Beam test results of the first full-scale prototype of CMS RE 1/2 resistive plate chamber

International Nuclear Information System (INIS)

Ying Jun; Ban Yong; Ye Yanlin; Cai Jianxin; Qian Sijin; Wang Quanjin; Liu Hongtao

2005-01-01

The authors reported the muon beam test results of the first full-scale prototype of CMS RE 1/2 Resistive Plate Chamber (RPC). The bakelite surface is treated using a special technology without oil to make it smooth enough. The full scale RE 1/2 RPC with honeycomb supporting frame is strong and thin enough to be fitted to the limited space of CMS design for the inner Forward RPC. The muon beam test was performed at CERN Gamma Irradiation Facility (GIF). The detection efficiency of this full scale RPC prototype is >95% even at very high irradiation background. The time resolution (less than 1.2 ns) and spatial resolution are satisfactory for the muon trigger device in future CMS experiments. The noise rate is also calculated and discussed

A new type of resistive plate chamber: The multigap RPC

International Nuclear Information System (INIS)

Cerron Zeballos, E.; Crotty, I.; Hatzifotiadou, D.; Lamas Valverde, J.; Neupane, S.; Williams, M.C.S.; Zichichi, A.

1996-01-01

This Letter describes the multigap resistive plate chamber (RPC). The goal is to obtain a much improved time resolution, keeping the advantages of the wide gap RPC in comparison with the conventional narrow gap RPC (smaller dynamic range and thus lower charge per avalanche which gives higher rate capability and lower power dissipation in the gas gap). (orig.)

A new type of resistive plate chamber the multigap RPC

CERN Document Server

Cerron-Zeballos, E; Hatzifotiadou, D; Lamas-Valverde, J; Neupane, S; Williams, M C S; Zichichi, Antonino

1996-01-01

This paper describes the multigap resistive plate chamber (RPC). The goal is to obtain a much improved time resolution, keeping the advantages of the wide gap RPC in comparison with the conventional narrow gap RPC (smaller dynamic range and thus lower charge per avalanche which gives higher rate capability and lower power dissipation in the gas gap).

High rate, fast timing Glass RPC for the high $\\eta$ CMS muon detectors

CERN Document Server

INSPIRE-00185093; Lagarde, François; Laktineh, Imad; Buridon, Victor; Chen, Xiushan; Combaret, Christophe; Eynard, Alexis; Germani, Lionel; Grenier, Gerald; Mathez, Hervé; Mirabito, Laurent; Petrukhin, Alexei; Steen, Arnaud; Tromeur, William; Wang, Yi; Gong, A.; Moreau, Nathalie; de la Taille, Christophe; Dulucq, Fréderic

2017-02-11

The HL-LHC phase is designed to increase by an order of magnitude the amount of data to be collected by the LHC experiments. To achieve this goal in a reasonable time scale the instantaneous luminosity would also increase by an order of magnitude up to $6 \\cdot 10^{34}$ cm$^{-2}$s$^{-1}$. The region of the forward muon spectrometer ($|\\eta| > 1.6$) is not equipped with RPC stations. The increase of the expected particles rate up to 2 kHz/cm$^2$ ( including a safety factor 3 ) motivates the installation of RPC chambers to guarantee redundancy with the CSC chambers already present. The actual RPC technology of CMS cannot sustain the expected background level. A new generation Glass-RPC (GRPC) using low resistivity glass (LR) is proposed to equip at least the two most far away of the four high eta muon stations of CMS. The design of small size prototypes and the studies of their performances under high rate particles flux is presented.

High rate, fast timing Glass RPC for the high ${\\eta}$ CMS muon detectors

CERN Document Server

Lagarde, F.; Laktineh, I.; Buridon, V.; Chen, X.; Combaret, C.; Eynard, A.; Germani, L.; Grenier, G.; Mathez, H.; Mirabito, L.; Petrukhin, A.; Steen, A.; Tromeur, W.; Wang, Y.; Gong, A.; Moreau, N.; de la Taille, C.; Dulucq, F.; Cimmino, A.; Crucy, S.; Fagot, A.; Gul, M.; Rios, A.A.O.; Tytgat, M.; Zaganidis, N.; Aly, S.; Assran, Y.; Radi, A.; Sayed, A.; Singh, G.; Abbrescia, M.; Iaselli, G.; Maggi, M.; Pugliese, G.; Verwilligen, P.; Van Doninck, W.F.; Colafranceschi, S.; Sharmag, A.; Benussi, L.; Bianco, S.; Piccolo, D.; Primavera, F.; Bhatnagar, V.; Kumari, R.; Mehta, A.; Singh, J.; Ahmad, A.; Ahmed, W.; Asghar, M.I.; Awan, I.M.; Hoorani, R.; Muhammad, S.; Shahzad, H.; Shah, M.A.; Cho, S.W.; Choi, S.Y.; Hong, B.; Kang, M.H.; Lee, K.S.; Lim, J.H.; Park, S.K.; Kim, M.S.; Carpinteyro Bernardino, S.; Pedraza, I.; Uribe Estradam, C.; Carrillo Moreno, S.; Vazquez Valencia, F.; Pant, L.M.; Buontempo, S.; Cavallo, N.; Esposito, M.; Fabozzi, F.; Lanza, G.; Orso, I.; Lista, L.; Meola, S.; Merola, M.; Paolucci, P.; Thyssen, F.; Braghieri, A.; Magnani, A.; Montagna, P.; Riccardi, C.; Salvini, P.; Vai, I.; Vitulo, P.; Ban, Y.; Qian, S.J.; Choi, M.; Choi, Y.; Goh, J.; Kim, D.; Aleksandrov, A.; Hadjiiska, R.; Iaydjiev, P.; Rodozov, M.; Stoykova, S.; Sultanov, G.; Vutova, M.; Dimitrov, A.; Litov, L.; Pavlov, B.; Petkov, P.; Bagaturia, I.; Lomidze, D.; Avila, C.; Cabrera, A.; Sanabria, J.C.; Crotty, I.; Vaitkus, J.

2016-09-09

The HL-LHC phase is designed to increase by an order of magnitude the amount of data to be collected by the LHC experiments. To achieve this goal in a reasonable time scale the instantaneous luminosity would also increase by an order of magnitude up to $6.10^{34} cm^{-2} s^{-1}$ . The region of the forward muon spectrometer ($|{\\eta}| > 1.6$) is not equipped with RPC stations. The increase of the expected particles rate up to $2 kHz/cm^{2}$ (including a safety factor 3) motivates the installation of RPC chambers to guarantee redundancy with the CSC chambers already present. The actual RPC technology of CMS cannot sustain the expected background level. The new technology that will be chosen should have a high rate capability and provides a good spatial and timing resolution. A new generation of Glass-RPC (GRPC) using low-resistivity (LR) glass is proposed to equip at least the two most far away of the four high ${\\eta}$ muon stations of CMS. First the design of small size prototypes and studies of their perfor...

Recycling Waste Bakelite As A Carbon Resource In Ironmaking

Directory of Open Access Journals (Sweden)

James Ransford Dankwah

2015-02-01

Full Text Available Abstract Bakelite is a 3-dimensional cross-linked network structured thermosetting polymer which is difficult to recycle after use. However it contains high levels of carbon and CaCO3 that can be recovered for use as reductant and fluxing agent in ironmaking. In this work we report the use of post-consumer bakelite as reductant for the production of metallic iron from iron oxide in a horizontal tube furnace through the composite pellet approach.Gas emission studies were conducted by pyrolysing raw bakelite at different temperatures within the temperature range 1200-1600 C in a horizontal tube furnace. Following thiscomposite pellets were then formed from mixtures of iron oxide and post-consumer bakelite.The iron oxide-bakelite composites were heated from room temperature to 1200 C and then between 1200-1600 C in a continuous stream of pure argon and the off gas was analysed continuously using an infrared IR gas analyser. Elemental analyses of samples of the reduced metal were performed chemically for its oxygen content using a LECO oxygennitrogen analyser. The extent of reduction after ten minutes was determined from the oxygen content. Gas emission studies revealed the emission of large volumes of the reductant gases CO and CH4along with CO2.It is further demonstrated that post-consumer bakelite is effective at reducing iron oxide to produce metallic iron.

Study of an avalanche-mode resistive plate chamber

International Nuclear Information System (INIS)

Ying, J.; Ban, Y.; Liu, H.T.; Zhu, Z.M.; Zhu, Z.Y.; Chen, T.; Ma, J.G.; Ye, Y.L.

2000-01-01

Resistive plate chambers (RPCs) are widely used to detect high-energy charged particles, especially muons, due to the high gain, moderate time and spatial resolution, simple design and low cost of these detectors. While the simple streamer mode is adequate for cosmic-ray and low-rate accelerator experiments, the avalanche mode is required for high-rate experiments such as CMS at LHC. In this paper construction of a medium-sized double-gap RPC made of Chinese materials is reported. The experimental set-up of cosmic-ray and muon beam tests are introduced. The avalanche mode was clearly observed. Good efficiency and time resolution were obtained from the beam test at CERN under normal irradiation conditions. At very high radiation background the chamber efficiency decreases, indicating the necessity to change the resistivity value of the Chinese bakelites. (author)

Mechanisms Affecting Performance of the BaBar Resistive Plate Chambers and Searches for Remediation

International Nuclear Information System (INIS)

Lu, Changguo

2003-01-01

The BaBar experiment at PEPII relies on the Instrumentation of the Flux Return (IFR) for both muon identification and KL detection. The active detector is composed of Resistive Plate Chambers (RPC's) operated in streamer mode. Since the start of operation the RPC's have suffered persistent efficiency deterioration and dark current increase problems. The ''autopsy'' of bad BaBar RPC's revealed that in many cases uncured Linseed oil droplets had formed on the inner surface of the Bakelite plates, leading to current paths from oil ''stalagmites'' bridging the 2 mm gap. In this paper a possible model of this ''stalagmite'' formation and its effect on the dark current and efficiency of RPC chambers is presented. Laboratory test results strongly support this model. Based upon this model we are searching for solutions to eliminate the unfavorable effect of the oil stalagmites. The lab tests show that the stalagmite resistivity increases dramatically if exposed to the air, an observation that points to a possible way to remedy the damage and increase the efficiency. We have seen that flowing an oxygen gas mixture into the chamber helps to polymerize the uncured linseed oil. Consequently the resistivity of the bridged oil stalagmites increases, as does that of the oil coating on the frame edges and spacers, significantly reducing the RPC dark currents and low-efficiency regions. We have tested this idea on two chambers removed from BaBar because of their low efficiency and high dark current. These test results are reported in the paper, and two other remediation methods also mentioned. We continue to study this problem, and try to find new treatments with permanent improvement

Resistive plate chamber neutron and gamma sensitivity measurement with a {sup 252}Cf source

Energy Technology Data Exchange (ETDEWEB)

Abbrescia, M.; Altieri, S.; Baratti, V.; Barnaba, O.; Belli, G.; Bruno, G.; Colaleo, A.; DeVecchi, C.; Guida, R. E-mail: roberto.guida@pv.infn.it; Iaselli, G.; Imbres, E.; Loddo, F.; Maggi, M.; Marangelli, B.; Musitelli, G.; Nardo, R.; Natali, S.; Nuzzo, S.; Pugliese, G.; Ranieri, A.; Ratti, S.; Riccardi, C.; Romano, F.; Torre, P.; Vicini, A.; Vitulo, P.; Volpe, F

2003-06-21

A bakelite double gap Resistive Plate Chamber (RPC), operating in avalanche mode, has been exposed to the radiation emitted from a {sup 252}Cf source to measure its neutron and gamma sensitivity. One of the two gaps underwent the traditional electrodes surface coating with linseed oil. RPC signals were triggered by fission events detected using BaF{sub 2} scintillators. A Monte Carlo code, inside the GEANT 3.21 framework with MICAP interface, has been used to identify the gamma and neutron contributions to the total number of collected RPC signals. A neutron sensitivity of (0.63{+-}0.02)x10{sup -3} (average energy 2 MeV) and a gamma sensitivity of (14.0{+-}0.5)x10{sup -3} (average energy 1.5 MeV) have been measured in double gap mode. Measurements done in single gap mode have shown that both neutron and gamma sensitivity are independent of the oiling treatment.

Aging studies for the CMS RPC system

CERN Document Server

Eysermans, Jan

2017-01-01

Aging effects are studied for the Resistive Plate Chambers (RPC) at the Compact Muon Solenoid (CMS) experiment at the CERN Large Hadron Colider (LHC), which can manifest themselves during the High-Luminosity LHC (HL-LHC) running period. A dedicated consolidation program is set up using the CERN Gamma Irradiation Facility ++, where RPC detectors are exposed to a high gamma flux for a long term period equivalent to the HL-LHC operational time. Based on the past operational experience, the high background conditions are estimated and the RPC are tested under such circumstances. Several parameters are monitored as function of integrated charge and dedicated test beam periods allows measuring the detector efficiency as function of the background rate. In this work, an overview of the measurements which were performed for these studies is given. After having accumulated a significant amount of the total irradiation, no aging effects or degradation of the RPC detectors have been observed. These results suggest that ...

CMS endcap RPC gas gap production for upgrade

International Nuclear Information System (INIS)

Park, S K; Choi, S; Hong, B; Jeng, Y Gun; Kang, M; Lee, K S; Sim, K-S; Colaleo, A; Pugliese, G; Loddo, F; Calabria, C; Maggi, M; Verwillingen, P; Berzano, U; Carrillo, C; Aleksandrov, A; Genchev, V; Iaydjiev, P; Rodozov, M; Shopova, M

2012-01-01

The CMS experiment will install a RE4 layer of 144 new Resistive Plate Chambers (RPCs) on the existing york YE3 at both endcap regions to trigger high momentum muons from the proton-proton interaction. In this paper, we present the detailed procedures used in the production of new RPC gas gaps adopted in the CMS upgrade. Quality assurance is enforced as ways to maintain the same quality of RPC gas gaps as the existing 432 endcap RPC chambers that have been operational since the beginning of the LHC operation. (technical report)

Effect of the linseed oil surface treatment on the performance of resistive plate chambers

International Nuclear Information System (INIS)

Abbrescia, M.; Colaleo, A.; Iaselli, G.; Maggi, M.; Marangelli, B.; Natali, S.; Nuzzo, S.; Ranieri, A.; Romano, F.; Arena, V.; Bonomi, G.; Braj, A.; Gianini, G.; Liguori, G.; Ratti, S.P.; Riccardi, C.; Viola, L.; Vitulo, P.

1997-01-01

Results on the behaviour of several bakelite resistive plate chambers (RPCs) without the linseed oil treatment of the internal electrodes will be presented. Efficiency, collected charge and cluster size distributions will be compared to the ones of a standard oiled RPC. Currents and single rate are the quantities most affected by the surface treatment of the electrodes beyond the optical/mechanical properties. A factor 4 less in currents and at least a factor 10 less in single rate is achieved using standard oiled RPCs operated in streamer mode. (orig.)

The transformation of waste Bakelite to replace natural fine aggregate in cement mortar

OpenAIRE

Usahanunth, Nopagon; Tuprakay, Seree

2017-01-01

Bakelite material has been used to produce the various components for cars and consumer goods industry in Thailand. The growth of Bakelite consumption increases Bakelite waste. Bakelite waste is prohibited from disposing of direct landfilling and open burning because of the improper disposal and emission reasons. A large amount of this waste needs the large safe space of warehouse area for keeping which becomes a waste management problem. Size reduction by milling machine is helpful for waste...

Study of mechanical properties and recommendations for the application of waste Bakelite aggregate concrete

OpenAIRE

Nopagon Usahanunth; Seree Tuprakay; Waranon Kongsong; Sirawan Ruangchuay Tuprakay

2018-01-01

Bakelite waste from industrial manufacturing may be a hazard to the environment and public health. The utilization of waste Bakelite (WB) to replace natural aggregates (NA), such as natural coarse aggregate (NCA) and natural fine aggregate (NFA), in concrete and mortar is an approach for reducing both waste plastic and natural material. This research examines the utilization of waste Bakelite aggregate (WBA) in concrete and mortar mixtures to form waste Bakelite aggregate concrete (WBAC) and ...

The transformation of waste Bakelite to replace natural fine aggregate in cement mortar

Directory of Open Access Journals (Sweden)

Nopagon Usahanunth

2017-06-01

Full Text Available Bakelite material has been used to produce the various components for cars and consumer goods industry in Thailand. The growth of Bakelite consumption increases Bakelite waste. Bakelite waste is prohibited from disposing of direct landfilling and open burning because of the improper disposal and emission reasons. A large amount of this waste needs the large safe space of warehouse area for keeping which becomes a waste management problem. Size reduction by milling machine is helpful for waste handling and storing, however, the post-milling waste Bakelite plastic utilization shall be studied to maintain the waste storing capacity. There are some studies of the milling machine used for waste plastic size reduction. However, the particular study of milling machine application for waste size reduction and its milling waste utilization is still insufficient in Thailand. The purpose of this research is the use of waste Bakelite aggregate milling machine for Bakelite waste size reduction and use of the post-milling waste Bakelite as a fine aggregate to replace natural sand material in cement mortar. The waste Bakelite fine aggregate (WBFA was mixed in cement mortar mixture with the proportion 0% 20% 40% 60% 80% and 100% by volume for cement mortar sample preparation. The mortar sample was tested for compressive strength follow ASTM standard. The compressive test result of mortar samples will be compared between conventional mortar (0% WBFA and waste Bakelite mortar (WBM as well as comparing with the mortar standard. From an analysis of the sample test data found that the WBFA content in cement mortar mixture can predict the strength of WBM. The compressive strength of WBM at 28 days age with the fraction of WBFA is not exceeded 11.03%, and 23.08% respectively can be met the mortar standard according to the equation. The utilization of WBM to develop mortar non-structural mortar product can be usable from a technical point of view.

A new surface treatment for the prototype Rcs of the BESIII spectrometer

International Nuclear Information System (INIS)

Zhang Jiawen; Du Zizhen; Han Jifeng; Li Jiancheng; Li Rubai; Liu Qian; Qian, Sen; Wang Yifang; Xie Yigang; Xie Yuguang; Zhao Jianbin; Min Fasu; Zhao Haiquan; Zhao, T.

2005-01-01

The prototype resistive plate chambers (RPCs) for the BESIII spectrometer were constructed by using resistive electrodes made from a special type of phenolic paper laminates developed by us. The surface quality of these laminates is superior to other bakelite plates that have been used to construct RPCs elsewhere. A method for adjusting the resistivety of these laminates was also developed. Extensive studies were conducted by using a number of prototype RPCs in the last several years. Tests have shown prototype RPCs made by using our resistive plates without the linseed oil treatment can achieve the level of performance comparable to RPCs with linseed oil treated bakelite or resistive glass electrodes. In this paper, we will discuss the construction of these prototype RPCs. The test results of a prototype RPC that have been monitored for a year will be reported. Based on favorable test results of prototypes, the RPC production for the muon identifier of the BESIII spectrometer has started at the Beijing Gaonengkedi Science and Technology Co. Ltd. in early 2004 using the technology that we developed

Study of mechanical properties and recommendations for the application of waste Bakelite aggregate concrete

Directory of Open Access Journals (Sweden)

Nopagon Usahanunth

2018-06-01

Full Text Available Bakelite waste from industrial manufacturing may be a hazard to the environment and public health. The utilization of waste Bakelite (WB to replace natural aggregates (NA, such as natural coarse aggregate (NCA and natural fine aggregate (NFA, in concrete and mortar is an approach for reducing both waste plastic and natural material. This research examines the utilization of waste Bakelite aggregate (WBA in concrete and mortar mixtures to form waste Bakelite aggregate concrete (WBAC and waste Bakelite mortar (WBM. The tests cover the physical and chemical properties of WBA, the mechanical properties of WBAC and WBM (including the extraction of chemical substances from WBA utilization to replace NCA and NFA, and recommendations for the application of replacement. The results indicate that WBA particles of different sizes can replace both fine and coarse natural aggregates. Its weight is less than natural aggregate but the absorption rate is higher. As for recommendations for the application, it was found that replacing 20% of NCA with waste Bakelite coarse aggregate in concrete (WBAC-RNCA was the most suitable proportion, owing to its mechanical properties and safety for the environment and public health, and because its material cost is acceptable. However, the use of waste Bakelite fine aggregate to replace NFA (WBAC-RNFA in concrete is not appropriate, because its mechanical properties are not sufficient, and it is considered unsafe for the environment and health. Moreover, WBM is not a suitable material for plastering work, since it may be a hazard to the environment and public health, and its cost is higher than conventional mortar. Keywords: Waste Bakelite, Aggregate, Concrete, Mortar

MUON DETECTORS: RPC

CERN Multimedia

P. Paolucci

2011-01-01

RPC detector calibration, HV scan Thanks to the high LHC luminosity and to the corresponding high number of muons created in the first part of the 2011 the RPC community had, for the first time, the possibility to calibrate every single detector element (roll).The RPC steering committee provided the guidelines for both data-taking and data analysis and a dedicated task force worked from March to April on this specific issue. The main goal of the RPC calibration was to study the detector efficiency as a function of high-voltage working points, fit the obtained “plateau curve” with a sigmoid function and determine the “best” high-voltage working point of every single roll. On 18th and 19th March, we had eight runs at different voltages. On 27th March, the full analysis was completed, showing that 60% of the rolls had already a very good fit with an average efficiency greater than 93% in the plateau region. To improve the fit we decided to take three more runs (15th April...

New RPC front-end electronics for hades

CERN Document Server

Gil, Alejandro; Cabanelas, P; Díaz, J; Garzón, J A; González-Díaz, D; König, W; Lange, J S; Marín, J; Montes, N; Skott, P; Traxler, M

2007-01-01

Time-of-flight (TOF) detectors are mainly used for both particle identification and triggering. Resistive Plate Chamber (RPC) detectors are becoming widely used because of their excellent TOF capabilities and reduced cost. The new ESTRELA* RPC wall, which is being installed in the HADES detector at Darmstadt GSI, will contain 1024 RPC modules, covering an active area of around 7 m2. It has excellent TOF and good charge resolutions. Its Front-End electronics is based on a 8-layer Mother-Board providing impedance matched paths for the output signals of each of the eight 4-channel Daughter-Boards to the TDC.

Track resolution in the RPC chamber

International Nuclear Information System (INIS)

Cardarelli, R.; Aielli, G.; Camarri, P.; Di Ciaccio, A.; Liberti, B.; Santonico, R.

2007-01-01

A new very promising read out, in addition to the well-known charge centroid method, is proposed for improving the space resolution in the Resistive Plate Chamber (RPC) in the sub-millimeter range. The method is based on the read out of the signal propagating in the graphite electrode which was simulated using a distributed resistance-capacitance model in SPICE. The results show that a good space-time correlation in the diffusion process is only possible by suitable signal processing. Three RPC detectors with the new layout and dedicated electronics were tested. The measured space resolution was in the order of a few 100μm

MUON DETECTORS: RPC

CERN Multimedia

P. Paolucci

2012-01-01

  2011 data-taking was very satisfactory for both the RPC detector and trigger. The RPC system ran very smoothly in 2011, showing an excellent stability and very high data-tacking efficiency. Data loss for RPC was about 0.37%, corresponding to 19 pb−1. Most of the performance studies, based on 2011 data, are now completed and the results have been already approved by CMS to be presented at the RPC 2012 conference (February 2012 at LNF). During 2011, the number of disconnected chambers increased from six to eight corresponding to 0.8% of the full system, while the single-gap-mode chambers increased from 28 to 31. Most of the problematic chambers are due to bad high-voltage connection and electronic failures that can be solved only during the 2013-2014 Long Shutdown. 98.4% of the electronic channels were operational. The average detection efficiency in 2011 was about 95%, which was the same value measured during the HV scan done at the beginning of the 2011 data-taking. Efficiency has be...

Systematic study of RPC performances in polluted or varying gas mixtures compositions: an online monitor system for the RPC gas mixture at LHC

CERN Document Server

Capeans, M; Mandelli, B

2012-01-01

The importance of the correct gas mixture for the Resistive Plate Chamber (RPC) detector systems is fundamental for their correct and safe operation. A small change in the percentages of the gas mixture components can alter the RPC performance and this will rebound on the data quality in the ALICE, ATLAS and CMS experiments at CERN. A constant monitoring of the gas mixture injected in the RPCs would avoid such kind of problems. A systematic study has been performed to understand RPC performances with several gas mixture compositions and in the presence of common gas impurities. The systematic analysis of several RPC performance parameters in different gas mixtures allows the rapid identification of any variation in the RPC gas mixture. A set-up for the online monitoring of the RPC gas mixture in the LHC gas systems is also proposed.

High counting rate resistive-plate chamber

International Nuclear Information System (INIS)

Peskov, V.; Anderson, D.F.; Kwan, S.

1993-05-01

Parallel-plate avalanche chambers (PPAC) are widely used in physics experiments because they are fast ( 5 counts/mm 2 . A resistive-plate chamber (RPC) is similar to the PPAC in construction except that one or both of the electrodes are made from high resistivity (≥10 10 Ω·cm) materials. In practice RPCs are usually used in the spark mode. Resistive electrodes are charged by sparks, locally reducing the actual electric field in the gap. The size of the charged surface is about 10 mm 2 , leaving the rest of the detector unaffected. Therefore, the rate capability of such detectors in the spark mode is considerably higher than conventional spark counters. Among the different glasses tested the best results were obtained with electron type conductive glasses, which obey Ohm's law. Most of the work with such glasses was done with high pressure parallel-plate chambers (10 atm) for time-of-flight measurements. Resistive glasses have been expensive and produced only in small quantities. Now resistive glasses are commercially available, although they are still expensive in small scale production. From the positive experience of different groups working with the resistive glasses, it was decided to review the old idea to use this glass for the RPC. This work has investigated the possibility of using the RPC at 1 atm and in the avalanche mode. This has several advantages: simplicity of construction, high rate capability, low voltage operation, and the ability to work with non-flammable gases

R&D; towards future upgrade of the CMS RPC system

CERN Document Server

Pugliese, Gabriella

2016-01-01

The CMS experiment at the CERN Large Hadron Collider (LHC) is equipped with a redundant muon trigger system based on Drift Tubes Chambers (DT) in the barrel region and Cathode Strip Chamber (CSC) in the endcap regions and Resistive Plate Chambers (RPC) in both regions up to | η | = 1.6. In view of the High Luminosity LHC (HL-LHC) phase, to keep the same muon performance new muon stations will be installed in the forward region (1.6< | η | <2.4) and in the very forward region up to | η | = 2.8. The 3th and 4th stations will be equipped with a new generation of RPC with improved performance (iRPC), capable of handling the challenging con- ditions expected at the HL-LHC. An extensive R&D; program has been undertaken to define the detector design and related electronics that meet the HL-LHC requirements. A summary of iRPC performance results is here reported.

Study of the molecular structure and dynamics of bakelite with neutron cross section measurements

International Nuclear Information System (INIS)

Voi, D.L.

1990-06-01

The molecular structure and dynamics of calcined bakelite were studied with neutron transmission and scattering cross section measurements. The total cross sections determined were correlated with data obtained with infra-red spectroscopy, elemental analysis and other techniques to get the probable molecular formulae of bakelite. The total cross section determined showed a deviation smaller than 5% from the literature values. The frequency distribution as well as overall experimental results allowed to suggest a structural model like polycyclic hydrocarbons for bakelite calcined at 800 0 C. (F.E.). 65 refs, 31 figs, 5 tabs

MUON DETECTORS: RPC

CERN Multimedia

Pierluigi Paolucci

2013-01-01

In the second part of 2013 the two main activities of the RPC project are the reparation and maintenance of the present system and the construction and installation of the RE4 system. Since the opening of the barrel, repair activities on the gas, high-voltage and electronic systems are being done in parallel, in agreement with the CMS schedule. In YB0, the maintenance of the RPC detector was in the shadow of other interventions, nevertheless the scaffolding turned out to be a good solution for our gas leaks searches. Here we found eight leaking channels for about 100 l/h in total. 10 RPC/DT modules were partially extracted –– 90 cm –– in YB0, YB–1 and YB–2 to allow for the replacement of FE and LV distribution boards. Intervention was conducted on an additional two chambers on the positive endcap to solve LV and threshold control problems. Until now we were able to recover 0.67% of the total number of RPC electronic channels (1.5% of the channels...

Molecular dynamical and structural studies for the bakelite by neutron cross section measurements

International Nuclear Information System (INIS)

Voi, D.L.

1992-05-01

Neutron reaction cross sections were determined by transmission and scattering measurements, to study the dynamics and molecular structure of calcined bakelites. Total cross sections were determined, with a deviation smaller than 5%, from the literature values, by neutron transmission method and a specially devised approximation. These cross sections were then correlated with data obtained with infra-red spectroscopy, elemental analysis and other techniques to get the probable molecular formulae of bakelite. Double differential scattering cross sections, scattering law values and frequency distributions were determined with 15% error using the neutron inelastic scattering method. The frequency distributions as well as the overall results from all experimental techniques used in this work allowed to suggest a structural model like polycyclic hydrocarbons, for calcined bakelite at 800 0 C. (author)

First results of CMS RPC performance at 13 TeV

CERN Document Server

Pedraza-Morales, M.I.; Shopova, M.

2016-12-01

The muon spectrometer of the CMS (Compact Muon Solenoid) experiment at the Large Hadron Collider (LHC) is equipped with a redundant system made of Resistive Plate Chambers (RPCs) and Drift Tube (DT) chambers in the barrel, RPC and Cathode Strip Chambers (CSCs) in the endcap region. In this paper, the first results of the performance of the RPC system during 2015 with the LHC running at 13 TeV is presented. The stability of the RPC performance, in terms of efficiency, cluster size and noise, is reported.

ATLAS RPC commissioning status and cosmic ray test results

CERN Document Server

Bianco, Michele

2009-01-01

The muon trigger system of the ATLAS experiment consists of several sub-systems and each of them need to be tested and certified before LHC operation. In the barrel region Resistive Plate Chambers are employed. RPC detector and its level-1 trigger electronics are designed to detect and select high momentum muons with high time resolution and good tracking capability for a total surface of about 4000 m2. The commissioning phase provided an unique opportunity to demonstrate, before LHC start-up, the functionality of the muon trigger components such as detector chambers, level-1 trigger electronics, detector slow control system, data acquisition chain, software and computing. We present the status of ATLAS RPC detector, the problems met during the commissioning and the solutions found and, finally, its performances as obtained by acquiring cosmic rays.

Application of Gas Chromatographic analysis to RPC detectors in the ATLAS experiment at CERN-LHC

CERN Document Server

De Asmundis, R

2007-01-01

Starting from 2007 a large number (1200) Resistive Plate Chambers (RPC) detectors will be used as muon trigger detectors in the ATLAS Experiment at CERN-LHC accelerator. RPC are gaseous detector in which the quality and the stability of the gas mixture as well as the design of the gas supplying system, play a fundamental role in their functioning. RPC are foreseen to work more than ten years in the high radiation environment of ATLAS and the gas mixture acts really as a "lifeguard" for the detectors. For this reason a great attention has been devoted to the gas studies in order to optimize RPC performance, robustness and reliability in a high radiation environment. In this paper we describe the work done to decide how to supply and control in an optimal way the gas to the detectors, in order to ensure their best performance for a long time. The activity, based on Gas Chromatographic (GC) analysis, has been carried on a sample of final RPC working in radiation conditions much more intense than those foreseen f...

MUON DETECTORS: RPC

CERN Multimedia

P. Paolucci

2011-01-01

The RPC muon detector and trigger are working very well, contributing positively to the high quality of CMS data. Most of 2011 has been used to improve the stability of our system and the monitoring tools used online and offline by the shifters and experts. The high-voltage working point is corrected, chamber-by-chamber, for pressure variation since July 2011. Corrections are applied at PVSS level during the stand-by mode (no collision) and are not changed until the next fill. The single detector calibration, HV scan, of February and the P-correction described before were very important steps towards fine-tuning the stability of the RPC performances. A very detailed analysis of the RPC performances is now ongoing and from preliminary results we observe an important improvements of the cluster size stability in time. The maximum oscillation of the cluster size run by run is now about 1%. At the same time we are not observing the same stability in the detection efficiency that shows an oscillation of about ...

Uniformity and Stability of the CMS RPC Detector at the LHC

CERN Document Server

Costantini, S; Cimmino, A.; Garcia, G.; Lellouch, J.; Marinov, A.; Ocampo, A.; Strobbe, N.; Thyssen, F.; Tytgat, M.; Verwilligen, P.; Yazgan, E.; Zaganidis, N.; Dimitrov, A.; Hadjiiska, R.; Litov, L.; Pavlov, B.; Petkov, P.; Aleksandrov, A.; Genchev, V.; Iaydjiev, P.; Rodozov, M.; Shopova, M.; Sultanov, G.; Ban, Y.; Cai, J.; Ge, Y.; Li, Q.; Qian, S.; Xue, Z.; Avila, C.; Chaparro, L.F.; Gomez, J.P.; Gomez Moreno, B.; Osorio Oliveros, A.F.; Sanabria, J.C.; Assran, Y.; Sharma, A.; Abbrescia, M.; Calabria, C.; Colaleo, A.; Loddo, F.; Maggi, M.; Pugliese, G.; Benussi, L.; Bianco, S.; Colafranceschi, S.; Piccolo, D.; Buontempo, S.; Carrillo, C.; Iorio, O.; Paolucci, P.; Berzano, U.; Gabusi, M.; Vitulo, P.; Kang, M.; Lee, K.S.; Park, S.K.; Shin, S.; Choi, Y.; Goh, J.; Kim, M.S.; Seo, H.

2013-01-01

The Resistive Plate Chambers (RPCs) are employed in the CMS experiment at the LHC as dedicated trigger system both in the barrel and in the endcap. This note presents results of the RPC detector uniformity and stability during the 2011 data taking period, and preliminary results obtained with 2012 data. The detector uniformity has been ensured with a dedicated High Voltage scan with LHC collisions, in order to determine the optimal operating working voltage of each individual RPC chamber installed in CMS. Emphasis is given on the procedures and results of the High Voltage calibration. Moreover, an increased detector stability has been obtained by automatically taking into account temperature and atmospheric pressure variations in the CMS cavern.

CMS RPC muon detector performance with 2010-2012 LHC data

CERN Document Server

INSPIRE-00316302; Ban, Y.; Cai, J.; Li, Q.; Liu, S.; Qian, S.; Wang, D.; Xu, Z.; Zhang, F.; Choi, Y.; Kim, D.; Goh, J.; Choi, S.; Hong, B.; Kang, J.W.; Kang, M.; Kwon, J.H.; Lee, K.S.; Lee, S.K.; Park, S.K.; Pant, L.M.; Mohanty, A.K.; Chudasama, R.; Singh, J.B.; Bhatnagar, V.; Mehta, A.; Kumar, R.; Cauwenbergh, S.; Costantini, S.; Cimmino, A.; Crucy, S.; Fagot, A.; Garcia, G.; Ocampo, A.; Poyraz, D.; Salva, S.; Thyssen, F.; Tytgat, M.; Zaganidis, N.; Doninck, W.V.; Cabrera, A.; Chaparro, L.; Gomez, J.P.; Gomez, B.; Sanabria, J.C.; Avila, C.; Ahmad, A.; Muhammad, S.; Shoaib, M.; Hoorani, H.; Awan, I.; Ali, I.; Ahmed, W.; Asghar, M.I.; Shahzad, H.; Sayed, A.; Ibrahim, A.; Aly, S.; Assran, Y.; Radi, A.; Elkafrawy, T.; Sharma, A.; Colafranceschi, S.; Abbrescia, M.; Calabria, C.; Colaleo, A.; Iaselli, G.; Loddo, F.; Maggi, M.; Nuzzo, S.; Radogna, R.; Venditti, R.; Verwilligen, P.; Benussi, L.; Bianco, S.; Piccolo, D.; Paolucci, P.; Buontempo, S.; Cavallo, N.; Merola, M.; Fabozzi, F.; Iorio, O.M.; Braghieri, A.; Montagna, P.; Riccardi, C.; Salvini, P.; Vitulo, P.; Vai, I.; Magnani, A.; Dimitrov, A.; Litov, L.; Pavlov, B.; Petkov, P.; Aleksandrov, A.; Genchev, V.; Iaydjiev, P.; Rodozov, M.; Sultanov, G.; Vutova, M.; Stoykova, S.; Hadjiiska, R.; Ibargüen, H.S.; Morales, M.I.P.; Bernardino, S.C.; Bagaturia, I.; Tsamalaidze, Z.; Crotty, I.; Kim, M.S.

2014-12-05

The muon spectrometer of the CMS (Compact Muon Solenoid) experiment at the Large Hadron Collider (LHC) is equipped with a redundant system made of Resistive Plate Chambers and Drift Tube in barrel and RPC and Cathode Strip Chamber in endcap region. In this paper, the operations and performance of the RPC system during the first three years of LHC activity will be reported. The integrated charge was about 2 mC/cm$^{2}$, for the most exposed detectors. The stability of RPC performance, with particular attention on the stability of detector performance such as efficiency, cluster size and noise, will be reported. Finally, the radiation background levels on the RPC system have been measured as a function of the LHC luminosity. Extrapolations to the LHC design conditions and HL-LHC are also discussed.

Effect Of RPC Compositions On: Compressive Strength and Absorption

Directory of Open Access Journals (Sweden)

Ahmed Sultan Ali

2016-03-01

Full Text Available Concrete is a critical material for the construction of infrastructure facilities throughout the world. A new material known as Reactive Powder Concrete (RPC, or sometimes called Ultra-High Performance Concrete (UHPC, is becoming available that differs significantly from traditional concretes. It is an ultra high strength and high ductility composite material with advanced mechanical properties. It consists of special concrete whose microstructure is optimized by precise gradation of all particles in the mix to yield maximum density. Different RPC mixes in the experimental investigation of the present study the mechanical properties of RPC including compressive strength, density and absorption. The main variables used in the production of the different RPC mixes of the present research are three, namely, type of pozzolanic admixture (metakaolin, micro silica, and silica fume, type of fibers (steel and polypropylene fibers and volume fraction of fibers (1.0,1.5, and 2.0%. The experimental results indicated that RPC mixes with silica fume gave the highest values of compressive strength and density and lowest value of absorption in comparison with RPC using micro silica or metakaolin where metakaolin was the third in such comparisons. However the RPC mixes used in the present investigation gave group compressive strength ranging between 164 -195 MPa. It was also found that the use of steel fibers with high volume fraction (2% in an RPC mix increases the compressive strength by 8% and density of the concrete by 2.5% and reduces its absorption by 13%, unlike an RPC mix using polypropylene fibers of lesser volume fraction.

