Premedication with oral Dextromethorphan reduces intra-operative Morphine requirement

Directory of Open Access Journals (Sweden)

R Talakoub

2005-09-01

Full Text Available Background: Intra-operative pain has adverse effects on hemodynamic parameters. Due to complications of opioids for pain relief, using non-opioids medication is preferred. The purpose of this study was to investigate the effect of oral dextrometorphan premedication on intra-operative Morphine requirement. Methods: After approval of the Ethics committee and informed consent, 40 adult patients who stand in American Society of Anesthesiologists Physical Status I and II, under general anesthesia for elective laparatomy were selected and classified in two equal groups randomly. In group A, oral dextromethorphan (60mg was administered at 10 PM and 6 AM preoperatively. In group B, placebo (dextrose was administered. After induction of general anesthesia and before skin incision, intravenous morphine (0.01 mg/kg was administered. During surgery, when systolic blood pressure or heart rate was increased more than 20% of the preoperative baseline, 0.01 mg/kg morphine was administered. At the end of surgery, the totally prescribed morphine (mg/kg and maximal increase in systolic, diastolic, mean arterial blood pressure and heart rate relative to the baseline values were calculated and statistically compared with student’s t-test. Results: The mean dose of administered morphine during surgery was significantly less in group A than group B (P<0.0001. Also, Maximal increase in systolic, diastolic and mean arterial blood pressure was significantly less in group A (p<0.003, p<0.004, p<0.0001, respectively. There was no significant difference in maximal heart rate increase between two groups (p<0.114. Conclusion: Oral dextromethorphan premedication may decrease intra-operative morphine requirement and reduce maximal increase in systolic and mean arterial blood pressure during surgery. Key words: Dextromethorphan, Morphine, Intra-operative, Premedication Hemodynamic

Assessment of summer rainfall forecast skill in the Intra-Americas in GFDL high and low-resolution models

Science.gov (United States)

Krishnamurthy, Lakshmi; Muñoz, Ángel G.; Vecchi, Gabriel A.; Msadek, Rym; Wittenberg, Andrew T.; Stern, Bill; Gudgel, Rich; Zeng, Fanrong

2018-05-01

The Caribbean low-level jet (CLLJ) is an important component of the atmospheric circulation over the Intra-Americas Sea (IAS) which impacts the weather and climate both locally and remotely. It influences the rainfall variability in the Caribbean, Central America, northern South America, the tropical Pacific and the continental Unites States through the transport of moisture. We make use of high-resolution coupled and uncoupled models from the Geophysical Fluid Dynamics Laboratory (GFDL) to investigate the simulation of the CLLJ and its teleconnections and further compare with low-resolution models. The high-resolution coupled model FLOR shows improvements in the simulation of the CLLJ and its teleconnections with rainfall and SST over the IAS compared to the low-resolution coupled model CM2.1. The CLLJ is better represented in uncoupled models (AM2.1 and AM2.5) forced with observed sea-surface temperatures (SSTs), emphasizing the role of SSTs in the simulation of the CLLJ. Further, we determine the forecast skill for observed rainfall using both high- and low-resolution predictions of rainfall and SSTs for the July-August-September season. We determine the role of statistical correction of model biases, coupling and horizontal resolution on the forecast skill. Statistical correction dramatically improves area-averaged forecast skill. But the analysis of spatial distribution in skill indicates that the improvement in skill after statistical correction is region dependent. Forecast skill is sensitive to coupling in parts of the Caribbean, Central and northern South America, and it is mostly insensitive over North America. Comparison of forecast skill between high and low-resolution coupled models does not show any dramatic difference. However, uncoupled models show improvement in the area-averaged skill in the high-resolution atmospheric model compared to lower resolution model. Understanding and improving the forecast skill over the IAS has important implications

Echo-planar magnetic resonance imaging (EPI) with high-resolution matrix in intra-axial brain tumors

International Nuclear Information System (INIS)

Bruening, R.; Scheidler, J.; Porn, U.; Reiser, M.; Seelos, K.; Yousry, T.; Exner, H.; Rosen, B.R.

1999-01-01

The aim of this study was to assess the potential of high-speed interleaved echo-planar imaging (EPI) to achieve diagnostic image quality comparable to T2-weighted imaging in patients with brain tumors. Seventeen patients with intra-axial, supratentorial tumors (10 untreated gliomas, 7 radiated gliomas) were investigated on a 1.5-T scanner. The conventional scan (SE, TR/TE = 2200/80 ms, 18 slices) was acquired in 8 min, 4 s, and EPI (TR/TE = 3000/80 ms, 18 slices) was completed in 25 s. The films were compared in a blinded trail by three radiologists. On the general impression and anatomic display, both sequences were rated to be of similar quality. Artifacts were slightly more pronounced at the skull base and around surgical clips using EPI. Tumor delineation was nearly equivalent using EPI, compared with the T2-weighted sequence. Echo-planar imaging reached diagnostic quality in all patients. Interleaved high-resolution EPI yielded sufficient quality to depict intra-axial, supratentorial brain tumors. Since EPI can be obtained in a small fraction of the time needed for conventional spin echo, in addition to other indications it could be considered to study patients unable to cooperate. (orig.)

Application of Intra-Oral Dental Scanners in the Digital Workflow of Implantology

Science.gov (United States)

van der Meer, Wicher J.; Andriessen, Frank S.; Wismeijer, Daniel; Ren, Yijin

2012-01-01

Intra-oral scanners will play a central role in digital dentistry in the near future. In this study the accuracy of three intra-oral scanners was compared. Materials and methods: A master model made of stone was fitted with three high precision manufactured PEEK cylinders and scanned with three intra-oral scanners: the CEREC (Sirona), the iTero (Cadent) and the Lava COS (3M). In software the digital files were imported and the distance between the centres of the cylinders and the angulation between the cylinders was assessed. These values were compared to the measurements made on a high accuracy 3D scan of the master model. Results: The distance errors were the smallest and most consistent for the Lava COS. The distance errors for the Cerec were the largest and least consistent. All the angulation errors were small. Conclusions: The Lava COS in combination with a high accuracy scanning protocol resulted in the smallest and most consistent errors of all three scanners tested when considering mean distance errors in full arch impressions both in absolute values and in consistency for both measured distances. For the mean angulation errors, the Lava COS had the smallest errors between cylinders 1–2 and the largest errors between cylinders 1–3, although the absolute difference with the smallest mean value (iTero) was very small (0,0529°). An expected increase in distance and/or angular errors over the length of the arch due to an accumulation of registration errors of the patched 3D surfaces could be observed in this study design, but the effects were statistically not significant. Clinical relevance For making impressions of implant cases for digital workflows, the most accurate scanner with the scanning protocol that will ensure the most accurate digital impression should be used. In our study model that was the Lava COS with the high accuracy scanning protocol. PMID:22937030

A high-resolution, multi-stop, time-to-digital converter for nuclear time-of-flight measurements

International Nuclear Information System (INIS)

Spencer, D.F.; Cole, J.; Drigert, M.; Aryaeinejad, R.

2006-01-01

A high-resolution, multi-stop, time-to-digital converter (TDC) was designed and developed to precisely measure the times-of-flight (TOF) of incident neutrons responsible for induced fission and capture reactions on actinide targets. The minimum time resolution is ±1 ns. The TDC design was implemented into a single, dual-wide CAMAC module. The CAMAC bus is used for command and control as well as an alternative data output. A high-speed ECL interface, compatible with LeCroy FERA modules, was also provided for the principle data output path. An Actel high-speed field programmable gate array (FPGA) chip was incorporated with an external oscillator and an internal multiple clock phasing system. This device implemented the majority of the high-speed register functions, the state machine for the FERA interface, and the high-speed counting circuit used for the TDC conversion. An external microcontroller was used to monitor and control system-level changes. In this work we discuss the performance of this TDC module as well as its application

Superselective intra-arterial chemoradiotherapy for advanced oral cancer

International Nuclear Information System (INIS)

Kobayashi, Wataru; Sakaki, Hirotaka; Kakehata, Shinya; Kawaguchi, Hideo; Takai, Yoshihiro; Kimura, Hiroto; Teh, Beng Gwan

2012-01-01

Functional preservation is important in the treatment of advanced oral cancer in terms of patient's quality of life (QOL), therefore surgery is not ideal for advanced oral cancer. In order to ensure both curability and functional preservation, superselective intra-arterial chemoradiotherapy (SSIACRT), which is considered to be superior to conventional surgical treatment, has been conducted. Thirty-four patients with advanced oral cancer have been treated with SSIACRT with a combination of nedaplatin (CDGP) and docetaxel (DOC) since 2003. Complete response was achieved in 30 (89%) out of the 34 patients. Amongst the 25 patients with positive neck diseases, 23 (92%) were assessed as disease-free. The 5-year overall survival rate was 71.4%. Wide resection of both primary and neck lesions was avoidable and oral cavity function (swallowing, speech, mastication) after SSIACRT was satisfactory. A problem for SSIACRT is the development of late adverse events of xerostomia and osteoradionecrosis. (author)

Echo-planar magnetic resonance imaging (EPI) with high-resolution matrix in intra-axial brain tumors

Energy Technology Data Exchange (ETDEWEB)

Bruening, R.; Scheidler, J.; Porn, U.; Reiser, M. [Institute of Diagnostic Radiology, Klinikum Grosshadern, University of Munich (Germany); Seelos, K.; Yousry, T. [Department of Neuroradiology, Institute of Diagnostic Radiology, Klinikum Grosshadern, University of Munich (Germany); Exner, H. [Institute for Medical Epidemiology, Klinikum Grosshadern, University of Munich, Munich (Germany); Rosen, B.R. [Department of Radiology, Massachusetts General Hospital, NMR Center, Charlestown, MA (United States)

1999-09-01

The aim of this study was to assess the potential of high-speed interleaved echo-planar imaging (EPI) to achieve diagnostic image quality comparable to T2-weighted imaging in patients with brain tumors. Seventeen patients with intra-axial, supratentorial tumors (10 untreated gliomas, 7 radiated gliomas) were investigated on a 1.5-T scanner. The conventional scan (SE, TR/TE = 2200/80 ms, 18 slices) was acquired in 8 min, 4 s, and EPI (TR/TE = 3000/80 ms, 18 slices) was completed in 25 s. The films were compared in a blinded trail by three radiologists. On the general impression and anatomic display, both sequences were rated to be of similar quality. Artifacts were slightly more pronounced at the skull base and around surgical clips using EPI. Tumor delineation was nearly equivalent using EPI, compared with the T2-weighted sequence. Echo-planar imaging reached diagnostic quality in all patients. Interleaved high-resolution EPI yielded sufficient quality to depict intra-axial, supratentorial brain tumors. Since EPI can be obtained in a small fraction of the time needed for conventional spin echo, in addition to other indications it could be considered to study patients unable to cooperate. (orig.) With 3 figs., 3 tabs., 27 refs.

Comparison of caries detection methods using varying numbers of intra-oral digital photographs with visual examination for epidemiology in children

Science.gov (United States)

2013-01-01

Background This was a method comparison study. The aim of study was to compare caries information obtained from a full mouth visual examination using the method developed by the British Association for the Study of Community Dentistry (BASCD) for epidemiological surveys with caries data obtained from eight, six and four intra-oral digital photographs of index teeth in two groups of children aged 5 years and 10/11 years. Methods Five trained and calibrated examiners visually examined the whole mouth of 240 5-year-olds and 250 10-/11-year-olds using the BASCD method. The children also had intra-oral digital photographs taken of index teeth. The same 5 examiners assessed the intra-oral digital photographs (in groups of 8, 6 and 4 intra-oral photographs) for caries using the BASCD criteria; dmft/DMFT were used to compute Weighted Kappa Statistic as a measure of intra-examiner reliability and intra-class correlation coefficients as a measure of inter-examiner reliability for each method. A method comparison analysis was performed to determine the 95% limits of agreement for all five examiners, comparing the visual examination method with the photographic assessment method using 8, 6 and 4 intra-oral photographs. Results The intra-rater reliability for the visual examinations ranged from 0.81 to 0.94 in the 5-year-olds and 0.90 to 0.97 in the 10-/11-year-olds. Those for the photographic assessments in the 5-year-olds were for 8 intra-oral photographs, 0.86 to 0.94, for 6 intra-oral photographs, 0.85 to 0.98 and for 4 intra-oral photographs, 0.80 to 0.96; for the 10-/11-year-olds were for 8 intra-oral photographs 0.84 to 1.00, for 6 intra-oral photographs 0.82 to 1.00 and for 4 intra-oral photographs 0.72 to 0.98. The 95% limits of agreement were −1.997 to 1.967, -2.375 to 2.735 and −2.250 to 2.921 respectively for the 5-year-olds and −2.614 to 2.027, -2.179 to 3.887 and −2.594 to 2.163 respectively for the 10-/11-year-olds. Conclusions The photographic

Micro-Doppler Ambiguity Resolution for Wideband Terahertz Radar Using Intra-Pulse Interference.

Science.gov (United States)

Yang, Qi; Qin, Yuliang; Deng, Bin; Wang, Hongqiang; You, Peng

2017-04-29

Micro-Doppler, induced by micro-motion of targets, is an important characteristic of target recognition once extracted via parameter estimation methods. However, micro-Doppler is usually too significant to result in ambiguity in the terahertz band because of its relatively high carrier frequency. Thus, a micro-Doppler ambiguity resolution method for wideband terahertz radar using intra-pulse interference is proposed in this paper. The micro-Doppler can be reduced several dozen times its true value to avoid ambiguity through intra-pulse interference processing. The effectiveness of this method is proved by experiments based on a 0.22 THz wideband radar system, and its high estimation precision and excellent noise immunity are verified by Monte Carlo simulation.

Effect of intra-oral aging on t→m phase transformation, microstructure, and mechanical properties of Y-TZP dental ceramics.

Science.gov (United States)

Miragaya, Luciana Meireles; Guimarães, Renato Bastos; Souza, Rodrigo Othávio de Assunção E; Santos Botelho, Glauco Dos; Antunes Guimarães, José Guilherme; da Silva, Eduardo Moreira

2017-08-01

The aim of the present study was to evaluate the influence of intra-oral aging on the tetragonal-to-monoclinic (t→m) phase transformation of two Y-TZP dental ceramics - Lava Frame (Frame) and Lava Plus (Plus) - and determine the impact of this response on their microstructures and mechanical properties: flexural strength, Young's modulus, microhardness and fracture toughness. Standardized ceramic specimens were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM). After the baseline analysis, the specimens were attached to personalized intra-oral resin appliances and exposed to the oral cavity of 20 subjects for 60 days and then analyzed again. Specimens produced for mechanical properties evaluation were also analyzed before and after the 60-day intra-oral aging. The data were analyzed using two-way ANOVA and Tukey HSD's post hoc test (α=0.05). Weibull analysis was used to evaluate the strength reliability. Both Y-TZP ceramics suffered t→m phase transformation after 60-day intra-oral aging (Plus=4.7%/Frame=7.7%). SEM and AFM analyses showed dislodgement of ZrO 2 grains and a significant increase in roughness after intra-oral aging for both ceramics. Both Y-TZP ceramics suffered a decrease on flexural strength, Young's modulus and fracture toughness after intra-oral aging (pdental ceramics. Copyright © 2017 Elsevier Ltd. All rights reserved.

Chemoradiotherapy using retrograde superselective intra-arterial infusion for advanced oral cancer

International Nuclear Information System (INIS)

Mitsudo, Kenji; Iwai, Toshinori; Mitsunaga, Sachiyo

2011-01-01

Concurrent chemoradiotherapy using retrograde superselective intra-arterial infusion demonstrates good local control and overall survival rates due to the advantage of simultaneous infusion of anticancer agent with the synergistic effects of chemotherapy and radiotherapy. This study evaluated the therapeutic results, overall survival and local control rates in patients with advanced oral cancer treated with definitive concurrent chemoradiotherapy using retrograde superselective intra-arterial infusion. A total of 688 patients with carcinoma of the head and neck were referred to our institution between January 2001 and December 2006. Among them, 175 patients with carcinoma of the oral cavity underwent definitive concurrent chemoradiotherapy using retrograde superselective intra-arterial infusion. Treatment consisted of superselective intra-arterial infusions (docetaxel, total 60 mg/m 2 , cisplatin, total 125-150 mg/m 2 ) and daily concurrent radiotherapy (total 50-60 Gy) for 5-6 weeks. Four weeks after the completion of all treatments, patients underwent biopsy of the primary lesion and radiological examinations. Complete response (CR) of the primary site was achieved in 160 (91.4%) of the 175 patients. Residual disease at the primary site was seen in 15 patients (8.6%), and 14 patients (8.0%) showed local recurrence during follow-up. Five-year survival and local control rates were 71.6% and 82.2%, respectively. (author)

The efficacy of superselective intra-arterial infusion in patients with T4 oral cancer. Comparison with conventional chemotherapy

International Nuclear Information System (INIS)

Arakaki, Keiichi; Arasaki, Akira; Kano, Takeshi

2009-01-01

Since 1985, we have applied systematic treatment to improve radicality and postoperative oral dysfunction, as well as maxillofacial deformity. However, most T4 cases of oral cancer have remained difficult to treat, and diverse methods and results for progressive cancer have been reported by many institutions. For high-grade malignancy cases, we changed the treatment from bleomycin or cisplatin in induction chemotherapy to targeted intra-arterial infusions of carboplatin with radiation-combined therapy. In this study, we compared the effects of conventional therapy with targeted intra-arterial infusions of carboplatin for T4 cases of oral cancer. In this retrospective review, we analyzed a subset of patients who were treated with induction chemotherapy using bleomycin (BLM) and targeted intra-arterial infusions of carboplatin (CBDCA) with radiation-combined therapy patients who received treatment between June 1985 and December 2006. Of the 105 patients who had T4 disease, the proportion with grade IIb to IV in the carboplatin with radiation-combined therapy (88.9%) was higher than that in induction chemotherapy (45.0%). Targeted chemoradiation therapy followed by surgical salvage is a highly effective approach for the regional control of patients with T4, although additional strategies are required to address the problem of distant metastases. (author)

Clinical study of concurrent chemoradiation with superselective intra-arterial docetaxel-nedaplatin for oral cancers

International Nuclear Information System (INIS)

Kobayashi, Wataru; Sakaki, Hirotaka; Sato, Hisashi; Nakagawa, Hiroshi; Kubota, Kosei; Kimura, Hiroto; Teh, B.G.

2010-01-01

Recently, superselective intra-arterial chemotherapy concurrent with radiotherapy has become popular in advanced head and neck carcinoma treatment. Twenty patients with advanced oral cancers were treated by radiation (66 Gy) and chemotherapy with superselective intra-arterial docetaxel (40 mg/mm 2 )-nedaplatin (80 mg/mm 2 ) infusion between 2003 and 2009. Complete response in the primary and regional cervical region was obtained in 17 (85%) out of the 20 patients. Five-year survival rate was 74.1% and major adverse effects were leukopenia and mucositis. Five patients (25%) developed distant metastasis post-treatment. Intra-arterial docetaxel-nedaplatin infusion concurrent with radiotherapy is an effective treatment for advanced oral cancers but severe complications and distant metastasis are problems that need to be solved. (author)

Superselective intra-arterial chemotherapy for oral cancer

International Nuclear Information System (INIS)

Ikemura, Kunio; Oya, Ryouichi; Nakamura, Syouichi

2007-01-01

We demonstrated the superselective intra-arterial infusion method which is composed of carboplatin infusion, administration of tegafur/uracil (UFT) and concomitant radiotherapy (twice a day) for oral squamous cell carcinoma. This study was conducted in three institutions, and the results were compared with those of Robbins et al. (RADPLAT). Tumor volume and blood vessel density play a significant role in predicting local control and they may help to know the limit of the treatment by collecting data. We consider that superselective intra-arterial chemotherapy with concomitant radiotherapy is the most efficacious method for treating cases with inoperable squamous cell carcinoma in the head and neck. For these cases, however, our method needs further investigation to improve several aspects in order to produce the best results. Additionally, radiotherapy after hyperbaric oxygen therapy was found to be effective for the control of T4 tumors. For this purpose, it is recommended that irradiation be conducted within 15 minutes after decompression. (author)

Continuous measurement of intra-oral pH and temperature: development, validation of an appliance and a pilot study.

Science.gov (United States)

Choi, J E; Loke, C; Waddell, J N; Lyons, K M; Kieser, J A; Farella, M

2015-08-01

To describe a novel approach for continuous measurement of intra-oral pH and temperature in individuals carrying out normal daily activities over 24 h. We designed, validated and constructed a custom-made appliance fitted with a pH probe and a thermocouple. Six subjects wore the appliance over a 24-h period for two non-consecutive days, while the intra-oral pH and temperature were measured continuously and recorded. Intra-oral pH and temperature were very similar across different recording days, the difference being not statistically significant (P ≥ 0.14). There was a noticeable difference in the pattern of variation of pH between day and night. During the day, the mean pH was 7.3 (±0.4) and dropped markedly only after consumption of acidic food and drinks. The intra-oral pH decreased slowly during sleep with an average pH of 6.6 (±0.4) being recorded. The difference between day and night was statistically significant (P = 0.002). The mean intra-oral temperature was 33.9 °C (±0.9) during daytime and 35·9 °C (±0·5) during sleep (P = 0.013) with minor fluctuations occurring over 24 h. The continuous and simultaneous intra-oral pH and temperature measurement system described in this report is reliable, easy to construct, able to measure variables over a sustained period and may serve as a future diagnostic tool in a number of applications. © 2015 John Wiley & Sons Ltd.

On the tip of the tongue: learning typing and pointing with an intra-oral computer interface.

Science.gov (United States)

Caltenco, Héctor A; Breidegard, Björn; Struijk, Lotte N S Andreasen

2014-07-01

To evaluate typing and pointing performance and improvement over time of four able-bodied participants using an intra-oral tongue-computer interface for computer control. A physically disabled individual may lack the ability to efficiently control standard computer input devices. There have been several efforts to produce and evaluate interfaces that provide individuals with physical disabilities the possibility to control personal computers. Training with the intra-oral tongue-computer interface was performed by playing games over 18 sessions. Skill improvement was measured through typing and pointing exercises at the end of each training session. Typing throughput improved from averages of 2.36 to 5.43 correct words per minute. Pointing throughput improved from averages of 0.47 to 0.85 bits/s. Target tracking performance, measured as relative time on target, improved from averages of 36% to 47%. Path following throughput improved from averages of 0.31 to 0.83 bits/s and decreased to 0.53 bits/s with more difficult tasks. Learning curves support the notion that the tongue can rapidly learn novel motor tasks. Typing and pointing performance of the tongue-computer interface is comparable to performances of other proficient assistive devices, which makes the tongue a feasible input organ for computer control. Intra-oral computer interfaces could provide individuals with severe upper-limb mobility impairments the opportunity to control computers and automatic equipment. Typing and pointing performance of the tongue-computer interface is comparable to performances of other proficient assistive devices, but does not cause fatigue easily and might be invisible to other people, which is highly prioritized by assistive device users. Combination of visual and auditory feedback is vital for a good performance of an intra-oral computer interface and helps to reduce involuntary or erroneous activations.

Targeted intra-arterial carboplatin chemoradiotherapy and tegafur/uracil for oral and oropharyngeal cancer

International Nuclear Information System (INIS)

Oya, Ryoichi; Takagi, Shinji; Inenaga, Ryuichiro; Nakamura, Shoichi; Ikemura, Kunio; Onari, Nobuhiro; Imada, Hajime; Korogi, Yukunori

2006-01-01

The aim of this study was to evaluate the usefulness of targeted intra-arterial carboplatin chemoradiotherapy in allowing less invasive surgery for patients with oral and oropharyngeal squamous cell carcinoma. Twenty patients with previously untreated squamous cell carcinoma of the oral cavity and oropharynx (T4; 8, T2; 12 patients) were treated with targeted transfemoral intra-arterial carboplatin infusion with concurrent hyperfractionated radiotherapy and the administration of tegafur/uracil (UFT). Of 20 patients, 15 underwent surgery after completion of one course of targeted chemoradiotherapy, and five were given another course or radiotherapy only. Eighteen (90%) of 20 patients had a clinically complete response at the primary site and two (10%) had a partial response. Of the 15 patients who underwent tumor resection, 11 (73%) showed histopathological disappearance of cancer cells at the primary site. Sixteen (80%) of 20 tumors were controlled at the primary site within a mean follow-up of 30 months. Adverse effects were relatively mild. Targeted intra-arterial chemoradiotherapy caused a down-staging of tumors and facilitated the use of less invasive surgery in patients with squamous cell carcinoma of the oral cavity and oropharynx as a result of its favorable anti-tumor effect. (author)

High-Performance Data Converters

DEFF Research Database (Denmark)

Steensgaard-Madsen, Jesper

-resolution internal D/A converters are required. Unit-element mismatch-shaping D/A converters are analyzed, and the concept of mismatch-shaping is generalized to include scaled-element D/A converters. Several types of scaled-element mismatch-shaping D/A converters are proposed. Simulations show that, when implemented...... in a standard CMOS technology, they can be designed to yield 100 dB performance at 10 times oversampling. The proposed scaled-element mismatch-shaping D/A converters are well suited for use as the feedback stage in oversampled delta-sigma quantizers. It is, however, not easy to make full use of their potential......-order difference of the output signal from the loop filter's first integrator stage. This technique avoids the need for accurate matching of analog and digital filters that characterizes the MASH topology, and it preserves the signal-band suppression of quantization errors. Simulations show that quantizers...

Reliability of intra-oral quantitative sensory testing (QST) in patients with atypical odontalgia and healthy controls - a multicentre study.

Science.gov (United States)

Baad-Hansen, L; Pigg, M; Yang, G; List, T; Svensson, P; Drangsholt, M

2015-02-01

The reliability of comprehensive intra-oral quantitative sensory testing (QST) protocol has not been examined systematically in patients with chronic oro-facial pain. The aim of the present multicentre study was to examine test-retest and interexaminer reliability of intra-oral QST measures in terms of absolute values and z-scores as well as within-session coefficients of variation (CV) values in patients with atypical odontalgia (AO) and healthy pain-free controls. Forty-five patients with AO and 68 healthy controls were subjected to bilateral intra-oral gingival QST and unilateral extratrigeminal QST (thenar) on three occasions (twice on 1 day by two different examiners and once approximately 1 week later by one of the examiners). Intra-class correlation coefficients and kappa values for interexaminer and test-retest reliability were computed. Most of the standardised intra-oral QST measures showed fair to excellent interexaminer (9-12 of 13 measures) and test-retest (7-11 of 13 measures) reliability. Furthermore, no robust differences in reliability measures or within-session variability (CV) were detected between patients with AO and the healthy reference group. These reliability results in chronic orofacial pain patients support earlier suggestions based on data from healthy subjects that intra-oral QST is sufficiently reliable for use as a part of a comprehensive evaluation of patients with somatosensory disturbances or neuropathic pain in the trigeminal region. © 2014 John Wiley & Sons Ltd.

Rehabilitation of a Patient with an Intra Oral Prosthesis and an Extra Oral Orbital Prosthesis Retained with Magnets

OpenAIRE

Pattanaik, Seema; Wadkar, Aarti P.

2011-01-01

This clinical case report deals with a rehabilitation of a patient with an extensive maxillary and orbital defect using an intra oral prosthesis obturating the maxillary defect and extra oral orbital prosthesis retained with rare-earth magnets for secondary retention; primary retention was derived by snug fit of the prosthesis to underlying and adjacent tissues. The rehabilitation resulted in improved function, esthetics and comfort to the patient thus enabling him to lead a normal life.

Hi-C 2.0: An optimized Hi-C procedure for high-resolution genome-wide mapping of chromosome conformation.

Science.gov (United States)

Belaghzal, Houda; Dekker, Job; Gibcus, Johan H

2017-07-01

Chromosome conformation capture-based methods such as Hi-C have become mainstream techniques for the study of the 3D organization of genomes. These methods convert chromatin interactions reflecting topological chromatin structures into digital information (counts of pair-wise interactions). Here, we describe an updated protocol for Hi-C (Hi-C 2.0) that integrates recent improvements into a single protocol for efficient and high-resolution capture of chromatin interactions. This protocol combines chromatin digestion and frequently cutting enzymes to obtain kilobase (kb) resolution. It also includes steps to reduce random ligation and the generation of uninformative molecules, such as unligated ends, to improve the amount of valid intra-chromosomal read pairs. This protocol allows for obtaining information on conformational structures such as compartment and topologically associating domains, as well as high-resolution conformational features such as DNA loops. Copyright © 2017 Elsevier Inc. All rights reserved.

Mission profile resolution effects on lifetime estimation of doubly-fed induction generator power converter

DEFF Research Database (Denmark)

Zhang, Guanguan; Zhou, Dao; Blaabjerg, Frede

2017-01-01

, and the corresponding thermal modeling of power semiconductors are discussed. Accordingly, effects of different mission profiles on the consumed lifetime of the power converter are evaluated. In the above three thermal cycles, the IGBT of the grid-side converter and the diode of the rotor-side converter are more...... fragile, and the total consumed lifetimes are higher. Moreover, the short-term thermal cycles with milliseconds resolution induce the unbalance of the lifetime between the diode and IGBT of the grid-side converter, while thermal cycles with hour, second, and millisecond resolution consumes the similar......In the wind energy generation system, mission profiles are complicated, which range from seconds to years. In order to estimate the consumed lifetime of the power converter, wind speed profiles with the time resolution of 1 hour, 1 second and 0.5 millisecond are studied in this paper...

High resolution distributed time-to-digital converter (TDC) in a White Rabbit network

International Nuclear Information System (INIS)

Pan, Weibin; Gong, Guanghua; Du, Qiang; Li, Hongming; Li, Jianmin

2014-01-01

The Large High Altitude Air Shower Observatory (LHAASO) project consists of a complex detector array with over 6000 detector nodes spreading over 1.2 km 2 areas. The arrival times of shower particles are captured by time-to-digital converters (TDCs) in the detectors' frontend electronics, the arrival direction of the high energy cosmic ray are then to be reconstructed from the space-time information of all detector nodes. To guarantee the angular resolution of 0.5°, a time synchronization of 500 ps (RMS) accuracy and 100 ps precision must be achieved among all TDC nodes. A technology enhancing Gigabit Ethernet, called the White Rabbit (WR), has shown the capability of delivering sub-nanosecond accuracy and picoseconds precision of synchronization over the standard data packet transfer. In this paper we demonstrate a distributed TDC prototype system combining the FPGA based TDC and the WR technology. With the time synchronization and data transfer services from a compact WR node, separate FPGA-TDC nodes can be combined to provide uniform time measurement information for correlated events. The design detail and test performance will be described in the paper

High resolution distributed time-to-digital converter (TDC) in a White Rabbit network

Energy Technology Data Exchange (ETDEWEB)

Pan, Weibin, E-mail: pwb.thu@gmail.com; Gong, Guanghua; Du, Qiang; Li, Hongming; Li, Jianmin

2014-02-21

The Large High Altitude Air Shower Observatory (LHAASO) project consists of a complex detector array with over 6000 detector nodes spreading over 1.2 km{sup 2} areas. The arrival times of shower particles are captured by time-to-digital converters (TDCs) in the detectors' frontend electronics, the arrival direction of the high energy cosmic ray are then to be reconstructed from the space-time information of all detector nodes. To guarantee the angular resolution of 0.5°, a time synchronization of 500 ps (RMS) accuracy and 100 ps precision must be achieved among all TDC nodes. A technology enhancing Gigabit Ethernet, called the White Rabbit (WR), has shown the capability of delivering sub-nanosecond accuracy and picoseconds precision of synchronization over the standard data packet transfer. In this paper we demonstrate a distributed TDC prototype system combining the FPGA based TDC and the WR technology. With the time synchronization and data transfer services from a compact WR node, separate FPGA-TDC nodes can be combined to provide uniform time measurement information for correlated events. The design detail and test performance will be described in the paper.

Comparison of intra-oral and study cast measurements in the assessment of malocclusion.

Science.gov (United States)

Ovsenik, Maja; Farcnik, Franc M; Verdenik, Ivan

2004-06-01

Malocclusion assessment methods are based on registrations and measurements made on study casts, which requires that impressions be taken. In addition to being costly and time-consuming, this process can be unpleasant for very young children. Therefore, the aim of this study was to evaluate the reliability of intra-oral measurements that compute a malocclusion index score to determine malocclusion severity in the mixed dentition. The research was part of a longitudinal study in Slovenia on a sample of 530 3-year-old children. At 8 years of age (mean 8.5 years, standard deviation 0.2), a cohort of 101 children (44 boys, 57 girls) was randomly selected in a cross-sectional study. Quantitative registrations of space and occlusal anomalies were performed intra-orally as well as on study casts. Kappa (kappa) statistics were used to evaluate the agreement between clinical and study cast malocclusion assessments. Systematic bias of measurements was tested using Wilcoxon's signed rank test. The results showed complete agreement between the two measurements for anterior crossbite, anterior open bite and overjet scores (kappa = 1); excellent reliability for the buccal segment relationship (kappa = 0.93), transverse occlusion of posterior teeth (kappa = 0.87); and substantial agreement for overbite (kappa = 0.79) and midline deviation (kappa = 0.71). For the remainder of the traits the agreement was moderate: rotation of incisors (kappa = 0.58), crowding of upper incisors (kappa = 0.51), axial inclination of teeth (kappa = 0.44) and lower incisor crowding (kappa = 0.41). Intra-orally small, but statistically significant scoring of lower incisor rotation and crowding was identified. On the study casts the most favourable axial inclination was found for buccal segment occlusion. Overall classification into severity grades, based on the total malocclusion score, showed excellent agreement between the two methods (kappa = 0.89), without statistically significant bias

Combination of retrograde superselective intra-arterial chemotherapy and Seldinger method in locally advanced oral cancer

Directory of Open Access Journals (Sweden)

Masataka Uehara

2015-01-01

Full Text Available The nonsurgical strategies for locally advanced oral cancer are desirable. Superselective intra-arterial infusion with radiotherapy was utilized for this purpose, and there are two types of superselective intra-arterial infusion methods: The Seldinger method and the retrograde superselective intra-arterial chemotherapy (HFT method. In one case, the HFT method was applied to locally advanced tongue cancer, and the Seldinger method was used for additional administration of cisplatin (CDDP to compensate for a lack of drug flow in the HFT method. In another case, the HFT method was applied to locally advanced lower gingival cancer. The Seldinger method was applied to metastatic lymph nodes. In both cases, additional administration of CDDP using the Seldinger method resulted in a complete response. The combination of the HFT and Seldinger methods was useful to eradicate locally advanced oral cancer because each method compensated for the defects of the other.

Fluoride and urea chewing gums in an intra-oral experimental caries model

NARCIS (Netherlands)

Sjogren, K; Ruben, J; Lingstrom, P; Lundberg, AB; Birkhed, D

2002-01-01

The aim of the present investigation was to evaluate the effect of sugar-free chewing gums containing fluoride (F) and urea in an intra-oral experimental caries model. Placebo chewing gums (without any active ingredient) and no gum served as controls. Fifteen subjects participated in a cross-over,

The Soft Seal disposable laryngeal mask airway in adults: comparison of two insertion techniques without intra-oral manipulation.

Science.gov (United States)

Kuvaki, B; Küçükgüçlü, S; Iyilikçi, L; Tuncali, B E; Cinar, O

2008-10-01

We investigated whether insertion of the disposable Soft Seal laryngeal mask airway (SSLM) was successful without intra-oral digital manipulation. One hundred patients undergoing anaesthesia using the SSLM were randomly assigned into two groups. Insertion was performed by either a direct or a rotational technique, both without intra-oral digital manipulation. The primary outcome measure was successful insertion at first attempt. Other outcomes included insertion time, fibreoptic assessment of the airway view and airway morbidity. The first attempt success rate was higher (98%) with the direct technique than with the rotational technique (75%; p = 0.002) but insertion time was faster with the latter method (mean [range] 15 [8-50] s) than with the direct method (20 [8-56] s; p = 0.035). Fibreoptic assessment and airway morbidity were similar in both groups. We conclude that the SSLM can be successfully inserted without intra-oral digital manipulation.

The combined use of radiotherapy and immunochemotherapy with Krestin for intra-oral cancer

International Nuclear Information System (INIS)

Komatsu, Yukihisa; Kuroda, Manabu

1981-01-01

Interstitial irradiation with needles 226 Ra was performed on 3 patients with intra-oral cancer. Krestin, an immunotherapeutic agent, was administered three times a day. All patients were also given 600 mg of FT-207/day as adjuvant chemotherapy. Moreover, one of them was also given 0.75 mg/day of eskinon every day. As parameters of immunological competence, PPD and PHA intracutaneous responses and the lymphocyte count in peripheral blood were used. Ulcers of intra-oral cancer were completely heated and there was no lymph node enargement. Though there were changes in PPD intracutaneous responses among three patients, positive responses were maintained. Absolute values of the lymphocyte count in peripheral blood were almost above 1,000/mm 3 in patients treated with both krestin and FT-207, but those in a patient treated with additional eskinon decreased gradually to 450/mm 3 . (Tsunoda, M.)

Daily concurrent chemoradiotherapy with docetaxel (DOC) and cisplatin (CDDP) using superselective intra-arterial infusion via superficial temporal artery for advanced oral cancer

International Nuclear Information System (INIS)

Mitsudo, Kenji; Fukui, Takafumi; Shigetomi, Toshio

2007-01-01

Superselective intra-arterial chemotherapy via superficial temporal artery (HFT method) is feasible for daily concurrent radiotherapy and chemotherapy for oral cancer. The possibility of organ preservation in cases of advanced oral cancer was evaluated. Treatment consisted of superselective intra-arterial infusions (docetaxel (DOC) total 60 mg/m 2 , cisplatin (CDDP) total 100 mg/m 2 ) and concurrent radiotherapy (total 40 Gy) for four weeks. Patients with T3 and T4 oral cancer were treated with four-week daily concurrent chemoradiotherapy, and the clinical response was evaluated after treatment. Clinical complete response (CR) of primary sites was obtained in 23 patients, and the same treatment was continued for one or two weeks. Local recurrence was observed in four patients (17.4%), all of whom all patients underwent salvage operation, and the final local control rate was 95.6% (22 of 23 cases). One patient died of neck metastasis, and one died of local recurrence. One-year and 3-year survival rates were estimated by Kaplan-Meier's method to be 95.5% and 79.5%, respectively. In this treatment, it is important to identify the tumor's feeding artery and deliver a sufficient amount of anticancer drug to the tumor. Superselective intra-arterial chemotherapy for oral cancer has the advantage of delivering a high concentration of chemotherapeutic agents into the tumor bed with fewer systemic toxic effects than seen with systemic chemotherapy. Superselective intra-arterial chemotherapy using the HFT method can preserve organs and minimize functional disturbance, thus contributing to patients' quality of life (QOL). (author)

First measurements with new high-resolution gadolinium-GEM neutron detectors

CERN Document Server

Pfeiffer, Dorothea; Birch, Jens; Etxegarai, Maddi; Hall-Wilton, Richard; Höglund, Carina; Hultman, Lars; Llamas-Jansa, Isabel; Oliveri, Eraldo; Oksanen, Esko; Robinson, Linda; Ropelewski, Leszek; Schmidt, Susann; Streli, Christina; Thuiner, Patrik

2016-05-17

European Spallation Source instruments like the macromolecular diffractometer, NMX, require an excellent neutron detection efficiency, high-rate capabilities, time resolution, and an unprecedented spatial resolution in the order of a few hundred micrometers over a wide angular range of the incoming neutrons. For these instruments solid converters in combination with Micro Pattern Gaseous Detectors (MPGDs) are a promising option. A GEM detector with gadolinium converter was tested on a cold neutron beam at the IFE research reactor in Norway. The {\\mu}TPC analysis, proven to improve the spatial resolution in the case of $^{10}$B converters, is extended to gadolinium based detectors. For the first time, a Gd-GEM was successfully operated to detect neutrons with an estimated efficiency of 10% at a wavelength of 2 {\\AA} and a position resolution better than 350 {\\mu}m.

Panoramic dental radiography with an intra-oral X-ray tube

International Nuclear Information System (INIS)

Hollender, L.

1980-01-01

Surveys of the complete dentition and jaws can be obtained in various ways. Panoramic radiography with an intra-oral X-ray tube results in a lower radiation exposure than other methods, and is less time-consuming. However, the symmetrical views generally employed result in relatively poor imaging of the molars. This disadvantage can be overcome by using lateral projections which also cause less discomfort for the patient and, particularly in combination with intensifying screens, a further reduction in radiation exposure. Some possible future trends are suggested. (Auth.)

High-speed and high-resolution analog-to-digital and digital-to-analog converters

NARCIS (Netherlands)

van de Plassche, R.J.

1989-01-01

Analog-to-digital and digital-to-analog converters are important building blocks connecting the analog world of transducers with the digital world of computing, signal processing and data acquisition systems. In chapter two the converter as part of a system is described. Requirements of analog

A review of toxicity superselective intra-arterial concurrent chemoradiotherapy (SIACC) for oral cancer

International Nuclear Information System (INIS)

Shiraishi, Takeshi; Uehara, Masataka; Ikeda, Mihoko; Tajima, Nobutaka; Ikeda, Hideyoshi; Kawasaki, Takako; Asahina, Izumi

2011-01-01

Superselective intra-arterial concurrent chemoradiotherapy (SIACC) for oral cancer has been favored for its efficacy and ability to not damage organs. SIACC was applied to 13 previously untreated patients with oral cancer for the purpose of avoiding surgical resection of the primary tumor in our hospital from 2007 to 2009. Although a complete response of the primary tumor was achieved in all cases, various adverse events also occurred. All patients experienced leucopenia, and most patients suffered from mucotitis and dry mouth. One patient had dizziness and nausea due to the catheter insertion into the vertebra artery. Although SIACC is an important treatment strategy for oral cancer, careful attention for adverse events should be taken into account during and after treatment. (author)

High-resolution DNA content analysis of microbiopsy samples in oral lichen planus.

Science.gov (United States)

Pentenero, M; Monticone, M; Marino, R; Aiello, C; Marchitto, G; Malacarne, D; Giaretti, W; Gandolfo, S; Castagnola, P

2017-04-01

DNA aneuploidy has been reported to be a predictor of poor prognosis in both premalignant and malignant lesions. In oral lichen planus (OLP), this hypothesis remains to be proved. This study aimed to determine the rate of occurrence of DNA aneuploidy in patients with OLP by high-resolution DNA flow cytometry. Patients with OLP were consecutively enrolled. Tissue samples were subdivided for formalin fixation and routine histological assessment and for immediate storage at -20°C for later DNA ploidy analysis, which was performed by DAPI staining of the extracted nuclei and excitation with a UV lamp. The DNA aneuploid sublines were characterized by the DNA Index. A DNA aneuploid status was observed in two of 77 patients with OLP (2.6%). When considering the clinical aspect of the OLP lesions, both DNA aneuploid cases had a reticular clinical aspect. DNA aneuploidy is an uncommon event in OLP and less frequent compared to other non-dysplastic and non-OLP oral potentially malignant disorders. The extremely low rate of DNA aneuploidy could represent an occasional finding or reflect the low rate of malignant transformation observed in patients with OLP even if the real prognostic value of DNA ploidy analysis in patients with OLP remains to be confirmed. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Intra-oral orthosis vs amitriptyline in chronic tension-type headache: a clinical and laser evoked potentials study

Directory of Open Access Journals (Sweden)

Sardaro Michele

2006-05-01

Full Text Available Abstract Background In the present study, we examined clinical and laser-evoked potentials (LEP features in two groups of chronic tension-type headache (CTTH patients treated with two different approaches: intra-oral appliance of prosthesis, aiming to reduce muscular tenderness, and 10 mg daily amitriptyline. Methods Eighteen patients with diagnosed CTTH participated in this open label, controlled study. A baseline evaluation was performed for clinical features, Total Tenderness Score (TTS and a topographic analysis of LEPs obtained manually and the pericranial points stimulation in all patients vs. healthy subjects. Thereafter, patients were randomly assigned to a two-month treatment by either amitriptyline or intra-oral appliance. Results and discussion Both the intra-oral appliance and amitriptyline significantly reduced headache frequency. The TTS was significantly reduced in the group treated with the appliance. The amplitude of P2 response elicited by stimulation of pericranial zones showed a reduction after amitriptyline treatment. Both therapies were effective in reducing headache severity, the appliance with a prevalent action on the pericranial muscular tenderness, amitriptyline reducing the activity of the central cortical structures subtending pain elaboration Conclusion The results of this study may suggest that in CTTH both the interventions at the peripheral and central levels improve the outcome of headache.

Using Adobe Acrobat to create high-resolution line art images.

Science.gov (United States)

Woo, Hyoun Sik; Lee, Jeong Min

2009-08-01

The purpose of this article is to introduce a method for using Adobe Acrobat to make high-resolution and high-quality line art images. High-resolution and high-quality line art images for radiology journal submission can be generated using Adobe Acrobat as a steppingstone, and the customized PDF conversion settings can be used for converting hybrid images, including both bitmap and vector components.

Analysis of Intra- and Intersubject Variability in Oral Drug Absorption in Human Bioequivalence Studies of 113 Generic Products.

Science.gov (United States)

Sugihara, Masahisa; Takeuchi, Susumu; Sugita, Masaru; Higaki, Kazutaka; Kataoka, Makoto; Yamashita, Shinji

2015-12-07

In this study, the data of 113 human bioequivalence (BE) studies of immediate release (IR) formulations of 74 active pharmaceutical ingredients (APIs) conducted at Sawai Pharmaceutical Co., Ltd., was analyzed to understand the factors affecting intra- and intersubject variabilities in oral drug absorption. The ANOVA CV (%) calculated from area under the time-concentration curve (AUC) in each BE study was used as an index of intrasubject variability (Vintra), and the relative standard deviation (%) in AUC was used as that of intersubject variability (Vinter). Although no significant correlation was observed between Vintra and Vinter of all drugs, Vintra of class 3 drugs was found to increase in association with a decrease in drug permeability (P(eff)). Since the absorption of class 3 drugs was rate-limited by the permeability, it was suggested that, for such drugs, the low P(eff) might be a risk factor to cause a large intrasubject variability. To consider the impact of poor water solubility on the variability in BE study, a parameter of P(eff)/Do (Do; dose number) was defined to discriminate the solubility-limited and dissolution-rate-limited absorption of class 2 drugs. It was found that the class 2 drugs with a solubility-limited absorption (P(eff)/Do high intrasubject variability. Furthermore, as a reason for high intra- or intersubject variability in AUC for class 1 drugs, effects of drug metabolizing enzymes were investigated. It was demonstrated that intrasubject variability was high for drugs metabolized by CYP3A4 while intersubject variability was high for drugs metabolized by CYP2D6. For CYP3A4 substrate drugs, the Km value showed the significant relation with Vintra, indicating that the affinity to the enzyme can be a parameter to predict the risk of high intrasubject variability. In conclusion, by analyzing the in house data of human BE study, low permeability, solubility-limited absorption, and high affinity to CYP3A4 are identified as risk factors for

Daily concurrent preoperative chemoradiotherapy using superselective intra-arterial infusion via superficial temporal artery for advanced oral cancer. Histological evaluation of metastatic cervical lymph nodes

International Nuclear Information System (INIS)

Mitsudo, Kenji; Yamamoto, Noriyuki; Shigetomi, Toshio

2010-01-01

Superselective intra-arterial chemotherapy via a superficial temporal artery has become feasible for daily concurrent radiotherapy and chemotherapy in patients with oral cancer. In this study, histopathological effects on metastatic cervical lymph nodes in cases of advanced oral cancer using superselective intra-arterial chemoradiotherapy were evaluated. Thirty-seven oral cancer patients with cervical lymph node metastasis were treated with preoperative chemoradiotherapy using superselective intra-arterial infusion via the superficial temporal artery. The treatment consisted of superselective intra-arterial infusions (docetaxel, total 60 mg/m 2 ; cisplatin, total 100-150 mg/m 2 ) and concurrent radiotherapy (total 40-60 Gy) for 4-6 weeks, followed by surgery. In cases in which the catheter was inserted into the facial artery, grade III or IV (Oboshi-Shimosato classification) in the cervical lymph node metastasis was obtained in 20 (83.3%) of 24 patients. And, forty-six (88.5%) of 52 metastatic lymph nodes showed grade III or IV. This method was an effective regimen for oral cancer with cervical lymph node metastasis. (author)

High resolution data acquisition

Science.gov (United States)

Thornton, Glenn W.; Fuller, Kenneth R.

1993-01-01

A high resolution event interval timing system measures short time intervals such as occur in high energy physics or laser ranging. Timing is provided from a clock (38) pulse train (37) and analog circuitry (44) for generating a triangular wave (46) synchronously with the pulse train (37). The triangular wave (46) has an amplitude and slope functionally related to the time elapsed during each clock pulse in the train. A converter (18, 32) forms a first digital value of the amplitude and slope of the triangle wave at the start of the event interval and a second digital value of the amplitude and slope of the triangle wave at the end of the event interval. A counter (26) counts the clock pulse train (37) during the interval to form a gross event interval time. A computer (52) then combines the gross event interval time and the first and second digital values to output a high resolution value for the event interval.

Catheter placement via the occipital artery to achieve superselective intra-arterial chemotherapy for oral cancer

International Nuclear Information System (INIS)

Iwai, Toshinori; Mitsudo, Kenji; Fukui, Takafumi

2008-01-01

Superselective intra-arterial chemotherapy via the superficial temporal artery (STA) has become useful for oral cancer. However, this method can not be performed if catheter placement via the STA is impossible. Therefore, we report a surgical method for catheter placement via the occipital artery (OA) to achieve retrograde superselective intra-arterial chemotherapy. Preoperatively, three-dimensional computed tomography angiography was performed to identify the course of the external carotid artery and the relationship between OA and the target artery. Ten patients with oral cancer underwent catheter placement via the OA with Doppler ultrasound and Harmonic Scalpel under local anesthesia. Catheter placement via the OA was superselectively successful in all the patients. The mean exposure time of OA and mean operating time were 17.5 min and 70.5 min, respectively. Catheter placement via the OA is useful when catheter placement via the STA is impossible. Three-dimensional vascular mapping and the use of Doppler ultrasound and Harmonic Scalpel can shorten the surgical time. (author)

Intra- and interrater reliability of the Chicago Classification of achalasia subtypes in pediatric high-resolution esophageal manometry (HRM) recordings.

Science.gov (United States)

Singendonk, M M J; Rosen, R; Oors, J; Rommel, N; van Wijk, M P; Benninga, M A; Nurko, S; Omari, T I

2017-11-01

Subtyping achalasia by high-resolution manometry (HRM) is clinically relevant as response to therapy and prognosis have shown to vary accordingly. The aim of this study was to assess inter- and intrarater reliability of diagnosing achalasia and achalasia subtyping in children using the Chicago Classification (CC) V3.0. Six observers analyzed 40 pediatric HRM recordings (22 achalasia and 18 non-achalasia) twice by using dedicated analysis software (ManoView 3.0, Given Imaging, Los Angeles, CA, USA). Integrated relaxation pressure (IRP4s), distal contractile integral (DCI), intrabolus pressurization pattern (IBP), and distal latency (DL) were extracted and analyzed hierarchically. Cohen's κ (2 raters) and Fleiss' κ (>2 raters) and the intraclass correlation coefficient (ICC) were used for categorical and ordinal data, respectively. Based on the results of dedicated analysis software only, intra- and interrater reliability was excellent and moderate (κ=0.89 and κ=0.52, respectively) for differentiating achalasia from non-achalasia. For subtyping achalasia, reliability decreased to substantial and fair (κ=0.72 and κ=0.28, respectively). When observers were allowed to change the software-driven diagnosis according to their own interpretation of the manometric patterns, intra- and interrater reliability increased for diagnosing achalasia (κ=0.98 and κ=0.92, respectively) and for subtyping achalasia (κ=0.79 and κ=0.58, respectively). Intra- and interrater agreement for diagnosing achalasia when using HRM and the CC was very good to excellent when results of automated analysis software were interpreted by experienced observers. More variability was seen when relying solely on the software-driven diagnosis and for subtyping achalasia. Therefore, diagnosing and subtyping achalasia should be performed in pediatric motility centers with significant expertise. © 2017 John Wiley & Sons Ltd.

ORAL MYIASIS CONVERTING TO ORAL SQUAMOUS CELL CARCINOMA

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Akshay

2015-10-01

Full Text Available INTRODUCTION: Oral Myiasis, a condition of infestation of the body by fly larvae (maggots is a rare pathology in humans. It is associated with poor oral hygiene, alcoholism, senility, suppurating lesions, severe halitosis. It is seen frequently in tropical countries and hot climatic regions. The reported cases in literature of oral Myiasis associated with oral cancer are few. The treatment is a mechanical removal of the maggots but a systemic treatment with Ivermectin, a semi - synthetic macrolide antibiotic, has been used successfully for treatment for oral m yiasis. We present a case of 55 yr old male alcoholic patient with oral myiasis with extensive proliferative growth of oral cavity. Our patient was managed with manual debridement and administration of systemic ivermect in along with antibiotic coverage. Incisional biopsy of the proliferative lesion showed well differentiated squamous cell carcinoma. Thus our patient showed presence of oral myiasis in association with oral squamous cell carcinoma.

High-speed image converter x-ray studies

International Nuclear Information System (INIS)

Bryukhnevitch, G.I.; Kas'yanov, Yu.S.; Korobkin, V.V.; Prokhorov, A.M.; Stepanov, B.M.; Chevokin, V.K.; Schelev, M.Ya.

1975-01-01

Two X-ray high-speed image-converter cameras (ICC) have been developed. In the first one a soft X-ray radiation is converted into visible light with the aid of a 0.5ns response time, plastic scintillator. The second camera incorporates a photocathode which is sensitive to visible and X-ray radiation. Its calculated temporal resolution approaches 5 to 7ps. Both developed cameras were employed for studies of X-ray radiation emitted by laser plasma. For the smooth nanosecond excited laser pulses, a noticeable amplitude modulation was recorded in all laser pulses reflected by plasma as well as in each third pulse of X-ray plasma radiation. It was also observed that the duration of X-ray plasma radiation is 20 to 40% shorter than that of the incident nanosecond laser pulses and this duration being 3 to 6 times longer than that of the picosecond irradiating pulses. The half-width of the recorded X-ray plasma pulses was 30 to 60ps. (author)

Treatment of Enterococcal Peritonitis in Peritoneal Dialysis Patients by Oral Amoxicillin or Intra-Peritoneal Vancomcyin: a Retrospective Study

Directory of Open Access Journals (Sweden)

Cheuk Chun Szeto

2017-10-01

Full Text Available Background/Aims: Enterococcal peritonitis in peritoneal dialysis (PD patients is associated with a high complication rate. The optimal treatment regimen of PD-related enterococcal peritonitis is controversial. The latest international guideline recommends intra-peritoneal (IP vancomycin. Although ampicillin is often effective for systemic enterococcal infections, they have little in vitro activity when added to common PD solutions. Since oral amoxicillin achieves therapeutic drug level in the peritoneal cavity, we explore the efficacy of oral amoxicillin for enterococcal peritonitis. Methods: We studied 105 episodes of enterococcal peritonitis over 20 years in our unit; 43 (41.0% were treated with oral amoxicillin, and 62 (59.0% with IP vancomycin. Their clinical outcome was reviewed. Result: The overall primary response rate to oral amoxicillin and IP vancomycin was 76.4% and 85.5%, respectively (p = 0.3. The complete cure rate of oral amoxicillin and IP vancomycin was 55.8% and 54.8%, respectively (p = 0.8. When the 5 episodes of ampicillin-resistant Enterococcus episodes were excluded, the primary response rate and complete cure rate of oral amoxicillin were 86.8% and 63.2%, respectively. Conclusion: Oral amoxicillin has an excellent primary response rate and complete cure rate for PD-related peritonitis episodes caused by Enterococcus species, indicating that oral amoxicillin is a valid and convenient therapeutic option for enterococcal peritonitis episodes.

