Zuverlässigkeit digitaler Schaltungen unter Einfluss von intrinsischem Rauschen

NASA Astrophysics Data System (ADS)

Kleeberger, V. B.; Schlichtmann, U.

2011-08-01

Die kontinuierlich fortschreitende Miniaturisierung in integrierten Schaltungen führt zu einem Anstieg des intrinsischen Rauschens. Um den Einfluss von intrinsischem Rauschen auf die Zuverlässigkeit zukünftiger digitaler Schaltungen analysieren zu können, werden Methoden benötigt, die auf CAD-Verfahren wie Analogsimulation statt auf abschätzenden Berechnungen beruhen. Dieser Beitrag stellt eine neue Methode vor, die den Einfluss von intrinsischem Rauschen in digitalen Schaltungen für eine gegebene Prozesstechnologie analysieren kann. Die Amplituden von thermischen, 1/f und Schrotrauschen werden mit Hilfe eines SPICE Simulators bestimmt. Anschließend wird der Einfluss des Rauschens auf die Schaltungszuverlässigkeit durch Simulation analysiert. Zusätzlich zur Analyse werden Möglichkeiten aufgezeigt, wie die durch Rauschen hervorgerufenen Effekte im Schaltungsentwurf mit berücksichtigt werden können. Im Gegensatz zum Stand der Technik kann die vorgestellte Methode auf beliebige Logikimplementierungen und Prozesstechnologien angewendet werden. Zusätzlich wird gezeigt, dass bisherige Ansätze den Einfluss von Rauschen bis um das Vierfache überschätzen.

Multi Electrode Geoelectric on the Borehole Wall. Determination of Groundwater Velocity and Dispersion Parameters

NASA Astrophysics Data System (ADS)

Kessels, W.; Thorenz, C.; Rifai, H.

2002-05-01

A single well technique to determine groundwater flow and transport parameters is presented. Multi-electrode arrays are placed on a borehole wall by an inflatable packer or are installed behind the plastic casing. For measurements, a salt tracer is injected between the electrodes. This salt tracer cloud is afterwards moving in the natural groundwater flow field. The observation of this movement by geoelectric measurements is the basis for the determination of groundwater velocity and the dispersion parameters. The geoelectric observations are performed with n borehole electrodes and one earth connection. Thus, either n independent two point measurements or n*(n-1)/2 pole-to-pole measurements can be performed. The whole procedure consists of three phases: 1. Measurement of the basic conductivity without tracer. 2. Measurement during the injection. 3. Measurement after injection To test the method, measurements in a lab aquifer filled with sand are carried out. The results are discussed and the limitations of the method are shown. Here, the interpretation is restricted on two point geoelectric measurements and the transport equation for NaCl-tracered water. Due to the density contrast, the tracer shows a vertical movement which is not related to the natural velocity field. Numerical calculations with the finite-element-method simulator ROCKFLOW (Kolditz et al., 1999) reproduced this behaviour. The currently used interpretation code is based on an analytic solution of the transport equation. The parameters velocity and dispersion length are calculated by inversion. In the two scientific drillings CAT-LUD1 and CAT-LUD1A in the northern part of Germany multi-electrode installations behind the casing are tested in situ. A multi-electrode packer system is designed and build. References: Kessels, W., Zoth, G.(1997): Doppelmantel - Packers mit geoelektrischer Meßtechnik zur Bestimmung der Abstandsgeschwindigkeit des Grundwassers, Patentanmeldung Az:19855048.0 NLf

One-step endosonography-guided drainage of a pancreatic pseudocyst: a new technique of stent delivery through the echo endoscope.

PubMed

Vilmann, P; Hancke, S; Pless, T; Schell-Hincke, J D; Henriksen, F W

1998-10-01

We report here the first case of a one-step endosonography(EUS)-guided pseudocyst drainage. A prototype large channel curved array echo endoscope (Pentax FG-38 UX) and a prototype delivery system for placement of an endoprosthesis was used for the procedure. The delivery system (GIP MedicinTechnik GmbH/Medi-Globe Corporation) consists of a handle part with a piston, a metal ring sheath, a plastic catheter with a diathermy needle and a double pigtail endoprosthesis (8.5 Fr). When mounted on the endoscope the endoprosthesis can be advanced out of the distal end of the endoscope. The introduction of the stent as well as the stent release can be monitored entirely by ultrasound. The procedure was tested in a 76-year-old woman with a pseudocyst measuring 60 mm in diameter located in the tail of the pancreas. The procedure was well tolerated by the patient, and there were no procedural complications. The advantage of a large channel echo endoscope and our new prototype delivery system is that the endoprosthesis can be inserted in to a pancreatic cyst guided exclusively by EUS without exchange of endoscopes, catheters or guide wires. Further studies are warranted.

Benefits and challenges in practice-oriented psychotherapy research in Germany: the TK and the QS-PSY-BAY projects of quality assurance in outpatient psychotherapy.

PubMed

Strauss, Bernhard Michael; Lutz, Wolfgang; Steffanowski, Andres; Wittmann, Werner W; Boehnke, Jan R; Rubel, Julian; Scheidt, Carl E; Caspar, Franz; Vogel, Heiner; Altmann, Uwe; Steyer, Rolf; Zimmermann, Anna; Bruckmayer, Ellen; von Heymann, Friedrich; Kramer, Dietmar; Kirchmann, Helmut

2015-01-01

Two patient-focused long-term research projects performed in the German outpatient psychotherapy system are focused on in this article. The TK (Techniker Krankenkasse) project is the first study to evaluate a quality assurance and feedback system with regard to its practical feasibility in German routine care. The other study ("Quality Assurance in Outpatient Psychotherapy in Bavaria"; QS-PSY-BAY) was designed to test a new approach for quality assurance in outpatient psychotherapy using electronic documentation of patient characteristics and outcome parameters. In addition this project provides the opportunity to analyze data on health-related costs for the patients undergoing outpatient psychotherapy. Both projects and their results indicating high effect sizes are briefly described. From the perspectives of the research teams, advisory boards and other stakeholders, the experiences with these projects are discussed focusing on obstacles, challenges, difficulties, and benefits in developing and implementing the studies. The triangle collaboration of therapists, researchers, and health insurance companies/health service institutions turned out to be fruitful in both studies. Despite some controversies between the partners the experiences indicate the importance of practiced-research collaborations to provide relevant information about the delivery of outpatient psychotherapy in the health system.

[EEG-adjusted target-controlled infusion : Propofol target concentration with different doses of remifentanil].

PubMed

Büttner, N; Schultz, B; Grouven, U; Schultz, A

2010-02-01

The aim of this study was to examine to what extent the use of electroencephalography (EEG) monitoring leads to an adaptation of the target-controlled infusion (TCI) concentration of propofol during propofol anaesthesia with different doses of remifentanil. With ethics committee approval 60 patients (27-69 years old) with American Society of Anesthesiologists classification (ASA) I-III received anaesthestics with propofol (TCI, Diprifusor, AstraZeneca, Wedel, Deutschland) and 0.2, 0.4, or 0.6 microg/kg body weight remifentanil, respectively (groups 1-3). Anaesthesia was maintained at a level of deep hypnosis (EEG stages D(2)/E(0), EEG monitor: Narcotrend, version 2.0/5.0, manufacturer: MT MonitorTechnik, Bad Bramstedt, Germany). During the steady state the propofol concentration in groups 1-3 was 3.02+/-0.86, 1.93+/-0.53 and 1.60+/-0.55 microg/ml, respectively (p<0.001). Women had a higher propofol consumption than men (p<0.05). Dreams during anaesthesia were more often reported by women than by men (p<0.05). The need for postoperative analgesia decreased with an increasing intraoperative remifentanil dose (p<0.05). The study demonstrates that remifentanil has both analgetic and hypnotic effects. With increasing remifentanil dose the propofol requirement decreased and in this context EEG monitoring is useful to adapt the target concentrations of propofol to the patients' age and gender.

'Know before you go': information-seeking behaviour of German patients receiving health services abroad in light of the provisions of Directive 2011/24/EU.

PubMed

Panteli, Dimitra; Wagner, Caroline; Verheyen, Frank; Busse, Reinhard

2015-07-01

While Directive 2011/24/EU on cross-border patient mobility makes specific provisions in relation to information availability and accessibility, little empirical evidence exists to guide best practice. This paper explores the information-seeking behaviour of German patients who received planned care abroad. A postal survey among German patients treated in other European countries was carried out by Techniker Krankenkasse, a major German sickness fund. The influence of certain predictors on whether patients informed themselves before travelling for care was investigated using multiple logistic regression. Types and sources of information were analysed using descriptive statistics. Information activity was contingent on patients' level of education, type of service, regularity of treatment abroad and awareness of entitlement to cross-border services. Respondents most frequently enquired about elements of reimbursement, entitlement to services and cost-saving, and consulted their sickness fund for information. Differences in both content and medium of choice were observed between patient groups. A structured and inclusive approach to information provision should be adopted. National Contact Points should collaborate with a range of stakeholders, who will vary depending on the health care system; however, patient organizations, health professionals and third-party payers should always be represented. Dynamically monitoring cross-border movements can help determine the range, medium and language of relevant information. © The Author(s) 2015.

Compact propane fuel processor for auxiliary power unit application

NASA Astrophysics Data System (ADS)

Dokupil, M.; Spitta, C.; Mathiak, J.; Beckhaus, P.; Heinzel, A.