RPC HADES-TOF wall cosmic ray test performance

Energy Technology Data Exchange (ETDEWEB)

Blanco, A., E-mail: alberto@coimbra.lip.pt [Laboratorio de Instrumentacao e Fisica Experimental de Particulas, LIP, Coimbra (Portugal); Belver, D.; Cabanelas, P. [LabCAF, Universidade de Santiago de Compostela, USC, Santiago de Compostela (Spain); Diaz, J. [Instituto de Fisica Corpuscular IFIC (CSIC-Universidad de Valencia), Valencia (Spain); Fonte, P. [Laboratorio de Instrumentacao e Fisica Experimental de Particulas, LIP, Coimbra (Portugal); Instituto Superior de Engenharia de Coimbra, ISEC, Coimbra (Portugal); Garzon, J.A. [LabCAF, Universidade de Santiago de Compostela, USC, Santiago de Compostela (Spain); Gil, A. [Instituto de Fisica Corpuscular IFIC (CSIC-Universidad de Valencia), Valencia (Spain); Gonzalez-Diaz, D.; Koenig, W.; Kolb, B. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); Lopes, L. [Laboratorio de Instrumentacao e Fisica Experimental de Particulas, LIP, Coimbra (Portugal); Palka, M. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); Pereira, A. [Laboratorio de Instrumentacao e Fisica Experimental de Particulas, LIP, Coimbra (Portugal); and others

2012-01-01

In this work we present results concerning the cosmic ray test, prior to the final installation and commissioning of the new Resistive Plate Chamber (RPC) Time of Flight (TOF) wall for the High-Acceptance DiElectron Spectrometer (HADES) at GSI. The TOF wall is composed of six equal sectors, each one constituted by 186 individual 4-gaps glass-aluminium shielded RPC cells distributed in six columns and 31 rows in two partially overlapping layers, covering an area of 1.26 m{sup 2}. All sectors were tested with the final Front End Electronic (FEE) and Data AcQuisition system (DAQ) together with Low Voltage (LV) and High Voltage (HV) systems. Results confirm a very uniform average system time resolution of 77 ps sigma together with an average multi-hit time resolution of 83 ps. Crosstalk levels below 1% (in average), moderate timing tails along with an average longitudinal position resolution of 8.4 mm sigma are also confirmed.

RPC HADES-TOF wall cosmic ray test performance

International Nuclear Information System (INIS)

Blanco, A.; Belver, D.; Cabanelas, P.; Díaz, J.; Fonte, P.; Garzon, J.A.; Gil, A.; Gonzalez-Díaz, D.; Koenig, W.; Kolb, B.; Lopes, L.; Palka, M.; Pereira, A.

2012-01-01

In this work we present results concerning the cosmic ray test, prior to the final installation and commissioning of the new Resistive Plate Chamber (RPC) Time of Flight (TOF) wall for the High-Acceptance DiElectron Spectrometer (HADES) at GSI. The TOF wall is composed of six equal sectors, each one constituted by 186 individual 4-gaps glass-aluminium shielded RPC cells distributed in six columns and 31 rows in two partially overlapping layers, covering an area of 1.26 m 2 . All sectors were tested with the final Front End Electronic (FEE) and Data AcQuisition system (DAQ) together with Low Voltage (LV) and High Voltage (HV) systems. Results confirm a very uniform average system time resolution of 77 ps sigma together with an average multi-hit time resolution of 83 ps. Crosstalk levels below 1% (in average), moderate timing tails along with an average longitudinal position resolution of 8.4 mm sigma are also confirmed.

Study of the performance of RPC system installed at the CMS experiment

CERN Document Server

SHOPOVA, Mariana

2016-01-01

The CMS (Compact Muon Solenoid) experiment is a general purpose detector, located at the CERN Large Hadron Collider (LHC). It has a muon spectrometer equipped with a redundant system composed of three different detector technologies - Resistive Plate Chambers (RPCs) and Drift Tubes (DTs) in the barrel and RPC and Cathode Strip Chambers (CSCs) in the endcap region. All three are used for muon reconstruction and triggering. The RPC detector system consists of a total of 1056 double-gap chambers, covering the pseudo-rapidity region up to eta below 1.6. Here are presented the Resistive Plate Chambers performance results for the period of 2015 and 2016 with pp collisions at 13 TeV. The stability of the RPC performance is reported in terms of efficiency, cluster size and rate distributions.

ATLAS RPC Quality Assurance results at INFN Lecce

CERN Document Server

INSPIRE-00211509; Borjanovic, I.; Cataldi, G.; Cazzato, A.; Chiodini, G.; Coluccia, M. R.; Creti, P.; Gorini, E.; Grancagnolo, F.; Perrino, R.; Primavera, M.; Spagnolo, S.; Tassielli, G.; Ventura, A.

2006-01-01

The main results of the quality assurance tests performed on the Resistive Plate Chamber used by the ATLAS experiment at LHC as muon trigger chambers are reported and discussed. Since July 2004, about 270 RPC units has been certified at INFN Lecce site and delivered to CERN, for being integrated in the final muon station of the ATLAS barrel region. We show the key RPC characteristics which qualify the performance of this detector technology as muon trigger chamber in the harsh LHC enviroments. These are dark current, chamber efficiency, noise rate, gas volume tomography, and gas leakage.

Performance of the Low-Jitter High-Gain/Bandwidth Front-End Electronics of the HADES tRPC Wall

Science.gov (United States)

Belver, Daniel; Cabanelas, P.; Castro, E.; Garzon, J. A.; Gil, A.; Gonzalez-Diaz, D.; Koenig, W.; Traxler, M.

2010-10-01

A front-end electronics (FEE) chain for accurate time measurements has been developed for the new Resistive Plate Chamber (RPC)-based Time-of-Flight (TOF) wall of the High Acceptance Di-Electron Spectrometer (HADES). The wall covers an area of around 8 m2, divided in 6 sectors. In total, 1122 4-gap timing RPC cells are read-out by 2244 time and charge sensitive channels. The FEE chain consists of 2 custom-made boards: a 4-channel DaughterBOard (DBO) and a 32-channel MotherBOard (MBO). The DBO uses a fast 2 GHz amplifier feeding a dual high-speed discriminator. The time and charge information are encoded, respectively, in the leading edge and the width of an LVDS signal. Each MBO houses up to 8 DBOs providing them regulated voltage supply, threshold values via DACs, test signals and, additionally, routing out a signal proportional to the channel multiplicity needed for a 1st level trigger decision. The MBO delivers LVDS signals to a multi-purpose Trigger Readout Board (TRB) for data acquisition. The FEE allows achieving a system resolution around 75 ps fulfilling comfortably the requirements of the HADES upgrade .

Performances of RPCs in the BaBar Experiment

Energy Technology Data Exchange (ETDEWEB)

Messner, Robert

2003-09-26

The BaBar experiment uses a big system based on RPC detectors to discriminate muons from pions and to identify neutral hadrons. About 2000 m{sup 2} of RPC chambers have been working at SLAC since the end of 1998. We report on the performances of the RPC chambers focusing on new problems discovered in the RPC behavior. These problems started very soon after the installation of the chambers on the detector when the high ambient temperature triggered an increase of dark currents inside the chambers and a reduction of the efficiency. Careful analysis of the BaBar data and dedicated R&D efforts in the laboratory have helped to identify the main source of the trouble in the linseed oil varnish on the bakelite electrodes.

Rate-capability study for a four-gap phenolic RPC with a Cs-137 source

CERN Document Server

Lee, Kyong Sei

2014-01-01

We report test results of a prototype four-gap phenolic resistive plate chamber (RPC) with high-rate gamma rays irradiated from a 200-mCi 137Cs source. The detector signals of the prototype four-gap RPC were digitized at charge thresholds of 80, 130, and 170 fC by using a 32-channel front-end-electronics board, previously developed for the current double-gap RPCs in CMS. We confirmed from the test that the cosmic muons were reliably measured with efficiencies higher than 95pct up to a gamma-background rate of 5.3 kHz cm-2. We concluded from the present R and D that use of the current four-gap phenolic RPCs is advantageous to the high-η triggers in CMS in virtue of the high rate capability.

Study of the impact of environmental parameters on the operation of CMS RPCs

CERN Document Server

Assran, Yasser

2011-01-01

CMS (Compact Muon Solenoid) is a general purpose detector designed to run at the highest luminosity at Large Hadron Collider (LHC), CERN, Geneva, Switzerland. The muon system of the CMS experiment relies on Drift Tubes (DT), Cathode Strip Chambers (CSC) and Resistive Plate Chambers (RPC). RPCs are dedicated for the first level muon trigger and they are characterized by bakelite electrodes delimited in a specialized gas volume filled with operational gas mixture. This analysis has been done for the RPC chambers installed in CMS experiment at CERN. The Currents of CMS RPCs chambers are analyzed as a function of environmental parameters such as Temperature, Humidity and pressure, which are important for the operation of the muon detector system. A novel Neural Network approach has been used to analyze the data and to build a model using experimental measurements and combining the results of the simulations. Data from RPC Chambers in CMS experiment are taken and compared to the results from neural Network.

Effective deleting of residual photoconductivity in high-resistance layers GaAs

International Nuclear Information System (INIS)

Sadaev, B.S.; Kadirova, I.T.; Sharipov, E.I.

2004-01-01

Full text: The phenomenon of residual photoconductivity as the storage of optical memory (OM) represents practical interest in micro and optoelectronics. The finding - out of the nature OM represents undoubtedly and scientific interest. Now residual photoconductivity (RPC) is explained by potential barriers arising because of non-monocharacteristical of distribution components of the semiconductor or carriers of a current in volume. Depending on a nature non-monocharacteristical the time relaxation RPC changes in a wide limit. The special interest represents RPC created by impurity. In the given work the results of research of a nature RPC created photos by ionization of the filled centres of chrome in compensated epitaxilogic layers arsenide galls are resulted. Epitaxilogic layers were brought up by a vertical method ZFE. Highness was reached (achieved) by special indemnification of the residual donors deep acceptors of chrome. Substrates served n-GoAs. Lassitude of i-layers has made 70-80 microns. Specific resistance of layers has made (1/3) 108 om·sm. (T= 300 K). The structures were photosensitive as at low (T = 77 K) and at room temperatures. The photosensitivity of structures in impurity to a strip of absorption chrome (= 1,4 microns) was comparable (compared) with own. The researches show, that the structures have RPC. Size RPC the greatest ambassador impurity of illumination is carrying out photoionization Cr2 + - of the centres. That is established, RPC impurity of a photocurrent is effectively erased only at certain length of a wave of external illumination

MUON DETECTORS: RPC

CERN Multimedia

G. Iaselli.

Substantial progress has been made on the RPC system resulting in a high standard of operation. Impressive improvements have been made in the online software and DCS PVSS protocols that ensure robustness of the configuration phase and reliability of the detector monitoring tasks. In parallel, an important upgrade of CCU ring connectivity was pursued to avoid noise pick-up and consequent  data transmission errors during operation with magnetic field. While the barrel part is already well synchronized thanks to the long cosmics runs, some refinements are still required on the forward part. The "beam splashes" have been useful to cross check  the existing delay constants, but further efforts will be made as soon as a substantial sample of beam-halo events is available. Progress has been made on early detector performance studies. The RPC DQM tool is being extensively used and minor bugs have been found. More plots have been added and more people have been tr...

DAQ system for testing RPC front-end electronics of the INO experiment

International Nuclear Information System (INIS)

Hari Prasad, K.; Sukhwani, Menka; Kesarkar, Tushar A.; Kumar, Sandeep; Chandratre, V.B.; Das, D.; Shinde, R.R.; Satyanarayana, B.

2015-01-01

The Resistive Plate Chamber (RPC) is the active detector element in the INO experiment. The in-house developed ANUSPARSH-III ASICs are being used as front-end electronics of the detector. The 2 m X 2 m RPC being used has 64-readout channels on X-side and 64-readout channels on Y-side. In order to test and validate the FE along with the RPC, a 64-channel DAQ system has been designed and developed. The detector parameters to be measured are noise rate, efficiency, hit pattern register and time resolution. The salient features of the DAQ system are: 64-channel LVDS receiver in FPGA, FPGA based parameter calculations and a micro controller for acquiring the processed data from FPGAs and sent through Ethernet and USB interfaces. The DAQ system consists of following parts: Two FPGAs each receiving 32 LVDS channels, FPGA firm-ware, micro controller firm-ware, Ethernet interface, embedded web server hosting data analysis software, USB interface, and Lab-windows based data analysis software. The DAQ system has been tested at TIFR with 1 m X 1 m RPC

MUON DETECTORS: RPC

CERN Multimedia

G. Iaselli

2010-01-01

During the technical stop, the RPC team was part of the CMS task force team working on bushing replacements in the Endcap cooling system, also validating the repairs in terms of connectivity (HV, LV and signal cables), and gas leak, on RE chambers. In parallel, the RPC team profited from the opportunity to cure several known problems: six chambers with HV problems (1 off + 5 single gaps) were recovered on both gaps; four known HV problems were localized at chamber level; additional temperature sensors were installed on cooling pipes on negative REs; one broken LV module in RE-1 was replaced. During the last month, the RPC group has made big improvements in the operations tools. New trigger supervisor software has substantially reduced the configuration time. Monitoring is now more robust and more efficient in providing prompt diagnostics. The detector has been under central DCS control for two weeks. Improvements have been made to both functionality and documentation and no major problems were found. Beam s...

A high-voltage test for the ATLAS RPC qualification

CERN Document Server

Aielli, G; Cardarelli, R; Di Ciaccio, A; Di Simone, A; Liberti, B; Santonico, R

2004-01-01

The RPC production sequence for the ATLAS experiment includes a specific test of current absorption at the operating point, which concerns the RPC "gas volumes", namely the bare detectors not yet assembled with the read-out panels and the mechanical support structures. The test, which is carried out at the production site, consists of two phases. The gas volumes are initially conditioned with pure argon, keeping the voltage constant just above the breakdown value of about 2 kV. The final test, performed after the volumes have undergone inner surface varnishing with linseed oil, is based on the measurement of the current-voltage characteristics with the binary operating gas, C//2H//2F//4/i-C//4H//1//0 = 95/5. The results presented here concern 45% of the total foreseen production.

A high-voltage test for the ATLAS RPC qualification

International Nuclear Information System (INIS)

Aielli, G.; Camarri, P.; Cardarelli, R.; Di Ciaccio, A.; Di Simone, A.; Liberti, B.; Santonico, R.

2004-01-01

The RPC production sequence for the ATLAS experiment includes a specific test of current absorption at the operating point, which concerns the RPC 'gas volumes', namely the bare detectors not yet assembled with the read-out panels and the mechanical support structures. The test, which is carried out at the production site, consists of two phases. The gas volumes are initially conditioned with pure argon, keeping the voltage constant just above the breakdown value of about 2 kV. The final test, performed after the volumes have undergone inner surface varnishing with linseed oil, is based on the measurement of the current-voltage characteristics with the binary operating gas, C2H2F4/i-C4H10=95/5. The results presented here concern 45% of the total foreseen production

MUON DETECTORS: RPC

CERN Multimedia

P. Paolucci

2012-01-01

  Since the start of data-taking in 2012, the RPCs have been operating in a stable manner with average chamber efficiencies above 95%. At present, the number of missing electronic channels is 1.2%; the number of disconnected chambers is 9, while 34 chambers are in single-gap mode. All those numbers are stable since the 2011 run. So far in 2012 no luminosity has been lost due to RPCs. During the winter shutdown, link board protections have been installed everywhere and are working properly, which makes the system more robust than before. A new “gas resistance” measurement campaign showed a clear stability of this parameter, which is proportional to the gap resistivity. No differences with respect to 2011 were found. A new efficiency calculation method has been validated, where now only DT/CSC segments of high quality that are associated with a stand-alone muon track are used to reduce the effect of punch-through segments. With this method, the observed oscillations in the RPC e...

RPC Trigger Robustness: Status Report

CERN Document Server

Di Mattia, A; Nisati, A; Pastore, F; Vari, R; Veneziano, Stefano; Aielli, G; Camarri, P; Cardarelli, R; Di Ciaccio, A; Di Simone, A; Liberti, B; Santonico, R

2002-01-01

The present paper describes the Level-1 Barrel Muon Trigger performance as expected with the current configuration of the RPC detectors designed for the Barrel Muon Spectrometer of ATLAS. Results of a beam test performed at the X5-GIF facility at CERN are presented in order to show the trigger efficiency with different conditions of RPC detection efficiency and several background rates. Small (50$\\times$50 cm$^2$) RPC chambers with final Front-end electronics and splitter boards are used in the test, while the coincidence logic is applied off-line using a detailed simulation of the coincidence matrix.

MUON DETECTORS: RPC

CERN Multimedia

P. Paolucci

2013-01-01

  In 2013 the main activities of the RPC project are: maintenance and repair of the present system, RE4 chambers installation, and commissioning and upgrade of the online and offline software. About 25 FTE are working on the three items since January and will continue until the end of 2014. Three groups of physicists and technicians (HV, Gas and Front-End) are ready for the repair of the present system. Most of the equipment needed has been tested in the laboratory and is ready to be used at P5. The foreseen interventions have been included in the CMS schedule; they will begin in June 2013 and finish in summer 2014. DPG and Online experts are designing the upgrade of the RPC online and offline tools in order to integrate the new RE4 chambers and at the same time improve them using the experience from the 2010–2012 data-taking period. The RPC RE4 upgrade project is proceeding very well; it is on schedule and within the budget. 17 chambers have been built and tested at CERN, Ghent (Belg...

MUON DETECTORS: RPC

CERN Document Server

G. Iaselli

The RPC group has invested a large effort in the study of trigger spikes observed during CRAFT data taking. The chambers are susceptible to noise generated by the flickering of fluorescent and projector lamps in the cavern (with magnetic field on). Soon after the end of CRAFT, it was possible to reproduce the phenomena using a waveform generator and to study possible modifications to be implemented in the grounding schema. Hardware actions have been already taken in order to reduce the detector sensitivity: star washers on the chamber front panels and additional shielding have been added where possible. During the shutdown maintenance activity many different problems were tackled on the barrel part. A few faulty high voltage connector/cable problems were fixed; now only two RPC chambers are left with single-gap mode operation. One chamber in YB+2 was replaced due to gas leakage. All the front-end electronic boards were replaced in 3 chambers (stations MB2 and MB3 in YB-2), that had been damaged after the coo...

Online gas analysis and diagnosis for RPC detectors in the ATLAS experiment

International Nuclear Information System (INIS)

De Asmundis, Riccardo

2007-01-01

Resistive Plate Counters (RPC) detectors need a very strict control of gas parameters: motivations for this statement come from both the request of stability in the detector working point, and chemical consideration concerning potentially aggressive materials generated during the ionization processes into the sensitive gap; the latter point can be relevant because of a possible damage to the internal surface of the detector that has to be avoided in order to ensure an high detection efficiency of the RPC during their ten years or more of operation in ATLAS. In order to understand these aspects, detailed studies on gas behavior have been carried on at the GIF-X5 at CERN (2002-2005), based on Gas Chromatographic and spectroscopy techniques. Main results of these analysis are presented here, together with the design of the online analyzer to be installed on ATLAS conceived to keep control of gas quality and to trigger maintenance interventions on the gas system, in particular on the purification subsystem

Preliminary Cluster Size and Efficiencies results of CMS RPC at GIF++

CERN Document Server

Gonzalez Blanco Gonzalez, Genoveva

2016-01-01

A brief description and first preliminary results of the Efficiencies and Cluster Size measurements of the CMS Resistive Plate Chambers, will be presented inside the Gamma Irradiation Facility GIF++ at CERN. Preliminary studies that sets the base performance measurements of CMS RPC for starting aging studies.

Radiation Tests of Real-Sized Prototype RPCs for the Future CMS RPC Upscope

CERN Document Server

Lee, K.S.; Choi, S.Y.; Hong, B.; Go, Y.; Kang, M.H.; Lim, J.H.; Park, S.K.; Cimmino, A.; Crucy, S.; Fagot, A.; Gul, M.; Rios, A.A.O.; Tytgat, M.; Zaganidis, N.; Aly, S.; Assran, Y.; Radi, A.; Sayed, A.; Singh, G.; Abbrescia, M.; Iaselli, G.; Maggi, M.; Pugliese, G.; Verwilligen, P.; Doninck, W.van; Colafranceschi, S.; Sharma, A.; Benussi, L.; Bianco, S.; Piccolo, D.; Primavera, F.; Bhatnagar, V.; Kumarl, R.; Metha, A.; Singh, J.; Ahmad, A.; Ahmad, M.; Ahmed, W.; Asghar, M.I.; Awan, I.M.; Hassan, Q.; Hoorani, H.; Khan, W.A.; Khurshid, T.; Muhammad, S.; Shah, M.A.; Shahzad, H.; Kim, M.S.; Goutzvitz, M.; Grenier, G.; Lagarde, F.; Laktineh, I.B.; Carpinteyro Bernardino, S.; Uribe Estrada, C.; Pedraza, I.; Severiano, C.B.; Carrillo Moreno, S.; Vazquez Valencia, F.; Pant, L.M.; Buontempo, S.; Cavallo, N.; Esposito, M.; Fabozzi, F.; Lanza, G.; Lista, L.; Meola, S.; Merola, M.; Orso, I.; Paolucci, P.; Thyssen, F.; Braghieri, A.; Magnani, A.; Montagna, P.; Riccardi, C.; Salvini, P.; Vai, I.; Vitulo, P.; Ban, Y.; Qian, S.J.; Choi, M.; Choi, Y.; Goh, J.; Kim, D.; Aleksandrov, A.; Hadjiiska, R.; Iaydjiev, P.; Rodozov, M.; Stoykova, S.; Sultanov, G.; Vutova, M.; Dimitrov, A.; Litov, L.; Pavlov, B.; Petkov, P.; Lomidze, D.; Avila, C.; Cabrera, A.; Sanabria, J.C.; Crotty, I.; Vaitkus, J.

2016-08-10

We report on a systematic study of double-gap and four-gap phenolic resistive plate chambers (RPCs) for future high-{\\eta} RPC triggers in the CMS. In the present study, we constructed real-sized double-gap and four-gap RPCs with gap thicknesses of 1.6 and 0.8 mm, respectively, with 2-mm-thick phenolic high-pressure-laminated (HPL) plates. We examined the prototype RPCs for cosmic rays and 100 GeV muons provided by the SPS H4 beam line at CERN. We applied maximum gamma rates of 1.5 kHz cm-2 provided by 137Cs sources at Korea University and the GIF++ irradiation facility installed at the SPS H4 beam line to examine the rate capabilities of the prototype RPCs. In contrast to the case of the four-gap RPCs, we found the relatively high threshold was conducive to effectively suppressing the rapid increase of strip cluster sizes of muon hits with high voltage, especially when measuring the narrow-pitch strips. The gamma-induced currents drawn in the four-gap RPC were about one-fourth of those drawn in the double-ga...

The upgrade of the RPC-based ALICE Muon Trigger arXiv

CERN Document Server

INSPIRE-00033003

The ALICE Muon Trigger is currently yielded by a detector currently composed of 72 Bakelite single-gap Resistive Plate Chambers operated in maxi-avalanche mode, arranged in four 5.5x6.5 m2 detection planes. In order to meet the requirements posed by the forthcoming LHC high luminosity runs starting from 2021 onwards, in which ALICE will be read out in continuous mode, the Muon Trigger will become a Muon Identifier and will undergo a major upgrade. In the current setup, signals from about 21k strips are discriminated by 2400 non-amplified Front End (FEE) cards, whose thresholds are provided by external analog voltages (one for each chamber side). All these cards will be replaced with discriminators equipped with a pre-amplification stage which will allow a reduction in the operating high voltage of the detectors, thus prolonging their lifetime. Furthermore, their reference thresholds will be passed via wireless (and I2C chained per chamber side) allowing the tuning of the values at the single card level. Moreo...

Avalanche fluctuations within the multigap resistive plate chamber

International Nuclear Information System (INIS)

Cerron Zeballos, E.; Crotty, I.; Lamas Valverde, J.; Veenhof, R.J.; Williams, M.C.S.; Zichichi, A.

1996-01-01

The multigap resistive plate chamber (MRPC) was originally designed to have improved time resolution (compared to the wide gap RPC), but also to keep the good high rate behaviour and ease of construction associated with the wide gap RPC. However in addition we observed a very long efficiency plateau, even at high rates. Here we consider fluctuations in avalanche growth, and show that the inherent ''averaging'' of these fluctuations can account for the enhanced performance of the multigap RPC. (orig.)

New high-temperature flame-resistant resin matrix for RP/C

Science.gov (United States)

Kourtides, D. A.

1981-01-01

The processing parameters of graphite composites utilizing graphite fabric and epoxy or other advanced thermoset and thermoplastic resins as matrices are discussed. The evaluated properties include anaerobic char yield, limiting oxygen index, smoke evolution, moisture absorption, and high-temperature mechanical properties. It is shown that graphite composites having the highest char yield exhibit optimum fire-resistant properties.

Study of the RPC Level-1 trigger efficiency in the compact muon solenoid at LHC with cosmic ray data

Energy Technology Data Exchange (ETDEWEB)

Iorio, A.O.M., E-mail: oiorio@cern.ch

2012-01-01

We report a study of the Resistive Plate Chambers (RPC) Level-1 (L1) trigger system efficiency in the Barrel of the Compact Muon Solenoid (CMS) detector of LHC in the same region covered also by the DT trigger system. The method used to study the efficiency exploits the independency of the CMS Drift Tube (DT) and RPC trigger systems. Muon tracks in the event are triggered and reconstructed using the Drift Tube subsystem only, and for each of them we search for a compatible RPC L1 trigger object. We discuss in detail the method and the results of the performance obtained with cosmic ray data taken in 2008-2009.

RPC industries - UV and EB equipment manufacturers

International Nuclear Information System (INIS)

Rodrigues, A.M.

1987-01-01

RPC Industries has been manufacturing electron beam and ultraviolet equipment for the industrial processing of materials for more than 15 years. RPC maintains its headquarters and electron processor manufacturing plant in Hayward, California. UV equipment is made in the company's plant near Chicago. Sales offices are maintained in New York, Illinois, and California in the USA, and in Germany, Japan, Australia, Italy, Israel, and Sweden. Complete testing and pilot facilities are available in Hayward (EB) and near Chicago (UV). Described below are the basic system components, applications and advantages of RPC's UV and EB systems. (orig.)

Resistive Plate Chambers commissioning and performance results for 2015

CERN Document Server

CMS Collaboration

2016-01-01

The Resistive Plate Chamber (RPC) detector system at the Compact Muon Solenoid experiment at the LHC confers robustness and redundancy to the muon trigger. During the first long shutdown of the LHC (2013-2014) the CMS muon RPC system has been upgraded with 144 double-gap chambers on the forth forward stations. A total of 1056 double-gap chambers cover the pseudo-rapidity region up to 1.6. The main detector parameters are constantly and closely monitored to achieve operational stability and high quality data in the harsh conditions of the second run period of the LHC (13 TeV and 25 ns bunch spacing). Resistive Plate Chambers (RPC) performance results for 2015 with pp collisions at 13 TeV are presented. These results include the occupancy, efficiency of newly installed detectors after applying new working point, history plots for the RPC relevant variables such as: Cluster Size, Efficiency, percentage of inactive detector during operation and Rates and overall system noise. RPC variables are studied as funct...

The RPC system for the CMS experiment at the LHC

Energy Technology Data Exchange (ETDEWEB)

Abbrescia, M.; Colaleo, A.; Iaselli, G.; Loddo, F.; Maggi, M.; Marangelli, B.; Natali, S.; Nuzzo, S.; Pugliese, G.; Ranieri, A.; Romano, F.; Altieri, S.; Belli, G.; Bruno, G. E-mail: giacomo.bruno@cern.ch; Guida, R.; Ratti, S.P.; Riccardi, C.; Torre, P.; Vitulo, P

2003-08-01

The CMS detector at the LHC has a redundant muon system. Two independent muon systems are used in the L1 trigger. One of them is based on wire chambers, the other on RPC detectors. Properly combining the answers of the two systems results in a highly efficient L1 trigger with high flexibility from the point of view of rate control. Simulation results show, however, that the RPC system suffers from false triggers caused by coincidence of spurious hits. System improvements, which could avoid oiling the chambers, are possible. RPCs have also proved to be very useful for muon track reconstruction.

Performance of ATLAS RPC Level-1 Muon trigger during the 2015 data taking

CERN Document Server

Corradi, Massimo; The ATLAS collaboration

2016-01-01

The Level-1 Muon Barrel Trigger is one of the main elements of the event selection of the ATLAS experiment at the Large Hadron Collider. Its input stage consists of an array of processors receiving the full granularity of data from Resistive Plate Chambers in the central area of the ATLAS detector ("Barrel"). The trigger efficiency and the level of synchronisation of its elements with the rest of ATLAS and the LHC clock are crucial figures of this system: many parameters of the constituent RPC detector and the trigger electronics have to be constantly and carefully checked to assure a correct functioning of the Level-1 selection. Notwithstanding the complexity of such a large array of integrated RPC detectors, the ATLAS Level-1 system has resumed operations successfully after the past 2 year shutdown, with levels similar to those of Run 1. We present the inclusive monitoring of the RPC+L1 system that we have developed to characterise the behaviour of the system, using reconstructed muons in events selected by...

QA in Radiation Therapy: The RPC Perspective

Science.gov (United States)

Ibbott, G. S.

2010-11-01

The Radiological Physics Center (RPC) is charged with assuring the consistent delivery of radiation doses to patients on NCI-sponsored clinical trials. To accomplish this, the RPC conducts annual mailed audits of machine calibration, dosimetry audit visits to institutions, reviews of treatment records, and credentialing procedures requiring the irradiation of anthropomorphic phantoms. Through these measurements, the RPC has gained an understanding of the level of quality assurance practiced in this cohort of institutions, and a database of measurements of beam characteristics of a large number of treatment machines. The results of irradiations of phantoms have yielded insight into the delivery of advanced technology treatment procedures.

QA in Radiation Therapy: The RPC Perspective

International Nuclear Information System (INIS)

Ibbott, G S

2010-01-01

The Radiological Physics Center (RPC) is charged with assuring the consistent delivery of radiation doses to patients on NCI-sponsored clinical trials. To accomplish this, the RPC conducts annual mailed audits of machine calibration, dosimetry audit visits to institutions, reviews of treatment records, and credentialing procedures requiring the irradiation of anthropomorphic phantoms. Through these measurements, the RPC has gained an understanding of the level of quality assurance practiced in this cohort of institutions, and a database of measurements of beam characteristics of a large number of treatment machines. The results of irradiations of phantoms have yielded insight into the delivery of advanced technology treatment procedures.

Laser beam studies of RPC behaviour in avalanche mode

Energy Technology Data Exchange (ETDEWEB)

Golovatyuk, V. E-mail: slava@le.infn.it; Grancagnolo, F.; Perrino, R

2003-08-01

Primary ionization is created inside the gas gap of a small size (10x20 cm{sup 2}) RPC, analogous to the RPC of the ATLAS muon detector, by focusing a pulsed (width {<=}0.5 ns) nitrogen laser beam (transverse diameter {approx}15 {mu}m). With this set-up we can characterize the behaviour of the RPC by measuring such parameters as drift velocity and gas amplification. For an ATLAS-like gas mixture (97% C{sub 2}H{sub 2}F{sub 4}, 3% isobutane and a small addition of SF{sub 6}), we have evidence of a space charge influence on RPC rate capability.

The Upgrade of the CMS RPC System during the First LHC Long Shutdown

CERN Document Server

Tytgat, M.; Verwilligen, P.; Zaganidis, N.; Aleksandrov, A.; Genchev, V.; Iaydjiev, P.; Rodozov, M.; Shopova, M.; Sultanov, G.; Assran, Y.; Abbrescia, M.; Calabria, C.; Colaleo, A.; Iaselli, G.; Loddo, F.; Maggi, M.; Pugliese, G.; Benussi, L.; Bianco, S.; Caponero, M.; Colafranceschi, S.; Felli, F.; Piccolo, D.; Saviano, G.; Carrillo, C.; Berzano, U.; Gabusi, M.; Vitulo, P.; Kang, M.; Lee, K.S.; Park, S.K.; Shin, S.; Sharma, A.

2012-01-01

The CMS muon system includes in both the barrel and endcap region Resistive Plate Chambers (RPC). They mainly serve as trigger detectors and also improve the reconstruction of muon parameters. Over the years, the instantaneous luminosity of the Large Hadron Collider gradually increases. During the LHC Phase 1 (~first 10 years of operation) an ultimate luminosity is expected above its design value of 10^34/cm^2/s at 14 TeV. To prepare the machine and also the experiments for this, two long shutdown periods are scheduled for 2013-2014 and 2018-2019. The CMS Collaboration is planning several detector upgrades during these long shutdowns. In particular, the muon detection system should be able to maintain a low-pT threshold for an efficient Level-1 Muon Trigger at high particle rates. One of the measures to ensure this, is to extend the present RPC system with the addition of a 4th layer in both endcap regions. During the first long shutdown, these two new stations will be equipped in the region |eta|<1.6 with...

VT Boundaries - RPC polygons

Data.gov (United States)

Vermont Center for Geographic Information — (Link to Metadata) The BNDHASH dataset depicts Vermont villages, towns, counties, Regional Planning Commissions (RPC), and LEPC (Local Emergency Planning Committee)...

Study of the molecular structure and dynamics of bakelite with neutron cross section measurements; Estudo da estrutura e da dinamica moleculares da baquelite atraves de medidas de secoes de choque para neutrons

Energy Technology Data Exchange (ETDEWEB)

Voi, D L

1990-06-01

The molecular structure and dynamics of calcined bakelite were studied with neutron transmission and scattering cross section measurements. The total cross sections determined were correlated with data obtained with infra-red spectroscopy, elemental analysis and other techniques to get the probable molecular formulae of bakelite. The total cross section determined showed a deviation smaller than 5% from the literature values. The frequency distribution as well as overall experimental results allowed to suggest a structural model like polycyclic hydrocarbons for bakelite calcined at 800{sup 0} C. (F.E.). 65 refs, 31 figs, 5 tabs.

Characterization of RPC operation with new environmental friendly mixtures for LHC application and beyond

International Nuclear Information System (INIS)

Guida, R.; Capeans, M.; Mandelli, B.

2016-01-01

The large muon trigger systems based on Resistive Plate Chambers (RPC) at the LHC experiments are currently operated with R134a based mixture. Unfortunately R134a is considered a greenhouse gas with high impact on the enviroment and therefore will be subject to regulations aiming in strongly reducing the available quantity on the market. The immediat effects might be instability on the price and incertitude in the product availability. Alternative gases (HFO-1234yf and HFO-1234ze) have been already identified by industry for specific applications as replacement of R134a. Moreover, HFCs similar to the R134a but with lower global warming potential (GWP) are already available (HFC-245fa, HFC-32, HFC-152a). The present contribution describes the results obtained with RPCs operated with new enviromemtal friendly gases. A particular attention has been addressed to the possibility of maintening the current operation conditions (i.e. currently used applied voltage and front-end electronics) in order to be able to use a new mixture for RPC systems even where the common infrastructure (i.e. high voltage and detector components) cannot be replaced for operation at higher applied voltages.

Performance of a multigap RPC prototype for the LHCb muon system

CERN Document Server

Colrain, P; De Paula, L S; Gandelman, M; Lamas-Valverde, J; Moraes, D; Polycarpo, E; Schmidt, B; Schneider, T; Wright, A; Maréchal, B

2000-01-01

Several technologies are under consideration for the muon system of the LHCb experiment. Resistive Plate Chambers (RPCs) are one of the favourite candidates for the outer areas where the particle fluxes are expected to be at most some kHz/cm/sup 2/. This work describes the results obtained with a multigap RPC prototype under various beam conditions at the CERN facilities. (9 refs).

Comparison Study of Axial Behavior of RPC-CFRP Short Columns

Directory of Open Access Journals (Sweden)

Taghreed Khaleefa Mohammed Ali

2015-05-01

Full Text Available In this paper, the axial behaviors of reactive powder     concrete (RPC short  columns confined with carbon fiber reinforced polymer (CFRP were   investigated. All the specimens have square cross section of 100 mm × 100   mm and length of 400 mm with aspect ratio 4. The experimental work consists   of three groups. The first group consists of six specimens of RPC with 2%  micro steel fiber, without ordinary reinforcing steel and confining by zero, one and two layer of CFRP respectively. The second group consists of six    specimens of RPC with 2% micro steel fiber and minimum ordinary reinforcing  steel and confining by zero, one and two layers of CFRP respectively. The third  group consists of four specimens of RPC without micro steel fiber and ordinary  reinforcing steel and confining by one and two layers of CFRP respectively.  Experimental data for strength, longitudinal and lateral displacement and  failure mode were obtained for each test. The toughness (area under the curve  for each test was obtained by using numerical integration. The RPC columns confined with CFRP showed stiffer behavior compared with RPC columns without CFRP. The ultimate load of the RPC columns with 2% micro steel  fiber + two layers of CFRP + minimum ordinary reinforcement were more than that of the RPC columns with 2% micro steel fiber + minimum ordinary   reinforcement and without CFRP by about 1.333.

First results on RB2 muon barrel RPC detector for CMS

Energy Technology Data Exchange (ETDEWEB)

Abbrescia, M.; Altieri, S.; Belli, G.; Bruno, G.; Colaleo, A. E-mail: anna.colaleo@cern.ch; Guida, R.; Iaselli, G.; Loddo, F.; Maggi, M.; Marangelli, B.; Natali, S.; Nuzzo, S.; Pugliese, G.; Ranieri, A.; Ratti, S.P.; Riccardi, C.; Romano, F.; Torre, P.; Vanini, S.; Vitulo, P

2003-08-01

The first CMS MB2 station, with one RPC and one DT module, has been tested with a muon beam under a high intensity photon flux at the CERN Gamma Irradiation Facility during the Autumn 2001 test. Results on efficiency, rate capability, cluster size and spatial resolution, for the RPC detector, are reported here. Studies with a small percentage of SF{sub 6} in the gas mixture, in order to decrease the noise rate, have also been carried out.

RPC operation at high temperature

CERN Document Server

Aielli, G; Cardarelli, R; Di Ciaccio, A; Di Stante, L; Liberti, B; Paoloni, A; Pastori, E; Santonico, R

2003-01-01

The resistive electrodes of RPCs utilised in several current experiments (ATLAS, CMS, ALICE, BABAR and ARGO) are made of phenolic /melaminic polymers, with room temperature resistivities ranging from 10**1**0 Omega cm, for high rate operation in avalanche mode, to 5 multiplied by 10**1**1 Omega cm, for streamer mode operation at low rate. The resistivity has however a strong temperature dependence, decreasing exponentially with increasing temperature. We have tested several RPCs with different electrode resistivities in avalanche as well as in streamer mode operation. The behaviours of the operating current and of the counting rate have been studied at different temperatures. Long-term operation has also been studied at T = 45 degree C and 35 degree C, respectively, for high and low resistivity electrodes RPCs.

Geometrical Acceptance Analysis for RPC PAC Trigger

CERN Document Server

Seo, Eunsung

2010-01-01

The CMS(Compact Muon Solenoid) is one of the four experiments that will analyze the collision results of the protons accelerated by the Large Hardron Collider(LHC) at CERN(Conseil Europen pour la Recherche Nuclaire). In case of the CMS experiment, the trigger system is divided into two stages : The Level-1 Trigger and High Level Trigger. The RPC(Resistive Plate Chamber) PAC(PAttern Comparator) Trigger system, which is a subject of this thesis, is a part of the Level-1 Muon Trigger System. Main task of the PAC Trigger is to identify muons, measures transverse momenta and select the best muon candidates for each proton bunch collision occurring every 25 ns. To calculate the value of PAC Trigger efficiency for triggerable muon, two terms of different efficiencies are needed ; acceptance efficiency and chamber efficiency. Main goal of the works described in this thesis is obtaining the acceptance efficiency of the PAC Trigger in each logical cone. Acceptance efficiency is a convolution of the chambers geometry an...