A multi-channel data acquisition system with high resolution based on microcomputer

International Nuclear Information System (INIS)

An Qi; Wang Yanfang; Xing Tao

1995-01-01

The paper introduces the principle of a multi-channel data acquisition system with high resolution based on the microcomputer.The system consists of five parts.They are analog-to-digital converter, data buffer area, trigger logic circuit, control circuit, and digital-to-analog converter

Development of high speed integrated circuit for very high resolution timing measurements

International Nuclear Information System (INIS)

Mester, Christian

2009-10-01

A multi-channel high-precision low-power time-to-digital converter application specific integrated circuit for high energy physics applications has been designed and implemented in a 130 nm CMOS process. To reach a target resolution of 24.4 ps, a novel delay element has been conceived. This nominal resolution has been experimentally verified with a prototype, with a minimum resolution of 19 ps. To further improve the resolution, a new interpolation scheme has been described. The ASIC has been designed to use a reference clock with the LHC bunch crossing frequency of 40 MHz and generate all required timing signals internally, to ease to use within the framework of an LHC upgrade. Special care has been taken to minimise the power consumption. (orig.)

Development of high speed integrated circuit for very high resolution timing measurements

Energy Technology Data Exchange (ETDEWEB)

Mester, Christian

2009-10-15

A multi-channel high-precision low-power time-to-digital converter application specific integrated circuit for high energy physics applications has been designed and implemented in a 130 nm CMOS process. To reach a target resolution of 24.4 ps, a novel delay element has been conceived. This nominal resolution has been experimentally verified with a prototype, with a minimum resolution of 19 ps. To further improve the resolution, a new interpolation scheme has been described. The ASIC has been designed to use a reference clock with the LHC bunch crossing frequency of 40 MHz and generate all required timing signals internally, to ease to use within the framework of an LHC upgrade. Special care has been taken to minimise the power consumption. (orig.)

Patient doses during intra-oral radiography in dental offices

International Nuclear Information System (INIS)

Sakaino, Rie; Harata, Yasuo; Okano, Tomohiro; Sato, Kenji; Yosue, Takashi; Nishikawa, Keiichi; Sano, Tsukasa; Kobayashi, Ikuo

2011-01-01

Measurement of patient entrance dose (PED) and dose area product (DAP) at various dental offices in the Tokyo bay area and comparison of PEDs with the existing diagnostic reference levels recommended in the United Kingdom (UK). The survey included 28 dental clinics categorized by the type of intra-oral radiography used. PED was measured by placing an optically stimulated luminescence dosimeter (OSLD) at the tip of the cone. Exposure parameters were those used for the adult mandibular molar region in the respective clinics. The OSLD readings were calibrated using an ionizing chamber manufactured according to standards of the Japan Quality Assurance Organization. The area (A), of the X-ray beam, was calculated by exposing an X-ray film placed at the tip of the cone and measuring the exposed area. Then the DAP was calculated as the product of PED times A. The PED estimated at various dental clinics differed by a factor of 120. The mean, minimum, maximum, median and third quartile values of PEDs were 4.99, 0.18, 21.7, 3.60 and 5.76 mGy, respectively. At 60-70 kV, PEDs observed in clinics using digital imaging systems were below 2.1 mGy which was lower than that of clinics using films that were E-speed or faster. It was also observed that PEDs were directly proportional to the tube current and exposure time. The mean, minimum, maximum, median and third quartile of DAPs were 13.0, 0.45, 61.4, 9.34 and 13.4 cGy cm 2 , respectively. The DAP values showed a linear correlation coefficient of 0.99 with PED values. Measurement of PED and DAP using OSLD and X-ray film can play a useful role in optimization of radiation protection for patients during intra-oral radiography. This method can be conveniently applied to set up diagnostic reference levels by carrying out mass surveys in Japan. (author)

Management of cancer therapy-induced oral mucositis pain and xerostomia with extra- and intra oral laser irradiation

Science.gov (United States)

Libik, T. V.; Gileva, O. S.; Danilov, K. V.; Grigorev, S. S.; Pozdnyakova, A. A.

2017-09-01

This study evaluated the efficacy of combined (intra- and extraoral) low-level laser therapy (LLLT) and conventional pharmacological modalities in prevention and treatment of oral mucositis (OM) and associated pain and xerostomia in patients with head and neck cancer (HNC) undergoing concurrent chemoradiotherapy (CRT). A prospective comparative randomized study was conducted with 21 patients with head and neck cancer subjected to CRT. Eleven patients received extra- and intraoral LLLT daily from the 1st day until the end of CRT-course before each session during 5 consecutive days, and the other 10 patients received conventional preventive and treatment procedures based on the use of benzidamine 0.15% solution also throughout the duration of CRT, including weekends. OM was measured using an oral toxicity scale (OTS), oral pain was measured using the color-numeric visual analogue scale (VAS), unstimulated salivary flow rate measured by the spitting technique (ml/min), dry mouth symptoms were self-estimated by patients using The Xerostomia Inventory (XI). The LLLT group showed lower mean OTS and VAS scores, lower level of reduction of salivary flow rate during the course of CRT. In both groups, no interruption of CRT was needed. The prophylactic use of both treatments proposed in this study seems to reduce the incidence of severe OM lesions. However, the LLLT was more effective in delaying the appearance of severe OM, oral pain and xerostomia.

Comparison between oral and intra-articular antinociceptive effect of dexketoprofen and tramadol combination in monosodium iodoacetate-induced osteoarthritis in rats.

Science.gov (United States)

Cialdai, Cecilia; Giuliani, Sandro; Valenti, Claudio; Tramontana, Manuela; Maggi, Carlo Alberto

2013-08-15

Dexketoprofen and tramadol, alone or in combination, were evaluated after oral or intra-articular administration on knee osteoarthritis nociception induced by intra-articular (i.ar.) monosodium iodoacetate (MIA, 1 mg/25 µl) in the rat right knee while the left knee received saline (25 µl). Seven days after MIA treatment, dexketoprofen, tramadol, their combination or the vehicle were administered. Nociception was evaluated as alteration in hind limb weight distribution with Incapacitance tester at different time-points after drug administration. Oral dexketoprofen (0.1-1 mg/kg) or tramadol (0.5-5 mg/kg) induced maximal antinociception at 1 and 5 mg/kg, respectively. Their combination dose-dependently increased the intensity and duration of antinociception, that was additive and lasted up to 3 days. Also the intra-articular administration of dexketoprofen or tramadol (10-100 µg/25 µl) inhibited MIA-induced nociception, and the combination of the lower doses (10 µg/25 µl) produced a long lasting more than additive antinociceptive effect indicating a synergistic interaction between the two drugs. This effect was significantly reduced by naloxone (10 μg/25 μl, i.ar.) co-administered with both compounds. The intra-articular administration of both drugs at 10 µg/25 µl in the contralateral control knee joint provoked a marked synergistic antinociceptive effect indicating significant systemic diffusion through synovial membrane. The oral or intra-articular combination of dexketoprofen and tramadol produced additive or synergistic antinociceptive effects, respectively, in the model of MIA-induced osteoarthritis in rats, that might allow to obtain therapeutic advantages with lower side effects. © 2013 Elsevier B.V. All rights reserved.

Measurement of scattered and transmitted X-rays from intra-oral and panoramic dental X-ray equipment.

Science.gov (United States)

Holroyd, John Richard

2018-04-10

To quantify the levels of transmitted radiation arising from the use of intra-oral dental X-ray equipment and scattered radiation arising from the use of both intra-oral and panoramic X-ray equipment. Methods: Levels of scattered radiation were measured at 1 m from a phantom, using an 1800 cc ion chamber. Transmitted radiation was measured using both: i) a phantom and Dose Area Product (DAP) meter, ii) a patient and an 1800 cc ion chamber. Results: For intra-oral radiography the patient study gave a maximum transmission of 1.80% (range 0.04% to 1.80%, mean 0.26%) and the phantom study gave a maximum transmission of 6% (range 2% to 6%, mean 5%). The maximum scattered radiation, per unit DAP, was 5.5 nGy (mGy cm2)-1 at 70 kVp and a distance of 1 m. For panoramic radiography the maximum scattered radiation was 9.3 nGy (mGy cm2)-1 at 80 kVp and a distance of 1 m. Conclusions: Typical doses from scattered and transmitted radiation in modern dental practice have been measured and values are presented to enable the calculation of adequate protection measures for dental radiography rooms. Advances in knowledge: Previous studies have used a phantom and measured radiation doses at 1 m from the phantom to determine the radiation dose transmitted through a patient, whereas this study uses both patient and phantom measurements together with a large area dose meter, positioned to capture the entire X-ray beam, to ensure more realistic dose measurements can be made. © 2018 IOP Publishing Ltd.

Retrograde superselective intra-arterial chemotherapy and daily concurrent radiotherapy for stage III and IV oral cancer: Analysis of therapeutic results in 112 cases

International Nuclear Information System (INIS)

Mitsudo, Kenji; Koizumi, Toshiyuki; Iida, Masaki; Iwai, Toshinori; Nakashima, Hideyuki; Oguri, Senri; Kioi, Mitomu; Hirota, Makoto; Koike, Izumi; Hata, Masaharu; Tohnai, Iwai

2014-01-01

Purpose: To evaluate the therapeutic results and rate of organ preservation in patients with stage III or IV oral cancer treated with retrograde superselective intra-arterial chemotherapy and daily concurrent radiotherapy. Materials and methods: One hundred and twelve patients with stage III and IV oral squamous cell carcinoma underwent intra-arterial chemoradiotherapy. Catheterization from the superficial temporal and occipital arteries was performed. Treatment consisted of superselective intra-arterial chemotherapy (docetaxel, total 60 mg/m 2 , cisplatin, total 150 mg/m 2 ) and daily concurrent radiotherapy (total of 60 Gy) for 6 weeks. Results: The median follow-up for all patients was 46.2 months (range, 10–76 months). After intra-arterial chemoradiotherapy, primary site complete response was achieved in 98 (87.5%) of 112 cases. Five-year survival and local control rates were 71.3% and 79.3%, respectively. Grade 3 or 4 toxicities included mucositis in 92.0%, neutropenia in 30.4%, dermatitis in 28.6%, anemia in 26.8%, and thrombocytopenia in 7.1% of patients. Grade 3 toxicities included dysphagia in 72.3%, nausea/vomiting in 21.4%, fever in 8.0%, and renal failure in 0.9% of patients. Conclusion: Retrograde superselective intra-arterial chemotherapy and daily concurrent radiotherapy for stage III and IV oral cancer provided good overall survival and local control

Intra-and-Inter Species Biomass Prediction in a Plantation Forest: Testing the Utility of High Spatial Resolution Spaceborne Multispectral RapidEye Sensor and Advanced Machine Learning Algorithms

Directory of Open Access Journals (Sweden)

Timothy Dube

2014-08-01

Full Text Available The quantification of aboveground biomass using remote sensing is critical for better understanding the role of forests in carbon sequestration and for informed sustainable management. Although remote sensing techniques have been proven useful in assessing forest biomass in general, more is required to investigate their capabilities in predicting intra-and-inter species biomass which are mainly characterised by non-linear relationships. In this study, we tested two machine learning algorithms, Stochastic Gradient Boosting (SGB and Random Forest (RF regression trees to predict intra-and-inter species biomass using high resolution RapidEye reflectance bands as well as the derived vegetation indices in a commercial plantation. The results showed that the SGB algorithm yielded the best performance for intra-and-inter species biomass prediction; using all the predictor variables as well as based on the most important selected variables. For example using the most important variables the algorithm produced an R2 of 0.80 and RMSE of 16.93 t·ha−1 for E. grandis; R2 of 0.79, RMSE of 17.27 t·ha−1 for P. taeda and R2 of 0.61, RMSE of 43.39 t·ha−1 for the combined species data sets. Comparatively, RF yielded plausible results only for E. dunii (R2 of 0.79; RMSE of 7.18 t·ha−1. We demonstrated that although the two statistical methods were able to predict biomass accurately, RF produced weaker results as compared to SGB when applied to combined species dataset. The result underscores the relevance of stochastic models in predicting biomass drawn from different species and genera using the new generation high resolution RapidEye sensor with strategically positioned bands.

Daily concurrent chemoradiotherapy using superselective intra-arterial infusion via superficial temporal artery. Preoperative therapy for stage III, IV oral cancer

International Nuclear Information System (INIS)

Tohnai, Iwai; Mitsudo, Kenji; Nishiguchi, Hiroaki; Fukui, Takafumi; Yamamoto, Noriyuki; Ueda, Minoru; Fuwa, Nobukazu

2005-01-01

Recently, daily concurrent chemoradiotherapy using new superselective intra-arterial infusion via superficial temporal arterial artery is attracting attention. The catheter with curved tip is inserted superselectively to the feeding artery of the tumor via the superficial temporal artery, allowing long-term catheterization. Forty-one patients with stage III, IV oral cancer were treated. Radiotherapy (total dose: 40 Gy/4 weeks) and superselective intra-arterial infusion chemotherapy using docetaxel (total dose: 60 mg/m 2 , 15 mg/m 2 /week) and cisplatin (total dose: 100 mg/m 2 , 5 mg/m 2 /day) were concurrently performed daily, followed by surgery. In 35 patients, intra-arterial infusion was successful (success rate: 85.4%) and no major complication was observed. The clinical effects were complete response (CR) in 29 patients (82.9%), and pathological effects of resected tumor after surgery were pathological CR in 31 (88.6%). This method promises to be a new strategy of choice for the treatment of oral cancer. (author)

Intra-annual wave resource characterization for energy exploitation: A new decision-aid tool

International Nuclear Information System (INIS)

Carballo, R.; Sánchez, M.; Ramos, V.; Fraguela, J.A.; Iglesias, G.

2015-01-01

Highlights: • A decision-aid tool is developed for computing the monthly performance of WECs. • It allows the generation of high-resolution monthly characterization matrices. • The decision-aid tool is implemented to the Death Coast (N Spain). • The monthly matrices can be obtained at any coastal location within the Death Coast. • The tool is applied to a coastal location of a proposed wave farm. - Abstract: The wave energy resource is usually characterized by a significant variability throughout the year. In estimating the power performance of a Wave Energy Converter (WEC) it is fundamental to take into account this variability; indeed, an estimate based on mean annual values may well result in a wrong decision making. In this work, a novel decision-aid tool, iWEDGE (intra-annual Wave Energy Diagram GEnerator) is developed and implemented to a coastal region of interest, the Death Coast (Spain), one of the regions in Europe with the largest wave resource. Following a comprehensive procedure, and based on deep water wave data and high-resolution numerical modelling, this tool provides the monthly high-resolution characterization matrices (or energy diagrams) for any location of interest. In other words, the information required for the accurate computation of the intra-annual performance of any WEC at any location within the region covered is made available. Finally, an application of iWEDGE to the site of a proposed wave farm is presented. The results obtained highlight the importance of the decision-aid tool herein provided for wave energy exploitation

High frequency, high time resolution time-to-digital converter employing passive resonating circuits.

Science.gov (United States)

Ripamonti, Giancarlo; Abba, Andrea; Geraci, Angelo

2010-05-01

A method for measuring time intervals accurate to the picosecond range is based on phase measurements of oscillating waveforms synchronous with their beginning and/or end. The oscillation is generated by triggering an LC resonant circuit, whose capacitance is precharged. By using high Q resonators and a final active quenching of the oscillation, it is possible to conjugate high time resolution and a small measurement time, which allows a high measurement rate. Methods for fast analysis of the data are considered and discussed with reference to computing resource requirements, speed, and accuracy. Experimental tests show the feasibility of the method and a time accuracy better than 4 ps rms. Methods aimed at further reducing hardware resources are finally discussed.

High frequency, high time resolution time-to-digital converter employing passive resonating circuits

International Nuclear Information System (INIS)

Ripamonti, Giancarlo; Abba, Andrea; Geraci, Angelo

2010-01-01

A method for measuring time intervals accurate to the picosecond range is based on phase measurements of oscillating waveforms synchronous with their beginning and/or end. The oscillation is generated by triggering an LC resonant circuit, whose capacitance is precharged. By using high Q resonators and a final active quenching of the oscillation, it is possible to conjugate high time resolution and a small measurement time, which allows a high measurement rate. Methods for fast analysis of the data are considered and discussed with reference to computing resource requirements, speed, and accuracy. Experimental tests show the feasibility of the method and a time accuracy better than 4 ps rms. Methods aimed at further reducing hardware resources are finally discussed.

Efficacy of concurrent chemoradiotherapy with superselective intra-arterial docetaxel-nedaplatin for metastatic cervical lymph nodes in oral cancers

International Nuclear Information System (INIS)

Kobayashi, Wataru; Sato, Hisashi; Sakaki, Hirotaka

2012-01-01

The purpose of this study was to evaluate the efficacy of concurrent chemoradiation with intra-arterial docetaxel-nedaplatin infusion to metastatic cervical lymph nodes in oral cancers. Sixteen patients with advanced oral cancer accompanied by cervical lymph node metastasis were treated between 2003 and 2009 at Hirosaki University Hospital. A total of 66 Gy of external beam irradiation concurrent with 2 to 3 courses of intra-arterial chemotherapy infusion via the femoral artery with a combination of docetaxel (40 mg/m 2 ) and nedaplatin (80 mg/m 2 ) was conducted. Amongst the 16 patients, 6 received a total anticancer drug delivery to the primary tumor and 10 received a partial delivery to the nodal disease. The feeding artery to the nodal disease was the facial artery in 3 patients and the occipital artery in 3 patients. The remaining 4 patients received anticancer drug infusion to the external carotid artery with arterial redistribution technique where embolization was applied in order to achieve an antitumor effect due to a high local concentration. Treatment effect was evaluated by computed tomography (CT), magnetic resonance imaging and positron emission tomography-CT (PET-CT). Metastatic cervical lymph nodes disappeared in 15 out of the 16 patients (93.8%) post-treatment. Neck dissection was performed for the patient with residual nodal disease. One patient had neck recurrence at level V in ipsilateral neck. The three-year overall survival rate was 74.6% with a median follow-up duration of 27 months. Intra-arterial docetaxel-nedaplatin infusion concurrent with radiotherapy is an effective treatment not only for primary disease but also for metastatic cervical lymph nodes. (author)

Daily concurrent preoperative chemoradiotherapy using new superselective intra-arterial infusion via superficial temporal artery for oral cancer. Cervical lymph node metastasis

International Nuclear Information System (INIS)

Yamamoto, Noriyuki; Mitsudo, Kenji; Tohnai, Iwai

2007-01-01

Seventeen oral cancer patients with cervical lymph node metastasis were treated by preoperative chemoradiotherapy using superselective intra-arterial infusion via the superficial temporal artery. Radiotherapy (total dose: 40 Gy/4 weeks) and superselective intra-arterial infusion chemotherapy using docetaxel (DOC) (total dose: 60 mg/m 2 , 15 mg/m 2 /week) and cisplatin (CDDP) (total dose: 100 mg/m 2 , 5 mg/m 2 /day) were performed, followed by surgery. The pathological effects of resected lymph node metastasis after surgery were grade III, IV (Oboshi-Shimosato classification) in level I, II. This method is a promising strategy for oral cancer with cervical lymph node metastasis. (author)

High-frequency matrix converter with square wave input

Science.gov (United States)

Carr, Joseph Alexander; Balda, Juan Carlos

2015-03-31

A device for producing an alternating current output voltage from a high-frequency, square-wave input voltage comprising, high-frequency, square-wave input a matrix converter and a control system. The matrix converter comprises a plurality of electrical switches. The high-frequency input and the matrix converter are electrically connected to each other. The control system is connected to each switch of the matrix converter. The control system is electrically connected to the input of the matrix converter. The control system is configured to operate each electrical switch of the matrix converter converting a high-frequency, square-wave input voltage across the first input port of the matrix converter and the second input port of the matrix converter to an alternating current output voltage at the output of the matrix converter.

High-frequency high-voltage high-power DC-to-DC converters

Science.gov (United States)

Wilson, T. G.; Owen, H. A.; Wilson, P. M.

1982-09-01

A simple analysis of the current and voltage waveshapes associated with the power transistor and the power diode in an example current-or-voltage step-up (buck-boost) converter is presented. The purpose of the analysis is to provide an overview of the problems and design trade-offs which must be addressed as high-power high-voltage converters are operated at switching frequencies in the range of 100 kHz and beyond. Although the analysis focuses on the current-or-voltage step-up converter as the vehicle for discussion, the basic principles presented are applicable to other converter topologies as well.

A Fast Time-to-Pulse Height Converter

Energy Technology Data Exchange (ETDEWEB)

Aspelund, O

1962-12-15

A fast time-to-pulse height converter representing a development of Green and Bell's gated beam converter is described. The converter is compatible with 2 input pulses in the stop channel and exhibits excellent linearity and time resolution properties. High stability and large output pulses are obtained by using a large time constant in the converting network.

Influence of intra-oral sensory impairment by anaesthesia on food comminution and mixing in dentate subjects.

Science.gov (United States)

Yoshida, E; Fueki, K; Wakabayashi, N

2015-06-01

Sensory input from sensory receptors regarding food morsels can affect jaw motor behaviours during mastication. The aim was to clarify the effects of intra-oral sensory input on the food-comminuting and food-mixing capacities of dentate subjects. Eleven dentate subjects without sensory dysfunction in their oro-facial region participated in this study. Local anaesthesia was achieved on the periodontal structures and on the oral mucosa of the subjects' preferred chewing side by injecting a lidocaine solution with adrenalin. At baseline (control) and after anaesthesia, data on the subjects' food-comminuting and food-mixing capacities were gathered. The food-comminuting capacity was quantified by measuring the degree of pulverisation of peanuts (objective hardness; 45.3 [Newton, N]) after a prescribed 20 chewing strokes. The food-mixing capacity was measured as the degree of immixture of a two-coloured paraffin wax cube after 10 chewing strokes. Wax cubes of three different hardness levels were used (soft, medium and hard: 20.3, 32.6 and 75.5 [N], respectively) and were chewed in random order. After anaesthesia, the subjects' food-comminuting capacity significantly decreased (P food-mixing capacity for each hardness level of the wax cubes (P food-mixing capacity (P deterioration of the mixing capacity increased as the hardness increased. In conclusion, intra-oral sensory input can affect both food-comminuting and food-mixing capacities. © 2015 John Wiley & Sons Ltd.

Acceptability and attractiveness of intra- and extra-oral orthodontic appliances.

Science.gov (United States)

Abu Alhaija, Elham S J; Karajeh, M A

2013-01-01

To evaluate the acceptability of different intra-oral and extra-oral orthodontic appliances, to rank orthodontic appliances from the most to the least attractive and to investigate the factors that may affect the acceptance of orthodontic treatment. A random sample of 800 students (schoolchildren and university students) were invited to participate in this study and a total of 688 students were included (86%). A self-administrated structured questionnaire was constructed for the purpose of this study. More than one-half in each age group (53%) claimed that they would accept to have orthodontic treatment. Acceptance of the different orthodontic appliances was affected by gender, age and type of school. Removable appliance was reported as the most acceptable and facemask was reported as the least acceptable orthodontic appliances. Majority of subjects ranked ceramic and facemask appliances as the most and the least attractive orthodontic appliances, respectively. The predictor variables for the acceptance of orthodontic treatment were perceived demand for orthodontic treatment, perceived positive effect of orthodontic treatment and expected benefits from orthodontic treatment. Removable appliance was the most acceptable orthodontic appliance whereas ceramic appliance was ranked as the most attractive one. Facemask was the least acceptable and the least attractive option.

High-speed charge-to-time converter ASIC for the Super-Kamiokande detector

Energy Technology Data Exchange (ETDEWEB)

Nishino, H., E-mail: nishino@post.kek.j [Institute for Cosmic Ray Research, University of Tokyo, Chiba 277-8582 (Japan); Awai, K.; Hayato, Y.; Nakayama, S.; Okumura, K.; Shiozawa, M.; Takeda, A. [Institute for Cosmic Ray Research, University of Tokyo, Chiba 277-8582 (Japan); Ishikawa, K.; Minegishi, A. [Iwatsu Test Instruments Corporation, Tokyo 168-8511 (Japan); Arai, Y. [The Institute of Particle and Nuclear Studies, KEK, Ibaraki 305-0801 (Japan)

2009-11-11

A new application-specific integrated circuit (ASIC), the high-speed charge-to-time converter (QTC) IWATSU CLC101, provides three channels, each consisting of preamplifier, discriminator, low-pass filter, and charge integration circuitry, optimized for the waveform of a photomultiplier tube (PMT). This ASIC detects PMT signals using individual built-in discriminators and drives output timing signals whose width represents the integrated charge of the PMT signal. Combined with external input circuits composed of passive elements, the QTC provides full analog signal processing for the detector's PMTs, ready for further processing by time-to-digital converters (TDCs). High-rate (>1MHz) signal processing is achieved by short-charge-conversion-time and baseline-restoration circuits. Wide-range charge measurements are enabled by offering three gain ranges while maintaining a short cycle time. QTC chip test results show good analog performance, with efficient detection for a single photoelectron signal, four orders of magnitude dynamic range (0.3mVapprox3V; 0.2approx2500pC), 1% charge linearity, 0.2 pC charge resolution, and 0.1 ns timing resolution. Test results on ambient temperature dependence, channel isolation, and rate dependence also meet specifications.

High-speed charge-to-time converter ASIC for the Super-Kamiokande detector

International Nuclear Information System (INIS)

Nishino, H.; Awai, K.; Hayato, Y.; Nakayama, S.; Okumura, K.; Shiozawa, M.; Takeda, A.; Ishikawa, K.; Minegishi, A.; Arai, Y.

2009-01-01

A new application-specific integrated circuit (ASIC), the high-speed charge-to-time converter (QTC) IWATSU CLC101, provides three channels, each consisting of preamplifier, discriminator, low-pass filter, and charge integration circuitry, optimized for the waveform of a photomultiplier tube (PMT). This ASIC detects PMT signals using individual built-in discriminators and drives output timing signals whose width represents the integrated charge of the PMT signal. Combined with external input circuits composed of passive elements, the QTC provides full analog signal processing for the detector's PMTs, ready for further processing by time-to-digital converters (TDCs). High-rate (>1MHz) signal processing is achieved by short-charge-conversion-time and baseline-restoration circuits. Wide-range charge measurements are enabled by offering three gain ranges while maintaining a short cycle time. QTC chip test results show good analog performance, with efficient detection for a single photoelectron signal, four orders of magnitude dynamic range (0.3mV∼3V; 0.2∼2500pC), 1% charge linearity, 0.2 pC charge resolution, and 0.1 ns timing resolution. Test results on ambient temperature dependence, channel isolation, and rate dependence also meet specifications.

Long-term stability of intra-oral maxillary distraction in unilateral cleft lip and palate: a case report.

Science.gov (United States)

Nevzatoğlu, Sirin; Küçükkeleş, Nazan; Güzel, Zeki

2013-11-01

This case report presents short and long-term treatment results of a unilateral cleft lip and palate patient treated with a modified intra-oral tooth-bone borne distraction appliance. The chief complaints of a 16 year-old, unilateral cleft lip and palate patient were poor facial aesthetics, crowding and a fistula. Severe maxillary retrognathism was treated via distraction osteogenesis of the maxilla and performed using an intra-oral tooth-bone borne appliance. Treatment continued to completion with a multibracket system. At an eight-year review following the distraction procedure, the short and long-term results were determined cephalometrically. Following the distraction, A-point advanced 7 mm, 2 mm of which relapsed during fixed appliance treatment. At the end of the active treatment, the patient's skeletal and dental Class III relationship improved to Class I, which was preserved at the long-term review. The profile was markedly improved by the distraction osteogenesis. In cases of severe maxillary retrognathism as a result of a cleft lip and palate, maxillary distraction osteogenesis provides a viable alternative to orthognathic surgery.

High Efficiency Power Converter for Low Voltage High Power Applications

DEFF Research Database (Denmark)

Nymand, Morten

The topic of this thesis is the design of high efficiency power electronic dc-to-dc converters for high-power, low-input-voltage to high-output-voltage applications. These converters are increasingly required for emerging sustainable energy systems such as fuel cell, battery or photo voltaic based......, and remote power generation for light towers, camper vans, boats, beacons, and buoys etc. A review of current state-of-the-art is presented. The best performing converters achieve moderately high peak efficiencies at high input voltage and medium power level. However, system dimensioning and cost are often...

High Current, Low Voltage Power Converter [20kA, 6V] LHC Converter Prototype

CERN Document Server

Jørgensen, H E; Dupaquier, A; Fernqvist, G

1998-01-01

The superconducting LHC accelerator requires high currents (~12.5kA) and relatively low voltages (~10 V) for its magnets. The need to install the power converters underground is the driving force for reduced volume and high efficiency. Moreover, the LHC machine will require a very high level of performance from the power converters, particularly in terms of DC stability, dynamic response and also in matters of EMC. To meet these requirements soft-switching techniques will be used. This paper describes the development of a [20kA,6V] power converter intended as a stable high-current source for D CCT calibration and an evaluation prototype for the future LHC converters. The converter is made with a modular concept with five current sources [4kA,6V] in parallel. The 4kA sources are built as plu g-in modules: a diode rectifier on the AC mains with a damped L-C passive filter, a Zero Voltage Switching inverter working at 20 kHz and an output stage (high frequency transformers, Schottky rectifi ers and output filter...

High Efficiency Power Converter for Low Voltage High Power Applications

DEFF Research Database (Denmark)

Nymand, Morten

The topic of this thesis is the design of high efficiency power electronic dc-to-dc converters for high-power, low-input-voltage to high-output-voltage applications. These converters are increasingly required for emerging sustainable energy systems such as fuel cell, battery or photo voltaic based...

Construction of a high resolution electron beam profile monitor

International Nuclear Information System (INIS)

Norem, J.; Dawson, J.; Haberichter, W.; Novak, W.; Reed, L.; Yang, X.F.

1993-01-01

Bremsstrahlung from an electron beam on a heavy target can be used to image the beam profile using collimators and slits. The limiting resolution using this system is determined by Fresnel diffraction, and is ∼ √(λd/2), where λ is the photon wavelength and d is determined by the linear dimensions of the system. For linear colliders this resolution could be a few nm. The highest resolution requires detectors which see only high energy, (small λ), photons, and this is accomplished by converting photons to pairs, and detecting Cherenkov light in a nearly forward angle with a CCD detector or streak camera. Tests are planned at the Argonne APS and SLAC FFTB

The prophylactic effect of neck irradiation combined with intra-oral electron beam irradiation for early tongue cancer

International Nuclear Information System (INIS)

Kawamori, Jiro; Kamata, Rikisaburo; Sanuki, Eiichi

1993-01-01

Between 1967 and 1988, 102 patients with Stage T1-2N0 squamous cell carcinoma of the tongue were treated with uneven fractional irradiation therapy (intra-oral electron beam irradiation with and without prophylactic ipsilateral upper neck irradiation at the Dept. of Radiology, Nihon University School of Medicine. Of 102 primary lesions, 89 cases were controlled with this therapy. In this study, these 89 cases were investigated in order to analyze the prophylactic effect of upper neck irradiation. Of the 89 patients, 42 received only intra-oral electron beam irradiation, while the remaining 47 received a combination of intra-oral electron beam irradiation and prophylactic irradiation to the ipsilateral upper neck. Twenty three of the 89 (25.8%) developed metastasis to the neck after the radiotherapy. A breakdown of these 23 cases reveals that 3/21 (14.3%) received 40-50 Gy to the neck, 9/26 (34.6%) received 20-40 Gy to the neck, and 11/42 (26.2%) received no irradiation to the neck (p<0.05 between first and second groups, and between first and third groups). The neck metastasis was classified into one of three categories based on the region in which it first appeared (ipsilateral upper neck, ipsilateral lower neck or contralateral neck). The first metastasis was seen in the ipsilateral upper neck, in the ipsilateral lower neck and in the contralateral neck in 17, 4 and 2 patients, respectively. In 1/19 who had received 40-50 Gy, in 5/21 who had received 20-40 Gy and in 11/42 who had not received neck irradiation the first metastasis appeared in the ipsilateral upper neck. The five year survival rate was 94%, 75% and 85% in the patients receiving 40-50 Gy, 20-40 Gy and no neck irradiation, respectively. These results suggest that prophylactic irradiation of 40-50 Gy to the ipsilateral upper neck might decrease the incidence of neck metastasis and slightly prolong survival time. (author)

Inter- and intrarater reliability of the Chicago Classification in pediatric high-resolution esophageal manometry recordings

NARCIS (Netherlands)

Singendonk, M. M. J.; Smits, M. J.; Heijting, I. E.; van Wijk, M. P.; Nurko, S.; Rosen, R.; Weijenborg, P. W.; Abu-Assi, R.; Hoekman, D. R.; Kuizenga-Wessel, S.; Seiboth, G.; Benninga, M. A.; Omari, T. I.; Kritas, S.

2015-01-01

The Chicago Classification (CC) facilitates interpretation of high-resolution manometry (HRM) recordings. Application of this adult based algorithm to the pediatric population is unknown. We therefore assessed intra and interrater reliability of software-based CC diagnosis in a pediatric cohort.

Time lens for high-resolution neutron time-of-flight spectrometers

International Nuclear Information System (INIS)

Baumann, K.; Gaehler, R.; Grigoriev, P.; Kats, E.I.

2005-01-01

We examine in analytic and numeric ways the imaging effects of temporal neutron lenses created by traveling magnetic fields. For fields of parabolic shape we derive the imaging equations, investigate the time magnification, the evolution of the phase-space element, the gain factor, and the effect of finite beam size. The main aberration effects are calculated numerically. The system is technologically feasible and should convert neutron time-of-flight instruments from pinhole to imaging configuration in time, thus enhancing intensity and/or time resolution. Further fields of application for high-resolution spectrometry may be opened

PV source based high voltage gain current fed converter

Science.gov (United States)

Saha, Soumya; Poddar, Sahityika; Chimonyo, Kudzai B.; Arunkumar, G.; Elangovan, D.

2017-11-01

This work involves designing and simulation of a PV source based high voltage gain, current fed converter. It deals with an isolated DC-DC converter which utilizes boost converter topology. The proposed converter is capable of high voltage gain and above all have very high efficiency levels as proved by the simulation results. The project intends to produce an output of 800 V dc from a 48 V dc input. The simulation results obtained from PSIM application interface were used to analyze the performance of the proposed converter. Transformer used in the circuit steps up the voltage as well as to provide electrical isolation between the low voltage and high voltage side. Since the converter involves high switching frequency of 100 kHz, ultrafast recovery diodes are employed in the circuitry. The major application of the project is for future modeling of solar powered electric hybrid cars.

Research & Implementation of AC - DC Converter with High Power Factor & High Efficiency

Directory of Open Access Journals (Sweden)

Hsiou-Hsian Nien

2014-05-01

Full Text Available In this paper, we design and develop a high power factor, high efficiency two-stage AC - DC power converter. This paper proposes a two-stage AC - DC power converter. The first stage is boost active power factor correction circuit. The latter stage is near constant frequency LLC resonant converter. In addition to traditional LLC high efficiency advantages, light-load conversion efficiency of this power converter can be improved. And it possesses high power factor and near constant frequency operating characteristics, can significantly reduce the electromagnetic interference. This paper first discusses the main structure and control manner of power factor correction circuit. And then by the LLC resonant converter equivalent model proceed to circuit analysis to determine the important parameters of the converter circuit elements. Then design a variable frequency resonant tank. The resonant frequency can change automatically on the basis of the load to reach near constant frequency operation and a purpose of high efficiency. Finally, actually design and produce an AC – DC power converter with output of 190W to verify the characteristics and feasibility of this converter. The experimental results show that in a very light load (9.5 W the efficiency is as high as 81%, the highest efficiency of 88% (90 W. Full load efficiency is 87%. At 19 W ~ 190 W power changes, the operating frequency change is only 0.4 kHz (AC 110 V and 0.3 kHz (AC 220 V.

Daily concurrent chemoradiotherapy with docetaxel (DOC) and cisplatin (CDDP) using superselective intra-arterial infusion via the superficial temporal artery for stage III and IV oral cancer. Possibility of organ preservation in advanced oral cancer

International Nuclear Information System (INIS)

Mitsudo, Kenji; Tohnai, Iwai; Fuwa, Nobukazu

2006-01-01

Superselective intra-arterial chemotherapy via the superficial temporal artery has become feasible for daily concurrent radiotherapy and chemotherapy for head and neck cancer. This novel method was used for oral cancer, and its efficacy was evaluated. Treatment consisted of superselective intra-arterial infusions (Docetaxel (DOC) total 60 mg/m 2 , Cisplatin (CDDP) total 100 mg/m 2 ) and concurrent radiotherapy (total 40 Gy) for four weeks as preoperative therapy. Thirty-four patients with stage III and IV oral cancer received surgery after this treatment, and pathological CR was obtained in 31 patients (91%). The possibility of organ preservation for advanced oral cancer was evaluated from this result. Patients with oral cancer stage III and IV were treated for four-week daily concurrent chemoradiotherapy, and the clinical response was evaluated after treatment. Clinical CR of primary sites was obtained in 15 patients, and the same treatment was continued one or two weeks. Thirteen patients (80%) were disease-free in the primary sites, and two (20%) relapsed. Two patients died of distant metastasis, and one died of local recurrence. This method can preserve organs and minimize functional disturbance, thus contributing to patient QOL. (author)

Conception and realization of a multichannel amplitude converter

International Nuclear Information System (INIS)

Bendebiche, L.

1992-11-01

A compact Analog to Digital Converter system suitable for high resolution γ-ray analysers has been developed based on the ADADC84 12-bit converter from Analog Devices. The converter was equipped with a peak detector and a stretcher, and with a memory card providing the sliding scale circuits, the lower threshold, the channel number identification and the zero suppression. The conversion time is 10 μs and the differential non linearity is less than ±1% for a 12-bit resolution. The converter consists of a 12-bit spectroscopy analog-to-digital converter (ADC) while the memory card includes a 8K 24-bit buffer memory. The two cards are plugged into a slot of an IBM PC AT and using an emulation software converts the micro-computer into a full-featured pulse height analyser. In data acquisition mode, the cards can operate independently, making the computer free for other tasks. The software offers acquisition control, visualization, data handling functions and various types of result presentation

Extra Oral Periapical Radiography: A Review

Directory of Open Access Journals (Sweden)

Rachna Kaul

2014-01-01

Full Text Available Background: Intra oral periapical radiographs remain the backbone of diagnostic assessment of dento-facial pathologies. However, in some clinical situation like in developmentally disabled individuals, those with an exaggerated gag reflex, pediatric dental patients and anxious dental patients, it may be very difficult to obtain an intra-oral periapical radiograph of diagnostic quality. In such situations, extra oral periapical radiographs are very useful. They are obtained by placing a sensor outside the oral cavity and then making the radiographic exposure using a digital X ray machine for intra oral radiographs. The radiation dose in this technique is much lesser as compared to panoramic radiographs. This article reviews the technique, advantages, disadvantages and indications of extra oral periapical radiographs.

Converting high boiling hydrocarbons

Energy Technology Data Exchange (ETDEWEB)

Terrisse, H; DuFour, L

1929-02-12

A process is given for converting high boiling hydrocarbons into low boiling hydrocarbons, characterized in that the high boiling hydrocarbons are heated to 200 to 500/sup 0/C in the presence of ferrous chloride and of such gases as hydrogen, water gas, and the like gases under a pressure of from 5 to 40 kilograms per square centimeter. The desulfurization of the hydrocarbons occurs simultaneously.

The Use Of Oral Ranolazine To Convert New Or Paroxysmal Atrial Fibrillation: A Review Of Experience With Implications For Possible "Pill In The Pocket" Approach To Atrial Fibrillation

Directory of Open Access Journals (Sweden)

David K Murdock

2009-09-01

Full Text Available Background: Atrial fibrillation (AF is the most common arrhythmia requiring treatment. High dose oral anti-arrhythmics may cardiovert some paroxysmal AF. This "pill in pocket" approach has allowed patients to treat themselves on an as needed basis. Pro-arrhythmic concerns have limited the usefulness of this approach to patients without structural heart disease. Ranolazine is an anti-anginal agent, which inhibits abnormal late Na+ channel currents in cardiomyocytes and decreases sodium-calcium overload. Ranolazine is a potent inhibitor of after-depolarizations, which have been implicated in the initiation and propagation of AF. Because ranolazine has no known pro-arrhythmic effects, it could be useful as a safe "pill in the pocket" agent if it were effective in converting AF. We describe our experience using oral ranolazine to convert new or paroxysmal AF. Method: 2000 mg of ranolazine were administered to 18 patients with new (11 patients or paroxysmal (7 patients AF of at least 3, but not greater than 48 hours duration. Most patients (14 were in the hospital at the time ranolazine was administered. Age, sex, echocardiographic data, associated health conditions and structural heart disease were recorded. Successful conversion was defined as restoring sinus rhythm within 6 hours of ranolazine administration. Results: All but 1 patient had some form of structural heart disease and all but 2 patients had left atrial enlargement. Thirteen of 18 patients converted to sinus rhythm. No pro-arrhythmic effects, hemodynamic instability, adverse rate effects, or perceived intolerance (other than constipation were noted. The 72% conversion rate was comparable to other reported "pill in the pocket" protocols. Conclusion: High dose oral ranolazine shows utility as a possible safe agent to convert new or paroxysmal AF. Lack of blinded controls and small numbers limits the power of this observation.

High-power converters and AC drives

CERN Document Server

Wu, Bin

2017-01-01

This new edition reflects the recent technological advancements in the MV drive industry, such as advanced multilevel converters and drive configurations. It includes three new chapters, Control of Synchronous Motor Drives, Transformerless MV Drives, and Matrix Converter Fed Drives. In addition, there are extensively revised chapters on Multilevel Voltage Source Inverters and Voltage Source Inverter-Fed Drives. This book includes a systematic analysis on a variety of high-power multilevel converters, illustrates important concepts with simulations and experiments, introduces various megawatt drives produced by world leading drive manufacturers, and addresses practical problems and their mitigations methods.

High power density dc/dc converter: Selection of converter topology

Science.gov (United States)

Divan, Deepakraj M.

1990-01-01

The work involved in the identification and selection of a suitable converter topology is described. Three new dc/dc converter topologies are proposed: Phase-Shifted Single Active Bridge DC/DC Converter; Single Phase Dual Active Bridges DC/DC Converter; and Three Phase Dual Active Bridges DC/DC Converter (Topology C). The salient features of these topologies are: (1) All are minimal in structure, i.e., each consists of an input and output bridge, input and output filter and a transformer, all components essential for a high power dc/dc conversion process; (2) All devices of both the bridges can operate under near zero-voltage conditions, making possible a reduction of device switching losses and hence, an increase in switching frequency; (3) All circuits operate at a constant frequency, thus simplifying the task of the magnetic and filter elements; (4) Since, the leakage inductance of the transformer is used as the main current transfer element, problems associated with the diode reverse recovery are eliminated. Also, this mode of operation allows easy paralleling of multiple modules for extending the power capacity of the system; (5) All circuits are least sensitive to parasitic impedances, infact the parasitics are efficently utilized; and (6) The soft switching transitions, result in low electromagnetic interference. A detailed analysis of each topology was carried out. Based on the analysis, the various device and component ratings for each topology operating at an optimum point, and under the given specifications, are tabulated and discussed.

Effect of preoperative oral S-1 combined with regional intra-arterial chemotherapy on malignant molecule expression in locally advanced unresectable gastric cancer tissue

Directory of Open Access Journals (Sweden)

Lei Liu

2016-11-01

Full Text Available Objective: To study the effect of preoperative oral S-1 combined with regional intra-arterial chemotherapy on malignant molecule expression in locally advanced unresectable gastric cancer tissue. Methods: A total of 144 patients with locally advanced gastric cancer receiving surgical resection after neoadjuvant chemotherapy in our hospital between May 2012 and August 2015 were selected and randomly divided into experimental group who received preoperative oral S-1 combined with regional intra-arterial chemotherapy and control group who received preoperative intravenous systemic chemotherapy. The levels of serum tumor markers were determined after chemotherapy, and the expression levels of tumor suppressor genes and cell cycle-related molecules in tumor tissue were determined after surgical resection. Results: After neoadjuvant chemotherapy, the serum G-17, TK-1, CEA, CA19-9, CA12-5, CA72-4 and CK, CK-MB, ALT, AST levels of experimental group were significantly lower than those of control group; after surgical resection, the p16, p27, PTEN and TXNIP mRNA levels in tumor tissue of experimental group were significantly higher than those of control group while CyclinB2, CyclinD1, CyclinE, CDK1 and CDK2 mRNA levels were significantly lower than those of control group. Conclusions: Preoperative oral S-1 combined with regional intra-arterial chemotherapy can more effectively kill gastric cancer cells, reduce tumor load, inhibit cell cycle and promote cell apoptosis.

High-resolution melt-curve analysis of random amplified polymorphic DNA (RAPD-HRM) for the characterisation of pathogenic leptospires: intra-serovar divergence, inter-serovar convergence, and evidence of attenuation in Leptospira reference collections.

Science.gov (United States)

Tulsiani, S M; Craig, S B; Graham, G C; Cobbold, R C; Dohnt, M F; Burns, M-A; Jansen, C C; Leung, L K-P; Field, H E; Smythe, L D

2010-07-01

High-resolution melt-curve analysis of random amplified polymorphic DNA (RAPD-HRM) is a novel technology that has emerged as a possible method to characterise leptospires to serovar level. RAPD-HRM has recently been used to measure intra-serovar convergence between strains of the same serovar as well as inter-serovar divergence between strains of different serovars. The results indicate that intra-serovar heterogeneity and inter-serovar homogeneity may limit the application of RAPD-HRM in routine diagnostics. They also indicate that genetic attenuation of aged, high-passage-number isolates could undermine the use of RAPD-HRM or any other molecular technology. Such genetic attenuation may account for a general decrease seen in titres of rabbit hyperimmune antibodies over time. Before RAPD-HRM can be further advanced as a routine diagnostic tool, strains more representative of the wild-type serovars of a given region need to be identified. Further, RAPD-HRM analysis of reference strains indicates that the routine renewal of reference collections, with new isolates, may be needed to maintain the genetic integrity of the collections.

Analysis and Design of High-Order Parallel Resonant Converters

Science.gov (United States)

Batarseh, Issa Eid

1990-01-01

In this thesis, a special state variable transformation technique has been derived for the analysis of high order dc-to-dc resonant converters. Converters comprised of high order resonant tanks have the advantage of utilizing the parasitic elements by making them part of the resonant tank. A new set of state variables is defined in order to make use of two-dimensional state-plane diagrams in the analysis of high order converters. Such a method has been successfully used for the analysis of the conventional Parallel Resonant Converters (PRC). Consequently, two -dimensional state-plane diagrams are used to analyze the steady state response for third and fourth order PRC's when these converters are operated in the continuous conduction mode. Based on this analysis, a set of control characteristic curves for the LCC-, LLC- and LLCC-type PRC are presented from which various converter design parameters are obtained. Various design curves for component value selections and device ratings are given. This analysis of high order resonant converters shows that the addition of the reactive components to the resonant tank results in converters with better performance characteristics when compared with the conventional second order PRC. Complete design procedure along with design examples for 2nd, 3rd and 4th order converters are presented. Practical power supply units, normally used for computer applications, were built and tested by using the LCC-, LLC- and LLCC-type commutation schemes. In addition, computer simulation results are presented for these converters in order to verify the theoretical results.

Sheppard-Taylor Isolated High Boost DC-DC Converter

DEFF Research Database (Denmark)

Chub, Andrii; Siwakoti, Yam Prasad; Vinnikov, Dmitri

2017-01-01

This paper presents a new galvanically isolated step-up dc-dc converter intended for low-power but high step-up applications. The proposed converter is capable of regulating output voltage within a wide range of the input voltage or load variations. In contrast to competitors, the converter can...

Ground-glass opacity: High-resolution computed tomography and 64-multi-slice computed tomography findings comparison

International Nuclear Information System (INIS)

Sergiacomi, Gianluigi; Ciccio, Carmelo; Boi, Luca; Velari, Luca; Crusco, Sonia; Orlacchio, Antonio; Simonetti, Giovanni

2010-01-01

Objective: Comparative evaluation of ground-glass opacity using conventional high-resolution computed tomography technique and volumetric computed tomography by 64-row multi-slice scanner, verifying advantage of volumetric acquisition and post-processing technique allowed by 64-row CT scanner. Methods: Thirty-four patients, in which was assessed ground-glass opacity pattern by previous high-resolution computed tomography during a clinical-radiological follow-up for their lung disease, were studied by means of 64-row multi-slice computed tomography. Comparative evaluation of image quality was done by both CT modalities. Results: It was reported good inter-observer agreement (k value 0.78-0.90) in detection of ground-glass opacity with high-resolution computed tomography technique and volumetric Computed Tomography acquisition with moderate increasing of intra-observer agreement (k value 0.46) using volumetric computed tomography than high-resolution computed tomography. Conclusions: In our experience, volumetric computed tomography with 64-row scanner shows good accuracy in detection of ground-glass opacity, providing a better spatial and temporal resolution and advanced post-processing technique than high-resolution computed tomography.

A `big-mac` high converting water reactor

Energy Technology Data Exchange (ETDEWEB)

Ronen, Y; Dali, Y [Ben-Gurion Univ. of the Negev, Beersheba (Israel). Dept. of Nuclear Engineering

1996-12-01

Currently an effort is being made to get rid of plutonium. Therefore, at this time, a scientific study of a high converting reactor seems to be out of place. However , it is our opinion that the future of nuclear energy lies, among other things in the clever utilization of plutonium. It is also our opinion that one of the best ways to utilize plutonium is in high converting water reactors (authors).

Thermochemoradiation Therapy Using Superselective Intra-arterial Infusion via Superficial Temporal and Occipital Arteries for Oral Cancer With N3 Cervical Lymph Node Metastases

International Nuclear Information System (INIS)

Mitsudo, Kenji; Koizumi, Toshiyuki; Iida, Masaki; Iwai, Toshinori; Oguri, Senri; Yamamoto, Noriyuki; Itoh, Yoshiyuki; Kioi, Mitomu; Hirota, Makoto; Tohnai, Iwai

2012-01-01

Purpose: To evaluate the therapeutic results and histopathological effects of treatment with thermochemoradiation therapy using superselective intra-arterial infusion via the superficial temporal and occipital arteries for N3 cervical lymph node metastases of advanced oral cancer. Methods and Materials: Between April 2005 and September 2010, 9 patients with N3 cervical lymph node metastases of oral squamous cell carcinoma underwent thermochemoradiation therapy using superselective intra-arterial infusion with docetaxel (DOC) and cisplatin (CDDP). Treatment consisted of hyperthermia (2-8 sessions), superselective intra-arterial infusions (DOC, total 40-60 mg/m 2 ; CDDP, total 100-150 mg/m 2 ) and daily concurrent radiation therapy (total, 40-60 Gy) for 4-6 weeks. Results: Six of 9 patients underwent neck dissection 5-8 weeks after treatment. In four of these 6 patients, all metastatic lymph nodes, including those at N3, were grade 3 (non-viable tumor cells present) or grade 4 (no tumor cells present) tumors, as classified by the system by Shimosato et al (Shimosato et al Jpn J Clin Oncol 1971;1:19-35). In 2 of these 6 patients, the metastatic lymph nodes were grade 2b (destruction of tumor structures with a small amount of residual viable tumor cells). The other 3 patients did not undergo neck dissection due to distant metastasis after completion of thermochemoradiation therapy (n=2) and refusal (n=1). The patient who refused neck dissection underwent biopsy of the N3 lymph node and primary sites and showed grade 3 cancer. During follow-up, 5 patients were alive without disease, and 4 patients died due to pulmonary metastasis (n=3) and noncancer-related causes (n=1). Five-year survival and locoregional control rates were 51% and 88%, respectively. Conclusions: Thermochemoradiation therapy using intra-arterial infusion provided good histopathologic effects and locoregional control rates in patients with N3 metastatic lymph nodes. However, patients with N3 metastatic

Thermochemoradiation Therapy Using Superselective Intra-arterial Infusion via Superficial Temporal and Occipital Arteries for Oral Cancer With N3 Cervical Lymph Node Metastases

Energy Technology Data Exchange (ETDEWEB)

Mitsudo, Kenji, E-mail: mitsudo@yokohama-cu.ac.jp [Department of Oral and Maxillofacial Surgery, Yokohama City University Graduate School of Medicine, Yokohama (Japan); Koizumi, Toshiyuki; Iida, Masaki; Iwai, Toshinori; Oguri, Senri [Department of Oral and Maxillofacial Surgery, Yokohama City University Graduate School of Medicine, Yokohama (Japan); Yamamoto, Noriyuki [Department of Oral and Maxillofacial Surgery, Nagoya University Graduate School of Medicine, Nagoya (Japan); Itoh, Yoshiyuki [Department of Radiology, Nagoya University Graduate School of Medicine, Nagoya (Japan); Kioi, Mitomu; Hirota, Makoto; Tohnai, Iwai [Department of Oral and Maxillofacial Surgery, Yokohama City University Graduate School of Medicine, Yokohama (Japan)

2012-08-01

Purpose: To evaluate the therapeutic results and histopathological effects of treatment with thermochemoradiation therapy using superselective intra-arterial infusion via the superficial temporal and occipital arteries for N3 cervical lymph node metastases of advanced oral cancer. Methods and Materials: Between April 2005 and September 2010, 9 patients with N3 cervical lymph node metastases of oral squamous cell carcinoma underwent thermochemoradiation therapy using superselective intra-arterial infusion with docetaxel (DOC) and cisplatin (CDDP). Treatment consisted of hyperthermia (2-8 sessions), superselective intra-arterial infusions (DOC, total 40-60 mg/m{sup 2}; CDDP, total 100-150 mg/m{sup 2}) and daily concurrent radiation therapy (total, 40-60 Gy) for 4-6 weeks. Results: Six of 9 patients underwent neck dissection 5-8 weeks after treatment. In four of these 6 patients, all metastatic lymph nodes, including those at N3, were grade 3 (non-viable tumor cells present) or grade 4 (no tumor cells present) tumors, as classified by the system by Shimosato et al (Shimosato et al Jpn J Clin Oncol 1971;1:19-35). In 2 of these 6 patients, the metastatic lymph nodes were grade 2b (destruction of tumor structures with a small amount of residual viable tumor cells). The other 3 patients did not undergo neck dissection due to distant metastasis after completion of thermochemoradiation therapy (n=2) and refusal (n=1). The patient who refused neck dissection underwent biopsy of the N3 lymph node and primary sites and showed grade 3 cancer. During follow-up, 5 patients were alive without disease, and 4 patients died due to pulmonary metastasis (n=3) and noncancer-related causes (n=1). Five-year survival and locoregional control rates were 51% and 88%, respectively. Conclusions: Thermochemoradiation therapy using intra-arterial infusion provided good histopathologic effects and locoregional control rates in patients with N3 metastatic lymph nodes. However, patients with N3

Design and assessment of a 6 ps-resolution time-to-digital converter with 5 MGy gamma-dose tolerance for nuclear instrumentation

International Nuclear Information System (INIS)

Cao, Y.; Leroux, P.; De Cock, W.; Steyaert, M.

