubules; the specimens treated by Duraphat and Er:YAG laser and immersed in EDTA (group 3) showed homogeneous surface, closed and protected dentinal tubules, maintenance of the fluoride varnish on the dentin surface and around the dentinal tubules, showing feasible and efficiency of these therapies the feasibility.(author)

  20. REFRIGERAÇÃO UTILIZANDO PASTILHAS DE EFEITO PELTIER

    Directory of Open Access Journals (Sweden)

    Antonio Luiz P. S. Campos

    2010-06-01

    Full Text Available Pastilhas de Peltier são dispositivos baseados no efeito Peltier e são aplicadas para produzir efeito refrigerador ou aquecedor. Este trabalho aborda conceitos envolvidos na fabricação e funcionamento desses dispositivos tais como: histórico do efeito Peltier e desenvolvimento de placas de efeito Peltier. É feito um estudo de eficiência da refrigeração de água utilizando uma placa de efeito Peltier existente no Campus Natal – Zona Norte. Para isso, é implementada uma estrutura de refrigeração de água e são feitas medições para determinar a eficiência de sistema. Por fim, são apresentadas conclusões sobre o estudo desenvolvido.

  1. Centrifugal barrel polishing of 1.3 GHz Nb cavities

    Energy Technology Data Exchange (ETDEWEB)

    Tamashevich, Yegor; Foster, Brian [DESY, Hamburg (Germany); Hamburg Univ. (Germany); Navitski, Aliaksandr; Steder, Lea; Elsen, Eckhard [DESY, Hamburg (Germany)

    2013-07-01

    Superconducting radio-frequency (SRF) cavities are the key components of particle accelerators such as the European X-ray Free Electron Laser (XFEL, under construction) and the planned future International Linear Collider (ILC). Steady progress in surface treatment techniques of SRF cavities in both the achievable quality factor Q and the accelerating electric field Eacc makes new accelerators and ambitious projects feasible. One of the alternative surface preparation techniques which is actually being explored is centrifugal barrel polishing (CBP) pioneered at KEK in Japan in mid-nineties by T. Hiuchi et al. CBP is a mechanical polishing of cavities and results in around 10 x smaller surface roughness and mirror-like surface as compared to chemistry alone. Q and E{sub acc} are expected to be at least as high as for chemically treated cavities. CBP eliminates the bulk chemistry and has the potential to completely replace the chemistry. The University of Hamburg is installing a CBP machine to study it as a cavity preparation and repair technique for 9-cell 1.3 GHz SRF cavities at the Deutsche Elektronen-Synchrotron (DESY). The setup and first commissioning tests will be presented and discussed.

  2. ISR RF cavities

    CERN Multimedia

    1983-01-01

    In each ISR ring the radiofrequency cavities were installed in one 9 m long straight section. The RF system of the ISR had the main purpose to stack buckets of particles (most of the time protons)coming from the CPS and also to accelerate the stacked beam. The installed RF power per ring was 18 kW giving a peak accelerating voltage of 20 kV. The system had a very fine regulation feature allowing to lower the voltage down to 75 V in a smooth and well controlled fashion.

  3. Efeito dos parâmetros de extrusão termoplástica sobre as propriedades tecnológicas de farinhas pré-cozidas elaboradas com arroz e feijão Effect of the thermoplastic extrusion parameters on the technological properties of pre-cooked flours prepared with rice and beans

    Directory of Open Access Journals (Sweden)

    Ana Vânia Carvalho

    2012-12-01

    Full Text Available O objetivo deste trabalho foi obter uma farinha pré-gelatinizada elaborada a partir de farinha mista de arroz e feijão, e avaliar a influência das formulações e condições do processamento sobre as propriedades tecnológicas e o teor proteico do produto final. Para a elaboração da farinha pré-gelatinizada mista, utilizou-se o planejamento experimental completo 2³ com pontos centrais e axiais, testando-se os parâmetros porcentagem de farinha de feijão, umidade e temperatura de processamento, tendo como respostas teor de proteína (Y1, índice de absorção de água (Y2 e índice de solubilidade em água (Y3. As formulações testadas foram processadas em extrusora monorrosca. A temperatura na zona 3 do extrusor variou entre 46 e 114 °C, conforme o planejamento experimental. Os ensaios processados foram submetidos à secagem em estufa com circulação de ar a 50 °C por cerca de 15 horas, apresentando umidade final entre 4 e 6%, sendo, a seguir, triturados em moinho de facas e armazenados em sacos de polietileno até o momento das análises. Para a variável teor de proteína, somente a porcentagem de farinha de feijão foi significativa e com efeito positivo, ou seja, aumentando-se a quantidade desta farinha, o produto final terá um maior teor proteico, independentemente da temperatura ou da umidade utilizada no processamento. Para a variável índice de absorção de água, a farinha de feijão, o teor de umidade, a temperatura e a interação umidade e temperatura foram significativos. Observou-se maior índice de absorção de água em temperaturas intermediárias (60 a 80 °C e altas umidades (17 a 20%. Para a resposta índice de solubilidade em água, as variáveis umidade, temperatura e a interação umidade e temperatura também foram significativas, observando-se maiores índices de solubilidade em água em temperaturas mais elevadas (100 °C e umidades mais baixas (14%. De acordo com o planejamento experimental, a farinha

  4. Oral cavity eumycetoma

    Directory of Open Access Journals (Sweden)

    Gisele Alborghetti Nai

    2011-06-01

    Full Text Available Mycetoma is a pathological process in which eumycotic (fungal or actinomycotic causative agents from exogenous source produce grains. It is a localized chronic and deforming infectious disease of subcutaneous tissue, skin and bones. We report the first case of eumycetoma of the oral cavity in world literature. CASE REPORT: A 43-year-old male patient, complaining of swelling and fistula in the hard palate. On examination, swelling of the anterior and middle hard palate, with fistula draining a dark liquid was observed. The panoramic radiograph showed extensive radiolucent area involving the region of teeth 21-26 and the computerized tomography showed communication with the nasal cavity, suggesting the diagnosis of periapical cyst. Surgery was performed to remove the lesion. Histopathological examination revealed purulent material with characteristic grain. Gram staining for bacteria was negative and Grocott-Gomori staining for the detection of fungi was positive, concluding the diagnosis of eumycetoma. The patient was treated with ketoconazole for nine months, and was considered cured at the end of treatment. CONCLUSION: Histopathological examination, using histochemical staining, and direct microscopic grains examination can provide the distinction between eumycetoma and actinomycetoma accurately.

  5. Applications of cavity optomechanics

    Science.gov (United States)

    Metcalfe, Michael

    2014-09-01

    "Cavity-optomechanics" aims to study the quantum properties of mechanical systems. A common strategy implemented in order to achieve this goal couples a high finesse photonic cavity to a high quality factor mechanical resonator. Then, using feedback forces such as radiation pressure, one can cool the mechanical mode of interest into the quantum ground state and create non-classical states of mechanical motion. On the path towards achieving these goals, many near-term applications of this field have emerged. After briefly introducing optomechanical systems and describing the current state-of-the-art experimental results, this article summarizes some of the more exciting practical applications such as ultra-sensitive, high bandwidth accelerometers and force sensors, low phase noise x-band integrated microwave oscillators and optical signal processing such as optical delay-lines, wavelength converters, and tunable optical filters. In this rapidly evolving field, new applications are emerging at a fast pace, but this article concentrates on the aforementioned lab-based applications as these are the most promising avenues for near-term real-world applications. New basic science applications are also becoming apparent such as the generation of squeezed light, testing gravitational theories and for providing a link between disparate quantum systems.

  6. In situ Measurements of the SPS 200MHz Accelerating Cavity III

    CERN Document Server

    Kramer, Patrick; Caspers, Fritz; Vollinger, Christine; Montesinos, Eric; CERN. Geneva. ATS Department

    2015-01-01

    The main 200MHz travelling wave RF system of the SPS consists of two 5-tank and two 4-tank cavities. This system will be modified during LS 2, and the preparation work has already started. The 5 tank 200MHz travelling wave cavity III was measured in reflection. This Internal Note presents results obtained for the matching of cavity and feeder line, by looking at both frequency and time domain data. Techniques for estimating the feeder line attenuation are also presented.

  7. Cavity coalescence in superplastic deformation

    Energy Technology Data Exchange (ETDEWEB)

    Stowell, M.J.; Livesey, D.W.; Ridley, N.

    1984-01-01

    An analysis of the probability distribution function of particles randomly dispersed in a solid has been applied to cavitation during superplastic deformation and a method of predicting cavity coalescence developed. Cavity size distribution data were obtained from two microduplex nickel-silver alloys deformed superplastically to various extents at elevated temperature, and compared to theoretical predictions. Excellent agreement occurred for small void sizes but the model underestimated the number of voids in the largest size groups. It is argued that the discrepancy results from a combination of effects due to non-random cavity distributions and to enhanced growth rates and incomplete spheroidization of the largest cavities.

  8. Surface state photonic bandgap cavities

    OpenAIRE

    Rahachou, A. I.; Zozoulenko, I. V.

    2005-01-01

    We propose and analyze a new type of a resonant high-Q cavity for lasing, sensing or filtering applications, which is based on a surface states of a finite photonic crystal. We demonstrate that such the cavity can have a Q factor comparable with that one of conventional photonic band-gap defect mode cavities. At the same time, the distinguished feature of the surface mode cavity is that it is situated directly at the surface of the photonic crystal. This might open up new possibilities for de...

  9. Nanofriction in Cavity Quantum Electrodynamics.

    Science.gov (United States)

    Fogarty, T; Cormick, C; Landa, H; Stojanović, Vladimir M; Demler, E; Morigi, Giovanna

    2015-12-01

    The dynamics of cold trapped ions in a high-finesse resonator results from the interplay between the long-range Coulomb repulsion and the cavity-induced interactions. The latter are due to multiple scatterings of laser photons inside the cavity and become relevant when the laser pump is sufficiently strong to overcome photon decay. We study the stationary states of ions coupled with a mode of a standing-wave cavity as a function of the cavity and laser parameters, when the typical length scales of the two self-organizing processes, Coulomb crystallization and photon-mediated interactions, are incommensurate. The dynamics are frustrated and in specific limiting cases can be cast in terms of the Frenkel-Kontorova model, which reproduces features of friction in one dimension. We numerically recover the sliding and pinned phases. For strong cavity nonlinearities, they are in general separated by bistable regions where superlubric and stick-slip dynamics coexist. The cavity, moreover, acts as a thermal reservoir and can cool the chain vibrations to temperatures controlled by the cavity parameters and by the ions' phase. These features are imprinted in the radiation emitted by the cavity, which is readily measurable in state-of-the-art setups of cavity quantum electrodynamics.

  10. Nanofriction in Cavity Quantum Electrodynamics.

    Science.gov (United States)

    Fogarty, T; Cormick, C; Landa, H; Stojanović, Vladimir M; Demler, E; Morigi, Giovanna

    2015-12-01

    The dynamics of cold trapped ions in a high-finesse resonator results from the interplay between the long-range Coulomb repulsion and the cavity-induced interactions. The latter are due to multiple scatterings of laser photons inside the cavity and become relevant when the laser pump is sufficiently strong to overcome photon decay. We study the stationary states of ions coupled with a mode of a standing-wave cavity as a function of the cavity and laser parameters, when the typical length scales of the two self-organizing processes, Coulomb crystallization and photon-mediated interactions, are incommensurate. The dynamics are frustrated and in specific limiting cases can be cast in terms of the Frenkel-Kontorova model, which reproduces features of friction in one dimension. We numerically recover the sliding and pinned phases. For strong cavity nonlinearities, they are in general separated by bistable regions where superlubric and stick-slip dynamics coexist. The cavity, moreover, acts as a thermal reservoir and can cool the chain vibrations to temperatures controlled by the cavity parameters and by the ions' phase. These features are imprinted in the radiation emitted by the cavity, which is readily measurable in state-of-the-art setups of cavity quantum electrodynamics. PMID:26684118

  11. Generation of GHZ-type and \\emph{W}-type entangled coherent states of three-cavity fields

    CERN Document Server

    Yuan, C H; Zhang, Z M; Yuan, Chun-Hua; Ou, Yong-Cheng; Zhang, Zhi-Ming

    2005-01-01

    We present experimental schemes to prepare the three-cavity GHZ-type and \\emph{W}-type entangled coherent states in the context of dispersive cavity quantum electrodynamics. The schemes can be easily generalized to prepare the GHZ-type and \\emph{W}-type entangled coherent states of $n$-cavity fields. The discussion of our schemes indicates that it can be realized by current technologies.

  12. Surface preparation of niobium

    International Nuclear Information System (INIS)

    Any discussion of surface preparation for superconducting rf-surfaces is certainly connected with the question what is the best recipe for achieving high Q-values and high break-down fields. Since the break-down in a cavity is not understood so far and because several mechanisms play a role, it also is not possible to give one recipe which always works. Nevertheless in the past certain preparation techniques for niobium surfaces have been developed and certain rules for preparation can be applied. In the following the to-days state of the art will be described and it is attempted to give a short description of the surface in conjunction with the methods of surface treatments, which generally can be applied to niobium cavities. (orig./WTR)

  13. A Scanning Cavity Microscope

    CERN Document Server

    Mader, Matthias; Hänsch, Theodor W; Hunger, David

    2014-01-01

    Imaging of the optical properties of individual nanosystems beyond fluorescence can provide a wealth of information. However, the minute signals for absorption and dispersion are challenging to observe, and only specialized techniques requiring sophisticated noise rejection are available. Here we use signal enhancement in a scanning optical microcavity to demonstrate ultra-sensitive imaging. Harnessing multiple interactions of probe light with a sample within an optical resonator, we achieve a 1700-fold signal enhancement compared to diffraction-limited microscopy. We demonstrate quantitative imaging of the extinction cross section of gold nanoparticles with a sensitivity below 1 nm2, we show a method to improve spatial resolution potentially below the diffraction limit by using higher order cavity modes, and we present measurements of the birefringence and extinction contrast of gold nanorods. The demonstrated simultaneous enhancement of absorptive and dispersive signals promises intriguing potential for opt...

  14. Fiber cavities for atom chips

    OpenAIRE

    Klappauf, B.G.; Horak, P.; Kazansky, P. G.

    2003-01-01

    We present experimental realizations of several micro-cavities, constructed from standard fiber optic components, which meet the theoretical criteria for single atom detection from laser-cooled samples. We discuss integration of these cavities into state-of-the-art 'atom chips'.

  15. Technical tasks in superconducting cavities

    Energy Technology Data Exchange (ETDEWEB)

    Saito, Kenji [High Energy Accelerator Research Organization, Tsukuba, Ibaraki (Japan)

    1997-11-01

    The feature of superconducting rf cavities is an extremely small surface resistance on the wall. It brings a large energy saving in the operation, even those are cooled with liquid helium. That also makes possible to operate themselves in a higher field gradient comparing to normal conducting cavities, and brings to make accelerators compact. These merits are very important for the future accelerator engineering which is planed at JAERI for the neutron material science and nuclear waste transmutation. This machine is a high intensity proton linac and uses sc cavities in the medium and high {beta} sections. In this paper, starting R and D of proton superconducting cavities, several important technical points which come from the small surface resistance of sc cavities, are present to succeed it and also differences between the medium and high - {beta} structures are discussed. (author)

  16. Mechanical Properties of Niobium Cavities

    Energy Technology Data Exchange (ETDEWEB)

    Ciovati, Gianluigi [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Dhakal, Pashupati [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Matalevich, Joseph R. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Myneni, Ganapati Rao [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)

    2015-09-01

    The mechanical stability of bulk Nb cavity is an important aspect to be considered in relation to cavity material, geometry and treatments. Mechanical properties of Nb are typically obtained from uniaxial tensile tests of small samples. In this contribution we report the results of measurements of the resonant frequency and local strain along the contour of single-cell cavities made of ingot and fine-grain Nb of different purity subjected to increasing uniform differential pressure, up to 6 atm. Measurements have been done on cavities subjected to different heat treatments. Good agreement between finite element analysis simulations and experimental data in the elastic regime was obtained with a single set of values of Young’s modulus and Poisson’s ratio. The experimental results indicate that the yield strength of medium-purity ingot Nb cavities is higher than that of fine-grain, high-purity Nb.

  17. Entanglement Transfer Between Cavity Fields and Excitons in a Driven Quantum Dot System

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    We investigate entanglement transfer from two separate cavities to the excitons in two quantum dots separately placed in the two cavities. The cavity fields and the excitons are treated as two continuous-variable (CV) subsystems. The time-dependent characteristic functions in the Wigner representation for the two subsystems are analytically obtained. Under the conditions that one of the two CV subsystems is initially prepared in a two-mode squeezed vacuum state and the other in its lowest energy state, we show that the entanglement reciprocation between the cavity Reids and the excitons is realizable.

  18. Entanglement reciprocation between two charge qubits and two-cavity field

    Institute of Scientific and Technical Information of China (English)

    Hui-ping CUI; Yan SHAN; Jian ZOU; Bin SHAO

    2008-01-01

    We propose a simple scheme to generate twomode entangled coherent state in two separated cavities and realize the entanglement reciprocation between the superconducting charge qubits and continuous-variable system.By measuring the state of charge qubits,we find that the entanglement of two charge qubits,which are initially prepared in the maximally entangled state,can be transferred to the two-cavity field,and at this time the two-cavity field is in the entangled coherent state.We also find that the entanglement can be retrieved back to the two charge qubits after measuring the state of the two-cavity field.

  19. Field dependent surface resistance of niobium on copper cavities

    Science.gov (United States)

    Junginger, T.

    2015-07-01

    The surface resistance RS of superconducting cavities prepared by sputter coating a niobium film on a copper substrate increases significantly stronger with the applied rf field compared to cavities of bulk material. A possible cause is that the thermal boundary resistance between the copper substrate and the niobium film induces heating of the inner cavity wall, resulting in a higher RS. Introducing helium gas in the cavity, and measuring its pressure as a function of applied field allowed to conclude that the inner surface of the cavity is heated up by less than 120 mK when RS increases with Eacc by 100 n Ω . This is more than one order of magnitude less than what one would expect from global heating. Additionally, the effects of cooldown speed and low temperature baking have been investigated in the framework of these experiments. It is shown that for the current state of the art niobium on copper cavities there is only a detrimental effect of low temperature baking. A fast cooldown results in a lowered RS.

  20. Cavity-assisted quantum bath engineering

    Science.gov (United States)

    Murch, Kater

    2013-03-01

    In practice, quantum systems are never completely isolated, but instead interact with degrees of freedom in the surrounding environment, eventually leading to decoherence. Precision measurement techniques such as nuclear magnetic resonance and interferometry, as well as envisioned quantum schemes for computation, simulation, and data encryption, rely on the ability to prepare and preserve delicate quantum superpositions and entanglement. The conventional route to long-lived quantum coherence involves minimizing coupling to a dissipative bath. Paradoxically, it is possible to instead engineer specific couplings to a quantum environment that allow dissipation to actually preserve coherence. I will discuss our recent demonstration of quantum bath engineering for a superconducting qubit coupled to a microwave cavity. By tailoring the spectrum of microwave photon shot noise in the cavity, we create a dissipative environment that autonomously relaxes the qubit to an arbitrarily specified coherent superposition of the ground and excited states. In the presence of background thermal excitations, this mechanism increases the state purity and effectively cools the dressed atom state to a low temperature. We envision that future multi-qubit implementations could enable the preparation of entangled many-body states suitable for quantum simulation and computation. This work was supported by the IARPA CSQ program.

  1. The application of the CEREC bluecam digital impressions in experimental teaching of cavity preparation%瓷睿刻蓝光照相数字化印模技术在牙体窝洞制备实验课教学中的应用

    Institute of Scientific and Technical Information of China (English)

    贺维; 施斌

    2015-01-01

    Objective To introduces the functions and characteristics of the chairside economical restoration of esthetic ceramics(CEREC) Biuecam digital impressions,and to study its application in experimental teaching of cavity preparation.Methods One hundred and twenty students were divided into experiment group and control group,every group has sixty students.The experiment group was taught by CEREC Bluecam digital impressions system (new teaching method) and the control group was taught by teacher direction with magnifying glass (traditional teaching method) in experimental teaching of cavity preparation.The questionnaire survey and the grades for the student' s works were made.The data was analyzed by SPSS 18.0.Results Compared with control group,the students in experiment group had better grades and gave good evaluation in the new teaching method.Conclusions The CEREC Bluecam digital impressions teaching model is a better method for medical students to master the operation of tooth cavity preparation and strengthen the adaptive faculty of mentality than traditional teaching method.%目的 介绍数字化印模技术的功能和特点,探索瓷睿刻蓝光照相数字化印模技术在牙体窝洞制备实验课教学中的应用效果.方法 选择湖北医药学院2012级口腔医学专业120名学生为研究对象,将其随机分为实验组和对照组,每组各60名学生.实验组由教师采用瓷睿刻蓝光照相数字化印模系统进行教学(以下简称新教学方法),对照组由教师采用头戴式放大镜观察指导方法进行教学(传统教学方法).课后就新教学方法对实验组学生进行问卷调查,并对两组学生的牙体窝洞制备体数字化印模混合随机编号后,由不参加此次研究的3位高年资医师进行评分.将收集到的数据用SPSS 18.0进行统计分析.结果 实验组学生牙体窝洞制备体得分高于对照组学生,并且实验组学生对新教学方法的评价较好.结论 与传统教学方

  2. Beam - cavity interaction beam loading

    International Nuclear Information System (INIS)

    The interaction of a beam with a cavity and a generator in cyclic accelerators or storage rings is investigated. Application of Maxwell's equations together with the nonuniform boundary condition allows one to get an equivalent circuit for a beam-loaded cavity. The general equation for beam loading is obtained on the basis of the equivalent circuit, and the beam admittance is calculated. Formulas for power consumption by a beam-loaded cavity are derived, and the optimal tuning and coupling factor are analyzed. (author)

  3. Preparation and Application of the Prussian Blue/Chitosan Hybrid Film Modified Zinc Oxide Cavities Array/Indium-Tin Oxide Electrode%普鲁士蓝/壳聚糖杂化膜修饰氧化锌球腔阵列/氧化铟锡电极制备及应用

    Institute of Scientific and Technical Information of China (English)

    周宇; 朱庆亮; 尹凡; 孙磊; 周丽娟; 刘亚娟

    2012-01-01

    用Langmuir-Blodgett技术制成了附着聚苯乙烯小球的氧化铟锡(InSnO)模板。将此模板水平置于由硝酸锌及柠檬酸组成的前驱体溶胶中,用溶胶-凝胶法制得氧化锌球腔阵列/氧化铟锡电极。采用电沉积法得到普鲁士蓝/壳聚糖杂化膜修饰的氧化锌球腔阵列/氧化铟锡电极。该电极在pH 7.0~8.0的溶液中具有良好的电化学活性,过氧化氢浓度在7.67×10-7~4.72×10-4mol.L-1范围内与相应的电流响应值呈线性关系,检出限(3S/N)为2.4×10-7mol.L-1。测定2.0×10-5mol.L-1过氧化氢溶液时,其相对标准偏差(n=10)为3.8%。%A pattern plate of indium-tin oxide (InSnO) fixed with polystyrene microballs was prepared by applying the Langmuir-Blodgette technique. The pattern plate was placed horizontally into a precuisor sol containing Zn(NO3 )2 and citric acid, and the ZnO cavities array/InSnO electrode was prepared by the Sol-Jel method. The prussian blue (PB)/chitosan hybrid film modified ZnO cavities array/InSnO electrode was obtained by electrode- position technique. This modified electrode showed good electrochemical activity in solution of pH 7.0-8. 0, and linear relationship was obtained between values of response current and concentration of Hz 02 in the range of 7. 67 × 10^-7-4. 72×10^-4mol·L^-1 , with detection limit (3S/N) of 2.4×10^-7mol · L^-1. Value of RSD (n=10) found in determination of 2.0× 10^-5mol· L^-1 H2O2 was 3.8 %.

  4. New thin film techniques for SC cavities and photo cathodes

    CERN Document Server

    Antoine, C Z

    2013-01-01

    The EuCARD monograph 12, ¨Materials and surface aspects in the development of SRF niobium cavities¨ is a comprehensive review on the state of the art materials and material preparation for SRF cavities, and includes a chapter on state of the art film technology, paving the ground for future research and development. This chapter focuses on innovative multi-layered films to overcome materials limitation at high field, and on innovative coating technologies for traditional materials, and is the basis for the future Thin Film Task in Eucard-2.

  5. A polarization converter array using a twisted-azimuthal liquid crystal in cylindrical polymer cavities.

    Science.gov (United States)

    Wang, Xiahui; Xu, Miao; Ren, Hongwen; Wang, Qionghua

    2013-07-01

    We report a simple method to prepare an array of polarization converters using a twisted-azimuthal nematic liquid crystal (NLC) in cylindrical polymer cavities. When a NLC is filled in a cylindrical polymer cavity, LC in the cavity presents concentrically circular orientations. By treating LC on one side of the cavity with homogeneous alignment, a twisted-azimuthal texture is formed. Such a LC texture can convert a linear polarization light to either radial or azimuthal polarization light depending on the polarization direction of the incident light. The LC surface on the other side of the cavity is convex, so the light after passing through the cavity can be focused as well. The LC texture can be fixed firmly using polymer network. In comparison with previous polarization converters, our polarization converter has the merits of individually miniature size, array of pattern, and lens character. Our polarization converter array has potential applications in tight focusing, imaging, and material processing. PMID:23842407

  6. Multi-purpose 805 MHz Pillbox RF Cavity for Muon Acceleration Studies

    Energy Technology Data Exchange (ETDEWEB)

    Kurennoy, Sergey S. [Los Alamos National Laboratory; Chan, Kwok-Chi Dominic [Los Alamos National Laboratory; Jason, Andrew [Los Alamos National Laboratory; Miyadera, Haruo [Los Alamos National Laboratory; Turchi, Peter J. [Los Alamos National Laboratory

    2011-01-01

    An 805 MHz RF pillbox cavity has been designed and constructed to investigate potential muon beam acceleration and cooling techniques. The cavity can operate at vacuum or under pressure to 100 atmospheres, at room temperature or in a liquid nitrogen bath at 77 K. The cavity is designed for easy assembly and disassembly with bolted construction using aluminum seals. The surfaces of the end walls of the cavity can be replaced with different materials such as copper, aluminum, beryllium, or molybdenum, and with different geometries such as shaped windows or grid structures. Different surface treatments such as electro polished, high-pressure water cleaned, and atomic layer deposition are being considered for testing. The cavity has been designed to fit inside the 5-Tesla solenoid in the MuCool Test Area at Fermilab. Current status of the cavity prepared for initial conditioning and operation in the external magnetic field is discussed.

  7. Practical scheme for remote preparation of a photon-photon entangled state

    Institute of Scientific and Technical Information of China (English)

    Tan Jia; Fang Mao-Fa

    2006-01-01

    We present a scheme to remotely prepare a photon-photon entangled state via entanglement swapping in cavity QED. Using two successive processes of appropriate atom-cavity interaction and subsequent measurements, we obtain the entangled state with certain probability.

  8. Geometry-Invariant Resonant Cavities

    CERN Document Server

    Liberal, Iñigo; Engheta, Nader

    2015-01-01

    Resonant cavities are one of the basic building blocks in various disciplines of science and technology, with numerous applications ranging from abstract theoretical modeling to everyday life devices. The eigenfrequencies of conventional cavities are a function of its geometry, and, thus, the size and shape of a resonant cavity is selected in order to operate at a specific frequency. Here, we demonstrate theoretically the existence of geometry-invariant resonant cavities, i.e., resonators whose eigenfrequency is invariant with respect to geometrical deformations. This effect is obtained by exploiting the unusual properties of zero-index metamaterials, which enable decoupling of the time and spatial field variations. This new class of resonators may inspire alternative design concepts, and it might lead to the first generation of deformable resonant devices.

  9. Vibration insensitive optical ring cavity

    Institute of Scientific and Technical Information of China (English)

    Miao Jin; Jiang Yan-Yi; Fang Su; Bi Zhi-Yi; Ma Long-Sheng

    2009-01-01

    The mounting configuration of an optical ring cavity is optimized for vibration insensitivity by finite element analysis. A minimum response to vertical accelerations is found by simulations made for different supporting positions.

