Omeprazole promotes proximal duodenal mucosal bicarbonate secretion in humans

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Mertz-Nielsen, A; Hillingsø, Jens; Bukhave, K

1996-01-01

with control experiments. Also the combination of omeprazole and ranitidine increased (p = 0.05) duodenal bicarbonate secretion, while ranitidine alone caused no change in either basal or stimulated secretion. In the stomach basal as well as vagally stimulated bicarbonate secretion was independent of the means...

Effect of omeprazole and cimetidine on healing of chronic gastric ulcers and gastric acid secretion in rats

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Poulsen, Steen Seier

1988-01-01

The effect of omeprazole and cimetidine on healing of chronic gastric ulcers and gastric acid secretion was investigated in rats. The effect of three doses of omeprazole given orally once daily for 25 days was investigated. In controls median ulcer healing was 19.6% after 25 days. Omeprazole...... increased median ulcer healing from 36% at 145 mumole/kg/day to 80% at 580 mumole/kg/day. Basal and pentagastrin stimulated gastric acid secretion decreased dose-dependently by nearly 90% at a dose of 580 mumole/kg/day 22-24 hr after the last dose of omeprazole. Cimetidine given twice daily, in a dose...... that initially inhibits gastric acid secretion by 95%, reduced acid secretion by only 50% 11 hr after the last dose. Median ulcer healing after treatment with cimetidine for 25 days was 41%. This study demonstrates that omeprazole has a more long-acting inhibitory effect on gastric acid secretion compared...

A double-blind placebo-controlled study on the effects of omeprazole on gut hormone secretion and gastric emptying rate

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Rasmussen, L; Qvist, N; Oster-Jørgensen, E

1997-01-01

BACKGROUND: The present study was designed to investigate whether an effect of omeprazole on gastric emptying is related to changes in the secretion of selected gut hormones. METHODS: The studies were performed in healthy men after 10 days' treatment with 40 mg omeprazole daily/placebo. Food inge...

Effect of omeprazole and sucralfate on prepyloric gastric ulcer. A double blind comparative trial and one year follow up.

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Sørensen, H T; Rasmussen, H H; Balslev, I; Boesby, S; Boné, J; Kruse, A; Rasmussen, S N

1994-01-01

This study compared healing rates, relief of symptoms, frequency of adverse events, and proportion of patients in remission after one year follow up in 104 patients with active prepyloric ulcer during treatment with 40 mg omeprazole once daily or 2 g sucralfate twice daily, using a randomised double blind controlled trial. Healing rates after two, four, and six weeks were (omeprazole/sucralfate) 49%/23%; 83%/59%; 90%/70% respectively. After two weeks, omeprazole was more efficient than sucralfate in relief of daytime and nocturnal epigastric pain, nausea, and heartburn. The proportion of patients in remission after one year follow up was significantly higher in the omeprazole group (p < 0.01). Of the healed patients ulcers recurred in 36% in the omeprazole group and in 46% in the sucralfate group. It is concluded that the ulcer healing rate was higher and symptom relief was more pronounced in the omeprazole group compared with the sucralfate group, and that more patients were still in remission after a one year follow up period. PMID:8020815

Lack of drug interaction between omeprazole, lansoprazole, pantoprazole and theophylline

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Dilger, Karin; Zheng, Zhichang; Klotz, Ulrich

1999-01-01

Aims Theophylline is a model substrate of cytochrome P4501A2. The ability of the proton pump inhibitors (PPI) omeprazole, lansoprazole and pantoprazole to induce cytochrome P4501A2 has not yet been unequivocally resolved. The aim of this comprehensive study was to compare directly the effect of the three PPI on the absorption and disposition of theophylline. Methods Twenty healthy, nonsmoking, male and female volunteers (extensive metabolisers of cytochrome P4502C19 and Helicobacter pylori negative) participated in a randomized, double-blind, four-period, placebo-controlled crossover study. In each of the four periods they received either omeprazole (40 mg), lansoprazole (60 mg), pantoprazole (80 mg) or placebo once daily for 10 days. Sustained release theophylline (350 mg twice daily) was coadministered from day 8–10. Pharmacokinetics of theophylline as well as of all three PPI were determined at steady-state (day 10). Results In all periods, point estimates and 90% confidence intervals of the area under the concentration-time curves (AUC), maximum steady-state concentrations and peak-trough fluctuations of theophylline were not altered by PPI pretreatment and met the required limits for bioequivalence. Point estimates (90% confidence intervals) of the AUC ratios of theophylline plus PPI to theophylline alone were 0.92 (0.87–0.97), 0.90 (0.85–0.95) and 1.00 (0.95–1.06) for omeprazole, lansoprazole and pantoprazole, respectively. Conclusions Concomitant intake of omeprazole, lansoprazole or pantoprazole at high therapeutic doses does not affect the absorption and disposition of theophylline. PMID:10510158

Investigating the presence of omeprazole in waters by liquid chromatography coupled to low and high resolution mass spectrometry: degradation experiments.

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Boix, C; Ibáñez, M; Sancho, J V; Niessen, W M A; Hernández, F

2013-10-01

Omeprazole is one of the most consumed pharmaceuticals around the world. However, this compound is scarcely detected in urban wastewater and surface water. The absence of this pharmaceutical in the aquatic ecosystem might be due to its degradation in wastewater treatment plants, as well as in receiving water. In this work, different laboratory-controlled degradation experiments have been carried out on surface water in order to elucidate generated omeprazole transformation products (TPs). Surface water spiked with omeprazole was subjected to hydrolysis, photo-degradation under both sunlight and ultraviolet radiation and chlorination. Analyses by liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (LC-QTOF MS) permitted identification of up to 17 omeprazole TPs. In a subsequent step, the TPs identified were sought in surface water and urban wastewater by LC-QTOF MS and by LC coupled to tandem mass spectrometry with triple quadrupole. The parent omeprazole was not detected in any of the samples, but four TPs were found in several water samples. The most frequently detected compound was OTP 5 (omeprazole sulfide), which might be a reasonable candidate to be included in monitoring programs rather than the parent omeprazole. Copyright © 2013 John Wiley & Sons, Ltd.

Efficacy of omeprazole/sodium bicarbonate treatment in gastroesophageal reflux disease: a systematic review

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Fátima Higuera-de-la-Tijera

2018-04-01

Full Text Available Resumen INTRODUCCIÓN Los inhibidores de la bomba de protones son la terapia médica más efectiva para la enfermedad de reflujo gastroesofágico, pero su inicio de acción puede ser lento. OBJETIVO Evaluar la literatura referida a la eficacia del omeprazol y bicarbonato de sodio en la enfermedad por reflujo gastroesofágico. MÉTODOS Revisión sistemática de la literatura desde el año 2000. Se revisaron los manuscritos relativos a la efectividad del tratamiento de la enfermedad por reflujo gastroesofágico. Se extrajo la información relevante, la cual fue subsecuentemente analizada con estadística descriptiva. RESULTADOS Se incluyó información de cuatro estudios. Dos estudios compararon la eficacia de omeprazol y bicarbonato de sodio versus omeprazol, y un estudio comparó la eficacia de la dosis diaria matutina con la nocturna. El otro estudio comparó omeprazol más bicarbonato de sodio y alginato versus omeprazol. No hubo diferencia entre omeprazol con bicarbonato de sodio y omeprazol. Sin embargo, hubo una tendencia hacia una respuesta más sostenida y una mayor proporción de alivio total sostenido por 30 minutos con omeprazol y bicarbonato de sodio. CONCLUSIÓN La terapia con omeprazol y bicarbonato de sodio no es más efectiva que el omeprazol en el tratamiento de la enfermedad por reflujo gastroesofágico. Sin embargo, la información sugiere que puede tener una respuesta más sostenida y un alivio total de mayor duración.

Comparison of aloe vera and omeprazole in the treatment of equine gastric ulcer syndrome.

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Bush, J; van den Boom, R; Franklin, S

2018-01-01

Anecdotally, aloe vera is used to treat gastric ulceration, although no studies have yet investigated its efficacy in horses. To test the hypothesis that aloe vera would be noninferior to omeprazole in the treatment of equine gastric ulcer syndrome. Randomised, blinded clinical trial. Forty horses with grade ≥2 lesions of the squamous and/or glandular mucosa were randomly assigned to one of two groups. Horses received either aloe vera inner leaf gel (17.6 mg/kg bwt) b.i.d. or omeprazole (4 mg/kg bwt) s.i.d. for approximately 28 days, after which a repeat gastroscopic examination was performed to determine disease resolution. Horses with persistent lesions were offered a further 28 days of treatment with omeprazole (4 mg/kg bwt s.i.d.) and were re-examined on completion of treatment. Efficacy analyses were based on 39 horses that completed the trial. Equine squamous gastric disease (ESGD) was observed in 38 horses; improvement and healing rates in these horses were 56% and 17%, respectively, in the aloe vera group, and 85% and 75%, respectively, in the omeprazole group. Healing was less likely to occur in horses with prolonged gastric emptying. Equine glandular gastric disease (EGGD) was less common than ESGD (n = 14) and numbers were too small to perform meaningful statistical analyses. The hypothesis that aloe vera would be noninferior to omeprazole was not supported. No placebo control group was included. Limited numbers preclude any comment on the efficacy of aloe vera in the treatment of EGGD. Treatment with aloe vera was inferior to treatment with omeprazole. © 2017 EVJ Ltd.

A Prospective, Placebo-Controlled Pilot Evaluation of the Effect of Omeprazole on Serum Calcium, Magnesium, Cobalamin, Gastrin Concentrations, and Bone in Cats.

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Gould, E; Clements, C; Reed, A; Giori, L; Steiner, J M; Lidbury, J A; Suchodolski, J S; Brand, M; Moyers, T; Emery, L; Tolbert, M K

2016-05-01

Chronic proton pump inhibitor administration has been associated with electrolyte and cobalamin deficiency, disrupted bone homeostasis, hypergastrinemia, and rebound acid hypersecretion in humans. It is unknown if this occurs in cats. Prolonged oral omeprazole results in altered bone mineral density or content, serum calcium, magnesium, cobalamin, and gastrin concentrations in healthy cats. Six healthy adult DSH cats. In a within subjects, before and after design, cats received placebo followed by omeprazole (0.83-1.6 mg/kg PO q12h) for 60 days each. Analysis of serum calcium, magnesium, cobalamin, and gastrin concentrations was performed on days 0, 30, and 60. Bone density and content were evaluated on days 0 and 60 of each intervention. Continuous data were analyzed using a two-way ANOVA (α = 0.006). On day 60 of omeprazole administration, continuous intragastric pH monitoring was performed in 2 cats to evaluate the effects of abrupt withdrawal of omeprazole. No significant changes were detected between treatments for any variables, except serum gastrin, which was significantly higher during omeprazole treatment in comparison to placebo (P = 0.002). Evidence of gastric hyperacidity was seen in both cats in which intragastric pH monitoring was performed following cessation of omeprazole. Although further studies with larger populations of cats will be needed to draw any definitive conclusions, these preliminary results suggest that prolonged PPI treatment results in hypergastrinemia and abrupt PPI withdrawal might result in RAH in cats. Copyright © 2016 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

Esophagectomy with gastroplasty in advanced megaesophagus: late results of omeprazole use

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Celso de Castro Pochini

Full Text Available Objective: To analyze the late results of advanced Chagasic megaesophagus treatment by esophagectomy associated with the use of proton pump inhibitor (omeprazole as for the incidence of esophagitis and Barrett's esophagus in the remaining stump. Methods : We studied patients with advanced megaesophagus undergoing esophagectomy and transmediastinal esophagogastroplasty. Patients were divided into three groups: A (20 with esophageal replacement by full stomach, without the use of omeprazole; B (20 with esophageal replacement by full stomach, with omeprazole 40 mg/day introduced after the first postoperative endoscopy and maintained for six years; and C (30 with esophageal replacement by gastric tube with use of omeprazole. Dysphagia, weight loss and BMI were clinical parameters we analyzed. Upper gastrointestinal endoscopy was performed in all patients, and determined the height of the anastomosis, the aspect of the mucosa, with special attention to possible injuries arising from gastroesophageal reflux, and the patency of the esophagogastric anastomosis. Results : We studied 50 patients, 28 males (56% and 22 (44% females. All underwent endoscopy every year. In the first endoscopy, erosive esophagitis was present in nine patients (18% and Barrett's esophagus, in four (8%; in the last endoscopy, erosive esophagitis was present in five patients (8% and Barrett's esophagus in one (2%. When comparing groups B and C, there was no evidence that the manufacturing of a gastric tube reduced esophagitis and Barrett's esophagus. However, when comparing groups A and C, omeprazole use was correlated with reduction of reflux complications such as esophagitis and Barrett's esophagus (p <0.005. Conclusion : The use of omeprazole (40 mg/day reduced the onset of erosive esophagitis and Barrett's esophagus during the late postoperative period.

Prophylactic therapy with omeprazole for prevention of equine gastric ulcer syndrome (EGUS) in horses in active training: A meta-analysis.

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Mason, L V; Moroney, J R; Mason, R J

2018-04-17

Guidelines regarding the impact and value of prophylaxis or maintenance therapy in equine gastric ulcer syndrome (EGUS) are not well-established or defined. The merits and the magnitude of effects of prophylaxis for spontaneous or recurrent squamous gastric ulceration in horses in training are uncertain. To pool data from randomised controlled trials (RCTs) to eliminate reporting bias and evaluate the efficacy of prophylactic omeprazole in the prevention of EGUS in training horses, and secondarily to compare prophylactic dosages of omeprazole. Meta-analysis. This meta-analysis was conducted according to the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A systematic literature search identified RCTs comparing omeprazole prophylaxis with sham in prevention of EGUS. Data were analysed using the Mantel-Haenszel test method to calculate risk ratio (RR) or mean difference (MD) with 95% confidence intervals (CIs). Primary outcome was efficacy of prophylaxis. Secondary outcome was endoscopic severity of ulceration. The influence of study characteristics on the outcomes was examined by subgroup analyses. In preventing gastric ulcer occurrence, omeprazole prophylaxis was superior to sham in training horses (7 trials, 566 horses, RR 0.28, 95% CI 0.18-0.43; 23.4% in omeprazole prophylaxis vs. 77.2% in sham; high quality evidence). Prevalence of ulceration was 75.3 and 87.2% in the sham arms of the 1 mg/kg and 2 mg/kg omeprazole groups, respectively. Severity scores were significantly lower for omeprazole vs. sham (mean difference [MD] -1.05; 95% CI -1.35 to -0.69). Subgroup analyses comparing prophylactic omeprazole dosages resulted in a mean difference of -0.94 and -1.60 for the 1 and 2 mg/kg groups, respectively. Studies showed heterogeneity with regard to prophylactic dose. Omeprazole prophylaxis in active training horses significantly reduces gastric ulceration compared with no prophylaxis (sham) with the

A review of omeprazole use in the treatment of acid-related disorders in children.

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Zimmermann, A E; Walters, J K; Katona, B G; Souney, P E; Levine, D

2001-05-01

Acid peptic disease is a common problem, with a similar prevalence of gastroesophageal reflux disease (GERD) in adults and children. The presentation of GERD in infants and children varies from crying, irritability, or sleep disturbance to feeding difficulties, vomiting, or rumination. Helicobacter pylori (HP)-related diseases and gastric and duodenal ulcers are much more common in adults than in children, who are more likely to have gastritis or duodenitis. However, because HP infection is most likely acquired in childhood, treatment of children with endoscopically documented active HP disease may minimize the potential risk for peptic ulcer or gastric cancer in adulthood, although this is yet to be proved. Omeprazole has been shown to be effective in the treatment of acid-related diseases. This paper reviews the literature on the use and administration of omeprazole for the treatment of GERD, peptic ulcer disease, HP infection, and other acid-related conditions in children. Studies were identified through searches of MEDLINE and Science Citation Index for the period 1986 to November 2000, and from the reference lists of identified articles. The search terms used included omeprazole, proton pump inhibitor (PPI), children, pediatrics, routes of administration, GERD, HP infection, esophagitis, and administration. In addition, the manufacturer of omeprazole was asked for relevant unpublished information. Marketed and extemporaneous formulations of omeprazole have been administered to children aged 2 months to 18 years for the treatment of erosive esophagitis, gastric ulcer, duodenal ulcer, HP infection, and related conditions at dosages of 5 to 80 mg/d (0.2-3.5 mg/kg/d) for periods ranging from 14 days to 36 months with a low incidence of adverse effects. The initial dose most consistently reported to heal esophagitis and provide relief of symptoms of GERD appears to be 1 mg/kg per day. In uncontrolled clinical trials and case reports to date, omeprazole has been

Enantioselective disposition of omeprazole, pantoprazole, and lansoprazole in a same Brazilian subjects group.

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Cassiano, Neila M; Oliveira, Regina V; Bernasconi, Gilberto C R; Cass, Quezia B

2012-04-01

This work reports the result of the enantioselective disposition of pantoprazole, omeprazole, and lansoprazole in a same group of Brazilian health subjects. Ten nongenotyped healthy subjects were used for this study. Each subject received a single oral dose of 80 mg of pantoprazole, 40 mg of omeprazole, and 30 mg of lansoprazole, and the plasma concentrations of the enantiomers were measured for 8 h postdose. For pantoprazole and omeprazole, among the 10 volunteers investigated, only one volunteer (Subject # 4) presented higher plasma concentrations of the (+)-enantiomer than those of (-)-enantiomer. Nevertheless, the area under the concentration-time curve of the (+)-lansoprazole was higher than those the (-)-lansoprazole for all subjects. The comparison of proton pump inhibitors' enantiomers disposition from a single group volunteer demonstrated that pantoprazole and omeprazole can be used to differentiate extensive from poor CYP2C19 metabolizer while lansoprazole cannot do it. Copyright © 2011 Wiley Periodicals, Inc.

Prediction of Relative In Vivo Metabolite Exposure from In Vitro Data Using Two Model Drugs: Dextromethorphan and Omeprazole

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Lutz, Justin D.

2012-01-01

Metabolites can have pharmacological or toxicological effects, inhibit metabolic enzymes, and be used as probes of drug-drug interactions or specific cytochrome P450 (P450) phenotypes. Thus, better understanding and prediction methods are needed to characterize metabolite exposures in vivo. This study aimed to test whether in vitro data could be used to predict and rationalize in vivo metabolite exposures using two model drugs and P450 probes: dextromethorphan and omeprazole with their primary metabolites dextrorphan, 5-hydroxyomeprazole (5OH-omeprazole), and omeprazole sulfone. Relative metabolite exposures were predicted using metabolite formation and elimination clearances. For dextrorphan, the formation clearances of dextrorphan glucuronide and 3-hydroxymorphinan from dextrorphan in human liver microsomes were used to predict metabolite (dextrorphan) clearance. For 5OH-omeprazole and omeprazole sulfone, the depletion rates of the metabolites in human hepatocytes were used to predict metabolite clearance. Dextrorphan/dextromethorphan in vivo metabolite/parent area under the plasma concentration versus time curve ratio (AUCm/AUCp) was overpredicted by 2.1-fold, whereas 5OH-omeprazole/omeprazole and omeprazole sulfone/omeprazole were predicted within 0.75- and 1.1-fold, respectively. The effect of inhibition or induction of the metabolite's formation and elimination on the AUCm/AUCp ratio was simulated. The simulations showed that unless metabolite clearance pathways are characterized, interpretation of the metabolic ratios is exceedingly difficult. This study shows that relative in vivo metabolite exposure can be predicted from in vitro data and characterization of secondary metabolism of probe metabolites is critical for interpretation of phenotypic data. PMID:22010218

A comparison of oral omeprazole and intravenous cimetidine in reducing complications of duodenal peptic ulcer

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Khaleghian Farzaneh

2006-01-01

Full Text Available Abstract Background Gastrointestinal bleeding is a common problem and its most common etiology is peptic ulcer disease. Ulcer rebleeding is considered a perilous complication for patients. To reduce the rate of rebleeding and to fasten the improvement of patients' general conditions, most emergency departments in Iran use H2-blockers before endoscopic procedures (i.e. intravenous omeprazole is not available in Iran. The aim of this study was to compare therapeutic effects of oral omeprazole and intravenous cimetidine on reducing rebleeding rates, duration of hospitalization, and the need for blood transfusion in duodenal ulcer patients. Methods In this clinical trial, 80 patients with upper gastrointestinal bleeding due to duodenal peptic ulcer and endoscopic evidence of rebleeding referring to emergency departments of Imam and Sina hospitals in Tabriz, Iran were randomly assigned to two equal groups; one was treated with intravenous cimetidine 800 mg per day and the other, with 40 mg oral omeprazole per day. Results No statistically significant difference was found between cimetidine and omeprazole groups in regards to sex, age, alcohol consumption, cigarette smoking, NSAID consumption, endoscopic evidence of rebleeding, mean hemoglobin and mean BUN levels on admission, duration of hospitalization and the mean time of rebleeding. However, the need for blood transfusion was much lower in omeprazole than in cimetidine group (mean: 1.68 versus 3.58 units, respectively; p Conclusion This study demonstrated that oral omeprazole significantly excels intravenous cimetidine in reducing the need for blood transfusion and lowering rebleeding rates in patients with upper gastrointestinal bleeding. Though not statistically significant (p = 0.074, shorter periods of hospitalization were found for omeprazole group which merits consideration for cost minimization.

Effects of omeprazole in improving concurrent chemoradiotherapy efficacy in rectal cancer.

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Zhang, Jin-Liang; Liu, Min; Yang, Qing; Lin, Shi-Yong; Shan, Hong-Bo; Wang, Hui-Yun; Xu, Guo-Liang

2017-04-14

To explore the effects of omeprazole on chemoradiotherapy efficacy and tumor recurrence in rectal cancer. The medical data of 125 rectal cancer patients who received the same neoadjuvant chemoradiotherapy (CRT) followed by surgery were retrospectively collected. Patients who received omeprazole (OME) orally at a dose of 20 mg at least once daily for six days and/or intravenously at 40 mg a day were recognized as eligible OME users (EOU). Otherwise, patients were regarded as non-eligible OME users (non-EOU). Moreover, a preferred OME dose cut-off of 200 mg on tumor recurrence was obtained by receiver operating characteristic (ROC) curves. Patients were divided into two groups: the effective OME group (EOG, OME ≥ 200 mg) and the non-effective OME group (non-EOG, OME cancer treatment for relieving common side effects of chemotherapy, omeprazole has a synergetic effect in improving CRT efficacy and decreasing rectal cancer recurrence.

Peak distortion in the column liquid chromatographic determination of omeprazole dissolved in borax buffer.

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Arvidsson, T; Collijn, E; Tivert, A M; Rosén, L

1991-11-22

Injection of a sample containing omeprazole dissolved in borax buffer (pH 9.2) into a reversed-phase liquid chromatographic system consisting of a mixture of acetonitrile and phosphate buffer (pH 7.6) as the mobile phase and a C18 surface-modified silica as the solid phase resulted under special conditions in split peaks of omeprazole. The degree of peak split and the retention time of omeprazole varied with the concentration of borax in the sample solution and the ionic strength of the mobile phase buffer as well as with the column used. Borax is eluted from the column in a broad zone starting from the void volume of the column. The retention is probably due to the presence of polyborate ions. The size of the zone varies with the concentration of borax in the sample injected. In the borax zone the pH is increased compared with the pH of the mobile phase, and when omeprazole (a weak acid) is co-eluting in the borax zone its retention is affected. In the front part and in the back part of the borax zone, pH gradients are formed, and these gradients can induce the peak splitting. When the dissolving medium is changed to a phosphate buffer or an ammonium buffer at pH 9 no peak distortion of omeprazole is observed.

The effects of dose and diet on the pharmacodynamics of omeprazole in the horse.

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Sykes, B W; Underwood, C; Greer, R; McGowan, C M; Mills, P C

2017-07-01

Conflicting data are presented in the current literature regarding the efficacy of omeprazole for suppressing gastric acidity in the horse. The objective of this study was to investigate the duration of intraday acid suppression achieved with two doses of omeprazole under two different dietary conditions. A four-way crossover design. Six adult Thoroughbred horses instrumented with percutaneous gastrotomy tubes were used. Intragastric pH was measured for continuous 23 h periods (08.00-07.00 h) for six consecutive days (Days 0-5). Baseline data was recorded on Day 0 and omeprazole administered on Days 1-5. Two doses (1 mg/kg and 4 mg/kg bwt per os once a day) and two diets (a high grain/low fibre [HG/LF] and ad libitum hay [HAY)] diet) were studied. Data for the percent (%) time pH was above 4 (%tpH>4) and median intraday pH was reported for two measurement locations and analysed using generalised estimating equations. An effect of both diet and dose was evident with mean %tpH>4 and the mean of the median intraday pHs typically higher at the higher (4 mg/kg bwt) dose and in HG/LF diet. The overall efficacy of omeprazole in raising intragastric pH was good under the HG/LF conditions but relatively poor in the HAY diet. A cumulative effect of dosing, not previously reported in the horse, was observed. The overall efficacy of omeprazole in raising ventral gastric pH was less than previously reported. Both dose and diet may play a role in the efficacy of omeprazole in the horse. Therefore, the use of singular dosing recommendations that encompass all horse types and management conditions may not be appropriate and dosing recommendations that take into account the diet of the horse may be advantageous. © 2016 EVJ Ltd.

Comparison of Omeprazole with Ranitidine for Treatment of Symptoms Associated with Gastroesophageal Reflux Disease and Uncomplicated Duodenal Ulcer

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Andre P Archambault

1996-01-01

Full Text Available This randomized, single-blind, parallel group study was conducted to compare omeprazole with ranitidine for the treatment of symptoms associated with gastroesophageal reflux disease (GERD, uncomplicated duodenal ulcer (DU or both. After baseline assessments, patients were randomized to receive daily treatment with either 20 mg omeprazole or 300 mg ranitidine for four weeks. In total, 1481 patients (1001 omeprazole, 480 ranitidine with a diagnosis of GERD (n=904 and/or DU (n=577, confirmed by endoscopy or barium meal and reporting moderate to severe symptoms, were included in the analyses. The seventy of overall daytime symptoms reported by the omeprazole group at clinic visits was lower than that reported by the ranitidine group at week 2 for the entire patient group (P=0.0002 and at both weeks 2 and 4 for the subgroup of patients with GERD (P=0.0001 and P=0.001, respectively. The severity of overall night-time symptoms reported by the omeprazole group was lower than that reported by the ranitidine group at week 4 for all patients as a whole (P=0.042 and at both weeks 2 and 4 for the subgroup of patients with GERD (P=0.035 and P=0.010, respectively. There were no significant differences in reports of adverse events. In the omeprazole group, 19% of patients at week 2 and 15% of patients at week 4 reported adverse events, while the corresponding results from the ranitidine group were 21% and 11%. In conclusion, patients with GERD, DU or both treated with omeprazole 20 mg daily for four weeks showed statistically significant reductions in symptoms compared with patients treated with ranitidine 300 mg daily for the same period of time. The percentage of patients with any remaining daytime symptoms was 12% lower in the omeprazole group compared with the ranitidine group at week 2, and 7% lower at week 4. Five per cent fewer patients in the omeprazole group experienced night-time symptoms at either week 2 or week 4.

Nizatidine and omeprazole enhance the effect of metronidazole on Helicobacter pylori in vitro

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Chen, Ming; Jensen, Bente; Zhai, Lin

2002-01-01

to reverse antibiotic resistance do not necessarily have an antibiotic or chemotherapeutic effect in the sense of growth inhibition. Therefore, it was decided to investigate the effect of nizatidine and omeprazole on the oxidative respiratory chain, as it is known that metronidazole is able to inhibit...... the activity of fumarate reductase of H. pylori. This enzyme is a key enzyme in the alternative respiratory chain under anaerobic conditions. Nizatidine was, in these preliminary experiments, found to inhibit fumarate reductase in a dose-dependent way, like metronidazole, whereas omeprazole had almost...... no effect on fumarate reductase. No other significant effects on the enzymes of the respiratory chain were found. The synergistic effect of nizatidine on metronidazole resistant H. pylori strains could be explained by the effect on fumarate reductase, whereas the effect of omeprazole is different and could...

Omeprazole and lansoprazole enantiomers induce CYP3A4 in human hepatocytes and cell lines via glucocorticoid receptor and pregnane X receptor axis.

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Novotna, Aneta; Dvorak, Zdenek

2014-01-01

Benzimidazole drugs lansoprazole and omeprazole are used for treatment of various gastrointestinal pathologies. Both compounds cause drug-drug interactions because they activate aryl hydrocarbon receptor and induce CYP1A genes. In the current paper, we examined the effects of lansoprazole and omeprazole enantiomers on the expression of key drug-metabolizing enzyme CYP3A4 in human hepatocytes and human cancer cell lines. Lansoprazole enantiomers, but not omeprazole, were equipotent inducers of CYP3A4 mRNA in HepG2 cells. All forms (S-, R-, rac-) of lansoprazole and omeprazole induced CYP3A4 mRNA and protein in human hepatocytes. The quantitative profiles of CYP3A4 induction by individual forms of lansoprazole and omeprazole exerted enantiospecific patterns. Lansoprazole dose-dependently activated pregnane X receptor PXR in gene reporter assays, and slightly modulated rifampicin-inducible PXR activity, with similar potency for each enantiomer. Omeprazole dose-dependently activated PXR and inhibited rifampicin-inducible PXR activity. The effects of S-omeprazole were much stronger as compared to those of R-omeprazole. All forms of lansoprazole, but not omeprazole, slightly activated glucocorticoid receptor and augmented dexamethasone-induced GR transcriptional activity. Omeprazole and lansoprazole influenced basal and ligand inducible expression of tyrosine aminotransferase, a GR-target gene, in HepG2 cells and human hepatocytes. Overall, we demonstrate here that omeprazole and lansoprazole enantiomers induce CYP3A4 in HepG2 cells and human hepatocytes. The induction comprises differential interactions of omeprazole and lansoprazole with transcriptional regulators PXR and GR, and some of the effects were enantiospecific. The data presented here might be of toxicological and clinical importance, since the effects occurred in therapeutically relevant concentrations.

Pharmacokinetic and pharmacodynamic effects of two omeprazole formulations on stomach pH and gastric ulcer scores.

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Raidal, S L; Andrews, F M; Nielsen, S G; Trope, G

2017-11-01

Limited data are available on the relative pharmacokinetics and pharmacodynamics of different omeprazole formulations. To compare pharmacokinetic and pharmacodynamic effects of a novel omeprazole formulation against a currently registered product. Masked 2 period, 2 treatment crossover. Twelve clinically healthy horses were studied over two 6-day treatment periods. Horses were randomly assigned to receive a novel omeprazole paste (Ulcershield: ULS) or a currently registered reference omeprazole product (OMO). Gastric pH was measured continuously for 10 h on the day prior to commencing treatment (Day -1) and after 6 days of oral treatment (Day 5) using in situ antimony pH probes within an indwelling nasogastric tube. Plasma pharmacokinetics were determined on Days 0 and 6. Treatment significantly (Pulcer severity scores (both P = 0.004), with no difference between treatments (P = 0.688). Comparison of mean log area under time-plasma concentration curves demonstrated that, although the lower limit of the 90% confidence interval was within the -20% limit for bioequivalence, the upper limit was exceeded, suggesting that the test product could have greater bioavailability than the reference product. The small sample size, large interhorse plasma omeprazole concentrations, and low bioavailability of omeprazole impacted the sensitivity of the bioequivalence analysis. ULS matched or slightly exceeded OMO plasma concentrations. Both products resulted in equivalent increases in gastric pH, gastric pH profiles and decrease in gastric ulcer scores. Thus, ULS was pharmacodynamically equivalent to OMO and was associated with an equivalent beneficial effect on gastric squamous mucosal ulceration. © 2017 EVJ Ltd.

Differential effects of omeprazole and lansoprazole enantiomers on aryl hydrocarbon receptor in human hepatocytes and cell lines.

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Novotna, Aneta; Srovnalova, Alzbeta; Svecarova, Michaela; Korhonova, Martina; Bartonkova, Iveta; Dvorak, Zdenek

2014-01-01

Proton pump inhibitors omeprazole and lansoprazole contain chiral sulfur atom and they are administered as a racemate, i.e. equimolar mixture of S- and R-enantiomers. The enantiopure drugs esomeprazole and dexlansoprazole have been developed and introduced to clinical practice due to their improved clinical and therapeutic properties. Since omeprazole and lansoprazole are activators of aryl hydrocarbon receptor (AhR) and inducers of CYP1A genes, we examined their enantiospecific effects on AhR-CYP1A pathway in human cancer cells and primary human hepatocytes. We performed gene reporter assays for transcriptional activity of AhR, RT-PCR analyses for CYP1A1/2 mRNAs, western blots for CYP1A1/2 proteins and EROD assay for CYP1A1/2 catalytic activity. Lansoprazole and omeprazole enantiomers displayed differential effects on AhR-CYP1A1/2 pathway. In general, S-enantiomers were stronger activators of AhR and inducers of CYP1A genes as compared to R-enantiomers in lower concentrations, i.e. 1-10 µM for lansoprazole and 10-100 µM for omeprazole. In contrast, R-enantiomers were stronger AhR activators and CYP1A inducers than S-enantiomers in higher concentrations, i.e. 100 µM for lansoprazole and 250 µM for omeprazole. In conclusion, we provide the first evidence of enantiospecific effects of omeprazole and lansoprazole on AhR signaling pathway.

Effectiveness differences of ranitidine and omeprazole in prevention of stress ulcer and its effect on pneumonia occurrence and outcome of acute stroke patients

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Batubara, C. A.; Ritarwan, K.; Rambe, A. S.

2018-03-01

Stress ulcer is one ofacute stroke complications. Giving ranitidine or omeprazole may prevent stress ulcer, but may increase the occurrence of pneumonia. Thus, it will affect the outcome of acute stroke. The method was experimental with a randomized control-group pretest - posttest design. This study divided the subjects into two groups, ranitidine 300mg and omeprazole 20mg group.We observed the patients whether stress ulcer or pneumonia occurred during hospitalization. Then, we measured the outcome by the National Institutes of Health Stroke Scaleand modified Rankin Scale. There were 32 subjects in this study. Only 1 (3.1%) subject suffered stress ulcer, and 3 (3.1%) suffered pneumonia in ranitidine group. Moreover, 2 (6.2%) subjects suffered pneumonia in omeprazole group. The differences were not significant between the two groups (p = 0.31 and p = 0.54). There was no significant effect and difference effect on the administration of both medications to the outcome at day 14. These results indicate that ranitidine and omeprazole have anequal effectiveness in the prevention of stress ulcer and also have equal effect on the occurrence of pneumonia, and both have no effect on the outcome of acute stroke patients.

Efficacy of omeprazole on cough, pulmonary function and quality of life of patients with sulfur mustard lung injury: A placebo-control, cross-over clinical trial study

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Mohammad Hossein Emami

2014-01-01

Full Text Available Background: Gastro-esophageal reflux disease (GERD is prevalent and related to more severe disease in patients with respiratory problems. We evaluated the effects of antireflux therapy in warfare victims of exposure to Mustard gas with chronic cough. Materials and Methods: This randomized, double-blind, placebo-controlled, cross-over study was conducted on 45 cases of sulfur mustard injury with chronic cough (≥8 weeks and GERD. Patients were randomized into two groups, receiving either 20 mg twice daily omeprazole-placebo (OP or matching placebo (placebo-omeprazole [PO] for 4 months, followed by a 1-month washout period and the alternative treatment for 4 months. Assessments included GERD and cough, quality of life, and pulmonary function using spirometry. Leicester Cough Questionnaire and SF-36 were used for measuring quality of life. Results: Patients in the OP group experienced a more decrease than those in the PO group in severity of Leicester cough scores during the first 4-month of trial. After crossing the groups, the OP group experienced an increase (P = 0.036 and the PO group experienced a nonsignificant decrease (P = 0.104 in the severity of scores. The OP group also experienced improvement in GERD symptoms and quality of life at the end of the trial, but changes in the PO group was not significant. There was no significant change in respiratory function indices in any groups. Conclusion: Long-term treatment with high-dose omeprazole improved GERD as well as cough, and quality of life, but not changed respiratory function indices in sulfur mustard injured cases with respiratory symptoms.

A randomized, 2-period, crossover design study to assess the effects of dexlansoprazole, lansoprazole, esomeprazole, and omeprazole on the steady-state pharmacokinetics and pharmacodynamics of clopidogrel in healthy volunteers.

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Frelinger, Andrew L; Lee, Ronald D; Mulford, Darcy J; Wu, Jingtao; Nudurupati, Sai; Nigam, Anu; Brooks, Julie K; Bhatt, Deepak L; Michelson, Alan D

2012-04-03

The aim of this study was to assess the effects of different proton pump inhibitors (PPIs) on the steady-state pharmacokinetics and pharmacodynamics of clopidogrel. Metabolism of clopidogrel requires cytochrome P450s (CYPs), including CYP2C19. However, PPIs may inhibit CYP2C19, potentially reducing the effectiveness of clopidogrel. A randomized, open-label, 2-period, crossover study of healthy subjects (n = 160, age 18 to 55 years, homozygous for CYP2C19 extensive metabolizer genotype, confined, standardized diet) was conducted. Clopidogrel 75 mg with or without a PPI (dexlansoprazole 60 mg, lansoprazole 30 mg, esomeprazole 40 mg, or, as a positive control to maximize potential interaction and demonstrate assay sensitivity, omeprazole 80 mg) was given daily for 9 days. Pharmacokinetics and pharmacodynamics were assessed on days 9 and 10. Pharmacodynamic end-points were vasodilator-stimulated phosphoprotein P2Y(12) platelet reactivity index, maximal platelet aggregation to 5 and 20 μmol/l adenosine diphosphate, and VerifyNow P2Y12 platelet response units. Pharmacokinetic and pharmacodynamic responses with omeprazole demonstrated assay sensitivity. The area under the curve for clopidogrel active metabolite decreased significantly with esomeprazole but not with dexlansoprazole or lansoprazole. Similarly, esomeprazole but not dexlansoprazole or lansoprazole significantly reduced the effect of clopidogrel on vasodilator-stimulated phosphoprotein platelet reactivity index. All PPIs decreased the peak plasma concentration of clopidogrel active metabolite (omeprazole > esomeprazole > lansoprazole > dexlansoprazole) and showed a corresponding order of potency for effects on maximal platelet aggregation and platelet response units. Generation of clopidogrel active metabolite and inhibition of platelet function were reduced less by the coadministration of dexlansoprazole or lansoprazole with clopidogrel than by the coadministration of esomeprazole or omeprazole. These

Omeprazole blocks STAT6 binding to the eotaxin-3 promoter in eosinophilic esophagitis cells.

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Xi Zhang

Full Text Available Patients who have esophageal eosinophilia without gastroesophageal reflux disease (GERD nevertheless can respond to proton pump inhibitors (PPIs, which can have anti-inflammatory actions independent of effects on gastric acid secretion. In esophageal cell cultures, omeprazole has been reported to inhibit Th2 cytokine-stimulated expression of eotaxin-3, an eosinophil chemoattractant contributing to esophageal eosinophilia in eosinophilic esophagitis (EoE. The objective of this study was to elucidate molecular mechanisms underlying PPI inhibition of IL-4-stimulated eotaxin-3 production by esophageal cells.Telomerase-immortalized and primary cultures of esophageal squamous cells from EoE patients were treated with IL-4 in the presence or absence of acid-activated omeprazole or lansoprazole. We measured eotaxin-3 protein secretion by ELISA, mRNA expression by PCR, STAT6 phosphorylation and nuclear translocation by Western blotting, eotaxin-3 promoter activation by an exogenous reporter construct, and STAT6, RNA polymerase II, and trimethylated H3K4 binding to the endogenous eotaxin-3 promoter by ChIP assay. Omeprazole in concentrations ≥5 µM significantly decreased IL-4-stimulated eotaxin-3 protein secretion and mRNA expression. Lansoprazole also blocked eotaxin-3 protein secretion. Omeprazole had no effect on eotaxin-3 mRNA stability or on STAT6 phosphorylation and STAT6 nuclear translocation. Rather, omeprazole blocked binding of IL-4-stimulated STAT6, RNA polymerase II, and trimethylated H3K4 to the eotaxin-3 promoter.PPIs, in concentrations achieved in blood with conventional dosing, significantly inhibit IL-4-stimulated eotaxin-3 expression in EoE esophageal cells and block STAT6 binding to the promoter. These findings elucidate molecular mechanisms whereby patients with Th2 cytokine-driven esophageal eosinophilia can respond to PPIs, independent of effects on gastric acid secretion.

Therapeutic usage of omeprazole and corticoid in a dog with hydrocephalus unresponsive to conventional therapyUso terapêutico da associação do omeprazol com corticóide em um cão com hidrocefalia não-responsiva ao tratamento convencional

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Alexandre Mendes Amude

2013-05-01

Full Text Available Medical therapy for hydrocephalus includes the administration of medications to limit the production of the cerebrospinal fluid (CSF resulting in reduced intracranial pressure (ICP. This report describes the clinical findings in one dog with congenital hydrocephalus that was unresponsive to conventional medical treatment with steroids, but demonstrated good response to omeprazole when this drug was added to the steroid. Omeprazole might decrease the CSF production by about 26% according to experimental studies with healthy dogs, but the usage of the omeprazole in clinical trials with affected dogs such as hydrocephalic animals is lacking. The results of this report might suggest that omeprazole can be used added to steroids to ameliorate the neurological status in dogs with increased ICP by hydrocephalus.O tratamento médico para a hidrocefalia inclui a administração de medicamentos para limitar a produção do fluido cerebroespinhal (FCE, resultando em redução da pressão intracraniana (PIC. Este trabalho descreve os achados clínicos em um cão com hidrocefalia congênita não responsiva ao tratamento médico convencional com esteróides mas que apresentou boa resposta à associação omeprazolesteróides. O omeprazol pode diminuir a produção de FCE em cerca de 26% de acordo com estudos experimentais realizados com cães saudáveis. Porém, o uso do omeprazol em ensaios clínicos com cães enfermos, como os animais hidrocefálicos, não é descrito. Os resultados deste trabalho sugerem que o omeprazol pode ser empregado em associação ao corticóide para melhorar o estado neurológico em cães com aumento da PIC devido à hidrocefalia.

Quality of omeprazole purchased via the Internet and personally imported into Japan: comparison with products sampled in other Asian countries.

Science.gov (United States)

Rahman, Mohammad Sofiqur; Yoshida, Naoko; Sugiura, Sakura; Tsuboi, Hirohito; Keila, Tep; Kiet, Heng Bun; Zin, Theingi; Tanimoto, Tsuyoshi; Kimura, Kazuko

2018-03-01

To evaluate the quality of omeprazole personally imported into Japan via the Internet and to compare the quality of these samples with previously collected samples from two other Asian countries. The samples were evaluated by observation, authenticity investigation and pharmacopoeial quality analysis. Quality comparison of some selected samples was carried out by dissolution profiling, Raman spectroscopy and principle component analysis (PCA). Observation of the Internet sites and samples revealed some discrepancies including the delivery of a wrong sample and the selling of omeprazole without a prescription, although it is a prescription medicine. Among the 28 samples analysed, all passed the identification test, 26 (93%) passed the quantity and content uniformity tests and all passed the dissolution test. Dissolution profiling confirmed that all the personally imported omeprazole samples remained intact in the acid medium. On the other hand, six samples from two of the same manufacturers, previously collected during surveys in Cambodia and Myanmar, frequently showed premature omeprazole release in acid. Raman spectroscopy and PCA showed significant variation between omeprazole formulations in personally imported samples and the samples from Cambodia and Myanmar. Our results indicate that the pharmaceutical quality of omeprazole purchased through the Internet was sufficient, as determined by pharmacopeial tests. However, omeprazole formulations distributed in different market segments by the same manufacturers were of diverse quality. Measures are needed to ensure consistent quality of products and to prevent entry of substandard products into the legitimate supply chain. © 2018 The Authors. Tropical Medicine & International Health Published by John Wiley & Sons Ltd.

A pilot study comparing the effect of orally administered esomeprazole and omeprazole on gastric fluid pH in horses.

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Huxford, K E; Dart, A J; Perkins, N R; Bell, R; Jeffcott, L B

2017-11-01

AIMS To compare the efficacy of an enteric coated esomeprazole paste with an enteric coated omeprazole paste to increase gastric pH after oral administration in horses. METHODS Nine adult Standardbred horses were randomly assigned to three groups, each containing three horses, for a study comprising three phases of 10 days, with an 18-day washout period between each phase. In each phase, three horses received either 0.5 mg/kg esomeprazole, 1 mg/kg omeprazole or a placebo, as an oral paste, once daily for 10 days (Days 0-9). Over the course of study all horses received all three treatments. Gastric fluid samples were collected using a gastroscope on Days 1, 3, 5, 8 and 10, with food and water withheld for 16 hours prior to collection of samples. The pH of all samples was measured immediately after collection. RESULTS Mean pH (3.38; SD 1.75) of the gastric fluid samples in the horses that received the placebo was lower than in the horses that received esomeprazole (6.28; SD 1.75) or omeprazole (6.13; SD 1.75) (phorses receiving esomeprazole and those receiving omeprazole (p=0.56). CONCLUSIONS AND CLINICAL RELEVANCE Under these study conditions, esomeprazole paste was equally as effective as omeprazole paste in increasing gastric pH in horses. Enteric coated esomeprazole, may be a therapeutic alternative to omeprazole for the prevention of gastric ulcers in horses.

Non-steroidal anti-inflammatory drugs and gastroprotection with proton pump inhibitors: a focus on ketoprofen/omeprazole.

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Gigante, Antonio; Tagarro, Ignacio

2012-04-01

Non-steroidal anti-inflammatory drugs (NSAIDs) are among the most commonly prescribed agents for rheumatic disorders such as osteoarthritis (OA), rheumatoid arthritis (RA) and ankylosing spondylitis (AS). Despite the known association between NSAID use and gastropathy, however, only around one-third of patients at risk of NSAID-induced gastrointestinal toxicity receive adequate gastroprotection, and as many as 44% of these patients are non-adherent. We review the co-prescription of proton pump inhibitors (PPIs) for the prevention of NSAID-induced gastropathy, with a particular focus on the first fixed-dose NSAID/PPI formulation: ketoprofen/omeprazole modified-release capsules. The ketoprofen/omeprazole fixed-dose combination is available in doses of 100 mg/20 mg, 150 mg/20 mg or 200 mg/20 mg as a single capsule for once-daily administration. Ketoprofen monotherapy has been shown to be generally equivalent to other NSAIDs when used in the treatment of OA. In RA, ketoprofen has demonstrated equivalent efficacy to diclofenac, indometacin, piroxicam, aceclofenac, phenylbutazone, naproxen and flurbiprofen. Studies comparing ketoprofen with ibuprofen and sulindac in patients with RA have, in general, favoured ketoprofen. Studies in AS have generally reported similar efficacy between ketoprofen and phenylbutazone and pirprofen. Prophylaxis with omeprazole is effective for the prevention of gastroduodenal ulcers, maintenance of remission and alleviation of dyspeptic symptoms in NSAID recipients. Omeprazole is well tolerated, and adverse events are generally gastrointestinal in nature. The fixed-dose combination of ketoprofen and omeprazole has demonstrated bioequivalence to the respective monotherapies. The incidence of digestive symptoms and the need for dose reduction was reported to be lower with the combination than with its components. Ketoprofen/omeprazole modified-release capsules are the first fixed-dose NSAID/PPI formulation to be approved. This formulation

Comparison of the effect of a single dose of omeprazole or lansoprazole on intragastric pH in Japanese participants: a two-way crossover study.

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Funaki, Yasushi; Tokudome, Kentaro; Izawa, Shinya; Tamura, Yasuhiro; Kondo, Yoshihiro; Iida, Akihito; Mizuno, Mari; Ogasawara, Naotaka; Sasaki, Makoto; Kasugai, Kunio

2013-03-01

It is known that the pharmacokinetic profile of proton pump inhibitors (PPIs) after postprandial administration may differ among PPIs. The purpose of this study was to compare the inhibitory effects of gastric acid secretion by PPIs administered after a meal, based on a 24-hour intragastric pH monitoring. Ten healthy men who provided written informed consent participated in the study. They were given a 20-mg omeprazole tablet and a 30-mg lansoprazole orally dispersing tablet in a two-way crossover manner. At baseline, the anti-HP-IgG antibody levels in blood and the pepsinogen (PG) I/II ratio were measured. Participants were given a standardized meal and 200 mL of water at 9:30 am, 13:30 pm, and 18.30 pm. Participants took the PPI after breakfast. Two of the ten participants tested positive for Helicobacter pylori infection. The PG I/II ratio indicated negative gastric atrophy in all the participants. The percentage 24-hour intragastric pH > 4 holding times (median, range) with omeprazole and lansoprazole were 29.3, 19.3-50.0% and 27.8, 13.0-42.3%, respectively, which shows that with the administration of omeprazole, the pH was maintained at >4 for a longer period (p lansoprazole (p lansoprazole, a single postprandial dose of omeprazole showed a more rapid and sustained acid-inhibitory effect. Copyright © 2012. Published by Elsevier B.V.

The proton pump inhibitor, omeprazole, but not lansoprazole or pantoprazole, is a metabolism-dependent inhibitor of CYP2C19: implications for coadministration with clopidogrel.

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Ogilvie, Brian W; Yerino, Phyllis; Kazmi, Faraz; Buckley, David B; Rostami-Hodjegan, Amin; Paris, Brandy L; Toren, Paul; Parkinson, Andrew

2011-11-01

As a direct-acting inhibitor of CYP2C19 in vitro, lansoprazole is more potent than omeprazole and other proton pump inhibitors (PPIs), but lansoprazole does not cause clinically significant inhibition of CYP2C19 whereas omeprazole does. To investigate this apparent paradox, we evaluated omeprazole, esomeprazole, R-omeprazole, lansoprazole, and pantoprazole for their ability to function as direct-acting and metabolism-dependent inhibitors (MDIs) of CYP2C19 in pooled human liver microsomes (HLM) as well as in cryopreserved hepatocytes and recombinant CYP2C19. In HLM, all PPIs were found to be direct-acting inhibitors of CYP2C19 with IC(50) values varying from 1.2 μM [lansoprazole; maximum plasma concentration (C(max)) = 2.2 μM] to 93 μM (pantoprazole; C(max) = 6.5 μM). In addition, we identified omeprazole, esomeprazole, R-omeprazole, and omeprazole sulfone as MDIs of CYP2C19 (they caused IC(50) shifts after a 30-min preincubation with NADPH-fortified HLM of 4.2-, 10-, 2.5-, and 3.2-fold, respectively), whereas lansoprazole and pantoprazole were not MDIs (IC(50) shifts lansoprazole, or pantoprazole, as irreversible (or quasi-irreversible) MDIs of CYP2C19. These results have important implications for the mechanism of the clinical interaction reported between omeprazole and clopidogrel, as well as other CYP2C19 substrates.

Effects of omeprazole and cisapride treatment in Japanese asthmatics with reflux esophagitis

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Katsuya Fujimori

1997-01-01

Full Text Available In the United States and Europe, gastroesophageal reflux (GER is receiving attention as a potential cause of bronchial asthma. Few Japanese case reports have described this relationship. Therefore, we investigated the effect of omeprazole and cisapride on pulmonary function tests, blood gases and home peak expiratory flow rates (PEFR in six Japanese outpatients with asthma and proven GER. After 8 weeks of treatment, reflux esophagitis had improved in all patients. However, the parameters of pulmonary function showed no change other than a significant post- treatment increase in home PEFR (4.4-27.7% in three patients. These results suggest that anti-reflux (omeprazole and cisapride treatment will produce small improvements in the PEFR in some Japanese asthmatics with GER.

Comparison of outcomes twelve years after antireflux surgery or omeprazole maintenance therapy for reflux esophagitis

DEFF Research Database (Denmark)

Lundell, Lars; Miettinen, Pekka; Myrvold, Helge E

2009-01-01

with esophagitis enrolled from outpatient clinics in Nordic countries. Of the 155 patients randomly assigned to each arm of the study, 154 received omeprazole (1 withdrew before therapy began), and 144 received surgery (11 withdrew before surgery). In patients who remained in remission after treatment, post....... Heartburn and regurgitation were significantly more common in patients given omeprazole, whereas dysphagia, rectal flatulence, and the inability to belch or vomit were significantly more common in surgical patients. The therapies were otherwise well-tolerated. CONCLUSIONS: As long-term therapeutic...

Using omeprazole to link the components of the post-prandial alkaline tide in the spiny dogfish, Squalus acanthias.

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Wood, Chris M; Schultz, Aaron G; Munger, R Stephen; Walsh, Patrick J

2009-03-01

After a meal, dogfish exhibit a metabolic alkalosis in the bloodstream and a marked excretion of basic equivalents across the gills to the external seawater. We used the H(+), K(+)-ATPase pump inhibitor omeprazole to determine whether these post-prandial alkaline tide events were linked to secretion of H(+) (accompanied by Cl(-)) in the stomach. Sharks were fitted with indwelling stomach tubes for pretreatment with omeprazole (five doses of 5 mg omeprazole per kilogram over 48 h) or comparable volumes of vehicle (saline containing 2% DMSO) and for sampling of gastric chyme. Fish were then fed an involuntary meal by means of the stomach tube consisting of minced flatfish muscle (2% of body mass) suspended in saline (4% of body mass total volume). Omeprazole pre-treatment delayed the post-prandial acidification of the gastric chyme, slowed the rise in Cl(-) concentration of the chyme and altered the patterns of other ions, indicating inhibition of H(+) and accompanying Cl(-) secretion. Omeprazole also greatly attenuated the rise in arterial pH and bicarbonate concentrations and reduced the net excretion of basic equivalents to the water by 56% over 48 h. Arterial blood CO(2) pressure (Pa(CO(2))) and plasma ions were not substantially altered. These results indicate that elevated gastric H(+) secretion (as HCl) in the digestive process is the major cause of the systemic metabolic alkalosis and the accompanying rise in base excretion across the gills that constitute the alkaline tide in the dogfish.

Disposition of the anti-ulcer medications ranitidine, cimetidine, and omeprazole following administration of multiple doses to exercised Thoroughbred horses.

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Knych, H K; Stanley, S D; Arthur, R M; McKemie, D S

2017-01-01

The use of anti-ulcer medications, such as cimetidine, ranitidine, and omeprazole, is common in performance horses. The use of these drugs is regulated in performance horses, and as such a withdrawal time is necessary prior to competition to avoid a medication violation. To the authors' knowledge, there are no reports in the literature describing repeated oral administrations of these drugs in the horse to determine a regulatory threshold and related withdrawal time recommendations. Therefore, the objective of the current study was to describe the disposition and elimination pharmacokinetics of these anti-ulcer medications following oral administration to provide data upon which appropriate regulatory recommendations can be established. Nine exercised Thoroughbred horses were administered 20 mg/kg BID of cimetidine or 8 mg/kg BID of ranitidine, both for seven doses or 2.28 g of omeprazole SID for four doses. Blood samples were collected, serum drug concentrations were determined, and elimination pharmacokinetic parameters were calculated. The serum elimination half-life was 7.05 ± 1.02, 7.43 ± 0.851 and 3.94 ± 1.04 h for cimetidine, ranitidine, and omeprazole, respectively. Serum cimetidine and ranitidine concentrations were above the LOQ and omeprazole and omeprazole sulfide below the LOQ in all horses studied upon termination of sample collection. © 2016 John Wiley & Sons Ltd.

Perbandingan Efektivitas antara Omeprazol dan Lansoprazol terhadap Perbaikan Kualitas Hidup Penderita Rinosinusitis Kronik Akibat Refluks Laringofaring

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Tantri Kurniawati

2012-09-01

Full Text Available Laryngopharyngeal reflux (LPR is the reflux of gastric acid through the esophagus that reaches laringopharyngeal area. The prevalence of LPR in the range 15–20%, and caused chronic rhinosinusitis (CRS. The incidence of LPR in patients with CRS has ranged between 37–72%. The prevalence of CRS 16,3% in adults and affecting quality of life. Omeprazole and lansoprazole are proton pump inhibitors (PPIs for LPR’s therapy and also a therapy for CRS with LPR as the etiology. This research method was randomized clinical trial with open trial observation, conducted in June to December 2009. Twenty subjects with consecutive sampling method, divided into two groups (with simple randomization, the first group received omeprazole and the other lansoprazole. The subjects conducted complete physical otolaryngology examination, sino-nasal outcome test 20, reflux symptom index and reflux finding score with fiber optic rhinolaryngoscopy. These data was obtained before therapy, after 2 weeks and two months therapy, analyzed with Wilcoxon’s and Mann-Whitney’s test. There was no effectivity difference between omperazole and lansoprazole in reducing the level of severity of LPR (p>0.05, but quality of life improvement was better in lansoprazole than omeprazole group (p<0.05. In conclusion, lansoprazole is more effective than omeprazole in improvement of quality of life in patients with chronic rhinosinusitis caused by LPR

New chromatographic method for separating Omeprazole from its degradation components and the quantitatively determining it in its pharmaceutical products

International Nuclear Information System (INIS)

Touma, M.; Rajab, A.; Seuleiman, M.