2011-01-01

Time-to-Digital Converters (TDCs) are key building blocks in time-based mixed-signal systems, used for the digitization of analog signals in time domain. A short survey on state-of-the-art TDCs is given. In order to realize a TDC with picosecond time resolution as well as multi MGy gamma-dose radiation tolerance, a novel multi-stage noise-shaping (MASH) delta-sigma (ΔΣ) TDC structure is proposed. The converter, implemented in 0.13 μm, achieves a time resolution of 5.6 ps and an ENOB of 11 bits, when the over sampling ratio (OSR) is 250. The TDC core consumes only 1.7 mW, and occupies an area of 0.11 mm 2 . Owing to the usage of circuit level radiation hardened-by-design techniques, such as passive RC oscillators and constant-g m biasing, the TDC exhibits enhanced radiation tolerance. At a low dose rate of 1.2 kGy/h, the frequency of the counting clock in the TDC remains constant up to at least 160 kGy. Even after a total dose of 3.4 MGy at a high dose rate of 30 kGy/h, the TDC still achieves a time resolution of 10.5 ps with an OSR of 250. (authors)

Design and assessment of a 6 ps-resolution time-to-digital converter with 5 MGy gamma-dose tolerance for nuclear instrumentation

Energy Technology Data Exchange (ETDEWEB)

Cao, Y. [ESAT-MICAS Div., Katholieke Universiteit Leuven, B-3001 Heverlee (Belgium); SCK.CEN, Belgian Nuclear Research Centre, B-2400 Mol (Belgium); Leroux, P. [ESAT-MICAS Div., Katholieke Universiteit Leuven, B-3001 Heverlee (Belgium); ICT-RELIC Div., Katholieke Hogeschool Kempen, B-2440 Geel (Belgium); De Cock, W. [SCK.CEN, Belgian Nuclear Research Centre, B-2400 Mol (Belgium); Steyaert, M. [ESAT-MICAS Div., Katholieke Universiteit Leuven, B-3001 Heverlee (Belgium)

2011-07-01

Time-to-Digital Converters (TDCs) are key building blocks in time-based mixed-signal systems, used for the digitization of analog signals in time domain. A short survey on state-of-the-art TDCs is given. In order to realize a TDC with picosecond time resolution as well as multi MGy gamma-dose radiation tolerance, a novel multi-stage noise-shaping (MASH) delta-sigma ({Delta}{Sigma}) TDC structure is proposed. The converter, implemented in 0.13 {mu}m, achieves a time resolution of 5.6 ps and an ENOB of 11 bits, when the over sampling ratio (OSR) is 250. The TDC core consumes only 1.7 mW, and occupies an area of 0.11 mm{sup 2}. Owing to the usage of circuit level radiation hardened-by-design techniques, such as passive RC oscillators and constant-g{sub m} biasing, the TDC exhibits enhanced radiation tolerance. At a low dose rate of 1.2 kGy/h, the frequency of the counting clock in the TDC remains constant up to at least 160 kGy. Even after a total dose of 3.4 MGy at a high dose rate of 30 kGy/h, the TDC still achieves a time resolution of 10.5 ps with an OSR of 250. (authors)

Development of Compton X-ray spectrometer for high energy resolution single-shot high-flux hard X-ray spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Kojima, Sadaoki, E-mail: kojima-s@ile.osaka-u.ac.jp, E-mail: sfujioka@ile.osaka-u.ac.jp; Ikenouchi, Takahito; Arikawa, Yasunobu; Sakata, Shohei; Zhang, Zhe; Abe, Yuki; Nakai, Mitsuo; Nishimura, Hiroaki; Shiraga, Hiroyuki; Fujioka, Shinsuke, E-mail: kojima-s@ile.osaka-u.ac.jp, E-mail: sfujioka@ile.osaka-u.ac.jp; Azechi, Hiroshi [Institute of Laser Engineering, Osaka University, 2-6 Yamada-oka, Suita, Osaka 565-0871 (Japan); Ozaki, Tetsuo [National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu 509-5292 (Japan); Miyamoto, Shuji; Yamaguchi, Masashi; Takemoto, Akinori [Laboratory of Advanced Science and Technology for Industry, University of Hyogo, 3-1-2 Kouto, Kamigori-cho, Ako-gun, Hyogo 678-1205 (Japan)

2016-04-15

Hard X-ray spectroscopy is an essential diagnostics used to understand physical processes that take place in high energy density plasmas produced by intense laser-plasma interactions. A bundle of hard X-ray detectors, of which the responses have different energy thresholds, is used as a conventional single-shot spectrometer for high-flux (>10{sup 13} photons/shot) hard X-rays. However, high energy resolution (Δhv/hv < 0.1) is not achievable with a differential energy threshold (DET) X-ray spectrometer because its energy resolution is limited by energy differences between the response thresholds. Experimental demonstration of a Compton X-ray spectrometer has already been performed for obtaining higher energy resolution than that of DET spectrometers. In this paper, we describe design details of the Compton X-ray spectrometer, especially dependence of energy resolution and absolute response on photon-electron converter design and its background reduction scheme, and also its application to the laser-plasma interaction experiment. The developed spectrometer was used for spectroscopy of bremsstrahlung X-rays generated by intense laser-plasma interactions using a 200 μm thickness SiO{sub 2} converter. The X-ray spectrum obtained with the Compton X-ray spectrometer is consistent with that obtained with a DET X-ray spectrometer, furthermore higher certainly of a spectral intensity is obtained with the Compton X-ray spectrometer than that with the DET X-ray spectrometer in the photon energy range above 5 MeV.

A multichannel time-to-digital converter ASIC with better than 3 ps RMS time resolution

International Nuclear Information System (INIS)

Perktold, L; Christiansen, J

2014-01-01

The development of a new multichannel, fine-time resolution time-to-digital converter (TDC) ASIC is currently under development at CERN. A prototype TDC has been designed, fabricated and successfully verified with demonstrated time resolutions of better than 3 ps-rms. Least-significant-bit (LSB) sizes as small as 5 ps with a differential-non-linearity (DNL) of better than ±0.9 LSB and integral-non-linearity (INL) of better than ±1.3 LSB respectively have been achieved. The contribution describes the implemented architecture and presents measurement results of a prototype ASIC implemented in a commercial 130 nm technology

High-resolution flood modeling of urban areas using MSN_Flood

Directory of Open Access Journals (Sweden)

Michael Hartnett

2017-07-01

Full Text Available Although existing hydraulic models have been used to simulate and predict urban flooding, most of these models are inadequate due to the high spatial resolution required to simulate flows in urban floodplains. Nesting high-resolution subdomains within coarser-resolution models is an efficient solution for enabling simultaneous calculation of flooding due to tides, surges, and high river flows. MSN_Flood has been developed to incorporate moving boundaries around nested domains, permitting alternate flooding and drying along the boundary and in the interior of the domain. Ghost cells adjacent to open boundary cells convert open boundaries, in effect, into internal boundaries. The moving boundary may be multi-segmented and non-continuous, with recirculating flow across the boundary. When combined with a bespoke adaptive interpolation scheme, this approach facilitates a dynamic internal boundary. Based on an alternating-direction semi-implicit finite difference scheme, MSN_Flood was used to hindcast a major flood event in Cork City resulting from the combined pressures of fluvial, tidal, and storm surge processes. The results show that the model is computationally efficient, as the 2-m high-resolution nest is used only in the urban flooded region. Elsewhere, lower-resolution nests are used. The results also show that the model is highly accurate when compared with measured data. The model is capable of incorporating nested sub-domains when the nested boundary is multi-segmented and highly complex with lateral gradients of elevation and velocities. This is a major benefit when modelling urban floodplains at very high resolution.

A high efficiency photovoltaic module integrated converter with the asymmetrical half-bridge flyback converter

Energy Technology Data Exchange (ETDEWEB)

Kim, Heeje; Kim, Jongrak; Shin, Dongsul [Department of Electrical Engineering, Pusan National University, Jangjeon, Geumjeong, Busan 609-735 (Korea); Kim, Hosung; Lee, Kyungjun [Department of Electrical Engineering, Pusan National University, Jangjeon, Geumjeong, Busan 609-735 (Korea); New and Renewable Energy System Research Center, Korea Electro-technology Research Institute, 28-1, Sungju-dong Changwon-si, Kyungsannam-do, 641-120 (Korea); Kim, Jonghyun; Yoo, Dongwook [New and Renewable Energy System Research Center, Korea Electro-technology Research Institute, 28-1, Sungju-dong Changwon-si, Kyungsannam-do, 641-120 (Korea)

2010-08-15

A module integrated converter (MIC) for a photovoltaic (PV) cell is important part of power conditioning system (PCS). It performs maximum power point tracking of a PV cell to generate the power as much as possible from solar energy. There are several methods for connection between the PV modules and the MICs. In order to avoid partial shading effects, converter-per-module approach was proposed. The MIC that performs maximum power point tracking (MPPT), if it is low efficiency, is no use. The MIC whose output is connected to the output of PV module was proposed for high efficiency. However, there are some problems. In this study, an asymmetrical half-bridge flyback converter is proposed instead of the original flyback converter with same method to solve the problems. The proposed MIC was built to verify the performance. The new topology using soft switching technique showed good performance for the efficiency. At the higher power, the efficiency of the proposed converter is higher than existing converter. (author)

High-contrast resolution of film-screen systems in oral and maxillofacial radiology

International Nuclear Information System (INIS)

Kaeppler, G.; Reinert, S.

2007-01-01

Purpose: The aim was to determine differences in high-contrast resolution of film-screen systems used in dental panoramic and cephalometric radiography by calculating the modulation transfer function (MTF). The radiographs used to determine the MTF should be taken by the same X-ray units as those used for patient radiographs. Materials and methods: The MTF was determined using a lead grid and according to DIN 6867 - 2 for 11 film-screen systems (speed 250, speed class 200 and 400) used in dental radiographic diagnostics. The optical density was measured using a microdensitometer developed by PTB. Results: With 10% of the modulation transfer factor, newly developed film-screen systems (speed class 200 and 400) demonstrated a resolution of 4.9 to 6 line pairs per mm (panoramic radiography). In cephalometric radiography a film-screen system (speed class 400 and green-sensitive film) had a resolution of 4.2 line pairs per mm and surpassed two film-screen systems (speed class 400, resolution of 3 line pairs per mm, blue-sensitive films). (orig.)

Pneumocystis carinii pneumonia in acquired immunodeficiency syndrome - correlation of high-resolution computed tomography and anatomopathology

International Nuclear Information System (INIS)

Marchiori, Edson; Moreira, Luiza Beatriz; Capone, Domenico; Moraes, Heleno Pinto de; Pereira, Cyntia Inez Guedes Soares

2001-01-01

We present the main findings observed on the high-resolution computed tomography examinations of 15 patients with acquired immunodeficiency syndrome and Pneumocystis carinii pneumonia. The high-resolution computed tomography and autopsy findings of 5 patients were also compared. The most frequently observed high-resolution computed tomography patterns were ground-glass attenuation, consolidation areas, crazy-paving pattern and cysts. Nodules and intralobular reticulation were less frequently observed. Ground-glass attenuation and consolidation areas corresponded to alveolar filling with inflammatory exudate. Thickening of the interlobular septa was due to cell infiltration and edema. One patient presented interlobular reticulation, and the pathology study revealed alveolar septa thickening due to cell infiltration and fibrosis. Nodules observed in one of the patients corresponded to a patchy intra alveolar accumulation of microorganisms and inflammatory cells forming a 'granulomatous' pattern. (author)

Switching power converters medium and high power

CERN Document Server

Neacsu, Dorin O

2013-01-01

An examination of all of the multidisciplinary aspects of medium- and high-power converter systems, including basic power electronics, digital control and hardware, sensors, analog preprocessing of signals, protection devices and fault management, and pulse-width-modulation (PWM) algorithms, Switching Power Converters: Medium and High Power, Second Edition discusses the actual use of industrial technology and its related subassemblies and components, covering facets of implementation otherwise overlooked by theoretical textbooks. The updated Second Edition contains many new figures, as well as

GOSSIPO-4: an array of high resolution TDCs with a PLL control

NARCIS (Netherlands)

Zappon, F.; van Beuzekom, M.; Gromov, V.; Kluit, R.; Fang, X.; Kruth, A.

2012-01-01

GOSSIPO-4 is a prototype chip featuring an array of high resolution Time to Digital Converters with a PLL control that has been taped out the 9th of August 2011. This prototype is the successor of GOSSIPO-3 test chip and the precursor of the 65k pixel chip TimePix3. The prototype is being developed

Structure elucidation and quantification of impurities formed between 6-aminocaproic acid and the excipients citric acid and sorbitol in an oral solution using high-resolution mass spectrometry and nuclear magnetic resonance spectroscopy.

Science.gov (United States)

Schou-Pedersen, Anne Marie V; Cornett, Claus; Nyberg, Nils; Østergaard, Jesper; Hansen, Steen Honoré

2015-03-25

Concentrated solutions containing 6-aminocaproic acid and the excipients citric acid and sorbitol have been studied at temperatures of 50°C, 60°C, 70°C and 80°C as well as at 20°C. It has previously been reported that the commonly employed citric acid is a reactive excipient, and it is therefore important to thoroughly investigate a possible reaction between 6-aminocaproic acid and citric acid. The current study revealed the formation of 3-hydroxy-3,4-dicarboxy-butanamide-N-hexanoic acid between 6-aminocaproic acid and citric acid by high-resolution mass spectrometry (HRMS) and nuclear magnetic resonance spectroscopy (NMR). Less than 0.03% of 6-aminocaproic acid was converted to 3-hydroxy-3,4-dicarboxy-butanamide-N-hexanoic acid after 30 days of storage at 80°C. Degradation products of 6-aminocaproic acid were also observed after storage at the applied temperatures, e.g., dimer, trimer and cyclized 6-aminocaproic acid, i.e., caprolactam. No reaction products between D-sorbitol and 6-aminocaproic acid could be observed. 3-Hydroxy-3,4-dicarboxy-butanamide-N-hexanoic acid, dimer and caprolactam were also observed after storage at 20°C for 3 months. The findings imply that an oral solution of 6-aminocaproic acid is relatively stable at 20°C at the pH values 4.00 and 5.00 as suggested in the USP for oral formulations. Compliance with the ICH guideline Q3B is expected. Copyright © 2015 Elsevier B.V. All rights reserved.

Towards a versatile active wavelength converter for all-optical networks based on quasi-phase matched intra-cavity difference-frequency generation.

Science.gov (United States)

Torregrosa, Adrián J; Maestre, Haroldo; Capmany, Juan

2013-11-18

The availability of reconfigurable all-optical wavelength converters for an efficient and flexible use of optical resources in WDM (wavelength division multiplexing) networks is still lacking at present. We propose and report preliminary results on a versatile active technique for multiple and tunable wavelength conversions in the 1500-1700 nm spectral region. The technique is based on combining broadband quasi-phase matched intra-cavity parametric single-pass difference-frequency generation close to degeneracy in a diode-pumped tunable laser. A periodically poled stoichiometric lithium tantalate crystal is used as the nonlinear medium, with a parametric pump wave generated in a continuous-wave self-injection locked Cr3+:LiCAF tunable laser operating at around 800 nm.

Efficient Wide Range Converters (EWiRaC): A new family of high efficient AC-DC Converters

DEFF Research Database (Denmark)

Petersen, Lars; Andersen, Michael Andreas E.

2006-01-01

The performance in terms of efficiency of the existing power supplies used for PFC is very dependent on the input voltage range. The boost converter is the most commonly used PFC converter because of its simplicity and high efficiency. But, the boost converter as well as other known converters...... suffers a major penalty in efficiency when used at the low end of the voltage range (90VAC) in a universal voltage range application (90-270VAC). This paper addresses this problem by suggesting a new family of converters that effectively reduces the apparent voltage range with a factor of 2 by changing...... the converter topology according to the input voltage. This new converter type has been named: efficient wide range converter (EWiRaC). The performance of the EWiRaC is experimental verified in a universal input range (90-270VAC) application with an output voltage of 185VDC capable of 500W output power. The EWi...

A high-switching-frequency flyback converter in resonant mode

NARCIS (Netherlands)

Li, Jianting; van Horck, Frank B.M.; Daniel, Bobby J.; Bergveld, Henk Jan

2017-01-01

The demand of miniaturization of power systems has accelerated the research on high-switching-frequency power converters. A flyback converter in resonant mode that features low switching losses, less transformer losses, and low switching noise at high switching frequency is investigated in this

Switching transients in high-frequency high-power converters using power MOSFET's

Science.gov (United States)

Sloane, T. H.; Owen, H. A., Jr.; Wilson, T. G.

1979-01-01

The use of MOSFETs in a high-frequency high-power dc-to-dc converter is investigated. Consideration is given to the phenomena associated with the paralleling of MOSFETs and to the effect of stray circuit inductances on the converter circuit performance. Analytical relationships between various time constants during the turning-on and turning-off intervals are derived which provide estimates of plateau and peak levels during these intervals.

Study on a Novel High-Efficiency Bridgeless PFC Converter

Directory of Open Access Journals (Sweden)

Cao Taiqiang

2014-01-01

Full Text Available In order to implement a high-efficiency bridgeless power factor correction converter, a new topology and operation principles of continuous conduction mode (CCM and DC steady-state character of the converter are analyzed, which show that the converter not only has bipolar-gain characteristic but also has the same characteristic as the traditional Boost converter, while the voltage transfer ratio is not related with the resonant branch parameters and switching frequency. Based on the above topology, a novel bridgeless Bipolar-Gain Pseudo-Boost PFC converter is proposed. With this converter, the diode rectifier bridge of traditional AC-DC converter is eliminated, and zero-current switching of fast recovery diode is achieved. Thus, the efficiency is improved. Next, we also propose the one-cycle control policy of this converter. Finally, experiments are provided to verify the accuracy and feasibility of the proposed converter.

Ultra-high Efficiency DC-DC Converter using GaN Devices

DEFF Research Database (Denmark)

Ramachandran, Rakesh

2016-01-01

properties of GaN devices can be utilized in power converters to make them more compact and highly efficient. This thesis entitled “Ultra-high Efficiency DC-DC Converter using GaN devices” focuses on achieving ultra-high conversion efficiency in an isolated dc-dc converter by the optimal utilization of Ga...... for many decades. However, the rate of improvement slowed as the silicon power materials asymptotically approached its theoretical bounds. Compared to Si, wideband gap materials such as Silicon Carbide (SiC) and Gallium Nitride (GaN) are promising semiconductors for power devices due to their superior...... in this thesis. Efficiency measurements from the hardware prototype of both the topologies are also presented in this thesis. Finally, the bidirectional operation of an optimized isolated dc-dc converter is presented. The optimized converter has achieved an ultra-high efficiency of 98.8% in both directions...

Self-oscillating Galvanic Isolated Bidirectional Very High Frequency DC-DC Converter

DEFF Research Database (Denmark)

Pedersen, Jeppe Arnsdorf; Madsen, Mickey Pierre; Knott, Arnold

2015-01-01

This paper describes a galvanic isolated bidirectional Very High Frequency (VHF = 30 MHz - 300MHz) ClassE converter. The reason for increasing the switching frequency is to minimize the passive components in the converter. To make the converter topology bidirectional the rectifier has to be synch......This paper describes a galvanic isolated bidirectional Very High Frequency (VHF = 30 MHz - 300MHz) ClassE converter. The reason for increasing the switching frequency is to minimize the passive components in the converter. To make the converter topology bidirectional the rectifier has...

Super-resolution processing for pulsed neutron imaging system using a high-speed camera

International Nuclear Information System (INIS)

Ishizuka, Ken; Kai, Tetsuya; Shinohara, Takenao; Segawa, Mariko; Mochiki, Koichi

2015-01-01

Super-resolution and center-of-gravity processing improve the resolution of neutron-transmitted images. These processing methods calculate the center-of-gravity pixel or sub-pixel of the neutron point converted into light by a scintillator. The conventional neutron-transmitted image is acquired using a high-speed camera by integrating many frames when a transmitted image with one frame is not provided. It succeeds in acquiring the transmitted image and calculating a spectrum by integrating frames of the same energy. However, because a high frame rate is required for neutron resonance absorption imaging, the number of pixels of the transmitted image decreases, and the resolution decreases to the limit of the camera performance. Therefore, we attempt to improve the resolution by integrating the frames after applying super-resolution or center-of-gravity processing. The processed results indicate that center-of-gravity processing can be effective in pulsed-neutron imaging with a high-speed camera. In addition, the results show that super-resolution processing is effective indirectly. A project to develop a real-time image data processing system has begun, and this system will be used at J-PARC in JAEA. (author)

Very High Frequency Half Bridge DC/DC Converter

DEFF Research Database (Denmark)

Madsen, Mickey Pierre; Knott, Arnold; Andersen, Michael A. E.

2014-01-01

This paper presents the first, off chip, class DE (resonant half bridge) converter working in the Very High Frequency (VHF) range. The benefits of using half bridge circuits both in the inverter and rectifier part of a VHF resonant dc/dc converter are analyzed and design equations for all...

Low cost time to digital converter in real time with +-1 ns resolution

Energy Technology Data Exchange (ETDEWEB)

Lenzi, G; Podini, P; Reverberi, R [Parma Univ. (Italy). Istituto di Fisica; Pernestaal, K [Uppsala Univ. (Sweden). Fysiska Institutionen

1977-04-15

A time to digital converter (TDC) with a time resolution of 1 ns has been designed. The deadtime is T+0.6 ..mu..s where T is the measured time. The time range can be preselected between 0.3 and 10 ..mu..s. The TDC has one START and three mutually exclusive STOP inputs which accept standard pulses (-16 mA). The time information is presented as a bit binary word, including the activated stop input address. The instrument has been successfully used in ..mu../sup +/SR (muon spin rotation) measurements and has proven itself advantageous over the more common TAC+ADC combination.

Analysis of transistor and snubber turn-off dynamics in high-frequency high-voltage high-power converters

Science.gov (United States)

Wilson, P. M.; Wilson, T. G.; Owen, H. A., Jr.

Dc to dc converters which operate reliably and efficiently at switching frequencies high enough to effect substantial reductions in the size and weight of converter energy storage elements are studied. A two winding current or voltage stepup (buck boost) dc-to-dc converter power stage submodule designed to operate in the 2.5-kW range, with an input voltage range of 110 to 180 V dc, and an output voltage of 250 V dc is emphasized. In order to assess the limitations of present day component and circuit technologies, a design goal switching frequency of 10 kHz was maintained. The converter design requirements represent a unique combination of high frequency, high voltage, and high power operation. The turn off dynamics of the primary circuit power switching transistor and its associated turn off snubber circuitry are investigated.

High-precision performance testing of the LHC power converters

CERN Document Server

Bastos, M; Dreesen, P; Fernqvist, G; Fournier, O; Hudson, G

2007-01-01

The magnet power converters for LHC were procured in three parts, power part, current transducers and control electronics, to enable a maximum of industrial participation in the manufacturing and still guarantee the very high precision (a few parts in 10-6) required by LHC. One consequence of this approach was several stages of system tests: factory reception tests, CERN reception tests, integration tests , short-circuit tests and commissioning on the final load in the LHC tunnel. The majority of the power converters for LHC have now been delivered, integrated into complete converter and high-precision performance testing is well advanced. This paper presents the techniques used for high-precision testing and the results obtained.

Radiography of oral cavity disorders [dentistry, stomatology

International Nuclear Information System (INIS)

Hennet, P.

1995-01-01

Radiographic examination in odonto-stomatology can he made easier by using intra-oral dental films and a dental X-ray machine. Parallel and bissecting angle techniques allow X-ray pictures to be taken with intra-and extra-oral films. Radiography provides information for diagnosis but it also allows the evaluation of dental treatments

A refined, rapid and reproducible high resolution melt (HRM-based method suitable for quantification of global LINE-1 repetitive element methylation

Directory of Open Access Journals (Sweden)

Tse M Yat

2011-12-01

Full Text Available Abstract Background The methylation of DNA is recognized as a key mechanism in the regulation of genomic stability and evidence for its role in the development of cancer is accumulating. LINE-1 methylation status represents a surrogate measure of genome-wide methylation. Findings Using high resolution melt (HRM curve analysis technology, we have established an in-tube assay that is linear (r > 0.9986 with a high amplification efficiency (90-105%, capable of discriminating between partcipant samples with small differences in methylation, and suitable for quantifying a wide range of LINE-1 methylation levels (0-100%--including the biologically relevant range of 50-90% expected in human DNA. We have optimized this procedure to perform using 2 μg of starting DNA and 2 ng of bisulfite-converted DNA for each PCR reaction. Intra- and inter-assay coefficients of variation were 1.44% and 0.49%, respectively, supporting the high reproducibility and precision of this approach. Conclusions In summary, this is a completely linear, quantitative HRM PCR method developed for the measurement of LINE-1 methylation. This cost-efficient, refined and reproducible assay can be performed using minimal amounts of starting DNA. These features make our assay suitable for high throughput analysis of multiple samples from large population-based studies.

Outcomes and challenges of global high-resolution non-hydrostatic atmospheric simulations using the K computer

Science.gov (United States)

Satoh, Masaki; Tomita, Hirofumi; Yashiro, Hisashi; Kajikawa, Yoshiyuki; Miyamoto, Yoshiaki; Yamaura, Tsuyoshi; Miyakawa, Tomoki; Nakano, Masuo; Kodama, Chihiro; Noda, Akira T.; Nasuno, Tomoe; Yamada, Yohei; Fukutomi, Yoshiki

2017-12-01

This article reviews the major outcomes of a 5-year (2011-2016) project using the K computer to perform global numerical atmospheric simulations based on the non-hydrostatic icosahedral atmospheric model (NICAM). The K computer was made available to the public in September 2012 and was used as a primary resource for Japan's Strategic Programs for Innovative Research (SPIRE), an initiative to investigate five strategic research areas; the NICAM project fell under the research area of climate and weather simulation sciences. Combining NICAM with high-performance computing has created new opportunities in three areas of research: (1) higher resolution global simulations that produce more realistic representations of convective systems, (2) multi-member ensemble simulations that are able to perform extended-range forecasts 10-30 days in advance, and (3) multi-decadal simulations for climatology and variability. Before the K computer era, NICAM was used to demonstrate realistic simulations of intra-seasonal oscillations including the Madden-Julian oscillation (MJO), merely as a case study approach. Thanks to the big leap in computational performance of the K computer, we could greatly increase the number of cases of MJO events for numerical simulations, in addition to integrating time and horizontal resolution. We conclude that the high-resolution global non-hydrostatic model, as used in this five-year project, improves the ability to forecast intra-seasonal oscillations and associated tropical cyclogenesis compared with that of the relatively coarser operational models currently in use. The impacts of the sub-kilometer resolution simulation and the multi-decadal simulations using NICAM are also reviewed.

Intravenous versus oral etoposide

DEFF Research Database (Denmark)

Ali, Abir Salwa; Grönberg, Malin; Langer, Seppo W.

2018-01-01

High-grade gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs, G3) are aggressive cancers of the digestive system with poor prognosis and survival. Platinum-based chemotherapy (cisplatin/carboplatin + etoposide) is considered the first-line palliative treatment. Etoposide is frequently...... administered intravenously; however, oral etoposide may be used as an alternative. Concerns for oral etoposide include decreased bioavailability, inter- and intra-patient variability and patient compliance. We aimed to evaluate possible differences in progression-free survival (PFS) and overall survival (OS......) in patients treated with oral etoposide compared to etoposide given as infusion. Patients (n = 236) from the Nordic NEC study were divided into three groups receiving etoposide as a long infusion (24 h, n = 170), short infusion (≤ 5 h, n = 33) or oral etoposide (n = 33) according to hospital tradition. PFS...

Intra-operative mapping of the atria: the first step towards individualization of atrial fibrillation therapy?

Science.gov (United States)

Kik, Charles; Mouws, Elisabeth M J P; Bogers, Ad J J C; de Groot, Natasja M S

2017-07-01

Atrial fibrillation (AF), an age-related progressive disease, is becoming a worldwide epidemic with a prevalence rate of 33 million. Areas covered: In this expert review, an overview of important results obtained from previous intra-operative mapping studies is provided. In addition, our novel intra-operative high resolution mapping studies, its surgical considerations and data analyses are discussed. Furthermore, the importance of high resolution mapping studies of both sinus rhythm and AF for the development of future AF therapy is underlined by our most recent results. Expert commentary: Progression of AF is determined by the extensiveness of electropathology which is defined as conduction disorders caused by structural damage of atrial tissue. The severity of electropathology is a major determinant of therapy failure. At present, we do not have any diagnostic tool to determine the degree of electropathology in the individual patient and we can thus not select the most optimal treatment modality for the individual patient. An intra-operative, high resolution scale, epicardial mapping approach combined with quantification of electrical parameters may serve as a diagnostic tool to stage AF in the individual patient and to provide patient tailored therapy.

Clinically Detectable Dental Identifiers Observed in Intra-oral Photographs and Extra-oral Radiographs, Validated for Human Identification Purposes.

Science.gov (United States)

Angelakopoulos, Nikolaos; Franco, Ademir; Willems, Guy; Fieuws, Steffen; Thevissen, Patrick

2017-07-01

Screening the prevalence and pattern of dental identifiers contributes toward the process of human identification. This research investigated the uniqueness of clinical dental identifiers in photographs and radiographs. Panoramic and lateral cephalometric radiographs and five intra-oral photographs of 1727 subjects were used. In a target set, two observers examined different subjects. In a subset, both observers examined the same subjects (source set). The distance between source and target subjects was quantified for each identifier. The percentage of subjects in the target set being at least as close as the correct subject was assessed. The number of molars (34.6%), missing teeth (42%), and displaced teeth (59.9%) were the most unique identifiers in photographs and panoramic and lateral cephalometric radiographs, respectively. The pattern of rotated teeth (14.9%) was the most unique in photographs, while displaced teeth was in panoramic (37.6%) and lateral cephalometric (54.8%) radiographs. Morphological identifiers were the most unique, highlighting their importance for human identifications. © 2016 American Academy of Forensic Sciences.

High-Feedback Operation of Power Electronic Converters

Directory of Open Access Journals (Sweden)

Gennady Y. Mikhal'chenko

2013-03-01

Full Text Available The purpose of this review is to provide a survey of some of the most important bifurcation phenomena that one can observe in pulse-modulated converter systems when operating with high corrector gain factors. Like other systems with switching control, electronic converter systems belong to the class of piecewise-smooth dynamical systems. A characteristic feature of such systems is that the trajectory is “sewed” together from subsequent discrete parts. Moreover, the transitions between different modes of operation in response to a parameter variation are often qualitatively different from the bifurcations we know for smooth systems. The review starts with an introduction to the concept of border-collision bifurcations and also demonstrates the approach by which the full dynamics of the piecewise-linear, time-continuous system can be reduced to the dynamics of a piecewise-smooth map. We describe the main bifurcation structures that one observes in three different types of converter systems: (1 a DC/DC converter; (2 a multi-level DC/DC converter; and (3 a DC/AC converter. Our focus will be on the bifurcations by which the regular switching dynamics becomes unstable and is replaced by ergodic or resonant periodic dynamics on the surface of a two-dimensional torus. This transition occurs when the feedback gain is increased beyond a certain threshold, for instance in Electronics 2013, 2 114 order to improve the speed and accuracy of the output voltage regulation. For each of the three converter types, we discuss a number of additional bifurcation phenomena, including the formation and reconstruction of multi-layered tori and the appearance of phase-synchronized quasiperiodicity. Our numerical simulations are compared with experimentally observed waveforms.

Low power very high frequency resonant converter with high step down ratio

DEFF Research Database (Denmark)

Madsen, Mickey Pierre; Knott, Arnold; Andersen, Michael A. E.

2013-01-01

This paper presents the design of a resonant converter with a switching frequency in the very high frequency range (30-300MHz), a large step down ratio and low output power. This gives the designed converters specifications which are far from previous results. The class E inverter and rectifier...

A column level, low power, 1 M sample/s double ramp A/D converter for monolithic active pixel sensors in high energy physics

International Nuclear Information System (INIS)

Pillet, N.; Heini, S.; Hu, Y.

2010-01-01

Monolithic active pixel sensors (MAPS) using standard low cost CMOS technologies available from industrial manufacturers have demonstrated excellent tracking performances for minimum ionizing particles. The need for highly granular, fast, thin sensors with a full digital output drives an R and D effort, aiming to design and optimize a low power high speed A/D converter integrated at the column level. Following this main issue, a double digital ramp A/D converter has been proposed for CMOS monolithic active pixel sensors in this paper. This A/D converter responds to the constraints of size, power dissipation and precision for CMOS sensors for particle detection. It also represents a first step in order to reach the high speed of conversion needed for this kind of application. The A/D converter has a resolution of 4 bits for conversion speed of 1 M sample/s with only 264 μW of static consumption in a very particular pitch of 25 μmx900 μm.

Error-Free Text Typing Performance of an Inductive Intra-Oral Tongue Computer Interface for Severely Disabled Individuals.

Science.gov (United States)

Andreasen Struijk, Lotte N S; Bentsen, Bo; Gaihede, Michael; Lontis, Eugen R

2017-11-01

For severely paralyzed individuals, alternative computer interfaces are becoming increasingly essential for everyday life as social and vocational activities are facilitated by information technology and as the environment becomes more automatic and remotely controllable. Tongue computer interfaces have proven to be desirable by the users partly due to their high degree of aesthetic acceptability, but so far the mature systems have shown a relatively low error-free text typing efficiency. This paper evaluated the intra-oral inductive tongue computer interface (ITCI) in its intended use: Error-free text typing in a generally available text editing system, Word. Individuals with tetraplegia and able bodied individuals used the ITCI for typing using a MATLAB interface and for Word typing for 4 to 5 experimental days, and the results showed an average error-free text typing rate in Word of 11.6 correct characters/min across all participants and of 15.5 correct characters/min for participants familiar with tongue piercings. Improvements in typing rates between the sessions suggest that typing ratescan be improved further through long-term use of the ITCI.

Research on high power intra-channel crosstalk attack in optical networks

Science.gov (United States)

Ren, Shuai; Zhang, Yinfa; Wang, Jingyu; Zhang, Jumei; Rao, Xuejun; Fang, Yuanyuan

2017-02-01

The mechanism of high power intra-channel crosstalk attack is analyzed theoretically and the conclusion that power of attack signal and crosstalk coefficient of optical switch are the main factors for which high power intra-channel have destructive effect on quality of legitimate signals is drawn. Effects of high power intra-channel crosstalk attack on quality of legitimate signals and its capability of attack propagation are investigated quantitatively by building the simulation system in VPI software. The results show that legitimate signals through the first and the second stage optical switch are affected by attack and legitimate signal through the third stage optical switch is almost unaffected by attack when power of original attack signal (OAS) is above 20dB more than that of legitimate signals and crosstalk coefficient of optical switch is -20dB at optical cross connect 1 (OXC1). High power intra-channel crosstalk attack has a certain capability of attack propagation. Attack capability of OAS can be propagated to OXC3 when power of OAS is 27dB more than that of legitimate signals and crosstalk coefficient of optical switch is -20dB. We also find that the secondary attack signal (SAS) does not have capability of attack propagation.

Accuracy assessment of high frequency 3D ultrasound for digital impression-taking of prepared teeth

Science.gov (United States)

Heger, Stefan; Vollborn, Thorsten; Tinschert, Joachim; Wolfart, Stefan; Radermacher, Klaus

2013-03-01

Silicone based impression-taking of prepared teeth followed by plaster casting is well-established but potentially less reliable, error-prone and inefficient, particularly in combination with emerging techniques like computer aided design and manufacturing (CAD/CAM) of dental prosthesis. Intra-oral optical scanners for digital impression-taking have been introduced but until now some drawbacks still exist. Because optical waves can hardly penetrate liquids or soft-tissues, sub-gingival preparations still need to be uncovered invasively prior to scanning. High frequency ultrasound (HFUS) based micro-scanning has been recently investigated as an alternative to optical intra-oral scanning. Ultrasound is less sensitive against oral fluids and in principal able to penetrate gingiva without invasively exposing of sub-gingival preparations. Nevertheless, spatial resolution as well as digitization accuracy of an ultrasound based micro-scanning system remains a critical parameter because the ultrasound wavelength in water-like media such as gingiva is typically smaller than that of optical waves. In this contribution, the in-vitro accuracy of ultrasound based micro-scanning for tooth geometry reconstruction is being investigated and compared to its extra-oral optical counterpart. In order to increase the spatial resolution of the system, 2nd harmonic frequencies from a mechanically driven focused single element transducer were separated and corresponding 3D surface models were calculated for both fundamentals and 2nd harmonics. Measurements on phantoms, model teeth and human teeth were carried out for evaluation of spatial resolution and surface detection accuracy. Comparison of optical and ultrasound digital impression taking indicate that, in terms of accuracy, ultrasound based tooth digitization can be an alternative for optical impression-taking.

Two phase interleaved buck converter for driving high power LEDs

DEFF Research Database (Denmark)

Beczkowski, Szymon; Munk-Nielsen, Stig

2011-01-01

The goal of this paper is to evaluate an interleaved buck topology for driving high current light-emitting diodes. Low output capacitor value allows the use of non-electrolytic capacitors extending the lifetime of the converter. Converter is operated as a constant, regulated current source which...... increases luminous efficacy of LED compared to PWM dimmed system. Because of the low dynamic resistance of LEDs the duty cycle of the converter does not change greatly with controlled current. By setting the input voltage of the buck converter to around twice the voltage of diode strings, converter can...

High-resolution crystal structures of Drosophila melanogaster angiotensin-converting enzyme in complex with novel inhibitors and antihypertensive drugs.

Science.gov (United States)

Akif, Mohd; Georgiadis, Dimitris; Mahajan, Aman; Dive, Vincent; Sturrock, Edward D; Isaac, R Elwyn; Acharya, K Ravi

2010-07-16

Angiotensin I-converting enzyme (ACE), one of the central components of the renin-angiotensin system, is a key therapeutic target for the treatment of hypertension and cardiovascular disorders. Human somatic ACE (sACE) has two homologous domains (N and C). The N- and C-domain catalytic sites have different activities toward various substrates. Moreover, some of the undesirable side effects of the currently available and widely used ACE inhibitors may arise from their targeting both domains leading to defects in other pathways. In addition, structural studies have shown that although both these domains have much in common at the inhibitor binding site, there are significant differences and these are greater at the peptide binding sites than regions distal to the active site. As a model system, we have used an ACE homologue from Drosophila melanogaster (AnCE, a single domain protein with ACE activity) to study ACE inhibitor binding. In an extensive study, we present high-resolution structures for native AnCE and in complex with six known antihypertensive drugs, a novel C-domain sACE specific inhibitor, lisW-S, and two sACE domain-specific phosphinic peptidyl inhibitors, RXPA380 and RXP407 (i.e., nine structures). These structures show detailed binding features of the inhibitors and highlight subtle changes in the orientation of side chains at different binding pockets in the active site in comparison with the active site of N- and C-domains of sACE. This study provides information about the structure-activity relationships that could be utilized for designing new inhibitors with improved domain selectivity for sACE. 2010 Elsevier Ltd. All rights reserved.

High Efficiency Reversible Fuel Cell Power Converter

DEFF Research Database (Denmark)

Pittini, Riccardo

as well as different dc-ac and dc-dc converter topologies are presented and analyzed. A new ac-dc topology for high efficiency data center applications is proposed and an efficiency characterization based on the fuel cell stack I-V characteristic curve is presented. The second part discusses the main...... converter components. Wide bandgap power semiconductors are introduced due to their superior performance in comparison to traditional silicon power devices. The analysis presents a study based on switching loss measurements performed on Si IGBTs, SiC JFETs, SiC MOSFETs and their respective gate drivers...

High-feedback Operation of Power Electronic Converters

DEFF Research Database (Denmark)

Zhusubaliyev, Zhanybai T.; Mosekilde, Erik; Andriyanov, Alexey I.

2013-01-01

The purpose of this review is to provide a survey of some of the most important bifurcation phenomena that one can observe in pulse-modulated converter systems when operating with high corrector gain factors. Like other systems with switching control, electronic converter systems belong...... to the class of piecewise-smooth dynamical systems. A characteristic feature of such systems is that the trajectory is “sewed” together from subsequent discrete parts. Moreover, the transitions between different modes of operation in response to a parameter variation are often qualitatively different from...

Multi-Port High Voltage Gain Modular Power Converter for Offshore Wind Farms

Directory of Open Access Journals (Sweden)

Sen Song

2018-06-01

Full Text Available In high voltage direct current (HVDC power transmission of offshore wind power systems, DC/DC converters are applied to transfer power from wind generators to HVDC terminals, and they play a crucial role in providing a high voltage gain, high efficiency, and high fault tolerance. This paper introduces an innovative multi-port DC/DC converter with multiple modules connected in a scalable matrix configuration, presenting an ultra-high voltage step-up ratio and low voltage/current rating of components simultaneously. Additionally, thanks to the adoption of active clamping current-fed push–pull (CFPP converters as sub-modules (SMs, soft-switching is obtained for all power switches, and the currents of series-connected CFPP converters are auto-balanced, which significantly reduce switching losses and control complexity. Furthermore, owing to the expandable matrix structure, the output voltage and power of a modular converter can be controlled by those of a single SM, or by adjusting the column and row numbers of the matrix. High control flexibility improves fault tolerance. Moreover, due to the flexible control, the proposed converter can transfer power directly from multiple ports to HVDC terminals without bus cable. In this paper, the design of the proposed converter is introduced, and its functions are illustrated by simulation results.

Extra-oral halitosis : an overview

NARCIS (Netherlands)

Tangerman, A.; Winkel, E. G.

Halitosis can be subdivided into intra-oral and extra-oral halitosis, depending on the place where it originates. Most reports now agree that the most frequent sources of halitosis exist within the oral cavity and include bacterial reservoirs such as the dorsum of the tongue, saliva and periodontal

Developing Local Scale, High Resolution, Data to Interface with Numerical Storm Models

Science.gov (United States)

Witkop, R.; Becker, A.; Stempel, P.

2017-12-01

High resolution, physical storm models that can rapidly predict storm surge, inundation, rainfall, wind velocity and wave height at the intra-facility scale for any storm affecting Rhode Island have been developed by Researchers at the University of Rhode Island's (URI's) Graduate School of Oceanography (GSO) (Ginis et al., 2017). At the same time, URI's Marine Affairs Department has developed methods that inhere individual geographic points into GSO's models and enable the models to accurately incorporate local scale, high resolution data (Stempel et al., 2017). This combination allows URI's storm models to predict any storm's impacts on individual Rhode Island facilities in near real time. The research presented here determines how a coastal Rhode Island town's critical facility managers (FMs) perceive their assets as being vulnerable to quantifiable hurricane-related forces at the individual facility scale and explores methods to elicit this information from FMs in a format usable for incorporation into URI's storm models.

[High-contrast resolution of film-screen systems in oral and maxillofacial radiology].

Science.gov (United States)

Kaeppler, G; Reinert, S

2007-11-01

The aim was to determine differences in high-contrast resolution of film-screen systems used in dental panoramic and cephalometric radiography by calculating the modulation transfer function (MTF). The radiographs used to determine the MTF should be taken by the same x-ray units as those used for patient radiographs. The MTF was determined using a lead grid and according to DIN 6867-2 for 11 film-screen systems (speed 250, speed class 200 and 400) used in dental radiographic diagnostics. The optical density was measured using a microdensitometer developed by PTB. With 10% of the modulation transfer factor, newly developed film-screen systems (speed class 200 and 400) demonstrated a resolution of 4.9 to 6 line pairs per mm (panoramic radiography). In cephalometric radiography a film-screen system (speed class 400 and green-sensitive film) had a resolution of 4.2 line pairs per mm and surpassed two film-screen systems (speed class 400, resolution of 3 line pairs per mm, blue-sensitive films). The relevance of this study is underlined by the diagnostic reference doses defined in the German X-ray Ordinance (RöV) which are also intended for dentistry. Film-screen systems (speed 250, speed class 200) previously used in dental panoramic and cephalometric radiography can be replaced by newly developed film-screen systems (speed class 400). In dental radiography dose reductions are possible with film-screen systems (speed class 400) without impairing diagnostic accuracy. The introduction of newly developed film-screen systems (speed class 400) requires lower milliampere-seconds and therefore an adjustment of the x-ray units to lower milliampere settings.

Measurement of spectra for intra-oral X-ray beams using biological materials as attenuator

International Nuclear Information System (INIS)

Zenóbio, Madelon A.F.; Nogueira-Tavares, Maria S.; Zenóbio, Elton G.; Squair, Peterson Lima; Santos, Marcus A.P.; Silva, Teógenes A. da

2011-01-01

In diagnostic radiology, the radiation interaction probability in matter is a strong function of the X-ray energy. The knowledge of the X-ray energy spectral distribution allows optimizing the radiographic imaging system in order to obtain high quality images with as low as reasonably achievable patient doses. In this study, transmitted X-ray spectra through dentin and enamel that are existing materials in intra-oral radiology were experimentally determined in an X-ray equipment with 40–70 kV variable range. Dentin and enamel samples with 0.4–3.8 and 0.6–2.6 mm thick were used as attenuators. X-ray transmitted spectra were measured with XR-100T model CdTe detector and half-value layers (HVL) were determined. Characteristics of both dentin and enamel transmitted spectra showed that they have differences in the penetration power in matter and in the spectrum distribution. The results will be useful for phantom developments based on dentin and enamel for image quality control in dental radiology. - Highlights: ► The X-ray energy spectral distribution, optimize the radiographic imaging system. Transmitted X-ray spectra through dentin and enamel were experimentally determined. X-ray transmitted spectra were measured (XR-100T model CdTe detector). The transmitted spectra showed differences in the penetration power and spectrum distribution. Dentin and enamel transmitted spectra will be useful for phantom developments.

High-resolution X-ray television and high-resolution video recorders

International Nuclear Information System (INIS)

Haendle, J.; Horbaschek, H.; Alexandrescu, M.

1977-01-01

The improved transmission properties of the high-resolution X-ray television chain described here make it possible to transmit more information per television image. The resolution in the fluoroscopic image, which is visually determined, depends on the dose rate and the inertia of the television pick-up tube. This connection is discussed. In the last few years, video recorders have been increasingly used in X-ray diagnostics. The video recorder is a further quality-limiting element in X-ray television. The development of function patterns of high-resolution magnetic video recorders shows that this quality drop may be largely overcome. The influence of electrical band width and number of lines on the resolution in the X-ray television image stored is explained in more detail. (orig.) [de

Digital control of high-frequency switched-mode power converters

CERN Document Server

Corradini, Luca; Mattavelli, Paolo; Zane, Regan

This book is focused on the fundamental aspects of analysis, modeling and design of digital control loops around high-frequency switched-mode power converters in a systematic and rigorous manner Comprehensive treatment of digital control theory for power converters Verilog and VHDL sample codes are provided Enables readers to successfully analyze, model, design, and implement voltage, current, or multi-loop digital feedback loops around switched-mode power converters Practical examples are used throughout the book to illustrate applications of the techniques developed Matlab examples are also

High Voltage Bi-directional Flyback Converter for Capacitive Actuator

DEFF Research Database (Denmark)

Thummala, Prasanth; Zhang, Zhe; Andersen, Michael A. E.

2013-01-01

in the converter, including the most dominating parameters of the high voltage transformer viz., self-capacitance and leakage inductance. The specific capacitive load for this converter is a dielectric electro active polymer (DEAP) actuator, which can be used as an effective replacement for conventional actuators...... in a number of applications. In this paper, the discharging energy efficiency definition is introduced. The proposed converter has been experimentally tested with the film capacitive load and the DEAP actuator, and the experimental results are shown together with the efficiency measurements....

Spline-based high-accuracy piecewise-polynomial phase-to-sinusoid amplitude converters.

Science.gov (United States)

Petrinović, Davor; Brezović, Marko

2011-04-01

We propose a method for direct digital frequency synthesis (DDS) using a cubic spline piecewise-polynomial model for a phase-to-sinusoid amplitude converter (PSAC). This method offers maximum smoothness of the output signal. Closed-form expressions for the cubic polynomial coefficients are derived in the spectral domain and the performance analysis of the model is given in the time and frequency domains. We derive the closed-form performance bounds of such DDS using conventional metrics: rms and maximum absolute errors (MAE) and maximum spurious free dynamic range (SFDR) measured in the discrete time domain. The main advantages of the proposed PSAC are its simplicity, analytical tractability, and inherent numerical stability for high table resolutions. Detailed guidelines for a fixed-point implementation are given, based on the algebraic analysis of all quantization effects. The results are verified on 81 PSAC configurations with the output resolutions from 5 to 41 bits by using a bit-exact simulation. The VHDL implementation of a high-accuracy DDS based on the proposed PSAC with 28-bit input phase word and 32-bit output value achieves SFDR of its digital output signal between 180 and 207 dB, with a signal-to-noise ratio of 192 dB. Its implementation requires only one 18 kB block RAM and three 18-bit embedded multipliers in a typical field-programmable gate array (FPGA) device. © 2011 IEEE

Application of digital control techniques for satellite medium power DC-DC converters

Science.gov (United States)

Skup, Konrad R.; Grudzinski, Pawel; Nowosielski, Witold; Orleanski, Piotr; Wawrzaszek, Roman

2010-09-01

The objective of this paper is to present a work concerning a digital control loop system for satellite medium power DC-DC converters that is done in Space Research Centre. The whole control process of a described power converter bases on a high speed digital signal processing. The paper presents a development of a FPGA digital controller for voltage mode stabilization that was implemented using VHDL. The described controllers are a classical digital PID controller and a bang-bang controller. The used converter for testing is a simple model of 5-20 W, 200 kHz buck power converter. A high resolution digital PWM approach is presented. Additionally a simple and effective solution of filtering of an analog-to-digital converter output is presented.

Laser-induced local activation of Mg-doped GaN with a high lateral resolution for high power vertical devices

Science.gov (United States)

Kurose, Noriko; Matsumoto, Kota; Yamada, Fumihiko; Roffi, Teuku Muhammad; Kamiya, Itaru; Iwata, Naotaka; Aoyagi, Yoshinobu

2018-01-01

A method for laser-induced local p-type activation of an as-grown Mg-doped GaN sample with a high lateral resolution is developed for realizing high power vertical devices for the first time. As-grown Mg-doped GaN is converted to p-type GaN in a confined local area. The transition from an insulating to a p-type area is realized to take place within about 1-2 μm fine resolution. The results show that the technique can be applied in fabricating the devices such as vertical field effect transistors, vertical bipolar transistors and vertical Schottkey diode so on with a current confinement region using a p-type carrier-blocking layer formed by this technique.

Radiographic detection of artificial intra-bony defects in the edentulous area.

Science.gov (United States)

Van Assche, N; Jacobs, R; Coucke, W; van Steenberghe, D; Quirynen, M

2009-03-01

Since intra-bony pathologies might jeopardize implant outcome, their preoperative detection is crucial. In sixteen human cadaver bloc sections from upper and lower jaws, artificial defects with progressively increasing size (n=7) have been created. From each respective defect, analogue and digital intra-oral radiographs were taken, the latter processed via a periodontal filter and afterwards presented in black-white as well as in colour, resulting in three sets of 7 images per bloc section. Eight observers were asked to diagnosis an eventual defect on randomly presented radiographs, and at another occasion to rank each set based on the defect size. The clinicians were only able to identify a defect, when the junctional area was involved, except for bony pieces with a very homogeneous structure. For longitudinal evaluation of healing bone (e.g. after tooth extraction), colour digital images can be recommended. These observations indicate that intra-oral radiographs are not always reliable for the detection of any intra-bony defect.

A Novel Quasi-SEPIC High-Voltage Boost DC-DC Converter

DEFF Research Database (Denmark)

Siwakoti, Yam Prasad; N. Soltani, Mohsen; Blaabjerg, Frede

2017-01-01

This paper proposes a modified coupled-inductor SEPIC dc-dc converter for low power and high voltage gain applications such as for piezoelectric drive systems. The converter uses the same components as of SEPIC converter with an additional diode. Compared to conventional topologies with similar...... voltage gain expression, the proposed topology uses less components to achieve same or even higher voltage gain. This helps to design a very compact and light weight converter with higher power density at lower cost. Due to brevity, the principle of operation, theoretical analysis and comparison supported...

High Current Planar Transformer for Very High Efficiency Isolated Boost DC-DC Converters

DEFF Research Database (Denmark)

Pittini, Riccardo; Zhang, Zhe; Andersen, Michael A. E.

2014-01-01

This paper presents a design and optimization of a high current planar transformer for very high efficiency dc-dc isolated boost converters. The analysis considers different winding arrangements, including very high copper thickness windings. The analysis is focused on the winding ac-resistance a......This paper presents a design and optimization of a high current planar transformer for very high efficiency dc-dc isolated boost converters. The analysis considers different winding arrangements, including very high copper thickness windings. The analysis is focused on the winding ac......-resistance and transformer leakage inductance. Design and optimization procedures are validated based on an experimental prototype of a 6 kW dcdc isolated full bridge boost converter developed on fully planar magnetics. The prototype is rated at 30-80 V 0-80 A on the low voltage side and 700-800 V on the high voltage side...... with a peak efficiency of 97.8% at 80 V 3.5 kW. Results highlights that thick copper windings can provide good performance at low switching frequencies due to the high transformer filling factor. PCB windings can also provide very high efficiency if stacked in parallel utilizing the transformer winding window...

Long standing intra oral acid burn

NARCIS (Netherlands)

Kumar, V.V.; Ebenezer, S.; Lobbezoo, F.