Study of the CMS RPC detector performance in high radiation background conditions

CERN Document Server

Miguel Colin, Osvaldo

2017-01-01

The RPC system at the CMS Detector is operating successfully from beginning of the data taking. The high instantaneous luminosity causes an extremely high flux of ionizing particles. The long period of operation (Run1 and Run2) in a huge radiation background conditions, gives the opportunity to study the operation capability of the RPCs and also to predict a data-driven extrapolation about the expecting particle rates at HL LHC (High Luminosity) scenario. The obtained results in terms of measured rate, currents and integrated charged will be presented in the poster. When it is possible they will be compared to the relevant results obtained from the dedicated study where a set of test chambers have been irradiated at GIF++ laboratory setup.

CMS RPC detectors assembled in Pakistan installed on the backside of the YE+1 endcap yoke

CERN Multimedia

Walter Van Doninck, VUB-Brussels and CERN

2006-01-01

Resistive Plate Chambers (RPCs) are sensitive to the passage of muons and provide a "trigger" signal for CMS. This image shows RPC detectors, which were assembled in Pakistan, installed on the backside of an endcap yoke disc, known as YE+1.

Performance of glass RPC with industrial silk-screen-printed electrodes

International Nuclear Information System (INIS)

Ambrosio, M.; Candela, A.; De Deo, M.; D'Incecco, M.; Gamba, D.; Giuliano, A.; Gustavino, C.; Morganti, S.; Redaelli, N.; Tonazzo, A.; Trinchero, G.C.

2003-01-01

In this paper we describe the performance of several Glass RPCs, where the water-based graphite coating is replaced by a synthetic coating applied using the screen printing technique. As expected, the performance of the detectors is good and reproducible due to the accurate control of the coating resistivity value. The resistance of the coating to the action of mechanical and chemical agents permits an easy electrode cleaning and mounting with respect to the RPC coated with the graphite varnish. This coating, together with the use of float glass as electrode material, allows an industrial production, where the detector characteristics can be tailored as a function of the experiment requirements

Custom pulse generator for RPC testing

International Nuclear Information System (INIS)

Gil, A.; Castro, E.; Diaz, J.; Fonte, P.; Garzon, J.A.; Montes, N.; Zapata, M.

2009-01-01

We present a pulse generator able to generate pulses statistically similar to the ones produced by RPC cells. The device generates up to four arrays of fast and narrow random-like pulses. Polarity, maximum amplitudes, widths and pulse rate in each channel may be modified independently in order to simulate different RPC setups and environments. This portable and cost-effective pulse generator is a versatile instrument for testing FE-Electronics and different real detector features related with the signal propagation inside the detector. It has been developed in the framework of the ESTRELA project of the HADES experiment at GSI.

Charge Distribution Dependency on Gap Thickness of CMS Endcap RPC

CERN Document Server

Park, Sung K.; Lee, Kyongsei

2016-01-01

We report a systematic study of charge distribution dependency of CMS Resistive Plate Chamber (RPC) on gap thickness. Prototypes of double-gap RPCs with six different gap thickness ranging from from 1.0 to 2.0 mm in 0.2-mm steps have been built with 2-mm-thick phenolic high-pressure-laminated plates. The efficiencies of the six gaps are measured as a function of the effective high voltages. We report that the strength of the electric fields of the gap is decreased as the gap thickness is increased. The distributions of charges in six gaps are measured. The space charge effect is seen in the charge distribution at the higher voltages. The logistic function is used to fit the charge distribution data. Smaller charges can be produced within smaller gas gap. But the digitization threshold should be also lowered to utilize these smaller charges.

A configurable tracking algorithm to detect cosmic muon tracks for the CMS-RPC based technical trigger

CERN Document Server

Rajan, R T; Loddo, F; Maggi, M; Ranieri, A; Abbrescia, M; Guida, R; Iaselli, G; Nuzzo, S; Pugliese, G; Roselli, G; Trentadue, R; Tupputi, b, S; Benussi, L; Bertani, M; Bianco, S; Fabbri, F; Cavallo, N; Cimmino, e, A; Lomidze, D; Noli, P; Paolucci, P; Piccolo, D; Polese, G; Sciacca, C; Baesso, g, P; Belli, G; Necchi, M; Ratti, S P; Pagano, D; Vitulo, P; Viviani, C; Dimitrov, A; Litov, L; Pavlov, B; Petkov, P; Genchev, V; Iaydjiev, P; Bunkowski, K; Kierzkowski, K; Konecki, M; Kudla, I; Pietrusinski, M; Pozniak, K

2009-01-01

In the CERN CMS experiment at LHC Collider special trigger signals called Technical Triggers will be used for the purpose of test and calibration. The Resistive Plate Chambers (RPC) based Technical Trigger system is a part of the CMS muon trigger system and is designed to detect cosmic muon tracks. It is based on two boards, namely RBC (RPC Balcony Collector) and TTU (Technical Trigger Unit). The proposed tracking algorithm (TA) written in VHDL and implemented in the TTU board detects single or multiple cosmic muon tracks at every bunch crossing along with their track lengths and corresponding chamber coordinates. The TA implementation in VHDL and its preliminary simulation results are presented.

RPC gas recovery by open loop method

Energy Technology Data Exchange (ETDEWEB)

Joshi, Avinash [Alpha Pneumatics, 11, Krishna Kutir, Madanlal Dhigra Road, Panch Pakhadi (India)], E-mail: alpha_pneumatics@hotmail.com

2009-05-01

RPC detectors require to be flushed with small but continuous flow of gas mixture. Dealing with large number of detectors, gas consumption to very large volumes. Gas flow is a running expense and constituent gases are too expensive to be treated as consumables. Exhaust gas mixture from detectors is a potential environmental hazard if discharged directly into the atmosphere. Storage of gases on a large scale also leads to inventory- and safety-related problems. A solution to these problems is the recovery and reuse of exhaust gas mixture from RPC detectors. Close loop method employs recirculation of exhausted gas mixture after purification, analysis and addition of top-up quantities. In open loop method, under consideration here, individual component gases are separated from gas mixture and reused as source. During open loop process, gases liquefiable at low pressures are separated from ones liquefiable at high pressure. The gas phase components within each group are successively separated by either fractional condensation or gravity separation. Gas mixture coming from RPC exhaust is first desiccated by passage through molecular sieve adsorbent type (3A+4A). Subsequent scrubbing over basic activated alumina removes toxic and acidic contaminants such as S{sub 2}F{sub 10} produced during corona (arcing) discharge. In the first stage of separation isobutane and freon are concentrated by diffusion and liquefied by fractional condensation by cooling upto -30 deg. C. Liquefied gases are returned to source tanks. In the second stage of separation, argon and sulphur hexafluoride, the residual gases, are concentrated by settling due to density difference. SF{sub 6} is stored for recovery by condensation at high pressure while argon is further purified by thermal cracking of crossover impurities at 1000 deg. C followed by wet scrubbing.

RPC gas recovery by open loop method

International Nuclear Information System (INIS)

Joshi, Avinash

2009-01-01

RPC detectors require to be flushed with small but continuous flow of gas mixture. Dealing with large number of detectors, gas consumption to very large volumes. Gas flow is a running expense and constituent gases are too expensive to be treated as consumables. Exhaust gas mixture from detectors is a potential environmental hazard if discharged directly into the atmosphere. Storage of gases on a large scale also leads to inventory- and safety-related problems. A solution to these problems is the recovery and reuse of exhaust gas mixture from RPC detectors. Close loop method employs recirculation of exhausted gas mixture after purification, analysis and addition of top-up quantities. In open loop method, under consideration here, individual component gases are separated from gas mixture and reused as source. During open loop process, gases liquefiable at low pressures are separated from ones liquefiable at high pressure. The gas phase components within each group are successively separated by either fractional condensation or gravity separation. Gas mixture coming from RPC exhaust is first desiccated by passage through molecular sieve adsorbent type (3A+4A). Subsequent scrubbing over basic activated alumina removes toxic and acidic contaminants such as S 2 F 10 produced during corona (arcing) discharge. In the first stage of separation isobutane and freon are concentrated by diffusion and liquefied by fractional condensation by cooling upto -30 deg. C. Liquefied gases are returned to source tanks. In the second stage of separation, argon and sulphur hexafluoride, the residual gases, are concentrated by settling due to density difference. SF 6 is stored for recovery by condensation at high pressure while argon is further purified by thermal cracking of crossover impurities at 1000 deg. C followed by wet scrubbing.

MUON DETECTORS: RPC

CERN Multimedia

P. Paolucci

2011-01-01

During data-taking in 2010 the RPC system behaviour was very satisfactory for both the detector and trigger performances. Most of the data analyses are now completed and many results and plots have been approved in order to be published in the muon detector paper. A very detailed analysis of the detector efficiency has been performed using 60 million muon events taken with the dedicated RPC monitor stream. The results have shown that the 96.3% of the system was working properly with an average efficiency of 95.4% at 9.35 kV in the Barrel region and 94.9% at 9.55 kV in the Endcap. Cluster size goes from 1.6 to 2.2 showing a clear and well-known correlation with the strip pitch. Average noise in the Barrel is less than 0.4 Hz/cm2 and about 98% of full system has averaged noise less then 1 Hz/cm2. A linear dependence of the noise versus the luminosity has been preliminary observed and is now under study. Detailed chamber efficiency maps have shown a few percent of chambers with a non-uniform efficiency distribu...

The Production of Corporate Research to Manufacture Doubt About the Health Hazards of Products: An Overview of the Exponent Bakelite® Simulation Study.

Science.gov (United States)

Egilman, David

2018-01-01

Although corporate sponsorship of research does not necessarily lead to biased results, in some industries, it has resulted in the publication of inaccurate and misleading data. Some companies have hired scientific consulting firms to retrospectively calculate exposures to hazardous products during use that are no longer manufactured or sold. As an example, this paper reviews one such study-a litigation-generated study of Union Carbide Corporation's asbestos-containing product, Bakelite®. This analysis is based on previously secret documents, produced as a result of litigation. The study generated asbestos fiber exposure measurements which resulted in underestimates of actual exposures to create doubt about the hazards associated with manufacture and manipulation of Bakelite®.

High rate resistive plate chambers: An inexpensive, fast, large area detector of energetic charged particles for accelerator and non-accelerator applications

International Nuclear Information System (INIS)

Wuest, C.R.; Ables, E.; Bionta, R.M.; Clamp, O.; Haro, M.; Mauger, G.J.; Miller, K.; Olson, H.; Ramsey, P.

1993-05-01

Resistive Plate Chambers, or RPCs, have been used until recently as large detectors of cosmic ray muons. They are now finding use as fast large-area trigger and muon detection systems for different high energy physics detectors such the L3 Detector at LEP and future detectors to be built at the Superconducting Super Collider (SSC) and at the Large Hadron Collider (LHC) at CERN. RPC systems at these accelerators must operate with high efficiency, providing nanosecond timing resolution in particle fluences up to a few tens of kHz/cm 2 -- with thousands of square meters of active area. RPCs are simple and cheap to construct. The authors report here recent work on RPCs using new materials that exhibit a combination of desirable RPC features such as low bulk resistivity, high dielectric strength, low mass, and low cost. These new materials were originally developed for use in electronics assembly areas and other applications, where static electric charge buildup can damage sensitive electrical systems

Whole-Body Single-Bed Time-of-Flight RPC-PET: Simulation of Axial and Planar Sensitivities With NEMA and Anthropomorphic Phantoms

Science.gov (United States)

Crespo, Paulo; Reis, João; Couceiro, Miguel; Blanco, Alberto; Ferreira, Nuno C.; Marques, Rui Ferreira; Martins, Paulo; Fonte, Paulo

2012-06-01

A single-bed, whole-body positron emission tomograph based on resistive plate chambers has been proposed (RPC-PET). An RPC-PET system with an axial field-of-view (AFOV) of 2.4 m has been shown in simulation to have higher system sensitivity using the NEMA NU2-1994 protocol than commercial PET scanners. However, that protocol does not correlate directly with lesion detectability. The latter is better correlated with the planar (slice) sensitivity, obtained with a NEMA NU2-2001 line-source phantom. After validation with published data for the GE Advance, Siemens TruePoint and TrueV, we study by simulation their axial sensitivity profiles, comparing results with RPC-PET. Planar sensitivities indicate that RPC-PET is expected to outperform 16-cm (22-cm) AFOV scanners by a factor 5.8 (3.0) for 70-cm-long scans. For 1.5-m scans (head to mid-legs), the sensitivity gain increases to 11.7 (6.7). Yet, PET systems with large AFOV provide larger coverage but also larger attenuation in the object. We studied these competing effects with both spherical- and line-sources immersed in a 27-cm-diameter water cylinder. For 1.5-m-long scans, the planar sensitivity drops one order of magnitude in all scanners, with RPC-PET outperforming 16-cm (22-cm) AFOV scanners by a factor 9.2 (5.3) without considering the TOF benefit. A gain in the effective sensitivity is expected with TOF iterative reconstruction. Finally, object scatter in an anthropomorphic phantom is similar for RPC-PET and modern, scintillator-based scanners, although RPC-PET benefits further if its TOF information is utilized to exclude scatter events occurring outside the anthropomorphic phantom.

Charge distribution dependency on gap thickness of CMS endcap RPC

CERN Document Server

Park, Sung Keun

2016-01-01

We present a systematic study of charge distribution dependency of CMS Resistive Plate Chamber (RPC) on gap thickness.Prototypes of double-gap with five different gap thickness from 1.8mm to 1.0mm in 0.2mm steps have been built with 2mm thick phenolic high-pressure-laminated (HPL) plates. The charges of cosmic-muon signals induced on the detector strips are measured as a function of time using two four-channel 400-MHz fresh ADCs. In addition, the arrival time of the muons and the strip cluster sizes are measured by digitizing the signal using a 32-channel voltage-mode front-end-electronics and a 400-MHz 64-channel multi-hit TDC. The gain and the input impedance of the front-end-electronics were 200mV/mV and 20 Ohm, respectively.

Detector Control System for CMS RPC at GIF++

CERN Document Server

Gul, Muhammad

2016-01-01

In the framework of the High Luminosity LHC upgrade program, the CMS muon groupbuilt several different RPC prototypes that are now under test at the new CERN Gamma Irradiation Facility (GIF++). A dedicated Detector Control System has been developed using the WinCC-OA tool to control and monitor these prototype detectors and to store the measured parameters data.

A New Image Processing Procedure Integrating PCI-RPC and ArcGIS-Spline Tools to Improve the Orthorectification Accuracy of High-Resolution Satellite Imagery

Directory of Open Access Journals (Sweden)

Hongying Zhang

2016-10-01

Full Text Available Given the low accuracy of the traditional remote sensing image processing software when orthorectifying satellite images that cover mountainous areas, and in order to make a full use of mutually compatible and complementary characteristics of the remote sensing image processing software PCI-RPC (Rational Polynomial Coefficients and ArcGIS-Spline, this study puts forward a new operational and effective image processing procedure to improve the accuracy of image orthorectification. The new procedure first processes raw image data into an orthorectified image using PCI with RPC model (PCI-RPC, and then the orthorectified image is further processed using ArcGIS with the Spline tool (ArcGIS-Spline. We used the high-resolution CBERS-02C satellite images (HR1 and HR2 scenes with a pixel size of 2 m acquired from Yangyuan County in Hebei Province of China to test the procedure. In this study, when separately using PCI-RPC and ArcGIS-Spline tools directly to process the HR1/HR2 raw images, the orthorectification accuracies (root mean square errors, RMSEs for HR1/HR2 images were 2.94 m/2.81 m and 4.65 m/4.41 m, respectively. However, when using our newly proposed procedure, the corresponding RMSEs could be reduced to 1.10 m/1.07 m. The experimental results demonstrated that the new image processing procedure which integrates PCI-RPC and ArcGIS-Spline tools could significantly improve image orthorectification accuracy. Therefore, in terms of practice, the new procedure has the potential to use existing software products to easily improve image orthorectification accuracy.

MUON DETECTORS: RPC

CERN Multimedia

P. Paolucci

2012-01-01

The RPC system is operating with a very high uptime, an average chamber efficiency of about 95% and an average cluster size around 1.8. The average number of active channels is 97.7%. Eight chambers are disconnected and forty are working in single-gap mode due to high-voltage problems. The total luminosity lost due to RPCs in 2012 is 88.46 pb–1. One of the main goals of 2012 was to improve the stability of the endcap trigger that is strongly correlated to the performances of the detector, due to the 3-out-3 trigger logic. At beginning of 2011 the instability of the detector efficiency was about 10%. Detailed studies found that this was mainly due to the strong correlation between the performance of the detector and the atmospheric pressure (P). Figure XXY shows the linear correlation between the average cluster size of the endcap chamber versus P. This effect is expected for gaseous detectors and can be reduced by correcting the applied high-voltage working point (HVapp) according to the followi...

3dRPC: a web server for 3D RNA-protein structure prediction.

Science.gov (United States)

Huang, Yangyu; Li, Haotian; Xiao, Yi

2018-04-01

RNA-protein interactions occur in many biological processes. To understand the mechanism of these interactions one needs to know three-dimensional (3D) structures of RNA-protein complexes. 3dRPC is an algorithm for prediction of 3D RNA-protein complex structures and consists of a docking algorithm RPDOCK and a scoring function 3dRPC-Score. RPDOCK is used to sample possible complex conformations of an RNA and a protein by calculating the geometric and electrostatic complementarities and stacking interactions at the RNA-protein interface according to the features of atom packing of the interface. 3dRPC-Score is a knowledge-based potential that uses the conformations of nucleotide-amino-acid pairs as statistical variables and that is used to choose the near-native complex-conformations obtained from the docking method above. Recently, we built a web server for 3dRPC. The users can easily use 3dRPC without installing it locally. RNA and protein structures in PDB (Protein Data Bank) format are the only needed input files. It can also incorporate the information of interface residues or residue-pairs obtained from experiments or theoretical predictions to improve the prediction. The address of 3dRPC web server is http://biophy.hust.edu.cn/3dRPC. yxiao@hust.edu.cn.

Electronic system of the RPC Muon Trigger in CMS experiment at LHC accelerator (Elektroniczny system trygera mionowego RPC w eksperymencie CMS akceleratora LHC

CERN Document Server

Bialkowska, H

2009-01-01

This paper presents implementation of distributed, multichannel electronic measurement system for RPC - based Muon Trigger in the CMS experiment at LHC. The introduction shortly describes the research aims of LHC and shows the metrological requirements for CMS - good spatial and time resolution, and possibility to estimate multiple physical parameters from registered collisions of particles. Further the paper describes RPC Muon Trigger consisting of 200 000 independent channels for position measurement. The first part of the paper presents the functional structure of the system in the context of requirements put by the CMS experiment, like global triggering system and data acquisition. The second part describes the hardware solutions used in particular parts of the RPC detector measuremnt system and shows some test results. The paper has a digest and overview nature.

First joint test beam of CMS Drift Tubes (DT) and Resistive Plate Chambers (RPC)

CERN Multimedia

Paolo Giacomelli

2001-01-01

The first full size muon drift tube chamber ever built for the CMS barrel with the final cell design (constructed at CIEMAT, Madrid) was succesfully tested with a muon beam in September 2001 at the Gamma Irradiation Facility (GIF) at CERN. For the first time also both muon detectors for the CMS barrel (DT + RPC) were coupled together. The results of this test were fully succesful and confirmed the excellent performance of both detectors together in a radiation environment.

A Four-Gap Glass-RPC Time-of-Flight Array with 90 ps Time Resolution

CERN Document Server

Akindinov, A; Formenti, F; Golovine, V; Klempt, W; Kluge, A; Martemyanov, A N; Martinengo, P; Pinhão, J; Smirnitsky, A V; Spegel, M; Szymanski, P; Zalipska, J

2001-01-01

In this paper, we describe the performance of a prototype developed in the context of the ALICE time-of-flight research and development system. The detector module consists of a 32-channel array of 3 x 3 cm2 glass resistive plate chamber (RPC) cells, each of which has four accurately space gaps of 0.3 mm thickness arranged as a pair of double-gap resisitive plate chambers. Operated with a nonflammable gas mixture at atmospheric pressure, the system achieved a time resolution of 90 ps at 98% efficiency with good uniformity and moderate crosstalk. This result shows the feasibility of large-area high-resolution time-of-flight systems based on RPCs at affordable cost.

An Investigation of the dependence of CMS RPC operation on environmental parameters

Energy Technology Data Exchange (ETDEWEB)

Assran, Y. [Faculty of Petroleum and Mining Eng., Suez Canal University (Egypt); Colafranceschi, S. [INFN Laboratori Nazionali di Frascati, Via E. Fermi 40, I-00044 Frascati (Italy); Doninck, W.A. [Vrije Universiteit Brussel, B-1050 Brussels (Belgium); Sharma, A. [CERN, CH-1211, Geneva (Switzerland); Wickramage, N., E-mail: nwickram@cern.ch [EHEP, Tata Institute of Fundamental Research, Mumbai (India)

2011-06-15

In this paper an analysis is presented on performance of RPC chambers installed in the cosmic ray test stand at ISR, CERN. The currents of RPC chambers are studied as a function of environmental parameters such as temperature, humidity and pressure, which are important for the operation of the RPC detector system at CMS. A neural network approach has been used to analyze the data and to build a model using experimental measurements and combining the results of the simulations.

RPC Detector Performance Results for 2016 and 2017

CERN Document Server

CMS Collaboration

2018-01-01

This note presents the summary of the RPC detector performance during 2017 and the comparison with 2016. A part of the performance results have been obtained with the tracker tracks extrapolation method, explained here. The data driven predictions of the RPC rates and integrated charge to the HL-LHC conditions have been presented as well. The results after the detailed background study of the effect of the newly installed shielding are shown. The history of the efficiency and cluster size vs time and instantaneous luminosity have been presented, as well.

Development of conductive coated polyester film as RPC electrodes using screen printing

International Nuclear Information System (INIS)

Kalmani, S.D.; Mondal, N.K.; Satyanarayana, B.; Verma, P.; Datar, V.M.

2009-01-01

Each of the three 16 kton ICAL detector modules at the India-based Neutrino Observatory (INO) will use RPCs as the active element, sandwiched between 6 cm thick soft iron plates, for measurements on atmospheric neutrinos. The electrodes of the RPC are float glass sheets having a volume resistivity of about 10 12 -10 13 Ω cm (at room temperature) covered with carbon/graphite or a conductive paint with a surface resistivity of ∼800 kΩ/square to 1 MΩ/square to apply high voltage on the glass surface, so that this surface does not shield the discharge signal from the external pickup plates and is small compared to the resistivity of the glass to provide a uniform potential across the entire surface. We initially coated the surface with locally available graphite powder, mixed with lacquer and thinner, and were able to get a few hundred kΩ/square resistivity. However, we observed a drastic reduction in surface resistivity with time and it came unstuck from the glass. Subsequently a conductive paint developed by Kansai-Nerolac was used. This paint uses modified acrylic resin as binder, conductive black pigment and solvents, which include aromatic hydrocarbons and alcohols. At room temperature, the surface dries in 10 minutes, while complete drying takes ∼18 hours. The spraying is done at a pressure of 4 kg/cm 2 with the glass plate kept at a distance of 8-10 in. Using this paint, we are able to achieve the required resistance of ∼ few hundred kΩ/square. We still need to study the long term stability and best curing method. We need to automate the procedure to get a uniform coat and to coat a large number of glasses for the final detector. While robotic systems are available abroad costing about 5 000 000 rupees, we are exploring other alternatives. In particular, we are in the process of developing a polyester film, with a conductive coating on one side, which can be glued on to the glass. The coating was done using on a local commercial screen printing

Development of conductive coated polyester film as RPC electrodes using screen printing

Science.gov (United States)

Kalmani, S. D.; Mondal, N. K.; Satyanarayana, B.; Verma, P.; Datar, V. M.

2009-05-01

Each of the three 16 kton ICAL detector modules at the India-based Neutrino Observatory (INO) will use RPCs as the active element, sandwiched between 6 cm thick soft iron plates, for measurements on atmospheric neutrinos. The electrodes of the RPC are float glass sheets having a volume resistivity of about 10 12-10 13 Ω cm (at room temperature) covered with carbon/graphite or a conductive paint with a surface resistivity of ˜800 kΩ/square to 1 MΩ/square to apply high voltage on the glass surface, so that this surface does not shield the discharge signal from the external pickup plates and is small compared to the resistivity of the glass to provide a uniform potential across the entire surface. We initially coated the surface with locally available graphite powder, mixed with lacquer and thinner, and were able to get a few hundred kΩ/square resistivity. However, we observed a drastic reduction in surface resistivity with time and it came unstuck from the glass. Subsequently a conductive paint developed by Kansai-Nerolac was used. This paint uses modified acrylic resin as binder, conductive black pigment and solvents, which include aromatic hydrocarbons and alcohols. At room temperature, the surface dries in 10 minutes, while complete drying takes ˜18 hours. The spraying is done at a pressure of 4 kg/cm 2 with the glass plate kept at a distance of 8-10 in. Using this paint, we are able to achieve the required resistance of ˜ few hundred kΩ/square. We still need to study the long term stability and best curing method. We need to automate the procedure to get a uniform coat and to coat a large number of glasses for the final detector. While robotic systems are available abroad costing about 5 000 000 rupees, we are exploring other alternatives. In particular, we are in the process of developing a polyester film, with a conductive coating on one side, which can be glued on to the glass. The coating was done using on a local commercial screen printing machine

Fabrication of 1m x 1m readout strips panel and quality verification of new set of SFS dielectric material

International Nuclear Information System (INIS)

Kumar, A.; Pandey, A.; Sogarwal, Hariom; Marimuthu, N.; Singh, V.; Subrahmanyam, V.S.

2016-01-01

India based Neutrino Observatory (INO) is going to use ∼ 30,000 Resistive Plate Chamber (RPC) as an active detector. Resistive Plate chambers are parallel plate fast gaseous detector made up of high resistivity (10"1"2 ohm) of glass or bakelite. Glass plates work as electrodes of positive and negative potential. When a charged particle passes through chamber it ionizes the gas and charge move towards opposite electrodes. The pick-up panels pick these signals. Signals are sent to front end electronics. The characteristic impedance of the strips of the panels should be matched with front end electronics which helps in minimizing the reflected signal. Since INO is an underground laboratory, all material used in it must be fireproof. Since ∼ 60,000 pick-up panels are going to be used in INO hence it should be cheaper also. We recently received a new set of Silicon Fiber Sheets - a dielectric material, of 25 pieces of 1m x 0.5m having thickness 05 mm. We fabricated a set of readout strips panel of dimension 1m x 1m. We will present this work in detail

Application of PSpice circuit simulator in development of resistive plate chamber detector

International Nuclear Information System (INIS)

Wang Yaping; Cai Xu

2008-01-01

An electrical model was presented for resistive plate chamber (RPC) detector. The readout signals of RPC detector were studied with PSpice simulation based on the model. The simulation results show a good agreement with real data and authoritative data. Physical performance of RPC detector can be predicted by the PSpice simulation, so this is an efficient means to optimize RPC detector's research and development. (authors)

RPC Production at General Tecnica: a mass scale production

International Nuclear Information System (INIS)

Della Volpe, D.; Morganti, S.

2006-01-01

The construction of LHC has deeply changed the RPC production. The enormous amount of detector needed and the strong requirements on gas volume quality had a deep impact on the production chain and on the QC and QA at the production site. This basically has brought the RPC from an almost hand-crafted detector to a medium scale mass product. The most critical aspects of the production chain have been modified and/or improved introducing new and more rigorous QC and QA procedures to guarantee the detector quality and improve the management of storage and the procurement on materials. Here it will be presented the work carried on in the last four year at the production site to improve and check the quality and the results achieved. Something like 10000 RPC were produced between 2002 and 2005. Also a preliminary and rough analysis on the efficiencies of the various phases in the chain production based on ATLAS production will be presented

MUON DETECTORS: RPC

CERN Multimedia

G. Pugliese

2010-01-01

In the second half of 2010 run, the overall behavior of the RPC system has been very satisfactory, both in terms of detector and trigger performance. This result was achieved through interventions by skilled personnel and fine-tuned analysis procedures. The hardware was quite stable: both gas and power systems did not present significant problems during the data-taking period, confirming the high reliability achieved. Only few interventions on some HV or LV channels were necessary during the periodical technical accesses. The overall result is given by the stable percentage of active channels at about 98.5%. The single exception was at beginning of the ion collisions, when it dipped to 97.4% because of the failure of one LV module, although this was recovered after a few days. The control and monitoring software is now more robust and efficient, providing prompt diagnostics on the status of the entire system. Significant efforts were made in collaboration with the CMS cooling team to secure proper working ...

MUON DETECTORS: RPC

CERN Multimedia

G. Iaselli

During the last 3 months the RPC group has made impressive improvements in the refinement of the operation tools and understanding of the detector. The full barrel and part of the plus end cap participated systematically to global runs producing millions of trigger on cosmics. The main monitoring tools were robust and efficient in controlling the detector and in diagnosis of problems. After the refinement of the synchronization procedure, detailed studies of the chamber performances, as a function of high voltage and front-end threshold, were pursued. In parallel, new tools for the prompt analysis were developed which have enabled a fast check of the data at the CMS Centre. This effort has been very valuable since it has helped in discovering many minor bugs in the reconstruction software and database which are now being fixed. Unfortunately, a large part of the RE2 station has developed increasing operational current. Some preliminary investigation leads to the conclusion that the serial gas circulation e...

The Time Structure of Hadronic Showers in Imaging Calorimeters with Scintillator and RPC Readout

CERN Document Server

Simon, Frank

2013-01-01

The intrinsic time structure of hadronic showers has been studied to evaluate its influence on the timing capability and on the required integration time of highly granular hadronic calorimeters in future collider experiments. The experiments have been carried with systems of 15 detector cells, using both scintillator tiles with SiPM readout and RPCs, read out with fast digitizers and deep buffers. These were installed behind the CALICE scintillator - Tungsten and RPC - Tungsten calorimeters as well as behind the CALICE semi-digital RPC - Steel calorimeter during test beam periods at the CERN SPS. We will discuss the technical aspects of these systems, and present results on the measurement of the time structure of hadronic showers in steel and tungsten calorimeters. These are compared to GEANT4 simulations, providing important information for the validation and the improvement of the physics models. In addition, a comparison of the observed time structure with scintillator and RPC active elements will be pre...

SU-C-BRD-07: The Radiological Physics Center (RPC): 45 Years of Improving Radiotherapy Dosimetry

Energy Technology Data Exchange (ETDEWEB)

Followill, D; Lowenstein, J; Molineu, A; Alvarez, P; Summers, P; Kry, S [UT MD Anderson Cancer Center, Houston, TX (United States)

2014-06-15

Purpose: The RPC, established in 1968 has contributed to the development, conduct, and QA of NCI funded multi-institutional cooperative group clinical trials and institutions, primarily in the USA/Canada and 242 other countries, participating in trials. Methods: The RPC QA program components were designed to audit the radiation dose calculation chain from the NIST traceable reference beam calibration, to inclusion of dosimetry parameters used to calculate tumor doses, to the delivery of the radiation dose. The QA program included: 1) remote TLD/OSLD audit of machine output, 2) on-site dosimetry review visits, 3) credentialing for advanced technologies, and 4) review of patient treatment records. The RPC presented and published their findings to the radiation oncology community. Results: The number of institutions monitored by the RPC increased from around 1200 in the late 90s, to ∼2000 in 2013. There were over 4000 megavoltage therapy machines and ∼28,000 therapy beams in the 1991 institutions monitored by the RPC by the end of 2013. Within the 14,000 photon, electron and proton beam outputs remotely monitored with TLD/OSLD annually, between 10-20% of the institutions have one or more beams outside the RPC 5% criterion. Dosimetry site visits to photon and proton centers continue to result in 2-4 recommendations affecting key dosimetry parameters that impact patient treatment times. One in four patient treatment records reviewed by the RPC have their dose data corrected by >5% before trial groups use them for outcomes analysis. Twelve of fourteen clinically active proton centers are approved to participate in NCI funded clinical trials. The RPC published 222 peer reviewed articles since 1972. Conclusion: Findings from the RPC suggest that human errors continue to play a role in radiotherapy discrepancies and without the RPC independent QA program, the number of undetected errors and time elapsed before their discovery would have been greater. Work supported by

Performance of ATLAS RPC Level-1 muon trigger during the 2015 data taking

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00001854; The ATLAS collaboration

2016-01-01

RPCs are used in the ATLAS experiment at the LHC for muon trigger in the barrel region, which corresponds to |eta|<1.05. The status of the barrel trigger system during the 2015 data taking is presented, including measurements of the RPC detector efficiencies and of the trigger performance. The RPC system has been active in more than 99.9% of the ATLAS data taking, showing very good reliability. The RPC detector efficiencies were close to Run-1 and to design value. The trigger efficiency for the high-pT thresholds used in single-muon triggers has been approximately 4% lower than in Run 1, mostly because of chambers disconnected from HV due to gas leaks. Two minor upgrades have been performed in preparation of Run 2 by adding the so-called feet and elevator chambers to increase the system acceptance. The feet chambers have been commissioned during 2015 and are included in the trigger since the last 2015 runs. Part of the elevator chambers are still in commissioning phase and will probably need a replacement ...

Investigating the feasibility of 3D dosimetry in the RPC IMRT H and N phantom

Energy Technology Data Exchange (ETDEWEB)

Sakhalkar, H S; Sterling, D [Department of Radiation Oncology Physics, Duke University Medical Center, Durham, NC (United States); Adamovics, J [Department of Chemistry and Biology, Rider University, Lawrenceville, NJ (United States); Ibbott, G [Department of Radiation Physics, M. D. Anderson Cancer Center, Houston, Tx (United States); Oldham, M, E-mail: mark.oldham@duke.edu

2009-05-01

An urgent requirement for 3D dosimetry has been recognized because of high failure rate ({approx}25%) in RPC credentialing, which relies on point and 2D dose measurements. Comprehensive 3D dosimetry is likely to resolve more errors and improve IMRT quality assurance. This work presents an investigation of the feasibility of PRESAGE/optical-CT 3D dosimetry in the Radiologic Physics Center (RPC) IMRT H and N phantom. The RPC H and N phantom (with standard and PRESAGE dosimetry inserts alternately) was irradiated with the same IMRT plan. The TLD and EBT film measurement data from standard insert irradiation was provided by RPC. The 3D dose measurement data from PRESAGE insert irradiation was readout using the OCTOPUS{sup TM} 5X optical-CT scanner at Duke. TLD, EBT and PRESAGE dose measurements were inter-compared with Eclipse calculations to evaluate consistency of planning and delivery. Results showed that the TLD point dose measurements agreed with Eclipse calculations to within 5% dose-difference. Relative dose comparison between Eclipse dose, EBT dose and PRESAGE dose was conducted using profiles and gamma comparisons (4% dose-difference and 4 mm distance-to-agreement). Profiles showed good agreement between measurement and calculation except along steep dose gradient regions where Eclipse modelling might be inaccurate. Gamma comparisons showed that the measurement and calculation showed good agreement (>96%) if edge artefacts in measurements are ignored. In conclusion, the PRESAGE/optical-CT dosimetry system was found to be feasible as an independent dosimetry tool in the RPC IMRT H and N phantom.

Investigating the feasibility of 3D dosimetry in the RPC IMRT H and N phantom

International Nuclear Information System (INIS)

Sakhalkar, H S; Sterling, D; Adamovics, J; Ibbott, G; Oldham, M

2009-01-01

An urgent requirement for 3D dosimetry has been recognized because of high failure rate (∼25%) in RPC credentialing, which relies on point and 2D dose measurements. Comprehensive 3D dosimetry is likely to resolve more errors and improve IMRT quality assurance. This work presents an investigation of the feasibility of PRESAGE/optical-CT 3D dosimetry in the Radiologic Physics Center (RPC) IMRT H and N phantom. The RPC H and N phantom (with standard and PRESAGE dosimetry inserts alternately) was irradiated with the same IMRT plan. The TLD and EBT film measurement data from standard insert irradiation was provided by RPC. The 3D dose measurement data from PRESAGE insert irradiation was readout using the OCTOPUS TM 5X optical-CT scanner at Duke. TLD, EBT and PRESAGE dose measurements were inter-compared with Eclipse calculations to evaluate consistency of planning and delivery. Results showed that the TLD point dose measurements agreed with Eclipse calculations to within 5% dose-difference. Relative dose comparison between Eclipse dose, EBT dose and PRESAGE dose was conducted using profiles and gamma comparisons (4% dose-difference and 4 mm distance-to-agreement). Profiles showed good agreement between measurement and calculation except along steep dose gradient regions where Eclipse modelling might be inaccurate. Gamma comparisons showed that the measurement and calculation showed good agreement (>96%) if edge artefacts in measurements are ignored. In conclusion, the PRESAGE/optical-CT dosimetry system was found to be feasible as an independent dosimetry tool in the RPC IMRT H and N phantom.

The physics of Resistive Plate Chambers

CERN Document Server

Riegler, Werner

2004-01-01

Over the last 3 years we investigated theoretical aspects of Resistive Plate Chambers (RPC) in order to clarify some of the outstanding questions on space charge effects, high efficiency of small gap RPCs, charge spectra, signal shape and time resolution. In a series of reports we analyzed RPC performance including all detector aspects covering primary ionization, avalanche multiplication, space charge effects, signal induction in presence of resistive materials, crosstalk along detectors with long strips and front-end electronics. Using detector gas parameters entirely based on theoretical predictions and physical models for avalanche development and space charge effects we are able to reproduce measurements for 2 and 0.3 mm RPCs to very high accuracy without any additional assumptions. This fact gives a profound insight into the workings of RPCs and also underlines the striking difference in operation regime when compared to wire chambers. A summary of this work as well as recent results on three-dimensiona...

ATLAS RPC performance on a dedicated cosmic ray test-stand

International Nuclear Information System (INIS)

Liberti, B.; Aielli, G.; Camarri, P.; Cardarelli, R.; Corradi, M.; Di Ciaccio, A.; Di Stante, L.; Palummo, L.; Pastori, E.; Salamon, A.; Santonico, R.; Solfaroli, E.

2008-01-01

596 RPC chambers have been assembled in the ATLAS Muon Spectrometer, covering a 7300 m 2 sensitive area with 355.000 read out channels. 1116 RPC Units were produced and tested before integration and installation on the experiment [A. Aloisio et al., 'The trigger chambers of the ATLAS muon spectrometer: production and tests', Nuclear Instruments and Methods A535 (2004) 265-271]. 192 ATLAS RPCs, the Barrel Outer Large (BOL) units were tested in INFN Roma Tor Vergata test stand

CytoscapeRPC: a plugin to create, modify and query Cytoscape networks from scripting languages.