  10. SRF Cavity Fabrication and Materials

    CERN Document Server

    Singer, W

    2014-01-01

    The technological and metallurgical requirements of material for highgradient superconducting cavities are described. High-purity niobium, as the preferred metal for the fabrication of superconducting accelerating cavities, should meet exact specifications. The content of interstitial impurities such as oxygen, nitrogen, and carbon must be below 10μg/g. The hydrogen content should be kept below 2μg/g to prevent degradation of the Q-value under certain cool-down conditions. The material should be free of flaws (foreign material inclusions or cracks and laminations) that can initiate a thermal breakdown. Defects may be detected by quality control methods such as eddy current scanning and identified by a number of special methods. Conventional and alternative cavity fabrication methods are reviewed. Conventionally, niobium cavities are fabricated from sheet niobium by the formation of half-cells by deep drawing, followed by trim machining and Electron-Beam Welding (EBW). The welding of half-cells is a delicate...

  11. Niobium LEP 2 accelerating cavities

    CERN Multimedia

    An accelerating cavity from LEP. This could be cut open to show the layer of niobium on the inside. Operating at 4.2 degrees above absolute zero, the niobium is superconducting and carries an accelerating field of 6 million volts per metre with negligible losses. Each cavity has a surface of 6 m2. The niobium layer is only 1.2 microns thick, ten times thinner than a hair. Such a large area had never been coated to such a high accuracy. A speck of dust could ruin the performance of the whole cavity so the work had to be done in an extremely clean environment. These challenging requirements pushed European industry to new achievements. 256 of these cavities were used in an upgrade of the LEP accelerator to double the energy of the particle beams.

  12. LEP Radio Frequency Copper Cavities

    CERN Multimedia

    The pulse of a particle accelerator. 128 of these radio frequency cavities were positioned around CERN's 27-kilometre LEP ring to accelerate electrons and positrons. The acceleration was produced by microwave electric oscillations at 352 MHz. The electrons and positrons were grouped into bunches, like beads on a string, and the copper sphere at the top stored the microwave energy between the passage of individual bunches. This made for valuable energy savings as it reduced the heat generated in the cavity.

  13. TESLA superconducting RF cavity development

    Energy Technology Data Exchange (ETDEWEB)

    Koepke, K. [Fermi National Accelerator Lab., Batavia, IL (United States); TESLA Collaboration

    1995-05-01

    The TESLA collaboration has made steady progress since its first official meeting at Cornell in 1990. The infrastructure necessary to assemble and test superconducting rf cavities has been installed at the TESLA Test Facility (TTF) at DESY. 5-cell, 1.3 GHz cavities have been fabricated and have reached accelerating fields of 25 MV/m. Full sized 9-cell copper cavities of TESLA geometry have been measured to verify the higher order modes present and to evaluate HOM coupling designs. The design of the TESLA 9-cell cavity has been finalized and industry has started delivery. Two prototype 9-cell niobium cavities in their first tests have reached accelerating fields of 10 MV/m and 15 MV/m in a vertical dewar after high peak power (HPP) conditioning. The first 12 m TESLA cryomodule that will house 8 9-cell cavities is scheduled to be delivered in Spring 1995. A design report for the TTF is in progress. The TTF test linac is scheduled to be commissioned in 1996/1997. (orig.).

  14. Simultaneous measurement of temperature and refractive index using focused ion beam milled Fabry-Perot cavities in optical fiber micro-tips.

    Science.gov (United States)

    André, Ricardo M; Warren-Smith, Stephen C; Becker, Martin; Dellith, Jan; Rothhardt, Manfred; Zibaii, M I; Latifi, H; Marques, Manuel B; Bartelt, Hartmut; Frazão, Orlando

    2016-06-27

    Optical fiber micro-tips are promising devices for sensing applications in small volume and difficult to access locations, such as biological and biomedical settings. The tapered fiber tips are prepared by dynamic chemical etching, reducing the size from 125 μm to just a few μm. Focused ion beam milling is then used to create cavity structures on the tapered fiber tips. Two different Fabry-Perot micro-cavities have been prepared and characterized: a solid silica cavity created by milling two thin slots and a gap cavity. A third multi-cavity structure is fabricated by combining the concepts of solid silica cavity and gap cavity. This micro-tip structure is analyzed using a fast Fourier transform method to demultiplex the signals of each cavity. Simultaneous measurement of temperature and external refractive index is then demonstrated, presenting sensitivities of - 15.8 pm/K and -1316 nm/RIU, respectively.

  15. Exploration of material removal rate of srf elliptical cavities as a function of media type and cavity shape on niobium and copper using centrifugal barrel polishing (cbp)

    Energy Technology Data Exchange (ETDEWEB)

    Palczewski, Ari [JLAB; Ciovati, Gianluigi [JLAB; Li, Yongming [PEKING; Geng, Rongli [JLAB

    2013-09-01

    Centrifugal barrel polishing (cbp) for SRF application is becoming more wide spread as the technique for cavity surface preparation. CBP is now being used in some form at SRF laboratories around the world including in the US, Europe and Asia. Before the process can become as mature as wet chemistry like eletro-polishing (EP) and buffered chemical polishing (BCP) there are many questions which remain unanswered. One of these topics includes the uniformity of removal as a function of cavity shape and material type. In this presentation we show CBP removal rates for various media types on 1.3 GHz TESLA and 1.5 GHz CEBAF large/fine grain niobium cavities, and 1.3GHz low surface field copper cavity. The data will also include calculated RF frequency shift modeling non-uniform removal as a function of cavity position and comparing them with CBP results.

  16. Cavity Control and Cooling of Nanoparticles in High Vacuum

    Science.gov (United States)

    Millen, James

    2016-05-01

    Levitated systems are a fascinating addition to the world of optically-controlled mechanical resonators. It is predicted that nanoparticles can be cooled to their c.o.m. ground state via the interaction with an optical cavity. By freeing the oscillator from clamping forces dissipation and decoherence is greatly reduced, leading to the potential to produce long-lived, macroscopically spread, mechanical quantum states, allowing tests of collapse models and any mass limit of quantum physics. Reaching the low pressures required to cavity-cool to the ground state has proved challenging. Our approach is to cavity cool a beam of nanoparticles in high vacuum. We can cool the c.o.m. motion of nanospheres, and control the rotation of nanorods, with the potential to produce cold, aligned nanostructures. Looking forward, we will utilize novel microcavities to enhance optomechanical cooling, preparing particles in a coherent beam ideally suited to ultra-high mass interferometry at 107 a.m.u.

  17. Cavity Cooling of Nanoparticles: Towards Matter-Wave experiments

    Science.gov (United States)

    Millen, James; Kuhn, Stefan; Arndt, Markus

    2016-05-01

    Levitated systems are a fascinating addition to the world of optically-controlled mechanical resonators. It is predicted that nanoparticles can be cooled to their c.o.m. ground state via the interaction with an optical cavity. By freeing the oscillator from clamping forces dissipation and decoherence is greatly reduced, leading to the potential to produce long-lived, macroscopically spread, mechanical quantum states, allowing tests of collapse models and any mass limit of quantum physics. Reaching the low pressures required to cavity-cool to the ground state has proved challenging. Our approach is to cavity cool a beam of nanoparticles in high vacuum. We can cool the c.o.m. motion of nanospheres a few hundred nanometers in size. Looking forward, we will utilize novel microcavities to enhance optomechanical cooling, preparing particles in a coherent beam ideally suited to ultra-high mass interferometry at 107 a.m.u.

  18. 3D cavity detection technique and its application based on cavity auto scanning laser system

    Institute of Scientific and Technical Information of China (English)

    LIU Xi-ling; LI Xi-bing; LI Fa-ben; ZHAO Guo-yan; QIN Yu-hui

    2008-01-01

    Ground constructions and mines are severely threatened by underground cavities especially those unsafe or inaccessible ones. Safe and precise cavity detection is vital for reasonable cavity evaluation and disposal. The conventional cavity detection methods and their limitation were analyzed. Those methods cannot form 3D model of underground cavity which is used for instructing the cavity disposal; and their precisions in detection are always greatly affected by the geological circumstance. The importance of 3D cavity detection in metal mine for safe exploitation was pointed out; and the 3D cavity laser detection method and its principle were introduced. A cavity auto scanning laser system was recommended to actualize the cavity 3D detection after comparing with the other laser detection systems. Four boreholes were chosen to verify the validity of the cavity auto scanning laser system. The results show that the cavity auto scanning laser system is very suitable for underground 3D cavity detection, especially for those inaccessible ones.

  19. Normal Conducting RF Cavity for MICE

    International Nuclear Information System (INIS)

    Normal conducting RF cavities must be used for the cooling section of the international Muon Ionization Cooling Experiment (MICE), currently under construction at Rutherford Appleton Laboratory (RAL) in the UK. Eight 201-MHz cavities are needed for the MICE cooling section; fabrication of the first five cavities is complete. We report the cavity fabrication status including cavity design, fabrication techniques and preliminary low power RF measurements.

  20. Interference control of perfect photon absorption in cavity quantum electrodynamics

    CERN Document Server

    Wang, Liyong; Zhu, Yifu; Agarwal, G S

    2016-01-01

    We propose and analyze a scheme for controlling coherent photon transmission and reflection in a cavity-quantum-electrodynamics (CQED) system consisting of an optical resonator coupled with three-level atoms coherently prepared by a control laser from free space. When the control laser is off and the cavity is excited by two identical light fields from two ends of the cavity, the two input light fields can be completely absorbed by the CQED system and the light energy is converted into the excitation of the polariton states, but no light can escape from the cavity. Two distinct cases of controlling the perfect photon absorption are analyzed: (a) when the control laser is tuned to the atomic resonance and creates electromagnetically induced transparency, the prefect photon absorption is suppressed and the input light fields are nearly completely transmitted through the cavity; (b) when the control laser is tuned to the polariton state resonance and inhibits the polariton state excitation, the perfect photon ab...

  1. First coupled CH power cavity for the FAIR proton injector

    Energy Technology Data Exchange (ETDEWEB)

    Brodhage, Robert; Vinzenz, Wolfgang [GSI Helmholtzzentrum fuer Schwerionenforschung (Germany); Almomani, Ali; Ratzinger, Ulrich [Institut fuer Angewandte Physik, Uni Frankfurt (Germany)

    2014-07-01

    For the research program with cooled antiprotons at FAIR a dedicated 70 MeV, 70 mA proton injector is required. The main acceleration of this room temperature linac will be provided by six CH cavities operated at 325 MHz. Each cavity will be powered by a 2.5 MW Klystron. For the second acceleration unit from 11.5 MeV to 24.2 MeV a 1:2 scaled model has been built. Low level RF measurements have been performed to determine the main parameters and to prove the concept of coupled CH cavities. In 2012, the assembly and tuning of the first power prototype was finished. Until then, the cavity was tested with a preliminary aluminum drift tube structure, which was used for precise frequency and field tuning. In 2013 the final drift tube structure has been welded inside the main tanks and the preparation for copper plating has taken place. This paper reports on the main tuning and commissioning steps towards that novel type of DTL, and it shows the latest results measured on a fully operational and copper plated CH proton cavity.

  2. First coupled CH power cavity for the FAIR proton injector

    Energy Technology Data Exchange (ETDEWEB)

    Brodhage, Robert; Ratzinger, Ulrich [IAP, Frankfurt University, Frankfurt am Main (Germany); Vinzenz, Wolfgang; Clemente, Gianluigi [GSI, Darmstadt (Germany)

    2013-07-01

    For the research program with cooled antiprotons at FAIR a dedicated 70 MeV, 70 mA proton injector is required. The main acceleration of this room temperature linac will be provided by six CH cavities operated at 325 MHz. Each cavity will be powered by a 2.5 MW Klystron. For the second acceleration unit from 11.5 MeV to 24.2 MeV a 1:2 scaled model has been built. Low level RF measurements have been performed to determine the main parameters and to prove the concept of coupled CH cavities. In Summer 2012, the assembly and tuning of the first power prototype was finished. Until then, the cavity was tested with a preliminary aluminum drift tube structure, which was used for precise frequency and field tuning. Before Spring 2013 the final drift tube structure will be welded inside the main tanks and the preparation for copper plating will take place. This paper reports on the main tuning and commissioning steps towards that novel type of DTL and it shows the latest results measured on a fully operational CH proton cavity.

  3. Superposition of Fock states via adiabatic passage in a coupled four-level atom-cavity system

    Institute of Scientific and Technical Information of China (English)

    Gong Shang-Qing; Jin Shi-Qi; Li Ru-Xin; Zheng Zhen-Xun; Xu Zhi-Zhan

    2004-01-01

    We have investigated the behaviour of an atom-cavity system via a stimulated Raman adiabatic passage technique in a four-level system, in which two dark states are present. We find, because of the coherent control field, that a superposition of Fock states can be prepared, even when the cavity is initially not in its vacuum state. This method provides a way to generate arbitrary quantum states of a cavity field.

  4. Atom-assisted quadrature squeezing of a mechanical oscillator inside a dispersive cavity

    Science.gov (United States)

    Biswas, Asoka; Chauhan, Anil Kumar

    2016-05-01

    Measurement of position of a mesoscopic harmonic oscillator below standard quantum limit in cavity optomechanics has seen a growing interest in recent times. If the oscillator is suspended inside the cavity (with both the mirrors fixed) at a position where the cavity frequency becomes extremum (a membrane-in-the-middle setup), large squeezing can be achieved by conditional measurement of thermal photons; however the cavity decay degrades such squeezing. Here we propose an atom-cavity-oscillator hybrid scheme, in which the effect of cavity decay is eliminated via dispersive coupling of the cavity mode. The atom in Λ configuration is considered to be trapped on either side of the membrane inside the cavity. We show that a considerable amount of squeezing (far beyond the 3 dB limit) can be achieved that is not affected by spontaneous emission of the atom. The squeezing depends upon the initial preparation of the atomic states. Further, the external classical fields, that drive the atomic transition and the cavity mode, control the degree of squeezing and can also lead to a strong effective atom-oscillator coupling. Effect of thermal phonon bath on squeezing is studied in terms of the squeezing spectrum. The results are supported by the detailed analytical calculations.

  5. RRR Characteristics for SRF Cavities

    CERN Document Server

    Jung, Yoochul; Joung, Mijoung

    2015-01-01

    The first heavy ion accelerator is being constructed by the rare isotope science project (RISP) launched by the Institute of Basic Science (IBS) in South Korea. Four different types of superconducting cavities were designed, and prototypes were fabricated such as a quarter wave resonator (QWR), a half wave resonator (HWR) and a single spoke resonator (SSR). One of the critical factors determining performances of the superconducting cavities is a residual resistance ratio (RRR). The RRR values essentially represent how much niobium is pure and how fast niobium can transmit heat as well. In general, the RRR degrades during electron beam welding due to the impurity incorporation. Thus it is important to maintain RRR above a certain value at which a niobium cavity shows target performance. In this study, RRR degradation related with electron beam welding conditions, for example, welding power, welding speed, and vacuum level will be discussed.

  6. RRR Characteristics for SRF cavities

    Science.gov (United States)

    Jung, Yoochul; Hyun, Myungook; Joung, Mijoung

    2015-10-01

    The first heavy ion accelerator is being constructed by the rare isotope science project (RISP) launched by the Institute of Basic Science (IBS) in South Korea. Four different types of superconducting cavities were designed, and prototypes such as a quarter-wave resonator (QWR), a half-wave resonator (HWR) and a single-spoke resonator (SSR) were fabricated. One of the critical factors determining the performances of superconducting cavities is the residual resistance ratio (RRR). The RRR values essentially represent how pure niobium is and how fast niobium can transmit heat. In general, the RRR degrades during electron beam welding due to impurity incorporation. Thus, it is important to maintain the RRR above a certain value at which a niobium cavity shows target performance. In this study, RRR degradation related with electron beam welding conditions, for example, the welding power, welding speed, and vacuum level, will be discussed.

  7. Cavity QED with atomic mirrors

    CERN Document Server

    Chang, D E; Gorhskov, A V; Kimble, H J

    2012-01-01

    A promising approach to merge atomic systems with scalable photonics has emerged recently, which consists of trapping cold atoms near tapered nanofibers. Here, we describe a novel technique to achieve strong, coherent coupling between a single atom and photon in such a system. Our approach makes use of collective enhancement effects, which allow a lattice of atoms to form a high-finesse cavity within the fiber. We show that a specially designated "impurity" atom within the cavity can experience strongly enhanced interactions with single photons in the fiber. Under realistic conditions, a "strong coupling" regime can be reached, wherein it becomes feasible to observe vacuum Rabi oscillations between the excited impurity atom and a cavity photon. This technique can form the basis for a scalable quantum information network using atom-nanofiber systems.

  8. Influence of Er:YAG laser ablation on cavity surface and cavity shape

    Science.gov (United States)

    Jelinkova, Helena; Dostalova, Tatjana; Krejsa, Otakar; Hamal, Karel; Kubelka, Jiri; Prochazka, Stanislav

    1996-04-01

    The cavity surface and shape after Er:YAG laser ablation at different energies, number of pulses and at a different repetition rate were observed. Longitudinal sections of extracted human incisors and transverse sections of ivory tusk were cut and polished to flat and glazed surfaces. The samples thickness was from 3 to 5 mm. The Er:YAG laser was operating in a free-running (long pulse) mode. The laser radiation was focused onto the tooth surface by CaF2 lens (f equals 55 mm). During the experiment, the teeth were steady and the radiation was delivered by a special mechanical arm fixed in a special holder; fine water mist was also used (water-mJ/min, a pressure of two atm, air-pressure three atm). The shapes of the prepared cavities were studied either by using a varying laser energies (from 70 mJ to 500 mJ) for a constant number of pulses, or a varying number of pulses (from one to thirty) for constant laser energy. The repetition rate was changed from 1 to 2 Hz. For evaluating the surfaces, shapes, and profiles, scanning electron microscopy and photographs from a light microscope were used. The results were analyzed both quantitatively and qualitatively. It is seen that there is no linear relation between the radiation pulse energy and the size of the prepared holes. With increasing the incident energy the cavity depth growth is limited. There exists some saturation not only in the enamel and dentin but especially in the homogeneous ivory.

  9. Sterility of the uterine cavity

    DEFF Research Database (Denmark)

    Møller, Birger R.; Kristiansen, Frank V.; Thorsen, Poul;

    1995-01-01

    In a prospective open study the sterility of the uterine cavity was evaluated in 99 women admitted for hysterectomy. The indications for hysterectomy were in most cases persistent irregular vaginal bleeding and fibromyomas of the uterus. Samples for both aerobic and anaerobic bacteria, Chlamydia...... trachomatis, yeasts and viruses were taken preoperatively from the apex of the vagina and cervical os. Immediately after hysterectomy the uterus was opened under sterile conditions and samples obtained from the isthmus and fundus of the uterine cavity for microbiological examination. Wet smears were taken...

  10. Protein dynamics: hydration and cavities

    Directory of Open Access Journals (Sweden)

    Heremans K.

    2005-01-01

    Full Text Available The temperature-pressure behavior of proteins seems to be unique among the biological macromolecules. Thermodynamic as well as kinetic data show the typical elliptical stability diagram. This may be extended by assuming that the unfolded state gives rise to volume and enthalpy-driven liquid-liquid transitions. A molecular interpretation follows from the temperature and the pressure dependence of the hydration and cavities. We suggest that positron annihilation spectroscopy can provide additional quantitative evidence for the contributions of cavities to the dynamics of proteins. Only mature amyloid fibrils that form from unfolded proteins are very resistant to pressure treatment.

  11. Nanobeam Cavities for Reconfigurable Photonics

    OpenAIRE

    Deotare, Parag

    2012-01-01

    We investigate the design, fabrication, and experimental characterization of high quality factor photonic crystal nanobeam cavities, with theoretical quality factors of \\(1.4 × 10^7\\) in silicon, operating at ~1550 nm. By detecting the cross-polarized resonantly scattered light from a normally incident laser beam, we measure a quality factor of nearly \\(7.5 × 10^5\\). We show on-chip integration of the cavities using waveguides and an inverse taper geometry based mode size converters, and also...

  12. Synchronization in an optomechanical cavity.

    Science.gov (United States)

    Shlomi, Keren; Yuvaraj, D; Baskin, Ilya; Suchoi, Oren; Winik, Roni; Buks, Eyal

    2015-03-01

    We study self-excited oscillations (SEO) in an on-fiber optomechanical cavity. Synchronization is observed when the optical power that is injected into the cavity is periodically modulated. A theoretical analysis based on the Fokker-Planck equation evaluates the expected phase space distribution (PSD) of the self-oscillating mechanical resonator. A tomography technique is employed for extracting PSD from the measured reflected optical power. Time-resolved state tomography measurements are performed to study phase diffusion and phase locking of the SEO. The detuning region inside which synchronization occurs is experimentally determined and the results are compared with the theoretical prediction. PMID:25871175

  13. Cavity Solitons in VCSEL Devices

    Directory of Open Access Journals (Sweden)

    S. Barbay

    2011-01-01

    Full Text Available We review advances on the experimental study of cavity solitons in VCSELs in the past decade. We emphasize on the design and fabrication of electrically or optically pumped broad-area VCSELs used for CSs formation and review different experimental configurations. Potential applications of CSs in the field of photonics are discussed, in particular the use of CSs for all-optical processing of information and for VCSELs characterization. Prospects on self-localization studies based on vertical cavity devices involving new physical mechanisms are also given.

  14. Plasma Processing of SRF Cavities for the next Generation Of Particle Accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Vuskovic, Leposava

    2015-11-23

    The cost-effective production of high frequency accelerating fields are the foundation for the next generation of particle accelerators. The Ar/Cl2 plasma etching technology holds the promise to yield a major reduction in cavity preparation costs. Plasma-based dry niobium surface treatment provides an excellent opportunity to remove bulk niobium, eliminate surface imperfections, increase cavity quality factor, and bring accelerating fields to higher levels. At the same time, the developed technology will be more environmentally friendly than the hydrogen fluoride-based wet etching technology. Plasma etching of inner surfaces of standard multi-cell SRF cavities is the main goal of this research in order to eliminate contaminants, including niobium oxides, in the penetration depth region. Successful plasma processing of multi-cell cavities will establish this method as a viable technique in the quest for more efficient components of next generation particle accelerators. In this project the single-cell pill box cavity plasma etching system is developed and etching conditions are determined. An actual single cell SRF cavity (1497 MHz) is plasma etched based on the pill box cavity results. The first RF test of this plasma etched cavity at cryogenic temperature is obtained. The system can also be used for other surface modifications, including tailoring niobium surface properties, surface passivation or nitriding for better performance of SRF cavities. The results of this plasma processing technology may be applied to most of the current SRF cavity fabrication projects. In the course of this project it has been demonstrated that a capacitively coupled radio-frequency discharge can be successfully used for etching curved niobium surfaces, in particular the inner walls of SRF cavities. The results could also be applicable to the inner or concave surfaces of any 3D structure other than an SRF cavity.

  15. Entanglement swapping between atom and cavity and generation of entangled state of cavity fields

    Institute of Scientific and Technical Information of China (English)

    Chen Ai-Xi; Deng Li

    2007-01-01

    This paper proposes a scheme where entanglement swapping between atom and cavity can be realized. A-type three-level atoms interacting resonantly with cavity field are considered. By detecting atom and cavity field, it realizes entanglement swapping between atom and cavity. It uses the technique of entanglement swapping to generate an entangled state of two cavity fields by measuring on atoms. It discusses the experimental feasibility of the proposed scheme and application of entangled state of cavity fields.

  16. Quantum-state input-output relations for absorbing cavities

    International Nuclear Information System (INIS)

    The quantized electromagnetic field inside and outside an absorbing high-Q cavity is studied, with special emphasis on the absorption losses in the coupling mirror and their influence on the outgoing field. Generalized operator input-output relations are derived, which are used to calculate the Wigner function of the outgoing field. To illustrate the theory, the preparation of the outgoing field in a Schroedinger cat-like state is discussed

  17. Efeito priming entre figuras de partes do corpo

    OpenAIRE

    Oliveira, Felipe Santos de

    2010-01-01

    Um estímulo visual (letra, palavra ou objeto) pode ter um efeito duradouro sobre o processamento de estímulos subsequentes. Neste trabalho, investigamos o efeito priming de figuras de mãos humanas (esquerda/direita, vista palmar/dorsal) sobre o Tempo de Reação Manual (TRM) em uma tarefa usando as mesmas figuras como estímulo alvo. Os pares de figuras podiam ser iguais ou não, de acordo com parâmetros como lateralidade ou vista. Três experimentos foram realizados (lateralidade, vista e cor). N...

  18. Efeitos colaterais do metilfenidato Side effects of methylphenidate

    OpenAIRE

    Giuseppe Pastura; Paulo Mattos

    2004-01-01

    OBJETIVOS: Revisar os principais efeitos colaterais do metilfenidato, em curto e longo prazos, no tratamento de crianças com Transtorno do Déficit de Atenção (TDAH). FONTES DE DADOS: Revisão de literatura nos últimos doze anos através de pesquisa no Medline e Lilacs. RESULTADOS: Dentre os efeitos colaterais que surgem em curto prazo, prevalecem a redução de apetite, insônia, cefaléia e dor abdominal, sendo a maioria autolimitada, dose-dependente e de média intensidade. Dentre aqueles em longo...

  19. Droplet based cavities and lasers

    DEFF Research Database (Denmark)

    Mølhave, Kristian; Kristensen, Anders; Mortensen, Asger

    2009-01-01

    The self-organized and molecularly smooth surface on liquid microdroplets makes them attractive as optical cavities with very high quality factors. This chapter describes the basic theory of optical modes in spherical droplets. The mechanical properties including vibrational excitation are also d...

  20. Cavity length below chute aerators

    Institute of Scientific and Technical Information of China (English)

    WU JianHua; RUAN ShiPing

    2008-01-01

    It is proved that air entrainment is one of the efficient measures dealing with cavitation control for the release works of hydropower projects. There are many factors to be considered in designing a chute aerator. One of the most important factors concerns the cavity length below the aerator, which has outstanding effects on air entrainment against cavitation damage. It is crucial to determine reasonable emergence angle for the calculation of the cavity length. In the present paper the overall effects of structural and hydraulic parameters on the emergence angle of the flow from the aerator were analyzed. Four improved expressions of the emergence angle with weight coefficient were investigated through experimental data of 68 points observed from 12 aerators of 6 hydropower projects, of both model and prototype, on the basis of error theory. A method to calculate the cavity length below aerators was suggested, which considers overall effects of the above mentioned parameters. Comparison between the method in this paper and the other five methods of calculating the cavity length showed that the present method is much more reliable than the existing methods while the mean error of the method is less than others.

  1. Cavity length below chute aerators

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    It is proved that air entrainment is one of the efficient measures dealing with cavi-tation control for the release works of hydropower projects. There are many factors to be considered in designing a chute aerator. One of the most important factors concerns the cavity length below the aerator,which has outstanding effects on air entrainment against cavitation damage. It is crucial to determine reasonable emergence angle for the calculation of the cavity length. In the present paper the overall effects of structural and hydraulic parameters on the emergence angle of the flow from the aerator were analyzed. Four improved expressions of the emer-gence angle with weight coefficient were investigated through experimental data of 68 points observed from 12 aerators of 6 hydropower projects,of both model and prototype,on the basis of error theory. A method to calculate the cavity length be-low aerators was suggested,which considers overall effects of the above men-tioned parameters. Comparison between the method in this paper and the other five methods of calculating the cavity length showed that the present method is much more reliable than the existing methods while the mean error of the method is less than others.

  2. Large-mode enhancement cavities.

    Science.gov (United States)

    Carstens, Henning; Holzberger, Simon; Kaster, Jan; Weitenberg, Johannes; Pervak, Volodymyr; Apolonski, Alexander; Fill, Ernst; Krausz, Ferenc; Pupeza, Ioachim

    2013-05-01

    In passive enhancement cavities the achievable power level is limited by mirror damage. Here, we address the design of robust optical resonators with large spot sizes on all mirrors, a measure that promises to mitigate this limitation by decreasing both the intensity and the thermal gradient on the mirror surfaces. We introduce a misalignment sensitivity metric to evaluate the robustness of resonator designs. We identify the standard bow-tie resonator operated close to the inner stability edge as the most robust large-mode cavity and implement this cavity with two spherical mirrors with 600 mm radius of curvature, two plane mirrors and a round trip length of 1.2 m, demonstrating a stable power enhancement of near-infrared laser light by a factor of 2000. Beam radii of 5.7 mm × 2.6 mm (sagittal × tangential 1/e(2) intensity radius) on all mirrors are obtained. We propose a simple all-reflective ellipticity compensation scheme. This will enable a significant increase of the attainable power and intensity levels in enhancement cavities. PMID:23670017

  3. Field emission in RF cavities

    Energy Technology Data Exchange (ETDEWEB)

    Bonin, B. [CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France). Dept. d`Astrophysique, de la Physique des Particules, de la Physique Nucleaire et de l`Instrumentation Associee

    1996-01-01

    Electron field emission limits the accelerating gradient in superconducting cavities. It is shown how and why it is an important problem. The phenomenology of field emission is then described, both in DC and RF regimes. Merits of a few plausible `remedies` to field emission are discussed. (author). 20 refs.