With focus on mobile applications a fuel cell auxiliary power unit (APU) using liquefied petroleum gas (LPG) is currently being developed at the Centre for Fuel Cell Technology (Zentrum für BrennstoffzellenTechnik, ZBT gGmbH). The system is consisting of an integrated compact and lightweight fuel processor and a low temperature PEM fuel cell for an electric power output of 300 W. This article is presenting the current status of development of the fuel processor which is designed for a nominal hydrogen output of 1 k Wth,H2 within a load range from 50 to 120%. A modular setup was chosen defining a reformer/burner module and a CO-purification module. Based on the performance specifications, thermodynamic simulations, benchmarking and selection of catalysts the modules have been developed and characterised simultaneously and then assembled to the complete fuel processor. Automated operation results in a cold startup time of about 25 min for nominal load and carbon monoxide output concentrations below 50 ppm for steady state and dynamic operation. Also fast transient response of the fuel processor at load changes with low fluctuations of the reformate gas composition have been achieved. Beside the development of the main reactors the transfer of the fuel processor to an autonomous system is of major concern. Hence, concepts for packaging have been developed resulting in a volume of 7 l and a weight of 3 kg. Further a selection of peripheral components has been tested and evaluated regarding to the substitution of the laboratory equipment.

Eine selbstkonsistente Carleman Linearisierung zur Analyse von Oszillatoren

NASA Astrophysics Data System (ADS)

Weber, Harry; Mathis, Wolfgang

2017-09-01

Die Analyse nichtlinearer dynamischer Schaltungen ist bis heute eine herausfordernde Aufgabe, da nur selten analytische Lösungen angegeben werden können. Daher wurden eine Vielzahl von Methoden entwickelt, um eine qualitative oder quantitative Näherung für die Lösungen der Netzwerkgleichung zu erhalten. Oftmals wird beispielsweise eine Kleinsignalanalyse mit Hilfe einer Taylorreihe in einem Arbeitspunkt durchgeführt, die nach den Gliedern erster Ordnung abgebrochen wird. Allerdings ist diese Linearisierung nur in der Nähe des stabilen Arbeitspunktes für hyperbolische Systeme gültig. Besonders für die Analyse des dynamischen Verhaltens von Oszillatoren treten jedoch nicht-hyperbolische Systeme auf, sodass diese Methode nicht angewendet werden kann Mathis (2000). Carleman hat gezeigt, dass nichtlineare Differentialgleichungen mit polynomiellen Nichtlinearitäten in ein unendliches System von linearen Differentialgleichungen transformiert werden können Carleman (1932). Wird das unendlichdimensionale Gleichungssystem für numerische Zwecke abgebrochen, kann bei Oszillatoren der Übergang in eine stationäre Schwingung (Grenzzyklus) nicht wiedergegeben werden. In diesem Beitrag wird eine selbstkonsistente Carleman Linearisierung zur Untersuchung von Oszillatoren vorgestellt, die auch dann anwendbar ist, wenn die Nichtlinearitäten keinen Polynomen entsprechen. Anstelle einer linearen Näherung um einen Arbeitspunkt, erfolgt mit Hilfe der Carleman Linearisierung eine Approximation auf einem vorgegebenen Gebiet. Da es jedoch mit der selbstkonsistenten Technik nicht möglich ist, das stationäre Verhalten von Oszillatoren zu beschreiben, wird die Berechnung einer Poincaré-Abbildung durchgeführt. Mit dieser ist eine anschließende Analyse des Oszillators möglich.

Neue Laser und Strahlquellen - alte und neue Risiken?

PubMed

Paasch, Uwe; Schwandt, Antje; Seeber, Nikolaus; Kautz, Gerd; Grunewald, Sonja; Haedersdal, Merete

2017-05-01

Die Entwicklungen im Bereich dermatologischer Laser, hochenergetischer Blitzlampen, LED und neuer Energie- und Strahlquellen der letzten Jahre haben gezeigt, dass mit neuen Wellenlängen, Konzepten und Kombinationen zusätzliche, zum Teil über den ästhetischen Bereich hinaus gehende therapeutische Optionen für den Dermatologen erschlossen werden konnten. Wurden bisher zum Beispiel mit fraktionalen Lasern Falten behandelt, sind eben diese Systeme heute in Kombination mit Medikamenten wichtige Werkzeuge bei der Behandlung von Narben, bei Feldkanzerisierung und epithelialen Tumoren. Die Anforderungen an den die Indikation stellenden und vorzugsweise therapierenden Arzt steigen mit der immer komplexer werdenden Technik und den zunehmenden Komorbiditäten und Komedikationen einer älter werdenden Patientenklientel. Parallel etabliert wurden, zunächst für einige wenige Indikationen, Geräte für die Heimanwendung, die sich durch geringe Leistung und spezielle Sicherheitsvorkehrungen zur Vermeidung von Unfällen, Risiken und Nebenwirkungen auszeichnen. Trotz der reduzierten Effizienz solcher Selbstbehandlungsmaßnahmen steigt die Wahrscheinlichkeit einer Fehlanwendung, da die Grundvoraussetzung für eine korrekte Therapie, nämlich die exakte Diagnose und Indikationsstellung, nicht vorausgesetzt werden kann. Bei einer Haarentfernung können so Pigmenttumoren, bei einer Faltentherapie neoplastische Hautveränderungen adressiert und zu erwartende, unvorhergesehene und neue Nebenwirkungen und Komplikationen induziert werden. In diesem Szenario ist es wichtig, alle potenziellen Anwender dieser neuen Technologien vor deren Einsatz so zu qualifizieren, dass den Therapierten maximale Therapiesicherheit bei höchster Effizienz unter dem Leitbild diagnosis certa - ullae therapiae fundamentum garantiert wird. © 2017 Deutsche Dermatologische Gesellschaft (DDG). Published by John Wiley & Sons Ltd.

[Disease management programs in Germany: Validity of the medical documentation].

PubMed

Linder, R; Horenkamp-Sonntag, D; Engel, S; Köppel, D; Heilmann, T; Verheyen, F

2014-01-01

The specific documentation for disease management programs (DMP) in Germany with respect to § 137 Social Code Book V is the basis for evaluating the DMP. DMP run up costs of the order of a billion euro without assessing evidence-based benefit so far. Aim of this study was to question if and to which extent this documentation may be suitable for reliable quality assurance in its present form. Data of nearly 300000 insured persons of a German Statutory Health Insurance (Techniker Krankenkasse, TK) which were continuously registered from July 1st 2009 until December 31st 2010 in a DMP were analyzed. We analyzed how items which were components of claims data and of DMP documentation were matched. With regard to prescriptions there were some considerable differences. Prescription of glibenclamid was documented twice as frequently in the DMP documentation compared to prescriptions filled in pharmacies. Only a fraction of emergency hospitalizations documented in the claims data were found in the DMP documentation. Investigations of the fundus oculi for diabetics are mentioned three times more frequently in the DMP documentation than they are accounted by ophthalmologists. There are considerable differences between claims data and DMP specific documentation. The latter shows a plainly reduced validity for investigated fields in the documentation forms. Reasons for this are manifold. Former evaluations of DM Ps carried out just on the basis of DMP documentation are thus highly questionable. Therefore, the DMPs themselves and their documentation have to be reformed. © Georg Thieme Verlag KG Stuttgart · New York.

Informed consumer or unlucky visitor? A profile of German patients who received dental services abroad.

PubMed

Panteli, Dimitra; Augustin, Uta; Röttger, Julia; Struckmann, Verena; Verheyen, Frank; Wagner, Caroline; Busse, Reinhard

2015-10-01

A common characteristic of sending countries in cross-border dental care is that of high costs and/or high copayments for dental services. This study aims to provide an insight into the characteristics of German patients receiving planned and emergency (unplanned) dental care abroad and their satisfaction with received services. The Europabefragung is a postal survey carried out by Techniker Krankenkasse for patients who are treated in EU/EEA countries. This study uses data from the Europabefragung 2012. The survey was sent to 45 189 individuals; descriptive statistics for the subset of respondents who received emergency (unplanned) or planned dental treatment are presented. There were 18 339 responses to the questionnaire, out of which 17 543 were deemed valid; 1416 respondents had received emergency (unplanned) (78%) or planned (22%) dental care and were included in the analysis. There were clear differences between unplanned and planned treatments regarding country and type of treatment as well as satisfaction with different aspects of treatment and the need for follow-up care. Overall, satisfaction with treatment was high for both groups; individuals who had received planned treatment were more satisfied on all aspects of care and reported a need for follow-up care less frequently. While German patients who received both emergency (unplanned) and planned services abroad are mostly satisfied with their experience, some concerns arise with regard to continuity of care. Types of information provided to patients seeking care abroad and dissemination modalities should be carefully planned. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

[Part-time Work and Men's Health : Results based on Routine Data of a Statutory Health Insurance Scheme].

PubMed

Grobe, Thomas G

2016-08-01

With the introduction of a new occupational classification at the end of 2011, employment characteristics are reported by employees to social insurance agencies in Germany in more detail than in previous years. In addition to other changes, the new classification allows a distinction between full- and part-time work to be made. This provided a reason to consider the health-related aspects of part-time work on the basis of data from a statutory health insurance scheme. Our analysis is based on the data of 3.8 million employees insured with the Techniker Krankenkasse (TK), a statutory health insurance scheme, in 2012. In addition to daily information on employment situations, details of periods and diagnoses of sick leave and the drugs prescribed were available. Although approximately 50 % of women of middle to higher working age worked part-time in 2012, the corresponding percentage of men employed in part-time work was less than 10 %. Overall, part-time employees were on sick leave for fewer days than full-time employees, but among men, sick leave due to mental disorders was longer for part-time employees than for full-time employees, whereas women working part time were affected to a lesser extent by corresponding periods of absence than those working full time. The results provide indications for the assertion that men in gender-specifically atypical employment situations are more frequently affected by mental disorders. Further evidence supports this assertion. With the long-term availability of these new employment characteristics, longitudinal analyses could help to clarify this cause-effect relationship.

Pacing strategies during the swim, cycle and run disciplines of sprint, Olympic and half-Ironman triathlons.