Science.gov (United States)

Bot, Jan J; Reinders, Marcel J T

2011-09-01

CytoscapeRPC is a plugin for Cytoscape which allows users to create, query and modify Cytoscape networks from any programming language which supports XML-RPC. This enables them to access Cytoscape functionality and visualize their data interactively without leaving the programming environment with which they are familiar. Install through the Cytoscape plugin manager or visit the web page: http://wiki.nbic.nl/index.php/CytoscapeRPC for the user tutorial and download. j.j.bot@tudelft.nl; j.j.bot@tudelft.nl.

Automatically visualise and analyse data on pathways using PathVisioRPC from any programming environment.

Science.gov (United States)

Bohler, Anwesha; Eijssen, Lars M T; van Iersel, Martijn P; Leemans, Christ; Willighagen, Egon L; Kutmon, Martina; Jaillard, Magali; Evelo, Chris T

2015-08-23

Biological pathways are descriptive diagrams of biological processes widely used for functional analysis of differentially expressed genes or proteins. Primary data analysis, such as quality control, normalisation, and statistical analysis, is often performed in scripting languages like R, Perl, and Python. Subsequent pathway analysis is usually performed using dedicated external applications. Workflows involving manual use of multiple environments are time consuming and error prone. Therefore, tools are needed that enable pathway analysis directly within the same scripting languages used for primary data analyses. Existing tools have limited capability in terms of available pathway content, pathway editing and visualisation options, and export file formats. Consequently, making the full-fledged pathway analysis tool PathVisio available from various scripting languages will benefit researchers. We developed PathVisioRPC, an XMLRPC interface for the pathway analysis software PathVisio. PathVisioRPC enables creating and editing biological pathways, visualising data on pathways, performing pathway statistics, and exporting results in several image formats in multiple programming environments. We demonstrate PathVisioRPC functionalities using examples in Python. Subsequently, we analyse a publicly available NCBI GEO gene expression dataset studying tumour bearing mice treated with cyclophosphamide in R. The R scripts demonstrate how calls to existing R packages for data processing and calls to PathVisioRPC can directly work together. To further support R users, we have created RPathVisio simplifying the use of PathVisioRPC in this environment. We have also created a pathway module for the microarray data analysis portal ArrayAnalysis.org that calls the PathVisioRPC interface to perform pathway analysis. This module allows users to use PathVisio functionality online without having to download and install the software and exemplifies how the PathVisioRPC interface can be

Performances of the ATLAS RPC Level-1 Muon trigger during the Run-II data taking

CERN Document Server

Alberghi, Gian Luigi; The ATLAS collaboration

2018-01-01

The Level-1 Muon Barrel Trigger is one of the main elements of the event selection of the ATLAS experiment at the Large Hadron Collider. Its input stage consists of an array of processors receiving the full granularity of data from Resistive Plate Chambers in the central area of the ATLAS detector ("Barrel"). The RPCs, placed in the barrel region of the ATLAS detector, are arranged in three concentric double layers and operate in a strong magnetic toroidal field. RPC detectors cover the pseudo-rapidity range |η|<1.05 for a total surface of more than 4000 m2 and about 3600 gas volumes. The Level-1 Muon Trigger in the barrel region allows to select muon candidates with respect to their transverse momentum and associates them with the correct bunch-crossing number. The trigger system is able to take a decision within a latency of about 2 μs. We illustrate the selections, strategy and validation for an unbiased determination of the efficiency and timing of the RPC and the L1 from data; and show the results w...

Temperature effect on RPC performance in the ARGO-YBJ experiment

Energy Technology Data Exchange (ETDEWEB)

Aielli, G. [Dipartimento di Fisica dell' Universita ' Tor Vergata' , via della Ricerca Scientifica 1, 00133 Roma (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Tor Vergata, via della Ricerca Scientifica 1, 00133 Roma (Italy); Bacci, C. [Dipartimento di Fisica dell' Universita ' Roma Tre' , via della Vasca Navale 84, 00146 Roma (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Roma3, via della Vasca Navale 84, 00146 Roma (Italy); Bartoli, B. [Istituto Nazionale di Fisica Nucleare, Sezione di Napoli, Complesso Universitario di Monte Sant' Angelo, via Cinthia, 80126 Napoli (Italy); Dipartimento di Fisica dell' Universita di Napoli, Complesso Universitario di Monte Sant' Angelo, via Cinthia, 80126 Napoli (Italy); Bernardini, P. [Dipartimento di Fisica dell' Universita del Salento, via per Arnesano, 73100 Lecce (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Lecce, via per Arnesano, 73100 Lecce (Italy); Bi, X.J. [Key Laboratory of Particle Astrophyics, Institute of High Energy Physics, Chinese Academy of Science, P.O. Box 918, 100049 Beijing (China); Bleve, C. [Dipartimento di Fisica dell' Universita del Salento, via per Arnesano, 73100 Lecce (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Lecce, via per Arnesano, 73100 Lecce (Italy); Branchini, P.; Budano, A. [Istituto Nazionale di Fisica Nucleare, Sezione di Roma3, via della Vasca Navale 84, 00146 Roma (Italy); Bussino, S. [Dipartimento di Fisica dell' Universita ' Roma Tre' , via della Vasca Navale 84, 00146 Roma (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Roma3, via della Vasca Navale 84, 00146 Roma (Italy); Calabrese Melcarne, A.K. [Istituto Nazionale di Fisica Nucleare - CNAF - viale Berti-Pichat 6/2, 40127 Bologna (Italy); Camarri, P. [Dipartimento di Fisica dell' Universita ' Tor Vergata' , via della Ricerca Scientifica 1, 00133 Roma (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Tor Vergata, via della Ricerca Scientifica 1, 00133 Roma (Italy)] (and others)

2009-09-11

The ARGO-YBJ experiment has been taking data for nearly 2 years. In order to monitor continuously the performance of the Resistive Plate Chamber detectors and to study the daily temperature effects on the detector performance, a cosmic ray muon telescope was setup near the carpet detector array in the ARGO-YBJ laboratory. Based on the measurements performed using this telescope, it is found that, at the actual operating voltage of 7.2 kV, the temperature effect on the RPC time resolution is about 0.04ns/deg. C and on the particle detection efficiency is about 0.03%/deg. C. Based on these figures we conclude that the environmental effects do not affect substantially the angular resolution of the ARGO-YBJ detector.

The micro-gap resistive plate chamber

CERN Document Server

Cerron-Zeballos, E; Lamas-Valverde, J; Platner, E D; Roberts, J; Williams, M C S; Zichichi, A

1999-01-01

Previously we have found that the freon C/sub 2/F/sub 5/H has very good properties when used in a resistive plate chamber (RPC) with a single gap of 2 mm. In this paper we report on the performance of a multigap RPC consisting of 4 gaps of 0.8 mm filled with a gas mixture containing this freon. (7 refs).

[Molecular cloning and characterization of cDNA of the rpc10+ gene encoding the smallest subunit of nuclear RNA polymerases of Schizosaccharomyces pombe].

Science.gov (United States)

Shpakovskiĭ, G V; Lebedenko, E N

1997-05-01

The full-length cDNA of the rpc10+ gene encoding mini-subunit Rpc10, which is common for all three nuclear RNA polymerases of the fission yeast Schizosaccharomyces pombe, was cloned and sequenced. The Rpc10 subunit of Sz. pombe and its homologs from S. cerevisiae and H. sapiens are positively charged proteins with a highly conserved C-terminal region and an invariant zinc-binding domain (Zn-finger) of a typical amino acid composition: YxCx2Cx12RCx2CGxR. Functional tests of heterospecific complementation, using tetrad analysis or plasmid shuffling, showed that the Rpc10 subunit of Sz. pombe can successfully replace the homologous ABC10 alpha subunit in nuclear RNA polymerases I-III of S. cerevisiae.

HF production in CMS-Resistive Plate Chambers

International Nuclear Information System (INIS)

Abbrescia, M.; Colaleo, A.; Guida, R.; Iaselli, G.; Loddo, F.; Maggi, M.; Marangelli, B.; Natali, S.; Nuzzo, S.; Pugliese, G.; Ranieri, A.; Romano, F.; Trentadue, R.; Cavallo, N.; Fabozzi, F.; Paolucci, P.; Piccolo, D.; Polese, G.; Sciacca, C.; Belli, G.; Necchi, M.; Ratti, S.; Riccardi, C.; Torre, P.; Vitulo, P.; Anguelov, T.; Genchev, V.; Panev, B.; Piperov, S.; Sultanov, G.; Vankov, P.; Litov, L.; Pavlov, B.; Petkov, P.

2006-01-01

The formation of highly reactive compounds in the gas mixture during Resistive Plate Chambers (RPCs) operation at the CERN Gamma Irradiation Facility (GIF) is studied. Results from two different types of chambers are discussed: 50 x 50 cm 2 RPC prototypes and two final CMS-RB1 chambers. The RB1 detectors were also connected to a closed loop gas system. Gas composition, possible additional impurities as well as fluoride ions have been monitored in different gamma irradiation conditions both in open and closed loop mode. The chemical composition of the RPC electrode surface has also been analyzed using an electron microscope equipped with an EDS/X-ray

The RPC-based IFR system at BaBar experiment: preliminary results

International Nuclear Information System (INIS)

Piccolo, Davide; Palano, A.; Bagnasco, S.; Buzzo, A.; Contri, R.; Crosetti, G.; Lo Vetere, M.; Macri, M.; Monge, R.; Passaggio, S.; Patrignani, C.; Robutti, E.; Santroni, A.; Anulli, F.; Baldini, R.; Calcaterra, A.; De Sangro, R.; Falciai, D.; Finocchiaro, G.; Patteri, P.; Peruzzi, I.; Piccolo, M.; Yu, Z.; Zallo, A.; Cavallo, N.; De Nardo, G.; Fabozzi, F.; Gatto, C.; Lista, L.; Paolucci, P.; Sciacca, C.; Bionta, R.; Wright, D.; Band, H.; Johnson, J.

2002-01-01

The IFR system is a RPC-based detector used to identify muons and neutral hadrons in the BaBar experiment at PEP II machine in SLAC. The RPC system can be used to reconstruct the trajectory of muons, pions and neutral hadrons interacting in the iron of the IFR. The different range and hit pattern allow to discriminate different particles crossing the IFR. An overview of the system design and the preliminary results on the IFR performances are reported

The RPC-based IFR system at BaBar experiment preliminary results

CERN Document Server

Piccolo, D; Bagnasco, S; Baldini, R; Band, H R; Bionta, R; Buzzo, A; Calcaterra, A; Cavallo, N; Contri, R; Crosetti, G; De Nardo, Gallieno; De Sangro, R; Fabozzi, F; Falciai, D; Finocchiaro, G; Gatto, C; Johnson, J; Lista, L; Lo Vetere, M; Macri, M; Monge, R; Palano, A; Paolucci, P; Passaggio, S; Patrignani, C; Patteri, P; Peruzzi, I; Piccolo, M; Robutti, E; Santroni, A; Sciacca, C; Wright, D; Yu, Z; Zallo, A

2002-01-01

The IFR system is a RPC-based detector used to identify muons and neutral hadrons in the BaBar experiment at PEP II machine in SLAC. The RPC system can be used to reconstruct the trajectory of muons, pions and neutral hadrons interacting in the iron of the IFR. The different range and hit pattern allow to discriminate different particles crossing the IFR. An overview of the system design and the preliminary results on the IFR performances are reported.

Detector Control System and Efficiency Performance for CMS RPC at GIF++

CERN Document Server

Gul, Muhammad; Cimmino, A; Crucy, S; Fagot, A; Rios, A A O; Tytgat, M; Zaganidis, N; Aly, S; Assran, Y; Radi, A; Sayed, A; Singh, G; Abbrescia, M; Iaselli, G; Maggi, M; Pugliese, G; Verwilligen, P; Doninck, W V; Colafranceschi, S; Sharma, A; Benussi, L; Bianco, S; Piccolo, D; Primavera, F; Bhatnagar, V; Kumari, R; Mehta, A; Singh, J; Ahmad, A; Asghar, M I; Muhammad, S; Awan, I A; Hoorani, H R; Ahmed, W; Shahzad, H; Shah, M A; Cho, S W; Choi, S Y; Hong, B; Kang, M H; Lee, K S; Lim, J H; Park, S K; Kim, M; Goutzvitz, M; Grenier, G; Lagarde, F; Estrada, C U; Pedraza, I; Severiano, C B; Carrillo Moreno, S; Vazquez Valencia, F; Pant, L M; Buontempo, S; Cavallo, N; Esposito, M; Fabozzi, F; Lanza, G; Lista, L; Meola, S; Merola, M; Orso, I; Paolucci, P; Thyssen, F; Braghieri, A; Magnani, A; Montagna, P; Riccardi, C; Salvini, P; Vai, I; Vitulo, P; Ban, Y; Qian, S J; Choi, M; Choi, Y; Goh, J; Kim, D; Aleksandrov, A; Hadjiiska, R; Iaydjiev, P; Rodozov, M; Stoykova, S; Sultanov, G; Vutova, M; Dimitrov, A; Litov, L; Pavlov, B; Petkov, P; Lomidze, D; Bagaturia, I; Avila, C; Cabrera, A; Sanabria, J C; Crotty, I; Vaitkus, J

2016-01-01

In the framework of the High Luminosity LHC upgrade program, the CMS muon group built several different RPC prototypes that are now under test at the new CERN Gamma Irradiation Facility (GIF++). A dedicated Detector Control System has been developed using the WinCC-OA tool to control and monitor these prototype detectors and to store the measured parameters data.

Resistive Plate Chamber Performance During the CMS Magnet Test Cosmic Challenge

CERN Document Server

Trentadue, R

2008-01-01

The CMS detector at the CERN Large Hadron Collider (LHC) is equipped with a redundant muon system based on Drift Tubes Chambers (barrel region) and Cathode Strip Chamber (endcap region), and Resistive Plate Chamber (RPC). During the summer and fall 2006 a first integrated test of an entire CMS slice was performed at the SX5 experimental surface hall. The RPC chambers were operated with cosmic rays. The results on the RPC performance are reported.

Close loop gas recirculation and purification system for INO RPC system

International Nuclear Information System (INIS)

Joshi, A.V.; Kalmani, S.D.; Mondal, N.K.; Satyanarayana, B.; Verma, P.

2013-01-01

Close loop gas recirculation system (CLS) is designed to overcome problems. The present system is a pilot unit catering to about 12 RPC detectors of 2m ÃâĂŤ 2m size. The gas mixture is prepared in required concentration, in-situ, and circulated throughout the loop at controlled flow rates. The pressure band is adjusted to be within 20mm of water column. A Programmable Logic Controller (PLC) keeps track of pressure and flow rates, process sequence and safety conditions. The loss of gas is continuously monitored to assess effectiveness of CLS. The concentration of gas components in the mixtures is monitored by sampling through Residual Gas Analyzer (RGA). The RPC performance parameters, such as leakage current, noise rate, efficiency and cross-talk are monitored vis-a-vis CLS parameters. It has been found that RPC parameters respond in coordination with CLS functioning. Room pressure and temperature also seem to have influence on both of them

Streamer free operation of a 2 mm gap resistive plate chamber with $C_{2}F_{5}H$

CERN Document Server

Cerron-Zeballos, E; Hatzifotiadou, D; Lamas-Valverde, J; Williams, M C S; Zichichi, A

1999-01-01

It is necessary to operate the resistive plate chamber (RPC) in avalanche mode to obtain high efficiency at elevated particle fluxes. We examine this mode of operation with a 2 mm gap RPC using gas mixtures containing C/sub 2/F/sub 4/H/sub 2/ and C/sub 2/F/sub 5/H. In order to explain the data we propose that the avalanche growth is strongly limited by space charge effects. (10 refs).

The RPC LVL1 trigger system of the muon spectrometer of the ATLAS experiment at LHC

CERN Document Server

Aielli, G; Alviggi, M G; Biglietti, M; Bocci, V; Brambilla, Elena; Camarri, P; Canale, V; Caprio, M A; Cardarelli, R; Carlino, G; Cataldi, G; Chiodini, G; Conventi, F; De Asmundis, R; Della Pietra, M; Della Volpe, D; Di Ciaccio, A; Di Mattia, A; Di Simone, A; Falciano, S; Gorini, E; Grancagnolo, F; Iengo, P; Liberti, B; Luminari, L; Nisati, A; Pastore, F; Patricelli, S; Perrino, R; Petrolo, E; Primavera, M; Sekhniaidze, G; Spagnolo, S; Salamon, A; Santonico, R; Vari, R; Veneziano, Stefano

2004-01-01

The ATLAS Trigger System has been designed to reduce the LHC interaction rate of about 1 GHz to the foreseen storage rate of about 100 Hz. Three trigger levels are applied in order to fulfill such a requirement. A detailed simulation of the ATLAS experiment including the hardware components and the logic of the Level-1 Muon trigger in the barrel of the muon spectrometer has been performed. This simulation has been used not only to evaluate the performances of the system but also to optimize the trigger logic design. In the barrel of the muon spectrometer the trigger will be given by means of resistive plate chambers (RPCs) working in avalanche mode. Before being mounted on the experiment, accurate quality tests with cosmic rays are carried out on each RPC chamber using the test station facility of the INFN and University laboratory of Napoli. All working parameters are measured and the uniformity of the efficiency on the whole RPC surface is required. A summary of the Napoli cosmic rays tests, together with a...

Testing of a resistive plate chamber using NINO-ASIC based front end electronics

International Nuclear Information System (INIS)

Mondal, M.; Saini, J.; Ahammed, Z.; Chattopadhyay, S.; Ganai, R.; Barai, C.

2017-01-01

The Resistive Plate Chamber (RPC) has shown promising results while testing with the NINO FEE board. It has shown ∼ 80% efficiency in detecting cosmic muons with a noise rate of ∼ 40 Hz/cm 2 . The low threshold in the NINO board may be a possible reason for high noise rate. We plan to test the RPC for different gas mixtures to achieve an efficiency above 95%. The calibration of the NINO onboard threshold with input pulse amplitude need to be done. The time resolution of RPC is ∼ 2.66 ns at 12 kV for avalanche mode gas mixture. The minimum time resolution of the RPC has to determined by measuring the time spectra over the full plateau region of voltages. The signal charge has to be measured by time over- threshold for slewing correction. As J7 input of the board was not working properly, efficiency and noise rate data for the particular input has not been measured

R and D towards future CMS RPC upgrades

CERN Document Server

Fagot, A.; Cimmino, A; Gul, M.; Rios, A.A.O.; Tytgat, M.; Zaganidis, N.; Aly, S.; Assran, Y.; Radi, A.; Sayed, A.; Singh, G.; Abbrescia, M.; Iaselli, G.; Maggi, M.; Pugliese, G.; Verwilligen, P.; Van Doninck, W.; Colafranceschi, S.; Sharma, A.; Benussi, L.; Bianco, S.; Piccolo, D.; Primavera, F.; Bhatnagar, V.; Kumari, R.; Mehta, A.; Singh, J.; Ahmad, A.; Ahmed, W.; Asghar, M.I.; Awan, I.M.; Hoorani, H.R.; Muhammad, S.; Shah, M.A.; Shahzad, H.; Cho, S.W.; Choi, S.Y.; Hong, B.; Kang, M.H.; Lee, K.S.; Lim, J.H.; Park, S.K.; Kim, M.S.; Gouzevitch, M.; Grenier, G.; Lagarde, F.; Laktineh, I.B.; Bernardino, S.Carpinteyro; Estrada, C.Uribe; Pedraza, I.; Carrillo Moreno, S.; Vazquez Valencia, F.; Pant, L.M.; Buontempo, S.; Cavallo, N.; Esposito, M.; Fabozzi, F.; Lanza, G.; Orso, I.; Lista, L.; Meola, S.; Merola, M.; Paolucci, P.; Thyssen, F.; Braghieri, A.; Magnani, A.; Montagna, P.; Riccardi, C.; Salvini, P.; Vai, I.; Vitulo, P.; Ban, Y.; Qian, S.J.; Choi, M.; Choi, Y.; Goh, J.; Kim, D.; Aleksandrov, A.; Hadjiiska, R.; Iaydjiev, P.; Rodozov, M.; Stoykova, S.; Sultanov, G.; Vutova, M.; Dimitrov, A.; Litov, L.; Pavlov, B.; Petkov, P.; Bagaturia, I.; Lomidze, D.; Avila, C.; Cabrera, A.; Sanabria, J.C.; Crotty, I.; Vaitkus, J.

2016-09-26

High pseudo-rapidity region of CMS muon system is covered only by Cathode Strip Chambers (CSC) and lacks redundant coverage despite the fact that it is a challenging region for muons in terms of backgrounds and momentum resolution. In order to maintain good efficiency for the muon trigger in this region additional RPC are planned to be installed in stations RE31 and RE41. The stations will use RPCs with lower granularity but good timing resolution to mitigate background effects and complete the redundancy of the system. R and D activities will be presented in the talk.

Compressive behaviour of hybrid fiber-reinforced reactive powder concrete after high temperature

International Nuclear Information System (INIS)

Zheng, Wenzhong; Li, Haiyan; Wang, Ying

2012-01-01

Highlights: ► We complete the high temperature test and compression test of RPC after 20–900 °C. ► The presence of steel fiber and polypropylene fiber can prevent RPC from spalling. ► Compressive strength increases first and then decreases with elevated temperatures. ► Microstructure deterioration is the root cause of macro-properties recession. ► Equations to express the compressive strength change with temperature are proposed. -- Abstract: This study focuses on the compressive properties and microstructures of reactive powder concrete (RPC) mixed with steel fiber and polypropylene fiber after exposure to 20–900 °C. The volume dosage of steel fiber and polypropylene fiber is (2%, 0.1%), (2%, 0.2%) and (1%, 0.2%). The effects of heating temperature, fiber content and specimen size on the compressive properties are analyzed. The microstructures of RPC exposed to different high temperatures are studied by scanning electron microscope (SEM). The results indicate that the compressive strength of hybrid fiber-reinforced RPC increases at first, then decreases with the increasing temperature, and the basic reason for the degradation of macro-mechanical properties is the deterioration of RPC microstructure. Based on the experimental results, equations to express the relationships of the compressive strength with the heating temperatures are established. Compared with normal-strength and high-strength concrete, the hybrid fiber-reinforced RPC has excellent capacity in resistance to high temperature.

Simulation of the CMS Resistive Plate Chambers

CERN Document Server

Hadjiiska, R; Pavlov, B; Petkov, P; Dimitrov, A; Beernaert, K; Cimmino, A; Costantini, S; Garcia, G; Lellouch, J; Marinov, A; Ocampo, A; Strobbe, N; Thyssen, F; Tytgat, M; Verwilligen, P; Yazgan, E; Zaganidis, N; Aleksandrov, A; Genchev, V; Iaydjiev, P; Rodozov, M; Shopova, M; Sultanov, G; Ban, Y; Cai, J; Xue, Z; Ge, Y; Li, Q; Qian, S; Avila, C; Chaparro, L F; Gomez, J P; Moreno, B Gomez; Oliveros, A F Osorio; Sanabria, J C; Assran, Y; Sharma, A; Abbrescia, M; Colaleo, A; Pugliese, G; Loddo, F; Calabria, C; Maggi, M; Benussi, L; Bianco, S; Colafranceschi, S; Piccolo, D; Carrillo, C; Iorio, O; Buontempo, S; Paolucci, P; Vitulo, P; Berzano, U; Gabusi, M; Kang, M; Lee, K S; Park, S K; Shin, S; Kim, M S; Seo, H; Goh, J; Choi, Y; Shoaib, M

2013-01-01

The Resistive Plate Chamber (RPC) muon subsystem contributes significantly to the formation of the trigger decision and reconstruction of the muon trajectory parameters. Simulation of the RPC response is a crucial part of the entire CMS Monte Carlo software and directly influences the final physical results. An algorithm based on the parametrization of RPC efficiency, noise, cluster size and timing for every strip has been developed. Experimental data obtained from cosmic and proton-proton collisions at $\\sqrt{s}=7$ TeV have been used for determination of the parameters. A dedicated validation procedure has been developed. A good agreement between the simulated and experimental data has been achieved.

Completion of installation of DT and RPC chambers before Cosmic Challenge

CERN Multimedia

Mimmo Dattola

2006-01-01

All the drift tube ("DT") and resistive plate chambers ("RPC") packages foreseen to be installed in the central barrel ring ("YB0") before the magnet test have been installed (some are missing in the photograph but have since been installed). These silver-coloured rectangular boxes in the gaps between the steel of the rings (red in the image) detect muons. Chambers for Sectors 4 and 5 (sector 1 is at the 9 o'clock position and the counting is clockwise) as well as a couple of chambers in the support "feet" (sectors 9 and 11) will be installed after the magnet test. Chambers for sectors 1 and 7 will be installed in the underground cavern ("UXC") - the latter will be in the places used for the lifting and lowering of the ring.

Calibration of the RPC charge readout in the ARGO-YBJ experiment

Energy Technology Data Exchange (ETDEWEB)

Aielli, G. [Dipartimento di Fisica dell& #x27; Universita & #x27; Tor Vergata& #x27; , via della Ricerca Scientifica 1, 00133 Roma (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Tor Vergata, via della Ricerca Scientifica 1, 00133 Roma (Italy); Bacci, C. [Dipartimento di Fisica dell& #x27; Universita & #x27; Roma Tre& #x27; , via della Vasca Navale 84, 00146 Roma (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Roma3, via della Vasca Navale 84, 00146 Roma (Italy); Bartoli, B. [Dipartimento di Fisica dell& #x27; Universita di Napoli, Complesso Universitario di Monte Sant& #x27; Angelo, via Cintia, 80126 Napoli (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Napoli, Complesso Universitario di Monte Sant& #x27; Angelo, via Cintia, 80126 Napoli (Italy); Bernardini, P. [Dipartimento di Fisica dell& #x27; Universita del Salento, via per Arnesano, 73100 Lecce (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Lecce, via per Arnesano, 73100 Lecce (Italy); Bi, X.J. [Key Laboratory of Particle Astrophyics, Institute of High Energy Physics, Chinese Academy of Science, P.O. Box 918, 100049 Beijing (China); Bleve, C. [Dipartimento di Fisica dell& #x27; Universita del Salento, via per Arnesano, 73100 Lecce (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Lecce, via per Arnesano, 73100 Lecce (Italy); Branchini, P.; Budano, A. [Istituto Nazionale di Fisica Nucleare, Sezione di Roma3, via della Vasca Navale 84, 00146 Roma (Italy); and others

2012-01-01

The charge readout of Resistive Plate Chambers (RPCs) is implemented in the ARGO-YBJ experiment to measure the charged particle density of the shower front up to 10{sup 4}/m{sup 2}, enabling the study of the primary cosmic rays with energies in the 'knee' region. As the first time for RPCs being used this way, a telescope with RPCs and scintillation detectors is setup to calibrate the number of charged particles hitting a RPC versus its charge readout. Air shower particles are taken as the calibration beam. The telescope was tested at sea level and then moved to the ARGO-YBJ site for coincident operation with the ARGO-YBJ experiment. The charge readout shows good linearity with the particle density in the dynamic range (up to 200/m{sup 2}).

Functional requirements for an intelligent RPC. [remote power controller for spaceborne electrical distribution system

Science.gov (United States)

Aucoin, B. M.; Heller, R. P.

1990-01-01

An intelligent remote power controller (RPC) based on microcomputer technology can implement advanced functions for the accurate and secure detection of all types of faults on a spaceborne electrical distribution system. The intelligent RPC will implement conventional protection functions such as overcurrent, under-voltage, and ground fault protection. Advanced functions for the detection of soft faults, which cannot presently be detected, can also be implemented. Adaptive overcurrent protection changes overcurrent settings based on connected load. Incipient and high-impedance fault detection provides early detection of arcing conditions to prevent fires, and to clear and reconfigure circuits before soft faults progress to a hard-fault condition. Power electronics techniques can be used to implement fault current limiting to prevent voltage dips during hard faults. It is concluded that these techniques will enhance the overall safety and reliability of the distribution system.

Performances of the Front-End Electronics for the HADES RPC TOF wall on a 12C beam

International Nuclear Information System (INIS)

Belver, D.; Cabanelas, P.; Castro, E.; Diaz, J.; Garzon, J.A.; Gil, A.; Gonzalez-Diaz, D.; Koenig, W.; Traxler, M.; Zapata, M.

2009-01-01

A Front-End Electronics (FEE) chain for timing accurate measurements has been developed for the RPC wall upgrade of the High-Acceptance DiElectron Spectrometer (HADES). The wall will cover an area of around 8m 2 with 1122 RPC cells (2244 electronic channels). The FEE chain consists of two boards: a four-channel DaughterBOard (DBO) and a 32-channel MotherBOard (MBO). The DBO uses a fast 2 GHz amplifier feeding a discriminator. The time and the charge information are encoded in the leading and the trailing edge (by a charge to width method) of an LVDS signal. Each MBO houses up to eight DBOs providing them regulated voltage supply, threshold values via DACs, test signals and collection of their trigger outputs. The MBO delivers LVDS signals to a time-to-digital converter readout board (TRB) based on HPTDC for data acquisition. In this work, we present the performance of the FEE measured using: (a) narrow electronic test pulses and (b) real signals read out in a fully instrumented RPC sextant installed in its final position at the HADES. The detector was exposed to particles coming from reactions of a 12 C beam on Be and Nb targets at 2 GeV/A kinetic energy. Results for the whole electronic chain (DBO+MBO+TRB) show a timing jitter of around 40 ps/channel for pulses above 100 fC and 80 ps/channel for beam data taken with the RPC.

Performances of the Front-End Electronics for the HADES RPC TOF wall on a 12C beam

Science.gov (United States)

Belver, D.; Cabanelas, P.; Castro, E.; Díaz, J.; Garzón, J. A.; Gil, A.; Gonzalez-Diaz, D.; Koenig, W.; Traxler, M.; Zapata, M.

2009-05-01

A Front-End Electronics (FEE) chain for timing accurate measurements has been developed for the RPC wall upgrade of the High-Acceptance DiElectron Spectrometer (HADES). The wall will cover an area of around 8 m with 1122 RPC cells (2244 electronic channels). The FEE chain consists of two boards: a four-channel DaughterBOard (DBO) and a 32-channel MotherBOard (MBO). The DBO uses a fast 2 GHz amplifier feeding a discriminator. The time and the charge information are encoded in the leading and the trailing edge (by a charge to width method) of an LVDS signal. Each MBO houses up to eight DBOs providing them regulated voltage supply, threshold values via DACs, test signals and collection of their trigger outputs. The MBO delivers LVDS signals to a time-to-digital converter readout board (TRB) based on HPTDC for data acquisition. In this work, we present the performance of the FEE measured using: (a) narrow electronic test pulses and (b) real signals read out in a fully instrumented RPC sextant installed in its final position at the HADES. The detector was exposed to particles coming from reactions of a 12C beam on Be and Nb targets at 2 GeV/A kinetic energy. Results for the whole electronic chain (DBO+MBO+TRB) show a timing jitter of around 40 ps/channel for pulses above 100 fC and 80 ps/channel for beam data taken with the RPC.

The inclusion of RPC only segments in the Barrel Muon Track Finder

CERN Document Server

CMS Collaboration

2018-01-01

On November 3, 2017 during the LHC fill 6360 and from the run number 306121 RPC-only segments were enable to trigger. In this document we show the impact of the RPC-only segments in the Barrel Muon Track Finder efficiency performance. The efficiency measurement was done with Tag and Probe cut and count following the Muon POG working point recommendations (tight ID and Particle Flow isolation requirements more details can be found in https://cds.cern.ch/record/2054113). The used dataset was ZMuMu corresponding to each period.

Effect of the ohmic drop in a RPC-LIKE chamber for measurements of electron transport parameters

Energy Technology Data Exchange (ETDEWEB)

Petri, Anna R.; Gonçalves, Josemary A.C.; Bueno, Carmen C., E-mail: annapetri@usp.br, E-mail: josemary@ipen.br, E-mail: ccbueno@ipen.br [Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil); Mangiarotti, Alessio, E-mail: alessio@if.usp.br [Universidade de São Paulo (IF/USP), SP (Brazil). Instituto de Física

2017-07-01

The main advantage of Resistive Plate Chambers (RPCs), applied, for instance, in High-Energy Experiments and Positron Emission Tomography (PET), is that it is spark-protected due to the presence of, at least, one high resistive electrode. However, the ohmic drop across the latter can affect the charge multiplication significantly. In this work, we investigate this effect in a RPC-like chamber. The counter was filled with nitrogen at atmospheric pressure and the primary ionization was produced by the incidence of nitrogen pulsed laser beam on an aluminum cathode. The illumination area of the cathode was measured using a foil of millimetric paper overlaid on this electrode. In this way, the resistance of the glass anode could be estimated using the known resistivity of the glass (ρ=2×10{sup 12} Ω.cm). Therefore, the voltage drop across the dielectric was calculated by the product of the current across the gas gap and the anode resistance. In order to mitigate the effect of the resistive electrode, the laser beam intensity was limited by interposing metallic meshes between the laser and the chamber window. The dependence of the ohmic drop from the applied voltage was analyzed. The results obtained shown that, without the meshes, the ohmic drop corresponds up to 7% of the applied voltage, preventing the detection system to reach values of density-normalized electric fields in the gas gap (E{sub eff}/N) higher than 166 Td. By minimizing the laser beam intensity and, consequently, the primary ionization, the ohmic drop represented only 0.2% of the applied voltage, extending the E{sub eff} /N range up to 175 Td. (author)

Characterization of 3 mm glass electrodes and development of RPC detectors for INO-ICAL experiment

Energy Technology Data Exchange (ETDEWEB)

Kaur, Daljeet; Kumar, Ashok; Gaur, Ankit; Kumar, Purnendu; Hasbuddin, Md.; Mishra, Swati; Kumar, Praveen; Naimuddin, Md., E-mail: nayeem@cern.ch

2015-02-21

India-based Neutrino Observatory (INO) is a multi-institutional facility, planned to be built up in South India. The INO facility will host a 51 kton magnetized Iron CALorimeter (ICAL) detector to study atmospheric muon neutrinos. Iron plates have been chosen as the target material whereas Resistive Plate Chambers (RPCs) have been chosen as the active detector element for the ICAL experiment. Due to the large number of RPCs needed (∼28,000 of 2 m×2 m in size) for ICAL experiment and for the long lifetime of the experiment, it is necessary to perform a detailed R and D such that each and every parameter of the detector performance can be optimized to improve the physics output. In this paper, we report on the detailed material and electrical properties studies for various types of glass electrodes available locally. We also report on the performance studies carried out on the RPCs made with these electrodes as well as the effect of gas composition and environmental temperature on the detector performance. We also lay emphasis on the usage of materials for RPC electrodes and the suitable environmental conditions applicable for operating the RPC detector for optimal physics output at INO-ICAL experiment.

Data-driven performance evaluation method for CMS RPC trigger ...

Indian Academy of Sciences (India)

level triggers, to handle the large stream of data produced in collision. The information transmitted from the three muon subsystems (DT, CSC and RPC) are collected by the Global Muon Trigger (GMT) Board and merged. A method for evaluating ...

The slow control system of the HADES RPC wall

International Nuclear Information System (INIS)

Gil, A.; Blanco, A.; Castro, E.; Díaz, J.; Garzón, J.A.; Gonzalez-Diaz, D.; Fouedjio, L.; Kolb, B.W.; Palka, M.; Traxler, M.; Trebacz, R.; Zumbruch, P.

2012-01-01

The control and monitoring system for the new HADES RPC time of flight wall installed at GSI Helmholtzzentrum für Schwerionenforschung GmbH (Darmstadt, Germany), is described. The slow control system controls/monitors about 6000 variables from different physical devices via a distributed architecture, which uses intensively the 1-wire ® bus. The software implementation is based on the Experimental Physics and Industrial Control System (EPICS) software tool kit providing low cost, reliability and adaptability without requiring large hardware resources. The control and monitoring system attends five different subsystems: front-end electronics, low voltage, high voltage, gases, and detector.

Performances of the Front-End Electronics for the HADES RPC TOF wall on a {sup 12}C beam

Energy Technology Data Exchange (ETDEWEB)

Belver, D. [LabCAF, USC, Universidade de Santiago de Compostela, Dep. de Fisica de Particulas, Santiago de Compostela 15782 (Spain)], E-mail: danielbf@usc.es; Cabanelas, P.; Castro, E. [LabCAF, USC, Universidade de Santiago de Compostela, Dep. de Fisica de Particulas, Santiago de Compostela 15782 (Spain); Diaz, J. [Instituto de Fisica Corpuscular, CSIC-Universidad de Valencia, Valencia 46071 (Spain); Garzon, J.A. [LabCAF, USC, Universidade de Santiago de Compostela, Dep. de Fisica de Particulas, Santiago de Compostela 15782 (Spain); Gil, A. [Instituto de Fisica Corpuscular, CSIC-Universidad de Valencia, Valencia 46071 (Spain); Gonzalez-Diaz, D.; Koenig, W.; Traxler, M. [Gesellschaft fuer Schwerionenforschung, GSI, 64291 Darmstadt (Germany); Zapata, M. [LabCAF, USC, Universidade de Santiago de Compostela, Dep. de Fisica de Particulas, Santiago de Compostela 15782 (Spain)

2009-05-01

A Front-End Electronics (FEE) chain for timing accurate measurements has been developed for the RPC wall upgrade of the High-Acceptance DiElectron Spectrometer (HADES). The wall will cover an area of around 8m{sup 2} with 1122 RPC cells (2244 electronic channels). The FEE chain consists of two boards: a four-channel DaughterBOard (DBO) and a 32-channel MotherBOard (MBO). The DBO uses a fast 2 GHz amplifier feeding a discriminator. The time and the charge information are encoded in the leading and the trailing edge (by a charge to width method) of an LVDS signal. Each MBO houses up to eight DBOs providing them regulated voltage supply, threshold values via DACs, test signals and collection of their trigger outputs. The MBO delivers LVDS signals to a time-to-digital converter readout board (TRB) based on HPTDC for data acquisition. In this work, we present the performance of the FEE measured using: (a) narrow electronic test pulses and (b) real signals read out in a fully instrumented RPC sextant installed in its final position at the HADES. The detector was exposed to particles coming from reactions of a {sup 12}C beam on Be and Nb targets at 2 GeV/A kinetic energy. Results for the whole electronic chain (DBO+MBO+TRB) show a timing jitter of around 40 ps/channel for pulses above 100 fC and 80 ps/channel for beam data taken with the RPC.

An Emergency Georeferencing Framework for GF-4 Imagery Based on GCP Prediction and Dynamic RPC Refinement

Directory of Open Access Journals (Sweden)

Pengfei Li

2017-10-01

Full Text Available GaoFen-4 (GF-4 imagery has very potential in terms of emergency response due to its gazing mode. However, only poor geometric accuracy can be obtained using the rational polynomial coefficient (RPC parameters provided, making ground control points (GCPs necessary for emergency response. However, selecting GCPs is traditionally time-consuming, labor-intensive, and not fully reliable. This is mainly due to the facts that (1 manual GCP selection is time-consuming and cumbersome because of too many human interventions, especially for the first few GCPs; (2 typically, GF-4 gives planar array imagery acquired at rather large tilt angles, and the distortion introduces problems in image matching; (3 reference data will not always be available, especially under emergency circumstances. This paper provides a novel emergency georeferencing framework for GF-4 Level 1 imagery. The key feature is GCP prediction based on dynamic RPC refinement, which is able to predict even the first GCP and the prediction will be dynamically refined as the selection goes on. This is done by two techniques: (1 GCP prediction using RPC parameters and (2 dynamic RPC refinement using as few as only one GCP. Besides, online map services are also adopted to automatically provide reference data. Experimental results show that (1 GCP predictions improve using dynamic RPC refinement; (2 GCP selection becomes more efficient with GCP prediction; (3 the integration of online map services constitutes a good example for emergency response.