2007-01-01

New chromatographic method for Quantitative Determination of Omeprazole in its Pharmaceutical Products was produced. Omeprazole and its degradation components were well separated in same chromatogram by using high perfume liquid chromatography (HPLC). The new analytical method has been validated by these characteristic tests (accuracy, precision, range, linearity, specificity/selectivity, limit of detection (LOD) and limit of quantitative (LOQ) ).(author)

Histopathology of the gastric oxyntic mucosa in two different patient groups during long-term treatment with omeprazole

DEFF Research Database (Denmark)

Hage, Esther; Hendel, Lene; Gustafsen, Jens

2003-01-01

OBJECTIVES: Hypochlorhydria, hypergastrinaemia, inflammation and Helicobacter pylori infection, dose and duration of omeprazole treatment may separately, or in combination, influence the proliferation of enterochromaffin-like (ECL) cells and parietal cell changes in gastric mucosa. To assess the ...... of gastric mucosal inflammation, omeprazole dose, duration of treatment and acid inhibition. The level of gastrin secretion and high plasma gastrin appear to accelerate ECL cell proliferation and parietal cell changes possibly influenced by chronic gastritis and H. pylori infection....

Drug-drug interaction of microdose and regular-dose omeprazole with a CYP2C19 inhibitor and inducer.

Science.gov (United States)

Park, Gab-Jin; Bae, Soo Hyeon; Park, Wan-Su; Han, Seunghoon; Park, Min-Ho; Shin, Seok-Ho; Shin, Young G; Yim, Dong-Seok

2017-01-01

A microdose drug-drug interaction (DDI) study may be a valuable tool for anticipating drug interaction at therapeutic doses. This study aimed to compare the magnitude of DDIs at microdoses and regular doses to explore the applicability of a microdose DDI study. Six healthy male volunteer subjects were enrolled into each DDI study of omeprazole (victim) and known perpetrators: fluconazole (inhibitor) and rifampin (inducer). For both studies, the microdose (100 μg, cold compound) and the regular dose (20 mg) of omeprazole were given at days 0 and 1, respectively. On days 2-9, the inhibitor or inducer was given daily, and the microdose and regular dose of omeprazole were repeated at days 8 and 9, respectively. Full omeprazole pharmacokinetic samplings were performed at days 0, 1, 8, and 9 of both studies for noncompartmental analysis. The magnitude of the DDI, the geometric mean ratios (with perpetrator/omeprazole only) of maximum concentration (C max ) and area under the curve to the last measurement (AUC t ) of the microdose and the regular dose were compared. The geometric mean ratios in the inhibition study were: 2.17 (micro) and 2.68 (regular) for C max , and 4.07 (micro), 4.33 (regular) for AUC t . For the induction study, they were 0.26 (micro) and 0.21 (regular) for C max , and 0.16 (micro) and 0.15 (regular) for AUC t . There were no significant statistical differences in the magnitudes of DDIs between microdose and regular-dose conditions, regardless of induction or inhibition. Our results may be used as partial evidence that microdose DDI studies may replace regular-dose studies, or at least be used for DDI-screening purposes.

Drug–drug interaction of microdose and regular-dose omeprazole with a CYP2C19 inhibitor and inducer

Science.gov (United States)

Park, Gab-jin; Bae, Soo Hyeon; Park, Wan-Su; Han, Seunghoon; Park, Min-Ho; Shin, Seok-Ho; Shin, Young G; Yim, Dong-Seok

2017-01-01

Purpose A microdose drug–drug interaction (DDI) study may be a valuable tool for anticipating drug interaction at therapeutic doses. This study aimed to compare the magnitude of DDIs at microdoses and regular doses to explore the applicability of a microdose DDI study. Patients and methods Six healthy male volunteer subjects were enrolled into each DDI study of omeprazole (victim) and known perpetrators: fluconazole (inhibitor) and rifampin (inducer). For both studies, the microdose (100 μg, cold compound) and the regular dose (20 mg) of omeprazole were given at days 0 and 1, respectively. On days 2–9, the inhibitor or inducer was given daily, and the microdose and regular dose of omeprazole were repeated at days 8 and 9, respectively. Full omeprazole pharmacokinetic samplings were performed at days 0, 1, 8, and 9 of both studies for noncompartmental analysis. Results The magnitude of the DDI, the geometric mean ratios (with perpetrator/omeprazole only) of maximum concentration (Cmax) and area under the curve to the last measurement (AUCt) of the microdose and the regular dose were compared. The geometric mean ratios in the inhibition study were: 2.17 (micro) and 2.68 (regular) for Cmax, and 4.07 (micro), 4.33 (regular) for AUCt. For the induction study, they were 0.26 (micro) and 0.21 (regular) for Cmax, and 0.16 (micro) and 0.15 (regular) for AUCt. There were no significant statistical differences in the magnitudes of DDIs between microdose and regular-dose conditions, regardless of induction or inhibition. Conclusion Our results may be used as partial evidence that microdose DDI studies may replace regular-dose studies, or at least be used for DDI-screening purposes. PMID:28408803

Residual solvent determination by head space gas chromatography with flame ionization detector in omeprazole API

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Saurabh Pandey

2011-06-01

Full Text Available Residual solvents in pharmaceutical samples are monitored using gas chromatography with head space. Based on good manufacturing practices, measuring residual solvents is mandatory for the release testing of all active pharmaceutical ingredients (API. The analysis of residual organic solvents (methanol, acetone, cyclohexane, dichloromethane, toluene in Omeprazole, an active pharmaceutical ingredient was investigated. Omeprazole is a potent reversible inhibitor of the gastric proton pump H+/K+-ATPase. The Head space gas chromatography (HSGC method described in this investigation utilized a SPB TM-624, Supelco, 30 m long x 0.25 mm internal diameter, 1.4µm-thick column. Since Omeprazole is a thermally labile compound, the selection of the proper injector temperature is critical to the success of the analysis. The injector temperature was set at 170ºC to prevent degradation. The initial oven temperature was set at 40ºC for 12 min and programmed at a rate of 10ºC min-1 to a final temperature of 220ºC for 5 min. Nitrogen was used as a carrier gas. The sample solvent selected was N,N-dimethylacetamide. The method was validated to be specific, linear, precise, sensitive, rugged and showed excellent recovery.Solventes residuais em amostras farmacêuticas são monitoradas utilizando-se cromatografia a gás "headspace". Com base nas boas práticas de fabricação, a medida de solventes residuais é obrigatória para o teste de liberação de todos os ingredientes farmacêuticos (API. Efetuou-se a análise de solventes orgânicos residuais (metanol, acetona, cicloexano, diclorometano, tolueno em omeprazol, ingrediente farmacêutico ativo. O omeprazol é potente inibidor reversível da bomba de prótons H+/K+-ATPase. A cromatografia a gás "headspace" (HSGC descrita nessa pesquisa utilizou um SPB TM-624, Supelco, de 30 m de comprimento x 0,25 mm de diâmetro interno, e coluna de 1,4 µm de espessura. Considerando-se que o omeprazol é termicamente l

Comparing omeprazole with fluoxetine for treatment of patients with heartburn and normal endoscopy who failed once daily proton pump inhibitors: double-blind placebo-controlled trial.

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Ostovaneh, M R; Saeidi, B; Hajifathalian, K; Farrokhi-Khajeh-Pasha, Y; Fotouhi, A; Mirbagheri, S S; Emami, H; Barzin, G; Mirbagheri, S A

2014-05-01

Patients with heartburn but without esophageal erosion respond less well to proton pump inhibitors (PPIs). There is a growing body of evidence implicating the role of psychological comorbidities in producing reflux symptoms. Pain modulators improve symptoms in patients with other functional gastrointestinal disorders. We aimed to compare the efficacy of fluoxetine with omeprazole and placebo to achieve symptomatic relief in patients with heartburn and normal endoscopy who failed once daily PPIs. Endoscopy-negative patients with heartburn who failed once daily PPIs were randomly allocated to receive 6 weeks treatment of fluoxetine, omeprazole, or placebo. Random allocation was stratified according to ambulatory pH monitoring study. Percentage of heartburn-free days and symptom severity was assessed. Sixty patients with abnormal and 84 patients with normal pH test were randomized. Subjects receiving fluoxetine experienced more improvement in percentage of heartburn-free days (median 35.7, IQR 21.4-57.1) than those on omeprazole (median 7.14, IQR 0-50, p heartburn-free days (median improvement, 57.1, IQR 35.7-57.1 vs 13.9, IQR, 0-45.6 and 7.14, 0-23.8, respectively, p heartburn and normal endoscopy who failed once daily PPIs. The superiority of fluoxetine was mostly attributed to those with normal esophageal pH rather than those with abnormal pH (ClinicalTrials.gov, number NCT01269788). © 2014 John Wiley & Sons Ltd.

Efeito do omeprazol e do pantoprazol sobre a regeneração hepática após hepatectomia parcial em ratos Effect of omeprazole and pantoprazole on liver regeneration after partial hepatectomy in rats

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Gustavo Barreto de Melo

2003-12-01

Full Text Available OBJETIVO: Avaliar os efeitos do omeprazol e do pantoprazol sobre a regeneração hepática após hepatectomia parcial. MÉTODOS: Cinqüenta e oito ratos Wistar machos foram divididos em 4 grupos: Grupo SHAM, Grupo HP, Grupo PANTO e Grupo OMEP. Eles foram submetidos a hepatectomia parcial de 67% (Grupos HP, PANTO e OMEP ou laparotomia (Grupo SHAM. Os fígados foram removidos 32 e 56 horas após a operação. Depois, os animais foram sacrificados. Em todos os grupos, as substâncias (solução salina, omeprazol e pantoprazol foram aplicadas diariamente a partir do momento em que foram operados até o sacrifício. RESULTADOS: O índice de mitose no Grupo SHAM não foi significativo. Trinta e duas horas após a hepatectomia, a contagem de mitoses foi de 1,2 ± 1,09 para o Grupo HP, 1,2 ± 1,6 para o Grupo OMEP e 2,6 ± 3,2 para o Grupo PANTO. Na análise após 56 horas, os valores foram 1,6 ± 0,89 para o HP, 2 ± 1,8 para o OMEP e 2,6 ± 0,54 para o PANTO. Esses resultados não foram estatisticamente significativos. CONCLUSÃO: O omeprazol e o pantoprazol, agentes inibidores da bomba de prótons (H+, K+-ATPase, não interferem na regeneração hepática 32 e 56 horas após hepatectomia parcial a 67% em ratos.PURPOSE: To assess the effects of omeprazole and pantoprazole on liver regeneration after partial hepatectomy. METHODS: Fifty eight male Wistar rats were divided into 4 groups: SHAM, HP, PANTO and OMEP Groups. They were submitted to 67% partial hepatectomy (HP, PANTO and OMEP Groups or laparotomy (SHAM Group. Their livers were removed 32 and 56 hours after the operation. Then, the animals were sacrificed. In all groups, the substances (saline solution, omeprazole and pantoprazole were injected once daily from the moment they were operated on until the time of sacrifice. RESULTS: In SHAM Group the mitotic index was not significant. Thirty two hours after hepatectomy, the mitosis index was 1.2 ± 1.09 in HP Group, 1.2 ± 1.6 in OMEP Group and 2

Dose-Finding Study of Omeprazole on Gastric pH in Neonates with Gastro-Esophageal Acid Reflux Using a Bayesian Sequential Approach.

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Florentia Kaguelidou

Full Text Available Proton pump inhibitors are frequently administered on clinical symptoms in neonates but benefit remains controversial. Clinical trials validating omeprazole dosage in neonates are limited. The objective of this trial was to determine the minimum effective dose (MED of omeprazole to treat pathological acid reflux in neonates using reflux index as surrogate marker.Double blind dose-finding trial with continual reassessment method of individual dose administration using a Bayesian approach, aiming to select drug dose as close as possible to the predefined target level of efficacy (with a credibility interval of 95%.Neonatal Intensive Care unit of the Robert Debré University Hospital in Paris, France.Neonates with a postmenstrual age ≥ 35 weeks and a pathologic 24-hour intra-esophageal pH monitoring defined by a reflux index ≥ 5% over 24 hours were considered for participation. Recruitment was stratified to 3 groups according to gestational age at birth.Five preselected doses of oral omeprazole from 1 to 3 mg/kg/day.Primary outcome, measured at 35 weeks postmenstrual age or more, was a reflux index <5% during the 24-h pH monitoring registered 72±24 hours after omeprazole initiation.Fifty-four neonates with a reflux index ranging from 5.06 to 27.7% were included. Median age was 37.5 days and median postmenstrual age was 36 weeks. In neonates born at less than 32 weeks of GA (n = 30, the MED was 2.5mg/kg/day with an estimated mean posterior probability of success of 97.7% (95% credibility interval: 90.3-99.7%. The MED was 1mg/kg/day for neonates born at more than 32 GA (n = 24.Omeprazole is extensively prescribed on clinical symptoms but efficacy is not demonstrated while safety concerns do exist. When treatment is required, the daily dose needs to be validated in preterm and term neonates. Optimal doses of omeprazole to increase gastric pH and decrease reflux index below 5% over 24 hours, determined using an adaptive Bayesian design differ

Dose-Finding Study of Omeprazole on Gastric pH in Neonates with Gastro-Esophageal Acid Reflux Using a Bayesian Sequential Approach.

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Kaguelidou, Florentia; Alberti, Corinne; Biran, Valerie; Bourdon, Olivier; Farnoux, Caroline; Zohar, Sarah; Jacqz-Aigrain, Evelyne

2016-01-01

Proton pump inhibitors are frequently administered on clinical symptoms in neonates but benefit remains controversial. Clinical trials validating omeprazole dosage in neonates are limited. The objective of this trial was to determine the minimum effective dose (MED) of omeprazole to treat pathological acid reflux in neonates using reflux index as surrogate marker. Double blind dose-finding trial with continual reassessment method of individual dose administration using a Bayesian approach, aiming to select drug dose as close as possible to the predefined target level of efficacy (with a credibility interval of 95%). Neonatal Intensive Care unit of the Robert Debré University Hospital in Paris, France. Neonates with a postmenstrual age ≥ 35 weeks and a pathologic 24-hour intra-esophageal pH monitoring defined by a reflux index ≥ 5% over 24 hours were considered for participation. Recruitment was stratified to 3 groups according to gestational age at birth. Five preselected doses of oral omeprazole from 1 to 3 mg/kg/day. Primary outcome, measured at 35 weeks postmenstrual age or more, was a reflux index reflux index ranging from 5.06 to 27.7% were included. Median age was 37.5 days and median postmenstrual age was 36 weeks. In neonates born at less than 32 weeks of GA (n = 30), the MED was 2.5mg/kg/day with an estimated mean posterior probability of success of 97.7% (95% credibility interval: 90.3-99.7%). The MED was 1mg/kg/day for neonates born at more than 32 GA (n = 24). Omeprazole is extensively prescribed on clinical symptoms but efficacy is not demonstrated while safety concerns do exist. When treatment is required, the daily dose needs to be validated in preterm and term neonates. Optimal doses of omeprazole to increase gastric pH and decrease reflux index below 5% over 24 hours, determined using an adaptive Bayesian design differ among neonates. Both gestational and postnatal ages account for these differences but their differential impact on omeprazole

Características de las dispensaciones de omeprazol en una farmacia comunitaria

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Ezquieta MF

2010-06-01

Full Text Available INTRODUCCIÓN Omeprazol es uno de los principios que más se dispensa en la farmacia comunitaria. Pertenece al grupo de los inhibidores de la bomba de protones (IBP y actúa inhibiendo la secreción de H+ al estómago, disminuyendo en consecuencia los síntomas derivados de una excesiva acidez gástrica. OBJETIVOS Estudiar las características de la utilización de omeprazol 20 mg por los pacientes en una farmacia comunitaria, tratando de investigar las causas de la elevada prevalencia de uso de este medicamento entre dicha población. RESULTADOS La primera prescripción fue del médico de familia en un 59% de los casos y del especialista en el 41%. Un 61% de los pacientes dejó de tomarlo y tuvo que volver por sentir molestias gástricas. Un 44% no sabe hasta cuándo tiene que tomarlo y un 35% cree que debe tomarlo siempre. Un 55% lo toma por estar tomando al mismo tiempo un AINE. DISCUSIÓN Este estudio se encuentra limitado por el reducido número de encuestas en una sola farmacia comunitaria. Los resultados apuntan a que las causas de la elevada utilización de omeprazol pueden ser varias: el uso de AINE durante largos periodos de tiempo en dosis elevadas, el envejecimiento de la población que necesita utilizar un AINE como antiagregante o toma varios medicamentos, el uso en indicaciones poco precisas o el empleo para afecciones gástricas menores y la gastroprotección en pacientes polimedicados sin factores de riesgo. Otro factor que también podría influir es el posible rebote ácido tras la supresión del tratamiento, que deriva en la utilización crónica del medicamento.

Histamine stimulates chloride secretion in omeprazole-inhibited frog gastric mucosa

International Nuclear Information System (INIS)

McGreevy, J.; Barton, R.; Housinger, T.

1986-01-01

Omeprazole (OME) stops hydrogen ion (H) secretion in the histamine (HIST)-stimulated gastric mucosa while the chloride (Cl) which had accompanied the H continues to be pumped into the lumen. This finding suggests that the Cl pump is independent of the H/K ATP-ase driven H pump. To test this hypothesis, 16 Ussing-chambered frog mucosas were exposed to OME prior to HIST stimulation. If the Cl pump is independent, HIST should stimulate Cl secretion in the OME-inhibited mucosa. A 1 hr control (CON) interval preceded exposure to OME (10 -4 M) in the nutrient solution. Potential difference (PD), short-circuit current (Isc), resistance (R), H flux (J/sup H/) and Cl flux (J/sup Cl/ with 36 Cl) were measured every 15 min. After 1 hr of OME exposure, HIST (10 -5 M) was added to the nutrient solution. The findings demonstrate that HIST stimulates Cl secretion in the OME-inhibited bullfrog gastric mucosa

The anti-secretory and anti-ulcer activities of esomeprazole in comparison with omeprazole in the stomach of rats and rabbits.

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Bastaki, Salim M A; Chandranath, Irwin S; Singh, Jaipaul

2008-02-01

Proton pump inhibitors (PPIs) are widely used to treat hyperacid secretion and stomach ulcers. The study investigated the anti-secretory and anti-ulcer effects of esomeprazole, the S-isomer of omeprazole on dimaprit, histamine and dibutyryl adenosine 3, 5 cyclic monophosphate (dbcAMP)-evoked gastric acid secretion, acidified ethanol (AE) and indomethacin (INDO)-induced haemorrhagic lesions and on prostaglandin E2 (PGE2) level in the rat in vivo and rabbit in vitro preparations. The effect of omeprazole was also investigated for comparison. Dimaprit-induced acid secretion was significantly (P stomach tissue homogenate. The results show that esomeprazole and omeprazole were equally effective against gastric haemorrhagic lesions induced by either AE or INDO and in inhibiting dimaprit-, dbcAMP- and histamine-induced gastric acid secretion in the rat and rabbit stomach both in vivo and in vitro. The gastro-protective effect of esomeprazole was found to be proportional to the bound PGE2 levels in the glandular area of the stomach.

Occurrence of ventilator-associated pneumonia in mechanically ventilated pediatric intensive care patients during stress ulcer prophylaxis with sucralfate, ranitidine, and omeprazole.

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Yildizdas, Dincer; Yapicioglu, Hacer; Yilmaz, Hayri Levent

2002-12-01

The purpose of the study was to evaluate the effects of sucralfate, ranitidine, and omeprazole use on incidence of ventilatory-associated pneumonia (VAP) and mortality in ventilated pediatric critical care patients. This prospective study was conducted at the pediatric intensive care unit (PICU) between August 2000 and February 2002. A total of 160 patients who needed mechanical ventilation were randomized into 4 groups according to the computer-generated random number table: group (S), (n = 38) received sucralfate suspension 60 mg/kg/d in 4 doses via the nasogastric tube that was flushed with 10 mL of sterile water; group (R), (n = 42) received ranitidine 2 mg/kg/d intravenously in 4 doses; group (O), (n = 38) received omeprazole 1 mg/kg/d intravenously in 2 doses; and group (P), (n = 42) did not receive any medication for stress ulcer prophylaxis. Treatment was begun within 6 hours of PICU admission. Seventy patients (44%) developed VAP. VAP rate was 42% (16 of 38) in the sucralfate group, 48% (20 of 42) in the ranitidine group, 45% (17 of 38) in the omeprazole group, and 41% (17 of 42) in the nontreated group. Overall mortality rate was 22% (35 of 160); it was 21% (8 of 38) in the sucralfate group, 23% (10 of 42) in the ranitidine group, 21% (8 of 38) in the omeprazole group, and 21% (9 of 42) in the nontreated group. Our results did not show any difference in the incidence of VAP and mortality in mechanically ventilated PICU patients treated with ranitidine, omeprazole, or sucralfate, or nontreated subjects (P =.963, confidence interval [CI] = 0.958-0.968; P =.988, CI = 0.985-0.991, respectively). Nine patients (5.6%) had macroscopic bleeding. There was no statistically significant difference in macroscopic bleeding between groups. Our results did not show any difference in the incidence of VAP, macroscopic stress ulcer bleeding, and mortality in the mechanically ventilated PICU patients treated with ranitidine, omeprazole, or sucralfate, or nontreated subjects

Drug–drug interaction of microdose and regular-dose omeprazole with a CYP2C19 inhibitor and inducer

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Park G

2017-03-01

Full Text Available Gab-jin Park,1 Soo Hyeon Bae,1 Wan-Su Park,1 Seunghoon Han,1 Min-Ho Park,2 Seok-Ho Shin,2 Young G Shin,2 Dong-Seok Yim1,2 1Department of Clinical Pharmacology and Therapeutics, Seoul St Mary’s Hospital, PIPET (Pharmacometrics Institute for Practical Education and Training, College of Medicine, Catholic University of Korea, Seoul, South Korea; 2College of Pharmacy, Chungnam National University, Daejeon, South Korea Purpose: A microdose drug–drug interaction (DDI study may be a valuable tool for anticipating drug interaction at therapeutic doses. This study aimed to compare the magnitude of DDIs at microdoses and regular doses to explore the applicability of a microdose DDI study. Patients and methods: Six healthy male volunteer subjects were enrolled into each DDI study of omeprazole (victim and known perpetrators: fluconazole (inhibitor and rifampin (inducer. For both studies, the microdose (100 µg, cold compound and the regular dose (20 mg of omeprazole were given at days 0 and 1, respectively. On days 2–9, the inhibitor or inducer was given daily, and the microdose and regular dose of omeprazole were repeated at days 8 and 9, respectively. Full omeprazole pharmacokinetic samplings were performed at days 0, 1, 8, and 9 of both studies for noncompartmental analysis. Results: The magnitude of the DDI, the geometric mean ratios (with perpetrator/omeprazole only of maximum concentration (Cmax and area under the curve to the last measurement (AUCt of the microdose and the regular dose were compared. The geometric mean ratios in the inhibition study were: 2.17 (micro and 2.68 (regular for Cmax, and 4.07 (micro, 4.33 (regular for AUCt. For the induction study, they were 0.26 (micro and 0.21 (regular for Cmax, and 0.16 (micro and 0.15 (regular for AUCt. There were no significant statistical differences in the magnitudes of DDIs between microdose and regular-dose conditions, regardless of induction or inhibition. Conclusion: Our results may be

A Novel Method for Pain Relief in Chronic Pancreatitis: an Old Drug in a New Pack: a Controlled Study.

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Pujahari, Aswini Kumar

2017-12-01

Most of pain-relieving agents in chronic pancreatitis are nonspecific and unpredictable. Omeprazole induces hypergastrinemia due to reduced gastric acidity. Raised serum gastrin, in turn, modulates to reduce secretin level. Secretin is responsible for secretion of almost 80 % bicarbonate-rich pancreatic juice from the ductular epithelium without affecting enzyme output. It is a prospective randomized study in patients with CT-confirmed chronic pancreatitis. The control group got the standard care and 60 mg of omeprazole twice daily was added to the test group. Absence of pain relief at 14 days was considered as failure. Pain relief, weight gain and any toxic effect of omeprazole were reviewed at 12 months. One hundred thirty-seven cases were included, with an age range of 19 to 72 years. (mean 42.67). The majority of them were alcoholic males. At 2 weeks, pain relief was noted in 47/69(68.1 %) and 63/65(96.96 %) in the control and omeprazole group, respectively. At the end of 1 year, the omeprazole group had greater weight gain (95 %) than the control group (69.5 %). All the pseudocysts in the omeprazole group and most in the control group resolved. No side effect of omeprazole was seen. The high-dose omeprazole (HDO) group of patients had significantly better pain relief in chronic pancreatitis than those treated with conventional therapy. A high number of cases gained weight in the HDO group than the controlled group. No patient had clinical, endoscopic, biochemical, or haematological toxicity of HDO. More studies are necessary.

Thermodynamic models for determination of the solubility of omeprazole in pure and mixture organic solvents from T = (278.15 to 333.15) K

International Nuclear Information System (INIS)

Hu, Yonghong; Wu, Gang; Gu, Pengfei; Yang, Wenge; Wang, Chunxiao; Ding, Zhiwen; Cao, Yang

2016-01-01

Highlights: • The solubility increased with increasing temperature. • The data were fitted using the modified Apelblat equation and other models. • The Gibbs energy, enthalpy and entropy were calculated by the van’t Hoff analysis. - Abstract: Data on corresponding (solid + liquid) equilibrium of omeprazole in different solvents are essential for a preliminary study of industrial applications. In this paper, the (solid + liquid) equilibrium of omeprazole in water, methanol, ethanol, 1-butanol, acetonitrile, acetone, ethyl acetate, tetrahydrofuran pure solvents and (tetrahydrofuran + ethyl acetate) mixture solvents were explored within the temperatures from 278.15 K to 333.15 K under atmosphere pressure. For the temperature range investigated, the solubility of omeprazole in the solvents increased with increasing temperature. From (278.15 to 333.15) K, the solubility of omeprazole in tetrahydrofuran is superior to other selected pure solvents. The modified Apelblat model, the Buchowski–Ksiazaczak λh model, and the ideal model were adopted to describe and predict the change tendency of solubility. Computational results showed that the modified Apelblat model has advantages than the other two models. Numerical values of the solubility were fitted using a modified Apelblat equation, a variant of the combined nearly ideal binary solvent/Redich–Kister (CNIBS/R–K) model and Jouyban–Acree model in (tetrahydrofuran + ethyl acetate) binary solvent mixture. Computational results showed that the CNIBS/R–K model is superior to the other equations. In addition, the calculated thermodynamic parameters indicate that in each solvent studied the dissolution of omeprazole is endothermic, non-spontaneous and is an entropy-driven process.

A phase 1 randomized study evaluating the effect of omeprazole on the pharmacokinetics of a novel 5-hydroxytryptamine receptor 4 agonist, revexepride (SSP-002358), in healthy adults

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Pierce, David; Corcoran, Mary; Velinova, Maria; Hossack, Stuart; Hoppenbrouwers, Mieke; Martin, Patrick

2015-01-01

Background About 30% of patients with gastroesophageal reflux disease continue to experience symptoms despite treatment with proton pump inhibitors. The 5-hydroxytryptamine 4 receptor agonist revexepride (SSP-002358) is a novel prokinetic that stimulates gastrointestinal motility, which has been suggested as a continued cause of symptoms in these patients. The aim of this study was to assess whether revexepride pharmacokinetics were affected by co-administration of omeprazole, in preparation for a proof-of-concept evaluation of revexepride added to proton pump inhibitor treatment. Methods In this phase 1, open-label, randomized, two-period crossover study, healthy adults aged 18–55 years were given a single dose of revexepride 1 mg or revexepride 1 mg + omeprazole 40 mg. Pharmacokinetic parameters were assessed for up to 48 hours after administration of the investigational product. Adverse events, clinical chemistry and hematology parameters, electrocardiograms, and vital signs were monitored. Results In total, 42 participants were enrolled and 40 completed the study. The median age was 24 years (18–54 years), 55% were women and 93% were white. The pharmacokinetic parameters of revexepride were similar without or with omeprazole co-administration. The mean area under the plasma concentration–time curve from time 0 to infinity (AUC0–∞) was 23.3 ng · h/mL (standard deviation [SD]: 6.33 ng · h/mL) versus 24.6 ng · h/mL (SD: 6.31 ng · h/mL), and maximum plasma concentrations (Cmax) were 3.89 ng/mL (SD: 1.30 ng/mL) and 4.12 ng/mL (SD: 1.29 ng/mL) in participants without and with omeprazole, respectively. For AUC0–∞ and Cmax, the 90% confidence intervals for the ratios of geometric least-squares means (with:without omeprazole) were fully contained within the pre-defined equivalence limits of 0.80–1.25. Mean apparent terminal phase half-life was 9.95 hours (SD: 2.06 hours) without omeprazole, and 11.0 hours (SD: 3.25 hours) with omeprazole. Conclusion

Enantioselective endocrine disrupting effects of omeprazole studied in the H295R cell assay and by molecular modeling

DEFF Research Database (Denmark)

Sørensen, Amalie Møller; Hansen, Cecilie Hurup; Bonomo, Silvia

2016-01-01

) and its two enantiomers on the human steroidogenesis using the H295R cell line. Differences in production of 16 steroid hormones were analyzed using LC-MS/MS. Additionally, to evaluate the differences in binding modes of these enantiomers, docking and molecular dynamics (MD) simulations of S-omeprazole (S......-OME) and R-omeprazole (R-OME) in CYP17A1, CYP19A1 and CYP21A2 were carried out. Exposing H295R cells to OME and its enantiomers resulted in an increase of progesterone (PRO) and 17α-hydroxy-progesterone (OH-PRO) levels. At the same time, a decrease in the corticosteroid and androgen synthesis was observed...

Omeprazole induces heme oxygenase-1 in fetal human pulmonary microvascular endothelial cells via hydrogen peroxide-independent Nrf2 signaling pathway

International Nuclear Information System (INIS)

Patel, Ananddeep; Zhang, Shaojie; Shrestha, Amrit Kumar; Maturu, Paramahamsa; Moorthy, Bhagavatula; Shivanna, Binoy

2016-01-01

Omeprazole (OM) is an aryl hydrocarbon receptor (AhR) agonist and a proton pump inhibitor that is used to treat humans with gastric acid related disorders. Recently, we showed that OM induces NAD (P) H quinone oxidoreductase-1 (NQO1) via nuclear factor erythroid 2-related factor 2 (Nrf2)-dependent mechanism. Heme oxygenase-1 (HO-1) is another cytoprotective and antioxidant enzyme that is regulated by Nrf2. Whether OM induces HO-1 in fetal human pulmonary microvascular endothelial cells (HPMEC) is unknown. Therefore, we tested the hypothesis that OM will induce HO-1 expression via Nrf2 in HPMEC. OM induced HO-1 mRNA and protein expression in a dose-dependent manner. siRNA-mediated knockdown of AhR failed to abrogate, whereas knockdown of Nrf2 abrogated HO-1 induction by OM. To identify the underlying molecular mechanisms, we determined the effects of OM on cellular hydrogen peroxide (H 2 O 2 ) levels since oxidative stress mediated by the latter is known to activate Nrf2. Interestingly, the concentration at which OM induced HO-1 also increased H 2 O 2 levels. Furthermore, H 2 O 2 independently augmented HO-1 expression. Although N-acetyl cysteine (NAC) significantly decreased H 2 O 2 levels in OM-treated cells, we observed that OM further increased HO-1 mRNA and protein expression in NAC-pretreated compared to vehicle-pretreated cells, suggesting that OM induces HO-1 via H 2 O 2 -independent mechanisms. In conclusion, we provide evidence that OM transcriptionally induces HO-1 via AhR - and H 2 O 2 - independent, but Nrf2 - dependent mechanisms. These results have important implications for human disorders where Nrf2 and HO-1 play a beneficial role. - Highlights: • Omeprazole induces HO-1 in human fetal lung cells. • AhR deficiency fails to abrogate omeprazole-mediated induction of HO-1. • Nrf2 knockdown abrogates omeprazole-mediated HO-1 induction in human lung cells. • Hydrogen peroxide depletion augments omeprazole-mediated induction of HO-1.

A phase 1 randomized study evaluating the effect of omeprazole on the pharmacokinetics of a novel 5-hydroxytryptamine receptor 4 agonist, revexepride (SSP-002358, in healthy adults

Directory of Open Access Journals (Sweden)

Pierce D

2015-02-01

Full Text Available David Pierce,1 Mary Corcoran,2 Maria Velinova,3 Stuart Hossack,4 Mieke Hoppenbrouwers,5 Patrick Martin,21Shire, Basingstoke, UK; 2Shire, Wayne, PA, USA; 3PRA International, Zuidlaren, the Netherlands; 4Covance, Leeds, UK; 5Shire-Movetis NV, Turnhout, BelgiumBackground: About 30% of patients with gastroesophageal reflux disease continue to experience symptoms despite treatment with proton pump inhibitors. The 5-hydroxytryptamine 4 receptor agonist revexepride (SSP-002358 is a novel prokinetic that stimulates gastrointestinal motility, which has been suggested as a continued cause of symptoms in these patients. The aim of this study was to assess whether revexepride pharmacokinetics were affected by co-administration of omeprazole, in preparation for a proof-of-concept evaluation of revexepride added to proton pump inhibitor treatment.Methods: In this phase 1, open-label, randomized, two-period crossover study, healthy adults aged 18–55 years were given a single dose of revexepride 1 mg or revexepride 1 mg + omeprazole 40 mg. Pharmacokinetic parameters were assessed for up to 48 hours after administration of the investigational product. Adverse events, clinical chemistry and hematology parameters, electrocardiograms, and vital signs were monitored.Results: In total, 42 participants were enrolled and 40 completed the study. The median age was 24 years (18–54 years, 55% were women and 93% were white. The pharmacokinetic parameters of revexepride were similar without or with omeprazole co-administration. The mean area under the plasma concentration–time curve from time 0 to infinity (AUC0–∞ was 23.3 ng · h/mL (standard deviation [SD]: 6.33 ng · h/mL versus 24.6 ng · h/mL (SD: 6.31 ng · h/mL, and maximum plasma concentrations (Cmax were 3.89 ng/mL (SD: 1.30 ng/mL and 4.12 ng/mL (SD: 1.29 ng/mL in participants without and with omeprazole, respectively. For AUC0–∞ and Cmax, the 90% confidence intervals for the ratios of geometric least

Omeprazole induces heme oxygenase-1 in fetal human pulmonary microvascular endothelial cells via hydrogen peroxide-independent Nrf2 signaling pathway

Energy Technology Data Exchange (ETDEWEB)

Patel, Ananddeep; Zhang, Shaojie; Shrestha, Amrit Kumar; Maturu, Paramahamsa; Moorthy, Bhagavatula; Shivanna, Binoy, E-mail: shivanna@bcm.edu

2016-11-15

Omeprazole (OM) is an aryl hydrocarbon receptor (AhR) agonist and a proton pump inhibitor that is used to treat humans with gastric acid related disorders. Recently, we showed that OM induces NAD (P) H quinone oxidoreductase-1 (NQO1) via nuclear factor erythroid 2-related factor 2 (Nrf2)-dependent mechanism. Heme oxygenase-1 (HO-1) is another cytoprotective and antioxidant enzyme that is regulated by Nrf2. Whether OM induces HO-1 in fetal human pulmonary microvascular endothelial cells (HPMEC) is unknown. Therefore, we tested the hypothesis that OM will induce HO-1 expression via Nrf2 in HPMEC. OM induced HO-1 mRNA and protein expression in a dose-dependent manner. siRNA-mediated knockdown of AhR failed to abrogate, whereas knockdown of Nrf2 abrogated HO-1 induction by OM. To identify the underlying molecular mechanisms, we determined the effects of OM on cellular hydrogen peroxide (H{sub 2}O{sub 2}) levels since oxidative stress mediated by the latter is known to activate Nrf2. Interestingly, the concentration at which OM induced HO-1 also increased H{sub 2}O{sub 2} levels. Furthermore, H{sub 2}O{sub 2} independently augmented HO-1 expression. Although N-acetyl cysteine (NAC) significantly decreased H{sub 2}O{sub 2} levels in OM-treated cells, we observed that OM further increased HO-1 mRNA and protein expression in NAC-pretreated compared to vehicle-pretreated cells, suggesting that OM induces HO-1 via H{sub 2}O{sub 2}-independent mechanisms. In conclusion, we provide evidence that OM transcriptionally induces HO-1 via AhR - and H{sub 2}O{sub 2} - independent, but Nrf2 - dependent mechanisms. These results have important implications for human disorders where Nrf2 and HO-1 play a beneficial role. - Highlights: • Omeprazole induces HO-1 in human fetal lung cells. • AhR deficiency fails to abrogate omeprazole-mediated induction of HO-1. • Nrf2 knockdown abrogates omeprazole-mediated HO-1 induction in human lung cells. • Hydrogen peroxide depletion augments

Neutron activation analysis of chemical impurities in manipulated samples of omeprazole

International Nuclear Information System (INIS)

Sepe, Fernanda Peixoto; Leal, Alexandre Soares; Gomes, Tatiana Cristina Bomfim; Menezes, Maria Angela de Barros Correia; Silva, Maria Aparecida

2011-01-01

In this work, samples of Omeprazole (C 17 H 19 N 3 O 3 S), a largely used drug in the treatment of dyspepsia and peptic ulcer, were acquired from five different pharmacies of manipulation - or retail pharmacies which prepare personalized drugs under medical recommendation - in Belo Horizonte/Brazil and investigated using the k 0 - Neutron Activation Analysis (NAA). The preliminary results showed the presence of elements not foreseen in the original formula. It confirms the potential risk offered by medicines without suitable inspection. (author)

Development and validation of new analytical methods for simultaneous estimation of Drotaverine hydrochloride in combination with Omeprazole in a pharmaceutical dosage form

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Smita Sharma

2017-02-01

Full Text Available A rapid and precise method (in accordance with ICH guidelines is developed for the quantitative simultaneous determination of Drotaverine hydrochloride and Omeprazole in a combined pharmaceutical dosage form. Three methods are described for the simultaneous determination of Drotaverine hydrochloride and Omeprazole in a binary mixture. The first method was based on UV-Spectrophotometric determination of two drugs, using Vierordt!s simultaneous equation method. It involves absorbance measurement at 226.8 nm (λmax of Drotaverine hydrochloride and 269.4 nm (λmax of Omeprazole in methanol; linearity was obtained in the range of 5–30 μg ml−1 for both the drugs. The second method was based on HPLC separation of the two drugs using potassium dihydrogen phosphate buffer pH 5.0: Acetonitrile: Triethylamine (60:40:0.5, v/v as a mobile phase. Areas were recorded at 260 nm for both the drugs and retention time was found to be 2.71 min. and 3.87 min for Drotaverine hydrochloride and Omeprazole, respectively at 1.0 mL/min flow rate. The selected chromatographic conditions were found to determine Drotaverine hydrochloride and Omeprazole quantitatively in a combined dosage form without any physical separation. The method has been validated for linearity, accuracy and precision. Linearity was found over the range of 5–30 μg mL−1 for both drugs. The third method was based on HPTLC method for simultaneous quantification of these compounds in pharmaceutical dosage forms. Precoated silica gel 60 F254 plate was used as stationary phase. The separation was carried out using Glacial acetic acid:Cyclohexane:Methanol:(80:15:5 v/v/v as mobile phase. The proposed method was found to be fast, accurate, precise, reproducible and rugged and can be used for a simultaneous analysis of these drugs in combined formulations.

A Phase 1 Pharmacokinetic Study of Cysteamine Bitartrate Delayed-Release Capsules Following Oral Administration with Orange Juice, Water, or Omeprazole in Cystinosis.

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Armas, Danielle; Holt, Robert J; Confer, Nils F; Checani, Gregg C; Obaidi, Mohammad; Xie, Yuli; Brannagan, Meg

2018-02-01

Cystinosis is a rare, metabolic, autosomal recessive, genetic lysosomal storage disorder characterized by an accumulation of cystine in various organs and tissues. Cysteamine bitartrate (CB) is a cystine-depleting aminothiol agent approved in the United States and Europe in immediate-release and delayed-release (DR) formulations for the treatment of nephropathic cystinosis in children and adults. It is recommended that CBDR be administered with fruit juice (except grapefruit juice) for maximum absorption. Omeprazole is a proton pump inhibitor that inhibits gastric acid secretion and, theoretically, may cause the premature release of cysteamine by increasing intragastric pH, thereby affecting the PK of CBDR. This open-label, three-period, randomized study in healthy adult subjects was designed primarily to compare the pharmacokinetics of CBDR capsules after a single oral dose administered with orange juice, water, or multiple oral doses of omeprazole with water at steady state. A total of 32 subjects were randomly assigned to receive study agents in one of two treatment sequences. All subjects completed the study and baseline characteristics of the overall population and the two treatment sequence populations were similar. Peak mean plasma cysteamine concentrations following co-administration of CBDR capsules with orange juice (1892 ng/mL) were higher compared with co-administration with water (1663 ng/mL) or omeprazole 20 mg and water (1712 ng/mL). Mean time to peak plasma concentration was shorter with omeprazole co-administration (2.5 h) compared with orange juice (3.5 h) or water (3.0 h). Statistical comparisons between treatment groups indicated that exposure as assessed by AUC 0-t , AUC 0-∞ , and C max were all within the 80-125% bioequivalence ranges for all comparisons. All treatments were generally well tolerated. Overall, the pharmacokinetics of cysteamine bitartrate DR capsules are not significantly impacted by co-administration with orange juice

Neutron activation analysis of chemical impurities in manipulated samples of omeprazole

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Sepe, Fernanda Peixoto; Leal, Alexandre Soares; Gomes, Tatiana Cristina Bomfim; Menezes, Maria Angela de Barros Correia; Silva, Maria Aparecida, E-mail: asleal@cdtn.br [Nuclear Technology Development Centre/Brazilian Commission for Nuclear Energy (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

2011-07-01

In this work, samples of Omeprazole (C{sub 17}H{sub 19}N{sub 3}O{sub 3}S), a largely used drug in the treatment of dyspepsia and peptic ulcer, were acquired from five different pharmacies of manipulation - or retail pharmacies which prepare personalized drugs under medical recommendation - in Belo Horizonte/Brazil and investigated using the k{sub 0} - Neutron Activation Analysis (NAA). The preliminary results showed the presence of elements not foreseen in the original formula. It confirms the potential risk offered by medicines without suitable inspection. (author)

Omeprazole induces NAD(P)H quinone oxidoreductase 1 via aryl hydrocarbon receptor-independent mechanisms: Role of the transcription factor nuclear factor erythroid 2–related factor 2

Energy Technology Data Exchange (ETDEWEB)

Zhang, Shaojie; Patel, Ananddeep; Moorthy, Bhagavatula; Shivanna, Binoy, E-mail: shivanna@bcm.edu

2015-11-13

Activation of the aryl hydrocarbon receptor (AhR) transcriptionally induces phase I (cytochrome P450 (CYP) 1A1) and phase II (NAD(P)H quinone oxidoreductase 1 (NQO1) detoxifying enzymes. The effects of the classical and nonclassical AhR ligands on phase I and II enzymes are well studied in human hepatocytes. Additionally, we observed that the proton pump inhibitor, omeprazole (OM), transcriptionally induces CYP1A1 in the human adenocarcinoma cell line, H441 cells via AhR. Whether OM activates AhR and induces the phase II enzyme, NAD(P)H quinone oxidoreductase 1 (NQO1), in fetal primary human pulmonary microvascular endothelial cells (HPMEC) is unknown. Therefore, we tested the hypothesis that OM will induce NQO1 in HPMEC via the AhR. The concentrations of OM used in our experiments did not result in cytotoxicity. OM activated AhR as evident by increased CYP1A1 mRNA expression. However, contrary to our hypothesis, OM increased NQO1 mRNA and protein via an AhR-independent mechanism as AhR knockdown failed to abrogate OM-mediated increase in NQO1 expression. Interestingly, OM activated Nrf2 as evident by increased phosphoNrf2 (S40) expression in OM-treated compared to vehicle-treated cells. Furthermore, Nrf2 knockdown abrogated OM-mediated increase in NQO1 expression. In conclusion, we provide evidence that OM induces NQO1 via AhR-independent, but Nrf2-dependent mechanisms. - Highlights: • We investigated whether omeprazole induces NQO1 in human fetal lung cells. • Omeprazole induces the phase II enzyme, NQO1, in human fetal lung cells. • AhR deficiency fails to abrogate omeprazole-mediated induction of NQO1. • Omeprazole increases phosphoNrf2 (S40) protein expression in human fetal lung cells. • Nrf2 knockdown abrogates the induction of NQO1 by omeprazole in human lung cells.

Proteção da recuperação funcional do miocárdio pelo omeprazol após isquemia-reperfusão em corações isolados de ratos Myocardium functional recovery protection by omeprazole after ischemia-reperfusion in isolated rat hearts

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Otoni Moreira Gomes

2010-09-01

ischemia period induction. The following parameters were registered after the stabilization period (t0, and after the reperfusion period (t30: heart rate (HR, coronary flow (CoF, systolic pressure (SP, +dP/dt and -dP/dt. The Kruskal-Wallis test (P0.05 between groups among HR and CoF values. Differences (P<0.05 occurred between groups, I e II after the reperfusion period (t30 regarding systolic pressure reduced for 28.0±3.6% in the control group GI and for 79.0±5.9% in GII; The +dP/dtmax declined to be only 31.0±5.6% in GI, preserving 99.4±11.2% values in GII (P<0.05. The t30 -dP/dtmax values were GI 26.0±7.3% and GII 82.0±2.2% (P<0.05. CONCLUSION: The omeprazole administration before ischemia induction significantly protected the myocardium function recovery.

Control rod position control device

International Nuclear Information System (INIS)

Ubukata, Shinji.

1997-01-01

The present invention provides a control rod position control device which stores data such as of position signals and driving control rod instruction before and after occurrence of abnormality in control for the control rod position for controlling reactor power and utilized the data effectively for investigating the cause of abnormality. Namely, a plurality of individual control devices have an operation mismatching detection circuit for outputting signals when difference is caused between a driving instruction given to the control rod position control device and the control rod driving means and signals from a detection means for detecting an actual moving amount. A general control device collectively controls the individual control devices. In addition, there is also disposed a position storing circuit for storing position signals at least before and after the occurrence of the control rod operation mismatching. With such procedures, the cause of the abnormality can be determined based on the position signals before and after the occurrence of control rod mismatching operation stored in the position storing circuit. Accordingly, the abnormality cause can be determined to conduct restoration in an early stage. (I.S.)

Twice-daily dosing of esomeprazole effectively inhibits acid secretion in CYP2C19 rapid metabolisers compared with twice-daily omeprazole, rabeprazole or lansoprazole.

Science.gov (United States)

Sahara, S; Sugimoto, M; Uotani, T; Ichikawa, H; Yamade, M; Iwaizumi, M; Yamada, T; Osawa, S; Sugimoto, K; Umemura, K; Miyajima, H; Furuta, T

2013-11-01

Twice-daily dosing of proton pump inhibitors (PPIs) is used to treat Helicobacter pylori or acid-related diseases, such as gastro-oesophageal reflux disease (GERD) refractory to standard dose of a PPI. Genetic polymorphisms of CYP2C19 are involved to different extents in the metabolism of four kinds of PPIs (omeprazole, lansoprazole, rabeprazole and esomeprazole) available in Japan. To compare acid-inhibitory effects of the four PPIs dosed twice daily in relation to CYP2C19 genotype. We performed 24-h pH monitoring studies on Day 7 of PPI treatment for 40 Japanese H. pylori-negative volunteers [15 CYP2C19 rapid metabolisers (RMs), 15 intermediate metabolisers (IMs) and 10 poor metabolisers (PMs)] using a randomised four-way crossover design: omeprazole 20 mg, esomeprazole 20 mg, lansoprazole 30 mg and rabeprazole 10 mg twice daily. Although median pH values with esomeprazole, omeprazole, lansoprazole and rabeprazole were 5.7 (3.5-7.2), 5.5 (2.4-7.2), 5.5 (3.7-7.3) and 5.2 (2.5-7.3), respectively (no statistically significant differences), CYP2C19 genotype-dependent differences were smaller for esomeprazole and rabeprazole compared with values for omeprazole and lansoprazole. In CYP2C19 RMs, the median pH with esomeprazole [5.4 (3.5-6.8)] was significantly higher than those with omeprazole [5.0 (2.4-5.9), P = 0.018], lansoprazole [4.7 (3.7-5.5), P = 0.017] or rabeprazole [4.8 (2.5-6.4), P = 0.002]. In IMs and PMs, the median pH was >5.0 independent of the PPI. In intermediate and rapid metabolisers of CYP2C19, PPIs dosed twice daily could attain sufficient acid suppression, while in CYP2C19 RMs, esomeprazole 20 mg twice daily caused the strongest inhibition of the four PPIs. Therefore, esomeprazole may be effective in Japanese population when dosed twice daily. © 2013 John Wiley & Sons Ltd.

Omeprazole and misoprostol for preventing gastric mucosa effects caused by indomethacin and celecoxib in rats Omeprazol e misoprostol na prevenção de lesões de mucosa gástrica causadas por indometacina e celecoxib em ratos

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Míriam Elias Cavallini

2006-06-01

Full Text Available PURPOSE: To evaluate and to compare macro and microscopically the intense injuries of the gastric mucosa of rats which were caused by NSAIDS celecoxib and indomethacin and the gastric cytoprotection with omeprazole and misoprostol. METHODS: The sample is formed by one hundred and fifty Wistar rats with average weight 200 g, distributed in four groups, such as: Group A, subdivided in groups A1 and A2 - pre-treatment with omeprazole (20 mg/rat during seven days and on the 8th day - use of NSAIDS, concerning A1 (20 rats were given celecoxib (1mg/rat and A2 (20 rats were given indomethacin. The Group B, subdivided in group B1 and B2 - pre-treatment with misoprostol (20mg/rat during seven days and on the 8th day use of NSAIDS, concerning B1 (20 rats were given celecoxib (1 mg/ rat and B2 (20 rats were given indomethacin (12.5 mg/rat. The Group C: were not given cytoprotection during seven days, from the 7th to the 8th day - fast of food and water ad libitum, on the 8th day of NSAIDS use, concerning C1 (20 rats were given celecoxib, C2 (20 rats were given indomethacin (12.5 mg/ rat, C3 (20 rats were given celecoxib (200mg/rato, and Group D - control group, concerning 10 rats were observed during seven days ingesting food and water ad libitum. On the 9th day, the stomachs were taken out and were macro and microscopically evaluated for the identification of the gastric injuries. RESULTS: On the macroscopic studies, the groups A2, B2 and C2 presented a remarkable high number of injuries for cm² /animal, respectively 18.55 injuries for cm² /animal, 16.25 injuries for cm² /animal and 13.55 injuries for cm²/animal. On the microscopic studies, the percentage of the injured mucosa, presented expressive difference among the groups A1, B1, C1 when compared to the groups A2, B2, C2 (pOBJETIVO: Avaliar e comparar macro e microscopicamente as lesões agudas da mucosa gástrica de ratos provocadas pelos AINEs celecoxib e indometacina e a citoproteção g

Delayed-release oral suspension of omeprazole for the treatment of erosive esophagitis and gastroesophageal reflux disease in pediatric patients: a review

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Alice Monzani

2010-03-01

Full Text Available Alice Monzani, Giuseppina Oderda1Department of Pediatrics, Università del Piemonte Orientale, Novara, ItalyAbstract: Omeprazole is a proton-pump inhibitor indicated for gastroesophageal reflux disease and erosive esophagitis treatment in children. The aim of this review was to evaluate the efficacy of delayed-release oral suspension of omeprazole in childhood esophagitis, in terms of symptom relief, reduction in reflux index and/or intragastric acidity, and endoscopic and/or histological healing. We systematically searched PubMed, Cochrane and EMBASE (1990 to 2009 and identified 59 potentially relevant articles, but only 12 articles were suitable to be included in our analysis. All the studies evaluated symptom relief and reported a median relief rate of 80.4% (range 35%–100%. Five studies reported a significant reduction of the esophageal reflux index within normal limits (<7% in all children, and 4 studies a significant reduction of intra-gastric acidity. The endoscopic healing rate, reported by 9 studies, was 84% after 8-week treatment and 95% after 12-week treatment, the latter being significantly higher than the histological healing rate (49%. In conclusion, omeprazole given at a dose ranging from 0.3 to 3.5 mg/kg once daily (median 1 mg/kg once daily for at least 12 weeks is highly effective in childhood esophagitis.Keywords: proton pump inhibitors, children, ranitidine, H2-blockers

Comparative clinical evaluation on herbal formulation Pepsil, Safoof-e-Katira and Omeprazole in gastro esophageal reflux disease.

Science.gov (United States)

Toseef, Muhammad Umar; Saeed, Aftab; Mohi-Ud-Din, Ejaz; Usmanghani, Khan; Nazar, Halima; Nawaz, Allah; Ahmad, Irshad; Siddiqui, Faheem Ahmed

2015-05-01

This study was conducted to evaluate the role of Unani herbal drugs Pepsil and Safoof-e-katira on the gastro esophageal reflux disease (GERD). This was multicentre randomized case control study conducted at Matab Hakeem Muhammad Noor-ud-din, Burewala; Aziz Muhammad din Medical and Surgical Centre, Burewala and Shifa-ul-mulk Memorial Hospital, Hamdard University Karachi. The patients were selected according to inclusion and exclusion criteria. In test group-1 the male female ratio was 40%, 60%; test group-2 was 42%, 58% and in control group was 44%, 56% respectively. The observed symptoms in the study were increased appetite (TG-1-95%, TG-2-95% and CG-89%), difficulty in swallowing (TG-1-93%, TG-2-96% and TC-94%), belching/burping (TG-1-97%, TG-2-97% and CG-95%), vomiting (TG-1-90%, TG-2-96% and CG-89%), heart burn (TG-1-100%, TG-2-100% and CG-98%), palpitation (TG-1-100%, TG-2-100% and CG-97%), epigastric pain (TG-1-97%, TG-2-97% and CG-90%), abdominal cramps (TG-1-97%, TG-2-98% and CG-95%), tenesmus (TG-1-100%, TG-2-100% and CG-97%), flatulence (TG-1-100%, TG-2-75% and CG-95%), wakeup during sleep (TG-1-94%, TG-2-87% and CG-94%). The p-value of the results of the symptoms was 0.000 except flatulence where the value was 0.001. The statistical results of the study prescribed that all the drugs studied (Pepsil, Safoof-e-katira and Omeprazole) are highly significant. The herbal coded drug Pepsil showed no side effects and unani herbal drug safoof-e-katira showed minimum result of 75% in the patients while Omeprazole resulted with some side effects. In the result it can be concluded that the herbal coded drug Pepsil is a potent herbal drug for gastro esophageal reflux disease.

Bismuth-Based Quadruple Therapy with Bismuth Subcitrate, Metronidazole, Tetracycline and Omeprazole in the Eradication of Helicobacter pylori

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Raymond Lahaie

2001-01-01

Full Text Available BACKGROUND: A previous study showed that 14 days of qid bismuth-based triple therapy with tetracycline 500 mg, metronidazole 250 mg and colloidal bismuth subcitrate 120 mg resulted in excellent Helicobacter pylori eradication rates (89.5%. The present study looked at a shorter treatment period by adding omeprazole and by reducing the dose of tetracycline.