PubMed

Wu, Sam Shi Xuan; Peiffer, Jeremiah J; Brisswalter, Jeanick; Nosaka, Kazunori; Lau, Wing Yin; Abbiss, Chris R

2015-05-01

This study investigated the influence of distance on self-selected pacing during the swim, cycle and run disciplines of sprint, Olympic and half-Ironman (HIM) distance triathlon races. Eight trained male triathletes performed the three individual races in <2 months. Participants' bikes were fitted with Schoberer Rad Meßtechnik to monitor speed, power output and heart rate during the cycle discipline. Global positioning system was worn to determine speed and heart rate during the swim and run disciplines. An even swim pacing strategy was adopted across all distances. A more stochastic pacing was observed during the HIM cycle [standard deviation of exposure variation analysis (EVASD) = 3.21 ± 0.61] when compared with the sprint cycle discipline (EVASD = 3.84 ± 0.44, p = 0.018). Only 20.9 ± 4.1 % of the cycling time was spent more than 10 % above the mean power output in the HIM, compared with 43.8 ± 2.9 % (p = 0.002) and 37.7 ± 11.1 % (p = 0.039) during the sprint and Olympic distance triathlons, respectively. Conversely, 13.6 ± 5.1 % of the cycling time was spent 5-10 % below the mean power output during the HIM, compared with 5.9 ± 1.2 % (p = 0.034) and 8.0 ± 5.1 % (p = 0.045) during the sprint and Olympic distance triathlons, respectively. A negative pacing strategy was adopted during the sprint distance run, compared with positive pacing strategy during the Olympic and HIM. Results of this study suggest that pacing strategies during triathlon are highly influenced by distance and discipline, and highlight the importance of developing pacing strategies based on distance, strengths and individual fitness.

Addison's disease with polyglandular autoimmunity carries a more than 2·5-fold risk for adrenal crises: German Health insurance data 2010-2013.

PubMed

Meyer, Gesine; Badenhoop, Klaus; Linder, Roland

2016-09-01

Adrenal crises are potentially life-threatening complications in patients with adrenal insufficiency (AI). Our objective was to investigate the frequency of adrenal crises in different forms of AI. The Statutory Health Insurance (SHI) database of the Techniker Krankenkasse - covering more than 12% of the German population - was analysed for diagnostic codes from 1 January 2010 to 31 December 2013. By analysis of routine data from a large healthcare provider. Diagnoses of AI were recorded and classified in primary AI, secondary AI and autoimmune polyglandular syndrome (APS). The ICD-code E27·2 (AC) was retrieved in all cohorts. We found a prevalence of 222/million for secondary and 126/million for primary AI. AC was documented with a frequency of 4·8/100 patient years. Crises were significantly more frequent in patients with primary (7·6/100 patient years) compared to those with secondary AI (3·2/100 patient years; P < 0·0001). Prevalence of crises was higher in individuals with APS (10·9/100 patient years) and highest in patients with primary AI and type 1 diabetes (12·5/100 patient years). Applying a SHI database comprising more than 9 million individuals, we identified robust data about the risk of AC in different groups of patients with AI. Our data confirm and extend the clinical observation that patients with APS are at highest risk for AC. Approximately 1 of 8 patients with primary AI and type 1 diabetes suffers from an AC each year. Specific targeting of efforts aiming at the prevention of AC is necessary. © 2016 John Wiley & Sons Ltd.

Continuity of care in the cross-border context: insights from a survey of German patients treated abroad.

PubMed

Panteli, Dimitra; Wagner, Caroline; Verheyen, Frank; Busse, Reinhard

2015-08-01

Continuity of care is important for outcomes and patient satisfaction and includes additional considerations in the context of cross-border health care. Although this has been discussed in research and was picked up in the recently transposed Directive on patients' rights (2011/24/EU), there is limited evidence about related issues actually encountered by patients crossing borders. An anonymous postal survey was carried out by the Techniker Krankenkasse, one of the largest sickness funds in Germany. The questionnaire was sent to 45 189 individuals who had received treatment in EU/EEA countries and included items on relational, management and informational continuity. The survey had a response rate of 41% (n = 17 543). Of those respondents who had travelled for care (n = 3307), ∼19% (n = 570) did so due to a relationship of trust with a given provider. Only 8% of all respondents required emergency follow-up services due to complications, the majority of which was obtained back in Germany. Twelve percentage of those who were prescribed medication abroad (n = 4208) reported problems, spanning unknown products, dispensation and reimbursement. Information exchange between providers across borders was rare and largely carried out by the patients themselves. Although relational continuity may be important to specific groups of patients travelling for care, it is primarily informational continuity and its interrelation with management continuity that need to be addressed in the cross-border context. Information exchange should be endorsed at European level. Additional focus is required on informing patients about documentation rights and requirements and providing health records that are comprehensive and comprehensible. © The Author 2015. Published by Oxford University Press on behalf of the European Public Health Association. All rights reserved.

Socioeconomic factors and effect of evidence-based patient information about primary prevention of type 2 diabetes mellitus--are there interactions?

PubMed

Genz, Jutta; Haastert, Burkhard; Müller, Hardy; Verheyen, Frank; Cole, Dennis; Rathmann, Wolfgang; Nowotny, Bettina; Roden, Michael; Giani, Guido; Ohmann, Christian; Icks, Andrea

2014-08-18

Having shown in a recent randomized controlled trial that evidence-based patient information (EBPI) significantly increased knowledge on primary prevention of diabetes compared to standard patient information, we now investigated interaction between socioeconomic status (SES) and the effect of an EBPI. 1,120 visitors (aged 40-70 years, without known diabetes) to the "Techniker Krankenkasse" and the "German Diabetes Center" websites were randomized. The intervention group received a newly developed on-line EBPI, the control group standard on-line information. The primary outcome measure was knowledge, classified as "good/average/poor". We analyzed associations of knowledge with socioeconomic variables (education, vocational training, employment, subjective social status) combined with intervention effect including interactions, adjusted for possible confounding by knowledge before intervention, self-reported blood glucose measurements, blood pressure, blood lipid levels, age and gender. Logistic regression models were fitted to the subpopulation (n = 647) with complete values in these variables.Education (high vs. low) was significantly associated with knowledge (good vs. average/poor); however, there was no significant interaction between education and intervention. After adjustment, the other socioeconomic variables were not significantly associated with knowledge. Socioeconomic variables did not significantly change the effect of the intervention. There was a tendency towards a lower effect where lower educated individuals were concerned. Possibly the power was too low to detect interaction effects. Larger studies using SES-specific designs are needed to clarify the effect of SES. We suggest considering the socioeconomic status when evaluating a decision aid, e.g. an EBPI, to ensure its effectiveness not only in higher socioeconomic groups. Current Controlled Trials ISRCTN22060616 (Date assigned: 12 September 2008).

Performance of the 13C-urea breath test for the diagnosis of H. pylori infection using a substrate synthesized in Brazil: A preliminary study.

PubMed

Coelho, Luiz Gonzaga; Sant'Ana, Carlos Roberto; Oliveira, Ricardo Brandt de; Cezar, Raíra César E; Araujo, Aline Cordeiro Campos de; Silva, Raisa Cristina Teodoro da; Trindade, Osmar Reni; Coelho, Maria Clara; Ferrioli, Eduardo; Bendassolli, José Albertino

2018-06-07

The 13C-urea breath test is the main non-invasive test for the diagnosis of Helicobacter pylori infection. The availability of this test throughout the country is limited, mainly due to the difficulty in obtaining the labeled isotope from abroad. Recently, researchers from the Nuclear Energy Center in Agriculture at the University of São Paulo (CENA/USP) succeeded in synthesizing 13C-enriched urea for Helicobacter pylori diagnosis. The aim of the study was to compare the performance of the 13C-urea breath test using 13C-urea acquired abroad with that of a test using 13C-urea synthesized in Brazil. Sixty-four dyspeptic patients participated in the study (24 men and 40 women). Initially, the patients performed the 13C-urea breath test using the imported substrate (Euriso-Top, France). Seven to fourteen days later, all the patients repeated the test using the Brazilian substrate. The samples from both examinations were processed in an infrared isotope analyzer (IRIS, Wagner Analisen Technik, Germany), and all delta over baseline (DOB) [%] values above four were considered positive results. Twenty-seven patients (42%) exhibited negative results for Helicobacter pylori infection, and thirty-seven patients (58%) exhibited positive results when tested using the foreign substrate (gold standard). There was a 100% concordance regarding the presence or absence of infection when the gold standard results were compared with those obtained using the Brazilian substrate. Similar performance in the diagnosis of Helicobacter pylori infection was demonstrated when using the 13C-urea breath test with the Brazilian 13C-urea substrate and the test with the substrate produced abroad. This validation represents an important step toward increasing the availability of the 13C-urea breath test throughout the country, which will have a positive influence on the management of Helicobacter pylori infection.

[Challenges of an integrative and personalised health care for health economics and the insurance system].

PubMed

Schoch, Goentje-Gesine; Würdemann, E

2014-11-01

"Stratifying medicine" is a topic of increasing importance in the public health system. There are several questions related to "stratifying medicine". This paper reconsiders definitions, opportunities and risks related to "stratifying medicine" as well as the main challenges of "stratifying medicine" from the perspective of a public health insurance. The application of the term and the definition are important points to discuss. Terms such as "stratified medicine", "personalised medicine" or "individualised medicine" are used. The Techniker Krankenkasse prefers "stratifying medicine", because it usually means a medicine that tailors therapy to specific groups of patients by biomarkers. OPPORTUNITIES AND RISKS: "Stratifying medicine" is associated with various hopes, e. g., the avoidance of ineffective therapies and early detection of diseases. But "stratifying medicine" also carries risks, such as an increase in the number of cases by treatment of disease risks, a duty for health and the weakening of the criteria of evidence-based medicine. The complexity of "stratifying medicine" is a big challenge for all involved parties in the health system. A lot of interrelations are still not completely understood. So the statutory health insurance faces the challenge of making innovative therapy concepts accessible in a timely manner to all insured on the one hand but on the other hand also to protect the community from harmful therapies. Information and advice to patients related to "stratifying medicine" is of particular importance. The equitable distribution of fees for diagnosis and counselling presents a particular challenge. The solidarity principle of public health insurance may be challenged by social and ethical issues of "stratifying medicine". "Stratifying medicine" offers great potential to improve medical care. However, false hopes must be avoided. Providers and payers should measure chances and risks of "stratifying medicine" together for the welfare of the

Literature Research on the Mechanical Properties of Fibre Composise Materials Analysis of the State of the Art. Volume I. (Schrifttumsrecherche zum Festigkeitsverhalten von Faserverbundwerkstoffen-Analyse des Standes der Technik-),

DTIC Science & Technology

1980-08-11

cross - Bruttoquerschni tt section Zahl der Flugstunden = number of flight hours Fig 2.8 Fatigue strength of ...Relationship between residual strength, strain increase and development of damage as a function of the number of cycles (Ref 732) 118 / 0 /+45 / 90 /- CFK ... cross -section) only the nett cross -section. Number of 900 where intralaminar cracks ha! increased further. cracks had occurred 4. Delaminations

a Precise, Low-Cost Rtk Gnss System for Uav Applications

NASA Astrophysics Data System (ADS)

Stempfhuber, W.; Buchholz, M.