  4. Hybrid Vertical-Cavity Laser

    DEFF Research Database (Denmark)

    2010-01-01

    The present invention provides a light source (2) for light circuits on a silicon platform (3). A vertical laser cavity is formed by a gain region (101) arranged between a top mirror (4) and a bottom grating-mirror (12) in a grating region (11) in a silicon layer (10) on a substrate. A waveguide...

  5. A 200 MHz prebunching cavity

    CERN Multimedia

    1977-01-01

    This cavity was installed in the PS ring and proved very efficient in providing a modulation on the PS beam before it is injected into the SPS machine. Moreover it allowed longitudinal instabilities studies at high intensities. Roberto Cappi stands on the left.

  6. Generation of multi-atom W states via Raman transition in an optical cavity

    International Nuclear Information System (INIS)

    A simple scheme is proposed to generate the W state of N λ-type neutral atoms trapped in an optical cavity via Raman transition. Conditional on no photon leakage from the cavity, the N-qubit W state can be prepared perfectly by turning on a classical coupling field for an appropriate time. Compared with the previous ones, our scheme requires neither individual laser addressing of the atoms, nor demand for controlling N atoms to go through an optical cavity simultaneously with a constant velocity. We investigate the influence of cavity decay using the quantum jump approach and show that the preparation time decreases and the success probability increases with atom number because of a collective enhancement of the coupling. (general)

  7. Nanobeam cavities for Reconfigurable Photonics

    Science.gov (United States)

    Deotare, Parag B.

    We investigate the design, fabrication, and experimental characterization of high quality factor photonic crystal nanobeam cavities, with theoretical quality factors of 1.4 x 107 in silicon, operating at ˜ 1550 nm. By detecting the cross-polarized resonantly scattered light from a normally incident laser beam, we measure a quality factor of nearly 7.5 x 105. We show on-chip integration of the cavities using waveguides and an inverse taper geometry based mode size converters, and also demonstrate tuning of the optical resonance using thermo-optic effect. We also study coupled cavities and show that the single nanobeam cavity modes are coupled into even and odd superposition modes. Using electrostatic force and taking advantage of the highly dispersive nature of the even mode to the nanobeam separation, we demonstrate dynamically reconfigurable optical filters tunable continuously and reversibly over a 9.5 nm wavelength range. The electrostatic force, obtained by applying bias voltages directly to the nanobeams, is used to control the spacing between the nanobeams, which in turn results in tuning of the cavity resonance. The observed tuning trends were confirmed through simulations that modeled the electrostatic actuation as well as the optical resonances in our reconfigurable geometries. Finally we demonstrate reconfiguration of coupled cavities by using optical gradient force induced mechanical actuation. Propagating waveguide modes that exist over wide wavelength range are used to actuate the structures and in that way control the resonance of a localized cavity mode. Using this all-optical approach, more than 18 linewidths of tuning range is demonstrated. Using an on-chip temperature self-referencing method that we developed, we determined that 20% of the total tuning was due to optomechanical reconfiguration and the rest due to thermo-optic effects. By operating the device at frequencies higher than the thermal cut-off, we show high speed operation dominated by

  8. Effect of respiratory muscle training on pulmonary function in preoperative preparation of tobacco smokers Efeito do treinamento dos músculos respiratórios sobre a função pulmonar no preparo pré-operatório de tabagistas

    Directory of Open Access Journals (Sweden)

    Carrie Chueiri Ramos Galvan

    2007-04-01

    Full Text Available PURPOSE: To evaluate the effect of utilization of a specific training program of respiratory muscles on pulmonary function in tobacco smokers. METHODS: Fifty asymptomatic tobacco smokers with age superior to 30 years were studied, at the moments: A0 - initial evaluation followed by protocol of respiratory exercises; A1 - reevaluation after 10 minutes of protocol application; and A2 - final reevaluation after 2 weeks of training utilizing the same protocol 3 times per week. The evaluation was realized through measures of maximum respiratory pressures (PImax and PEmax, respiratory peak flow (IPF and EPF, maximum voluntary ventilation (MVV, forced vital capacity (FVC and forced expiratory volume at the 1st second (FEV1. RESULTS: There was no improvement from initial to final evaluation in FVC and FEV1. But there were significant increases in the variables IPF, EPF, MVV and PImax at evaluations A1 and A2. The PEmax variable increased only at evaluation A2. CONCLUSION: The application of the protocol of respiratory exercises with and without additional load in tobacco smokers produced immediate improvement in the performance of respiratory muscles, but this gain was more accentuated after 2 weeks of exercise.OBJETIVO: Avaliar o efeito da utilização de um programa de treinamento específico dos músculos respiratórios sobre a função pulmonar em indivíduos tabagistas. MÉTODOS: Foram estudados 50 indivíduos tabagistas assintomáticos com idade superior a 30 anos, nos seguintes momentos: A0 - avaliação inicial seguida do protocolo de exercícios respiratórios; A1 - reavaliação após 10 minutos da aplicação do protocolo; e A2 -reavaliação final após duas semanas de treinamento utilizando o mesmo protocolo três vezes por semana. A avaliação foi realizada através das medidas de pressões respiratórias máximas (PImax. e PEmax., picos de fluxo respiratórios (PFI e PFE, ventilação voluntária máxima (VVM, capacidade vital For

  9. Generation of four-particle GHZ states in bimodal cavity QED

    Institute of Scientific and Technical Information of China (English)

    Yang Zhen-Biao

    2007-01-01

    We propose a scheme for preparing four-particle Greenberger-Horne-Zeilinger states using two identical bimodal cavities, each supports two modes with different frequencies. This scheme is an alternative to another published work[Christopher C Gerry 1996 Phys. Rev. A 53 4591]. Comparisons between them are discussed. The fidelity and the probability of success influenced by cavity decay for the generated states are also considered.

  10. Continuous Pump Assisted Conditional Synthesis of Nonclassical States in a Dispersive Cavity QED

    Institute of Scientific and Technical Information of China (English)

    GUOJian-Hong

    2003-01-01

    The interaction of N identical atoms with both a quantized cavity field and an external classical pumping field with the fields being degenerate in frequency, is studied in the regime where the atoms and fields are highly detuned. This dispersive interaction can be used to generate coherent states for the cavity field. By preparing the injected atoms in a superposition of the bare atomic states, various types of Schroedinger-cat-like states may be generated.

  11. Continuous Pump Assisted Conditional Synthesis of Nonclassical States in a Dispersive Cavity QED

    Institute of Scientific and Technical Information of China (English)

    GUO Jian-Hong

    2003-01-01

    The interaction of N identical atoms with both a quantized cavity field and an external classical pumpingfield with the fields being degenerate in frequency, is studied in the regime where the atoms and fields are highly detuned.This dispersive interaction can be used to generate coherent states for the cavity field. By preparing the injected atomsin a superposition of the bare atomic states, various types of Schrodinger-cat-like states may be generated.

  12. FAST TRACK COMMUNICATION: Two interacting atoms in a cavity: exact solutions, entanglement and decoherence

    Science.gov (United States)

    Torres, J. M.; Sadurní, E.; Seligman, T. H.

    2010-05-01

    We address the problem of two interacting atoms of different species inside a cavity and find the explicit solutions of the corresponding eigenvalues and eigenfunctions using a new variant. This model encompasses various commonly used models. By way of example we obtain closed expressions for concurrence and purity as a function of time for the case where the cavity is prepared in a number state. We discuss the behaviour of these quantities and their relative behaviour in the concurrence-purity plane.

  13. Deep drawing experiences of niobium disk for PEFP SRF cavity prototype

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Han Sung; An, Sun; Zhang, Liping; Tang, Yazhe; Li, Ying Min; Kwon, Hyeok Jung; Cho, Yong Sub [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2009-05-15

    A superconducting radio frequency (SRF) cavity with a geometrical beta of 0.42 has been designed to accelerate a proton beam after 100 MeV for an extension of Proton Engineering Frontier Project (PEFP). The designed cavity shape is an elliptical and the resonant frequency is 700 MHz. In order to confirm the RF and mechanical properties of the cavity, two prototypes of copper cavities have been fabricated and tested. Based on the experiences gained with the copper prototypes, two niobium prototypes have been designed. One is two-cell cavity and the other is five cell cavity. The two-cell cavity is for finalizing the niobium cavity production procedure and testing the cavity RF properties at a low temperature and moderate power level. The five-cell cavity is for checking the production quality and testing vertical test system in the future. Both of them are under fabrication. Through the fabrication of the niobium prototype, several issues such as deep drawing, electron beam welding and surface treatment will be addressed. The drawing of the PEPF SRF low beta cavity is shown in Fig. 1. Major parameters for the cavity are like following. - Frequency: 700 MHz - Operating mode: TM010 pi mode - Cavity type: Elliptical - Geometrical beta: 0.42 - Number of cells: 5 per cavity - Accelerating gradient: 8 MV/m - Epeak/Eacc: 3.71 - Bpeak/Eacc: 7.47 mT/(MV/m) - R/Q: 102.3 ohm - Epeak: 29.68 MV/m - Field flatness: 1.56 % - Cell to cell coupling: 1.41 % - Geometrical factor: 121.68 ohm - Cavity wall thickness: 4.3 mm - Lorentz force detuning: 0.4 Hz/(MV/m)2 - Stiffening structure: Double ring - Effective length: 0.45 m - External Q of FPC: 8.0E5 {+-}20 % - HOM load: less than 2 W - HOM Qext requirement: less than 3.0E5 At present, all the niobium disk and plates for cavity and NbTi flanges for beam pipe flange are prepared.

  14. Stages of Lip and Oral Cavity Cancer

    Science.gov (United States)

    ... common treatment for all stages of lip and oral cavity cancer. Surgery may include the following: Wide local excision : Removal ... cancer may have spread from the lip and oral cavity. Plastic surgery : An operation that restores or improves the appearance ...

  15. Optical cavity furnace for semiconductor wafer processing

    Science.gov (United States)

    Sopori, Bhushan L.

    2014-08-05

    An optical cavity furnace 10 having multiple optical energy sources 12 associated with an optical cavity 18 of the furnace. The multiple optical energy sources 12 may be lamps or other devices suitable for producing an appropriate level of optical energy. The optical cavity furnace 10 may also include one or more reflectors 14 and one or more walls 16 associated with the optical energy sources 12 such that the reflectors 14 and walls 16 define the optical cavity 18. The walls 16 may have any desired configuration or shape to enhance operation of the furnace as an optical cavity 18. The optical energy sources 12 may be positioned at any location with respect to the reflectors 14 and walls defining the optical cavity. The optical cavity furnace 10 may further include a semiconductor wafer transport system 22 for transporting one or more semiconductor wafers 20 through the optical cavity.

  16. What Are Oral Cavity and Oropharyngeal Cancers?

    Science.gov (United States)

    ... Research Get Involved Find Local ACS Learn About Cancer » Oral Cavity and Oropharyngeal Cancer » Detailed Guide » What are ... how cancers start and spread, see What Is Cancer? Oral cavity cancer, or just oral cancer, is cancer ...

  17. Buffer Chemical Polishing and RF Testing of the 56 MHz SRF Cavity

    Energy Technology Data Exchange (ETDEWEB)

    Burrill,A.

    2009-01-01

    The 56 MHz cavity presents a unique challenge in preparing it for RF testing prior to construction of the cryomodule. This challenge arises due to the physical dimensions and subsequent weight of the cavity, and is further complicated by the coaxial geometry, and the need to properly chemically etch and high pressure rinse the entire inner surface prior to RF testing. To the best of my knowledge, this is the largest all niobium SRF cavity to be chemically etched and subsequently tested in a vertical dewar at 4K, and these processes will be the topic of this technical note.

  18. A simple scheme for generating multi-atom GHZ state via cavity QED

    Institute of Scientific and Technical Information of China (English)

    Wang Jun; Yu Long-Bao; Ye Liu

    2007-01-01

    This paper proposes a simple scheme for generating a three-atom GHZ state via cavity quantum electrodynamics (QED). The task can be achieved through the interaction between two EPR states, which can be prepared easily with current technology. In this scheme, the cavity field is only virtually excited during the interaction process, and no quantum information transfer between the atoms and the cavity is required. Thus it greatly prolongs the efficient decoherent time. Moreover, this scheme is also applicable for generating an .N-atom GHZ state.

  19. Cavity-water interface is polar

    OpenAIRE

    Friesen, Allan D.; Matyushov, Dmitry V.

    2010-01-01

    We present the results of numerical simulations of the electrostatics and dynamics of water hydration shells surrounding Kihara cavities given by a Lennard-Jones (LJ) layer at the surface of a hard-sphere cavity. The local dielectric response of the hydration layer substantially exceeds that of bulk water, with the magnitude of the dielectric constant peak in the shell increasing with the growing cavity size. The polar shell propagates into bulk water to approximately the cavity radius. The s...

  20. Theory and technology for superconducting cavities

    CERN Document Server

    Lengeler, Herbert

    1993-01-01

    The course will address Physicist and Engineers who are newcomers in the field of accelerators and accelerating cavities. The elements of RF-Superconductivity will be presented with special relevance to accelerating cavities. The present ststus of achievable accelerating fields and RF losses will be given and their link to the special technologies for cavity fabrication and surface treatments will be stressed. Cavity auxiliaries like main couplers, higher order mode couplers and frequency tuners will be described.

  1. Prototype storage cavity for LEP accelerating RF

    CERN Multimedia

    1980-01-01

    The principle of an RF storage cavity was demonstrated with this prototype, working at 500 MHz. Ian Wilso seems to hold it in his hands. The storage cavities had 4 portholes, 1 each for: RF feed; tuning; connection to the accelerating cavity; vacuum pump. The final storage cavities were larger, to suit the lower LEP accelerating frequency of 352.2 MHz. See also 8002294, 8006510X, 8109346, 8407619X, and Annual Report 1980, p.115.

  2. Cavity QED experiments with ion Coulomb crystals

    DEFF Research Database (Denmark)

    Herskind, Peter Fønss; Dantan, Aurélien; Marler, Joan;

    2009-01-01

    Cavity QED experimental results demonstrating collective strong coupling between ensembles of atomic ions cooled into Coulomb crystals and optical cavity fields have been achieved. Collective Zeeman coherence times of milliseconds have furthermore been obtained.......Cavity QED experimental results demonstrating collective strong coupling between ensembles of atomic ions cooled into Coulomb crystals and optical cavity fields have been achieved. Collective Zeeman coherence times of milliseconds have furthermore been obtained....

  3. Biodiesel metílico de Dipteryx lacunifera: preparação, caracterização e efeito de antioxidantes na estabilidade à oxidação Methyl biodiesel from Dipteryx lacunifera: preparation, characterization and effect of antioxidant on the oxidation stability

    OpenAIRE

    Francisca Diana da Silva Araújo; Carla Verônica Rodarte de Moura; Mariana H. Chaves

    2010-01-01

    The objective of this work was to study the potentialities of Dipteryx lacunifera Ducke seeds oil for biodiesel production. The yield in oil was of 46.11 ± 0.37%. Methyl biodiesel was prepared by base catalyzed transesterification yielding 88.13% and percentage conversion of triglycerides to corresponding methyl ester of 89.1%. The addition of the tertiary butylhydroquinone (TBHQ, 50 ppm), butylated hydroxytoluene (BHT, 50 ppm) and cashew nut shell liquid (CNSL, 2000 ppm) antioxidants in the ...

  4. Nanometer cavities studied by positron annihilation

    International Nuclear Information System (INIS)

    Positronium (Ps) is trapped in cavities in insulating solids, and the lifetime of ortho Ps is determined by the size of the cavity. The information on the properties of the cavities obtained by use of the standard slow positron beam and the 'normal' positron annihilation techniques is compared for several selected cases. (author)

  5. Power coupler for the ILC crab cavity

    Energy Technology Data Exchange (ETDEWEB)

    Burt, G.; Dexter, A.; Jenkins, R.; /Lancaster U.; Beard, C.; Goudket, P.; McIntosh, P.A.; /Daresbury; Bellantoni, Leo; /Fermilab

    2007-06-01

    The ILC crab cavity will require the design of an appropriate power coupler. The beam-loading in dipole mode cavities is considerably more variable than accelerating cavities, hence simulations have been performed to establish the required external Q. Simulations of a suitable coupler were then performed and were verified using a normal conducting prototype with variable coupler tips.

  6. Entanglement generation and quantum information transfer between spatially-separated qubits in different cavities

    Science.gov (United States)

    Yang, Chui-Ping; Su, Qi-Ping; Nori, Franco

    2013-11-01

    The generation and control of quantum states of spatially-separated qubits distributed in different cavities constitute fundamental tasks in cavity quantum electrodynamics (QED). An interesting question in this context is how to prepare entanglement and realize quantum information transfer between qubits located at different cavities, which are important in large-scale quantum information processing. In this paper, we consider a physical system consisting of two cavities and three qubits. Two of the qubits are placed in two different cavities while the remaining one acts as a coupler, which is used to connect the two cavities. We propose an approach for generating quantum entanglement and implementing quantum information transfer between the two spatially-separated inter-cavity qubits. The quantum operations involved in this proposal are performed by a virtual photon process; thus the cavity decay is greatly suppressed during operations. In addition, to complete these tasks, only one coupler qubit and one operation step are needed. Moreover, there is no need to apply classical pulses, so that the engineering complexity is much reduced and the operation procedure is greatly simplified. Finally, our numerical results illustrate that high-fidelity implementation of this proposal using superconducting phase qubits and one-dimensional transmission line resonators is feasible for current circuit QED implementations. This proposal can also be applied to other types of superconducting qubits, including flux and charge qubits.

  7. Non-reacting flow visualization of supersonic combustor based on cavity and cavity-strut flameholder

    Science.gov (United States)

    Zhao, Yanhui; Liang, Jianhan; Zhao, Yuxin

    2016-04-01

    Nano-particle planer laser scattering and particle image velocimetry technology are employed to observe the flow field of scramjet combustors based on cavity and cavity-strut flameholder. Density field and velocity distribution inside combustors are obtained. Mainstream fluid enters into cavity nearby side wall in experimental observation because side wall shock waves interact with bottom wall boundary layer. Cavity fluid is entrained into mainstream in the middle of combustor meanwhile. Flow past cavity displays obvious three dimensional characteristics in both combustors. But cavity-strut combustor displays asymmetrical flow field because of strut configuration. Mass exchange between mainstream and cavity fluid is evaluated by statistic mass flow rate into cavity. Mass flow rate near side wall is raised to 6.62 times of the value in the middle of cavity combustor while it is 5.1 times in cavity-strut combustor. Further study is needed to injection strategies and realistic flow characteristics on condition of combustion.

  8. RF cavity vacuum interlock system

    Science.gov (United States)

    Jordan, K.; Crawford, K.; Bundy, R.; Dylla, H. F.; Heckman, J.; Marshall, J.; Nichols, R.; Osullivan, S.; Preble, J.; Robb, J.

    1992-03-01

    The Continuous Electron Beam Accelerator Facility (CEBAF), a continuous wave (CW) 4 GeV Electron Accelerator is undergoing construction in Newport News, Virginia. When completed in 1994, the accelerator will be the largest installation of radio-frequency superconductivity. Production of cryomodules, the fundamental building block of the machine, has started. A cryomodule consists of four sets of pairs of 1497 MHz, 5 cell niobium cavities contained in separate helium vessels and mounted in a cryostat with appropriate end caps for helium supply and return. Beam vacuum of the cavities, the connecting beam piping, the waveguides, and the cryostat insulating vacuum are crucial to the performance of the machine. The design and initial experience of the vacuum systems for the first 2 1/4 cryomodules that makeup the 45 MEV injector are discussed.

  9. A micropillar for cavity optomechanics

    Energy Technology Data Exchange (ETDEWEB)

    Kuhn, Aurélien; Neuhaus, Leonhard; Deléglise, Samuel; Briant, Tristan; Cohadon, Pierre-François; Heidmann, Antoine [Laboratoire Kastler Brossel, UPMC-ENS-CNRS, Paris (France); Van Brackel, Emmanuel [Département de Physique, ENS, Paris (France); Chartier, Claude; Ducloux, Olivier; Le Traon, Olivier [Département Mesures Physiques, ONERA, Châtillon (France); Michel, Christophe; Pinard, Laurent; Flaminio, Raffaele [Laboratoire des Matériaux Avancés, IN2P3-CNRS, Lyon (France)

    2014-12-04

    Demonstrating the quantum ground state of a macroscopic mechanical object is a major experimental challenge in physics, at the origin of the rapid emergence of cavity optomechanics. We have developed a new generation of optomechanical devices, based on a microgram quartz micropillar with a very high mechanical quality factor. The structure is used as end mirror in a Fabry-Perot cavity with a high optical finesse, leading to ultra-sensitive interferometric measurement of the resonator displacement. We expect to reach the ground state of this optomechanical resonator by combining cryogenic cooling in a dilution fridge at 30 mK and radiation-pressure cooling. We have already carried out a quantum-limited measurement of the micropillar thermal noise at low temperature.

  10. Cavity Voltage Phase Modulation MD

    CERN Document Server

    Mastoridis, Themistoklis; Molendijk, John; Timko, Helga; CERN. Geneva. ATS Department

    2016-01-01

    The LHC RF/LLRF system is currently configured for extremely stable RF voltage to minimize transient beam loading effects. The present scheme cannot be extended beyond nominal beam current since the demanded power would exceed the peak klystron power and lead to saturation. A new scheme has therefore been proposed: for beam currents above nominal (and possibly earlier), the cavity phase modulation by the beam will not be corrected (transient beam loading), but the strong RF feedback and One-Turn Delay feedback will still be active for loop and beam stability in physics. To achieve this, the voltage set point will be adapted for each bunch. The goal of this MD was to test a new algorithm that would adjust the voltage set point to achieve the cavity phase modulation that would minimize klystron forward power.

  11. EFEITO DE CALDAS SOBRE Corynespora cassiicola

    Directory of Open Access Journals (Sweden)

    Mercia Celoto

    2014-11-01

    Full Text Available The target spot (Corynespora cassiicola, main leaf disease occurred in barbados cherry in the regionof Junqueirópolis, SP, causing severe defoliates of plants. After the cleaning prune, producers apply line sulfhur in plants, for presenting fungicidal, insecticide and acaricide action. The objective of this study was to assess the effect of line sulfhur (75% and 3% - used by producers, bordeaux mixture (75% and „calda Viçosa‟ (75% on Corynespora cassiicola. The syrups were incorporate into potato-dextrose-agar or spore suspension for determination of inhibition of the mycelia growth and spores germination. Leaves barbados cherry, with symptoms of target spot, were treated with syrups. In wet champer, high humidity, was verified that sporulation occured in lesions, however the spores lost viability by presence of syrups in surface. In vitro, line sulfhur to 75% inhibited completely the mycelia growth of the fungus. Line sulfhur, Bordeaux mixture and „calda Viçosa‟ inhibited completely the spores germination. For the reasons, the use of syrups in barbados cherry, can contribute in reduction of souce of inoculum of the pathogen. A mancha alvo (Corynespora cassiicola é a principal doença da cultura da acerola, na região de Junqueirópolis, SP, causando desfolha precoce nas plantas. Após a realização da poda de limpeza anual, os produtores aplicam a calda sulfocálcica nas plantas, por apresentar ação fungicida, inseticida e acaricida. O objetivo deste trabalho foi avaliar em condições in vitro e in vivo o efeito das caldas sulfocálcica, bordalesa e Viçosa sobre Corynespora cassiicola. As caldas foram utilizadas nas seguintes concentrações: calda sulfocálcica (75 e 3% - concentração utilizada por produtores, calda Bordalesa (75% e calda Viçosa (75%. As caldas foram incorporadas em meio de batata-dextrose-ágar ou suspensão de esporos para determinação das inibições do crescimento micelial e da germinação de esporos

  12. Status of the ILC Crab Cavity Development

    Energy Technology Data Exchange (ETDEWEB)

    Burt, G.; Dexter, A.; /Cockcroft Inst. Accel. Sci. Tech.; Beard, C.; Goudket, P.; McIntosh, P.; /Daresbury; Bellantoni, L.; /Fermilab; Grimm, T.; Li, Z.; Xiao, L.; /SLAC

    2011-10-20

    The International Linear Collider (ILC) will require two dipole cavities to 'crab' the electron and positron bunches prior to their collision. It is proposed to use two 9 cell SCRF dipole cavities operating at a frequency of 3.9 GHz, with a transverse gradient of 3.8MV/m in order to provide the required transverse kick. Extensive numerical modelling of this cavity and its couplers has been performed. Aluminium prototypes have been manufactured and tested to measure the RF properties of the cavity and couplers. In addition single cell niobium prototypes have been manufactured and tested in a vertical cryostat. The International Collider (ILC) [1] collides bunches of electrons and positrons at a crossing angle of 14 mrad. The angle between these bunches causes a loss in luminosity due to geometric effects [2]. The luminosity lost from this geometric effect can be recovered by rotating the bunches into alignment prior to collision. One possible method of rotating the bunches is to use a crab cavity [3]. A crab cavity is a transverse defecting cavity, where the phase of the cavity is such that the head and tail of the bunch receive equal and opposite kicks. As the bunches are only 500 nm wide in the horizontal plane, the cavity phase must be strictly controlled to avoid the bunch centre being deflected too much. In order to keep the phase stability within the required limits it is required that the cavity be superconducting to avoid thermal effects in both the cavity and its RF source. At the location of the crab cavity in the ILC there is only 23 cm separation between the centre of the cavity and the extraction line, hence the cavity must be small enough to fit in this space. This, along with the difficulty of making high frequency SRF components, set the frequency of the cavity to 3.9 GHz.

  13. LHC crab cavity final report

    CERN Document Server

    Burt, G et al

    2013-01-01

    A compact 400 MHz SRF crab cavity is designed for LHC. The design has low surface fields, has no hard multipactor barriers and fits within the transverse space available on the HL-LHC. The structure has been designed to have a constant deflecting voltage across the beam-pipe aperture and this has been verified on an aluminium model. The structure includes designs for the input and lower order mode couplers.

  14. Retention proposal in complex cavities.

    OpenAIRE

    Pedro Alvarez Rodríguez; Eduardo M. Curbeira Hernández; Eduardo Duarte Marrero; Yisell Peláez Rivas; Aracelis Navarro Sánchez

    2003-01-01

    Background: Dental Operatory is the main structure in which Odontology lies. It is not an easy discipline that gives enjoyable results with little effort due to the difficulties that a correct reconstruction of a destroyed dental element offers.The frequency with which pulpar injury occurs while anchoring additional retainers in complex cavities, the technical difficulties the lack of these devices cause and the need to simplify dental procedures lead this study to show the advantages to subs...

  15. Effect of Ca and Li additions on densification and electrical conductivity of 10 mol% gadolinia-doped ceria prepared by the coprecipitation technique; Efeito de adicoes de litio e calcio na densificacao e na condutividade eletrica da ceria-10% mol gadolinia preparada pela tecnica de co-precipitacao

    Energy Technology Data Exchange (ETDEWEB)

    Porfirio, T.C.