First results of the cosmic rays test of the RPC of the ATLAS muon spectrometer at LHC

CERN Document Server

Alviggi, M G; Caprio, M A; Carlino, G; De Asmundis, R; Della Pietra, M; Della Volpe, D; Iengo, P; Patricelli, S; Sekhniaidze, G

2004-01-01

The trigger for the Barrel Muon Spectrometer of the ATLAS experiment at LHC will be given by means of Resistive Plate Chambers working in avalanche mode. Before being mounted on the experimental apparatus each RPC chamber will undergo detailed quality control tests. A dedicated cosmic rays test station with good tracking resolution is operational in Naples University and INFN laboratory. All working parameters of RPCs are monitored and measured. Moreover, the uniformity of the efficiency on the whole surface is measured. A brief description of the test station and results for the first 148 Units will be presented.

Efecto de la hormona de crecimiento (GH en el catch-up de ratas con retardo prenatal de crecimiento (RPC

Directory of Open Access Journals (Sweden)

Quintero, Fabián

2005-01-01

Full Text Available El presente trabajo analiza los cambios morfométricos en el crecimiento postnatal de ratas RPC tratadas con GH. Ratas Wistar se dividieron en: Control (C, Sham-operado (Sh, RPC y RPC+GH. El RPC fue inducido por ligamiento de las arterias uterinas a los 14 días de gestación. La GH fue administrada desde los 21 hasta los 60 días de edad (Genotropin® 3.0 mg/kg/día. A los animales Sh se les inyectó sólo el diluyente. Los animales se radiografiaron a los 84 días de edad y se relevaron longitudes, anchos y alturas neurocraneana y esplacnocraneana y longitudes y anchos femoral, humeral y tibial, longitud de la columna y anchos pélvico inferior, medio y superior. Los datos fueron procesados mediante análisis de componentes principales (ACP y discriminante (AD. El primer componente del ACP mostró efecto tamaño y el segundo forma, separando los sexos y los tratamientos. Los valores de F del AD fueron altamente significativos. La primera función quedó definida por los anchos pélvico medio y superior y la longitud tibial, explicando el 66% de la varianza. La segunda por el ancho pélvico superior y longitud tibial, explicando un 18% más de la variación total. La longitud tibial discriminó entre sexos y el ancho pélvico superior entre tratamientos. El análisis separó a los RPC de los RPC+GH y agrupó a éstos últimos con los Sh. Se concluye que el tratamiento con GH en animales RPC permite el catch up en tamaño y forma corporal, siendo más efectivo en las hembras.

Performance and simulation of a double-gap resistive plate chamber in the avalanche mode

CERN Document Server

Ahn Sung Hwan; Hong Byung Sik; Hong Seong Jong; Ito, M; Kang, T I; Kim, B I; Kim, J H; Kim, Y J; Kim, Y U; Koo, D G; Lee Hyup Woo; Lee, K B; Lee Kyong Sei; Lee Seok Jae; Lim, J K; Moon, D H; Nam, S K; Park, S; Park, W J; Rhee June Tak; Ryu, M S; Sim Kwang Souk

2004-01-01

We present a detailed analysis of the time and the charge signals of a prototype double-gap resistive plate chamber for the endcap region of the Compact Muon Solenoid (CMS) detector at the Large Hadron Collider (LHC). The chamber was built with relatively low-resistivity bakelite. The time and the charge results demonstrate that the high- voltage plateau, which satisfies various CMS requirements for the efficiency, the noise cluster rate, the fraction of the large signal, and the streamer probability, can be extended at least up to 400 V with the present design. In addition, a simple avalanche multiplication model is studied in detail. The model can reproduce the experimental charge spectra reasonably well. The charge information enables us to estimate the effective Townsend coefficient in avalanche-mode operation.

75 FR 16499 - Royalty Policy Committee (RPC) Notice of Renewal

Science.gov (United States)

2010-04-01

..., Minerals Management Service; Denver, Colorado 80225-0165; telephone number (303) 231-3392. Certification I... DEPARTMENT OF THE INTERIOR Royalty Policy Committee (RPC) Notice of Renewal AGENCY: Minerals... Secretary of the Interior on the management of Federal and Indian mineral leases and revenues under the laws...

The wide gap resistive plate chamber

International Nuclear Information System (INIS)

Crotty, I.; Lamas Valverde, J.; Hatzifotiadou, D.; Williams, M.C.S.; Zichichi, A.

1995-01-01

The resistive plate chamber (RPC) has good time and position resolution; these factors (coupled to its simple construction) make it an attractive candidate for muon trigger systems at future colliders. However, operated in spark mode, the RPC has severe rate problems that make it unusable above 10 Hz/cm 2 . We have previously published our results concerning the operation of the RPC in spark and in avalanche mode; we have shown that the rate limit can be increased to 150 Hz/cm 2 if the RPC is operated in avalanche mode. Here, we discuss the performance of chambers with 6 and 8 mm gas gaps (compared to the more usual 2 mm gap). We outline the reasons for this choice, and also discuss anode versus cathode strip readout. We have measured the efficiency versus flux, and also show that an enhanced rate limit can be obtained if only a small region of the chamber is exposed to the beam (spot illumination). Finally we have tested the performance of chambers constructed with other materials for the resistiv e plate and compare it to chambers constructed with our preferred plastic, melamine laminate. (orig.)

Time structure measurement of the ATLAS RPC gap current

CERN Document Server

Aielli, G; The ATLAS collaboration

2010-01-01

The current absorbed by an RPC represents the sum of the charge delivered in the gas by the ionizing events interesting the gap, integrated by the electrodes time constant. This is typically of the order of tens of ms thus dominating the gas discharge time scale and characterizing the granular structure observed in the current signal. In most cases this structure is considered as noise to be further integrated to observe the average gap current, used often as a detector monitoring parameter or to precisely measure the uncorrelated background rate effects. A remarkable case is given if a large number of particles is passing trough the detector within an integration time constant producing a current peak clearly detectable above the average noise. The ATLAS RPC system is equipped with a dedicated current monitoring based on an ADC capable of reading out the average value as well as the transient peaks of the currents above a given threshold. A study on such data was used to spot the gap HV noise, to monitor the...

Radiation-hard ceramic Resistive Plate Chambers for forward TOF and T0 systems

Energy Technology Data Exchange (ETDEWEB)

Akindinov, A., E-mail: Alexander.Akindinov@cern.ch [Institute for Theoretical and Experimental Physics, Moscow (Russian Federation); Dreyer, J.; Fan, X.; Kämpfer, B. [Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); Kiselev, S. [Institute for Theoretical and Experimental Physics, Moscow (Russian Federation); Kotte, R.; Garcia, A. Laso [Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); Malkevich, D. [Institute for Theoretical and Experimental Physics, Moscow (Russian Federation); Naumann, L. [Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); Nedosekin, A.; Plotnikov, V. [Institute for Theoretical and Experimental Physics, Moscow (Russian Federation); Stach, D. [Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); Sultanov, R.; Voloshin, K. [Institute for Theoretical and Experimental Physics, Moscow (Russian Federation)

2017-02-11

Resistive Plate Chambers with ceramic electrodes are the main candidates for a use in precise multi-channel timing systems operating in high-radiation conditions. We report the latest R&D results on these detectors aimed to meet the requirements of the forward T0 counter at the CBM experiment. RPC design, gas mixture, limits on the bulk resistivity of ceramic electrodes, efficiency, time resolution, counting rate capabilities and ageing test results are presented.

Experimental results on RPC neutron sensitivity

Energy Technology Data Exchange (ETDEWEB)

Abbrescia, M.; Altieri, S.; Baratti, V.; Barnaba, O.; Belli, G.; Bruno, G.; Colaleo, A.; De Vecchi, C.; Guida, R. E-mail: roberto.guida@pv.infn.it; Iaselli, G.; Imbres, E.; Loddo, F.; Maggi, M.; Marangelli, B.; Musitelli, G.; Nardo, R.; Natali, S.; Nuzzo, S.; Pugliese, G.; Ranieri, A.; Ratti, S.; Riccardi, C.; Romano, F.; Torre, P.; Vicini, A.; Vitulo, P

2003-08-01

RPC neutron sensitivity has been studied during two tests done with different neutrons energies. In the first test, neutrons from spontaneous fission events of {sup 252}Cf were used (average energy 2 MeV); while in the second test neutrons were produced using a 50 MeV deuteron beam on a 1 cm thick beryllium target (average energy 20 MeV). Preliminary results show that the neutron sensitivity in double gap mode is (0.52{+-}0.03)x10{sup -3} at about 2 MeV and (5.3{+-}0.5)x10{sup -3} at about 20 MeV.

Measurement of cosmic muon angular distribution and vertical integrated flux by 2 m × 2 m RPC stack at IICHEP-Madurai

International Nuclear Information System (INIS)

Pethuraj, S.; Datar, V.M.; Majumder, G.; Ravindran, K.C.; Satyanarayana, B.; Mondal, N.K.

2017-01-01

The 50 kton INO-ICAL is a proposed underground high energy physics experiment at Theni, India (9 o 57' N , 77 o 16' E ) to study the neutrino oscillation parameters using atmospheric neutrinos. The Resistive Plate Chamber (RPC) has been chosen as the active detector element for the ICAL detector. An experimental setup consisting of 12 layers of glass RPCs of size 2 m × 2 m has been built at IICHEP, Madurai to study the long term stability and performance of RPCs which are produced on a large scale in Indian industry. In this paper, the studies on the performance of RPCs are presented along with the angular distribution of muons at Madurai (9 o 56' N ,78 o 00' E and Altitude ≈ 160 m from sea level).

Measurement of cosmic muon angular distribution and vertical integrated flux by 2 m × 2 m RPC stack at IICHEP-Madurai

Science.gov (United States)

Pethuraj, S.; Datar, V. M.; Majumder, G.; Mondal, N. K.; Ravindran, K. C.; Satyanarayana, B.

2017-09-01

The 50 kton INO-ICAL is a proposed underground high energy physics experiment at Theni, India (9o57'N, 77o16'E) to study the neutrino oscillation parameters using atmospheric neutrinos. The Resistive Plate Chamber (RPC) has been chosen as the active detector element for the ICAL detector. An experimental setup consisting of 12 layers of glass RPCs of size 2 m × 2 m has been built at IICHEP, Madurai to study the long term stability and performance of RPCs which are produced on a large scale in Indian industry. In this paper, the studies on the performance of RPCs are presented along with the angular distribution of muons at Madurai (9o56'N,78o00'E and Altitude ≈ 160 m from sea level).

Test of freonless operation of resistive plate chambers with glass electrodes--1 mm gas gap vs 2 mm gas gap

CERN Document Server

Sakaue, H; Takahashi, T; Teramoto, Y

2002-01-01

Non-freon gas mixtures (Ar/iso-C sub 4 H sub 1 sub 0) were tested as the chamber gas for 1 and 2 mm gas gap Resistive Plate Chambers (RPCs) with float glass as the resistive electrodes, operated in the streamer mode. With the narrower (1 mm) gas gap, streamer charge is reduced (approx 1/3), which reduces the dead time (and dead area), associated with each streamer, improving the detection efficiency. The best performance was obtained for two cases: Ar/iso-C sub 4 H sub 1 sub 0 =50/50 and 60/40. For the 50/50 mixture, a detection efficiency of better than 98% was obtained for the 1 mm gap RPC, while the efficiency was 95% for the 2 mm gap RPC, each operated as a double-gap RPC. The measured time resolution (rms) was 1.45+-0.05 (2.52+-0.09) ns for the 1 (2) mm gap RPC for the 50/50 mixture.

RPC Calculations for K-forbidden Transitions in {sup 183}W, Evidence for Large Inertial Parameter Connected with High-lying Rotational Bands

Energy Technology Data Exchange (ETDEWEB)

Malmskog, S G [AB Atomenergi, Nykoeping (Sweden); Wahlborn, S [Div. of Theore tical Physics, Royal Inst. of Technology Stockholm (Sweden)

1967-09-15

Recent measurements have shown that the transitions deexciting the 453 keV 7/2{sup -} level in {sup 183}W to the K = 1/2{sup -} and 3/2{sup -} bands are strongly retarded. The data for B(M1) and B(E2) are analyzed in terms of the RPC model (rotation + particle motion + coupling). With the {delta}K = 1 (Coriolis) coupling, the K-forbidden M1-transitions proceed via admixtures of high-lying 5/2{sup -} bands. A reasonable and unambiguous fit to the data is obtained by varying the strength of the coupling. Allowing for various uncertainties and corrections, one finds that the inertial parameter (the inverse of the coupling constant, i. e. 2J(2{pi}){sup 2}/({Dirac_h}){sup 2} may have values between roughly 1 and 3 times the rigid rotator value of 2J(2{pi}){sup 2}/({Dirac_h}){sup 2}, thus being unexpectedly large. Calculations with the {delta}K=2 coupling were also performed and turn out not to give better agreement with experiment.

Purification of supercoiled DNA of plasmid Col E1 by RPC-5 chromatography

Energy Technology Data Exchange (ETDEWEB)

Best, A.N.; Allison, D.P.; Novelli, G.D.

1981-07-01

Col E1 DNA can be purified to a high degree by RPC-5 chromatography of a partially purified cell lysate with a very shallow linear NaC1 gradient at pH 7.8. Electron micrographs demonstrated that the purest fractions were composed of 93% supercoiled (form I) DNA and 7% open circular (form II) DNA. The actual chromatography can be accomplished in 13 to 14 h and is designed for the production of several milligrams of plasmid DNA.

The EEE Project: Cosmic rays, multigap resistive plate chambers and high school students

CERN Document Server

Abbrescia, M.; Antolini, R; Avanzini, C; Baldini Ferroli, R; Bencivenni, G; Bossini, E; Bressan, E; Chiavassa, A; Cicalo, C; Cifarelli, L; Coccia, E; De Gruttula, D; De Pasquale, S; Di Giovanni, A; D'Incecco, M; Doroud, K; Dreucci, M; Fabbri, FL; Frolov, V; Garbini, M; Gemme, G; Gnesi, I; Gustavino, C; Hatzifotiadu, D; La Rocca, P; Li, S; Moro, R; Miozzi, S; Massai, M; Maggiora, A; Librizzi, F; Piragino, G; Pilo, F; Perasso, L; Paoletti, R; Righini, GC; Scapparone, E; Sartorelli, G; Romano, F; Serci, S; Selvi, M; Scribano, A; Riggi, F; Regano, A; Squarcia, S; Spandre, G; Toselli, F; Taiuti, M; Zichichi, A; Zouyevski, R; Williams, MCS; Votano, L; Siddi, E; Panareo, M

2012-01-01

The Gas Gain Monitoring (GGM) system of the Resistive Plate Chamber (RPC) muon detector in the Compact Muon Solenoid (CMS) experiment provides fast and accurate determination of the stability in the working point conditions due to gas mixture changes in the closed loop recirculation system. In 2011 the GGM began to operate using a feedback algorithm to control the applied voltage, in order to keep the GGM response insensitive to environmental temperature and atmospheric pressure variations. Recent results are presented on the feedback method used and on alternative algorithms.

Muon Identification performance: hadron mis-Id measurements and RPC Muon selections

CERN Document Server

CMS Collaboration

2014-01-01

Pion, kaon, proton mis-identification probabilities as muons have been measured for different Muon ID algorithms. Results from two independent analyses are presented. The performance of a new muon ID algorithm based on matching of inner tracks with hits in muon RPC chambers is also presented.

Measurement of cosmic muon angular distribution and vertical integrated flux by 2 m × 2 m RPC stack at IICHEP-Madurai

Energy Technology Data Exchange (ETDEWEB)

Pethuraj, S. [Homi Bhabha National Institute, Mumbai-400094, Maharashtra (India); Datar, V.M.; Majumder, G.; Ravindran, K.C.; Satyanarayana, B. [Tata Institute of Fundamental Research, Mumbai-400005, Maharashtra (India); Mondal, N.K., E-mail: s.pethuraj@tifr.res.in, E-mail: vivek.datar@tifr.res.in, E-mail: gobinda@tifr.res.in, E-mail: nabak.mondal@gmail.com, E-mail: kcravi@tifr.res.in, E-mail: bsn@tifr.res.in [Saha Institute of Nuclear Physics, Kolkata-700064, West Bengal (India)

2017-09-01

The 50 kton INO-ICAL is a proposed underground high energy physics experiment at Theni, India (9{sup o}57' N , 77{sup o}16' E ) to study the neutrino oscillation parameters using atmospheric neutrinos. The Resistive Plate Chamber (RPC) has been chosen as the active detector element for the ICAL detector. An experimental setup consisting of 12 layers of glass RPCs of size 2 m × 2 m has been built at IICHEP, Madurai to study the long term stability and performance of RPCs which are produced on a large scale in Indian industry. In this paper, the studies on the performance of RPCs are presented along with the angular distribution of muons at Madurai (9{sup o}56' N ,78{sup o}00' E and Altitude ≈ 160 m from sea level).

Results on long-term performances and laboratory tests of the L3 RPC system at LEP

CERN Document Server

Alviggi, M G; Conventi, F; De Asmundis, R; Della Pietra, M; Della Volpe, D; Patricelli, S; Paolucci, P; Piccolo, D; Sciacca, C; Sekhniaidze, G

2003-01-01

The RPC detectors in the L3 experiment at LEP work as a trigger system for the Forward-Backward Muon Spectrometer. It consists of 192 bi-gap RPCs working in streamer mode. We monitored the behaviour of the system over seven years of data taking at LEP. To investigate the ageing of the RPCs after this long-term operation, we report the main results obtained from 1994 to 2000, together with the results of tests performed on some RPC chambers in our test site in Napoli with cosmic rays after the dismantling of L3.

Test and performances of the RPC trigger chambers of the ATLAS experiment at LHC

CERN Document Server

Aielli, G; Ammosov, A; Biglietti, M; Brambilla, Elena; Camarri, P; Canale, V; Caprio, M A; Cardarelli, R; Carlino, G; Cataldi, G; Chiodini, G; Di Simone, A; Di Ciaccio, A; Della Volpe, D; De Asmundis, R; Della Pietra, M; Grancagnolo, F; Gorini, E; Iengo, P; Liberti, B; Patricelli, S; Perrino, R; Primavera, M; Santonico, R; Sehkniadze, G; Spagnolo, S; Sviridov, Yu; Zaetz, V G

2004-01-01

RPCs will be used as trigger detectors in the barrel region of the Muon Spectrometer of the ATLAS experiment at LHC. The total number of RPC units to be installed is 1088, covering a total surface of about 3500m**2. ATLAS RPCs work in avalanche mode with C//2H//2F //4/C//4H //1//0/SF//6 (94.7%/5%/0.3%) gas mixture. A cosmic ray test stand has been designed and built in Naples laboratories in order to carry out a complete test of the ATLAS RPC units. Since August 2002 about 300 units have been tested. A description of the test stand, test procedure and results are presented.

Response of resistive plate chamber to e+/e- at E < 100 MeV

International Nuclear Information System (INIS)

Rhee, J T; Jamil, M; Chun, Christopher; Yin, Bingzhu; Jeon, Y J

2006-01-01

Resistive plate chambers (RPCs) will be installed as one of the important tracking detectors both in the endcap and barrel area CMS muon stations. These stations will be exposed to high gamma, neutron and positron/electron background radiation environment during the LHC machine operation. For the safe operation of these detectors, it is necessary to monitor these kinds of radiation. A simulation test has been carried out with the RPC at e + /e - fluxes using the dose and fluence equivalent to LHC 10 years operation. The simulation studies of RPC to e + /e - of energy 0.1 < E < 100 MeV have been performed using the GEANT 3.21 and GEANT4 Monte Carlo packages. By employing these two packages, good agreement of the simulation results is attained

Status of the present ATLAS RPC system and overview towards HL-LHC

CERN Document Server

Alberghi, Gian Luigi; The ATLAS collaboration

2018-01-01

The RPC system covers the barrel region of the ATLAS muon spectrometer in the pseudo-rapidity range of |eta|<1.05 with six independent detector layers, and solely provides the L1 trigger signal and the track coordinate in the non-bending plane of the muon candidates. The system has been designed to operate up to the nominal LHC luminosity (1e34cm-2s-1) which has been already exceeded thanks to the excellent performance of the collider. The experience in operating the present RPC system, up to the maximum instantaneous luminosity of 2.05 x 1e34 cm-2 s-1 reached in 2017, is reported. The performance of the system, in the severe background and pileup conditions of the last data taking period, is presented together with the improved tools implemented in order to have an effective monitoring of the detector status. The plans to successfully operate the present system during the HL-LHC phase are also introduced.

Web-based monitoring tools for Resistive Plate Chambers in the CMS experiment at CERN

International Nuclear Information System (INIS)

Kim, M.S.; Ban, Y.; Cai, J.; Li, Q.; Liu, S.; Qian, S.; Wang, D.; Xu, Z.; Zhang, F.; Choi, Y.; Kim, D.; Goh, J.; Choi, S.; Hong, B.; Kang, J.W.; Kang, M.; Kwon, J.H.; Lee, K.S.; Lee, S.K.; Park, S.K.

2014-01-01

The Resistive Plate Chambers (RPC) are used in the CMS experiment at the trigger level and also in the standard offline muon reconstruction. In order to guarantee the quality of the data collected and to monitor online the detector performance, a set of tools has been developed in CMS which is heavily used in the RPC system. The Web-based monitoring (WBM) is a set of java servlets that allows users to check the performance of the hardware during data taking, providing distributions and history plots of all the parameters. The functionalities of the RPC WBM monitoring tools are presented along with studies of the detector performance as a function of growing luminosity and environmental conditions that are tracked over time

Sensitivity and environmental response of the CMS RPC gas gain monitoring system

CERN Document Server

Benussi, L.; Colafranceschi, S.; Fabbri, F.L.; Giardoni, M.; Ortenzi, B.; Paolozzi, A.; Passamonti, L.; Pierluigi, D.; Ponzio, B.; Russo, A.; Colaleo, A.; Loddo, F.; Maggi, M.; Ranieri, A.; Abbrescia, M.; Iaselli, G.; Marangelli, B.; Natali, S.; Nuzzo, S.; Pugliese, G.; Romano, F.; Roselli, G.; Trentadue, R.; Tupputi, S.; Guida, R.; Polese, G.; Sharma, A.; Cimmino, A.; Lomidze, D.; Paolucci, D.; Piccolo, P.; Baesso, P.; Necchi, M.; Pagano, D.; Ratti, S.P.; Vitulo, P.; Viviani, C.

Results from the gas gain monitoring (GGM) system for the muon detector using RPC in the CMS experiment at the LHC is presented. The system is designed to provide fast and accurate determination of any shift in the working point of the chambers due to gas mixture changes.

Rate effects in resistive plate chambers

International Nuclear Information System (INIS)

Lippmann, C.; Riegler, W.; Kalweit, A.

2006-01-01

The resistive plates in RPCs cause a drop of the electric field in the gas gap at high particle rates or large gas gain, which affects efficiency and time resolution. This effect is typically estimated by assuming the particle flux to be a DC current that causes a voltage drop when it passes through the resistive plate. In an improved model by Abbrescia (Nucl. Instr. Meth. A 533 (2004) 7), the fluctuation of the field in the gas gap is modelled by assuming that the avalanche partially discharges a small capacitor which gets recharged with a time constant characteristic for the given RPC. In our approach, the effect is calculated by using the exact analytic solution for the time dependent electric field of a point charge sitting on the surface of a resistive plate in an RPC. This is, by definition, the best possible approximation to reality. The solution is obtained using the quasi-static approximation of Maxwell's equations. The formulas are presented as integral representations with 'cured' integrands, which allow easy numerical evaluation for Monte Carlo simulations. The solutions show that the charges in RPCs are 'destroyed' with a continuous distribution of time constants which are related in a very intuitive way to some limiting cases. Using these formulas we present a Monte Carlo simulation of rate effects, proving the applicability of this approach. Finally, we compare the Monte Carlo results to analytical calculations, similar to the ones proposed by Gonzalez-Diaz et al. (see proceedings of this conference)

Design and Commissioning of the ATLAS Muon Spectrometer RPC Read Out Driver

CERN Document Server

Aloisio, A; Cevenini, F; Della Pietra; Della Volpe; Izzo, V

2008-01-01

The RPC subsystem of the ATLAS muon spectrometer provides the Level-1 trigger in the barrel and it is read out by a specific DAQ system. On-detector electronics pack the RPC data in frames, tagged with an event number assigned by the trigger logic, and transmit them to the counting room on optical fibre. Data from each sector are then routed together to a Read-Out Driver (ROD) board. This is a custom processor that parses the frames, checks their coherence and builds a data structure for all the RPCs of one of the 32 sectors of the spectrometer. Each ROD sends the event fragments to a Read-Out subsystem for further event building and analysis. The ROD is a VME64x board, designed around two Xilinx Virtex-II FPGAs and an ARM7 microcontroller. In this paper we describe the board architecture and the event binding algorithm. The boards have been installed in the ATLAS USA15 control room and have been successfully used in the ATLAS commissioning runs.

Application of the ATLAS DAQ and Monitoring System for MDT and RPC Commissioning

CERN Document Server

Pasqualucci, E

2007-01-01

The ATLAS DAQ and monitoring software are currently commonly used to test detectors during the commissioning phase. In this paper, their usage in MDT and RPC commissioning is described, both at the surface pre-commissioning and commissioning stations and in the ATLAS pit. Two main components are heavily used for detector tests. The ROD Crate DAQ software is based on the ATLAS Readout application. Based on the plug-in mechanism, it provides a complete environment to interface any kind of detector or trigger electronics to the ATLAS DAQ system. All the possible flavours of this application are used to test and run the MDT and RPC detectors at the pre-commissioning and commissioning sites. Ad-hoc plug-ins have been developed to implement data readout via VME, both with ROD prototypes and emulating final electronics to read out data with temporary solutions, and to provide trigger distribution and busy management in a multi-crate environment. Data driven event building functionality is also used to combine data f...

CMS Resistive Plate Chambers performance at $\\sqrt{s}=$13 TeV

CERN Document Server

Cabrera Mora, Andres Leonardo

2016-01-01

During 2015, the Large Hadron Collider (LHC) at CERN has reached the record-breaking center-of-mass energy of 13 TeV for proton-proton collisions. The LHC restarted operations successfully after a two-year technical stop, known as Long Shutdown 1 (LS1), needed for servicing and consolidating the CERN accelerator complex. The Compact Muon Solenoid detector, a general-purpose detector at LHC, benefited from LS1 by performing crucial tasks necessary to operate the detector at higher energies. In particular, the Resistive Plate Chamber (RPC) system, one of the three muon detector technologies in CMS, was serviced, re-commissioned, and upgraded with 144 new chambers to enhance muon trigger efficiency. The CMS RPC system confers robustness and redundancy to the muon trigger. A total of 1056 double-gap chambers cover the pseudo-rapidity region $ \\lvert\\eta\\rvert \\leq$1.6. The CMS RPC collaboration has exploited early data samples at 13 TeV for detector performance studies. These data allowed for a first characte...

First DT+RPC chambers installation round in the UX5 cavern

CERN Multimedia

Jesus Puerta-Pelayo

2007-01-01

DT+RPC packages corresponding to sectors 1 and 7 of the barrel region cannot be installed on surface, since the lowering gantry from SX5 to UX5 uses their gaps to hold the wheels. Therefore this installation has to be carried out in the cavern. These pictures illustrate the first installation round on YB+2 right after the lowering. A total of 8 chambers were successfully installed in 2 days.

Beam test results of a resistive plate chamber made of Chinese bakelites

CERN Document Server

Ying, J; Ban, Y; Liu Hong Tao; Zhu, Z M; Zhu, Z Y; Chen, T; Ma Jing Guo; Qian, S J

2001-01-01

The detailed beam test results of the first Chinese made avalanche mode resistive plate chamber are reported. The experimental set-ups at CERN GIF area are introduced. The detection efficiency, position resolution and time resolution of the chamber fulfil requirements as muon trigger for the future LHC experiments, while the rate capability is not good enough if the chamber is used at forward region. The applicability and the further possible improvements of the chamber are discussed. (12 refs).

Performance of CMS Resistive Plate Chambers in CRAFT and early 2015 collisions at 13 TeV

CERN Document Server

CMS Collaboration

2015-01-01

Resistive Plate Chambers (RPC) performance results with cosmics data at 3.8 T and p-p collision data at 13 TeV for 2015 are presented. These results include plots of relevant RPC variables such as occupancy, cluster size, efficiency and residuals. RPC cluster size, measured with cosmic rays at 3.8 T during 2015, is presented and compared with 2012 results. During the first long shutdown of the LHC (2013-2014) the CMS muon system has been upgraded with 144 double-gap chambers on the forth forward stations. During the commissioning period, the system has been successfully run and experimental data has been collected and analyzed in details. Occupancy and efficiency results of newly installed chambers using 13 TeV p-p data are reported. The results of the 2015 HV Scan, performed at 0 T magnetic field, are presented and compared with the 2012 HV scan results at 3.8 T. These results are comparable since RPC efficiency is independent of the magnetic field surrounding the chambers.

The Front-End Electronics for the HADES RPC Wall (ESTRELA-FEE)

International Nuclear Information System (INIS)

Belver, D.; Garzon, J.A.; Gil, A.; Gonzalez-Diaz, D.; Koenig, W.; Lange, S.; Marin, J.; Montes, N.; Skott, P.; Traxler, M.; Zapata, M.

2006-01-01

A new front-end electronics (FEE) system for RPC timing measurements has been developed for the ESTRELA project, which is part of the upgrade of the HADES experiment at GSI. The RPCs will cover an area of 8 m 2 with 2048 electronic channels. The chain consists on 2 boards: a 4-channel daughterboard (DB) and a 32-channel motherboard (MB). The DB uses a fast 2 GHz amplifier that feeds a discriminator with a constant threshold and an operational amplifier for a charge measurement by a Time-Over-Threshold (ToT) method for the integrated signal (for a slewing correction). The MB is connected to 8 DB, and provides voltage regulation, DACs for signal thresholds and a trigger logic. The MB delivers the differential output signals to an external HPTDC chip. Results are presented for (a) narrow electronic test pulses and for (b) RPC signals from gamma photons, showing a timing jitter around 15 ps/channel (for pulses above 100 fC) and 30-40 ps/channel, respectively. Tests with coincidently firing channels reveal levels of cross-talk below a 1% for a threshold of 25 fC, with a degradation of the time resolution of 10 ps at most

Installation of last DT+RPC packages for the muon barrel detector of CMS

CERN Multimedia

Jesus Puerta-Pelayo

2007-01-01

On friday 26 October 2007 the last BMu package (DT+RPC chambers) was installed in the cavern into the iron yoke of CMS. This operation marked the completion of the central muon detector of CMS. Some pictures of this last installation round (8 chambers in total in YB-2 and YB-1) are shown here.

Perilaku Histeretik Subassemblage Balok-Kolom Interior Prategang Parsial Reactive Powder Concrete dalam Pemodelan Finite Element

Directory of Open Access Journals (Sweden)

Siti Aisyah Nurjannah

2015-12-01

Full Text Available Research on concrete in some countries has produced a concrete type of Ultra High Performance Concrete (UHPC which has the strength, ductility, modulus of elasticity, and high durability, namely Reactive Powder Concrete (RPC. Research on structural engineering using RPC material in various countries have shown better performance than structures made of Normal Concrete (NC or High Performance Concrete (HPC in resisting both monotonic and cyclic loads. Research showed that structures using RPC that resisted cyclic loading had an appropriate hysteretic performance. In this study, research was conducted using RPC material and structure modeling with non-linear finite element method (NL-FEM. The material test results were used as parts of the input of the interior partial prestressed beam-column subassemblage structures (S-RPC modelled using the NL-FEM. As a comparison, there were models of interior partial prestressed beam-column subassemblage used NC materials (S-NC. To analyze the hysteretic behavior of the models, there were variations of Partial Prestressed Ratio (PPR values of S-RPC and S-NC models. Analysis of modeling results showed superior performance and better hysteretic behavior of all S-RPC models compared with the S-NC models in terms of ductility, energy dissipation, stiffness, and strength. From the modeling results, there were optimum PPR values of the S-RPC models which ranged between 21.39% and 37.34%. Meanwhile, the optimum PPR value of S-NC model was 34.15%.

First installation of DT and RPC packages into the CMS iron yoke

CERN Multimedia

Jesus Puerta-Pelayo

2004-01-01

These pictures illustrate the installation process of muon barrel packages (DT + RPC) into the pockets of the CMS iron yoke at SX5. The chambers are first transported in groups of four from the ISR area (where they are certified and coupled together) to the construction hall in Cessy (neighbouring France), called Point 5 (or SX5). Once there, they pass through a fast high voltage and electronic certification test, before being slid into the insertion cradle. This cradle is attached to the yoke and aligned to the chamber rails, allowing an easy insertion. A rate of 3 chambers per day can be achieved. This set of pictures was taken during the first final insertion round at Point 5, where most chambers for the lower part of YB+2 were installed.

Performance of low-resistivity single and dual-gap RPCs for LHCb

CERN Document Server

Adinolfi, M; Messi, R; Pacciani, L; Paoluzi, L; Santovetti, E

2000-01-01

Resistive plate chambers (RPC) are strong candidates for the outer regions of the LHCb muon detector. We have tested single-gap and dual-gap detectors built with low-resistivity phenolic plates ( rho =9*10/sup 9/ Omega cm) and operated in avalanche mode. Measurements have been performed over a wide range of beam intensities and on the GIF at CERN. The results are presented and discussed, with special emphasis on the detection efficiency. (6 refs).

Clock and trigger distribution for CBM-TOF quality evaluation of RPC super module detector assemblies

Science.gov (United States)

Li, C.; Huang, X.; Cao, P.; Wang, J.; An, Q.

2018-03-01

RPC Super module (SM) detector assemblies are used for charged hadron identification in the Time-of-Flight (TOF) spectrometer at the Compressed Baryonic Matter (CBM) experiment. Each SM contains several multi-gap Resistive Plate Chambers (MRPCs) and provides up to 320 electronic channels in total for high-precision time measurements. Time resolution of the Time-to-Digital Converter (TDC) is required to be better than 20 ps. During mass production, the quality of each SM needs to be evaluated. In order to meet the requirements, the system clock signal as well as the trigger signal should be distributed precisely and synchronously to all electronics modules within the evaluation readout system. In this paper, a hierarchical clock and trigger distribution method is proposed for the quality evaluation of CBM-TOF SM detectors. In a first stage, the master clock and trigger module (CTM) allocated in a 6U PXI chassis distributes the clock and trigger signals to the slave CTM in the same chassis. In a second stage, the slave CTM transmits the clock and trigger signals to the TDC readout module (TRM) through one optical link. In a third stage, the TRM distributes the clock and trigger signals synchronously to 10 individual TDC boards. Laboratory test results show that the clock jitter at the third stage is less than 4 ps (RMS) and the trigger transmission latency from the master CTM to the TDC is about 272 ns with 11 ps (RMS) jitter. The overall performance complies well with the required specifications.

A very large multigap resistive plate chamber

CERN Document Server

Cerron-Zeballos, E; Hatzifotiadou, D; Kim, D W; Lamas-Valverde, J; Lee, S C; Platner, E D; Roberts, J; Williams, M C S; Zichichi, A

1999-01-01

We have built and tested a very large multigap resistive plate chamber (MRPC). We discuss the suitability of the multigap RPC for the construction of large area modules. We give details of the construction technique and results from a scan across the surface of the chamber. We also report on the implementation of `half-strip resolution', where we improve the spatial resolution by a factor 2 without increasing the number of read-out channels. (9 refs).

The design and test of VME clock distribution module of the Daya Bay RPC readout system

International Nuclear Information System (INIS)

Zhao Heng; Liang Hao; Zhou Yongzhao

2011-01-01

It describes the design of the VME Clock Distribution module of the Daya Bay RPC readout system, including the function and the hardware structure of the module and the logic design of the FPGA on the module. After the building and debugging of the module, a series of tests have been made to check its function and stability. (authors)

The HARP resistive plate chambers: Characteristics and physics performance

International Nuclear Information System (INIS)

Ammosov, V.; Boyko, I.; Chelkov, G.; Dedovitch, D.; Dumps, R.; Dydak, F.; Elagin, A.; Gapienko, V.; Gostkin, M.; Guskov, A.; Kroumchtein, Z.; Koreshev, V.; Linssen, L.; Nefedov, Yu.; Nikolaev, K.; Semak, A.; Sviridov, Yu.; Usenko, E.; Wotschack, J.; Zaets, V.; Zhemchugov, A.

2007-01-01

The HARP Resistive Plate Chamber (RPC) system was designed for time-of-flight measurement in the large-angle acceptance region of the HARP spectrometer. It comprised 46 four-gap glass RPCs covering an area of ∼8m 2 . The design of the RPCs, their operation, intrinsic properties, and system performance are described. The intrinsic time resolution of the RPCs is better than 130ps leading to a system time resolution of ∼175ps

High-performance liquid chromatography of oligoguanylates at high pH

Science.gov (United States)

Stribling, R.; Deamer, D. (Principal Investigator)

1991-01-01

Because of the stable self-structures formed by oligomers of guanosine, standard high-performance liquid chromatography techniques for oligonucleotide fractionation are not applicable. Previously, oligoguanylate separations have been carried out at pH 12 using RPC-5 as the packing material. While RPC-5 provides excellent separations, there are several limitations, including the lack of a commercially available source. This report describes a new anion-exchange high-performance liquid chromatography method using HEMA-IEC BIO Q, which successfully separates different forms of the guanosine monomer as well as longer oligoguanylates. The reproducibility and stability at high pH suggests a versatile role for this material.

Study on the performance of large area MRPC with high position resolution

Energy Technology Data Exchange (ETDEWEB)

Yue Qian, E-mail: yueq@mail.tsinghua.edu.cn [Department of Engineering Physics, Tsinghua University, Beijing 100084 (China); Key Laboratory of Particle and Radiation Imaging, Tsinghua University, Ministry of Education (China); Wu Yucheng; Li Yuanjing; Ye Jin; Cheng Jianping; Wang Yi; Li Jin [Department of Engineering Physics, Tsinghua University, Beijing 100084 (China); Key Laboratory of Particle and Radiation Imaging, Tsinghua University, Ministry of Education (China)

2012-01-01

Multi-gap resistive plate chamber (MRPC), which is mostly developed in high energy physics domain with excellent time resolution, is also highlighted in imaging applications. A set of 50 cm Multiplication-Sign 50 cm large area MRPC with high position resolution was successfully developed by our group and different experiments have been done to test its performances. Cosmic ray muons were used to do the test and proper high voltage and working gas were chosen. Data analysis indicates its good detection efficiency and good position resolution, which encourages further study of its application in RPC-PET and muon tomography.