2011-09-01

High accuracy with real-time positioning of moving objects has been considered a standard task of engineering geodesy for 10 to 15 years. An absolute positioning accuracy of 1-3 cm is generally possible worldwide and is further used in many areas of machine guidance (machine control and guidance), and farming (precision farming) as well as for various special applications (e.g. railway trolley, mining, etc.). The cost of the measuring instruments required for the use of geodetic L1/L2 receivers with a local reference station amounts to approximately USD 30,000 to 50,000. Therefore, dual frequency RTK GNSS receivers are not used in the mass market. Affordable GPS/GNSS modules have already reached the mass market in various areas such as mobile phones, car navigation, the leisure industry, etc. Kinematic real-time positioning applications with centimetre or decimetre levels could also evolve into a mass product. In order for this to happen, the costs for such systems must lie between USD 1,000 to 2,000. What exactly low-cost means is determined by the precise specifications of the given individual application. Several university studies in geodesy focus on the approach of high-accuracy positioning by means of single frequency receivers for static applications [e.g. GLABSCH et. al. 2009, SCHWIEGER and GLÄSER 2005, ALKAN 2010, REALINI et. al. 2010, KORTH and HOFMANN 2011]. Although intelligent approaches have been developed that compute a trajectory in the post-processing mode [REALINI et. al., 2010], at present, there are only a very few GNSS Low-Cost Systems that enable real-time processing. This approach to precise position determination by means of the computation of static raw data with single frequency receivers is currently being explored in a research project at the Beuth Hochschule für Technik Berlin - and is being further developed for kinematic applications. The project is embedded in the European Social Fund. It is a follow-up project in the area of

Thermodynamic Processes Involving Liquefied Natural Gas at the LNG Receiving Terminals / Procesy termodynamiczne z wykorzystaniem skroplonego gazu ziemnego w terminalach odbiorczych LNG

NASA Astrophysics Data System (ADS)

Łaciak, Mariusz

2013-06-01

The increase in demand for natural gas in the world, cause that the production of liquefied natural gas (LNG) and in consequences its regasification becoming more common process related to its transportation. Liquefied gas is transported in the tanks at a temperature of about 111K at atmospheric pressure. The process required to convert LNG from a liquid to a gas phase for further pipeline transport, allows the use of exergy of LNG to various applications, including for electricity generation. Exergy analysis is a well known technique for analyzing irreversible losses in a separate process. It allows to specify the distribution, the source and size of the irreversible losses in energy systems, and thus provide guidelines for energy efficiency. Because both the LNG regasification and liquefaction of natural gas are energy intensive, exergy analysis process is essential for designing highly efficient cryogenic installations. Wzrost zapotrzebowania na gaz ziemny na świecie powoduje, że produkcja skroplonego gazu ziemnego (LNG), a w konsekwencji jego regazyfikacja, staje się coraz bardziej powszechnym procesem związanym z jego transportem. Skroplony gaz transportowany jest w zbiornikach w temperaturze około 111K pod ciśnieniem atmosferycznym. Przebieg procesu regazyfikacji niezbędny do zamiany LNG z fazy ciekłej w gazową dla dalszego transportu w sieci, umożliwia wykorzystanie egzergii LNG do różnych zastosowań, między innymi do produkcji energii elektrycznej. Analiza egzergii jest znaną techniką analizowania nieodwracalnych strat w wydzielonym procesie. Pozwala na określenie dystrybucji, źródła i wielkości nieodwracalnych strat w systemach energetycznych, a więc ustalić wytyczne dotyczące efektywnego zużycia energii. Ponieważ zarówno regazyfikacja LNG jak i skraplanie gazu ziemnego są energochłonne, proces analizy egzergii jest niezbędny do projektowania wysoce wydajnych instalacji kriogenicznych.

Clinical performance of removable dental prostheses in the moderately reduced dentition: a systematic literature review.

PubMed

Moldovan, Ovidiu; Rudolph, Heike; Luthardt, Ralph G

2016-09-01

Evidence-based therapeutic recommendations for removable dental prostheses are still lacking. The aim of the present study was a systematic review and meta-analysis of the survival rates of removable dentures in the moderately reduced dentition. In 2014, a systematic literature search in established medical databases (MEDLINE, EMBASE, BIOSIS, SciSearch, Cochrane, FIZ Technik Web) and a hand search of relevant dental journals were conducted. The search terms were relevant MeSH terms, free search terms, and combinations of the two. The search included RCTs, prospective and retrospective studies on survival rates of removable dental prostheses in the moderately reduced dentition with at least 15 participants, an observation period of at least 2 years, and a dropout rate of less than 25 %. The selection of relevant publications was carried out at the title, abstract, and full-text level by at least two of the authors involved. The publications included were tabulated and analyzed. Of the original 12,994 matches, 1923 were analyzed by title, 650 by abstract, and 111 according to the full text. The final review included 19 publications, of which 6 were multiple publications. Cast-metal framework dentures exhibited failure rates of between 33 and 50 % after 5 years. One study with a 25-year observation period reported failure rates of 50 %. Better results were obtained with proper pretreatment and a good recall scheme. Bilateral attachment prostheses showed failure rates of between 11 and 30 % after 5 years. Unilateral attachment prostheses showed failure rates of 75 % after 5 years. Double-crown prostheses dentures show failure rates of 0 to 21.7 % after 3 to 6 years. Heterogeneous study designs and data analyses rendered a meta-analysis impossible, so that an evaluation at the highest level of evidence could not be performed. Within the limitations of this study, it would be correct to state that removable dental prostheses, given suitable pretreatment and

Characterization of particle exposure in ferrochromium and stainless steel production.

PubMed

Järvelä, Merja; Huvinen, Markku; Viitanen, Anna-Kaisa; Kanerva, Tomi; Vanhala, Esa; Uitti, Jukka; Koivisto, Antti J; Junttila, Sakari; Luukkonen, Ritva; Tuomi, Timo

2016-07-01

This study describes workers' exposure to fine and ultrafine particles in the production chain of ferrochromium and stainless steel during sintering, ferrochromium smelting, stainless steel melting, and hot and cold rolling operations. Workers' personal exposure to inhalable dust was assessed using IOM sampler with a cellulose acetate filter (AAWP, diameter 25 mm; Millipore, Bedford, MA). Filter sampling methods were used to measure particle mass concentrations in fixed locations. Particle number concentrations and size distributions were examined using an SMPS+C sequential mobile particle sizer and counter (series 5.400, Grimm Aerosol Technik, Ainring, Germany), and a hand-held condensation particle counter (CPC, model 3007, TSI Incorporated, MN). The structure and elemental composition of particles were analyzed using TEM-EDXA (TEM: JEM-1220, JEOL, Tokyo, Japan; EDXA: Noran System Six, Thermo Fisher Scientific Inc., Madison,WI). Workers' personal exposure to inhalable dust averaged 1.87, 1.40, 2.34, 0.30, and 0.17 mg m(-3) in sintering plant, ferrochromium smelter, stainless steel melting shop, hot rolling mill, and the cold rolling mill, respectively. Particle number concentrations measured using SMPS+C varied from 58 × 10(3) to 662 × 10(3) cm(-3) in the production areas, whereas concentrations measured using SMPS+C and CPC3007 in control rooms ranged from 24 × 10(3) to 243 × 10(3) cm(-3) and 5.1 × 10(3) to 97 × 10(3) cm(-3), respectively. The elemental composition and the structure of particles in different production phases varied. In the cold-rolling mill non-process particles were abundant. In other sites, chromium and iron originating from ore and recycled steel scrap were the most common elements in the particles studied. Particle mass concentrations were at the same level as that reported earlier. However, particle number measurements showed a high amount of ultrafine particles, especially in sintering, alloy smelting and melting, and tapping

Determining the Optimum Cut-Off Grades in Sulfide Copper Deposits / Określanie Optymalnej Wartości Odcięcia Zawartości Procentowej Pierwiastka Użytecznego W Złożach Siarczku Miedzi

NASA Astrophysics Data System (ADS)

Rahimi, Esmaeil; Oraee, Kazem; Shafahi, Zia Aldin; Ghasemzadeh, Hasan

2015-03-01

Optimum cut-off grades determination in mining life affects production planning and ultimate pit limit and it is also important from social, economical and environmental aspects. Calculation of optimum cut-off grades has been less considered for mines containing various mineral processing methods. In this paper, an optimization technique is applied to obtain optimum cut-off grades for both concentration and heap leaching processes. In this technique, production costs and different recoveries of heap leaching method directed into modeling different annual cash flows in copper mines. Considering the governing constraints, the Lagrange multiplier method is practiced to optimize the cut-off grades in which the objective function is supposed to maximize Net Present Value. The results indicate the effect of heap leaching process on the optimum cut-off grades of primary and secondary sulfide deposits. Określanie optymalnego poziomu odcięcia dla zawartości procentowej pierwiastka użytecznego ma poważny wpływ na planowanie produkcji, określanie ostatecznych limitów zasobów złoża; jest to także ważna kwestia z punktu widzenia kwestii społecznych, ekonomicznych i środowiskowych. Obliczanie optymalnego poziomu odcięcia dla zawartości procentowej pierwiastka użytecznego nie było zwykle szeroko rozważane w przypadku kopalni prowadzących ciągły system przeróbki. W pracy tej przedstawiono technikę optymalizacji określania poziomu zawartości procentowej pierwiastka użytecznego z uwzględnieniem zarówno procesów koncentracji jak i ługowania. W metodzie uwzględniono koszty produkcji i różne wskaźniki odzysku rudy, wielkości te wykorzystane zostały do modelowania rocznych przepływów gotówki w kopalniach miedzi. Uwzględniając narzucone ograniczenia, zastosowano metodę mnożników Lagrange'a w celu optymalizacji określania poziomu zawartości procentowej pierwiastka użytecznego, gdzie przyjętą funkcją celu jest

A CNN based Hybrid approach towards automatic image registration

NASA Astrophysics Data System (ADS)

Arun, Pattathal V.; Katiyar, Sunil K.

