Comparison of teeth discolorations induced by Mineral trioxide aggregate, Calcium-enriched mixture and Biodentine using spectrophotometric analysis

Introduction: Most of the materials used in endodontic procedures may lead to discoloration.This study compared the discolorations induced following treatment by MTA, CEM ,and Biodentine using a spectrophotometric analysis. Material & Methods: In this experimental study Forty extracted mandibular anterior teeth were selected and sectioned from 2 mm below Cemento Enamel Junction (CEJ) using a disc. A retrograde method was used for drilling cavities 2 mm away from incisal edge. Then the cavities were washed using 5.25% NaOCL and normal saline and the samples were divided randomly into 4 groups. The cavities in groups 1, 2, and 3 were filled by MTA Angleus, Cem cement, and Biodentine, respectively as deep as CEJ level and they were sealed by 2mm of A3 composite color. All of cavities of group 4/control, were all filled by composite A3. Then the samples were stored in a glass incubator with 100% humidity and under laboratory light .they were exposed to a spectrophotometric analysis within 6 periods from placement including base line, 1 week, 2 weeks, 1 month, 3 months, 6 months. The data were analyzed by SPSS 17 ,Tukey HSD and ANOVA statistical test. Results: The results showed no statistically significant difference in discoloration rate during measurement periodsin each group. However, the discoloration rate varied in various materials. The minimum and maximum discolorations occurred in Biodentine and MTA, respectively and their difference was statistically significant. (p=0.033)Other groups showed no statistically significant difference. Conclusion: The biodentinehad minimum discolorations compared with other two materials; thus, it seems that it can be recommended for cosmetic areas

Small-Signal Dynamic DQ Model of Modular Multilevel Converter for System Studies

This work was funded by the European Research Council under the Ideas program in FP7 under Grant 259328, 2010. Paper no. TPWRD-00046-2015.Peer reviewedPostprin

Integrated Trajectory-Tracking and Vibration Control of Kinematically-Constrained Warehousing Cable Robots

With the explosion of e-commerce in recent years, there is a strong desire for automated material handling solutions including warehousing robots. Cable driven parallel robots (CDPRs) are a relatively new concept which has yet to be explored for high-speed pick-&-place applications in the industry. Compared to rigid-link parallel robots, a CDPR possesses significant advantages including: large workspace, low moving inertia, high-speed motion, low power consumption, and incurring minimal maintenance cost. On the other hand, the main disadvantages of the CDPRs are the cable’s unilateral force exerting capability and low rigidity which is resulting in undesired vibrations of their moving platform. Kinematically-constrained CDPRs (KC-CDPRs) include a special class of CDPRs which provide a considerably higher level of stiffness in undesired degrees of freedom (DOFs) via connecting a set of constrained cables to the same actuator. Nevertheless, undesired vibrations of the moving platform are still their main problem which request more attention and investigation. Dynamic modeling, stiffness optimization, vibration and trajectory-tracking control, and stiffness-based trajectory-planning of redundant KC-CDPRs are studied in this thesis. As a new technique, we separate the moving platform’s vibration equations from its desired (nominal) equations of motion. The obtained vibration model forms a linear parametric variable (LPV) dynamic system which is based for the following contributions: 1) Proposing a new tension optimization approach to minimize undesired perturbations under external disturbances in a desired direction; and demonstrating the effectiveness of kinematically-constrained actuation method in vibration attenuation of CDPRs in undesired DOFs. 2) Providing the opportunity of using a wide class of well-established robust and optimal LPV-based control methods, such as H∞ control techniques, for trajectory-tracking control of CDPRs to minimize the effect of disturbances on the robot operation; and showing the effectiveness of kinematically-constrained actuation method in control design simplification of such robots. 3) Proposing the concept of stiffness-based trajectory-planning to find the stiffness-optimum geometry of trajectories for KC-CDPRs; and designing a time-optimal zero-to-zero continuous-jerk motion to track such trajectories. All the proposed concepts are developed for a generic KC-CDPR and verified via numerical analysis and experimental tests of a real planar warehousing KC-CDPR