Photocatalytic and photoelectrocatalytic degradation of the drug omeprazole on nanocrystalline titania films in alkaline media: Effect of applied electrical bias on degradation and transformation products

Energy Technology Data Exchange (ETDEWEB)

Tantis, Iosif [Department of Chemical Engineering, University of Patras, Caratheodory 1, University Campus, GR-26504 Patras (Greece); Bousiakou, Leda [Department of Physics and Astronomy, King Saud University, Riyadh (Saudi Arabia); Department of Automation Engineering, Technological Educational Institute of Pireaus, GR-12244 Athens (Greece); Frontistis, Zacharias; Mantzavinos, Dionissios [Department of Chemical Engineering, University of Patras, Caratheodory 1, University Campus, GR-26504 Patras (Greece); Konstantinou, Ioannis; Antonopoulou, Maria [Department of Environmental and Natural Resources Management, University of Patras, GR-30100 Agrinio (Greece); Karikas, George-Albert [Department of Medical Laboratories Technology, Technological Educational Institute of Athens, 12210 Athens (Greece); Lianos, Panagiotis, E-mail: lianos@upatras.gr [Department of Chemical Engineering, University of Patras, Caratheodory 1, University Campus, GR-26504 Patras (Greece); FORTH/ICE-HT, P.O. Box 1414, GR-26504 Patras (Greece)

2015-08-30

Highlights: • Photocatalytic and photoelectrocatalytic degradation of the proton pump omeprazole. • Improvement of photocatalysis rate by applying a moderate forward bias. • Highlighting of the advantages of photoelectrocatalysis in a straightforward manner. • HPLC and HR-LC–MS analysis of transformation products. - Abstract: Photocatalytic and photoelectrocatalytic degradation of the drug omeprazole has been studied in the presence of nanocrystalline titania films supported on glass slides or transparent FTO electrodes in alkaline environment. Its photocatalytic degradation rate was assessed by its UV absorbance and by HPLC, while its transformation products were analyzed by HR-LC–MS. Based on UV absorbance, omeprazole can be photocatalytically degraded at an average rate of 6.7 × 10{sup −4} min{sup −1} under low intensity UVA irradiation of 1.5 mW cm{sup −2} in the presence of a nanoparticulate titania film. This corresponds to degradation of 1.4 mg of omeprazole per gram of the photocatalyst per liter of solution per hour. The photodegradation rate can be accelerated in a photoelectrochemical cell by applying a forward bias. In this case, the maximum rate reached under the present conditions was 11.6 × 10{sup −4} min{sup −1} by applying a forward bias of +0.6 V vs. Ag/AgCl. Four major transformation products were successfully identified and their profiles were followed by HR-LC–MS. The major degradation path includes the scission of the sulfoxide bridge into the corresponding pyridine and benzimidazole ring derivates and this is accompanied by the release of sulfate anions in the reaction mixture.

Clinical Efficacy of Omeprazole Combined with Sucralfate for Acute Hemorrhagic G astritis%奥美拉唑与硫糖铝联用治疗52例急性出血性胃炎的疗效观察

Institute of Scientific and Technical Information of China (English)

罗丹

2015-01-01

目的：研究奥美拉唑与硫糖铝联用治疗急性出血性胃炎的临床疗效。方法：选取2011年7月～2014年7月于本院进行治疗的104例急性出血性胃炎患者，分为对照组53例和观察组52例，对照组单纯给予奥美拉唑进行治疗，观察组采用奥美拉唑与硫糖铝联用进行治疗，对比观察2组患者的临床疗效。结果：观察组患者治疗的总有效率（96．15％）显著高于对照组（73．08％），P＜0．05，差异具有统计学意义。结论：奥美拉唑与硫糖铝联用治疗急性出血性胃炎的临床疗效确切，值得临床推广应用。%Objective:To study the clinical curative effect of omeprazole combined with sucralfate for acute hemorrhagic gastritis. Methods:from 2011 July to 2014 July,104 cases with acute hemorrhagic gastritis in Shenyang Weikang Hospital were treated,they were randomly divided into the control grou(p52 cases) and observation group(52 cases); The control group only received omeprazole treat -ment,and the observation group received omeprazole combined with sucralfate scheme , the clinical efficacy were compared between the two groups.Results:the total effective rate of treatment in the observation group and the control group was respectively 96.15%and 73. 08% , P<0.05, the difference has statistical significance.Conclusion:omeprazole combined with sucralfate for acute hemorrhagic gastri-tis has outstanding curative effects, and it is worthy of clinical application.

Spectroscopic Characterization of Omeprazole and Its Salts

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Tomislav Vrbanec

2017-01-01

Full Text Available During drug development, it is important to have a suitable crystalline form of the active pharmaceutical ingredient (API. Mostly, the basic options originate in the form of free base, acid, or salt. Substances that are stable only within a certain pH range are a challenge for the formulation. For the prazoles, which are known to be sensitive to degradation in an acid environment, the formulation is stabilized with alkaline additives or with the application of API formulated as basic salts. Therefore, preparation and characterization of basic salts are needed to monitor any possible salinization of free molecules. We synthesized salts of omeprazole from the group of alkali metals (Li, Na, and K and alkaline earth metals (Mg, Ca. The purpose of the presented work is to demonstrate the applicability of vibrational spectroscopy to discriminate between the OMP and OMP-salt molecules. For this reason, the physicochemical properties of 5 salts were probed using infrared and Raman spectroscopy, NMR, TG, DSC, and theoretical calculation of vibrational frequencies. We found out that vibrational spectroscopy serves as an applicable spectroscopic tool which enables an accurate, quick, and nondestructive way to determine the characteristic of OMP and its salts.

Development of a multiparticulate system containing enteric-release mini-tablets of omeprazole

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Volnei Jose Tondo Filho

2014-09-01

Full Text Available The main aim of this study was to develop a multiparticulate system containing mini-tablets of omeprazole formulated with an enteric polymer with pH-dependent solubility. Pre-formulation studies showed good flow and compaction capacity, leading to the production ofhigh quality mini-tablets. The mini-tablets were coated in a fluidized bed with hydroxypropylmethylcellulose /Eudragit(r L30D55 and packed into hard gelatin capsules. The dissolution profile showed gastro-resistance and zero-order kinetics. The dissolution profile for the formulation containing lactose as the diluent and coated with 12% (tablet weight gain of polymer was similar to that ofthe reference drug.

Phenobarbital Treatment at a Neonatal Age Results in Decreased Efficacy of Omeprazole in Adult Mice.

Science.gov (United States)

Tien, Yun-Chen; Piekos, Stephanie C; Pope, Chad; Zhong, Xiao-Bo

2017-03-01

Drug-drug interactions (DDIs) occur when the action of one drug interferes with or alters the activity of another drug taken concomitantly. This can lead to decreased drug efficacy or increased toxicity. Because of DDIs, physicians in the clinical practice attempt to avoid potential interactions when multiple drugs are coadministrated; however, there is still a large knowledge gap in understanding how drugs taken in the past can contribute to DDIs in the future. The goal of this study was to investigate the consequence of neonatal drug exposure on efficacy of other drugs administered up through adult life. We selected a mouse model to test phenobarbital exposure at a neonatal age and its impact on efficacy of omeprazole in adult life. The results of our experiment show an observed decrease in omeprazole's ability to raise gastric pH in adult mice that received single or multiple doses of phenobarbital at a neonatal age. This effect may be associated with the permanent induction of cytochrome P450 enzymes in adult liver after neonatal phenobarbital treatment. Our data indicates that DDIs may result from drugs administered in the past in an animal model and should prompt re-evaluation of how DDIs are viewed and how to avoid long-term DDIs in clinical practice. Copyright © 2017 by The American Society for Pharmacology and Experimental Therapeutics.

Modeling the cost-effectiveness of ilaprazole versus omeprazole for the treatment of newly diagnosed duodenal ulcer patients in China.

Science.gov (United States)

Xuan, J W; Song, R L; Xu, G X; Lu, W Q; Lu, Y J; Liu, Z

2016-11-01

To evaluate the cost-effectiveness of 10 mg ilaprazole once-daily vs 20 mg omeprazole once-daily to treat newly-diagnosed duodenal ulcer patients in China. A decision tree model was constructed and the treatment impact was projected up to 1 year. The CYP2C19 polymorphism distribution in the Chinese population, the respective cure rates in the CYP2C19 genotype sub-groups, the impact of Duodenal Ulcer (DU) on utility value and drug-related side-effect data were obtained from the literature. The total costs of medications were calculated to estimate the treatment costs based on current drug retail prices in China. Expert surveys were conducted when published data were not available. Probabilistic sensitivity analysis was performed to gauge the robustness of the results. Ilaprazole, when compared with omeprazole, achieved a better overall clinical efficacy. For the overall population, ilaprazole achieved an incremental cost effectiveness ratio (ICER) of ¥132 056 per QALY gained. This is less than the WHO recommended threshold of 3-times the average GDP per capita in China (2014). Furthermore, sub-group analysis showed that ilaprazole is cost-effective in every province in CYP2C19 hetEM patients and in the most developed provinces in CYP2C19 homEM patients. Probabilistic sensitivity analysis suggests that the results are robust with 97% probability that ilaprozole is considered cost-effective when a threshold of 3-times China's average GDP per capita is considered. This study didn't have the data of ilaprazole combined with Hp eradication therapy. Caution should be taken when extrapolating these findings to DU patients with an Hp eradication therapy. The cost-effectiveness analysis results demonstrated that ilaprazole would be considered a cost-effective therapy, compared with omeprazole, in Chinese DU patients based on the efficacy projections in various CYP2C19 polymorphism types.

Plasma position control device

International Nuclear Information System (INIS)

Takase, Haruhiko.

1987-01-01

Purpose: To conduct position control stably to various plasmas and reduce the burden on the control coil power source. Constitution: Among the proportional, integration and differentiation controls, a proportional-differentiation control section and an integration control section are connected in parallel. Then, a signal switching circuit is disposed to the control signal input section for the proportional-differentiation control section such that either a present position of plasmas or deviation between the present plasma position and an aimed value can be selected as a control signal depending on the control procedures or the state of the plasmas. For instance, if a rapid response is required for the control, the deviation between the present plasma position and the aimed value is selected as the input signal to conduct proportional, integration and differentiation controls. While on the other hand, if it is intended to reduce the burden on the control coil power source, it is adapted such that the control signal inputted to the proportional-differentiation control section itself can select the present plasma position. (Yoshihara, H.)

Einfluss von Thujonen und Omeprazol auf die Aktivität der glatten Muskelzelle im Ileum der Ratte

OpenAIRE

Huhnstock, Stefan

2010-01-01

Untersucht wurde der Einfluss von Thujonen (α Thujon, αβThujon, natürliches Mischthujon) und Omeprazol auf die Ruheaktivität, den Basaltonus, die pharmakologisch vorstimulierte glatte Muskulatur ,sowie die elektrisch induzierte Kontraktionen und die elektrisch induzierte Relaxation unter nicht-adrenergen nicht-cholinergen Bedingungen an der glatten Muskelzelle im Ileum von Ratten. Auf die Ruheaktivität und den Basaltonus hatten die Substanzen keinen Einfluss. Thujone hatten einen signifikante...

Investigating the presence of omeprazole in waters by liquid chromatography coupled to low and high resolution mass spectrometry. (I) Degradation experiments.

NARCIS (Netherlands)

Boix, C; Ibáñez, M.; Zamora, T.; Sancho, J.V.; Niessen, W.M.A.; Hernández, F.

2013-01-01

Omeprazole is one of the most consumed pharmaceuticals around the world. However, this compound is scarcely detected in urban wastewater and surface water. The absence of this pharmaceutical in the aquatic ecosystem might be due to its degradation in wastewater treatment plants, as well as in

Gastroprotective actions of Taraxacum coreanum Nakai water extracts in ethanol-induced rat models of acute and chronic gastritis.

Science.gov (United States)

Yang, Hye Jeong; Kim, Min Jung; Kwon, Dae Young; Kang, Eun Seon; Kang, Suna; Park, Sunmin

2017-08-17

Taraxacum coreanum Nakai has been traditionally used for treating inflammatory diseases including gastrointestinal diseases. We studied whether water extracts of Taraxacum coreanum Nakai (TCN) had a protective effect on acute and chronic gastritis induced by ethanol/HCl in an animal model of gastritis and its mechanism was also explored. In the acute study, rats were orally administered 0.15g/mL dextrin (normal-control), 0.15g/mL dextrin (control), 0.05g/mL TCN (TCN-L), 0.15g/mL TCN (TCN-H), or 0.01g/mL omeprazole (orally; positive-control), followed by oral administration of 1mL of 60% ethanol plus 150mM HCl (inducer). In the chronic study, rats were administered 10% diluted inducer in drinking water, and 0.6% dextrin, 0.2% or 0.6% TCN, and 0.05% omeprazole were administered in chow for 4 weeks. Acid content, gastric structure, oxidative stress, and markers of inflammation in the stomach tissue were measured at the end of experiment. Acute and chronic ethanol/HCl administration caused the inner layer of the stomach to redden, hemorrhage, and edema in the control group; TCN-H reduced these symptoms more effectively than did the omeprazole positive-control. Acid production and total acidity in the stomach increased in the control group, which was markedly suppressed by omeprazole. TCN also reduced the acid production and acidity, but not to the same degree as omeprazole. H-E and PAS staining revealed that in the inner layer of the stomach, cellular structure was disrupted, with an increased nuclear size and thickness, disarrangement, and decreased mucin in the control group. TCN prevented the cellular disruption in the inner layer, and TCN-H was more effective than the positive-control. This was associated with oxidative stress and inflammation. TCN dose-dependently reduced the infiltration of mast cells and TNF-α expression in the inner layer of the stomach, and decreased lipid peroxides by increasing superoxide dismutase and glutathione peroxidase expression. TCN

Addition of all-trans-retinoic acid to omeprazole and sucralfate therapy improves the prognosis of gastric dysplasia.

Science.gov (United States)

Jin, Jianjun; Li, Xiaozhen; Xing, Luqi; Chang, Yongchao; Wu, Lijuan; Jin, Zhe; Su, Xiuli; Bai, Yanli; Zheng, Yufeng; Jiang, Yalin; Zhao, Xiao; Lu, Lan; Gao, Qiang

2015-04-01

To investigate the efficacy of all-trans retinoic acid (ATRA) in human gastric dysplasia. In this double-blind study, patients with precancerous gastric dysplasia with or without intestinal metaplasia (IM) received either conventional treatment consisting of omeprazole and sucralfate (control group) or conventional treatment plus ATRA. Gastric mucosal biopsies were performed before and after drug treatment and were analysed histologically; expression of retinoblastoma (Rb) protein and HER2 protein in gastric mucosa were measured using immunohistochemistry. A total of 122 patients were included in the study, 63 in the ATRA group and 59 in the control group. In the ATRA group, dysplasia was attenuated in 43 out of 63 patients (68%) compared with 22 out of 59 patients (37%) in the control group; however, IM was not affected by treatment in either group. ATRA treatment was associated with significantly increased Rb expression and decreased HER2 expression in gastric mucosa. The use of conventional therapy plus ATRA for gastric dysplasia was associated with improved efficacy compared with conventional therapy alone. It was also accompanied by increased Rb expression and decreased HER2 expression in gastric mucosa. The addition of ATRA to conventional therapy for gastritis may improve the prognosis of gastric dysplasia. © The Author(s) 2015 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Slow, spontaneous degradation of lansoprazole, omeprazole and pantoprazole tablets: isolation and structural characterization of the toxic antioxidants 3H-benzimidazole-2-thiones.

Science.gov (United States)

Rajab, A; Touma, M; Rudler, H; Afonso, C; Seuleiman, M

2013-09-01

The spontaneous degradation of lansoprazole, omeprazole and pantoprazole tablets upon long-term and forced storage conditions was determined by high performance liquid chromatography (HPLC). The more abundant products could be isolated by liquid chromatography and their molecular weights determined by Mass Spectrometry (MS). Their structures, established according to their spectroscopic data, were compared to those of either the literature or of authentic samples. Thus lansoprazole led mainly to a mixture of 3H-benzimidazole-2-thione (2a) and 3H-benzimidazole-2-one (2c), omeprazole mainly to a mixture of 5-methoxy-3H-benzimidazole-2-thione (1a) and 2-hydroxymethyl-3, 5-dimethyl-4-methoxypyridine (1b), and pantoprazole, to 5-difluoromethoxy-3H-benzimidazole-2-thione (3a) and 2-hydroxymethyl-3, 4-dimethoxypyridine (3b). Although some of the degradation products had already been observed under different conditions, the detection of benzimidazole-2-thiones is unprecedented and their involvement as possible physiological, yet toxic antioxidants must be emphasized. Plausible, unified mechanisms for the formation of the different degradation products observed herein and in previous papers from the literature are suggested.

Automatic positioning control device for automatic control rod exchanger

International Nuclear Information System (INIS)

Nasu, Seiji; Sasaki, Masayoshi.

1982-01-01

Purpose: To attain accurate positioning for a control rod exchanger. Constitution: The present position for an automatic control rod exchanger is detected by a synchro generator. An aimed stopping position for the exchanger, a stop instruction range depending on the distantial operation delay in the control system and the inertia-running distance of the mechanical system, and a coincidence confirmation range depending on the required positioning accuracy are previously set. If there is a difference between the present position and the aimed stopping position, the automatic exchanger is caused to run toward the aimed stopping position. A stop instruction is generated upon arrival at the position within said stop instruction range, and a coincidence confirmation signal is generated upon arrival at the position within the coincidence confirmation range. Since uncertain factors such as operation delay in the control system and the inertia-running distance of the mechanical system that influence the positioning accuracy are made definite by the method of actual measurement or the like and the stop instruction range and the coincidence confirmation range are set based on the measured data, the accuracy for the positioning can be improved. (Ikeda, J.)

Potentiation of the action of metronidazole on Helicobacter pylori by omeprazole and bismuth subcitrate

DEFF Research Database (Denmark)

Andersen, L P; Colding, H; Kristiansen, J E

2000-01-01

test (Etest). With 0.5 MIC of either of the two drugs, the susceptibility of all H. pylori4 mg/l) reverted to being metronidazole sensitive. These results suggested that either bismuth salts or proton pump inhibitors may be effective in the treatment of some infections with metronidazole-resistant H...... to regimens that include proton pump inhibitors. In the present study, the synergistic effect of subinhibitory concentrations (0.25-0.5 MIC) of either bismuth subcitrate or omeprazole with metronidazole on the susceptibility of 42 H. pylori strains was investigated by agar dilution method and the Epsilometer......Treatment failures using triple therapy that include metronidazole, are common in patients infected with metronidazole-resistant Helicobacter pylori in the gastric mucosa. Higher eradication rates in such patients have been described when treatment regimens include bismuth salts compared...

The Clinical Efficacy of Omeprazole and Sucralfate in Acute Hemorrhagic Gastritis%奥美拉唑联合硫糖铝治疗急性出血性胃炎临床疗效观察

Institute of Scientific and Technical Information of China (English)

李桂芬

2016-01-01

Objective In order to investigate the clinical efficacy of omeprazole and sucralfate in acute hemorrhagic gastritis. Methods 102 cases of acute hemorrhagic gastritis patients were selected, and randomly divided into two groups, control group received conventional treatment, study group received conventional treatment, as well as omeprazole and sucralfate. The blood loss, hospital stay, bleeding time, and the incidence of adverse drug reactions in two groups were compared. Results The average blood loss, average bleeding time and hospital stay in the study group were signiifcantly lower than the control group (P<0.05), adverse drug reactions was 3.9% in the study group, significantly lower than the 15.7% in the control group (χ2=3.99, P=0.04). Conclusion Sucralfate and omeprazole in acute hemorrhagic gastritis can quickly stop the bleeding, shorter hospital stays and effective bleeding time, with low incidence of adverse reactions.%目的：探讨奥美拉唑联合硫糖铝治疗急性出血性胃炎的临床效果。方法选取我院收治的102例急性出血性胃炎患者，并随机分为两组，对照组给予常规治疗，观察组接受常规治疗以及奥美拉唑和硫糖铝联合治疗。观察并比较两组患者治疗后的出血量、住院时间、止血时间以及药物不良反应发生情况。结果观察组平均出血量、平均止血时间和平均住院时间低于对照组（P＜0.05）；观察组药物不良反应发生率为3.9%，低于对照组的15.7%（χ2=3.99，P=0.04）。结论硫糖铝与奥美拉唑联合治疗急性出血性胃炎能够快速止血，有效缩短住院时间与出血时间，且不良反应发生率较低。

Bioavailability of two single-dose oral formulations of omeprazole 20 mg: an open-label, randomized sequence, two-period crossover comparison in healthy Mexican adult volunteers.

Science.gov (United States)

Poo, Jorge Luis; Galán, Juan Francisco; Rosete, Alejandra; de Lago, Alberto; Oliva, Iván; González-de la Parra, Mario; Jiménez, Patricia; Burke-Fraga, Victoria; Namur, Salvador

2008-04-01

Omeprazole is a proton-pump inhibitor that acts to reduce acid secretion in the stomach and is used for treating various acid-related gastrointestinal disorders. There are several generic formulations of omeprazole available in Mexico; however, a literature search failed to identify published data concerning the bioavailability of these formulations in the Mexican population. The aim of this study was to compare the bioavailability of 2 oral formulations of omeprazole 20-mg capsules, marketed for use in Mexico, in healthy volunteers: Inhibitron (test formulation) and LosecA 20 mg (reference formulation). This study used a single-dose, open-label, randomized sequence, 2 x 2 crossover (2 administration periods x 2 treatments) design to compare the 2 formulations. Eligible subjects were healthy adult Mexican volunteers of both sexes. Subjects were randomly assigned in a 1:1 ratio to receive a single 20-mg dose of the test formulation followed by the reference formulation, or vice versa, with a 7-day washout period between administration periods. After a 12-hour (overnight) fast, subjects received a single, 20-mg dose of the corresponding formulation. Plasma samples were obtained over a 12-hour period after administration. Plasma omeprazole concentrations were analyzed by a nonstereospecific high-performance liquid chromatography method. For analysis of pharmacokinetic properties, including C(max), AUC from time 0 (baseline) to time t (AUC(0-t)), and AUC from baseline to infinity (AUC(0-infinity)), blood samples were drawn at baseline and 0.17, 0.33, 0.50, 0.75, 1, 1.25, 1.50, 1.75, 2, 2.50, 3, 4, 6, 8, and 12 hours after administration. The formulations were considered bioequivalent if the natural log (ln)-transformed ratios of C(max) and AUC were within the predetermined equivalence range of 80% to 125%, and if P disability, or required intervention to prevent permanent impairment or damage. Thirty-four subjects were enrolled and completed the study (25 men and 9

Mercapto-ordered carbohydrate-derived porous carbon electrode as a novel electrochemical sensor for simple and sensitive ultra-trace detection of omeprazole in biological samples

Energy Technology Data Exchange (ETDEWEB)

Kalate Bojdi, Majid [Department of Chemistry, Faculty of Science, Shahid Beheshti University, Tehran 1983963113 (Iran, Islamic Republic of); Faculty of Chemistry, Kharazmi (Tarbiat Moallem) University, Tehran (Iran, Islamic Republic of); Behbahani, Mohammad [Department of Chemistry, Faculty of Science, Shahid Beheshti University, Tehran 1983963113 (Iran, Islamic Republic of); Mashhadizadeh, Mohammad Hosein [Faculty of Chemistry, Kharazmi (Tarbiat Moallem) University, Tehran (Iran, Islamic Republic of); Bagheri, Akbar [Department of Chemistry, Faculty of Science, Shahid Beheshti University, Tehran 1983963113 (Iran, Islamic Republic of); Hosseiny Davarani, Saied Saeed, E-mail: ss-hosseiny@sbu.ac.ir [Department of Chemistry, Faculty of Science, Shahid Beheshti University, Tehran 1983963113 (Iran, Islamic Republic of); Farahani, Ali [Department of Chemistry, Faculty of Science, Shahid Beheshti University, Tehran 1983963113 (Iran, Islamic Republic of)

2015-03-01

We are introducing mercapto-mesoporous carbon modified carbon paste electrode (mercapto-MP-C-CPE) as a new sensor for trace determination of omeprazole (OM) in biological samples. The synthesized modifier was characterized by thermogravimetry analysis (TGA), differential thermal analysis (DTA), transmission electron microscopy (TEM), Fourier transform infrared spectrometry (FT-IR), X-ray diffraction (XRD), elemental analysis (CHN) and N{sub 2} adsorption surface area measurement (BET). The electrochemical response characteristic of the modified-CPE toward OM was investigated by cyclic and differential pulse voltammetry (CV and DPV). The proposed sensor displayed a good electrooxidation response to the OM, its linear range is 0.25 nM to 25 μM with a detection limit of 0.04 nM under the optimized conditions. The prepared modified electrode shows several advantages such as high sensitivity, long-time stability, wide linear range, ease of preparation and regeneration of the electrode surface by simple polishing and excellent reproducibility. - Highlights: • A modified nanoporous carbon as a novel sensor • High stability and good repeatability and reproducibility by the prepared sensor • Trace determination of omeprazole • Biological and pharmaceutical samples.

Mercapto-ordered carbohydrate-derived porous carbon electrode as a novel electrochemical sensor for simple and sensitive ultra-trace detection of omeprazole in biological samples

International Nuclear Information System (INIS)

Kalate Bojdi, Majid; Behbahani, Mohammad; Mashhadizadeh, Mohammad Hosein; Bagheri, Akbar; Hosseiny Davarani, Saied Saeed; Farahani, Ali

2015-01-01

We are introducing mercapto-mesoporous carbon modified carbon paste electrode (mercapto-MP-C-CPE) as a new sensor for trace determination of omeprazole (OM) in biological samples. The synthesized modifier was characterized by thermogravimetry analysis (TGA), differential thermal analysis (DTA), transmission electron microscopy (TEM), Fourier transform infrared spectrometry (FT-IR), X-ray diffraction (XRD), elemental analysis (CHN) and N 2 adsorption surface area measurement (BET). The electrochemical response characteristic of the modified-CPE toward OM was investigated by cyclic and differential pulse voltammetry (CV and DPV). The proposed sensor displayed a good electrooxidation response to the OM, its linear range is 0.25 nM to 25 μM with a detection limit of 0.04 nM under the optimized conditions. The prepared modified electrode shows several advantages such as high sensitivity, long-time stability, wide linear range, ease of preparation and regeneration of the electrode surface by simple polishing and excellent reproducibility. - Highlights: • A modified nanoporous carbon as a novel sensor • High stability and good repeatability and reproducibility by the prepared sensor • Trace determination of omeprazole • Biological and pharmaceutical samples

Fractional-Order Control of Pneumatic Position Servosystems

Directory of Open Access Journals (Sweden)

Cao Junyi

2011-01-01

Full Text Available A fractional-order control strategy for pneumatic position servosystem is presented in this paper. The idea of the fractional calculus application to control theory was introduced in many works, and its advantages were proved. However, the realization of fractional-order controllers for pneumatic position servosystems has not been investigated. Based on the relationship between the pressure in cylinder and the rate of mass flow into the cylinder, the dynamic model of pneumatic position servo system is established. The fractional-order controller for pneumatic position servo and its implementation in industrial computer is designed. The experiments with fractional-order controller are carried out under various conditions, which include sine position signal with different frequency and amplitude, step position signal, and variety inertial load. The results show the effectiveness of the proposed scheme and verify their fine control performance for pneumatic position servo system.

Validation of ISTTOK Plasma Position Controller

International Nuclear Information System (INIS)

Valcarcel, D. F.; Carvalho, I. S.; Carvalho, B. B.; Fernandes, H.; Silva, C.; Duarte, P.; Duarte, A.; Carvalho, P. J.; Pereira, T.

2008-01-01

Active control of plasma position on the ISTTOK tokamak is of extreme importance due to the inherent instability caused by an unfavourable curvature of the external equilibrium magnetic field. The consequences of this instability can be suppressed by applying a dynamic equilibrium field. A digital real-time plasma position control system for ISTTOK has been developed to perform this task. This system uses magnetic measurements to determine the plasma position and feeds the control signal to power supplies that generate the equilibrium fields. After commissioning, the results obtained have shown some discrepancies between the magnetic plasma position reconstruction and several other diagnostics, such as tomography. This discrepancy at some extent is due to the effect of the external magnetic fields on the poloidal magnetic measurements. This work presents a study that addresses this issue. In a future work it will lead to the development of a corrected plasma position algorithm, aiming at obtaining improved performance of plasma discharges and controlled plasma column displacements

Plasma position control on Alcator C

International Nuclear Information System (INIS)

Pribyl, P.A.

1981-05-01

The Alcator C MHD equilibrium is investigated from the standpoint of determining the plasma position. A review of equilibrium theory is presented, indicating that the central flux surfaces of the plasma should be displaced about 1 to 2 cm from the outermost. Further, the plasma should have a slightly noncircular cross-section. A comparison is made between the observed and predicted profiles. Flux loops sensitive to plasma position generate the error signal for the feedback control circuit. This measurement agrees with other position-sensitive diagnostics, such as limiter heating, and centroids of density, soft x-ray, and electron cyclotron emission. A linear model is developed for the position control feedback system, including the vertical field SCR supply, plasma, and feedback electronics. Operation of the control system agrees well with that predicted by the model, with acceptable plasma position being maintained for the duration of the discharge. The feedback control system is in daily use for Alcator C runs

Control rod position detection device

International Nuclear Information System (INIS)

Akita, Haruo; Ogiwara, Sakae.

1996-01-01

The device of the present invention is used in a back-up shut down system of an LMFBR type reactor which is easy for maintenance, has high reliability and can recognize the position of control rods accurately. Namely, a permanent magnet is disposed to a control rod extension tube connected to the lower portion of the control rod. The detector guide tube is disposed in the vicinity of the control rod extension tube. A detector having a detection coil is inserted into a detector tube. With such constitution, the control rod can be detected at one position using the following method. (1) the movement of the magnetic field of the permanent magnet is detected by the detection coil. (2) a plurality of grooves are formed on the control rod extension tube, and the movement of the grooves is detected. In addition, the detection coil is inserted into the detector guide tube, and the signals from the detection coil are inputted to a signal processing circuit disposed at the outside of the reactor vessel using an MI cable to enable the maintenance of the detector. Further, if the detector comprises a detection coil and an excitation coil, the position of a dropped control rod can be recognized at a plurality of points. (I.S.)

Active vibration control of clamped beams using positive position feedback controllers with moment pair

International Nuclear Information System (INIS)

Shin, Chang Joo; Jeong, Weui Bong; Hong, Chin Suk

2012-01-01

This paper investigates the active vibration control of clamp beams using positive position feedback (PPF) controllers with a sensor/ moment pair actuator. The sensor/moment pair actuator which is the non-collocated configuration leads to instability of the control system when using the direct velocity feedback (DVFB) control. To alleviate the instability problem, a PPF controller is considered in this paper. A parametric study of the control system with PPF controller is first conducted to characterize the effects of the design parameters (gain and damping ratio in this paper) on the stability and performance. The gain of the controller is found to affect only the relative stability. Increasing the damping ratio of the controller slightly improves the stability condition while the performance gets worse. In addition, the higher mode tuned PPF controller affects the system response at the lower modes significantly. Based on the characteristics of PPF controllers, a multi-mode controllable SISO PPF controller is then considered and tuned to different modes (in this case, three lowest modes) numerically and experimentally. The multi-mode PPF controller can be achieved to have a high gain margin. Moreover, it reduces the vibration of the beam significantly. The vibration levels at the tuned modes are reduced by about 11 dB

Control rod position detector for nuclear reactor

International Nuclear Information System (INIS)

Kudo, Mitsuru; Fujiwara, Hiroshi.

1981-01-01

Purpose: To improve the reliability of a control rod position detector by detecting a reactive code with a combination of control rod position change signals produced from vertical and horizontal axis decoders, generation an error signal and thus simultaneously detecting the operation of more than two lead switches. Constitution: Horizontal and vertical axis position signals responsive to changes in the control rod position are applied from lead switches connected in a predetermined matrix connection corresponding to the notches of the positions of respective position detecting probes, the reactive output from the decoder is detected by a reactive code detecting circuit, which in turn generates a fault signal, and the control rod position code converted in a notch number generating circuit is converted to a predetermined value indicating invalidity. Accordingly, a fault caused by the simultaneous operation of a plurality of failed lead switches can be effectively detected. (Yoshino, Y.)

Quality control in diagnostic immunohistochemistry: integrated on-slide positive controls.

Science.gov (United States)

Bragoni, A; Gambella, A; Pigozzi, S; Grigolini, M; Fiocca, R; Mastracci, L; Grillo, F

2017-11-01

Standardization in immunohistochemistry is a priority in modern pathology and requires strict quality control. Cost containment has also become fundamental and auditing of all procedures must take into account both these principles. Positive controls must be routinely performed so that their positivity guarantees the appropriateness of the immunohistochemical procedure. The aim of this study is to develop a low cost (utilizing a punch biopsy-PB-tool) procedure to construct positive controls which can be integrated in the patient's tissue slide. Sixteen frequently used control blocks were selected and multiple cylindrical samples were obtained using a 5-mm diameter punch biopsy tool, separately re-embedding them in single blocks. For each diagnostic immunoreaction requiring a positive control, an integrated PB-control section (cut from the appropriate PB-control block) was added to the top right corner of the diagnostic slide before immunostaining. This integrated control technique permitted a saving of 4.75% in total direct lab costs and proved to be technically feasible and reliable. Our proposal is easy to perform and within the reach of all pathology labs, requires easily available tools, its application costs is less than using external paired controls and ensures that a specific control for each slide is always available.

Once-daily omeprazole/sodium bicarbonate heals severe refractory reflux esophagitis with morning or nighttime dosing.

Science.gov (United States)

Orbelo, Diana M; Enders, Felicity T; Romero, Yvonne; Francis, Dawn L; Achem, Sami R; Dabade, Tushar S; Crowell, Michael D; Geno, Debra M; DeJesus, Ramona S; Namasivayam, Vikneswaran; Adamson, Steven C; Arora, Amindra S; Majka, Andrew J; Alexander, Jeffrey A; Murray, Joseph A; Lohse, Matthew; Diehl, Nancy N; Fredericksen, Mary; Jung, Kee Wook; Houston, Margaret S; O'Neil, Angela E; Katzka, David A

2015-01-01

Morning dose or twice-daily proton pump inhibitor (PPI) use is often prescribed to heal severe reflux esophagitis. Compare the effect of single dose morning (control arm) versus nighttime (experimental arm) omeprazole/sodium bicarbonate (Zegerid(®)) (IR-OME) on esophagitis and gastroesophageal reflux symptoms. Adult outpatients with Los Angeles grade C or D esophagitis were allocated to open-label 40 mg IR-OME once a day for 8 weeks in a prospective, randomized, parallel design, single center study. Esophagogastroduodenoscopy (EGD) and validated self-report symptom questionnaires were completed at baseline and follow-up. Intention-to-treat and per-protocol analyses were performed. Ninety-two of 128 (72 %) eligible subjects participated [64 (70 %) male, mean age 58 (range 19-86), median BMI 29 (range 21-51), 58 C:34 D]. Overall, 81 (88 %) subjects healed [n = 70 (76 %)] or improved [n = 11 (12 %)] erosions. There was no significant difference (morning vs. night) in mucosal healing [81 vs. 71 %, (p = 0.44)] or symptom resolution [heartburn (77 vs. 65 %, p = 0.12), acid regurgitation (82 vs. 73 %, p = 0.28)]. Prevalence of newly identified Barrett's esophagus was 14 % with half diagnosed only after treatment. Once-daily IR-OME (taken morning or night) effectively heals severe reflux esophagitis and improves GERD symptoms. Results support the clinical practice recommendation to repeat EGD after 8 weeks PPI therapy in severe esophagitis patients to assure healing and exclude Barrett's esophagus.

Fractional-Order Control of Pneumatic Position Servosystems

OpenAIRE

Junyi, Cao; Binggang, Cao

2011-01-01

A fractional-order control strategy for pneumatic position servosystem is presented in this paper. The idea of the fractional calculus application to control theory was introduced in many works, and its advantages were proved. However, the realization of fractional-order controllers for pneumatic position servosystems has not been investigated. Based on the relationship between the pressure in cylinder and the rate of mass flow into the cylinder, the dynamic model of pneumatic position servo ...

Omeprazole increases the efficacy of a soluble epoxide hydrolase inhibitor in a PGE2 induced pain model

International Nuclear Information System (INIS)

Goswami, Sumanta Kumar; Inceoglu, Bora; Yang, Jun; Wan, Debin; Kodani, Sean D.; Trindade da Silva, Carlos Antonio; Morisseau, Christophe; Hammock, Bruce D.

2015-01-01

Epoxyeicosatrienoic acids (EETs) are potent endogenous analgesic metabolites produced from arachidonic acid by cytochrome P450s (P450s). Metabolism of EETs by soluble epoxide hydrolase (sEH) reduces their activity, while their stabilization by sEH inhibition decreases both inflammatory and neuropathic pain. Here, we tested the complementary hypothesis that increasing the level of EETs through induction of P450s by omeprazole (OME), can influence pain related signaling by itself, and potentiate the anti-hyperalgesic effect of sEH inhibitor. Rats were treated with OME (100 mg/kg/day, p.o., 7 days), sEH inhibitor TPPU (3 mg/kg/day, p.o.) and OME (100 mg/kg/day, p.o., 7 days) + TPPU (3 mg/kg/day, p.o., last 3 days of OME dose) dissolved in vehicle PEG400, and their effect on hyperalgesia (increased sensitivity to pain) induced by PGE 2 was monitored. While OME treatment by itself exhibited variable effects on PGE 2 induced hyperalgesia, it strongly potentiated the effect of TPPU in the same assay. The significant decrease in pain with OME + TPPU treatment correlated with the increased levels of EETs in plasma and increased activities of P450 1A1 and P450 1A2 in liver microsomes. The results show that reducing catabolism of EETs with a sEH inhibitor yielded a stronger analgesic effect than increasing generation of EETs by OME, and combination of both yielded the strongest pain reducing effect under the condition of this study. - Highlights: • The soluble epoxide hydrolase (sEH) inhibitor TPPU is anti-hyperalgesic. • Omeprazole potentiates the anti-hyperalgesic actions of TPPU. • This potentiation is associated with increased P450 activity. • The potentiation is associated with an increase in fatty acid epoxide/diol ratio. • Joint use of sEH inhibitors and P450 inducers could result in drug–drug interactions.

A deterministic - approach controller design for electrohydraulic position servo control system

International Nuclear Information System (INIS)

Johari Osman

2000-01-01

This paper is concerned with the design of a tracking controller for controlling electrohydraulic position servo system based on a deterministic approach. The system is treated as an uncertain system with bounded uncertainties where the bounds are assumed known. It will be shown that the electrohydraulic position servo systems with the proposed controller is practically stable and tracks the desired position in spite of the uncertainties and nonlinearities present in the system (author)

Predictive IP controller for robust position control of linear servo system.

Science.gov (United States)

Lu, Shaowu; Zhou, Fengxing; Ma, Yajie; Tang, Xiaoqi

2016-07-01

Position control is a typical application of linear servo system. In this paper, to reduce the system overshoot, an integral plus proportional (IP) controller is used in the position control implementation. To further improve the control performance, a gain-tuning IP controller based on a generalized predictive control (GPC) law is proposed. Firstly, to represent the dynamics of the position loop, a second-order linear model is used and its model parameters are estimated on-line by using a recursive least squares method. Secondly, based on the GPC law, an optimal control sequence is obtained by using receding horizon, then directly supplies the IP controller with the corresponding control parameters in the real operations. Finally, simulation and experimental results are presented to show the efficiency of proposed scheme. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

Position control device for a control rod

International Nuclear Information System (INIS)

Ono, Takehiko; Kusaka, Shuji.

1976-01-01

Purpose: To reliably prevent dangerous operation in the control of the position of the control rod by checking for abnormal pulse motor coil excitation voltage and, at the time of occurrence of abnormality, immediately holding the control rod stationary lest it should be moved to an unsafe position, this being accomplished excitation from a compensating excitation system. Constitution: In an FBR reactor, a circuit for memorizing the correct output states of individual drive signals at arbitrary instants and consequtively producing the memorized results is provided, and the output of the circuit and the actual drive signal are compared at all times to discriminate whether the drive signal being compared is normal or not. When the actual drive signal is abnormal, a series signal varying after a predetermined pattern is shifted to enable replacement of the actual drive signal, so that irrespective of whether the problem drive signal is ''on'' or ''off'', a drive signal of the correct pattern may be supplied to the pulse motor to hold the control rod and prevent it from being moved toward the dangerous side due to its own weight or other causes. (Horiuchi, T.)

Upper limb position control in fibromyalgia

Directory of Open Access Journals (Sweden)

Bardal Ellen

2012-09-01

Full Text Available Abstract Background Motor problems are reported by patients with fibromyalgia (FM. However, the mechanisms leading to alterations in motor performance are not well understood. In this study, upper limb position control during sustained isometric contractions was investigated in patients with FM and in healthy controls (HCs. Methods Fifteen female FM patients and 13 HCs were asked to keep a constant upper limb position during sustained elbow flexion and shoulder abduction, respectively. Subjects received real-time visual feedback on limb position and both tasks were performed unloaded and while supporting loads (1, 2, and 3 kg. Accelerations of the dominant upper limb were recorded, with variance (SD of mean position and power spectrum analysis used to characterize limb position control. Normalized power of the acceleration signal was extracted for three frequency bands: 1–3 Hz, 4–7 Hz, and 8–12 Hz. Results Variance increased with load in both tasks (P 0.001 but did not differ significantly between patients and HCs (P > 0.17. Power spectrum analysis showed that the FM patients had a higher proportion of normalized power in the 1–3 Hz band, and a lower proportion of normalized power in the 8–12 Hz band compared to HCs (P 0.05. The results were consistent for all load conditions and for both elbow flexion and shoulder abduction. Conclusion FM patients exhibit an altered neuromuscular strategy for upper limb position control compared to HCs. The predominance of low-frequency limb oscillations among FM patients may indicate a sensory deficit.

A Solid-Contact Indium(III) Sensor based on a Thiosulfinate Ionophore Derived from Omeprazole

Energy Technology Data Exchange (ETDEWEB)

Abbas, Mohammad Nooredeen; Hend Samy Amer [National Research Centre, Cairo (Egypt)

2013-04-15

A novel solid-contact indium(III)-selective sensor based on bis-(1H-benzimidazole-5-methoxy-2-[(4-methoxy-3, 5-dimethyl-1-pyridinyl) 2-methyl]) thiosulfinate, known as an omeprazole dimer (OD) and a neutral ionophore, was constructed, and its performance characteristics were evaluated. The sensor was prepared by applying a membrane cocktail containing the ionophore to a graphite rod pre-coated with polyethylene dioxythiophene (PEDOT) conducting polymer as the ion-to-electron transducer. The membrane contained 3.6% OD, 2.3% oleic acid (OA) and 62% dioctyl phthalate (DOP) as the solvent mediator in PVC and produced a good potentiometric response to indium(III) ions with a Nernstian slope of 19.09 mV/decade. The constructed sensor possessed a linear concentration range from 3 Χ 10{sup -7} to 1 Χ 10{sup -2} M and a lower detection limit (LDL) of 1 Χ 10{sup -7} M indium(III) over a pH range of 4.0-7.0. It also displayed a fast response time and good selectivity for indium(III) over several other ions. The sensor can be used for longer than three months without any considerable divergence in potential. The sensor was utilized for direct and flow injection potentiometric (FIP) determination of indium(III) in alloys. The parameters that control the flow injection method were optimized. Indium(III) was quantitatively recovered, and the results agreed with those obtained using atomic absorption spectrophotometry, as confirmed by the f and t values. The sensor was also utilized as an indicator electrode for the potentiometric titration of fluoride in the presence of chloride, bromide, iodide and thiocyanate ions using indium(III) nitrate as the titrant.

Effects of omeprazole or anti-reflux surgery on lower oesophageal sphincter characteristics and oesophageal acid exposure over 10 years.

Science.gov (United States)

Emken, Birgitte-Elise G; Lundell, Lars R; Wallin, Lene; Myrvold, Helge E; Engström, Cecilia; Montgomery, Madeleine; Malm, Anders R; Lind, Tore; Hatlebakk, Jan G

2017-01-01

To compare the effect of anti-reflux surgery (ARS) versus proton pump inhibitor therapy on lower oesophageal sphincter (LOS) function and oesophageal acid exposure in patients with chronic gastro-oesophageal reflux disease (GORD) over a decade of follow-up. In this randomised, prospective, multicentre study we compared LOS pressure profiles, as well as oesophageal exposure to acid, at baseline and at 1 and 10 years after randomisation to either open ARS (n = 137) or long-term treatment with omeprazole (OME) 20-60 mg daily (n = 108). Median LOS resting pressure and abdominal length increased significantly and remained elevated in patients operated on with ARS, as opposed to those on OME. The proportion of total time (%) with oesophageal pH acid exposure was normalised in both groups, with no significant differences, and bilirubin exposure was within normal limits. After 10 years, patients with or without Barrett's oesophagus did not differ in acid reflux control between the two treatment options. Open ARS and OME were both effective in normalising acid reflux into the oesophagus even when studied over a period of 10 years. Anatomically and functionally the LOS was repaired durably by surgery, with increased resting pressure and abdominal length.

Cylinder Position Servo Control Based on Fuzzy PID

Directory of Open Access Journals (Sweden)

Shibo Cai

2013-01-01

Full Text Available The arbitrary position control of cylinder has always been the hard challenge in pneumatic system. We try to develop a cylinder position servo control method by combining fuzzy PID with the theoretical model of the proportional valve-controlled cylinder system. The pressure differential equation of cylinder, pressure-flow equation of proportional valve, and moment equilibrium equation of cylinder are established. And the mathematical models of the cylinder driving system are linearized. Then fuzzy PID control algorithm is designed for the cylinder position control, including the detail analysis of fuzzy variables and domain, fuzzy logic rules, and defuzzification. The stability of the proposed fuzzy PID controller is theoretically proved according to the small gain theorem. Experiments for targets position of 250 mm, 300 mm, and 350 mm were done and the results showed that the absolute error of the position control is less than 0.25 mm. And comparative experiment between fuzzy PID and classical PID verified the advantage of the proposed algorithm.

Plasma position control in TCABR Tokamak

International Nuclear Information System (INIS)

Galvao, R.M.O.; Kuznetsov, Yu. K.; Nascimento, I.C.; Fonseca, A.M.M.; Silva, R.P. da; Ruchko, L.F.; Tuszel, A.G.; Reis, A.P. dos; Sanada, E.K.

1998-01-01

The plasma control position in the TCABR tokamak is described. The TCA tokamak was transferred from the Centre de Recherches en Physique des Plasmas, Lausanne, to the Institute of Physics of University of Sao Paulo, renamed TCABR (α=0.18 m, R = 0.62 m, B = 1 T,I p = 100 kA). The control system was reconstructed using mainly components obtained from the TCA tokamak. A new method of plasma position determination is used in TCABR to improve its accuracy. A more detailed theoretical analysis of the feed forward and feedback control is performed as compared with. (author)

Omeprazole increases the efficacy of a soluble epoxide hydrolase inhibitor in a PGE{sub 2} induced pain model

Energy Technology Data Exchange (ETDEWEB)

Goswami, Sumanta Kumar; Inceoglu, Bora; Yang, Jun; Wan, Debin; Kodani, Sean D. [Department of Entomology and Nematology, UC Davis Comprehensive Cancer Center, University of California, Davis, CA (United States); Trindade da Silva, Carlos Antonio [Department of Entomology and Nematology, UC Davis Comprehensive Cancer Center, University of California, Davis, CA (United States); Department of Genetics and Biochemistry, Federal University of Uberlandia, MG (Brazil); Morisseau, Christophe [Department of Entomology and Nematology, UC Davis Comprehensive Cancer Center, University of California, Davis, CA (United States); Hammock, Bruce D., E-mail: bdhammock@ucdavis.edu [Department of Entomology and Nematology, UC Davis Comprehensive Cancer Center, University of California, Davis, CA (United States)

2015-12-15

Epoxyeicosatrienoic acids (EETs) are potent endogenous analgesic metabolites produced from arachidonic acid by cytochrome P450s (P450s). Metabolism of EETs by soluble epoxide hydrolase (sEH) reduces their activity, while their stabilization by sEH inhibition decreases both inflammatory and neuropathic pain. Here, we tested the complementary hypothesis that increasing the level of EETs through induction of P450s by omeprazole (OME), can influence pain related signaling by itself, and potentiate the anti-hyperalgesic effect of sEH inhibitor. Rats were treated with OME (100 mg/kg/day, p.o., 7 days), sEH inhibitor TPPU (3 mg/kg/day, p.o.) and OME (100 mg/kg/day, p.o., 7 days) + TPPU (3 mg/kg/day, p.o., last 3 days of OME dose) dissolved in vehicle PEG400, and their effect on hyperalgesia (increased sensitivity to pain) induced by PGE{sub 2} was monitored. While OME treatment by itself exhibited variable effects on PGE{sub 2} induced hyperalgesia, it strongly potentiated the effect of TPPU in the same assay. The significant decrease in pain with OME + TPPU treatment correlated with the increased levels of EETs in plasma and increased activities of P450 1A1 and P450 1A2 in liver microsomes. The results show that reducing catabolism of EETs with a sEH inhibitor yielded a stronger analgesic effect than increasing generation of EETs by OME, and combination of both yielded the strongest pain reducing effect under the condition of this study. - Highlights: • The soluble epoxide hydrolase (sEH) inhibitor TPPU is anti-hyperalgesic. • Omeprazole potentiates the anti-hyperalgesic actions of TPPU. • This potentiation is associated with increased P450 activity. • The potentiation is associated with an increase in fatty acid epoxide/diol ratio. • Joint use of sEH inhibitors and P450 inducers could result in drug–drug interactions.

Robust Position Control of Electro-mechanical Systems

OpenAIRE

Rong Mei; Mou Chen

2013-01-01

In this work, the robust position control scheme is proposed for the electro-mechanical system using the disturbance observer and backstepping control method. To the external unknown load of the electro-mechanical system, the nonlinear disturbance observer is given to estimate the external unknown load. Combining the output of the developed nonlinear disturbance observer with backstepping technology, the robust position control scheme is proposed for the electro-mechanical system. The stabili...

Heartburn treatment in primary care: randomised, double blind study for 8 weeks

Science.gov (United States)

Hatlebakk, Jan G; Hyggen, Arild; Madsen, Per H; Walle, Per O; Schulz, Tom; Mowinckel, Petter; Bernklev, Tomm; Berstad, Arnold

1999-01-01

Objective To compare the effects and tolerability of omeprazole and cisapride with that of placebo for control of heartburn in primary care patients. Design Randomised, double blind, placebo controlled study. Setting 65 primary care practices in Norway. Participants 483 untreated patients with complaints of heartburn ⩾3 days a week, with at most grade 1 reflux oesophagitis. Interventions Omeprazole 20 mg once daily, cisapride 20 mg twice daily, or placebo for 8 weeks. Main outcome measures Adequate control of heartburn, defined as ⩽1 day of the past 7 days with no more than mild heartburn, after 4 weeks of treatment. Results In the all patients treated analysis, adequate control of heartburn was achieved in 71% of patients taking omeprazole, 22% taking cisapride, and 18% taking placebo after 4 weeks of treatment (omeprazole v cisapride and placebo, Pheartburn whereas cisapride 20 mg twice daily was not significantly more effective than placebo. Key messagesIn primary care patients, heartburn is commonly treated empiricallyMost randomised clinical trials of treatment for heartburn have been conducted in specialist care, and documentation for empirical treatment is limitedOmeprazole was significantly more effective than cisapride or placebo in controlling heartburn and other symptoms of gastro-oesophageal reflux after 2, 4, and 8 weeks, whereas cisapride did not differ significantly from placeboOmeprazole should be considered as a first choice for empirical treatment of heartburn in primary care PMID:10463897

Robust control design for the plasma horizontal position control on J-TEXT Tokamak

International Nuclear Information System (INIS)

Yu, W.Z.; Chen, Z.P.; Zhuang, G.; Wang, Z.J.

2013-01-01

It is extremely important for tokamak to control the plasma position during routine discharge. However, the model of plasma in tokamak usually contains much of the uncertainty, such as structured uncertainties and unmodeled dynamics. Compared with the traditional PID control approach, robust control theory is more suitable to handle this problem. In the paper, we propose a H ∞ robust control scheme to control the horizontal position of plasma during the flat-top phase of discharge on Joint Texas Experimental Tokamak (J-TEXT) tokamak. First, the model of our plant for plasma horizontal position control is obtained from the position equilibrium equations. Then the H ∞ robust control framework is used to synthesize the controller. Based on this, an H ∞ controller is designed to minimize the regulation/tracking error. Finally, a comparison study is conducted between the optimized H ∞ robust controller and the traditional PID controller in simulations. The simulation results of the H ∞ robust controller show a significant improvement of the performance with respect to those obtained with traditional PID controller, which is currently used on our machine

Consensus positive position feedback control for vibration attenuation of smart structures

Science.gov (United States)

Omidi, Ehsan; Nima Mahmoodi, S.

2015-04-01

This paper presents a new network-based approach for active vibration control in smart structures. In this approach, a network with known topology connects collocated actuator/sensor elements of the smart structure to one another. Each of these actuators/sensors, i.e., agent or node, is enhanced by a separate multi-mode positive position feedback (PPF) controller. The decentralized PPF controlled agents collaborate with each other in the designed network, under a certain consensus dynamics. The consensus constraint forces neighboring agents to cooperate with each other such that the disagreement between the time-domain actuation of the agents is driven to zero. The controller output of each agent is calculated using state-space variables; hence, optimal state estimators are designed first for the proposed observer-based consensus PPF control. The consensus controller is numerically investigated for a flexible smart structure, i.e., a thin aluminum beam that is clamped at its both ends. Results demonstrate that the consensus law successfully imposes synchronization between the independently controlled agents, as the disagreements between the decentralized PPF controller variables converge to zero in a short time. The new consensus PPF controller brings extra robustness to vibration suppression in smart structures, where malfunctions of an agent can be compensated for by referencing the neighboring agents’ performance. This is demonstrated in the results by comparing the new controller with former centralized PPF approach.

Anti-Windup Scheme for Practical Control of Positioning Systems

Directory of Open Access Journals (Sweden)

Wahyudi Tarig Faisal and Abdulgani Albagul

2012-10-01

Full Text Available Positioning systems generally need a good controller to achieve high accuracy, fast response and robustness. In addition, ease of controller design and simplicity of controller structure are very important for practical application.  For satisfying these requirements, nominal characteristic trajectory following controller (NCTF has been proposed as a practical point-to-point (PTP positioning control. However, the effect of actuator saturation can not be completely compensated for due to the integrator windup as the plant parameters vary. This paper presents a method to improve the NCTF controller for overcoming the problem of integrator windup using simple and classical tracking anti-windup scheme. The improved NCTF controller is evaluated through simulation using a rotary positioning system. The results show that the improved NCTF controller is adequate to compensate for the effect of integrator windup. Keywords: Positioning, point-to-point, integrator windup, compensation, controller, robustness.

Control of plasma position in the CASTOR tokamak

International Nuclear Information System (INIS)

Valovic, M.

1988-11-01

A simple servo-system designed for plasma position control in the CASTOR tokamak is described. Both radial and vertical plasma displacements were minimized using two servo-loops consisting of detection coils, a conventional electric controller and an amplifier operated as an unipolar voltage-controlled current source. To ensure the optimum conditions in the start-up phase of the discharge, currents in the servo-systems were externally preprogrammed. The prescribed plasma position was maintained with the accuracy of 3 mm. The feedback control improves plasma parameters, e.g. it removes the positional disruption at the end of the tokamak discharge. (J.U.). 4 figs., 3 refs

Robust hydraulic position controller by a fuzzy state controller

International Nuclear Information System (INIS)

Zhao, T.; Van der Wal, A.J.

1994-01-01

In nuclear industry, one of the most important design considerations of controllers is their robustness. Robustness in this context is defined as the ability of a system to be controlled in a stable way over a wide range of system parameters. Generally the systems to be controlled are linearized, and stability is subsequently proven for this idealized system. By combining classical control theory and fuzzy set theory, a new kind of state controller is proposed and successfully applied to a hydraulic position servo with excellent robustness against variation of system parameters

Sensorless SPMSM Position Estimation Using Position Estimation Error Suppression Control and EKF in Wide Speed Range

Directory of Open Access Journals (Sweden)

Zhanshan Wang

2014-01-01

Full Text Available The control of a high performance alternative current (AC motor drive under sensorless operation needs the accurate estimation of rotor position. In this paper, one method of accurately estimating rotor position by using both motor complex number model based position estimation and position estimation error suppression proportion integral (PI controller is proposed for the sensorless control of the surface permanent magnet synchronous motor (SPMSM. In order to guarantee the accuracy of rotor position estimation in the flux-weakening region, one scheme of identifying the permanent magnet flux of SPMSM by extended Kalman filter (EKF is also proposed, which formed the effective combination method to realize the sensorless control of SPMSM with high accuracy. The simulation results demonstrated the validity and feasibility of the proposed position/speed estimation system.

Real-time horizontal position control for Aditya-upgrade tokamak

International Nuclear Information System (INIS)

Kumar, Rohit; Ghosh, Joydeep; Tanna, Rakesh L.

2015-01-01

Position of plasma column is required to be controlled in real time for improved operation of any tokamak. A PID based system for real-time horizontal plasma position control has been designed for Aditya Upgrade tokamak. Modelling of transfer functions of actuators, plasma and diagnostic system are carried out for ADITYA-U tokamak. The PID controller is optimized using MATLAB-SIMULINK for horizontal position control. Further feed-forward loop is implemented where disturbance due to density variation is suppressed, which results in improved performance as compared to conventional PID operation. In this paper the detailed design of the whole system for real time control of plasma horizontal position in Aditya Upgrade tokamak is presented. (author)

Positive sliding mode control for blood glucose regulation

Science.gov (United States)

Menani, Karima; Mohammadridha, Taghreed; Magdelaine, Nicolas; Abdelaziz, Mourad; Moog, Claude H.