    2010-07-01

    Ceria containing rare-earth ceramics are potential candidates for application in intermediate-temperature solid oxide fuel cells. One of the main problems related to these ceramic materials is their relatively low sinterability. In this work, the effects of Ca and Li additions on densification and electrical conductivity of 10 mol% gadolinia-doped ceria was investigated. Ceramic compositions containing 1.5 mol% Ca or Li were prepared by the oxalate coprecipitation technique. Results of sintered density and electrical conductivity were compared to those of ceramic samples obtained by solid state reactions showing the effects of the synthesis method on densification and total electrical conductivity of the sintered materials. (author)

  16. Biodiesel metílico de Dipteryx lacunifera: preparação, caracterização e efeito de antioxidantes na estabilidade à oxidação Methyl biodiesel from Dipteryx lacunifera: preparation, characterization and effect of antioxidant on the oxidation stability

    Directory of Open Access Journals (Sweden)

    Francisca Diana da Silva Araújo

    2010-01-01

    Full Text Available The objective of this work was to study the potentialities of Dipteryx lacunifera Ducke seeds oil for biodiesel production. The yield in oil was of 46.11 ± 0.37%. Methyl biodiesel was prepared by base catalyzed transesterification yielding 88.13% and percentage conversion of triglycerides to corresponding methyl ester of 89.1%. The addition of the tertiary butylhydroquinone (TBHQ, 50 ppm, butylated hydroxytoluene (BHT, 50 ppm and cashew nut shell liquid (CNSL, 2000 ppm antioxidants in the biodiesel contributed to the increase of the induction period of 2.97 h for 8.08; 6.06 and 6.02 h, respectively.

  17. Preparatory procedure and equipment for the European x-ray free electron laser cavity implementation

    Energy Technology Data Exchange (ETDEWEB)

    Reschke, D.; Bandelmann, R.; Buettner, T.; Escherich, K.; Goessel, A.; v.d.Horst, B.; Iversen, J.; Klinke, D.; Kreps, G.; Krupka, N.; Lilje, L.; /DESY /Fermilab

    2010-07-01

    The European x-ray free electron laser is under construction at Deutsches Elektronen-Synchrotron (DESY). The electron beam energy of up to 17.5 GeV will be achieved by using superconducting accelerator technology. Final prototyping, industrialization, and new infrastructure are the actual challenges with respect to the accelerating cavities. This paper describes the preparation strategy optimized for the cavity preparation procedure in industry. For the industrial fabrication and preparation, several new hardware components have been already developed at DESY. The design and construction of a semiautomated rf-measurement machine for dumbbells and end groups are described. In a collaboration among FNAL, KEK, and DESY, an automatic cavity tuning machine has been designed and four machines are under construction. The functionality of these machines with special attention to safety aspects is described in this paper. A new high pressure rinsing system has been developed and is operational.

  18. Botryomycosis in a lung cavity.

    Science.gov (United States)

    Vinay, D; Ramasubramanian, V; Gopalakrishnan, Ram; Jessani, Laxman G

    2016-01-01

    Botryomycosis is a rare pyogranulomatous disease characterized by suppurative and often granulomatous bacterial infection of the skin, soft tissues and viscera. Only about 90 cases have been reported in world literature till date: 75% of them are cases of cutaneous botryomycosis. Of the 18 reported cases of primary pulmonary botryomycosis, only one had histologically proven botryomycosis in a lung cavity. We report here a case of primary pulmonary botryomycosis occurring in a lung cavity, which is to the best of our knowledge first such case from India. The index case was a 62 year old female who presented to us with recurrent episodes of non-massive streaky hemoptysis with CT chest revealing 'Air Crescent' sign with a probable fungal ball in a left upper lobe cavity. Left upper pulmonary lobectomy was done and histopathology of the cavitary tissue revealed Splendore-Hoeppli phenomenon and features suggestive of Botryomycosis. Tissue culture from the cavitary specimen grew Pseudomonas aeruginosa. Botryomycosis can mimic Aspergilloma radiologically as was seen in our case, but therapy is often a combination of both medical and surgical measures unlike Aspergilloma. PMID:27625451

  19. LHC crab-cavity aspects and strategy

    Energy Technology Data Exchange (ETDEWEB)

    Calaga, R.; Tomas, R.; Zimmermann, F.

    2010-05-23

    The 3rd LHC Crab Cavity workshop (LHC-CC09) took place at CERN in October 2009. It reviewed the current status and identified a clear strategy towards a future crab-cavity implementation. Following the success of crab cavities in KEK-B and the strong potential for luminosity gain and leveling, CERN will pursue crab crossing for the LHC upgrade. We present a summary and outcome of the variousworkshop sessions which have led to the LHC crab-cavity strategy, covering topics like layout, cavity design, integration, machine protection, and a potential validation test in the SPS.

  20. Control of Cavity Resonance Using Oscillatory Blowing

    Science.gov (United States)

    Scarfe, Alison Lamp; Chokani, Ndaona

    2000-01-01

    The near-zero net mass oscillatory blowing control of a subsonic cavity flow has been experimentally investigated. An actuator was designed and fabricated to provide both steady and oscillatory blowing over a range of blowing amplitudes and forcing frequencies. The blowing was applied just upstream of the cavity front Wall through interchangeable plate configurations These configurations enabled the effects of hole size, hole shape, and blowing angle to be examined. A significant finding is that in terms of the blowing amplitude, the near zero net mass oscillatory blowing is much more effective than steady blowing; momentum coefficients Lip two orders of magnitude smaller than those required for steady blowing are sufficient to accomplish the same control of cavity resonance. The detailed measurements obtained in the experiment include fluctuating pressure data within the cavity wall, and hot-wire measurements of the cavity shear layer. Spectral and wavelet analysis techniques are applied to understand the dynamics and mechanisms of the cavity flow with control. The oscillatory blowing, is effective in enhancing the mixing in the cavity shear layer and thus modifying the feedback loop associated with the cavity resonance. The nonlinear interactions in the cavity flow are no longer driven by the resonant cavity modes but by the forcing associated with the oscillatory blowing. The oscillatory blowing does not suppress the mode switching behavior of the cavity flow, but the amplitude modulation is reduced.

  1. Highly stable piezoelectrically tunable optical cavities

    CERN Document Server

    Möhle, Katharina; Döringshoff, Klaus; Nagel, Moritz; Peters, Achim

    2013-01-01

    We have implemented highly stable and tunable frequency references using optical high finesse cavities which incorporate a piezo actuator. As piezo material we used ceramic PZT, crystalline quartz, or PZN-PT single crystals. Lasers locked to these cavities show a relative frequency stability better than 1 x 10^{-14}, which is most likely not limited by the piezo actuators. The piezo cavities can be electrically tuned over more than one free spectral range (> 1.5 GHz) with only a minor decrease in frequency stability. Furthermore, we present a novel cavity design, where the piezo actuator is prestressed between the cavity spacer components. This design features a hermetically sealable intra cavity volume suitable for, e.g., cavity enhanced spectroscopy.

  2. Efeitos das condições de preparação e de modificação de superfície de membranas de PEUAPM na separação água/óleo Preparation and surface modification effects of UHMWPE membranes for oil/water separation

    Directory of Open Access Journals (Sweden)

    Laura H. de Carvalho

    2009-01-01

    Full Text Available Baixos custos operacionais, operação relativamente simples, scale-up e manutenção são as principais razões para uso de membrana no processo de separação numa variedade ampla de aplicações, incluindo purificação de efluentes aquosos. Neste trabalho, a influência dos parâmetros de processo na preparação de membranas de PEUAPM simétricas e assimétricas foi investigada. Membranas de PEUAPM tubulares simétricas foram preparadas com pó passante em peneiras de malha # 80 e # 100. As condições de processamento foram: a temperatura (200 e 220 °C; b pressões de compactação (0, 4 e 6 kgf/cm²; e c tempo de sinterização (90 minutos. Membranas assimétricas foram obtidas por deposição de um filme de PEAD sobre a superfície interna das membranas simétricas selecionadas. As Membranas foram caracterizadas por MEV, porosimetria de mercúrio e medidas de fluxo. Nossos dados indicam que, para membranas simétricas, a porosidade e fluxo permeado diminuíram com o aumento da temperatura e pressões de compactação. Redução mais acentuada nestas variáveis foi observada com membranas assimétricas.Low operational costs, relatively simple operation, scale-up and maintenance are the main reason for using membrane separation processes in a wide range of applications. The purpose of this work was to prepare, characterize and investigate the influence of processing parameters (T, P and of an internal surface modification on the performance of UHMWPE membranes. Sinterization was the technique used for membrane preparation. Tubular sintered UHMWPE membranes were prepared with powders sieved through #80 and #100 mesh. Processing conditions were: a temperature (200 and 220 °C; b compacting pressures (0, 4 and 6 kgf/cm²; and c sintering time (90 minutes. Surface modified membranes were obtained by internally impregnating selected UHMWPE membranes with a HDPE dilute solution. Membranes were characterized by SEM, mercury porosimetry water

  3. Multimode Strong Coupling in Superconducting Cavity Piezo-electromechanics

    CERN Document Server

    Han, Xu; Tang, Hong X

    2016-01-01

    High frequency mechanical resonators subjected to low thermal phonon occupancy are easier to be prepared to the ground state by direct cryogenic cooling. Their extreme stiffness, however, poses a significant challenge for external interrogations. Here we demonstrate a superconducting cavity piezo-electromechanical system in which multiple modes of a bulk acoustic resonator oscillating at $10\\,\\textrm{GHz}$ are coupled to a planar microwave superconducting resonator with a cooperativity exceeding $2\\times10^{3}$, deep in the strong coupling regime. By implementation of the non-contact coupling scheme to reduce mechanical dissipation, the system exhibits excellent coherence characterized by a frequency-quality factor product of $7.5\\times10^{15}\\,\\textrm{Hz}$. Interesting dynamics of temporal oscillations of the microwave energy is observed, implying the coherent conversion between phonons and photons. The demonstrated high frequency cavity piezo-electromechanics is compatible with superconducting qubits, repre...

  4. Automated image capture and defects detection by cavity inspection camera

    International Nuclear Information System (INIS)

    The defects as pit and scar make electric/magnetic field enhance and it cause field emission and quench in superconducting cavities. We used inspection camera to find these defects, but the current system which operated by human often mistake file naming and require long acquisition time. This study aims to solve these problems with introduction of cavity driving automation and defect inspection. We used rs232c of serial communication to drive of motor and camera for the automation of the inspection camera, and we used defect inspection software with defects reference images and pattern match software with the OpenCV lib. By the automation, we cut down the acquisition time from 8 hours to 2 hours, however defect inspection software is under preparation. The defect inspection software has a problem of complexity of image back ground. (author)

  5. Efeitos dos choques fiscais sobre o mercado de trabalho brasileiro

    Directory of Open Access Journals (Sweden)

    Diogo Baerlocher Carvalho

    2013-06-01

    Full Text Available Esse trabalho tem por objetivo entender quais os efeitos dos choques fiscais sobre o mercado de trabalho brasileiro. Em particular, utiliza se uma abordagem SVAR para avaliar esses efeitos sobre o emprego e o salário real. Os choques fiscais são identificados a partir da imposição de restrições de sinais puras sobre a relação dinâmica entre os gastos do governo, o produto real e a oferta de trabalho. As restrições são obtidas a partir de funções de resposta a impulso Bayesianas derivadas de um modelo DSGE na tradição da Nova Síntese Neoclássica. As funções de resposta a impulso obtidas a partir da abordagem SVAR mostram que choques fiscais aumentam o salário real e o emprego.

  6. A new method for sealing composite resin contraction gaps in lined cavities.

    Science.gov (United States)

    Torstenson, B; Brännström, M; Mattsson, B

    1985-03-01

    Composite resin restorations are often applied in cavities where cervical margins are left unetched, resulting in poorer adaptation in this area. Recent experiments have indicated the possibility of impregnating with resin the gap caused by polymerization contraction. Cavities were prepared in vitro and in vivo. A thin liner was applied inside and outside the cavity. Except for the cervical wall, enamel margins were bevelled and acid-etched, and the cavities restored with Concise Enamel Bond and Composite. In another series, cavities with unetched enamel were restored. Since the liner was placed outside the cavity margins, excess material could be removed without blockage of the air-filled gap. Enamel Bond with a fluorescent additive was applied to various margins. Ground sections were prepared, and the penetration of this resin into the gap was examined with a microscope. In most teeth, the resin penetrated from 0.5 to 2 mm from the cervical margins. Similar penetration was seen from unetched margins, except for the occlusal one. No penetration was seen at acid-etched margins. By impregnating gaps with low-viscous resin after the filling has cured, one can obtain an improved seal at unetched margins.

  7. Efeitos pleiotrópicos das estatinas na sepse

    Directory of Open Access Journals (Sweden)

    Silvana Menegoto Nogueira Di Giusto

    2014-04-01

    Full Text Available O objetivo do presente estudo foi revisar os efeitos da terapia com estatinas em pacientes com quadro de sepse. Foi realizada uma busca bibliográfica de artigos na base de dados MEDLINE/PubMed, SciELO e LILACS, no período de publicação delimitado entre 2009 e 2013. Foram incluídos artigos referentes a ensaios clínicos randomizados controlados e estudos de coorte observacionais clínicos. Foram encontrados diversos estudos clínicos e observacionais que investigaram o efeito do uso de estatinas em infecções e em sepse, tanto de uso contínuo pré-hospitalar (com ou sem interrupção durante internação ou com início imediato pós-internação. Alguns estudos descrevem prováveis efeitos positivos e benéficos da terapia com estatinas no quadro de sepse, dentre eles a melhora dos parâmetros inflamatórios e da taxa de mortalidade, porém, esses resultados não se sustentam quando são aplicados métodos estatísticos que levam em conta diferentes variáveis, tais como idade, sexo, comorbidades e gravidade da doença. Até o momento nenhum estudo demonstrou evidências sólidas e significativas quanto à redução de mortalidade e morbidade no quadro séptico associado ao uso de estatinas, indicando que seu efeito benéfico e protetor ainda não foi plenamente delimitado, sendo necessários mais estudos que confirmem os resultados até agora encontrados. 

  8. Broadband Tuning of Optomechanical Cavities

    CERN Document Server

    Wiederhecker, Gustavo S; Lee, Sunwoo; Lipson, Michal

    2010-01-01

    We demonstrate broadband tuning of an optomechanical microcavity optical resonance by exploring the large optomechanical coupling of a double-wheel microcavity and its uniquely low mechanical stiffness. Using a pump laser with only 13 mW at telecom wavelengths we show tuning of the silicon nitride microcavity resonances over 32 nm. This corresponds to a tuning power efficiency of only 400 $\\mu$W/nm. By choosing a relatively low optical Q resonance ($\\approx$18,000) we prevent the cavity from reaching the regime of regenerative optomechanical oscillations. The static mechanical displacement induced by optical gradient forces is estimated to be as large as 60 nm.

  9. Basketballs as spherical acoustic cavities

    Science.gov (United States)

    Russell, Daniel A.

    2010-06-01

    The sound field resulting from striking a basketball is found to be rich in frequency content, with over 50 partials in the frequency range of 0-12 kHz. The frequencies are found to closely match theoretical expectations for standing wave patterns inside a spherical cavity. Because of the degenerate nature of the mode shapes, explicit identification of the modes is not possible without internal investigation with a microphone probe. A basketball proves to be an interesting application of a boundary value problem involving spherical coordinates.

  10. Great progress in developing 500 MHz single cell superconducting cavity in China

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Superconducting cavities have been adopted in many kinds of accelerator facilities such as synchrotron radiation light source, hard X-ray free electron laser linac, colliders and energy recovery linacs (ERL). The 500 MHz superconducting cavities will be a candidate to be installed in the high current accelerators and high current ERLs for their large beam aperture, low higher order modes impedance and high current threshold value. This paper presents great progress in the whole sequence of developing 500 MHz superconducting cavity in China. It describes the first in-house successful development of 500 MHz single cell superconducting cavity including the deep-drawing of niobium half cells, electron beam wielding of cavity, surface preparations and vertical testing. The highest accelerating gradient of the fabricated cavity #SCD-02 higher than 10 MV/m was obtained while the quality factor was better than 4×108 at 4.2 K, which has reached the world level of the same kind of cavities.

  11. Assessing the Performance of the Laser Fluorescence Technique in Detecting Proximal Caries Cavities

    Directory of Open Access Journals (Sweden)

    Majid Akbari

    Full Text Available Introduction: Diagnosing the necessity of cavity preparation and restoration in demineralized proximal areas is always considered as a challenge in restorative treatment planning. The purpose of this study was to assess the performance of the laser fluorescence (LF technique in detection of proximal cavities.Materials & Methods: In this clinical trial, 44 proximal surfaces in 38 dental students were evaluated. The selected patients had radiolucent proximal lesions restricted to inner half of enamel or outer third of dentine in bitewing radiographs (BW. DIAGNOdent pen (LF pen device was used to determine the presence or absence of caries cavities in suspected proximal surfaces. Orthodontic elastic separators were then placed in the contact areas to provide enough space for direct visual and tactile examination. The sensitivity, specificity and accuracy of the laser fluorescence technique were calculated versus the reference standard. The ROC curve was drawn and the best cut-off to determine the presence or absence of proximal cavities was determined.Results: Using DIAGNOdent pen, the optimal cut-off for detecting proximal cavities was 18. The sensitivity, specificity and accuracy of DIAGNOdent pen for diagnosing proximal caries cavities were 100 per cent, 97.3 per cent and 97.7 per cent, respectively. Conclusion: Due to the high diagnostic accuracy of DIAGNOdent pen in detecting proximal caries cavities, it can be used as a valuable supplement in restorative treatment planning.

  12. Nitrogen-Doped 9-Cell Cavity Performance in a Test Cryomodule for LCLS-II

    CERN Document Server

    Gonnella, Dan; Furuta, Fumio; Ge, Mingqi; Hall, Daniel; Ho, Vivian; Hoffstaetter, Georg; Liepe, Matthias; O'Connell, Tim; Posen, Sam; Quigley, Peter; Sears, James; Veshcherevich, Vadim; Grassellino, Anna; Romanenko, Alexander; Sergatskov, Dmitri

    2014-01-01

    The superconducting RF linac for LCLS-II calls for 1.3 GHz 9-cell cavities with an average intrinsic quality factor Q0 of 2.7x10^10 at 2 K and 16 MV/m accelerating gradient. Two niobium 9-cell cavities, prepared with nitrogen-doping at Fermilab, were assembled into the Cornell Horizontal Test Cryomodule (HTC) to test cavity performance in a cryomodule that is very similar to a full LCLS-II cryomodule. The cavities met LCLS-II specifications with an average quench field of 17 MV/m and an average Q0 of 3x10^10. The sensitivity of the cavities' residual resistance to ambient magnetic field was determined to be 0.5 nOhm/mG during fast cool down. In two cool downs, a heater attached to one of the cavity beam tubes was used to induce large horizontal temperature gradients. Here we report on the results of these first tests of nitrogen-doped cavities in cryomodule, which provide critical information for the LCLS-II project.

  13. Self-cavity lasing in optically pumped single crystals of p-sexiphenyl

    Science.gov (United States)

    Yanagi, Hisao; Tamura, Kenji; Sasaki, Fumio

    2016-08-01

    Organic single-crystal self-cavities are prepared by solution growth of p-sexiphenyl (p-6P). Based on Fabry-Pérot feedback inside a quasi-lozenge-shaped platelet crystal, edge-emitting laser is obtained under optical pumping. The multimode lasing band appears at the 0-1 or 0-2 vibronic progressions depending on the excitation conditions which affect the self-absorption effect. Cavity-size dependence of amplified spontaneous emission (ASE) is investigated with laser-etched single crystals of p-6P. As the cavity length of square-shaped crystal is reduced from 100 to 10 μm, ASE threshold fluence is decreased probably due to size-dependent light confinement in the crystal cavity.

  14. Self-cavity lasing in optically pumped single crystals of p-sexiphenyl

    Directory of Open Access Journals (Sweden)

    Hisao Yanagi

    2016-08-01

    Full Text Available Organic single-crystal self-cavities are prepared by solution growth of p-sexiphenyl (p-6P. Based on Fabry-Pérot feedback inside a quasi-lozenge-shaped platelet crystal, edge-emitting laser is obtained under optical pumping. The multimode lasing band appears at the 0-1 or 0-2 vibronic progressions depending on the excitation conditions which affect the self-absorption effect. Cavity-size dependence of amplified spontaneous emission (ASE is investigated with laser-etched single crystals of p-6P. As the cavity length of square-shaped crystal is reduced from 100 to 10 μm, ASE threshold fluence is decreased probably due to size-dependent light confinement in the crystal cavity.

  15. Rebuild of Capture Cavity 1 at Fermilab

    Energy Technology Data Exchange (ETDEWEB)

    Harms, E. [Fermilab; Arkan, T. [Fermilab; Borissov, E. [Fermilab; Dhanaraj, N. [Fermilab; Hocker, A. [Fermilab; Orlov, Y. [Fermilab; Peterson, T. [Fermilab; Premo, K. [Fermilab

    2014-01-01

    The front end of the proposed Advanced Superconducting Test Accelerator at Fermilab employs two single cavity cryomodules, known as 'Capture Cavity 1' and 'Capture Cavity 2', for the first stage of acceleration. Capture Cavity 1 was previously used as the accelerating structure for the A0 Photoinjector to a peak energy of ~14 MeV. In its new location a gradient of ~25 MV/m is required. This has necessitated a major rebuild of the cryomodule including replacement of the cavity with a higher gradient one. Retrofitting the cavity and making upgrades to the module required significant redesign. The design choices and their rationale, summary of the rebuild, and early test results are presented.

  16. Efeito residual de temephós em larvas de Aedes aegypti

    OpenAIRE

    Maria de Lourdes G Macoris; Maria Teresa M Andrighetti; Luiz Takaku

    1995-01-01

    Uma das estratégias de controle do Aedes aegypti é o uso do larvicida temephós, cujo efeito residual prolongado permite a programação de tratamentos focais. O objetivo deste estudo é verificar a duração do efeito residual do temephós simulando-se uma situação de campo. Recipientes plásticos com capacidade de um e cinco litros, foram tratados com temephós e seu efeito residual testado a cada trinta dias. Foram observadas diferentes durações do efeito residual, o qual foi maior nos recipientes ...

  17. As diferentes modalidades da crioterapia e os seus efeitos na resistência passiva muscular

    OpenAIRE

    Pereira, Luís Filipe Mendes

    2011-01-01

    Objectivo: A aplicação de crioterapia no tratamento de lesões faz parte do quotidiano dos fisioterapeutas e desportistas. Apesar do seu efeito analgésico e anti-inflamatório ser consensual, existe actualmente pouca informação relativamente ao seu efeito ao nível das propriedades visco-elásticas do tecido muscular. Deste modo, este estudo pretende analisar as diferentes modalidades da crioterapia e os seus efeitos, bem como o efeito da crioterapia na resistência passiva muscular...

  18. The effect of cavity disinfectants on the sealing ability of dentin bonding system: An in vitro study

    Directory of Open Access Journals (Sweden)

    Sharma Vivek

    2009-01-01

    Full Text Available Aim: This study was conducted to determine the effect of three cavity disinfectants (chlorhexidine gluconate based-Consepsis; benzalkonium chloride-based Tubulicid Red, iodine-potassium iodide/copper-sulphate based Ora-5 on the microleakage of a dentin bonding system, Clearfil SE Bond. Materials and Methods: Class V cavities were prepared on 45 extracted molars. The respective experimentalgroups were treated with cavity disinfectants and Clearfil SE Bond. Preparations without cavity disinfectants served as negative control and those with neither disinfectant nor dentin bonding resin application served as positive controls. After the cavity preparations were restored with resin composite (Clearfil APX, the specimens were subjected to dye penetration. Statistical analysis was performed using ANOVA (Kruskal-Wallis test. Results: Unlike Conspesis and Tubulicid Red, Ora-5 exhibited significantly higher microleakage and adversely affected the sealing ability of Clearfil SE bond. Only Consepsis and Tubulicid Red could be used as cavity disinfectants with Clearfil SE bond, without its sealing abilities being adversely affected. Conclusions: 1 Consepsis and Tubulicid Red can be used as cavity disinfectants with Clearfil SE Bond, without the sealing ability of Clearfil SE bond being affected. 2 Ora-5 is not an appropriate disinfectant to be used with this dentin bonding system, because it alters its sealing ability.

  19. Silicon Integrated Cavity Optomechanical Transducer

    Science.gov (United States)

    Zou, Jie; Miao, Houxun; Michels, Thomas; Liu, Yuxiang; Srinivasan, Kartik; Aksyuk, Vladimir

    2013-03-01

    Cavity optomechanics enables measurements of mechanical motion at the fundamental limits of precision imposed by quantum mechanics. However, the need to align and couple devices to off-chip optical components hinders development, miniaturization and broader application of ultrahigh sensitivity chip-scale optomechanical transducers. Here we demonstrate a fully integrated and optical fiber pigtailed optomechanical transducer with a high Q silicon micro-disk cavity near-field coupled to a nanoscale cantilever. We detect the motion of the cantilever by measuring the resonant frequency shift of the whispering gallery mode of the micro-disk. The sensitivity near the standard quantum limit can be reached with sub-uW optical power. Our on-chip approach combines compactness and stability with great design flexibility: the geometry of the micro-disk and cantilever can be tailored to optimize the mechanical/optical Q factors and tune the mechanical frequency over two orders of magnitudes. Electrical transduction in addition to optical transduction was also demonstrated and both can be used to effectively cool the cantilever. Moreover, cantilevers with sharp tips overhanging the chip edge were fabricated to potentially allow the mechanical cantilever to be coupled to a wide range of off-chip systems, such as spins, DNA, nanostructures and atoms on clean surfaces.

  20. Tunable Cavity Optomechanics with Ultracold Atoms

    CERN Document Server

    Purdy, T P; Botter, T; Brahms, N; Ma, Z -Y; Stamper-Kurn, D M

    2010-01-01

    We present an atom-chip-based realization of quantum cavity optomechanics with cold atoms localized within a Fabry-Perot cavity. Effective sub-wavelength positioning of the atomic ensemble allows for tuning the linear and quadratic optomechanical coupling parameters, varying the sensitivity to the displacement and strain of a compressible gaseous cantilever. We observe effects of such tuning on cavity optical nonlinearity and optomechanical frequency shifts, providing their first characterization in the quadratic-coupling regime.

  1. Dither Cavity Length Controller with Iodine Locking

    Directory of Open Access Journals (Sweden)

    Lawson Marty

    2016-01-01

    Full Text Available A cavity length controller for a seeded Q-switched frequency doubled Nd:YAG laser is constructed. The cavity length controller uses a piezo-mirror dither voltage to find the optimum length for the seeded cavity. The piezo-mirror dither also dithers the optical frequency of the output pulse. [1]. This dither in optical frequency is then used to lock to an Iodine absorption line.

  2. Ray splitting in paraxial optical cavities

    CERN Document Server

    Puentes, G; Woerdman, J P

    2003-01-01

    We present a numerical investigation of the ray dynamics in a paraxial optical cavity when a ray splitting mechanism is present. The cavity is a conventional two-mirror stable resonator and the ray splitting is achieved by inserting an optical beam splitter perpendicular to the cavity axis. We show that depending on the position of the beam splitter the optical resonator can become unstable and the ray dynamics displays a positive Lyapunov exponent.

  3. Development of a cavity enhanced aerosol albedometer

    OpenAIRE

    Zhao, W.; Xu, X.; Dong, M.; Chen, W.; X. Gu; Hu, C; Huang, Y.; Gao, X; Huang, W.; Zhang, W

    2014-01-01

    We report on the development of a cavity enhanced aerosol single scattering albedometer incorporating incoherent broad-band cavity-enhanced spectroscopy (IBBCEAS) approach and an integrating sphere (IS) for simultaneous in situ measurements of aerosol scattering and extinction coefficients in the exact same sample volume. The cavity enhanced albedometer employed a blue light-emitting diode (LED) based IBBCEAS approach for the measurement of wavelength-resolv...

  4. Effects of subsurface cavity expansion in clays

    OpenAIRE

    Au, SKA; Yeung, AT; Soga, K; Cheng, YM

    2007-01-01

    Subsurface cavity expansion in clay induced by compaction grouting can generate upward displacement of clay and/or increase in effective stress leading to consolidation, resulting in settlement compensation and/or shear strength enhancement respectively. However, the two potential benefits of subsurface cavity expansion may offset each other. Experiments and numerical simulations on the engineering behaviour of E-grade kaolin induced by subsurface pressure-controlled cavity expansion were con...

  5. Superconducting cavity driving with FPGA controller

    Science.gov (United States)

    Czarski, Tomasz; Koprek, Waldemar; Poźniak, Krzysztof T.; Romaniuk, Ryszard S.; Simrock, Stefan; Brandt, Alexander; Chase, Brian; Carcagno, Ruben; Cancelo, Gustavo; Koeth, Timothy W.