2013-06-01

Image registration is a key component of various image processing operations which involve the analysis of different image data sets. Automatic image registration domains have witnessed the application of many intelligent methodologies over the past decade; however inability to properly model object shape as well as contextual information had limited the attainable accuracy. In this paper, we propose a framework for accurate feature shape modeling and adaptive resampling using advanced techniques such as Vector Machines, Cellular Neural Network (CNN), SIFT, coreset, and Cellular Automata. CNN has found to be effective in improving feature matching as well as resampling stages of registration and complexity of the approach has been considerably reduced using corset optimization The salient features of this work are cellular neural network approach based SIFT feature point optimisation, adaptive resampling and intelligent object modelling. Developed methodology has been compared with contemporary methods using different statistical measures. Investigations over various satellite images revealed that considerable success was achieved with the approach. System has dynamically used spectral and spatial information for representing contextual knowledge using CNN-prolog approach. Methodology also illustrated to be effective in providing intelligent interpretation and adaptive resampling. Rejestracja obrazu jest kluczowym składnikiem różnych operacji jego przetwarzania. W ostatnich latach do automatycznej rejestracji obrazu wykorzystuje się metody sztucznej inteligencji, których największą wadą, obniżającą dokładność uzyskanych wyników jest brak możliwości dobrego wymodelowania kształtu i informacji kontekstowych. W niniejszej pracy zaproponowano zasady dokładnego modelowania kształtu oraz adaptacyjnego resamplingu z wykorzystaniem zaawansowanych technik, takich jak Vector Machines (VM), komórkowa sieć neuronowa (CNN), przesiewanie (SIFT), Coreset i

Dispersion modeling of accidental releases of toxic gases - utility for the fire brigades.

NASA Astrophysics Data System (ADS)

Stenzel, S.; Baumann-Stanzer, K.

2009-09-01

Several air dispersion models are available for prediction and simulation of the hazard areas associated with accidental releases of toxic gases. The most model packages (commercial or free of charge) include a chemical database, an intuitive graphical user interface (GUI) and automated graphical output for effective presentation of results. The models are designed especially for analyzing different accidental toxic release scenarios ("worst-case scenarios”), preparing emergency response plans and optimal countermeasures as well as for real-time risk assessment and management. The research project RETOMOD (reference scenarios calculations for toxic gas releases - model systems and their utility for the fire brigade) was conducted by the Central Institute for Meteorology and Geodynamics (ZAMG) in cooperation with the Viennese fire brigade, OMV Refining & Marketing GmbH and Synex Ries & Greßlehner GmbH. RETOMOD was funded by the KIRAS safety research program of the Austrian Ministry of Transport, Innovation and Technology (www.kiras.at). The main tasks of this project were 1. Sensitivity study and optimization of the meteorological input for modeling of the hazard areas (human exposure) during the accidental toxic releases. 2. Comparison of several model packages (based on reference scenarios) in order to estimate the utility for the fire brigades. For the purpose of our study the following models were tested and compared: ALOHA (Areal Location of Hazardous atmosphere, EPA), MEMPLEX (Keudel av-Technik GmbH), Trace (Safer System), Breeze (Trinity Consulting), SAM (Engineering office Lohmeyer). A set of reference scenarios for Chlorine, Ammoniac, Butane and Petrol were proceed, with the models above, in order to predict and estimate the human exposure during the event. Furthermore, the application of the observation-based analysis and forecasting system INCA, developed in the Central Institute for Meteorology and Geodynamics (ZAMG) in case of toxic release was

Determination of Groundwater Velocity and Dispersion Parameters by Borehole Wall Multielectrode Geoelectrics

NASA Astrophysics Data System (ADS)

Kessels, W.; Wuttke, M. W.

2007-05-01

measurements and vertical four point electrode interpretations. The transport equation for NaCl-tracered water is the basic rule to determine the groundwater transport velocity. Numerical calculations to simulate the measurement are carried out with the program FEFLOW. Due to the density contrast, the tracer undergoes vertical movement. Kessels, W., Zoth, G.(1998): Doppelmantel - Packer mit geoelektrischer Meßtechnik zur Bestimmung der Abstandsgeschwindigkeit des Grundwassers, Patent Az:19855048.0, GGA-Institut, Germany, Hannover. KESSELS, W., RIFAI, H., THORENZ, C., ZOTH, G.(2002): Multi Electrode Geoelectric on the Borehole Wall- Determination of groundwater velocity and dispersion parameters, AGU spring meeting, Washington KESSELS, W., ZOTH, G., WONIK, T., FULDA, C. (1999): THE USE OF SALT CARTRIDGES FOR FLUID LOGGING. XXIV GENERAL ASSEMBLY OF E.G.S. THE HAGUE, THE NETHERLANDS PANTELEIT,B., KESSELS, W., BINOT, F (2006): MUD TRACER TEST DURING SOFT ROCK DRILLING; W.R.R., VOL. 42, W11415, DOI:10.1029/2005WR004487

The Application of Modern Techniques and Measurement Devices for Identification of Copper Ore Types and Their Properties / Wykorzystanie nowoczesnych technik i urządzeń pomiarowych do identyfikacji typów rud miedzi i ich właściwości

NASA Astrophysics Data System (ADS)

Krawczykowska, Aldona; Trybalski, Kazimierz; Krawczykowski, Damian

2013-06-01

The paper concerns the application of modern methods and research techniques for investigations of copper ore properties. It presents the procedure and tools which, when put together, can constitute a source of information on properties of different products of processing and, simultaneously, can be used in the process control and optimization. The copper ore of one of the branches of the KHGM Polska Miedz plc was investigated. The ore samples represented each of the three lithological types occurring in the Polish deposits, i.e. carbonate, shale and sandstone ores. The paper presents the results of microscopic analyses, image analysis of scanning photographs and application procedures of the obtained information for the identification of ore types (application of neuron networks to the recognition of lithological compositions). The present publication will present sample results of modelling of classification identifying two types of ores, i.e. carbonate-shale and sandstone. Summing up the predictions of ore type fractions in respective mixtures for the considered problem of classification it can be stated that the prediction results are good and confirm the lithological predominance of certain ore types in the investigated mixtures. The experimental part comprised the determination of mineralogical and lithological composition of ores (optical microscope) and also elemental composition in the microareas of analysed samples (scanning microscope). Next, the image analysis was performed and subsequently the models classifying the ore types were made. W rudzie miedzi przerabianej w zakładach wzbogacania O/ZWR KGHM Polska Miedź S.A. można wyróżnić trzy typy litologiczne: rudę węglanową, łupkową i piaskowcową. Typy te różnią się właściwościami między innymi takimi jak: rodzaj i zawartość minerałów miedzi, rodzaj minerałów nieużytecznych, zawartość miedzi, twardość i podatność na rozdrabnianie, ale także wielkością i kształtem ziaren minerałów miedzionośnych oraz rodzajem ich skupień i wpryśnięć. Niezwykle istotne jest właściwe rozpoznanie rudy pod względem petrograficzno-mineralogicznym. Znajomość właściwości przerabianej rudy pozwala na pełniejsze jej wykorzystanie poprzez właściwe prowadzenie i sterowanie procesami, dobór ich parametrów takich m.in. jak: czas mielenia, parametry klasyfikacji, rodzaj odczynników flotacyjnych, czas flotacji. W artykule przedstawiono wyniki przeprowadzonych analiz mikroskopowych, analizy obrazów zdjęć skaningowych oraz procedury wykorzystania otrzymanych informacji do identyfikacji typów rud (zastosowanie sieci neuronowych do rozpoznawania składów litologicznych). W badaniach wykorzystano rudę miedzi, pochodzącą z jednego z zakładów górniczych KGHM Polska Miedź S.A. Pobrane próbki rudy reprezentowały każdy z trzech typów litologicznych występujących w krajowych złożach: węglanową, łupkową oraz piaskowcową. Przeprowadzono ilościową analizę mineralogiczno-petrograficzną przy pomocy mikroskopu optycznego w świetle odbitym, a wyniki przedstawiono w tabelach 1 i 2. Wyniki te określają ilościowo stopień uwolnienia i zrosty dla jednego rodzaju minerału. Pokazano także przykładowe zdjęcia mikroskopowe zgładów poszczególnych typów litologicznych rud oraz próbek proszkowych tych typów (rys. 1 i 2). W kolejnym etapie badań wykorzystano skaningowy mikroskop elektronowy. Zdjęcia morfologii próbek uzyskane z mikroskopu elektronowego (obrazy SEM) były przedmiotem komputerowej analizy obrazu, umożliwiającej mikrostrukturalną klasyfikację ilościową typów rud. Analizowano wszystkie próbki poszczególnych typów litologicznych rudy miedzi: węglanowej, łupkowej i piaskowcowej oraz mieszanki tych typów w trzech klasach ziarnowych: 0÷45 μm, 45÷71 μm i 71÷100 μm. Celem przekształceń wykorzystanych w procedurze komputerowej analizy obrazu jest otrzymanie poprawnie posegmentowanego obrazu binarnego, który umożliwiałby wyróżnienie badanych obiektów - pojedynczych (poszczególnych) ziaren oraz tła, a następnie wykonanie pomiarów parametrów zbinaryzowanych obiektów. Spośród dużej ilości parametrów dostępnych w używanym oprogramowaniu do identyfikacji typów rud wybrano najważniejsze z punktu widzenia opisu ziaren. Obok parametrów opisujących podstawowe właściwości geometryczne tj. pole powierzchni, wysokość, szerokość, średnice Feret'a, oraz opisujących kształt ziaren, np. współczynniki wypełnienia, kolistości, wybrano parametry szarości obiektów. W tabeli 3 podano wartości statystyczne zmiennych wykorzystywanych w obliczeniach modelowych, dla jednego z materiałów. Do analizy uzyskanych danych wykorzystano sieci neuronowe. W niniejszej publikacji przedstawiono przykładowe wyniki modelowania dla zagadnienia klasyfikacji identyfikującego dwa typy rud: węglanowo-łupkową i piaskowcową. Połączenie rud: węglanowej i łupkowej w jeden typ ma swoje technologiczne uzasadnienie. Obliczenia modelujące wykonano przy użyciu komputerowego programu do modelowania Statistica Neural Networks firmy StatSoft. W tabeli 4 i 5 przedstawiono charakterystyki ostatecznych najskuteczniejszych modeli sieci neuronowych klasyfikujących typy rud. Ogólnie modele sieci neuronowych, realizujące zagadnienie klasyfikacji typów rud, charakteryzowały się wysoką jakością działania oraz małymi błędami sieci dla poszczególnych podzbiorów danych (uczącego, walidacyjnego i testowego). Świadczy to o ich wysokiej stabilności i pewności działania w przypadku uruchamiania sieci na nowych zbiorach danych. Weryfikacja zdolności predykcyjnych najskuteczniejszych modeli sieci neuronowych polegała na uruchomieniu sieci na nowych danych charakterystycznych dla poszczególnych mieszanek, oraz na porównaniu i ocenie uzyskanych przewidywań z rzeczywistymi udziałami poszczególnych typów rud miedzi w analizowanych mieszankach. Na rysunkach 6 i 7 przedstawiono wyniki przewidywań udziałów odmian litologicznych rud miedzi w mieszankach. Podsumowując przewidywania udziałów typów rud w poszczególnych mieszankach dla rozważanego zagadnienia klasyfikacji można stwierdzić, że wyniki przewidywań są dobre i potwierdzają przewagę litologiczną określonych odmian rud w badanych mieszankach. Szczególnie istotny z technologicznego punktu widzenia jest wysoki stopień trafności przewidywań typów rud dla szerokiej klasy ziarnowej, która odpowiada zazwyczaj rzeczywistemu składowi ziarnowemu nadawy do procesu flotacji. Trafność tych przewidywań jest większa dla mieszanek z przewagą rudy piaskowcowej.