2017-11-01

Biological systems involving positive variables as concentrations are some examples of so-called positive systems. This is the case of the glycemia-insulinemia system considered in this paper. To cope with these physical constraints, it is shown that a positive sliding mode control (SMC) can be designed for glycemia regulation. The largest positive invariant set (PIS) is obtained for the insulinemia subsystem in open and closed loop. The existence of a positive SMC for glycemia regulation is shown here for the first time. Necessary conditions to design the sliding surface and the discontinuity gain are derived to guarantee a positive SMC for the insulin dynamics. SMC is designed to be positive everywhere in the largest closed-loop PIS of plasma insulin system. Two-stage SMC is employed; the last stage SMC2 block uses the glycemia error to design the desired insulin trajectory. Then the plasma insulin state is forced to track the reference via SMC1. The resulting desired insulin trajectory is the required virtual control input of the glycemia system to eliminate blood glucose (BG) error. The positive control is tested in silico on type-1 diabetic patients model derived from real-life clinical data.

Nano positioning control for dual stage using minimum order observer

International Nuclear Information System (INIS)

Kim, Hong Gun

2012-01-01

A nano positioning control is developed using the ultra-precision positioning apparatus such as actuator, sensor, guide, power transmission element with an appropriate control method. Using established procedures, a single plane X-Y stage with ultra-precision positioning is manufactured. A global stage for materialization with robust system is combined by using an AC servo motor with a ball screw and rolling guide. An ultra-precision positioning system is developed using a micro stage with an elastic hinge and piezo element. Global and micro servos for positioning with nanometer accuracy are controlled simultaneously using an incremental encoder and a laser interferometer to measure displacement. Using established procedures, an ultra-precision positioning system (100 mm stroke and ±10 nm positioning accuracy) with a single plane X-Y stage is fabricated. Its performance is evaluated through simulation using Matlab. After analyzing previous control algorithms and adapting modern control theory, a dual servo algorithm is developed for a minimum order observer to secure the stability and priority on the controller. The simulations and experiments on the ultra precision positioning and the stability of the ultra-precision positioning system with single plane X-Y stage and the priority of the control algorithm are secured by using Matlab with Simulink and ControlDesk made in dSPACE

Nano positioning control for dual stage using minimum order observer

Energy Technology Data Exchange (ETDEWEB)

Kim, Hong Gun [Jeonju University, Jeonju (Korea, Republic of)

2012-03-15

A nano positioning control is developed using the ultra-precision positioning apparatus such as actuator, sensor, guide, power transmission element with an appropriate control method. Using established procedures, a single plane X-Y stage with ultra-precision positioning is manufactured. A global stage for materialization with robust system is combined by using an AC servo motor with a ball screw and rolling guide. An ultra-precision positioning system is developed using a micro stage with an elastic hinge and piezo element. Global and micro servos for positioning with nanometer accuracy are controlled simultaneously using an incremental encoder and a laser interferometer to measure displacement. Using established procedures, an ultra-precision positioning system (100 mm stroke and {+-}10 nm positioning accuracy) with a single plane X-Y stage is fabricated. Its performance is evaluated through simulation using Matlab. After analyzing previous control algorithms and adapting modern control theory, a dual servo algorithm is developed for a minimum order observer to secure the stability and priority on the controller. The simulations and experiments on the ultra precision positioning and the stability of the ultra-precision positioning system with single plane X-Y stage and the priority of the control algorithm are secured by using Matlab with Simulink and ControlDesk made in dSPACE.

Optimising position control of a solar parabolic trough

Directory of Open Access Journals (Sweden)

Puramanathan Naidoo

2011-03-01

Full Text Available In today’s climate of growing energy needs and increasing environmental concerns, alternatives to the use of non-renewable and polluting fossil fuels have to be investigated. One such alternative is solar energy. This study is based on the implementation of a mathematical computation – the PSA (Plataforma Solar de Almeria computation developed at PSA (the European Test Centre for solar energy applications – embedded in a control algorithm to locate the position of the sun. Tests were conducted on a solar parabolic trough (SPT constructed at the Solar Thermal Applications Research Laboratory of the Mangosuthu University of Technology (Durban, South Africa for optimal position control using the PSA value. The designed control algorithm embedded in an industrial Siemens S7-314 C-2PtP programmable logic controller compared the PSA computation to a measured position of the SPT to optimally rotate the SPT to a desired position with the constant movement of the sun. The two main angles of the sun relative to the position of the SPT on earth, the zenith angle and the azimuth angle, both calculated in the PSA from the vertical and horizontal planes, respectively, were applied to the control algorithm to generate an appropriate final tracking angle within a 0.007 radian (0° 24′ 3.6″ tolerance, in accordance to the construction specifications and solar collector testing standards of the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE, 1991. These values, together with the longitude and latitude applicable to the geographical location of the SPT, were processed in the control software to rotate the SPT to an optimal position with respect to the position of the sun in its daily path, for solar-to-thermal conversion.

Motivation enhances control of positive and negative emotional distractions.

Science.gov (United States)

Walsh, Amy T; Carmel, David; Harper, David; Grimshaw, Gina M

2018-01-03

Using cognitive control to ignore distractions is essential for successfully achieving our goals. In emotionally-neutral contexts, motivation can reduce interference from irrelevant stimuli by enhancing cognitive control. However, attention is commonly biased towards emotional stimuli, making them potent distractors. Can motivation aid control of emotional distractions, and does it do so similarly for positive and negative stimuli? Here, we examined how task motivation influences control of distraction from positive, negative, and neutral scenes. Participants completed a simple perceptual task while attempting to ignore task-irrelevant images. One group received monetary reward for fast and accurate task performance; another (control) group did not. Overall, both negative (mutilation) and positive (erotic) images caused greater slowing of responses than neutral images of people, but emotional distraction was reduced with reward. Crucially, despite the different motivational directions associated with negative and positive stimuli, reward reduced negative and positive distraction equally. Our findings suggest that motivation may encourage the use of a sustained proactive control strategy that can effectively reduce the impact of emotional distraction.

Control system design for nano-positioning using piezoelectric actuators

International Nuclear Information System (INIS)

Shan, Jinjun; Liu, Yanfang; Cui, Naigang; Gabbert, Ulrich

2016-01-01

This paper presents a systematic control system design for nano-positioning of a piezoelectric actuator (PEA). PEAs exhibit hysteresis nonlinearity, which can dramatically limit the application and performance of linear feedback control theory. Thus the hysteresis is compensated for based on the Maxwell resistive capacitor (MRC) model first. Then a proportional plus integral (PI) controller and a proportional double integral plus lead compensation (PII and L) controller are designed for the hysteresis-compensated PEA to account for model uncertainty, disturbance, and noise. The robust stability of both controllers is proved. The effectiveness of the proposed control scheme is demonstrated experimentally. Both controllers achieve fast precise positioning. The 2% settling times for the PI controller and the PII and L controller are 1.5 ms and 4.7 ms, respectively. The positioning resolution is upto 1 nm for both controllers. (paper)

Tracking control mechanisms for positioning automatic CRD exchanger

International Nuclear Information System (INIS)

Koizumi, Akira; Takada, Satoshi.

1984-01-01

Purpose: To enable completely automatic positioning for the automatic CRD (control rod drives) exchanger, as well as shorten the time for the exchanging operation and save the operator's labour. Constitution: Images of a target attached to the lower flange face of CRD are picked up by a fiber scope mounted to a mounting head. The images are converted through I.T.V. into electrical signals, passed through a cable and then sent to a pattern recognition mechanism. The position for the images of the target is calculated and the calculated position is sent to a drive control section, where the position for the images of the target is compared with a reference position for the images (exactly aligned position) and the moving amount of the mounting head is calculated to move the driving section and thereby complete the positioning. (Kawakami, Y.)

Plasma position control device for thermonuclear device

Energy Technology Data Exchange (ETDEWEB)

Onozuka, Masanori [Mitsubishi Heavy Industries Ltd., Tokyo (Japan); Fujita, Jun-ya; Ioki, Kimihiro

1995-10-03

The present invention concerns plasma position control coils having a feeder line structure not requiring high strength for the support portion. Namely, the coils are formed by twisting feeder lines extended from plasma position control coils in a vacuum vessel. The twisted feeder lines are supported using an appropriate structural member. Electromagnetic load is generated to the feeder lines being extended from the position control coils and traversing toroidal fields at a current introduction lines and at current delivery lines respectively. However, since the feeder lines have substantially spiral shape consisting of two twisted lines, the electromagnetic load and the moment caused by the generated load which are inversed to each other are off set. Accordingly, only extremely small force is exerted on the fittings which support the feeder lines. Therefore, small strength may suffice for the fittings and the gaps of mounting the fittings may be made longer. (I.S.).

Plasma position control device for thermonuclear device

International Nuclear Information System (INIS)

Onozuka, Masanori; Fujita, Jun-ya; Ioki, Kimihiro.

1995-01-01

The present invention concerns plasma position control coils having a feeder line structure not requiring high strength for the support portion. Namely, the coils are formed by twisting feeder lines extended from plasma position control coils in a vacuum vessel. The twisted feeder lines are supported using an appropriate structural member. Electromagnetic load is generated to the feeder lines being extended from the position control coils and traversing toroidal fields at a current introduction lines and at current delivery lines respectively. However, since the feeder lines have substantially spiral shape consisting of two twisted lines, the electromagnetic load and the moment caused by the generated load which are inversed to each other are off set. Accordingly, only extremely small force is exerted on the fittings which support the feeder lines. Therefore, small strength may suffice for the fittings and the gaps of mounting the fittings may be made longer. (I.S.)

Impulse position control algorithms for nonlinear systems

Energy Technology Data Exchange (ETDEWEB)

Sesekin, A. N., E-mail: sesekin@list.ru [Ural Federal University, 19 S. Mira, Ekaterinburg, 620002 (Russian Federation); Institute of Mathematics and Mechanics, Ural Division of Russian Academy of Sciences, 16 S. Kovalevskaya, Ekaterinburg, 620990 (Russian Federation); Nepp, A. N., E-mail: anepp@urfu.ru [Ural Federal University, 19 S. Mira, Ekaterinburg, 620002 (Russian Federation)

2015-11-30

The article is devoted to the formalization and description of impulse-sliding regime in nonlinear dynamical systems that arise in the application of impulse position controls of a special kind. The concept of trajectory impulse-sliding regime formalized as some limiting network element Euler polygons generated by a discrete approximation of the impulse position control This paper differs from the previously published papers in that it uses a definition of solutions of systems with impulse controls, it based on the closure of the set of smooth solutions in the space of functions of bounded variation. The need for the study of such regimes is the fact that they often arise when parry disturbances acting on technical or economic control system.

Impulse position control algorithms for nonlinear systems

Science.gov (United States)

Sesekin, A. N.; Nepp, A. N.

2015-11-01

The article is devoted to the formalization and description of impulse-sliding regime in nonlinear dynamical systems that arise in the application of impulse position controls of a special kind. The concept of trajectory impulse-sliding regime formalized as some limiting network element Euler polygons generated by a discrete approximation of the impulse position control This paper differs from the previously published papers in that it uses a definition of solutions of systems with impulse controls, it based on the closure of the set of smooth solutions in the space of functions of bounded variation. The need for the study of such regimes is the fact that they often arise when parry disturbances acting on technical or economic control system.

Optogenetic control of organelle transport and positioning

NARCIS (Netherlands)

van Bergeijk, Petra; Adrian, Max; Hoogenraad, Casper C; Kapitein, Lukas C

2015-01-01

Proper positioning of organelles by cytoskeleton-based motor proteins underlies cellular events such as signalling, polarization and growth. For many organelles, however, the precise connection between position and function has remained unclear, because strategies to control intracellular organelle

Car-Like Mobile Robot Oriented Positioning by Fuzzy Controllers

Directory of Open Access Journals (Sweden)

Noureddine Ouadah

2008-11-01

Full Text Available In this paper, fuzzy logic controllers (FLC are used to implement an efficient and accurate positioning of an autonomous car-like mobile robot, respecting final orientation. To accomplish this task, called "Oriented Positioning", two FLC have been developed: robot positioning controller (RPC and robot following controller (RFC. Computer simulation results illustrate the effectiveness of the proposed technique. Finally, real-time experiments have been made on an autonomous car-like mobile robot called "Robucar", developed to perform people transportation. Obtained results from experiments demonstrate the effectiveness of the proposed control strategy.

Development of the 'JFT-2' tokamak plasma position control system

International Nuclear Information System (INIS)

Fujisawa, Noboru; Matsuzaki, Yoshimi; Suzuki, Norio; Murai, Katsuji; Suzuki, Satoshi.

1980-01-01

Digital control technique was applied to control the plasma position in the JFT-2 tokamak experiment device. The detail of the JFT-2 is described elsewhere. The plasma position control system consists of a Hitachi control computer, HIDIC 80, and a Hitachi micro-computer, HIDIC 08E. The plasma position is detected by the position control computer, and compared with a preset value. Then, a reference signal is supplied to the micro-computer controlling power source, and the phase control of the thyristor controlling power source is performed. Since the behavior of plasma is very fast, the fast control is required. The control of the thyristor controlling power source is made by direct digital control (DDC). The main component of the hardware of the present system is the micro-computer HIDIC 08E. The software is the direct task system without the operating system (OS). The results of experiments showed that the feedback control of the system worked well. (Kato, T.)

Effect of Helicobacter pylori eradication and antisecretory maintenance therapy on peptic ulcer recurrence in cirrhotic patients: a prospective, cohort 2-year follow-up study.

Science.gov (United States)

Tzathas, Charalambos; Triantafyllou, Konstantinos; Mallas, Elias; Triantafyllou, George; Ladas, Spiros D

2008-07-01

The role of Helicobacter pylori eradication to cure peptic ulcer disease in patients with cirrhosis is not clear. To investigate the course of peptic ulcer disease in cirrhotics, first after healing with either H. pylori eradication or omeprazole therapy and second while on omeprazole maintenance therapy after recurrence. Prospective cohort study in a tertiary-care hospital in Greece. Out of 365 consecutive cirrhotic patients who underwent endoscopy, 67 had peptic ulcer and 30 were enrolled. H. pylori positive patients received eradication therapy and H. pylori negative patients received omeprazole treatment. Follow-up endoscopies were performed at 12 and 24 months or when symptoms recurred. Patients with ulcer recurrence were treated with omeprazole maintenance therapy. The main outcome measurement of the study was peptic ulcer relapse rate during follow-up. Twenty-eight patients with healed ulcers were followed for up to 2 years. During follow-up, ulcer relapsed in 17 patients (8/18 H. pylori positive and 9/10 H. pylori negative at study entry, P=0.041), including 2 patients who died from ulcer bleeding. No further ulcer relapse was observed in the remaining 15 patients who received omeprazole maintenance therapy for the rest of follow-up. H. pylori negative status (P=0.002) and severity of cirrhosis (P=0.015) at study entry were independently related to shorter peptic ulcer relapse-free time. H. pylori eradication does not protect all cirrhotics from ulcer recurrence and the majority of ulcers recur in H. pylori negative patients. Therefore, omeprazole maintenance treatment is mandatory, irrespectively of H. pylori status.

Advanced control of piezoelectric micro-nano-positioning systems

CERN Document Server

Xu, Qingsong

2016-01-01

This book explores emerging methods and algorithms that enable precise control of micro-/nano-positioning systems. The text describes three control strategies: hysteresis-model-based feedforward control and hysteresis-model-free feedback control based on and free from state observation. Each paradigm receives dedicated attention within a particular part of the text. Readers are shown how to design, validate and apply a variety of new control approaches in micromanipulation: hysteresis modelling, discrete-time sliding-mode control and model-reference adaptive control. Experimental results are provided throughout and build up to a detailed treatment of practical applications in the fourth part of the book. The applications focus on control of piezoelectric grippers. Advanced Control of Piezoelectric Micro-/Nano-Positioning Systems will assist academic researchers and practising control and mechatronics engineers interested in suppressing sources of nonlinearity such as hysteresis and drift when combining positi...

Coordinated joint motion control system with position error correction

Science.gov (United States)

Danko, George L.

2016-04-05

Disclosed are an articulated hydraulic machine supporting, control system and control method for same. The articulated hydraulic machine has an end effector for performing useful work. The control system is capable of controlling the end effector for automated movement along a preselected trajectory. The control system has a position error correction system to correct discrepancies between an actual end effector trajectory and a desired end effector trajectory. The correction system can employ one or more absolute position signals provided by one or more acceleration sensors supported by one or more movable machine elements. Good trajectory positioning and repeatability can be obtained. A two joystick controller system is enabled, which can in some cases facilitate the operator's task and enhance their work quality and productivity.

Automation of Aditya tokamak plasma position control DC power supply

Energy Technology Data Exchange (ETDEWEB)

Arambhadiya, Bharat, E-mail: bharat@ipr.res.in; Raj, Harshita; Tanna, R.L.; Edappala, Praveenlal; Rajpal, Rachana; Ghosh, Joydeep; Chattopadhyay, P.K.; Kalal, M.B.

2016-11-15

Highlights: • Plasma position control is very essential for obtaining repeatable high temperature, high-density discharges of longer durations in tokomak. • The present capacitor bank has limitations of maximum current capacity and position control beyond 200 ms. • The installation of a separate set of coils and a DC power supply can control the plasma position beyond 200 ms. • A high power thyristor (T588N1200) triggers for DC current pulse of 300 A fires precisely at required positions to modify plasma position. • The commissioning is done for the automated in-house, quick and reliable solution. - Abstract: Plasma position control is essential for obtaining repeatable high temperature, high-density discharges of longer duration in tokamaks. Recently, a set of external coils is installed in the vertical field mode configuration to control the radial plasma position in ADITYA tokamak. The existing capacitor bank cannot provide the required current pulse beyond 200 ms for position control. This motivated to have a DC power supply of 500 A to provide current pulse beyond 200 ms for the position control. The automatization of the DC power supply mandated interfaces with the plasma control system, Aditya Pulse Power supply, and Data acquisition system for coordinated discharge operation. A high current thyristor circuit and a timer circuit have been developed for controlling the power supply automatically for charging vertical field coils of Aditya tokamak. Key protection interlocks implemented in the development ensure machine and occupational safety. Fiber-optic trans-receiver isolates the power supply with other subsystems, while analog channel is optically isolated. Commissioning and testing established proper synchronization of the power supply with tokamak operation. The paper discusses the automation of the DC power supply with main circuit components, timing control, and testing results.

Self-tuning control studies of the plasma vertical position problem

International Nuclear Information System (INIS)

Zheng, Guang Lin; Wellstead, P.E.; Browne, M.L.

1993-01-01

The plasma vertical position system in a tokamak device can be open-loop unstable with time-varying dynamics, such that the instability increases with system dynamical changes. Time-varying unstable dynamics makes the plasma vertical position a particularly difficult one to control with traditional fixed-coefficient controllers. A self-tuning technique offers a new solution of the plasma vertical position control problem by an adaptive control approach. Specifically, the self-tuning controller automatically tunes the controller parameters without an a priori knowledge of the system dynamics and continuously tracks dynamical changes within the system, thereby providing the system with auto-tuning and adaptive tuning capabilities. An overview of the self-tuning methods is given, and their applicability to a simulation of the Joint European Torus (JET) vertical plasma positions system is illustrated. Specifically, the applicability of pole-assignment and generalized predictive control self-tuning methods to the vertical plasma position system is demonstrated. 26 refs., 16 figs., 1 tab

Assessment of Pharmacokinetic Interactions Between Obeticholic Acid and Caffeine, Midazolam, Warfarin, Dextromethorphan, Omeprazole, Rosuvastatin, and Digoxin in Phase 1 Studies in Healthy Subjects.

Science.gov (United States)

Edwards, Jeffrey E; Eliot, Lise; Parkinson, Andrew; Karan, Sharon; MacConell, Leigh

2017-09-01

Obeticholic acid (OCA), a potent and selective farnesoid X receptor agonist, is indicated for the treatment of primary biliary cholangitis (PBC). We investigated the potential drug-drug interaction effect of OCA on metabolic CYP450 enzymes and drug transporters. Five phase 1 single-center, open-label, fixed-sequence, inpatient studies were conducted in healthy adult subjects to evaluate the effect of oral daily doses of 10 or 25 mg OCA on single-dose plasma pharmacokinetics of specific probe substrates for enzymes CYP1A2 (caffeine, R-warfarin), CYP3A (midazolam, R-warfarin), CYP2C9 (S-warfarin), CYP2D6 (dextromethorphan), CYP2C19 (omeprazole), and drug transporters, BCRP/OATP1B1/OATP1B3 (rosuvastatin), and P-gp (digoxin). OCA showed no substantial suppression/inhibition of S-warfarin, digoxin, and dextromethorphan and weak interactions with caffeine, omeprazole, rosuvastatin, and midazolam. The maximal pharmacodynamic responses (E max ) to warfarin-based INR, PT, and aPTT were reduced by 11%, 11%, and 1%, respectively, for the 10-mg dose group and by 7%, 7% and 0%, respectively, for the 25-mg dose group. Overall, drugs dosed in combination with OCA were well tolerated, and most adverse events were mild in severity. No clinically important trends were noted in laboratory evaluations, vital signs, or 12-lead ECGs. In these studies, OCA showed weak to no suppression/inhibition of metabolic enzymes and drug transporters at the highest recommended therapeutic dose in patients with PBC. On the basis on these analyses, monitoring and maintenance of target INR range are required during coadministration of OCA with drugs that are metabolized by CYP1A2 (R-warfarin). Intercept Pharmaceuticals, Inc.

Digital control of plasma position in Damavand tokamak

Energy Technology Data Exchange (ETDEWEB)

Emami, M.; Babazadeh, A.R.; Roshan, M.V.; Memarzadeh, M.; Habibi, H. [Atomic Energy Organization of Iran (AEOI), Tehran (Iran, Islamic Republic of). Nuclear Fusion Research Center. Plasma Physics Lab.

2002-03-01

Plasma position control is one of the important issues in the design and operation of tokamak fusion research device. Since a tokamak is basically an electrical system consisting of power supplies, coils, plasma and eddy currents, a model in which these components are treated as an electrical circuits is used in designing Damavand plasma position control system. This model is used for the simulation of the digital control system and its parameters have been verified experimentally. In this paper, the performance of a high-speed digital controller as well as a simulation study and its application to the Damavand tokamak is discussed. (author)

Positive affect improves working memory: implications for controlled cognitive processing.

Science.gov (United States)

Yang, Hwajin; Yang, Sujin; Isen, Alice M

2013-01-01

This study examined the effects of positive affect on working memory (WM) and short-term memory (STM). Given that WM involves both storage and controlled processing and that STM primarily involves storage processing, we hypothesised that if positive affect facilitates controlled processing, it should improve WM more than STM. The results demonstrated that positive affect, compared with neutral affect, significantly enhanced WM, as measured by the operation span task. The influence of positive affect on STM, however, was weaker. These results suggest that positive affect enhances WM, a task that involves controlled processing, not just storage processing. Additional analyses of recall and processing times and accuracy further suggest that improved WM under positive affect is not attributable to motivational differences, but results instead from improved controlled cognitive processing.

Plasma position and shape control for ITER

International Nuclear Information System (INIS)

Portone, A.; Gribov, Y.; Huguet, M.

1995-01-01

Key features and main results about the control of the plasma shape in ITER are presented. A control algorithm is designed to control up to 6 gaps between the plasma separatrix and the plasma facing components during the reference burn phase. Nonlinear simulations show the performances of the controller in the presence of plasma vertical position offsets, beta drops and power supply voltage saturation

Fractional-order positive position feedback compensator for active vibration control of a smart composite plate

Science.gov (United States)

Marinangeli, L.; Alijani, F.; HosseinNia, S. Hassan

2018-01-01

In this paper, Active Vibration Control (AVC) of a rectangular carbon fibre composite plate with free edges is presented. The plate is subjected to out-of-plane excitation by a modal vibration exciter and controlled by Macro Fibre Composite (MFC) transducers. Vibration measurements are performed by using a Laser Doppler Vibrometer (LDV) system. A fractional-order Positive Position Feedback (PPF) compensator is proposed, implemented and compared to the standard integer-order PPF. MFC actuator and sensor are positioned on the plate based on maximal modal strain criterion, so as to control the second natural mode of the plate. Both integer and fractional-order PPF allowed for the effective control of the second mode of vibration. However, the newly proposed fractional-order controller is found to be more efficient in achieving the same performance with less actuation voltage. Moreover, it shows promising performance in reducing spillover effect due to uncontrolled modes.

Modeling And Position Control Of Scara Type 3D Printer

Directory of Open Access Journals (Sweden)

Ahmet Saygamp305n Ogulmuamp351

2015-08-01

Full Text Available In this work a scara robot type 3D printer system is dynamically modeled and position control of the system is realized. For this aim computer aided design model of three degrees of freedom robotic system is created using SolidWorks program then obtained model is exported to MATLABSimMechanics software for position control. Also mathematical model of servo motors used in robotic 3D printer system is included in control methodology to design proportional controllers. Uncontrolled and controlled position results are simulated and given in the form of the graphics.

Positive Exchange of Flight Controls Program

Science.gov (United States)

1995-03-10

This advisory circular provides guidance for all pilots, especially student pilots, flight instructors, and pilot examiners, on the recommended procedure to use for the positive exchange of flight controls between pilots when operating an aircraft.

奥美拉唑联合硫糖铝治疗急性出血性胃炎临床效果分析%The Analysis of Clinical Effect of Omeprazole Combined with Sucralfate in Treatment of Acute Hemorrhagic Gastritis

Institute of Scientific and Technical Information of China (English)

覃桂聪; 黄璐

2013-01-01

目的:探讨急性出血性胃炎的治疗方法及其临床效果.方法:92例患者随机分为治疗组46例,对照组46例,两组接受消化内科常规治疗,治疗组在此基础上接受奥美拉唑联合硫糖铝治疗,分析干预前后结果.结果:治疗组与对照组相比较,治疗组效果优于对照组,差异有统计学意义(P＜0.05)；治疗组与对照组相比较,治疗组复发率低于对照组,差异有统计学意义(P＜0.05)；患者无明显药物不良反应,用药依从性良好.结论:奥美拉唑联合硫糖铝治疗急性出血性胃炎临床效果显著,安全性高,值得进一步推广使用.%Objective: To study acute hemorrhagic gastritis treatment method and clinical effect. Method: 92 patients were randomly divided into the treatment group (46 cases) and control group (46 cases) , Both groups accepted digestive internal conventional treatment, the treatment group accepted omeprazole combined with sucralfate treatment addtional, analysed the results before and after the intervention. Result: The treatment group and control group were compared, the effect of the treatment group was better than that of control group (P < 0.05) ; and the the recurrence rate was lower intreatment group than those of the control group, the difference was statistically significant (P < 0. 05) ; The patient had no obvious adverse effect, and have good drug compliance. Conclusion: The clinical effect of omeprazole combined with sucralfate in treatment of acute hemorrhagic gastritis is remarkable, high safety, it is worthy of promotion.

Experimental Study on Position Control System Using Encoderless Magnetic Motion

Energy Technology Data Exchange (ETDEWEB)

Kim, Hong Youn; Heo, Hoon [Korea Univ., Seoul (Korea, Republic of); Yun, Young Min; Shim, Ho Keun; Kwon, Young Mok [TPC Mechatronics, Daejeon (Korea, Republic of)

2016-01-15

A position control system composed of the PMLSM(Permanent Magnet Linear Synchronous Motor), unlike conventional linear permanent magnet synchronous motor is fixed to the permanent magnet moving coil rails (permanent magnet = stator, coil = mover), the coil is fixed, moving the permanent magnet, we propose a position control system (permanent magnet = mover, coil = stator) structure. Position is measured not using conventional encoder or resolver but by adopting vector control method using 2 hall sensors generating rectangular signal. This method estimate the velocity and position of mover by using the quadruple of two hall sensor signal instead of encoder signal. Vector control of PMLSM using 2 hall sensor generating rectangular wave is proved to control the system stable and efficiently through simulation. Also hardware experiment reveals that the position control performance is measured within the range of 30-50μ in the accuracy of 10-20μ, which is improved twice to the conventional method. The proposed method exhibits its economical efficiency and practical usefulness. The vector control technique using two hall sensors can be installed in narrow place, accordingly it can be implemented on the system where the conventional encoder or resolver cannot operate.

Position Control of a Pneumatic Muscle Actuator Using RBF Neural Network Tuned PID Controller

Directory of Open Access Journals (Sweden)

Jie Zhao

2015-01-01

Full Text Available Pneumatic Muscle Actuator (PMA has a broad application prospect in soft robotics. However, PMA has highly nonlinear and hysteretic properties among force, displacement, and pressure, which lead to difficulty in accurate position control. A phenomenological model is developed to portray the hysteretic behavior of PMA. This phenomenological model consists of linear component and hysteretic component force. The latter component is described by Duhem model. An experimental apparatus is built up and sets of experimental data are acquired. Based on the experimental data, parameters of the model are identified. Validation of the model is performed. Then a novel cascade position PID controller is devised for a 1-DOF manipulator actuated by PMA. The outer loop of the controller is to cope with position control whilst the inner loop deals with pressure dynamics within PMA. To enhance the adaptability of the PID algorithm to the high nonlinearities of the manipulator, PID parameters are tuned online using RBF Neural Network. Experiments are performed and comparison between position response of RBF Neural Network based PID controller and that of classic PID controller demonstrates the effectiveness of the novel adaptive controller on the manipulator.

Development of Vision Control Scheme of Extended Kalman filtering for Robot's Position Control

International Nuclear Information System (INIS)

Jang, W. S.; Kim, K. S.; Park, S. I.; Kim, K. Y.

2003-01-01

It is very important to reduce the computational time in estimating the parameters of vision control algorithm for robot's position control in real time. Unfortunately, the batch estimation commonly used requires too murk computational time because it is iteration method. So, the batch estimation has difficulty for robot's position control in real time. On the other hand, the Extended Kalman Filtering(EKF) has many advantages to calculate the parameters of vision system in that it is a simple and efficient recursive procedures. Thus, this study is to develop the EKF algorithm for the robot's vision control in real time. The vision system model used in this study involves six parameters to account for the inner(orientation, focal length etc) and outer (the relative location between robot and camera) parameters of camera. Then, EKF has been first applied to estimate these parameters, and then with these estimated parameters, also to estimate the robot's joint angles used for robot's operation. finally, the practicality of vision control scheme based on the EKF has been experimentally verified by performing the robot's position control

Effects of Rolapitant Administered Intravenously on the Pharmacokinetics of a Modified Cooperstown Cocktail (Midazolam, Omeprazole, Warfarin, Caffeine, and Dextromethorphan) in Healthy Subjects.

Science.gov (United States)

Wang, Xiaodong; Zhang, Zhi-Yi; Arora, Sujata; Wang, Jing; Lu, Sharon; Powers, Dan; Kansra, Vikram

2018-04-25

Rolapitant is a selective, long-acting neurokinin-1 receptor antagonist, approved in the United States and Europe for prevention of delayed chemotherapy-induced nausea and vomiting in adults. This open-label study evaluated the effects of a new intravenous formulation of rolapitant on cytochrome P450 (CYP) enzyme (CYP3A, CYP1A2, CYP2C9, CYP2C19, and CYP2D6) activity. On days 1 and 14, 36 healthy volunteers received a modified Cooperstown cocktail (midazolam 3 mg [CYP3A substrate], caffeine 200 mg [CYP1A2 substrate], S-warfarin 10 mg [CYP2C9 substrate] + vitamin K 10 mg, omeprazole 40 mg [CYP2C19 substrate], and dextromethorphan 30 mg [CYP2D6 substrate]). On day 7, subjects received the modified Cooperstown cocktail after 166.5-mg rolapitant infusion. On days 21, 28, and 35, subjects received oral dextromethorphan. Maximum plasma concentration (C max ) and area under the plasma concentration-time curve (AUC 0-last ) of probe drugs post- vs pre-rolapitant administration were assessed using geometric least-squares mean ratios (GMRs) with 90%CIs. The 90%CIs of the GMRs were within the 0.80-1.25 no-effect limits for caffeine and S-warfarin C max and AUC 0-last . For midazolam C max and AUC 0-last and omeprazole C max , the 90%CIs of the GMRs were marginally outside these limits. Intravenous rolapitant coadministration increased dextromethorphan exposure, peaking 14 days post-rolapitant administration (GMRs: C max , 2.74, 90%CI 2.21-3.40; AUC 0-last , 3.36, 90%CI 2.74-4.13). Intravenous rolapitant 166.5 mg and probe drugs were well tolerated when coadministered. These data suggest that intravenous rolapitant is not an inhibitor of CYP3A, CYP2C9, CYP2C19, or CYP1A2 but is a moderate inhibitor of CYP2D6. © 2018, The American College of Clinical Pharmacology.

FPGA based Fuzzy Logic Controller for plasma position control in ADITYA Tokamak

International Nuclear Information System (INIS)

Suratia, Pooja; Patel, Jigneshkumar; Rajpal, Rachana; Kotia, Sorum; Govindarajan, J.

2012-01-01

Highlights: ► Evaluation and comparison of the working performance of FLC is done with that of PID Controller. ► FLC is designed using MATLAB Fuzzy Logic Toolbox, and validated on ADITYA RZIP model. ► FLC was implemented on a FPGA. The close-loop testing is done by interfacing FPGA to MATLAB/Simulink. ► Developed FLC controller is able to maintain the plasma column within required range of ±0.05 m and was found to give robust control against various disturbances and faster and smoother response compared to PID Controller. - Abstract: Tokamaks are the most promising devices for obtaining nuclear fusion energy from high-temperature, ionized gas termed as Plasma. The successful operation of tokamak depends on its ability to confine plasma at the geometric center of vacuum vessel with sufficient stability. The quality of plasma discharge in ADITYA Tokamak is strongly related to the radial position of the plasma column in the vacuum vessel. If the plasma column approaches too near to the wall of vacuum vessel, it leads to minor or complete disruption of plasma. Hence the control of plasma position throughout the entire plasma discharge duration is a fundamental requirement. This paper describes Fuzzy Logic Controller (FLC) which is designed for radial plasma position control. This controller is tested and evaluated on the ADITYA RZIP control model. The performance of this FLC was compared with that of Proportional–Integral–Derivative (PID) Controller and the response was found to be faster and smoother. FLC was implemented on a Field Programmable Gate Array (FPGA) chip with the use of a Very High-Speed Integrated-Circuits Hardware Description-Language (VHDL).

Car-Like Mobile Robot Oriented Positioning by Fuzzy Controllers

Directory of Open Access Journals (Sweden)

Noureddine Ouadah

2008-09-01

Full Text Available In this paper, fuzzy logic controllers (FLC are used to implement an efficient and accurate positioning of an autonomous car-like mobile robot, respecting final orientation. To accomplish this task, called “Oriented Positioning”, two FLC have been developed: robot positioning controller (RPC and robot following controller (RFC. Computer simulation results illustrate the effectiveness of the proposed technique. Finally, real-time experiments have been made on an autonomous car-like mobile robot called “Robucar”, developed to perform people transportation. Obtained results from experiments demonstrate the effectiveness of the proposed control strategy.

A compound control strategy combining velocity compensation with ADRC of electro-hydraulic position servo control system.

Science.gov (United States)

Gao, Bingwei; Shao, Junpeng; Yang, Xiaodong

2014-11-01

In order to enhance the anti-jamming ability of electro-hydraulic position servo control system at the same time improve the control precision of the system, a compound control strategy that combines velocity compensation with Active Disturbance Rejection Controller (ADRC) is proposed, and the working principle of the compound control strategy is given. ADRC controller is designed, and the extended state observer is used for observing internal parameters uncertainties and external disturbances, so that the disturbances of the system are suppressed effectively. Velocity compensation controller is designed and the compensation model is derived to further improve the positioning accuracy of the system and to achieve the velocity compensation without disturbance. The compound control strategy is verified by the simulation and experiment respectively, and the simulation and experimental results show that the electro-hydraulic position servo control system with ADRC controller can effectively inhibit the external disturbances, the precise positioning control is realized after introducing the velocity compensation controller, and verify that the compound control strategy is effective. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

Control of spool position of on/off solenoid operated hydraulic valve by sliding-mode controller

Energy Technology Data Exchange (ETDEWEB)

Lee, Jae Hak; Hong, Hyun Wook; Park, Myeong Kwan [Pusan National University, Busan (Korea, Republic of); Yun, Young Won [KHPS, Busan (Korea, Republic of)

2015-11-15

The use of on/off solenoid operated hydraulic valves instead of proportional valves has been attracting the interest of many researchers and engineers. However, there exist difficulties in controlling the on/off valve because of highly nonlinear characteristics including hysteresis and saturation. This paper considers the application of on/off solenoid operated hydraulic valves to control position of a hydraulic cylinder with the aim of evaluating, feasibility and practicability of their implementation and understanding the potential benefits when they are used in existing hydraulic systems. Assuming that only the current is measured, a sliding mode observer is designed to estimate the spool position and velocity. To alleviate the aforementioned difficulties in controlling the spool position, a nonlinear observer-based controller of an on/off solenoid valve is designed, taking into account the estimated values, based on a nonlinear model including hysteresis and saturation. The control objective is to track a desired spool trajectory. Simulation and experimental results illustrate the efficiency of the designed controller. The proposed controller is validated again in a single-rod hydraulic actuator. Experimental results show that the fluid flow through the valve orifice by controlling the spool position was successfully controlled.

Peer Positive Social Control and Men's Health-Promoting Behaviors.

Science.gov (United States)

Houle, Janie; Meunier, Sophie; Coulombe, Simon; Mercerat, Coralie; Gaboury, Isabelle; Tremblay, Gilles; de Montigny, Francine; Cloutier, Lyne; Roy, Bernard; Auger, Nathalie; Lavoie, Brigitte

2017-09-01

Men are generally thought to be less inclined to take care of their health. To date, most studies about men's health have focused on deficits in self-care and difficulties in dealing with this sphere of their life. The present study reframes this perspective, using a salutogenic strengths-based approach and seeking to identify variables that influence men to take care of their health, rather than neglect it. This study focuses on the association between peer positive social control and men's health behaviors, while controlling for other important individual and social determinants (sociodemographic characteristics, health self-efficacy, home neighborhood, spousal positive social control, and the restrictive emotionality norm). In a mixed-method study, 669 men answered a self-reported questionnaire, and interviews were conducted with a maximum variation sample of 31 men. Quantitative results indicated that, even after controlling for sociodemographic variables and other important factors, peer positive social control was significantly associated with the six health behaviors measured in the study (health responsibility, nutrition, physical activity, interpersonal relations, stress management, and spirituality). Interview results revealed that peer positive social control influenced men's health behaviors through three different mechanisms: shared activity, being inspired, and serving as a positive role model for others. In summary, friends and coworkers could play a significant role in promoting various health behaviors among adult men in their daily life. Encouraging men to socialize and discuss health, and capitalizing on healthy men as role models appear to be effective ways to influence health behavior adoption among this specific population.

Position Control of Linear Synchronous Motor Drives with Exploitation of Forced Dynamics Control Principles

Directory of Open Access Journals (Sweden)

Jan Vittek

2004-01-01

Full Text Available Closed-loop position control of mechanisms directly driven by linear synchronous motors with permanent magnets is presented. The control strategy is based on forced dynamic control, which is a form of feedback linearisation, yielding a non-liner multivariable control law to obtain a prescribed linear speed dynamics together with the vector control condition of mutal orthogonality between the stator current and magnetic flux vectors (assuming perfect estimates of the plant parameters. Outer position control loop is closed via simple feedback with proportional gain. Simulations of the design control sysstem, including the drive with power electronic switching, predict the intended drive performance.

A digital position-indication system for control rods

International Nuclear Information System (INIS)

Nishizawa, Yukio; Hayakawa, Toshifumi

1979-01-01

Systems that detect and indicate the position of the control rods that regulate the thermal output of a nuclear reactor play a particularly important role in monitoring its operational status. Conventionally, control rod position indication in pressurized water reactors has been of the analog type, utilizing the principle of the differential transformer. The present digital system was developed with the objective of achieving greater stability, greater accuracy, and higher reliability. The article gives a general description of the system and describes its advantages. (author)

INDOOR POSITIONING AND NAVIGATION BASED ON CONTROL SPHERECAL PANORAMIC IMAGES

Directory of Open Access Journals (Sweden)

T.-C. Huang

2016-06-01

Full Text Available Continuous indoor and outdoor positioning and navigation is the goal to achieve in the field of mobile mapping technology. However, accuracy of positioning and navigation will be largely degraded in indoor or occluded areas, due to receiving weak or less GNSS signals. Targeting the need of high accuracy indoor and outdoor positioning and navigation for mobile mapping applications, the objective of this study is to develop a novel method of indoor positioning and navigation with the use of spherical panoramic image (SPI. Two steps are planned in the technology roadmap. First, establishing a control SPI database that contains a good number of well-distributed control SPIs pre-acquired in the target space. A control SPI means an SPI with known exterior orientation parameters, which can be solved with a network bundle adjustment of SPIs. Having a control SPI database, the target space will be ready to provide the service of positioning and navigation. Secondly, the position and orientation of a newly taken SPI can be solved by using overlapped SPIs searched from the control SPI database. The method of matching SPIs and finding conjugate image features will be developed and tested. Two experiments will be planned and conducted in this paper to test the feasibility and validate the test results of the proposed methods. Analysis of appropriate number and distribution of needed control SPIs will also be included in the experiments with respect to different test cases.

Selective control of attention supports the positivity effect in aging.

Science.gov (United States)

Sasse, Laura K; Gamer, Matthias; Büchel, Christian; Brassen, Stefanie

2014-01-01

There is emerging evidence for a positivity effect in healthy aging, which describes an age-specific increased focus on positive compared to negative information. Life-span researchers have attributed this effect to the selective allocation of cognitive resources in the service of prioritized emotional goals. We explored the basic principles of this assumption by assessing selective attention and memory for visual stimuli, differing in emotional content and self-relevance, in young and old participants. To specifically address the impact of cognitive control, voluntary attentional selection during the presentation of multiple-item displays was analyzed and linked to participants' general ability of cognitive control. Results revealed a positivity effect in older adults' selective attention and memory, which was particularly pronounced for self-relevant stimuli. Focusing on positive and ignoring negative information was most evident in older participants with a generally higher ability to exert top-down control during visual search. Our findings highlight the role of controlled selectivity in the occurrence of a positivity effect in aging. Since the effect has been related to well-being in later life, we suggest that the ability to selectively allocate top-down control might represent a resilience factor for emotional health in aging.

Robust position control of induction motor using fuzzy logic control

International Nuclear Information System (INIS)

Kim, Sei Chan; Kim, Duk Hun; Yang, Seung Ho; Won, Chung Yuen

1993-01-01

In recent years, fuzzy logic or fuzzy set theory has reveived attention of a number of researchers in the area of power electronics and motion control. The paper describes a vector-controlled induction motor position servo drive where fuzzy control is used to get robustness against parameter variation and load torque disturbance effects. Both coarse and fine control with the help of look-up rule tables are used to improve transient response and system settling time. The performance characteristics are then compared with those of proportional-integral(PI) control. The simulation results clearly indicate the superiority of fuzzy control with larger number of rules. The fuzzy controller was implemented with a 16-bit microprocessor and tested in laboratory on a 3-hp IGBT inverter induction motor drive system. The test results verify the simulation performance. (Author)

Novel electro-hydraulic position control system for primary mirror supporting system

Directory of Open Access Journals (Sweden)

Xiongbin Peng

2016-05-01

Full Text Available In the field of modern large-scale telescope, primary mirror supporting system technology faces the difficulties of theoretically uniform output force request and bias compensation. Therefore, a novel position control system combining hydraulic system with servo motor system is introduced. The novel system ensures uniform output force on supporting points without complicating the mechanical structure. The structures of both primary mirror supporting system and novel position system are described. Then, the mathematical model of novel position control system is derived for controller selection. A proportional–derivative controller is adopted for simulations and experiments of step response and triangle path tracking. The results show that proportional–derivative controller guarantees the system with micrometer-level positioning ability. A modified proportional–derivative controller is utilized to promote system behavior with faster response overshoot. The novel position control system is then applied on primary mirror supporting system. Coupling effect is observed among actuator partitions, and relocation of virtual pivot supporting point is chosen as the decoupling measurement. The position keeping ability of the primary mirror supporting system is verified by rotating the mirror cell at a considerably high rate. The experiment results show that the decoupled system performs better with smaller bias and shorter recovery time.

Selective control of attention supports the positivity effect in aging.

Directory of Open Access Journals (Sweden)

Laura K Sasse

Full Text Available There is emerging evidence for a positivity effect in healthy aging, which describes an age-specific increased focus on positive compared to negative information. Life-span researchers have attributed this effect to the selective allocation of cognitive resources in the service of prioritized emotional goals. We explored the basic principles of this assumption by assessing selective attention and memory for visual stimuli, differing in emotional content and self-relevance, in young and old participants. To specifically address the impact of cognitive control, voluntary attentional selection during the presentation of multiple-item displays was analyzed and linked to participants' general ability of cognitive control. Results revealed a positivity effect in older adults' selective attention and memory, which was particularly pronounced for self-relevant stimuli. Focusing on positive and ignoring negative information was most evident in older participants with a generally higher ability to exert top-down control during visual search. Our findings highlight the role of controlled selectivity in the occurrence of a positivity effect in aging. Since the effect has been related to well-being in later life, we suggest that the ability to selectively allocate top-down control might represent a resilience factor for emotional health in aging.

Incentive-Rewarding Mechanism for User-position Control in Mobile Services

Science.gov (United States)

Yoshino, Makoto; Sato, Kenichiro; Shinkuma, Ryoichi; Takahashi, Tatsuro

When the number of users in a service area increases in mobile multimedia services, no individual user can obtain satisfactory radio resources such as bandwidth and signal power because the resources are limited and shared. A solution for such a problem is user-position control. In the user-position control, the operator informs users of better communication areas (or spots) and navigates them to these positions. However, because of subjective costs caused by subjects moving from their original to a new position, they do not always attempt to move. To motivate users to contribute their resources in network services that require resource contributions for users, incentive-rewarding mechanisms have been proposed. However, there are no mechanisms that distribute rewards appropriately according to various subjective factors involving users. Furthermore, since the conventional mechanisms limit how rewards are paid, they are applicable only for the network service they targeted. In this paper, we propose a novel incentive-rewarding mechanism to solve these problems, using an external evaluator and interactive learning agents. We also investigated ways of appropriately controlling rewards based on user contributions and system service quality. We applied the proposed mechanism and reward control to the user-position control, and demonstrated its validity.

Position calibration of a 3-DOF hand-controller with hybrid structure

Science.gov (United States)

Zhu, Chengcheng; Song, Aiguo

2017-09-01

A hand-controller is a human-robot interactive device, which measures the 3-DOF (Degree of Freedom) position of the human hand and sends it as a command to control robot movement. The device also receives 3-DOF force feedback from the robot and applies it to the human hand. Thus, the precision of 3-DOF position measurements is a key performance factor for hand-controllers. However, when using a hybrid type 3-DOF hand controller, various errors occur and are considered originating from machining and assembly variations within the device. This paper presents a calibration method to improve the position tracking accuracy of hybrid type hand-controllers by determining the actual size of the hand-controller parts. By re-measuring and re-calibrating this kind of hand-controller, the actual size of the key parts that cause errors is determined. Modifying the formula parameters with the actual sizes, which are obtained in the calibrating process, improves the end position tracking accuracy of the device.

New approach for control rod position indication system for light water power reactor

International Nuclear Information System (INIS)

Bahuguna, Sushil; Dhage, Sangeeta; Nawaj, S.; Salek, C.; Lahiri, S.K.; Marathe, P.P.; Mukhopadhyay, S.; Taly, Y.K.

2015-01-01

Control rod position indication system is an important system in a nuclear power plant to monitor and display control rod position in all regimes of reactor operation. A new approach to design a control rod position indication system for sensing absolute position of control rod in Light Water Power Reactor has been undertaken. The proposed system employs an inductive type, hybrid measurement strategy providing both analog position as well as digital zone indication with built-in temperature compensation. The new design approach meets single failure criterion through redundancy in design without sacrificing measurement resolution. It also provides diversity in measurement technique by indirect position sensing based on analysis of drive coil current signature. Prototype development and qualification at room temperature of the control rod position indication system (CRPIS) has been demonstrated. The article presents the design philosophy of control rod position indication system, the new measurement strategy for sensing absolute position of control rod, position estimation algorithm for both direct and indirect sensing and a brief account associated processing electronics. (author)

Preliminary performance test of control rod position indicator for ballscrew type CEDM

International Nuclear Information System (INIS)

Yoo, J. Y.; Kim, J. H.; Hu, H.; Lee, J. S.; Kim, J. I.

2003-01-01

The reliability and accuracy of the information on control rod position are very important to the reactor safety and the design of the core protection system. A survey on the RSPT(Reed Switch Position Transmitter) type control rod position indication system and its actual implementation in the exiting nuclear power plants in Korea was performed first. The prototype of control rod position indicator having the high performance for the ballscrew type CEDM was developed on the basis of RSPT technology identified through the survey. The characteristics of control rod position indicator was defined and documented through design procedure and preliminary performance test

Design and reliability analysis of DP-3 dynamic positioning control architecture

Science.gov (United States)

Wang, Fang; Wan, Lei; Jiang, Da-Peng; Xu, Yu-Ru

2011-12-01

As the exploration and exploitation of oil and gas proliferate throughout deepwater area, the requirements on the reliability of dynamic positioning system become increasingly stringent. The control objective ensuring safety operation at deep water will not be met by a single controller for dynamic positioning. In order to increase the availability and reliability of dynamic positioning control system, the triple redundancy hardware and software control architectures were designed and developed according to the safe specifications of DP-3 classification notation for dynamically positioned ships and rigs. The hardware redundant configuration takes the form of triple-redundant hot standby configuration including three identical operator stations and three real-time control computers which connect each other through dual networks. The function of motion control and redundancy management of control computers were implemented by software on the real-time operating system VxWorks. The software realization of task loose synchronization, majority voting and fault detection were presented in details. A hierarchical software architecture was planed during the development of software, consisting of application layer, real-time layer and physical layer. The behavior of the DP-3 dynamic positioning control system was modeled by a Markov model to analyze its reliability. The effects of variation in parameters on the reliability measures were investigated. The time domain dynamic simulation was carried out on a deepwater drilling rig to prove the feasibility of the proposed control architecture.

Gastroesophageal reflux disease and its association with bronchiolitis obliterans syndrome in allogeneic hematopoietic stem cell transplant recipients.

Science.gov (United States)

Khalid, Mohammed; Aljurf, Mahmoud; Saleemi, Sarfraz; Khan, Mohammed Qaseem; Khan, Basha; Ahmed, Shad; Ibrahim, Khalid El Tayeb; Mobeireek, Abdullah; Al Mohareb, Fahad; Chaudhri, Naeem

2013-06-01

Bronchiolitis obliterans syndrome is a significant postallogeneic hematopoietic stem cell transplant problem. Recent data in lung transplant patients suggest an association with gastroesophageal reflux disease and bronchiolitis obliterans syndrome. We studied posthematopoietic stem cell transplant patients with bronchiolitis obliterans syndrome for gastroesophageal reflux disease and its response to a proton pump inhibitor. Seven postallogeneic hematopoietic stem cell transplant patients with bronchiolitis obliterans syndrome were studied. Gastroesophageal reflux disease was assessed by 24-hour pH monitoring with a Bravo catheter-free radio pH capsule. Patients with positive gastroesophageal reflux disease were started on omeprazole. Pretreatment and posttreatment pulmonary function tests were done at 3-month intervals. Of 7 patients, 5 had positive results for gastroesophageal reflux disease (71%). Omeprazole had a disease-stabilizing effect on the patients' pulmonary function tests. Our study shows a significant association between bronchiolitis obliterans syndrome and gastroesophageal reflux disease in postallogeneic hematopoietic stem cell transplant patients. Use of omeprazole may have a disease-stabilizing effect in short-term follow-up.

Structure of the automatic system for plasma equilibrium position control

International Nuclear Information System (INIS)

Gubarev, V.F.; Krivonos, Yu.G.; Samojlenko, Yu.I.; Snegur, A.A.

1978-01-01

Considered are the principles of construction of the automatic system for plasma filament equilibrium position control inside the discharge chamber for the installation of a tokamak type. The combined current control system in control winding is suggested. The most powerful subsystem creates current in the control winding according to the program calculated beforehand. This system provides plasma rough equilibrium along the ''big radius''. The subsystem performing the current change in small limits according to the principle of feed-back coupling is provided simultaneously. The stabilization of plasma position is achieved in the discharge chamber. The advantage of construction of such system is in decreasing of the automatic requlator power without lowering the requirements to the accuracy of equilibrium preservation. The subsystem of automatic control of plasma position over the vertical is put into the system. Such an approach to the construction of the automatic control system proves to be correct; it is based on the experience of application of similar devices for some existing thermonuclear plants

Hysteresis Analysis and Positioning Control for a Magnetic Shape Memory Actuator

Science.gov (United States)

Lin, Jhih-Hong; Chiang, Mao-Hsiung

2015-01-01

Magnetic shape memory alloys (MSM alloys), a new kind of smart materials, have become a potential candidate in many engineering fields. MSMs have the advantage of bearing a huge strain, much larger than other materials. In addition, they also have fast response. These characteristics make MSM a good choice in micro engineering. However, MSMs display the obvious hysteresis phenomenon of nonlinear behavior. Thus the difficulty in using the MSM element as a positioning actuator is increased due to the hysteresis. In this paper, the hysteresis phenomenon of the MSM actuator is analyzed, and the closed-loop positioning control is also implemented experimentally. For that, a modified fuzzy sliding mode control (MFSMC) is proposed. The MFSMC and the PID control are used to design the controllers for realizing the positioning control. The experimental results are compared under different experimental conditions, such as different frequency, amplitude, and loading. The experimental results show that the precise positioning control of MFSMC can be achieved satisfactorily. PMID:25853405

Attentional control mediates the effect of social anxiety on positive affect☆

Science.gov (United States)

Morrison, Amanda S.; Heimberg, Richard G.

2015-01-01

The goal of the present studies was to examine whether attentional control, a self-regulatory attentional mechanism, mediates the effect of social anxiety on positive affect. We tested this mediation in two studies using undergraduate students selected to represent a broad range of severity of social anxiety. Self-report assessments of social anxiety, attentional control, and positive affect were collected in a cross-sectional design (Study 1) and in a longitudinal design with three assessment points (Study 2). Results of both studies supported the hypothesized mediational model. Specifically, social anxiety was inversely related to attentional control, which itself positively predicted positive affect. This mediation remained significant even when statistically controlling for the effects of depression. Additionally, the hypothesized model provided superior model fit to theoretically-grounded equivalent models in both studies. Implications of these findings for understanding diminished positive affect in social anxiety are discussed. PMID:23254261

Integrated shell approach to vertical position control on PBX-M

International Nuclear Information System (INIS)

Hatcher, R.E.; Okabayashi, M.

1995-03-01

The PBX-M device produces highly shaped discharges that, because of the negative external magnetic field decay index required, are vertically unstable. Vertical positional stability in PBX-M has been achieved by directly controlling the n = 0 component of the eddy current in the passive shell instead of the commonly used function of magnetic flux signals. Because the active coil is controlled via currents in the passive shell we call this an ''integrated shell'' approach to vertical position control. We present results of these experiments and make comparisons between the two methods of control

Position Control of the Single Spherical Wheel Mobile Robot by Using the Fuzzy Sliding Mode Controller

Directory of Open Access Journals (Sweden)

Hamed Navabi

2017-01-01

Full Text Available A spherical wheel robot or Ballbot—a robot that balances on an actuated spherical ball—is a new and recent type of robot in the popular area of mobile robotics. This paper focuses on the modeling and control of such a robot. We apply the Lagrangian method to derive the governing dynamic equations of the system. We also describe a novel Fuzzy Sliding Mode Controller (FSMC implemented to control a spherical wheel mobile robot. The nonlinear nature of the equations makes the controller nontrivial. We compare the performance of four different fuzzy controllers: (a regulation with one signal, (b regulation and position control with one signal, (c regulation and position control with two signals, and (d FSMC for regulation and position control with two signals. The system is evaluated in a realistic simulation and the robot parameters are chosen based on a LEGO platform, so the designed controllers have the ability to be implemented on real hardware.

Application of Adaptive Sliding Mode Position Controller with PI ...

African Journals Online (AJOL)

PISMC) techniques for controlling the rotor position of PMDC motor drive system. In particular, since SMC is robust in the presence of the matched uncertainties and external disturbances, the desired position is perfectly tracked. In addition, the ...

Evaluation of antiulcer activity of indole-3-carbinol and/or omeprazole on aspirin-induced gastric ulcer in rats.