    2006-12-01

    A digital control of superconducting cavities for a linear accelerator is presented. FPGA-based controller, supported by Matlab system, was applied. Electrical model of a resonator was used for design of a control system. Calibration of the signal path is considered. Identification of cavity parameters has been carried out for adaptive control algorithm. Feed-forward and feedback modes were applied in operating the cavities. Required performance has been achieved; i.e. driving on resonance during filling and field stabilization during flattop time, while keeping reasonable level of the power consumption. Representative results of the experiments are presented for different levels of the cavity field gradient.

  6. Optically coupled cavities for wavelength switching

    International Nuclear Information System (INIS)

    An optical bistable device which presents hysteresis behavior is proposed and experimentally demonstrated. The system finds applications in wavelength switching, pulse reshaping and optical bistability. It is based on two optically coupled cavities named master and slave. Each cavity includes a semiconductor optical amplifier (SOA), acting as the gain medium of the laser, and two pair of fiber Bragg gratings (FBG) which define the lasing wavelength (being different in each cavity). Finally, a variable optical coupler (VOC) is employed to couple both cavities. Experimental characterization of the system performance is made analyzing the effects of the coupling coefficient between the two cavities and the driving current in each SOA. The properties of the hysteretic bistable curve and switching can be controlled by adjusting these parameters and the loss in the cavities. By selecting the output wavelength (λ1 or λ2) with an external filter it is possible to choose either the invert or non-invert switched signal. Experiments were developed employing both optical discrete components and a photonic integrated circuit. They show that for 8 m-long cavities the maximum switching frequency is about 500 KHz, and for 4 m-long cavities a minimum rise-time about 21 ns was measured. The switching time can be reduced by shortening the cavity lengths and using photonic integrated circuits.

  7. Optimization of a lasertron double output cavity

    International Nuclear Information System (INIS)

    Double output cavities have been used experimentally to increase the efficiency of high-power klystrons. We have used particle-in-cell simulations with the 2 + 1/2 dimensional code MASK to optimize the design of double output cavities for the lasertron under development at SLAC. We discuss design considerations for double output cavities (e.g., optimum choice of voltages and phases, efficiency, wall interception, breakdown). We describe how one calculates the cavity impedance matrix from the gap voltages and phases. Some results of the effect of varying voltage, perveance, and pulse are reported

  8. Single-mode cavity with HOMs absorber

    International Nuclear Information System (INIS)

    We present a new 500 MHz cavity which has a simple damped structure for the 1.5 GeV high-brilliant VUV ring. The feature of the cavity design is that higher-order modes (HOMs) propagate out from the cavity through the beam duct with a large diameter and are absorbed in resistive parts in the duct. A low power measurement on a prototype model of the cavity was carried out and the Q-values of HOMs were confirmed to strongly reduce. Thus the coupled-bunch instabilities due to HOMs are expected to be sufficiently suppressed. (author)

  9. Engineering topological materials in microwave cavity arrays

    CERN Document Server

    Anderson, Brandon M; Owens, Clai; Schuster, David I; Simon, Jonathan

    2016-01-01

    We present a scalable architecture for the exploration of interacting topological phases of photons in arrays of microwave cavities, using established techniques from cavity and circuit quantum electrodynamics. A time-reversal symmetry breaking (non-reciprocal) flux is induced by coupling the microwave cavities to ferrites, allowing for the production of a variety of topological band structures including the $\\alpha=1/4$ Hofstadter model. Effective photon-photon interactions are included by coupling the cavities to superconducting qubits, and are sufficient to produce a $\

  10. Mechanical Properties of Ingot Nb Cavities

    Energy Technology Data Exchange (ETDEWEB)

    Ciovati, Gianluigi; Dhakal, Pashupati; Kneisel, Peter; Mammosser, John; Matalevich, Joseph; Rao Myneni, Ganapati

    2014-07-01

    This contribution presents the results of measurements of the resonant frequency and of strain along the contour of a single-cell cavity made of ingot Nb subjected to increasing uniform differential pressure, up to 6 atm. The data were used to infer mechanical properties of this material after cavity fabrication, by comparison with the results from simulation calculations done with ANSYS. The objective is to provide useful information about the mechanical properties of ingot Nb cavities which can be used in the design phase of SRF cavities intended to be built with this material.

  11. Design of the ILC Crab Cavity System

    Energy Technology Data Exchange (ETDEWEB)

    Adolphsen, C.; Beard, C.; Bellantoni, L.; Burt, G.; Carter, R.; Chase, B.; Church, M.; Dexter, A.; Dykes, M.; Edwards, H.; Goudket, P; Jenkins, R.; Jones, R.M.; Kalinin,; Khabiboulline, T.; Ko, K.; Latina, A.; Li, Z.; Ma, L.; McIntosh, P.; Ng, C.; /SLAC /Daresbury /Fermilab /Cockcroft Inst. Accel. Sci. Tech. /CERN

    2007-08-15

    The International Linear Collider (ILC) has a 14 mrad crossing angle in order to aid extraction of spent bunches. As a result of the bunch shape at the interaction point, this crossing angle at the collision causes a large luminosity loss which can be recovered by rotating the bunches prior to collision using a crab cavity. The ILC baseline crab cavity is a 9-cell superconducting dipole cavity operating at a frequency of 3.9 GHz. In this paper the design of the ILC crab cavity and its phase control system, as selected for the RDR in February 2007 is described in fuller detail.

  12. Introductory lecture on waveguides and cavities

    International Nuclear Information System (INIS)

    This lecture has two parts: waveguides and cavities. Basic topics are discussed which can serve as bases for the following lectures. Many of the results obtained in the first part concerning waveguides are applied in the second part in the discussion on cavity properties, since a cavity can be considered as a part of a waveguide, a cavity resonant mode being a superposition of two counter-travelling waves in the waveguide. In deriving most of the mathematical formulas, complex number representation - that is, phasor forms - are used. For the final results, however, real number representations are also provided as much as possible as an aid to a more intuitive understanding. (author)

  13. Floquet approach to bichromatically driven cavity-optomechanical systems

    Science.gov (United States)

    Malz, Daniel; Nunnenkamp, Andreas

    2016-08-01

    We develop a Floquet approach to solve time-periodic quantum Langevin equations in the steady state. We show that two-time correlation functions of system operators can be expanded in a Fourier series and that a generalized Wiener-Khinchin theorem relates the Fourier transform of their zeroth Fourier component to the measured spectrum. We apply our framework to bichromatically driven cavity optomechanical systems, a setting in which mechanical oscillators have recently been prepared in quantum-squeezed states. Our method provides an intuitive way to calculate the power spectral densities for time-periodic quantum Langevin equations in arbitrary rotating frames.

  14. Dynamics of atom-field entanglement in a bimodal cavity

    CERN Document Server

    Deçordi, G L

    2015-01-01

    We investigate some aspects of the dynamics and entanglement of bipartite quantum system (atom-quantized field), coupled to a third ``external" subsystem (quantized field). We make use of the Raman coupled model; a three-level atom in a lambda configuration interacting with two modes of the quantized cavity field. We consider the far off resonance limit, which allows the derivation of an effective Hamiltonian of a two-level atom coupled to the fields. We also make a comparison with the situation in which one of the modes is treated classically rather than prepared in a quantum field (coherent state).

  15. Anatomy and Disorders of the Oral Cavity of Ornamental Fish.

    Science.gov (United States)

    Roberts-Sweeney, Helen E

    2016-09-01

    Ornamental fish represent the largest and most diverse group of exotic animals kept as pets. The specific oral anatomy of each family or selected species has evolved to suit the natural environment, feeding behaviors, food or prey type, and location of the food/prey in the water column. The anatomy can change over the life of the animal, from fry to adult. The oral cavity of fish is susceptible to many problems including infectious and parasitic diseases, trauma, and neoplasia. Diagnosis may involve wet mount preparations of exfoliative cytology from the lesion, histopathology, and bacterial or fungal culture. PMID:27497201

  16. Preparation of two and four-atom entangled states

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A scheme for preparing two and four-atom entangled states is presented. It is based on atom-cavity-field interactions. Firatly, the cav ity is prepared in the superposition of the number states through the atom under going a two-photon transition, the secondly, the two or four identical two-lev el atoms, which are all initially in their ground states, are sent through the c avity sequentially and can make resonant single-photon transition in the cavity . Then atomic entangled states are created and the cavity is left in the vacuum state.

  17. Controlling dipole squeezing of two atoms inside a cavity via manipulating an atom outside the cavity

    Institute of Scientific and Technical Information of China (English)

    Liu Tang-Kun; Wang Ji-Suo; Feng Jian; Zhan Ming-Sheng

    2004-01-01

    Considering that three two-level atoms are initially in the GHZ single state and two of the atoms are simultaneously put into a cavity initially in the coherent state, we investigate the dipole squeezing properties of the two atoms inside the cavity under the condition of resonant interaction. It is shown that dipole squeezing properties of the two atoms inside the cavity are strongly affected by rotation manipulating of the atom outside the cavity.

  18. Hydrodynamic Drag on Streamlined Projectiles and Cavities

    KAUST Repository

    Jetly, Aditya

    2016-04-19

    The air cavity formation resulting from the water-entry of solid objects has been the subject of extensive research due to its application in various fields such as biology, marine vehicles, sports and oil and gas industries. Recently we demonstrated that at certain conditions following the closing of the air cavity formed by the initial impact of a superhydrophobic sphere on a free water surface a stable streamlined shape air cavity can remain attached to the sphere. The formation of superhydrophobic sphere and attached air cavity reaches a steady state during the free fall. In this thesis we further explore this novel phenomenon to quantify the drag on streamlined shape cavities. The drag on the sphere-cavity formation is then compared with the drag on solid projectile which were designed to have self-similar shape to that of the cavity. The solid projectiles of adjustable weight were produced using 3D printing technique. In a set of experiments on the free fall of projectile we determined the variation of projectiles drag coefficient as a function of the projectiles length to diameter ratio and the projectiles specific weight, covering a range of intermediate Reynolds number, Re ~ 104 – 105 which are characteristic for our streamlined cavity experiments. Parallel free fall experiment with sphere attached streamlined air cavity and projectile of the same shape and effective weight clearly demonstrated the drag reduction effect due to the stress-free boundary condition at cavity liquid interface. The streamlined cavity experiments can be used as the upper bound estimate of the drag reduction by air layers naturally sustained on superhydrophobic surfaces in contact with water. In the final part of the thesis we design an experiment to test the drag reduction capacity of robust superhydrophobic coatings deposited on the surface of various model vessels.

  19. Superconducting cavities developments efforts at RRCAT

    International Nuclear Information System (INIS)

    Superconducting RE cavities are the work-horse for many existing and proposed linear accelerators. Raja Ramanna Centre for Advanced Technology (RRCAT) has initiated a comprehensive R and D program for development of Superconducting RF cavities suitable for high energy accelerator application like SNS and ADS. For the initial phase of technology demonstration several prototype 1.3 GHz single cell-cavities have been developed. The work began with development of prototype single cell cavities in aluminum and copper. This helped in development of cavity manufacturing process, proving various tooling and learning on various mechanical and RF qualification processes. The parts manufacturing was done at RRCAT and Electron beam welding was carried out at Indian industry. These cavities further served during commissioning trials for various cavity processing infrastructure being developed at RRCAT and are also a potential candidate for Niobium thin film deposition R and D. Based on the above experience, few single cell cavities were developed in fine grain niobium. The critical technology of forming and machining of niobium and the intermediate RF qualification were developed at RRCAT. The EB welding of bulk niobium cavities was carried out in collaboration with IUAC, New Delhi at their facility. As a next logical step efforts are now on for development of multicell cavities. The prototype dumbbells and end group made of aluminium, comprising of RF and HOM couplers ports have also been developed, with their LB welding done at Indian industry. In this paper we shall present the development efforts towards manufacturing of 1.3 GHz single cell cavities and their initial processing and qualification. (author)

  20. Investigation of Microscopic Materials Limitations of Superconducting RF Cavities

    Energy Technology Data Exchange (ETDEWEB)

    Anlage, Steven [Univ. of Maryland, College Park, MD (United States)

    2014-07-23

    The high-field performance of SRF cavities is often limited by breakdown events below the intrinsic limiting surface fields of Nb, and there is abundant evidence that these breakdown events are localized in space inside the cavity. Also, there is a lack of detailed understanding of the causal links between surface treatments and ultimate RF performance at low temperatures. An understanding of these links would provide a clear roadmap for improvement of SRF cavity performance, and establish a cause-and-effect ‘RF materials science’ of Nb. We propose two specific microscopic approaches to addressing these issues. First is a spatially-resolved local microwave-microscope probe that operates at SRF frequencies and temperatures to discover the microscopic origins of breakdown, and produce quantitative measurements of RF critical fields of coatings and films. Second, RF Laser Scanning Microscopy (LSM) has allowed visualization of RF current flow and sources of nonlinear RF response in superconducting devices with micro-meter spatial resolution. The LSM will be used in conjunction with surface preparation and characterization techniques to create definitive links between physical and chemical processing steps and ultimate cryogenic microwave performance. We propose to develop RF laser scanning microscopy of small-sample Nb pieces to establish surface-processing / RF performance relations through measurement of RF current distributions on micron-length scales and low temperatures.

  1. Leaky Modes of Dielectric Cavities

    CERN Document Server

    Mansuripur, Masud; Jakobsen, Per

    2016-01-01

    In the absence of external excitation, light trapped within a dielectric medium generally decays by leaking out (and also by getting absorbed within the medium). We analyze the leaky modes of a parallel-plate slab, a solid glass sphere, and a solid glass cylinder, by examining those solutions of Maxwell's equations (for dispersive as well as non-dispersive media) which admit of a complex-valued oscillation frequency. Under certain circumstances, these leaky modes constitute a complete set into which an arbitrary distribution of the electromagnetic field residing inside a dielectric body can be expanded. We provide completeness proofs, and also present results of numerical calculations that illustrate the relationship between the leaky modes and the resonances of dielectric cavities formed by a simple parallel-plate slab, a glass sphere, and a glass cylinder.

  2. Cavity Voltage Phase Modulation MD

    CERN Document Server

    Mastoridis, T; Butterworth, A; Molendijk, J; Tuckmantel, J

    2012-01-01

    The LHC RF/LLRF system is currently setup for extremely stable RF voltage to minimize transient beam loading eects. The present scheme cannot be extended beyond nominal beam current since the demanded power would push the klystrons to saturation. For beam currents above nominal (and possibly earlier), the cavity phase modulation by the beam will be not be corrected (transient beam loading), but the strong RF feedback and One-Turn Delay feedback will still be active for loop and beam stability in physics. To achieve this, the voltage set point will be adapted for each bunch. The goal of this MD was to test an iterative algorithm that would adjust the voltage set point to achieve the optimal phase modulation for klystron forward power considerations.

  3. Scheme for realizing assisted cloning of an unknown two-atom entangled state via cavity QED

    Institute of Scientific and Technical Information of China (English)

    Zhan You-Bang

    2008-01-01

    This paper proposes a scheme where one can realize quantum cloning of an unknown two-atom entangled state with assistance of a state preparer in cavity QED.The first stage of the scheme requires usual teleportation.In the second stage of the scheme,with the assistance of the preparer,the perfect copies of an unknown atomic entangled state can be produced.

  4. [Estimation of antimicrobial means action efficacy in children oral cavities by pH-test].

    Science.gov (United States)

    Guliamov, S S

    2009-01-01

    Possibility of mixed saliva pH determination in the efficacy of antimicrobial mean action was assessed using fluctuations in hydrogen index (pH following consumption of sweets in teenagers according to Stephan curve). Antimicrobial activity of chlorhexidine-containing preparation Eludrile and Elgidium-tooth paste, as well as furacillin solution in oral cavities of teenagers was estimated. PMID:19365352

  5. The HIE-ISOLDE Superconducting Cavities: Surface Treatment and Niobium Thin Film Coating

    CERN Document Server

    Lanza, G; Ferreira, L M A; Gustafsson, A E; Pasini, M; Trilhe, P; Palmieri, V

    2010-01-01

    CERN has designed and prepared new facilities for the surface treatment and niobium sputter coating of the HIE-ISOLDE superconducting cavities. We describe here the design choices, as well as the results of the first surface treatments and test coatings.

  6. Realization of GHZ States and the GHZ Test via Cavity QED

    CERN Document Server

    Guerra, E S

    2004-01-01

    In this article we discuss the realization of atomic GHZ states involving three-level atoms and we show explicitly how to use this state to perform the GHZ test in which it is possible to decide between local realism theories and quantum mechanics. The experimental realizations proposed makes use of the interaction of Rydberg atoms with a cavity prepared in a coherent state.

  7. Scheme for Implementation of Quantum Game in Cavity QED

    International Nuclear Information System (INIS)

    We propose an experimentally feasible scheme to implement two-player quantum game in cavity quantum electrodynamics (QED). During the process, the cavity is only virtually excited, thus our scheme is insensitive to the cavity field states and cavity decay. The scheme can be realized in the range of current cavity QED techniques.

  8. A scheme for implementing quantum game in cavity QED

    Institute of Scientific and Technical Information of China (English)

    CaoShuai; Fang Mao-Fa; Liu Jian-Bin; Wang Xin-Wen; Zheng Xiao-juan

    2009-01-01

    In this paper, we propose a scheme fot implementing quantum game (QG) in cavity quantum electrodynam-ics(QED). In the scheme, the cavity is only virtually excited and thus the proposal is insensitive to the cavity fields states and cavity decay. So our proposal can be experimentally realized in the range of current cavity QED techniques.

  9. Scheme for Implementation of Quantum Game in Cavity QED

    Institute of Scientific and Technical Information of China (English)

    ZHANG Li-Chun; CAO Shu-Ai; WU Yue-Qin; FANG Mao-Fa; LI Huai-Fan; ZHENG Xiao-Juan; ZHAO Ren; WANG Xin-Wen; LI Ze-Hua

    2008-01-01

    We propose an experimentally feasible scheme to implement two-player quantum game in cavity quantum electrodynamics (QED). During the process, the cavity is only virtually excited, thus our scheme is insensitive to the cavity field states and cavity decay. The scheme can be realized in the range of current cavity QED techniques.

  10. Cavity Pressure Behaviour in Micro Injection Moulding

    DEFF Research Database (Denmark)

    Griffiths, C.A.; Dimov, S.S.; Scholz, S.;

    2010-01-01

    as well as with the filling of the cavity by the polymer melt. In this paper, two parameters derived from cavity pressure over time (i.e. pressure work). The influence of four µIM parameters (melt temperature, mould temperature, injection speed, aand packing pressure) on the two pressure...

  11. Superconducting accelerating four-cell cavity

    CERN Multimedia

    1980-01-01

    A close view of the four-cell cavity. This was a prototype designed for LEP2 (LEP1 had warm copper cavities as accelerating elements). The first successful tests were made in December 1980 - reaching a Q = 10^6. (see photo 8012650X)

  12. Temperature stabilization of optofluidic photonic crystal cavities

    DEFF Research Database (Denmark)

    Kamutsch, Christian; Smith, Cameron L.C.; Graham, Alexandra;

    2009-01-01

    We present a principle for the temperature stabilization of photonic crystal (PhC) cavities based on optofluidics. We introduce an analytic method enabling a specific mode of a cavity to be made wavelength insensitive to changes in ambient temperature. Using this analysis, we experimentally...

  13. Continuous optical discharge in a laser cavity

    Science.gov (United States)

    Chivel', Yu. A.

    2016-08-01

    Optical discharge in a laser cavity is experimentally studied. A significant increase in the absorption of laser radiation (up to total absorption) is revealed. Optical schemes for initiation and maintaining of optical discharge in the cavity are proposed for technological applications of the optical discharge.

  14. A spherical cavity in an Einstein universe

    Energy Technology Data Exchange (ETDEWEB)

    Kofinti, N.K.

    1980-03-01

    Suitable metric forms for the regions and a outside a sperical cavity in an Einstein universe are derived by means of perturbation. It is shown that for low proper pressure, the cavity behaves like ''negative'' Schwarzchild mass. Finally, the possibility of carrying over to the exact theory a proposed definition of the gravitational field in a matter is examined.

  15. Spallation neutron source RF cavity bias system

    International Nuclear Information System (INIS)

    The Spallation Neutron Source r.f. cavity bias system is described under the topic headings: bias system, r.f. cavity, cables, d.c. bias power supply, transistor regulator and control system. Calculation of 4 core 300 mm solid aluminium cable inductance, coaxial shunt frequency response and transistor regulator computed frequency response, are discussed in appendices 1-3. (U.K.)

  16. Large grain cavities from pure niobium ingot

    Science.gov (United States)

    Myneni, Ganapati Rao; Kneisel, Peter; Cameiro, Tadeu

    2012-03-06

    Niobium cavities are fabricated by the drawing and ironing of as cast niobium ingot slices rather than from cold rolled niobium sheet. This method results in the production of niobium cavities having a minimum of grain boundaries at a significantly reduced cost as compared to the production of such structures from cold rolled sheet.

  17. Cone beam computed tomographic evaluation of two access cavity designs and instrumentation on the thickness of peri-cervical dentin in mandibular anterior teeth

    Science.gov (United States)

    Varghese, Vinny Sara; George, John V.; Mathew, Sylvia; Nagaraja, Shruthi; Indiresha, H. N.; Madhu, K. S.

    2016-01-01

    Background and Objectives: The aim of the study was to determine the effect of two access cavity designs on the peri-cervical dentin thickness before and after instrumentation using cone beam computed tomography (CBCT). Materials and Methods: Sixty mandibular anterior teeth were divided into two groups of thirty teeth each: Group I: conventional access cavity preparation, where access was prepared just above the cingulum and Group II: incisal access cavity preparation, where access was prepared in proximity to the incisal edge. CBCT scans were taken preoperatively, following access cavity preparation and post instrumentation. 200 μm thick slices were obtained 4mm apical and coronal to the cemento-enamel junction. The peri-cervical dentin thickness was calculated on the facial, lingual, mesial, and distal for all the three obtained scans. Results: The analysis showed that access cavity preparation and instrumentation resulted in a significant loss of tooth structure in Group I on all surfaces, but in Group II, there was a significant loss of tooth structure only in the mesial, lingual, and distal surfaces (P < 0.05). Conclusion: Incisal access cavity preparation resulted in lesser loss of dentin in the peri-cervical region. PMID:27656065

  18. Cone beam computed tomographic evaluation of two access cavity designs and instrumentation on the thickness of peri-cervical dentin in mandibular anterior teeth

    Science.gov (United States)

    Varghese, Vinny Sara; George, John V.; Mathew, Sylvia; Nagaraja, Shruthi; Indiresha, H. N.; Madhu, K. S.

    2016-01-01

    Background and Objectives: The aim of the study was to determine the effect of two access cavity designs on the peri-cervical dentin thickness before and after instrumentation using cone beam computed tomography (CBCT). Materials and Methods: Sixty mandibular anterior teeth were divided into two groups of thirty teeth each: Group I: conventional access cavity preparation, where access was prepared just above the cingulum and Group II: incisal access cavity preparation, where access was prepared in proximity to the incisal edge. CBCT scans were taken preoperatively, following access cavity preparation and post instrumentation. 200 μm thick slices were obtained 4mm apical and coronal to the cemento-enamel junction. The peri-cervical dentin thickness was calculated on the facial, lingual, mesial, and distal for all the three obtained scans. Results: The analysis showed that access cavity preparation and instrumentation resulted in a significant loss of tooth structure in Group I on all surfaces, but in Group II, there was a significant loss of tooth structure only in the mesial, lingual, and distal surfaces (P cavity preparation resulted in lesser loss of dentin in the peri-cervical region. PMID:27656065

  19. Air flow in a collapsing cavity

    CERN Document Server

    Peters, Ivo R; Lohse, Detlef; van der Meer, Devaraj

    2013-01-01

    We experimentally study the airflow in a collapsing cavity created by the impact of a circular disk on a water surface. We measure the air velocity in the collapsing neck in two ways: Directly, by means of employing particle image velocimetry of smoke injected into the cavity and indirectly, by determining the time rate of change of the volume of the cavity at pinch-off and deducing the air flow in the neck under the assumption that the air is incompressible. We compare our experiments to boundary integral simulations and show that close to the moment of pinch-off, compressibility of the air starts to play a crucial role in the behavior of the cavity. Finally, we measure how the air flow rate at pinch-off depends on the Froude number and explain the observed dependence using a theoretical model of the cavity collapse.

  20. Vertical external cavity surface emitting semiconductor lasers

    CERN Document Server

    Holm, M

    2001-01-01

    Active stabilisation showed a relative locked linewidth of approx 3 kHz. Coarse tuning over 7 nm was achieved using a 3-plate birefingent filter plate while fine-tuning using cavity length change allowed tuning over 250 MHz. Vertical external cavity semiconductor lasers have emerged as an interesting technology based on current vertical cavity semiconductor laser knowledge. High power output into a single transverse mode has attracted companies requiring good fibre coupling for telecommunications systems. The structure comprises of a grown semiconductor Bragg reflector topped with a multiple quantum well gain region. This is then included in an external cavity. This device is then optically pumped to promote laser action. Theoretical modelling of AIGaAs based VECSEL structures was undertaken, showing the effect of device design on laser characteristics. A simple 3-mirror cavity was constructed to assess the static characteristics of the structure. Up to 153 mW of output power was achieved in a single transver...

  1. Vertical-Cavity Surface-Emitting Lasers

    Science.gov (United States)

    Wilmsen, Carl W.; Temkin, Henryk; Coldren, Larry A.

    2002-01-01

    1. Introduction to VCSELs L. A. Coldren, C. W. Wilmsen and H. Temkin; 2. Fundamental issues in VCSEL design L. A. Coldren and Eric R. Hegblom; 3. Enhancement of spontaneous emission in microcavities E. F. Schubert and N. E. J. Hunt; 4. Epitaxy of vertical-cavity lasers R. P. Schneider Jr and Y. H. Young; 5. Fabrication and performance of vertical-cavity surface-emitting lasers Kent D. Choquette and Kent Geib; 6. Polarization related properties of vertical cavity lasers Dmitri Kuksenkov and Henryk Temkin; 7. Visible light emitting vertical cavity lasers Robert L. Thornton; 8. Long-wavelength vertical-cavity lasers Dubrakovo I. Babic, Joachim Piprek and John E. Bowers; 9. Overview of VCSEL applications Richard C. Williamson; 10. Optical interconnection applications and required characteristics Kenichi Kasahara; 11. VCSEL-based fiber-optic data communications Kenneth Hahn and Kirk Giboney; 12. VCSEL-based smart pixels for free space optoelectronic processing C. W. Wilmsen.

  2. Aspergillosis complicating a microwave ablation cavity.

    Science.gov (United States)

    Singh, Saurabh; Bandula, Steven; Brown, Jeremy; Whelan, Jeremy; Illing, Rowland

    2016-01-01

    We present a case of a patient who following chemotherapy developed semi-invasive pulmonary aspergillosis and an aspergilloma in a lung cavity previously formed by microwave ablation (MWA). A 55-year-old woman presented with cough and shortness of breath after finishing three cycles of chemotherapy for a metastatic nerve sheath tumour. She had been treated by MWA for pulmonary metastases 2 years previously which resulted in a residual right apical lung cavity. Postchemotherapy imaging showed that this cavity had enlarged, developed a thicker wall and contained lobulated soft tissue with a crescent sign on coronal reformats. In addition, the patient's Aspergillus-specific IgG was markedly raised. Treatment with itraconazole improved the symptoms and reduced the cavity size and wall thickness. This case shows that persisting lung cavities after MWA are a potential site for semi-invasive aspergillosis and has implications for the timing of chemotherapy in patient with metastatic lung disease. PMID:27624446

  3. Cavity cooling a single charged levitated nanosphere.

    Science.gov (United States)

    Millen, J; Fonseca, P Z G; Mavrogordatos, T; Monteiro, T S; Barker, P F

    2015-03-27

    Optomechanical cavity cooling of levitated objects offers the possibility for laboratory investigation of the macroscopic quantum behavior of systems that are largely decoupled from their environment. However, experimental progress has been hindered by particle loss mechanisms, which have prevented levitation and cavity cooling in a vacuum. We overcome this problem with a new type of hybrid electro-optical trap formed from a Paul trap within a single-mode optical cavity. We demonstrate a factor of 100 cavity cooling of 400 nm diameter silica spheres trapped in vacuum. This paves the way for ground-state cooling in a smaller, higher finesse cavity, as we show that a novel feature of the hybrid trap is that the optomechanical cooling becomes actively driven by the Paul trap, even for singly charged nanospheres. PMID:25860743

  4. Performance of 3-cell Seamless Niobium cavities

    Energy Technology Data Exchange (ETDEWEB)

    Kneisel, Peter K. [JLAB; Ciovati, Gianluigi [JLBA; Jelezov, I. [DESY, Hamburg; Singer, W. [DESY, Hamburg; Singer, X. [DESY, Hamburg

    2009-11-01

    In the last several months we have surface treated and cryogenically tested three TESLA-type 3-cell cavities, which had been manufactured at DESY as seamless assemblies by hydroforming. The cavities were completed at JLab with beam tube/flange assemblies. All three cavities performed very well after they had been post-purified with titanium at 1250C for 3 hrs. The cavities, two of which consisted of an end cell and 2 center cells and one was a center cell assembly, achieved gradients of Eacc = 32 MV/m, 34 MV/m and 35 MV/m without quenches. The performance was limited by the appearance of the “Q-drop” in the absence of field emission. This contribution reports about the various measurements undertaken with these cavities.