Evaluation of Blasting Patterns Using Operational Research Models / Ocena Planów Prac Strzałowych W Oparciu O Metody Badań Operacyjnych

NASA Astrophysics Data System (ADS)

Monjezi, Masoud; Farzaneh, Farhad; Asadi, Ahmad

2013-09-01

Blasting is one of the most important operations, which has a great technical and economical effect on the mining projects. Criteria such as fragmentation (operation ultimate objective) and ground vibration, flyrock, airblast, etc. (operation side effects) should be considered in the assessment of blasting operation. A suitable pattern should be able to provide both reasonable (required) fragmentation and blasting side effects. In order to evaluate blasting performance, operational research models such as multi attribute decision making technique (MADM) can be applied. Technique for order preference by similarity to an ideal solution (TOPSIS), a branch of MADM, is a strong method for pattern ranking. The other quantitative method which is applied in the evaluation of systems' efficiency is data envelopment analysis (DEA) model. In this paper, an attempt has been made to develop a new hybrid MADM model for selecting the most appropriate blasting pattern in Chadormalu iron mine, Iran. In this regard, DEA method was utilized to select the efficient blast patterns thereafter TOPSIS was used to recognize the most suitable pattern amongst the selected patterns by DEA method. It was concluded that the patterns J, G and B are the most appropriate patterns for blasting operations in the Chadormalu iron mine. Prace strzałowe to jedne z kluczowych operacji w znacznym stopniu determinujące efektywność ekonomiczną wielu projektów górniczych. W planowaniu prac strzałowych uwzględnić należy podstawowe kryteria, takie jak rozdrobnienie skał (ostateczny cel operacji), wibracje podłoża, występowanie rozrzutu skał, i podmuchów powietrza (efekty uboczne). Odpowiedni harmonogram prac zapewnić powinien zarówno odpowiedni poziom rozdrobnienia (wymiary brył) jak i ograniczenie skutków ubocznych prac. Dla oceny skuteczności prac strzałowych zastosować można modele badań operacyjnych, np. modele oparte o wielokryterialną technikę decyzyjną MADM, a technika

Mineral trapping of CO2 in operated geothermal reservoirs - Numerical simulations on various scales

NASA Astrophysics Data System (ADS)

Kühn, Michael; Stanjek, Helge; Peiffer, Stefan; Clauser, Christoph

2013-04-01

the combination of geothermal energy production and CO2 storage is not economical. Acknowledgements: The work presented here was part of the CO2Trap project in the research and development program GEOTECHNOLOGIEN funded by the German Ministry of Education and Research (BMBF) and the German Research Foundation (DFG) (grant 03G0614A-C). References Back M., Kühn M., Stanjek H., Peiffer S. (2008) Reactivity of alkaline lignite fly ashes towards CO2 in water. Environmental Science & Technology 42(12), 4520-4526, doi: 10.1021/es702760v. Kühn M., Clauser C. (2006) Mineral trapping of CO2 in geothermal reservoirs. Chemie Ingenieur Technik 78(4), 425-434, doi: 10.1002/cite.200600019 (in German). Kühn M., Clauser C., Vosbeck K., Stanjek H., Meyn V., Back M., Peiffer S. (2009) Mineral trapping of CO2 in operated hydrogeothermal reservoirs. In: Grobe M., Pashin J. C., Dodge R. L. (eds.) Carbon dioxide sequestration in geological media—State of the science: AAPG Studies in Geology 59, p. 545-552.

Dispersion modeling of accidental releases of toxic gases - Comparison of the models and their utility for the fire brigades.

NASA Astrophysics Data System (ADS)

Stenzel, S.; Baumann-Stanzer, K.

2009-04-01

Synex Ries & Greßlehner GmbH. RETOMOD was funded by the KIRAS safety research program at the Austrian Ministry of Transport, Innovation and Technology (www.kiras.at). One of the main tasks of this project was 1. Sensitivity study and optimization of the meteorological input for modeling of the hazard areas (human exposure) during the accidental toxic releases. 2. Comparison of several model packages (based on reference scenarios) in order to estimate the utility for the fire brigades. This presentation introduces the project models used and presents the results of task 2. The results of task 1 are presented by Baumann-Stanzer and Stenzel in this session. For the purpose of this study the following models were tested and compared: ALOHA (Areal Location of Hazardous atmosphere, EPA), MEMPLEX (Keudel av-Technik GmbH), Breeze (Trinity Consulting), SAFER System, SAM (Engineering office Lohmeyer), COMPAS. A set of reference scenarios for Chlorine, Ammoniac, Butane and Petrol were proceed in order to reliably predict and estimate the human exposure during the event. The models simulated the accidental release from the mentioned above gases and estimates the potential toxic areas. Since the inputs requirement differ from model to model, and the outputs are based on different criteria for toxic areas and exposure, a high degree of caution in the interpretation of the model results is needed.

Seeking realistic upper-bounds for internal reliability of systems with uncorrelated observations

NASA Astrophysics Data System (ADS)

Prószyński, Witold

2014-06-01

ów. Jako punkt wyjściowy w analizie przyjęto uzyskaną na drodze empirycznej formułę (Adamczewski 2003), nazwaną prawem błędów grubych, pozwalającą wyznaczyć prawdopodobieństwo wystąpienia w sieci określonej liczby błędów grubych. Przy użyciu pomocniczej zależności wyprowadzonej na podstawie gaussowskiego rozkładu błędów dokonano modyfikacji formuły Adamczewskiego, przekształcając ją w jawną funkcję liczby obserwacji w sieci. Umożliwiło to skonstruowanie narzędzi niezbędnych do analizy, i ostatecznie sformułowanie wskazań co do wyznaczania górnych limitów niezawodności wewnętrznej sieci. Ponieważ formuła Adamczewskiego uzyskana została dla sieci klasycznych, wskazania niniejsze powinny być potraktowane jako wstępna propozycja wymagająca sprawdzenia w odniesieniu do nowoczesnych technik pomiarowych.