Science.gov (United States)

El-Shinnawy, Nashwa A; Abd-Elmageid, Samira A; Alshailabi, Eda M A

2014-05-01

The present work is an attempt to elucidate the antiulcer activity of indole-3-carbinol (I3C), which is one of the anticarcinogenic phytochemicals found in the vegetables of Cruciferae family such as broccoli and cauliflower, alone or in combination with omeprazole (OMP), a proton pump inhibitor, to diminish the effects of induced acute gastric ulcer by aspirin (ASA) in male albino rats. A total of 48 adult male albino rats were used in the present study. Animals were divided into eight experimental groups (six animals each group). They were given different experimental inductions of ASA at a dose of 500 mg/kg/body weight, OMP at a dose of 20 mg/kg/body weight and I3C at a dose of 20 mg/kg/body weight either alone or in combination with each other orally for a duration of 7 days. Inner stomach features, ulcer index, pH activity, body weight, stomach weight, hematological investigations, serum total protein albumin and reduced glutathione activity were investigated in addition to the histological, histochemical and immunohistochemical stain of cyclooxygenase-2 to the stomach tissue of normal control, ulcerated and treated ulcerated rats. The results of this study revealed that oral administration of ASA to rats produced the expected characteristic mucosal lesions. OMP accelerated ulcer healing but the administration of I3C either alone or in combination with OMP to ASA-ulcerated rats produced a profound protection to the gastric mucosa from injury induced by ASA. Our results suggested that administration of antiulcer natural substances such as I3C in combination with the perused treatment such as OMP is a very important initiative in the development of new strategies in ulcer healing.

Dissociable influences of reward motivation and positive emotion on cognitive control.

Science.gov (United States)

Chiew, Kimberly S; Braver, Todd S

2014-06-01

It is becoming increasingly appreciated that affective and/or motivational influences contribute strongly to goal-oriented cognition and behavior. An unresolved question is whether emotional manipulations (i.e., direct induction of affectively valenced subjective experience) and motivational manipulations (e.g., delivery of performance-contingent rewards and punishments) have similar or distinct effects on cognitive control. Prior work has suggested that reward motivation can reliably enhance a proactive mode of cognitive control, whereas other evidence is suggestive that positive emotion improves cognitive flexibility, but reduces proactive control. However, a limitation of the prior research is that reward motivation and positive emotion have largely been studied independently. Here, we directly compared the effects of positive emotion and reward motivation on cognitive control with a tightly matched, within-subjects design, using the AX-continuous performance task paradigm, which allows for relative measurement of proactive versus reactive cognitive control. High-resolution pupillometry was employed as a secondary measure of cognitive dynamics during task performance. Robust increases in behavioral and pupillometric indices of proactive control were observed with reward motivation. The effects of positive emotion were much weaker, but if anything, also reflected enhancement of proactive control, a pattern that diverges from some prior findings. These results indicate that reward motivation has robust influences on cognitive control, while also highlighting the complexity and heterogeneity of positive-emotion effects. The findings are discussed in terms of potential neurobiological mechanisms.

Feedback control of plasma position in the HL-1 tokamak

International Nuclear Information System (INIS)

Yuan Baoshan; Jiao Boliang; Yang Kailing

1991-01-01

In the HL-1 tokamak with a thick copper shell, the control of plasma position is successfully performed by a feedback-feedforward system with dual mode regulator and the equilibrium field coils outside the shell. The plasma position can be controlled within ±2 mm in both vertical and horizontal directions under the condition that the iron core of transformer is not saturated

POSITION CONTROL OF BRUSHLESS DC MOTOR BASED ON DIGITAL SIGNAL PROCESSING

Directory of Open Access Journals (Sweden)

Çetin GENÇER

2006-01-01

Full Text Available Brushless DC Motors (BLDC have been used widely high performance control systems which are depended on to development of power electronic and control technology. In these motors to fed commutated supply, the control of position without oscilation has been required. In this study, position control of BLDC with digital signal processing has been implemented by a proportional-derivative (PD controller because of its simple structure. It has been seen that the controller which is proposed from simulation and experimental studies, has a quick dynamic responce with nonoscillation.

Signal differentiation in position tracking control of dc motors

International Nuclear Information System (INIS)

Beltran-Carbajal, F; Valderrabano-Gonzalez, A; Rosas-Caro, J C

2015-01-01

An asymptotic differentiation approach with respect to time is used for on-line estimation of velocity and acceleration signals in controlled dc motors. The attractive feature of this differentiator of signals is that it does not require any system mathematical model, which allows its use in engineering systems that require the signal differentiation for its control, identification, fault detection, among other applications. Moreover, it is shown that the differentiation approach can be applied for output signals showing a chaotic behavior. In addition a differential flatness control scheme with additional integral compensation of the output error is proposed for tracking tasks of position reference trajectories for direct current electric motors using angular position measurements only

Dynamic Positioning of Ships : A nonlinear control design study

NARCIS (Netherlands)

Muhammad, S.

2012-01-01

Dynamic positioning (DP) is relatively a new technique used to maintain the position and heading of ships in various offshore operations. Due to the features like better safety and operating efficiency, DP systems are becoming more and more popular. This thesis mainly focusses on the control system

Position and attitude tracking control for a quadrotor UAV.

Science.gov (United States)

Xiong, Jing-Jing; Zheng, En-Hui

2014-05-01

A synthesis control method is proposed to perform the position and attitude tracking control of the dynamical model of a small quadrotor unmanned aerial vehicle (UAV), where the dynamical model is underactuated, highly-coupled and nonlinear. Firstly, the dynamical model is divided into a fully actuated subsystem and an underactuated subsystem. Secondly, a controller of the fully actuated subsystem is designed through a novel robust terminal sliding mode control (TSMC) algorithm, which is utilized to guarantee all state variables converge to their desired values in short time, the convergence time is so small that the state variables are acted as time invariants in the underactuated subsystem, and, a controller of the underactuated subsystem is designed via sliding mode control (SMC), in addition, the stabilities of the subsystems are demonstrated by Lyapunov theory, respectively. Lastly, in order to demonstrate the robustness of the proposed control method, the aerodynamic forces and moments and air drag taken as external disturbances are taken into account, the obtained simulation results show that the synthesis control method has good performance in terms of position and attitude tracking when faced with external disturbances. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

Study of Globus-M Tokamak Poloidal System and Plasma Position Control

Science.gov (United States)

Dokuka, V. N.; Korenev, P. S.; Mitrishkin, Yu. V.; Pavlova, E. A.; Patrov, M. I.; Khayrutdinov, R. R.

2017-12-01

In order to provide efficient performance of tokamaks with vertically elongated plasma position, control systems for limited and diverted plasma configuration are required. The accuracy, stability, speed of response, and reliability of plasma position control as well as plasma shape and current control depend on the performance of the control system. Therefore, the problem of the development of such systems is an important and actual task in modern tokamaks. In this study, the measured signals from the magnetic loops and Rogowski coils are used to reconstruct the plasma equilibrium, for which linear models in small deviations are constructed. We apply methods of the H∞-optimization theory to the synthesize control system for vertical and horizontal position of plasma capable to working with structural uncertainty of the models of the plant. These systems are applied to the plasma-physical DINA code which is configured for the tokamak Globus-M plasma. The testing of the developed systems applied to the DINA code with Heaviside step functions have revealed the complex dynamics of plasma magnetic configurations. Being close to the bifurcation point in the parameter space of unstable plasma has made it possible to detect an abrupt change in the X-point position from the top to the bottom and vice versa. Development of the methods for reconstruction of plasma magnetic configurations and experience in designing plasma control systems with feedback for tokamaks provided an opportunity to synthesize new digital controllers for plasma vertical and horizontal position stabilization. It also allowed us to test the synthesized digital controllers in the closed loop of the control system with the DINA code as a nonlinear model of plasma.

Using Positive Deviance for Determining Successful Weight-Control Practices

Science.gov (United States)

Stuckey, Heather L.; Boan, Jarol; Kraschnewski, Jennifer L.; Miller-Day, Michelle; Lehman, Erik B.; Sciamanna, Christopher N.

2013-01-01

Based on positive deviance (examining the practices of successful individuals), we identified five primary themes from 36 strategies that help to maintain long-term weight loss (weight control) in 61 people. We conducted in-depth interviews to determine what successful individuals did and/or thought about regularly to control their weight. The themes included weight-control practices related to (a) nutrition: increase water, fruit, and vegetable intake, and consistent meal timing and content; (b) physical activity: follow and track an exercise routine at least 3×/week; (c) restraint: practice restraint by limiting and/or avoiding unhealthy foods; (d) self-monitor: plan meals, and track calories/weight progress; and (e) motivation: participate in motivational programs and cognitive processes that affect weight-control behavior. Using the extensive data involving both the practices and practice implementation, we used positive deviance to create a comprehensive list of practices to develop interventions for individuals to control their weight. PMID:20956609

Variable pattern contamination control under positive pressure

International Nuclear Information System (INIS)

Philippi, H.M.

1997-01-01

Airborne contamination control in nuclear and biological laboratories is traditionally achieved by directing the space ventilation air at subatmospheric pressures in one fixed flow pattern. However, biological and nuclear contamination flow control in the new Biological Research Facility, to be commissioned at the Chalk River Laboratories in 1996, will have the flexibility to institute a number of contamination control patterns, all achieved at positive (above atmospheric) pressures. This flexibility feature, made possible by means of a digitally controlled ventilation system, changes the facility ventilation system from being a relatively rigid building service operated by plant personnel into a flexible building service which can be operated by the facility research personnel. This paper focuses on and describes the application of these unique contamination control features in the design of the new Biological Research Facility. 3 refs., 7 figs

Variable pattern contamination control under positive pressure

Energy Technology Data Exchange (ETDEWEB)

Philippi, H.M. [Chalk River Labs., Ontario (Canada)

1997-08-01

Airborne contamination control in nuclear and biological laboratories is traditionally achieved by directing the space ventilation air at subatmospheric pressures in one fixed flow pattern. However, biological and nuclear contamination flow control in the new Biological Research Facility, to be commissioned at the Chalk River Laboratories in 1996, will have the flexibility to institute a number of contamination control patterns, all achieved at positive (above atmospheric) pressures. This flexibility feature, made possible by means of a digitally controlled ventilation system, changes the facility ventilation system from being a relatively rigid building service operated by plant personnel into a flexible building service which can be operated by the facility research personnel. This paper focuses on and describes the application of these unique contamination control features in the design of the new Biological Research Facility. 3 refs., 7 figs.

奥美拉唑联合硫糖铝治疗急性出血性胃炎临床效果分析%The Analysis of Clinical Effect of Omeprazole Combined with Sucralfate in Treatment of Acute Hemorrhagic Gastritis

Institute of Scientific and Technical Information of China (English)

韦琪

2017-01-01

Objective To explore the incidence of omeprazole combined with sucralfate in the clinical effect of the treatment of acute hemorrhagic gastritis and adverse reactions,to provide reference for the treatment of acute hemorrhagic gastritis.Methods 100 cases of acute hemorrhagic gastritis in our hospital from February 2014 to February 2016 were randomly divided into control group(n=50)and experimental group(n=50).The former only omeprazole treatment,which combined with the former sucralfate treatment,compared two groups of patients with clinical efficacy,adverse reactions and hospitalization time difference.Results the clinical total efficiency of the experimental group(92％)was significantly higher than the control group(72％),the former(8％)adverse reaction rate is slightly lower than the latter(18％),the average hospitalization time of the patients in the experimental group[(10.5 + 1.8)d]was significantly shorter than the control group[(18.7 + 1.9)d],the above difference were statistically significant(P<0.05).Conclusion the efficacy of omeprazole combined with sucralfate in the treatment of acute hemorrhagic gastritis,the incidence of headache,diarrhea and other adverse reactions were lower,and the hospitalization time was shorter,can improve the prognosis of the patients,promote the rehabilitation of patients discharged from the hospital,the higher the value of clinical application.%目的 探究奥美拉唑联合硫糖铝在急性出血性胃炎的临床治疗效果以及不良反应发生情况,为急性出血性胃炎的治疗提供参考.方法 随机选取2014年2月至2016年2月我院收治的急性出血性胃炎患者100例,将其分为对照组(50例)和实验组(50例).前者单用奥美拉唑治疗,后者在前者的基础上联用硫糖铝治疗,对比两组患者的临床有效率、不良反应发生情况和住院时间长短差异.结果 实验组临床总有效率(92.0％)显著高于对照组(72.0％)、前者(8.0�

Um ensaio randomizado duplo-cego e controlado por placebo com probióticos em casos de supercrescimento bacteriano no intestino delgado em crianças tratadas com omeprazol

Directory of Open Access Journals (Sweden)

Badriul Hegar

2013-08-01

Full Text Available OBJETIVO: Avaliar a incidência de SBID em crianças tratadas com omeprazol e testar se os probióticos influenciam essa incidência. MÉTODOS: Um ensaio duplo-cego controlado por placebo foi realizado em 70 crianças tratadas oralmente, durante 4 semanas, com 20 mg de omeprazol por dia. Desses, 36 indivíduos receberam diária e simultaneamente Lactobacillus rhamnosus R0011 (1,9 x 10(9 cfu e Lactobacillus acidophillus R0052 (0,1 x 10(9 cfu (grupo probiótico, enquanto 34 receberam placebo (grupo placebo. O diagnóstico de SBID teve como base o desenvolvimento de sintomas sugestivos em combinação com um teste respiratório com glicose positivo. RESULTADOS: Após um mês de tratamento com IBP, 30% (21/70 apresentaram um teste respiratório positivo sugerindo SBID; desses, 62% foram sintomáticos. Cinco crianças desenvolveram sintomas parecidos com os de SBID, mas apresentaram um teste respiratório negativo; 44 (63% não apresentavam sintomas e tiveram teste respiratório negativo. Não houve diferença na incidência de testes respiratórios positivos no grupo probiótico em comparação ao grupo placebo (33% em comparação a 26,5%; p: 0,13. CONCLUSÕES: Como houve sintomas sugestivos de SBID em 26% das crianças tratadas com IBP e o teste respiratório com glicose deu resultados anormais em 72% delas, esse efeito colateral deve ser levado em consideração com mais frequência. O probiótico testado não reduziu o risco de desenvolver SBID.

Performance estimation of control rod position indicator due to aging of magnet

International Nuclear Information System (INIS)

Yu, Je Yong; Kim, Ji Ho; Huh, Hyung; Choi, Myoung Hwan; Sohn, Dong Seong

2009-01-01

The Control Element Drive Mechanism (CEDM) for the integral reactor is designed to raise and lower the control rod in steps of 2mm in order to satisfy the design features of the integral reactor which are the soluble boron free operation and the use of a nuclear heating for the reactor start-up. The actual position of the control rod could be achieved to sense the magnet connected to the control rod by the position indicator around the upper pressure housing of CEDM. It is sufficient that the actual position information of control rod at 20mm interval from the position indicator is used for the core safety analysis. As the magnet moves upward along the position indicator assembly from the bottom to the top in the upper pressure housing, the output voltage increases linearly step-wise at 0.2VDC increments. Between every step there are transient areas which occur by a contact closing of three reed switches which is the 2-3-2 contact closing sequence. In this paper the output voltage signal corresponding to the position of control rod was estimated on the 2-1-2 contact closing sequence due to the aging of the magnet.

Positive and negative dimensions of weight control motivation.

Science.gov (United States)

Stotland, S; Larocque, M; Sadikaj, G

2012-01-01

This study examined weight control motivation among patients (N=5460 females and 547 males) who sought weight loss treatment with family physicians. An eight-item measure assessed the frequency of thoughts and feelings related to weight control "outcome" (e.g. expected physical and psychological benefits) and "process" (e.g. resentment and doubt). Factor analysis supported the existence of two factors, labeled Positive and Negative motivation. Positive motivation was high (average frequency of thoughts about benefits was 'every day') and stable throughout treatment, while Negative motivation declined rapidly and then stabilized. The determinants of changes in the Positive and Negative dimensions during treatment were examined within 3 time frames: first month, months 2-6, and 6-12. Maintenance of high scores on Positive motivation was associated with higher BMI and more disturbed eating habits. Early reductions in Negative motivation were greater for those starting treatment with higher weight and more disturbed eating habits, but less depression and stress, while later reductions in Negative motivation were predicted by improvements in eating habits, weight, stress and perfectionism. Clinicians treating obesity should be sensitive to fluctuations in both motivational dimensions, as they are likely to play a central role in determining long-term behavior and weight change. Copyright © 2011 Elsevier Ltd. All rights reserved.

Nonlinear control of ships minimizing the position tracking errors

Directory of Open Access Journals (Sweden)

Svein P. Berge

1999-07-01

Full Text Available In this paper, a nonlinear tracking controller with integral action for ships is presented. The controller is based on state feedback linearization. Exponential convergence of the vessel-fixed position and velocity errors are proven by using Lyapunov stability theory. Since we only have two control devices, a rudder and a propeller, we choose to control the longship and the sideship position errors to zero while the heading is stabilized indirectly. A Virtual Reference Point (VRP is defined at the bow or ahead of the ship. The VRP is used for tracking control. It is shown that the distance from the center of rotation to the VRP will influence on the stability of the zero dynamics. By selecting the VRP at the bow or even ahead of the bow, the damping in yaw can be increased and the zero dynamics is stabilized. Hence, the heading angle will be less sensitive to wind, currents and waves. The control law is simulated by using a nonlinear model of the Japanese training ship Shiojimaru with excellent results. Wind forces are added to demonstrate the robustness and performance of the integral controller.

Robust Operation of Tendon-Driven Robot Fingers Using Force and Position-Based Control Laws

Science.gov (United States)

Abdallah, Muhammad E (Inventor); Platt, Jr., Robert J. (Inventor); Reiland, Matthew J (Inventor); Hargrave, Brian (Inventor); Diftler, Myron A (Inventor); Strawser, Philip A (Inventor); Ihrke, Chris A. (Inventor)

2013-01-01

A robotic system includes a tendon-driven finger and a control system. The system controls the finger via a force-based control law when a tension sensor is available, and via a position-based control law when a sensor is not available. Multiple tendons may each have a corresponding sensor. The system selectively injects a compliance value into the position-based control law when only some sensors are available. A control system includes a host machine and a non-transitory computer-readable medium having a control process, which is executed by the host machine to control the finger via the force- or position-based control law. A method for controlling the finger includes determining the availability of a tension sensor(s), and selectively controlling the finger, using the control system, via the force or position-based control law. The position control law allows the control system to resist disturbances while nominally maintaining the initial state of internal tendon tensions.

Does treatment of gastro-esophageal reflux disease with omeprazole decrease allergic rhinitis symptoms?

Directory of Open Access Journals (Sweden)

Afshin Shirkani

2014-08-01

Full Text Available Background: Allergic rhinitis is the most common type of allergic disease among population. Its accurate treatment is very important for cutting of allergic march. On the other hand, gasteroesophageal reflux disease (GERD is one of the most common gastrointestinal problems among allergic patients mainly asthmatic cases. It might conflict treatment. Despite of asthma, a few studies have been conducted on the impact of GERD treatment on allergic rhinitis symptoms. In this study, we assessed GERD treatment and its effects on improving of allergic rhinitis patients with GERD. Materials and Methods: In a prospective cross-sectional study, March - September 2012, 103 consecutive patients with persistent moderate to severe seasonal allergic rhinitis enrolled. For allergic rhinitis patients with GERD 20 mg omeperazole once daily for 6 weeks prescribed, empirically. Conventional allergy treatment continued and finally the allergic rhinitis symptoms were assessed clinically and recorded before, 5th, 10th and 30th days of omeprazole treatment period. Results: Our study included 103 patients with seasonal allergic rhinitis who were divided into GERD (n=33, 38% and non-GERD (n=70, 68% groups with the mean age 28 and 25.7 years, respectively. The first group developed significant improvement for GERD symptoms on days 5, 10 and 30 after beginning of therapy (P=0.03. No association was found between GERD treatment and relief of allergic symptoms or TNSS improvement (P>0.05. Data analyzed by Epi info (ver 7 and SPSS software (ver 11.5, and by Chi squeare test and paired T test. P lower than 0.05 was considered as significant. Conclusion: This study showed no significant association between empirical treatment of GERD and improvement of allergic symptoms in patients with allergic rhinitis. However, further studies with a larger sample size might be needed.

Pneumatic Rotary Actuator Position Servo System Based on ADE-PD Control

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Yeming Zhang

2018-03-01

Full Text Available In order to accurately control the rotation position of a pneumatic rotary actuator, the flow state of the gas and the motion state of the pneumatic rotary actuator in the pneumatic rotary actuator position servo system are analyzed in this paper. The mathematical model of the system and the experiment platform are established after that. An Adaptive Differential Evolution (ADE algorithm which adaptively ameliorates the scaling factor and crossover probability in the process of individual evolution is proposed and applied to the parameter optimization of PD controller. The experimental platform is used to compare the controller with Differential Evolution (DE algorithm and NCD-PID controller. Finally, the characteristics of the system are tested by increasing the inertial load. The experimental results illustrate that system using ADE-PD control strategy has greater position precision and faster response than using DE-PD and NCD-PID strategies, and shows great robustness.

RODMOD: a code for control rod positioning

International Nuclear Information System (INIS)

Vondy, D.R.; Fowler, T.B.

1978-11-01

The report documents a computer code which has been implemented to position control rods according to a prescribed schedule during the calculation of a reactor history. Control rods may be represented explicitly with or without internal black absorber conditions in selected energy groups, or fractional insertion may be done, or both, in a problem. There is provision for control rod follower, movement of materials through a series of zones in a closed loop, and shutdown rod insertion and subsequent removal to allow the reactor history calculation to be continued. This code is incorporated in the system containing the VENTURE diffusion theory neutronics and the BURNER exposure codes for routine use. The implemented automated procedures cause the prescribed control rod insertion schedule to be applied without the access of additional user input data during the calculation of a reactor operating history

Tool position tracking control of a nonlinear uncertain flexible robot ...

Indian Academy of Sciences (India)

Robot manipulators have become progressively important in the field of flexible ... this research, tracking of tool position and minimization of motor torque are ...... and Menhaj M B 2013a Position and current control of a permanent-magnet syn-.

Plasma position control in a tokamak reactor around ignition

International Nuclear Information System (INIS)

Carretta, U.; Minardi, E.; Bacelli, N.

1986-01-01

Plasma position control in a tokamak reactor in the phase approaching ignition is closely related to burn control. If ignited burn corresponds to a thermally unstable situation the plasma becomes sensitive to the thermal instability already in the phase when ignition is approached so that the trajectory in the position-pressure (R,p) space becomes effectively unpredictable. For example, schemes involving closed cycles around ignition can be unstable in the heating-cooling phases, and the deviations may be cumulative in time. Reliable plasma control in pressure-position (p, R) space is achieved by beforehand constraining the p, R trajectory rigidly with suitable feedback vertical field stabilization, which is to be established already below ignition. A scheme in which ignition is approached in a stable and automatic way by feedback stabilization on the vertical field is proposed and studied in detail. The values of the gain coefficient ensuring stabilization and the associated p and R excursions are discussed both analytically, with a 0-D approximation including non-linear effects, and numerically with a 1-D code in cylindrical geometry. Profile effects increase the excursions, in particular above ignition. (author)

Gastrin release: Antrum microdialysis reveals a complex neural control

DEFF Research Database (Denmark)

Ericsson, P; Håkanson, R; Rehfeld, Jens F.

2010-01-01

We used microdialysis to monitor local gastrin release in response to food, acid blockade and acute vagal excitation. For the first time, gastrin release has been monitored continuously in intact conscious rats in a physiologically relevant experimental setting in a fashion that minimizes...... in serum regardless of the prandial state. The rats were conscious during microdialysis except when subjected to electrical vagal stimulation. Acid blockade (omeprazole treatment of freely fed rats for 4 days), or bilateral sectioning of the abdominal vagal trunks (fasted, 3 days post-op.), raised...... the gastrin concentration in blood as well as microdialysate. The high gastrin concentration following omeprazole treatment was not affected by vagotomy. Vagal excitation stimulated the G cells: electrical vagal stimulation and pylorus ligation (fasted rats) raised the gastrin concentration transiently...

Magnetic sensorless control of plasma position and shape in a tokamak

International Nuclear Information System (INIS)

Nakamura, K.; Luo, J.R.; Wang, H.Z.

2005-01-01

Magnetic sensorless sensing and control experiments of the plasma horizontal position have been carried out in the superconducting tokamak HT-7. The sensing is made focusing on the ripple frequency component of the power supply with thyristor and directly from them without time integration. There is no drift problem of integrator of magnetic sensors. Two kinds of control experiments were carried out, to keep the position constant and swing the position in a triangular waveform. And magnetic sensorless sensing of plasma shape is discussed. (author)

Research of Control Strategy in the Large Electric Cylinder Position Servo System

Directory of Open Access Journals (Sweden)

Yongguang Liu

2015-01-01

Full Text Available An ideal positioning response is very difficult to realize in the large electric cylinder system that is applied in missile launcher because of the presence of many nonlinear factors such as load disturbance, parameter variations, lost motion, and friction. This paper presents a piecewise control strategy based on the optimized positioning principle. The combined application of position interpolation method and modified incremental PID with dead band is proposed and applied into control system. The experimental result confirms that this combined control strategy is not only simple to be applied into high accuracy real-time control system but also significantly improves dynamic response, steady accuracy, and anti-interference performance, which has very important significance to improve the smooth control of the large electric cylinder.

Design and performance analysis of position-based impedance control for an electrohydrostatic actuation system

Directory of Open Access Journals (Sweden)

Yongling FU

2018-03-01

Full Text Available Electrohydrostatic actuator (EHA is a type of power-by-wire actuator that is widely implemented in the aerospace industry for flight control, landing gears, thrust reversers, thrust vector control, and space robots. This paper presents the development and evaluation of position-based impedance control (PBIC for an EHA. Impedance control provides the actuator with compliance and facilitates the interaction with the environment. Most impedance control applications utilize electrical or valve-controlled hydraulic actuators, whereas this work realizes impedance control via a compact and efficient EHA. The structures of the EHA and PBIC are firstly introduced. A mathematical model of the actuation system is established, and values of its coefficients are identified by particle swarm optimization. This model facilitates the development of a position controller and the selection of target impedance parameters. A nonlinear proportional-integral position controller is developed for the EHA to achieve the accurate positioning requirement of PBIC. The controller compensates for the adverse effect of stiction, and a position accuracy of 0.08 mm is attained. Various experimental results are presented to verify the applicability of PBIC to the EHA. The compliance of the actuator is demonstrated in an impact test. Keywords: Actuation system, Aerospace, Electrohydrostatic actuator, Force control, Nonlinear dynamics, Particle swarm optimization, Position control

Position and Attitude Alternate of Path Tracking Heading Control

Directory of Open Access Journals (Sweden)

Baocheng Tan

2014-03-01

Full Text Available The path tracking control algorithm is one of the key problems in the control system design of autonomous vehicle. In this paper, we have conducted dynamic modeling for autonomous vehicle, the relationship between course deviation and yaw rate and centroid deflection angle. From the angle of the dynamics and geometrical, this paper have described the path tracking problem, analyzed the emergence of the eight autonomous vehicles pose binding - position and attitude alternate control methods to identify the relationship between posture and the controlling variables, and design a controller, the experimental results verify the feasibility and effectiveness of this control method.

A modern automatic Carriage-Trolley Position Control System for Dhruva fuelling machine

International Nuclear Information System (INIS)

Agrawal, Ankit; Hari Balakrishna; Narvekar, J.P.; Sanadhya, Vivek

2014-01-01

A fully automatic absolute encoder based position control system has been designed developed implemented and commissioned for the Dhruva Fuelling Machine A (FM/A). This supports both the coarse and fine positioning modes. Provision for fully manual positioning as a standby system has been retained. This system replaces the ageing peg counting based incremental positioner used briefly during the early period after the Dhruva FM/A was commissioned. The older system suffered from peg detection skipping problems; hence it was not being used. Only full manual positioning was being carried out. This paper describes the automatic Carriage Trolley Position Control System (CTPCS). (author)

Could positive affect help engineer robot control systems?

Science.gov (United States)

Quirin, Markus; Hertzberg, Joachim; Kuhl, Julius; Stephan, Achim

2011-11-01

Emotions have long been seen as counteracting rational thought, but over the last decades, they have been viewed as adaptive processes to optimize human (but also animal) behaviour. In particular, positive affect appears to be a functional aspect of emotions closely related to that. We argue that positive affect as understood in Kuhl's PSI model of the human cognitive architecture appears to have an interpretation in state-of-the-art hybrid robot control architectures, which might help tackle some open questions in the field.

A randomized controlled trial of positioning treatments in infants with positional head shape deformities.

Science.gov (United States)

Hutchison, B Lynne; Stewart, Alistair W; De Chalain, Tristan B; Mitchell, Edwin A

2010-10-01

Randomized controlled trials of treatment for deformational plagiocephaly and brachycephaly have been lacking in the literature. Infants (n = 126) presenting to a plagiocephaly clinic were randomized to either positioning strategies or to positioning plus the use of a Safe T Sleep™ positioning wrap. Head shape was measured using a digital photographic technique, and neck function was assessed. They were followed up at home 3, 6 and 12 months later. There was no difference in head shape outcomes for the two treatment groups after 12 months of follow-up, with 42% of infants having head shapes in the normal range by that time. Eighty per cent of children showed good improvement. Those that had poor improvement were more likely to have both plagiocephaly and brachycephaly and to have presented later to clinic. Most infants improved over the 12-month study period, although the use of a sleep positioning wrap did not increase the rate of improvement. © 2010 The Author(s)/Journal Compilation © 2010 Foundation Acta Paediatrica.

Improved Position Sensor for Feedback Control of Levitation

Science.gov (United States)

Hyers, Robert; Savage, Larry; Rogers, Jan

2004-01-01

An improved optoelectronic apparatus has been developed to provide the position feedback needed for controlling the levitation subsystem of a containerless-processing system. As explained, the advantage of this apparatus over prior optoelectronic apparatuses that have served this purpose stems from the use of an incandescent lamp, instead of a laser, to illuminate the levitated object. In containerless processing, a small object to be processed is levitated (e.g., by use of a microwave, low-frequency electromagnetic, electrostatic, or acoustic field) so that it is not in contact with the wall of the processing chamber or with any other solid object during processing. In the case of electrostatic or low-frequency electromagnetic levitation, real-time measurement of the displacement of the levitated object from its nominal levitation position along the vertical axis (and, in some cases, along one or two horizontal axes) is needed for feedback control of the levitating field.

Automatic beam position control at Los Alamos Spallation Radiation Effects Facility (LASREF)

International Nuclear Information System (INIS)

Oothoudt, M.; Pillai, C.; Zumbro, M.

1997-01-01

Historically the Los Alamos Spallation Radiation Effects Facility (LASREF) has used manual methods to control the position of the 800 kW, 800 MeV proton beam on targets. New experiments, however, require more stringent position control more frequently than can be done manually for long periods of time. Data from an existing harp is used to automatically adjust steering magnets to maintain beam position to required tolerances

Angular Position Tracking Control of a Quadcopter

Directory of Open Access Journals (Sweden)

T. V. Glazkov

2017-01-01

Full Text Available The paper dwells on tracking the quad-copter angular position with desired quality parameters of transient processes. The aerial vehicle is considered as a rigid body with six degrees of freedom.  A full rigid body quad-copter mathematical model is considered without the assumption of smallness of the Euler angles.Among the most well known methods of non-linear stabilization are feedback linearization and backstepping. The backstepping approach allows us to have an effective solution of the stabilization problems with uncertainties available in the system. However, in synthesis of the feedback through backstepping, there is still an urgent issue: how to ensure desirable quality of transients in the closed-loop system. The paper presents a solution of this problem using as an example the tracking a given (programmed change of the angular position of a quad-copter.The control algorithms obtained in this paper are implemented using the Rolling Spider MATLAB Toolbox (ROSMAT tool package on the Parrot Rolling Spider quad-copter. A numerical simulation and experiments have shown the efficiency of obtained control laws, with the transient processes taking into account the desired quality indicators. However, the experiments showed that lack of terms in the mathematical model to describe the aerodynamic effects, resulted in the instability of the quad-copter flight near the obstacle (the effect of the reflected airflow.Further research can be aimed at solving the control problem in question using a mathematical model of the quad-copter motion that takes into account various aerodynamic effects.One of the potential application areas for the theoretical results, obtained in the paper, is to solve the problems of automatic control of unmanned aerial vehicles.

Sensory systems for a control rod position using reed switches for the integral reactor

International Nuclear Information System (INIS)

Yu, J. Y.; Choi, S.; Kim, J. H.; Lee, D. J.

2007-01-01

The system-integrated modular advanced reactor (SMART) currently under development at the Korea Atomic Energy Research Institute is being designed with a soluble boron free operation and the use of nuclear heating for the reactor start-up. These design features require a Control Element Drive Mechanism (CEDM) for the SMART to have a fine-step movement capability as well as a high reliability for a fine reactivity control. Also the reliability and accuracy of the information for the control rod position is very important to the reactor safety as well as the design of the core protection system. The position indicator is classified as a Class 1E component because the rod position signal of the position indicator is used in the safety related systems. Therefore it will be separated from the control systems to the extent that a failure of any single control system component of a channel and shall have sufficient independence, redundancy, and testability to perform its safety functions assuming a single failure. The position indicator is composed of a permanent magnet, reed switches and a voltage divider. Four independent position indicators around the upper pressure housing provide an indication of the position of a control rod comprising of a permanent magnet with a magnetic field concentrator which moves with the extension shaft connected to the control rod. The zigzag arranged reed switches are positioned along a line parallel to the path of the movement of the permanent magnet and it is activated selectively when the permanent magnet passes by. A voltage divider electrically connected to the reed switches provides a signal commensurate with the position of the control rod. The signal may then be transmitted to a position indicating device. In order to monitor the operating condition of the rotary step motor of CEDM, the angular position detector was installed at the top of the rotary step motor by means of connecting between the planetary gear and the rotating

Positive and Negative Perfectionism in Migrainus Patients Compaired with Control Group

Directory of Open Access Journals (Sweden)

H Afshar

2008-01-01

Full Text Available ABSTRACT: Introduction & Objective: The positive and negative effects of perfectionism on human cognition, affection and behavior have been emphasized. Perfectionism has been conceptualized as a multidimensional construct, with both adaptive and maladaptive aspects, which is one of the common personality traits that cause lifelong stress in human and results in anxiety, depression and physical and mental distress.The aim of this study was to assess the positive and negative perfectionism in migrainus patients in comparison with control group. Materials & Methods: This is an analytical (Case-control study which was performed on 91 migraine patients and 88 healthy individuals. The pqtients and controls completed a standard 40 item questionnaire for perfectionism – PANPS (20 for positive and 20 for negative perfectionism . The patients in both groups were matched for gender and age. Mean of positive and negative perfectionism scores for two groups was statistically analysed using SPSS software. Results: Mean positive perfectionism score was 83.47±8.5 for migraine group and 65.47±7.54 for control group (p=0.0001. The difference between two groups was significant. Mean of negative perfectionism score was 74.12±10.6 for migraine group and 51.79±7.8 for control group(p=0.0001. Conclusion: The results show that migraine patients have higher mean of perfectionism scores than healthy individuals. Based on this study and other clinical experiences more attention to psychotherapy is necessary for better management of migraine and recognition of personality profile in migraine patient helps to reduce patient’s complaints.

Nonlinear control of marine vehicles using only position and attitude measurements

Energy Technology Data Exchange (ETDEWEB)

Paulsen, Marit Johanne

1996-12-31

This thesis presents new results on the design and analysis of nonlinear output feedback controllers for auto pilots and dynamic positioning systems for ships and underwater vehicles. Only position and attitude measurements of the vehicle are used in the control design. The underlying idea of the work is to use certain structural properties of the equations of motion in the controller design and analysis. New controllers for regulation and tracking have been developed and the stability of the resulting closed-loop systems has been rigorously established. The results are supported by simulations. The following problems have been investigated covering design of passive controller for regulation, comparison of two auto pilots, nonlinear damping compensation for tracking, tracking control for nonlinear ships, and output tracking control with wave filtering for multivariable models of possibly unstable vehicles. 97 refs., 32 figs.

Strategies for the plasma position and shape control in IGNITOR

International Nuclear Information System (INIS)

Ramogida, G.; Alladio, F.; Albanese, R.

2006-01-01

The control of the plasma position and shape is a crucial issue in IGNITOR as in every compact, high field, elongated tokamak. The capability of the Poloidal Field Coil system, as presently designed, to provide an effective vertical stabilization of the plasma has been investigated using the CREATE L response model [R. Albanese, F. Villone, '' The Linearized CREATE L Plasma Response Model for the Control of Current, Position and Shape in Tokamaks '', Nucl. Fus., vol. 38, p. 723 (1998)]. This linearized MHD model assumes an axisymmetric deformable plasma described by few global parameters. An optimization of the vertical position control strategy has been carried out and the most effective coil combination has been selected to stabilize the plasma while fulfilling engineering constraints on the coils and minimizing the required power and voltage. The two pairs of coils selected for the vertical control will be fed up with up-down anti-symmetric currents provided by a dedicated supply and overlapped to the scenario currents. The growth rate of the vertical instability and the power required by the active stabilization system have been estimated with this model, indicating that it is possible to design a control system able to guarantee a stability region that includes the most interesting operation conditions. An assessment of the requirements for the plasma cross section shape control has been carried out considering independent perturbations of the plasma global parameters as disturbances and showing that the undesired shape modification rejection is possible with the present PFC and power supply system. The PF coils have been ranked with respect to their capability to restore the shape modifications due to different plasma disturbances and the most effective coil combination, that minimizes recovery time and voltage required, has been selected. In order to have additional means to monitor and control the centre of the plasma column, under demanding conditions

a positive control plasmid for reporter gene assay

African Journals Online (AJOL)

STORAGESEVER

2008-07-04

Jul 4, 2008 ... qualification as a positive control for luciferase reporter gene assays. Key words: Reporter gene plasmid, luciferase assay, cytomegalovirus promoter/enhancer, human melanoma cell line. INTRODUCTION. Reporter genes, often called reporters, have become a precious tool in studies of gene expression ...

The control system position to the electric probe in the Tokamak Novillo

International Nuclear Information System (INIS)

Sanchez Garcia, A.M.

1993-01-01

The electric probe are used to determine the parameters of electronic temperatures, the electron density and the plasma potential in Tokamak machines. On this machines the electric probes are used only in the plasma edge due to the intensive flow of high energy particles. This is the region in which the plasma density and temperature are relatively low. It is showed, in this work, the design and construction of an electro mechanic system which is used to control the position of the probe into the discharge chamber. This system is called T he control system position to the electric probe in the tokamak Novillo . This controller is a minimum system that is in charge , by a programming, to rule a step motor by a logic sequence commutation. This is done with the purpose of slide the probe in a radial way with a milli metric precision into the discharge chamber. To this purpose it is used a step motor, due it is principal characteristic is the control of the end element position without a feedback needing of the wrong signal. The system function consist on reading, through a board, the corresponding data to the position where it is wanted to place the probe, it also displays by a numeric indicator the position in which the probe is located (in an interval from 0 to 100 mm), and provide the logic sequence commutation for the step motor. The minimum system is constituted by the micro controller 8748-8 that gives with all precision the control of the electric probe position in the Tokamak Novillo, by programming, associated circuits, amplification unit bi phase unipolar and switching power (they supply the power to the control circuit and to the step motor too), avoiding the destruction of the electric probe. (Author). 17 refs, 29 figs

Diagnosis and Fault-Tolerant Control for Thruster-Assisted Position Mooring System

DEFF Research Database (Denmark)

Nguyen, Trong Dong; Blanke, Mogens; Sørensen, Asgeir

2007-01-01

Development of fault-tolerant control systems is crucial to maintain safe operation of o®shore installations. The objective of this paper is to develop a fault- tolerant control for thruster-assisted position mooring (PM) system with faults occurring in the mooring lines. Faults in line......'s pretension or line breaks will degrade the performance of the positioning of the vessel. Faults will be detected and isolated through a fault diagnosis procedure. When faults are detected, they can be accommodated through the control action in which only parameter of the controlled plant has to be updated...... to cope with the faulty condition. Simulations will be carried out to verify the advantages of the fault-tolerant control strategy for the PM system....

Critical element study on autonomous position control of articulated-arm type manipulator

International Nuclear Information System (INIS)

Oka, Kiyoshi; Kakudate, Satoshi; Nakahira, Masataka

1994-10-01

An articulated-arm type manipulator can be operated effectively in a restricted space due to its flexibility and it can be attractive for a wide range of in-vessel maintenance such as viewing, inspection and limiter handling in fusion experimental reactors. In case of the in-vessel maintenance using a flexible manipulator, it is quite essential to develop an autonomous control method for compensating a deflection of manipulator so as to minimize the maintenance time with high precision. For this purpose, a new position control method using a combination of neural network predictor with a rigid inverse kinematics is being developed. The key features of this method are to simplify a kinematics modeling of flexible manipulator, to enable quick position compensation in stead of ordinary large matrix compensation, and to be applicable to a wide variety of manipulator characteristics. A sub-scaled model of flexible manipulator with 4 joints has been fabricated for a benchmark experiments of the autonomous position control. Comparing analytical simulation with experiments using the flexible manipulator, it has been demonstrated that the new position control method gives significant improvement in control performance with high precision in order of a figure. In addition, further optimization can be possible by adding other non-linear predictors such as radial basis function and fuzzy modeling. This paper describes the details of a sub-scaled flexible manipulator and a neural network position control system as well as results of analytical simulation and benchmark experiments. (author)

A Position Sensorless Control Method for SRM Based on Variation of Phase Inductance

Science.gov (United States)

Komatsuzaki, Akitomo; Miki, Ichiro

Switched reluctance motor (SRM) drives are suitable for variable speed industrial applications because of the simple structure and high-speed capability. However, it is necessary to detect the rotor position with a position sensor attached to the motor shaft. The use of the sensor increases the cost of the drive system and machine size, and furthermore the reliability of the system is reduced. Therefore, several approaches to eliminate the position sensor have already been reported. In this paper, a position sensorless control method based on the variation of the phase inductance is described. The phase inductance regularly varies with the rotor position. The SRM is controlled without the position sensor using the de-fluxing period and the phase inductance. The turn-off timing is determined by computing the difference of angle between the sampling point and the aligned point and the variation of angle during the de-fluxing period. In the magnetic saturation region, the phase inductance at the current when the effect of the saturation starts is computed and the sensorless control can be carried out using this inductance. Experimental results show that the SRM is well controlled without the position sensor using the proposed method.

Position Control of Pneumatic Actuator Using Self-Regulation Nonlinear PID

Directory of Open Access Journals (Sweden)

Syed Najib Syed Salim

2014-01-01

Full Text Available The enhancement of nonlinear PID (N-PID controller for a pneumatic positioning system is proposed to improve the performance of this controller. This is executed by utilizing the characteristic of rate variation of the nonlinear gain that is readily available in N-PID controller. The proposed equation, namely, self-regulation nonlinear function (SNF, is used to reprocess the error signal with the purpose of generating the value of the rate variation, continuously. With the addition of this function, a new self-regulation nonlinear PID (SN-PID controller is proposed. The proposed controller is then implemented to a variably loaded pneumatic actuator. Simulation and experimental tests are conducted with different inputs, namely, step, multistep, and random waveforms, to evaluate the performance of the proposed technique. The results obtained have been proven as a novel initiative at examining and identifying the characteristic based on a new proposal controller resulting from N-PID controller. The transient response is improved by a factor of 2.2 times greater than previous N-PID technique. Moreover, the performance of pneumatic positioning system is remarkably good under various loads.

Multiple Acid Sensors Control Helicobacter pylori Colonization of the Stomach.

Science.gov (United States)

Huang, Julie Y; Goers Sweeney, Emily; Guillemin, Karen; Amieva, Manuel R

2017-01-01

Helicobacter pylori's ability to respond to environmental cues in the stomach is integral to its survival. By directly visualizing H. pylori swimming behavior when encountering a microscopic gradient consisting of the repellent acid and attractant urea, we found that H. pylori is able to simultaneously detect both signals, and its response depends on the magnitudes of the individual signals. By testing for the bacteria's response to a pure acid gradient, we discovered that the chemoreceptors TlpA and TlpD are each independent acid sensors. They enable H. pylori to respond to and escape from increases in hydrogen ion concentration near 100 nanomolar. TlpD also mediates attraction to basic pH, a response dampened by another chemoreceptor TlpB. H. pylori mutants lacking both TlpA and TlpD (ΔtlpAD) are unable to sense acid and are defective in establishing colonization in the murine stomach. However, blocking acid production in the stomach with omeprazole rescues ΔtlpAD's colonization defect. We used 3D confocal microscopy to determine how acid blockade affects the distribution of H. pylori in the stomach. We found that stomach acid controls not only the overall bacterial density, but also the microscopic distribution of bacteria that colonize the epithelium deep in the gastric glands. In omeprazole treated animals, bacterial abundance is increased in the antral glands, and gland colonization range is extended to the corpus. Our findings indicate that H. pylori has evolved at least two independent receptors capable of detecting acid gradients, allowing not only survival in the stomach, but also controlling the interaction of the bacteria with the epithelium.

Positioning and tracking control system analysis for mobile free space optical network

Science.gov (United States)

Li, Yushan; Refai, Hazem; Sluss, , James J., Jr.; Verma, Pramode; LoPresti, Peter

2005-08-01

Free Space Optical (FSO) communication has evolved to be applied to the mobile network, because it can provide up to 2.5Gbps or higher data rate wireless communication. One of the key challenges with FSO systems is to maintain the Line of Sight (LOS) between transmitter and receiver. In this paper, the feasibility and performance of applying the FSO technology to the mobile network is explored, and the design plan of the attitude positioning and tracking control system of the FSO transceiver is investigated. First, the system architecture is introduced, the requirements for the control system are analyzed, the involved reference frames and frame transformation are presented. Second, the control system bandwidth is used to evaluate the system performance in controlling a positioning system consisting of a gimbal and a steering mirror, some definitions to describe the positioning accuracy and tracking capacity are given. The attitude control of a FSO transceiver is split into 2 similar channels: pitch and yaw. Using an equivalent linear control system model, the simulations are carried out, with and without the presence of uncertainties that includes GPS data errors and sensor measurement errors. Finally, based on the simulation results in the pitch channel, the quantitative evaluation on the performance of the control system is given, including positioning accuracy, tracking capability and uncertainty tolerance.

Mercapto-ordered carbohydrate-derived porous carbon electrode as a novel electrochemical sensor for simple and sensitive ultra-trace detection of omeprazole in biological samples.

Science.gov (United States)

Kalate Bojdi, Majid; Behbahani, Mohammad; Mashhadizadeh, Mohammad Hosein; Bagheri, Akbar; Hosseiny Davarani, Saied Saeed; Farahani, Ali

2015-03-01

We are introducing mercapto-mesoporous carbon modified carbon paste electrode (mercapto-MP-C-CPE) as a new sensor for trace determination of omeprazole (OM) in biological samples. The synthesized modifier was characterized by thermogravimetry analysis (TGA), differential thermal analysis (DTA), transmission electron microscopy (TEM), Fourier transform infrared spectrometry (FT-IR), X-ray diffraction (XRD), elemental analysis (CHN) and N2 adsorption surface area measurement (BET). The electrochemical response characteristic of the modified-CPE toward OM was investigated by cyclic and differential pulse voltammetry (CV and DPV). The proposed sensor displayed a good electrooxidation response to the OM, its linear range is 0.25nM to 25μM with a detection limit of 0.04nM under the optimized conditions. The prepared modified electrode shows several advantages such as high sensitivity, long-time stability, wide linear range, ease of preparation and regeneration of the electrode surface by simple polishing and excellent reproducibility. Copyright © 2014 Elsevier B.V. All rights reserved.

Explicit Generalized Predictive Control of Speed and Position of PMSM Drives

Czech Academy of Sciences Publication Activity Database

Belda, Květoslav; Vošmik, D.

2016-01-01

Roč. 63, č. 6 (2016), s. 3889-3896 ISSN 0278-0046 Institutional support: RVO:67985556 Keywords : current limitation * field weakening * motion control * permanent magnet synchronous motors * position control * predictive control * speed control Subject RIV: BC - Control Systems Theory Impact factor: 7.168, year: 2016 http://library.utia.cas.cz/separaty/2016/AS/belda-0457259.pdf

Hybrid Force and Position Control Strategy of Robonaut Performing Object Transfer Task

Directory of Open Access Journals (Sweden)

Chen Gang

2018-01-01

Full Text Available This paper proposes a coordinated hybrid force/position control strategy of robonaut performing object transfer operation. Firstly, the constraint relationships between robonaut and object are presented. Base on them, the unified dynamic model of the robonaut and object is established to design the hybrid force/position control method. The movement, the internal force and the external constraint force of the object are considered as the control targets of the control system. Finally, a MATLAB simulation of the robonaut performing object transfer task verifies the correctness and effectiveness of the proposed method. The results show that all the targets can be control accurately by using the method proposed in this paper. The presented control method can control both internal and external forces while maintaining control accuracy, which is a common control strategy.

Development of control rod position indicator using seismic-resistance reed switches for integral reactor

International Nuclear Information System (INIS)

Yu, Je Yong; Kim, Ji Ho; Huh, Hyung; Choi, Myoung Hwan; Sohn, Dong Seong

2008-01-01

The Reed Switch Position Transmitter (RSPT) is used as a position indicator for the control rod in commercial nuclear power plants made by ABB-CE. But this position indicator has some problems when directly adopting it to the integral reactor. The Control Element Drive Mechanism (CEDM) for the integral reactor is designed to raise and lower the control rod in steps of 2mm in order to satisfy the design features of the integral reactor which are the soluble boron free operation and the use of a nuclear heating for the reactor start-up. Therefore the resolution of the position indicator for the integral reactor should be achieved to sense the position of the control rod more precisely than that of the RSPT of the ABB-CE. This paper adopts seismic resistance reed switches to the position indicator in order to reduce the damages or impacts during the handling of the position indicator and earthquake

Position Control of a 3-CPU Spherical Parallel Manipulator

Directory of Open Access Journals (Sweden)

Massimo Callegari

2013-01-01

Full Text Available The paper presents the first experimental results on the control of a prototypal robot designed for the orientation of parts or tools. The innovative machine is a spherical parallel manipulator actuated by 3 linear motors; several position control schemes have been tested and compared with the final aim of designing an interaction controller. The relative simplicity of machine kinematics allowed to test algorithms requiring the closed-loop evaluation of both inverse and direct kinematics; the compensation of gravitational terms has been experimented as well.

Boundary mediated position control of traveling waves

Science.gov (United States)

Martens, Steffen; Ziepke, Alexander; Engel, Harald

Reaction control is an essential task in biological systems and chemical process industry. Often, the excitable medium supporting wave propagation exhibits an irregular shape and/or is limited in size. In particular, the analytic treatment of wave phenomena is notoriously difficult due to the spatial modulation of the domain's. Recently, we have provided a first systematic treatment by applying asymptotic perturbation analysis leading to an approximate description that involves a reduction of dimensionality; the 3D RD equation with spatially dependent NFBCs on the reactants reduces to a 1D reaction-diffusion-advection equation. Here, we present a novel method to control the position ϕ (t) of traveling waves in modulated domains according to a prespecified protocol of motion. Given this protocol, the ``optimal'' geometry of reactive domains Q (x) is found as the solution of the perturbatively derived equation of motion. Noteworthy, such a boundary control can be expressed in terms of the uncontrolled wave profile and its propagation velocity, rendering detailed knowledge of the reaction kinetics unnecessary. German Science Foundation DFG through the SFB 910 ''Control of Self-Organizing Nonlinear Systems''.

Maternal sensitivity and latency to positive emotion following challenge: pathways through effortful control.

Science.gov (United States)

Conway, Anne; McDonough, Susan C; Mackenzie, Michael; Miller, Alison; Dayton, Carolyn; Rosenblum, Katherine; Muzik, Maria; Sameroff, Arnold

2014-01-01

The ability to self-generate positive emotions is an important component of emotion regulation. In this study, we focus on children's latency to express positive emotions following challenging situations and assess whether this ability operates through early maternal sensitivity and children's effortful control. Longitudinal relations between maternal sensitivity, infant negative affect, effortful control, and latency to positive emotion following challenge were examined in 156 children who were 33 months of age. Structural equation models supported the hypothesis that maternal sensitivity during infancy predicted better effortful control and, in turn, shorter latencies to positive emotions following challenge at 33 months. Directions for future research are discussed. © 2014 Michigan Association for Infant Mental Health.

Tri-code inductance control rod position indicator with several multi-coding-bars

International Nuclear Information System (INIS)

Shi Jibin; Jiang Yueyuan; Wang Wenran

2004-01-01

A control rod position indicator named as tri-code inductance control rod position indicator with multi-coding-bars, which possesses simple structure, reliable operation and high precision, is developed. The detector of the indicator is composed of K coils, a compensatory coil and K coding bars. Each coding bar consists of several sections of strong magnetic cores, several sections of weak magnetic cores and several sections of non-magnetic portions. As the control rod is withdrawn, the coding bars move in the center of the coils respectively, while the constant alternating current passes the coils and makes them to create inductance alternating voltage signals. The outputs of the coils are picked and processed, and the tri-codes indicating rod position can be gotten. Moreover, the coding principle of the detector and its related structure are introduced. The analysis shows that the indicator owns more advantage over the coils-coding rod position indicator, so it can meet the demands of the rod position indicating in nuclear heating reactor (NHR). (authors)

Position feedback control of a nonmagnetic body levitated in magnetic fluid

International Nuclear Information System (INIS)

Lee, J H; Nam, Y J; Park, M K; Yamane, R

2009-01-01

This paper is concerned with the position feedback control of a magnetic fluid actuator which is characterized by the passive levitation of a nonmagnetic body immersed in a magnetic fluid under magnetic fields. First of all, the magnetic fluid actuator is designed based on the ferrohydrostatic relation. After manufacturing the actuator, its static and dynamic characteristics are investigated experimentally. With the aid of the dynamic governing relation obtained experimentally and the proportional-derivative controller, the position tracking control of the actuator is carried out both theoretically and experimentally. As a result, the applicability of the proposed magnetic fluid actuator to various engineering devices is verified.

Position Control of an X4-Flyer Using a Tether

Directory of Open Access Journals (Sweden)

, Keigo Watanabe

2014-10-01

Full Text Available In Japan, aging of infrastructures, such as roads, bridges, and water and sewer services, etc. poses a problem, and it is required to extend the life-span of such infrastructures by maintenance. Among infrastructures, especially bridges are periodically inspected by short range visual observations, which check the damage and deterioration of the surface. However, since there are some cases where the short range visual observation is difficult, an alternative method is required so as to replace the short range visual observation with it. So, "X4-Flyer" is very attractive because of realizing a movement at high altitude easily. The objective of this study is to develop a tethered X4- Flyer, so that the conventional short range visual observation of bridges is replaced by it. In this paper, a method for the measurement and control of the position is described by using a tether for controlling the position of the X4-Flyer. In addition, it is checked whether the tethered X4-Flyer can control the position using the proposed method or not, letting it fly in a state in which a tether is being attached.

Continuous, saturation, and discontinuous tokamak plasma vertical position control systems

Energy Technology Data Exchange (ETDEWEB)

Mitrishkin, Yuri V., E-mail: y_mitrishkin@hotmail.com [M. V. Lomonosov Moscow State University, Faculty of Physics, Moscow 119991 (Russian Federation); Pavlova, Evgeniia A., E-mail: janerigoler@mail.ru [M. V. Lomonosov Moscow State University, Faculty of Physics, Moscow 119991 (Russian Federation); Kuznetsov, Evgenii A., E-mail: ea.kuznetsov@mail.ru [Troitsk Institute for Innovation and Fusion Research, Moscow 142190 (Russian Federation); Gaydamaka, Kirill I., E-mail: k.gaydamaka@gmail.com [V. A. Trapeznikov Institute of Control Sciences of the Russian Academy of Sciences, Moscow 117997 (Russian Federation)

2016-10-15

Highlights: • Robust new linear state feedback control system for tokamak plasma vertical position. • Plasma vertical position relay control system with voltage inverter in sliding mode. • Design of full models of multiphase rectifier and voltage inverter. • First-order unit approximation of full multiphase rectifier model with high accuracy. • Wider range of unstable plant parameters of stable control system with multiphase rectifier. - Abstract: This paper is devoted to the design and comparison of unstable plasma vertical position control systems in the T-15 tokamak with the application of two types of actuators: a multiphase thyristor rectifier and a transistor voltage inverter. An unstable dynamic element obtained by the identification of plasma-physical DINA code was used as the plasma model. The simplest static feedback state space control law was synthesized as a linear combination of signals accessible to physical measurements, namely the plasma vertical displacement, the current, and the voltage in a horizontal field coil, to solve the pole placement problem for a closed-loop system. Only one system distinctive parameter was used to optimize the performance of the feedback system, viz., a multiple real pole. A first-order inertial unit was used as the rectifier model in the feedback. A system with a complete rectifier model was investigated as well. A system with the voltage inverter model and static linear controller was brought into a sliding mode. As this takes place, real time delays were taken into account in the discontinuous voltage inverter model. The comparison of the linear and sliding mode systems showed that the linear system enjoyed an essentially wider range of the plant model parameters where the feedback system was stable.