  5. Efeito protetor do aleitamento materno contra a obesidade infantil

    Directory of Open Access Journals (Sweden)

    Balaban Geni

    2004-01-01

    Full Text Available OBJETIVO: Apresentar uma revisão da literatura sobre a hipótese de que o aleitamento materno teria um efeito protetor contra a obesidade infantil, a plausibilidade biológica dessa hipótese e os mecanismos potencialmente envolvidos. FONTES DOS DADOS: Informações coletadas a partir de artigos publicados em revistas científicas indexadas, livros e teses de pós-graduação. A maioria dos artigos foi identificada a partir das bases de dados MEDLINE e Scielo, usando as palavras-chave "aleitamento materno", "sobrepeso", "obesidade", "crianças" e "adolescentes". O período pesquisado foi de 1980 a 2002. Outros artigos foram identificados a partir das referências bibliográficas citadas nos primeiros artigos. SÍNTESE DOS DADOS: A maioria dos estudos revisados relatou um efeito protetor do aleitamento materno contra a obesidade infantil; alguns estudos não encontraram associação entre aleitamento materno e obesidade; um estudo, com um pequeno tamanho amostral, relatou maior adiposidade entre as crianças que receberam aleitamento materno. Diferentes definições de exposição e desfecho dificultam a comparação entre os estudos. Imprinting metabólico foi sugerido como um mecanismo potencialmente envolvido para explicar a associação. Aspectos comportamentais também podem estar envolvidos. CONCLUSÃO: O aleitamento materno parece ter um efeito protetor contra a obesidade infantil, porém essa questão merece uma investigação mais aprofundada.

  6. Efeitos colaterais do metilfenidato Side effects of methylphenidate

    Directory of Open Access Journals (Sweden)

    Giuseppe Pastura

    2004-01-01

    Full Text Available OBJETIVOS: Revisar os principais efeitos colaterais do metilfenidato, em curto e longo prazos, no tratamento de crianças com Transtorno do Déficit de Atenção (TDAH. FONTES DE DADOS: Revisão de literatura nos últimos doze anos através de pesquisa no Medline e Lilacs. RESULTADOS: Dentre os efeitos colaterais que surgem em curto prazo, prevalecem a redução de apetite, insônia, cefaléia e dor abdominal, sendo a maioria autolimitada, dose-dependente e de média intensidade. Dentre aqueles em longo prazo, são descritas alterações discretas de pressão arterial e freqüência cardíaca e uma possível discreta diminuição da estatura. O abuso e a dependência ao medicamento são observados muito raramente. CONCLUSÕES: O perfil de efeitos colaterais do metilfenidato é seguro, não parecendo justificar o seu uso constrito no Brasil, ante os benefícios robustos amplamente demonstrados na literatura.OBJECTIVE: To review main short-term and long-term side effects of methylphenidate in the treatment of Attention-Deficit Disorder in children. SOURCE OF DATA: a 12-year review in Medline and Lilacs. RESULTS: Among those side effects showed in the short-term, anorexia, insomnia, headache and abdominal pain are the most common ones, being the majority self-limited, dose-dependent and of medium intensity. Long-term side effects consist of mild blood pressure and heart rate increase and possible light growth suppression effect. Abuse and dependency are very rare. CONCLUSIONS: Methylphenidate side effects profile is safe and does not seem to justify its restricted use in Brazil, considering its solid benefits widely demonstrated in literature.

  7. A economia continental chinesa e seu efeito gravitacional

    Directory of Open Access Journals (Sweden)

    Diego Pautasso

    2011-11-01

    Full Text Available O presente artigo aborda o desenvolvimento nacional e a inserção internacional da China. O objetivo é discutir como a formação de uma economia continental na China tem se transformado num fator de projeção desse país no sistema internacional, analisando como a formação de uma economia continental produz uma espécie de efeito gravitacional favorecendo a formulação da estratégia internacional chinesa nesta conjuntura de transição sistêmica. O artigo desenvolve-se discutindo com análises recorrentes sobre o processo de desenvolvimento e de inserção da internacional da China. O argumento central defendido no artigo é que o desenvolvimento da economia continental e a ampliação da capacidade econômica tornam-se um instrumento da política externa chinesa. Em outras palavras, a China tende a criar um forte efeito gravitacional em escala global e utilizar-se disso como parte de sua estratégia internacional. O artigo organiza-se da seguinte forma: na primeira parte, discorremos sobre a evolução recente do desenvolvimento chinês, centrando foco nos desafios da formação de uma economia de dimensões continentais; na segunda, abordamos como o incremento da capacidade econômica chinesa implica num crescente efeito gravitacional do país em escala global; por fim, argumentamos que a diplomacia da China utiliza-se dessas prerrogativas (capacidade econômica para desencadear uma estratégia internacional que permita ao país, nesse quadro de transição sistêmica, ampliar seu espaço de atuação internacional buscando as linhas de menor resistência.

  8. HIE-ISOLDE cavity production – results from thermal modelling of the cavity during sputtering

    CERN Document Server

    Kupiainen, P

    2013-01-01

    The HIE-ISOLDE project is in the phase of cavity production and optimization. Cavities are made of copper and sputtered niobium. We build an ANSYS model to model thermal distributions and heat flows in the cavity structure. We limited the analysis to handle the cavity during sputtering and investigated the effect of different coating power. The aim was to check how results compare to experimental data and vary boundary conditions to improve the model. With two boundary conditions (fixed room and cavity top temperatures), we observed a power loss due to fixed temperature, as expected. The temperature gradient between the bottom and top cavity did not reach the values of the experimental data. With one boundary condition (fixed temperature on sputtering chamber structure), the expected linear proportionality was observed clearly between the temperatures of the cavity and the power. The temperature gradients were also observed to increase with power. We observed an offset in the data compared to experimental dat...

  9. Efeito dos incêndios florestais na qualidade do ar

    OpenAIRE

    Miranda, Ana Isabel

    1998-01-01

    Os incêndios florestais podem ser considerados como um processo de combustão natural em grande escala, que consome diversas espécies vegetais numa área geográfica específica Consequentemente, consistem numa fonte potencial de elevadas quantidades de poluentes para a atmosfera, sendo indispensável conhecer o seu impacto na qualidade do ar. O objectivo principal deste trabalho consiste no estudo do efeito das emissões dos incêndios florestais na qualidade do ar. Para tal, foram d...

  10. O Efeito de Pulfrich e a Esclerose Múltipla

    OpenAIRE

    Ferreira, J.; Abegão Pinto, L; D. Amado; Cunha, JP

    2011-01-01

    Introdução: O efeito de Pulfrich é um fenómeno psicofísico em que o movimento lateral/pendular de um objecto num plano bidimensional pode ser interpretado pelo córtex visual como um movimento tridimensional devido à diferença relativa do tempo de latência entre os dois olhos. Objectivo: Determinar se a neuropatia óptica desmielinizante unilateral ou assimétrica origina o fenómeno de Pulfrich. Métodos: Pesquisámos em 22 doentes com o diagnóstico de neuropatia óptica desmielinizante a per...

  11. O EFEITO CHAMARIZ NAS DECISÕES DE INVESTIMENTO

    Directory of Open Access Journals (Sweden)

    César Augusto Tibúrcio Silva

    2012-03-01

    Full Text Available O estudo das fi nanças comportamentais vem ganhando destaque e sendo objeto de diversos trabalhos acadêmicos. Muitos conceitos tradicionais de economia, sobre o homem econômico, têm sido questionados, ao se considerarem aspectos observados na prática. Principalmente, a partir dos modernos estudos de economia comportamental, aponta-se que o homem se comporta de maneira enviesada e irracional, para tomar suas decisões. É infl uenciado por detalhes que podem levá-lo a fazer escolhas menos vantajosas, relacionadas ao seu dinheiro, e nem mesmo se dar conta disso. O efeito chamariz refere-se à infl uência que um item, a ser escolhido, exerce sobre aqueles que farão uma escolha, inclusive levando- os a tomar uma decisão que, anteriormente, era duvidosa, ou até mesmo a mudar uma escolha anterior. Esse efeito mostra como o homem cria falsas bases de comparação, para simplifi car um ambiente de escolha entre opções. O trabalho faz uma pesquisa sobre uma decisão de investimento, em que há duas situações, com a presença ou não de um chamariz, algo que pode infl uenciar a decisão fi nal dos investidores. Participaram da pesquisa 386 alunos de graduação do curso de Ciências Contábeis, de cinco universidades, do Distrito Federal. Os alunos foram considerados investidores capazes de analisar índices de liquidez e de julgar qual seria a melhor opção para investir. Viu-se que as pessoas se sentem incentivadas a investir em empresas nas quais foi criada uma falsa base de comparação, pela presença do chamariz. Esse efeito é observado com maior intensidade em alguns grupos específi cos de investidores. Sugere-se a elaboração de novas pesquisas na área, com o objetivo de observar esse efeito em outras situações e de divulgar o estudo das fi nanças comportamentais.

  12. In Vitro Evaluation of Access Cavity Location Effect on Fracture Resistance of Maxillary Central Endodontically Treated Teeth

    OpenAIRE

    Shirinzad, M.; Z. Khamverdi; S. Ghorbani

    2014-01-01

    Introduction & Objective: Preparation of access cavity to root canal is a critical phase in endo-dontic treatment. The purpose of this study was to evaluate the effect of access cavity loca-tion (labial or palatal) on fracture resistance of endodontically treated maxillary central teeth. Materials & Methods: In this experimental laboratorial study, 84 intact human maxillary central incisors with similar dimensions were selected. The teeth were divided into 4 test groups as follows: Group 1 : ...

  13. Prototype superconducting radio-frequency cavity for LEP

    CERN Multimedia

    1985-01-01

    This niobium superconducting cavity was part of the prototype stages for an upgrade to LEP, known as LEP-2. Superconducting cavities would eventually replace the traditional copper cavities and allow beam energies of 100 GeV.

  14. On the field dependent surface resistance of niobium on copper cavities

    CERN Document Server

    Junginger, Tobias

    2015-01-01

    The surface resistance Rs of superconducting cavities prepared by sputter coating a thin niobium film on a copper substrate increases significantly stronger with the applied RF field compared to cavities of bulk material. A possible cause is that due to the thermal boundary resistance between the copper substrate and the niobium film Rs is enhanced due to global heating of the inner cavity wall. Introducing helium gas in the cavity and measuring its pressure as a function of applied field allowed to conclude that the inner surface of the cavity is heated up by only 60+/-60 mK when Rs increases with Eacc by 100 nOhm. This is more than one order of magnitude less than what one would expect from global heating. Additionally the effect of cooldown speed and low temperature baking have been investigated in the framework of these experiments. It is shown that for current state of the art niobium on copper cavities there is only a detrimental effect of low temperature baking. A fast cooldown results in a lowered Rs.

  15. Microleakage of three self-etch bonding agents in class 5 composite cavities

    Directory of Open Access Journals (Sweden)

    Saeed Nemati Anaraki

    2016-07-01

    Full Text Available Background and Aims: Microleakage is one of the most common problems in bonding systems, which cause different clinical shortcomings such as post operative sensitivity, marginal discoloration and pulp necrosis that can decrease those using bonding systems. The aim of this study was to compare the microleakage of three self etch bonding agents (generation 6 and 7 in class 5 composite cavities. Materials and Methods: In this experimental study, 30 facial class 5 cavities were prepared in 30 human premolar teeth which were freshly extracted for orthodontic purposes. Cl V cavities were prepared in 2*3*2 mm dimensions. Occlusal margins were in enamel and gingival ones in cementum and randomly divided into 3 groups of 10 each. Then the cavities were treated by clearhil SE Bond (Kuraray, Japan, G Bond (GC, Japan, and Opti Bond Solo Plus (Kerr, USA, according to the manufacturers’ insductions. Then the cavities were filled using Z100 resin composite. The specimens were then immersed in a 50% AgNo solution for 24 hrs. Then, the teeth were cut buccolingually to be evaluated for dye penetration with stereomicroscope. Data were analyzed using Kruskal-Wallis test. Results: This study revealed that Opti bond solo plus had type1 microleakage (dye penetration up to 1/3 of cavity in 80% of specimen, and type 4 microleakage (along axial wall in 10%. Clearfil SE bond had no leakage in 50%, type1 in 40% and type 2 (up to 2/3 of cavity in 10%. But there was no significant difference in the microleakage at the gingival margins between 3 groups (P>0.05. Conclusion: Clearfil SE Bond and G bond could prevent microleakage more effectively than that of Opti Bond Solo Plus on the occlusal margins. However, no difference in the microleakage on the gingival surfaces was found.

  16. Present status of superconducting cavity developments

    Energy Technology Data Exchange (ETDEWEB)

    Ouchi, Nobuo; Kusano, Joichi; Hasegawa, Kazuo [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment] [and others

    1997-11-01

    An R and D work of a superconducting (SC) cavity for the high intensity proton linac has begun at JAERI in collaboration with KEK. The RF field calculation and the structural analysis have been made to determine the cavity shape in the proton energy range between 100 and 1500 MeV. The results indicate the feasibility of a SC proton linac. A vertical test stand with clean room, water rinsing system, cavity evacuation pumping system, cryostat and data acquisition system has been installed to demonstrate the cavity performance. A single cell cavity of {beta}=0.5 has been fabricated and tested at the test stand to obtain the Q-value and the maximum surface electric field strength. The measured Q-values have been found to be high enough for our requirement while the field strength was limited to about 75% of the specification by the multipacting. We describe the preliminary design of the SC cavity, the overview of the vertical test stand and experimental results of the single cell cavity. (author)

  17. Optimized Multi-Ion Cavity Coupling

    Science.gov (United States)

    Begley, Stephen; Vogt, Markus; Gulati, Gurpreet Kaur; Takahashi, Hiroki; Keller, Matthias

    2016-06-01

    Recent technological advances in cavity quantum electrodynamics (CQED) are paving the way to utilize multiple quantum emitters confined in a single optical cavity. In such systems, it is crucially important to control the quantum mechanical coupling of individual emitters to the cavity mode. In this regard, combining ion trap technologies with CQED provides a particularly promising approach due to the well-established motional control over trapped ions. Here, we experimentally demonstrate coupling of up to five trapped ions in a string to a high-finesse optical cavity. By changing the axial position and spacing of the ions in a fully deterministic manner, we systematically characterize their coupling to the cavity mode through visibility measurements of the cavity emission. In good agreement with the theoretical model, the results demonstrate that the geometrical configuration of multiple trapped ions can be manipulated to obtain optimal cavity coupling. Our system presents a new ground for exploring CQED with multiple quantum emitters, enabled by the highly controllable collective light-matter interaction.

  18. Demonstration of superconducting micromachined cavities

    Science.gov (United States)

    Brecht, T.; Reagor, M.; Chu, Y.; Pfaff, W.; Wang, C.; Frunzio, L.; Devoret, M. H.; Schoelkopf, R. J.

    2015-11-01

    Superconducting enclosures will be key components of scalable quantum computing devices based on circuit quantum electrodynamics. Within a densely integrated device, they can protect qubits from noise and serve as quantum memory units. Whether constructed by machining bulk pieces of metal or microfabricating wafers, 3D enclosures are typically assembled from two or more parts. The resulting seams potentially dissipate crossing currents and limit performance. In this letter, we present measured quality factors of superconducting cavity resonators of several materials, dimensions, and seam locations. We observe that superconducting indium can be a low-loss RF conductor and form low-loss seams. Leveraging this, we create a superconducting micromachined resonator with indium that has a quality factor of two million, despite a greatly reduced mode volume. Inter-layer coupling to this type of resonator is achieved by an aperture located under a planar transmission line. The described techniques demonstrate a proof-of-principle for multilayer microwave integrated quantum circuits for scalable quantum computing.

  19. Demonstration of superconducting micromachined cavities

    Energy Technology Data Exchange (ETDEWEB)

    Brecht, T., E-mail: teresa.brecht@yale.edu; Reagor, M.; Chu, Y.; Pfaff, W.; Wang, C.; Frunzio, L.; Devoret, M. H.; Schoelkopf, R. J. [Department of Applied Physics, Yale University, New Haven, Connecticut 06511 (United States)

    2015-11-09

    Superconducting enclosures will be key components of scalable quantum computing devices based on circuit quantum electrodynamics. Within a densely integrated device, they can protect qubits from noise and serve as quantum memory units. Whether constructed by machining bulk pieces of metal or microfabricating wafers, 3D enclosures are typically assembled from two or more parts. The resulting seams potentially dissipate crossing currents and limit performance. In this letter, we present measured quality factors of superconducting cavity resonators of several materials, dimensions, and seam locations. We observe that superconducting indium can be a low-loss RF conductor and form low-loss seams. Leveraging this, we create a superconducting micromachined resonator with indium that has a quality factor of two million, despite a greatly reduced mode volume. Inter-layer coupling to this type of resonator is achieved by an aperture located under a planar transmission line. The described techniques demonstrate a proof-of-principle for multilayer microwave integrated quantum circuits for scalable quantum computing.

  20. FPGA based real time RF cavity simulator for superconducting RF cavity

    International Nuclear Information System (INIS)

    RF cavity is one of the most important component in an accelerator, it is used for producing appropriate electromagnetic fields to accelerate the charged particles. The response of RF cavity to an input RF signal depends on the various operating conditions. Actual operating conditions of RF cavity are difficult to create in lab and also RF cavity is not easily available which limits the study and testing of RF systems that involve RF cavity. This calls for the requirement of a real time hardware model of the RF cavity which can be integrated with other RF systems for their testing in lab. This limitation is even more severe for superconducting RF cavities which need to be operated with the required cryogenics. Thus a real time hardware model of the superconducting RF cavity has been realized on FPGA. Real time RF Cavity simulator can be used to study the response of RF cavity under various operating conditions and for testing and optimization of other RF sub-systems particularly the Low Level RF feedback control systems in lab

  1. Efeito priming entre figuras de partes do corpo

    Directory of Open Access Journals (Sweden)

    Oliveira, Felipe Santos de

    2010-01-01

    Full Text Available Um estímulo visual (letra, palavra ou objeto pode ter um efeito duradouro sobre o processamento de estímulos subsequentes. Neste trabalho, investigamos o efeito priming de figuras de mãos humanas (esquerda/direita, vista palmar/dorsal sobre o Tempo de Reação Manual (TRM em uma tarefa usando as mesmas figuras como estímulo alvo. Os pares de figuras podiam ser iguais ou não, de acordo com parâmetros como lateralidade ou vista. Três experimentos foram realizados (lateralidade, vista e cor. Neles, a figura de uma mão não-informativa era apresentada por 200 ms no centro de uma tela de computador. Após 1000ms, uma segunda mão era apresentada no mesmo local até a resposta, a qual consistia em pressionar o interruptor esquerdo ou o direito dependendo da lateralidade (Exp. I, da vista (Exp. II ou da cor (Exp. III do estímulo alvo. Os resultados mostraram que a apresentação prévia da figura de uma mão influencia o TRM ao segundo estímulo apenas quando a seleção da resposta é baseada em uma característica corporal (lateralidade ou vista

  2. Efeitos da acupuntura no tratamento da ansiedade: revisao integrativa

    Directory of Open Access Journals (Sweden)

    Sueli Leiko Takamatsu Goyatá

    2016-06-01

    Full Text Available RESUMO Objetivo: avaliar as evidências científicas disponíveis na literatura sobre os efeitos da acupuntura no tratamento da ansiedade e a qualidade desses estudos. Método: revisão integrativa, realizada nas bases/bancos de dados CINAHL, LILACS, PUBMEDPICO, SciELO, The Cochrane Library, no período entre 2001 a 2014. Os descritores anxiety, acupuncture therapy, acupuncture e anxiety disorders foram combinados entre si para garantir a ampla busca de estudos primários. Resultados: dos 514 artigos, 67 foram selecionados para leitura na íntegra e 19 incluídos. Desses, 11 apresentaram forte nível de evidência. Dos seis artigos de estudos clínicos randomizados, cinco apresentaram qualidade classificada como razoável. Dois estudos utilizaram acupunturistas enfermeiros para a aplicação da intervenção. Os resultados mostram efeitos positivos e estatisticamente significativos do uso da acupuntura para tratamento de indivíduos com ansiedade. Conclusão: a acupuntura parece ser um tratamento promissor para a ansiedade, no entanto, há necessidade de melhorar a qualidade metodológica das pesquisas nessa temática.

  3. Clamshell microwave cavities having a superconductive coating

    Energy Technology Data Exchange (ETDEWEB)

    Cooke, D. Wayne (Los Alamos, NM); Arendt, Paul N. (Los Alamos, NM); Piel, Helmut (Wuppertal, DE)

    1994-01-01

    A microwave cavity including a pair of opposing clamshell halves, such halves comprised of a metal selected from the group consisting of silver, copper, or a silver-based alloy, wherein the cavity is further characterized as exhibiting a dominant TE.sub.011 mode is provided together with an embodiment wherein the interior concave surfaces of the clamshell halves are coated with a superconductive material. In the case of copper clamshell halves, the microwave cavity has a Q-value of about 1.2.times.10.sup.5 as measured at a temperature of 10K and a frequency of 10 GHz.

  4. Coherent cavity networks with complete connectivity

    OpenAIRE

    Kyoseva, Elica S.; Beige, Almut; Kwek, Leong Chuan

    2011-01-01

    When cavity photons couple to an optical fiber with a continuum of modes, they usually leak out within a finite amount of time. However, if the fiber is about one meter long and linked to a mirror, photons bounce back and forth within the fiber on a much faster time scale. As a result, {\\em dynamical decoupling} prevents the cavity photons from entering the fiber. In this paper we use the simultaneous dynamical decoupling of a large number of distant cavities from the fiber modes of linear op...

  5. Q degradations in superconducting niobium cavities

    International Nuclear Information System (INIS)

    In the past year, several laboratories around the world have observed degradations of the Q value of superconducting niobium cavities made from high thermal conductivity niobium under certain cooldown conditions. Especially under slow cooldown or warmup to temperatures < 200 K of larger systems severe degradations have been reported. A systematic study of the influence of the cooldown speed, warmup conditions, multiple cooldowns and chemical surface treatment on cavity performance of cavities manufactured from niobium of different purity has been conducted. Possible cures such as anodic oxidation are being explored and results of these investigations are reported

  6. Piezoelectric Voltage Coupled Reentrant Cavity Resonator

    CERN Document Server

    Carvalho, Natalia C; Floch, Jean-Michel Le; Tobar, Michael Edmund

    2014-01-01

    A piezoelectric voltage coupled microwave reentrant cavity has been developed. The central cavity post is bonded to a piezoelectric actuator allowing the voltage control of small post displacements over a high dynamic range. We show that such a cavity can be implemented as a voltage tunable resonator, a transducer for exciting and measuring mechanical modes of the structure and a transducer for measuring comparative sensitivity of the piezoelectric material. Experiments were conducted at room and cryogenic temperatures with results verified using Finite Element software.

  7. LHC Crab Cavity Coupler Test Boxes

    CERN Document Server

    Mitchell, James; Burt, Graeme; Calaga, Rama; Macpherson, Alick; Montesinos, Eric; Silva, Subashini; Tutte, Adam; Xiao, Binping

    2016-01-01

    The LHC double quarter wave (DQW) crab cavities have two different types of Higher Order Mode (HOM) couplers in addition to a fundamental power coupler (FPC). The FPC requires conditioning, so to achieve this we have designed a radio-frequency (RF) quarter wave resonator to provide high transmission between two opposing FPCs. For the HOM couplers we must ensure that the stop-band filter is positioned at the cavity frequency and that peak transmission occurs at the same frequencies as the strongest HOMs. We have designed two test boxes which preserve the cavity spectral response in order to test the couplers.

  8. RF cavity evaluation with the code SUPERFISH

    International Nuclear Information System (INIS)

    The computer code SUPERFISH calculates axisymmetric rf fields and is most applicable to re-entrant cavities of an Alvarez linac. Some sample results are shown for the first Alvarez's in NUMATRON project. On the other hand the code can also be effectivily applied to TE modes excited in an RFQ linac when the cavity is approximately considered as positioning at an infinite distance from the symmetry axis. The evaluation was made for several RFQ cavities, models I, II and a test linac named LITL, and useful results for the resonator design were obtained. (author)

  9. Cavity-Controlled Chemistry in Molecular Ensembles

    Science.gov (United States)

    Herrera, Felipe; Spano, Frank C.

    2016-06-01

    The demonstration of strong and ultrastrong coupling regimes of cavity QED with polyatomic molecules has opened new routes to control chemical dynamics at the nanoscale. We show that strong resonant coupling of a cavity field with an electronic transition can effectively decouple collective electronic and nuclear degrees of freedom in a disordered molecular ensemble, even for molecules with high-frequency quantum vibrational modes having strong electron-vibration interactions. This type of polaron decoupling can be used to control chemical reactions. We show that the rate of electron transfer reactions in a cavity can be orders of magnitude larger than in free space for a wide class of organic molecular species.

  10. Cavity-controlled chemistry in molecular ensembles

    CERN Document Server

    Herrera, Felipe

    2015-01-01

    The demonstration of strong and ultrastrong coupling regimes of cavity QED with polyatomic molecules has opened new routes to control chemical dynamics at the nanoscale. We show that strong resonant coupling of a cavity field with an electronic transition can effectively decouple collective electronic and nuclear degrees of freedom in a disordered molecular ensemble, even for molecules with high-frequency quantum vibrational modes having strong electron-vibration interactions. This type of polaron decoupling can be used to control chemical reactions. We show that the rate of electron transfer reactions in a cavity can be orders of magnitude larger than in free space, for a wide class of organic molecular species.

  11. Micro-Cavity Fluidic Dye Laser

    DEFF Research Database (Denmark)

    Helbo, Bjarne; Kristensen, Anders; Menon, Aric Kumaran

    2003-01-01

    We have successfully designed, fabricated and characterized a micro-cavity fluidic dye laser with metallic mirrors, which can be integrated with polymer based lab-on-a-chip microsystems without further processing steps. A simple rate-equation model is used to predict the average pumping power...... threshold for lasing as function of cavity-mirror reflectance, laser dye concentration and cavity length. The laser device is characterized using the laser dye Rhodamine 6G dissolved in ethanol. Lasing is observed, and the influence of dye concentration is investigated....

  12. Shallow Cavities in Multiple-Planet Systems

    OpenAIRE

    Duffell, Paul C.; Dong, Ruobing

    2014-01-01

    Large cavities are often observed in protoplanetary disks, which might suggest the presence of planets opening gaps in the disk. Multiple planets are necessary to produce a wide cavity in the gas. However, multiple planets may also be a burden to the carving out of very deep gaps. When additional planets are added to the system, the time-dependent perturbations from these additional satellites can stir up gas in the gap, suppressing cavity opening. In this study, we perform two-dimensional nu...

  13. Realization of symmetric sharing of entanglement in semiconductor microcrystallites coupled by a cavity field

    CERN Document Server

    Liu, Y; Koashi, M; Imoto, N; Liu, Yu-xi; Miranowicz, Adam; Koashi, Masato; Imoto, Nobuyuki

    2002-01-01

    The entanglement of excitonic states in a system of $N$ spatially separated semiconductor microcrystallites is investigated. The interaction among the different microcrystallites is mediated by a single-mode cavity field. It is found that the symmetric sharing of the entanglement (measured by the concurrence) between any pair of the excitonic state with $N$ qubits defined by the number states (vacuum and a single-exciton states) or the coherent states (odd and even coherent states) can be prepared by the cavity field for this system.