Comparison of performance of partial prestressed beam-column subassemblages made of reactive powder concrete and normal concrete materials using finite element models

Science.gov (United States)

Nurjannah, S. A.; Budiono, B.; Imran, I.; Sugiri, S.

2016-04-01

Research on concrete material continues in several countries and had produced a concrete type of Ultra High Performance Concrete (UHPC) which has a better compressive strength, tensile strength, flexural strength, modulus of elasticity, and durability than normal concrete (NC) namely Reactive Powder Concrete (RPC). Researches on structures using RPC material showed that the RPC structures had a better performance than the NC structures in resisting gravity and lateral cyclic loads. In this study, an experiment was conducted to apply combination of constant axial and lateral cyclic loads to a prototype of RPC interior partial prestressed beam-column subassemblage (prototype of BCS-RPC) with a value of Partial Prestressed Ratio (PPR) of 31.72% on the beam. The test results were compared with finite element model of beam-column subassemblage made of RPC by PPR of 31.72% (BCS-RPC-31.72). Furthermore, there was BCS-RPC modeling with PPR of 21.39% (BCS-RPC-21.39) and beam-column subassemblages made of NC materials modeling with a value of PPR at 21.09% (BCS-NC-21.09) and 32.02% (BCS-NC-32.02). The purpose of this study was to determine the performance of the BCS-RPC models compared to the performance of the BCS-NC models with PPR values below and above 25%, which is the maximum limit of permitted PPR. The results showed that all models of BCS-RPC had a better performance than all models of BCS-NC and the BCS-RPC model with PPR above 25% still behaved ductile and was able to dissipate energy well.

Development and evaluation of the muon trigger detector using a resistive plate chamber

International Nuclear Information System (INIS)

Park, Byeong Hyeon

2010-08-01

The PHENIX Experiment is the largest of the four experiments that have taken data at the Relativistic Heavy Ion Collider. PHENIX, the Pioneering High Energy Nuclear Interaction experiment, is an exploratory experiment for the investigation of high energy collisions of heavy ions and protons. PHENIX is designed specifically to measure direct probes of the collisions such as electrons, muons, and photons. The primary goal of PHENIX is to discover and study a new state of matter called the Quark-Gluon Plasma. Among many particles, muons coming from W-boson decay gives us key information to analyze the spin of proton. Resistive plate chambers are proposed as a suitable solution as a muon trigger because of their fast response and good time resolution, flexibility in signal readout, robustness and the relatively low cost of production. The RPC detectors for upgrade were assembled and their performances were evaluated. The procedure to make the detectors better was optimized and described in detail in this thesis. The code based on ROOT was written and by using this the performance of the detectors made was evaluated, and all of the modules for north muon arm met the criteria and installation at PHENIX completed in November 2009. As RPC detectors that we made showed fast response, capacity of covering wide area with a resonable price and good spatial resolution, this will give the opportunity for applications,such as diagnosis and customs inspection system

A study on heat resistance of high temperature resistant coating

Energy Technology Data Exchange (ETDEWEB)

Zhang, Liping; Wang, Xueying; Zhang, Qibin; Qin, Yanlong; Lin, Zhu [Research Institute of Engineering Technology of CNPC, Tianjin (China)

2005-04-15

A high temperature resistant coating has been developed, which is mainly for heavy oil production pipes deserved the serious corrosion. The coating has excellent physical and mechanical performance and corrosion resistance at room and high temperature. In order to simulate the underground working condition of heavy oil pipes,the heat resistance of the high temperature resistant coating has been studied. The development and a study on the heat resistance of the DHT high temperature resistance coating have been introduced in this paper

A study on heat resistance of high temperature resistant coating

International Nuclear Information System (INIS)

Zhang, Liping; Wang, Xueying; Zhang, Qibin; Qin, Yanlong; Lin, Zhu

2005-01-01

A high temperature resistant coating has been developed, which is mainly for heavy oil production pipes deserved the serious corrosion. The coating has excellent physical and mechanical performance and corrosion resistance at room and high temperature. In order to simulate the underground working condition of heavy oil pipes,the heat resistance of the high temperature resistant coating has been studied. The development and a study on the heat resistance of the DHT high temperature resistance coating have been introduced in this paper

Mechanical properties of steel fiber reinforced reactive powder concrete following exposure to high temperature reaching 800 deg. C

Energy Technology Data Exchange (ETDEWEB)

Tai, Yuh-Shiou, E-mail: ystai@cc.cma.edu.tw [Department of Civil Engineering, ROC Military Academy, Kaohsiung, Taiwan (China); Pan, Huang-Hsing; Kung, Ying-Nien [Department of Civil Engineering, Kaohsiung University of Applied Sciences, Kaohsiung, Taiwan (China)

2011-07-15

Highlights: > The stress-strain relation of reactive powder concrete after exposure to high temperatures are tested by using displacement control. > Develops regression formulae to estimate the mechanical properties of RPC. > Valuable experimental data have been obtained about RPC with various fiber contents. These data include compressive strength, peak strain and modulus of elasticity. - Abstract: This study investigates the stress-strain relation of RPC in quasi-static loading after an elevated temperature. The cylinder specimens of RPC with {phi} 50 mm x 100 mm are examined at the room temperature and after 200-800 deg. C. Experimental results indicate that the residual compressive strength of RPC after heating from 200-300 deg. C increases more than that at room temperature, but, significantly decreases when the temperature exceeds 300 deg. C. The residual peak strains of RPC also initially increase up to 400-500 deg. C, then decrease gradually beyond 500 deg. C. Meanwhile, Young's modulus diminishes with an increasing temperature. Based on the regression analysis results, this study also develops regression formulae to estimate the mechanical properties of RPC after an elevated temperature, thus providing a valuable reference for industrial applications and design.

A comparison of the wide gap and narrow gap resistive plate chamber

International Nuclear Information System (INIS)

Cerron Zeballos, E.; Crotty, I.; Hatzifotiadou, D.; Valverde, J.L.; Neupane, S.; Peskov, V.; Singh, S.; Williams, M.C.S.; Zichichi, A.

1996-01-01

In this paper we study the performance of a wide gap RPC and compare it with that of a narrow gap RPC, both operated in avalanche mode. We have studied the total charge produced in the avalanche. We have measured the dependence of the performance with rate. In addition we have considered the effect of the tolerance of gas gap and calculated the power dissipated in these two types of RPC. We find that the narrow gap RPC has better timing ability; however the wide gap has superior rate capability, lower power dissipation in the gas volume and can be constructed with less stringent mechanical tolerances. (orig.)

A comparison of the wide gap and narrow gap resistive plate chamber

CERN Document Server

Cerron-Zeballos, E; Hatzifotiadou, D; Lamas-Valverde, J; Neupane, S; Peskov, Vladimir; Singh, S; Williams, M C S; Zichichi, Antonino

1996-01-01

In this paper we study the performance of a wide gap RPC and compare it with that of a narrow gap RPC, both operated in avalanche mode. We have studied the total charge produced in the avalanche. We have measured the dependence of the performance with rate. In addition we have considered the effect of the tolerance of gas gap and calculated the power dissipated in these two types of RPC. We find that the narrow gap RPC has better timing ability; however the wide gap has superior rate capability, lower power dissipation in the gas volume and can be constructed with less stringent mechanical tolerances.

Comparison of cyclic fatigue life of nickel-titanium files: an examination using high-speed camera

Directory of Open Access Journals (Sweden)

Taha Özyürek

2017-08-01

Full Text Available Objectives To determine the actual revolutions per minute (rpm values and compare the cyclic fatigue life of Reciproc (RPC, VDW GmbH, WaveOne (WO, Dentsply Maillefer, and TF Adaptive (TFA, Axis/SybronEndo nickel-titanium (NiTi file systems using high-speed camera. Materials and Methods Twenty RPC R25 (25/0.08, 20 WO Primary (25/0.08, and 20 TFA ML 1 (25/0.08 files were employed in the present study. The cyclic fatigue tests were performed using a dynamic cyclic fatigue testing device, which has an artificial stainless steel canal with a 60° angle of curvature and a 5-mm radius of curvature. The files were divided into 3 groups (group 1, RPC R25 [RPC]; group 2, WO Primary [WO]; group 3, TF Adaptive ML 1 [TFA]. All the instruments were rotated until fracture during the cyclic fatigue test and slow-motion videos were captured using high-speed camera. The number of cycles to failure (NCF was calculated. The data were analyzed statistically using one-way analysis of variance (ANOVA, p < 0.05. Results The slow-motion videos were indicated that rpm values of the RPC, WO, and TFA groups were 180, 210, and 425, respectively. RPC (3,464.45 ± 487.58 and WO (3,257.63 ± 556.39 groups had significantly longer cyclic fatigue life compared with TFA (1,634.46 ± 300.03 group (p < 0.05. There was no significant difference in the mean length of the fractured fragments. Conclusions Within the limitation of the present study, RPC and WO NiTi files showed significantly longer cyclic fatigue life than TFA NiTi file.

Development and Evaluation of the Muon Trigger Detector Using a Resistive Plate Chamber

International Nuclear Information System (INIS)

Park, Byeong Hyeon; Kim, Yong Kyun; Kang, Jeong Soo; Kim, Young Jin; Choi, Ihn Jea; Kim, Chong; Hong, Byung Sik

2011-01-01

The PHENIX Experiment is the largest of the four experiments that have taken data at the Relativistic Heavy Ion Collider. PHENIX, the Pioneering High Energy Nuclear Interaction eXperiment, is designed specifically to measure direct probes of the collisions such as electrons, muons, and photons. The primary goal of PHENIX is to discover and study a new state of matter called the Quark-Gluon Plasma. Among many particles, muons coming from W-boson decay gives us key information to analyze the spin of proton. Resistive plate chambers are proposed as a suitable solution as a muon trigger because of their fast response and good time resolution, flexibility in signal readout, robustness and the relatively low cost of production. The RPC detectors for upgrade were assembled and their performances were evaluated. The procedure to make the detectors better was optimized and described in detail in this thesis. The code based on ROOT was written and by using this the performance of the detectors made was evaluated, and all of the modules for north muon arm met the criteria and installation at PHENIX completed in November 2009. As RPC detectors that we made showed fast response, capacity of covering wide area with a resonable price and good spatial resolution, this will give the opportunity for applications, such as diagnosis and customs inspection system

Simulation of Resistive Plate Chamber sensitivity to neutrons

Energy Technology Data Exchange (ETDEWEB)

Altieri, S. E-mail: saverio.altieri@pv.infn.it; Belli, G.; Bruno, G.; Merlo, M.; Ratti, S.P.; Riccardi, C.; Torre, P.; Vitulo, P.; Abbrescia, M.; Colaleo, A.; Iaselli, G.; Loddo, F.; Maggi, M.; Marangelli, B.; Natali, S.; Nuzzo, S.; Pugliese, G.; Ranieri, A.; Romano, F

2001-04-01

The Resistive Plate Chambers (RPCs) sensitivity to neutrons has been simulated using GEANT code with MICAP and FLUKA interfaces. The calculations have been performed as a function of the neutrons energy in the range 0.02 eV-1 GeV. To evaluate the response of the detector in the LHC background environment, the neutron energy spectrum expected in the CMS muon barrel has been taken into account; a hit rate due to neutrons of about 0.6 Hz cm{sup -2} has been estimated for a 250x250 cm{sup 2} RPC in the RB1 station.

Testing of multigap Resistive Plate Chambers for Electron Ion Collider Detector Development

Science.gov (United States)

Hamilton, Hannah; Phenix Collaboration

2015-10-01

Despite decades of research on the subject, some details of the spin structure of the nucleon continues to be unknown. To improve our knowledge of the nucleon spin structure, the construction of a new collider is needed. This is one of the primary goals of the proposed Electron Ion Collider (EIC). Planned EIC spectrometers will require good particle identification. This can be provided by time of flight (TOF) detectors with excellent timing resolutions of 10 ps. A potential TOF detector that could meet this requirement is a glass multigap resistive plate chamber (mRPC). These mRPCs can provide excellent timing resolution at a low cost. The current glass mRPC prototypes have a total of twenty 0.1 mm thick gas gaps. In order to test the feasibility of this design, a cosmic test stand was assembled. This stand used the coincidence of scintillators as a trigger, and contains fast electronics. The construction, the method of testing, and the test results of the mRPCs will be presented.

Comparing Novel Multi-Gap Resistive Plate Chamber Models

Science.gov (United States)

Stien, Haley; EIC PID Consortium Collaboration

2016-09-01

Investigating nuclear structure has led to the fundamental theory of Quantum Chromodynamics. An Electron Ion Collider (EIC) is a proposed accelerator that would further these investigations. In order to prepare for the EIC, there is an active detector research and development effort. One specific goal is to achieve better particle identification via improved Time of Flight (TOF) detectors. A promising option is the Multi-Gap Resistive Plate Chamber (mRPC). These detectors are similar to the more traditional RPCs, but their active gas gaps have dividers to form several thinner gas gaps. These very thin and accurately defined gas gaps improve the timing resolution of the chamber, so the goal is to build an mRPC with the thinnest gaps to achieve the best possible timing resolution. Two different construction techniques have been employed to make two mRPCs. The first technique is to physically separate the gas gaps with sheets of glass that are .2mm thick. The second technique is to 3D print the layered gas gaps. A comparison of these mRPCs and their performances will be discussed and the latest data presented. This research was supported by US DOE MENP Grant DE-FG02-03ER41243.

Long-term performance of double gap resistive plate chambers under gamma irradiation

International Nuclear Information System (INIS)

Abbrescia, M.; Colaleo, A.; Guarrasi, L.; Iaselli, G.; Loddo, F.; Maggi, M.; Marangelli, B.; Natali, S.; Nuzzo, S.; Pugliese, G.; Ranieri, A.; Romano, F.; Altieri, S.; Belli, G.; Bruno, G.; Gianini, G.; Ratti, S.P.; Riccardi, C.; Torre, P.; Viola, L.; Vitulo, P.

2002-01-01

In this paper, we describe a dedicated test to study possible long-term aging effects on Resistive Plate Chambers (RPCs). A double gap detector was operated under gamma irradiation for a period approximately equal to 10 years of LHC in the CMS-barrel region: an integrated dose of about 1.6 Gy and a total charge of about 0.05 C/cm 2 gap were accumulated on the chamber. The results show no relevant aging effect. Also the RPC sensitivity to 60 Co gamma energies is measured

Effect of neutron irradiation on vitreous carbon

International Nuclear Information System (INIS)

Kurolenkin, E.I.; Virgil'ev, Yu.S.; Chugunova, T.K.

1989-01-01

The change in mass (m), volume (V), specific electric resistance (ρ), coefficient of linear thermal expansion (α), dynamic elasticity modulus (E), and limit of bending strength (σ) of vitreous carbon are studied upon neutron irradiation. Samples for study were two forms of vitreous carbon obtained by hardening thermally reactive polymers at 900-1,000 degree K. Phenol-formaldehyde (bakelite lacquer A, Bakelite A) and furfural-phenol-formaldehyde (FM-2) resin were used. They were irradiated in the experimental water - water VVR-M reactor between 360-1,030 degree K. The maximal neutron flux was 1.65·10 21 neut/cm 2 . Neutron irradiation of vitreous carbon led to its shrinkage and accompanied weakening. Shrinkage and weakening of vitreous carbon was decreased with an increase of treatment and irradiation temperatures

Long-term performance of double gap resistive plate chambers under gamma irradiation

CERN Document Server

Abbrescia, M; Guarrasi, L; Iaselli, Giuseppe; Loddo, F; Maggi, M; Marangelli, B; Natali, S; Nuzzo, S; Pugliese, G; Ranieri, A; Romano, F; Altieri, S; Belli, G; Bruno, G; Gianini, G; Ratti, S P; Riccardi, C; Torre, P; Viola, L; Vitulo, P

2002-01-01

In this paper, we describe a dedicated test to study possible long- term aging effects on Resistive Plate Chambers (RPCs). A double gap detector was operated under gamma irradiation for a period approximately equal to 10 years of LHC in the CMS-barrel region: an integrated dose of about 1.6 Gy and a total charge of about 0.05 C/cm /sup 2/ gap were accumulated on the chamber. The results show no relevant aging effect. Also the RPC sensitivity to /sup 60/Co gamma energies is measured. (9 refs).

Long-term performance of double gap resistive plate chambers under gamma irradiation

Energy Technology Data Exchange (ETDEWEB)

Abbrescia, M.; Colaleo, A.; Guarrasi, L.; Iaselli, G.; Loddo, F.; Maggi, M.; Marangelli, B.; Natali, S.; Nuzzo, S.; Pugliese, G. E-mail: gabriella.pugliese@ba.infn.it; Ranieri, A.; Romano, F.; Altieri, S.; Belli, G.; Bruno, G.; Gianini, G.; Ratti, S.P.; Riccardi, C.; Torre, P.; Viola, L.; Vitulo, P

2002-01-21

In this paper, we describe a dedicated test to study possible long-term aging effects on Resistive Plate Chambers (RPCs). A double gap detector was operated under gamma irradiation for a period approximately equal to 10 years of LHC in the CMS-barrel region: an integrated dose of about 1.6 Gy and a total charge of about 0.05 C/cm{sup 2} gap were accumulated on the chamber. The results show no relevant aging effect. Also the RPC sensitivity to {sup 60}Co gamma energies is measured.

Operation of Resistive Plate Chamber Detectors with a New Environmentally Friendly Freon

CERN Document Server

Lewis, Helen Elizabeth

2014-01-01

RPC particle gas detectors at CERN provide a vital element to the physics experiments carried out on the LHC. While their current operation and working gas mixtures are successful, environ- mental and economic factors force a revision of the mixture, specifically the eventual replacement of the current Freon gas R134-a with a newer, less environmentally harmful formulation, namely R1234-yf. The methods and results presented here outline the detector response to the introduction of the new Freon and its behavior under various mixtures. The electronegativity and hence impact on RPC parameters was investigated. It was found that the new Freon gas is indeed electroneg- ative, and suppresses the RPC signal. The mixture was modified to include Argon to increase ionization, and the final results of the operation of the RPC were satisfactory. Further work to refine the mixture for future implementation is necessary.

Electronics design of the RPC system for the OPERA muon

International Nuclear Information System (INIS)

Acquafredda, R.; Ambrosio, M.; Consiglio, L.

2004-01-01

The present document describes the front-end electronics of the RPC system that instruments the magnet muon spectrometer of the OPERA experiment. The main task of the OPERA spectrometer is to provide particle tracking information for muon identification and simplify the matching between the Precision Trackers. As no trigger has been foreseen for the experiment, the spectrometer electronics must be self-triggered with single-plane readout capability. Moreover, precision time information must be added within each event frame for off-line reconstruction. The read-out electronics is made of three different stages: the Front-End Boards (FEBs) system, the Controller Boards (CBs) system and Trigger Boards (TBs) system. The FEB system provides discrimination of the strip incoming signals; a FAST-OR output of the input signals is also available for trigger plane signal generation. FEB signals are required by the CB system that provides the zero suppression and manages the communication to the DAQ and Slow Control. A Trigger Board allows to operate in both self-trigger mode (the FEB's FAST-OR signal starts the plane acquisition) or in external-trigger mode (different conditions can be set on the FAST-OR signals generated from different planes)

Retrofitting of Reinforced Concrete Beams using Reactive Powder Concrete (RPC)

Science.gov (United States)

Karthik, S.; Sundaravadivelu, Karthik

2017-07-01

Strengthening of existing damaged structures is one of the leading studies in civil engineering. The purpose of retrofitting is to structurally treat the member with an aim to restore the structure to its original strength. The focus of this project is to study the behaviour of damaged Reinforced Concrete beam retrofitted with Reactive Powder Concrete (RPC) Overlay. Reinforced concrete beams of length 1200 mm, width 100 mm and depth 200 mm were casted with M30 grade of concrete in the laboratory and cured for 28 days. One beam is taken as control and are tested under two point loading to find out ultimate load. Remaining beams are subjected to 90 % ultimate load of control beams. The partially damaged beams are retrofitted with Reactive Powder Concrete Overlay at the full tension face of the beam and side overlay depends upon the respectable retrofitting techniques with 10 mm and 20 mm thick layer to find optimum. Materials like steel fibres are added to enhance the ductility by eliminating coarse particle for homogeneity of the structure. Finally, the modes of failure for retrofitted beams are analysed experimentally under two point loading & compared the results with Control beam.

Development of a cosmic rack for characterization of RPCs

International Nuclear Information System (INIS)

Sehgal, S.T.; Pant, L.M.

2011-01-01

A newly designed cosmic rack has been commissioned this year in the RPC Lab., in NPD-BARC. The rack consists of nine shelves each providing a clear area of 160 cm x 225 cm. Each of the shelf is separated by a distance of 30 cm, providing sufficient distance for fast electronics to respond and also providing an easy access for loading and removing the RPCs. The total height of the cosmic rack is 2.8 metres. A typical fully integrated RPCs covers an approximate area of 2 m 2 and weighs about 60-70 kg. The rack has been basically designed, keeping in mind the varied requirements as regards to the RPCs based current and futuristic programmes which are listed as follows: 1. Testing of large area trapezoidal bakelite gas-gaps and RPCs for the CMS experiment, keeping in mind the production rate of five RPCs per month. 2. The proposed muon tomography programme with 1m x 1m glass RPCs and 3. Characterization of glass RPCs (1m x 2m) for the INO experiment in near future

Performance of a resistive plate chamber equipped with a new prototype of amplified front-end electronics

CERN Document Server

Marchisone, Massimiliano

2016-01-01

ALICE is the LHC experiment dedicated to the study of heavy-ion collisions. At forward rapidity a muon spectrometer detects muons from low mass mesons, quarkonia, open heavy-flavor hadrons as well as weak bosons. A muon selection based on transverse momentum is made by a trigger system composed of 72 resistive plate chambers (RPCs). For the LHC Run 1 and the ongoing Run 2 the RPCs have been equipped with a non-amplified FEE called ADULT. However, in view of an increase in luminosity expected for Run 3 (2021-2023) the possibility to use an amplified FEE has been explored in order to improve the counting rate limitation and to prevent the aging of the detector, by reducing the charge per hit. A prototype of this new electronics (FEERIC) has been developed and tested first with cosmic rays before equipping one RPC in the ALICE cavern with it. In this talk the most important performance indicators - efficiency, dark current, dark rate, cluster size and total charge - of an RPC equipped with this new FEE will be r...

Upgrade of the ALICE muon trigger electronics

International Nuclear Information System (INIS)

Dupieux, P; Joly, B; Jouve, F; Manen, S; Vandaële, R

2014-01-01

The ALICE muon trigger is a large scale detector based on single gap bakelite RPCs. An upgrade of the electronics is needed in order to withstand the increase of luminosity after the LHC Long Shutdown-2 in 2018-2019. The detector will be read out at the minimum bias rate of 100 kHz in Pb–Pb collisions (including a safety factor of 2), two orders of magnitude above the present design. For the most exposed RPCs and in the present conditions of operation, the total integrated charge could be as high as 100 mC/cm 2 with rates up to 100 Hz/cm 2 , which is above the present limit for safe operation. In order to overcome these limitations, upgrade projects of the Front-End (FE) and Readout Electronics are scheduled. The readout upgrade at high rate with low dead time requires changing most of the present electronics. It involves a new design for the 234 Local cards receiving the LVDS signals from the FE electronics and the 16 Regional concentrator cards. The readout chain is completed by a single Common Readout Unit developed for most ALICE sub-detectors. The new architecture of the muon trigger readout will be briefly presented. The present FE electronics, designed for the streamer mode, must be replaced to prevent ageing of the RPCs in the future operating conditions. The new FE called FEERIC (for Front-End Electronics Rapid Integrated Circuit) will have to perform amplification of the analog input signals. This will allow for RPC operation in a low-gain avalanche mode, with a much smaller charge deposit (factor 3-5) in the detector as compared to the present conditions. The purpose is to discriminate RPC signals with a charge threshold around 100 fC, in both polarities, and with a time jitter below 1 ns. We will describe the FE card and FEERIC ASIC features and first prototype performance, report on test results obtained on a cosmic test bench and discuss ongoing developments

Resistive plate chambers for 2013-2014 muon upgrade in CMS at LHC

International Nuclear Information System (INIS)

Colafranceschi, S.; Sharma, A.; Chudasama, R.; Pant, L.M.; Mohanty, A.K.; Sehgal, R.; Sehgal, S.T.; Thomas, R.G.; Bhandari, V.; Chand, S.; Kumar, A.; Kumar, S.; Singh, A.; Singh, V.; Aly, S.; Aly, R.; Elkafrawy, T.; Ibrahim, A.; Radi, A.; Sayed, A.

2014-01-01

During 2013 and 2014 (Long Shutdown LS1) the CMS experiment is upgrading the forward region installing a fourth layer of RPC detectors in order to complete and improve the muon system performances in the view of the foreseen high luminosity run of LHC. The new two endcap disks consists of 144 double-gap RPC chambers assembled at three different production sites: CERN, Ghent (Belgium) and BARC (India). The chamber components as well as the final detectors are subjected to full series of tests established in parallel at all the production sites. All assembly and test operations have been engineered in order to standardize and improve detector production. In this work the complete chamber construction, quality control procedures and preliminary results will be detailed

High counting rate, two-dimensional position sensitive timing RPC

CERN Document Server

Petrovici, M.; Simion, V; Bartos, D; Caragheorgheopol, G; Deppner, I; Adamczewski-Musch, J; Linev, S; Williams, MCS; Loizeau, P; Herrmann, N; Doroud, K; Radulescu, L; Constantin, F

2012-01-01

Resistive Plate Chambers (RPCs) are widely employed as muon trigger systems at the Large Hadron Collider (LHC) experiments. Their large detector volume and the use of a relatively expensive gas mixture make a closed-loop gas circulation unavoidable. The return gas of RPCs operated in conditions similar to the experimental background foreseen at LHC contains large amount of impurities potentially dangerous for long-term operation. Several gas-cleaning agents, characterized during the past years, are currently in use. New test allowed understanding of the properties and performance of a large number of purifiers. On that basis, an optimal combination of different filters consisting of Molecular Sieve (MS) 5Å and 4Å, and a Cu catalyst R11 has been chosen and validated irradiating a set of RPCs at the CERN Gamma Irradiation Facility (GIF) for several years. A very important feature of this new configuration is the increase of the cycle duration for each purifier, which results in better system stabilit...

Time and position resolution of high granularity, high counting rate MRPC for the inner zone of the CBM-TOF wall

CERN Document Server

Petriş, M.

2016-09-13

Multi-gap RPC prototypes with readout on a multi-strip electrode were developed for the small polar angle region of the CBM-TOF subdetector, the most demanding zone in terms of granularity and counting rate. The prototypes are based on low resistivity ($\\sim$10$^{10}$ $\\Omega$cm) glass electrodes for performing in high counting rate environment. The strip width/pitch size was chosen such to fulfill the impedance matching with the front-end electronics and the granularity requirements of the innermost zone of the CBM-TOF wall. The in-beam tests using secondary particles produced in heavy ion collisions on a Pb target at SIS18 - GSI Darmstadt and SPS - CERN were focused on the performance of the prototype in conditions similar to the ones expected at SIS100/FAIR. An efficiency larger than 98\\% and a system time resolution in the order of 70~-~80~ps were obtained in high counting rate and high multiplicity environment.

High temperature resistant cermet and ceramic compositions

Science.gov (United States)

Phillips, W. M. (Inventor)

1978-01-01

Cermet compositions having high temperature oxidation resistance, high hardness and high abrasion and wear resistance, and particularly adapted for production of high temperature resistant cermet insulator bodies are presented. The compositions are comprised of a sintered body of particles of a high temperature resistant metal or metal alloy, preferably molybdenum or tungsten particles, dispersed in and bonded to a solid solution formed of aluminum oxide and silicon nitride, and particularly a ternary solid solution formed of a mixture of aluminum oxide, silicon nitride and aluminum nitride. Also disclosed are novel ceramic compositions comprising a sintered solid solution of aluminum oxide, silicon nitride and aluminum nitride.

Effect of Glide Path Creating on Cyclic Fatigue Resistance of Reciproc and Reciproc Blue Nickel-titanium Files: A Laboratory Study.

Science.gov (United States)

Özyürek, Taha; Uslu, Gülşah; Yılmaz, Koray; Gündoğar, Mustafa

2018-06-01

The purpose of this article was to compare the cyclic fatigue resistance of Reciproc and Reciproc Blue files (VDW GmbH, Munich, Germany) that were used to prepare root canals of mandibular molar teeth with or without a glide path. Sixty Reciproc R25 and 60 Reciproc Blue R25 files were used. The Reciproc and Reciproc Blue groups were divided into 3 subgroups (ie, as received condition, used without a glide path, and used with a glide path). All the instruments were rotated in a stainless steel artificial canal with an inner diameter of 1.5 mm, a 60° angle of curvature, and a radius of curvature of 5 mm until fracture occurred. The number of cycle to fracture was calculated, and the length of the fractured segments was measured. The Kruskal-Wallis test was performed to statistically analyze the data using SPSS 21.0 software (IBM Corp, Armonk, NY) at a 5% significance level. The cyclic fatigue resistance of as received condition Reciproc Blue files was found to be higher than as received condition Reciproc files (P  .05). There was no statistically significant difference in the mean length of the fractured fragments of the instruments (P > .05). Within the limitations of this in vitro study, it was concluded that creating a glide path using ProGlider files had no effect on the cyclic fatigue resistance of RPC and RPC Blue files. Copyright © 2018 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Development of high-performance concrete having high resistance to chloride penetration

International Nuclear Information System (INIS)

Oh, Byung Hwan; Cha, Soo Won; Jang, Bong Seok; Jang, Seung Yup

2002-01-01

The resistance to chloride penetration is one of the simplest measures to determine the durability of concrete, e.g. resistance to freezing and thawing, corrosion of steel in concrete and other chemical attacks. Thus, high-performance concrete may be defined as the concrete having high resistance to chloride penetration as well as high strength. The purpose of this paper is to investigate the resistance to chloride penetration of different types of concrete and to develop high-performance concrete that has very high resistance to chloride penetration, and thus, can guarantee high durability. A large number of concrete specimens have been tested by the rapid chloride permeability test method as designated in AASHTO T 277 and ASTM C 1202. The major test variables include water-to-binder ratios, type of cement, type and amount of mineral admixtures (silica fume, fly ash and blast-furnace slag), maximum size of aggregates and air-entrainment. Test results show that concrete containing optimal amount of silica fume shows very high resistance to chloride penetration, and high-performance concrete developed in this study can be efficiently employed to enhance the durability of concrete structures in severe environments such as nuclear power plants, water-retaining structures and other offshore structures

Automated Orthorectification of VHR Satellite Images by SIFT-Based RPC Refinement

Directory of Open Access Journals (Sweden)

Hakan Kartal

2018-06-01

Full Text Available Raw remotely sensed images contain geometric distortions and cannot be used directly for map-based applications, accurate locational information extraction or geospatial data integration. A geometric correction process must be conducted to minimize the errors related to distortions and achieve the desired location accuracy before further analysis. A considerable number of images might be needed when working over large areas or in temporal domains in which manual geometric correction requires more labor and time. To overcome these problems, new algorithms have been developed to make the geometric correction process autonomous. The Scale Invariant Feature Transform (SIFT algorithm is an image matching algorithm used in remote sensing applications that has received attention in recent years. In this study, the effects of the incidence angle, surface topography and land cover (LC characteristics on SIFT-based automated orthorectification were investigated at three different study sites with different topographic conditions and LC characteristics using Pleiades very high resolution (VHR images acquired at different incidence angles. The results showed that the location accuracy of the orthorectified images increased with lower incidence angle images. More importantly, the topographic characteristics had no observable impacts on the location accuracy of SIFT-based automated orthorectification, and the results showed that Ground Control Points (GCPs are mainly concentrated in the “Forest” and “Semi Natural Area” LC classes. A multi-thread code was designed to reduce the automated processing time, and the results showed that the process performed 7 to 16 times faster using an automated approach. Analyses performed on various spectral modes of multispectral data showed that the arithmetic data derived from pan-sharpened multispectral images can be used in automated SIFT-based RPC orthorectification.

Upgrades of the CMS muon system in preparation of HL-LHC

CERN Document Server

Teyssier, Daniel Francois

2017-01-01

The present CMS muon system operates three different detector types in the barrel drift tubes (DT) and resistive plate chambers (RPC), along with cathode strip chambers (CSC) and another set of RPCs in the forward regions. In order to cope with increasingly challenging conditions various upgrades are planned to the trigger and muon systems. New detectors will be added to improve the performance in the critical forward region large-area triple-foil gas electron multiplier (GEM) detectors will already be installed in LS2 in the pseudo-rapidity region $1.6 < \\eta < 2.4$, aiming at suppressing the rate of background triggers while maintaining high trigger efficiency for low transverse momentum muons. For the High Luminosity (HL)-LHC operations, the muon forward region should be enhanced with another large area GEM based station, called GE2/1, and with two new generation RPC stations, called RE3/1 and RE4/1, having low resistivity electrodes. These detectors will combine tracking and triggering capabil...

Security Implications of OPC, OLE, DCOM, and RPC in Control Systems

Energy Technology Data Exchange (ETDEWEB)

2006-01-01

OPC is a collection of software programming standards and interfaces used in the process control industry. It is intended to provide open connectivity and vendor equipment interoperability. The use of OPC technology simplifies the development of control systems that integrate components from multiple vendors and support multiple control protocols. OPC-compliant products are available from most control system vendors, and are widely used in the process control industry. OPC was originally known as OLE for Process Control; the first standards for OPC were based on underlying services in the Microsoft Windows computing environment. These underlying services (OLE [Object Linking and Embedding], DCOM [Distributed Component Object Model], and RPC [Remote Procedure Call]) have been the source of many severe security vulnerabilities. It is not feasible to automatically apply vendor patches and service packs to mitigate these vulnerabilities in a control systems environment. Control systems using the original OPC data access technology can thus inherit the vulnerabilities associated with these services. Current OPC standardization efforts are moving away from the original focus on Microsoft protocols, with a distinct trend toward web-based protocols that are independent of any particular operating system. However, the installed base of OPC equipment consists mainly of legacy implementations of the OLE for Process Control protocols.

Upgrade of the ATLAS Muon System for the HL-LHC

CERN Document Server

Amelung, Christoph; The ATLAS collaboration

2018-01-01

The muon spectrometer of the ATLAS detector will be significantly upgraded during the Phase-II upgrade in Long Shutdown 3 in order to cope with the operational conditions at the High-Luminosity LHC in Run 4 and beyond. Most of the electronics for the Resistive Plate Chambers (RPC), Thin Gap Chambers (TGC), and Monitored Drift Tube (MDT) chambers will be replaced to make them compatible with the higher trigger rates and longer latencies necessary for the new level-0 trigger. The MDT chambers will be integrated into the level-0 trigger in order to sharpen the momentum threshold. Additional RPC chambers will be installed in the inner barrel layer to increase the acceptance and robustness of the trigger. Some of the MDT chambers in the inner barrel layer will be replaced with new small-diameter MDTs. New TGC triplet chambers in the barrel-endcap transition region will replace the current TGC doublets to suppress the high trigger rate from random coincidences in this region. The power system for the RPC, TGC, and ...

dCache: implementing a high-end NFSv4.1 service using a Java NIO framework

CERN Multimedia

CERN. Geneva

2012-01-01

dCache is a high performance scalable storage system widely used by HEP community. In addition to set of home grown protocols we also provide industry standard access mechanisms like WebDAV and NFSv4.1. This support places dCache as a direct competitor to commercial solutions. Nevertheless conforming to a protocol is not enough; our implementations must perform comparably or even better than commercial systems. To achieve this, dCache uses two high-end IO frameworks from well know application servers: GlassFish and JBoss. This presentation describes how we implemented an rfc1831 and rfc2203 compliant ONC RPC (Sun RPC) service based on the Grizzly NIO framework, part of the GlassFish application server. This ONC RPC service is the key component of dCache’s NFSv4.1 implementation, but is independent of dCache and available for other projects. We will also show some details of dCache NFS v4.1 implementations, describe some of the Java NIO techniques used and, finally, present details of our performance e...

High temperature resistant cermet and ceramic compositions. [for thermal resistant insulators and refractory coatings

Science.gov (United States)

Phillips, W. M. (Inventor)

1978-01-01

High temperature oxidation resistance, high hardness and high abrasion and wear resistance are properties of cermet compositions particularly to provide high temperature resistant refractory coatings on metal substrates, for use as electrical insulation seals for thermionic converters. The compositions comprise a sintered body of particles of a high temperature resistant metal or metal alloy, preferably molybdenum or tungsten particles, dispersed in and bonded to a solid solution formed of aluminum oxide and silicon nitride, and particularly a ternary solid solution formed of a mixture of aluminum oxide, silicon nitride and aluminum nitride. Ceramic compositions comprising a sintered solid solution of aluminum oxide, silicon nitride and aluminum nitride are also described.

Concretes with high mechanical resistance

International Nuclear Information System (INIS)

Mauny, Pierre.

1973-01-01

Description is given of a method for manufacturing concretes with high mechanical resistance in compression, obtained by mixing gravels highly resistant to compression, sand and cement in an aqueous medium. Use is made of sands of porous ceramics, such as terra-cotta, of a grain size from 0,1 to 5mm, the pore diameter of which is from 0.5 to 15 microns, chosen so as to be slighty bigger than the crystals of the cement used. This can be applied to the pre-stressed structures used in the nuclear field [fr

Relações genotípicas entre componentes da resistência pós-colheita em tomate Cereja e Salada Genotypic relationships between components of postharvest resistance of Cherry and Salad tomato

Directory of Open Access Journals (Sweden)

Fábio Moreira Sobreira

2009-07-01

Full Text Available Este trabalho objetivou avaliar a necessidade de realizar análise de trilha individualizada para tomates tipo Salada (L. esculentum e Cereja (L. esculentum var. cerasiforme, visando obter informações sobre quais variáveis estão relacionadas com a resistência pós-colheita (RPC, e orientar a seleção de materiais para programas de melhoramento. Realizaram-se análises de variâncias, correlações genotípicas, diagnóstico de multicolinearidade e o desdobramento das correlações genotípicas por meio de análise de trilha. As variáveis mais explicativas da RPC em tomates tipo Salada foram o diâmetro da cicatriz do pedúnculo (DCP e o diâmetro médio do fruto (DMF; a espessura do mesocarpo (ESP e o peso médio dos frutos (PMF em tipo Cereja. Em tomates Cereja, ganhos podem ser obtidos na RPC por meio de seleção indireta via ESP. Estes serão maiores se dentre os frutos de maior ESP forem selecionados os de menor PMF. No caso de Salada, deve-se selecionar indiretamente os frutos de menor DCP e dentre estes os de maior DMF. A análise de trilha deve ser realizada considerando cada tipo de tomate, visto que as variáveis explicativas diferem entre estes.This study aimed to evaluate the need for individual path analysis to Cherry (L. esculentum var. cerasiforme and Salad (L. esculentum tomatoes type, seeking information about which variables are associated with post-harvest resistance (PHR, and guide the selection of material for breeding programs. We performed the variance analysis, genotypic correlations, multicolinearity diagnosis, and the display of genotypic correlations through path analysis. The more explicatory variables of PHR in Salad tomatoes type were the peduncle scar diameter (PSD and the fruit mean diameter (FMD; the mesocarp thickness (MST and fruit mean weight (FMW in cherry type. For Cherry tomatoes, gains can be obtained in the PHR through indirect selection by MST. This will be greatest if among the fruits with more

High temperature resistant nanofiber by bubbfil-spinning

Directory of Open Access Journals (Sweden)

Li Ya

2015-01-01

Full Text Available Heat-resisting nanofibers have many potential applications in various industries, and the bubbfil spinning is the best candidate for mass-production of such materials. Polyether sulfone/zirconia solution with a bi-solvent system is used in the experiment. Experimental result reveals that polyether sulfone/zirconia nanofibers have higher resistance to high temperature than pure polyether sulfone fibers, and can be used as high-temperature-resistant filtration materials.