Continuous, saturation, and discontinuous tokamak plasma vertical position control systems

International Nuclear Information System (INIS)

Mitrishkin, Yuri V.; Pavlova, Evgeniia A.; Kuznetsov, Evgenii A.; Gaydamaka, Kirill I.

2016-01-01

Highlights: • Robust new linear state feedback control system for tokamak plasma vertical position. • Plasma vertical position relay control system with voltage inverter in sliding mode. • Design of full models of multiphase rectifier and voltage inverter. • First-order unit approximation of full multiphase rectifier model with high accuracy. • Wider range of unstable plant parameters of stable control system with multiphase rectifier. - Abstract: This paper is devoted to the design and comparison of unstable plasma vertical position control systems in the T-15 tokamak with the application of two types of actuators: a multiphase thyristor rectifier and a transistor voltage inverter. An unstable dynamic element obtained by the identification of plasma-physical DINA code was used as the plasma model. The simplest static feedback state space control law was synthesized as a linear combination of signals accessible to physical measurements, namely the plasma vertical displacement, the current, and the voltage in a horizontal field coil, to solve the pole placement problem for a closed-loop system. Only one system distinctive parameter was used to optimize the performance of the feedback system, viz., a multiple real pole. A first-order inertial unit was used as the rectifier model in the feedback. A system with a complete rectifier model was investigated as well. A system with the voltage inverter model and static linear controller was brought into a sliding mode. As this takes place, real time delays were taken into account in the discontinuous voltage inverter model. The comparison of the linear and sliding mode systems showed that the linear system enjoyed an essentially wider range of the plant model parameters where the feedback system was stable.

Reduced susceptibility of Enterococcus spp. isolates from Cairo University Hospital to tigecycline: Highlight on the influence of proton pump inhibitors.

Science.gov (United States)

Hassan, Reem Mostafa; Ghaith, Doaa Mohammad; Ismail, Dalia Kadry; Zafer, Mai Mahmoud

2018-03-01

The incidence of reduced susceptibility to tigecycline (TIG) is increasing. This study aimed to analyse the in vitro activity of TIG against Enterococcus spp. isolates recovered from hospitalised patients and to evaluate the effect of omeprazole on the in vitro antimicrobial activity of TIG against several enterococcal species. A total of 67 Enterococcus clinical isolates were identified by MALDI-TOF/MS and multiplex PCR. Minimum inhibitory concentrations (MICs) of TIG alone and in combination with omeprazole (10, 30 and 60mg/L) were determined by broth microdilution. Antibiotic susceptibility to other antibiotics was determined by disk diffusion. The presence of van, tet(X) and tet(X1) genes was tested by multiplex PCR. Of the 67 Enterococcus isolates, 2 (3.0%) were resistant to TIG and 13 (19.4%) were intermediate-resistant according to EUCAST. The frequencies of resistance to norfloxacin (80.6%), doxycycline (80.6%), levofloxacin (74.6%) and ciprofloxacin (71.6%) were highest, whilst that of vancomycin (25.4%) was lowest. The vanA gene was detected in 11 Enterococcus isolates (8 Enterococcus faecalis, 3 Enterococcus faecium), vanB in 3 Enterococcus isolates (2 E. faecium, 1 E. faecalis) and vanC-2/3 in 3 Enterococcus casseliflavus. Nine isolates (13.4%) were positive for tet(X1). TIG resistance occurred both in patients receiving or not TIG and/or omeprazole. Omeprazole increased TIG MICs by 4-128-fold. The possibility of selection of TIG-non-susceptible Enterococcus in the gut may occur with long-term use of omeprazole. Omeprazole influenced TIG activity in a concentration-dependent manner. To our knowledge; this is the first report of TIG-non-susceptible Enterococcus spp. in Egypt. Copyright © 2017 International Society for Chemotherapy of Infection and Cancer. Published by Elsevier Ltd. All rights reserved.

Robust independent modal space control of a coupled nano-positioning piezo-stage

Science.gov (United States)

Zhu, Wei; Yang, Fufeng; Rui, Xiaoting

2018-06-01

In order to accurately control a coupled 3-DOF nano-positioning piezo-stage, this paper designs a hybrid controller. In this controller, a hysteresis observer based on a Bouc-Wen model is established to compensate the hysteresis nonlinearity of the piezoelectric actuator first. Compared to hysteresis compensations using Preisach model and Prandt-Ishlinskii model, the compensation method using the hysteresis observer is computationally lighter. Then, based on the proposed dynamics model, by constructing the modal filter, a robust H∞ independent modal space controller is designed and utilized to decouple the piezo-stage and deal with the unmodeled dynamics, disturbance, and hysteresis compensation error. The effectiveness of the proposed controller is demonstrated experimentally. The experimental results show that the proposed controller can significantly achieve the high-precision positioning.

Development of EPICS based beam-line experimental control employing motor controller for precision positioning

International Nuclear Information System (INIS)

Tuli, Anupriya; Jain, Rajiv; Vora, H.S.

2015-01-01

In a Synchrotron Radiation Source the beamline experiments are carried out in radiation prone environment, inside the hutch, which demands to conduct experiments remotely. These experiments involves instrument control and data acquisition from various devices. Another factor which attributes to system complexity is precise positioning of sample and placement of detectors. A large number of stepper motors are engaged for achieving the required precision positioning. This work is a result of development of Experimental Physics and Industrial Control System (EPICS) based control system to interface a stepper motor controller developed indigenously by Laser Electronics Support Division of RRCAT. EPICS is an internationally accepted open source software environment which follows toolkit approach and standard model paradigm. The operator interface for the control system software was implemented using CSS BOY. The system was successfully tested for Ethernet based remote access. The developed control software comprises of an OPI and alarm handler (EPICS ALH). Both OPI and ALH are linked with PV's defined in database files. The development process resulted into a set of EPICS based commands for controlling stepper motor. These commands are independent of operator interface, i.e. stepper motor can be controlled by using these set of commands directly on EPICS prompt. This command set is illustrated in the above table. EPICS Alarm Handler was also tested independently by running these commands on EPIC prompt. If not using ALH, operator can read the alarm status of a PV using 'SEVR' and 'STAT' attributes. (author)

Effects of an acidic beverage (Coca-Cola) on absorption of ketoconazole.

Science.gov (United States)

Chin, T W; Loeb, M; Fong, I W

1995-08-01

Absorption of ketoconazole is impaired in patients with achlorhydria. The purpose of this study was to determine the effectiveness of a palatable acidic beverage (Coca-Cola Classic, pH 2.5) in improving the absorption of ketoconazole in the presence of drug-induced achlorhydria. A prospective, randomized, three-way crossover design with a 1-week wash-out period between each treatment was employed. Nine healthy nonsmoking, nonobese volunteers between 22 and 41 years old were studied. Each subject was randomized to receive three treatments: (A) ketoconazole 200-mg tablet with water (control), (B) omeprazole (60 mg) followed by ketoconazole (200 mg) taken with water, and (C) omeprazole (60 mg) followed by ketoconazole (200 mg) taken with 240 ml of Coca-Cola Classic. The pH values of gastric aspirates were checked after omeprazole was administered to confirm attainment of a pH of > 6. Multiple serum samples were obtained for measurements of ketoconazole concentrations by high-pressure liquid chromatography. The mean area under the ketoconazole concentration-time curve from zero to infinity for the control treatment (17.9 +/- 13.1 mg.h/liter) was significantly greater than that for treatment B (3.5 +/- 5.1 mg.h/liter; 16.6% +/- 15.0% of control). The mean peak concentration was highest for the control treatment (4.1 +/- 1.9 micrograms/ml), for which the mean peak concentration showed a significant increase over that for treatment B. The absorption of ketoconazole was reduced in the presence of omeprazole-induced achlorhydria. However, drug absorption was significantly increased, to approximately 65% of the mean for the control treatment, when the drug was taken with an acidic beverage, such as Coca-Cola.

Position Control of Switched Reluctance Motor Using Super Twisting Algorithm

Directory of Open Access Journals (Sweden)

Muhammad Rafiq Mufti

2016-01-01

Full Text Available The inherent problem of chattering in traditional sliding mode control is harmful for practical application of control system. This paper pays a considerable attention to a chattering-free control method, that is, higher-order sliding mode (super twisting algorithm. The design of a position controller for switched reluctance motor is presented and its stability is assured using Lyapunov stability theorem. In order to highlight the advantages of higher-order sliding mode controller (HOSMC, a classical first-order sliding mode controller (FOSMC is also applied to the same system and compared. The simulation results reflect the effectiveness of the proposed technique.

Musical Applications and Design Techniques for the Gametrak Tethered Spatial Position Controller

DEFF Research Database (Denmark)

Freed, Adrian; Overholt, Daniel; Hansen, Anne-Marie

2009-01-01

The Gametrak spatial position controller has been saved from the fate of so many discontinued gaming controllers to become an attractive and increasingly popular platform for experimental musical controllers, math and science manipulatives, large scale interactive installations and as a playful...... tangible gaming interface that promotes inter-generational creative play and discovery . After introducing the peculiarities of the GameTrak and comparing it to related spatial position sensing systems we survey musical applications of the device. The short paper format cannot do justice to the depth...

Stability of position control system in JIPP T-II

International Nuclear Information System (INIS)

Sakurai, Keiichi; Tanahashi, Shygo

1980-01-01

Computations and experiments on the stability of a feedback control system for maintaining a plasma column in equilibrium are described. The time response of the displacement of the plasma to the desired position is examined by solving the equation of motion of the plasma column. We show that the stability of the feedback control system is improved by using an additional term which represents the shift velocity of the plasma column. (author)

[Relationship between the prone position and achieving head control at 3 months].

Science.gov (United States)

Pérez-Machado, J L; Rodríguez-Fuentes, G

2013-10-01

Owing to the significant increase of mild motor delays and the strong intolerance of infants to be placed on prone position observed in the Physiotherapy Unit of the Maternal and Children's University Hospital of the Canaries (HUMIC), a study was conducted to determine whether positioning infants in the prone position while awake affected the achievement and quality of head control at three months. A prospective comparative practice-based study of a representative sample of 67 healthy infants born in the HUMIC, and divided into an experimental group (n = 35) and control group (n = 32). The Alberta Infant Motor Scale (AIMS) and a parent questionnaire were used as measurement tools. The intervention consisted of regular home visits to the experimental group (from the first to the third month). The two groups were evaluated in their homes at the end of 3 months. The differences in mean raw score of the AIMS at 3 months were, 16.26 in the experimental group and 10.38 in control group (P<.001). The percentile mean was 94 in the experimental group, and less than 50 (42) in the control group. All of the experimental group babies achieved the head control, with only 8 in the control group (25%). The significant findings suggest a direct relationship between the time spent in the prone position when the baby is awake and the achievement of head control at three months. Copyright © 2012 Asociación Española de Pediatría. Published by Elsevier Espana. All rights reserved.

Real-time digital control of plasma position and shape on the TEXTOR tokamak

International Nuclear Information System (INIS)

Mitri, Mikhael

2009-01-01

Beside the objective of contributing to the controlled thermonuclear fusion research and ultimately the development of a fusion based power plant, the main objectives of the thesis are a substantial improvement of plasma vertical position control and plasma shape control as well as a better understanding of formerly unexplained effects, e.g. disturbance fields. As for the vertical position control, a deep analysis has to be undertaken to identify the problem sources. Accurate control of the plasma position is very difficult to achieve. This is mainly due to the complexity of the tokamak and the difficulty in measuring or modelling all relevant discharge variables. Any models would be highly nonlinear and time varying. Thus, for simulation and controller design, a simplified, but nevertheless accurate model has to be developed, based on physics and measured data of the process. Furthermore, the quality of the measured position has to be improved by using new inductive sensors, integrators, and hardware. The integration drift problem has to be analysed and resolved by developing a drift-free integration method. Concerning the shape control, a better understanding of the relation between the stray fields and the iron core saturation is required. Furthermore, the influence on the plasma elongation has to be determined. Upon this, a shape compensation algorithm has to be developed accordingly. The accuracy of the shape control has to be better than 1%. (orig.)

Wideband Motion Control by Position and Acceleration Input Based Disturbance Observer

Science.gov (United States)

Irie, Kouhei; Katsura, Seiichiro; Ohishi, Kiyoshi

The disturbance observer can observe and suppress the disturbance torque within its bandwidth. Recent motion systems begin to spread in the society and they are required to have ability to contact with unknown environment. Such a haptic motion requires much wider bandwidth. However, since the conventional disturbance observer attains the acceleration response by the second order derivative of position response, the bandwidth is limited due to the derivative noise. This paper proposes a novel structure of a disturbance observer. The proposed disturbance observer uses an acceleration sensor for enlargement of bandwidth. Generally, the bandwidth of an acceleration sensor is from 1Hz to more than 1kHz. To cover DC range, the conventional position sensor based disturbance observer is integrated. Thus, the performance of the proposed Position and Acceleration input based disturbance observer (PADO) is superior to the conventional one. The PADO is applied to position control (infinity stiffness) and force control (zero stiffness). The numerical and experimental results show viability of the proposed method.

Hybrid PD and effective multi-mode positive position feedback control for slewing and vibration suppression of a smart flexible manipulator

International Nuclear Information System (INIS)

Lou, Jun-qiang; Wei, Yan-ding; Yang, Yi-ling; Xie, Feng-ran

2015-01-01

A hybrid control strategy for slewing and vibration suppression of a smart flexible manipulator is presented in this paper. It consists of a proportional derivative controller to realize motion control, and an effective multi-mode positive position feedback (EMPPF) controller to suppress the multi-mode vibration. Rather than treat each mode equally as the standard multi-mode PPF, the essence of the EMPPF is that control forces of different modes are applied according to the mode parameters of the respective modes, so the vibration modes with less vibration energy receive fewer control forces. Stability conditions for the close loop system are established through stability analysis. Optimal parameters of the EMPPF controller are obtained using the method of root locus analysis. The performance of the proposed strategy is demonstrated by simulation and experiments. Experimental results show that the first two vibration modes of the manipulator are effectively suppressed. The setting time of the setup descends approximately 55%, reaching 3.12 s from 5.67 s. (paper)

Hybrid PD and effective multi-mode positive position feedback control for slewing and vibration suppression of a smart flexible manipulator

Science.gov (United States)

Lou, Jun-qiang; Wei, Yan-ding; Yang, Yi-ling; Xie, Feng-ran

2015-03-01

A hybrid control strategy for slewing and vibration suppression of a smart flexible manipulator is presented in this paper. It consists of a proportional derivative controller to realize motion control, and an effective multi-mode positive position feedback (EMPPF) controller to suppress the multi-mode vibration. Rather than treat each mode equally as the standard multi-mode PPF, the essence of the EMPPF is that control forces of different modes are applied according to the mode parameters of the respective modes, so the vibration modes with less vibration energy receive fewer control forces. Stability conditions for the close loop system are established through stability analysis. Optimal parameters of the EMPPF controller are obtained using the method of root locus analysis. The performance of the proposed strategy is demonstrated by simulation and experiments. Experimental results show that the first two vibration modes of the manipulator are effectively suppressed. The setting time of the setup descends approximately 55%, reaching 3.12 s from 5.67 s.

Position Mooring Control Based on a Structural Reliability Criterion

DEFF Research Database (Denmark)

Fang, Shaoji; Leira, Bernt J.; Blanke, Mogens

2013-01-01

is achieved using structural reliability indices in a cost function, where both the mean mooring-line tension and dynamic effects are considered. An optimal set-point is automatically produced without need for manual interaction. The parameters of the extreme value distribution are calculated on-line thereby...... mooring lines simultaneously from exceeding a stress threshold, this paper suggests a new algorithm to determine the reference position and an associated control system. The safety of each line is assessed through a structural reliability index. A reference position where all mooring lines are safe...

Electro-Pneumatic Control System with Hydraulically Positioning Actuator Motor

Directory of Open Access Journals (Sweden)

V. N. Pilgunov

2016-01-01

Full Text Available A compressibility of the actuating fluid of a pneumatic drive (compressed air leads to significant landing of the pneumatic cylinder piston at the time of stop and hold of the load, a constant component of which can fluctuate significantly for the holding period.There are a lot of factors, which have a significant impact on the landing value of piston. Those are: an initial position of the piston at its stop, which determines the volume of the an active area of the piston, a value of the constant load component at the time of stop and its variation for the holding period, a transfer coefficient of the position component of the load, an active area of the pneumatic cylinder piston, as well as reduction in atmospheric pressure, which can significantly affect the operation of the control systems of small aircrafts flying at high altitudes.To reduce the landing value of piston due to changing value of the constant load component for its holding period, it is proposed to use a hydraulic positioner, which comprises a hydraulic cylinder the rod of which is rigidly connected to the rod of the pneumatic cylinder through the traverse, a cross-feed valve of the hydro-cylinder cavities with discrete electro-magnetic control, and adjustable chokes.A programmable logic controller provides the hydraulic positioner control. At the moment the piston stops and the load is held the cross-feed valve overlaps the hydro-cylinder cavities thereby locking the pneumatic cylinder piston and preventing its landing. With available pneumatic cylinder-controlled signal the cross-feed valve connects the piston and rod cavities of the positioner hydro-cylinder, the pneumatic cylinder piston is released and becomes capable of moving.A numerical estimate of landing of the pneumatic cylinder piston and its positioning quality is of essential interest. For this purpose, a technique to calculate the landing of piston has been developed taking into consideration that different

Identification and control of plasma vertical position using neural network in Damavand tokamak

International Nuclear Information System (INIS)

Rasouli, H.; Rasouli, C.; Koohi, A.

2013-01-01

In this work, a nonlinear model is introduced to determine the vertical position of the plasma column in Damavand tokamak. Using this model as a simulator, a nonlinear neural network controller has been designed. In the first stage, the electronic drive and sensory circuits of Damavand tokamak are modified. These circuits can control the vertical position of the plasma column inside the vacuum vessel. Since the vertical position of plasma is an unstable parameter, a direct closed loop system identification algorithm is performed. In the second stage, a nonlinear model is identified for plasma vertical position, based on the multilayer perceptron (MLP) neural network (NN) structure. Estimation of simulator parameters has been performed by back-propagation error algorithm using Levenberg–Marquardt gradient descent optimization technique. The model is verified through simulation of the whole closed loop system using both simulator and actual plant in similar conditions. As the final stage, a MLP neural network controller is designed for simulator model. In the last step, online training is performed to tune the controller parameters. Simulation results justify using of the NN controller for the actual plant.

Identification and control of plasma vertical position using neural network in Damavand tokamak

Energy Technology Data Exchange (ETDEWEB)

Rasouli, H. [School of Plasma Physics and Nuclear Fusion, Institute of Nuclear Science and Technology, AEOI, P.O. Box 14155-1339, Tehran (Iran, Islamic Republic of); Advanced Process Automation and Control (APAC) Research Group, Faculty of Electrical Engineering, K.N. Toosi University of Technology, P.O. Box 16315-1355, Tehran (Iran, Islamic Republic of); Rasouli, C.; Koohi, A. [School of Plasma Physics and Nuclear Fusion, Institute of Nuclear Science and Technology, AEOI, P.O. Box 14155-1339, Tehran (Iran, Islamic Republic of)

2013-02-15

In this work, a nonlinear model is introduced to determine the vertical position of the plasma column in Damavand tokamak. Using this model as a simulator, a nonlinear neural network controller has been designed. In the first stage, the electronic drive and sensory circuits of Damavand tokamak are modified. These circuits can control the vertical position of the plasma column inside the vacuum vessel. Since the vertical position of plasma is an unstable parameter, a direct closed loop system identification algorithm is performed. In the second stage, a nonlinear model is identified for plasma vertical position, based on the multilayer perceptron (MLP) neural network (NN) structure. Estimation of simulator parameters has been performed by back-propagation error algorithm using Levenberg-Marquardt gradient descent optimization technique. The model is verified through simulation of the whole closed loop system using both simulator and actual plant in similar conditions. As the final stage, a MLP neural network controller is designed for simulator model. In the last step, online training is performed to tune the controller parameters. Simulation results justify using of the NN controller for the actual plant.

Modeling and controller design of a 6-DOF precision positioning system

Science.gov (United States)

Cai, Kunhai; Tian, Yanling; Liu, Xianping; Fatikow, Sergej; Wang, Fujun; Cui, Liangyu; Zhang, Dawei; Shirinzadeh, Bijan

2018-05-01

A key hurdle to meet the needs of micro/nano manipulation in some complex cases is the inadequate workspace and flexibility of the operation ends. This paper presents a 6-degree of freedom (DOF) serial-parallel precision positioning system, which consists of two compact type 3-DOF parallel mechanisms. Each parallel mechanism is driven by three piezoelectric actuators (PEAs), guided by three symmetric T-shape hinges and three elliptical flexible hinges, respectively. It can extend workspace and improve flexibility of the operation ends. The proposed system can be assembled easily, which will greatly reduce the assembly errors and improve the positioning accuracy. In addition, the kinematic and dynamic model of the 6-DOF system are established, respectively. Furthermore, in order to reduce the tracking error and improve the positioning accuracy, the Discrete-time Model Predictive Controller (DMPC) is applied as an effective control method. Meanwhile, the effectiveness of the DMCP control method is verified. Finally, the tracking experiment is performed to verify the tracking performances of the 6-DOF stage.

Arrangement of permanent magnet and reed switches for control rod position indicator of SMART CEDM

International Nuclear Information System (INIS)

Yoo, J. Y.; Kim, J. I.; Kim, J. H.; Hur, H.; Jang, M. H.

2001-01-01

The reliability and accuracy of the information on control rod position are very important to the reactor safety and the design of the core protection system. A survey on the RSPT(Reed Switch Position Transmitter) type control rod position indication system and its actual implementation in the exiting nuclear power plants in Korea was performed first. The control rod position indicator having the high performance for SMART was developed on the basis of RSPT technology identified through the survey. The arrangement of permanent magnet and reed switches is the most important procedure in the design of control rod position indication. In this study, the characteristics of permanent magnet and reed switches are introduced and the calculation method for arrangement of permanent magnet and reed switch is presented

A test of positive affect induction for countering self-control depletion in cigarette smokers.

Science.gov (United States)

Shmueli, Dikla; Prochaska, Judith J

2012-03-01

The self-control strength model posits that exerting self-control on one task, such as resisting temptations, will deplete self-control and impair subsequent self-regulatory performance, such as controlling smoking. The current study examined interventions designed to replenish depleted self-control strength to prevent tobacco use by inducing positive affect. In a 2 × 2 design, 200 participants were randomized to either (1) resist eating from a plate of desserts (high temptation) or from a plate of raw vegetables (low temptation) and then (2) undergo a positive or neutral affect induction. Two inductions were compared (video vs. writing technique). Participants were then given a 10-min recess. Whether or not participants smoked during the recess, assessed by self-report and biochemical verification, served as the primary dependent variable. The interaction between depletion and exposure group was significant, Wald's χ² = 9.66, df = 3, p desserts, 65.5% to 85% smoked if they were in the neutral video or writing conditions versus 10.5% in the positive affect video group. Positive affect elicited with a video was able to counteract the detrimental effects of self-control depletion on smoking behavior, while writing exercises were associated with smoking. Implications for tobacco cessation intervention are discussed. PsycINFO Database Record (c) 2012 APA, all rights reserved.

A Clustered Randomized Controlled Trial of the Positive Prevention PLUS Adolescent Pregnancy Prevention Program.

Science.gov (United States)

LaChausse, Robert G

2016-09-01

To determine the impact of Positive Prevention PLUS, a school-based adolescent pregnancy prevention program on delaying sexual intercourse, birth control use, and pregnancy. I randomly assigned a diverse sample of ninth grade students in 21 suburban public high schools in California into treatment (n = 2483) and control (n = 1784) groups that participated in a clustered randomized controlled trial. Between October 2013 and May 2014, participants completed baseline and 6-month follow-up surveys regarding sexual behavior and pregnancy. Participants in the treatment group were offered Positive Prevention PLUS, an 11-lesson adolescent pregnancy prevention program. The program had statistically significant impacts on delaying sexual intercourse and increasing the use of birth control. However, I detected no program effect on pregnancy rates at 6-month follow-up. The Positive Prevention PLUS program demonstrated positive impacts on adolescent sexual behavior. This suggests that programs that focus on having students practice risk reduction skills may delay sexual activity and increase birth control use.

The plasma position control of ITER EDA plasma

International Nuclear Information System (INIS)

Senda, Ikuo; Nishio, Satoshi; Tsunematsu, Toshihide; Nishino, Toru; Fujieda, Hirobumi.

1994-09-01

The study on the plasma position control of ITER EDA performed by Japan Home Team during the sensitivity study in 1994 is summarized. The controllabilities of plasmas in the Outline Design and elongated version are compared. The model used to describe the motion of the plasma is a rigid model. The PD feedback control is applied with respect to the displacements of the plasma from the equilibrium. Three types of fluctuations, which initiate the motion of the plasma, are examined, namely a finite horizontal fluctuation field, a small horizontal fluctuation field such that the motion of the plasma is governed by the passive structures and an abrupt change of the poloidal beta β p and internal inductance l i . In the simulations of finite horizontal fluctuation fields, controls depend on the strength of the fluctuations, for instance, 3-5V is needed for 5-10G of fluctuation fields in the Outline Design. When the fluctuation field is small and the plasma displacement grows in a characteristic time of the passive structures, a few volt of the control voltage is enough to obtain good controllability. It is shown that the control when (β p , l i ) changes simultaneously is demanding and a large control voltage is required to maintain satisfactory control. Comparing the elongated version with the Outline Design, the control voltage which is larger than the Outline Design by a factor of 2-3 is required to obtain the same controllability in the elongated version. (author)

Conceptual Design of Angular Position Detector for Control Element Drive Mechanism of Small and Medium Reactor

International Nuclear Information System (INIS)

Yu, Je-Yong; Huh, Hyung; Kim, Ji-Ho; Choi, Suhn

2007-01-01

When the small and medium reactor is designed with a soluble boron free operation and nuclear heating for the reactor start-up, the design features require a Control Element Drive Mechanism (CEDM) to have a fine-step movement capability as well as a high reliability for a fine reactivity control. Also the reliability and accuracy of the information for the control rod position is important to the reactor safety as well as to design of the core protection system. The position signal of control rod is classified as a Class 1E because the rod position signal is used in the safety related systems. Therefore it will be separated from the control systems to the extent that a failure of any single control system component of a channel and shall have sufficient independence, redundancy, and testability to perform its safety functions assuming a single failure. The position indicator is composed of a permanent magnet, reed switches and a voltage divider. Four independent position indicators around the upper pressure housing provide an indication of the position of a control rod comprising of a permanent magnet with a magnetic field concentrator which moves with the extension shaft connected to the control rod. The zigzag arranged reed switches are positioned along a line parallel to the path of the movement of the permanent magnet and it is activated selectively when the permanent magnet passes by. A voltage divider electrically connected to the reed switches provides a signal commensurate with the position of the control rod. The signal may then be transmitted to a position indicating device. But position indicator can not recognize the malfunction of the rotary step motor of CEDM instantly because its signal output is changed after the control rod moves more than a distance of reed switch interval

Position, Attitude, and Fault-Tolerant Control of Tilting-Rotor Quadcopter

Science.gov (United States)

Kumar, Rumit

The aim of this thesis is to present algorithms for autonomous control of tilt-rotor quadcopter UAV. In particular, this research work describes position, attitude and fault tolerant control in tilt-rotor quadcopter. Quadcopters are one of the most popular and reliable unmanned aerial systems because of the design simplicity, hovering capabilities and minimal operational cost. Numerous applications for quadcopters have been explored all over the world but very little work has been done to explore design enhancements and address the fault-tolerant capabilities of the quadcopters. The tilting rotor quadcopter is a structural advancement of traditional quadcopter and it provides additional actuated controls as the propeller motors are actuated for tilt which can be utilized to improve efficiency of the aerial vehicle during flight. The tilting rotor quadcopter design is accomplished by using an additional servo motor for each rotor that enables the rotor to tilt about the axis of the quadcopter arm. Tilting rotor quadcopter is a more agile version of conventional quadcopter and it is a fully actuated system. The tilt-rotor quadcopter is capable of following complex trajectories with ease. The control strategy in this work is to use the propeller tilts for position and orientation control during autonomous flight of the quadcopter. In conventional quadcopters, two propellers rotate in clockwise direction and other two propellers rotate in counter clockwise direction to cancel out the effective yawing moment of the system. The variation in rotational speeds of these four propellers is utilized for maneuvering. On the other hand, this work incorporates use of varying propeller rotational speeds along with tilting of the propellers for maneuvering during flight. The rotational motion of propellers work in sync with propeller tilts to control the position and orientation of the UAV during the flight. A PD flight controller is developed to achieve various modes of the

Single axis control of ball position in magnetic levitation system using fuzzy logic control

Science.gov (United States)

Sahoo, Narayan; Tripathy, Ashis; Sharma, Priyaranjan

2018-03-01

This paper presents the design and real time implementation of Fuzzy logic control(FLC) for the control of the position of a ferromagnetic ball by manipulating the current flowing in an electromagnet that changes the magnetic field acting on the ball. This system is highly nonlinear and open loop unstable. Many un-measurable disturbances are also acting on the system, making the control of it highly complex but interesting for any researcher in control system domain. First the system is modelled using the fundamental laws, which gives a nonlinear equation. The nonlinear model is then linearized at an operating point. Fuzzy logic controller is designed after studying the system in closed loop under PID control action. The controller is then implemented in real time using Simulink real time environment. The controller is tuned manually to get a stable and robust performance. The set point tracking performance of FLC and PID controllers were compared and analyzed.

Enhancement of control rod drive mechanism seating position detector for JRR-3

International Nuclear Information System (INIS)

Ohuchi, Satoshi; Kurumada, Osamu; Kamiishi, Eigo; Sato, Masayuki; Ikekame, Yoshinori; Wada, Shigeru

2016-06-01

The purpose of the control rod drive mechanism seating position detector for JRR-3 is one of methods for confirming the shutdown condition of the reactor and sending out the seat position signal to other systems. The detector has been utilizing more than 25 years with maintenance regularly. However, some troubles occurred recently. Moreover, the detector has already been discontinued, and it is confirmed that the successor detector is unsuitable for the control rod drive mechanism of JRR-3. Therefore, it was necessary to select the adequate detector to the control rod drive mechanism of JRR-3. Accordingly, we built a test device with the aim of verifying several detectors for integrity and function. At the time of the test for performance confirmation, it was occurred unexpected problems. Nevertheless, we devise improvement of the problems and took measures. Thus we were able to make adequate detector for JRR-3 and replace to enhanced detector. This paper reports the Enhanced of Control rod drive mechanism seating position detector. (author)

Design of a Single-Cell Positioning Controller Using Electroosmotic Flow and Image Processing

Directory of Open Access Journals (Sweden)

Jhong-Yin Chen

2013-05-01

Full Text Available The objective of the current research was not only to provide a fast and automatic positioning platform for single cells, but also improved biomolecular manipulation techniques. In this study, an automatic platform for cell positioning using electroosmotic flow and image processing technology was designed. The platform was developed using a PCI image acquisition interface card for capturing images from a microscope and then transferring them to a computer using human-machine interface software. This software was designed by the Laboratory Virtual Instrument Engineering Workbench, a graphical language for finding cell positions and viewing the driving trace, and the fuzzy logic method for controlling the voltage or time of an electric field. After experiments on real human leukemic cells (U-937, the success of the cell positioning rate achieved by controlling the voltage factor reaches 100% within 5 s. A greater precision is obtained when controlling the time factor, whereby the success rate reaches 100% within 28 s. Advantages in both high speed and high precision are attained if these two voltage and time control methods are combined. The control speed with the combined method is about 5.18 times greater than that achieved by the time method, and the control precision with the combined method is more than five times greater than that achieved by the voltage method.

The position control of a capsule filled with magnetic fluid

International Nuclear Information System (INIS)

Rhee, E.J.; Park, M.K.; Yamane, R.; Oshima, S.

2002-01-01

In this paper, in order to establish the technique of a nozzle-flapper system of a servo valve using magnetic fluid in hydraulic system, a governing equation regarding the levitation of a capsule filled with magnetic fluid is formulated. Using PID control, an experiment for the position control of a capsule was performed. The experimental results were compared with the simulation results found by the governing equation

Plasma position and shape control device for thermonuclear device

International Nuclear Information System (INIS)

Takeuchi, Kazuhiro; Abe, Mitsushi; Kinoshita, Shigemi.

1993-01-01

A plasma position and shape control system is constituted with a measuring device, a quenching probability calculation section and a control calculation section. A quenching probability is calculated in the quenching probability calculation section by using a measuring data on temperature, electric current and magnetic field of superconductive coils, based on a margin upto a limit value. The control calculation section selects a control method which decreases applied voltage or current instruction value as the quenching probability of the coils is higher. Since the quenching probability of the superconductive coils can be forecast and a state of low quenching danger can be selected, the safety of the device is improved. When the quenching danger is allowed to a predetermined value, a wide operation region can be provided. (N.H.)

Linear quadratic Gaussian controller design for plasma current, position and shape control system in ITER

International Nuclear Information System (INIS)

Belyakov, V.; Kavin, A.; Rumyantsev, E.; Kharitonov, V.; Misenov, B.; Ovsyannikov, A.; Ovsyannikov, D.; Veremei, E.; Zhabko, A.; Mitrishkin, Y.

1999-01-01

This paper is focused on the linear quadratic Gaussian (LQG) controller synthesis methodology for the ITER plasma current, position and shape control system as well as power derivative management system. It has been shown that some poloidal field (PF) coils have less influence on reference plasma-wall gaps control during plasma disturbances and hence they have been used to reduce total control power derivative by means of the additional non-linear feedback. The design has been done on the basis of linear models. Simulation was provided for non-linear model and results are presented and discussed. (orig.)

Position controller for the arm of a neutron diffractometer using fuzzy logic

International Nuclear Information System (INIS)

Ayala P, G.F.

1994-01-01

The neutron diffractometer is an important instrument coupled to one of the radial outlets of the TRIGA-3-Salazar Reactor and is used mainly to analyze textures and crystal lattices. One of its main components is the velocity analysis goniometer which controls in a tangential way the movements of the sensor requiring for this a resolution of a hundredth of degree, but at the same time wide displacements are required. It is necessary to design and construct a system on the basis of a micro controller which control the long movements in a rapid way and with the needed accuracy. In this work, a proposition is presented: to replace the A.C. motor with a D.C. motor with a wide range of velocity and supplied with a card (DAC) to control the velocity by means of digital data. Moreover, a programmed micro controller with an algorithm based on fuzzy logic receiving data in BCD will be use. The use of micro controller will allow to set free the personal computer of the position of the goniometer; nevertheless, the system will report to the P C and its control program about the present position of the goniometer and the time when the desired position is reached. It is also consider that the user will be away from the system (a minimum of 15 meters) in order to avoid the zone with a high intensity of background radiation. (Author)

Assessment of clinical effect on acute hemorrhagic gastritis combined with omeprazole in the treatment effect of sucralfate%奥美拉唑联合硫糖铝治疗急性出血性胃炎临床效果评价

Institute of Scientific and Technical Information of China (English)

黄金红

2014-01-01

目的：分析急性出血性胃炎中奥美拉唑联合硫糖铝的治疗效果。方法：从我院住院治疗患者中选取66例急性出血性胃炎患者进行研究，以随机标准将全部患者分成对照组和观察组，对照组患者采用法莫替丁治疗，观察组患者采用奥美拉唑联合硫糖铝治疗。对比2组治疗后的效果，观察不良反应。结果：对照组治愈28例，无效5例，总的治疗有效率为84．8％，观察组治愈32例，无效1例，总的治疗有效率为97．0％；治疗过程中2组患者均未出现较为严重的不良反应。结论：在急性出血性胃炎的治疗中，采用奥美拉唑联合硫糖铝治疗，不仅能提高治疗效果，而且安全性较高，临床中值得推广。%Objective:To analyze the acute hemorrhagic gastritis combined with omeprazole in the treatment effect of sucralfate .Meth-ods:From our hospital in patients with a total of 66 patients with acute hemorrhagic gastritis were studied , using randomstandard would all patients were divided into control group and observation group .Conclusion:In the treatment of acute hemorrhagic gastritis , using omeprazole combined with sucralfate treatment , not only could improve the treatment effect , and high safety , worthy of promotion in clinical therapy .

The Marketing & Positive Impacts of Behavioral Control System on Societies & Countries

Directory of Open Access Journals (Sweden)

Ahmad Adel Mostafa

2015-03-01

Full Text Available Behavioral control systems are one of the most prominent tools used by managers and marketers for different internal and external purposes. One of the most important external purposes they have been used for is influencing consumer behavior. This paper explores the positive effects of implementing such systems on societies. It discusses consumer perception of the systems, their influence on their financial behavior in different contexts, how can they create order and how as well as to what extent should it be implemented and finally how can minimize negative consumer behavior. A judgment based sample of typical consumers was surveyed using questionnaires for collecting primary data on these aspects. Secondary data from Egypt, Singapore and Malaysia was also used as an example of using behavioral control systems. Results show that consumers in general have a positive attitude towards imposing such systems. However, there were worries about misuse, abuse and overuse of theses systems’ policies. Consequently, data shows that behavioral control systems can positively enhance and influence consumer behavior as long as it is used to balance both consumer and retailer interests in a moderate, risk free manner.

Feedback control of horizontal position and plasma surface shape in a non-circular tokamak

International Nuclear Information System (INIS)

Moriyama, Shin-ichi; Nakamura, Kazuo; Nakamura, Yukio; Itoh, Satoshi

1986-01-01

The linear model for the coupled horizontal position and plasma surface shape control in the non-circular tokamak device was described. It enables us to estimate easily the displacement and the distortion due to the changes in plasma pressure and current density distribution. The PI-controller and the optimal regulator were designed with the linear model. Transient-response analysis of the control system in the TRIAM-1M tokamak showed that the optimal regulator is superior to the PI-controller with regard to the mutual-interference between the position control system and the elongation control system. (author)

Control rod position and temperature coefficients in HTTR power-rise tests. Interim report

International Nuclear Information System (INIS)

Fujimoto, Nozomu; Nojiri, Naoki; Takada, Eiji; Saito, Kenji; Kobayashi, Shoichi; Sawahata, Hiroaki; Kokusen, Sigeru

2001-03-01

Power-rise tests of the High Temperature Engineering Test Reactor (HTTR) have been carried out aiming to achieve 100% power. So far, 50% of power operation and many tests have been carried out. In the HTTR, temperature change in core is so large to achieve the outlet coolant temperature of 950degC. To improve the calculation accuracy of the HTTR reactor physics characteristics, control rod positions at criticality and temperature coefficients were measured at each step to achieve 50% power level. The calculations were carried out using Monte Carlo code and diffusion theory with temperature distributions in the core obtained by reciprocal calculation of thermo-hydraulic code and diffusion theory. Control rod positions and temperature coefficients were calculated by diffusion theory and Monte Carlo method. The test results were compared to calculation results. The control rod positions at criticality showed good agreement with calculation results by Monte Carlo method with error of 50 mm. The control position at criticality at 100% was predicted around 2900mm. Temperature coefficients showed good agreement with calculation results by diffusion theory. The improvement of calculation will be carried out comparing the measured results up to 100% power level. (author)

The Influence of PZT Actuators Positioning in Active Structural Acoustic Control

Directory of Open Access Journals (Sweden)

P. Švec

2007-01-01

Full Text Available This paper deals with the effect of secondary actuator positioning in an active structural acoustics control (ASAC experiment. The ASAC approach is based on minimizing the sound radiation from structures to the far field by controlling the structural vibrations. In this article a rectangular steel plate structure was assumed with one secondary actuator attached to it. As a secondary actuator, a specially designed piezoelectric stripe actuator was used. We studied the effect of the position of the actuator on the pattern and on the radiated sound field of the structural vibration, with and without active control. The total radiated power was also measured. The experimental data was confronted with the results obtained by a numerical solution of the mathematical model used. For the solution, the finite element method in the ANSYS software package was used. 

Position Control of an X4-Flyer Using a Tether

Directory of Open Access Journals (Sweden)

Yusuke Ouchi

2016-05-01

Full Text Available In Japan, aging of infrastructures, such as roads,bridges, and water and sewer services, etc. poses a problem, andit is required to extend the life-span of such infrastructures bymaintenance. Among infrastructures, especially bridges areperiodically inspected by short range visual observations, whichcheck the damage and deterioration of the surface. However,since there are some cases where the short range visualobservation is difficult, an alternative method is required so as toreplace the short range visual observation with it. So, "X4-Flyer"is very attractive because of realizing a movement at high altitudeeasily. The objective of this study is to develop a tethered X4-Flyer, so that the conventional short range visual observation ofbridges is replaced by it. In this paper, a method for themeasurement and control of the position is described by using atether for controlling the position of the X4-Flyer. In addition, itis checked whether the tethered X4-Flyer can control the positionusing the proposed method or not, letting it fly in a state in whicha tether is being attached

A remote handling rate-position controller for telemanipulating in a large workspace

International Nuclear Information System (INIS)

Barrio, Jorge; Ferre, Manuel; Suárez-Ruiz, Francisco; Aracil, Rafael

2014-01-01

This paper presents a new haptic rate-position controller, which allows manipulating a slave robot in a large workspace using a small haptic device. This control algorithm is very effective when the master device is much smaller than the slave device. Haptic information is displayed to the user so as to be informed when a change in the operation mode occurs. This controller allows performing tasks in a large remote workspace by using a haptic device with a reduced workspace such as Phantom. Experimental results have been carried out using a slave robot from Kraft Telerobotics and a commercial haptic interface as a master device. A curvature path following task has been simulated using the proposed controller which was compared with the force-position control algorithm. Results obtained show that higher accuracy is obtained when the proposed method is used, spending a similar amount of time to perform the task

A remote handling rate-position controller for telemanipulating in a large workspace

Energy Technology Data Exchange (ETDEWEB)

Barrio, Jorge, E-mail: jordi.barrio@upm.es; Ferre, Manuel, E-mail: m.ferre@upm.es; Suárez-Ruiz, Francisco, E-mail: fa.suarez@upm.es; Aracil, Rafael, E-mail: rafael.aracil@upm.es

2014-01-15

This paper presents a new haptic rate-position controller, which allows manipulating a slave robot in a large workspace using a small haptic device. This control algorithm is very effective when the master device is much smaller than the slave device. Haptic information is displayed to the user so as to be informed when a change in the operation mode occurs. This controller allows performing tasks in a large remote workspace by using a haptic device with a reduced workspace such as Phantom. Experimental results have been carried out using a slave robot from Kraft Telerobotics and a commercial haptic interface as a master device. A curvature path following task has been simulated using the proposed controller which was compared with the force-position control algorithm. Results obtained show that higher accuracy is obtained when the proposed method is used, spending a similar amount of time to perform the task.

Design of L1 -Adaptive Controller for Single Axis Positioning Table

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Amjad Jalil Humaidi

2017-11-01

Full Text Available L1 adaptive controller has proven to provide fast adaptation with guaranteed transients in a large variety of systems. It is commonly used for controlling systems with uncertain time-varying unknown parameters. The effectiveness of L1 adaptive controller for position control of single axis has been examined and compared with Model Reference Adaptive Controller (MRAC. The Linear servo motor is one of the main constituting elements of the x-y table which is mostly used in automation application. It is characterized by time-varying friction and disturbance

Virtual reality simulation of fuzzy-logic control during underwater dynamic positioning

Science.gov (United States)

Thekkedan, Midhin Das; Chin, Cheng Siong; Woo, Wai Lok

2015-03-01

In this paper, graphical-user-interface (GUI) software for simulation and fuzzy-logic control of a remotely operated vehicle (ROV) using MATLAB™ GUI Designing Environment is proposed. The proposed ROV's GUI platform allows the controller such as fuzzy-logic control systems design to be compared with other controllers such as proportional-integral-derivative (PID) and sliding-mode controller (SMC) systematically and interactively. External disturbance such as sea current can be added to improve the modelling in actual underwater environment. The simulated results showed the position responses of the fuzzy-logic control exhibit reasonable performance under the sea current disturbance.

Positive control for cytotoxicity evaluation of dental vinyl polysiloxane impression materials using sodium lauryl sulfate.

Science.gov (United States)

Kwon, Jae-Sung; Lee, Sang-Bae; Kim, Kwang-Mahn; Kim, Kyoung-Nam

2014-11-01

Vinyl polysiloxane (VPS) is elastomeric dental impression material which, despite having very few reports of adverse reactions, has shown high levels of cytotoxicity that is difficult to be interpreted without referencing to the positive control material. Therefore, in this study, positive control VPS was developed using sodium lauryl sulfate (SLS) for the reference of cytotoxicity test. The positive control VPS with SLS was formed with a different proportion of SLS (0, 1, 2, 4, 8 and 16 wt%) added to the base. The cytotoxicity test was then carried out using the extractions or dilutions of the extractions from each of the test samples using murine fibroblast cells (L929). The final product of positive control VPS behaved similar to commercially available VPS; being initially liquid-like and then becoming rubber-like. Ion chromatography showed that the level of SLS released from the product increased as the proportion of added SLS increased, consequently resulting in an increased level of cytotoxicity. Also, the commercially available VPS was less cytotoxic than the positive control VPS with more or equal to 2 wt% of SLS. However, even the VPS with the highest SLS (16 wt%) did not cause oral mucosa irritation during the animal study. The positive control VPS was successfully produced using SLS, which will be useful in terms of providing references during in vitro cytotoxicity testing.

Design of magnetic flux concentrator of permancent magnet for control rod position indicator of SMART CEDM

International Nuclear Information System (INIS)

Yoo, J. Y.; Kim, J. H.; Hur, H.; Kim, J. I.

2002-01-01

The reliability and accuracy of the information on control rod position are very important to the reactor safety and the design of the core protection system. A survey on the RSPT(Reed Switch Position Transmitter) type control rod position indication system and its actual implementation in the exiting nuclear power plants in Korea was performed first. The control rod position indicator having the high performance for SMART was developed on the basis of RSPT technology identified through the survey. The arrangement of permanent magnet and reed switches is the most important procedure in the design of control rod position indication. In this study, the magnetic flux concentrator of permanent magnet is introduced and the calculation method for effective flux area for reed switch is presented

Reappraisal of bicarbonate secretion by the human oesophagus

DEFF Research Database (Denmark)

Mertz-Nielsen, A; Hillingsø, J; Bukhave, Klaus

1997-01-01

BACKGROUND AND AIMS: Administration of omeprazole to healthy volunteers was recently reported to increase proximal duodenal mucosalbicarbonate secretion. As human oesophagus also secretes bicarbonate, the hypothesis was tested that omeprazole may stimulate oesophagealbicarbonate secretion and thus......: The median rates (95% confidence intervals)of intrinsic oesophageal bicarbonate secretion, corrected for contaminating salivary and gastric bicarbonate, were 89 (33-150) and 121 (63-203)mumol/h/10 cm (p > 0.5) in omeprazole and ranitidine treated subjects respectively. Salivary and gastric bicarbonate...... be overestimated. As omeprazole and ranitidine did not affect bicarbonate secretion differently there was no evidence that omeprazole acts on icarbonate secretory cells in the oesophageal mucosa....

An energy-saving nonlinear position control strategy for electro-hydraulic servo systems.

Science.gov (United States)

Baghestan, Keivan; Rezaei, Seyed Mehdi; Talebi, Heidar Ali; Zareinejad, Mohammad

2015-11-01

The electro-hydraulic servo system (EHSS) demonstrates numerous advantages in size and performance compared to other actuation methods. Oftentimes, its utilization in industrial and machinery settings is limited by its inferior efficiency. In this paper, a nonlinear backstepping control algorithm with an energy-saving approach is proposed for position control in the EHSS. To achieve improved efficiency, two control valves including a proportional directional valve (PDV) and a proportional relief valve (PRV) are used to achieve the control objectives. To design the control algorithm, the state space model equations of the system are transformed to their normal form and the control law through the PDV is designed using a backstepping approach for position tracking. Then, another nonlinear set of laws is derived to achieve energy-saving through the PRV input. This control design method, based on the normal form representation, imposes internal dynamics on the closed-loop system. The stability of the internal dynamics is analyzed in special cases of operation. Experimental results verify that both tracking and energy-saving objectives are satisfied for the closed-loop system. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

Position Control Method For Pick And Place Robot Arm For Object Sorting System

Directory of Open Access Journals (Sweden)

Khin Moe Myint

2015-08-01

Full Text Available The more increase the number of industries in developing countries the more require labourers or workers in that. To reduce the cost of labour force and to increase the manufacturing capacity of industries the advanced robot arms are more needed. The aim of this journal is to eliminate the manual control for object sorting system.Robot arm design in this research uses two joints three links and servo motors to drive. Microcontroller is used to generate required PWM signal for servo motors. In this research the position control of robot arm was designed by using kinematic control methods. There are two types of kinematic control methods which are forward and reverse kinematic methods. In forward kinematic method the input parameters are the joint angles and link length of robot arm and then the output is the position at XYZ coordinate of tool or gripper. In inverse kinematic the input parameters are position at XYZ coordinate of gripper and the link length of robot arm and then the output parameters are the joint angles. So kinematic methods can explain the analytical description of the geometry motion of the manipulator with reference to a robot coordinate system fixed to a frame without consideration of the forces or the moments causing the movements. For sorting system Metal detector is used to detect the metal or non-metal. This position control of pick and place robot arm is fully tested and the result is obtained more precisely.

Determination of the plasma position for its real-time control in the COMPASS tokamak

International Nuclear Information System (INIS)

Janky, F.; Havlicek, J.; Valcarcel, D.; Hron, M.; Horacek, J.; Kudlacek, O.; Panek, R.; Carvalho, B.B.

2011-01-01

An efficient horizontal and vertical stabilization of the plasma column position are essential for a reliable tokamak operation. Plasma position is generally determined by plasma current, plasma pressure and external vertical and horizontal magnetic fields. Such fields are generated by poloidal field coils and proper algorithm for the current control have to by applied, namely, in case of fast feedback loops. This paper presents a real-time plasma position reconstruction algorithms developed for the COMPASS tokamak. Further, its implementation in the MARTe (Multithreaded Application Real-Time executor) is described and the first results from test of the algorithm for real-time control of horizontal plasma positions are presented.

Determination of the plasma position for its real-time control in the COMPASS tokamak

Energy Technology Data Exchange (ETDEWEB)

Janky, F., E-mail: jankyf@ipp.cas.cz [Institute of Plasma Physics, AS CR, v.v.i., Association EURATOM/IPP.CR, Za Slovankou 3, 182 00 Prague (Czech Republic); Charles University in Prague, Faculty of Mathematics and Physics, V Holesovickach 2, CZ-18000 Prague (Czech Republic); Havlicek, J. [Institute of Plasma Physics, AS CR, v.v.i., Association EURATOM/IPP.CR, Za Slovankou 3, 182 00 Prague (Czech Republic); Charles University in Prague, Faculty of Mathematics and Physics, V Holesovickach 2, CZ-18000 Prague (Czech Republic); Valcarcel, D. [Associacao EURATOM/IST, Instituto de Plasmas e Fusao Nuclear - Laboratorio Associado, Instituto Superior Tecnico, P1049-001 Lisboa (Portugal); Hron, M.; Horacek, J. [Institute of Plasma Physics, AS CR, v.v.i., Association EURATOM/IPP.CR, Za Slovankou 3, 182 00 Prague (Czech Republic); Kudlacek, O. [Czech Technical University, Faculty of Nuclear Sciences and Physical Engineering, Technicka 2, 166 27 Prague (Czech Republic); Panek, R. [Institute of Plasma Physics, AS CR, v.v.i., Association EURATOM/IPP.CR, Za Slovankou 3, 182 00 Prague (Czech Republic); Carvalho, B.B. [Associacao EURATOM/IST, Instituto de Plasmas e Fusao Nuclear - Laboratorio Associado, Instituto Superior Tecnico, P1049-001 Lisboa (Portugal)

2011-10-15

An efficient horizontal and vertical stabilization of the plasma column position are essential for a reliable tokamak operation. Plasma position is generally determined by plasma current, plasma pressure and external vertical and horizontal magnetic fields. Such fields are generated by poloidal field coils and proper algorithm for the current control have to by applied, namely, in case of fast feedback loops. This paper presents a real-time plasma position reconstruction algorithms developed for the COMPASS tokamak. Further, its implementation in the MARTe (Multithreaded Application Real-Time executor) is described and the first results from test of the algorithm for real-time control of horizontal plasma positions are presented.

Gastroprotective effect of garlic in indomethacin induced gastric ulcer in rats.

Science.gov (United States)

El-Ashmawy, Nahla E; Khedr, Eman G; El-Bahrawy, Hoda A; Selim, Hend M

2016-01-01

Garlic, in its natural plant state, has a great history in ancient medicine as a remedy for many diseases. In our study, the gastroprotective effect of aged garlic extract (AGE) and the possible underlying mechanisms were investigated in an experimental model of indomethacin-induced gastric ulcer. Male Wistar rats were divided into four groups: (normal control, n = 20), ulcer control (indomethacin group, n = 20), (omeprazole group, n = 30) and (garlic group, n = 20). Each dose of garlic and omeprazole was given to rats orally daily for 10 consecutive days before induction of ulcer by indomethacin. Indomethacin was given as a single oral dose (100 mg/kg). Four hours later after indomethacin treatment, the rats were sacrificed and gastric tissue was obtained for histopathological examination, calculation of ulcer index and measurement of oxidative stress markers as well as gastroprotective mediators. The results showed that indomethacin induced gastric ulcer (ulcer index = 2900), was associated with a significant increase of tumor necrosis factor-alpha and malondialdehyde, and significant decrease of the gastroprotective mediators prostaglandin E2, glutathione (GSH) and nitric oxide (NO) compared with normal control. Pretreatment with AGE produced comparable results with those obtained in the omeprazole group; the preventive index in the AGE group was 83.4% compared with 94.5% in the omeprazole group. The prophylactic role of AGE in indomethacin-induced ulcer was, in part, mediated by decreasing oxidative stress and increasing gastric level of PGE2, GSH, and NO. AGE corrected the histopathological abnormalities in gastric tissue and proved a promising gastroprotective role in gastric ulcer. Copyright © 2016 Elsevier Inc. All rights reserved.

Conflicting results between randomized trials and observational studies on the impact of proton pump inhibitors on cardiovascular events when coadministered with dual antiplatelet therapy: systematic review.

Science.gov (United States)

Melloni, Chiara; Washam, Jeffrey B; Jones, W Schuyler; Halim, Sharif A; Hasselblad, Victor; Mayer, Stephanie B; Heidenfelder, Brooke L; Dolor, Rowena J

2015-01-01

Discordant results have been reported on the effects of concomitant use of proton pump inhibitors (PPIs) and dual antiplatelet therapy (DAPT) for cardiovascular outcomes. We conducted a systematic review comparing the effectiveness and safety of concomitant use of PPIs and DAPT in the postdischarge treatment of unstable angina/non-ST-segment-elevation myocardial infarction patients. We searched for clinical studies in MEDLINE, EMBASE, and the Cochrane Database of Systematic Reviews, from 1995 to 2012. Reviewers screened and extracted data, assessed applicability and quality, and graded the strength of evidence. We performed meta-analyses of direct comparisons when outcomes and follow-up periods were comparable. Thirty-five studies were eligible. Five (4 randomized controlled trials and 1 observational) assessed the effect of omeprazole when added to DAPT; the other 30 (observational) assessed the effect of PPIs as a class when compared with no PPIs. Random-effects meta-analyses of the studies assessing PPIs as a class consistently reported higher event rates in patients receiving PPIs for various clinical outcomes at 1 year (composite ischemic end points, all-cause mortality, nonfatal MI, stroke, revascularization, and stent thrombosis). However, the results from randomized controlled trials evaluating omeprazole compared with placebo showed no difference in ischemic outcomes, despite a reduction in upper gastrointestinal bleeding with omeprazole. Large, well-conducted observational studies of PPIs and randomized controlled trials of omeprazole seem to provide conflicting results for the effect of PPIs on cardiovascular outcomes when coadministered with DAPT. Prospective trials that directly compare pharmacodynamic parameters and clinical events among specific PPI agents in patients with unstable angina/non-ST-segment-elevation myocardial infarction treated with DAPT are warranted. © 2015 American Heart Association, Inc.