  14. Entanglement of separate nitrogen-vacancy centers coupled to a whispering-gallery mode cavity

    CERN Document Server

    Yang, W L; Feng, M; Du, J F

    2010-01-01

    We present a quantum electrodynamical model involving nitrogen-vacancy centers coupled to a whispering-gallery mode cavity. Two schemes are considered to create W state and Bell state, respectively. One of the schemes makes use of the Raman transition with the cavity field virtually excited; The other enables the Bell state preparation and quantum information transfer by virtue of dark state evolution and adiabatic passage, which is tolerant to ambient noise and experimental parameter fluctuations. We justify our schemes by considering the experimental feasibility and challenge using currently available technology.

  15. Two interacting atoms in a cavity: exact solutions, entanglement and decoherence

    Energy Technology Data Exchange (ETDEWEB)

    Torres, J M; SadurnI, E; Seligman, T H, E-mail: mau@fis.unam.m [Instituto de Ciencias FIsicas, Universidad Nacional Autonoma de Mexico, CP 62210 Cuernavaca, Morelos (Mexico)

    2010-05-14

    We address the problem of two interacting atoms of different species inside a cavity and find the explicit solutions of the corresponding eigenvalues and eigenfunctions using a new variant. This model encompasses various commonly used models. By way of example we obtain closed expressions for concurrence and purity as a function of time for the case where the cavity is prepared in a number state. We discuss the behaviour of these quantities and their relative behaviour in the concurrence-purity plane. (fast track communication)

  16. Microleakage of contemporary composite systems in dentin cavities

    Directory of Open Access Journals (Sweden)

    Stojanac Igor

    2009-01-01

    Full Text Available This study evaluated microleakage in vitro of self-etch and multi-step, total-etch adhesive systems. Ninety extracted non-carious human molars were randomly assigned to nine groups (n=10 and restored with nine different composite systems: Gluma CPS/Charisma, Syntac Sprint/Tetric Ceram, 3M Single Bond/Silux, Admira Bond/Admira, Optibond Solo Plus/Herculite, Trendy Bond/Saremco, Excite/Tetric Ceram, Syntac Sprint/Compoglass and Promt-L-Pop/Silux. Cavities (2 mm diameter/2 mm deep were prepared on the facial and lingual surfaces of each tooth previously abraded with a silicon-carbide abrasion discs to produce two level dentin surfaces with whole margins in dentin.Each group of composite systems was treated following the manufacturer's instructions. After they were finished and polished, the specimens were subjected to 100 thermal cycles in baths of 4 degrees+/-2 degrees C and 58 degrees+/-2 degrees C with 60 seconds of dwell time for each bath. After the thermocycling, the specimens were sealed with acid-resistant varnish, leaving a 1-mm window around the cervical margin interface, and immersed in 1% methylene blue buffered solution for 4 hours. Then the specimens were sectioned longitudinally in half and evaluated under stereomicroscopy at 30 times magnification, using inserted millimeter measurer. Each specimen was measured for dye penetration, thickness of composite filling and distance from the bottom of cavity to the pulp chamber. The data were analyzed using Kruskal-Wallis Analysis of Variance (ANOVA and Pearson t- test. Syntac Sprint/Tetric Ceram, 3M Single Bond/Silux, Admira Bond/Admira, Optibond Solo Plus/Herculite and Gluma CPS/Charisma showed the least microleakage at the occlusal part of the cavity. There was no significant difference of microleakage at gingival part of cavity for all tested composite systems and the best sealing ability showed 3M Single Bond/Silux. Self-etch and multi-step, total-etch adhesive systems showed more or

  17. Striped-double cavity fabry-perot interferometers using both glass and air cavities

    Energy Technology Data Exchange (ETDEWEB)

    Perry, S; Steinmetz, L

    1998-07-08

    We have used piezo-driven Fabry-Perot interferometers in the past far many continuous velocity-time measurements of fast moving surfaces. In order to avoid the annoying drift of some of these devices, we have developed and used inexpensive, solid glass, striped etalons with lengths up to 64 mm. Usable apertures are 35 mm by 80 mm with a finess of 25. A roundabout technique was devised for double cavity operation. We built a passive thermal housing for temperature stability, with tilt and height adjustments. We have also developed and used our first fixed etalon air-spaced cavity with a rotatable glass double- cavity insert. The rotation allows the referee cavity fractional order to be adjusted separately from that of the main cavity. It needs very little thermal protection, and eliminates the need for a roundabout scheme for double cavity operation, but is more costly than the solid glass version I

  18. Effect of Extension and Type of Composite-Restored Class II Cavities on Biomechanical Properties of Teeth: A Three Dimensional Finite Element Analysis.

    Directory of Open Access Journals (Sweden)

    Azam Valian

    2015-04-01

    Full Text Available Controversy exists regarding cavity preparation for restoration of interproximal caries in posterior teeth in terms of preserving the tooth structure and suitable stress distribution. This study aimed to assess the effect of extension and type of class II cavities and the remaining tooth structure in maxillary premolars restored with composite resin on the biomechanical properties of teeth using finite element method (FEM.Using FEM, eight three-dimensional (3D models of class II cavities in maxillary premolars with variable mesiodistal (MD dimensions, variable thickness of the residual wall in-between the mesial and distal cavities and different locations of the wall were designed. Other dimensions were the same in all models. Cavities were restored with composite resin. A load equal to the masticatory force (200N was applied to the teeth. Finite element analysis (FEA was used to calculate the von Mises stress.Stress in the enamel margin increased by increasing the MD dimensions of the cavities. Deviation of the residual wall between the mesial and distal cavities from the tooth center was found to be an important factor in increasing stress concentration in the enamel. Increasing the MD dimensions of the cavity did not cause any increase in stress concentration in dentin.Increasing the MD dimensions of the cavities, decreasing the thickness of the residual wall between the mesial and distal cavities and its deviation from the tooth center can increase stress concentration in the enamel but not in dentin.

  19. Coupled Photonic Crystal Cavity Array Laser

    DEFF Research Database (Denmark)

    Schubert, Martin

    This thesis describes the design, fabrication and characterization of photonic crystal slab lasers. The main focus is on coupled photonic crystal cavity lasers which are examined in great detail. The cavity type which is mainly explored consists of a defect formed by a single missing hole...... are identified such as the size and material for the carrier wafer in the III-V etch and the importance of removing all remains of the e-beam lithography mask after the etch of the hard mask. Detailed simulations are shown for a simple system with two coupled cavities in different coupling directions....... The results are in good agreement with standard coupled mode theory. Also a novel type of photonic crystal structure is proposed called lambda shifted cavity which is a twodimensional photonic crystal laser analog of a VCSEL laser. Detailed measurements of the coupled modes in the photonic crystals...

  20. Degreasing and cleaning superconducting RF Niobium cavities

    Energy Technology Data Exchange (ETDEWEB)

    Rauchmiller, Michael; Kellett, Ron; /Fermilab

    2011-09-01

    The purpose and scope of this report is to detail the steps necessary for degreasing and cleaning of superconducting RF Niobium cavities in the A0 clean room. It lists the required equipment and the cleaning procedure.

  1. Nb3Sn for Radio Frequency Cavities

    Energy Technology Data Exchange (ETDEWEB)

    Godeke, A.

    2006-12-18

    In this article, the suitability of Nb3Sn to improve theperformance of superconducting Radio-Frequency (RF)cavities is discussed.The use of Nb3Sn in RF cavitiesis recognized as an enabling technology toretain a veryhigh cavity quality factor (Q0) at 4.2 K and tosignificantly improve the cavity accelerating efficiency per unitlength(Eacc). This potential arises through the fundamental properties ofNb3Sn. The properties that are extensively characterized in theliterature are, however, mainly related to improvements in currentcarrying capacity (Jc) in the vortex state. Much less is available forthe Meissner state, which is of key importance to cavities. Relevantdata, available for the Meissner state is summarized, and it is shown howthis already validates the use of Nb3Sn. In addition, missing knowledgeis highlighted and suggestions are given for further Meissner statespecific research.

  2. Malignant melanoma of the oral cavity

    Directory of Open Access Journals (Sweden)

    Ebenezer Jagadish

    2006-01-01

    Full Text Available Oral malignant melanoma is a rare disease. The common sites of its occurrence are the palate and gingiva with the maxillary arch being affected 80% of the time. Because of their presence at relatively obscure areas in the oral cavity, most of the malignant melanomas of the oral cavity are diagnosed at a late stage. These lesions are associated with poor prognosis. The dental clinician must therefore carefully examine the head, neck, and oral cavity, and any pigmented lesion that may exhibit growth potential must be biopsied. This article describes a case of malignant melanoma that was present in the oral cavity and briefly reviews the relevant literature that explains the nature of this lesion.

  3. Photonic crystal cavities with metallic Schottky contacts

    International Nuclear Information System (INIS)

    We report about the fabrication and analysis of high Q photonic crystal cavities with metallic Schottky-contacts. The structures are based on GaAs n-i membranes with an InGaAs quantum well in the i-region and nanostructured low ohmic metal top-gates. They are designed for photocurrent readout within the cavity and fast electric manipulations. The cavity structures are characterized by photoluminescence and photocurrent spectroscopy under resonant excitation. We find strong cavity resonances in the photocurrent spectra and surprisingly high Q-factors up to 6500. Temperature dependent photocurrent measurements in the region between 4.5 K and 310 K show an exponential enhancement of the photocurrent signal and an external quantum efficiency up to 0.26

  4. Working on an LHC superconducting cavity

    CERN Multimedia

    Laurent Guiraud

    2000-01-01

    The delicate superconducting equipment for CERN’s LHC collider has to be assembled in ultra-clean conditions to safeguard performance. Here we see the power supply being installed on one of the superconducting cavities.

  5. On Catastrophe and Cavitation for Spherical Cavity

    Institute of Scientific and Technical Information of China (English)

    MingJIN; KefuHUANG; 等

    1999-01-01

    This work deals with catastrophe of a spherical cavity and cavitation of a spherical cavity for Hooke material with 1/2 Poisson's ratio.A nonlinear problem.which is the Cauchy traction problem,is solved analytically.The governing equations are written on the deformed region or on the present configuration.And the conditions are described on moving boundary.A closed form solution is found.Furthermore,a bifurcation solution in closed form is given from the trivial homogeneous solution of a solid sphere.The results indicate that there is a tangent bifurcation on the displacement-load curve for a sphere with a cavity.On the tangent bifurcation point,the cavity grows up suddenly,which is a kind of catastrophe,And there is a pitchfork bifurcation on the displacement-load curve for a solid sphere.On the pitchfork bifurcation point.there is a cavitation in the solid sphere.

  6. LEP superconducting cavities go into storage

    CERN Multimedia

    Patrice Loïez

    2001-01-01

    Superconducting radio-frequency cavities from the LEP-2 phase (1996-2000) are put into storage in the tunnel that once housed the Intersecting Storage Rings (ISR), the world’s first proton collider, located at CERN.

  7. Photon filters in a microwave cavity

    CERN Document Server

    Larson, J

    2003-01-01

    In an earlier paper we have concluded that time-dependent parameters in atom-mode interaction can be utilized to modify the quantum field in a cavity. When an atom shoots through the cavity field, it is expected to experience a trigonometric time dependence of its coupling constant. We investigate the possibilities this offers to modify the field. As a point of comparison we use the solvable Rosen-Zener model, which has parameter dependencies roughly similar to the ones expected in a real cavity. We do confirm that by repeatedly sending atoms through the cavity, we can obtain filters on the photon states. Highly non-classical states can be obtained. We find that the Rosen-Zener model is more sensitive to the detuning than the case of a trigonometric coupling.

  8. section of an accelerating cavity from LEP

    CERN Multimedia

    This is a section of an accelerating cavity from LEP, cut in half to show the layer of niobium on the inside. Operating at 4.2 degrees above absolute zero, the niobium is superconducting and carries an accelerating field of 6 million volts per metre with negligible losses. Each cavity has a surface of 6 m2. The niobium layer is only 1.2 microns thick, ten times thinner than a hair. Such a large area had never been coated to such a high accuracy. A speck of dust could ruin the performance of the whole cavity so the work had to be done in an extremely clean environment. These challenging requirements pushed European industry to new achievements. 256 of these cavities are now used in LEP to double the energy of the particle beams.

  9. Reducing the convective losses of cavity receivers

    Science.gov (United States)

    Flesch, Robert; Grobbel, Johannes; Stadler, Hannes; Uhlig, Ralf; Hoffschmidt, Bernhard

    2016-05-01

    Convective losses reduce the efficiency of cavity receivers used in solar power towers especially under windy conditions. Therefore, measures should be taken to reduce these losses. In this paper two different measures are analyzed: an air curtain and a partial window which covers one third of the aperture opening. The cavity without modifications and the usage of a partial window were analyzed in a cryogenic wind tunnel at -173°C. The cryogenic environment allows transforming the results from the small model cavity to a large scale receiver with Gr≈3.9.1010. The cavity with the two modifications in the wind tunnel environment was analyzed with a CFD model as well. By comparing the numerical and experimental results the model was validated. Both modifications are capable of reducing the convection losses. In the best case a reduction of about 50 % was achieved.

  10. Wakefield Damping for the CLIC Crab Cavity

    Energy Technology Data Exchange (ETDEWEB)

    Ambattu, P.K.; Burt, G.; Dexter, A.C.; Carter, R.G.; /Cockcroft Inst. Accel. Sci. Tech. /Lancaster U.; Khan, V.; Jones, R.M.; /Cockcroft Inst. Accel. Sci. Tech. /Manchester U.; Dolgashev, V.; /SLAC

    2011-12-01

    A crab cavity is required in the CLIC to allow effective head-on collision of bunches at the IP. A high operating frequency is preferred as the deflection voltage required for a given rotation angle and the RF phase tolerance for a crab cavity are inversely proportional to the operating frequency. The short bunch spacing of the CLIC scheme and the high sensitivity of the crab cavity to dipole kicks demand very high damping of the inter-bunch wakes, the major contributor to the luminosity loss of colliding bunches. This paper investigates the nature of the wakefields in the CLIC crab cavity and the possibility of using various damping schemes to suppress them effectively.

  11. Wakefield damping for the CLIC crab cavity

    CERN Document Server

    Ambattu, P K; Dexter, A C; Carter, R G; Khan, V; Jones, R M; Dolgashev, V

    2009-01-01

    A crab cavity is required in the CLIC to allow effective head-on collision of bunches at the IP. A high operating frequency is preferred as the deflection voltage required for a given rotation angle and the RF phase tolerance for a crab cavity are inversely proportional to the operating frequency. The short bunch spacing of the CLIC scheme and the high sensitivity of the crab cavity to dipole kicks demand very high damping of the inter-bunch wakes, the major contributor to the luminosity loss of colliding bunches. This paper investigates the nature of the wakefields in the CLIC crab cavity and the possibility of using various damping schemes to suppress them effectively.

  12. WAKEFIELD DAMPING FOR THE CLIC CRAB CAVITY

    CERN Document Server

    Ambattu, P; Dexter, A; Carter, R; Khan, V; Jones, R; Dolgashev, V

    2009-01-01

    A crab cavity is required in the CLIC to allow effective head-on collision of bunches at the IP. A high operating frequency is preferred as the deflection voltage required for a given rotation angle and the RF phase tolerance for a crab cavity are inversely proportional to the operating frequency. The short bunch spacing of the CLIC scheme and the high sensitivity of the crab cavity to dipole kicks demand very high damping of the inter-bunch wakes, the major contributor to the luminosity loss of colliding bunches. This paper investigates the nature of the wakefields in the CLIC crab cavity and the possibility of using various damping schemes to suppress them effectively.

  13. Collapse of Non-Axisymmetric Cavities

    OpenAIRE

    Enriquez, Oscar R.; Peters, Ivo R.; Gekle, Stephan; Schmidt, Laura; Versluis, Michel; van der Meer, Devaraj; Lohse, Detlef

    2009-01-01

    A round disk with a harmonic disturbance impacts on a water surface and creates a non-axisymmetric cavity which collapses under the influence of hydrostatic pressure. We use disks deformed with mode m=2 to m=6. For all mode numbers we find clear evidence for a phase inversion of the cavity wall during the collapse. We present a fluid dynamics video showing high speed imaging of different modes, pointing out the characteristic features during collapse.

  14. Resonance control in SRF cavities at FNAL

    Energy Technology Data Exchange (ETDEWEB)

    Schappert, W.; Pischalnikov, Y.; /Fermilab; Scorrano, M.; /INFN, Pisa

    2011-03-01

    The Lorentz force can dynamically detune pulsed Superconducting RF cavities. Considerable additional RF power can be required to maintain the accelerating gradient if no effort is made to compensate for this detuning. Compensation systems using piezo actuators have been used successfully at DESY and elsewhere to control Lorentz Force Detuning (LFD). Recently, Fermilab has developed an adaptive compensation system for cavities in the Horizontal Test Stand, in the SRF Accelerator Test Facility, and for the proposed Project X.

  15. Electrically Pumped Vertical-Cavity Amplifiers

    DEFF Research Database (Denmark)

    Greibe, Tine

    2007-01-01

    In this work, the design of electrically pumped vertical cavity semiconductor optical amplifiers (eVCAs) for use in a mode-locked external-cavity laser has been developed, investigated and analysed. Four different eVCAs, one top-emitting and three bottom emitting structures, have been designed...... and discussed. The thesis concludes with recommendations for further work towards the realisation of compact electrically pumped mode-locked vertical externalcavity surface emitting lasers....

  16. The comet Halley diamagnetic cavity boundary

    Science.gov (United States)

    Cravens, T. E.; Lindgren, C. J.; Puhl, P.

    1995-01-01

    The magnetometer onboard the Giotto spacecraft observed a diamagnetic cavity surrounding the nucleus of comet Halley. A narrow transition layer with enhanced plasma density is formed at this shock-like boundary as a flux of cometary ions flowing into it from within the cavity is removed by electron-ion recombination. We examine the structure of this layer using both a two-dimensional magnetohydrodynamical model and a one- dimensional hybrid code.

  17. LHC Crab Cavity Progress and Outlook

    CERN Document Server

    Calaga, R

    2013-01-01

    Three novel superconducting RF crab cavity designs proposed for the LHC luminosity upgrade have rapidly progressed. First Niobium prototypes are reaching close to the design performance and beyond. The highlights of the RF test results from the prototypes along with design modifications for initial beam tests in the SPS are presented. The status of the cryomodule development, integration into the SPS and the beam tests in view of validating the crab cavity system for LHC upgrade are addressed.

  18. Cavity QED with Multiple Hyperfine Levels

    CERN Document Server

    Birnbaum, K M; Kimble, H J

    2006-01-01

    We calculate the weak-driving transmission of a linearly polarized cavity mode strongly coupled to the D2 transition of a single Cesium atom. Results are relevant to future experiments with microtoroid cavities, where the single-photon Rabi frequency g exceeds the excited-state hyperfine splittings, and photonic bandgap resonators, where g is greater than both the excited- and ground-state splitting.

  19. Cavity QED on a nanofiber using a composite photonic crystal cavity

    CERN Document Server

    Yalla, Ramachandrarao; Nayak, Kali P; Hakuta, Kohzo

    2014-01-01

    We demonstrate cavity QED conditions in the Purcell regime for single quantum emitters on the surface of an optical nanofiber. The cavity is formed by combining an optical nanofiber and a nanofabricated grating to create a composite photonic crystal cavity. Using this technique, significant enhancement of the spontaneous emission rate into the nanofiber guided modes is observed for single quantum dots. Our results pave the way for enhanced on-fiber light-matter interfaces with clear applications to quantum networks.

  20. Cavity quantum electrodynamics on a nanofiber using a composite photonic crystal cavity.

    Science.gov (United States)

    Yalla, Ramachandrarao; Sadgrove, Mark; Nayak, Kali P; Hakuta, Kohzo

    2014-10-01

    We demonstrate cavity QED conditions in the Purcell regime for single quantum emitters on the surface of an optical nanofiber. The cavity is formed by combining an optical nanofiber and a nanofabricated grating to create a composite photonic crystal cavity. By using this technique, significant enhancement of the spontaneous emission rate into the nanofiber guided modes is observed for single quantum dots. Our results pave the way for enhanced on-fiber light-matter interfaces with clear applications to quantum networks.

  1. The emission properties of an atom inside a cavity when manipulating the atoms outside the cavity

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wen; YE Liu; XIONG Kuang-wei; ZHANG Jin

    2003-01-01

    Considering three two-level atoms initially in the GHZ state, then one atom of them is put into an initially empty cavity and made resonant interaction. It is shown that the emission properties of the atom inside the cavity can be affected only when both of the atoms outside the cavity have been manipulated. This conclusion can also be generalized to n two-level atoms.

  2. Preparation of Highly Squeezed States and Multi-component Entangled Coherent States via the Raman Interaction

    Institute of Scientific and Technical Information of China (English)

    ZHENG Sbi-Biao

    2002-01-01

    A method is presented for generating highly squeezed states of a cavity field via the atom-cavity field interaction of the Raman type. In the scheme a sequence of three-level A-type atoms interacts with a cavity field, displaced by a classical source, in a Rarman manner. Then the atomic states are measured. By this way the cavity field may collapse onto a superposition of several coherent states, which exhibits strong squeezing. The scheme can also be used to prepare superpositions of many two-mode coherent states for two cavity fields. The coherent states in each mode are on a straight line. This is the first way for preparing multi-component entangled coherent states of this type in cavity QED.

  3. "Fine grain Nb tube for SRF cavities"

    Energy Technology Data Exchange (ETDEWEB)

    Robert E. Barber

    2012-07-08

    Superconducting radio frequency (SRF) cavities used in charged particle linear accelerators, are currently fabricated by deep drawing niobium sheets and welding the drawn dishes together. The Nb sheet has a non-uniform microstructure, which leads to unpredictable cavity shape and surface roughness, and inconsistent "spring-back" during forming. In addition, weld zones cause hot spots during cavity operation. These factors limit linear accelerator performance and increase cavity manufacturing cost. Equal channel angular extrusion (ECAE) can be used to refine and homogenize the microstructure of Nb tube for subsequent hydroforming into SRF cavities. Careful selection of deformation and heat treatment conditions during the processing steps can give a uniform and consistent microstructure in the tube, leading to improved deformability and lower manufacturing costs. Favorable microstructures were achieved in short test samples of RRR Nb tube, which may be particularly suitable for hydroforming into SRF cavity strings. The approach demonstrated could be applicable to microstructure engineering of other tube materials including tantalum, titanium, and zirconium.

  4. Study of CSR longitudinal bunch compression cavity

    International Nuclear Information System (INIS)

    The scheme of longitudinal bunch compression cavity for the Cooling Storage Ring (CSR)is an important issue. Plasma physics experiments require high density heavy ion beam and short pulsed bunch,which can be produced by non-adiabatic compression of bunch implemented by a fast compression with 90 degree rotation in the longitudinal phase space. The phase space rotation in fast compression is initiated by a fast jump of the RF-voltage amplitude. For this purpose, the CSR longitudinal bunch compression cavity, loaded with FINEMET-FT-1M is studied and simulated with MAFIA code. In this paper, the CSR longitudinal bunch compression cavity is simulated and the initial bunch length of 238U72+ with 250 MeV/u will be compressed from 200 ns to 50 ns.The construction and RF properties of the CSR longitudinal bunch compression cavity are simulated and calculated also with MAFIA code. The operation frequency of the cavity is 1.15 MHz with peak voltage of 80 kV, and the cavity can be used to compress heavy ions in the CSR. (authors)

  5. Beam induced RF cavity transient voltage

    International Nuclear Information System (INIS)

    We calculate the transient voltage induced in a radio frequency (RF) cavity by the injection of a relativistic bunched beam into a circular accelerator. A simplified model of the beam induced voltage, using a single tone current signal, is generated and compared with the voltage induced by a more realistic model of a point-like bunched beam. The high Q limit of the bunched beam model is shown to be related simply to the simplified model. Both models are shown to induce voltages at the resonant frequency ωr of the cavity and at an integer multiple of the bunch revolution frequency (i.e. the accelerating frequency for powered cavity operation) hω0. The presence of two nearby frequencies in the cavity leads to a modulation of the carrier wave exp(jhω0t). A special emphasis is placed in this paper on studying the modulation function. These models prove useful for computing the transient voltage induced in superconducting RF cavities, which was the motivation behind this research. The modulation of the transient cavity voltage discussed in this paper is the physical basis of the recently observed and explained new kind of longitudinal rigid dipole mode which differs from the conventional Robinson mode

  6. Flux expulsion variation in SRF cavities

    CERN Document Server

    Posen, S; Romanenko, A; Melnychuk, O; Sergatskov, D A; Martinello, M; Checchin, M; Crawford, A C

    2015-01-01

    Treating a cavity with nitrogen doping significantly increases $Q_0$ at medium fields, reducing cryogenic costs for high duty factor linear accelerators such as LCLS II. N-doping also makes cavities more sensitive to increased residual resistance due to trapped magnetic flux, making it critical to either have extremely effective magnetic shielding, or to prevent flux from being trapped in the cavity during cooldown. In this paper, we report on results of a study of flux expulsion. We discuss possible ways in which flux can be pinned in the inner surface, outer surface, or bulk of a cavity, and we present experimental results studying these mechanisms. We show that grain structure appears to play a key role and that a cavity that expelled flux poorly changed to expelling flux well after a high temperature furnace treatment. We further show that after furnace treatment, this cavity exhibited a significant improvement in quality factor when cooled in an external magnetic field. We conclude with implications for ...

  7. Cavity Mode Frequencies and Large Optomechanical Coupling in Two-Membrane Cavity Optomechanics

    CERN Document Server

    Li, J; Malossi, N; Vitali, D

    2015-01-01

    We study the cavity mode frequencies of a Fabry-Perot cavity containing two vibrating dielectric membranes and the corresponding optomechanical coupling. Due to optical interference, extremely large optomechanical coupling of the membrane relative motion is achieved when the two membranes are placed very close to a resonance of the inner cavity formed by the two membranes, and in the limit of highly reflective membranes. The upper bound of the coupling strength is given by the optomechanical coupling associated with the much shorter inner cavity, consistently with the analysis of A. Xuereb et al., Phys. Rev. Lett. 109, 223601 (2012).

  8. Vector cavity solitons in broad area Vertical-Cavity Surface-Emitting Lasers.

    Science.gov (United States)

    Averlant, Etienne; Tlidi, Mustapha; Thienpont, Hugo; Ackemann, Thorsten; Panajotov, Krassimir

    2016-01-01

    We report the experimental observation of two-dimensional vector cavity solitons in a Vertical-Cavity Surface-Emitting Laser (VCSEL) under linearly polarized optical injection when varying optical injection linear polarization direction. The polarization of the cavity soliton is not the one of the optical injection as it acquires a distinct ellipticity. These experimental results are qualitatively reproduced by the spin-flip VCSEL model. Our findings open the road to polarization multiplexing when using cavity solitons in broad-area lasers as pixels in information technology. PMID:26847004

  9. Efeito das cipselas de Cichorium intybus em ratinhos expostos a CCI4

    OpenAIRE

    Oliveira, Sónia Marlene Rodrigues

    2009-01-01

    Cichorium intybus é amplamente utilizada na medicina tradicional devido aos seus supostos efeitos hepatoprotectores. Este trabalho teve por objectivo estudar os possíveis efeitos protectores do extracto de cipselas (frutos) de C. intybus no fígado, rim, baço, testículo e epidídimo de ratinhos. Realizaram-se análises histopatológicas e bioquímicas. Os efeitos protectores destas cipselas foram estudados por comparação com os controlos negativo e positivo, NaCl 0,9% e CCl4 em duas...

  10. Entanglement dynamics of high-dimensional bipartite field states inside the cavities in dissipative environments

    Energy Technology Data Exchange (ETDEWEB)

    Tahira, Rabia; Ikram, Manzoor; Zubairy, M Suhail [Centre for Quantum Physics, COMSATS Institute of Information Technology, Islamabad (Pakistan); Bougouffa, Smail [Department of Physics, Faculty of Science, Taibah University, PO Box 30002, Madinah (Saudi Arabia)

    2010-02-14

    We investigate the phenomenon of sudden death of entanglement in a high-dimensional bipartite system subjected to dissipative environments with an arbitrary initial pure entangled state between two fields in the cavities. We find that in a vacuum reservoir, the presence of the state where one or more than one (two) photons in each cavity are present is a necessary condition for the sudden death of entanglement. Otherwise entanglement remains for infinite time and decays asymptotically with the decay of individual qubits. For pure two-qubit entangled states in a thermal environment, we observe that sudden death of entanglement always occurs. The sudden death time of the entangled states is related to the number of photons in the cavities, the temperature of the reservoir and the initial preparation of the entangled states.