Degradation in the efficiency of glass Resistive Plate Chambers operated without external gas supply

Science.gov (United States)

Baesso, P.; Cussans, D.; Thomay, C.; Velthuis, J.; Burns, J.; Quillin, S.; Stapleton, M.; Steer, C.

2015-06-01

Resistive plate chambers (RPC) are particle detectors commonly used by the high energy physics community. Their normal operation requires a constant flow of gas mixture to prevent self-poisoning which reduces the chamber's capability to detect particles. We studied how quickly the efficiency of two RPCs drops when operated in sealed mode, i.e. without refreshing the gas mixture. The test aim is to determine how RPCs could be used as particle detectors in non-laboratory applications, such as those exploiting muon tomography for geological imaging or homeland security. The two sealed RPCs were operated in proportional mode for a period of more than three months, and their efficiencies were recorded continuously and analysed in 8-hours intervals. The results show that the efficiency drops on average by 0.79 ± 0.01 % every 24 hours of operation and returns close to the initial value after purging the old gas mixture and flushing the chambers with fresh gas.

Corrosion-Resistant High-Entropy Alloys: A Review

Directory of Open Access Journals (Sweden)

Yunzhu Shi

2017-02-01

Full Text Available Corrosion destroys more than three percent of the world’s gross domestic product. Therefore, the design of highly corrosion-resistant materials is urgently needed. By breaking the classical alloy-design philosophy, high-entropy alloys (HEAs possess unique microstructures, which are solid solutions with random arrangements of multiple elements. The particular locally-disordered chemical environment is expected to lead to unique corrosion-resistant properties. In this review, the studies of the corrosion-resistant HEAs during the last decade are summarized. The corrosion-resistant properties of HEAs in various aqueous environments and the corrosion behavior of HEA coatings are presented. The effects of environments, alloying elements, and processing methods on the corrosion resistance are analyzed in detail. Furthermore, the possible directions of future work regarding the corrosion behavior of HEAs are suggested.

Mechanism of high-temperature resistant water-base mud

Energy Technology Data Exchange (ETDEWEB)

Luo, P

1981-01-01

Based on experiments, the causes and laws governing the changes in the performance of water-base mud under high temperature are analyzed, and the requisites and mechanism of treating agents resisting high temperature are discussed. Ways and means are sought for inhibiting, delaying and making use of the effect of high temperature on the performance of mud, while new ideas and systematic views have been expressed on the preparation of treating agents and set-up of a high temperature resistant water-base mud system. High temperature dispersion and high temperature surface inactivation of clay in the mud, as well as their effect and method of utilization are reviewed. Subjects also touched upon include degradation and cross-linking of the high-temperature resistant treating agents, their use and effect. Based on the above, the preparation of a water-base and system capable of resisting 180 to 250/sup 0/C is recommended.

High corrosion-resistant fuel spacers

International Nuclear Information System (INIS)

Yoshida, Toshimi; Takase, Iwao; Ikeda, Shinzo; Masaoka, Isao; Nakajima, Junjiro.

1986-01-01

Purpose: To enable manufacturing BWR fuel spacers by prior-art production process, using a zirconium-base alloy having very excellent corrosion resistance. Method: A highly improved nodular-resistant, corrosion-resistant zirconium alloy is devised by adding a slight amount of niobium, titanium and vanadium to zircaloy, of which fuel spacers are produced. That is, there can be obtained an alloy having much more excellent nodular resistance than conventional zircaloy, and free from a large change in plasticity, workability, and weldability, by adding to zirconium about 1.5 % of tin, about 0.15 % of iron, about 0.05 % of chromium, about 0.05 % of nickel, and 0.05 to 0.5 % of at least one or two kinds of niobium, titanium and vanadium. Using this zirconium-base alloy can manufacture fuel spacers by the same manufacturing process, thus improving economy and reliability. (Kamimura, M.)

Physiological and genetics studies of highly radiation-resistant bacteria

International Nuclear Information System (INIS)

Keller, L.C.

1981-01-01

The phenomenon of radiation resistance was studied using micrococci and Moraxella-Acinetobacter capable of surviving very high doses of gamma radiation which were isolated from foods. Physiological age, or growth phase, was found to be an important factor in making comparisons of radiation-resistance among different bacteria and their mutants. Radiation-resistant bacteria were highly resistant to the lethal effect of nitrosoguanidine used for mutagenesis. Studies of relative resistance of radiation-resistant bacteria, radiation-sensitive mutants, and nonradiation-resistant bacteria to killing by different chemical mutagens did not reveal a correlation between the traits of radiation resistance and mutagen resistance among different strains. Comparisons of plasmid profiles of radiation-resistant bacteria and selected radiation-sensitive mutants suggested the possibility that plasmids may carry genes involved in radiation resistance

High temperature oxidation resistant cermet compositions

Science.gov (United States)

Phillips, W. M. (Inventor)

1976-01-01

Cermet compositions are designed to provide high temperature resistant refractory coatings on stainless steel or molybdenum substrates. A ceramic mixture of chromium oxide and aluminum oxide form a coating of chromium oxide as an oxidation barrier around the metal particles, to provide oxidation resistance for the metal particles.

The ATLAS RPC detector control system: Problems, solutions and new opportunities

International Nuclear Information System (INIS)

Aielli, G.; Camarri, P.; Cardarelli, R.; Di Ciaccio, A.; Di Stante, L.; Liberti, B.; Pastori, E.; Polini, A.; Salamon, A.; Santonico, R.

2009-01-01

The development of large detector systems for the LHC experimental apparatus induced to consider the problem of monitoring and controlling the different sub-detectors under a new perspective. On one side the necessity of a powerful tool which permits to a relatively experienced user to safely manage the detector for all the standard purposes and inform on the detector status and quality of the data pushed the LHC scientific community to adopt a common development platform and as much as possible uniform front ends. On the other side the monitoring of short- and long-term behavior of unprecedented complex detectors systems built by thousands of independent detectors offered a problem and an opportunity: the problem is in terms of careful and optimized design of the control system combining a rational use of software and database tools and all the experience accumulated previously in the long ageing studies which evidenced case by case the main source of problems and the ideal tools to control them; the opportunity consists in the availability of such a statistically large number of detectors which would expand the chances to understand deeply the systematic aspects of the detector physics hardly reachable in small detector sample tests even though on a long-time scale. Here we will present the architecture, the present status and the perspective applications and potentialities of the ATLAS RPC detector control system in view of the forthcoming startup of the ATLAS experiment.

Corrosion resistance of high-performance materials titanium, tantalum, zirconium

CERN Document Server

2012-01-01

Corrosion resistance is the property of a material to resist corrosion attack in a particular aggressive environment. Although titanium, tantalum and zirconium are not noble metals, they are the best choice whenever high corrosion resistance is required. The exceptionally good corrosion resistance of these high–performance metals and their alloys results from the formation of a very stable, dense, highly adherent, and self–healing protective oxide film on the metal surface. This naturally occurring oxide layer prevents chemical attack of the underlying metal surface. This behavior also means, however, that high corrosion resistance can be expected only under neutral or oxidizing conditions. Under reducing conditions, a lower resistance must be reckoned with. Only very few inorganic and organic substances are able to attack titanium, tantalum or zirconium at ambient temperature. As the extraordinary corrosion resistance is coupled with an excellent formability and weldability these materials are very valua...

Oxidation resistant high creep strength austenitic stainless steel

Science.gov (United States)

Brady, Michael P.; Pint, Bruce A.; Liu, Chain-Tsuan; Maziasz, Philip J.; Yamamoto, Yukinori; Lu, Zhao P.

2010-06-29

An austenitic stainless steel displaying high temperature oxidation and creep resistance has a composition that includes in weight percent 15 to 21 Ni, 10 to 15 Cr, 2 to 3.5 Al, 0.1 to 1 Nb, and 0.05 to 0.15 C, and that is free of or has very low levels of N, Ti and V. The alloy forms an external continuous alumina protective scale to provide a high oxidation resistance at temperatures of 700 to 800.degree. C. and forms NbC nanocarbides and a stable essentially single phase fcc austenitic matrix microstructure to give high strength and high creep resistance at these temperatures.

Simulation and prototyping of 2 m long resistive plate chambers for detection of fast neutrons and multi-neutron event identification

Energy Technology Data Exchange (ETDEWEB)

Elekes, Z., E-mail: z.elekes@hzdr.de [Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); Aumann, T. [GSI Helmholtzzentrumfür Schwerionenforschung, Darmstadt (Germany); Technische Universität Darmstadt, Darmstadt (Germany); Bemmerer, D. [Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); Boretzky, K. [GSI Helmholtzzentrumfür Schwerionenforschung, Darmstadt (Germany); Caesar, C. [GSI Helmholtzzentrumfür Schwerionenforschung, Darmstadt (Germany); Technische Universität Darmstadt, Darmstadt (Germany); Cowan, T.C. [Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); Technische Universität Dresden, Dresden (Germany); Hehner, J.; Heil, M. [GSI Helmholtzzentrumfür Schwerionenforschung, Darmstadt (Germany); Kempe, M. [Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); Rossi, D. [GSI Helmholtzzentrumfür Schwerionenforschung, Darmstadt (Germany); Röder, M. [Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); Technische Universität Dresden, Dresden (Germany); Simon, H. [GSI Helmholtzzentrumfür Schwerionenforschung, Darmstadt (Germany); Sobiella, M.; Stach, D. [Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); Reinhardt, T. [Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); Technische Universität Dresden, Dresden (Germany); Wagner, A.; Yakorev, D. [Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); Zilges, A. [Universität zu Köln, Köln (Germany); Zuber, K. [Technische Universität Dresden, Dresden (Germany)

2013-02-11

Resistive plate chamber (RPC) prototypes of 2 m length were simulated and built. The experimental tests using a 31 MeV electron beam, discussed in details, showed an efficiency higher than 90% and an excellent time resolution of around σ=100ps. Furthermore, comprehensive simulations were performed by GEANT4 toolkit in order to study the possible use of these RPCs for fast neutron (200 MeV–1 GeV) detection and multi-neutron event identification. The validation of simulation parameters was carried out via a comparison to experimental data. A possible setup for invariant mass spectroscopy of multi-neutron emission is presented and the characteristics are discussed. The results show that the setup has a high detection efficiency. Its capability of determining the momentum of the outgoing neutrons and reconstructing the relative energy between the fragments from nuclear reactions is demonstrated for different scenarios.

Production of low-affinity penicillin-binding protein by low- and high-resistance groups of methicillin-resistant Staphylococcus aureus.

Science.gov (United States)

Murakami, K; Nomura, K; Doi, M; Yoshida, T

1987-01-01

Methicillin- and cephem-resistant Staphylococcus aureus (137 strains) for which the cefazolin MICs are at least 25 micrograms/ml could be classified into low-resistance (83% of strains) and high-resistance (the remaining 17%) groups by the MIC of flomoxef (6315-S), a 1-oxacephalosporin. The MICs were less than 6.3 micrograms/ml and more than 12.5 micrograms/ml in the low- and high-resistance groups, respectively. All strains produced penicillin-binding protein 2' (PBP 2'), which has been associated with methicillin resistance and which has very low affinity for beta-lactam antibiotics. Production of PBP 2' was regulated differently in low- and high-resistance strains. With penicillinase-producing strains of the low-resistance group, cefazolin, cefamandole, and cefmetazole induced PBP 2' production about 5-fold, while flomoxef induced production 2.4-fold or less. In contrast, penicillinase-negative variants of low-resistance strains produced PBP 2' constitutively in large amounts and induction did not occur. With high-resistance strains, flomoxef induced PBP 2' to an extent similar to that of cefazolin in both penicillinase-producing and -negative strains, except for one strain in which the induction did not occur. The amount of PBP 2' induced by beta-lactam antibiotics in penicillinase-producing strains of the low-resistance group correlated well with resistance to each antibiotic. Large amounts of PBP 2' in penicillinase-negative variants of the low-resistance group did not raise the MICs of beta-lactam compounds, although these strains were more resistant when challenged with flomoxef for 2 h. Different regulation of PBP 2' production was demonstrated in the high- and low-resistance groups, and factor(s) other than PBP 2' were suggested to be involved in the methicillin resistance of high-resistance strains. Images PMID:3499861

Resistance Exercise Attenuates High-Fructose, High-Fat-Induced Postprandial Lipemia

Directory of Open Access Journals (Sweden)

Jessie R. Wilburn

2015-01-01

Full Text Available Introduction Meals rich in both fructose and fat are commonly consumed by many Americans, especially young men, which can produce a significant postprandial lipemic response. Increasing evidence suggests that aerobic exercise can attenuate the postprandial increase in plasma triacylglycerols (TAGs in response to a high-fat or a high-fructose meal. However, it is unknown if resistance exercise can dampen the postprandial lipemic response to a meal rich in both fructose and fat. Methods Eight apparently healthy men (Mean ± SEM; age = 27 ± 2 years participated in a crossover study to examine the effects of acute resistance exercise on next-day postprandial lipemia resulting from a high-fructose, high-fat meal. Participants completed three separate two-day conditions in a random order: (1 EX-COMP: a full-body weightlifting workout with the provision of additional kilocalories to compensate for the estimated net energy cost of exercise on day 1, followed by the consumption of a high-fructose, high-fat liquid test meal the next morning (day 2 (~600 kcal and the determination of the plasma glucose, lactate, insulin, and TAG responses during a six-hour postprandial period; (2 EX-DEF: same condition as EX-COMP but without exercise energy compensation on day 1; and (3 CON: no exercise control. Results The six-hour postprandial plasma insulin and lactate responses did not differ between conditions. However, the postprandial plasma TAG concentrations were 16.5% and 24.4% lower for EX-COMP (551.0 ± 80.5 mg/dL x 360 minutes and EX-DEF (499.4 ± 73.5 mg/dL x 360 minutes, respectively, compared to CON (660.2 ± 95.0 mg/dL x 360 minutes ( P < 0.05. Conclusions A single resistance exercise bout, performed ~15 hours prior to a high-fructose, high-fat meal, attenuated the postprandial TAG response, as compared to a no-exercise control condition, in healthy, resistance-trained men.

Resistance Exercise Attenuates High-Fructose, High-Fat-Induced Postprandial Lipemia.

Science.gov (United States)

Wilburn, Jessie R; Bourquin, Jeffrey; Wysong, Andrea; Melby, Christopher L

2015-01-01

Meals rich in both fructose and fat are commonly consumed by many Americans, especially young men, which can produce a significant postprandial lipemic response. Increasing evidence suggests that aerobic exercise can attenuate the postprandial increase in plasma triacylglycerols (TAGs) in response to a high-fat or a high-fructose meal. However, it is unknown if resistance exercise can dampen the postprandial lipemic response to a meal rich in both fructose and fat. Eight apparently healthy men (Mean ± SEM; age = 27 ± 2 years) participated in a crossover study to examine the effects of acute resistance exercise on next-day postprandial lipemia resulting from a high-fructose, high-fat meal. Participants completed three separate two-day conditions in a random order: (1) EX-COMP: a full-body weightlifting workout with the provision of additional kilocalories to compensate for the estimated net energy cost of exercise on day 1, followed by the consumption of a high-fructose, high-fat liquid test meal the next morning (day 2) (~600 kcal) and the determination of the plasma glucose, lactate, insulin, and TAG responses during a six-hour postprandial period; (2) EX-DEF: same condition as EX-COMP but without exercise energy compensation on day 1; and (3) CON: no exercise control. The six-hour postprandial plasma insulin and lactate responses did not differ between conditions. However, the postprandial plasma TAG concentrations were 16.5% and 24.4% lower for EX-COMP (551.0 ± 80.5 mg/dL × 360 minutes) and EX-DEF (499.4 ± 73.5 mg/dL × 360 minutes), respectively, compared to CON (660.2 ± 95.0 mg/dL × 360 minutes) (P < 0.05). A single resistance exercise bout, performed ~15 hours prior to a high-fructose, high-fat meal, attenuated the postprandial TAG response, as compared to a no-exercise control condition, in healthy, resistance-trained men.

Creep resistant high temperature martensitic steel

Energy Technology Data Exchange (ETDEWEB)

Hawk, Jeffrey A.; Jablonski, Paul D.; Cowen, Christopher J.

2017-01-31

The disclosure provides a creep resistant alloy having an overall composition comprised of iron, chromium, molybdenum, carbon, manganese, silicon, nickel, vanadium, niobium, nitrogen, tungsten, cobalt, tantalum, boron, copper, and potentially additional elements. In an embodiment, the creep resistant alloy has a molybdenum equivalent Mo(eq) from 1.475 to 1.700 wt. % and a quantity (C+N) from 0.145 to 0.205. The overall composition ameliorates sources of microstructural instability such as coarsening of M.sub.23C.sub.6carbides and MX precipitates, and mitigates or eliminates Laves and Z-phase formation. A creep resistant martensitic steel may be fabricated by preparing a melt comprised of the overall composition followed by at least austenizing and tempering. The creep resistant alloy exhibits improved high-temperature creep strength in the temperature environment of around 650.degree. C.

Creep resistant high temperature martensitic steel

Science.gov (United States)

Hawk, Jeffrey A.; Jablonski, Paul D.; Cowen, Christopher J.

2015-11-13

The disclosure provides a creep resistant alloy having an overall composition comprised of iron, chromium, molybdenum, carbon, manganese, silicon, nickel, vanadium, niobium, nitrogen, tungsten, cobalt, tantalum, boron, and potentially additional elements. In an embodiment, the creep resistant alloy has a molybdenum equivalent Mo(eq) from 1.475 to 1.700 wt. % and a quantity (C+N) from 0.145 to 0.205. The overall composition ameliorates sources of microstructural instability such as coarsening of M.sub.23C.sub.6 carbides and MX precipitates, and mitigates or eliminates Laves and Z-phase formation. A creep resistant martensitic steel may be fabricated by preparing a melt comprised of the overall composition followed by at least austenizing and tempering. The creep resistant alloy exhibits improved high-temperature creep strength in the temperature environment of around 650.degree. C.

High chlorpyrifos resistance in Culex pipiens mosquitoes: strong synergy between resistance genes

Science.gov (United States)

Alout, H; Labbé, P; Berthomieu, A; Makoundou, P; Fort, P; Pasteur, N; Weill, M

2016-01-01

We investigated the genetic determinism of high chlorpyrifos resistance (HCR), a phenotype first described in 1999 in Culex pipiens mosquitoes surviving chlorpyrifos doses ⩾1 mg l−1 and more recently found in field samples from Tunisia, Israel or Indian Ocean islands. Through chlorpyrifos selection, we selected several HCR strains that displayed over 10 000-fold resistance. All strains were homozygous for resistant alleles at two main loci: the ace-1 gene, with the resistant ace-1R allele expressing the insensitive G119S acetylcholinesterase, and a resistant allele of an unknown gene (named T) linked to the sex and ace-2 genes. We constructed a strain carrying only the T-resistant allele and studied its resistance characteristics. By crossing this strain with strains harboring different alleles at the ace-1 locus, we showed that the resistant ace-1R and the T alleles act in strong synergy, as they elicited a resistance 100 times higher than expected from a simple multiplicative effect. This effect was specific to chlorpyrifos and parathion and was not affected by synergists. We also examined how HCR was expressed in strains carrying other ace-1-resistant alleles, such as ace-1V or the duplicated ace-1D allele, currently spreading worldwide. We identified two major parameters that influenced the level of resistance: the number and the nature of the ace-1-resistant alleles and the number of T alleles. Our data fit a model that predicts that the T allele acts by decreasing chlorpyrifos concentration in the compartment targeted in insects. PMID:26463842

Performance of the E771 RPC muon detector at Fermilab

International Nuclear Information System (INIS)

Cataldi, G.; Creti, P.; Elia, V.; Fiore, G.; Gorini, E.; Grancagnolo, F.; Panareo, M.; Pinto, C.; Antoniazzi, L.; Introzzi, G.; Lanza, A.; Liguori, G.; Torre, P.; Corti, G.

1994-01-01

The technique of resistive plate counters, equipped with pad readout instead of strips, has been successfully used for the first time in a high rate environment. The performance of the muon detector of E771, based on this technique, is illustrated in detail, including the dependence of the efficiency on the local rate of incident particles. (orig.)

Method of separate determination of high-ohmic sample resistance and contact resistance

Directory of Open Access Journals (Sweden)

Vadim A. Golubiatnikov

2015-09-01

Full Text Available A method of separate determination of two-pole sample volume resistance and contact resistance is suggested. The method is applicable to high-ohmic semiconductor samples: semi-insulating gallium arsenide, detector cadmium-zinc telluride (CZT, etc. The method is based on near-contact region illumination by monochromatic radiation of variable intensity from light emitting diodes with quantum energies exceeding the band gap of the material. It is necessary to obtain sample photo-current dependence upon light emitting diode current and to find the linear portion of this dependence. Extrapolation of this linear portion to the Y-axis gives the cut-off current. As the bias voltage is known, it is easy to calculate sample volume resistance. Then, using dark current value, one can determine the total contact resistance. The method was tested for n-type semi-insulating GaAs. The contact resistance value was shown to be approximately equal to the sample volume resistance. Thus, the influence of contacts must be taken into account when electrophysical data are analyzed.

Polymeric media for tritium fixation

International Nuclear Information System (INIS)

Franz, J.A.; Burger, L.L.

1975-01-01

The synthesis and leach testing of several polymeric media for tritium fixation are presented. Tritiated bakelite, poly(acrylonitrile) and polystyrene successfully fixed tritium. Tritium leach rates at the tracer level appear to be negligible. Advantages and disadvantages of the processes are discussed, and further bench-scale investigations underway are reported. Rough cost estimates are presented for the different media and are compared with alternate approaches such as deep-well injection and long-term tank storage. Polymeric media costs are high compared to deep-well storage and are of the same order of magnitude per liter of water as for isotopic enrichment. With this limitation, polymeric media can be economically feasible only for highly concentrated tritiated wastes. It is recommended that the bakelite and polystyrene processes be examined on a larger scale to permit more accurate cost analysis and process design. (auth)

Stability of High Temperature Standard Platinum Resistance Thermometers at High Temperatures

OpenAIRE

Y. A. ABDELAZIZ; F. M. MEGAHED

2010-01-01

An investigation of the stability of high temperature standard platinum resistance thermometers HTSPRTs has been carried out for two different designs thermometers (with nominal resistance 0.25 Ω and 2.5 Ω) from two different suppliers. The thermometers were heated for more than 160 hours at temperatures above 960 0C using a vertical furnace with a ceramic block. A study was made of the influence of the heat treatment on the stability of the resistance at the triple point of water, and on the...

Common support and integration of the BMS/BMF type MDT/RPC chambers of the muon spectrometer of the ATLAS experiment

International Nuclear Information System (INIS)

Barashkov, A.V.; Glonti, G.L.; Gongadze, A.L.; Gostkin, M.I.; Gus'kov, A.V.; Dedovich, D.V.; Demichev, M.A.; Zhemchugov, A.S.; Il'yushenko, E.N.; Kotov, S.A.; Korolevich, Ya.V.; Kruchonok, V.G.; Krumshtejn, Z.V.; Kuznetsov, N.K.; Lomidze, D.D.; Potrap, I.N.; Kharchenko, D.V.; Tskhadadze, Eh.G.; Chepurnov, V.F.; Shelkov, G.A.; Podkladkin, S.Yu.; Sekhniaidze, G.G.

2005-01-01

The common support system for muon BMS/BMF drift chambers with trigger RPC chambers for the muon spectrometer of the ATLAS experiment is described. The support systems are intended for the chambers integration into combined modules and for the subsequent installation in the experimental set-up. The technology of chambers integration is described. The sagging of the drift chambers was tested by tilting the modules at different angles. The measurements were performed by means of the RASNIK optical system. The normal operation of kinematic supports was confirmed. We also present the method of the sag regulation for the BMS/BMF chambers lying in the horizontal plane which provides the minimum difference between signal wire and detector tube body sags when the modules are later installed in their working positions

Genetic Determinants of High-Level Oxacillin Resistance in Methicillin-Resistant Staphylococcus aureus.

Science.gov (United States)

Pardos de la Gandara, Maria; Borges, Vitor; Chung, Marilyn; Milheiriço, Catarina; Gomes, João Paulo; de Lencastre, Herminia; Tomasz, Alexander

2018-06-01

Methicillin-resistant Staphylococcus aureus (MRSA) strains carry either a mecA - or a mecC -mediated mechanism of resistance to beta-lactam antibiotics, and the phenotypic expression of resistance shows extensive strain-to-strain variation. In recent communications, we identified the genetic determinants associated with the stringent stress response that play a major role in the antibiotic resistant phenotype of the historically earliest "archaic" clone of MRSA and in the mecC -carrying MRSA strain LGA251. Here, we sought to test whether or not the same genetic determinants also contribute to the resistant phenotype of highly and homogeneously resistant (H*R) derivatives of a major contemporary MRSA clone, USA300. We found that the resistance phenotype was linked to six genes ( fruB , gmk , hpt , purB , prsA , and relA ), which were most frequently targeted among the analyzed 20 H*R strains (one mutation per clone in 19 of the 20 H*R strains). Besides the strong parallels with our previous findings (five of the six genes matched), all but one of the repeatedly targeted genes were found to be linked to guanine metabolism, pointing to the key role that this pathway plays in defining the level of antibiotic resistance independent of the clonal type of MRSA. Copyright © 2018 American Society for Microbiology.

Development of radiation-resisting high molecular-weight materials

International Nuclear Information System (INIS)

Nakagawa, Tsutomu

1976-01-01

The excellent radiation-resisting polyvinyl chloride developed at the opportunity of the research on the relationships between the protection of living body and the polymer-technological protection from radiation is reviewed. The report is divided into four main parts, namely 1) the change in the molecular arrangement of market-available, high molecular-weight materials by gamma-ray irradiation, 2) the protection of high molecular-weight materials from radiation, 3) the relationships between the biological radiation-protective substances and the change to radiation-resisting property of synthesized high molecular-weight substances, and 4) the development of the radiation-resisting high molecular-weight materials as metal-collecting agents. Attention is paid to the polyvinyl chloride having N-methyl-dithio-carbamate radical (PMD), synthesized by the author et. al., that has excellent radiation-resisting property. PMD has some possibility to form thiol- and amino-radicals necessary to protect living things from radiation. It is believed that the protection effects of N-methyl-dithio-carbamate radical are caused by the relatively stable S radical produced by the energy transfer. PMD film is suitable for the irradiation of foods, because it hardly changes the permeability of oxygen and carbon dioxide. PMD produces mercaptide or chelate. A new metal-collecting agent (PSDC) having reactivity with the metallic ions with radiation-resisting property was developed, which is derived from polyvinyl chloride and sodium N-methyl-N-carboxy-methyl-dithio-carbamate. (Iwakiri, K.)

Ultrahigh hardness and high electrical resistivity in nano-twinned, nanocrystalline high-entropy alloy films

Science.gov (United States)

Huo, Wenyi; Liu, Xiaodong; Tan, Shuyong; Fang, Feng; Xie, Zonghan; Shang, Jianku; Jiang, Jianqing

2018-05-01

Nano-twinned, nanocrystalline CoCrFeNi high-entropy alloy films were produced by magnetron sputtering. The films exhibit a high hardness of 8.5 GPa, the elastic modulus of 161.9 GPa and the resistivity as high as 135.1 μΩ·cm. The outstanding mechanical properties were found to result from the resistance of deformation created by nanocrystalline grains and nano-twins, while the electrical resistivity was attributed to the strong blockage effect induced by grain boundaries and lattice distortions. The results lay a solid foundation for the development of advanced films with structural and functional properties combined in micro-/nano-electronic devices.

A graphene integrated highly transparent resistive switching memory device

Science.gov (United States)

Dugu, Sita; Pavunny, Shojan P.; Limbu, Tej B.; Weiner, Brad R.; Morell, Gerardo; Katiyar, Ram S.

2018-05-01

We demonstrate the hybrid fabrication process of a graphene integrated highly transparent resistive random-access memory (TRRAM) device. The indium tin oxide (ITO)/Al2O3/graphene nonvolatile memory device possesses a high transmittance of >82% in the visible region (370-700 nm) and exhibits stable and non-symmetrical bipolar switching characteristics with considerably low set and reset voltages (ITO/Al2O3/Pt device and studied its switching characteristics for comparison and a better understanding of the ITO/Al2O3/graphene device characteristics. The conduction mechanisms in high and low resistance states were analyzed, and the observed polarity dependent resistive switching is explained based on electro-migration of oxygen ions.

Iron-niobium-aluminum alloy having high-temperature corrosion resistance

Science.gov (United States)

Hsu, Huey S.

1988-04-14

An alloy for use in high temperature sulfur and oxygen containing environments, having aluminum for oxygen resistance, niobium for sulfur resistance and the balance iron, is discussed. 4 figs., 2 tabs.

Direct Shear Behavior of Fiber Reinforced Concrete Elements

Directory of Open Access Journals (Sweden)

Hussein Al-Quraishi

2018-01-01

Full Text Available Improving the accuracy of load-deformation behavior, failure mode, and ultimate load capacity for reinforced concrete members subjected to in-plane loadings such as corbels, wall to foundation connections and panels need shear strength behavior to be included. Shear design in reinforced concrete structures depends on crack width, crack slippage and roughness of the surface of cracks. This paper illustrates results of an experimental investigation conducted to investigate the direct shear strength of fiber normal strength concrete (NSC and reactive powder concrete (RPC. The tests were performed along a pre-selected shear plane in concrete members named push-off specimens. The effectiveness of concrete compressive strength, volume fraction of steel fiber, and shear reinforcement ratio on shear transfer capacity were considered in this study. Furthermore, failure modes, shear stress-slip behavior, and shear stress-crack width behavior were also presented in this study. Tests’ results showed that volume fraction of steel fiber and compressive strength of concrete in NSC and RPC play a major role in improving the shear strength of concrete. As expectedly, due to dowel action, the shear reinforcement is the predominant factor in resisting the shear stress. The shear failure of NSC and RPC has the sudden mode of failure (brittle failure with the approximately linear behavior of shear stress-slip relationship till failure. Using RPC instead of NSC with the same amount of steel fibers in constructing the push-off specimen result in high shear strength. In NSC, shear strength influenced by the three major factors; crack surface friction, aggregate interlock and steel fiber content if present. Whereas, RPC has only steel fiber and cracks surface friction influencing the shear strength. Due to cementitious nature of RPC in comparisons with NSC, the RPC specimen shows greater cracks width. It is observed that the Mattock model gives very satisfactory

Overall Low Extended-Spectrum Cephalosporin Resistance but high Azithromycin Resistance in Neisseria gonorrhoeae in 24 European Countries, 2015.

Science.gov (United States)

Cole, Michelle J; Spiteri, Gianfranco; Jacobsson, Susanne; Woodford, Neil; Tripodo, Francesco; Amato-Gauci, Andrew J; Unemo, Magnus

2017-09-11

Surveillance of Neisseria gonorrhoeae antimicrobial susceptibility in Europe is performed through the European Gonococcal Antimicrobial Surveillance Programme (Euro-GASP), which additionally provides data to inform the European gonorrhoea treatment guideline; currently recommending ceftriaxone 500 mg plus azithromycin 2 g as first-line therapy. We present antimicrobial susceptibility data from 24 European countries in 2015, linked to epidemiological data of patients, and compare the results to Euro-GASP data from previous years. Antimicrobial susceptibility testing by MIC gradient strips or agar dilution methodology was performed on 2134 N. gonorrhoeae isolates and interpreted using EUCAST breakpoints. Patient variables associated with resistance were established using logistic regression to estimate odds ratios (ORs). In 2015, 1.7% of isolates were cefixime resistant compared to 2.0% in 2014. Ceftriaxone resistance was detected in only one (0.05%) isolate in 2015, compared with five (0.2%) in 2014. Azithromycin resistance was detected in 7.1% of isolates in 2015 (7.9% in 2014), and five (0.2%) isolates displayed high-level azithromycin resistance (MIC ≥ 256 mg/L) compared with one (0.05%) in 2014. Ciprofloxacin resistance remained high (49.4%, vs. 50.7% in 2014). Cefixime resistance significantly increased among heterosexual males (4.1% vs. 1.7% in 2014), which was mainly attributable to data from two countries with high cefixime resistance (~11%), however rates among men-who-have-sex-with-men (MSM) and females continued to decline to 0.5% and 1%, respectively. Azithromycin resistance in MSM and heterosexual males was higher (both 8.1%) than in females (4.9% vs. 2.2% in 2014). The association between azithromycin resistance and previous gonorrhoea infection, observed in 2014, continued in 2015 (OR 2.1, CI 1.2-3.5, p resistance and low overall resistance to ceftriaxone and cefixime. The low cephalosporin resistance may be attributable to the effectiveness

RPC performance vs. front-end electronics

International Nuclear Information System (INIS)

Cardarelli, R.; Aielli, G.; Camarri, P.; Di Ciaccio, A.; Di Stante, L.; Liberti, B.; Pastori, E.; Santonico, R.; Zerbini, A.

2012-01-01

Moving the amplification from the gas to the front-end electronics was a milestone in the development of Resistive Plate Chambers. Here we discuss the historical evolution of RPCs and we show the results obtained with newly developed front-end electronics with threshold in the fC range.

Current voltage characteristics of composite superconductors with high contact resistance

International Nuclear Information System (INIS)

Akhmetov, A.A.; Baev, V.P.

1984-01-01

An experimental study has been made of current-voltage characteristics of composite superconductors with contact resistance between superconducting filaments and normal metal with high electrical conductivity. It is shown that stable resistive states exist in such conductors over a wide range of currents. The presence of resistive states is interpreted in terms of the resistive domain concept. The minimum and maximum currents of resistive states are found to be dependent on the electrical resistance of normal metal and magnetic field. (author)

High Performance Liquid Chromatographic Analysis of Phytoplankton Pigments Using a C16-Amide Column

Science.gov (United States)

A reverse-phase high performance liquid chromatographic (RP-HPLC) method was developed to analyze in a single run, most polar and non-polar chlorophylls and carotenoids from marine phytoplankton. The method is based on a RP-C16-Amide column and a ternary gradient system consistin...

Does High-Dose Antimicrobial Chemotherapy Prevent the Evolution of Resistance?

Science.gov (United States)

Day, Troy; Read, Andrew F.

2016-01-01

High-dose chemotherapy has long been advocated as a means of controlling drug resistance in infectious diseases but recent empirical studies have begun to challenge this view. We develop a very general framework for modeling and understanding resistance emergence based on principles from evolutionary biology. We use this framework to show how high-dose chemotherapy engenders opposing evolutionary processes involving the mutational input of resistant strains and their release from ecological competition. Whether such therapy provides the best approach for controlling resistance therefore depends on the relative strengths of these processes. These opposing processes typically lead to a unimodal relationship between drug pressure and resistance emergence. As a result, the optimal drug dose lies at either end of the therapeutic window of clinically acceptable concentrations. We illustrate our findings with a simple model that shows how a seemingly minor change in parameter values can alter the outcome from one where high-dose chemotherapy is optimal to one where using the smallest clinically effective dose is best. A review of the available empirical evidence provides broad support for these general conclusions. Our analysis opens up treatment options not currently considered as resistance management strategies, and it also simplifies the experiments required to determine the drug doses which best retard resistance emergence in patients. PMID:26820986

Stability of High Temperature Standard Platinum Resistance Thermometers at High Temperatures

Directory of Open Access Journals (Sweden)

Y. A. ABDELAZIZ

2010-05-01

Full Text Available An investigation of the stability of high temperature standard platinum resistance thermometers HTSPRTs has been carried out for two different designs thermometers (with nominal resistance 0.25 Ω and 2.5 Ω from two different suppliers. The thermometers were heated for more than 160 hours at temperatures above 960 0C using a vertical furnace with a ceramic block. A study was made of the influence of the heat treatment on the stability of the resistance at the triple point of water, and on the relative resistance W(Ga at the melting point of gallium. The thermometers showed a correlation between the drift note and the values of W(Ga. It was found also that the HTSPRT which has a sensor with strip shaped support and low nominal resistance is more stable than the HTSPRT which has a sensor in the form of a coil wound on silica cross. The 0.25 Ω thermometer has better stability @ 7x10-6 0C (at TPW after 40 hour. Factors affecting the stability and accuracy of HTSPRT also will be discussed.

High prevalence of multi-drug resistant Klebsiella pneumoniae in a ...

African Journals Online (AJOL)

The lowest resistance rates were documented for Carbapenems (23.2%). For specific antibiotics, there was high resistance to commonly used antibiotics (over 80% for Ceftriaxone, Cefipime, Gentamycin and Ceftazidime). The antibiotics with least resistance were Amikacin and Meropenem (21% and 7 % respectively).

High resistance ratio of bipolar resistive switching in a multiferroic/high-K Bi(Fe0.95Cr0.05)O3/ZrO2/Pt heterostructure

Science.gov (United States)

Dong, B. W.; Miao, Jun; Han, J. Z.; Shao, F.; Yuan, J.; Meng, K. K.; Wu, Y.; Xu, X. G.; Jiang, Y.

2018-03-01

An novel heterostructure composed of multiferroic Bi(Fe0.95Cr0.05)O3 (BFCO) and high-K ZrO2 (ZO) layers is investigated. Ferroelectric and electrical properties of the BFZO/ZO heterostructure have been investigated. A pronounced bipolar ferroelectric resistive switching characteristic was achieved in the heterostructure at room temperature. Interestingly, the BFCO/ZO structures exhibit a reproducible resistive switching with a high On/Off resistance ratio ∼2×103 and long retention time. The relationship between polarization and band structure at the interface of BFCO/ZO bilayer under the positive and negative sweepings has been discussed. As a result, the BFCO/ZO multiferroic/high-K heterostructure with high On/Off resistance ratio and long retention characterizes, exhibits a potential in future nonvolatile memory application.

Experimental Studies on the Effects of Thermal Bumps in the Flow-Field around a Flat Plate using a Hypersonic Wind Tunnel

Science.gov (United States)

2012-07-01

Bakelite Hylem F1361, which is a thermosetting plastic consisting of a medium weave fabric reinforced laminate with Melamine resin binder. This composite...can be used for high-speed flow control. The laser ablation was conducted on the aluminium alloy plate inside a pressure chamber, where the

Development of Creep-Resistant and Oxidation-Resistant Austenitic Stainless Steels for High Temperature Applications

Science.gov (United States)

Maziasz, Philip J.