Strategies for the plasma position and shape control in IGNITOR

International Nuclear Information System (INIS)

Villone, F.; Albanese, R.; Ambrosino, G.; Pironti, A.; Rubinacci, G.; Ramogida, G.; Alladio, F.; Bombarda, F.; Coletti, A.; Cucchiaro, A.; Maddaluno, G.; Pizzicaroli, G.; Pizzuto, A.; Roccella, M.; Santinelli, M.; Coppi, B.

2007-01-01

The capability of the poloidal field coil system, as presently designed, to provide an effective vertical stabilization of the plasma in the IGNITOR machine has been investigated using the CREATE L response model. An optimization of the vertical position control strategy has been carried out and the most effective coil combination has been selected to stabilize the plasma while fulfilling engineering constraints on the coils and minimizing the required power and voltage. The growth rate of the vertical instability and the power required by the active stabilization system has been estimated with this model. The possible failure of the relevant electromagnetic diagnostics has been taken into account, evaluating the robustness of the plasma position reconstruction strategy. A realistic description of the power supply system has permitted to carry out the optimization of the proportional-integrative-derivative (PID) controller, both with a voltage and a current loop control scheme. An assessment of the requirements for the plasma cross section shape control has been carried out considering perturbations of the plasma global parameters independent of each other and showing that the undesired shape modification rejection is possible with the present PFC and power supply system. The PF coils have been rated relative to their capability to restore shape modifications due to different plasma disturbances. The most effective coil combination, that minimizes recovery time and voltage required, has been identified

A randomised controlled trial in comparing maternal and neonatal outcomes between hands-and-knees delivery position and supine position in China.

Science.gov (United States)

Zhang, Hongyu; Huang, Shurong; Guo, Xiaolan; Zhao, Ningning; Lu, Yujing; Chen, Min; Li, Yingxia; Wu, Junqin; Huang, Lihua; Ma, Fenglan; Yang, Yuhong; Zhang, Xiaoli; Zhou, Xiaoyu; Guo, Renfei; Cai, Wenzhi

2017-07-01

the supine position is the most frequently offered for birth delivery in China and many other countries, but the hands-and-knees position is now gaining prominence with doctors in China. This study aims to examine the differences in maternal and neonatal outcomes among low-risk women who gave birth either in the hands-and-knees position or the supine position. a randomised controlled trial was conducted in 11 hospitals in China from May to December in 2012. In total, 1400 women were recruited and randomly allocated to either the experimental group (n=700, 446 completed the protocol) who delivered in hands-and-knees position and the control group (n=700, 440 completed the protocol) who delivered in supine position. Women who could not maintain the randomised position during the second stage of labour were allowed to withdraw from the study. The primary maternal outcome measured was rate of episiotomy. Secondary outcomes included degree of perineum laceration, rate of emergency caesarean section, rate of shoulder dystocia, and duration of labour, postpartum bleeding, neonatal Apgar score, and the rate of neonatal asphyxia. Because outcome data were only collected for women who gave birth in the randomised position, per-protocol analyses were used to compare groups. The primary outcome, episiotomy, was also compared between groups using logistic regression adjusting for maternal age，gestational age at birth, whether the woman was primiparous, the process of second stage of labour and birthweight. as compared with the control group, the experimental group had lower rates of episiotomy and second-degree perineum laceration (including episiotomy), and higher rates of intact perineum and first-degree perineum laceration, with a longer duration of second stage of labour. No significant differences were found in the amount of postpartum bleeding, shoulder dystocia, neonatal asphyxia and neonatal Apgar scores at 1minute and 5minutes. Adjusted for maternal age, gestational

Pull-pull position control of dual motor wire rope transmission.

Science.gov (United States)

Guo, Quan; Jiao, Zongxia; Yan, Liang; Yu, Qian; Shang, Yaoxing

2016-08-01

Wire rope transmission is very efficient because of the small total moving object mass. The wire rope could only transmit pulling force. Therefore it has to be kept in a tightened state during transmission; in high speed applications the dynamic performance depends on the rope's stiffness, which can be adjusted by the wire rope tension. To improve the system dynamic performance output, this paper proposes a novel pull-pull method based on dual motors connected by wire ropes, for precise, high speed position control applications. The method can regulate target position and wire rope tension simultaneously. Wire ropes remain in a pre-tightening state at all times, which prevents the influence of elasticity and reduces the position tracking error in the changing direction process. Simulations and experiments were conducted; the results indicate that both position precision and superior dynamic performance can be synchronously achieved. The research is relevant to space craft precision pointing instruments.

Development of a mcirocontroller to the positioning control of an ionization chamber

International Nuclear Information System (INIS)

Manfrini, Francisco A.L.; Rocha, Cristina S.C.; Reis, Renato J.; Oliveira, Arno Heeren de

2007-01-01

It was developed a microcontroller to positioning of ionization chamber with high precision. Considering the high sensitivity of intensity of radiation with the distance source-detector is necessary to develop an eletronics able to control position the detector with high precision. The project was based on microcontroller AT 89S8252 of Atmel company. (author)

A switched energy saving position controller for variable-pressure electro-hydraulic servo systems.

Science.gov (United States)

Tivay, Ali; Zareinejad, Mohammad; Rezaei, S Mehdi; Baghestan, Keivan

2014-07-01

The electro-hydraulic servo system (EHSS) demonstrates a relatively low level of efficiency compared to other available actuation methods. The objective of this paper is to increase this efficiency by introducing a variable supply pressure into the system and controlling this pressure during the task of position tracking. For this purpose, an EHSS structure with controllable supply pressure is proposed and its dynamic model is derived from the basic laws of physics. A switching control structure is then proposed to control both the supply pressure and the cylinder position at the same time, in a way that reduces the overall energy consumption of the system. The stability of the proposed switching control system is guaranteed by proof, and its performance is verified by experimental testing. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

Asymmetric positive feedback loops reliably control biological responses.

Science.gov (United States)

Ratushny, Alexander V; Saleem, Ramsey A; Sitko, Katherine; Ramsey, Stephen A; Aitchison, John D

2012-04-24

Positive feedback is a common mechanism enabling biological systems to respond to stimuli in a switch-like manner. Such systems are often characterized by the requisite formation of a heterodimer where only one of the pair is subject to feedback. This ASymmetric Self-UpREgulation (ASSURE) motif is central to many biological systems, including cholesterol homeostasis (LXRα/RXRα), adipocyte differentiation (PPARγ/RXRα), development and differentiation (RAR/RXR), myogenesis (MyoD/E12) and cellular antiviral defense (IRF3/IRF7). To understand why this motif is so prevalent, we examined its properties in an evolutionarily conserved transcriptional regulatory network in yeast (Oaf1p/Pip2p). We demonstrate that the asymmetry in positive feedback confers a competitive advantage and allows the system to robustly increase its responsiveness while precisely tuning the response to a consistent level in the presence of varying stimuli. This study reveals evolutionary advantages for the ASSURE motif, and mechanisms for control, that are relevant to pharmacologic intervention and synthetic biology applications.

Protective Effect of ECQ on Rat Reflux Esophagitis Model.

Science.gov (United States)

Jang, Hyeon-Soon; Han, Jeong Hoon; Jeong, Jun Yeong; Sohn, Uy Dong

2012-12-01

This study was designed to determine the protective effect of Rumex Aquaticus Herba extracts containing quercetin-3-β-D-glucuronopyranoside (ECQ) on experimental reflux esophagitis. Reflux esophagitis was induced by surgical procedure. The rats were divided into seven groups, namely normal group, control group, ECQ (1, 3, 10, 30 mg/kg) group and omeprazole (30 mg/kg) group. ECQ and omeprazole groups received intraduodenal administration. The Rats were starved for 24 hours before the experiments, but were freely allowed to drink water. ECQ group attenuated the gross esophagitis significantly compared to that treated with omeprazole in a dose-dependent manner. ECQ decreased the volume of gastric juice and increased the gastric pH, which are similar to those of omeprazole group. In addition, ECQ inhibited the acid output effectively in reflux esophagitis. Significantly increased amounts of malondialdehyde (MDA), myeloperoxidase (MPO) activity and the mucosal depletion of reduced glutathione (GSH) were observed in the reflux esophagitis. ECQ administration attenuated the decrement of the GSH levels and affected the MDA levels and MPO activity. These results suggest that the ECQ has a protective effect which may be attributed to its multiple effects including anti-secretory, anti-oxidative and anti-inflammatory actions on reflux esophagitis in rats.

Precision position control of servo systems using adaptive back-stepping and recurrent fuzzy neural networks

International Nuclear Information System (INIS)

Kim, Han Me; Kim, Jong Shik; Han, Seong Ik

2009-01-01

To improve position tracking performance of servo systems, a position tracking control using adaptive back-stepping control(ABSC) scheme and recurrent fuzzy neural networks(RFNN) is proposed. An adaptive rule of the ABSC based on system dynamics and dynamic friction model is also suggested to compensate nonlinear dynamic friction characteristics. However, it is difficult to reduce the position tracking error of servo systems by using only the ABSC scheme because of the system uncertainties which cannot be exactly identified during the modeling of servo systems. Therefore, in order to overcome system uncertainties and then to improve position tracking performance of servo systems, the RFNN technique is additionally applied to the servo system. The feasibility of the proposed control scheme for a servo system is validated through experiments. Experimental results show that the servo system with ABS controller based on the dual friction observer and RFNN including the reconstruction error estimator can achieve desired tracking performance and robustness

Asynchronous L1-gain control of uncertain switched positive linear systems with dwell time.

Science.gov (United States)

Li, Yang; Zhang, Hongbin

2018-04-01

In this paper, dwell time (DT) stability, L 1 -gain performance analysis and asynchronous L 1 -gain controller design problems of uncertain switched positive linear systems (SPLSs) are investigated. Via a time-scheduled multiple linear co-positive Lyapunov function (TSMLCLF) approach, convex sufficient conditions of DT stability and L 1 -gain performance of SPLSs with interval and polytopic uncertainties are presented. Furthermore, by utilizing the feature that the TSMLCLF keeps decreasing even if the controller is running asynchronously with the system, the asynchronous L 1 -gain controller design problem of SPLSs with interval and polytopic uncertainties is investigated. Convex sufficient conditions of the existence of time-varying asynchronous state-feedback controller which can ensure the closed-loop system's positivity, stability and L 1 -gain performance are established, and the controller gain matrices can be calculated instantaneously online. The obtained L 1 -gain in the paper is standard. All the results are presented in terms of linear programming. A practical example is provided to show the effectiveness of the results. Copyright © 2018 ISA. Published by Elsevier Ltd. All rights reserved.

Analysis of magnetic field and hysteresis of reed switches for control rod position indicator of SMART CEDM

International Nuclear Information System (INIS)

Yoo, J. W.; Kim, J. H.; Heo, H.; Kim, J. I.; Jang, M. H.

2002-01-01

The reliability and accuracy of the information on control rod position are very important to the reactor safety and the design of the core protection system. A survey on the RSPT(Reed Switch Position Transmitter) type control rod position indication system and its actual implementation in the exiting nuclear power plants in Korea was performed first. The control rod position indicator having the high performance for SMART was developed on the basis of RSPT technology identified through the survey. The hysteresis of reed switches is one of the important factors in a repeat accuracy of control rod position indication. In this study, the hysteresis of reed switches is introduced and the design method using the magnetic analysis of reed switches in presented

Positive Analysis of Invasive Species Control as a Dynamic Spatial Process

OpenAIRE

Buyuktahtakin, Esra; Feng, Zhuo; Olsson, Aaryn; Frisvold, George B.; Szidarovszky, Ferenc

2010-01-01

This paper models control of invasive buffelgrass (Pennisetum ciliare), a fire-prone African bunchgrass spreading rapidly across the southern Arizona desert as a spatial dynamic process. Buffelgrass spreads over a gridded landscape. Weed carrying capacity, treatment costs, and damages vary over grid cells. Damage from buffelgrass depends on its spatial distribution in relation to valued resources. We conduct positive analysis of recommended heuristic strategies for buffelgrass control, evalua...

Affective processing in positive schizotypy: Loose control of social-emotional information.

Science.gov (United States)

Papousek, Ilona; Weiss, Elisabeth M; Mosbacher, Jochen A; Reiser, Eva M; Schulter, Günter; Fink, Andreas

2014-10-30

Behavioral studies suggested heightened impact of emotionally laden perceptual input in schizophrenia spectrum disorders, in particular in patients with prominent positive symptoms. De-coupling of prefrontal and posterior cortices during stimulus processing, which is related to loosening of control of the prefrontal cortex over incoming affectively laden information, may underlie this abnormality. Pre-selected groups of individuals with low versus high positive schizotypy (lower and upper quartile of a large screening sample) were tested. During exposure to auditory displays of strong emotions (anger, sadness, cheerfulness), individuals with elevated levels of positive schizotypal symptoms showed lesser prefrontal-posterior coupling (EEG coherence) than their symptom-free counterparts (right hemisphere). This applied to negative emotions in particular and was most pronounced during confrontation with anger. The findings indicate a link between positive symptoms and a heightened impact particularly of threatening emotionally laden stimuli which might lead to exacerbation of positive symptoms and inappropriate behavior in interpersonal situations. Copyright © 2014 Elsevier Inc. All rights reserved.

Design and analysis of plasma position and shape control in superconducting tokamak JT-60SC

Energy Technology Data Exchange (ETDEWEB)

Matsukawa, M. E-mail: matsukaw@naka.jaeri.go.jp; Ishida, S.; Sakasai, A.; Urata, K.; Senda, I.; Kurita, G.; Tamai, H.; Sakurai, S.; Miura, Y.M.; Masaki, K.; Shimada, K.; Terakado, T

2003-09-01

The analyses of the plasma position and shape control in the superconducting tokamak JT-60SC in JAERI are presented. The vacuum vessel and stabilizing plates located closely to the plasma are modeled in 3 dimension, and we can take into account the large ports in the vacuum vessel. The linear numerical model used in the design for the plasma feedback control system is based on Grad-Shafranov equation, which allows the plasma surface deformation. For a slower control of the plasma shape, the superconducting equilibrium field (EF) coils outside toroidal field coils are used, while for a fast control of the plasma position, in-vessel normal conducting coils (IV coil) are used. It is shown that the available loop voltages of the EF and IV coils are very limited, but there are sufficient accuracy and acceptable response time of plasma position and shape control.

Design and analysis of plasma position and shape control in superconducting tokamak JT-60SC

International Nuclear Information System (INIS)

Matsukawa, M.; Ishida, S.; Sakasai, A.; Urata, K.; Senda, I.; Kurita, G.; Tamai, H.; Sakurai, S.; Miura, Y.M.; Masaki, K.; Shimada, K.; Terakado, T.

2003-01-01

The analyses of the plasma position and shape control in the superconducting tokamak JT-60SC in JAERI are presented. The vacuum vessel and stabilizing plates located closely to the plasma are modeled in 3 dimension, and we can take into account the large ports in the vacuum vessel. The linear numerical model used in the design for the plasma feedback control system is based on Grad-Shafranov equation, which allows the plasma surface deformation. For a slower control of the plasma shape, the superconducting equilibrium field (EF) coils outside toroidal field coils are used, while for a fast control of the plasma position, in-vessel normal conducting coils (IV coil) are used. It is shown that the available loop voltages of the EF and IV coils are very limited, but there are sufficient accuracy and acceptable response time of plasma position and shape control

Hydrostatic control system for the height position of the JINR synchrotron

International Nuclear Information System (INIS)

Vasyutinskij, I.Yu.; Zinov'ev, L.P.; Karpov, I.I.

1978-01-01

Hydrostatic system with remote read-out is created for a more operative control of height position of synchrocyclotrone electromagnet. 3 hydrostatic heads with electrocontact registration of liquid level position were mounted on every electromagnet quadrant. The heads are placed under the magnet in centers of survey channel of the foundation and are switched on in series. Teh schemes of the main system units are given. The order of assembling and adjustment of hydrostatic system elements of the accelerator is described

Asymmetric Fuzzy Control of a Positive and Negative Pneumatic Pressure Servo System

Science.gov (United States)

Yang, Gang; Du, Jing-Min; Fu, Xiao-Yun; Li, Bao-Ren

2017-11-01

The pneumatic pressure control systems have been used in some fields. However, the researches on pneumatic pressure control mainly focus on constant pressure regulation. Poor dynamic characteristics and strong nonlinearity of such systems limit its application in the field of pressure tracking control. In order to meet the demand of generating dynamic pressure signal in the application of the hardware-in-the-loop simulation of aerospace engineering, a positive and negative pneumatic pressure servo system is provided to implement dynamic adjustment of sealed chamber pressure. A mathematical model is established with simulation and experiment being implemented afterwards to discuss the characteristics of the system, which shows serious asymmetry in the process of charging and discharging. Based on the analysis of the system dynamics, a fuzzy proportional integral derivative (PID) controller with asymmetric fuzzy compensator is proposed. Different from conventional adjusting mechanisms employing the error and change in error of the controlled variable as input parameters, the current chamber pressure and charging or discharging state are chosen as inputs of the compensator, which improves adaptability. To verify the effectiveness and performance of the proposed controller, the comparison experiments tracking sinusoidal and square wave commands are conducted. Experimental results show that the proposed controller can obtain better dynamic performance and relatively consistent control performance across the scope of work (2-140 kPa). The research proposes a fuzzy control method to overcome asymmetry and enhance adaptability for the positive and negative pneumatic pressure servo system.

FRF based position controller design through system identification for A hydraulic cylinder

Energy Technology Data Exchange (ETDEWEB)

Seo, Hyoung Kyu; Kim, Dong Hwan [Dept. of Mechanical Design and Robot Engineering, Seoul National University of Science and Technology, Seoul (Korea, Republic of); Park, Jong Won [Reliability Assessment Center, Korea Institute of Machinery and Materials, Daejeon (Korea, Republic of)

2015-11-15

In this study, we have focused on the design of a controller and an operating program for the operation of the hydraulic actuators used in a shaker. To control the motion of the shaker accurately, the position of each hydraulic cylinder should be controlled precisely even under an uncertain environment. For this purpose, we have suggested a control algorithm using an FRF (frequency response function) based control which senses the behavior of the actuator in advance, calculates a transfer function through the system identification method, and provides the final control input. The experimental results on the performance of this system were compared with that of a simple PID control algorithm.

Neural correlates of preparatory and regulatory control over positive and negative emotion.

Science.gov (United States)

Seo, Dongju; Olman, Cheryl A; Haut, Kristen M; Sinha, Rajita; MacDonald, Angus W; Patrick, Christopher J

2014-04-01

This study used functional magnetic resonance imaging to investigate brain activation during preparatory and regulatory control while participants (N = 24) were instructed either to simply view or decrease their emotional response to, pleasant, neutral or unpleasant pictures. A main effect of emotional valence on brain activity was found in the right precentral gyrus, with greater activation during positive than negative emotion regulation. A main effect of regulation phase was evident in the bilateral anterior prefrontal cortex (PFC), precuneus, posterior cingulate cortex, right putamen and temporal and occipital lobes, with greater activity in these regions during preparatory than regulatory control. A valence X regulation interaction was evident in regions of ventromedial PFC and anterior cingulate cortex, reflecting greater activation while regulating negative than positive emotion, but only during active emotion regulation (not preparation). Conjunction analyses revealed common brain regions involved in differing types of emotion regulation including selected areas of left lateral PFC, inferior parietal lobe, temporal lobe, right cerebellum and bilateral dorsomedial PFC. The right lateral PFC was additionally activated during the modulation of both positive and negative valence. Findings demonstrate significant modulation of brain activity during both preparation for, and active regulation of positive and negative emotional states.

Different transcriptional profiling between senescent and non-senescent human coronary artery endothelial cells (HCAECs) by Omeprazole and Lansoprazole treatment.

Science.gov (United States)

Costarelli, Laura; Giacconi, Robertina; Malavolta, Marco; Basso, Andrea; Piacenza, Francesco; Provinciali, Mauro; Maggio, Marcello G; Corsonello, Andrea; Lattanzio, Fabrizia

2017-04-01

Recent evidence suggests that high dose and/or long term use of proton pump inhibitors (PPIs) may increase the risk of adverse cardiovascular events in older patients, but mechanisms underlying these detrimental effects are not known. Taking into account that the senescent endothelial cells have been implicated in the genesis or promotion of age-related cardiovascular disease, we hypothesized an active role of PPIs in senescent cells. The aim of this study is to investigate the changes in gene expression occurring in senescent and non-senescent human coronary artery endothelial cells (HCAECs) following Omeprazole (OPZ) or Lansoprazole (LPZ) treatment. Here, we show that atherogenic response is among the most regulated processes in PPI-treated HCAECs. PPIs induced down-regulation of anti-atherogenic chemokines (CXCL11, CXCL12 and CX3CL1) in senescent but not in non-senescent cells, while the same chemokines were up-regulated in untreated senescent cells. These findings support the hypothesis that up-regulated anti-atherogenic chemokines may represent a defensive mechanism against atherosclerosis during cellular senescence, and suggest that PPIs could activate pro-atherogenic pathways by changing the secretory phenotype of senescent HCAECs. Moreover, the genes coding for fatty acid binding protein 4 (FABP4) and piezo-type mechanosensitive ion channel component 2 (PIEZO2) were modulated by PPIs treatment with respect to untreated cells. In conclusions, our results show that long-term and high dose use of PPI could change the secretory phenotype of senescent cells, suggesting one of the potential mechanisms by which use of PPI can increase adverse outcomes in older subjects.

BP neural network tuned PID controller for position tracking of a pneumatic artificial muscle.

Science.gov (United States)

Fan, Jizhuang; Zhong, Jun; Zhao, Jie; Zhu, Yanhe

2015-01-01

Although Pneumatic Artificial Muscle (PAM) has a promising future in rehabilitation robots, it's difficult to realize accurate position control due to its highly nonlinear properties. This paper deals with position control of PAM. To describe the hysteresis inside PAM, a polynomial based phenomenological function is developed. Based on the phenomenological model for PAM and analysis of pressure dynamics within PAM, an adaptive cascade controller is proposed. Both outer loop and inner loop employ BP Neural Network tuned PID algorithm. The outer loop is to handle high nonlinearities and unmodeled dynamics of PAM, while the inner loop is responsible for nonlinearities caused by pressure dynamics. Experimental results show high tracking accuracy as compared with a convention PID controller. The proposed controller is effective in improving performance of PAM and will be implemented in a rehabilitation robot.

Theoretical and experimental investigation of position-controlled semi-active friction damper for seismic structures

Science.gov (United States)

Lu, Lyan-Ywan; Lin, Tzu-Kang; Jheng, Rong-Jie; Wu, Hsin-Hsien

2018-01-01

A semi-active friction damper (SAFD) can be employed for the seismic protection of structural systems. The effectiveness of an SAFD in absorbing seismic energy is usually superior to that of its passive counterpart, since its slip force can be altered in real time according to structural response and excitation. Most existing SAFDs are controlled by adjusting the clamping force applied on the friction interface. Thus, the implementation of SAFDs in practice requires precision control of the clamping force, which is usually substantially larger than the slip force. This may increase the implementation complexity and cost of SAFDs. To avoid this problem, this study proposes a novel position-controlled SAFD, named the leverage-type controllable friction damper (LCFD). The LCFD system combines a traditional passive friction damper and a leverage mechanism with a movable central pivot. By simply controlling the pivot position, the damping force generated by the LCFD system can be adjusted in real time. In order to verify the feasibility of the proposed SAFD, a prototype LCFD was tested by using a shaking table. The test results demonstrate that the equivalent friction force and hysteresis loop of the LCFD can be regulated by controlling the pivot position. By considering 16 ground motions with two different intensities, the adaptive feature of the LCFD for seismic structural control is further demonstrated numerically.

Method of improving heterogeneous oil reservoir polymer flooding effect by positively-charged gel profile control

Science.gov (United States)

Zhao, Ling; Xia, Huifen

2018-01-01

The project of polymer flooding has achieved great success in Daqing oilfield, and the main oil reservoir recovery can be improved by more than 15%. But, for some strong oil reservoir heterogeneity carrying out polymer flooding, polymer solution will be inefficient and invalid loop problem in the high permeability layer, then cause the larger polymer volume, and a significant reduction in the polymer flooding efficiency. Aiming at this problem, it is studied the method that improves heterogeneous oil reservoir polymer flooding effect by positively-charged gel profile control. The research results show that the polymer physical and chemical reaction of positively-charged gel with the residual polymer in high permeability layer can generate three-dimensional network of polymer, plugging high permeable layer, and increase injection pressure gradient, then improve the effect of polymer flooding development. Under the condition of the same dosage, positively-charged gel profile control can improve the polymer flooding recovery factor by 2.3∼3.8 percentage points. Under the condition of the same polymer flooding recovery factor increase value, after positively-charged gel profile control, it can reduce the polymer volume by 50 %. Applying mechanism of positively-charged gel profile control technology is feasible, cost savings, simple construction, and no environmental pollution, therefore has good application prospect.

The constrained control of force and position in multi-joint movements.

Science.gov (United States)

van Ingen Schenau, G J; Boots, P J; de Groot, G; Snackers, R J; van Woensel, W W

1992-01-01

In many arm or leg movements the hand or foot has to exert an external force on the environment. Based on an inverse dynamical analysis of cycling, it is shown that the distribution of net moments in the joints needed to control the direction of the external force is often opposite to the direction of joint displacements associated with this task. Kinetic and kinematic data were obtained from five experienced cyclists during ergometer cycling by means of film analysis and pedal force measurement. An inverse dynamic analysis, based on a linked segments model, yielded net joint moments, joint powers and muscle shortening velocities of eight leg muscles. Activation patterns of the muscles were obtained by means of surface electromyography. The results show that the transfer of rotations in hip, knee and ankle joints into the translation of the pedal is constrained by conflicting requirements. This occurs between the joint moments necessary to contribute to joint power and the moments necessary to establish a direction of the force on the pedal which allows this force to do work on the pedal. Co-activation of mono-articular agonists and their bi-articular antagonists appear to provide a unique solution for these conflicting requirements: bi-articular muscles appear to be able to control the desired direction of the external force on the pedal by adjusting the relative distribution of net moments over the joints while mono-articular muscles appear to be primarily activated when they are in the position to shorten and thus to contribute to positive work. Examples are given to illustrate the universal nature of this constrained control of force (external) and position (joint). Based on this study and published data it is suggested that different processes may underlie the organization of the control of mono- and bi-articular muscles.

Control rod position fault diagnosis and its software realization of pressurized water reactor

International Nuclear Information System (INIS)

Chang Zhengke; Shao Dinghong

2004-11-01

PLC software is adopted in the Rod Position Monitoring System of QS2NPS. By this software, the position of control rods can be monitored in real time, the abnormal phenomena can be identified immediately, the correctness and timeliness of fault diagnosis are improved remarkably. the identification and recordance of rod position fault, the performance validation of measure channel are realized also. The function and effect of this software are introduced. (authors)

Guaranteed Cost Finite-Time Control of Fractional-Order Positive Switched Systems

Directory of Open Access Journals (Sweden)

Leipo Liu

2017-01-01

Full Text Available The problem of guaranteed cost finite-time control of fractional-order positive switched systems (FOPSS is considered in this paper. Firstly, a new cost function is defined. Then, by constructing linear copositive Lyapunov functions and using the average dwell time (ADT approach, a state feedback controller and a static output feedback controller are constructed, respectively, and sufficient conditions are derived to guarantee that the corresponding closed-loop systems are guaranteed cost finite-time stable (GCFTS. Such conditions can be easily solved by linear programming. Finally, two examples are given to illustrate the effectiveness of the proposed method.

Friction-resilient position control for machine tools—Adaptive and sliding-mode methods compared

DEFF Research Database (Denmark)

Papageorgiou, Dimitrios; Blanke, Mogens; Niemann, Hans Henrik

2018-01-01

Robust trajectory tracking and increasing demand for high-accuracy tool positioning have motivated research in advanced control design for machine tools. State-of-the-art industry solutions employ cascades of Proportional (P) and Proportional-Integral (PI) controllers for closed-loop servo contro...

Position and force control of a vehicle with two or more steerable drive wheels

Energy Technology Data Exchange (ETDEWEB)

Reister, D.B.; Unseren, M.A.

1992-10-01

When a vehicle with two or more steerable drive wheels is traveling in a circle, the motion of the wheels is constrained. The wheel translational velocity divided by the radius to the center of rotation must be the same for all wheels. When the drive wheels are controlled independently using position control, the motion of the wheels may violate the constraints and the wheels may slip. Consequently, substantial errors can occur in the orientation of the vehicle. A vehicle with N drive wheels has (N - 1) constraints and one degree of freedom. We have developed a new approach to the control of a vehicle with N steerable drive wheels. The novel aspect of our approach is the use of force control. To control the vehicle, we have one degree of freedom for the position on the circle and (N - 1) forces that can be used to reduce errors. Recently, Kankaanranta and Koivo developed a control architecture that allows the force and position degrees of freedom to be decoupled. In the work of Kankaanranta and Koivo the force is an exogenous input. We have made the force endogenous by defining the force in terms of the errors in satisfying the rigid body kinematic constraints. We have applied the control architecture to the HERMIES-III robot and have measured a dramatic reduction in error (more than a factor of 20) compared to motions without force control.

tDCS over the left prefrontal cortex enhances cognitive control for positive affective stimuli.

Science.gov (United States)

Vanderhasselt, Marie-Anne; De Raedt, Rudi; Brunoni, Andre R; Campanhã, Camila; Baeken, Chris; Remue, Jonathan; Boggio, Paulo S

2013-01-01

Transcranial Direct Current Stimulation (tDCS) is a neuromodulation technique with promising results for enhancing cognitive information processes. So far, however, research has mainly focused on the effects of tDCS on cognitive control operations for non-emotional material. Therefore, our aim was to investigate the effects on cognitive control considering negative versus positive material. For this sham-controlled, within-subjects study, we selected a homogeneous sample of twenty-five healthy participants. By using behavioral measures and event related potentials (ERP) as indexes, we aimed to investigate whether a single session of anodal tDCS of the left dorsolateral prefrontal cortex (DLPFC) would have specific effects in enhancing cognitive control for positive and negative valenced stimuli. After tDCS over the left DLPFC (and not sham control stimulation), we observed more negative N450 amplitudes along with faster reaction times when inhibiting a habitual response to happy compared to sad facial expressions. Gender did not influence the effects of tDCS on cognitive control for emotional information. In line with the Valence Theory of side-lateralized activity, this stimulation protocol might have led to a left dominant (relative to right) prefrontal cortical activity, resulting in augmented cognitive control specifically for positive relative to negative stimuli. To verify that tDCS induces effects that are in line with all aspects of the well known Valence Theory, future research should investigate the effects of tDCS over the left vs. right DLPFC on cognitive control for emotional information.

Position control of a floating nuclear power plant

International Nuclear Information System (INIS)

Motohashi, K.; Hamamoto, T.; Sasaki, R.; Kojima, M.

1993-01-01

In spite of the increasing demand of electricity in Japan, the sites of nuclear power plants suitable for conventional seismic regulations become severely limited. Under these circumstances, several types of advanced siting technology have been developed. Among them, floating power plants have a great advantage of seismic isolation that leads to the seismic design standardization and factory fabrication. The feasibility studies or preliminary designs of floating power plants enclosed by breakwaters in the shallow sea have been carried out last two decades in U.S. and Japan. On the other hand, there are few investigations on the dynamic behavior of floating power plants in the deep sea. The offshore floating nuclear power plants have an additional advantage in that large breakwaters are not required, although the safety checking is inevitable against wind-induced waves. The tension-leg platforms which have been constructed for oil drilling in the deep sea seem to be a promising offshore siting technology of nuclear power plants. The tension-leg mooring system can considerably restrain the heave and pitch of a floating power plant because of significant stiffness in the vertical direction. Different from seismic effects, wind-induced waves may be predicted in advance by making use of ocean weather forecasts using artificial satellites. According to the wave prediction, the position of the floating plant may be controlled by adjusting the water content in ballast tanks and the length of tension-legs before the expected load arrives. The position control system can reduce the wave force acting on the plant and to avoid the unfavorable response behavior of the plant. In this study a semi-submerged circular cylinder with tension-legs is considered as a mathematical model. The configuration of circular cylinder is effective because the dynamic behavior does not depend on incident wave directions. It is also unique in that it can obtain the closed-form solution of

Positioning of sensors for control of ventilation systems in broiler houses: a case study

Directory of Open Access Journals (Sweden)

Thayla Morandi Ridolfi de Carvalho Curi

Full Text Available ABSTRACT Ventilation systems are incorporated at intensive poultry farms to control environment conditions and thermal comfort of broilers. The ventilation system operates based on environmental data, particularly measured by sensors of temperature and relative humidity. Sensors are placed at different positions of the facility. Quality, number and positioning of the sensors are critical factors to achieve an efficient performance of the system. For this reason, a strategic positioning of the sensors associated to controllers could support the maintenance and management of the microclimate inside the facility. This research aims to identify the three most representative points for the positioning of sensors in order to support the ventilation system during the critical period from 12h00 to 15h00 on summer days. Temperature, relative humidity and wind speed were measured in four different tunnel ventilated barns at the final stage of the production cycle. The descriptive analysis was performed on these data. The Temperature and Humidity Index (THI was also calculated. Then, the geostatistical analysis of THI was performed by GS+ and the position of sensors was determined by ordinary kriging. The methodology was able to detect the most representative points for the positioning of sensors in a case study (southeastern Brazil. The results suggested that this strategic positioning would help controllers to obtain a better inference of the microclimate during the studied period (the hottest microclimate, considered critical in Brazil. In addition, these results allow developing a future road map for a decision support system based on 24 h monitoring of the ventilation systems in broiler houses.

A Comparison between Two Force-Position Controllers with Gravity Compensation Simulated on a Humanoid Arm

Directory of Open Access Journals (Sweden)

Giovanni Gerardo Muscolo

2013-01-01

Full Text Available The authors propose a comparison between two force-position controllers with gravity compensation simulated on the DEXTER bioinspired robotic arm. The two controllers are both constituted by an internal proportional-derivative (PD closed-loop for the position control. The force control of the two systems is composed of an external proportional (P closed-loop for one system (P system and an external proportional-integrative (PI closed-loop for the other system (PI system. The simulation tests performed with the two systems on a planar representation of the DEXTER, an eight-DOF bioinspired arm, showed that by varying the stiffness of the environment, with a correct setting of parameters, both systems ensure the achievement of the desired force regime and with great precision the desired position. The two controllers do not have large differences in performance when interacting with a lower stiffness environment. In case of an environment with greater rigidity, the PI system is more stable. The subsequent implementation of these control systems on the DEXTER robotic bioinspired arm gives guidance on the design and control optimisation of the arms of the humanoid robot named SABIAN.

Passive hybrid force-position control for tele-operation based on real-time simulation of a virtual mechanism

International Nuclear Information System (INIS)

Joly, L.; Andriot, C.

1995-01-01

Hybrid force-position control aims at controlling position and force in separate directions. It is particularly useful to perform certain robotic tasks. In tele-operation context, passivity is important because it ensures stability when the system interacts with any passive environment. In this paper, we propose an original approach to hybrid force-position control of a force reflecting tele-robot system. It is based on real-time simulation of a virtual mechanism corresponding to the task. the resulting control law is passive. Experiments on a 6 degrees of freedom tele-operation system consisting in following a bent pipe under several control modes validate the approach. (authors). 12 refs., 6 figs

Dynamics and feedback control of plasma equilibrium position in a tokamak

International Nuclear Information System (INIS)

Burenko, O.

1983-01-01

A brief history of the beginnings of nuclear fusion research involving toroidal closed-system magnetic plasma containment is presented. A tokamak machine is defined mathematically for the purposes of plasma equilibrium position perturbation analysis. The perturbation equations of a tokamak plasma equilibrium position are developed. Solution of the approximated perturbation equations is carried out. A unique, simple, and useful plasma displacement dynamics transfer function of a tokamak is developed. The dominant time constants of the dynamics transfer function are determined in a symbolic form. This symbolic form of the dynamics transfer function makes it possible to study the stability of a tokamak's plasma equilibrium position. Knowledge of the dynamics transfer function permits systematic syntheses of the required plasma displacement feedback control systems

Practical controller design for ultra-precision positioning of stages with a pneumatic artificial muscle actuator

Science.gov (United States)

Tang, T. F.; Chong, S. H.

2017-06-01

This paper presents a practical controller design method for ultra-precision positioning of pneumatic artificial muscle actuator stages. Pneumatic artificial muscle (PAM) actuators are safe to use and have numerous advantages which have brought these actuators to wide applications. However, PAM exhibits strong non-linear characteristics, and these limitations lead to low controllability and limit its application. In practice, the non-linear characteristics of PAM mechanism are difficult to be precisely modeled, and time consuming to model them accurately. The purpose of the present study is to clarify a practical controller design method that emphasizes a simple design procedure that does not acquire plants parameters modeling, and yet is able to demonstrate ultra-precision positioning performance for a PAM driven stage. The practical control approach adopts continuous motion nominal characteristic trajectory following (CM NCTF) control as the feedback controller. The constructed PAM driven stage is in low damping characteristic and causes severe residual vibration that deteriorates motion accuracy of the system. Therefore, the idea to increase the damping characteristic by having an acceleration feedback compensation to the plant has been proposed. The effectiveness of the proposed controller was verified experimentally and compared with a classical PI controller in point-to-point motion. The experiment results proved that the CM NCTF controller demonstrates better positioning performance in smaller motion error than the PI controller. Overall, the CM NCTF controller has successfully to reduce motion error to 3µm, which is 88.7% smaller than the PI controller.

Cervical Joint Position Sense in Hypobaric Conditions: A Randomized Double-Blind Controlled Trial.

Science.gov (United States)

Bagaianu, Diana; Van Tiggelen, Damien; Duvigneaud, N; Stevens, Veerle; Schroyen, Danny; Vissenaeken, Dirk; D'Hondt, Gino; Pitance, Laurent

2017-09-01

Well-adapted motor actions require intact and well-integrated information from all of the sensory systems, specifically the visual, vestibular, and somatosensory systems, including proprioception. Proprioception is involved in the sensorimotor control by providing the central nervous system with an updated body schema of the biomechanical and spatial properties of the body parts. With regard to the cervical spine, proprioceptive information from joint and muscle mechanoreceptors is integrated with vestibular and visual feedback to control head position, head orientation, and whole body posture. Postural control is highly complex and proprioception from joints is an important contributor to the system. Altitude has been used as a paradigm to study the mechanisms of postural control. Determining the mechanisms of postural control that are affected by moderate altitude is important as unpressurized aircrafts routinely operate at altitudes where hypoxia may be a concern. Deficits in motor performance arise when the reliance on proprioceptive feedback is abolished either experimentally or because of a disorder. As pilots require good neck motor control to counteract the weight of their head gear and proprioceptive information plays an important role in this process, the aim of this study was to determine if hypoxia at moderate altitudes would impair proprioception measured by joint position sense of the cervical spine in healthy subjects. Thirty-six healthy subjects (Neck Disability Index environment, a hypobaric chamber was used to simulate artificial moderate altitude. Head repositioning error was measured by asking the subject to perform a head-to-neutral task after submaximal flexion-extension and right/left rotation movements, and a head-to-target task, in which the subjects had to return to a 30° right and left rotation position. Exposure to artificial acute moderate altitude of 7,000 feet had no significant effects on cervical joint position sense measured by

Position automatic determination technology

International Nuclear Information System (INIS)

1985-10-01

This book tells of method of position determination and characteristic, control method of position determination and point of design, point of sensor choice for position detector, position determination of digital control system, application of clutch break in high frequency position determination, automation technique of position determination, position determination by electromagnetic clutch and break, air cylinder, cam and solenoid, stop position control of automatic guide vehicle, stacker crane and automatic transfer control.

Improving tokamak vertical position control in the presence of power supply voltage saturation

International Nuclear Information System (INIS)

Favez, J-Y; Lister, J B; Muellhaupt, Ph; Srinivasan, B

2005-01-01

The control of the current, position and shape of an elongated cross-section tokamak plasma is complicated by the so-called instability of the current vertical position. Linearized models all share the feature of a single unstable eigenmode, attributable to this vertical instability of the plasma equilibrium movement, and a large number of stable or marginally stable eigenmodes, attributable to zero or positive resistance in all other model circuit equations. Due to the size and therefore cost of the ITER tokamak, there will naturally be smaller margins in the poloidal field coil power supplies, implying that the feedback control will experience actuator saturation during large transients due to a variety of plasma disturbances. Current saturation is relatively benign, due to the integrating nature of the tokamak, resulting in a reasonable time horizon for strategically handling the approach to saturation which leads to the loss of one degree of freedom in the feedback control for each saturated coil. On the other hand, voltage saturation is produced by the feedback controller itself, with no intrinsic delay. This paper presents a feedback controller design approach which explicitly takes saturation of the power supply voltage into account when producing the power supply demand signals. We consider the vertically stabilizing part of the ITER controller (fast controller) with one power supply and therefore a single saturated input. We consider an existing ITER controller and enlarge its region of attraction to the full null controllable region by adding a continuous nonlinearity into the control. In a system with a single unstable eigenmode and a single stable eigenmode we have already provided a proof of the asymptotical stability of the closed loop system, and we have examined the performance of this new continuous nonlinear controller. We have subsequently extended this analysis to a system with a single eigenmode and multiple stable eigenmodes. The method

Studies on performances of the control system of plasma position and shape

International Nuclear Information System (INIS)

Aikawa, Hiroshi; Tsuzuki, Naohisa; Kimura, Toyoaki; Ogata, Atsushi; Ninomiya, Hiromasa

1978-09-01

Performance in the control system of plasma position and shape is determined by estimating the disturbing field, system functions and load variation of the controlled object. Various stray fields are considered as disturbing field. Plasma internal inductance and poloidal beta are taken into consideration as load variation of the controlled object. The required performance is obtained through considerations of plasma equilibrium, stability, impurity concentration and sensors accuracy. The results are described as requests to the poloidal power supply system. (author)

78 FR 979 - Petition for Positive Train Control Safety Plan Approval and System Certification of the...

Science.gov (United States)

2013-01-07

...] Petition for Positive Train Control Safety Plan Approval and System Certification of the Electronic Train... the Federal Railroad Administration (FRA) for Positive Train Control (PTC) Safety Plan (PTCSP) approval and system certification of the Electronic Train Management System (ETMS) as required by 49 U.S.C...

Development of three methods for control rod position monitoring based on fixed in-core neutron detectors

International Nuclear Information System (INIS)

Peng, Xingjie; Li, Qing; Wang, Kan

2015-01-01

Highlights: • Three methods are utilized separately to unfold the control rod position from the fixed in-core neutron detector measurements. • Fixed in-core neutron detector measurements are simulated by neutronics code SMART. • Numerical results show that all these methods can unfold the control rod position accurately. • Two correction strategies are proposed to correct the simulated fixed in-core detector signals. - Abstract: Nuclear reactor core power distribution on-line monitoring system is very important in core surveillance, and this system should have the ability to indicate some abnormal conditions, such as the unacceptable control rod misalignment. In this study, the methodologies of radial basis function neural network (RBFNN), group method of data handling (GMDH) and Levenberg–Marquardt (LM) algorithm are utilized separately to unfold the control rod position from the fixed in-core neutron detector measurements. For using these methods, a large number of in-core detector signals corresponding to various known rod positions are needed. These data can be generated by an advanced core calculation code. In this study, the neutronics code SMART was used. The simulation results show that all these methods can unfold the control rod position accurately, and the performance comparison shows that the regularized RBFNN performs best. Two correction strategies are proposed to correct the simulated fixed in-core detector signals and improve the rod position monitoring accuracy when there are mismatches between actual physical factors and modeled physical factors

Kept in His Care: The Role of Perceived Divine Control in Positive Reappraisal Coping

Directory of Open Access Journals (Sweden)

Reed T. DeAngelis

2017-07-01

Full Text Available A formidable body of literature suggests that numerous dimensions of religious involvement can facilitate productive coping. One common assumption in this field is that religious worldviews provide overarching frameworks of meaning by which to positively reinterpret stressors. The current study explicitly tests this assumption by examining whether perceived divine control—i.e., the notion that God controls the course and direction of one’s life—buffers the adverse effects of recent traumatic life events on one’s capacity for positive reappraisal coping. We analyze cross-sectional survey data from Vanderbilt University’s Nashville Stress and Health Study (2011–2014, a probability sample of non-Hispanic black and white adults aged 22 to 69 living in Davidson County, Tennessee (n = 1252. Findings from multivariate regression models confirm: (1 there was an inverse association between past-year traumatic life events and positive reappraisals; but (2 perceived divine control significantly attenuated this inverse association. Substantively, our findings suggest that people who believe God controls their life outcomes are better suited for positively reinterpreting traumatic experiences. Implications, limitations, and avenues for future research are discussed.

Membrane tension controls adhesion positioning at the leading edge of cells.

Science.gov (United States)

Pontes, Bruno; Monzo, Pascale; Gole, Laurent; Le Roux, Anabel-Lise; Kosmalska, Anita Joanna; Tam, Zhi Yang; Luo, Weiwei; Kan, Sophie; Viasnoff, Virgile; Roca-Cusachs, Pere; Tucker-Kellogg, Lisa; Gauthier, Nils C

2017-09-04

Cell migration is dependent on adhesion dynamics and actin cytoskeleton remodeling at the leading edge. These events may be physically constrained by the plasma membrane. Here, we show that the mechanical signal produced by an increase in plasma membrane tension triggers the positioning of new rows of adhesions at the leading edge. During protrusion, as membrane tension increases, velocity slows, and the lamellipodium buckles upward in a myosin II-independent manner. The buckling occurs between the front of the lamellipodium, where nascent adhesions are positioned in rows, and the base of the lamellipodium, where a vinculin-dependent clutch couples actin to previously positioned adhesions. As membrane tension decreases, protrusion resumes and buckling disappears, until the next cycle. We propose that the mechanical signal of membrane tension exerts upstream control in mechanotransduction by periodically compressing and relaxing the lamellipodium, leading to the positioning of adhesions at the leading edge of cells. © 2017 Pontes et al.

Robust Hinfinity position control synthesis of an electro-hydraulic servo system.

Science.gov (United States)

Milić, Vladimir; Situm, Zeljko; Essert, Mario

2010-10-01

This paper focuses on the use of the techniques based on linear matrix inequalities for robust H(infinity) position control synthesis of an electro-hydraulic servo system. A nonlinear dynamic model of the hydraulic cylindrical actuator with a proportional valve has been developed. For the purpose of the feedback control an uncertain linearized mathematical model of the system has been derived. The structured (parametric) perturbations in the electro-hydraulic coefficients are taken into account. H(infinity) controller extended with an integral action is proposed. To estimate internal states of the electro-hydraulic servo system an observer is designed. Developed control algorithms have been tested experimentally in the laboratory model of an electro-hydraulic servo system. Copyright © 2010 ISA. Published by Elsevier Ltd. All rights reserved.

tDCS over the left prefrontal cortex enhances cognitive control for positive affective stimuli.

Directory of Open Access Journals (Sweden)

Marie-Anne Vanderhasselt

Full Text Available Transcranial Direct Current Stimulation (tDCS is a neuromodulation technique with promising results for enhancing cognitive information processes. So far, however, research has mainly focused on the effects of tDCS on cognitive control operations for non-emotional material. Therefore, our aim was to investigate the effects on cognitive control considering negative versus positive material. For this sham-controlled, within-subjects study, we selected a homogeneous sample of twenty-five healthy participants. By using behavioral measures and event related potentials (ERP as indexes, we aimed to investigate whether a single session of anodal tDCS of the left dorsolateral prefrontal cortex (DLPFC would have specific effects in enhancing cognitive control for positive and negative valenced stimuli. After tDCS over the left DLPFC (and not sham control stimulation, we observed more negative N450 amplitudes along with faster reaction times when inhibiting a habitual response to happy compared to sad facial expressions. Gender did not influence the effects of tDCS on cognitive control for emotional information. In line with the Valence Theory of side-lateralized activity, this stimulation protocol might have led to a left dominant (relative to right prefrontal cortical activity, resulting in augmented cognitive control specifically for positive relative to negative stimuli. To verify that tDCS induces effects that are in line with all aspects of the well known Valence Theory, future research should investigate the effects of tDCS over the left vs. right DLPFC on cognitive control for emotional information.

Treatment of helicobacter pylori infection; a controlled randomized comparative clinical trial

International Nuclear Information System (INIS)

Mehmood, A.; Usmanghani, K.; Mohiuddin, E.; Akram, M.

2010-01-01

Helicobacter pylori induces chronic inflammation of the underlying gastric mucosa and is strongly linked to the development of duodenal and gastric carcinoma. A study was conducted to evaluate the efficacy of Pylorex, a herbal formulation, for treatment of H. pylori infection as compared to triple allopathic therapy (Omeprazole, Amoxicillin, Metronidazole). The therapeutic evaluations of these medicines were conducted on 97 clinically and immunologically diagnosed cases of H. pylori infection. H. pylori was eradicated in 16 (32.6%) out of 49 patients by the use of triple allopathic therapy (Control drugs), and in 9 (18.7%) out of 48 patients by the use of Pylorex (Test drug). Pylorex possesses a therapeutic value for the treatment of H. pylori associated symptoms but the eradication rate is superior in triple allopathic therapy. (author)

Study of intelligent system for control of the tokamak-ETE plasma positioning

International Nuclear Information System (INIS)

Barbosa, Luis Filipe de Faria Pereira Wiltgen

2003-01-01

The development of an intelligent neural control system of the neural type, capable to perform real time control of the plasma displacement in the experiment tokamak spheric - ETE (spherical tokamak experiment ) is presented. The ETE machine is in operation since Nov 2000, in the LAP - Plasma Associated Laboratory of the Brazilian Institute on Spatial Research (INPE) in Sao Jose dos Campos, S P, Brazil. The experiment is dedicated to study the magnetic confinement of a fusion plasma in a configuration favorable for the construction of future reactors. Nuclear fusion constitutes a renewable energy source with low environmental impact, which uses atomic energy in pacific applications for the sustainable development of humanity. One of the important questions for the attainment of fusion relates to the stability of the plasma and control of its position during the reactor operation. Therefore, the development of systems to control the plasma in tokamaks constitutes a necessary technological advance for the feasibility of nuclear fusion. In particular, the research carried out in this thesis concerns the proposal of a system to control the vertical displacement of the plasma in the ETE tokamak, aiming to obtain steady pulses in this machine. A Magnetic Levitation system (Mag Lev) was developed as part of this work, allowing to study the nonlinear behavior of a device that, from the aspect of position control, is similar (analogous) to the plasma in the ETE tokamak, This magnetic levitation system was designed, mathematically modeled and built in order to test both classical and intelligent type controllers. The results of this comparison are very promising for the use of intelligent controllers in the ETE tokamak as well as other control applications. (author)

Robust balancing and position control of a single spherical wheeled mobile platform

OpenAIRE

Yavuz, Fırat; Yavuz, Firat; Ünel, Mustafa; Unel, Mustafa

2016-01-01

Self-balancing mobile platforms with single spherical wheel, generally called ballbots, are suitable example of underactuated systems. Balancing control of a ballbot platform, which aims to maintain the upright orientation by rejecting external disturbances, is important during station keeping or trajectory tracking. In this paper, acceleration based balancing and position control of a single spherical wheeled mobile platform that has three single-row omniwheel drive m...

Bioengineering of Tobacco Mosaic Virus to Create a Non-Infectious Positive Control for Ebola Diagnostic Assays

Science.gov (United States)

Lam, Patricia; Gulati, Neetu M.; Stewart, Phoebe L.; Keri, Ruth A.; Steinmetz, Nicole F.

2016-03-01

The 2014 Ebola epidemic is the largest to date. There is no cure or treatment for this deadly disease; therefore there is an urgent need to develop new diagnostics to accurately detect Ebola. Current RT-PCR assays lack sensitive and reliable positive controls. To address this critical need, we devised a bio-inspired positive control for use in RT-PCR diagnostics: we encapsulated scrambled Ebola RNA sequences inside of tobacco mosaic virus to create a biomimicry that is non-infectious, but stable, and could therefore serve as a positive control in Ebola diagnostic assays. Here, we report the bioengineering and validation of this probe.

Implementation of CTRLPOS, a VENTURE module for control rod position criticality searches, control rod worth curve calculations, and general criticality searches

Energy Technology Data Exchange (ETDEWEB)

Smith, L.A.; Renier, J.P.

1994-06-01

A module in the VENTURE reactor analysis code system, CTRLPOS, is developed to position control rods and perform control rod position criticality searches. The module is variably dimensioned so that calculations can be performed with any number of control rod banks each having any number of control rods. CTRLPOS can also calculate control rod worth curves for a single control rod or a bank of control rods. Control rod depletion can be calculated to provide radiation source terms. These radiation source terms can be used to predict radiation doses to personnel and estimate the shielding and long-term storage requirements for spent control rods. All of these operations are completely automated. The numerous features of the module are discussed in detail. The necessary input data for the CTRLPOS module is explained. Several sample problems are presented to show the flexibility of the module. The results presented with the sample problems show that the CTRLPOS module is a powerful tool which allows a wide variety of calculations to be easily performed.

Position control of a single pneumatic artificial muscle with hysteresis compensation based on modified Prandtl-Ishlinskii model.

Science.gov (United States)

Zang, Xizhe; Liu, Yixiang; Heng, Shuai; Lin, Zhenkun; Zhao, Jie

2017-01-01

High-performance position control of pneumatic artificial muscles is limited by their inherent nonlinearity and hysteresis. This study aims to model the length/pressure hysteresis of a single pneumatic artificial muscle and to realize its accurate position tracking control with forward hysteresis compensation. The classical Prandtl-Ishlinskii model is widely used in hysteresis modelling and compensation. But it is only effective for symmetric hysteresis. Therefore, a modified Prandtl-Ishlinskii model is built to characterize the asymmetric length/pressure hysteresis of a single pneumatic artificial muscle, by replacing the classical play operators with two more flexible elementary operators to independently describe the ascending branch and descending branch of hysteresis loops. On the basis, a position tracking controller, which is composed of cascade forward hysteresis compensation and simple proportional pressure controller, is designed for the pneumatic artificial muscle. Experiment results show that the MPI model can reproduce the length/pressure hysteresis of the pneumatic artificial muscle, and the proposed controller for the pneumatic artificial muscle can track the reference position signals with high accuracy. By modelling the length/pressure hysteresis with the modified Prandtl-Ishlinskii model and using its inversion for compensation, precise position control of a single pneumatic artificial muscle is achieved.

Quantum dots for future nanophotonic devices : lateral ordering, position, and number control

NARCIS (Netherlands)

Nötzel, R.; Sritirawisarn, N.; Selçuk, E.; Wang, H.; Yuan, J.

2009-01-01

We review our recent advances in the lateral ordering, position, and number control of self-organized epitaxial semiconductor quantum dots based on self-organized anisotropic strain engineering, growth on patterned substrates, and selective area growth.

Position display device

International Nuclear Information System (INIS)

Nishizawa, Yukio.

1974-01-01

Object: To provide a device capable of easily and quickly reading mutual mounting relations of control bodies such as control rods mounted on a nuclear reactor and positions to which the control bodies are driven. Structure: A scanning circuit is provided to scan positions of controllably mounted control bodies such as control rods. Values detected by scanning the positions are converted into character signals according to the values and converted into preranked color signals. The character signals and color signals are stored in a memory circuit by synchronous signals in synchronism with the scanning in the scanning circuit. Outputs of the memory circuit are displayed by a display unit such as a color Braun tube in accordance with the synchronous signals to provide color representations according to positions to which control bodies are driven in the same positional relation as the mounting of the control bodies. (Kamimura, M.)

Controlling resonance energy transfer in nanostructure emitters by positioning near a mirror

Science.gov (United States)

Weeraddana, Dilusha; Premaratne, Malin; Gunapala, Sarath D.; Andrews, David L.

2017-08-01

The ability to control light-matter interactions in quantum objects opens up many avenues for new applications. We look at this issue within a fully quantized framework using a fundamental theory to describe mirror-assisted resonance energy transfer (RET) in nanostructures. The process of RET communicates electronic excitation between suitably disposed donor and acceptor particles in close proximity, activated by the initial excitation of the donor. Here, we demonstrate that the energy transfer rate can be significantly controlled by careful positioning of the RET emitters near a mirror. The results deliver equations that elicit new insights into the associated modification of virtual photon behavior, based on the quantum nature of light. In particular, our results indicate that energy transfer efficiency in nanostructures can be explicitly expedited or suppressed by a suitably positioned neighboring mirror, depending on the relative spacing and the dimensionality of the nanostructure. Interestingly, the resonance energy transfer between emitters is observed to "switch off" abruptly under suitable conditions of the RET system. This allows one to quantitatively control RET systems in a new way.