Finding the Best-Fit Polynomial Approximation in Evaluating Drill Data: the Application of a Generalized Inverse Matrix / Poszukiwanie Najlepszej ZGODNOŚCI W PRZYBLIŻENIU Wielomianowym Wykorzystanej do Oceny Danych Z ODWIERTÓW - Zastosowanie UOGÓLNIONEJ Macierzy Odwrotnej

NASA Astrophysics Data System (ADS)

Karakus, Dogan

2013-12-01

In mining, various estimation models are used to accurately assess the size and the grade distribution of an ore body. The estimation of the positional properties of unknown regions using random samples with known positional properties was first performed using polynomial approximations. Although the emergence of computer technologies and statistical evaluation of random variables after the 1950s rendered the polynomial approximations less important, theoretically the best surface passing through the random variables can be expressed as a polynomial approximation. In geoscience studies, in which the number of random variables is high, reliable solutions can be obtained only with high-order polynomials. Finding the coefficients of these types of high-order polynomials can be computationally intensive. In this study, the solution coefficients of high-order polynomials were calculated using a generalized inverse matrix method. A computer algorithm was developed to calculate the polynomial degree giving the best regression between the values obtained for solutions of different polynomial degrees and random observational data with known values, and this solution was tested with data derived from a practical application. In this application, the calorie values for data from 83 drilling points in a coal site located in southwestern Turkey were used, and the results are discussed in the context of this study. W górnictwie wykorzystuje się rozmaite modele estymacji do dokładnego określenia wielkości i rozkładu zawartości pierwiastka użytecznego w rudzie. Estymację położenia i właściwości skał w nieznanych obszarach z wykorzystaniem próbek losowych o znanym położeniu przeprowadzano na początku z wykorzystaniem przybliżenia wielomianowego. Pomimo tego, że rozwój technik komputerowych i statystycznych metod ewaluacji próbek losowych sprawiły, że po roku 1950 metody przybliżenia wielomianowego straciły na znaczeniu, nadal teoretyczna powierzchnia

Encounters with neighbours : current developments of concepts based on recurrence plots and their applications

NASA Astrophysics Data System (ADS)

Marwan, Norbert

2003-09-01

Komplexitätsmaße eingeführt, die geometrische Strukturen in den Recurrence Plots beschreiben. Diese neuen Maße erlauben die Identifikation von Chaos-Chaos-Übergängen in dynamischen Prozessen. In einem weiteren Schritt werden Cross Recurrence Plots eingeführt, mit denen zwei verschiedene Prozesse untersucht werden. Diese bivariate Analyse ermöglicht die Bewertung von Unterschieden zwischen zwei Prozessen oder das Anpassen der Zeitskalen von zwei Zeitreihen. Diese Technik kann auch genutzt werden, um ähnliche Abschnitte in zwei verschiedenen Datenreihen zu finden. Im Anschluß werden diese neuen Entwicklungen auf Daten verschiedener Art angewendet. Methoden, die auf Recurrence Plots basieren, können an die speziellen Probleme angepaßt werden, so daß viele weitere Anwendungen möglich sind. Durch die Anwendung der neu eingeführten Komplexitätsmaße können Chaos-Chaos-Übergänge in Herzschlagdaten vor dem Auftreten einer lebensbedrohlichen Herzrhythmusstörung festgestellt werden, was für die Entwicklung neuer Therapien dieser Herzrhythmusstörungen von Bedeutung sein könnte. In einem weiteren Beispiel, in dem EEG-Daten aus einem kognitiv orientierten Experiment untersucht werden, ermöglichen diese Komplexitätsmaße das Erkennen von spezifischen Reaktionen im Gehirn bereits in Einzeltests. Normalerweise können diese Reaktionen erst durch die Auswertung von vielen Einzeltests erkannt werden. Mit der Hilfe von Cross Recurrence Plots wird die Existenz einer klimatischen Zirkulation, die der heutigen El Niño/ Southern Oscillation sehr ähnlich ist, im Nordwesten Argentiniens vor etwa 34000 Jahren nachgewiesen. Außerdem können mit Cross Recurrence Plots die Zeitskalen verschiedener Bohrlochdaten aufeinander abgeglichen werden. Diese Methode kann auch dazu genutzt werden, ein geologisches Profil mit Hilfe eines Referenzprofiles mit bekannter Zeitskala zu datieren. Weitere Beispiele aus den Gebieten der Molekularbiologie und der Spracherkennung unterstreichen

3D-RTK Capability of Single Gnss Receivers

NASA Astrophysics Data System (ADS)

Stempfhuber, W.

2013-08-01

Small, aerial objects are now being utilised in many areas of civil object capture and monitoring. As a rule, the standard application of a simple GPS receiver with code solutions serves the 3D-positioning of the trajectories or recording positions. Without GPS correction information, these can be calculated at an accuracy of 10-20 metres. Corrected code solutions (DGPS) generally lie in the metre range. A precise 3D-positioning of the UAV (unmanned aerial vehicle) trajectories in the centimetre range provides significant improvements. In addition, the recording time of each sensor can be synchronized with the exact time stamp of the GNSS low-cost system. In recent years, increasing works on positioning from L1 GPS raw data have been published. Along with this, the carrier phase measurements with the established evaluation algorithms are analysed in the post processing method to centimetre-exact positions or to high-precision 3D trajectories [e.g. Schwieger and Gläser, 2005 or Korth and Hofmann 20011]. The use of reference information from local reference stations or a reference network serves the purpose of carrier phase ambiguity resolution. Furthermore, there are many activities worldwide in the area of PPP techniques (Precise Point Positioning). However, dual frequency receivers are primarily used in this instance. Moreover, very long initialisation times must be scheduled for this. A research project on the subject of low-cost RTK GNSS was developed for real-time applications at the Beuth Hochschule für Technik Berlin University of Applied Sciences [Stempfhuber 2012]. The overall system developed for the purpose of real-time applications with centimetre accuracy is modularly constructed and can be used for various applications (http://prof.beuthhochschule.de/stempfhuber/seite-publikation/). With hardware costing a few hundred Euro and a total weight of 500-800 g

Application of Multidimensional Data Visualization by Means of Self-Organizing Kohonen Maps to Evaluate Classification Possibilities of Various Coal Types / Zastosowanie Wizualizacji Wielowymiarowych Danych Za Pomocą Sieci Kohonena Do Oceny Możliwości Klasyfikacji Różnych Typów Węgla

NASA Astrophysics Data System (ADS)

Jamróz, Dariusz; Niedoba, Tomasz

2015-03-01

materiału. Nasuwa się więc pytanie, czy możliwa jest identyfikacja typu węgla za pomocą dostępnych danych. W tym celu zastosowano wielowymiarową technikę wizualizacji statystycznej. Istnieje wiele metod takiej wizualizacji, z których kilka było już przedmiotem wcześniejszych publikacji autorów. W tym wypadku autorzy zdecydowali się zastosować metodę sieci Kohonena. Metoda ta została opisana w rozdziale 2 pracy, gdzie oprócz opisu teoretycznego podano również główne wzory stosowane podczas modelowania tą metodą (wzory (1)-(5)). Do zbadania postawionego problemu wykorzystano optymalną liczbę iteracji i optymalny czas uczenia sieci. Pewnym problemem pojawiającym się przy takiej wizualizacji jest konieczność doboru parametrów, w celu uzyskania widoku, który w sposób czytelny prezentuje poszukiwane przez nas informacje. Należy wspomnieć, że w trakcie prowadzonych eksperymentów uzyskiwano widoki przy użyciu sieci neuronowej o wielkości od 10 × 10 do 100 × 100 neuronów. Widoki były uzyskiwane przy wartości parametru MAX_DISTANCE od 1 do wielkości sieci oraz parametru ITER od 1 do 5000. Eksperymenty były prowadzone dla różnych wzorów określających modyfikację wag. Przedstawione w pracy wyniki stanowią najbardziej czytelne z uzyskanych. Wizualizacja wielowymiarowa przy użyciu sieci Kohonena pozwala stwierdzić, że informacje zawarte w analizowanych siedmiowymiarowych danych są wystarczające do prawidłowej klasyfikacji typów węgla 31, 34.2 oraz 35, przy czym nawet zobrazowanie 3 typów węgla na jednym rysunku pozwala stwierdzić, że neurony reprezentujące próbki węgla danego typu gromadzą się w skupiskach, które można od siebie odseparować. Z tego wynika, że dane zawierają informacje wystarczające do prawidłowej klasyfikacji węgla. Zauważyć jednak warto, że przedstawienie przy pomocy sieci Kohonena, danych reprezentujących różne typy węgla parami, pozwala uzyskać jeszcze bardziej czytelne wyniki

PREFACE: Nanosafe2010: International Conference on Safe Production and Use of Nanomaterials

NASA Astrophysics Data System (ADS)

Sentein, Carole; Schuster, Frédéric; Tardif, François

2011-07-01

matters of interest to the NanoSafety community have been debated. The success of the conference confirms the need of such a global meeting with the aim of bridging the gap between the best scientists, engineers, exhibitors and participants from countries concerned with safe and responsible nanomaterial activities. Therefore, the third edition of the International NanoSafe Conference "NanoSafe2012" will be held in Grenoble at Minatec, 13-15 November 2012. The meeting was financially supported by generous contributions from the European Commission, La Région Rhône Alpes, la Ville de Grenoble, la Metro, and partners such as CEA, INERIS, Philips, Cordouan Technologies, Nanosight, TSI, Ecomesure, GRIMM Aerosol Technik, Particle Measuring Systems, Respirex, Lux Research, Dekati, Malvern Instruments, TSE Systems, INTERTEK ICS, NANO magazine and IOP Publishing. We would like to express our thanks to all the authors for their time and genuine efforts and to the reviewers for their fruitful comments during the preparation of this volume. The Conference OrganizersCarole SenteinFrédéric SchusterFrançois Tardif Conference photographs Local Organising CommitteeCarole SENTEIN (CEA)Dominique BAGUET (CEA)Didier MOLKO (MINATEC)Audrey SCARINGELLA (MINATEC)Frédéric SCHUSTER (CEA)François TARDIF (CEA) International Advisory CommitteeChair: Frédéric SCHUSTER (CEA, FR), François TARDIF (CEA, FR)Co-chair: Georgios KATALAGARIANAKIS (EC, BE)Paul AMYOTTE (Dalhousie U., CA)Mélanie AUFFAN (CEREGE, FR)Daniel BERNARD (ARKEMA, FR)Jorge BOCZKOWSKI (INSERM, FR)Jean-Yves BOTTERO (CEREGE, FR)Jacques BOUILLARD (INERIS, FR)Jean-Philippe BOURGOIN (CEA, FR)Marie CARRIERE (CEA, FR)Krunal CHOPRA (LSFI, IN)Rolf ECKHOFF (U. Bergen, NO)Michael ELLENBECKER (U. Massachusetts, USA)Claude EMOND (U. Montréal, CA)François GENDARMES (IRSN, FR)Peter HATTO (ISO, UK)Peter HOET (KUL, BE)Jean-Pierre KAISER (Empa, CH)Olivier LE BIHAN (INERIS, FR)Tinh NGUYEN (NIST, USA)Bernd NOWACK (Empa, CH)Günter OBERDÖRSTER (U

Book Review: Beitraege zur Astronomiegeschichte, Band 5 (Acta Historica Astronomiae Vol. 15)

NASA Astrophysics Data System (ADS)

Duerbeck, H. W.; Dick, W. R.; Hamel, J.