2015-01-01

Oral burn due to ingestion of corrosive substances can bring about debilitating consequences. It often brings mortality, and the survivors can have severe impairment of functions, especially in relation to the stomatognathic and gastrointestinal systems. This article presents a long-standing case

A new delay line loops shrinking time-to-digital converter in low-cost FPGA

Energy Technology Data Exchange (ETDEWEB)

Zhang, Jie, E-mail: zhangjie071063@163.com [State Key Laboratory of Geodesy and Earth’s Dynamics, Institute of Geodesy and Geophysics, CAS, Wuhan, China, 430077 (China); University of Chinese Academy of Sciences, Beijing, China, 100049 (China); Zhou, Dongming [State Key Laboratory of Geodesy and Earth’s Dynamics, Institute of Geodesy and Geophysics, CAS, Wuhan, China, 430077 (China)

2015-01-21

The article provides the design and test results of a new time-to-digital converter (TDC) based on delay line loops shrinking method and implemented in a low-cost field programmable gate array (FPGA) device. A technique that achieves high resolution with low cost and flexibility is presented. The technique is based on two delay line loops which are used to directly shrink the measured time interval in the designed TDC, and the resolution is dependent on the difference between the entire delay times of the two delay line loops. In order to realize high resolution and eliminate temperature influence, the two delay line loops consist of the same delay cells with the same number. A delay-locked loop (DLL) is used to stabilize the resolution against process variations and ambient conditions. Meanwhile, one method is used to accurately evaluate the resolution of the implemented TDC. The converter has been implemented in a general-propose FPGA device (Actel SmartFusion A2F200M3). A single shot resolution of the implemented converter is 63.3 ps and the measurement standard deviation is about 61.7 ps within the measurement range of 5 ns. - Highlights: • We provide a new FPGA-integrated time-to-digital converter based on delay line loops method which used two delay line loops to directly shrink time intervals with only rising edges. • The two delay line loops consist of the same delay cells with the same number and symmetrical structure. • The resolution is dependent on the difference between the entire delays of the two delay line loops. • We use delay-locked loop to stabilize the resolution against temperature and supply voltage.

A new delay line loops shrinking time-to-digital converter in low-cost FPGA

International Nuclear Information System (INIS)

Zhang, Jie; Zhou, Dongming

2015-01-01

The article provides the design and test results of a new time-to-digital converter (TDC) based on delay line loops shrinking method and implemented in a low-cost field programmable gate array (FPGA) device. A technique that achieves high resolution with low cost and flexibility is presented. The technique is based on two delay line loops which are used to directly shrink the measured time interval in the designed TDC, and the resolution is dependent on the difference between the entire delay times of the two delay line loops. In order to realize high resolution and eliminate temperature influence, the two delay line loops consist of the same delay cells with the same number. A delay-locked loop (DLL) is used to stabilize the resolution against process variations and ambient conditions. Meanwhile, one method is used to accurately evaluate the resolution of the implemented TDC. The converter has been implemented in a general-propose FPGA device (Actel SmartFusion A2F200M3). A single shot resolution of the implemented converter is 63.3 ps and the measurement standard deviation is about 61.7 ps within the measurement range of 5 ns. - Highlights: • We provide a new FPGA-integrated time-to-digital converter based on delay line loops method which used two delay line loops to directly shrink time intervals with only rising edges. • The two delay line loops consist of the same delay cells with the same number and symmetrical structure. • The resolution is dependent on the difference between the entire delays of the two delay line loops. • We use delay-locked loop to stabilize the resolution against temperature and supply voltage

Outphasing control of gallium nitride based very high frequency resonant converters

DEFF Research Database (Denmark)

Madsen, Mickey Pierre; Knott, Arnold; Andersen, Michael A. E.

2015-01-01

In this paper an outphasing modulation control method suitable for line regulation of very high frequency resonant converters is described. The pros and cons of several control methods suitable for very high frequency resonant converters are described and compared to outphasing modulation...

Integrated High Resolution Digital Color Light Sensor in 130 nm CMOS Technology

Directory of Open Access Journals (Sweden)

Drago Strle

2015-07-01

Full Text Available This article presents a color light detection system integrated in 130 nm CMOS technology. The sensors and corresponding electronics detect light in a CIE XYZ color luminosity space using on-chip integrated sensors without any additional process steps, high-resolution analog-to-digital converter, and dedicated DSP algorithm. The sensor consists of a set of laterally arranged integrated photodiodes that are partly covered by metal, where color separation between the photodiodes is achieved by lateral carrier diffusion together with wavelength-dependent absorption. A high resolution, hybrid, ∑∆ ADC converts each photo diode’s current into a 22-bit digital result, canceling the dark current of the photo diodes. The digital results are further processed by the DSP, which calculates normalized XYZ or RGB color and intensity parameters using linear transformations of the three photo diode responses by multiplication of the data with a transformation matrix, where the coefficients are extracted by training in combination with a pseudo-inverse operation and the least-mean square approximation. The sensor system detects the color light parameters with 22-bit accuracy, consumes less than 60 μA on average at 10 readings per second, and occupies approx. 0.8 mm2 of silicon area (including three photodiodes and the analog part of the ADC. The DSP is currently implemented on FPGA.

Integrated High Resolution Digital Color Light Sensor in 130 nm CMOS Technology.

Science.gov (United States)

Strle, Drago; Nahtigal, Uroš; Batistell, Graciele; Zhang, Vincent Chi; Ofner, Erwin; Fant, Andrea; Sturm, Johannes

2015-07-22

This article presents a color light detection system integrated in 130 nm CMOS technology. The sensors and corresponding electronics detect light in a CIE XYZ color luminosity space using on-chip integrated sensors without any additional process steps, high-resolution analog-to-digital converter, and dedicated DSP algorithm. The sensor consists of a set of laterally arranged integrated photodiodes that are partly covered by metal, where color separation between the photodiodes is achieved by lateral carrier diffusion together with wavelength-dependent absorption. A high resolution, hybrid, ∑∆ ADC converts each photo diode's current into a 22-bit digital result, canceling the dark current of the photo diodes. The digital results are further processed by the DSP, which calculates normalized XYZ or RGB color and intensity parameters using linear transformations of the three photo diode responses by multiplication of the data with a transformation matrix, where the coefficients are extracted by training in combination with a pseudo-inverse operation and the least-mean square approximation. The sensor system detects the color light parameters with 22-bit accuracy, consumes less than 60 μA on average at 10 readings per second, and occupies approx. 0.8 mm(2) of silicon area (including three photodiodes and the analog part of the ADC). The DSP is currently implemented on FPGA.

Influence of physical parameters on radiation protection and image quality in intra-oral radiology

Science.gov (United States)

Belinato, W.; Souza, D. N.

2011-10-01

In the world of diagnostic imaging, radiography is an important supplementary method for dental diagnosis. In radiology, special attention must be paid to the radiological protection of patients and health professionals, and also to image quality for correct diagnosis. In Brazil, the national rules governing the operation of medical and dental radiology were specified in 1998 by the National Sanitary Surveillance Agency, complemented in 2005 by the guide "Medical radiology: security and performance of equipment." In this study, quality control tests were performed in public clinics with dental X-ray equipment in the State of Sergipe, Brazil, with consideration of the physical parameters that influence radiological protection and also the quality of images taken in intra-oral radiography. The accuracy of the exposure time was considered acceptable for equipment with digital timers. Exposure times and focal-spot size variations can lead to increased entrance dose. Increased dose has also been associated with visual processing of radiographic film, which often requires repeating the radiographic examination.

Influence of physical parameters on radiation protection and image quality in intra-oral radiology

International Nuclear Information System (INIS)

Belinato, W.; Souza, D.N.

2011-01-01

In the world of diagnostic imaging, radiography is an important supplementary method for dental diagnosis. In radiology, special attention must be paid to the radiological protection of patients and health professionals, and also to image quality for correct diagnosis. In Brazil, the national rules governing the operation of medical and dental radiology were specified in 1998 by the National Sanitary Surveillance Agency, complemented in 2005 by the guide 'Medical radiology: security and performance of equipment.' In this study, quality control tests were performed in public clinics with dental X-ray equipment in the State of Sergipe, Brazil, with consideration of the physical parameters that influence radiological protection and also the quality of images taken in intra-oral radiography. The accuracy of the exposure time was considered acceptable for equipment with digital timers. Exposure times and focal-spot size variations can lead to increased entrance dose. Increased dose has also been associated with visual processing of radiographic film, which often requires repeating the radiographic examination.

Influence of physical parameters on radiation protection and image quality in intra-oral radiology

Energy Technology Data Exchange (ETDEWEB)

Belinato, W. [Instituto Federal de Ensino Basico, Tecnico e Tecnologico da Bahia, Av. Amazonas, 1350-45030-220, Zabele, Vitoria da Conquista, BA (Brazil); Departamento de Fisica, Universidade Federal de Sergipe, Av. Marechal Rondon s/n, 49100-000 Rosa Elze, Sao Cristovao, SE (Brazil); Souza, D.N., E-mail: divanizi@ufs.br [Departamento de Fisica, Universidade Federal de Sergipe, Av. Marechal Rondon s/n, 49100-000 Rosa Elze, Sao Cristovao, SE (Brazil)

2011-10-01

In the world of diagnostic imaging, radiography is an important supplementary method for dental diagnosis. In radiology, special attention must be paid to the radiological protection of patients and health professionals, and also to image quality for correct diagnosis. In Brazil, the national rules governing the operation of medical and dental radiology were specified in 1998 by the National Sanitary Surveillance Agency, complemented in 2005 by the guide 'Medical radiology: security and performance of equipment.' In this study, quality control tests were performed in public clinics with dental X-ray equipment in the State of Sergipe, Brazil, with consideration of the physical parameters that influence radiological protection and also the quality of images taken in intra-oral radiography. The accuracy of the exposure time was considered acceptable for equipment with digital timers. Exposure times and focal-spot size variations can lead to increased entrance dose. Increased dose has also been associated with visual processing of radiographic film, which often requires repeating the radiographic examination.

High-resolution 3D laser imaging based on tunable fiber array link

Science.gov (United States)

Zhao, Sisi; Ruan, Ningjuan; Yang, Song

2017-10-01

Airborne photoelectric reconnaissance system with the bore sight down to the ground is an important battlefield situational awareness system, which can be used for reconnaissance and surveillance of complex ground scene. Airborne 3D imaging Lidar system is recognized as the most potential candidates for target detection under the complex background, and is progressing in the directions of high resolution, long distance detection, high sensitivity, low power consumption, high reliability, eye safe and multi-functional. However, the traditional 3D laser imaging system has the disadvantages of lower imaging resolutions because of the small size of the existing detector, and large volume. This paper proposes a high resolution laser 3D imaging technology based on the tunable optical fiber array link. The echo signal is modulated by a tunable optical fiber array link and then transmitted to the focal plane detector. The detector converts the optical signal into electrical signals which is given to the computer. Then, the computer accomplishes the signal calculation and image restoration based on modulation information, and then reconstructs the target image. This paper establishes the mathematical model of tunable optical fiber array signal receiving link, and proposes the simulation and analysis of the affect factors on high density multidimensional point cloud reconstruction.

Breast density estimation from high spectral and spatial resolution MRI

Science.gov (United States)

Li, Hui; Weiss, William A.; Medved, Milica; Abe, Hiroyuki; Newstead, Gillian M.; Karczmar, Gregory S.; Giger, Maryellen L.

2016-01-01

Abstract. A three-dimensional breast density estimation method is presented for high spectral and spatial resolution (HiSS) MR imaging. Twenty-two patients were recruited (under an Institutional Review Board--approved Health Insurance Portability and Accountability Act-compliant protocol) for high-risk breast cancer screening. Each patient received standard-of-care clinical digital x-ray mammograms and MR scans, as well as HiSS scans. The algorithm for breast density estimation includes breast mask generating, breast skin removal, and breast percentage density calculation. The inter- and intra-user variabilities of the HiSS-based density estimation were determined using correlation analysis and limits of agreement. Correlation analysis was also performed between the HiSS-based density estimation and radiologists’ breast imaging-reporting and data system (BI-RADS) density ratings. A correlation coefficient of 0.91 (pdensity estimations. An interclass correlation coefficient of 0.99 (pdensity estimations. A moderate correlation coefficient of 0.55 (p=0.0076) was observed between HiSS-based breast density estimations and radiologists’ BI-RADS. In summary, an objective density estimation method using HiSS spectral data from breast MRI was developed. The high reproducibility with low inter- and low intra-user variabilities shown in this preliminary study suggest that such a HiSS-based density metric may be potentially beneficial in programs requiring breast density such as in breast cancer risk assessment and monitoring effects of therapy. PMID:28042590

Very High Frequency Resonant DC/DC Converters for LED Lighting

DEFF Research Database (Denmark)

Madsen, Mickey Pierre; Knott, Arnold; Andersen, Michael A. E.

2013-01-01

This paper presents a very high frequency DC/DC converter for LED lighting. Several resonant topologies are compared and their usability discussed. At the end the resonant SEPIC converter is chosen based on the achievable power density and total bill of material. Simulations of a 51 MHz converter...... with 40 V input and 15 V output are made. The simulation shows possibility of achieving efficiency up to 87 % even with a HEXFET Power MOSFET. Three prototypes of the simulated converter are implemented showing good correlation with simulations. The prototypes have efficiencies up to 84 % and power...

Practice of superselective intraarterial high-dose cisplatin chemoradiotherapy in the oral cavity

International Nuclear Information System (INIS)

Yoshida, Tomoyuki; Nakamura, Kazuhiro; Tsukahara, Kiyoaki; Inagaki, Taro; Ito, Hiroyuki; Shimizu, Akira; Takata, Daisuke; Okamoto, Isaku; Kondo, Takahito

2011-01-01

Superselective intraarterial infusion enables high-dose chemotherapeutic agents to be administered via tumor feeding vessels to neutralize and limit the adverse cisplatin effects acceptable. Between 1998 and 2008, we evaluated the efficacy of first-line therapy and adverse events in 30 subjects with oral squamous cell cancer undergoing simultaneous superselective intra arterial high-dose chemotherapy and radiotherapy. The 30 subjects- 23 men and 7 women aged 40 to 72- consisted of 3 T2, 12 T3, and 15 T4. Four patients had N0, 8 N1, 7 N2b, 8 N2c, and 3 N3 disease. Two were in CS II, 6 III, 17 IVa, and 5 IVb (III>93%, IV: 73%). Superselective intra arterial chemotherapy delivered through the femoral artery used the Seldinger technique. A single cisplatin dose of 100-550 mg/m 2 (mean 440 mg/m 2 ). Five minutes after intra arterial infusion, sodium thiosulphate (9 g/m 2 ) was administered via a peripheral cutaneous vein in the contralateral forearm. Concurrent radiotherapy started on Day 2 at 2 Gy per session for a total of 60 Gy. Two to 3 weeks later, 15 under went the second course of superselective intra arterial chemotherapy after tumor feeding vessels were visualized angiographically. Four (13.3%) subjects with Grade 3 or greater myelosuppression required granulocyte-colony stimulating factor (G-CSF). Grade 3 or greater mucositis was observed in 57% and Grade 4 mucositis occurred in 5 (16.7%). All adverse effects were reversible and no serious adverse events were prolonged. Among those responding to first-line therapy, 24 of the 30 (80%) achieved complete response (CR) and 6 (20%) partial response (PR), but no stable disease (SD) or no change (NC). Overall response was 100%. Histopathologically, 2 of 9 undergoing postchemoradiotherapy had no tumors. Clinical and pathological CR was 86.7%. Adverse events associated with this therapy associated events were considered relatively mild and within allowable limits. (author)

High Voltage Coil Current Sensor for DC-DC Converters Employing DDCC

Directory of Open Access Journals (Sweden)

M. Drinovsky

2015-12-01

Full Text Available Current sensor is an integral part of every switching converter. It is used for over-current protection, regulation and in case of multiphase converters for balancing. A new high voltage current sensor for coil-based current sensing in DC-DC converters is presented. The sensor employs DDCC with high voltage input stage and gain trimming. The circuit has been simulated and implemented in 0.35 um BCD technology as part of a multiphase DC-DC converter where its function has been verified. The circuit is able to sustain common mode voltage on the input up to 40 V, it occupies 0.387*0.345 mm2 and consumes 3.2 mW typically.

High Efficiency Boost Converter with Three State Switching Cell

DEFF Research Database (Denmark)

Klimczak, Pawel; Munk-Nielsen, Stig

2009-01-01

is on performance improvement of this type of the converter. Use of foil windings helps to reduce conduction losses in magnetic components and to reduce size of these components. Also it has been demonstrated that the regulation range of this type of converter can be increased by operation with duty cycle lower......The boost converter with the three-state switching cell seems to be a good candidate for a dc-dc stage for non-isolated generators based on alternative energy sources. It provides a high voltage gain, a reduced voltage stress on transistors and limited input current ripples. In this paper the focus...

High-Resolution Phenotypic Landscape of the RNA Polymerase II Trigger Loop.

Directory of Open Access Journals (Sweden)

Chenxi Qiu

2016-11-01

Full Text Available The active sites of multisubunit RNA polymerases have a "trigger loop" (TL that multitasks in substrate selection, catalysis, and translocation. To dissect the Saccharomyces cerevisiae RNA polymerase II TL at individual-residue resolution, we quantitatively phenotyped nearly all TL single variants en masse. Three mutant classes, revealed by phenotypes linked to transcription defects or various stresses, have distinct distributions among TL residues. We find that mutations disrupting an intra-TL hydrophobic pocket, proposed to provide a mechanism for substrate-triggered TL folding through destabilization of a catalytically inactive TL state, confer phenotypes consistent with pocket disruption and increased catalysis. Furthermore, allele-specific genetic interactions among TL and TL-proximal domain residues support the contribution of the funnel and bridge helices (BH to TL dynamics. Our structural genetics approach incorporates structural and phenotypic data for high-resolution dissection of transcription mechanisms and their evolution, and is readily applicable to other essential yeast proteins.

PCB Embedded Inductor for High-Frequency ZVS SEPIC Converter

DEFF Research Database (Denmark)

Dou, Yi; Ouyang, Ziwei; Thummala, Prasanth

2018-01-01

The volume and temperature rise of passive components, especially inductors, limit the momentum toward high power density in high-frequency power converters. To address the limitations, PCB integration of passive components should be considered with the benefit of low profile, excellent thermal...... characteristic and cost reduction. This paper investigates an embedded structure of inductors to further increase the power density of a low power DC-DC converter. A pair of coupling inductors have been embedded into the PCB. The detailed embedded process has been described and the characteristics of embedded...

Analysis of high voltage step-up nonisolated DC-DC boost converters

Science.gov (United States)

Alisson Alencar Freitas, Antônio; Lessa Tofoli, Fernando; Junior, Edilson Mineiro Sá; Daher, Sergio; Antunes, Fernando Luiz Marcelo

2016-05-01

A high voltage step-up nonisolated DC-DC converter based on coupled inductors suitable to photovoltaic (PV) systems applications is proposed in this paper. Considering that numerous approaches exist to extend the voltage conversion ratio of DC-DC converters that do not use transformers, a detailed comparison is also presented among the proposed converter and other popular topologies such as the conventional boost converter and the quadratic boost converter. The qualitative analysis of the coupled-inductor-based topology is developed so that a design procedure can be obtained, from which an experimental prototype is implemented to validate the theoretical assumptions.

Image-converter streak cameras with very high gain

International Nuclear Information System (INIS)

1975-01-01

A new camera is described with slit scanning and very high photonic gain (G=5000). Development of the technology of tubes and microchannel plates has enabled integration of such an amplifying element in an image converter tube which does away with the couplings and the intermediary electron-photon-electron conversions of the classical converter systems having external amplification. It is thus possible to obtain equal or superior performance while retaining considerable gain for the camera, great compactness, great flexibility in use, and easy handling. (author)

High Step-Up DC—DC Converter for AC Photovoltaic Module with MPPT Control

Science.gov (United States)

Sundar, Govindasamy; Karthick, Narashiman; Rama Reddy, Sasi

2014-08-01

This paper presents the high gain step-up BOOST converter which is essential to step up the low output voltage from PV panel to the high voltage according to the requirement of the application. In this paper a high gain BOOST converter with coupled inductor technique is proposed with the MPPT control. Without extreme duty ratios and the numerous turns-ratios of a coupled inductor this converter achieves a high step-up voltage-conversion ratio and the leakage energy of the coupled inductor is efficiently recycled to the load. MPPT control used to extract the maximum power from PV panel by controlling the Duty ratio of the converter. The PV panel, BOOST converter and the MPPT are modeled using Sim Power System blocks in MATLAB/SIMULINK environment. The prototype model of the proposed converter has been implemented with the maximum measured efficiency is up to 95.4% and full-load efficiency is 93.1%.

A high voltage gain quasi Z-source isolated DC/DC converter

DEFF Research Database (Denmark)

Siwakoti, Yam P.; Blaabjerg, Frede; Loh, Poh Chiang

2014-01-01

A compact quasi-Z-source DC/DC converter is presented with high voltage gain, isolated output, and improved efficiency. The improvements in size and performance were achieved by using a square wave inverter with only two output switches driving an isolating transformer in push-pull mode, followed...... by a voltage doubling output rectifier. The converter is well-suited to applications requiring a high voltage gain, especially renewable energy sources such as photovoltaic and fuel-cell power supplies. To demonstrate the converter's performance a prototype designed to output 400 V at 500 W was constructed...

A soft-switching coupled inductor bidirectional DC-DC converter with high-conversion ratio

Science.gov (United States)

Chao, Kuei-Hsiang; Jheng, Yi-Cing

2018-01-01

A soft-switching bidirectional DC-DC converter is presented herein as a way to improve the conversion efficiency of a photovoltaic (PV) system. Adoption of coupled inductors enables the presented converter not only to provide a high-conversion ratio but also to suppress the transient surge voltage via the release of the energy stored in leakage flux of the coupled inductors, and the cost can kept down consequently. A combined use of a switching mechanism and an auxiliary resonant branch enables the converter to successfully perform zero-voltage switching operations on the main switches and improves the efficiency accordingly. It was testified by experiments that our proposed converter works relatively efficiently in full-load working range. Additionally, the framework of the converter intended for testifying has high-conversion ratio. The results of a test, where a generating system using PV module array coupled with batteries as energy storage device was used as the low-voltage input side, and DC link was used as high-voltage side, demonstrated our proposed converter framework with high-conversion ratio on both high-voltage and low-voltage sides.

Clinical and histopathological studies on the squamous cell carcinoma of the tongue treated with radiation-combined intra-arterial chemotherapy

International Nuclear Information System (INIS)

Hoshi, Hideki

2000-01-01

Because oral cancer treatment has advanced, resulting in a higher survival rate, it is necessary to treat the preserved oral functions such as speech, mastication, and deglutition, as well as the aesthetics. Oral cancer treatment has been performed mainly by surgical therapy and radiation therapy, however, integrated treatment including chemotherapy has recently been performed. In this study, we evaluated the effectiveness and usefulness of radiation-combined intra-arterial chemotherapy for carcinomas of the tongue, which shows a high incident rate among oral cancers and has become more common recently, to establish treatment methods for preserving the function and morphology. The subjects were 63 patients who consulted our department and underwent radiation-combined intra-arterial chemotherapy. With this therapy, the case of complete response (CR) was clinically obtained in 43 patients, and the case of partial response (PR) was obtained in 17 patients with a 68.3% CR rate and a 95.2% therapeutic effectiveness rate. Maintenance therapy was performed in 44 patients without performing surgical therapy of the primary lesion in the primary treatment. Twenty-nine among 44 patients showed a good clinical course without recurrence of primary lesion. Regarding T4, a good clinical course without recurrence was observed in 3 patients in which PR was obtained, and surgical therapy was added to the primary treatment, showing a 57.1% local control rate in T4. Considering these results, there is a high possibility that radiation-combined intra-arterial chemotherapy for carcinomas of the tongue can be implemented for avoiding surgical therapy of the primary lesion in the primary treatment, and it is useful for preserving the function and morphology with a high local control rate. (author)

Clinical and histopathological studies on the squamous cell carcinoma of the tongue treated with radiation-combined intra-arterial chemotherapy

Energy Technology Data Exchange (ETDEWEB)

Hoshi, Hideki [Iwate Medical Coll., Morioka (Japan). School of Dentistry

2000-12-01

Because oral cancer treatment has advanced, resulting in a higher survival rate, it is necessary to treat the preserved oral functions such as speech, mastication, and deglutition, as well as the aesthetics. Oral cancer treatment has been performed mainly by surgical therapy and radiation therapy, however, integrated treatment including chemotherapy has recently been performed. In this study, we evaluated the effectiveness and usefulness of radiation-combined intra-arterial chemotherapy for carcinomas of the tongue, which shows a high incident rate among oral cancers and has become more common recently, to establish treatment methods for preserving the function and morphology. The subjects were 63 patients who consulted our department and underwent radiation-combined intra-arterial chemotherapy. With this therapy, the case of complete response (CR) was clinically obtained in 43 patients, and the case of partial response (PR) was obtained in 17 patients with a 68.3% CR rate and a 95.2% therapeutic effectiveness rate. Maintenance therapy was performed in 44 patients without performing surgical therapy of the primary lesion in the primary treatment. Twenty-nine among 44 patients showed a good clinical course without recurrence of primary lesion. Regarding T4, a good clinical course without recurrence was observed in 3 patients in which PR was obtained, and surgical therapy was added to the primary treatment, showing a 57.1% local control rate in T4. Considering these results, there is a high possibility that radiation-combined intra-arterial chemotherapy for carcinomas of the tongue can be implemented for avoiding surgical therapy of the primary lesion in the primary treatment, and it is useful for preserving the function and morphology with a high local control rate. (author)

Abstracts of International Conference on Experimental and Computing Methods in High Resolution Diffraction Applied for Structure Characterization of Modern Materials - HREDAMM

International Nuclear Information System (INIS)

2004-01-01

The conference addressed all aspects of high resolution diffraction. The topics of meeting include advanced experimental diffraction methods and computer data analysis for characterization of modern materials as well as the progress and new achievements in high resolution diffraction (X-ray, electrons, neutrons). Application of these methods for characterization of modern materials are widely presented among the invited, oral and poster contributions

A high gain modified SEPIC DC-to-DC boost converter for renewable energy application

DEFF Research Database (Denmark)

Maroti, Pandav Kiran; Padmanaban, Sanjeevikumar; Bhaskar, Mahajan Sagar

2017-01-01

The proposed work present the modified high gain Single Ended Primary Inductance Converter (SEPIC) for renewable energy applications. The voltage gain of proposed converter is very highly related to conventional dc-to-dc converter and recently projected converter based on conventional converter....... The key feature of projected converter is only one controlled device and voltage gain is increased without using a transformer and coupled inductor structure. The voltage gain of projected converter is increased by 10 times compared to the SEPIC converter by adding one extra inductor and capacitor...... in SEPIC converter for a duty ratio of 90%. The detailed analysis of the voltage gain with the voltage drop across passive device and working of projected converter is deliberated in details in the paper. The projected converter is simulated in Matrix Laboratory software (2014). The simulation results...

Medicine and ionizing rays: a help sheet in analysing risks in intra-oral dental radiology and applicable texts

International Nuclear Information System (INIS)

Gauron, C.

2009-01-01

This document proposes a synthesis of useful knowledge for radioprotection in the case of intra-oral dental radiology. In the first part, several aspects are considered: the concerned personnel, the course of treatment procedures, the hazards, the identification of the risk associated with ionizing radiation, the risk assessment and the determination of exposure levels, the strategy to control the risks (reduction of risks, technical measures concerning the installation or the personnel, teaching and information, prevention and medical monitoring), and risk control assessment. A second part indicates the various applicable legal and regulatory texts (European directives, institutions in charge of radioprotection, general arrangements applicable to workers and patients, and regulatory texts concerning worker protection or patient protection against ionizing radiations)

High-power three-port three-phase bidirectional DC-DC converter

NARCIS (Netherlands)

Tao, H.; Duarte, J.L.; Hendrix, M.A.M.

2007-01-01

This paper proposes a three-port three-phase bidirectional dc-dc converter suitable for high-power applications. The converter combines a slow primary source and a fast storage to power a common load (e.g., an inverter). Since this type of system is gaining popularity in sustainable energy

Aroma release in the oral cavity after wine intake is influenced by wine matrix composition.

Science.gov (United States)

Esteban-Fernández, Adelaida; Muñoz-González, Carolina; Jiménez-Girón, Ana; Pérez-Jiménez, María; Pozo-Bayón, María Ángeles

2018-03-15

The aim of this study has been to investigate if wine matrix composition might influence the interaction between odorants and oral mucosa in the oral cavity during a "wine intake-like" situation. Aroma released after exposing the oral cavity of three individuals to different wines (n=12) previously spiked with six target aromas was followed by an -in vivo intra-oral SPME approach. Results showed a significant effect of wine matrix composition on the intra-oral aroma release of certain odorants. Among the wine matrix parameters, phenolic compounds showed the largest impact. This effect was dependent on their chemical structure. Some phenolic acids (e.g. hippuric, caffeic) were associated to an increase in the intra-oral release of certain odorants (e.g. linalool, β-ionone), while flavonoids showed the opposite effect, decreasing the intra-oral release of aliphatic esters (ethyl hexanoate). This work shows for the first time, the impact of wine composition on oral-mucosa interactions under physiological conditions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Evaluation of a dentifrice containing 8% arginine, calcium carbonate, and sodium monofluorophosphate to repair acid-softened enamel using an intra-oral remineralization model.

Science.gov (United States)

Sullivan, R; Rege, A; Corby, P; Klaczany, G; Allen, K; Hershkowitz, D; Goldder, B; Wolff, M

2014-01-01

An intra-oral remineralization study was conducted to compare the ability of a dentifrice containing 8% arginine and calcium carbonate (Pro-Argin Technology), and 1450 ppm fluoride as sodium monofluorophosphate (MFP) to remineralize acid-softened bovine enamel specimens compared to a silica-based dentifrice with 1450 ppm fluoride as MFP. The intra-oral clinical study employed a double blind, two-treatment, crossover design, and used an upper palatal retainer to expose the enamel specimens to the oral environment during product use and periods of remineralization. The retainer was designed to house three partially demineralized bovine enamel samples. The study population was comprised of 30 adults, ages 18 to 70 years. The study consisted of two treatment phases with a washout period lasting seven (+/- three) days preceding each treatment phase. A silica-based dentifrice without fluoride was used during the washout period. The Test Dentifrice used in this study contained 8% arginine, calcium carbonate, and 1450 ppm fluoride as sodium monofluorophosphate (MFP). The Control Dentifrice was silica-based and contained 1450 ppm fluoride as MFP. The treatment period consisted of a three-day lead-in period with the assigned product. The panelists brushed two times per day during the three-day lead-in period with the assigned product. On the fourth day, the panelists began brushing with the assigned product with the retainer in their mouth. The panelists brushed for one minute, followed by a one-minute swish with the slurry and a rinse with 15 ml of water in the morning, in the afternoon, and night with the retainer in the mouth. The panelists brushed only their teeth and not the specimens directly. Changes in mineral content before and after treatment were measured using a Knoop microhardness tester. The results of the study showed that percent remineralization values for the Test Dentifrice and Control Dentifrice were 14.99% and 8.66%, respectively. A statistical analysis

ANL high resolution injector

International Nuclear Information System (INIS)

Minehara, E.; Kutschera, W.; Hartog, P.D.; Billquist, P.

1985-01-01

The ANL (Argonne National Laboratory) high-resolution injector has been installed to obtain higher mass resolution and higher preacceleration, and to utilize effectively the full mass range of ATLAS (Argonne Tandem Linac Accelerator System). Preliminary results of the first beam test are reported briefly. The design and performance, in particular a high-mass-resolution magnet with aberration compensation, are discussed. 7 refs., 5 figs., 2 tabs

Magnetically coupled high-gain Y-source isolated DC/DC converter

DEFF Research Database (Denmark)

Siwakoti, Yam P.; Loh, Poh Chiang; Blaabjerg, Frede

2014-01-01

A new form of magnetically coupled DC/DC converter is proposed for medium power applications (250 W to 2 kW), requiring a high-voltage gain, short inductive charging time and galvanic isolation. The proposed converter can be realised using a unique Y-source impedance network and a two-switch push...

Large-scale digitizer system, analog converters

International Nuclear Information System (INIS)

Althaus, R.F.; Lee, K.L.; Kirsten, F.A.; Wagner, L.J.

1976-10-01

Analog to digital converter circuits that are based on the sharing of common resources, including those which are critical to the linearity and stability of the individual channels, are described. Simplicity of circuit composition is valued over other more costly approaches. These are intended to be applied in a large-scale processing and digitizing system for use with high-energy physics detectors such as drift-chambers or phototube-scintillator arrays. Signal distribution techniques are of paramount importance in maintaining adequate signal-to-noise ratio. Noise in both amplitude and time-jitter senses is held sufficiently low so that conversions with 10-bit charge resolution and 12-bit time resolution are achieved

Improved methods for high resolution electron microscopy

Energy Technology Data Exchange (ETDEWEB)

Taylor, J.R.

1987-04-01

Existing methods of making support films for high resolution transmission electron microscopy are investigated and novel methods are developed. Existing methods of fabricating fenestrated, metal reinforced specimen supports (microgrids) are evaluated for their potential to reduce beam induced movement of monolamellar crystals of C/sub 44/H/sub 90/ paraffin supported on thin carbon films. Improved methods of producing hydrophobic carbon films by vacuum evaporation, and improved methods of depositing well ordered monolamellar paraffin crystals on carbon films are developed. A novel technique for vacuum evaporation of metals is described which is used to reinforce microgrids. A technique is also developed to bond thin carbon films to microgrids with a polymer bonding agent. Unique biochemical methods are described to accomplish site specific covalent modification of membrane proteins. Protocols are given which covalently convert the carboxy terminus of papain cleaved bacteriorhodopsin to a free thiol. 53 refs., 19 figs., 1 tab.

Time-interleaved high-speed D/A converters

NARCIS (Netherlands)

Olieman, E.

2016-01-01

This thesis is on power efficient very high-speed digital-to-analog converters (DACs) in CMOS technology, intended to generate signals from DC to RF. Components in RF signal chains are nowadays often moved from the analog domain to the digital domain. This allows for more flexibility and better

Investigation and improvement of high step- up converters for pv module applications

Directory of Open Access Journals (Sweden)

Hamed moradmand jazi

2017-01-01

Full Text Available sun is of the clean and cheapest sources of energy. Charging slight energy to electricity is carried out by PV modules. Since most electric consumers need Ac input voltage, the PV modules output voltage should be changed into Ac form. But, the voltage level of PV modules is much lower than the voltage needed in input stage of inverters. Because of large voltage level. Difference it is not possible to use the basic boost and buck-boost converters. The basic boost and buck-boost converters definitely can not be used in this applications, for, they will face extreme drop in efficiency in duty cycles closer to unity. In this paper The proposed converter is presented in order to decrease the voltage stress of coupled inductors based high step-up converters. The voltage stress in the proposed converter is lower than the high step-up boost converter with coupled inductors in identical condition. Also, soft switching condition for switches and diodes is realized by active clamp circuit, and with this technique and proper selection of duty cycle, large gain and high efficiency could be achieved ultimately. . In this paper theoretical analysis is used for analyzing the performance of the proposed converters, and in order to verify the theoretical analysis, simulated results from pspice software is provides.

Optimizing the design of very high power, high performance converters

International Nuclear Information System (INIS)

Edwards, R.J.; Tiagha, E.A.; Ganetis, G.; Nawrocky, R.J.

1980-01-01

This paper describes how various technologies are used to achieve the desired performance in a high current magnet power converter system. It is hoped that the discussions of the design approaches taken will be applicable to other power supply systems where stringent requirements in stability, accuracy and reliability must be met

A Switched-Capacitor Based High Conversion Ratio Converter for Renewable Energy Applications

DEFF Research Database (Denmark)

Li, Kerui; Yin, Zhijian; Yang, Yongheng

2017-01-01

A high step-up switched-capacitor based converter is proposed in this paper. The proposed converter features high conversion ratio, low voltage stress and continuous input current, which makes it very suitable for renewable energy applications like photovoltaic systems. More importantly...... voltage gain, low voltage stress on the switches, continuous input current, and relatively high efficiency....

A Novel Cyclic Time to Digital Converter Based on Triple-Slope Interpolation and Time Amplification

Directory of Open Access Journals (Sweden)

M. Rezvanyvardom

2015-09-01

Full Text Available This paper investigates a novel cyclic time-to-digital converter (TDC which employs triple-slope analog interpolation and time amplification techniques for digitizing the time interval between the rising edges of two input signals(Start and Stop. The proposed converter will be a 9-bit cyclic time-to-digital converter that does not use delay lines in its structure. Therefore, it has a low sensitivity to temperature, power supply and process (PVT variations. The other advantages of the proposed converter are low circuit complexity, and high accuracy compared with the time-to-digital converters that have previously been proposed. Also, this converter improves the time resolution and the dynamic range. In the same resolution, linear range and dynamic range, the proposed cyclic TDC reduces the number of circuit elements compared with the converters that have a similar circuit structure. Thus, the converter reduces the chip area, the power consumption and the figure of merit (FoM. In this converter, the integral nonlinearity (INL and differential nonlinearity (DNL errors are reduced. In order to evaluate the idea, the proposed time-to-digital converter is designed in TSMC 45 nm CMOS technology and simulated. Comparison of the theoretical and simulation results confirms the benefits of the proposed TDC.

10 ps resolution, 160 ns full scale range and less than 1.5% differential non-linearity time-to-digital converter module for high performance timing measurements

Energy Technology Data Exchange (ETDEWEB)

Markovic, B.; Tamborini, D.; Villa, F.; Tisa, S.; Tosi, A.; Zappa, F. [Politecnico di Milano, Dipartimento di Elettronica e Informazione, Piazza Leonardo da Vinci 32, 20133 Milano (Italy)

2012-07-15

We present a compact high performance time-to-digital converter (TDC) module that provides 10 ps timing resolution, 160 ns dynamic range and a differential non-linearity better than 1.5% LSB{sub rms}. The TDC can be operated either as a general-purpose time-interval measurement device, when receiving external START and STOP pulses, or in photon-timing mode, when employing the on-chip SPAD (single photon avalanche diode) detector for detecting photons and time-tagging them. The instrument precision is 15 ps{sub rms} (i.e., 36 ps{sub FWHM}) and in photon timing mode it is still better than 70 ps{sub FWHM}. The USB link to the remote PC allows the easy setting of measurement parameters, the fast download of acquired data, and their visualization and storing via an user-friendly software interface. The module proves to be the best candidate for a wide variety of applications such as: fluorescence lifetime imaging, time-of-flight ranging measurements, time-resolved positron emission tomography, single-molecule spectroscopy, fluorescence correlation spectroscopy, diffuse optical tomography, optical time-domain reflectometry, quantum optics, etc.

High Resolution, High-Speed Photography, an Increasingly Prominent Diagnostic in Ballistic Research Experiments

International Nuclear Information System (INIS)

Shaw, L.; Muelder, S.

1999-01-01

High resolution, high-speed photography is becoming a prominent diagnostic in ballistic experimentation. The development of high speed cameras utilizing electro-optics and the use of lasers for illumination now provide the capability to routinely obtain high quality photographic records of ballistic style experiments. The purpose of this presentation is to review in a visual manner the progress of this technology and how it has impacted ballistic experimentation. Within the framework of development at LLNL, we look at the recent history of large format high-speed photography, and present a number of photographic records that represent the state of the art at the time they were made. These records are primarily from experiments involving shaped charges. We also present some examples of current photographic technology, developed within the ballistic community, that has application to hydro diagnostic experimentation at large. This paper is designed primarily as an oral-visual presentation. This written portion is to provide general background, a few examples, and a bibliography

A high resolution pneumatic stepping actuator for harsh reactor environments

Science.gov (United States)

Tippetts, Thomas B.; Evans, Paul S.; Riffle, George K.

1993-01-01

A reactivity control actuator for a high-power density nuclear propulsion reactor must be installed in close proximity to the reactor core. The energy input from radiation to the actuator structure could exceed hundreds of W/cc unless low-cross section, low-absorptivity materials are chosen. Also, for post-test handling and subsequent storage, materials should not be used that are activated into long half-life isotopes. Pneumatic actuators can be constructed from various reactor-compatible materials, but conventional pneumatic piston actuators generally lack the stiffness required for high resolution reactivity control unless electrical position sensors and compensated electronic control systems are used. To overcome these limitations, a pneumatic actuator is under development that positions an output shaft in response to a series of pneumatic pulses, comprising a pneumatic analog of an electrical stepping motor. The pneumatic pulses are generated remotely, beyond the strong radiation environment, and transmitted to the actuator through tubing. The mechanically simple actuator uses a nutating gear harmonic drive to convert motion of small pistons directly to high-resolution angular motion of the output shaft. The digital nature of this actuator is suitable for various reactor control algorithms but is especially compatible with the three bean salad algorithm discussed by Ball et al. (1991).

Development of high torque belt CVT with torque converter; Torque converter tsuki daiyoryogata belt CVT no kaihatsu

Energy Technology Data Exchange (ETDEWEB)

Kurosawa, M; Fujikawa, T; Yoshida, K; Kobayahi, M [Nissan Motor Co. Ltd., Tokyo (Japan)

1997-10-01

Nissan has successfully developed a new belt CVT (Continuously Variable Transmission) with torque converter and has installed it 2L-class vehicle for the first time in the world. This paper describes about the technology of high torque transmission, the need of torque converter, the importance of electronic control and the introduce of driving mode. As the result the CVT has improved driving performance and fuel economy for current CVT and 4 speed automatic transmission. 13 figs., 2 tabs.

Investigation of a metallic photonic crystal high power microwave mode converter

Directory of Open Access Journals (Sweden)

Dong Wang

2015-02-01

Full Text Available It is demonstrated that an L band metallic photonic crystal TEM-TE11 mode converter is suitable for narrow band high power microwave application. The proposed mode converter is realized by partially filling metallic photonic crystals along azimuthal direction in a coaxial transmission line for phase-shifting. A three rows structure is designed and simulated by commercial software CST Microwave Studio. Simulation results show that its conversion efficiency is 99% at the center frequency 1.58 GHz. Over the frequency range of 1.56-1.625 GHz, the conversion efficiency exceeds 90 %, with a corresponding bandwidth of 4.1 %. This mode converter has a gigawatt level power handling capability which is suitable for narrow band high power microwave application. Using magnetically insulated transmission line oscillator(MILO as a high power microwave source, particle-in-cell simulation is carried out to test the performance of the mode converter. The expected TE11 mode microwave output is obtained and the MILO works well. Mode conversion performance of the converter is tested by far-field measurement method. And the experimental result confirms the validity of our design. Then, high power microwave experiment is carried out on a Marx-driven Blumlein water line pulsed power accelerator. Microwave frequency, radiated pattern and power are measured in the far-field region and the results agree well with simulation results. The experiment also reveals that no microwave breakdown or pulse shortening took place in the experimental setup.

Concept of dual-resolution light field imaging using an organic photoelectric conversion film for high-resolution light field photography.

Science.gov (United States)

Sugimura, Daisuke; Kobayashi, Suguru; Hamamoto, Takayuki

2017-11-01

Light field imaging is an emerging technique that is employed to realize various applications such as multi-viewpoint imaging, focal-point changing, and depth estimation. In this paper, we propose a concept of a dual-resolution light field imaging system to synthesize super-resolved multi-viewpoint images. The key novelty of this study is the use of an organic photoelectric conversion film (OPCF), which is a device that converts spectra information of incoming light within a certain wavelength range into an electrical signal (pixel value), for light field imaging. In our imaging system, we place the OPCF having the green spectral sensitivity onto the micro-lens array of the conventional light field camera. The OPCF allows us to acquire the green spectra information only at the center viewpoint with the full resolution of the image sensor. In contrast, the optical system of the light field camera in our imaging system captures the other spectra information (red and blue) at multiple viewpoints (sub-aperture images) but with low resolution. Thus, our dual-resolution light field imaging system enables us to simultaneously capture information about the target scene at a high spatial resolution as well as the direction information of the incoming light. By exploiting these advantages of our imaging system, our proposed method enables the synthesis of full-resolution multi-viewpoint images. We perform experiments using synthetic images, and the results demonstrate that our method outperforms other previous methods.

Dual-band and high-efficiency polarization converter based on metasurfaces at microwave frequencies

Science.gov (United States)

Liu, Yajun; Xia, Song; Shi, Hongyu; Zhang, Anxue; Xu, Zhuo

2016-06-01

We present a dual-band and high-efficiency polarization converter in microwave regime. The proposed converter can convert a linearly polarized wave to its cross-polarized wave for two distinct bands: Ku (11.5-20.0 GHz) and Ka (28.8-34.0 GHz). It can also convert the linearly polarized wave to a circularly polarized wave at four other frequencies. The experimental results are in good agreement with simulation results for both frequency bands. The polarization conversion ratio is above 0.94 for the Ku-band and 0.90 for the Ka-band. Furthermore, the converter can achieve dual-band and high-efficiency polarization conversion over angles of incidence up to 45°. The converter is also polarization-selective in that only the x- and y-polarized waves can be converted. The physical mechanism of the dual-band polarization conversion effect is interpreted via decomposed electric field components that couple with different plasmon resonance modes of the structure.

High-Efficiency Photovoltaic System Using Partially-Connected DC-DC Converter

Science.gov (United States)

Uno, Masatoshi; Kukita, Akio; Tanaka, Koji

Power conversion electronics for photovoltaic (PV) systems are desired to operate as efficiently as possible to exploit the power generated by PV modules. This paper proposes a novel PV system in which a dc-dc converter is partially connected to series-connected PV modules. The proposed system achieves high power-conversion efficiency by reducing the passing power and input/output voltages of the converter. The theoretical operating principle was experimentally validated. Resultant efficiency performances of the proposed and conventional systems demonstrated that the proposed system was more efficient in terms of power conversion though the identical converter was used for the both systems.

EMC Investigation of a Very High Frequency Self-oscillating Resonant Power Converter

DEFF Research Database (Denmark)

Pedersen, Jeppe Arnsdorf; Knott, Arnold; Andersen, Michael A. E.

2016-01-01

This paper focuses on the electromagnetic compatibility (EMC) performance of a Very High Frequency (VHF) converter and how to lower the emissions. To test the EMC performance a VHF converter is implemented with a Class-E inverter and a Class-DE rectifier. The converter is designed to deliver 3 W...... the regulations. This converter shows to be well below the levels for conducted emission even without filtering. For the radiated emissions the converter is above the limits without input and output filters. Several designs with different ways to lower the emissions are implemented and the different layouts...

Capacitor performance limitations in high power converter applications

DEFF Research Database (Denmark)

El-Khatib, Walid Ziad; Holbøll, Joachim; Rasmussen, Tonny Wederberg

2013-01-01

High voltage low inductance capacitors are used in converters as HVDC-links, snubber circuits and sub model (MMC) capacitances. They facilitate the possibility of large peak currents under high frequent or transient voltage applications. On the other hand, using capacitors with larger equivalent...... series inductances include the risk of transient overvoltages, with a negative effect on life time and reliability of the capacitors. These allowable limits of such current and voltage peaks are decided by the ability of the converter components, including the capacitors, to withstand them over...... the expected life time. In this paper results are described from investigations on the electrical environment of these capacitors, including all the conditions they would be exposed to, thereby trying to find the tradeoffs needed to find a suitable capacitor. Different types of capacitors with the same voltage...

Design of a high power, resonant converter for DC wind turbines

DEFF Research Database (Denmark)

Dincan, Catalin Gabriel; Kjær, Philip Carne; Chen, Yu-Hsing

2018-01-01

This paper presents a design procedure and loss estimation for a high power, medium voltage series resonant converter (entitled SRC#), intended for application in megawatt medium-voltage DC wind turbines. The converter is operated with a novel method of operation, entitled pulse removal technique...

Modified High Voltage Conversion Inverting Cuk DC-DC Converter for Renewable Energy Application

DEFF Research Database (Denmark)

Maroti, Pandav Kiran; Padmanaban, Sanjeevikumar; Wheeler, Patrick

2017-01-01

controlled device DC-DC topology. The voltage conversion ratio of proposed converter has increased by ten times of the conventional Cuk converterat a duty ratio of 90%. The detailed analysis of the voltage conversion ratio and losses occur due to internal resistance of components is done in the paper......The proposed exertion represents the modified high voltage conversion Cuk converter for renewable energy application. The proposed Cuk converter is a combination of the conventional boost converter and Cuk converter. The arrangement of the proposed converter make, such as, it becomes the single...

A New Very-High-Efficiency R4 Converter for High-Power Fuel Cell Applications

DEFF Research Database (Denmark)

Nymand, Morten; Andersen, Michael Andreas E.

2009-01-01

of fullbridge switching stages and power transformers, operate in parallel on primary side and in series on secondary side. Current sharing is guaranteed by series connection of transformer secondary windings and three small cascaded current balancing transformers on primary side. The detailed design of a 10 k......W prototype converter is presented. Input voltage range is 30-60 V and output voltage is 800 V. Test results, including voltage- and current waveforms and efficiency measurements, are presented. A record high converter efficiency of 98.2 % is achieved. The proposed R4 boost converter thus constitutes a low...

Superselective intra-arterial infusion of high-dose cisplatin combined with radiation therapy for head and neck carcinoma. Experience of Yamagata University Hospital

International Nuclear Information System (INIS)

Hamamoto, Yasushi; Niino, Keiji; Ishiyama, Hiromichi; Koike, Shuji; Hosoya, Takaaki; Aoyagi, Masaru

2003-01-01

Local effectiveness and complication of superselective intra-arterial infusion of high-dose cisdiamminedichloroplatinum (CDDP) (SIC) combined with radiation therapy (RT) were investigated. Between 1998 and 2000, 18 head and neck carcinomas including 10 maxillary carcinomas (T3; 1, T4; 9), 3 oral cavity carcinomas (T2; 1, T4; 2), and 5 oropharyngeal carcinomas (T2; 2, T4; 3) were treated with SIC and RT with or without surgery. CDDP of 100-150 mg/body was administered weekly in principle for 2-9 weeks (mean: 4.9) with the simultaneous administration of sodium thiosulfate. Radiation doses ranged from 40 Gy to 70 Gy (mean: 56.8 Gy). Complete response was obtained in 7 of 10 maxillary carcinomas, 2 of 3 oral-cavity carcinomas, and 2 of 5 oropharyngeal carcinomas, respectively. When surgical intervention was performed if necessary, 2-year local control rates for maxillary carcinoma, and other carcinoma including oral-cavity carcinoma and oropharyngeal carcinoma were 80% and 63% respectively. Two-year local control rates for T4 maxillary carcinoma, and other T4 carcinoma including oral-cavity carcinoma and oropharyngeal carcinoma were 78% and 40% respectively. Two-year overall survival rates for all cases, maxillary carcinoma, and oral-cavity/oropharyngeal carcinoma were 88%, 90% and 86% respectively. All local recurrences occurred within 6 months from the initiation of treatment. The systemic toxicity of weekly SIC was comparatively mild; however, a total CDDP dose of 1,000 mg or more and/or RT of 70 Gy induced complications of local soft tissue such as mucosal ulcer and fistula. SIC combined with RT is useful to improve the local control/survival rates and to avoid the aggressive surgery for locally advanced head and neck carcinoma. A high total dose of CDDP and/or RT of a comparatively high dose may be risk factors for local soft tissue complications. (author)

GaN-based High Power High Frequency Wide Range LLC Resonant Converter, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — SET Group will design, build and demonstrate a Gallium Nitride (GaN) based High Power High Frequency Wide Range LLC Resonant Converter capable of handling high power...

New non-linear control strategy for non-isolated DC/DC converter with high voltage ratio

Energy Technology Data Exchange (ETDEWEB)

Shahin, A.; Huang, B.; Martin, J.P.; Pierfederici, S.; Davat, B. [Groupe de Recherche en Electronique et en Electrotechnique de Nancy - INPL - Nancy Universite, 2, Avenue de la Foret de Haye, 54516 Vandoeuvre-les-Nancy Cedex (France)

2010-01-15

In this paper, a non-isolated DC/DC converter with high voltage ratio is proposed to allow the interface between a low voltage power source like fuel cell and a high voltage DC bus. To take into account the low voltage-high density characteristics of power sources, a cascaded structure composed of two sub-converters has been chosen and allows obtaining a high voltage ratio. The choice of each sub-converter is based on the requirements of the source and its performances. Consequently, we have chosen a three-interleaved boost converter as the 1st sub-converter whereas the 2nd sub-converter is a three-level boost converter. The control of the whole system is realized thanks to energetic trajectories planning based on flatness properties of the system. The control of both the current and the balance of voltage across the output serial capacitors of the three-level boost converter is ensured by non-linear controllers based on a new non-linear model. Experimental results allow validating the proposed power architecture and its associated control. (author)

New non-linear control strategy for non-isolated DC/DC converter with high voltage ratio

International Nuclear Information System (INIS)

Shahin, A.; Huang, B.; Martin, J.P.; Pierfederici, S.; Davat, B.

2010-01-01

In this paper, a non-isolated DC/DC converter with high voltage ratio is proposed to allow the interface between a low voltage power source like fuel cell and a high voltage DC bus. To take into account the low voltage-high density characteristics of power sources, a cascaded structure composed of two sub-converters has been chosen and allows obtaining a high voltage ratio. The choice of each sub-converter is based on the requirements of the source and its performances. Consequently, we have chosen a three-interleaved boost converter as the 1st sub-converter whereas the 2nd sub-converter is a three-level boost converter. The control of the whole system is realized thanks to energetic trajectories planning based on flatness properties of the system. The control of both the current and the balance of voltage across the output serial capacitors of the three-level boost converter is ensured by non-linear controllers based on a new non-linear model. Experimental results allow validating the proposed power architecture and its associated control.

Oral delivery of Angiotensin-converting enzyme 2 and Angiotensin-(1-7) bioencapsulated in plant cells attenuates pulmonary hypertension.

Science.gov (United States)

Shenoy, Vinayak; Kwon, Kwang-Chul; Rathinasabapathy, Anandharajan; Lin, Shina; Jin, Guiying; Song, Chunjuan; Shil, Pollob; Nair, Anand; Qi, Yanfei; Li, Qiuhong; Francis, Joseph; Katovich, Michael J; Daniell, Henry; Raizada, Mohan K

2014-12-01

Emerging evidences indicate that diminished activity of the vasoprotective axis of the renin-angiotensin system, constituting angiotensin-converting enzyme 2 (ACE2) and its enzymatic product, angiotensin-(1-7) [Ang-(1-7)] contribute to the pathogenesis of pulmonary hypertension (PH). However, long-term repetitive delivery of ACE2 or Ang-(1-7) would require enhanced protein stability and ease of administration to improve patient compliance. Chloroplast expression of therapeutic proteins enables their bioencapsulation within plant cells to protect against gastric enzymatic degradation and facilitates long-term storage at room temperature. Besides, fusion to a transmucosal carrier helps effective systemic absorption from the intestine on oral delivery. We hypothesized that bioencapsulating ACE2 or Ang-(1-7) fused to the cholera nontoxin B subunit would enable development of an oral delivery system that is effective in treating PH. PH was induced in male Sprague Dawley rats by monocrotaline administration. Subset of animals was simultaneously treated with bioencapsulaed ACE2 or Ang-(1-7) (prevention protocol). In a separate set of experiments, drug treatment was initiated after 2 weeks of PH induction (reversal protocol). Oral feeding of rats with bioencapsulated ACE2 or Ang-(1-7) prevented the development of monocrotaline-induced PH and improved associated cardiopulmonary pathophysiology. Furthermore, in the reversal protocol, oral ACE2 or Ang-(1-7) treatment significantly arrested disease progression, along with improvement in right heart function, and decrease in pulmonary vessel wall thickness. In addition, a combination therapy with ACE2 and Ang-(1-7) augmented the beneficial effects against monocrotaline-induced lung injury. Our study provides proof-of-concept for a novel low-cost oral ACE2 or Ang-(1-7) delivery system using transplastomic technology for pulmonary disease therapeutics. © 2014 American Heart Association, Inc.