Effectiveness of Mindfulness Training on Reduction of Distress of Patients Infected by Breast Cancer

AbstractThe cancer involves its infected people in all mental pressures; the pressures that affect their life, job and social relationships and if they are not solved, complicate the patient's status. Cognition therapy based on mindfulness is a method to reduce the distress. The objective of this study is to investigate the effectiveness of mindfulness training on reduction of distress of patients infected by breast cancer. For this purpose, 30 women infected by breast cancer hospitalized in Shohada Hospital of Tehran were selected through convenient method and processed randomly in two test and control groups. Before and after mindfulness training, the groups were tested with respect to the distress level. Mindfulness was trained to the test group during 8 sessions each 1 hour. The summary of ANCOVA between two groups of distress scores of testees in both pretest and posttest stages indicated that training the mindfulness has been effective on reduction of distress scores of trained patients. Thus, applying cognition therapy method based on mindfulness reduces the distress and defective thinking pattern of patients infected by cancer and this intervention method may be used independently or along with other treatment methods such as pharmacotherapy to reduce the distress of these sufferers

Spiritual Interventions and Distress in Mothers of Children with Cancer

AbstractThe purpose of this study was to evaluate the effectiveness of spiritual interventions in reducing distress in mothers of children with cancer. In a quasi-experimental study 12 mothers of children with cancer aged between 19 to 50 years old were selected and studied within six 90-minute group sessions in a spiritual intervention based program. Participants in a program based on repeated measures were tested in the first, third, sixth sessions and then 3 weeks after the last session (follow-up) with a Scale of Subjective Units of Distress (SUD). The results of repeated measures show that spiritual intervention improves distress of mothers of children with cancer in post-test phase and this increase remains sustained until follow-up

Parametric amplification and phase preserving amplitude regeneration of a 640 Gbit/s RZ-DPSK signal

We report the first experimental demonstration of parametric amplification and all-optical phase-preserving amplitude regeneration for a 640 Gbit/s return-to-zero (RZ) differential phase-shift keying (DPSK) optical time division multiplexed (OTDM) signal. In the designed gain-flattened singlepump fiber optical parametric amplifier (FOPA), 620 fs short optical pulses are successfully amplified with 15 dB gain with error-free performance and less than 1 dB power penalty. Phase-preserving amplitude regeneration based on gain saturation in the FOPA is carried out for optical signals with degraded optical signal-to-noise ratio. An improvement of 2.2 dB in receiver sensitivity at a bit-error-ratio of 10-9 has been successfully achieved after regeneration, together with 13.3 dB net gain.</p

The effectiveness of positive psychotherapy on the psychological well-being of breast cancer patients

Many cancer patients become very anxious and stressed in response to cancer diagnosis. The fear of disease symptoms incidence, the loss of abilities and facing death, creates serious crisis for the patient and threatens one’s well-being. This study aims to determine the effectiveness of positive psychotherapy on the psychological well-being of breast cancer patients. For this purpose, 24 patients with breast cancer in Shohada-e-Tajrish Hospital were selected through available sampling and were tested in terms of psychological well-being questionnaire. The results of analysis of covariance data, showed that positive psychotherapy is effective on the subscales of dominance, relationships and acceptance of psychological well-being in these patients but had no effect on the autonomy, growth, and goal. Therefore, this therapy can be used as an effective approach for the treatment of cancer patients

On-wafer characterization of mm-wave and THz circuits using electrooptic sampling