  11. Non-destructive detection of ions using atom-cavity collective strong coupling

    CERN Document Server

    Dutta, Sourav

    2016-01-01

    We present a technique, based on atoms coupled to an optical cavity, for non-destructive detection of trapped ions. We demonstrate the vacuum-Rabi splitting (VRS), arising due to the collective strong coupling of ultracold Rb atoms to a cavity, to change in presence of trapped Rb+ ions. The Rb+ ions are optically dark and the Rb atoms are prepared in a dark magneto-optical trap (MOT). The VRS is measured on an optically open transition of the initially dark Rb atoms. The measurement itself is fast, non-destructive and has sufficient fidelity to permit the measurement of atomic-state selective ion-atom collision rate. This demonstration illustrates a method based on atom-cavity coupling to measure two particle interactions generically and non-destructively.

  12. Effects of light curing method and resin composite composition on composite adaptation to the cavity wall.

    Science.gov (United States)

    Yoshikawa, Takako; Morigami, Makoto; Sadr, Alireza; Tagami, Junji

    2014-01-01

    This study aimed to evaluate the effects of the light curing method and resin composite composition on marginal sealing and resin composite adaptation to the cavity wall. Cylindrical cavities were prepared on the buccal or lingual cervical regions. The teeth were restored using Clearfil Liner Bond 2V adhesive system and filled with Clearfil Photo Bright or Palfique Estelite resin composite. The resins were cured using the conventional or slow-start light curing method. After thermal cycling, the specimens were subjected to a dye penetration test. The slow-start curing method showed better resin composite adaptation to the cavity wall for both composites. Furthermore, the slow-start curing method resulted in significantly improved dentin marginal sealing compared with the conventional method for Clearfil Photo Bright. The light-cured resin composite, which exhibited increased contrast ratios duringpolymerization, seems to suggest high compensation for polymerization contraction stress when using the slow-start curing method.

  13. Non-destructive monitoring of Bloch oscillations in an optical cavity

    CERN Document Server

    Keßler, H; Venkatesh, B P; Georges, Ch; Hemmerich, A

    2016-01-01

    Bloch oscillations are a hallmark of coherent wave dynamics in periodic potentials. They occur as the response of quantum mechanical particles in a lattice if a weak force is applied. In optical lattices with their perfect periodic structure they can be readily observed and employed as a quantum mechanical force sensor, for example, for precise measurements of the gravitational acceleration. However, the destructive character of the measurement process in previous experimental implementations poses serious limitations for the precision of such measurements. In this article we show that the use of an optical cavity operating in the regime of strong cooperative coupling allows one to directly monitor Bloch oscillations of a cloud of cold atoms in the light leaking out of the cavity. Hence, with a single atomic sample the Bloch oscillation dynamics can be mapped out, while in previous experiments, each data point required the preparation of a new atom cloud. The use of a cavity-based monitor should greatly impro...

  14. Multiparty Quantum Secret Sharing of Classical Message using Cavity Quantum Electrodynamic System

    Institute of Scientific and Technical Information of China (English)

    HAN Lian-Fang; LIU Yi-Min; ZHANG Zhan-Jun

    2006-01-01

    @@ An experimental feasible scheme of multiparty secret sharing of classical messages is proposed, based on a cavity quantum electrodynamic system. The secret messages are imposed on atomic Bell states initially in the sender's possession by local unitary operations. By swapping quantum entanglement of atomic Bell states, the secret messages are split into several parts and each part is distributed to a separate party. In this case, any subset of the entire party group can not read out the secret message but the entirety via mutual cooperations. In this scheme, to discriminate atomic Bell states, additional classical fields are employed besides the same highly-detuned single-mode cavities used to prepare atomic Bell states. This scheme is insensitive to the cavity decay and the thermal field, and usual joint Bell-state measurements are unnecessary.

  15. Preparing entangled states by Lyapunov control

    Science.gov (United States)

    Shi, Z. C.; Wang, L. C.; Yi, X. X.

    2016-09-01

    By Lyapunov control, we present a protocol to prepare entangled states such as Bell states in the context of cavity QED system. The advantage of our method is of threefold. Firstly, we can only control the phase of classical fields to complete the preparation process. Secondly, the evolution time is sharply shortened when compared to adiabatic control. Thirdly, the final state is steady after removing control fields. The influence of decoherence caused by the atomic spontaneous emission and the cavity decay is discussed. The numerical results show that the control scheme is immune to decoherence, especially for the atomic spontaneous emission from |2rangle to |1rangle . This can be understood as the state staying in an invariant subspace. Finally, we generalize this method in preparation of W state.

  16. IMRT in oral cavity cancer

    International Nuclear Information System (INIS)

    Except for early T1,2 N0 stages, the prognosis for patients with oral cavity cancer (OCC) is reported to be worse than for carcinoma in other sites of the head and neck (HNC). The aim of this work was to assess disease outcome in OCC following IMRT. Between January 2002 and January 2007, 346 HNC patients have been treated with curative intensity modulated radiation therapy (IMRT) at the Department of Radiation Oncology, University Hospital Zurich. Fifty eight of these (16%) were referred for postoperative (28) or definitive (30) radiation therapy of OCC. 40 of the 58 OCC patients (69%) presented with locally advanced T3/4 or recurred lesions. Doses between 60 and 70 Gy were applied, combined with simultaneous cisplatin based chemotherapy in 78%. Outcome analyses were performed using Kaplan Meier curves. In addition, comparisons were performed between this IMRT OCC cohort and historic in-house cohorts of 33 conventionally irradiated (3DCRT) and 30 surgery only patients treated over the last 10 years. OCC patients treated with postoperative IMRT showed the highest local control (LC) rate of all assessed treatment sequence subgroups (92% LC at 2 years). Historic postoperative 3DCRT patients and patients treated with surgery alone reached LC rates of ~70–80%. Definitively irradiated patients revealed poorest LC rates with ~30 and 40% following 3DCRT and IMRT, respectively. T1 stage resulted in an expectedly significantly higher LC rate (95%, n = 19, p < 0.05) than T2-4 and recurred stages (LC ~50–60%, n = 102). Analyses according to the diagnosis revealed significantly lower LC in OCC following definitive IMRT than that in pharyngeal tumors treated with definitive IMRT in the same time period (43% vs 82% at 2 years, p < 0.0001), while the LC rate of OCC following postoperative IMRT was as high as in pharyngeal tumors treated with postoperative IMRT (>90% at 2 years). Postoperative IMRT of OCC resulted in the highest local control rate of the assessed treatment

  17. Teleportation of a Weak Coherent Cavity Field State

    Science.gov (United States)

    Cardoso, Wesley B.; Qiang, Wen-Chao; Avelar, Ardiley T.

    2016-07-01

    In this paper we propose a scheme to teleport a weak coherent cavity field state. The scheme relies on the resonant atom-field interaction inside a high-Q cavity. The mean photon-number of the cavity field is assumed much smaller than one, hence the field decay inside the cavity can be effectively suppressed.

  18. Cavity polaritons in an organic single-crystalline rubrene microcavity

    Science.gov (United States)

    Tsuchimoto, Yuta; Nagai, Hikaru; Amano, Masamitsu; Bando, Kazuki; Kondo, Hisao

    2014-06-01

    We fabricated a single-crystalline rubrene microcavity using a simple solution technique and observed cavity polaritons in the microcavity at room temperature (RT). Large Rabi splitting energies were obtained from dispersion of the cavity polaritons. Furthermore, photoluminescence from the cavity polaritons was observed at RT. The findings will be of importance for the application of cavity polaritons.

  19. Compound parabolic concentrator with cavity for tubular absorbers

    Science.gov (United States)

    Winston, Roland

    1983-01-01

    A compond parabolic concentrator with a V-shaped cavity is provided in which an optical receiver is emplaced. The cavity redirects all energy entering between the receiver and the cavity structure onto the receiver, if the optical receiver is emplaced a distance from the cavity not greater than 0.27 r (where r is the radius of the receiver).

  20. Teleportation of atomic states with a weak coherent cavity field

    Institute of Scientific and Technical Information of China (English)

    Zheng Shi-Biao

    2005-01-01

    A scheme is proposed for the teleportation of an unknown atomic state. The scheme is based on the resonant interaction of atoms with a coherent cavity field. The mean photon-number of the cavity field is much smaller than one and thus the cavity decay can be effectively suppressed. Another adwntage of the scheme is that only one cavity is required.

  1. Scheme for implementing quantum secret sharing via cavity QED

    Institute of Scientific and Technical Information of China (English)

    Chen Zhi-Hua; Lin Xiu-Min

    2005-01-01

    An experimentally feasible scheme for implementing quantum secret sharing via cavity quantum electrodynamics (QED) is proposed. The scheme requires the large detuning of the cavity field from the atomic transition, the cavity is only virtually excited, thus the requirement on the quality factor of the cavity is greatly loosened.

  2. Control of ring lasers by means of coupled cavities

    DEFF Research Database (Denmark)

    Abitan, Haim; Andersen, Ulrik Lund; Skettrup, Torben;

    2000-01-01

    Summary form only. Coupling of optical cavities offers a means of controlling the properties of one cavity (e.g. a laser) by making adjustments to another, external cavity. In this contribution we consider a unidirectional ring laser (bow-tie laser) coupled to an external ring cavity. Using...

  3. Soliton laser: A computational two-cavity model

    DEFF Research Database (Denmark)

    Berg, P.; If, F.; Christiansen, Peter Leth;

    1987-01-01

    An improved computational two-cavity model of the soliton laser proposed and designed by Mollenauer and Stolen [Opt. Lett. 9, 13 (1984)] is obtained through refinements of (i) the laser cavity model, (ii) the pulse propagation in the fiber cavity, and (iii) the coupling between the two cavities. As...

  4. Comparison of the Remaining Tooth Structure and Fracture Resistance between Labial and Lingual Access Cavities in Permanent Anterior Teeth with Labial Caries: An In-vitro Study

    Directory of Open Access Journals (Sweden)

    Eftekhar B.

    2012-02-01

    Full Text Available Statement of Problem: Labial access cavity preparation is a conventional method in endodontic treatment of the anterior teeth, but in some conditions labial cavity preparation is recommended.Purpose: The aim of this study was to compare labial and lingual access cavity preparation in the permanent anterior teeth with labial caries in terms of the remaining tooth structure and fracture resistance. Materials and Method: In this experimental study, 150 intact permanent human anterior teeth were selected in 5 groups each with 30 teeth including the maxillary central, maxillary lateral, maxillary canine, mandibular incisors and mandibular canine. A class V cavity with similar ratios to dimensions of each tooth was prepared on the labial surface of all specimens. The volumes of each of these teeth were measured by Penta Pycnometer before and after class V cavity preparation (V1, V2. Each group was randomly divided into 2 equal subgroups (n=15. Access cavities were prepared labially in subgroup A and lingually in subgroup B; then, the remained volume of each tooth was measured again (V3. The mean proportional volume loss of each tooth was calculated through access preparation (V2-V3/V1. Then, the specimens were embedded in acrylic resin blocks and subjected to load with a universal testing machine.Results: The differences of mean of theremained volume and fracture resistance of the two subgroups were statistically significant in all groups ( p <0.05 and those teeth with labial access showed more remained volume and fracture resistance than lingual access. Conclusion: Labial access cavity preparation can enhance the remained volume and fracture resistance as compared to lingual access in endodontic treatment of the anterior teeth with labial caries especially in mandibular incisors.

  5. Impacto do efeito suporte e do efeito informação sobre a recuperação de reservas

    Directory of Open Access Journals (Sweden)

    Cruz Júnior Antônio Camilo

    2001-01-01

    Full Text Available Apesar do desenvolvimento de modernas técnicas de tratamento de minérios, a estimativa de teores ainda é uma parte importante na avaliação de reservas minerais. Nesse trabalho é apresentado o formalismo das funções de recuperação (curvas tonelagem x teor com o objetivo de esclarecer os seus efeitos inerentes à atividade mineira, tais como: o efeito suporte e o efeito informação. Exemplos práticos, embora acadêmicos, são apresentados de modo a tornar mais didáticos e aplicáveis os textos originais de Matheron, 1981 e 1984. O estudo do efeito suporte e do efeito informação, considerando que a seleção de blocos é feita sem restrições (seleção livre, mostrou que a mudança de suporte e que a tomada de decisão sobre valores estimados degradam significativamente as curvas de parametrização, no sentido de perda econômica.

  6. Efeito de uma classe de movimento em pessoas idosas institucionalizados

    OpenAIRE

    Pinheira, Vítor; Coutinho, António; Martins, Cláudia; Barata, Gonçalo; Batista, Joana; Duarte, Mariana

    2011-01-01

    Objectivo: Avaliar os efeitos de uma classe de movimento na força muscular, flexibilidade, equilíbrio, medo de queda, estado de saúde/qualidade de vida e desempenho físico, em pessoas idosas residentes em instituições para a terceira idade. Amostra: Amostra de conveniência constituída por 30 idosos, com uma média de idades de 79,40 ±1,37 anos, um IMC médio de 24,66 kg/m2 e que obtiveram uma pontuação mínima prévia de 10 pontos no Timed Up and Go Test. Material e Métodos: Estudo longitu...

  7. Efficient Characterization of Protein Cavities within Molecular Simulation Trajectories: trj_cavity.

    Science.gov (United States)

    Paramo, Teresa; East, Alexandra; Garzón, Diana; Ulmschneider, Martin B; Bond, Peter J

    2014-05-13

    Protein cavities and tunnels are critical in determining phenomena such as ligand binding, molecular transport, and enzyme catalysis. Molecular dynamics (MD) simulations enable the exploration of the flexibility and conformational plasticity of protein cavities, extending the information available from static experimental structures relevant to, for example, drug design. Here, we present a new tool (trj_cavity) implemented within the GROMACS ( www.gromacs.org ) framework for the rapid identification and characterization of cavities detected within MD trajectories. trj_cavity is optimized for usability and computational efficiency and is applicable to the time-dependent analysis of any cavity topology, and optional specialized descriptors can be used to characterize, for example, protein channels. Its novel grid-based algorithm performs an efficient neighbor search whose calculation time is linear with system size, and a comparison of performance with other widely used cavity analysis programs reveals an orders-of-magnitude improvement in the computational cost. To demonstrate its potential for revealing novel mechanistic insights, trj_cavity has been used to analyze long-time scale simulation trajectories for three diverse protein cavity systems. This has helped to reveal, respectively, the lipid binding mechanism in the deep hydrophobic cavity of a soluble mite-allergen protein, Der p 2; a means for shuttling carbohydrates between the surface-exposed substrate-binding and catalytic pockets of a multidomain, membrane-proximal pullulanase, PulA; and the structural basis for selectivity in the transmembrane pore of a voltage-gated sodium channel (NavMs), embedded within a lipid bilayer environment. trj_cavity is available for download under an open-source license ( http://sourceforge.net/projects/trjcavity ). A simplified, GROMACS-independent version may also be compiled. PMID:26580540

  8. JLab SRF Cavity Fabrication Errors, Consequences and Lessons Learned

    Energy Technology Data Exchange (ETDEWEB)

    Frank Marhauser

    2011-09-01

    Today, elliptical superconducting RF (SRF) cavities are preferably made from deep-drawn niobium sheets as pursued at Jefferson Laboratory (JLab). The fabrication of a cavity incorporates various cavity cell machining, trimming and electron beam welding (EBW) steps as well as surface chemistry that add to forming errors creating geometrical deviations of the cavity shape from its design. An analysis of in-house built cavities over the last years revealed significant errors in cavity production. Past fabrication flaws are described and lessons learned applied successfully to the most recent in-house series production of multi-cell cavities.

  9. Efeito de doses de paclobutrazol na cultura do alho

    Directory of Open Access Journals (Sweden)

    Resende Geraldo Milanez de

    2002-01-01

    Full Text Available O trabalho foi realizado no período de maio a outubro de 1991 no campo experimental do setor de olericultura da Ufla, Lavras, MG, com o objetivo de avaliar a influência de doses de paclobutrazol sobre o controle do pseudoperfilhamento e nas características morfológicas e comerciais do alho (Allium sativum L.. Utilizou-se o delineamento experimental de blocos ao acaso, com quatro doses de paclobutrazol (0, 500, 1.000 e 1.500 mg de i.a. L-1, em cinco repetições. Com o aumento das concentrações de paclobutrazol, houve uma redução na altura das plantas e no número de folhas por planta aos 60 e 90 dias após o plantio. A produtividade total e comercial de bulbos apresentou efeito significativo em relação às doses de paclobutrazol, sendo as concentrações de 725 e 778 mg L-1 as que proporcionaram as maiores produtividades. A porcentagem de bulbos pseudoperfilhados evidenciou efeito quadrático com o incremento das doses de paclobutrazol, cuja concentração de 1.163 mg L-1 propiciou maior redução na porcentagem de pseudoperfilhamento. A concentração de 744 mg L-1 de paclobutrazol proporcionou o maior peso médio de bulbo; e em relação a número de bulbilhos por bulbo, não se verificaram diferenças significativas entre os tratamentos.

  10. Dual-cavity basket promotes encapsulation in water in an allosteric fashion.

    Science.gov (United States)

    Chen, Shigui; Yamasaki, Makoto; Polen, Shane; Gallucci, Judith; Hadad, Christopher M; Badjić, Jovica D

    2015-09-30

    We prepared dual-cavity basket 1 to carry six (S)-alanine residues at the entrance of its two juxtaposed cavities (289 Å(3)). With the assistance of (1)H NMR spectroscopy and calorimetry, we found that 1 could trap a single molecule of 4 (K1 = 1.45 ± 0.40 × 10(4) M(-1), ITC), akin in size (241 Å(3)) and polar characteristics to nerve agent VX (289 Å(3)). The results of density functional theory calculations (DFT, M06-2X/6-31G*) and experiments ((1)H NMR spectroscopy) suggest that the negative homotropic allosterism arises from the guest forming C-H···π contacts with all three of the aromatic walls of the occupied basket's cavity. In response, the other cavity increases its size and turns rigid to prevent the formation of the ternary complex. A smaller guest 6 (180 Å(3)), akin in size and polar characteristics to soman (186 Å(3)), was also found to bind to dual-cavity 1, although giving both binary [1⊂6] and ternary [1⊂62] complexes (K1 = 7910 M(-1) and K2 = 2374 M(-1), (1)H NMR spectroscopy). In this case, the computational and experimental ((1)H NMR spectroscopy) results suggest that only two aromatic walls of the occupied basket's cavity form C-H···π contacts with the guest to render the singly occupied host flexible enough to undergo additional structural changes necessary for receiving another guest molecule. The structural adaptivity of dual-cavity baskets of type 1 is unique and important for designing multivalent hosts capable of effectively sequestering targeted guests in an allosteric manner to give stable supramolecular polymers. PMID:26348904

  11. Nonprobabilistic teleportation of field state via cavity QED

    OpenAIRE

    De Carvalho, Carlos Renato; Guerra, Emerson S.; Jalbert, Ginette; Garreau, Jean Claude

    2007-01-01

    International audience In this article we discuss a teleportation scheme of coherent states of cavity field. The experimental realization proposed makes use of cavity quatum electrodynamics involving the interaction of Rydberg atoms with micromaser and Ramsey cavities. In our scheme the Ramsey cavities and the atoms play the role of auxiliary systems used to teleport the state from a micromaser cavity to another. We show that, even if the correct atomic detection fails in the first trials,...

  12. Availability of tree cavities in a sal forest of Nepal

    OpenAIRE

    Bhusal P; Czeszczewik D; Walankiewicz W; Churski M; Baral R; Lamichhane BR; Mikusinski G

    2016-01-01

    Tree cavities are important structural elements of forest ecosystem that host numerous birds, mammals and other cavity-dependent organisms. Pattern of cavity distribution in temperate and boreal forests are relatively well studied, yet little is known about cavities in tropical and subtropical forests. We compared cavity availability in relation to tree condition (living tree and snag), tree species and DBH class between two different sites in a subtropical deciduous sal forest in Nepal: the ...

  13. Superconducting RF cavity R&D for future accelerators

    OpenAIRE

    Ginsburg, C.M.

    2009-01-01

    High-beta superconducting radiofrequency (SRF) elliptical cavities are being developed for several accelerator projects including Project X, the European XFEL, and the International Linear Collider (ILC). Fermilab has recently established an extensive infrastructure for SRF cavity R&D for future accelerators, including cavity surface processing and testing and cavity assembly into cryomodules. Some highlights of the global effort in SRF R&D toward improving cavity performance, and Fermilab SR...

  14. The influence of caries disclosing agents and cavity disinfectants on microleakage of gingival floor of class V composite resin restorations

    Directory of Open Access Journals (Sweden)

    Safarcherati H

    2007-06-01

    Full Text Available Background and Aim: An important purpose of adhesive dentistry is restriction of cavity preparation to carious dentin removal and conservation of sound dentin. Application of caries disclosing agents and cavity disinfectants can help achieving this goal. The aim of this study was to evaluate the effect of caries disclosing agents and cavity disinfectants on microleakage of composite resin restorations. Materials and Methods: This experimental in-vitro study was performed on class V cavities in 48 extracted human sound premolars. The teeth were randomly divided into four equal groups. In group 1 caries detector dye (Seek, Ultradent, USA and in group 2 cavity disinfectant (Consepsis, Ultradent, USA were applied on dentinal surfaces. In group 3 both mentioned materials were applied. Group 4 was considered as control group. PQ1 bonding agent and Amelogen composite were used to restore the cavities. Gingival microleakage was assessed by dye penetration. Data were analyzed by Kruskall Wallis and Dunn tests. P<0.05 was the level of significance.Results: Group 2 showed the least and group 4 showed the highest microleakage;however no statistical significant difference was found among the groups.Conclusion: The use of caries disclosing agent (Seek and cavity disinfectant (Consepsis Liquid did not adversely affect the sealing ability of dentin bonding resins.

  15. Cavity control system: optimization methods for single cavity driving and envelope detection

    Science.gov (United States)

    Czarski, Tomasz; Romaniuk, Ryszard S.; Pozniak, Krzysztof T.; Simrock, Stefan

    2004-07-01

    The paper is an introduction to the optimization methods of the linear accelerator cavity control system. Three distinct time periods of cavity operation are considered; filling with the EM field energy, field stabilization, and field decay. These periods represent completely different states and behavior of the cavity. The cavity could be operated by several different methods in each work phase: During the filling -- feedback and feed-forward alone, feedback and feed-forward together, self-tuning; During the flattop -- feed-forward and feedback alone or together, During the decay -- detuning and quality factor may be measured. The optimization is understood as a choice of the most efficient way of the cavity control during each period. The control may be done in terms of minimum power consumption from the klystron during whole work cycle and efficient field stabilization in the cavity, during flattop period. The introductory analysis of the cavity operational modes in three mentioned periods is presented in this paper. Additionally the alternative more precise algorithm of the cavity voltage envelope detection is proposed.

  16. Enhancing entanglement generation of two atoms in a cavity with white noise using classical driving fields

    Institute of Scientific and Technical Information of China (English)

    Jiansong Zhang; Aixi Chen

    2011-01-01

    We investigate the entanglement dynamics of a quantum system consisting of two two-level atoms in a cavity with classical driving fields in the presence of white noise. The cavity is initially prepared in the vacuum state. Generally, the entanglement of two atoms decreases with the intensity of the thermal fields and the coupling strength of the two-level atoms to the thermal fields. However, we find that the entanglement of the quantum system can be enhanced by adjusting the frequency and the strength of the classical driving fields in the presence of white noise.%@@ We investigate the entanglement dynamics of a quantum system consisting of two two-level atoms in a cavity with classical driving fields in the presence of white noise.The cavity is initially prepared in the vacuum state.Generally, the entanglement of two atoms decreases with the intensity of the thermal fields and the coupling 8trength of the two-level atoms to the thermal fields.However, we find that the entanglement of the quantum system can be enhanced by adjusting the frequency and the strength of the classical driving fields in the presence of white noise.

  17. Transferring of a Two-Mode Entangled State Between Two Cavities via Cavity QED

    Institute of Scientific and Technical Information of China (English)

    WU Tao; NI Zhi-Xiang; YE Liu

    2007-01-01

    We propose a scheme for transferring of a two-mode entanglement of zero- or one-photon entangled states between two cavities via atom-cavity field resonant interaction.In our proposal,in order to transfer the entangled state,we only need two identical two-level atoms and a two-mode cavity for receiving the teleported state.This scheme does not require Bell-state measurement and performing any transformations to reconstruct the initial state.And the transfer can occur with 100% success probability in a simple manner.And a network for transferring of a two-mode entangled state between cavities is suggested.This scheme can also be extended to transfer N-mode entangled state of cavity.

  18. Cavity nano-optomechanics: a nanomechanical system in a high finesse optical cavity

    CERN Document Server

    Stapfner, Sebastian; Hunger, David; Paulitschke, Philipp; Reichel, Jakob; Karrai, Khaled; Weig, Eva M; 10.1117/12.705901

    2011-01-01

    The coupling of mechanical oscillators with light has seen a recent surge of interest, as recent reviews report.[1, 2] This coupling is enhanced when confining light in an optical cavity where the mechanical oscillator is integrated as back- mirror or movable wall. At the nano-scale, the optomechanical coupling increases further thanks to a smaller optomechanical interaction volume and reduced mass of the mechanical oscillator. In view of realizing such cavity nano- optomechanics experiments, a scheme was proposed where a sub-wavelength sized nanomechanical oscillator is coupled to a high finesse optical microcavity.[3] Here we present such an experiment involving a single nanomechanical rod precisely positioned into the confined mode of a miniature Fabry-P\\'erot cavity.[4] We describe the employed stabilized cavity set-up and related finesse measurements. We proceed characterizing the nanorod vibration properties using ultrasonic piezo-actuation methods. Using the optical cavity as a transducer of nanomechan...

  19. Cavity-enhanced laser cooling of solid-state materials in a standing-wave cavity

    Institute of Scientific and Technical Information of China (English)

    Youhua Jia; Biao Zhong; Jianping Yin

    2008-01-01

    We propose a new method to cool the Yba+-doped ZBLANP glass in a standing-wave cavity. There are two advantages of this cavity-enhanced technique: the pumping power is greatly enhanced and the absorption of the cooling material is greatly increased. We introduce the basic principle of the cavity-enhanced laser cooling and discuss the cooling effect of a solid-state material in a cavity. From the theoretical study, it is found that the laser cooling effect is strongly dependent on the reflectivity of the cavity mirrors, the length of the solid material, the surface scattering of the material, and so on. Some optimal parameters for efficient laser cooling are obtained.

  20. CERN Developments for 704 MHz Superconducting Cavities

    CERN Document Server

    Capatina, O; Aviles Santillana, I; Arnau Izquierdo, G; Bonomi, R; Calatroni, S; Chambrillon, J; Gerigk, F; Garoby, R; Guinchard, M; Junginger, T; Malabaila, M; Marques Antunes Ferreira, L; Mikulas, S; Parma, V; Pillon, F; Renaglia, T; Schirm, K; Tardy, T; Therasse, M; Vacca, A; Valverde Alonso, N; Vande Craen, A

    2013-01-01

    The Superconducting Proton Linac (SPL) is an R&D effort coordinated by CERN in partnership with other international laboratories. It is aiming at developing key technologies for the construction of a multi-megawatt proton linac based on state-of-the-art RF superconducting technology, which would serve as a driver in new physics facilities for neutrinos and/or Radioactive Ion Beam (RIB). Amongst the main objectives of this R&D effort, is the development of 704 MHz bulk niobium beta=1 elliptical cavities, operating at 2 K with a maximum accelerating gradient of 25 MV/m, and the testing of a string of cavities integrated in a machine-type cryomodule. The cavity together with its helium tank had to be carefully designed in coherence with the innovative design of the cryomodule. New fabrication methods have also been explored. Five such niobium cavities and two copper cavities are in fabrication. The key design aspects are discussed, the results of the alternative fabrication methods presented and the stat...