High-Repeatable Data Acquisition Systems for Pulsed Power Converters in Particle Accelerator Structures

CERN Document Server

AUTHOR|(CDS)2087245; Martino, Michele; Zinno, Raffaele

In this Ph.D. thesis, the issues related to the metrological characterization of high-performance pulsed power converters are addressed. Initially, a background and a state of the art on the measurement systems needed to correctly operate a high-performance power converter are presented. As a matter of fact, power converters usually exploits digital control loops to enhance their performance. In this context the final performance of a power converter has to be validated by a reference instrument with higher metrological characteristics. In addition, an on-line measurement systemis also needed to digitize the quantity to be controlled with high accuracy. Then, in industrial applications of power converters metrology, specifications are given in terms of Worst-Case Uncertainty (WCU). Therefore, an analytical model for predicting the Worst-Case Uncertainty (WCU) of a measurement system is discussed and detailed for an instrument affected by Gaussian noise. Furthermore, the study and the design of a Reference Acq...

Investigating Enhancement Mode Gallium Nitride Power FETs in High Voltage, High Frequency Soft Switching Converters

DEFF Research Database (Denmark)

Nour, Yasser; Knott, Arnold; Jørgensen, Ivan Harald Holger

2016-01-01

An increased attention has been detected to develop smaller and lighter high voltage power converters in the range of 50V to 400V domain. The main applications for these converters are mainly focused for Power over Ethernet (PoE), LED lighting and AC adapters. This work will discuss a study...

UV-laser microdissection system - A novel approach for the preparation of high-resolution stable isotope records (δ13C/δ18O) from tree rings

Science.gov (United States)

Schollaen, Karina; Helle, Gerhard

2013-04-01

Intra-annual stable isotope (δ13C and δ18O) studies of tree rings at various incremental resolutions have been attempting to extract valuable seasonal climatic and environmental information or assessing plant ecophysiological processes. For preparing high-resolution isotope samples normally wood segments or cores are mechanically divided in radial direction or cut in tangential direction. After mechanical dissection, wood samples are ground to a fine powder and either cellulose is extracted or bulk wood samples are analyzed. Here, we present a novel approach for the preparation of high-resolution stable isotope records from tree rings using an UV-laser microdissection system. Firstly, tree-ring cellulose is directly extracted from wholewood cross-sections largely leaving the wood anatomical structure intact and saving time as compared to the classical procedure. Secondly, micro-samples from cellulose cross-sections are dissected with an UV-Laser dissection microscope. Tissues of interest from cellulose cross-sections are identified and marked precisely with a screen-pen and dissected via an UV-laser beam. Dissected cellulose segments were automatically collected in capsules and are prepared for stable isotope (δ13C and δ18O) analysis. The new techniques facilitate inter- and intra-annual isotope analysis on tree-ring and open various possibilities for comparisons with wood anatomy in plant eco-physiological studies. We describe the design and the handling of this novel methodology and discuss advantages and constraints given by the example of intra-annual oxygen isotope analysis on tropical trees.

Robust sigma delta converters : and their application in low-power highly-digitized flexible receivers

NARCIS (Netherlands)

Veldhoven, van R.H.M.; Roermund, van A.H.M.

2011-01-01

Sigma Delta converters are a very popular choice for the A/D converter in multi-standard, mobile and cellular receivers. Key A/D converter specifications are high dynamic range, robustness, scalability, low-power and low EMI. Robust Sigma Delta Converters presents a requirement derivation of a Sigma

X-Y Converter Family

DEFF Research Database (Denmark)

Bhaskar, Mahajan Sagar; Sanjeevikumar, Padmanaban; Wheeler, Patrick

2016-01-01

A New breed of a buck boost converter, named as the XY converter family is proposed in this article. In the XY family, 16 topologies are presented which are highly suitable for renewable energy applications which require a high ratio of DC-DC converter; such as a photovoltaic multilevel inverter...... system, high voltage automotive applications and industrial drives. Compared to the traditional boost converter and existing recent converters, the proposed XY converter family has the ability to provide a higher output voltage by using less number of power devices and reactive components. Other distinct...... features of the XY converter family are i) Single control switch ii) Provide negative output voltage iii) Non-isolated topologies iv) High conversion ratio without making the use of high duty cycle and v) modular structure. XY family is compared with the recent high step-up converters and the detailed...

Push-pull with recovery stage high-voltage DC converter for PV solar generator

Science.gov (United States)

Nguyen, The Vinh; Aillerie, Michel; Petit, Pierre; Pham, Hong Thang; Vo, Thành Vinh

2017-02-01

A lot of systems are basically developed on DC-DC or DC-AC converters including electronic switches such as MOS or bipolar transistors. The limits of efficiency are quickly reached when high output voltages and high input currents are needed. This work presents a new high-efficiency-high-step-up based on push-pull DC-DC converter integrating recovery stages dedicated to smart HVDC distributed architecture in PV solar energy production systems. Appropriate duty cycle ratio assumes that the recovery stage work with parallel charge and discharge to achieve high step-up voltage gain. Besides, the voltage stress on the main switch is reduced with a passive clamp circuit and thus, low on-state resistance Rdson of the main switch can be adopted to reduce conduction losses. Thus, the efficiency of a basic DC-HVDC converter dedicated to renewable energy production can be further improved with such topology. A prototype converter is developed, and experimentally tested for validation.

Role of light satellites in the high-resolution Earth observation domain

Science.gov (United States)

Fishman, Moshe

1999-12-01

Current 'classic' applications using and exploring space based earth imagery are exclusive, narrow niche tailored, expensive and hardly accessible. On the other side new, inexpensive and widely used 'consumable' applications will be only developed concurrently to the availability of appropriate imagery allowing that process. A part of these applications can be imagined today, like WWW based 'virtual tourism' or news media, but the history of technological, cultural and entertainment evolution teaches us that most of future applications are unpredictable -- they emerge together with the platforms enabling their appearance. The only thing, which can be ultimately stated, is that the definitive condition for such applications is the availability of the proper imagery platform providing low cost, high resolution, large area, quick response, simple accessibility and quick dissemination of the raw picture. This platform is a constellation of Earth Observation satellites. Up to 1995 the Space Based High Resolution Earth Observation Domain was dominated by heavy, super-expensive and very inflexible birds. The launch of Israeli OFEQ-3 Satellite by MBT Division of Israel Aircraft Industries (IAI) marked the entrance to new era of light, smart and cheap Low Earth Orbited Imaging satellites. The Earth Resource Observation System (EROS) initiated by West Indian Space, is based on OFEQ class Satellites design and it is capable to gather visual data of Earth Surface both at high resolution and large image capacity. The main attributes, derived from its compact design, low weight and sophisticated logic and which convert the EROS Satellite to valuable and productive system, are discussed. The major advantages of Light Satellites in High Resolution Earth Observation Domain are presented and WIS guidelines featuring the next generation of LEO Imaging Systems are included.

A voltage to frequency converter for astronomical photometry

Science.gov (United States)

Dunham, E.; Elliot, J. L.

1978-01-01

A voltage to frequency converter (VFC) for general use with photomultipliers is described. For high light levels, when the dead-time corrections for a photon counter would be excessive, the VFC maintains a linear response and allows the recording of data at high time resolution. Results of laboratory tests are given for the signal-to-noise characteristics, linearity, stability, and transient response of the VFC when used in conjunction with EMI 9658 and RCA C31034 photomultipliers.

Structure and Function of Intra-Annual Density Fluctuations: Mind the Gaps.

Science.gov (United States)

Battipaglia, Giovanna; Campelo, Filipe; Vieira, Joana; Grabner, Michael; De Micco, Veronica; Nabais, Cristina; Cherubini, Paolo; Carrer, Marco; Bräuning, Achim; Čufar, Katarina; Di Filippo, Alfredo; García-González, Ignacio; Koprowski, Marcin; Klisz, Marcin; Kirdyanov, Alexander V; Zafirov, Nikolay; de Luis, Martin

2016-01-01

Tree rings are natural archives of climate and environmental information with a yearly resolution. Indeed, wood anatomical, chemical, and other properties of tree rings are a synthesis of several intrinsic and external factors, and their interaction during tree growth. In particular, Intra-Annual Density Fluctuations (IADFs) can be considered as tree-ring anomalies that can be used to better understand tree growth and to reconstruct past climate conditions with intra-annual resolution. However, the ecophysiological processes behind IADF formation, as well as their functional impact, remain unclear. Are IADFs resulting from a prompt adjustment to fluctuations in environmental conditions to avoid stressful conditions and/or to take advantage from favorable conditions? In this paper we discuss: (1) the influence of climatic factors on the formation of IADFs; (2) the occurrence of IADFs in different species and environments; (3) the potential of new approaches to study IADFs and identify their triggering factors. Our final aim is to underscore the advantages offered by network analyses of data and the importance of high-resolution measurements to gain insight into IADFs formation processes and their relations with climatic conditions, including extreme weather events.

Ultra-high resolution protein crystallography

International Nuclear Information System (INIS)

Takeda, Kazuki; Hirano, Yu; Miki, Kunio

2010-01-01

Many protein structures have been determined by X-ray crystallography and deposited with the Protein Data Bank. However, these structures at usual resolution (1.5< d<3.0 A) are insufficient in their precision and quantity for elucidating the molecular mechanism of protein functions directly from structural information. Several studies at ultra-high resolution (d<0.8 A) have been performed with synchrotron radiation in the last decade. The highest resolution of the protein crystals was achieved at 0.54 A resolution for a small protein, crambin. In such high resolution crystals, almost all of hydrogen atoms of proteins and some hydrogen atoms of bound water molecules are experimentally observed. In addition, outer-shell electrons of proteins can be analyzed by the multipole refinement procedure. However, the influence of X-rays should be precisely estimated in order to derive meaningful information from the crystallographic results. In this review, we summarize refinement procedures, current status and perspectives for ultra high resolution protein crystallography. (author)

An intra-neural microstimulation system for ultra-high field magnetic resonance imaging and magnetoencephalography.

Science.gov (United States)

Glover, Paul M; Watkins, Roger H; O'Neill, George C; Ackerley, Rochelle; Sanchez-Panchuelo, Rosa; McGlone, Francis; Brookes, Matthew J; Wessberg, Johan; Francis, Susan T

2017-10-01

Intra-neural microstimulation (INMS) is a technique that allows the precise delivery of low-current electrical pulses into human peripheral nerves. Single unit INMS can be used to stimulate individual afferent nerve fibres during microneurography. Combining this with neuroimaging allows the unique monitoring of central nervous system activation in response to unitary, controlled tactile input, with functional magnetic resonance imaging (fMRI) providing exquisite spatial localisation of brain activity and magnetoencephalography (MEG) high temporal resolution. INMS systems suitable for use within electrophysiology laboratories have been available for many years. We describe an INMS system specifically designed to provide compatibility with both ultra-high field (7T) fMRI and MEG. Numerous technical and safety issues are addressed. The system is fully analogue, allowing for arbitrary frequency and amplitude INMS stimulation. Unitary recordings obtained within both the MRI and MEG screened-room environments are comparable with those obtained in 'clean' electrophysiology recording environments. Single unit INMS (current met. Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.

Comparison of efficacy of intra-articular morphine and steroid in patients with knee osteoarthritis

Directory of Open Access Journals (Sweden)

Serbülent Gökhan Beyaz

2012-01-01

Full Text Available Introduction: Primary therapeutic aim in treatment of osteoarthritis of the knee is to relieve the pain of osteoarthritis. The aim of this study was to compare the efficacy of intra-articular triamcinolone with intra-articular morphine in pain relief due to osteoarthritis of the knee in the elderly population. Materials and Methods: Patients between 50 and 80 years of age were randomized into three groups. Group M received morphine plus bupivacaine intra-articularly, Group T received triamcinolone plus bupivacaine intra-articularly, and Group C received saline plus bupivacaine intra-articularly. Patients were evaluated before injection and in 2nd, 4th, 6th, and 12th weeks after injection. First-line supplementary analgesic was oral paracetamol 1500 mg/day. If analgesia was insufficient with paracetamol, oral dexketoprofen trometamol 50 mg/day was recommended to patients. Results: After the intra-articular injection, there was statistically significant decrease in visual analog scale (VAS scores in Groups M and T, when compared to Group C. The decrease of VAS scores seen at the first 2 weeks continued steadily up to the end of 12th week. There was a significant decrease in Groups M and T in the WOMAC scores, when compared to Group C. There was no significant difference in the WOMAC scores between morphine and steroid groups. Significantly less supplementary analgesics was used in the morphine and steroid groups. Conclusion: Intra-articular morphine was as effective as intra-articular triamcinolone for analgesia in patients with osteoarthritis knee. Intra-articular morphine is possibly a better option than intra-articular steroid as it has lesser side effects.

The implementing of high resolution time measuring circuit based on FPGA

International Nuclear Information System (INIS)

Zhang Ji; Zeng Yun; Wang Zheng; Li Quiju; Lu Jifang; Wu Jinyuan

2011-01-01

It presents the implementing of TDC based on FPGA. The fine timing function part is accomplished through the time interpolators that are composed of the carry chain of intrinsic adders in FPGA. This architecture dates back to the latest technology-WUTDC (Wave Union TDC) that is developed to sub-divide the ultra-wide bins and improve the measure resolution. The board and the online test have been proved that the linearity of converters is satisfying and the time resolution is better than 40 ps. (authors)

High Efficiency Single Output ZVS-ZCS Voltage Doubled Flyback Converter

Science.gov (United States)

Kaliyaperumal, Deepa; Saju, Hridya Merin; Kumar, M. Vijaya

2016-06-01

A switch operating at high switching frequency increases the switching losses of the converter resulting in lesser efficiency. Hence this paper proposes a new topology which has resonant switches [zero voltage switching (ZVS)] in the primary circuit to eliminate the above said disadvantages, and voltage doubler zero current switching (ZCS) circuit in the secondary to double the output voltage, and hence the output power, power density and efficiency. The design aspects of the proposed topology for a single output of 5 V at 50 kHz, its simulation and hardware results are discussed in detail. The analysis of the results obtained from a 2.5 W converter reveals the superiority of the proposed converter.

Performance characteristics of high resolution semiconductor gamma ray spectrometry system

International Nuclear Information System (INIS)

Ko Ko Naing

1994-05-01

A high purity germanium (HPGe) gamma-ray detector has been used in Nuclear Research Laboratory, Department of Physics, Yangon University for over fourteen years. Now it is still being used and it is coupled to new peripheral devices, such as spectroscopy amplifier, analog to digital converter and computer fit-in S-100 multichannel analyser. Therefore, it is necessary to determine the important parameters: energy resolution, detecting efficiency and relative efficiency of the system. In the present work, these parameters were obtained by using mixed calibrated source. The results were compared to the data given by the manufacturer. Moreover, the parameters of another γ-ray detecting system NaI(T1) were also determined. In conclusion the results obtained from the above two measurements were compared and discussed

Performance characteristics of high resolution semiconductor gamma ray spectrometry system

Energy Technology Data Exchange (ETDEWEB)

Naing, Ko Ko

1994-05-01

A high purity germanium (HPGe) gamma-ray detector has been used in Nuclear Research Laboratory, Department of Physics, Yangon University for over fourteen years. Now it is still being used and it is coupled to new peripheral devices, such as spectroscopy amplifier, analog to digital converter and computer fit-in S-100 multichannel analyser. Therefore, it is necessary to determine the important parameters: energy resolution, detecting efficiency and relative efficiency of the system. In the present work, these parameters were obtained by using mixed calibrated source. The results were compared to the data given by the manufacturer. Moreover, the parameters of another {gamma}-ray detecting system NaI(T1) were also determined. In conclusion the results obtained from the above two measurements were compared and discussed

A Four-Phase High Voltage Conversion Ratio Bidirectional DC-DC Converter for Battery Applications

Directory of Open Access Journals (Sweden)

Li-Kun Xue

2015-06-01

Full Text Available This study presents a four-phase interleaved high voltage conversion ratio bidirectional DC-DC converter circuit based on coupled inductors and switched capacitors, which can eliminate the defects of conventional high voltage conversion ratio bidirectional DC-DC converters in terms of high-voltage/current stress, less efficiency and low-power limitation. Parallel channels are used to reduce current stress at the low-voltage side and series connected switched capacitors are used to enlarge voltage conversion ratio, reduce voltage stress and achieve auto current sharing. This paper proposes the operation principle, feature analysis and optimization design considerations. On this basis the objectives of high voltage conversion ratio, low voltage/current stress, high power density, high efficiency and high-power applications can be achieved. Some experimental results based on a 500 W prototype converter (24 V to 48 V at low-voltage side, 400 V at high-voltage side are given to verify the theoretical analysis and the effectiveness of the proposed converter.

Intra- and interrater reliability of the Chicago Classification of achalasia subtypes in pediatric high-resolution esophageal manometry (HRM) recordings

NARCIS (Netherlands)

Singendonk, M. M. J.; Rosen, R.; Oors, J.; Rommel, N.; van Wijk, M. P.; Benninga, M. A.; Nurko, S.; Omari, T. I.

2017-01-01

BackgroundSubtyping achalasia by high-resolution manometry (HRM) is clinically relevant as response to therapy and prognosis have shown to vary accordingly. The aim of this study was to assess inter- and intrarater reliability of diagnosing achalasia and achalasia subtyping in children using the

High-resolution characterization of a hepatocellular carcinoma genome.

Science.gov (United States)

Totoki, Yasushi; Tatsuno, Kenji; Yamamoto, Shogo; Arai, Yasuhito; Hosoda, Fumie; Ishikawa, Shumpei; Tsutsumi, Shuichi; Sonoda, Kohtaro; Totsuka, Hirohiko; Shirakihara, Takuya; Sakamoto, Hiromi; Wang, Linghua; Ojima, Hidenori; Shimada, Kazuaki; Kosuge, Tomoo; Okusaka, Takuji; Kato, Kazuto; Kusuda, Jun; Yoshida, Teruhiko; Aburatani, Hiroyuki; Shibata, Tatsuhiro

2011-05-01

Hepatocellular carcinoma, one of the most common virus-associated cancers, is the third most frequent cause of cancer-related death worldwide. By massively parallel sequencing of a primary hepatitis C virus-positive hepatocellular carcinoma (36× coverage) and matched lymphocytes (>28× coverage) from the same individual, we identified more than 11,000 somatic substitutions of the tumor genome that showed predominance of T>C/A>G transition and a decrease of the T>C substitution on the transcribed strand, suggesting preferential DNA repair. Gene annotation enrichment analysis of 63 validated non-synonymous substitutions revealed enrichment of phosphoproteins. We further validated 22 chromosomal rearrangements, generating four fusion transcripts that had altered transcriptional regulation (BCORL1-ELF4) or promoter activity. Whole-exome sequencing at a higher sequence depth (>76× coverage) revealed a TSC1 nonsense substitution in a subpopulation of the tumor cells. This first high-resolution characterization of a virus-associated cancer genome identified previously uncharacterized mutation patterns, intra-chromosomal rearrangements and fusion genes, as well as genetic heterogeneity within the tumor.

High resolution solar observations

International Nuclear Information System (INIS)

Title, A.

1985-01-01

Currently there is a world-wide effort to develop optical technology required for large diffraction limited telescopes that must operate with high optical fluxes. These developments can be used to significantly improve high resolution solar telescopes both on the ground and in space. When looking at the problem of high resolution observations it is essential to keep in mind that a diffraction limited telescope is an interferometer. Even a 30 cm aperture telescope, which is small for high resolution observations, is a big interferometer. Meter class and above diffraction limited telescopes can be expected to be very unforgiving of inattention to details. Unfortunately, even when an earth based telescope has perfect optics there are still problems with the quality of its optical path. The optical path includes not only the interior of the telescope, but also the immediate interface between the telescope and the atmosphere, and finally the atmosphere itself

High speed, High resolution terahertz spectrometers

International Nuclear Information System (INIS)

Kim, Youngchan; Yee, Dae Su; Yi, Miwoo; Ahn, Jaewook

2008-01-01

A variety of sources and methods have been developed for terahertz spectroscopy during almost two decades. Terahertz time domain spectroscopy (THz TDS)has attracted particular attention as a basic measurement method in the fields of THz science and technology. Recently, asynchronous optical sampling (AOS)THz TDS has been demonstrated, featuring rapid data acquisition and a high spectral resolution. Also, terahertz frequency comb spectroscopy (TFCS)possesses attractive features for high precision terahertz spectroscopy. In this presentation, we report on these two types of terahertz spectrometer. Our high speed, high resolution terahertz spectrometer is demonstrated using two mode locked femtosecond lasers with slightly different repetition frequencies without a mechanical delay stage. The repetition frequencies of the two femtosecond lasers are stabilized by use of two phase locked loops sharing the same reference oscillator. The time resolution of our terahertz spectrometer is measured using the cross correlation method to be 270 fs. AOS THz TDS is presented in Fig. 1, which shows a time domain waveform rapidly acquired on a 10ns time window. The inset shows a zoom into the signal with 100ps time window. The spectrum obtained by the fast Fourier Transformation (FFT)of the time domain waveform has a frequency resolution of 100MHz. The dependence of the signal to noise ratio (SNR)on the measurement time is also investigated

Intra-muscular hemangioma: A review

Directory of Open Access Journals (Sweden)

Shruti Nayak

2014-01-01

Full Text Available Intra-muscular hemangiomas (IMH are relatively uncommon benign vascular tumors, which account for less than 1% of all hemangiomas. IMH may be presented as a perceived sporting injury. Diagnosis of this lesion is important not only because of its rarity, but also due to dangers posed by misdiagnosis and mismanagement. They must be considered in the differential diagnosis of unexplained pain and swelling in muscles. IMH occurring in the oral cavity is reviewed below.

High-resolution Melting Analysis for Gene Scanning of Adenomatous Polyposis Coli (APC) Gene With Oral Squamous Cell Carcinoma Samples.

Science.gov (United States)

Chang, Ya-Sian; Lin, Chien-Yu; Yang, Shu-Fen; Ho, Cheng Mao; Chang, Jan-Gowth

2016-02-01

There have been many different mutations reported for the large adenomatous polyposis coli (APC) tumor suppressor gene. APC mutations result in inactivation of APC tumor suppressor action, allowing the progression of tumorigenesis. The present study utilized a highly efficient method to identify APC mutations and investigated the association between the APC genetic variants Y486Y, A545A, T1493T, and D1822V and susceptibility to oral squamous cell carcinoma (OSCC). High-resolution melting (HRM) analysis was used to characterize APC mutations. Genomic DNA was extracted from 83 patient specimens of OSCC and 50 blood samples from healthy control subjects. The 14 exons and mutation cluster region of exon 15 were screened by HRM analysis. All mutations were confirmed by direct DNA sequencing. Three mutations and 4 single nucleotide polymorphisms (SNPs) were found in this study. The mutations were c.573T>C (Y191Y) in exon 5, c.1005A>G (L335L) in exon 9, and c.1488A>T (T496T) in exon 11. Two SNPs, c.4479G>A (T1493T) and c.5465A>T (D1822V), were located in exon 15, whereas c.1458T>C (Y486Y) and c.1635G>A (A545A) were located in exon 11 and 13, respectively. There was no observed association between OSCC risk and genotype for any of the 4 APC SNPs. The mutation of APC is rare in Taiwanese patients with OSCC. HRM analysis is a reliable, accurate, and fast screening method for APC mutations.

Involvement of transient receptor potential vanilloid 2 in intra-oral incisional pain.

Science.gov (United States)

Urata, K; Shinoda, M; Ikutame, D; Iinuma, T; Iwata, K

2018-03-05

To examine whether transient receptor potential vanilloid 2 (TRPV2) contributes to the changes in intra-oral thermal and mechanical sensitivity following the incision of buccal mucosa. Buccal mucosal pain threshold was measured after the incision. Changes in the number of TRPV2-immunoreactive (IR) trigeminal ganglion (TG) neurons which innervate the whisker pad skin and buccal mucosa, changes in the number of isolectin B4-negative/isolectin B4-positive TRPV2-IR TG neurons which innervate the whisker pad skin and the buccal mucosa, and the effect of peripheral TRPV2 antagonism on the pain threshold of incisional whisker pad skin and buccal mucosa were examined after these injuries. Buccal mucosal pain hypersensitivities were induced on day 3 following the incision. The total number of TRPV2-IR TG neurons and the number of isolectin B4-negative TRPV2-IR TG neurons which innervate the whisker pad skin and buccal mucosa were increased. Buccal mucosal TRPV2 antagonism completely suppressed the heat and mechanical hypersensitivities, but not cold hypersensitivity. TRPV2 antagonist administration to the incisional whisker pad skin only partially suppressed pain hypersensitivities. The increased expression of TRPV2 in peptidergic TG neurons innervating the incisional buccal mucosa is predominantly involved in buccal mucosal heat hyperalgesia and mechanical allodynia following buccal mucosal incision. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd. All rights reserved.

Studies on the reliability of high-field intra-operative MRI in brain glioma resection

Directory of Open Access Journals (Sweden)

Zhi-jun SONG

2011-07-01

Full Text Available Objective To evaluate the reliability of high-field intra-operative magnetic resonance imaging(iMRI in detecting the residual tumors during glioma resection.Method One hundred and thirty-one cases of brain glioma(69 males and 62 females,aged from 7 to 79 years with mean of 39.6 years hospitalized from Nov.2009 to Aug.2010 were involved in present study.All the patients were evaluated using magnetic resonance imaging(MRI before the operation.The tumors were resected under conventional navigation microscope,and the high-field iMRI was used for all the patients when the operators considered the tumor was satisfactorily resected,while the residual tumor was difficult to detect under the microscope,but resected after being revealed by high-field iMRI.Histopathological examination was performed.The patients without residual tumors recieved high-field MRI scan at day 4 or 5 after operation to evaluate the accuracy of high-field iMRI during operation.Results High quality intra-operative images were obtained by using high-field iMRI.Twenty-eight cases were excluded because their residual tumors were not resected due to their location too close to functional area.Combined with the results of intra-operative histopathological examination and post-operative MRI at the early recovery stage,the sensitivity of high-field iMRI in residual tumor diagnosis was 98.0%(49/50,the specificity was 94.3%(50/53,and the accuracy was 96.1%(99/103.Conclusion High-quality intra-operative imaging could be acquired by high-field iMRI,which maybe used as a safe and reliable method in detecting the residual tumors during glioma resection.

Light weight, high power, high voltage dc/dc converter technologies

Science.gov (United States)

Kraus, Robert; Myers, Ira; Baumann, Eric

1990-01-01

Power-conditioning weight reductions by orders of magnitude will be required to enable the megawatt-power-level space systems envisioned by the Strategic Defense Initiative, the Air Force, and NASA. An interagency program has been initiated to develop an 0.1-kg/kW dc/dc converter technology base for these future space applications. Three contractors are in the first phase of a competitive program to develop a megawatt dc/dc converter. Researchers at NASA Lewis Research Center are investigating innovative converter topology control. Three different converter subsystems based on square wave, resonant, and super-resonant topologies are being designed. The components required for the converter designs cover a wide array of technologies. Two different switches, one semiconductor and the other gas, are under development. Issues related to thermal management and material reliability for inductors, transformers, and capacitors are being investigated in order to maximize power density. A brief description of each of the concepts proposed to meet the goals of this program is presented.

High endothelin-converting enzyme-1 expression independently predicts poor survival of patients with esophageal squamous cell carcinoma.

Science.gov (United States)

Wu, Ching-Fang; Lee, Ching-Tai; Kuo, Yao-Hung; Chen, Tzu-Haw; Chang, Chi-Yang; Chang, I-Wei; Wang, Wen-Lun

2017-09-01

Patients with esophageal squamous cell carcinoma have poor survival and high recurrence rate, thus an effective prognostic biomarker is needed. Endothelin-converting enzyme-1 is responsible for biosynthesis of endothelin-1, which promotes growth and invasion of human cancers. The role of endothelin-converting enzyme-1 in esophageal squamous cell carcinoma is still unknown. Therefore, this study investigated the significance of endothelin-converting enzyme-1 expression in esophageal squamous cell carcinoma clinically. We enrolled patients with esophageal squamous cell carcinoma who provided pretreated tumor tissues. Tumor endothelin-converting enzyme-1 expression was evaluated by immunohistochemistry and was defined as either low or high expression. Then we evaluated whether tumor endothelin-converting enzyme-1 expression had any association with clinicopathological findings or predicted survival of patients with esophageal squamous cell carcinoma. Overall, 54 of 99 patients with esophageal squamous cell carcinoma had high tumor endothelin-converting enzyme-1 expression, which was significantly associated with lymph node metastasis ( p = 0.04). In addition, tumor endothelin-converting enzyme-1 expression independently predicted survival of patients with esophageal squamous cell carcinoma, and the 5-year survival was poorer in patients with high tumor endothelin-converting enzyme-1 expression ( p = 0.016). Among patients with locally advanced and potentially resectable esophageal squamous cell carcinoma (stage II and III), 5-year survival was poorer with high tumor endothelin-converting enzyme-1 expression ( p = 0.003). High tumor endothelin-converting enzyme-1 expression also significantly predicted poorer survival of patients in this population. In patients with esophageal squamous cell carcinoma, high tumor endothelin-converting enzyme-1 expression might indicate high tumor invasive property. Therefore, tumor endothelin-converting enzyme-1 expression

High-Resolution Sonars: What Resolution Do We Need for Target Recognition?

Directory of Open Access Journals (Sweden)

Pailhas Yan

2010-01-01

Full Text Available Target recognition in sonar imagery has long been an active research area in the maritime domain, especially in the mine-counter measure context. Recently it has received even more attention as new sensors with increased resolution have been developed; new threats to critical maritime assets and a new paradigm for target recognition based on autonomous platforms have emerged. With the recent introduction of Synthetic Aperture Sonar systems and high-frequency sonars, sonar resolution has dramatically increased and noise levels decreased. Sonar images are distance images but at high resolution they tend to appear visually as optical images. Traditionally algorithms have been developed specifically for imaging sonars because of their limited resolution and high noise levels. With high-resolution sonars, algorithms developed in the image processing field for natural images become applicable. However, the lack of large datasets has hampered the development of such algorithms. Here we present a fast and realistic sonar simulator enabling development and evaluation of such algorithms.We develop a classifier and then analyse its performances using our simulated synthetic sonar images. Finally, we discuss sensor resolution requirements to achieve effective classification of various targets and demonstrate that with high resolution sonars target highlight analysis is the key for target recognition.

The high-grade interpolator: a means for enhancing the resolution of helical computed tomography images of the lung

International Nuclear Information System (INIS)

Garcia-Santos, J. M.; Torres del rio, S.; Blanco, A.; Rodriguez, R.; Parlorio, E.; Garcia, A.; Girela, E.; Hernandez, M. D.; Canteras, M.

2002-01-01

The purpose of this study was to demonstrate that the use of a high-grade interpolator in the reconstruction of images of the chest increases the resolution, independently of the high-resolution filter. Eight independent observers in two groups (experts and non experts) assessed (two readings separated by a time interval) the same section of the chest reconstructed four times (st-st, st-xs, b-st, b-xs), combining standard (st) and high-resolution (b) filters and standard (st) and high-grade (xs) interpolators. The images were classified from greater to lesser in terms of the resolution perceived. The results were used to compare the degree of resolution introduced by the interpolator and the filter and to determine whether or not there existed variability between observers and between the observations of each, and whether experience played a role in the findings. Six of the eight observers assigned the b-xs images the highest degree of resolution in the majority of cases, followed by the b-st image, the st-xs image and, finally, the st-st image). The other tow observers (one expert and one nonexpert) different only with respect to the order of the st-xs and b-st images, which they assigned the second and third places, respectively. The expert group showed no intra observer variability, while two of the nonexpert observers did. The high-grade interpolator enhances the resolution of images of the chest regardless of who evaluates them, while it does not substantially increase image noise. Thus, its use is recommended in helical computed tomography imaging of the lung. (Author) 10 refs

Ultracold neutron detectors based on {sup 10}B converters used in the qBounce experiments

Energy Technology Data Exchange (ETDEWEB)

Jenke, Tobias, E-mail: tjenke@ati.ac.at [Atominstitut TU Wien, Stadionallee 2, 1020 Wien (Austria); Cronenberg, Gunther; Filter, Hanno [Atominstitut TU Wien, Stadionallee 2, 1020 Wien (Austria); Geltenbort, Peter [Institut Laue-Langevin, 6 rue Jules Horowitz, 38042 Grenoble Cedex 9 (France); Klein, Martin [Physikalisches Institut Universität Heidelberg, Im Neuenheimer Feld 226, 69120 Heidelberg (Germany); Lauer, Thorsten [FRM II, TU München, Lichtenbergstraße 1, 85748 Garching (Germany); Mitsch, Kevin [Atominstitut TU Wien, Stadionallee 2, 1020 Wien (Austria); Saul, Heiko [Atominstitut TU Wien, Stadionallee 2, 1020 Wien (Austria); FRM II, TU München, Lichtenbergstraße 1, 85748 Garching (Germany); Seiler, Dominik [Physik Department, TU München, James-Franck-Straße, 85748 Garching (Germany); Stadler, David [Physikalisches Institut Universität Heidelberg, Im Neuenheimer Feld 226, 69120 Heidelberg (Germany); Thalhammer, Martin [Atominstitut TU Wien, Stadionallee 2, 1020 Wien (Austria); Abele, Hartmut, E-mail: abele@ati.ac.at [Atominstitut TU Wien, Stadionallee 2, 1020 Wien (Austria); Physikalisches Institut Universität Heidelberg, Im Neuenheimer Feld 226, 69120 Heidelberg (Germany); Physik Department, TU München, James-Franck-Straße, 85748 Garching (Germany)

2013-12-21

Gravity experiments with very slow, so-called ultracold neutrons connect quantum mechanics with tests of Newton's inverse square law at short distances. These experiments face a low count rate and hence need highly optimized detector concepts. In the frame of this paper, we present low-background ultracold neutron counters and track detectors with micron resolution based on a {sup 10}B converter. We discuss the optimization of {sup 10}B converter layers, detector design and concepts for read-out electronics focusing on high-efficiency and low-background. We describe modifications of the counters that allow one to detect ultracold neutrons selectively on their spin-orientation. This is required for searches of hypothetical forces with spin–mass couplings. The mentioned experiments utilize a beam-monitoring concept which accounts for variations in the neutron flux that are typical for nuclear research facilities. The converter can also be used for detectors, which feature high efficiencies paired with high spatial resolution of 1–2μm. They allow one to resolve the quantum mechanical wave function of an ultracold neutron bound in the gravity potential above a neutron mirror.

High Input Voltage Hall Thruster Discharge Converter, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — The overall scope of this Phase I/II effort is the development of a high efficiency 15kW (nominal) Hall thruster discharge converter. In Phase I, Busek Co. Inc. will...

GOSSIPO-4: an array of high resolution TDCs with a PLL control

International Nuclear Information System (INIS)

Zappon, F; Beuzekom, M van; Gromov, V; Kluit, R; Fang, X; Kruth, A

2012-01-01

GOSSIPO-4 is a prototype chip featuring an array of high resolution Time to Digital Converters with a PLL control that has been taped out the 9th of August 2011. This prototype is the successor of GOSSIPO-3 test chip and the precursor of the 65k pixel chip TimePix3. The prototype is being developed to test a set of new features that will be used in TimePix3, including a 8 pixel structure sharing one fast oscillator with a new topology, a PLL to provide the control voltage to the oscillators, a custom fast counter and a new small-area cell library.

A high voltage ratio and low ripple interleaved DC-DC converter for fuel cell applications.

Science.gov (United States)

Chang, Long-Yi; Chao, Kuei-Hsiang; Chang, Tsang-Chih

2012-01-01

This paper proposes a high voltage ratio and low ripple interleaved boost DC-DC converter, which can be used to reduce the output voltage ripple. This converter transfers the low DC voltage of fuel cell to high DC voltage in DC link. The structure of the converter is parallel with two voltage-doubler boost converters by interleaving their output voltages to reduce the voltage ripple ratio. Besides, it can lower the current stress for the switches and inductors in the system. First, the PSIM software was used to establish a proton exchange membrane fuel cell and a converter circuit model. The simulated and measured results of the fuel cell output characteristic curve are made to verify the correctness of the established simulation model. In addition, some experimental results are made to validate the effectiveness in improving output voltage ripple of the proposed high voltage ratio interleaved boost DC-DC converters.

No protection in chickens immunized by the oral or intra-muscular immunization route with Ascaridia galli soluble antigen

DEFF Research Database (Denmark)

Andersen, Janne Pleidrup; Norup, Liselotte R.; Dalgaard, Tina S.

2013-01-01

In chickens, the nematode Ascaridia galli is found with prevalences of up to 100% causing economic losses to farmers. No avian nematode vaccines have yet been developed and detailed knowledge about the chicken immune response towards A. galli is therefore of great importance. The objective...... of this study was to evaluate the induction of protective immune responses to A. galli soluble antigen by different immunization routes. Chickens were immunized with a crude extract of A. galli via an oral or intra-muscular route using cholera toxin B subunit as adjuvant and subsequently challenged with A...... immunization had an effect on both Th1 and Th2 cytokines in caecal tonsils and Meckel's diverticulum. Thus both humoral and cellular immune responses are inducible by soluble A. galli antigen, but in this study no protection against the parasite was achieved....

High efficiency and high-energy intra-cavity beam shaping laser

International Nuclear Information System (INIS)

Yang, Hailong; Meng, Junqing; Chen, Weibiao

2015-01-01

We present a technology of intra-cavity laser beam shaping with theory and experiment to obtain a flat-top-like beam with high-pulse energy. A radial birefringent element (RBE) was used in a crossed Porro prism polarization output coupling resonator to modulate the phase delay radially. The reflectively of a polarizer used as an output mirror was variable radially. A flat-top-like beam with 72.5 mJ, 11 ns at 20 Hz was achieved by a side-pumped Nd:YAG zigzag slab laser, and the optical-to-optical conversion efficiency was 17.3%. (paper)

High efficiency and high-energy intra-cavity beam shaping laser

Science.gov (United States)

Yang, Hailong; Meng, Junqing; Chen, Weibiao

2015-09-01

We present a technology of intra-cavity laser beam shaping with theory and experiment to obtain a flat-top-like beam with high-pulse energy. A radial birefringent element (RBE) was used in a crossed Porro prism polarization output coupling resonator to modulate the phase delay radially. The reflectively of a polarizer used as an output mirror was variable radially. A flat-top-like beam with 72.5 mJ, 11 ns at 20 Hz was achieved by a side-pumped Nd:YAG zigzag slab laser, and the optical-to-optical conversion efficiency was 17.3%.

High-Voltage DC-DC Converter Topology for PV Energy Utilization - Investigation and Implementation

DEFF Research Database (Denmark)

Sanjeevikumar, Padmanaban; Blaabjerg, Frede; Wheeler, Patrick

2017-01-01

This paper exploited the utilization of photovoltaic (PV) energy system with high-voltage (HV) output DC-DC converter. Classical boost converters are used for both renewable energy integration and HV applications, but limited by reducing output/efficiency in performance. Moreover, as parasitic...... elements suppress the power transfer ratio, converter needs to maximize the PV energy utilization. This investigation study focused to include additional parasitic elements (voltage-lift technique) to a standard DC-DC buck converter and to overcome all the above drawbacks to maximize the PV power...

An FPGA-Integrated Time-to-Digital Converter Based on a Ring Oscillator for Programmable Delay Line Resolution Measurement

Directory of Open Access Journals (Sweden)

Chao Chen

2014-01-01

Full Text Available We describe the architecture of a time-to-digital converter (TDC, specially intended to measure the delay resolution of a programmable delay line (PDL. The configuration, which consists of a ring oscillator, a frequency divider (FD, and a period measurement circuit (PMC, is implemented in a field programmable gate array (FPGA device. The ring oscillator realized in loop containing a PDL and a look-up table (LUT generates periodic oscillatory pulses. The FD amplifies the oscillatory period from nanosecond range to microsecond range. The time-to-digital conversion is based on counting the number of clock cycles between two consecutive pulses of the FD by the PMC. Experiments have been conducted to verify the performance of the TDC. The achieved relative errors for four PDLs are within 0.50%–1.21% and the TDC has an equivalent resolution of about 0.4 ps.

High-efficiency broadband polarization converter based on Ω-shaped metasurface

Science.gov (United States)

Zhang, Tianyao; Huang, Lingling; Li, Xiaowei; Liu, Juan; Wang, Yongtian

2017-11-01

The polarization state, which cannot be directly detected by human eyes, forms an important characteristic of electromagnetic waves. Control of polarization states has long been pursued for various applications. Conventional polarization converters can hardly meet the requirements in lab-on-chip systems, due to the involvement of bulk materials. Here, we propose the design and realization of a linear to circular polarization converter based on metasurfaces. The metasurface is deliberately designed using achiral two-fold mirror symmetry Ω-shaped antennas. The converter integrates a ground metal plane, a spacer dielectric layer and an antenna array, leading to a high conversion efficiency and broad operating bandwidth in the near infrared regime. The calculated Stokes parameters indicate an excellent conversion of linear to circular polarization for the reflected light. The tunability of the bandwidth by oblique incidence and by modulating the thickness of the dielectric layer is also introduced and demonstrated, which shows great flexibilities for such metasurface converters. The proposed metasurface may open up intriguing possibilities towards the realization of ultrathin nanophotonic devices for polarization manipulation and wavefront engineering.

Inter- and intra-agglomerate fracture in nanocrystalline nickel.

Science.gov (United States)

Shan, Zhiwei; Knapp, J A; Follstaedt, D M; Stach, E A; Wiezorek, J M K; Mao, S X

2008-03-14

In situ tensile straining transmission electron microscopy tests have been carried out on nanocrystalline Ni. Grain agglomerates (GAs) were found to form very frequently and rapidly ahead of an advancing crack with sizes much larger than the initial average grain size. High-resolution electron microscopy indicated that the GAs most probably consist of nanograins separated by low-angle grain boundaries. Furthermore, both inter- and intra-GA fractures were observed. The observations suggest that these newly formed GAs may play an important role in the formation of the dimpled fracture surfaces of nanocrystalline materials.

Oral Candida colonization in oral cancer patients and its relationship with traditional risk factors of oral cancer: a matched case-control study.

Science.gov (United States)

Alnuaimi, Ali D; Wiesenfeld, David; O'Brien-Simpson, Neil M; Reynolds, Eric C; McCullough, Michael J

2015-02-01

Candida, an opportunistic fungal pathogen, has been implicated in oral and oesophageal cancers. This study aimed to examine oral Candida carriage in 52 oral cancer patients and 104 age-, gender- and denture status-matched oral cancer-free subjects. We assessed general health, smoking and alcohol drinking habits, use of alcohol-containing mouthwash and periodontal status (community periodontal index of treatment needs). Yeasts were isolated using oral rinse technique and genetically identified via Real-Time PCR-High resolution melting curve analysis of conserved ribosomal DNA. Conditional and binary logistic regressions were used to identify explanatory variables that are risk factors for oral cancer. The frequencies of oral yeasts' presence and high oral colonization were significantly higher in oral cancer than non-oral cancer patients (p=001; p=0.033, respectively). No significant difference in the isolation profile of Candida species was found between the two groups, except C. parapsilosis was more frequent in non-oral cancer group. Differences were noticed in the incidence of C. albicans strains where significantly more C. albicans genotype-A was isolated from cancer patients and significantly more C. albicans genotype-B isolated from non-cancer patients. Multiple regression analyses showed significant association with cancer observed for alcohol drinking (OR=4.253; 95% CI=1.351, 13.386), Candida presence (OR=3.242; 95% CI=1.505, 6.984) and high oral colonization (OR=3.587; 95% CI=1.153, 11.162). These results indicate that there is a significant association between oral cancer occurrence and Candida oral colonization and that the observed genotypic diversity of C. albicans strains may play a role in oral carcinogenesis. Copyright © 2014 Elsevier Ltd. All rights reserved.

Oral cancer.

Science.gov (United States)

Gerson, S J

1990-01-01

In the U.S. oral cancer accounts for 2.1% of all cancers and 1% of cancer deaths. Two to three times as many males as females are affected. Blacks have more intra-oral cancer than whites, and their incidence and mortality rates have increased in recent years. The etiologic process very likely involves several factors. The major etiologic agents are tobacco (all types) and alcoholic beverages. Herpes simplex virus, human papilloma virus, and Candida have been implicated. Host factors include poor state of dentition, nutritional aberrations, cirrhosis of liver, lichen planus, and immunologic impairmant. Cellular changes include amplification of some oncogenes, alterations in antigen expression, production of gamma-glutamyl transpeptidase, and disturbance of keratin and involucrin production. Experimentally, cancer is readily produced on the hamster cheek pouch and rat oral mucosa. Unlike oral cancer in humans, most experimental lesions are exophytic, and they rarely metastasize.

A high speed digital-to-analogue converter

International Nuclear Information System (INIS)

Hallgren, B.I.

1974-02-01

An 8-bit Digital-to-Analogue converter of the current-weighting type has been constructed using 8 monolithic integrated circuit transistor arrays -one for each bit. The D/A-converter has a voltage output within the range 0 to -2V. The settling time to within half of the least significant bit is about 50 nsec. The temperature dependence and transient response of the converter has been analysed using computer aided design techniques. A comparison is made between the experimental and simulated transient performance. (Auth.)

AC Voltage Control of DC/DC Converters Based on Modular Multilevel Converters in Multi-Terminal High-Voltage Direct Current Transmission Systems

Directory of Open Access Journals (Sweden)

Rui Li

2016-12-01

Full Text Available The AC voltage control of a DC/DC converter based on the modular multilevel converter (MMC is considered under normal operation and during a local DC fault. By actively setting the AC voltage according to the two DC voltages of the DC/DC converter, the modulation index can be near unity, and the DC voltage is effectively utilized to output higher AC voltage. This significantly decreases submodule (SM capacitance and conduction losses of the DC/DC converter, yielding reduced capital cost, volume, and higher efficiency. Additionally, the AC voltage is limited in the controllable range of both the MMCs in the DC/DC converter; thus, over-modulation and uncontrolled currents are actively avoided. The AC voltage control of the DC/DC converter during local DC faults, i.e., standby operation, is also proposed, where only the MMC connected on the faulty cable is blocked, while the other MMC remains operational with zero AC voltage output. Thus, the capacitor voltages can be regulated at the rated value and the decrease of the SM capacitor voltages after the blocking of the DC/DC converter is avoided. Moreover, the fault can still be isolated as quickly as the conventional approach, where both MMCs are blocked and the DC/DC converter is not exposed to the risk of overcurrent. The proposed AC voltage control strategy is assessed in a three-terminal high-voltage direct current (HVDC system incorporating a DC/DC converter, and the simulation results confirm its feasibility.

Design of the Trap Filter for the High Power Converters with Parallel Interleaved VSCs

DEFF Research Database (Denmark)

Gohil, Ghanshyamsinh Vijaysinh; Bede, Lorand; Teodorescu, Remus

2014-01-01

The power handling capability of the state-of-the-art semiconductor devices is limited. Therefore, the Voltage Source Converters (VSCs) are often connected in parallel to realize high power converter. The switching frequency semiconductor devices, used in the high power VSCs, is also limited...

[To bite or to scan? Dental impressions with alginate, PVS or -intra-oral scanning; processing time and patient comfort. A pilotstudy].

Science.gov (United States)

Darroudi, M; Ariens, Z P A; Zinsmeister, V Z; Breuning, K H

2017-02-01

In recent years technology has enabled dental professionals to make digital dental models using intra-oral scanners. In a study involving 10 test cases, a comparison was made between the digital impression technique and 2 -conventional impression techniques, using alginate and Polivinyl Syloxane™. With the 3 different techniques, dental impressions were made of the lower and upper arches; the processing time required for each and the differences in patient comfort were recorded. The individuals in the test cases experienced no difference in comfort between the alginate and the digital impression. The impression technique involving Polivinyl Syloxane™ was experienced as less comfortable. The digital impression technique appeared to be the most time consuming.

A 380 V High Efficiency and High Power Density Switched-Capacitor Power Converter using Wide Band Gap Semiconductors

DEFF Research Database (Denmark)

Fan, Lin; Knott, Arnold; Jørgensen, Ivan Harald Holger

2018-01-01

. This paper presents such a high voltage low power switched-capacitor DC-DC converter with an input voltage upto 380 V (compatible with rectified European mains) and an output power experimentally validated up to 21.3 W. The wideband gap semiconductor devices of GaN switches and SiC diodes are combined...... to compose the proposed power stage. Their switching and loss characteristics are analyzed with transient waveforms and thermal images. Different isolated driving circuits are compared and a compact isolated halfbridge driving circuit is proposed. The full-load efficiencies of 98.3% and 97.6% are achieved......State-of-the-art switched-capacitor DC-DC power converters mainly focus on low voltage and/or high power applications. However, at high voltage and low power levels, new designs are anticipated to emerge and a power converter that has both high efficiency and high power density is highly desirable...

Berkeley High-Resolution Ball

International Nuclear Information System (INIS)

Diamond, R.M.

1984-10-01

Criteria for a high-resolution γ-ray system are discussed. Desirable properties are high resolution, good response function, and moderate solid angle so as to achieve not only double- but triple-coincidences with good statistics. The Berkeley High-Resolution Ball involved the first use of bismuth germanate (BGO) for anti-Compton shield for Ge detectors. The resulting compact shield permitted rather close packing of 21 detectors around a target. In addition, a small central BGO ball gives the total γ-ray energy and multiplicity, as well as the angular pattern of the γ rays. The 21-detector array is nearly complete, and the central ball has been designed, but not yet constructed. First results taken with 9 detector modules are shown for the nucleus 156 Er. The complex decay scheme indicates a transition from collective rotation (prolate shape) to single- particle states (possibly oblate) near spin 30 h, and has other interesting features

Study of GaN nanorods converted from β-Ga2O3

Science.gov (United States)

Li, Yuewen; Xiong, Zening; Zhang, Dongdong; Xiu, Xiangqian; Liu, Duo; Wang, Shuang; Hua, Xuemei; Xie, Zili; Tao, Tao; Liu, Bin; Chen, Peng; Zhang, Rong; Zheng, Youdou

2018-05-01

We report here high-quality β-Ga2O3 nanorods (NRs) grown on sapphire substrates by hydrothermal method. Ammoniating the β-Ga2O3 NRs results in strain-free wurtzite gallium nitride (GaN) NRs. It was shown by XRD and Raman spectroscopy that β-Ga2O3 was partially converted to GaN/β-Ga2O3 at 1000 °C and then completely converted to GaN NRs at 1050 °C, as confirmed by high-resolution transmission electron microscopy (HRTEM). There is no band-edge emission of β-Ga2O3 in the cathodoluminescence spectrum, and only a deep-level broad emission observed at 3.68-3.73 eV. The band edge emission (3.39 eV) of GaN NRs converted from β-Ga2O3 can also be observed.

Dual-band high-efficiency polarization converter using an anisotropic metasurface

Science.gov (United States)

Lin, Baoqin; Wang, Buhong; Meng, Wen; Da, Xinyu; Li, Wei; Fang, Yingwu; Zhu, Zihang

2016-05-01

In this work, a dual-band and high-efficiency reflective cross-polarization converter based on an anisotropic metasurface for linearly polarized electromagnetic waves is proposed. Its unit cell is composed of an elliptical disk-ring mounted on grounded dielectric substrate, which is an anisotropic structure with a pair of mutually perpendicular symmetric axes u and v along ± 45 ° directions with respect to y-axis direction. Both the simulation and measured results show that the polarization converter can convert x- or y-polarized incident wave to its cross polarized wave in the two frequency bands (6.99-9.18 GHz, 11.66-20.40 GHz) with the conversion efficiency higher than 90%; moreover, the higher frequency band is an ultra-wide one with a relative bandwidth of 54.5% for multiple plasmon resonances. In addition, we present a detailed analysis for the polarization conversion of the polarization converter, and derive a formula to calculate the cross- and co-polarization reflections at y-polarized incidence according to the phase differences between the two reflected coefficients at u-polarized and v-polarized incidences. The simulated, calculated, and measured results are all in agreement with the entire frequency regions.

US Mains Stacked Very High Frequency Self-oscillating Resonant Power Converter with Unified Rectifier

DEFF Research Database (Denmark)

Pedersen, Jeppe Arnsdorf; Madsen, Mickey Pierre; Mønster, Jakob Døllner

2016-01-01

This paper describes a Very High Frequency (VHF) converter made with three Class-E inverters and a single ClassDE rectifier. The converter is designed for the US mains (120 V, 60 Hz) and can deliver 9 W to a 60 V LED. The converter has a switching frequency of 37 MHz and achieves an efficiency...

A new soft-switched high step-up DC-DC converter with dual coupled inductors

DEFF Research Database (Denmark)

Forouzesh, Mojtaba; Shen, Yanfeng; Yari, Keyvan

2017-01-01

This paper introduces a new efficient high step-up dc-dc converter with a shared input path and dual series coupled inductors at the output. This converter is suitable for high power applications due to its shared input current that puts low current stresses on the low voltage side switches...

High Channel Count Time-to-Digital Converter and Lasercom Processor, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — High-channel-count, high-precision, and high-throughput time-to-digital converters (TDC) are needed to support detector arrays used in deep-space optical...

Oral chlorhexidine and microbial contamination during endoscopy

DEFF Research Database (Denmark)

Donatsky, Anders Meller; Holzknecht, Barbara Juliane; Arpi, Magnus

2013-01-01

BACKGROUND: One of the biggest concerns associated with transgastric surgery is contamination and risk of intra-abdominal infection with microbes introduced from the access route. The purpose of this study was to evaluate the effect of oral decontamination with chlorhexidine on microbial contamin......BACKGROUND: One of the biggest concerns associated with transgastric surgery is contamination and risk of intra-abdominal infection with microbes introduced from the access route. The purpose of this study was to evaluate the effect of oral decontamination with chlorhexidine on microbial...... contamination of the endoscope. METHODS: In a prospective, randomized, single-blinded, clinical trial the effect of chlorhexidine mouth rinse was evaluated. As a surrogate for the risk of intra-abdominal contamination during transgastric surgery, microbial contamination of the endoscope during upper endoscopy...... microbial contamination of the endoscope, but micro-organisms with abscess forming capabilities were still present. PPI treatment significantly increased CFU and should be discontinued before transgastric surgery....

High-Resolution PET Detector. Final report

International Nuclear Information System (INIS)

Karp, Joel

2014-01-01

The objective of this project was to develop an understanding of the limits of performance for a high resolution PET detector using an approach based on continuous scintillation crystals rather than pixelated crystals. The overall goal was to design a high-resolution detector, which requires both high spatial resolution and high sensitivity for 511 keV gammas. Continuous scintillation detectors (Anger cameras) have been used extensively for both single-photon and PET scanners, however, these instruments were based on NaI(Tl) scintillators using relatively large, individual photo-multipliers. In this project we investigated the potential of this type of detector technology to achieve higher spatial resolution through the use of improved scintillator materials and photo-sensors, and modification of the detector surface to optimize the light response function.We achieved an average spatial resolution of 3-mm for a 25-mm thick, LYSO continuous detector using a maximum likelihood position algorithm and shallow slots cut into the entrance surface

Crop Yield Predictions - High Resolution Statistical Model for Intra-season Forecasts Applied to Corn in the US

Science.gov (United States)

Cai, Y.