THz, the electromagnetic spectrum lying between millimeter waves and optics, is nowadays widely utilized in the applications such as material inspection, medicine, explosives detection and astronomy. Although optical and photonic based systems for generating THz waves can fully cover the upper band of the THz spectrum (from several THz to far infrared), they are inefficient at lower frequency bands i.e., mm-waves, and at the same time inappropriately bulky for portable applications. In contrast, recent progress in solid states electronics in conjunction with aggressive scaling of devices are promising to facilitate the future availability of THz systems realized as compact and cheap all-electronic solutions. THz microelectronics is an increasingly relevant field of activities, therefore. Without concerning about the challenges in the design and fabrication of such devices, their performance needs to be characterized with systems faster than the device itself; therefore, we face with limitations. Recently, the measurement bandwidth of microwave network analyzers equipped with extension modules has extended beyond 1 THz. However, their calibration is a challenging task and performing a full band measurement, due to a need for waveguide components, considerably increases the cost and time of measurement. Systematic errors in system calibration due to lack of precise models for devices at THz frequencies are also remarkable drawbacks of this approach. An eligible alternative for these systems is the use of electrooptic and photoconductive sampling which rely on optical and photonic approaches. These techniques with the help of femtosecond pulse lasers provide a very broadband measurement system far beyond today’s electronic devices bandwidth without suffering from the challenges of the electronic approach. In particular electrooptic sampling with non-contact probing can also perform useful high resolution near field scanning of devices. The aim of this thesis is to demonstrate the electrooptic sampling for the characterization of mm-wave and THz electronic devices. To this end, an extremely broadband (microwave to THz) device, which is a 65-nm CMOS nonlinear transmission line (NLTL), is used as the device under test. Before showing the measurement results for this device, the advances in THz electronics as well as their common the characterization techniques are reviewed. For the characterization, a rather compact EOS experimental setup featured with a large dynamic range, high sensitivity and high spatial resolution is presented. In the measurement phase, it is shown that what challenges in particular for the characterization of a nonlinear device we may face to and which scenarios can be used to overcome them. The relative jitter in EOS, known as the most prohibiting factor for achieving a high measurement bandwidth, is resolved with a novel synchronization technique called Laser Master Laser Slave (LM-LS). This is achieved by feeding the DUT with a microwave signal which is generated from the comb harmonics of the femtosecond laser. Since the signal is sampled by the laser itself, EOS provides a fully coherent heterodyne detection which helps to significantly increase the detection bandwidth of the system from 50 GHz up to 300 GHz which is presently restricted by the DUT fabrication technology i.e. the 65-nm CMOS. Furthermore, it is shown that for nonlinear devices, measurement with EOS can outperform traditional microwave network analyzer measurements and in particular it can detect hidden features like conversion losses which may not be observed by electronic techniques. In the end by performing photoconductive measurements for the DUT, a good comparison between electrooptic and photoconductive sampling in terms of their detection bandwidth and image resolution is demonstrated.THz, das elektromagnetische Spektrum, das zwischen Millimeterwellen und Optik liegt, ist weit verbreitet in Anwendungsgebieten wie Materialinspektion, Medizin, Entdeckung von Sprengstoffen und Astronomie. Obwohl auf Optik und Photonik basierende Systeme für Generation von Terahertz-wellen die oberen Bandbreit des THz-Spektrums vollig abdecken koennen, sind sie