Simultaneous positioning and orientation of a single nano-object by flow control: theory and simulations

International Nuclear Information System (INIS)

Mathai, Pramod P; Berglund, Andrew J; Alexander Liddle, J; Shapiro, Benjamin A

2011-01-01

In this paper, we theoretically describe a method to simultaneously control both the position and orientation of single nano-objects in fluids by precisely controlling the flow around them. We develop and simulate a control law that uses electro-osmotic flow (EOF) actuation to translate and rotate rigid nano-objects in two spatial dimensions. Using EOF to control nano-objects offers advantages as compared to other approaches: a wide class of objects can be manipulated (no magnetic or electric dipole moments are needed), the object can be controlled over a long range (>100 μm) with sub-micrometer accuracy, and control may be achieved with simple polydimethylsiloxane (PDMS) devices. We demonstrate the theory and numerical solutions that will enable deterministic control of the position and orientation of a nano-object in solution, which can be used, for example, to integrate nanostructures in circuits and orient sensors to probe living cells.

Imagined Positive Emotions and Inhibitory Control: The Differentiated Effect of Pride versus Happiness

Science.gov (United States)

Katzir, Maayan; Eyal, Tal; Meiran, Nachshon; Kessler, Yoav

2010-01-01

"Inhibitory control" is a cognitive mechanism that contributes to successful self-control (i.e., adherence to a long-term goal in the face of an interfering short-term goal). This research explored the effect of imagined positive emotional events on inhibition. The authors proposed that the influence of imagined emotions on inhibition…

Optimal Control Method of Robot End Position and Orientation Based on Dynamic Tracking Measurement

Science.gov (United States)

Liu, Dalong; Xu, Lijuan

2018-01-01

In order to improve the accuracy of robot pose positioning and control, this paper proposed a dynamic tracking measurement robot pose optimization control method based on the actual measurement of D-H parameters of the robot, the parameters is taken with feedback compensation of the robot, according to the geometrical parameters obtained by robot pose tracking measurement, improved multi sensor information fusion the extended Kalan filter method, with continuous self-optimal regression, using the geometric relationship between joint axes for kinematic parameters in the model, link model parameters obtained can timely feedback to the robot, the implementation of parameter correction and compensation, finally we can get the optimal attitude angle, realize the robot pose optimization control experiments were performed. 6R dynamic tracking control of robot joint robot with independent research and development is taken as experimental subject, the simulation results show that the control method improves robot positioning accuracy, and it has the advantages of versatility, simplicity, ease of operation and so on.

Automatic and controlled attentional orienting in the elderly: A dual-process view of the positivity effect.

Science.gov (United States)

Gronchi, G; Righi, S; Pierguidi, L; Giovannelli, F; Murasecco, I; Viggiano, M P

2018-04-01

The positivity effect in the elderly consists of an attentional preference for positive information as well as avoidance of negative information. Extant theories predict either that the positivity effect depends on controlled attentional processes (socio-emotional selectivity theory), or on an automatic gating selection mechanism (dynamic integration theory). This study examined the role of automatic and controlled attention in the positivity effect. Two dot-probe tasks (with the duration of the stimuli lasting 100 ms and 500 ms, respectively) were employed to compare the attentional bias of 35 elderly people to that of 35 young adults. The stimuli used were expressive faces displaying neutral, disgusted, fearful, and happy expressions. In comparison to young people, the elderly allocated more attention to happy faces at 100 ms and they tended to avoid fearful faces at 500 ms. The findings are not predicted by either theory taken alone, but support the hypothesis that the positivity effect in the elderly is driven by two different processes: an automatic attention bias toward positive stimuli, and a controlled mechanism that diverts attention away from negative stimuli. Copyright © 2018 Elsevier B.V. All rights reserved.

Automated positioning dual-axis solar tracking system with precision elevation and azimuth angle control

International Nuclear Information System (INIS)

Sidek, M.H.M.; Azis, N.; Hasan, W.Z.W.; Ab Kadir, M.Z.A.; Shafie, S.; Radzi, M.A.M.

2017-01-01

This paper presents a study on an automated positioning open-loop dual-axis solar tracking system. The solar tracker was designed and fabricated using standard cylindrical aluminium hollow and Polyuthrene (PE). The control system of the solar tracker was governed by Micro Controller Unit (MCU) with auxiliary devices which includes encoder and Global Positioning System (GPS). The sun path trajectory algorithm utilizing the astronomical equation and GPS information was also embedded in the system. The power generation performance of the dual-axis solar tracking system was compared with the fixed-tilted Photovoltaic (PV) system. It is found that the solar tracker is able to position itself automatically based on sun path trajectory algorithm with an accuracy of ±0.5°. The embedded Proportional Integral Derivative (PID) positioning system improves the tracking of elevation and azimuth angles with minimum energy consumption. It is reveals that the proposed solar tracker is able generate 26.9% and 12.8% higher power than fixed-tilted PV system on a clear and heavy overcast conditions respectively. Overall, the open-loop dual-axis solar tracker can be deployed automatically at any location on the earth with minimal configurations and is suitable for mobile solar tracking system. - Highlights: • Self-positioning dual-axis solar tracking system. • Precise control of elevation and azimuth angle. • Sun path trajectory based on astronomical equation and GPS. • Can achieve up to 26.9% higher power than fixed-tilted PV system under clear weather condition.

Pathways to Adolescents' Flourishing: Linking Self-Control Skills and Positivity Ratio through Social Support

Science.gov (United States)

Orkibi, Hod; Hamama, Liat; Gavriel-Fried, Belle; Ronen, Tammie

2018-01-01

This study focused on the ability to experience a high ratio of positive to negative emotions in 807 Israeli adolescents aged 12 to 15 years (50% girls). While considering possible gender differences, we tested a model positing that adolescents' self-control skills would link to their positivity ratio and indirectly through perceived social…

Open-loop position tracking control of a piezoceramic flexible beam using a dynamic hysteresis compensator

International Nuclear Information System (INIS)

Nguyen, Phuong-Bac; Choi, Seung-Bok

2010-01-01

This paper proposes a novel hysteresis compensator to enhance control accuracy in open-loop position tracking control of a piezoceramic flexible beam. The proposed hysteresis compensator consists of two components: a rate-independent hysteresis compensator and a nonlinear filter. The compensator is formulated based on the inverse Preisach model, while the weight coefficients of the filter are identified adaptively using a recursive least square (RLS) algorithm. In this work, two dynamic hysteresis compensators (or rate-independent hysteresis compensators) are developed by adopting two different nonlinear filters: Volterra and bilinear filters. In order to demonstrate the improved control accuracy of the proposed dynamic compensators, a flexible beam associated with the piezoceramic actuator is modeled using the finite element method (FEM) and Euler–Bernoulli beam theory. The beam model is then integrated with the proposed hysteresis model to achieve accurate position tracking control at the tip of the beam. An experimental investigation on the tip position tracking control is undertaken by realizing three different hysteresis compensators: a rate-independent hysteresis compensator, a rate-dependent hysteresis compensator with a Volterra nonlinear filter and a rate-independent hysteresis compensator with a bilinear nonlinear filter. It is shown that the proposed dynamic hysteresis compensators can provide much better tracking control accuracy than conventional rate-independent hysteresis compensators

MDEP Common Position No EPR-01 - Common positions on the EPR instrumentation and controls design

International Nuclear Information System (INIS)

2010-01-01

The purpose of the EPR Working Group (EPRWG) of the Multinational Design Evaluation Program (MDEP) is to identify common positions among the regulators reviewing the EPR Instrumentation and Controls (I and C) Systems in order to: 1. Promote understanding of each country 's regulatory decisions and basis for the decisions, 2. Enhance communication among the members and with external stakeholders, 3. Identify areas where harmonization and convergence of regulations, standards, and guidance can be achieved or improved, and 4. Supports standardization of new reactor designs. Since January 2008, the EPR I and C Technical Expert Subgroup (TESG) members met five times to exchange information regarding their country 's review of the EPR I and C design. The EPR I and C TESG consists of regulators from China, Canada, Finland, France, the United Kingdom, and the United States. The information exchange includes presentation of each country 's review status and technical issues, sharing of guidance documents, and sharing of regulatory decision documents. The TESG focused on the following four core areas of the EPR I and C design: 1. I and C System Independence (particularly for data communications), 2. Level of Defense and Diversity (back-up systems), 3. Qualification/quality of digital platforms, 4. Categorization/classification of systems and functions. As meetings were conducted, some areas were emphasized more depending on the significance of the issues for each country. During the TESG interactions, it became apparent that there were aspects of the EPR design where the countries had common agreement. On November 2, 2009, three of the subgroup countries, France, Finland and the United Kingdom, issued a joint regulatory position on the EPR I and C design as result of the 'Groupe Permanent' meeting in France. This statement of common positions expands upon that joint regulatory position

Anticipatory planning and control of grasp positions and forces for dexterous two-digit manipulation.

Science.gov (United States)

Fu, Qiushi; Zhang, Wei; Santello, Marco

2010-07-07

Dexterous object manipulation requires anticipatory control of digit positions and forces. Despite extensive studies on sensorimotor learning of digit forces, how humans learn to coordinate digit positions and forces has never been addressed. Furthermore, the functional role of anticipatory modulation of digit placement to object properties remains to be investigated. We addressed these questions by asking human subjects (12 females, 12 males) to grasp and lift an inverted T-shaped object using precision grip at constrained or self-chosen locations. The task requirement was to minimize object roll during lift. When digit position was not constrained, subjects could have implemented many equally valid digit position-force coordination patterns. However, choice of digit placement might also have resulted in large trial-to-trial variability of digit position, hence challenging the extent to which the CNS could have relied on sensorimotor memories for anticipatory control of digit forces. We hypothesized that subjects would modulate digit placement for optimal force distribution and digit forces as a function of variable digit positions. All subjects learned to minimize object roll within the first three trials, and the unconstrained device was associated with significantly smaller grip forces but larger variability of digit positions. Importantly, however, digit load force modulation compensated for position variability, thus ensuring consistent object roll minimization on each trial. This indicates that subjects learned object manipulation by integrating sensorimotor memories with sensory feedback about digit positions. These results are discussed in the context of motor equivalence and sensorimotor integration of grasp kinematics and kinetics.

A Sleep Position Trainer for positional sleep apnea

DEFF Research Database (Denmark)

Laub, Rasmus R; Tønnesen, Philip; Jennum, Poul J

2017-01-01

We tested the effect of the Sleep Position Trainer, a vibrational device, for positional sleep apnea in an open, randomized controlled trial with 101 patients, where 52 patients were allocated to Sleep Position Trainer and 49 patients to a non-treatment control group for 2 months (Part 1). All...... patients were then followed as a cohort for a period of 6 months with use of the Sleep Position Trainer (Part 2). The participants were assessed with polygraphy at entry, and after 2 and 6 months. The mean apnea-hypopnea index supine was 35 per h (SD, 18) in the Sleep Position Trainer group and 38 per h...... (SD, 15) in the control group at entry. In a per protocol analysis, the mean total apnea-hypopnea index at entry and after 2 months in the Sleep Position Trainer group was 18 per h (SD, 10) and 10 per h (SD, 9; P

Emotional modulation of control dilemmas: the role of positive affect, reward, and dopamine in cognitive stability and flexibility.

Science.gov (United States)

Goschke, Thomas; Bolte, Annette

2014-09-01

Goal-directed action in changing environments requires a dynamic balance between complementary control modes, which serve antagonistic adaptive functions (e.g., to shield goals from competing responses and distracting information vs. to flexibly switch between goals and behavioral dispositions in response to significant changes). Too rigid goal shielding promotes stability but incurs a cost in terms of perseveration and reduced flexibility, whereas too weak goal shielding promotes flexibility but incurs a cost in terms of increased distractibility. While research on cognitive control has long been conducted relatively independently from the study of emotion and motivation, it is becoming increasingly clear that positive affect and reward play a central role in modulating cognitive control. In particular, evidence from the past decade suggests that positive affect not only influences the contents of cognitive processes, but also modulates the balance between complementary modes of cognitive control. In this article we review studies from the past decade that examined effects of induced positive affect on the balance between cognitive stability and flexibility with a focus on set switching and working memory maintenance and updating. Moreover, we review recent evidence indicating that task-irrelevant positive affect and performance-contingent rewards exert different and sometimes opposite effects on cognitive control modes, suggesting dissociations between emotional and motivational effects of positive affect. Finally, we critically review evidence for the popular hypothesis that effects of positive affect may be mediated by dopaminergic modulations of neural processing in prefrontal and striatal brain circuits, and we refine this "dopamine hypothesis of positive affect" by specifying distinct mechanisms by which dopamine may mediate effects of positive affect and reward on cognitive control. We conclude with a discussion of limitations of current research, point to

Tungsten carbide-cobalt as a nanoparticulate reference positive control in in vitro genotoxicity assays.

Science.gov (United States)

Moche, Hélène; Chevalier, Dany; Barois, Nicolas; Lorge, Elisabeth; Claude, Nancy; Nesslany, Fabrice

2014-01-01

With the increasing human exposure to nanoparticles (NP), the evaluation of their genotoxic potential is of significant importance. However, relevance for NP of the routinely used in vitro genotoxicity assays is often questioned, and a nanoparticulate reference positive control would therefore constitute an important step to a better testing of NP, ensuring that test systems are really appropriate. In this study, we investigated the possibility of using tungsten carbide-cobalt (WC-Co) NP as reference positive control in in vitro genotoxicity assays, including 2 regulatory assays, the mouse lymphoma assay and the micronucleus assay, and in the Comet assay, recommended for the toxicological evaluation of nanomedicines by the French Agency of Human Health Products (Afssaps). Through these assays, we were able to study different genetic endpoints in 2 cell types commonly used in regulatory genotoxicity assays: the L5178Y mouse lymphoma cell line and primary cultures of human lymphocytes. Our results showed that the use of WC-Co NP as positive control in in vitro genotoxicity assays was conceivable, but that different parameters have to be considered, such as cell type and treatment schedule. L5178Y mouse lymphoma cells did not provide satisfactory results in the 3 performed tests. However, human lymphocytes were more sensitive to genotoxic effects induced by WC-Co NP, particularly after a 24-h treatment in the in vitro micronucleus assay and after a 4-h treatment in the in vitro Comet assay. Under such conditions, WC-Co could be used as a nanoparticulate reference positive control in these assays.

Vertical position control of the elongated INTOR plasma

International Nuclear Information System (INIS)

Ueda, Kojyu; Nishio, Satoshi; Fujisawa, Noboru; Sugihara, Masayoshi; Saito, Seiji; Miyamoto, Kenro.

1983-01-01

A newly devised rectangular shell, which has the sufficient shell effect for the stabilization of the fast mode, is presented, along with the studies of various kinds of shell-structures described on this paper. It can be expected that the rectangular shells have negligibly small effect on the breeding ratio by locating them separately on both of the front and rear surfaces of blanket. Some properties with the modelled feedback control system are elucidated under a disturbance field, B sub(d) = B sub(infinity).[1-exp(-t/tau sub(d))] (B sub(infinity): field strength at t = infinity, tau sub(d): time constant). They are studied for two kinds of decay indices, that is, -1.0 for the pump limiter and -1.3 for the divertor. Conclusively, the control system is found to have good characteristics. The PID controller seems to provide the stable control of vertical position better than the PI controller. The maximum of vertical displacement, Z sub(p)sup(max) under the disturbance field, B sub(d), are in proportion to B sub(infinity). The power required for its stabilization, P, are also in proportion to B sub(infinity)sup(2), and then to (Z sub(P)sup(MAX))sup(2), too. Therefore, some common basis for B sub(infinity) or Z sub(P)sup(MAX) is required for its estimation. Moreover, the power is found to be independent of selection of the PI or PID controller, and to have approximately the same relation with Z sub(P)sup(MAX). The difference of P between -1.0 and -1.3 in the decay index is very large when Z sub(P)sup(MAX) is more than -1.0 cm. For example, in the vicinity of Z sub(P)sup(MAX) = 1.0 cm, the power in the case of n = -1.0 is about one half of that in the case of n = -1.3. But it decreases abruptly when Z sub(P)sup(MAX) is less than 0.5 cm. (J.P.N.)

Enabling Spacecraft Formation Flying through Position Determination, Control and Enhanced Automation Technologies

Science.gov (United States)

Bristow, John; Bauer, Frank; Hartman, Kate; How, Jonathan

2000-01-01

Formation Flying is revolutionizing the way the space community conducts science missions around the Earth and in deep space. This technological revolution will provide new, innovative ways for the community to gather scientific information, share that information between space vehicles and the ground, and expedite the human exploration of space. Once fully matured, formation flying will result in numerous sciencecraft acting as virtual platforms and sensor webs, gathering significantly more and better science data than call be collected today. To achieve this goal, key technologies must be developed including those that address the following basic questions posed by the spacecraft: Where am I? Where is the rest of the fleet? Where do I need to be? What do I have to do (and what am I able to do) to get there? The answers to these questions and the means to implement those answers will depend oil the specific mission needs and formation configuration. However, certain critical technologies are common to most formations. These technologies include high-precision position and relative-position knowledge including Global Positioning System (GPS) mid celestial navigation; high degrees of spacecraft autonomy inter-spacecraft communication capabilities; targeting and control including distributed control algorithms, and high precision control thrusters and actuators. This paper provides an overview of a selection of the current activities NASA/DoD/Industry/Academia are working to develop Formation Flying technologies as quickly as possible, the hurdles that need to be overcome to achieve our formation flying vision, and the team's approach to transfer this technology to space. It will also describe several of the formation flying testbeds, such as Orion and University Nanosatellites, that are being developed to demonstrate and validate many of these innovative sensing and formation control technologies.

Positive affect and cognitive control: approach-motivation intensity influences the balance between cognitive flexibility and stability.

Science.gov (United States)

Liu, Ya; Wang, Zhenhong

2014-05-01

In most prior research, positive affect has been consistently found to promote cognitive flexibility. However, the motivational dimensional model of affect assumes that the influence of positive affect on cognitive processes is modulated by approach-motivation intensity. In the present study, we extended the motivational dimensional model to the domain of cognitive control by examining the effect of low- versus high-approach-motivated positive affect on the balance between cognitive flexibility and stability in an attentional-set-shifting paradigm. Results showed that low-approach-motivated positive affect promoted cognitive flexibility but also caused higher distractibility, whereas high-approach-motivated positive affect enhanced perseverance but simultaneously reduced distractibility. These results suggest that the balance between cognitive flexibility and stability is modulated by the approach-motivation intensity of positive affective states. Therefore, it is essential to incorporate motivational intensity into studies on the influence of affect on cognitive control.

Lansoprazole use and tuberculosis incidence in the United Kingdom Clinical Practice Research Datalink: A population based cohort.

Science.gov (United States)

Yates, Tom A; Tomlinson, Laurie A; Bhaskaran, Krishnan; Langan, Sinead; Thomas, Sara; Smeeth, Liam; Douglas, Ian J

2017-11-01

Recent in vitro and animal studies have found the proton pump inhibitor (PPI) lansoprazole to be highly active against Mycobacterium tuberculosis. Omeprazole and pantoprazole have no activity. There is no evidence that, in clinical practice, lansoprazole can treat or prevent incident tuberculosis (TB) disease. We studied a cohort of new users of lansoprazole, omeprazole, or pantoprazole from the United Kingdom Clinical Practice Research Datalink to determine whether lansoprazole users have a lower incidence of TB disease than omeprazole or pantoprazole users. Negative control outcomes of myocardial infarction (MI) and herpes zoster were also studied. Multivariable Cox proportional hazards regression was used to adjust for potential confounding by a wide range of factors. We identified 527,364 lansoprazole initiators and 923,500 omeprazole or pantoprazole initiators. Lansoprazole users had a lower rate of TB disease (n = 86; 10.0 cases per 100,000 person years; 95% confidence interval 8.1-12.4) than omeprazole or pantoprazole users (n = 193; 15.3 cases per 100,000 person years; 95% confidence interval 13.3-17.7), with an adjusted hazard ratio (HR) of 0.68 (0.52-0.89). No association was found with MI (adjusted HR 1.04; 95% confidence interval 1.00-1.08) or herpes zoster (adjusted HR 1.03; 95% confidence interval 1.00-1.06). Limitations of this study are that we could not determine whether TB disease was due to reactivation of latent infection or a result of recent transmission, nor could we determine whether lansoprazole would have a beneficial effect if given to people presenting with TB disease. In this study, use of the commonly prescribed and cheaply available PPI lansoprazole was associated with reduced incidence of TB disease. Given the serious problem of drug resistance and the adverse side effect profiles of many TB drugs, further investigation of lansoprazole as a potential antituberculosis agent is warranted.

On Position Sensorless Control for Permanent Magnet Synchronous Motor Based on a New Sliding Mode Observer

Directory of Open Access Journals (Sweden)

Qixin Zhu

2014-10-01

Full Text Available For the problems of buffeting and phase delay in traditional rotor detection in sensorless vector control of permanent magnet synchronous motor (PMSM, the Sigmoid function is proposed to replace sign function and the approach of piecewise linearization is proposed to compensate phase delay. To the problem that the output of traditional low pass filter contains high- order harmonic, two-stage filter including traditional low-pass filter and Kalman filter is proposed in this paper. Based on the output of traditional first-order low-pass filter, the Kalman filter is used to get modified back-EMF. The phase-locked loop control of rotor position is adopted to estimate motor position and speed. A Matlab/Simulink simulation model of PMSM position servo control system is established. The simulation analysis of the new sliding mode observer’s back-EMF detection, position and speed estimation, load disturbance and dynamic process are carried out respectively. Simulation results verify feasibility of the new sliding mode observer algorithm.

Assessment of Motor Control during Three-Dimensional Movements Tracking with Position-Varying Gravity Compensation

Directory of Open Access Journals (Sweden)

Yao Huang

2017-05-01

Full Text Available Active movements are important in the rehabilitation training for patients with neurological motor disorders, while weight of upper limb impedes movements due to muscles weakness. The objective of this study is to develop a position-varying gravity compensation strategy for a cable-based rehabilitation robot. The control strategy can estimate real-time gravity torque according to position feedback. Then, the performance of this control strategy was compared with the other two kinds of gravity compensation strategies (i.e., without compensation and with fixed compensation during movements tracking. Seven healthy subjects were invited to conduct tracking tasks along four different directions (i.e., upward, forward, leftward, and rightward. The performance of movements with different compensation strategies was compared in terms of root mean square error (RMSE between target and actual moving trajectories, normalized jerk score (NJS, mean velocity ratio (MVR of main motion direction, and the activation of six muscles. The results showed that there were significant effects in control strategies in all four directions with the RMSE and NJS values in the following order: without compensation > fixed compensation > position-varying compensation and MVR values in the following order: without compensation < fixed compensation < position-varying compensation (p < 0.05. Comparing with movements without compensation in all four directions, the activation of muscles during movements with position-varying compensation showed significant reductions, except the activations of triceps and in forward and leftward movements, the activations of upper trapezius and middle parts of deltoid in upward movements and the activations of posterior parts of deltoid in all four directions (p < 0.05. Therefore, with position-varying gravity compensation, the upper limb cable-based rehabilitation robotic system might assist subjects to perform movements with higher quality and

Controlled positioning of nanoparticles on graphene by noninvasive AFM lithography.

Science.gov (United States)

Bellido, Elena; Ojea-Jiménez, Isaac; Ghirri, Alberto; Alvino, Christian; Candini, Andrea; Puntes, Victor; Affronte, Marco; Domingo, Neus; Ruiz-Molina, Daniel

2012-08-21

Atomic force microscopy is shown to be an excellent lithographic technique to directly deposit nanoparticles on graphene by capillary transport without any previous functionalization of neither the nanoparticles nor the graphene surface while preserving its integrity and conductivity properties. Moreover this technique allows for (sub)micrometric control on the positioning thanks to a new three-step protocol that has been designed with this aim. With this methodology the exact target coordinates are registered by scanning the tip over the predetermined area previous to its coating with the ink and deposition. As a proof-of-concept, this strategy has successfully allowed the controlled deposition of few nanoparticles on 1 μm(2) preselected sites of a graphene surface with high accuracy.

Beam position monitor multiplexer controller upgrade at the LAMPF proton storage ring

International Nuclear Information System (INIS)

Scarborough, W.K.; Cohen, S.

1992-01-01

The beam position monitor (BPM) is one of the primary diagnostic tools used for the tuning of the proton storage ring (PSR) at the Clinton P. Anderson Meson Physics Facility (LAMPF). A replacement for the existing, monolithic, wire-wrapped microprocessor-based BPM multiplexer controller has been built. The controller has been redesigned as a modular system retaining the same functionality of the original system built in 1981. Individual printed circuit cards are used for each controller function to insure greater maintainability and ease of keeping a spare parts inventory. Programmable logic device technology has substantially reduced the component count of the new controller. Diagnostic software was written to support the development of the upgraded controller. The new software actually uncovered some flaws in the original CAMAC interface. (author)

Visual control improves the accuracy of hand positioning in Huntington’s disease

Directory of Open Access Journals (Sweden)

Emilia J. Sitek

2017-08-01

Full Text Available Background: The study aimed at demonstrating dependence of visual feedback during hand and finger positioning task performance among Huntington’s disease patients in comparison to patients with Parkinson’s disease and cervical dystonia. Material and methods: Eighty-nine patients participated in the study (23 with Huntington’s disease, 25 with Parkinson’s disease with dyskinesias, 21 with Parkinson’s disease without dyskinesias, and 20 with cervical dystonia, scoring ≥20 points on Mini-Mental State Examination in order to assure comprehension of task instructions. Neurological examination comprised of the motor section from the Unified Huntington’s Disease Rating Scale for Huntington’s disease, the Unified Parkinson’s Disease Rating Scale Part II–IV for Parkinson’s disease and the Toronto Western Spasmodic Torticollis Rating Scale for cervical dystonia. In order to compare hand position accuracy under visually controlled and blindfolded conditions, the patient imitated each of the 10 examiner’s hand postures twice, once under the visual control condition and once with no visual feedback provided. Results: Huntington’s disease patients imitated examiner’s hand positions less accurately under blindfolded condition in comparison to Parkinson’s disease without dyskinesias and cervical dystonia participants. Under visually controlled condition there were no significant inter-group differences. Conclusions: Huntington’s disease patients exhibit higher dependence on visual feedback while performing motor tasks than Parkinson’s disease and cervical dystonia patients. Possible improvement of movement precision in Huntington’s disease with the use of visual cues could be potentially useful in the patients’ rehabilitation.

78 FR 51078 - Reporting Requirements for Positive Train Control Expenses and Investments

Science.gov (United States)

2013-08-20

...] Reporting Requirements for Positive Train Control Expenses and Investments AGENCY: Surface Transportation... investments and expenses. PTC is an automated system designed to prevent train-to-train collisions and other..., PTC expenditures are incorporated into the R-1 under the category of ``capital investments and...

PIMS (Positioning In Macular hole Surgery) trial - a multicentre interventional comparative randomised controlled clinical trial comparing face-down positioning, with an inactive face-forward position on the outcome of surgery for large macular holes: study protocol for a randomised controlled trial.

Science.gov (United States)

Pasu, Saruban; Bunce, Catey; Hooper, Richard; Thomson, Ann; Bainbridge, James

2015-11-17

Idiopathic macular holes are an important cause of blindness. They have an annual incidence of 8 per 100,000 individuals, and prevalence of 0.2 to 3.3 per 1000 individuals with visual impairment. The condition occurs more frequently in adults aged 75 years or older. Macular holes can be repaired by surgery in which the causative tractional forces in the eye are released and a temporary bubble of gas is injected. To promote successful hole closure individuals may be advised to maintain a face-down position for up to 10 days following surgery. The aim of this study is to determine whether advice to position face-down improves the surgical success rate of closure of large (>400 μm) macular holes, and thereby reduces the need for further surgery. This will be a multicentre interventional, comparative randomised controlled clinical trial comparing face-down positioning with face-forward positioning. At the conclusion of standardised surgery across all sites, participants still eligible for inclusion will be allocated randomly 1:1 to 1 of the 2 treatment arms stratified by site, using random permuted blocks of size 4 or 6 in equal proportions. We will recruit 192 participants having surgery for large macular holes (>400 μm); 96 in each of the 2 arms of the study. The primary objective is to determine the impact of face-down positioning on the likelihood of closure of large (≥400 μm) full-thickness macular holes following surgery. This will be the first multicentre randomised control trial to investigate the value of face-down positioning following macular hole standardised surgery. UK CRN: 17966 (date of registration 26 November 2014).

The Efficacy of Saccharomyces boulardii CNCM I-745 in Addition to Standard Helicobacter pylori Eradication Treatment in Children.

Science.gov (United States)

Bin, Zhang; Ya-Zheng, Xu; Zhao-Hui, Deng; Bo, Chu; Li-Rong, Jiang; Vandenplas, Yvan

2015-03-01

This study aims to investigate Saccharomyces boulardii CNCM I-745 during Helicobacter pylori eradication in children. One hundred ninety-four H. pylori positive children were randomized in two groups. Therapy (omeprazole+clarithromycin+amoxicillin or omeprazole+clarithromycin+metronidazole in case of penicillin allergy) was given to both groups during two weeks. In the treatment group (n: 102) S. boulardii was added to the triple therapy, while the control group (n: 92) only received triple therapy. The incidence, onset, duration and severity of diarrhea and compliance to the eradication treatment were compared. A (13)C urea breath test was done 4 weeks after the end of eradication therapy in two groups of 21 patients aged 12 years and older to test the H. pylori eradication rate. In the treatment group, diarrhea occurred in 12 cases (11.76%), starting after 6.25±1.24 days, lasting 3.17±1.08 days, and compliance to eradication treatment was 100%. In the control group, diarrhea occurred in 26 cases (28.26%), starting after 4.05±1.11 days, lasting 4.02±0.87 days, and in six cases eradication treatment was stopped prematurely (p<0.05). The (13)C urea breath test showed successful H. pylori eradication in 71.4% of the patients in the treatment and in 61.9 % in the control group (not significant). S. boulardii has a beneficial effect on the prevention and treatment of diarrhea during H. pylori eradication in children. Although S. boulardii did only slightly increase H. pylori eradication rate, compliance to eradication treatment was improved.

A 3D Printed Linear Pneumatic Actuator for Position, Force and Impedance Control

Directory of Open Access Journals (Sweden)

Jeremy Krause

2018-05-01

Full Text Available Although 3D printing has the potential to provide greater customization and to reduce the costs of creating actuators for industrial applications, the 3D printing of actuators is still a relatively new concept. We have developed a pneumatic actuator with 3D-printed parts and placed sensors for position and force control. So far, 3D printing has been used to create pneumatic actuators of the bellows type, thus having a limited travel distance, utilizing low pressures for actuation and being capable of only limited force production and response rates. In contrast, our actuator is linear with a large travel distance and operating at a relatively higher pressure, thus providing great forces and response rates, and this the main novelty of the work. We demonstrate solutions to key challenges that arise during the design and fabrication of 3D-printed linear actuators. These include: (1 the strategic use of metallic parts in high stress areas (i.e., the piston rod; (2 post-processing of the inner surface of the cylinder for smooth finish; (3 piston head design and seal placement for strong and leak-proof action; and (4 sensor choice and placement for position and force control. A permanent magnet placed in the piston head is detected using Hall effect sensors placed along the length of the cylinder to measure the position, and pressure sensors placed at the supply ports were used for force measurement. We demonstrate the actuator performing position, force and impedance control. Our work has the potential to open new avenues for creating less expensive, customizable and capable actuators for industrial and other applications.

Determination of curve 1/M profile as a function of control rod bank position

International Nuclear Information System (INIS)

Pereira, Valmir; Martinez, Aquilino Senra; Silva, Fernando Carvalho da

2002-01-01

Determination of the subcritical multiplication curve profile (1/M) as a function of control rod bank position is of paramount importance to the development of a system which allows to foresee and also anticipate determination of criticality of a PWR reactor core. This work aims at determining this profile. For that, the 3D- two group-diffusion equations for a subcritical PWR reactor core with external neutron source is solved for different control rod bank positions. Results obtained are compared with the results from the corresponding eigenvalue problem, in order to verify how the external neutron source interferes with the reactor criticality search. (author)

Quantum dots for future nanophotonic devices : lateral ordering, position, and number control

NARCIS (Netherlands)

Nötzel, R.

2010-01-01

After the general aspects of InAs/InP (100) quantum dots (QDs) regarding the formation of QDs versus quantum dashes, wavelength tuning from telecom to mid-infrared region, and device applications, we discuss our recent progress on the lateral ordering, position, and number control of QDs.

Prone positioning in hypoxemic respiratory failure: meta-analysis of randomized controlled trials.

Science.gov (United States)

Kopterides, Petros; Siempos, Ilias I; Armaganidis, Apostolos

2009-03-01

Prone positioning is used to improve oxygenation in patients with hypoxemic respiratory failure (HRF). However, its role in clinical practice is not yet clearly defined. The aim of this meta-analysis was to assess the effect of prone positioning on relevant clinical outcomes, such as intensive care unit (ICU) and hospital mortality, days of mechanical ventilation, length of stay, incidence of ventilator-associated pneumonia (VAP) and pneumothorax, and associated complications. We used literature search of MEDLINE, Current Contents, and Cochrane Central Register of Controlled Trials. We focused only on randomized controlled trials reporting clinical outcomes in adult patients with HRF. Four trials met our inclusion criteria, including 662 patients randomized to prone ventilation and 609 patients to supine ventilation. The pooled odds ratio (OR) for the ICU mortality in the intention-to-treat analysis was 0.97 (95% confidence interval [CI], 0.77-1.22), for the comparison between prone and supine ventilated patients. Interestingly, the pooled OR for the ICU mortality in the selected group of the more severely ill patients favored prone positioning (OR, 0.34; 95% CI, 0.18-0.66). The duration of mechanical ventilation and the incidence of pneumothorax were not different between the 2 groups. The incidence of VAP was lower but not statistically significant in patients treated with prone positioning (OR, 0.81; 95% CI, 0.61-1.10). However, prone positioning was associated with a higher risk of pressure sores (OR, 1.49; 95% CI, 1.17-1.89) and a trend for more complications related to the endotracheal tube (OR, 1.30; 95% CI, 0.94-1.80). Despite the inherent limitations of the meta-analytic approach, it seems that prone positioning has no discernible effect on mortality in patients with HRF. It may decrease the incidence of VAP at the expense of more pressure sores and complications related to the endotracheal tube. However, a subgroup of the most severely ill patients may

Control of plasma poloidal shape and position in the DIII-D tokamak

International Nuclear Information System (INIS)

Walker, M.L.; Humphreys, D.A.; Ferron, J.R.

1997-11-01

Historically, tokamak control design has been a combination of theory driving an initial control design and empirical tuning of controllers to achieve satisfactory performance. This approach was in line with the focus of past experiments on simply obtaining sufficient control to study many of the basic physics issues of plasma behavior. However, in recent years existing experimental devices have required increasingly accurate control. New tokamaks such as ITER or the eventual fusion power plant must achieve and confine burning fusion plasmas, placing unprecedented demands on regulation of plasma shape and position, heat flux, and burn characteristics. Control designs for such tokamaks must also function well during initial device operation with minimal empirical optimization required. All of these design requirements imply a heavy reliance on plasma modeling and simulation. Thus, plasma control design has begun to use increasingly modern and sophisticated control design methods. This paper describes some of the history of plasma control for the DIII-D tokamak as well as the recent effort to implement modern controllers. This effort improves the control so that one may obtain better physics experiments and simultaneously develop the technology for designing controllers for next-generation tokamaks

Railway cognitive radio to enhance safety, security, and performance of positive train control.

Science.gov (United States)

2013-02-01

Robust and interoperable wireless communications are vital to Positive Train Control (PTC). The railway industry has started adopting software-defined radios (SDRs) for packet-data transmission. SDR systems realize previously fixed components as reco...

Approximation-Based Discrete-Time Adaptive Position Tracking Control for Interior Permanent Magnet Synchronous Motors.

Science.gov (United States)

Yu, Jinpeng; Shi, Peng; Yu, Haisheng; Chen, Bing; Lin, Chong

2015-07-01

This paper considers the problem of discrete-time adaptive position tracking control for a interior permanent magnet synchronous motor (IPMSM) based on fuzzy-approximation. Fuzzy logic systems are used to approximate the nonlinearities of the discrete-time IPMSM drive system which is derived by direct discretization using Euler method, and a discrete-time fuzzy position tracking controller is designed via backstepping approach. In contrast to existing results, the advantage of the scheme is that the number of the adjustable parameters is reduced to two only and the problem of coupling nonlinearity can be overcome. It is shown that the proposed discrete-time fuzzy controller can guarantee the tracking error converges to a small neighborhood of the origin and all the signals are bounded. Simulation results illustrate the effectiveness and the potentials of the theoretic results obtained.

Longitudinal investigation on learned helplessness tested under negative and positive reinforcement involving stimulus control.

Science.gov (United States)

Oliveira, Emileane C; Hunziker, Maria Helena

2014-07-01

In this study, we investigated whether (a) animals demonstrating the learned helplessness effect during an escape contingency also show learning deficits under positive reinforcement contingencies involving stimulus control and (b) the exposure to positive reinforcement contingencies eliminates the learned helplessness effect under an escape contingency. Rats were initially exposed to controllable (C), uncontrollable (U) or no (N) shocks. After 24h, they were exposed to 60 escapable shocks delivered in a shuttlebox. In the following phase, we selected from each group the four subjects that presented the most typical group pattern: no escape learning (learned helplessness effect) in Group U and escape learning in Groups C and N. All subjects were then exposed to two phases, the (1) positive reinforcement for lever pressing under a multiple FR/Extinction schedule and (2) a re-test under negative reinforcement (escape). A fourth group (n=4) was exposed only to the positive reinforcement sessions. All subjects showed discrimination learning under multiple schedule. In the escape re-test, the learned helplessness effect was maintained for three of the animals in Group U. These results suggest that the learned helplessness effect did not extend to discriminative behavior that is positively reinforced and that the learned helplessness effect did not revert for most subjects after exposure to positive reinforcement. We discuss some theoretical implications as related to learned helplessness as an effect restricted to aversive contingencies and to the absence of reversion after positive reinforcement. This article is part of a Special Issue entitled: insert SI title. Copyright © 2014. Published by Elsevier B.V.

Reciprocal associations between positive emotions and motivation in daily life: Network analyses in anhedonic individuals and healthy controls.

Science.gov (United States)

van Roekel, Eeske; Heininga, Vera E; Vrijen, Charlotte; Snippe, Evelien; Oldehinkel, Albertine J

2018-04-19

Anhedonia reflects a dysfunction in the reward system, which can be manifested in an inability to enjoy pleasurable situations (i.e., lack of positive emotions), but also by a lack of motivation to engage in pleasurable activities (i.e., lack of motivation). Little is known about the interrelations between positive emotions and motivation in daily life, and whether these associations are altered in anhedonic individuals. In the present study, we used a network approach to explore the reciprocal, lagged associations between positive emotions and motivation in anhedonic individuals (N = 66) and controls (N = 68). Participants (aged between 18 and 24 years) filled out momentary assessments of affect 3 times per day for 30 consecutive days. Our results showed that (a) anhedonic individuals and controls had similar moment-to-moment transfer of positive emotions; (b) in the anhedonic network feeling cheerful was the node with the highest outstrength, both within this group and compared with the control group; (c) feeling relaxed had the highest outstrength in the control network, and (d) anhedonic individuals had stronger pathways from positive emotions to motivation than controls. Taken together, our findings suggest that low levels of positive emotions lead to decreased motivation in the anhedonic group, which could instigate a negative spiral of low pleasure and low motivation. On a more positive note, we showed that cheerfulness had the highest outstrength in the network of anhedonic participants. Hence, interventions may focus on increasing cheerfulness in anhedonic individuals, as this will likely have the greatest impact on other positive emotions and motivations. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Position control of an electro-pneumatic system based on PWM technique and FLC.

Science.gov (United States)

Najjari, Behrouz; Barakati, S Masoud; Mohammadi, Ali; Futohi, Muhammad J; Bostanian, Muhammad

2014-03-01

In this paper, modeling and PWM based control of an electro-pneumatic system, including the four 2-2 valves and a double acting cylinder are studied. Dynamic nonlinear behavior of the system, containing fast switching solenoid valves and a pneumatic cylinder, as well as electrical, magnetic, mechanical, and fluid subsystems are modeled. A DC-DC power converter is employed to improve solenoid valve performance and suppress system delay. Among different position control methods, a proportional integrator derivative (PID) controller and fuzzy logic controller (FLC) are evaluated. An experimental setup, using an AVR microcontroller is implemented. Simulation and experimental results verify the effectiveness of the proposed control strategies. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

Fault Tolerant Position-mooring Control for Offshore Vessels

DEFF Research Database (Denmark)

Blanke, Mogens; Nguyen, Trong Dong

2018-01-01

Fault-tolerance is crucial to maintain safety in offshore operations. The objective of this paper is to show how systematic analysis and design of fault-tolerance is conducted for a complex automation system, exemplified by thruster assisted Position-mooring. Using redundancy as required....... Functional faults that are only detectable, are rendered isolable through an active isolation approach. Once functional faults are isolated, they are handled by fault accommodation techniques to meet overall control objectives specified by class requirements. The paper illustrates the generic methodology...... by a system to handle faults in mooring lines, sensors or thrusters. Simulations and model basin experiments are carried out to validate the concept for scenarios with single or multiple faults. The results demonstrate that enhanced availability and safety are obtainable with this design approach. While...

Global stabilisation of large-scale hydraulic networks with quantised and positive proportional controls

DEFF Research Database (Denmark)

Jensen, Tom Nørgaard; Wisniewski, Rafal

2013-01-01

a set of decentralised, logarithmic quantised and constrained control actions with properly designed quantisation parameters. That is, an attractor set with a compact basin of attraction exists. Subsequently, the basin can be increased by increasing the control gains. In our work, this result...... is extended by showing that an attractor set with a global basin of attraction exists for arbitrary values of positive control gains, given that the upper level of the quantiser is properly designed. Furthermore, the proof is given for general monotone quantisation maps. Since the basin of attraction...

A satellite digital controller or 'play that PID tune again, Sam'. [Position, Integral, Derivative feedback control algorithm for design strategy

Science.gov (United States)

Seltzer, S. M.

1976-01-01

The problem discussed is to design a digital controller for a typical satellite. The controlled plant is considered to be a rigid body acting in a plane. The controller is assumed to be a digital computer which, when combined with the proposed control algorithm, can be represented as a sampled-data system. The objective is to present a design strategy and technique for selecting numerical values for the control gains (assuming position, integral, and derivative feedback) and the sample rate. The technique is based on the parameter plane method and requires that the system be amenable to z-transform analysis.

Positioning performance of a maglev fine positioning system

Energy Technology Data Exchange (ETDEWEB)

Wronosky, J.B.; Smith, T.G.; Jordan, J.D.; Darnold, J.R.

1996-12-01

A wafer positioning system was recently developed by Sandia National Laboratories for an Extreme Ultraviolet Lithography (EUVL) research tool. The system, which utilizes a magnetically levitated fine stage to provide ultra-precise positioning in all six degrees of freedom, incorporates technological improvements resulting from four years of prototype development experience. System enhancements, implemented on a second generation design for an ARPA National Center for Advanced Information Component Manufacturing (NCAICM) project, introduced active structural control for the levitated structure of the system. Magnetic levitation (maglev) is emerging as an important technology for wafer positioning systems in advanced lithography applications. The advantages of maglev stem from the absence of physical contact. The resulting lack of friction enables accurate, fast positioning. Maglev systems are mechanically simple, accomplishing full six degree-of-freedom suspension and control with a minimum of moving parts. Power-efficient designs, which reduce the possibility of thermal distortion of the platen, are achievable. Manufacturing throughput will be improved in future systems with the addition of active structural control of the positioning stages. This paper describes the design, implementation, and functional capability of the maglev fine positioning system. Specifics regarding performance design goals and test results are presented.

Zigbee networking technology and its application in Lamost optical fiber positioning and control system

Science.gov (United States)

Jin, Yi; Zhai, Chao; Gu, Yonggang; Zhou, Zengxiang; Gai, Xiaofeng

2010-07-01

4,000 fiber positioning units need to be positioned precisely in LAMOST(Large Sky Area Multi-object Optical Spectroscopic Telescope) optical fiber positioning & control system, and every fiber positioning unit needs two stepper motors for its driven, so 8,000 stepper motors need to be controlled in the entire system. Wireless communication mode is adopted to save the installing space on the back of the focal panel, and can save more than 95% external wires compared to the traditional cable control mode. This paper studies how to use the ZigBee technology to group these 8000 nodes, explores the pros and cons of star network and tree network in order to search the stars quickly and efficiently. ZigBee technology is a short distance, low-complexity, low power, low data rate, low-cost two-way wireless communication technology based on the IEEE 802.15.4 protocol. It based on standard Open Systems Interconnection (OSI): The 802.15.4 standard specifies the lower protocol layers-the physical layer (PHY), and the media access control (MAC). ZigBee Alliance defined on this basis, the rest layers such as the network layer and application layer, and is responsible for high-level applications, testing and marketing. The network layer used here, based on ad hoc network protocols, includes the following functions: construction and maintenance of the topological structure, nomenclature and associated businesses which involves addressing, routing and security and a self-organizing-self-maintenance functions which will minimize consumer spending and maintenance costs. In this paper, freescale's 802.15.4 protocol was used to configure the network layer. A star network and a tree network topology is realized, which can build network, maintenance network and create a routing function automatically. A concise tree network address allocate algorithm is present to assign the network ID automatically.

Robust H∞ Control of Neutral System with Time-Delay for Dynamic Positioning Ships

Directory of Open Access Journals (Sweden)

Dawei Zhao

2015-01-01

Full Text Available Due to the input time-delay existing in most thrust systems of the ships, the robust H∞ controller is designed for the ship dynamic positioning (DP system with time-delay. The input delay system is turned to a neutral time-delay system by a state-derivative control law. The less conservative result is derived for the neutral system with state-derivative feedback by the delay-decomposition approach and linear matrix inequality (LMI. Finally, the numerical simulations demonstrate the asymptotic stability and robustness of the controller and verify that the designed DP controller is effective in the varying environment disturbances of wind, waves, and ocean currents.

Neural network control of focal position during time-lapse microscopy of cells.

Science.gov (United States)

Wei, Ling; Roberts, Elijah

2018-05-09

Live-cell microscopy is quickly becoming an indispensable technique for studying the dynamics of cellular processes. Maintaining the specimen in focus during image acquisition is crucial for high-throughput applications, especially for long experiments or when a large sample is being continuously scanned. Automated focus control methods are often expensive, imperfect, or ill-adapted to a specific application and are a bottleneck for widespread adoption of high-throughput, live-cell imaging. Here, we demonstrate a neural network approach for automatically maintaining focus during bright-field microscopy. Z-stacks of yeast cells growing in a microfluidic device were collected and used to train a convolutional neural network to classify images according to their z-position. We studied the effect on prediction accuracy of the various hyperparameters of the neural network, including downsampling, batch size, and z-bin resolution. The network was able to predict the z-position of an image with ±1 μm accuracy, outperforming human annotators. Finally, we used our neural network to control microscope focus in real-time during a 24 hour growth experiment. The method robustly maintained the correct focal position compensating for 40 μm of focal drift and was insensitive to changes in the field of view. About ~100 annotated z-stacks were required to train the network making our method quite practical for custom autofocus applications.

A Positive Control for Detection of Functional CD4 T Cells in PBMC: The CPI Pool.

Science.gov (United States)

Schiller, Annemarie; Zhang, Ting; Li, Ruliang; Duechting, Andrea; Sundararaman, Srividya; Przybyla, Anna; Kuerten, Stefanie; Lehmann, Paul V

2017-12-07

Testing of peripheral blood mononuclear cells (PBMC) for immune monitoring purposes requires verification of their functionality. This is of particular concern when the PBMC have been shipped or stored for prolonged periods of time. While the CEF (Cytomegalo-, Epstein-Barr and Flu-virus) peptide pool has become the gold standard for testing CD8 cell functionality, a positive control for CD4 cells is so far lacking. The latter ideally consists of proteins so as to control for the functionality of the antigen processing and presentation compartments, as well. Aiming to generate a positive control for CD4 cells, we first selected 12 protein antigens from infectious/environmental organisms that are ubiquitous: Varicella, Influenza, Parainfluenza, Mumps, Cytomegalovirus, Streptococcus , Mycoplasma , Lactobacillus , Neisseria , Candida , Rubella, and Measles. Of these antigens, three were found to elicited interferon (IFN)-γ-producing CD4 cells in the majority of human test subjects: inactivated cytomegalo-, parainfluenza-, and influenza virions (CPI). While individually none of these three antigens triggered a recall response in all donors, the pool of the three (the 'CPI pool'), did. One hundred percent of 245 human donors tested were found to be CPI positive, including Caucasians, Asians, and African-Americans. Therefore, the CPI pool appears to be suitable to serve as universal positive control for verifying the functionality of CD4 and of antigen presenting cells.

Tobacco control and the World Trade Organization: mapping member states' positions after the framework convention on tobacco control.

Science.gov (United States)

Eckhardt, Jappe; Holden, Chris; Callard, Cynthia D

2016-11-01

To note the frequency of discussions and disputes about tobacco control measures at the World Trade Organization (WTO) before and after the coming into force of the Framework Convention on Tobacco Control (FCTC). To review trends or patterns in the positions taken by members of the WTO with respect to tobacco control measures. To discuss possible explanations for these observed trends/patterns. We gathered data on tobacco-related disputes in the WTO since its establishment in 1995 and its forerunner, the General Agreement on Tariffs and Trade (GATT), prior-FCTC and post-FCTC. We also looked at debates on tobacco control measures within the WTO more broadly. To this end, we classified and coded the positions of WTO member states during discussions on tobacco control and the FCTC, from 1995 until 2013, within the Technical Barriers to Trade (TBT) Committee and the Trade-Related Aspects of Intellectual Property Rights (TRIPS) Council. There is a growing interest within the WTO for tobacco-related issues and opposition to tobacco control measures is moving away from high-income countries towards low(er) income countries. The growing prominence of tobacco issues in the WTO can be attributed at least in part to the fact that during the past decade tobacco firms have been marginalised from the domestic policy-making process in many countries, which has forced them to look for other ways and forums to influence decision-making. Furthermore, the finding that almost all recent opposition within the WTO to stronger tobacco regulations came from developing countries is consistent with a relative shift of transnational tobacco companies' lobbying efforts from developed to developing countries. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Testing links between childhood positive peer relations and externalizing outcomes through a randomized controlled intervention study.

Science.gov (United States)

Witvliet, Miranda; van Lier, Pol A C; Cuijpers, Pim; Koot, Hans M

2009-10-01

In this study, the authors used a randomized controlled trial to explore the link between having positive peer relations and externalizing outcomes in 758 children followed from kindergarten to the end of 2nd grade. Children were randomly assigned to the Good Behavior Game (GBG), a universal classroom-based preventive intervention, or a control condition. Children's acceptance by peers, their number of mutual friends, and their proximity to others were assessed annually through peer ratings. Externalizing behavior was annually rated by teachers. Reductions in children's externalizing behavior and improvements in positive peer relations were found among GBG children, as compared with control-group children. Reductions in externalizing behavior appeared to be partly mediated by the improvements in peer acceptance. This mediating role of peer acceptance was found for boys only. The results suggest that positive peer relations are not just markers, but they are environmental mediators of boys' externalizing behavior development. Implications for research and prevention are discussed. (c) 2009 APA, all rights reserved.

The Marketing & Positive Impacts of Behavioral Control System on Societies & Countries

OpenAIRE

Ahmad Adel Mostafa; Ahmed Mohamed Tawfik

2015-01-01

Behavioral control systems are one of the most prominent tools used by managers and marketers for different internal and external purposes. One of the most important external purposes they have been used for is influencing consumer behavior. This paper explores the positive effects of implementing such systems on societies. It discusses consumer perception of the systems, their influence on their financial behavior in different contexts, how can they create order and how as well ...

An Angular Method with Position Control for Block Mesh Squareness Improvement

Energy Technology Data Exchange (ETDEWEB)

Yao, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Stillman, D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2017-09-19

We optimize a target function de ned by angular properties with a position control term for a basic stencil with a block-structured mesh, to improve element squareness in 2D and 3D. Comparison with the condition number method shows that besides a similar mesh quality regarding orthogonality can be achieved as the former does, the new method converges faster and provides a more uniform global mesh spacing in our numerical tests.

Control of Pan-tilt Mechanism Angle using Position Matrix Method

Directory of Open Access Journals (Sweden)

Hendri Maja Saputra

2013-12-01

Full Text Available Control of a Pan-Tilt Mechanism (PTM angle for the bomb disposal robot Morolipi-V2 using inertial sensor measurement unit, x-IMU, has been done. The PTM has to be able to be actively controlled both manually and automatically in order to correct the orientation of the moving Morolipi-V2 platform. The x-IMU detects the platform orientation and sends the result in order to automatically control the PTM. The orientation is calculated using the quaternion combined with Madwick and Mahony filter methods. The orientation data that consists of angles of roll (α, pitch (β, and yaw (γ from the x-IMU are then being sent to the camera for controlling the PTM motion (pan & tilt angles after calculating the reverse angle using position matrix method. Experiment results using Madwick and Mahony methods show that the x-IMU can be used to find the robot platform orientation. Acceleration data from accelerometer and flux from magnetometer produce noise with standard deviation of 0.015 g and 0.006 G, respectively. Maximum absolute errors caused by Madgwick and Mahony method with respect to Xaxis are 48.45º and 33.91º, respectively. The x-IMU implementation as inertia sensor to control the Pan-Tilt Mechanism shows a good result, which the probability of pan angle tends to be the same with yaw and tilt angle equal to the pitch angle, except a very small angle shift due to the influence of roll angle..

Cognitive reappraisal and secondary control coping: associations with working memory, positive and negative affect, and symptoms of anxiety/depression.

Science.gov (United States)

Andreotti, Charissa; Thigpen, Jennifer E; Dunn, Madeleine J; Watson, Kelly; Potts, Jennifer; Reising, Michelle M; Robinson, Kristen E; Rodriguez, Erin M; Roubinov, Danielle; Luecken, Linda; Compas, Bruce E

2013-01-01

The current study examined the relations of measures of cognitive reappraisal and secondary control coping with working memory abilities, positive and negative affect, and symptoms of anxiety and depression in young adults (N=124). Results indicate significant relations between working memory abilities and reports of secondary control coping and between reports of secondary control coping and cognitive reappraisal. Associations were also found between measures of secondary control coping and cognitive reappraisal and positive and negative affect and symptoms of depression and anxiety. Further, the findings suggest that reports of cognitive reappraisal may be more strongly predictive of positive affect whereas secondary control coping may be more strongly predictive of negative affect and symptoms of depression and anxiety. Overall, the results suggest that current measures of secondary control coping and cognitive reappraisal capture related but distinct constructs and suggest that the assessment of working memory may be more strongly related to secondary control coping in predicting individual differences in distress.

A Toroidally Symmetric Plasma Simulation code for design of position and shape control on tokamak plasmas

International Nuclear Information System (INIS)

Takase, Haruhiko; Senda, Ikuo

1999-01-01

A Toroidally Symmetric Plasma Simulation (TSPS) code has been developed for investigating the position and shape control on tokamak plasmas. The analyses of three-dimensional eddy currents on the conducting components around the plasma and the two-dimensional magneto-hydrodynamic (MHD) equilibrium are taken into account in this code. The code can analyze the plasma position and shape control during the minor disruption in which the deformation of plasma is not negligible. Using the ITER (International Thermonuclear Experimental Reactor) parameters, some examples of calculations are shown in this paper. (author)

Global asymptotic stabilization of large-scale hydraulic networks using positive proportional controls

DEFF Research Database (Denmark)

Jensen, Tom Nørgaard; Wisniewski, Rafal

2014-01-01

An industrial case study involving a large-scale hydraulic network underlying a district heating system subject to structural changes is considered. The problem of controlling the pressure drop across the so-called end-user valves in the network to a designated vector of reference values under...... directional actuator constraints is addressed. The proposed solution consists of a set of decentralized positively constrained proportional control actions. The results show that the closed-loop system always has a globally asymptotically stable equilibrium point independently on the number of end......-users. Furthermore, by a proper design of controller gains the closed-loop equilibrium point can be designed to belong to an arbitrarily small neighborhood of the desired equilibrium point. Since there exists a globally asymptotically stable equilibrium point independently on the number of end-users in the system...

Position Control of Servo Systems Using Feed-Forward Friction Compensation

International Nuclear Information System (INIS)

Park, Min Gyu; Kim, Han Me; Shin, Jong Min; Kim, Jong Shik

2009-01-01

Friction is an important factor for precise position tracking control of servo systems. Servo systems with highly nonlinear friction are sensitive to the variation of operating condition. To overcome this problem, we use the LuGre friction model which can consider dynamic characteristics of friction. The LuGre friction model is used as a feed-forward compensator to improve tracking performance of servo systems. The parameters of the LuGre friction model are identified through experiments. The experimental result shows that the tracking performance of servo systems with higherly nonlinear friction can be improved by using feed-forward friction compensation

The data on health locus of control and its relationship with quality of life in HIV-positive patients