2017-12-01

Accurately forecasting crop yields has broad implications for economic trading, food production monitoring, and global food security. However, the variation of environmental variables presents challenges to model yields accurately, especially when the lack of highly accurate measurements creates difficulties in creating models that can succeed across space and time. In 2016, we developed a sequence of machine-learning based models forecasting end-of-season corn yields for the US at both the county and national levels. We combined machine learning algorithms in a hierarchical way, and used an understanding of physiological processes in temporal feature selection, to achieve high precision in our intra-season forecasts, including in very anomalous seasons. During the live run, we predicted the national corn yield within 1.40% of the final USDA number as early as August. In the backtesting of the 2000-2015 period, our model predicts national yield within 2.69% of the actual yield on average already by mid-August. At the county level, our model predicts 77% of the variation in final yield using data through the beginning of August and improves to 80% by the beginning of October, with the percentage of counties predicted within 10% of the average yield increasing from 68% to 73%. Further, the lowest errors are in the most significant producing regions, resulting in very high precision national-level forecasts. In addition, we identify the changes of important variables throughout the season, specifically early-season land surface temperature, and mid-season land surface temperature and vegetation index. For the 2017 season, we feed 2016 data to the training set, together with additional geospatial data sources, aiming to make the current model even more precise. We will show how our 2017 US corn yield forecasts converges in time, which factors affect the yield the most, as well as present our plans for 2018 model adjustments.

Design and experiment of a cross-shaped mode converter for high-power microwave applications

Energy Technology Data Exchange (ETDEWEB)

Peng, Shengren, E-mail: 785751053@qq.com; Yuan, Chengwei; Zhong, Huihuang; Fan, Yuwei [College of Optoelectronic Science and Engineering, National University of Defense Technology, Changsha 410073 (China)

2013-12-15

A compact mode converter, which is capable of converting a TM{sub 01} mode into a circularly polarized TE{sub 11} mode, was developed and experimentally studied with high-power microwaves. The converter, consisting of two turnstile junctions, is very short along the wave propagation direction, and therefore is suitable for designing compact and axially aligned high-power microwave radiation systems. In this paper, the principle of a converter working at 1.75 GHz is demonstrated, as well as the experimental results. The experimental and simulation results are in good agreement. At the center frequency, the conversion efficiency is more than 95%, the measured axial ratio is about 0.4 dB, and the power-handing capacity is excess of 1.9 GW.

Reduction of the jitter of single-flux-quantum time-to-digital converters for time-of-flight mass spectrometry

International Nuclear Information System (INIS)

Sano, K.; Muramatsu, Y.; Yamanashi, Y.; Yoshikawa, N.; Zen, N.; Ohkubo, M.

2014-01-01

Highlights: • We proposed single-flux-quantum (SFQ) time-to-digital converters (TDCs) for TOF-MS. • SFQ TDC can measure time intervals between multiple signals with high-resolution. • SFQ TDC can directly convert the time intervals into binary data. • We designed two types of SFQ TDCs to reduce the jitter. • The jitter is reduced to less than 100 ps. - Abstract: We have been developing a high-resolution superconducting time-of-flight mass spectrometry (TOF-MS) system, which utilizes a superconducting strip ion detector (SSID) and a single-flux-quantum (SFQ) time-to-digital converter (TDC). The SFQ TDC can measure time intervals between multiple input signals and directly convert them into binary data. In our previous study, 24-bit SFQ TDC with a 3 × 24-bit First-In First-Out (FIFO) buffer was designed and implemented using the AIST Nb standard process 2 (STP2), whose time resolution and dynamic range are 100 ps and 1.6 ms, respectively. In this study we reduce the jitter of the TDC by using two different approaches: one uses an on-chip clock generator with an on-chip low-pass filter for reducing the noise in the bias current, and the other uses a low-jitter external clock source at room temperature. We confirmed that the jitter is reduced to less than 100 ps in the latter approach

Reduction of the jitter of single-flux-quantum time-to-digital converters for time-of-flight mass spectrometry

Energy Technology Data Exchange (ETDEWEB)

Sano, K., E-mail: sano-kyosuke-cw@ynu.jp [Department Electrical and Computer Engineering, Yokohama National University, 79-5 Tokiwadai, Hodogaya, Yokohama 240-8501 (Japan); Muramatsu, Y.; Yamanashi, Y.; Yoshikawa, N. [Department Electrical and Computer Engineering, Yokohama National University, 79-5 Tokiwadai, Hodogaya, Yokohama 240-8501 (Japan); Zen, N.; Ohkubo, M. [Research Institute of Instrumentation Frontier, National Institute of Advanced Industrial Science and Technology, 1-1-1 Umezono, Tsukuba 305-8568 (Japan)

2014-09-15

Highlights: • We proposed single-flux-quantum (SFQ) time-to-digital converters (TDCs) for TOF-MS. • SFQ TDC can measure time intervals between multiple signals with high-resolution. • SFQ TDC can directly convert the time intervals into binary data. • We designed two types of SFQ TDCs to reduce the jitter. • The jitter is reduced to less than 100 ps. - Abstract: We have been developing a high-resolution superconducting time-of-flight mass spectrometry (TOF-MS) system, which utilizes a superconducting strip ion detector (SSID) and a single-flux-quantum (SFQ) time-to-digital converter (TDC). The SFQ TDC can measure time intervals between multiple input signals and directly convert them into binary data. In our previous study, 24-bit SFQ TDC with a 3 × 24-bit First-In First-Out (FIFO) buffer was designed and implemented using the AIST Nb standard process 2 (STP2), whose time resolution and dynamic range are 100 ps and 1.6 ms, respectively. In this study we reduce the jitter of the TDC by using two different approaches: one uses an on-chip clock generator with an on-chip low-pass filter for reducing the noise in the bias current, and the other uses a low-jitter external clock source at room temperature. We confirmed that the jitter is reduced to less than 100 ps in the latter approach.

Analysis of a high power, resonant DC-DC converter for DC wind turbines

DEFF Research Database (Denmark)

Dincan, Catalin Gabriel; Kjær, Philip Carne; Chen, Yu-Hsing

2018-01-01

This paper is introducing a new method of operation for a series resonant converter, with intended application in megawatt high-voltage DC wind turbines. Compared to a frequency controlled series resonant converter operated in sub resonant mode, the method (entitled pulse removal technique) allows...

A contribution to the design of fast code converters for position encoders

Science.gov (United States)

Denic, Dragan B.; Dincic, Milan R.; Miljkovic, Goran S.; Peric, Zoran H.

2016-10-01

Pseudorandom binary sequences (PRBS) are very useful in many areas of applications. Absolute position encoders based on PRBS have many advantages. However, the pseudorandom code is not directly applicable to the digital electronic systems, hence a converter from pseudorandom to natural binary code is needed. Recently, a fast pseudorandom/natural code converter based on Galois PRBS generator (much faster than previously used converter based on Fibonacci PRBS generator) was proposed. One of the main parts of the Galois code converter is an initial logic. The problem of the design of the initial logic has been solved only for some single values of resolution, but it is still not solved for any value of resolution, which significantly limits the applicability of the fast Galois code converter. This paper solves this problem presenting the solution for the design of the initial logic of the fast Galois pseudorandom/natural code converters used in the pseudorandom position encoders, in general manner, that is for any value of the resolution, allowing for a wide applicability of the fast Galois pseudorandom position encoders. Rigorous mathematical derivation of the formula for the designing of the initial logic is presented. Simulation of the proposed converter is performed in NI MultiSim software. The proposed solution, although developed for pseudorandom position encoders, can be used in many other fields where PRBS are used.

Application of a High-Power Reversible Converter in a Hybrid Traction Power Supply System

Directory of Open Access Journals (Sweden)

Gang Zhang

2017-03-01

Full Text Available A high-power reversible converter can achieve a variety of functions, such as recovering regenerative braking energy, expanding traction power capacity, and improving an alternating current (AC grid power factor. A new hybrid traction power supply scheme, which consists of a high-power reversible converter and two 12-pulse diode rectifiers, is proposed. A droop control method based on load current feed-forward is adopted to realize the load distribution between the reversible converter and the existing 12-pulse diode rectifiers. The direct current (DC short-circuit characteristics of the reversible converter is studied, then the relationship between the peak fault current and the circuit parameters is obtained from theoretical calculations and validated by computer simulation. The first two sets of 2 MW reversible converters have been successfully applied in Beijing Metro Line 10, the proposed hybrid application scheme and coordinated control strategy are verified, and 11.15% of average energy-savings is reached.

A High-Frequency Isolation (HFI Charging DC Port Combining a Front-End Three-Level Converter with a Back-End LLC Resonant Converter

Directory of Open Access Journals (Sweden)

Guowei Cai

2017-09-01

Full Text Available The high-frequency isolation (HFI charging DC port can serve as the interface between unipolar/bipolar DC buses and electric vehicles (EVs through the two-power-stage system structure that combines the front-end three-level converter with the back-end logical link control (LLC resonant converter. The DC output voltage can be maintained within the desired voltage range by the front-end converter. The electrical isolation can be realized by the back-end LLC converter, which has the bus converter function. According to the three-level topology, the low-voltage rating power devices can be adapted for half-voltage stress of the total DC grid, and the PWM phase-shift control can double the equivalent switching frequency to greatly reduce the filter volume. LLC resonant converters have advance characteristics of inverter-side zero-voltage-switching (ZVS and rectifier-side zero-current switching (ZCS. In particular, it can achieve better performance under quasi-resonant frequency mode. Additionally, the magnetizing current can be modified following different DC output voltages, which have the self-adaptation ZVS condition for decreasing the circulating current. Here, the principles of the proposed topology are analyzed in detail, and the design conditions of the three-level output filter and high-frequency isolation transformer are explored. Finally, a 20 kW prototype with the 760 V input and 200–500 V output are designed and tested. The experimental results are demonstrated to verify the validity and performance of this charging DC port system structure.

Halo sign nodules in angio invasive pulmonary aspergillosis: correlation of high-resolution computed tomography findings with anatomopathology; Nodulos com sinal do halo na aspergilose pulmonar angioinvasiva: correlacao da tomografia computadorizada de alta resolucao com a anatomopatologia

Energy Technology Data Exchange (ETDEWEB)

Marchiori, Edson [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Dept. de Radiologia; Valiante, Paulo Marcos [Universidade Federal, Rio de Janeiro, RJ (Brazil). Dept. de Patologia; Souza Junior, Arthur Soares [Faculdade de Medicina de Sao Jose do Rio Preto (FAMERP), SP (Brazil). Disciplina de Radiologia

2002-08-01

The aim of this study was to correlate the early findings observed on high-resolution computed tomography with anatomopathology results of patients with angio invasive aspergillosis. The authors studied two patients with leukemia. The nodules seen on high-resolution computed tomography corresponded to areas of hemorrhagic infarction, necrotic coagulation and fungal hyphae infiltration whereas ground glass halo corresponded to intra alveolar hemorrhage. Nodules with halo sign were closely correlated with anatomopathology findings. We concluded that the anatomopathology findings can clearly explain the image features of the lesions observed on high-resolution computed tomography. (author)

Awareness, Attitude and Oral Hygiene Practices of 5 and 12 year old ...

African Journals Online (AJOL)

Method: A questionnaire asking about oral health care, their oral hygiene practices, reasons for tooth cleaning, causes of tooth decay, sources of their information and frequency of dental visit was administered to them followed by intra-oral examination to assess the level of oral cleanliness using the Plaque Index (which is ...

New DC/DC High Step Up Isolated Converter with ZVS

Directory of Open Access Journals (Sweden)

Ehsan Movahedi

2014-10-01

Full Text Available In this paper we presents a soft switch sepic, flyback converter. At first the converter have hard switching in main switch and completely analysis then added auxiliary circuit for soft switching Auxiliary circuit in the converter is not only soft switching condition for the main switch but also prevents the spike voltage across the main switch when turned off that because leakage inductance. Therefore, the proposed converter efficiency in comparison with the previous converters increased and voltage stress on the main switch is reduced. Also the auxiliary switch in the converter have soft switching and thereby decrese losses. this converter Control with pwm.These converter have higher efficiency than the similar converters and the cost is low. Auxiliary circuit in the converter is not only soft switching condition for the main switch but also prevents the spike voltage across the main switch when turned off that because leakage inductance. Therefore, the proposed converter efficiency in comparison with the previous converters increased and voltage stress on the main switch is reduced.

Acute Abdomen Due to Uncontrolled Use of Warfarin: Spontaneous Intra-abdominal

Directory of Open Access Journals (Sweden)

Fatih Dal

2017-12-01

Full Text Available Warfarin is an oral anticoagulant, which is commonly used in the treatment and prophylaxis of thromboembolic conditions. Bleeding is the primary adverse effect associated with warfarin. The majority of warfarin-related bleedings are spontaneous minor hemorrhages occurring in the subcutaneous or intramuscular tissues and can be treated by decreasing the dose of oral anticoagulants. However, although rare, it is possible to encounter spontaneous major bleedings with increased risk of mortality. Conservative approach is the preferred initial therapy for hemodynamically stable patients with major intra-abdominal hemorrhages that we define as the intermediate group patients. Nevertheless, surgery is required for hemodynamically unstable patients with acute abdominal pain in cases of ongoing active hemorrhage, generalized peritonitis, obstruction, acute abdomen, intestinal ischemia, and perforation. In this article, we present a rare case of acute abdomen and spontaneous intra-abdominal hemorrhage resulting from uncontrolled use of warfarin and a new classification requirement.

Oral pulsed high-dose dexamethasone for myositis

NARCIS (Netherlands)

van der Meulen, M. F.; Hoogendijk, J. E.; Wokke, J. H.; de Visser, M.

2000-01-01

To study the short-term effect of oral pulsed high-dose dexamethasone for myositis we treated eight newly diagnosed patients with three 28-day cycles of oral dexamethasone. Primary outcome measures were muscle strength, pain, and serum creatine kinase activity. Six patients responded. Side effects

Laparoscopic Stephen-Fowler stage procedure: appropriate management for high intra-abdominal testes.

Science.gov (United States)

Agrawal, Amit; Joshi, Milind; Mishra, Pankaj; Gupta, Rahul; Sanghvi, Beejal; Parelkar, Sandesh

2010-03-01

The length of testicular vessels is the main length-limiting factor to bring down the testes in the scrotum. Fowler and Stephen proposed the division of testicular vessels, high and as far from the testes as possible to maintain collateral blood supply, to treat high intra-abdominal testes. Cortesi introduced the diagnostic laparoscopy and Jorden first did the laparoscopic orchiopexy for nonpalpable testes. We had done Fowler-Stephen staged orchiopexy for high intra-abdominal testes, in which both stages were done laparoscopically. In total, 17 testes of 13 patients had undergone laparoscopic staged Fowler-Stephen orchiopexy. The decision to perform a staged Fowler-Stephen orchiopexy was based on the distance of the testis from the deep inguinal ring on laparoscopy. If distance was more than 2.5 cm, then we proceeded to a laparoscopic staged Fowler-Stephen orchiopexy. In the first stage, testicular vessels were cauterized by bipolar diathermy. Laparoscopic second-stage Fowler-Stephen procedure was done 6 months after the first stage. Patients were regularly followed, and the success of the procedure was assessed by the size of the testes and the position in the scrotum. Testicular vascularity was assessed by color Doppler ultrasonography. There was no testicular atrophy on second stage and on follow-up. All testes were in the scrotum with good size on follow-up. There was no complication related to laparoscopy. In cases of high intra-abdominal testes, the staged Fowler-Stephen procedure should be the procedure of choice. This procedure yields a high success rate. Transaction of vessels by bipolar diathermy is a very safe, cost-effective method.

The clinical effect of combination therapy for oral cancer with S-1, superselective intra-arterial chemotherapy, and radiation therapy

International Nuclear Information System (INIS)

Yamamoto, Chika; Yoshikawa, Hiromasa; Fukumoto, Shunsuke; Higuchi, Takashi; Yoshida, Masanori; Yasumori, Koutarou; Horinouchi, Yasufumi; Uehara, Satoru

2011-01-01

Combination therapy with S-1, superselective intra-arterial infusion of carboplatin (CBDCA) and radiation therapy has been used to treat patients with oral cancer since 2005. In this study, the histopathological effects and toxicities following concurrent chemoradiotherapy were examined. The subjects consisted of 15 patients (10 men and 5 women) who were treated with S-1 (60-80 mg/day, 4 weeks), superselective intra-arterial infusion of CBDCA (300 mg/body) and radiation therapy (total dose 30-36 Gy) in our department from 2005 to 2009. Nine patients, showed T2 disease, 3 showed T3 disease, and another 3 showed T4 diseases. The primary cancer sites were the tongue (6 cases), buccal mucosa (4 cases), mandible gingival (3 cases), maxillary gingival (1 case), and the floor of the mouth (1 case). The histopathological effects were evaluated according to Oboshi-Shimosato classification. Grade IV was shown in 10 cases (66.7%), grade III in 1 case (6.7%), II bin 3 cases (20.0%), and II a in 1 case (6.7%). All patients completed the treatment. The pathological response of the resected tumor was grade IIb or higher in 14 cases (93.3%). While good histological effects were noted, there was one patient for whom viable tumor cells remained in the central part of the tumor. The present study indicates that further investigation is needed to determine the best dosing and dosing schedule. (author)

A Switched Capacitor Based AC/DC Resonant Converter for High Frequency AC Power Generation

Directory of Open Access Journals (Sweden)

Cuidong Xu

2015-09-01

Full Text Available A switched capacitor based AC-DC resonant power converter is proposed for high frequency power generation output conversion. This converter is suitable for small scale, high frequency wind power generation. It has a high conversion ratio to provide a step down from high voltage to low voltage for easy use. The voltage conversion ratio of conventional switched capacitor power converters is fixed to n, 1/n or −1/n (n is the switched capacitor cell. In this paper, A circuit which can provide n, 1/n and 2n/m of the voltage conversion ratio is presented (n is stepping up the switched capacitor cell, m is stepping down the switching capacitor cell. The conversion ratio can be changed greatly by using only two switches. A resonant tank is used to assist in zero current switching, and hence the current spike, which usually exists in a classical switching switched capacitor converter, can be eliminated. Both easy operation and efficiency are possible. Principles of operation, computer simulations and experimental results of the proposed circuit are presented. General analysis and design methods are given. The experimental result verifies the theoretical analysis of high frequency AC power generation.

Menadione (vitamin K3) is a catabolic product of oral phylloquinone (vitamin K1) in the intestine and a circulating precursor of tissue menaquinone-4 (vitamin K2) in rats.

Science.gov (United States)

Hirota, Yoshihisa; Tsugawa, Naoko; Nakagawa, Kimie; Suhara, Yoshitomo; Tanaka, Kiyoshi; Uchino, Yuri; Takeuchi, Atsuko; Sawada, Natsumi; Kamao, Maya; Wada, Akimori; Okitsu, Takashi; Okano, Toshio

2013-11-15

Mice have the ability to convert dietary phylloquinone (vitamin K1) into menaquinone-4 (vitamin K2) and store the latter in tissues. A prenyltransferase enzyme, UbiA prenyltransferase domain-containing 1 (UBIAD1), is involved in this conversion. There is evidence that UBIAD1 has a weak side chain cleavage activity for phylloquinone but a strong prenylation activity for menadione (vitamin K3), which has long been postulated as an intermediate in this conversion. Further evidence indicates that when intravenously administered in mice phylloquinone can enter into tissues but is not converted further to menaquinone-4. These findings raise the question whether phylloquinone is absorbed and delivered to tissues in its original form and converted to menaquinone-4 or whether it is converted to menadione in the intestine followed by delivery of menadione to tissues and subsequent conversion to menaquinone-4. To answer this question, we conducted cannulation experiments using stable isotope tracer technology in rats. We confirmed that the second pathway is correct on the basis of structural assignments and measurements of phylloquinone-derived menadione using high resolution MS analysis and a bioassay using recombinant UBIAD1 protein. Furthermore, high resolution MS and (1)H NMR analyses of the product generated from the incubation of menadione with recombinant UBIAD1 revealed that the hydroquinone, but not the quinone form of menadione, was an intermediate of the conversion. Taken together, these results provide unequivocal evidence that menadione is a catabolic product of oral phylloquinone and a major source of tissue menaquinone-4.

Menadione (Vitamin K3) Is a Catabolic Product of Oral Phylloquinone (Vitamin K1) in the Intestine and a Circulating Precursor of Tissue Menaquinone-4 (Vitamin K2) in Rats*

Science.gov (United States)

Hirota, Yoshihisa; Tsugawa, Naoko; Nakagawa, Kimie; Suhara, Yoshitomo; Tanaka, Kiyoshi; Uchino, Yuri; Takeuchi, Atsuko; Sawada, Natsumi; Kamao, Maya; Wada, Akimori; Okitsu, Takashi; Okano, Toshio

2013-01-01

Mice have the ability to convert dietary phylloquinone (vitamin K1) into menaquinone-4 (vitamin K2) and store the latter in tissues. A prenyltransferase enzyme, UbiA prenyltransferase domain-containing 1 (UBIAD1), is involved in this conversion. There is evidence that UBIAD1 has a weak side chain cleavage activity for phylloquinone but a strong prenylation activity for menadione (vitamin K3), which has long been postulated as an intermediate in this conversion. Further evidence indicates that when intravenously administered in mice phylloquinone can enter into tissues but is not converted further to menaquinone-4. These findings raise the question whether phylloquinone is absorbed and delivered to tissues in its original form and converted to menaquinone-4 or whether it is converted to menadione in the intestine followed by delivery of menadione to tissues and subsequent conversion to menaquinone-4. To answer this question, we conducted cannulation experiments using stable isotope tracer technology in rats. We confirmed that the second pathway is correct on the basis of structural assignments and measurements of phylloquinone-derived menadione using high resolution MS analysis and a bioassay using recombinant UBIAD1 protein. Furthermore, high resolution MS and 1H NMR analyses of the product generated from the incubation of menadione with recombinant UBIAD1 revealed that the hydroquinone, but not the quinone form of menadione, was an intermediate of the conversion. Taken together, these results provide unequivocal evidence that menadione is a catabolic product of oral phylloquinone and a major source of tissue menaquinone-4. PMID:24085302

High resolution sequence stratigraphy in China

International Nuclear Information System (INIS)

Zhang Shangfeng; Zhang Changmin; Yin Yanshi; Yin Taiju

2008-01-01

Since high resolution sequence stratigraphy was introduced into China by DENG Hong-wen in 1995, it has been experienced two development stages in China which are the beginning stage of theory research and development of theory research and application, and the stage of theoretical maturity and widely application that is going into. It is proved by practices that high resolution sequence stratigraphy plays more and more important roles in the exploration and development of oil and gas in Chinese continental oil-bearing basin and the research field spreads to the exploration of coal mine, uranium mine and other strata deposits. However, the theory of high resolution sequence stratigraphy still has some shortages, it should be improved in many aspects. The authors point out that high resolution sequence stratigraphy should be characterized quantitatively and modelized by computer techniques. (authors)

High-resolution 3 T MRI of traumatic and degenerative triangular fibrocartilage complex (TFCC) abnormalities using Palmer and Outerbridge classifications.

Science.gov (United States)

Nozaki, T; Rafijah, G; Yang, L; Ueno, T; Horiuchi, S; Hitt, D; Yoshioka, H

2017-10-01

To investigate the usefulness of high-resolution 3 T magnetic resonance imaging (MRI) for the evaluation of traumatic and degenerative triangular fibrocartilage complex (TFCC) abnormalities among three groups: patients presenting with wrist pain who were (a) younger than age 50 years or (b) age 50 or older (PT<50 and PT≥50, respectively), and (c) asymptomatic controls who were younger than age 50 years (AC). High-resolution 3 T MRI was evaluated retrospectively in 96 patients, including 47 PT<50, 38 PT≥50, and 11 AC. Two board-certified radiologists reviewed the MRI images independently. MRI features of TFCC injury were analysed according to the Palmer classification, and cartilage degeneration around the TFCC was evaluated using the Outerbridge classification. Differences in MRI findings among these groups were detected using chi-square test. Cohen's kappa was calculated to assess interobserver and intra-observer reliability. The incidence of Palmer class 1A, 1C and 1D traumatic TFCC injury was significantly (p<0.05) higher in PT≥50 than in PT<50 (class 1A: 47.4% versus 27.7%, class 1C: 31.6% versus 12.8%, and class 1D: 21.1% versus 2.1%). Likewise, MRI findings of TFCC degeneration were observed more frequently in PT≥50 than in PT<50 (p<0.01). Outerbridge grade 2 or higher cartilage degeneration was significantly (p<0.01) more frequently seen in PT≥50 than in PT<50 (55.3% versus 17% in the lunate, 28.9% versus 4.3% in the triquetrum, 73.7% versus 12.8% in the ulna). High-resolution wrist MRI at 3 T enables detailed evaluation of TFCC traumatic injury and degenerative changes using the Palmer and Outerbridge classifications, with good or excellent interobserver and intra-observer reliability. Copyright © 2017 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

Development of AMS high resolution injector system

International Nuclear Information System (INIS)

Bao Yiwen; Guan Xialing; Hu Yueming

2008-01-01

The Beijing HI-13 tandem accelerator AMS high resolution injector system was developed. The high resolution energy achromatic system consists of an electrostatic analyzer and a magnetic analyzer, which mass resolution can reach 600 and transmission is better than 80%. (authors)

Amplitude-to-code converter for photomultipliers operating at high loadings

International Nuclear Information System (INIS)

Arkhangel'skij, B.V.; Evgrafov, G.N.; Pishchal'nikov, Yu.M.; Shuvalov, R.S.

1982-01-01

An 11-bit amplitude-to-code converter intended for the analysis of photomultiplier pulses under high loadings is described. To decrease the volume of digit electronics in the converter an analog memory on capacities is envisaged. A well-known bridge circuit with diodes on the main carriers is selected as a gating circuit. The gate control is realized by a switching circuit on fast-response transistors with boundary frequency of 1.2-1.5 GHz. The converter main characteristics are given, namely, maximum output signal amplitude equal to -1.5 V, minimum pulse selection duration of 10 ns, maximum number of counts at Usub(input)=-1.0 V and tsub(selection)=50 ns amounting to 1400, integral nonlinearity of +-0.1%, conversion temperature instability of 0.2%/deg C in the temperature range of (+10-+40) deg C, maximum time of data storage equal to 300 ms, conversion coefficient instability of 0.42 counts, number of channels in a unit CAMAC block equal to 12

Novel strategy for the determination of illegal adulterants in health foods and herbal medicines using high-performance liquid chromatography with high-resolution mass spectrometry.

Science.gov (United States)

Wang, Zhe; Wu, Caisheng; Wang, Gangli; Zhang, Qingsheng; Zhang, Jinlan

2015-03-01

The detection, confirmation, and quantification of multiple illegal adulterants in health foods and herbal medicines by using a single analytical method are a challenge. This paper reports on a new strategy to meet this challenge by employing high-performance liquid chromatography coupled with high-resolution mass spectrometry and a mass spectral tree similarity filter technique. This analytical method can rapidly collect high-resolution, high-accuracy, optionally multistage mass data for compounds in samples. After a preliminary screening by retention time and high-resolution mass spectral data, known illegal adulterants can be detected. The mass spectral tree similarity filter technique has been applied to rapidly confirm these adulterants and simultaneously discover unknown ones. By using full-scan mass spectra as stem and data-dependent subsequent stage mass spectra to form branches, mass spectrometry data from detected compounds are converted into mass spectral trees. The known or unknown illegal adulterants in the samples are confirmed or discovered based on the similarity between their mass spectral trees and those of the references in a library, and they are finally quantified against standard curves. This new strategy has been tested by using 50 samples, and the illegal adulterants were rapidly and effectively detected, confirmed and quantified. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Resolution enhancement of low quality videos using a high-resolution frame

NARCIS (Netherlands)

Pham, T.Q.; Van Vliet, L.J.; Schutte, K.

2006-01-01

This paper proposes an example-based Super-Resolution (SR) algorithm of compressed videos in the Discrete Cosine Transform (DCT) domain. Input to the system is a Low-Resolution (LR) compressed video together with a High-Resolution (HR) still image of similar content. Using a training set of

A High Efficiency DC-DC Converter Topology Suitable for Distributed Large Commercial and Utility Scale PV Systems

Energy Technology Data Exchange (ETDEWEB)

Agamy, Mohammed S; Harfman-Todorovic, Maja; Elasser, Ahmed; Steigerwald, Robert L; Sabate, Juan A; Chi, Song; McCann, Adam J; Zhang, Li; Mueller, Frank

2012-09-01

In this paper a DC-DC power converter for distributed photovoltaic plant architectures is presented. The proposed converter has the advantages of simplicity, high efficiency, and low cost. High efficiency is achieved by having a portion of the input PV power directly fed forward to the output without being processed by the converter. The operation of this converter also allows for a simplified maximum power point tracker design using fewer measurements

Time-amplitude converter; Convertisseur temps-amplitude

Energy Technology Data Exchange (ETDEWEB)

Banner, M [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1961-07-01

It is normal in high energy physics to measure the time of flight of a particle in order to determine its mass. This can be done by the method which consists in transforming the time measurement into an analysis of amplitude, which is easier; a time-amplitude converter has therefore been built for this purpose. The apparatus here described uses a double grid control tube 6 BN 6 whose resolution time, as measured with a pulse generator, is 5 x 10{sup -11} s. The analysis of the response of a particle counter, made up of a scintillator and a photomultiplier, indicates that a time of resolution of 5 x 10{sup -10} s. can be obtained. A time of this order of magnitude is obtained experimentally with the converter. This converter has been used in the study of the time of flight of particles in a secondary beam of the accelerator Saturne. It has thus been possible to measure the energy spectrum of {pi}-mesons, of protons, and of deutons emitted from a polyethylene target bombarded by 1,4 and 2 GeV protons. (author) [French] Pour determiner la masse d'une particule, il est courant, en physique des hautes energies, de mesurer le temps de vol de cette particule. Cela peut etre fait par la methode qui consiste a transformer la mesure d'un temps en une analyse d'amplitude, plus aisee; aussi a-t-on, a cet effet, cree un convertisseur temps-amplitude. L'appareillage decrit dans cet article utilise un tube a double grille de commande 6 BN 6 dont le temps de resolution mesure avec un generateur d'impulsion est de 5.10{sup -11} s. L'analyse de la reponse d'un compteur de particules, constitue par un scintillateur et un photomultiplicateur, indique qu'un temps de resolution de 5.10{sup -10} s peut etre obtenu. Un temps de cet ordre est atteint experimentalement avec le convertisseur. Ce convertisseur a servi a l'etude du temps de vol des particules dans un faisceau secondaire de l'accelerateur Saturne. On a mesure ainsi le spectre d'energie des mesons {pi}, des protons, des deutons

High-definition resolution three-dimensional imaging systems in laparoscopic radical prostatectomy: randomized comparative study with high-definition resolution two-dimensional systems.

Science.gov (United States)

Kinoshita, Hidefumi; Nakagawa, Ken; Usui, Yukio; Iwamura, Masatsugu; Ito, Akihiro; Miyajima, Akira; Hoshi, Akio; Arai, Yoichi; Baba, Shiro; Matsuda, Tadashi

2015-08-01

Three-dimensional (3D) imaging systems have been introduced worldwide for surgical instrumentation. A difficulty of laparoscopic surgery involves converting two-dimensional (2D) images into 3D images and depth perception rearrangement. 3D imaging may remove the need for depth perception rearrangement and therefore have clinical benefits. We conducted a multicenter, open-label, randomized trial to compare the surgical outcome of 3D-high-definition (HD) resolution and 2D-HD imaging in laparoscopic radical prostatectomy (LRP), in order to determine whether an LRP under HD resolution 3D imaging is superior to that under HD resolution 2D imaging in perioperative outcome, feasibility, and fatigue. One-hundred twenty-two patients were randomly assigned to a 2D or 3D group. The primary outcome was time to perform vesicourethral anastomosis (VUA), which is technically demanding and may include a number of technical difficulties considered in laparoscopic surgeries. VUA time was not significantly shorter in the 3D group (26.7 min, mean) compared with the 2D group (30.1 min, mean) (p = 0.11, Student's t test). However, experienced surgeons and 3D-HD imaging were independent predictors for shorter VUA times (p = 0.000, p = 0.014, multivariate logistic regression analysis). Total pneumoperitoneum time was not different. No conversion case from 3D to 2D or LRP to open RP was observed. Fatigue was evaluated by a simulation sickness questionnaire and critical flicker frequency. Results were not different between the two groups. Subjective feasibility and satisfaction scores were significantly higher in the 3D group. Using a 3D imaging system in LRP may have only limited advantages in decreasing operation times over 2D imaging systems. However, the 3D system increased surgical feasibility and decreased surgeons' effort levels without inducing significant fatigue.

Energy-Efficient Capacitance-to-Digital Converters for Smart Sensor Applications

KAUST Repository

Alhoshany, Abdulaziz

2017-12-01

One of the key requirements in the design of wireless sensor nodes and miniature biomedical devices is energy efficiency. For a sensor node, which is a sensor and readout circuit, to survive on limited energy sources such as a battery or harvested energy, its energy consumption should be minimized. Capacitive sensors are candidates for use in energy-constrained applications, as they do not consume static power and can be used in a wide range of applications to measure different physical, chemical or biological quantities. However, the energy consumption is dominated by the capacitive interface circuit, i.e. the capacitance-to-digital converter (CDC). Several energy-efficient CDC architectures are introduced in this dissertation to meet the demand for high resolution and energy efficiency in smart capacitive sensors. First, we propose an energy-efficient CDC based on a differential successive-approximation data converter. The proposed differential CDC employs an energy-efficient operational transconductance amplifier (OTA) based on an inverter. A wide capacitance range with fine absolute resolution is implemented in the proposed coarse-fine DAC architecture which saves 89% of silicon area. The proposed CDC achieves an energy efficiency figure-of-merit () of 45.8fJ/step, which is the best reported energy efficiency to date. Second, we propose an energy efficient CDC for high-precision capacitive resolution by using oversampling and noise shaping. The proposed CDC achieves 150 aF absolute resolution and an energy efficiency of 187fJ/conversion-step which outperforms state of the art high-precision differential CDCs. In the third and last part, we propose an in-vitro cancer diagnostic biosensor-CMOS platform for low-power, rapid detection, and low cost. The introduced platform is the first to demonstrate the ability to screen and quantify the spermidine/spermine N1 acetyltransferase (SSAT) enzyme which reveals the presence of early-stage cancer, on the surface of a

High resolution, high speed ultrahigh vacuum microscopy

International Nuclear Information System (INIS)

Poppa, Helmut

2004-01-01

The history and future of transmission electron microscopy (TEM) is discussed as it refers to the eventual development of instruments and techniques applicable to the real time in situ investigation of surface processes with high resolution. To reach this objective, it was necessary to transform conventional high resolution instruments so that an ultrahigh vacuum (UHV) environment at the sample site was created, that access to the sample by various in situ sample modification procedures was provided, and that in situ sample exchanges with other integrated surface analytical systems became possible. Furthermore, high resolution image acquisition systems had to be developed to take advantage of the high speed imaging capabilities of projection imaging microscopes. These changes to conventional electron microscopy and its uses were slowly realized in a few international laboratories over a period of almost 40 years by a relatively small number of researchers crucially interested in advancing the state of the art of electron microscopy and its applications to diverse areas of interest; often concentrating on the nucleation, growth, and properties of thin films on well defined material surfaces. A part of this review is dedicated to the recognition of the major contributions to surface and thin film science by these pioneers. Finally, some of the important current developments in aberration corrected electron optics and eventual adaptations to in situ UHV microscopy are discussed. As a result of all the path breaking developments that have led to today's highly sophisticated UHV-TEM systems, integrated fundamental studies are now possible that combine many traditional surface science approaches. Combined investigations to date have involved in situ and ex situ surface microscopies such as scanning tunneling microscopy/atomic force microscopy, scanning Auger microscopy, and photoemission electron microscopy, and area-integrating techniques such as x-ray photoelectron

High-voltage transistor converter for pulsed x-ray sources

International Nuclear Information System (INIS)

Krasil'nikov, S.B.; Kristalinskii, A.L.; Lozovoi, L.N.; Markov, S.N.; Sindalovskii, E.I.

1986-01-01

A 24-V/12-kV converter for MIRA-2D and NORA pulsed x-ray sources is described. When the low-voltage supply varies within 20-26 V, the frequency stability of the x-ray pulses is higher by a factor of 3 ≅ 3 than when the PRIMA converter is used. For 14-24 V, the average output power of the converter is independent of the load impedance and increases linearly with an increase in supply voltage. The efficiency of the converter reaches 60%. The converter operates in the temperature range of -40 to +60 0 C

Discernibility of Burial Mounds in High-Resolution X-Band SAR Images for Archaeological Prospections in the Altai Mountains

Directory of Open Access Journals (Sweden)

Timo Balz

2016-09-01

Full Text Available The Altai Mountains are a heritage-rich archaeological landscape with monuments in almost every valley. Modern nation state borders dissect the region and limit archaeological landscape analysis to intra-national areas of interest. Remote sensing can help to overcome these limitations. Due to its high precision, Synthetic Aperture Radar (SAR data can be a very useful tool for supporting archaeological prospections, but compared to optical imagery, the detectability of sites of archaeological interest is limited. We analyzed the limitations of SAR using TerraSAR-X images in different modes. Based on ground truth, the discernibility of burial mounds was analyzed in different SAR acquisition modes. We show that very-high-resolution TerraSAR-X staring spotlight images are very well suited for the task, with >75% of the larger mounds being discernible, while in images with a lower spatial resolution only a few large sites can be detected, at rates below 50%.

A High Position Resolution X-ray Detector: an Edge on Illuminated Capillary Plate Combined with a Gas Amplification Structure

CERN Document Server

Iacobaeus, C.; Lund-Jensen, B.; Ostling, J.; Pavlopoulos, P.; Peskov, V.; Tokanai, F.

2006-01-01

We have developed and successfully tested a prototype of a new type of high position resolution hybrid X-ray detector. It contains a thin wall lead glass capillary plate converter of X-rays combined with a microgap parallel-plate avalanche chamber filled with gas at 1 atm. The operation of these converters was studied in a wide range of X-ray energies (from 6 to 60 keV) at incident angles varying from 0-90 degree. The detection efficiency, depending on the geometry, photon energy, incident angle and the mode of operation, was between 5-30 percent in a single step mode and up to 50 percent in a multi-layered combination. Depending on the capillary geometry, the position resolution achieved was between 0.050-0.250 mm in digital form and was practically independent of the photon energy or gas mixture. The usual lead glass capillary plates operated without noticeable charging up effects at counting rates of 50 Hz/mm2, and hydrogen treated capillaries up to 10E5 Hz/mm2. The developed detector may open new possibil...

SSP Technology Investigation of a High-Voltage DC-DC Converter

Science.gov (United States)

Pappas, J. A.; Grady, W. M.; George, Patrick J. (Technical Monitor)

2002-01-01

The goal of this project was to establish the feasibility of a high-voltage DC-DC converter based on a rod-array triggered vacuum switch (RATVS) for the Space Solar Power system. The RATVS has many advantages over silicon and silicon-carbide devices. The RATVS is attractive for this application because it is a high-voltage device that has already been demonstrated at currents in excess of the requirement for an SSP device and at much higher per-device voltages than existing or near-term solid state switching devices. The RATVS packs a much higher specific power rating than any solid-state device and it is likely to be more tolerant of its surroundings in space. In addition, pursuit of an RATVS-based system would provide NASA with a nearer-term and less expensive power converter option for the SSP.

A high resolution solar atlas for fluorescence calculations

Science.gov (United States)

Hearn, M. F.; Ohlmacher, J. T.; Schleicher, D. G.

1983-01-01

The characteristics required of a solar atlas to be used for studying the fluorescence process in comets are examined. Several sources of low resolution data were combined to provide an absolutely calibrated spectrum from 2250 A to 7000A. Three different sources of high resolution data were also used to cover this same spectral range. The low resolution data were then used to put each high resolution spectrum on an absolute scale. The three high resolution spectra were then combined in their overlap regions to produce a single, absolutely calibrated high resolution spectrum over the entire spectral range.

Psychological, behavioral, and clinical effects of intra-oral camera: a randomized control trial on adults with gingivitis.

Science.gov (United States)

Araújo, Mário-Rui; Alvarez, Maria-João; Godinho, Cristina A; Pereira, Cícero

2016-12-01

To evaluate the effects of using an intra-oral camera (IOC) during supportive periodontal therapy (SPT), on the psychological, behavioral, and clinical parameters of patients with gingivitis, outlined by evidence and a theory-based framework. A group of 78 adult patients with gingivitis receiving an SPT was randomized into two groups: IOC and control. Bleeding on Marginal Probing (BOMP), self-reported dental hygiene behaviors, and psychological determinants of behavior change (outcome expectancies, self-efficacy, and planning) and IOC opinion were evaluated 1 week before or during the appointment and 4 months later. Repeated-measures anova was used to compare groups over time. Almost all the patients brushed their teeth daily, while 78% either never or hardly ever used dental floss. The IOC group showed significant improvements in BOMP index (P < 0.001), self-reported flossing (P < 0.05), and self-efficacy (P < 0.05) compared to the control group. The use of IOC significantly improves clinical, behavioral, and psychological determinants of periodontal health 4 months after treatment. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

ASIC-enabled High Resolution Optical Time Domain Reflectometer

Science.gov (United States)

Skendzic, Sandra

Fiber optics has become the preferred technology in communication systems because of what it has to offer: high data transmission rates, immunity to electromagnetic interference, and lightweight, flexible cables. An optical time domain reflectometer (OTDR) provides a convenient method of locating and diagnosing faults (e.g. break in a fiber) along a fiber that can obstruct crucial optical pathways. Both the ability to resolve the precise location of the fault and distinguish between two discrete, closely spaced faults are figures of merit. This thesis presents an implementation of a high resolution OTDR through the use of a compact and programmable ASIC (application specific integrated circuit). The integration of many essential OTDR functions on a single chip is advantageous over existing commercial instruments because it enables small, lightweight packaging, and offers low power and cost efficiency. Furthermore, its compactness presents the option of placing multiple ASICs in parallel, which can conceivably ease the characterization of densely populated fiber optic networks. The OTDR ASIC consists of a tunable clock, pattern generator, precise timer, electrical receiver, and signal sampling circuit. During OTDR operation, the chip generates narrow electrical pulse, which can then be converted to optical format when coupled with an external laser diode driver. The ASIC also works with an external photodetector to measure the timing and amplitude of optical reflections in a fiber. It has a 1 cm sampling resolution, which allows for a 2 cm spatial resolution. While this OTDR ASIC has been previously demonstrated for multimode fiber fault diagnostics, this thesis focuses on extending its functionality to single mode fiber. To validate this novel approach to OTDR, this thesis is divided into five chapters: (1) introduction, (2) implementation, (3), performance of ASIC-based OTDR, (4) exploration in optical pre-amplification with a semiconductor optical amplifier, and

High-Efficiency High Step-Up DC-DC Converter with Dual Coupled Inductors for Grid-Connected Photovoltaic Systems

DEFF Research Database (Denmark)

Forouzesh, Mojtaba; Shen, Yanfeng; Siwakoti, Yam Prasad

2018-01-01

with a common ground connection of the input and output make the proposed topology a proper candidate for a transformer-less grid connected photovoltaic systems. The operating performance, analysis and mathematical derivations of the proposed dc-dc converter have been demonstrated in the paper. Moreover......This paper introduces a non-isolated high step-up dc-dc converter with dual coupled inductors suitable for distributed generation applications. By implementing an input parallel connection, the proposed dc-dc structure inherits shared input current with low ripple, which also requires small...... capacitive filter at its input. Moreover, this topology can reach high voltage gain by using dual coupled inductors in series connection at the output stage. The proposed converter uses active clamp circuits with a shared clamp capacitor for the main switches. In addition to the active clamp circuit...

Bidirectional dc-to-dc Power Converter

Science.gov (United States)

Griesbach, C. R.

1986-01-01

Solid-state, series-resonant converter uses high-voltage thyristors. Converter used either to convert high-voltage, low-current dc power to lowvoltage, high current power or reverse. Taking advantage of newly-available high-voltage thyristors to provide better reliability and efficiency than traditional converters that use vacuum tubes as power switches. New converter essentially maintenance free and provides greatly increased mean time between failures. Attractive in industrial applications whether or not bidirectional capability is required.

Comparison between Topical and Oral Tranexamic Acid in Management of Traumatic Hyphema

Science.gov (United States)

Jahadi Hosseini, Seyed Hamid Reza; Khalili, Mohammad Reza; Motallebi, Mahmoud

2014-01-01

Background: We sought to determine the efficacy of topical tranexamic acid (5%) in the management of traumatic hyphema. Methods: Thirty eyes with gross traumatic hyphema were enrolled in this study. The patients were treated with tranexamic acid (5%) eye drop every 6 hours for 5 days. The main outcome measures were best corrected visual acuity (BCVA), Intra-ocular pressure (IOP), day of clot absorption, and rate of rebleeding. These parameters were evaluated daily for 4 days and thereafter at the 8th and 14th days after treatment. The patients were also compared with two historical control groups of patients (80 eyes) with traumatic hyphema; the first control group was treated with oral placebo and the other group was treated with oral tranexamic acid at our department. Result: Prior to treatment, the mean logarithm of the minimum angle of resolution (logMAR) BCVA was 0.59±0.62. BCVA was increased to 0.08±0.14 at day 14 (Ptranexamic acid seems promising in the management of traumatic hyphema. However, the small sample size of the present study precludes the conclusion that topical tranexamic acid can replace the oral tranexamic acid. PMID:24753640

[Treatment of temporo-mandibular joint closed-lock using intra-articular injection of mepivacaine with immediate resolution durable in time (six months follow-up)].

Science.gov (United States)

Guarda Nardini, L; Tito, R; Beltrame, A

2002-01-01

The purpose of this study was to assess the value of intra-articular fluid injection under pressure, as a technique suggested for temporo-mandibular joint (TMJ) closed-lock treatment, and to determine if there is a persisting lock resolution in time. Twelve patients were studied at our centre, with a diagnosis of TMJ closed-lock, not amenable with conventional therapies. All patients underwent a MRI scan, confirming the presence of anteriorly displaced disk. This technique is based on intra-articular injection of anaesthetic (mepivacaine cloridrate) under pressure, using the so called pumping technique, that allows an inferior distraction of the condyle. The study has a six months follow-up. After closed-lock resolution all patients underwent physiotherapy with guided mouth opening, for one month. Mandibular function (maximal mouth opening) increased on average of 20.2 mm after treatment, and of 21.1 mm six months later (p=0.00000; with p<0.005). Pain decreased on average from VAS=6.75 to VAS=0.3 (p=0.00001; with p<0.005). The masticatory efficiency improved from VAS=5.25 to VAS=8.75 (p=0.002; p<0.005). Functional TMJ limitation level is significantly increased (p=0.002; p<0.005). Also, patient's efficacy judgement (mean value 3.58= good) and tolerability judgement (mean value 2.92=good) indicate that this therapy is well accepted. This technique is easy to perform, well tolerated and does not need specific instruments: it permits the resolution of TMJ closed-lock, decreases the pain and improves masticatory efficiency. All these effects persist in time. Subjects with recent closed-lock have an immediate and complete functional recovery while patients with chronic closed-lock do not.

A four channel time-to-digital converter ASIC with in-built calibration and SPI interface

International Nuclear Information System (INIS)

Hari Prasad, K.; Sukhwani, Menka; Saxena, Pooja; Chandratre, V.B.; Pithawa, C.K.

2014-01-01

A design of high resolution, wide dynamic range Time-to-Digital Converter (TDC) ASIC, implemented in 0.35 µm commercial CMOS technology is presented. The ASIC features four channel TDC with an in-built calibration and Serial Peripheral Interconnect (SPI) slave interface. The TDC is based on the vernier ring oscillator method in order to achieve both high resolution and wide dynamic range. This TDC ASIC is tested and found to have resolution of 127 ps (LSB), dynamic range of 1.8 µs and precision (σ) of 74 ps. The measured values of differential non-linearity (DNL) and integral non-linearity (INL) are 350 ps and 300 ps respectively

High-resolution SPECT for small-animal imaging

International Nuclear Information System (INIS)

Qi Yujin

2006-01-01

This article presents a brief overview of the development of high-resolution SPECT for small-animal imaging. A pinhole collimator has been used for high-resolution animal SPECT to provide better spatial resolution and detection efficiency in comparison with a parallel-hole collimator. The theory of imaging characteristics of the pinhole collimator is presented and the designs of the pinhole aperture are discussed. The detector technologies used for the development of small-animal SPECT and the recent advances are presented. The evolving trend of small-animal SPECT is toward a multi-pinhole and a multi-detector system to obtain a high resolution and also a high detection efficiency. (authors)

High spatial resolution whole-body MR angiography featuring parallel imaging: initial experience

International Nuclear Information System (INIS)

Quick, H.H.; Vogt, F.M.; Madewald, S.; Herborn, C.U.; Bosk, S.; Goehde, S.; Debatin, J.F.; Ladd, M.E.

2004-01-01

Materials and methods: whole-body multi-station MRA was performed with a rolling table platform (AngioSURF) on 5 volunteers in two imaging series: 1) standard imaging protocol, 2) modified high-resolution protocol employing PAT using the generalized autocalibrating partially parallel acquisitions (GRAPPA) algorithm with an acceleration factor of 3. For an intra-individual comparison of the two MR examinations, the arterial vasculature was divided into 30 segments. Signal-to-noise ratios (SNR) and contrast-to-noise ratios (CNR) were calculated for all 30 arterial segments of each subject. Vessel segment depiction was qualitatively assessed applying a 5-point scale to each of the segments. Image reconstruction times were recorded for the standard as well as the PAT protocol. Results: compared to the standard protocol, PAT allowed for increased spatial resolution through a 3-fold reduction in mean voxel size for each of the 5 stations. Mean SNR and CNR values over all specified vessel segments decreased by a factor of 1.58 and 1.56, respectively. Despite the reduced SNR and CNR, the depiction of all specified vessel segments increased in PAT images, reflecting the increased spatial resolution. Qualitative comparison of standard and PAT images showed an increase in vessel segment conspicuity with more detailed depiction of intramuscular arterial branches in all volunteers. The time for image data reconstruction of all 5 stations was significantly increased from about 10 minutes to 40 minutes when using the PAT acquisition. (orig.) [de

FERMI: a digital Front End and Readout MIcrosystem for high resolution calorimetry

International Nuclear Information System (INIS)

Alexanian, H.; Appelquist, G.; Bailly, P.

1995-01-01

We present a digital solution for the front-end electronics of high resolution calorimeters at future colliders. It is based on analogue signal compression, high speed A/D converters, a fully programmable pipeline and a digital signal processing (DSP) chain with local intelligence and system supervision. This digital solution is aimed at providing maximal front-end processing power by performing waveform analysis using DSP methods. For the system integration of the multichannel device a multi-chip, silicon-on-silicon multi-chip module (MCM) has been adopted. This solution allows a high level of integration of complex analogue and digital functions, with excellent flexibility in mixing technologies for the different functional blocks. This type of multichip integration provides a high degree of reliability and programmability at both the function and the system level, with the additional possibility of customising the microsystem to detector-specific requirements. For enhanced reliability in high radiation environments, fault tolerance strategies, i.e. redundancy, reconfigurability, majority voting and coding for error detection and correction, are integrated into the design. ((orig.))

Dynamic Sliding Mode Evolution PWM Controller for a Novel High-Gain Interleaved DC-DC Converter in PV System

Directory of Open Access Journals (Sweden)

Taizhou Bei

2014-01-01

Full Text Available Considering the disadvantages of the traditional high-gain DC-DC converter such as big size, high voltage stress of switches, and large input current ripple, a novel high-gain interleaved boost converter with coupled-inductor and switched-capacitor was proposed correspondingly and the operation principle together with the steady-state analysis of this converter was also described. Besides, a new control approach-dynamic sliding mode evolution PWM controller (DSME PWM for the novel topological converter based on both dynamic evolution and sliding mode control was also presented. From the simulation results and experimental validation the proposed converter can fulfill high-gain boost, low ripple of both the input current and the output voltage. Furthermore, MPPT technique can be also achieved in a short time by simulation. The efficiency and stability of the converter proposed in this paper can be improved.

Novel LY Converter Topologies for High Gain Transfer Ratio - A New Breed of XY Family

DEFF Research Database (Denmark)

Bhaskar, M.S.; Padmanaban, S.; Kulkarni, R.

2016-01-01

gain and minimum internal resistance; such as a photovoltaic MLI system, high voltage applications and electrical drives. The conspicuous features of proposed LY converter topologies are i) Single power control switch ii) Single Input source iii) Inverting output voltage iv) Transformer-less converter...... topologies v) High inverting voltage gain with moderate duty ratio vi) Less number of power devices and components. The proposed topologies have minimum internal resistance and its effect on voltage gain of LY converter is also discussed in detail. The simulation results are presented and the result...

High resolution time integration for SN radiation transport

International Nuclear Information System (INIS)

Thoreson, Greg; McClarren, Ryan G.; Chang, Jae H.

2009-01-01

First-order, second-order, and high resolution time discretization schemes are implemented and studied for the discrete ordinates (S N ) equations. The high resolution method employs a rate of convergence better than first-order, but also suppresses artificial oscillations introduced by second-order schemes in hyperbolic partial differential equations. The high resolution method achieves these properties by nonlinearly adapting the time stencil to use a first-order method in regions where oscillations could be created. We employ a quasi-linear solution scheme to solve the nonlinear equations that arise from the high resolution method. All three methods were compared for accuracy and convergence rates. For non-absorbing problems, both second-order and high resolution converged to the same solution as the first-order with better convergence rates. High resolution is more accurate than first-order and matches or exceeds the second-order method

M31 GLOBULAR CLUSTER ABUNDANCES FROM HIGH-RESOLUTION, INTEGRATED-LIGHT SPECTROSCOPY

International Nuclear Information System (INIS)

Colucci, Janet E.; Bernstein, Rebecca A.; Cameron, Scott; McWilliam, Andrew; Cohen, Judith G.

2009-01-01

We report the first detailed chemical abundances for five globular clusters (GCs) in M31 from high-resolution (R ∼ 25,000) spectroscopy of their integrated light (IL). These GCs are the first in a larger set of clusters observed as part of an ongoing project to study the formation history of M31 and its GC population. The data presented here were obtained with the HIRES echelle spectrograph on the Keck I telescope and are analyzed using a new IL spectra analysis method that we have developed. In these clusters, we measure abundances for Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Y, and Ba, ages ≥10 Gyr, and a range in [Fe/H] of -0.9 to -2.2. As is typical of Milky Way GCs, we find these M31 GCs to be enhanced in the α-elements Ca, Si, and Ti relative to Fe. We also find [Mg/Fe] to be low relative to other [α/Fe], and [Al/Fe] to be enhanced in the IL abundances. These results imply that abundances of Mg, Al (and likely O, Na) recovered from IL do display the inter- and intra-cluster abundance variations seen in individual Milky Way GC stars, and that special care should be taken in the future in interpreting low- or high-resolution IL abundances of GCs that are based on Mg-dominated absorption features. Fe-peak and the neutron-capture elements Ba and Y also follow Milky Way abundance trends. We also present high-precision velocity dispersion measurements for all five M31 GCs, as well as independent constraints on the reddening toward the clusters from our analysis.