ineffizient in den unteren Frequenzbändern, wie etwa dem mm-Wellenbereich, und gleichzeitig sind ihre Größen ungeeignet für tragbare Anwendungen. Im Gegensatz dazu versprechen die aktuellen Fortschritte in der Festkörper Elektronik in Verbindung mit einer aggressiven Skalierung von Bauelement, die zukünftige Verfügbarkeit von THz Systemen, als kompakte und preiswert voll-elektronische Lösungen. Daher ist die THz Mikroelektronik ein zunehmend relevantes Arbeitsfeld. Unabhängig von den Herausforderungen in Design und Fabrikation von THz Komponenten, müssen deren Leistungsfähigkeit mit Hilfe von Instrumenten charakterisiert werden, die schneller sind als die Komponente selbst, daher stößt man hier an Grenzen. Die aktuellen Messbandbreiten von Mikrowellen-Netzwerkanalysatoren, die mit Erweiterungsmodulen ausgestatten worden sind, gehen bereits über 1 THz Hinaus. Jedoch ist ihre Kalibrierung aufwendig und Messungen über die volle Bandbreite erhöhen, wegen der Notwendigkeit von Wellenleiterkomponenten, wesentlich die Kosten und den Zeitaufwand. Die systematischen Fehler in der Kalibrierung der Systeme, auf Grund des Mangels an präzisen Modellen für Komponenten im THz Frequenzbereich, sind ebenfalls ein bedeutender Nachteil dieses Ansatzes. Eine gute Alternative für diese Systeme ist elektrooptisches oder photokonduktives Abtasten, welche nicht elektronisch arbeiten sondern optik- und photonik-basiert sind. Diese Techniken stellen mit Hilfe von Femtosekunden-Lasern Breitbandsmesssysteme zur Verfügung, welche die Bandbreite der heutigen elektronischen Messgeräte bei weiten übertreffen, ohne durch die Herausforderungen von elektronischen Ansätzen beschränkt zu werden. Insbesondere durch das elektrooptische Abtasten mit Hilfe von kontaktlosen Probern können wertvolle, hochauflösunge Nahfeld-Scans von Komponenten durchgeführt. Das Ziel dieser Dissertation ist die Charakterisierung von mm-Wellen und THz Komponenten mit Hilfe des elektrooptischen Abtastens zu demonstrieren. Zu diesem Zweck wird eine extrem breitbandige (von Mikrowellen bis zu THz) Komponenten, eine 65-nm CMOS nichtlineare Diodenleitung, als DUT genutzt. Bevor die Messungsergebnisse für das Gerät gezeigt werden, werden sowohl die Fortschritte in der THz-Elektronik als auch deren häufigsten Charakterisierungsmethoden vorgestellt. Der für die Charakterisierung verwendete relativ kompakte elektrooptische Aufbau, welcher eine große Dynamik, hohe Sensitivität und hohe räumliche Auflösung aufweist, darauf folgend präsentiert. Der anschließende Abschnitt beschreibt die Messungen und zeigt mit welche Herausforderungen, insbesondere bei der Charakterisierung von nichtlinearem Komponenten, man konfrontieren wird und welche Szenarios als Lösung genutzt werden können. Der relative Jitter im elektrooptischen Abtasten, der meist am stärksten einschränkende Faktor für die Erreichung hoher Messbandbreiten, wird mit Hilfe einer neuartige Synchronisationstechnik, dem sogenannt Laser Master Laser Slave (LM-LS), entgegengewirkt. Dies ist durch die Versorgung des DUT mit Mikrowellensignal, die aus dem Harmonik-Kamm des Femtosekunden-Lasers generiert wird, erreicht. Da das Mikrowellensignal mit dem gleichen Laser abgetastet wird, erhöht das voll kohärente, elektrooptische Abtasten die Detektionsbandbreit von zuvor 50 GHz auf bis zu 300 GHz, was die derzeitige Grenze auf Grund der DUT Fabrikationstechnologie (65-nm CMOS) ist. Ausserdem wird gezeigt, dass elektrooptisches Abtasten für nichtlineare Komponenten die traditionelle Mikrowellenmessmethoden übertreffen kann. Insbesondere detektiert elektrooptisches Abtasten versteckte Eigenschaften, wie Umwandlungsverlusten, die nicht mit elektronischen Messungen beobachtet werden können. Abschließend demonstrieren die Messungen mit einem Photokonduktivdetektor eine gute Vergleichbarkeit von elektrooptischen und photokonduktiven Abtasten, insbesondere in Bezug auf Detektionsbandbreit und Bildauflösung

3-Level cascaded voltage source converters converter controller with dispatcher droop feedback for direct current transmission grids

This project was funded by European Research Council under the Ideas program in FP7; grant no 259328, 2010.Peer reviewedPublisher PD