2002-12-01

Pisa and the librarian Pozzetti at Bologna, and Karin Reich describes and edits Bessel's book critique of Gauss' Theoria Motus. How many one-time astronomers have to earn their living in other ways, become distracted from astronomical research, and vanish from the horizon of astronomical history? In the ninth paper, Hans-Joachim Ilgauds has traced the life of Georg Koch (1851-1905), who started his career as an astronomer at Leipzig Observatory in 1874. Later Koch worked at Hamburg Observatory, and then became an employee at the statistical office in Kiel, and finally director of the statistical office of the Hamburg revenue service. He was a collaborator for the statistical yearbook of German cities, and also contributed to a book investigating the causes and the impact of the cholera epidemic of 1892 in Hamburg. The last two papers deal with the circumstances of the discovery of the first Near-Earth asteroid (433) Eros. It was recorded on photographic plates taken at the Urania-Sternwarte Berlin and at Nice Observatory. The Berlin observer Witt announced the discovery, and only later, the Nice observer Charlois published a position of Eros. While all plates have disappeared, the authors Hans Scholl and Lutz D. Schmadel could prove that the Nice plate was poorly guided and Charlois would have been unable to discover the object. From a copy of the Berlin plate, published 50 years after the discovery by Witt's co-observer F. Linke, the exact position was determined, and the time of observation (which had not been published) was derived. The second article, by Lutz D. Schmadel, deals with the life of the Eros co-discoverer Felix Linke (1879-1959), who later worked in statistic offices, was a frequent writer of popular scientific articles, and later the editor of a journal, "Technik im Hotel'', and author of a book of the same title. As can be seen from the summaries given above, this collection of essays deals mainly with historical events that occurred in Germany and

Laboratory Method for Evaluating the Characteristics of Expansion Rock Bolts Subjected to Axial Tension / Laboratoryjna Metoda Badania Charakterystyk Kotew Rozprężnych Poddanych Rozciąganiu Osiowemu

NASA Astrophysics Data System (ADS)

Korzeniowski, Waldemar; Skrzypkowski, Krzysztof; Herezy, Łukasz

2015-03-01

stanowiska badawczego. Pomiar siły na stanowisku laboratoryjnym był wykonywany za pomocą czterech tensometrycznych czujników siły. Czujniki były rozmieszczone co 90 stopni na tarczy pomiarowej (Rys. 4). Całkowita siła rejestrowana podczas badań rozciągania żerdzi kotwowej była sumą wartości sił uzyskiwanych na poszczególnych czujnikach siły. Pomiar przemieszczeń elementów obudowy oraz wydłużenia żerdzi kotwowej był wykonywany za pomocą enkodera linkowego inkrementalnego. Enkoder przymocowany był na stałe do bloku siłowników (Rys. 6), natomiast linka enkodera przemieszczała się wraz z wysuwem tarczy pomiarowej (Rys. 6). W celu określenia odkształcenia materiału badanego elementu (żerdzi kotwowej) w badaniach zastosowano tensometry elektrooporowe typu kratowego (Rys. 7). Czujniki siły, przemieszczenia oraz odkształcenia zostały podłączone do uniwersalnego wzmacniacza pomiarowego QuantumX MX840, za pomocą wtyczek 15-pinowych. Podczas procesu rozciągania kotwy wyniki pomiarów siły, przemieszczenia oraz odkształcenia były rejestrowane na bieżąco za pomocą specjalistycznego programu z dziedziny technik pomiarowych "CATMAN - EASY". Wybór programu wynikał z możliwości współpracy z systemem operacyjnym MS Windows oraz połączenia komputera z uniwersalnym wzmacniaczem pomiarowym QuantumX MX840 poprzez kabel ethernetowy. Program umożliwiał bieżącą (on- -line) wizualizację i ocenę pomiaru. Ponadto po zakończeniu testu, tworzone były raporty dokumentujące wyniki pomiarów, które były zapisywane w rozszerzeniu pliku ASCII. Następnie dane były przesyłane do programu Microsoft Excel w celu analizy uzyskanych wyników. W badaniach zastosowano obudowę kotwową rozprężną, zainstalowaną w bloku symulującym górotwór o wytrzymałości skał na ściskanie wynoszącej 80MPa (Rys. 3), która była obciążana statycznie według ustalonego programu obciążenia uwzględniającego utrzymywanie zadanej osiowej siły rozci

Bewehrte Betonbauteile unter Betriebsbedingungen: Forschungsbericht

NASA Astrophysics Data System (ADS)

Eligehausen, Rolf; Kordina, Karl; Schießl, Peter

2000-09-01

Vorwort. Teil I: Rißbreiten (Gert König) 1 Ein mechanisches Modell zur Erhöhung der Vorhersagegenauigkeit über die Rißbreiten unter Betriebsbedingungen (Gert König und Michael Fischer). 1.1 Einleitung und Zielsetzung. 1.2 Versuchsprogramm. 1.3 Meßtechnik. 1.4 Belastung und Versuchsdurchführung. 1.5 Literatur. 2 Rißbreiten und Verformungszunahme vorgespannter Bauteile unter wiederholter Last - und Zwangbeanspruchung (Gert König und Michael Fischer). 2.1 Einleitung und Zielsetzung. 2.2 Versuchsprogramm. 2.3 Auswertung. 2.4 Ausblick. 2.5 Literatur. 3 Rißverhalten von Beton bei plötzlicher Abkühlung (Viktor Mechtcherine und Harald S. Müller). 3.1 Einleitung. 3.2 Experimentelle Untersuchungen. 3.3 Formulierung eines Stoffgesetzes für thermisch beanspruchten Beton. 3.4 Riß entwicklung in einer Betonplatte unter Temperaturschock. 3.5 Zusammenfassung. 3.6 Literatur. 4 Stahlfaserbeton unter Betriebsbedingungen bei Dauerbeanspruchung (Bo Soon Kang, Bernd Schnütgen und Friedhelm Stangenberg). 4.1 Einleitung. 4.2 Wirkung von Stahlfasern im Beton. 4.3 Versuchsprogramm. 4.4 Untersuchungen zum Verbundverhalten. 4.5 Untersuchungen zum Verhalten unter Biegebeanspruchung. 4.6 Theoretische Untersuchungen. 4.7 Literatur. 5 Experimentelle Untersuchungen an Stahlbeton-Zugkörpern unter wiederholter Belastung zur Ermittlung des versteifenden Einflusses der Mitwirkung des Betons zwischen den Rissen (Petra Seibel und Gerhard Mehlhorn). 5.1 Einleitung. 5.2 Ansatz zur Bestimmung der Mitwirkung des Betons zwischen den Rissen nach Eurocode 2, Model Code 90 und Günther. 5.3 Experimentelle Untersuchungen. 5.4 Ergebnisse. 5.5 Zusammenfassung. 5.6 Literatur. 6 Riß- und Verformungsverhalten von vorgefertigten Spannbetonträgern unter Betriebsbedingungen bei besonderer Berücksichtigung des Betonalters (Monika Maske, Heinz Meichsner und Lothar Schubert). 6.1 Einleitung. 6.2 Beschreibung der Fertigteilträger. 6.3 Belastungsversuche. 6.4 Ergebnisse. 6.5 Zusammenfassung. 6

Waterproof Anti-Explosive Powders for Coal Mines

NASA Astrophysics Data System (ADS)

Buczek, Bronisław; Vogt, Elżbieta

2014-03-01

ętrznej oraz penetrować w głąb porów, blokując je dla wilgoci. Drugi sposób hydrofobizacji sprowadzał się w uproszczeniu do zmieszania substratów: pyłu wapiennego i domieszki silikonowej - Sarsil® H-15, w parownicy (Vogt i Opaliński, 2009; Vogt i Hołownia, 2010). We wstępnych badaniach określono objętość preparatu, jaką trzeba dodać do pyłu w celu uzyskania optymalnych warunków kontaktu preparatu z ciałem stałym. Otrzymany po modyfikacji materiał był zbrylony w niewielkim stopniu, a jego całkowite rozdrobnienie uzyskano poprzez przecieranie pyłu przez sito o odpowiednim wymiarze oczek. Badanie właściwości tak otrzymanych hydrofobowych materiałów przeprowadzono w oparciu o PN (Polska Norma, 1994), jak również w oparciu o standardowe metody badania materiałów proszkowych z użyciem aparatu Powder Characteristic Tester (Index tables, Tablets & Capsules, 2005) (Tablica 2,3). Oceny stopnia hydrofobizacji materiałów po modyfikacji dokonano, w przypadku proszku hydrofobizowanego parami kwasu stearynowego, w oparciu o procedurę opisaną w Polskiej Normie (1994), oznaczając procentową zawartość kwasu stearynowego. Otrzymany podczas badań pył hydrofobizowany kwasem stearynowym zawierał 0,18% modyfikatora, co jest ilością dopuszczalną przez Polską Normę (1994).W celu oceny właściwości hydrofobowych materiału modyfikowanego roztworem silikonowym do badań zaadaptowano technikę pomiaru zwilżalności ziaren węglowych "film flotation" (Fuerstenau i Williams, 1987) przyjmując, jako materiał odniesienia hydrofobizowaną mączkę wapienną z Kopalni Kamienia Wapiennego w Małogoszczy. Opracowano metodę wyznaczania współczynnika C określonego, jako stopień hydrofobizacji (Vogt i Opaliński, 2009). Średnia wartość C = 84% wskazuje, że materiał modyfikowany preparatem silikonowym uzyskał odpowiednie właściwości hydrofobowe. Tym samym oba materiały po modyfikacji uzyskały zadowalające właściwości wodoodporne. Ponadto