Connect high speed analog-digital converter with EPICS based on LabVIEW

International Nuclear Information System (INIS)

Wang Wei; Chi Yunlong

2008-01-01

This paper introduce a method to connect high speed analog-digital converter (ADC212/100) with EPICS on Windows platform using LabVIEW. We use labVIEW to communicate with the converter, then use interface sub-VIs between LabVIEW and EPICS to access the EPICS IOC by Channel Access (CA). For the easy use graph programming language of LabVIEW, this method could shorten the develop period and reduce manpower cost. (authors)

Online readout and control unit for high-speed/high resolution readout of silicon tracking detectors

International Nuclear Information System (INIS)

Buerger, J.; Hansen, K.; Lange, W.; Nowak, T.; Prell, S.; Zimmermann, W.

1997-01-01

We are describing a high speed VME readout and control module developed and presently working at the H1 experiment at DESY in Hamburg. It has the capability to read out 4 x 2048 analogue data channels at sampling rates up to 10 MHz with a dynamic input range of 1 V. The nominal resolution of the A/D converters can be adjusted between 8 and 12 bit. At the latter resolution we obtain signal-to-noise ratio better than 61.4 dB at a conversion rate of 5 MSps. At this data rate all 8192 detector channels can be read out to the internal raw data memory and VME interface within about 410 μs and 510 μs, respectively. The pedestal subtracted signals can be analyzed on-line. At a raw data hit occupation of 10%, the VME readout time is 50 μs per module. Each module provides four complementary CMOS signals to control the front-end electronics and four independent sets of power supplies for analogue and digital voltages (10 V, 100 mA) to drive the front-end electronics and for the bias voltage (100 V, 1.2 mA) to assure the full functionality of the detectors and the readout. (orig.)

Online readout and control unit for high-speed/high resolution readout of silicon tracking detectors

Science.gov (United States)

Bürger, J.; Hansen, K.; Lange, W.; Nowak, T.; Prell, S.; Zimmermann, W.

1997-02-01

We are describing a high speed VME readout and control module developed and presently working at the H1 experiment at DESY in Hamburg. It has the capability to read out 4 × 2048 analogue data channels at sampling rates up to 10 MHz with a dynamic input range of 1 V. The nominal resolution of the A/D converters can be adjusted between 8 and 12 bit. At the latter resolution we obtain signal-to-noise ratio better than 61.4 dB at a conversion rate of 5 MSps. At this data rate all 8192 detector channels can be read out to the internal raw data memory and VME interface within about 410 μs and 510 μs, respectively. The pedestal subtracted signals can be analyzed on-line. At a raw data hit occupation of 10%, the VME readout time is 50 μs per module. Each module provides four complementary CMOS signals to control the front-end electronics and four independent sets of power supplies for analogue and digital voltages (10 V, 100 mA) to drive the front-end electronics and for the bias voltage (100 V, 1.2 mA) to assure the full functionality of the detectors and the readout.

Online readout and control unit for high-speed / high resolution readout of silicon tracking detectors

International Nuclear Information System (INIS)

Buerger, J.; Hansen, K.; Lange, W.; Nowak, T.; Prell, S.; Zimmermann, W.

1996-09-01

We are describing a high speed VME readout and control module developed and presently working at the H1 experiment at DESY in Hamburg. It has the capability to read out 4 x 2048 analogue data channels at sampling rates up to 10 MHz with a dynamic input range of 1 V. The nominal resolution of the A/D converters can be adjusted between 8 and 12 bit. At the latter resolution we obtain signal-to-noise ratio better than 61.4 dB at a conversion rate of 5 MSps. At this data rate all 8192 detector channels can be read out to the internal raw data memory and VME interface within about 410 μs and 510 μs, respectively. The pedestal subtracted signals can be analyzed on-line. At a raw data hit occupation of 10%, the VME readout time is 50 μs per module. Each module provides four complementary CMOS signals to control the front-end electronics and four independent sets of power supplies for analogue and digital voltages (10 V, 100 mA) to drive the front-end electronics and for the bias voltage (100 V, 1.2 mA) to assure the full functionality of the detectors and the readout. (orig.)

High tracking resolution detectors. Final Technical Report

International Nuclear Information System (INIS)

Vasile, Stefan; Li, Zheng

2010-01-01

High-resolution tracking detectors based on Active Pixel Sensor (APS) have been valuable tools in Nuclear Physics and High-Energy Physics research, and have contributed to major discoveries. Their integration time, radiation length and readout rate is a limiting factor for the planed luminosity upgrades in nuclear and high-energy physics collider-based experiments. The goal of this program was to demonstrate and develop high-gain, high-resolution tracking detector arrays with faster readout, and shorter radiation length than APS arrays. These arrays may operate as direct charged particle detectors or as readouts of high resolution scintillating fiber arrays. During this program, we developed in CMOS large, high-resolution pixel sensor arrays with integrated readout, and reset at pixel level. Their intrinsic gain, high immunity to surface and moisture damage, will allow operating these detectors with minimal packaging/passivation requirements and will result in radiation length superior to APS. In Phase I, we designed and fabricated arrays with calorimetric output capable of sub-pixel resolution and sub-microsecond readout rate. The technical effort was dedicated to detector and readout structure development, performance verification, as well as to radiation damage and damage annealing.

INTRA graphical package - INTRA-Graph 1.0

International Nuclear Information System (INIS)

Hofman, D.; Edlund, O.

2001-04-01

INTRA-Graph 1.0 has been developed at Studsvik Eco and Safety AB in the frame of the European Fusion Technology Programme for application in the safety analysis using the INTRA code. INTRA-Graph 1.0 is a graphical package producing 2-dimensional plots of results generated by the INTRA code. INTRA-Graph 1.0 has been developed by extending the Grace package source code, distributed under the terms of GNU General Public License. The changes in the Grace source files are limited to provide easy updates of the INTRA-Graph when a new version of Grace will be released. The INTRA-related functionality has been implemented in new source files. The present report describes and gives complete listing of these files. The changes in the Grace source files are also described and the listing of the changed parts of the files is presented. The report gives detailed explanations and examples of files required for installation and configuration of INTRA-Graph on the different types of Unix workstations

Dose and risk evaluation to the thyroid gland in intra-oral dental radiology

International Nuclear Information System (INIS)

Souza, Edmilson M.; Lima, Marco A.F.; Kelecom, Alphonse; Correa, Samanda C.A.; Silva, Ademir X.; Brito, Alan

2008-01-01

Intra-oral technique is one of the most frequently used procedures of dental radiology, allowing the detection of a variety of dental anomalies such as caries, dental trauma and periodontal lesions, while exposing patients to relatively low doses of radiation. However, although the adverse effects of doses generated by dental radiology are essentially stochastic, a number of epidemiological studies have provided evidence of an increased risk of thyroid tumors for dental radiography. Many studies have measured doses of radiation for dental radiography, but only a few have estimated thyroid dose. Furthermore, most of the studies on dose evaluation in dental radiology are based on standardized calculation phantoms, which neglect the variance of the patient size or even sex. The purpose of this study is to use the Monte Carlo code MCNPX and the FAX (Female Adult voXel) and MAX (Male Adult voXel) phantoms to investigate how absorbed doses to the thyroid gland in intraoral dental examinations vary in female and male patients. The lifetime cancer incidence attributable to dental examinations were estimated using the Biological Effects of Ionizing Radiations (BEIR) VII Committee Report. The phantoms study proved a useful trial for detecting the radiation dose to the thyroid gland and conclusively supported that the anatomy may be regarded as an influencing factor in radiation dose received during dental examination. Finally, the results have also confirmed that the association of the MCNPX code and the MAX and FAX phantoms is very useful in dosimetric studies on radiographic examinations of female and male patients. (author)

High-Resolution Wave Energy Assessment in Shallow Water Accounting for Tides

Directory of Open Access Journals (Sweden)

Dina Silva

2016-09-01

Full Text Available The wave energy in a shallow water location is evaluated considering the influence of the local tide and wind on the wave propagation. The target is the coastal area just north of the Portuguese city of Peniche, where a wave energy converter operates on the sea bottom. A wave modelling system based on SWAN has been implemented and focused on this coastal environment in a multilevel computational scheme. The first three SWAN computational belonging to this wave prediction system were defined using the spherical coordinates. In the highest resolution computational domain, Cartesian coordinates have been considered, with a resolution of 25 m in both directions. An in-depth analysis of the main characteristics of the environmental matrix has been performed. This is based on the results of eight-year model system simulations (2005–2012. New simulations have been carried out in the last two computational domains with the most relevant wave and wind patterns, considering also the tide effect. The results show that the tide level, together with the wind intensity and direction, may influence to a significant degree the wave characteristics. This especially concerns the wave power in the location where the wave converter operates.

Ultra high resolution tomography

Energy Technology Data Exchange (ETDEWEB)

Haddad, W.S.

1994-11-15

Recent work and results on ultra high resolution three dimensional imaging with soft x-rays will be presented. This work is aimed at determining microscopic three dimensional structure of biological and material specimens. Three dimensional reconstructed images of a microscopic test object will be presented; the reconstruction has a resolution on the order of 1000 A in all three dimensions. Preliminary work with biological samples will also be shown, and the experimental and numerical methods used will be discussed.

In vivo oral imaging with integrated portable photoacoustic microscopy and optical coherence tomography

Science.gov (United States)

Qin, Wei; Qi, Weizhi; Jin, Tian; Guo, Heng; Xi, Lei

2017-12-01

Oral diseases, especially oral cancers, are becoming serious health problems in humans. To image vasculatures and structures simultaneously in the human oral cavity which are tightly associated with various oral diseases, we develop a dual-modality portable optical resolution photoacoustic microscopy (ORPAM) and optical coherence tomography (OCT) system. This system utilizes a new rotary scanning mechanism and a compact design of the imaging head, making it portable and free of translation of the imaging interface or samples. Through the phantom experiments, both modalities yield high lateral resolutions of 8.1 μm (ORPAM) and 8.56 μm (OCT), respectively. The axial resolutions are measured to be 116.5 μm for ORPAM and 6.1 μm for OCT. In vivo imaging of a mouse ear was carried out to evaluate the performance of the system in biological tissues. In addition, in vivo oral imaging of a healthy human lip and monitoring recovery progress of a lip ulcer demonstrate the clinical potential of this system.

Converting Hangar High Expansion Foam Systems to Prevent Cockpit Damage: Full-Scale Validation Tests

Science.gov (United States)

2017-09-01

AFCEC-CO-TY-TR-2018-0001 CONVERTING HANGAR HIGH EXPANSION FOAM SYSTEMS TO PREVENT COCKPIT DAMAGE: FULL-SCALE VALIDATION TESTS Gerard G...manufacturer, or otherwise does not constitute or imply its endorsement, recommendation , or approval by the United States Air Force. The views and...09-2017 Final Test Report May 2017 Converting Hangar High Expansion Foam Systems to Prevent Cockpit Damage: Full-Scale Validation Tests N00173-15-D

The value of the intra-operative clinical mechanical axis measurement in open-wedge valgus high tibial osteotomies

NARCIS (Netherlands)

van de Pol, G.J.; Verdonschot, Nicolaas Jacobus Joseph; van Kampen, A.

2012-01-01

Introduction: In high tibial osteotomies (HTO) the correction needs to be precise and intra-operative assessment is essential. The purpose of this study was to evaluate the use of the intra-operative clinical mechanical axis measurement and compare it to the post-operative weight bearing situation

Development of a stability-indicating high performance liquid chromatography method for assay of erythromycin ethylsuccinate in powder for oral suspension dosage form

Directory of Open Access Journals (Sweden)

Fahimeh Kamarei

2014-12-01

Full Text Available In this study an effective method was developed to assay erythromycin ethylsuccinate for an oral suspension dosage form. The chromatographic separation was achieved on an X-Terra™ C18 analytical column. A mixture of acetonitrile–ammonium dihydrogen phosphate buffer (0.025 mol L-1 (60:40, V/V (pH 7.0 was used as the mobile phase, effluent flow rate monitored at 1.0 mL min−1, and UV detection at 205 nm. In forced degradation studies, the effects of acid, base, oxidation, UV light and temperature were investigated showing no interference in the peak of drug. The proposed method was validated in terms of specificity, linearity, robustness, precision and accuracy. The method was linear at concentrations ranging from 400 to 600 μg mL−1, precise (intra- and inter-day relative standard deviations <0.65, accurate (mean recovery; 99.5%. The impurities and degradation products of erythromycin ethylsuccinate were selectively determined with good resolution in both the raw material and the final suspension forms. The method could be useful for both routine analytical and quality control assays of erythromycin ethylsuccinate in commercial powder for an oral suspension dosage form and it could be a very powerful tool to investigate the chemical stability of erythromycin ethylsuccinate.

A high performance DC-DC converter with intelligent control for photovoltaic applications

OpenAIRE

M. Niroomand; M. Sherkat; M. Soheili

2013-01-01

In this paper, a SEPIC (Single-Ended Primary Inductance Converter) with high efficiency has been proposed for photovoltaic applications. In the proposed converter, an auxiliary circuit without any additional switches has been used. The switch works under ZCS and ZVS conditions. No auxiliary switch was added to the circuit, thus any additional drive circuit is not needed. The proposed control system based on fuzzy logic method, has shown the smart accurate and faster tracking of the maximum po...

Uniformity and Deviation of Intra-axonal Cross-sectional Area Coverage of the Gray-to-White Matter Interface

Directory of Open Access Journals (Sweden)

Stefan Sommer

2017-12-01

Full Text Available Diffusion magnetic resonance imaging (dMRI is a compelling tool for investigating the structure and geometry of brain tissue based on indirect measurement of the diffusion anisotropy of water. Recent developments in global top-down tractogram optimizations enable the estimation of streamline weights, which characterize the connection between gray matter areas. In this work, the intra-axonal cross-sectional area coverage of the gray-to-white matter interface was examined by intersecting tractography streamlines with cortical regions of interest. The area coverage is the ratio of streamline weights divided by the surface area at the gray-to-white matter interface and assesses the estimated percentage which is covered by intra-axonal space. A high correlation (r = 0.935 between streamline weights and the cortical surface area was found across all regions of interest in all subjects. The variance across different cortical regions exhibits similarities to myelin maps. Additionally, we examined the effect of different diffusion gradient subsets at a lower, clinically feasible spatial resolution. Subsampling of the initial high-resolution diffusion dataset did not alter the tendency of the area coverage at the gray-to-white matter interface across cortical areas and subjects. However, single-shell acquisition schemes with lower b-values lead to a steady increase in area coverage in comparison to the full acquisition scheme at high resolution.

Uncertainty of soil erosion modelling using open source high resolution and aggregated DEMs

Directory of Open Access Journals (Sweden)

Arun Mondal

2017-05-01

Full Text Available Digital Elevation Model (DEM is one of the important parameters for soil erosion assessment. Notable uncertainties are observed in this study while using three high resolution open source DEMs. The Revised Universal Soil Loss Equation (RUSLE model has been applied to analysis the assessment of soil erosion uncertainty using open source DEMs (SRTM, ASTER and CARTOSAT and their increasing grid space (pixel size from the actual. The study area is a part of the Narmada river basin in Madhya Pradesh state, which is located in the central part of India and the area covered 20,558 km2. The actual resolution of DEMs is 30 m and their increasing grid spaces are taken as 90, 150, 210, 270 and 330 m for this study. Vertical accuracy of DEMs has been assessed using actual heights of the sample points that have been taken considering planimetric survey based map (toposheet. Elevations of DEMs are converted to the same vertical datum from WGS 84 to MSL (Mean Sea Level, before the accuracy assessment and modelling. Results indicate that the accuracy of the SRTM DEM with the RMSE of 13.31, 14.51, and 18.19 m in 30, 150 and 330 m resolution respectively, is better than the ASTER and the CARTOSAT DEMs. When the grid space of the DEMs increases, the accuracy of the elevation and calculated soil erosion decreases. This study presents a potential uncertainty introduced by open source high resolution DEMs in the accuracy of the soil erosion assessment models. The research provides an analysis of errors in selecting DEMs using the original and increased grid space for soil erosion modelling.

PI and Fuzzy Control Strategies for High Voltage Output DC-DC Boost Power Converter - Hardware Implementation and Analysis

DEFF Research Database (Denmark)

Padmanaban, Sanjeevi Kumar; Blaabjerg, Frede; Siano, Pierluigi

2016-01-01

This paper presents the control strategies by Proportional-Integral (P-I) and Fuzzy Logic (FL) for a DC-DC boost power converter for high output voltage configuration. Standard DC-DC converters are traditionally used for high voltage direct current (HVDC) power transmission systems. But, lack its...... converter with inbuilt voltage-lift technique and overcome the aforementioned deficiencies. Further, the control strategy is adapted based on proportional-integral (P-I) and fuzzy logic, closed-loop controller to regulate the outputs and ensure the performances. Complete hardware prototype of EHV converter...... performances in terms of efficiency, reduced transfer gain and increased cost with sensor units. Moreover, the internal self-parasitic components reduce the output voltage and efficiency of classical high voltage converters (HVC). This investigation focused on extra high-voltage (EHV) DC-DC boost power...

A high resolution portable spectroscopy system

International Nuclear Information System (INIS)

Kulkarni, C.P.; Vaidya, P.P.; Paulson, M.; Bhatnagar, P.V.; Pande, S.S.; Padmini, S.

2003-01-01

Full text: This paper describes the system details of a High Resolution Portable Spectroscopy System (HRPSS) developed at Electronics Division, BARC. The system can be used for laboratory class, high-resolution nuclear spectroscopy applications. The HRPSS consists of a specially designed compact NIM bin, with built-in power supplies, accommodating a low power, high resolution MCA, and on-board embedded computer for spectrum building and communication. A NIM based spectroscopy amplifier and a HV module for detector bias are integrated (plug-in) in the bin. The system communicates with a host PC via a serial link. Along-with a laptop PC, and a portable HP-Ge detector, the HRPSS offers a laboratory class performance for portable applications

Intra-chromosomal aberrations observed after high-LET radiation exposure in vivo using a state-of-the-art cytogenetic technique

International Nuclear Information System (INIS)

Mitchell, C.R.; Geard, C.R.; Brenner, D.J.; Hande, P.; Azizova, T.V.; Burak, L.E.; Khokhryakov, V.F.; Vasienko, E.K.

2003-01-01

Multicolor banding fluorescence in situ hybridization (mBAND) was used to investigate the presence of stable intra-chromosomal aberrations in chromosomes 1, 2 and 5 in a population of individuals exposed previously to low and/or high-LET radiation. Peripheral blood lymphocytes were taken from healthy Russian nuclear workers occupationally exposed to plutonium α -particles, γ -rays or both at the Mayak complex from 1949 onwards. Metaphase spreads were produced and chromosomes hybridized with mBAND probes and scored for intra-chromosomal aberrations including inversions and deletions. A large difference between the intra-chromosomal aberration frequencies for the high-plutonium (∼1.1 Gy) and the high- γ exposed (∼1.5 Gy) individuals was observed in all three chromosomes studied (chromosome 1: 1.9 ± 0.5 % (n=7) vs. 0.1 ± 0.1% (n=5); chromosome 2: 1.7 ± 0.4% (n=7) vs. 0 [0 -0.3]% (n=6); chromosome 5: 3.7 ± 0.5 % (n=11) vs. 0.1 ± 0.1 % (n=11) (high-plutonium vs. high-γ exposure)). Controls (n=5) showed very few or no intra-chromosomal aberrations. Significantly fewer aberrations were observed in chromosomes 1 and 2 compared with chromosome 5, studied previously in this cohort, suggesting that intra-chromosomal changes involving chromosomes 1 and 2 may be more lethal to the cell than those involving chromosome 5. The dramatic differences in yields of intra-chromosomal aberrations in high-plutonium exposure relative to low may provide a means of discrimination to estimate both the dose and type of previous radiation exposure in populations

Comparative Study on  Paralleled vs. Scaled Dc-dc Converters  in High Voltage Gain Applications

DEFF Research Database (Denmark)

Klimczak, Pawel; Munk-Nielsen, Stig

2008-01-01

Today power converters are present in many commercial, medical and industrial applications. A lot of them are high power and high current applications. In order to increase power handling capability several transistors or diodes are paralleled often. However such paralleling may lead to converter...

High Resolution Elevation Contours

Data.gov (United States)

Minnesota Department of Natural Resources — This dataset contains contours generated from high resolution data sources such as LiDAR. Generally speaking this data is 2 foot or less contour interval.

Extension of least squares spectral resolution algorithm to high-resolution lipidomics data

Energy Technology Data Exchange (ETDEWEB)

Zeng, Ying-Xu [Department of Chemistry, University of Bergen, PO Box 7803, N-5020 Bergen (Norway); Mjøs, Svein Are, E-mail: svein.mjos@kj.uib.no [Department of Chemistry, University of Bergen, PO Box 7803, N-5020 Bergen (Norway); David, Fabrice P.A. [Bioinformatics and Biostatistics Core Facility, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL) and Swiss Institute of Bioinformatics (SIB), Lausanne (Switzerland); Schmid, Adrien W. [Proteomics Core Facility, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne (Switzerland)

2016-03-31

Lipidomics, which focuses on the global study of molecular lipids in biological systems, has been driven tremendously by technical advances in mass spectrometry (MS) instrumentation, particularly high-resolution MS. This requires powerful computational tools that handle the high-throughput lipidomics data analysis. To address this issue, a novel computational tool has been developed for the analysis of high-resolution MS data, including the data pretreatment, visualization, automated identification, deconvolution and quantification of lipid species. The algorithm features the customized generation of a lipid compound library and mass spectral library, which covers the major lipid classes such as glycerolipids, glycerophospholipids and sphingolipids. Next, the algorithm performs least squares resolution of spectra and chromatograms based on the theoretical isotope distribution of molecular ions, which enables automated identification and quantification of molecular lipid species. Currently, this methodology supports analysis of both high and low resolution MS as well as liquid chromatography-MS (LC-MS) lipidomics data. The flexibility of the methodology allows it to be expanded to support more lipid classes and more data interpretation functions, making it a promising tool in lipidomic data analysis. - Highlights: • A flexible strategy for analyzing MS and LC-MS data of lipid molecules is proposed. • Isotope distribution spectra of theoretically possible compounds were generated. • High resolution MS and LC-MS data were resolved by least squares spectral resolution. • The method proposed compounds that are likely to occur in the analyzed samples. • The proposed compounds matched results from manual interpretation of fragment spectra.

Extension of least squares spectral resolution algorithm to high-resolution lipidomics data

International Nuclear Information System (INIS)

Zeng, Ying-Xu; Mjøs, Svein Are; David, Fabrice P.A.; Schmid, Adrien W.

2016-01-01

Lipidomics, which focuses on the global study of molecular lipids in biological systems, has been driven tremendously by technical advances in mass spectrometry (MS) instrumentation, particularly high-resolution MS. This requires powerful computational tools that handle the high-throughput lipidomics data analysis. To address this issue, a novel computational tool has been developed for the analysis of high-resolution MS data, including the data pretreatment, visualization, automated identification, deconvolution and quantification of lipid species. The algorithm features the customized generation of a lipid compound library and mass spectral library, which covers the major lipid classes such as glycerolipids, glycerophospholipids and sphingolipids. Next, the algorithm performs least squares resolution of spectra and chromatograms based on the theoretical isotope distribution of molecular ions, which enables automated identification and quantification of molecular lipid species. Currently, this methodology supports analysis of both high and low resolution MS as well as liquid chromatography-MS (LC-MS) lipidomics data. The flexibility of the methodology allows it to be expanded to support more lipid classes and more data interpretation functions, making it a promising tool in lipidomic data analysis. - Highlights: • A flexible strategy for analyzing MS and LC-MS data of lipid molecules is proposed. • Isotope distribution spectra of theoretically possible compounds were generated. • High resolution MS and LC-MS data were resolved by least squares spectral resolution. • The method proposed compounds that are likely to occur in the analyzed samples. • The proposed compounds matched results from manual interpretation of fragment spectra.

High-efficiency, monolithic, multi-bandgap, tandem photovoltaic energy converters

Science.gov (United States)

Wanlass, Mark W [Golden, CO

2011-11-29

A monolithic, multi-bandgap, tandem solar photovoltaic converter has at least one, and preferably at least two, subcells grown lattice-matched on a substrate with a bandgap in medium to high energy portions of the solar spectrum and at least one subcell grown lattice-mismatched to the substrate with a bandgap in the low energy portion of the solar spectrum, for example, about 1 eV.

Benefits and Drawbacks of A High Frequency Gan Zvzcps Converter

Directory of Open Access Journals (Sweden)

Blanes J. M.

2017-01-01

Full Text Available This paper presents the benefits and drawbacks of replacing the traditional Si Mosfets transistors with enhancement mode GaN transistors in a Half-Bridge Zero Voltage and Zero Current Switching Power Switching (ZVZCPS converter. This type of converters is usually used as Electronic Power Converters (EPC for telecommunication satellites travelling-wave tube amplifiers (TWTAs. In this study, firstly the converter is theoretically analysed, obtaining its operation, losses and efficiency equations. From these equations, optimizations maps based on the main system parameters are obtained. These optimization maps are the key to quantify the potential benefits of GaN transistors in this type of converters. Theoretical results show that using GaN transistors, the frequency of the converter can be pushed from 125kHz to 830kHz without sacrificing the converter efficiency. This frequency increase is directly related to reduction on the EPC size and weight.

Management of an Endodontic Infection with an Extra Oral Sinus Tract in a Single Visit: A Case Report

OpenAIRE

Satish Kumar, Krishnamurthy; Subbiya, Arunajatesan; Vivekanandhan, Paramasivam; Prakash, Venkatachalam; Tamilselvi, Ramachandran

2013-01-01

Chronic apical periodontitis can drain through a sinus tract, which may be intra-oral or extra-oral, though an intra-oral drainage is more common. Though such cases can be treated in a single visit, there is no report on a single visit endodontic treatment for a chronic apical periodontitis with a draining sinus. This case report demonstrates that the apical periodontitis with a cutaneous sinus tract can be successfully treated endodontically as a single visit procedure, if the patient is in ...

Degradation of dental resin composites during intra-oral wear

NARCIS (Netherlands)

Yulianto, Heribertus Dedy Kusuma

2017-01-01

Dental resin composites have become an integral part of modern dentistry and used worldwide to restore missing tooth structures, to modify tooth color and anatomical contour, and to enhance aesthetics and function. The dentist should be aware that, the aggressive complexity of the oral environment

Ultra-high resolution coded wavefront sensor

KAUST Repository

Wang, Congli

2017-06-08

Wavefront sensors and more general phase retrieval methods have recently attracted a lot of attention in a host of application domains, ranging from astronomy to scientific imaging and microscopy. In this paper, we introduce a new class of sensor, the Coded Wavefront Sensor, which provides high spatio-temporal resolution using a simple masked sensor under white light illumination. Specifically, we demonstrate megapixel spatial resolution and phase accuracy better than 0.1 wavelengths at reconstruction rates of 50 Hz or more, thus opening up many new applications from high-resolution adaptive optics to real-time phase retrieval in microscopy.

Extra-oral dental radiography for disaster victims using a flat panel X-ray detector and a hand-held X-ray generator.

Science.gov (United States)

Ohtani, M; Oshima, T; Mimasaka, S

2017-12-01

Forensic odontologists commonly incise the skin for post-mortem dental examinations when it is difficult to open the victim's mouth. However, it is prohibited by law to incise dead bodies without permission in Japan. Therefore, we attempted using extra-oral dental radiography, using a digital X-ray equipment with rechargeable batteries, to overcome this restriction. A phantom was placed in the prone position on a table, and three plain dental radiographs were used per case: "lateral oblique radiographs" for left and right posterior teeth and a "contact radiograph" for anterior teeth were taken using a flat panel X-ray detector and a hand-held X-ray generator. The resolving power of the images was measured by a resolution test chart, and the scattered X-ray dose was measured using an ionization chamber-type survey meter. The resolving power of the flat panel X-ray detector was 3.0 lp/mm, which was less than that of intra-oral dental methods, but the three extra-oral plain dental radiographs provided the overall dental information from outside of the mouth, and this approach was less time-consuming. In addition, the higher dose of scattered X-rays was laterally distributed, but the dose per case was much less than that of intra-oral dental radiographs. Extra-oral plain dental radiography can be used for disaster victim identification by dental methods even when it is difficult to open the mouth. Portable and rechargeable devices, such as a flat panel X-ray detector and a hand-held X-ray generator, are convenient to bring and use anywhere, even at a disaster scene lacking electricity and water.

Resolution of methylphenidate osmotic release oral system-induced hair loss in two siblings after dose escalation.

Science.gov (United States)

Ardic, Ulku Akyol; Ercan, Eyup Sabri

2017-11-01

This report describes the cases of two siblings who experienced hair loss after treatment with methylphenidate (MPH) osmotic release oral system (OROS). Hair loss was resolved after discontinuation of the drug, but the children re-initiated treatment, after which hair loss again occurred, but they continued the treatment. After dose escalation, the hair loss resolved. This is the first report to describe resolution of OROS-MPH-induced hair loss after dose escalation. © 2017 Japan Pediatric Society.

Use of next-generation sequencing in oral cavity cancer

DEFF Research Database (Denmark)

Tabatabaeifar, Siavosh; Kruse, Torben A; Thomassen, Mads

Background: Oral cavity cancer is a subgroup of head and neck cancer which is the world’s 6th most common cancer form. Oral squamous cell carcinomas (OSCC) constitute almost all oral cavity cancers, and OSCC are primarily attributed by excessive alcohol consumption and tobacco exposure...... of tumour cells exists. Conclusions: Use of next generation sequencing in oral cavity cancer can give valuable insight into the biology of the disease. By investigating intra tumour heterogeneity we see that the different tumour specimens in each patient are quite homogenous, but evidence of heterogeneous...

Raman spectroscopic analysis of oral squamous cell carcinoma and oral dysplasia in the high-wavenumber region

Science.gov (United States)

Carvalho, Luis Felipe C. S.; Bonnier, Franck; O'Callaghan, Kate; O'Sullivan, Jeff; Flint, Stephen; Neto, Lazaro P. M.; Soto, Cláudio A. T.; dos Santos, Laurita; Martin, Airton A.; Byrne, Hugh J.; Lyng, Fiona M.

2015-06-01

Raman spectroscopy can provide a molecular-level signature of the biochemical composition and structure of cells with excellent spatial resolution and could be useful to monitor changes in composition for early stage and non-invasive cancer diagnosis, both ex-vivo and in vivo. In particular, the fingerprint spectral region (400-1,800 cm-1) has been shown to be very promising for optical biopsy purposes. However, limitations to discrimination of dysplastic and inflammatory processes based on the fingerprint region still persist. In addition, the Raman spectral signal of dysplastic cells is one important source of misdiagnosis of normal versus pathological tissues. The high wavenumber region (2,800-3,600 cm-1) provides more specific information based on N-H, O-H and C-H vibrations and can be used to identify the subtle changes which could be important for discrimination of samples. In this study, we demonstrate the potential of the highwavenumber spectral region by collecting Raman spectra of nucleoli, nucleus and cytoplasm from oral epithelial cancer (SCC-4) and dysplastic (DOK) cell lines and from normal oral epithelial primary cells, in vitro, which were then analyzed by area under the curve as a method to discriminate the spectra. In this region, we will show the discriminatory potential of the CH vibrational modes of nucleic acids, proteins and lipids. This technique demonstrated more efficient discrimination than the fingerprint region when we compared the cell cultures.

Molecular Epidemiologic Source Tracking of Orally Transmitted Chagas Disease, Venezuela

Science.gov (United States)

Segovia, Maikell; Martínez, Clara E.; Messenger, Louisa A.; Nessi, Anaibeth; Londoño, Juan C.; Espinosa, Raul; Martínez, Cinda; Alfredo, Mijares; Bonfante-Cabarcas, Rafael; Lewis, Michael D.; de Noya, Belkisyolé A.; Miles, Michael A.; Llewellyn, Martin S.

2013-01-01

Oral outbreaks of Chagas disease are increasingly reported in Latin America. The transitory presence of Trypanosoma cruzi parasites within contaminated foods, and the rapid consumption of those foods, precludes precise identification of outbreak origin. We report source attribution for 2 peri-urban oral outbreaks of Chagas disease in Venezuela via high resolution microsatellite typing. PMID:23768982

High resolution time integration for Sn radiation transport

International Nuclear Information System (INIS)

Thoreson, Greg; McClarren, Ryan G.; Chang, Jae H.

2008-01-01

First order, second order and high resolution time discretization schemes are implemented and studied for the S n equations. The high resolution method employs a rate of convergence better than first order, but also suppresses artificial oscillations introduced by second order schemes in hyperbolic differential equations. All three methods were compared for accuracy and convergence rates. For non-absorbing problems, both second order and high resolution converged to the same solution as the first order with better convergence rates. High resolution is more accurate than first order and matches or exceeds the second order method. (authors)

Structure of high-resolution NMR spectra

CERN Document Server

Corio, PL

2012-01-01

Structure of High-Resolution NMR Spectra provides the principles, theories, and mathematical and physical concepts of high-resolution nuclear magnetic resonance spectra.The book presents the elementary theory of magnetic resonance; the quantum mechanical theory of angular momentum; the general theory of steady state spectra; and multiple quantum transitions, double resonance and spin echo experiments.Physicists, chemists, and researchers will find the book a valuable reference text.

The First Non-Dispersive High-Resolution Spectroscopy of an X-ray-bright Galaxy Cluster

Science.gov (United States)

Yamaguchi, Hiroya; Hitomi Collaboration

2018-06-01

The Hitomi X-ray Observatory was equipped with the Soft X-ray Spectrometer (SXS), an X-ray microcalorimeter that achieved an energy resolution of 5 eV (@0.5-10 keV) for extended objects. This offered an unprecedented benchmark of atomic modeling and database for hot collisional plasmas, revealing both successes and challenges in the current atomic codes that are widely used by the X-ray astronomy community. I will review the Hitomi observations of the brightest part of the Perseus Cluster, whose X-ray spectrum is dominated by thermal emission from the intra-cluster medium (ICM). The SXS successfully measured the turbulent velocities and metal abundances of the ICM, which radically altered our understanding of the dynamics and chemical enrichment in this object. At the same time, the high-resolution X-ray data led to significant improvement in the atomic models, such as AtomDB and SPEX -- I will briefly overview how this improvement was made. Nevertheless, there are still significant discrepancies among the public atomic models, causing systematic uncertainties in measurements of the temperature, abundance, and degree of the resonance scattering. Requirements for future improvements will be summarized in this context.

Early Angiographic Resolution of Cerebral Vasospasm with High Dose Intravenous Milrinone Therapy

Directory of Open Access Journals (Sweden)

F. A. Zeiler

2015-01-01

Full Text Available Background. Treatment of symptomatic delayed cerebral ischemia (DCI after subarachnoid hemorrhage (SAH is difficult. Recent studies suggest intravenous (IV high dose milrinone as a potential therapy. The timing to angiographic response with this is unclear. Methods. We reviewed the chart of one patient admitted for SAH who developed symptomatic DCI and was treated with high dose IV milrinone. Results. A 66-year-old female was admitted with a Hunt and Hess clinical grade 4, World Federation of Neurological Surgeons (WFNS clinical grade 4, and SAH secondary to a left anterior choroidal artery aneurysm which was clipped. After bleed day 6, the patient developed symptomatic DCI. We planned for angioplasty of the proximal segments. We administered high dose IV milrinone bolus followed by continuous infusion which led to clinical improvement prior to angiography. The angiogram performed 1.5 hours after milrinone administration displayed resolution of the CT angiogram and MRI based cerebral vasospasm such that further intra-arterial therapy was aborted. She completed 6 days of continuous IV milrinone therapy, was transferred to the ward, and subsequently rehabilitated. Conclusions. High dose IV milrinone therapy for symptomatic DCI after SAH can lead to rapid neurological improvement with dramatic early angiographic improvement of cerebral vasospasm.

A high resolution detector for H0 → γγ

International Nuclear Information System (INIS)

Atiya, M.S.; Kycia, T.F.

1991-01-01

SSC detectors represent a challenging departure, both in size and precision, from currently operating detectors. In this note we enumerate some of the benefits of using high magnetic fields both to simplify the detector and improve its resolution and sensitivity. We have chosen an arrangement optimized to search for the reaction H 0 → γγ. The arrangement also has the excellent momentum resolution for muons and electrons considered critical for the discovery of such processes as H 0 → Z 0 Z 0 → ell + ell - ell + ell - , H 0 → Z 0 Z 0 → ell + ell - ell + ell - , new and narrow vector bosons, and bound states of extra generational quarks. This detection scheme represents an improvement in the H 0 → γγ mass resolution of at least a factor of 7 beyond the best currently proposed detectors. In addition, we have a significantly improved rejection of common H 0 → γγ backgrounds. As indeed most experiments do not exceed their initial projections, this extra factor could insure the unambiguous discovery of this decay should it indeed occur. As no reasonably realistic detector can achieve excellent detection for all physics signatures we chose to give tip on excellent hadron calorimetry. For Higgs masses between 80 and 150 GeV/c 2 the Higgs decay into two photons is an excellent signature. To date, all attempts to search for this decay mode have centered on the use of electromagnetic calorimetry. We are proposing a different approach. We will convert the two photons close to the production point and measure the momenta of the electron pairs

Multi-cell DC-DC converter with high step-down voltage ratio

NARCIS (Netherlands)

Tibola, G.; Duarte, J.L.; Blinov, A.

2015-01-01

The use of high voltage allows a power processing system to operate with low currents, improving efficiency. Nevertheless, final applications usually require low voltage inlet, which can be provided using modular multilevel converters submodules, for instance. However, every submodule's gate-unit

High-resolution multi-slice PET

International Nuclear Information System (INIS)

Yasillo, N.J.; Chintu Chen; Ordonez, C.E.; Kapp, O.H.; Sosnowski, J.; Beck, R.N.

1992-01-01

This report evaluates the progress to test the feasibility and to initiate the design of a high resolution multi-slice PET system. The following specific areas were evaluated: detector development and testing; electronics configuration and design; mechanical design; and system simulation. The design and construction of a multiple-slice, high-resolution positron tomograph will provide substantial improvements in the accuracy and reproducibility of measurements of the distribution of activity concentrations in the brain. The range of functional brain research and our understanding of local brain function will be greatly extended when the development of this instrumentation is completed

High resolution NMR spectroscopy of synthetic polymers in bulk

International Nuclear Information System (INIS)

Komorski, R.A.

1986-01-01

The contents of this book are: Overview of high-resolution NMR of solid polymers; High-resolution NMR of glassy amorphous polymers; Carbon-13 solid-state NMR of semicrystalline polymers; Conformational analysis of polymers of solid-state NMR; High-resolution NMR studies of oriented polymers; High-resolution solid-state NMR of protons in polymers; and Deuterium NMR of solid polymers. This work brings together the various approaches for high-resolution NMR studies of bulk polymers into one volume. Heavy emphasis is, of course, given to 13C NMR studies both above and below Tg. Standard high-power pulse and wide-line techniques are not covered

Rinoplastia do nariz negróide por via intra-oral sem ressecções externas: avaliação da eficácia da técnica

Directory of Open Access Journals (Sweden)

Castilho Helton Traber de

2002-01-01

Full Text Available OBJETIVO: Avaliar a eficácia da técnica de redução da largura da base nasal do nariz negróide, modificando a inclinação dos eixos das narinas pela mobilização de tecidos internos, por abordagem intra-oral, evitando cicatrizes externas. MÉTODOS: Foram operadas 11 pacientes adulta do sexo feminino, com idade variando entre 19 a 45 anos, distribuindo-se em 2 da raça caucasóide e 9 da raça negróide, sendo desta 5 de cor parda e 4 de cor negra. O método de fotografia foi padronizado, e as imagens em papel foram digitalizadas. Por meio de software foram mensurados nas fotografias pré-operatórias e com 3 meses após a rinoplastia, 8 índices relativos à base nasal baseados em pontos antropométricos. Os valores obtidos foram submetidos à análise estatística descritiva e inferencial. RESULTADOS: Não houve diferença estatisticamente significante em 7 índices relativos a redução da largura da base nasal e à inclinação dos eixos das narinas. Apenas houve alteração significante no aumento do Ângulo Nasolabial (p=0,001. CONCLUSÃO: A técnica de rinoplastia de nariz negróide por via intra-oral sem ressecções externas, apenas com mobilização dos tecidos internos, não é eficaz para a reduzir a largura da base nasal.

High resolution integral holography using Fourier ptychographic approach.

Science.gov (United States)

Li, Zhaohui; Zhang, Jianqi; Wang, Xiaorui; Liu, Delian

2014-12-29

An innovative approach is proposed for calculating high resolution computer generated integral holograms by using the Fourier Ptychographic (FP) algorithm. The approach initializes a high resolution complex hologram with a random guess, and then stitches together low resolution multi-view images, synthesized from the elemental images captured by integral imaging (II), to recover the high resolution hologram through an iterative retrieval with FP constrains. This paper begins with an analysis of the principle of hologram synthesis from multi-projections, followed by an accurate determination of the constrains required in the Fourier ptychographic integral-holography (FPIH). Next, the procedure of the approach is described in detail. Finally, optical reconstructions are performed and the results are demonstrated. Theoretical analysis and experiments show that our proposed approach can reconstruct 3D scenes with high resolution.

1 GHz GaAs Buck Converter for High Power Amplifier Modulation Applications

NARCIS (Netherlands)

Busking, E.B.; Hek, A.P. de; Vliet, F.E. van

2012-01-01

A fully integrated 1 GHz buck converter output stage, including on-chip inductor and DC output filtering has been realized, in a standard high-voltage breakdown GaAs MMIC technology. This is a significant step forward in designing highspeed power control of supply-modulated HPAs (high power

Intra-Mathematical Connections Made by High School Students in Performing Calculus Tasks

Science.gov (United States)

García-García, Javier; Dolores-Flores, Crisólogo

2018-01-01

In this article, we report the results of research that explores the intra-mathematical connections that high school students make when they solve Calculus tasks, in particular those involving the derivative and the integral. We consider mathematical connections as a cognitive process through which a person relates or associates two or more ideas,…

High-spatial resolution and high-spectral resolution detector for use in the measurement of solar flare hard x rays

International Nuclear Information System (INIS)

Desai, U.D.; Orwig, L.E.

1988-01-01

In the areas of high spatial resolution, the evaluation of a hard X-ray detector with 65 micron spatial resolution for operation in the energy range from 30 to 400 keV is proposed. The basic detector is a thick large-area scintillator faceplate, composed of a matrix of high-density scintillating glass fibers, attached to a proximity type image intensifier tube with a resistive-anode digital readout system. Such a detector, combined with a coded-aperture mask, would be ideal for use as a modest-sized hard X-ray imaging instrument up to X-ray energies as high as several hundred keV. As an integral part of this study it was also proposed that several techniques be critically evaluated for X-ray image coding which could be used with this detector. In the area of high spectral resolution, it is proposed to evaluate two different types of detectors for use as X-ray spectrometers for solar flares: planar silicon detectors and high-purity germanium detectors (HPGe). Instruments utilizing these high-spatial-resolution detectors for hard X-ray imaging measurements from 30 to 400 keV and high-spectral-resolution detectors for measurements over a similar energy range would be ideally suited for making crucial solar flare observations during the upcoming maximum in the solar cycle

Brachytherapy for early oral tongue cancer. Low dose rate to high dose rate

International Nuclear Information System (INIS)

Yamazaki, Hideya; Inoue, Takehiro; Yoshida, Ken; Yoshioka, Yasuo; Shimizutani, Kimishige; Inoue, Toshihiko; Furukawa, Souhei; Kakimoto, Naoya

2003-01-01

To examine the compatibility of low dose rate (LDR) with high dose rate (HDR) brachytherapy, we reviewed 399 patients with early oral tongue cancer (T1-2N0M0) treated solely by brachytherapy at Osaka University Hospital between 1967 and 1999. For patients in the LDR group (n=341), the treatment sources consisted of Ir-192 pin for 227 patients (1973-1996; irradiated dose, 61-85 Gy; median, 70 Gy), Ra-226 needle for 113 patients (1967-1986; 55-93 Gy; median, 70 Gy). Ra-226 and Ir-192 were combined for one patient. Ir-192 HDR (microSelectron-HDR) was used for 58 patients in the HDR group (1991-present; 48-60 Gy; median, 60 Gy). LDR implantations were performed via oral and HDR via a submental/submandibular approach. The dose rates at the reference point for the LDR group were 0.30 to 0.8 Gy/h, and for the HDR group 1.0 to 3.4 Gy/min. The patients in the HDR group received a total dose of 48-60 Gy (8-10 fractions) during one week. Two fractions were administered per day (at least a 6-h interval). The 3- and 5-year local control rates for patients in the LDR group were 85% and 80%, respectively, and those in the HDR group were both 84%. HDR brachytherapy showed the same lymph-node control rate as did LDR brachytherapy (67% at 5 years). HDR brachytherapy achieved the same locoregional result as did LDR brachytherapy. A converting factor of 0.86 is applicable for HDR in the treatment of early oral tongue cancer. (author)

Fine Particulate Matter Predictions Using High Resolution Aerosol Optical Depth (AOD) Retrievals

Science.gov (United States)

Chudnovsky, Alexandra A.; Koutrakis, Petros; Kloog, Itai; Melly, Steven; Nordio, Francesco; Lyapustin, Alexei; Wang, Jujie; Schwartz, Joel

2014-01-01

To date, spatial-temporal patterns of particulate matter (PM) within urban areas have primarily been examined using models. On the other hand, satellites extend spatial coverage but their spatial resolution is too coarse. In order to address this issue, here we report on spatial variability in PM levels derived from high 1 km resolution AOD product of Multi-Angle Implementation of Atmospheric Correction (MAIAC) algorithm developed for MODIS satellite. We apply day-specific calibrations of AOD data to predict PM(sub 2.5) concentrations within the New England area of the United States. To improve the accuracy of our model, land use and meteorological variables were incorporated. We used inverse probability weighting (IPW) to account for nonrandom missingness of AOD and nested regions within days to capture spatial variation. With this approach we can control for the inherent day-to-day variability in the AOD-PM(sub 2.5) relationship, which depends on time-varying parameters such as particle optical properties, vertical and diurnal concentration profiles and ground surface reflectance among others. Out-of-sample "ten-fold" cross-validation was used to quantify the accuracy of model predictions. Our results show that the model-predicted PM(sub 2.5) mass concentrations are highly correlated with the actual observations, with out-of- sample R(sub 2) of 0.89. Furthermore, our study shows that the model captures the pollution levels along highways and many urban locations thereby extending our ability to investigate the spatial patterns of urban air quality, such as examining exposures in areas with high traffic. Our results also show high accuracy within the cities of Boston and New Haven thereby indicating that MAIAC data can be used to examine intra-urban exposure contrasts in PM(sub 2.5) levels.

Improving Power Converter Reliability

DEFF Research Database (Denmark)

Ghimire, Pramod; de Vega, Angel Ruiz; Beczkowski, Szymon

2014-01-01

of a high-power IGBT module during converter operation, which may play a vital role in improving the reliability of the power converters. The measured voltage is used to estimate the module average junction temperature of the high and low-voltage side of a half-bridge IGBT separately in every fundamental......The real-time junction temperature monitoring of a high-power insulated-gate bipolar transistor (IGBT) module is important to increase the overall reliability of power converters for industrial applications. This article proposes a new method to measure the on-state collector?emitter voltage...... is measured in a wind power converter at a low fundamental frequency. To illustrate more, the test method as well as the performance of the measurement circuit are also presented. This measurement is also useful to indicate failure mechanisms such as bond wire lift-off and solder layer degradation...

High resolution photoelectron spectroscopy

International Nuclear Information System (INIS)

Arko, A.J.

1988-01-01

Photoelectron Spectroscopy (PES) covers a very broad range of measurements, disciplines, and interests. As the next generation light source, the FEL will result in improvements over the undulator that are larger than the undulater improvements over bending magnets. The combination of high flux and high inherent resolution will result in several orders of magnitude gain in signal to noise over measurements using synchrotron-based undulators. The latter still require monochromators. Their resolution is invariably strongly energy-dependent so that in the regions of interest for many experiments (h upsilon > 100 eV) they will not have a resolving power much over 1000. In order to study some of the interesting phenomena in actinides (heavy fermions e.g.) one would need resolving powers of 10 4 to 10 5 . These values are only reachable with the FEL

High Efficient Bidirectional Battery Converter for residential PV Systems

DEFF Research Database (Denmark)

Pham, Cam; Kerekes, Tamas; Teodorescu, Remus

2012-01-01

Photovoltaic (PV) installation is suited for the residential environment and the generation pattern follows the distribution of residential power consumption in daylight hours. In the cases of unbalance between generation and demand, the Smart PV with its battery storage can absorb or inject...... the power to balance it. High efficient bidirectional converter for the battery storage is required due high system cost and because the power is processed twice. A 1.5kW prototype is designed and built with CoolMOS and SiC diodes, >;95% efficiency has been obtained with 200 kHz hard switching....

Cascaded resonant bridge converters

Science.gov (United States)

Stuart, Thomas A. (Inventor)

1989-01-01

A converter for converting a low voltage direct current power source to a higher voltage, high frequency alternating current output for use in an electrical system where it is desired to use low weight cables and other circuit elements. The converter has a first stage series resonant (Schwarz) converter which converts the direct current power source to an alternating current by means of switching elements that are operated by a variable frequency voltage regulator, a transformer to step up the voltage of the alternating current, and a rectifier bridge to convert the alternating current to a direct current first stage output. The converter further has a second stage series resonant (Schwarz) converter which is connected in series to the first stage converter to receive its direct current output and convert it to a second stage high frequency alternating current output by means of switching elements that are operated by a fixed frequency oscillator. The voltage of the second stage output is controlled at a relatively constant value by controlling the first stage output voltage, which is accomplished by controlling the frequency of the first stage variable frequency voltage controller in response to second stage voltage. Fault tolerance in the event of a load short circuit is provided by making the operation of the first stage variable frequency voltage controller responsive to first and second stage current limiting devices. The second stage output is connected to a rectifier bridge whose output is connected to the input of the second stage to provide good regulation of output voltage wave form at low system loads.

Indications for Elective Tracheostomy in Reconstructive Surgery in Patients With Oral Cancer.

Science.gov (United States)

Leiser, Yoav; Barak, Michal; Ghantous, Yasmine; Yehudai, Noam; Abu El-Naaj, Imad

2017-01-01

Oral cancer surgery carries a high risk of upper airway obstruction; yet optimal airway management approach remains controversial. The purpose of the present study was to evaluate the use of tracheostomy in oncological patients undergoing oral cancer surgery with intra oral flap reconstruction. The study cohort included 75 patients with oral cancer, who underwent major intraoral resections and reconstruction with vascularized flaps. Thirty-six percent of the patients received elective tracheostomy (27 patients). Mean hospital stay of the patients with tracheostomy was 28.4 ± 12.5 days compared with 9.7 ± 2.1 days in the nontracheostomy patients. A scoring system rendered from this study suggests that patients with a total scoring at or above 8 should be considered for elective tracheostomy. With appropriate postoperative monitoring, selected patients can be managed without routine elective tracheostomy, yet, patients with comorbidities, mostly elderly patients, which undergo surgical resection and reconstruction in high-risk areas that can result in a bulky flap that pose danger to the postoperative airway, should receive elective tracheostomy.

Potent, selective, orally bioavailable inhibitors of tumor necrosis factor-alpha converting enzyme (TACE): discovery of indole, benzofuran, imidazopyridine and pyrazolopyridine P1' substituents.

Science.gov (United States)

Lu, Zhonghui; Ott, Gregory R; Anand, Rajan; Liu, Rui-Qin; Covington, Maryanne B; Vaddi, Krishna; Qian, Mingxin; Newton, Robert C; Christ, David D; Trzaskos, James; Duan, James J-W

2008-03-15

Potent and selective inhibitors of tumor necrosis factor-alpha converting enzyme (TACE) were discovered with several new heterocyclic P1' groups in conjunction with cyclic beta-amino hydroxamic acid scaffolds. Among them, the pyrazolopyridine provided the best overall profile when combined with tetrahydropyran beta-amino hydroxamic acid scaffold. Specifically, inhibitor 49 showed IC(50) value of 1 nM against porcine TACE and 170 nM in the suppression of LPS-induced TNF-alpha of human whole blood. Compound 49 also displayed excellent selectivity over a wide panel of MMPs as well as excellent oral bioavailability (F%>90%) in rat n-in-1 PK studies.

Correlation of geothermal springs with sub-surface fault terminations revealed by high-resolution, UAV-acquired magnetic data

Science.gov (United States)

Glen, Jonathan; A.E. Egger,; C. Ippolito,; N.Athens,

2013-01-01

There is widespread agreement that geothermal springs in extensional geothermal systems are concentrated at fault tips and in fault interaction zones where porosity and permeability are dynamically maintained (Curewitz and Karson, 1997; Faulds et al., 2010). Making these spatial correlations typically involves geological and geophysical studies in order to map structures and their relationship to springs at the surface. Geophysical studies include gravity and magnetic surveys, which are useful for identifying buried, intra-basin structures, especially in areas where highly magnetic, dense mafic volcanic rocks are interbedded with, and faulted against less magnetic, less dense sedimentary rock. High-resolution magnetic data can also be collected from the air in order to provide continuous coverage. Unmanned aerial systems (UAS) are well-suited for conducting these surveys as they can provide uniform, low-altitude, high-resolution coverage of an area without endangering crew. In addition, they are more easily adaptable to changes in flight plans as data are collected, and improve efficiency. We have developed and tested a new system to collect magnetic data using small-platform UAS. We deployed this new system in Surprise Valley, CA, in September, 2012, on NASA's SIERRA UAS to perform a reconnaissance survey of the entire valley as well as detailed surveys in key transition zones. This survey has enabled us to trace magnetic anomalies seen in ground-based profiles along their length. Most prominent of these is an intra-basin magnetic high that we interpret as a buried, faulted mafic dike that runs a significant length of the valley. Though this feature lacks surface expression, it appears to control the location of geothermal springs. All of the major hot springs on the east side of the valley lie along the edge of the high, and more specifically, at structural transitions where the high undergoes steps, bends, or breaks. The close relationship between the springs

Photography in Medicine and Oral Mucosa

Directory of Open Access Journals (Sweden)

Uğur Ergin

2012-12-01

Full Text Available Increasing demand on aesthetic dental restorations, spreading of digital cameras, easily sharing of the digital images increased the tendency of dentists to take digital dental photographs. Usage of SLR cameras and macro lenses are standard for dental photographs. By learning simple techniques and with some practice, clinicians can have excellent intra oral and extra oral photographs. These photographs can be used for documentation, increasing communication with patients and colleagues and laboratory, can provide auto control, and could better defend themselves in legal matters.

A method of pre-surgical oral orthopaedics.

Science.gov (United States)

DiBiase, D D; Hunter, S B

1983-01-01

A preliminary report of a technique of pre-surgical treatment in cleft lip and palate patients is outlined utilizing an adjustable intra-oral appliance with extra-oral strapping. The appliance is constructed with an adjustable spring for expansion and two shelves overlapping in the midline to allow palatal continuity during treatment. Frequently, only one appliance for each patient is required. The techniques of appliance construction, pre-surgical management and surgical repair of the lip are outlined.

High-resolution regional climate model evaluation using variable-resolution CESM over California

Science.gov (United States)

Huang, X.; Rhoades, A.; Ullrich, P. A.; Zarzycki, C. M.

2015-12-01

Understanding the effect of climate change at regional scales remains a topic of intensive research. Though computational constraints remain a problem, high horizontal resolution is needed to represent topographic forcing, which is a significant driver of local climate variability. Although regional climate models (RCMs) have traditionally been used at these scales, variable-resolution global climate models (VRGCMs) have recently arisen as an alternative for studying regional weather and climate allowing two-way interaction between these domains without the need for nudging. In this study, the recently developed variable-resolution option within the Community Earth System Model (CESM) is assessed for long-term regional climate modeling over California. Our variable-resolution simulations will focus on relatively high resolutions for climate assessment, namely 28km and 14km regional resolution, which are much more typical for dynamically downscaled studies. For comparison with the more widely used RCM method, the Weather Research and Forecasting (WRF) model will be used for simulations at 27km and 9km. All simulations use the AMIP (Atmospheric Model Intercomparison Project) protocols. The time period is from 1979-01-01 to 2005-12-31 (UTC), and year 1979 was discarded as spin up time. The mean climatology across California's diverse climate zones, including temperature and precipitation, is analyzed and contrasted with the Weather Research and Forcasting (WRF) model (as a traditional RCM), regional reanalysis, gridded observational datasets and uniform high-resolution CESM at 0.25 degree with the finite volume (FV) dynamical core. The results show that variable-resolution CESM is competitive in representing regional climatology on both annual and seasonal time scales. This assessment adds value to the use of VRGCMs for projecting climate change over the coming century and improve our understanding of both past and future regional climate related to fine

Section on High Resolution Optical Imaging (HROI)

Data.gov (United States)

Federal Laboratory Consortium — The Section on High Resolution Optical Imaging (HROI) develops novel technologies for studying biological processes at unprecedented speed and resolution. Research...

On Strategies of Improving Junior High School Students' Oral English Ability

Institute of Scientific and Technical Information of China (English)

罗茜

2015-01-01

With the increasingly frequent international exchanges,English,as an international language,has been attached greater importance.The oral English ability of junior high school students plays an indispensable role in their everyday study and social interaction,and it is the present junior school study that can lay a solid foundation for their future study and life. Therefore,to comprehensively improve their oral English ability is in urgent need and of paramount significance.This paper focuses on analyzing the external and internal factors influencing the cultivation of junior high school students' oral English ability,and put forwards the corresponding cultivating strategies of the oral English ability of junior high school students.

On Strategies of Improving Junior High School Students’ Oral English Ability

Institute of Scientific and Technical Information of China (English)

罗茜

2015-01-01

With the increasingly frequent international exchanges,English,as an international language,has been attached greater importance.The oral English ability of junior high school students plays an indispensable role in their everyday study and social interaction,and it is the present junior school study that can lay a solid foundation for their future study and life.Therefore,to comprehensively improve their oral English ability is in urgent need and of paramount significance.This paper focuses on analyzing the external and internal factors influencing the cultivation of junior high school students’oral English ability,and put forwards the corresponding cultivating strategies of the oral English ability of junior high school students.

Floating high step-down stacked dc-dc converter based on buck-boost cells

NARCIS (Netherlands)

Tibola, G.; Duarte, J.L.; Blinov, A.

2015-01-01

In some high power dc-dc applications, where high voltage is present, a converter with high step-down ratio is required in order to provide an isolated low power auxiliary supply. This requirement represents a challenge and many topologies are currently being researched. The analysis of a

High angular resolution at LBT

Science.gov (United States)

Conrad, A.; Arcidiacono, C.; Bertero, M.; Boccacci, P.; Davies, A. G.; Defrere, D.; de Kleer, K.; De Pater, I.; Hinz, P.; Hofmann, K. H.; La Camera, A.; Leisenring, J.; Kürster, M.; Rathbun, J. A.; Schertl, D.; Skemer, A.; Skrutskie, M.; Spencer, J. R.; Veillet, C.; Weigelt, G.; Woodward, C. E.

2015-12-01

High angular resolution from ground-based observatories stands as a key technology for advancing planetary science. In the window between the angular resolution achievable with 8-10 meter class telescopes, and the 23-to-40 meter giants of the future, LBT provides a glimpse of what the next generation of instruments providing higher angular resolution will provide. We present first ever resolved images of an Io eruption site taken from the ground, images of Io's Loki Patera taken with Fizeau imaging at the 22.8 meter LBT [Conrad, et al., AJ, 2015]. We will also present preliminary analysis of two data sets acquired during the 2015 opposition: L-band fringes at Kurdalagon and an occultation of Loki and Pele by Europa (see figure). The light curves from this occultation will yield an order of magnitude improvement in spatial resolution along the path of ingress and egress. We will conclude by providing an overview of the overall benefit of recent and future advances in angular resolution for planetary science.

A method for generating high resolution satellite image time series

Science.gov (United States)

Guo, Tao

2014-10-01

There is an increasing demand for satellite remote sensing data with both high spatial and temporal resolution in many applications. But it still is a challenge to simultaneously improve spatial resolution and temporal frequency due to the technical limits of current satellite observation systems. To this end, much R&D efforts have been ongoing for years and lead to some successes roughly in two aspects, one includes super resolution, pan-sharpen etc. methods which can effectively enhance the spatial resolution and generate good visual effects, but hardly preserve spectral signatures and result in inadequate analytical value, on the other hand, time interpolation is a straight forward method to increase temporal frequency, however it increase little informative contents in fact. In this paper we presented a novel method to simulate high resolution time series data by combing low resolution time series data and a very small number of high resolution data only. Our method starts with a pair of high and low resolution data set, and then a spatial registration is done by introducing LDA model to map high and low resolution pixels correspondingly. Afterwards, temporal change information is captured through a comparison of low resolution time series data, and then projected onto the high resolution data plane and assigned to each high resolution pixel according to the predefined temporal change patterns of each type of ground objects. Finally the simulated high resolution data is generated. A preliminary experiment shows that our method can simulate a high resolution data with a reasonable accuracy. The contribution of our method is to enable timely monitoring of temporal changes through analysis of time sequence of low resolution images only, and usage of costly high resolution data can be reduces as much as possible, and it presents a highly effective way to build up an economically operational monitoring solution for agriculture, forest, land use investigation

High-resolution TEM microscopy study of the creep behaviour of carbon-based cathode materials

Energy Technology Data Exchange (ETDEWEB)

Wang, Wei, E-mail: wwlyzwkj@126.com [College of Materials Science and Engineering, Henan University of Science and Technology, Luoyang 471023 (China); Collaborative Innovation Center of Nonferrous Metals Henan Province, Luoyang 471023 (China); Chen, Weijie [College of Materials Science and Engineering, Henan University of Science and Technology, Luoyang 471023 (China); Collaborative Innovation Center of Nonferrous Metals Henan Province, Luoyang 471023 (China); Gu, Wanduo [Collaborative Innovation Center of Nonferrous Metals Henan Province, Luoyang 471023 (China)

2017-02-27

Creep is in close relationship with the materials deterioration and deformation of the cathodes in aluminum reduction cells. The purpose of this work is to obtain the creep mechanism of the carbon cathode for aluminum electrolysis. A modified Rapoport equipment was used for measuring the creep strain of the semi-graphitic cathodes during aluminum electrolysis with CR=2.5 and at temperature of 945 ℃. The arrangement of carbon atom has been studied after hexagonal graphite converting into rhombohedral graphite during aluminum electrolysis by XRD and high-resolution transmission electron microscopy (HRTEM). The creep deformation of the carbon cathode has a close relationship with the mobile dislocation walls. These results will be helpful in controlling the cathode quality and its performance in aluminum reduction cells.

Current measurement in high-performance frequency converters; Strommessung in Hochleistungsumrichtern

Energy Technology Data Exchange (ETDEWEB)

Marien, Jan; Hetzler, Ullrich [Isabellenhuette Heusler GmbH und Co. KG, Dillenburg (Germany); Hornung, Hans-Georg; Zwinger, Stefan [Sensor-Technik Wiedemann GmbH, Kaufbeuren (Germany)

2011-04-15

The load cycles (raising, lowering, accelerating, braking) of cranes, lift trucks and other off-road vehicles are ideally suited for the efficient deployment of hybrid or full electrical drive technology. Current measurement is a key technology for advancing electrification. Sensor Technik Wiedemann places by her frequency converters on a shunt-based current measurement module from Isabellenhuette Heusler which permits highly accurate measurements. (orig.)

Object-based Morphological Building Index for Building Extraction from High Resolution Remote Sensing Imagery

Directory of Open Access Journals (Sweden)

LIN Xiangguo

2017-06-01

Full Text Available Building extraction from high resolution remote sensing images is a hot research topic in the field of photogrammetry and remote sensing. In this article, an object-based morphological building index (OBMBI is constructed based on both image segmentation and graph-based top-hat reconstruction, and OBMBI is used for building extraction from high resolution remote sensing images. First, bidirectional mapping relationship between pixels, objects and graph-nodes are constructed. Second, the OBMBI image is built based on both graph-based top-hat reconstruction and the above mapping relationship. Third, a binary thresholding is performed on the OBMBI image, and the binary image is converted into vector format to derive the building polygons. Finally, the post-processing is made to optimize the extracted building polygons. Two images, including an aerial image and a panchromatic satellite image, are used to test both the proposed method and classic PanTex method. The experimental results suggest that our proposed method has a higher accuracy in building extraction than the classic PanTex method. On average, the correctness, the completeness and the quality of our method are respectively 9.49%, 11.26% and 14.11% better than those of the PanTex.

Ability of High-Resolution Manometry to Determine Feeding Method and to Predict Aspiration Pneumonia in Patients With Dysphagia.

Science.gov (United States)

Park, Chul-Hyun; Lee, Yong-Taek; Yi, Youbin; Lee, Jung-Sang; Park, Jung Ho; Yoon, Kyung Jae

2017-07-01

The introduction of high-resolution manometry (HRM) offered an improved method to objectively analyze the status of pharynx and esophagus. At present, HRM for patients with oropharyngeal dysphagia has been poorly studied. We aimed to determine feeding method and predict the development of aspiration pneumonia in patients with oropharyngeal dysphagia using HRM. We recruited 120 patients with dysphagia who underwent both HRM and videofluoroscopic swallow study. HRM was used to estimate pressure events from velopharynx (VP) to upper esophageal sphincter (UES). Feeding methods were determined to non-oral or oral feeding according to dysphagia severity. We prospectively followed patients to assess the development of aspiration pneumonia. VP maximal pressure and UES relaxation duration were independently associated with non-oral feeding. Non-oral feeding was determined based on optimal cutoff value of 105.0 mm Hg for VP maximal pressure (95.0% sensitivity and 70.0% specificity) and 0.45 s for UES relaxation duration (76.3% sensitivity and 57.5% specificity), respectively. During a mean follow-up of 18.8 months, 15.8% of patients developed aspiration pneumonia. On multivariate Cox regression analysis, VP maximal pressure (Pdysphagia.

Design considerations for a high-spatial-resolution positron camera with dense-drift-space MWPC's

International Nuclear Information System (INIS)

Del Guerra, A.; Perez-Mendez, V.; Schwartz, G.; Nelson, W.R.

1982-10-01

A multiplane Positron Cameris is proposed, made of six MWPC modules arranged to form the lateral surface of a hexagonal prism. Each module (50 x 50 cm 2 ) has a 2 cm thick lead-glass tube converter on both sides of a MWPC pressurized to 2 atm. Experimental measurements are presented to show how to reduce the parallax error by determining in which of the two converter layers the photon has interacted. The results of a detailed Monte Carlo calculation for the efficiency of this type of converter are shown to be in excellent agreement with the experimental measurements. The expected performance of the Positron Camera is presented: a true coincidence rate of 56,000 counts/s (with an equal accidental coincidence rate and a 30% Compton scatter contamination) and a spatial resolution better than 5.0 mm (FWHM) for a 400 μ Ci point-like source embedded in a 10 cm radius water phantom

A high-voltage resonant converter for pulsed magnets

International Nuclear Information System (INIS)

Rafael, F.S.; Lira, A.C.; Apfelbaum, J.; Pomilio, J.A.

1992-01-01

A 500-W, 25-kV, parallel-loaded resonant converter has been built in order to feed the LNLS ring kicker magnets. The use of high frequency permits reduction of the transformer and filter sizes. The tank components are the transformer leakage inductance and winding capacitance. The switching frequency is 20 kHz, limited by the tank circuit characteristic. The load is an LC Pulse-Forming Network, which is discharged on the load by a thyratron tube. The current pulse rise and fall times are about 100 ns and the flat top is 200 ns, at 800 A. (author) 3 refs.; 7 figs

Understanding gastric forces calculated from high-resolution pill tracking.

Science.gov (United States)

Laulicht, Bryan; Tripathi, Anubhav; Schlageter, Vincent; Kucera, Pavel; Mathiowitz, Edith

2010-05-04

Although other methods exist for monitoring gastrointestinal motility and contractility, this study exclusively provides direct and quantitative measurements of the forces experienced by an orally ingested pill. We report motive forces and torques calculated from real-time, in vivo measurements of the movement of a magnetic pill in the stomachs of fasted and fed humans. Three-dimensional net force and two-dimensional net torque vectors as a function of time data during gastric residence are evaluated using instantaneous translational and rotational position data. Additionally, the net force calculations described can be applied to high-resolution pill tracking acquired by any modality. The fraction of time pills experience ranges of forces and torques are analyzed and correlate with the physiological phases of gastric digestion. We also report the maximum forces and torques experienced in vivo by pills as a quantitative measure of the amount of force pills experience during the muscular contractions leading to gastric emptying. Results calculated from human data are compared with small and large animal models with a translational research focus. The reported magnitude and direction of gastric forces experienced by pills in healthy stomachs serves as a baseline for comparison with pathophysiological states. Of clinical significance, the directionality associated with force vector data may be useful in determining the muscle groups associated with gastrointestinal dysmotility. Additionally, the quantitative comparison between human and animal models improves insight into comparative gastric contractility that will aid rational pill design and provide a quantitative framework for interpreting gastroretentive oral formulation test results.

Effect of image resolution manipulation in rearfoot angle measurements obtained with photogrammetry.

Science.gov (United States)

Sacco, I C N; Picon, A P; Ribeiro, A P; Sartor, C D; Camargo-Junior, F; Macedo, D O; Mori, E T T; Monte, F; Yamate, G Y; Neves, J G; Kondo, V E; Aliberti, S

2012-09-01

The aim of this study was to investigate the influence of image resolution manipulation on the photogrammetric measurement of the rearfoot static angle. The study design was that of a reliability study. We evaluated 19 healthy young adults (11 females and 8 males). The photographs were taken at 1536 pixels in the greatest dimension, resized into four different resolutions (1200, 768, 600, 384 pixels) and analyzed by three equally trained examiners on a 96-pixels per inch (ppi) screen. An experienced physiotherapist marked the anatomic landmarks of rearfoot static angles on two occasions within a 1-week interval. Three different examiners had marked angles on digital pictures. The systematic error and the smallest detectable difference were calculated from the angle values between the image resolutions and times of evaluation. Different resolutions were compared by analysis of variance. Inter- and intra-examiner reliability was calculated by intra-class correlation coefficients (ICC). The rearfoot static angles obtained by the examiners in each resolution were not different (P > 0.05); however, the higher the image resolution the better the inter-examiner reliability. The intra-examiner reliability (within a 1-week interval) was considered to be unacceptable for all image resolutions (ICC range: 0.08-0.52). The whole body image of an adult with a minimum size of 768 pixels analyzed on a 96-ppi screen can provide very good inter-examiner reliability for photogrammetric measurements of rearfoot static angles (ICC range: 0.85-0.92), although the intra-examiner reliability within each resolution was not acceptable. Therefore, this method is not a proper tool for follow-up evaluations of patients within a therapeutic protocol.

Vineyard Yield Estimation Based on the Analysis of High Resolution Images Obtained with Artificial Illumination at Night

Directory of Open Access Journals (Sweden)

Davinia Font

2015-04-01

Full Text Available This paper presents a method for vineyard yield estimation based on the analysis of high-resolution images obtained with artificial illumination at night. First, this paper assesses different pixel-based segmentation methods in order to detect reddish grapes: threshold based, Mahalanobis distance, Bayesian classifier, linear color model segmentation and histogram segmentation, in order to obtain the best estimation of the area of the clusters of grapes in this illumination conditions. The color spaces tested were the original RGB and the Hue-Saturation-Value (HSV. The best segmentation method in the case of a non-occluded reddish table-grape variety was the threshold segmentation applied to the H layer, with an estimation error in the area of 13.55%, improved up to 10.01% by morphological filtering. Secondly, after segmentation, two procedures for yield estimation based on a previous calibration procedure have been proposed: (1 the number of pixels corresponding to a cluster of grapes is computed and converted directly into a yield estimate; and (2 the area of a cluster of grapes is converted into a volume by means of a solid of revolution, and this volume is converted into a yield estimate; the yield errors obtained were 16% and −17%, respectively.

In vitro infrared thermography assessment of temperature peaks during the intra-oral welding of titanium abutments

Science.gov (United States)

Degidi, Marco; Nardi, Diego; Sighinolfi, Gianluca; Merla, Arcangelo; Piattelli, Adriano

2012-07-01

Control of heat dissipation and transmission to the peri-implant area during intra-oral welding is very important to limit potential damage to the surrounding tissue. The aim of this in vitro study was to assess, by means of thermal infrared imaging, the tissue temperature peaks associated with the thermal propagation pathway through the implants, the abutments and the walls of the slot of the scaffold, generated during the welding process, in three different implant systems. An in vitro polyurethane mandible model was prepared with a 7.0 mm v-shape slot. Effects on the maximum temperature by a single welding procedure were studied using different power supplies and abutments. A total of 36 welding procedures were tested on three different implant systems. The lowest peak temperature along the walls of the 7.0 mm v-shaped groove (31.6 ± 2 °C) was assessed in the specimens irrigated with sterile saline solution. The highest peak temperature (42.8 ± 2 °C) was assessed in the samples with a contemporaneous power overflow and premature pincers removal. The results of our study suggest that the procedures used until now appear to be effective to avoid thermal bone injuries. The peak tissue temperature of the in vitro model did not surpass the threshold limits above which tissue injury could occur.

Bedload transport rates in a gravel bedded-river derived from high-resolution monitoring using seismic impact plates

Science.gov (United States)

Downs, Peter; Soar, Philip

2015-04-01

Accurate characterisation of bedload transport rates is critical for a better understanding of geomorphological process dynamics, aquatic habitats, sediment budgets and strategies for catchment-scale initiatives in sediment management under conditions of climate change. However, rate estimation is challenging in practice: direct measurements are costly and logistically difficult to achieve with acceptable accuracy over geomorphologically-relevant time periods, and the uncertainty in transport rates predicted from empirical formulae and numerical simulation is rarely below 50 per cent. Partly reflecting these issues, passive technologies for continuous bedload monitoring are becoming increasingly popular. Sensors such as seismic impact plates offer the opportunity to characterise bedload activity at exceptionally high resolution - monitoring from the River Avon, (Devon, UK) indicated that despite significant intra-event and between-plate differences in apparent bedload transport aggregated over 5-minute periods, the magnitude-frequency product of discharge and impact frequency result in a highly plausible effective discharge, supporting the potential value of impact plates as indicators of relative sediment transport loads over annual timescales. Whereas the focus in bedload rate estimation to date has been on developing satisfactory sediment rating curves from detection signals, we instead develop a method for directly estimating bedload transport rates from impact plate data as a function of intensity of transport (count, n, per second), bed material mass (kg) and cross-stream transport variability. Bulk sediment samples are converted to a mass in transit for each instantaneous discharge according to the intensity of transport and a Monte Carlo simulation of the load in transit determined at random from the bed material particle size distribution. The lower detection threshold is determined using experimental calibration and the upper size limit is determined from

A comprehensive analysis and hardware implementation of control strategies for high output voltage DC-DC boost power converter

OpenAIRE

Padmanaban, Sanjeevikumar; Grandi, Gabriele; Blaabjerg, Frede; Wheeler, Patrick; Siano, Pierluigi; Hammami, Manel

2017-01-01

Classical DC-DC converters used in high voltage direct current (HVDC) power transmission systems, lack in terms of efficiency, reduced transfer gain and increased cost with sensor (voltage/current) numbers. Besides, the internal self-parasitic behavior of the power components reduces the output voltage and efficiency of classical HV converters. This paper deals with extra high-voltage (EHV) dc-dc boost converter by the application of voltage-lift technique to overcome the aforementioned defic...

Resolution enhancement of low-quality videos using a high-resolution frame

Science.gov (United States)

Pham, Tuan Q.; van Vliet, Lucas J.; Schutte, Klamer

2006-01-01

This paper proposes an example-based Super-Resolution (SR) algorithm of compressed videos in the Discrete Cosine Transform (DCT) domain. Input to the system is a Low-Resolution (LR) compressed video together with a High-Resolution (HR) still image of similar content. Using a training set of corresponding LR-HR pairs of image patches from the HR still image, high-frequency details are transferred from the HR source to the LR video. The DCT-domain algorithm is much faster than example-based SR in spatial domain 6 because of a reduction in search dimensionality, which is a direct result of the compact and uncorrelated DCT representation. Fast searching techniques like tree-structure vector quantization 16 and coherence search1 are also key to the improved efficiency. Preliminary results on MJPEG sequence show promising result of the DCT-domain SR synthesis approach.

High frequency Soft Switching Half Bridge Series-Resonant DC-DC Converter Utilizing Gallium Nitride FETs

DEFF Research Database (Denmark)

Nour, Yasser; Knott, Arnold; Petersen, Lars Press

2017-01-01

The need for efficient, smaller, lighter and cheaper power supply units drive the investigation of using high switching frequency soft switching resonant converters. This work presents an 88% efficient 48V nominal input converter switching at 6 MHz and output power of 21 Watts achieving power...... density of 7 W/cm3 for Power-over-Ethernet LED lighting applications. The switching frequency is used to control the output current delivered to the load resistance. The converter was tested using a constant resistance load. The performance and thermal behavior were investigated and reported in this work....

A cloud mask methodology for high resolution remote sensing data combining information from high and medium resolution optical sensors

Science.gov (United States)

Sedano, Fernando; Kempeneers, Pieter; Strobl, Peter; Kucera, Jan; Vogt, Peter; Seebach, Lucia; San-Miguel-Ayanz, Jesús

2011-09-01

This study presents a novel cloud masking approach for high resolution remote sensing images in the context of land cover mapping. As an advantage to traditional methods, the approach does not rely on thermal bands and it is applicable to images from most high resolution earth observation remote sensing sensors. The methodology couples pixel-based seed identification and object-based region growing. The seed identification stage relies on pixel value comparison between high resolution images and cloud free composites at lower spatial resolution from almost simultaneously acquired dates. The methodology was tested taking SPOT4-HRVIR, SPOT5-HRG and IRS-LISS III as high resolution images and cloud free MODIS composites as reference images. The selected scenes included a wide range of cloud types and surface features. The resulting cloud masks were evaluated through visual comparison. They were also compared with ad-hoc independently generated cloud masks and with the automatic cloud cover assessment algorithm (ACCA). In general the results showed an agreement in detected clouds higher than 95% for clouds larger than 50 ha. The approach produced consistent results identifying and mapping clouds of different type and size over various land surfaces including natural vegetation, agriculture land, built-up areas, water bodies and snow.

Pneumocystis carinii pneumonia in acquired immunodeficiency syndrome - correlation of high-resolution computed tomography and anatomopathology; Pneumocistose na sindrome da imunodeficiencia adquirida: correlacao da tomografia computadorizada de alta resolucao com a anatomopatologia

Energy Technology Data Exchange (ETDEWEB)

Marchiori, Edson; Moreira, Luiza Beatriz [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Dept. de Radiologia]. E-mail: edmarchiori@zipmail.com.br; Capone, Domenico [Universidade do Estado, Rio de Janeiro, RJ (Brazil). Faculdade de Medicina; Moraes, Heleno Pinto de [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Dept. de Patologia; Pereira, Cyntia Inez Guedes Soares

2001-12-01

We present the main findings observed on the high-resolution computed tomography examinations of 15 patients with acquired immunodeficiency syndrome and Pneumocystis carinii pneumonia. The high-resolution computed tomography and autopsy findings of 5 patients were also compared. The most frequently observed high-resolution computed tomography patterns were ground-glass attenuation, consolidation areas, crazy-paving pattern and cysts. Nodules and intralobular reticulation were less frequently observed. Ground-glass attenuation and consolidation areas corresponded to alveolar filling with inflammatory exudate. Thickening of the interlobular septa was due to cell infiltration and edema. One patient presented interlobular reticulation, and the pathology study revealed alveolar septa thickening due to cell infiltration and fibrosis. Nodules observed in one of the patients corresponded to a patchy intra alveolar accumulation of microorganisms and inflammatory cells forming a 'granulomatous' pattern. (author)

Intra-abdominal pressure during swimming.

Science.gov (United States)

Moriyama, S; Ogita, F; Huang, Z; Kurobe, K; Nagira, A; Tanaka, T; Takahashi, H; Hirano, Y

2014-02-01

The present study aimed to determine the intra-abdominal pressure during front crawl swimming at different velocities in competitive swimmers and to clarify the relationships between stroke indices and changes in intra-abdominal pressure. The subjects were 7 highly trained competitive collegiate male swimmers. Intra-abdominal pressure was measured during front crawl swimming at 1.0, 1.2 and 1.4 m · s(-1) and during the Valsalva maneuver. Intra-abdominal pressure was taken as the difference between minimum and maximum values, and the mean of 6 stable front crawl stroke cycles was used. Stroke rate and stroke length were also measured as stroke indices. There were significant differences in stroke rate among all velocities (P pressure and stroke rate or stroke length (P pressure and stroke indices when controlling for swimming velocity. These findings do not appear to support the effectiveness of trunk training performed by competitive swimmers aimed at increasing intra-abdominal pressure. © Georg Thieme Verlag KG Stuttgart · New York.

High-Resolution Mass Spectrometers

Science.gov (United States)

Marshall, Alan G.; Hendrickson, Christopher L.

2008-07-01

Over the past decade, mass spectrometry has been revolutionized by access to instruments of increasingly high mass-resolving power. For small molecules up to ˜400 Da (e.g., drugs, metabolites, and various natural organic mixtures ranging from foods to petroleum), it is possible to determine elemental compositions (CcHhNnOoSsPp…) of thousands of chemical components simultaneously from accurate mass measurements (the same can be done up to 1000 Da if additional information is included). At higher mass, it becomes possible to identify proteins (including posttranslational modifications) from proteolytic peptides, as well as lipids, glycoconjugates, and other biological components. At even higher mass (˜100,000 Da or higher), it is possible to characterize posttranslational modifications of intact proteins and to map the binding surfaces of large biomolecule complexes. Here we review the principles and techniques of the highest-resolution analytical mass spectrometers (time-of-flight and Fourier transform ion cyclotron resonance and orbitrap mass analyzers) and describe some representative high-resolution applications.

[Drug-induced oral ulcerations].

Science.gov (United States)

Madinier, I; Berry, N; Chichmanian, R M

2000-06-01

Different side effects of drugs have been described in the oral cavity, including oral ulcerations. Direct contact between drugs and oral mucosa may induce chemical burn or local hypersensitivity. Less frequently, these drug-induced oral ulcerations are part of a complex reaction with cutaneous or systemic manifestations. Sometimes, one or more oral ulcerations appear as the main side-effect of a drug, or exceptionally as solitary lesions. Solitary oral ulcerations usually appear after few weeks of treatment. In most of cases, these lesions resist to conventional treatments, with a rapid healing following the suppression of the responsible drug. This diagnosis is usually difficult, particularly with patients receiving multiple drug therapy. Besides, special attention must be paid to new drugs. Oral ulcerations following symptoms of burning mouth, metallic taste, dysgueusia or agueusia are strongly suggestive of a pharmacological origin. Most of the molecules able to induce solitary oral ulcerations are commonly prescribed in a) rheumatology: NSAI (diclofenac, flurbiprofen, indomethacin, naproxen), long-term rheumatoid arthritis therapy (azathioprine, methotrexate, penicillamine, gold compounds, tiopronin); b) cardiology: angiotensin-converting-enzyme inhibitors (captopril, enalapril), angiotensin 2-receptor antagonist (losartan), anti-angorous (nicorandil), c) psychiatry: antidepressants (fluoxetine, lithium), d) AIDS therapy (foscarnet, zalcitabine).

USGS High Resolution Orthoimagery Collection - Historical - National Geospatial Data Asset (NGDA) High Resolution Orthoimagery

Data.gov (United States)

U.S. Geological Survey, Department of the Interior — USGS high resolution orthorectified images from The National Map combine the image characteristics of an aerial photograph with the geometric qualities of a map. An...

Electron curing for high speed paper, film and foil converting

International Nuclear Information System (INIS)

Nablo, S.V.; Tripp, E.P.

1979-01-01

The status of self-shielded, compact electron processors for flexible web converting applications is reviewed. The uses of these units for a variety of laminating applications are described, with emphasis on the application techniques appropriate for low weight, (1 to 2 gm/m 2 ) 100% convertible adhesives. Performance data for electron cured adhesives with polyester/polyethylene systems is presented and compared with conventional urethane systems. The unique surface features of electron cured gravure coatings applied and cured at high speed are discussed, with reference to both paper and film substrates. An important advantage of electron curing of buried adhesive layers is the process quality control permitted by this 'all-electric' system. The performance characteristics of curing atmosphere control (inerting) for coatings are reviewed. Industrial experience with these processors has shown that effective inerting of coated flexible webs at speeds to 250 m/minute is both practical and economical. (author)

Intra-mathematical connections made by high school students in performing Calculus tasks

Science.gov (United States)

García-García, Javier; Dolores-Flores, Crisólogo

2018-02-01

In this article, we report the results of research that explores the intra-mathematical connections that high school students make when they solve Calculus tasks, in particular those involving the derivative and the integral. We consider mathematical connections as a cognitive process through which a person relates or associates two or more ideas, concepts, definitions, theorems, procedures, representations and meanings among themselves, with other disciplines or with real life. Task-based interviews were used to collect data and thematic analysis was used to analyze them. Through the analysis of the productions of the 25 participants, we identified 223 intra-mathematical connections. The data allowed us to establish a mathematical connections system which contributes to the understanding of higher concepts, in our case, the Fundamental Theorem of Calculus. We found mathematical connections of the types: different representations, procedural, features, reversibility and meaning as a connection.

Microwave testing of high-Tc based direct current to a single flux quantum converter

DEFF Research Database (Denmark)

Kaplunenko, V. K.; Fischer, Gerd Michael; Ivanov, Z. G.

1994-01-01

Design, simulation, and experimental investigations of a direct current to a single flux quantum converter loaded with a Josephson transmission line and driven by an external 70 GHz microwave oscillator are reported. The test circuit includes nine YBaCuO Josephson junctions aligned on the grain...... boundary of a 0°–32° asymmetric Y-ZrO2 bicrystal substrate. The performance of such converters is important for the development of the fast Josephson samplers required for testing of high-Tc rapid single flux quantum circuits in high-speed digital superconducting electronics. Journal of Applied Physics...

High throughput screening of ligand binding to macromolecules using high resolution powder diffraction

Science.gov (United States)

Von Dreele, Robert B.; D'Amico, Kevin

2006-10-31

A process is provided for the high throughput screening of binding of ligands to macromolecules using high resolution powder diffraction data including producing a first sample slurry of a selected polycrystalline macromolecule material and a solvent, producing a second sample slurry of a selected polycrystalline macromolecule material, one or more ligands and the solvent, obtaining a high resolution powder diffraction pattern on each of said first sample slurry and the second sample slurry, and, comparing the high resolution powder diffraction pattern of the first sample slurry and the high resolution powder diffraction pattern of the second sample slurry whereby a difference in the high resolution powder diffraction patterns of the first sample slurry and the second sample slurry provides a positive indication for the formation of a complex between the selected polycrystalline macromolecule material and at least one of the one or more ligands.

Intra-arterial thrombolysis of digital artery occlusions in a patient with polycythemia vera.

Science.gov (United States)

Jud, Philipp; Hafner, Franz; Gary, Thomas; Ghanim, Leyla; Lipp, Rainer; Brodmann, Marianne

2017-01-01

There are limited therapeutic options for the resolution of digital artery occlusions. Intra-arterial thrombolysis with anticoagulative and thrombolytic drugs successfully restored the blood flow in the affected digital arteries.

Superselective intra-arterial infusion chemotherapy for stage III/IV squamous cell carcinomas of the oral cavity: Midterm results

International Nuclear Information System (INIS)

Ikushima, I.; Korogi, Y.; Ishii, A.; Hirai, T.; Yamura, M.; Nishimura, R.; Baba, Y.; Yamashita, Y.; Shinohara, M.

2008-01-01

Purpose: We performed superselective intra-arterial infusion chemotherapy (SIC) according to a protocol in which drug distribution is evaluated by the use of interventional radiology (IVR)-computed tomography (CT) system, and the chemotherapy is combined with medium-dose conformal radiation therapy (CRT). We analyzed retrospectively the factors that affect the midterm survival ratio, including local response, for stage III and IV squamous cell carcinomas of the oral cavity. Materials and methods: Forty consecutive patients with stage III and IV squamous cell carcinomas of the oral cavity and who had undergone both SIC and CRT were enrolled. A microcatheter was placed in the appropriate feeding artery of the tumor and cisplatin (50 mg/body) was infused twice. CRT was administered with a dual-energy (4 and 10 MV) linear accelerator. The total and daily doses delivered were 30 and 2.0 Gy, respectively. Histopathologic effects were classified into five grades: grade 0 or 1 was defined as a poor response, and grade II or higher as a good response. Age, sex, stage, local response to treatment, mode of invasion and lymph node metastasis were analyzed, and differences in the midterm survival ratio were assessed. Results: The 3-year survival ratio of the 40 cases was 67%. A good local response (III or IV) was achieved in 75% of the cases. The survival ratio of the good local response group was significantly better than that of the poor response group (p = 0.04). Mode of invasion (p = 0.03) and lymph node metastasis (p = 0.01) were also predictive of survival. In the multivariable analysis of survival, however, no variables including good local response (p = 0.12), were predictive. Conslusion: Our new protocol improved local response, but it did not contribute to the survival ratio

Generation of real-time mode high-resolution water vapor fields from GPS observations

Science.gov (United States)

Yu, Chen; Penna, Nigel T.; Li, Zhenhong

2017-02-01

Pointwise GPS measurements of tropospheric zenith total delay can be interpolated to provide high-resolution water vapor maps which may be used for correcting synthetic aperture radar images, for numeral weather prediction, and for correcting Network Real-time Kinematic GPS observations. Several previous studies have addressed the importance of the elevation dependency of water vapor, but it is often a challenge to separate elevation-dependent tropospheric delays from turbulent components. In this paper, we present an iterative tropospheric decomposition interpolation model that decouples the elevation and turbulent tropospheric delay components. For a 150 km × 150 km California study region, we estimate real-time mode zenith total delays at 41 GPS stations over 1 year by using the precise point positioning technique and demonstrate that the decoupled interpolation model generates improved high-resolution tropospheric delay maps compared with previous tropospheric turbulence- and elevation-dependent models. Cross validation of the GPS zenith total delays yields an RMS error of 4.6 mm with the decoupled interpolation model, compared with 8.4 mm with the previous model. On converting the GPS zenith wet delays to precipitable water vapor and interpolating to 1 km grid cells across the region, validations with the Moderate Resolution Imaging Spectroradiometer near-IR water vapor product show 1.7 mm RMS differences by using the decoupled model, compared with 2.0 mm for the previous interpolation model. Such results are obtained without differencing the tropospheric delays or water vapor estimates in time or space, while the errors are similar over flat and mountainous terrains, as well as for both inland and coastal areas.

Texton-based super-resolution for achieving high spatiotemporal resolution in hybrid camera system

Science.gov (United States)

Kamimura, Kenji; Tsumura, Norimichi; Nakaguchi, Toshiya; Miyake, Yoichi

2010-05-01

Many super-resolution methods have been proposed to enhance the spatial resolution of images by using iteration and multiple input images. In a previous paper, we proposed the example-based super-resolution method to enhance an image through pixel-based texton substitution to reduce the computational cost. In this method, however, we only considered the enhancement of a texture image. In this study, we modified this texton substitution method for a hybrid camera to reduce the required bandwidth of a high-resolution video camera. We applied our algorithm to pairs of high- and low-spatiotemporal-resolution videos, which were synthesized to simulate a hybrid camera. The result showed that the fine detail of the low-resolution video can be reproduced compared with bicubic interpolation and the required bandwidth could be reduced to about 1/5 in a video camera. It was also shown that the peak signal-to-noise ratios (PSNRs) of the images improved by about 6 dB in a trained frame and by 1.0-1.5 dB in a test frame, as determined by comparison with the processed image using bicubic interpolation, and the average PSNRs were higher than those obtained by the well-known Freeman’s patch-based super-resolution method. Compared with that of the Freeman’s patch-based super-resolution method, the computational time of our method was reduced to almost 1/10.

Fast response double series resonant high-voltage DC-DC converter

International Nuclear Information System (INIS)

Lee, S S; Iqbal, S; Kamarol, M

2012-01-01

In this paper, a novel double series resonant high-voltage dc-dc converter with dual-mode pulse frequency modulation (PFM) control scheme is proposed. The proposed topology consists of two series resonant tanks and hence two resonant currents flow in each switching period. Moreover, it consists of two high-voltage transformer with the leakage inductances are absorbed as resonant inductor in the series resonant tanks. The secondary output of both transformers are rectified and mixed before supplying to load. In the resonant mode operation, the series resonant tanks are energized alternately by controlling two Insulated Gate Bipolar Transistor (IGBT) switches with pulse frequency modulation (PFM). This topology operates in discontinuous conduction mode (DCM) with all IGBT switches operating in zero current switching (ZCS) condition and hence no switching loss occurs. To achieve fast rise in output voltage, a dual-mode PFM control during start-up of the converter is proposed. In this operation, the inverter is started at a high switching frequency and as the output voltage reaches 90% of the target value, the switching frequency is reduced to a value which corresponds to the target output voltage. This can effectively reduce the rise time of the output voltage and prevent overshoot. Experimental results collected from a 100-W laboratory prototype are presented to verify the effectiveness of the proposed system.

High Step-Up Trans-Inverse (Tx^−1) DC–DC Converter for the Distributed Generation System

DEFF Research Database (Denmark)

Siwakoti, Yam Prasad; Blaabjerg, Frede; Loh, Poh Chiang

2016-01-01

This paper introduces a new magnetically coupled single-switch nonisolated dc–dc converter with a high-voltage gain. The topology utilizes magnetic coupling for boosting its output voltage, but unlike other converters with coupled magnetics, its voltage gain is increased by reducing its magnetic ...

Integrated power electronic converters and digital control

CERN Document Server

Emadi, Ali; Nie, Zhong

2009-01-01

Non-isolated DC-DC ConvertersBuck ConverterBoost ConverterBuck-Boost ConverterIsolated DC-DC ConvertersFlyback ConverterForward ConverterPush-Pull ConverterFull-Bridge ConverterHalf-Bridge ConverterPower Factor CorrectionConcept of PFCGeneral Classification of PFC CircuitsHigh Switching Frequency Topologies for PFCApplication of PFC in Advanced Motor DrivesIntegrated Switched-Mode Power ConvertersSwitched-Mode Power SuppliesThe Concept of Integrated ConverterDefinition of Integrated Switched-Mode Power Supplies (ISMPS)Boost-Type Integrated TopologiesGeneral Structure of Boost-Type Integrated T

Immersion Gratings for Infrared High-resolution Spectroscopy

Science.gov (United States)

Sarugaku, Yuki; Ikeda, Yuji; Kobayashi, Naoto; Kaji, Sayumi; Sukegawa, Takashi; Sugiyama, Shigeru; Nakagawa, Takao; Arasaki, Takayuki; Kondo, Sohei; Nakanishi, Kenshi; Yasui, Chikako; Kawakita, Hideyo

2016-10-01

High-resolution spectroscopy in the infrared wavelength range is essential for observations of minor isotopologues, such as HDO for water, and prebiotic organic molecules like hydrocarbons/P-bearing molecules because numerous vibrational molecular bands (including non-polar molecules) are located in this wavelength range. High spectral resolution enables us to detect weak lines without spectral line confusion. This technique has been widely used in planetary sciences, e.g., cometary coma (H2O, CO, and organic molecules), the martian atmosphere (CH4, CO2, H2O and HDO), and the upper atmosphere of gas giants (H3+ and organic molecules such as C2H6). Spectrographs with higher resolution (and higher sensitivity) still have a potential to provide a plenty of findings. However, because the size of spectrographs scales with the spectral resolution, it is difficult to realize it.Immersion grating (IG), which is a diffraction grating wherein the diffraction surface is immersed in a material with a high refractive index (n > 2), provides n times higher spectral resolution compared to a reflective grating of the same size. Because IG reduces the size of spectrograph to 1/n compared to the spectrograph with the same spectral resolution using a conventional reflective grating, it is widely acknowledged as a key optical device to realize compact spectrographs with high spectral resolution.Recently, we succeeded in fabricating a CdZnTe immersion grating with the theoretically predicted diffraction efficiency by machining process using an ultrahigh-precision five-axis processing machine developed by Canon Inc. Using the same technique, we completed a practical germanium (Ge) immersion grating with both a reflection coating on the grating surface and the an AR coating on the entrance surface. It is noteworthy that the wide wavelength range from 2 to 20 um can be covered by the two immersion gratings.In this paper, we present the performances and the applications of the immersion

Experimental prediction of severe droughts on seasonal to intra-annual time scales with GFDL High-Resolution Atmosphere Model

Science.gov (United States)

Yu, Z.; Lin, S.

2011-12-01

Regional heat waves and drought have major economic and societal impacts on regional and even global scales. For example, during and following the 2010-2011 La Nina period, severe droughts have been reported in many places around the world including China, the southern US, and the east Africa, causing severe hardship in China and famine in east Africa. In this study, we investigate the feasibility and predictability of severe spring-summer draught events, 3 to 6 months in advance with the 25-km resolution Geophysical Fluid Dynamics Laboratory High-Resolution Atmosphere Model (HiRAM), which is built as a seamless weather-climate model, capable of long-term climate simulations as well as skillful seasonal predictions (e.g., Chen and Lin 2011, GRL). We adopted a similar methodology and the same (HiRAM) model as in Chen and Lin (2011), which is used successfully for seasonal hurricane predictions. A series of initialized 7-month forecasts starting from Dec 1 are performed each year (5 members each) during the past decade (2000-2010). We will then evaluate the predictability of the severe drought events during this period by comparing model predictions vs. available observations. To evaluate the predictive skill, in this preliminary report, we will focus on the anomalies of precipitation, sea-level-pressure, and 500-mb height. These anomalies will be computed as the individual model prediction minus the mean climatology obtained by an independent AMIP-type "simulation" using observed SSTs (rather than using predictive SSTs in the forecasts) from the same model.

Low resolution scans can provide a sufficiently accurate, cost- and time-effective alternative to high resolution scans for 3D shape analyses

Directory of Open Access Journals (Sweden)

Ariel E. Marcy

2018-06-01

Full Text Available Background Advances in 3D shape capture technology have made powerful shape analyses, such as geometric morphometrics, more feasible. While the highly accurate micro-computed tomography (µCT scanners have been the “gold standard,” recent improvements in 3D surface scanners may make this technology a faster, portable, and cost-effective alternative. Several studies have already compared the two devices but all use relatively large specimens such as human crania. Here we perform shape analyses on Australia’s smallest rodent to test whether a 3D scanner produces similar results to a µCT scanner. Methods We captured 19 delicate mouse (Pseudomys delicatulus crania with a µCT scanner and a 3D scanner for geometric morphometrics. We ran multiple Procrustes ANOVAs to test how variation due to scan device compared to other sources such as biologically relevant variation and operator error. We quantified operator error as levels of variation and repeatability. Further, we tested if the two devices performed differently at classifying individuals based on sexual dimorphism. Finally, we inspected scatterplots of principal component analysis (PCA scores for non-random patterns. Results In all Procrustes ANOVAs, regardless of factors included, differences between individuals contributed the most to total variation. The PCA plots reflect this in how the individuals are dispersed. Including only the symmetric component of shape increased the biological signal relative to variation due to device and due to error. 3D scans showed a higher level of operator error as evidenced by a greater spread of their replicates on the PCA, a higher level of multivariate variation, and a lower repeatability score. However, the 3D scan and µCT scan datasets performed identically in classifying individuals based on intra-specific patterns of sexual dimorphism. Discussion Compared to µCT scans, we find that even low resolution 3D scans of very small specimens are

High resolution tomographic instrument development

International Nuclear Information System (INIS)

1992-01-01

Our recent work has concentrated on the development of high-resolution PET instrumentation reflecting in part the growing importance of PET in nuclear medicine imaging. We have developed a number of positron imaging instruments and have the distinction that every instrument has been placed in operation and has had an extensive history of application for basic research and clinical study. The present program is a logical continuation of these earlier successes. PCR-I, a single ring positron tomograph was the first demonstration of analog coding using BGO. It employed 4 mm detectors and is currently being used for a wide range of biological studies. These are of immense importance in guiding the direction for future instruments. In particular, PCR-II, a volume sensitive positron tomograph with 3 mm spatial resolution has benefited greatly from the studies using PCR-I. PCR-II is currently in the final stages of assembly and testing and will shortly be placed in operation for imaging phantoms, animals and ultimately humans. Perhaps the most important finding resulting from our previous study is that resolution and sensitivity must be carefully balanced to achieve a practical high resolution system. PCR-II has been designed to have the detection characteristics required to achieve 3 mm resolution in human brain under practical imaging situations. The development of algorithms by the group headed by Dr. Chesler is based on a long history of prior study including his joint work with Drs. Pelc and Reiderer and Stearns. This body of expertise will be applied to the processing of data from PCR-II when it becomes operational

High resolution tomographic instrument development

Energy Technology Data Exchange (ETDEWEB)

1992-08-01

Our recent work has concentrated on the development of high-resolution PET instrumentation reflecting in part the growing importance of PET in nuclear medicine imaging. We have developed a number of positron imaging instruments and have the distinction that every instrument has been placed in operation and has had an extensive history of application for basic research and clinical study. The present program is a logical continuation of these earlier successes. PCR-I, a single ring positron tomograph was the first demonstration of analog coding using BGO. It employed 4 mm detectors and is currently being used for a wide range of biological studies. These are of immense importance in guiding the direction for future instruments. In particular, PCR-II, a volume sensitive positron tomograph with 3 mm spatial resolution has benefited greatly from the studies using PCR-I. PCR-II is currently in the final stages of assembly and testing and will shortly be placed in operation for imaging phantoms, animals and ultimately humans. Perhaps the most important finding resulting from our previous study is that resolution and sensitivity must be carefully balanced to achieve a practical high resolution system. PCR-II has been designed to have the detection characteristics required to achieve 3 mm resolution in human brain under practical imaging situations. The development of algorithms by the group headed by Dr. Chesler is based on a long history of prior study including his joint work with Drs. Pelc and Reiderer and Stearns. This body of expertise will be applied to the processing of data from PCR-II when it becomes operational.

High resolution tomographic instrument development

Energy Technology Data Exchange (ETDEWEB)

1992-01-01

Our recent work has concentrated on the development of high-resolution PET instrumentation reflecting in part the growing importance of PET in nuclear medicine imaging. We have developed a number of positron imaging instruments and have the distinction that every instrument has been placed in operation and has had an extensive history of application for basic research and clinical study. The present program is a logical continuation of these earlier successes. PCR-I, a single ring positron tomograph was the first demonstration of analog coding using BGO. It employed 4 mm detectors and is currently being used for a wide range of biological studies. These are of immense importance in guiding the direction for future instruments. In particular, PCR-II, a volume sensitive positron tomograph with 3 mm spatial resolution has benefited greatly from the studies using PCR-I. PCR-II is currently in the final stages of assembly and testing and will shortly be placed in operation for imaging phantoms, animals and ultimately humans. Perhaps the most important finding resulting from our previous study is that resolution and sensitivity must be carefully balanced to achieve a practical high resolution system. PCR-II has been designed to have the detection characteristics required to achieve 3 mm resolution in human brain under practical imaging situations. The development of algorithms by the group headed by Dr. Chesler is based on a long history of prior study including his joint work with Drs. Pelc and Reiderer and Stearns. This body of expertise will be applied to the processing of data from PCR-II when it becomes operational.

HORIZONTAL AND VERTICAL INTRA-INDUSTRY TRADE OF TURKEY

Directory of Open Access Journals (Sweden)

NEVZAT ŞİMŞEK

2013-06-01

Full Text Available Crucial improvement have taken place in intra-industry trade literature since intra-industry trade phenomenon was empirically determined. Nowadays economists discuss on the necessity of distinguishing between horizontal and vertical intra-industry trade especially relating to product differentiation in each industry. As standard Grubel-Lloyd index does not determine the time when two way trade is taken into consideration, in this paper first of all Two-Way Trade index is used and then horizontal intra-industry trade and low-high quality vertical intra-industry trade are distinguished from each other regarding unit value differential. As a result of the analysis the findings show that low quality vertical intra-industry trade dominate in Turkey's intra-industry trade.

Compact high voltage, high peak power, high frequency transformer for converter type modulator applications.

Science.gov (United States)

Reghu, T; Mandloi, V; Shrivastava, Purushottam

2016-04-01

The design and development of a compact high voltage, high peak power, high frequency transformer for a converter type modulator of klystron amplifiers is presented. The transformer has been designed to operate at a frequency of 20 kHz and at a flux swing of ±0.6 T. Iron (Fe) based nanocrystalline material has been selected as a core for the construction of the transformer. The transformer employs a specially designed solid Teflon bobbin having 120 kV insulation for winding the high voltage secondary windings. The flux swing of the core has been experimentally found by plotting the hysteresis loop at actual operating conditions. Based on the design, a prototype transformer has been built which is per se a unique combination of high voltage, high frequency, and peak power specifications. The transformer was able to provide 58 kV (pk-pk) at the secondary with a peak power handling capability of 700 kVA. The transformation ratio was 1:17. The performance of the transformer is also presented and discussed.

Oral microbiota and cancer

Directory of Open Access Journals (Sweden)

Jukka H. Meurman

2010-08-01

Full Text Available Inflammation caused by infections may be the most important preventable cause of cancer in general. However, in the oral cavity the role of microbiota in carcinogenesis is not known. Microbial populations on mouth mucosa differ between healthy and malignant sites and certain oral bacterial species have been linked with malignancies but the evidence is still weak in this respect. Nevertheless, oral microorganisms inevitably up-regulate cytokines and other inflammatory mediators that affect the complex metabolic pathways and may thus be involved in carcinogenesis. Poor oral health associates statistically with prevalence of many types of cancer, such as pancreatic and gastrointestinal cancer. Furthermore, several oral micro-organisms are capable of converting alcohol to carcinogenic acetaldehyde which also may partly explain the known association between heavy drinking, smoking, poor oral health and the prevalence of oral and upper gastrointestinal cancer. A different problem is the cancer treatment-caused alterations in oral microbiota which may lead to the emergence of potential pathogens and subsequent other systemic health problems to the patients. Hence clinical guidelines and recommendations have been presented to control oral microbiota in patients with malignant disease, but also in this area the scientific evidence is weak. More controlled studies are needed for further conclusion.

High resolution Neutron and Synchrotron Powder Diffraction

International Nuclear Information System (INIS)

Hewat, A.W.

1986-01-01

The use of high-resolution powder diffraction has grown rapidly in the past years, with the development of Rietveld (1967) methods of data analysis and new high-resolution diffractometers and multidetectors. The number of publications in this area has increased from a handful per year until 1973 to 150 per year in 1984, with a ten-year total of over 1000. These papers cover a wide area of solid state-chemistry, physics and materials science, and have been grouped under 20 subject headings, ranging from catalysts to zeolites, and from battery electrode materials to pre-stressed superconducting wires. In 1985 two new high-resolution diffractometers are being commissioned, one at the SNS laboratory near Oxford, and one at the ILL in Grenoble. In different ways these machines represent perhaps the ultimate that can be achieved with neutrons and will permit refinement of complex structures with about 250 parameters and unit cell volumes of about 2500 Angstrom/sp3/. The new European Synchotron Facility will complement the Grenoble neutron diffractometers, and extend the role of high-resolution powder diffraction to the direct solution of crystal structures, pioneered in Sweden

High resolution (transformers.

Science.gov (United States)

Garcia-Souto, Jose A; Lamela-Rivera, Horacio

2006-10-16

A novel fiber-optic interferometric sensor is presented for vibrations measurements and analysis. In this approach, it is shown applied to the vibrations of electrical structures within power transformers. A main feature of the sensor is that an unambiguous optical phase measurement is performed using the direct detection of the interferometer output, without external modulation, for a more compact and stable implementation. High resolution of the interferometric measurement is obtained with this technique (transformers are also highlighted.

Development of an efficient DC-DC SEPIC converter using wide bandgap power devices for high step-up applications

Science.gov (United States)

Al-bayati, Ali M. S.; Alharbi, Salah S.; Alharbi, Saleh S.; Matin, Mohammad

2017-08-01

A highly efficient high step-up dc-dc converter is the major requirement in the integration of low voltage renewable energy sources, such as photovoltaic panel module and fuel cell stacks, with a load or utility. This paper presents the development of an efficient dc-dc single-ended primary-inductor converter (SEPIC) for high step-up applications. Three SEPIC converters are designed and studied using different combinations of power devices: a combination based on all Si power devices using a Si-MOSFET and a Si-diode and termed as Si/Si, a combination based on a hybrid of Si and SiC power devices using the Si-MOSFET and a SiC-Schottky diode and termed as Si/SiC, and a combination based on all SiC power devices using a SiC-MOSFET and the SiC-Schottky diode and termed as SiC/SiC. The switching behavior of the Si-MOSFET and SiC-MOSFET is characterized and analyzed within the different combinations at the converter level. The effect of the diode type on the converter's overall performance is also discussed. The switching energy losses, total power losses, and the overall performance effciency of the converters are measured and reported under different switching frequencies. Furthermore, the potential of the designed converters to operate efficiently at a wide range of input voltages and output powers is studied. The analysis and results show an outstanding performance efficiency of the designed SiC/SiC based converter under a wide range of operating conditions.