2018-01-01

Austenitic stainless steels are cost-effective materials for high-temperature applications if they have the oxidation and creep resistance to withstand prolonged exposure at such conditions. Since 1990, Oak Ridge National Laboratory (ORNL) has developed advanced austenitic stainless steels with creep resistance comparable to Ni-based superalloy 617 at 800-900°C based on specially designed "engineered microstructures" utilizing a microstructure/composition database derived from about 20 years of radiation effect data on steels. The wrought high temperature-ultrafine precipitate strengthened (HT-UPS) steels with outstanding creep resistance at 700-800°C were developed for supercritical boiler and superheater tubing for fossil power plants in the early 1990s, the cast CF8C-Plus steels were developed in 1999-2001 for land-based gas turbine casing and diesel engine exhaust manifold and turbocharger applications at 700-900°C, and, in 2015-2017, new Al-modified cast stainless steels with oxidation and creep resistance capabilities up to 950-1000°C were developed for automotive exhaust manifold and turbocharger applications. This article reviews and summarizes their development and their properties and applications.

Oat beta-glucan ameliorates insulin resistance in mice fed on high-fat and high-fructose diet

Directory of Open Access Journals (Sweden)

Jie Zheng

2013-12-01

Full Text Available Methods: This study sought to evaluate the impact of oat beta-glucan on insulin resistance in mice fed on high-fat and high-fructose diet with fructose (10%, w/v added in drinking water for 10 weeks. Results: The results showed that supplementation with oat beta-glucan could significantly reduce the insulin resistance both in low-dose (200 mg/kg−1 body weight and high-dose (500 mg/kg−1 body weight groups, but the high-dose group showed a more significant improvement in insulin resistance (P<0.01 compared with model control (MC group along with significant improvement in hepatic glycogen level, oral glucose, and insulin tolerance. Moreover, hepatic glucokinase activity was markedly enhanced both in low-dose and high-dose groups compared with that of MC group (P<0.05. Conclusion: These results suggested that supplementation of oat beta-glucan alleviated insulin resistance and the effect was dose dependent.

Effect of physiological age on radiation resistance of some bacteria that are highly radiation resistant

International Nuclear Information System (INIS)

Keller, L.C.; Maxcy, R.B.

1984-01-01

Physiological age-dependent variation in radiation resistance was studied for three bacteria that are highly radiation resistant: Micrococcus radiodurans, Micrococcus sp. isolate C-3, and Moraxella sp. isolate 4. Stationary-phase cultures of M. radiodurans and isolate C-3 were much more resistant to gamma radiation than were log-phase cultures. This pattern of relative resistance was reversed for isolate 4. Resistance of isolate 4 to UV light was also greater during log phase, although heat resistance and NaCl tolerance after heat stresses were greater during stationary phase. Radiation-induced injury of isolate 4 compared with injury of Escherichia coli B suggested that the injury process, as well as the lethal process, was affected by growth phase. The hypothesis that growth rate affects radiation resistance was tested, and results were interpreted in light of the probable confounding effect of methods used to alter growth rates of bacteria. These results indicate that dose-response experiments should be designed to measure survival during the most resistant growth phase of the organism under study. The timing is particularly important when extrapolations of survival results might be made to potential irradiation processes for foods. 17 references

Cementitious artificial aggregate particles for high-skid resistance pavements

OpenAIRE

DE LARRARD, François; MARTINEZ CASTILLO, Rafael; SEDRAN, Thierry; HAUZA, Philippe; POIRIER, Jean Eric

2012-01-01

For some critical road sections, a high skid resistance of wearing course is required to minimise the risk of traffic accidents. Nowadays this skid resistance is mainly brought by the use of special aggregates as calcined bauxite, a scarce and expensive material. The paper presents a patented technology, where a special high-performance mortar is produced and crushed at early age. These cementitious artificial aggregates (CAA) can display aggregate properties close to those of calcined bauxit...

Shape memory alloy resistance behaviour at high altitude for feedback control

Science.gov (United States)

Ng, W. T.; Sedan, M. F.; Abdullah, E. J.; Azrad, S.; Harithuddin, A. S. M.

2017-12-01

Many recent aerospace technologies are using smart actuators to reduce the system's complexity and increase its reliability. One such actuator is shape memory alloy (SMA) actuator, which is lightweight, produces high force and large deflection. However, some disadvantages in using SMA actuators have been identified and they include nonlinear response of the strain to input current, hysteresis characteristic that results in inaccurate control and less than optimum system performance, high operating temperatures, slow response and also high requirement of electrical power to obtain the desired actuation forces. It is still unknown if the SMA actuators can perform effectively at high altitude with low surrounding temperature. The work presented here covers the preliminary process of verifying the feasibility of using resistance as feedback control at high altitude for aerospace applications. Temperature and resistance of SMA actuator at high altitude is investigated by conducting an experiment onboard a high altitude balloon. The results from the high altitude experiment indicate that the resistance or voltage drop of the SMA wire is not significantly affected by the low surrounding temperature at high altitude as compared to the temperature of SMA. Resistance feedback control for SMA actuators may be suitable for aerospace applications.

High temperature creep strength of Advanced Radiation Resistant Oxide Dispersion Strengthened Steels

Energy Technology Data Exchange (ETDEWEB)

Noh, Sanghoon; Kim, Tae Kyu [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2014-05-15

Austenitic stainless steel may be one of the candidates because of good strength and corrosion resistance at the high temperatures, however irradiation swelling well occurred to 120dpa at high temperatures and this leads the decrease of the mechanical properties and dimensional stability. Compared to this, ferritic/martensitic steel is a good solution because of excellent thermal conductivity and good swelling resistance. Unfortunately, the available temperature range of ferritic/martensitic steel is limited up to 650 .deg. C. ODS steel is the most promising structural material because of excellent creep and irradiation resistance by uniformly distributed nano-oxide particles with a high density which is extremely stable at the high temperature in ferritic/martensitic matrix. In this study, high temperature strength of advanced radiation resistance ODS steel was investigated for the core structural material of next generation nuclear systems. ODS martensitic steel was designed to have high homogeneity, productivity and reproducibility. Mechanical alloying, hot isostactic pressing and hot rolling processes were employed to fabricate the ODS steels, and creep rupture test as well as tensile test were examined to investigate the behavior at high temperatures. ODS steels were fabricated by a mechanical alloying and hot consolidation processes. Mechanical properties at high temperatures were investigated. The creep resistance of advanced radiation resistant ODS steels was more superior than those of ferritic/ martensitic steel, austenitic stainless steel and even a conventional ODS steel.

CMOS pixel sensors on high resistive substrate for high-rate, high-radiation environments

Energy Technology Data Exchange (ETDEWEB)

Hirono, Toko, E-mail: thirono@uni-bonn.de [Physikalisches Institute der Universität Bonn, Bonn (Germany); Barbero, Marlon; Breugnon, Patrick; Godiot, Stephanie [CPPM, Aix-Marseille Universite, CNRS/IN2P3, Marseille (France); Gonella, Laura; Hemperek, Tomasz; Hügging, Fabian; Krüger, Hans [Physikalisches Institute der Universität Bonn, Bonn (Germany); Liu, Jian; Pangaud, Patrick [CPPM, Aix-Marseille Universite, CNRS/IN2P3, Marseille (France); Peric, Ivan [IPE, Karlsruher Institut für Technologie, Karlsruhe (Germany); Pohl, David-Leon [Physikalisches Institute der Universität Bonn, Bonn (Germany); Rozanov, Alexandre [CPPM, Aix-Marseille Universite, CNRS/IN2P3, Marseille (France); Rymaszewski, Piotr [Physikalisches Institute der Universität Bonn, Bonn (Germany); Wang, Anqing [CPPM, Aix-Marseille Universite, CNRS/IN2P3, Marseille (France); Wermes, Norbert [Physikalisches Institute der Universität Bonn, Bonn (Germany)

2016-09-21

A depleted CMOS active pixel sensor (DMAPS) has been developed on a substrate with high resistivity in a high voltage process. High radiation tolerance and high time resolution can be expected because of the charge collection by drift. A prototype of DMAPS was fabricated in a 150 nm process by LFoundry. Two variants of the pixel layout were tested, and the measured depletion depths of the variants are 166 μm and 80 μm. We report the results obtained with the prototype fabricated in this technology.

Borides - a new generation of highly resistant materials?

International Nuclear Information System (INIS)

Telle, R.

1988-01-01

High-duty ceramics are on advance in all sectors where materials with extremely good resistance to high temperatures and wear are required. The group of oxides, nitrides and carbides in use for quite a time now recently has been increased by the metal borides which offer among others economic advantages in certain applications. The drawbacks of these materials still to be reduced are their brittleness and susceptibility to oxidation and corrosion. Current research work on the thermodynamics of such systems, on the interaction between structure and properties, and on means to improve strength and resistance to wear are expected to soon open up new applications. (orig.) [de

Resistance Exercise Attenuates High-Fructose, High-Fat-Induced Postprandial Lipemia

OpenAIRE

Jessie R. Wilburn; Jeffrey Bourquin; Andrea Wysong; Christopher L. Melby

2015-01-01

Introduction Meals rich in both fructose and fat are commonly consumed by many Americans, especially young men, which can produce a significant postprandial lipemic response. Increasing evidence suggests that aerobic exercise can attenuate the postprandial increase in plasma triacylglycerols (TAGs) in response to a high-fat or a high-fructose meal. However, it is unknown if resistance exercise can dampen the postprandial lipemic response to a meal rich in both fructose and fat. Methods Eight ...

Effects of Different Water and Super Plasticizer Amount, Pre-Setting and Curing Regimes on the Behavior of Reactive Powder Concrete

Directory of Open Access Journals (Sweden)

M. A. Dashti Rahmatabadi

2014-12-01

Full Text Available Reactive Powder Concrete (RPC is an ultra high performance concrete which has superior mechanical and physical properties. The RPC is composed of cement and very fine powders such as crushed quartz (100–600 μm and silica fume with very low water/binder ratio (W/B (less than 0.20 and Super Plasticizer (SP. The RPC has a very high compressive and tensile strength with better durability properties than current high performance concretes. Application of very low water/binder ratio with a high dosage of super plasticizer, different heat curing processes and pre-setting pressure improve mechanical and physical properties of RPC. In this study, the RPC is composed of available materials in Iran. Two different mixing proportions, different water/binder ratios for preparation of samples, different super plasticizer dosages, five different (0, 25, 50, 100 and 150 MPa pre-setting pressure and 7 different curing regimes were used in samples preparation and experiments. Results showed that appropriate water/binder ratio and super plasticizer dosage, higher temperature and pre-setting pressure increase the workability, density and compressive strength of compositions.

The CMS RPC detector performance during Run-2 data taking

CERN Document Server

Shah, Mehar Ali

2017-01-01

The CMS experiment, located at the CERN Large Hadron Collider, has a redundant muon system composed by three different detector technologies Cathode Strip Chambers (in the forward regions), Drift Tubes (in the central region), and Resistive Plate Chambers (both in the central and forward regions). The RPCs are designed mainly as a trigger detector but they contribute also to the muon reconstruction. Thus the monitoring and the analysis of the system performance are necessary and essential for the final data quality. The main detector characteristics and the hit efficiency and cluster size will be presented in the paper. The stability of the system in the conditions of high instantaneous luminosity and high number of PU events will be presented in a view of history monitoring and stable trend.

Importance of establishing radiation protection culture in Radiology Department.

Science.gov (United States)

Ploussi, Agapi; Efstathopoulos, Efstathios P

2016-02-28

The increased use of ionization radiation for diagnostic and therapeutic purposes, the rapid advances in computed tomography as well as the high radiation doses delivered by interventional procedures have raised serious safety and health concerns for both patients and medical staff and have necessitated the establishment of a radiation protection culture (RPC) in every Radiology Department. RPC is a newly introduced concept. The term culture describes the combination of attitudes, beliefs, practices and rules among the professionals, staff and patients regarding to radiation protection. Most of the time, the challenge is to improve rather than to build a RPC. The establishment of a RPC requires continuing education of the staff and professional, effective communication among stakeholders of all levels and implementation of quality assurance programs. The RPC creation is being driven from the highest level. Leadership, professionals and associate societies are recognized to play a vital role in the embedding and promotion of RPC in a Medical Unit. The establishment of a RPC enables the reduction of the radiation dose, enhances radiation risk awareness, minimizes unsafe practices, and improves the quality of a radiation protection program. The purpose of this review paper is to describe the role and highlight the importance of establishing a strong RPC in Radiology Departments with an emphasis on promoting RPC in the Interventional Radiology environment.

Study of current instabilities in high resistivity gallium arsenide

International Nuclear Information System (INIS)

Barraud, A.

1968-01-01

We have shown the existence and made a study of the current oscillations produced in high-resistivity gallium arsenide by a strong electric field. The oscillations are associated with the slow travelling of a region of high electrical field across the whole sample. An experimental study of the properties of these instabilities has made it possible for us to distinguish this phenomenon from the Gunn effect, from acoustic-electric effects and from contact effects. In order to account for this type of instability, a differential trapping mechanism involving repulsive impurities is proposed; this mechanism can reduce the concentration of charge carriers in the conduction band at strong electrical fields and can lead to the production of a high-field domain. By developing this model qualitatively we have been able to account for all the properties of high-resistance gallium arsenide crystals subjected to a strong electrical field: increase of the Hall constant, existence of a voltage threshold for these oscillations, production of domains of high field, low rate of propagation of these domains, and finally the possibility of inverting the direction of the propagation of the domain without destroying the latter. A quantitative development of the model makes it possible to calculate the various characteristic parameters of these instabilities. Comparison with experiment shows that there is a good agreement, the small deviations coming especially from the lack of knowledge concerning transport properties in gallium arsenide subjected to high fields. From a study of this model, it appears that the instability phenomenon can occur over a wide range of repulsive centre concentrations, and also for a large range of resistivities. This is the reason why it appears systematically in gallium arsenide of medium and high resistivity. (authors) [fr

Electrical resistivity of UBe13 in high magnetic fields

International Nuclear Information System (INIS)

Schmiedeshoff, G.M.; Lacerda, A.; Fisk, Z.; Smith, J.L.

1996-01-01

We have measured the temperature dependent electrical resistivity of single and polycrystal samples of UBe 13 in high magnetic fields. Two maxima in the resistivity are observed at T M1 and T M2 . T M1 , the temperature of the colder maximum, increases quadratically with magnetic field H, a field dependence previously observed under hydrostatic pressure. The high temperature maximum at T M2 emerges in fields above about 4 T and increases linearly with H, a behavior which may be due to a sharpening of the crystal field levels associated with a depression of the Kondo effect by high magnetic fields. copyright 1996 The American Physical Society

Development of a high strength, hydrogen-resistant austenitic alloy

International Nuclear Information System (INIS)

Chang, K.M.; Klahn, D.H.; Morris, J.W. Jr.

1980-08-01

Research toward high-strength, high toughness nonmagnetic steels for use in the retaining rings of large electrical generators led to the development of a Ta-modified iron-based superalloy (Fe-36 Ni-3 Ti-3 Ta-0.5 Al-1.3 Mo-0.3 V-0.01 B) which combines high strength with good toughness after suitable aging. The alloy did, however, show some degradation in fatigue resistance in gaseous hydrogen. This sensitivity was associated with a deformation-induced martensitic transformation near the fracture surface. The addition of a small amount of chromium to the alloy suppressed the martensite transformation and led to a marked improvement in hydrogen resistance

Trigger system study of the dimuon spectrometer in the ALICE experiment at CERN-LHC; Etude du systeme de declenchement du spectrometre dimuons de l'experience alice au Cern-LHC

Energy Technology Data Exchange (ETDEWEB)

Roig, O

1999-12-01

This work is a contribution to the study of nucleus-nucleus collisions at the LHC with ALICE. The aim of this experiment is to search for a new phase of matter, the quark-gluon plasma (QGP). The dimuon forward spectrometer should measure one of the most promising probes of the QGP, the production of heavy quark vector mesons (J/{psi}, {gamma}, {gamma}', {gamma}'') through their muonic decays. The dimuon trigger selects the interesting events performing a cut on the transverse momentum of the tracks. The trigger decision is taken by a dedicated electronics using RPC (''Resistive Plate Chambers'') detector information. We have made our own R and D program on the RPC detector with various beam tests. We show the performances obtained during these tests of a low resistivity RPC operating in streamer mode. The ALICE requirements concerning the rate capability, the cluster size and the time resolution are fulfilled. We have optimised the trigger with simulations which include a complete description of the read-out planes and the trigger logic (algorithm). In particular, a technique of clustering is proposed and validated. A method called ''Ds reduction'' is introduced in order to limit the effects of combinatorial background on the trigger rates. The efficiencies and the trigger rates are calculated for Pb-Pb, Ca-Ca, p-p collisions at the LHC. Other more sophisticated cuts, on the invariant mass for example, using again the RPC information have been simulated but have not shown significant improvements of the trigger rates. (author)

Trigger system study of the dimuon spectrometer in the ALICE experiment at CERN-LHC

International Nuclear Information System (INIS)

Roig, O.

1999-12-01

This work is a contribution to the study of nucleus-nucleus collisions at the LHC with ALICE. The aim of this experiment is to search for a new phase of matter, the quark-gluon plasma (QGP). The dimuon forward spectrometer should measure one of the most promising probes of the QGP, the production of heavy quark vector mesons (J/ψ, γ, γ', γ'') through their muonic decays. The dimuon trigger selects the interesting events performing a cut on the transverse momentum of the tracks. The trigger decision is taken by a dedicated electronics using RPC (''Resistive Plate Chambers'') detector information. We have made our own R and D program on the RPC detector with various beam tests. We show the performances obtained during these tests of a low resistivity RPC operating in streamer mode. The ALICE requirements concerning the rate capability, the cluster size and the time resolution are fulfilled. We have optimised the trigger with simulations which include a complete description of the read-out planes and the trigger logic (algorithm). In particular, a technique of clustering is proposed and validated. A method called ''Ds reduction'' is introduced in order to limit the effects of combinatorial background on the trigger rates. The efficiencies and the trigger rates are calculated for Pb-Pb, Ca-Ca, p-p collisions at the LHC. Other more sophisticated cuts, on the invariant mass for example, using again the RPC information have been simulated but have not shown significant improvements of the trigger rates. (author)

Polystyrene negative resist for high-resolution electron beam lithography

Directory of Open Access Journals (Sweden)

Ma Siqi

2011-01-01

Full Text Available Abstract We studied the exposure behavior of low molecular weight polystyrene as a negative tone electron beam lithography (EBL resist, with the goal of finding the ultimate achievable resolution. It demonstrated fairly well-defined patterning of a 20-nm period line array and a 15-nm period dot array, which are the densest patterns ever achieved using organic EBL resists. Such dense patterns can be achieved both at 20 and 5 keV beam energies using different developers. In addition to its ultra-high resolution capability, polystyrene is a simple and low-cost resist with easy process control and practically unlimited shelf life. It is also considerably more resistant to dry etching than PMMA. With a low sensitivity, it would find applications where negative resist is desired and throughput is not a major concern.

RPC based 5D tracking concept for high multiplicity tracking trigger

CERN Document Server

Aielli, G; Cardarelli, R; Di Ciaccio, A; Distante, L; Liberti, B; Paolozzi, L; Pastori, E; Santonico, R

2018-01-01

The recently approved High Luminosity LHC project (HL-LHC) and the future col- liders proposals present a challenging experimental scenario, dominated by high pileup, radiation background and a bunch crossing time possibly shorter than 5 ns. This holds as well for muon systems, where RPCs can play a fundamental role in the design of the future experiments. The RPCs, thanks to their high space-time granularity, allows a sparse representation of the particle hits, in a very large parametric space containing, in addition to 3D spatial localization, also the pulse time and width associated to the avalanche charge. This 5D representation of the hits can be exploited to improve the performance of complex detectors such as muon systems and increase the discovery potential of a future experiment, by allowing a better track pileup rejection and sharper momentum resolution, an effective measurement of the particle velocity, to tag and trigger the non- ultrarelativistic particles, and the detection local multiple track ...

Development of high electrical resistance persistent current switch for high speed energization system

International Nuclear Information System (INIS)

Jizo, Y.; Furuta, Y.; Nakashima, H.

1986-01-01

Japanese National Railways is now developing a superconducting magnetically-levitated train system. A persistent current switch is incorporated in the super-conducting magnet used in the magnetically-levitated train. In recent years, the switch has been required to have higher electrical resistance during its off-state in order to realize the high speed energization/de-energization system of the superconducting magnets. The system aims to decrease evaporation volume of liquid helium during the energization/de-energization of the magnet, by means of energizing the superconducting magnet with high current increasing/decreasing rate. Consequently, it would be possible to decrease the dependence of the on-board magnet system upon the ground cooling system. Through the development of a stable superconductive wire material and a coil structure for the persistent current switch using many small model switches which were produced in order to improve their current carrying capacities, the authors have succeeded in manufacturing the high electrical resistance persistent current switch whose electrical resistance was 5 ohms. The switch, of cylindrical shape, has a diameter of about 100mm, a length of about 100mm. These 5 ohm PCSs are now functioning in stable conditions being incorporated in the superconducting magnets of No.2 vehicle of MLU001 at the JNR's Miyazaki test track. Further, the authors are now developing the PCS of still higher resistance values, such as 50 ohms, through studies for stabilization in structural aspects of the winding and obtaining results therefrom

Effect of Modified Red Pottery Clay on the Moisture Absorption Behavior and Weatherability of Polyethylene-Based Wood-Plastic Composites

Directory of Open Access Journals (Sweden)

Qingde Li

2017-01-01

Full Text Available Red pottery clay (RPC was modified using a silane coupling agent, and the modified RPC (mRPC was then used to enhance the performance of high-density polyethylene-based wood-plastic composites. The effect of the mRPC content on the performances of the composites was investigated through Fourier transform infrared spectrometry, differential mechanical analysis (DMA and ultraviolet (UV-accelerated aging tests. After adding the mRPC, a moisture adsorption hysteresis was observed. The DMA results indicated that the mRPC effectively enhanced the rigidity and elasticity of the composites. The mRPC affected the thermal gravimetric, leading to a reduction of the thermal degradation rate and a right-shift of the thermal degradation peak; the initial thermal degradation temperature was increased. After 3000 h of UV-accelerated aging, the flexural strength and impact strength both declined. For aging time between 0 and 1000 h, the increase in amplitude of ΔL* (luminescence and ΔE* (color reached a maximum; the surface fading did not became obvious. ΔL* and ΔE* increased more significantly between 1000 and 2000 h. These characterization results indicate that the chromophores of the mRPC became briefly active. However, when the aging times were higher than 2000 h, the photo-degradation reaction was effectively prevented by adding the mRPC. The best overall enhancement was observed for an mRPC mass percentage of 5%, with a storage modulus of 3264 MPa and an increase in loss modulus by 16.8%, the best anti-aging performance and the lowest degree of color fading.

Considerations in designing and using superconductors with high resistivity matrices

International Nuclear Information System (INIS)

Bartlett, R.J.; Carlson, R.V.; Laquer, H.L.; Migliori, A.

1976-01-01

Superconductors are often designed with matrices of much higher residual resistivities than copper for reasons of manufacturing (multifilamentary Nb 3 Sn in CuSn bronze) or loss reduction (mixed matrix NbTi with Cu and CuNi). The high resistivity matrix may complicate or degrade contact resistances at the joints, generate excess heat, reduce the stability of the conductor, and interfere with the observation of flux flow resistivities in the 10 -12 Ω-cm region. The minimization of these effects is discussed, presenting both simple and more refined models for the current transfer length, and it is shown how variations in transfer length (with current), particularly under significant self field conditions, can mimic flux flow resistivity

High resistivity in InP by helium bombardment

International Nuclear Information System (INIS)

Focht, M.W.; Macrander, A.T.; Schwartz, B.; Feldman, L.C.

1984-01-01

Helium implants over a fluence range from 10 11 to 10 16 ions/cm 2 , reproducibly form high resistivity regions in both p- and n-type InP. Average resistivities of greater than 10 9 Ω cm for p-type InP and of 10 3 Ω cm for n-type InP are reported. Results are presented of a Monte Carlo simulation of helium bombardment into the compound target InP that yields the mean projected range and the range straggling

High-Rate Fast-Time GRPC for the high eta CMS muon detectors

CERN Document Server

Mirabito, Laurent

2016-01-01

CMS detector. In their single-gap version we will show that they can stand rates of few ${\\rm kHz/cm}^2$. We also demonstrate that using multi-gap glass RPC, a time resolution of about 60 ps is achieved.

Abrasion Resistance of as-Cast High-Chromium Cast Iron

Directory of Open Access Journals (Sweden)

Pokusová Marcela

2014-12-01

Full Text Available High chromium cast irons are widely used as abrasion resistant materials. Their properties and wear resistance depend on carbides and on the nature of the matrix supporting these carbides. The paper presents test results of irons which contain (in wt.% 18-22 Cr and 2-5 C, and is alloyed by 1.7 Mo + 5 Ni + 2 Mn to improve the toughness. Tests showed as-cast irons with mostly austenitic matrix achieved hardness 36-53 HRC but their relative abrasion-resistance was higher than the tool steel STN 19436 heat treated on hardness 60 HRC.

Kapitza thermal resistance studied by high-frequency photothermal radiometry

International Nuclear Information System (INIS)

Horny, Nicolas; Chirtoc, Mihai; Hamaoui, Georges; Fleming, Austin; Ban, Heng

2016-01-01

Kapitza thermal resistance is determined using high-frequency photothermal radiometry (PTR) extended for modulation up to 10 MHz. Interfaces between 50 nm thick titanium coatings and silicon or stainless steel substrates are studied. In the used configuration, the PTR signal is not sensitive to the thermal conductivity of the film nor to its optical absorption coefficient, thus the Kapitza resistance is directly determined from single thermal parameter fits. Results of thermal resistances show the significant influence of the nature of the substrate, as well as of the presence of free electrons at the interface.

Radionuclidic contamination of 99Mo, 131I and 103Ru in the eluate of 99Mo-99mTc chromatographic generator: comparision on fission produced 99Mo from RPC, Nordio and ARI

International Nuclear Information System (INIS)

Soenarjo, Sunarhadijoso; Gunawan, Adang Hardi

1996-01-01

The 99 Mo- 99m Tc Chromatographic generators is the most popular system to provide 99m Tc medical radioisotope. Radioisotope Production Centre (RPC)- BATAN has routinely produced the generator loaded with 99 Mo prepared by 235 U fission. By using fission produced 99 Mo, the resulting 99m Tc is potentially contaminated by other fission products which are difficult to eliminate completely. In order to study the characteristic of the generator and radionuclidic impurity pattern of the 99m Tc eluates, an evaluation of gamma spectrometric determination has been carried out. The bulk solutions of 99 Mo produced by RPC BATAN (Indonesia), Nordion (Canada) and ARI (Australia) were loaded to generators manufactured between July 1993 to May 1994. The saline-eluate 99m Tc, in a total volume of 10 ml each, was subjected to gamma spectrometric determination. The radiation of 99m Tc was eliminated by lead shield of 0.6913 cm thickness. The 99m Tc yield fluctuation from 28 generators indicated that the characteristics of the generator columns were very good. The 99m Tc eluates were consistently contaminated by 99 Mo, 131 I and 103 Ru, although the contamination level in all cases did not exceed the maximum permissible levels. The fluctuation of radionuclidic impurities were probably caused by variation in the irradiation parameter or by variation in the 99 Mo separation methods. (author), 23 refs, 1 tab, 3 figs

Durability of ultra-high performance concretes: role of the cement matrix

International Nuclear Information System (INIS)

Matte, Veronique

1999-01-01

The Reactive Powder Concretes (RPC), composed of Portland cement, silica fume, crushed quartz, fine sand and steel fibers, exhibit a very dense microstructure which limits the penetration of aggressive agents. They appear suitable for the storage of nuclear waste. This study aimed to determine experimentally the evolution of the RPC microstructure during a leaching attack by pure water, and to supply data required for the RPC long-term prediction of durability under these severe conditions. The steel fibers and mineral inclusions (sand and quartz) were considered as inert materials in the degradation process. Thus RPC matrices, and also a pure cement paste, and a cement and silica fume paste, were studied. The materials were characterised before and after a leaching test: microstructure by means of scanning electron microscopy, porosity, chemical and mineralogical composition, and diffusivity. A superficial degradation proceeds along a straight leaching front related to the dissolution of the remaining anhydrous cement silicates (C 3 S and C 2 S). The leaching of mineral species is controlled by the ionic diffusions from the material towards the aggressive solution. The degradation kinetics is proportional to the square root of time. As long as a sound core remains, the global behaviour of the partly degraded material is determined by the properties of the sound core. Two models related to the matrix transformation were used: DIFFU-Ca which characterised the leaching of calcium, and the 3D computer simulation of Portland cement hydration and microstructure development, from BENTZ and GARBOCZI. The digital results show a good agreement with the experimental values. This validates the hydration rates predicted with BENTZ and GARBOCZI and the phenomenology implemented in DIFFU-Ca. At the end of the study, it could be said that RPC appears as a suitable candidate for nuclear waste storage. The foreseen degradation depth after a 300 years leaching is about 1.4 cm in our

Solidification structure and abrasion resistance of high chromium white irons

Science.gov (United States)

Doğan, Ö. N.; Hawk, J. A.; Laird, G.

1997-06-01

Superior abrasive wear resistance, combined with relatively low production costs, makes high Cr white cast irons (WCIs) particularly attractive for applications in the grinding, milling, and pumping apparatus used to process hard materials. Hypoeutectic, eutectic, and hypereutectic cast iron compositions, containing either 15 or 26 wt pct chromium, were studied with respect to the macrostructural transitions of the castings, solidification paths, and resulting microstructures when poured with varying superheats. Completely equiaxed macrostructures were produced in thick section castings with slightly hypereutectic compositions. High-stress abrasive wear tests were then performed on the various alloys to examine the influence of both macrostructure and microstructure on wear resistance. Results indicated that the alloys with a primarily austenitic matrix had a higher abrasion resistance than similar alloys with a pearlitic/bainitic matrix. Improvement in abrasion resistance was partially attributed to the ability of the austenite to transform to martensite at the wear surface during the abrasion process.

Probability based high temperature engineering creep and structural fire resistance

CERN Document Server

Razdolsky, Leo

2017-01-01

This volume on structural fire resistance is for aerospace, structural, and fire prevention engineers; architects, and educators. It bridges the gap between prescriptive- and performance-based methods and simplifies very complex and comprehensive computer analyses to the point that the structural fire resistance and high temperature creep deformations will have a simple, approximate analytical expression that can be used in structural analysis and design. The book emphasizes methods of the theory of engineering creep (stress-strain diagrams) and mathematical operations quite distinct from those of solid mechanics absent high-temperature creep deformations, in particular the classical theory of elasticity and structural engineering. Dr. Razdolsky’s previous books focused on methods of computing the ultimate structural design load to the different fire scenarios. The current work is devoted to the computing of the estimated ultimate resistance of the structure taking into account the effect of high temperatur...

High Velocity Oxidation and Hot Corrosion Resistance of Some ODS Alloys

Science.gov (United States)

Lowell, C. E.; Deadmore, D. L.

1977-01-01

Several oxide dispersion strengthened (ODS) alloys were tested for cyclic, high velocity, oxidation, and hot corrosion resistance. These results were compared to the resistance of an advanced, NiCrAl coated superalloy. An ODS FeCrAl were identified as having sufficient oxidation and hot corrosion resistance to allow potential use in an aircraft gas turbine without coating.

Characteristics of spring wheat genotypes exhibiting high resistance to FHB in terms of their resistance to other fungal diseases

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Danuta Kurasiak-Popowska

2016-09-01

Full Text Available The field experiment was carried out in 2010–2012 at the Dłoń Agricultural Research Station, the Poznań University of Life Sciences, Poland. The study was designed to evaluate the degree of infection by powdery mildew, brown rust, and septoria leaf blotch in 61 spring wheat genotypes differing in their resistance to Fusarium ssp. The vast majority of spring wheat genotypes in the collection of gene resources in the USA defined as resistant to Fusarium ssp. confirmed their resistance under Polish climatic conditions. The B .graminis infection rate of genotypes that are considered to be resistant to Fusarium head blight was high. The resistance ranged from 7 for Sumai 3 (PL2 up to 8.8 for Ning 8331 (in a 9-point scale. Most of the genotypes (56.5% were infected by Puccinia recondita at a level of 1–3 (in a 9-point scale. The genotypes of Sumai 3 exhibited high resistance to septoria leaf blotch, amounting to 1–2 in a 9-point scale; the resistance of Frontana ranged from 1 to 3.5, while the genotypes of Ning were infected by Mycosphaerella graminicola at 5–6.

Mechanisms of Evolution in High-Consequence Drug Resistance Plasmids

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Susu He

2016-12-01

Full Text Available The dissemination of resistance among bacteria has been facilitated by the fact that resistance genes are usually located on a diverse and evolving set of transmissible plasmids. However, the mechanisms generating diversity and enabling adaptation within highly successful resistance plasmids have remained obscure, despite their profound clinical significance. To understand these mechanisms, we have performed a detailed analysis of the mobilome (the entire mobile genetic element content of a set of previously sequenced carbapenemase-producing Enterobacteriaceae (CPE from the National Institutes of Health Clinical Center. This analysis revealed that plasmid reorganizations occurring in the natural context of colonization of human hosts were overwhelmingly driven by genetic rearrangements carried out by replicative transposons working in concert with the process of homologous recombination. A more complete understanding of the molecular mechanisms and evolutionary forces driving rearrangements in resistance plasmids may lead to fundamentally new strategies to address the problem of antibiotic resistance.

The CMS Barrel Muon Trigger Upgrade

CERN Document Server

Triossi, Andrea

2017-01-01

ABSTRACT: The increase of luminosity expected by LHC during Phase 1 will impose several constrains for rate reduction while maintaining high efficiency in the CMS Level 1 trigger system. The TwinMux system is the early layer of the muon barrel region that concentrates the information from different subdetectors DT, RPC and HO. It arranges and fan-out the slow optical trigger links from the detector chambers into faster links (10 Gbps) that are sent to the track finders. Results, from collision runs, that confirm the satisfactory operation of the trigger system up to the output of the barrel track finder, will be shown. SUMMARY: In view of the increase of luminosity during phase 1 upgrade of LHC, the muon trigger chain of the Compact Muon Solenoid (CMS) experiment underwent considerable improvements. The muon detector was designed for preserving the complementarity and redundancy of three separate muon detection systems, Cathode Strip Chambers (CSC), Drift Tubes (DT) and Resistive Plate Chambers (RPC), until ...

One-step patterning of double tone high contrast and high refractive index inorganic spin-on resist

Energy Technology Data Exchange (ETDEWEB)

Zanchetta, E.; Della Giustina, G.; Brusatin, G. [Industrial Engineering Department and INSTM, Via Marzolo 9, 35131 Padova (Italy)

2014-09-14

A direct one-step and low temperature micro-fabrication process, enabling to realize large area totally inorganic TiO₂ micro-patterns from a spin-on resist, is presented. High refractive index structures (up to 2 at 632 nm) without the need for transfer processes have been obtained by mask assisted UV lithography, exploiting photocatalytic titania properties. A distinctive feature not shared by any of the known available resists and boosting the material versatility, is that the system behaves either as a positive or as negative tone resist, depending on the process parameters and on the development chemistry. In order to explain the resist double tone behavior, deep comprehension of the lithographic process parameters optimization and of the resist chemistry and structure evolution during the lithographic process, generally uncommon in literature, is reported. Another striking property of the presented resist is that the negative tone shows a high contrast up to 19, allowing to obtain structures resolution down to 2 μm wide. The presented process and material permit to directly fabricate different titania geometries of great importance for solar cells, photo-catalysis, and photonic crystals applications.

Diagnostic Evasion of Highly-Resistant Microorganisms: A Critical Factor in Nosocomial Outbreaks.

Science.gov (United States)

Zhou, Xuewei; Friedrich, Alexander W; Bathoorn, Erik

2017-01-01

Highly resistant microorganisms (HRMOs) may evade screening strategies used in routine diagnostics. Bacteria that have evolved to evade diagnostic tests may have a selective advantage in the nosocomial environment. Evasion of resistance detection can result from the following mechanisms: low-level expression of resistance genes not resulting in detectable resistance, slow growing variants, mimicry of wild-type-resistance, and resistance mechanisms that are only detected if induced by antibiotic pressure. We reviewed reports on hospital outbreaks in the Netherlands over the past 5 years. Remarkably, many outbreaks including major nation-wide outbreaks were caused by microorganisms able to evade resistance detection by diagnostic screening tests. We describe various examples of diagnostic evasion by several HRMOs and discuss this in a broad and international perspective. The epidemiology of hospital-associated bacteria may strongly be affected by diagnostic screening strategies. This may result in an increasing reservoir of resistance genes in hospital populations that is unnoticed. The resistance elements may horizontally transfer to hosts with systems for high-level expression, resulting in a clinically significant resistance problem. We advise to communicate the identification of HRMOs that evade diagnostics within national and regional networks. Such signaling networks may prevent inter-hospital outbreaks, and allow collaborative development of adapted diagnostic tests.

High temperature resistive phase transition in A15 high temperature superconductors

International Nuclear Information System (INIS)

Chu, C.W.; Huang, C.Y.; Schmidt, P.H.; Sugawara, K.

1976-01-01

Resistive measurements were made on A15 high temperature superconductors. Anomalies indicative of a phase transition were observed at 433 0 K in a single crystal Nb 3 Sn and at 485 0 K in an unbacked Nb 3 Ge sputtered thin film. Results are compared with the high temperature transmission electron diffraction studies of Nb 3 Ge films by Schmidt et al. A possible instability in the electron energy spectrum is discussed

High resolution resistivity measurements at the Down Ampney research site

International Nuclear Information System (INIS)

Hallam, J.R.; Jackson, P.D.; Rainsbury, M.; Raines, M.

1991-01-01

A new high resolution resistivity surveying method is described for fault detection and characterisation. The resolution is shown to be significantly higher than conventional apparent resistivity profiling when applied to geological discontinuities such as faults. Nominal fault locations have been determined to an accuracy of 0.5 m, as proven by drilling. Two dimensional profiling and image enhancement of the resulting 2-D data set indicated the possibility of subsidiary fractures and/or lateral changes within the clay to clay' fault zone. The increased resolution allows greater confidence to be placed on both the fault detection and lateral perturbations derived from processed resistance and resistivity images. (Author)

Parallel Evolution of High-Level Aminoglycoside Resistance in Escherichia coli Under Low and High Mutation Supply Rates

Directory of Open Access Journals (Sweden)

Claudia Ibacache-Quiroga

2018-03-01

Full Text Available Antibiotic resistance is a major concern in public health worldwide, thus there is much interest in characterizing the mutational pathways through which susceptible bacteria evolve resistance. Here we use experimental evolution to explore the mutational pathways toward aminoglycoside resistance, using gentamicin as a model, under low and high mutation supply rates. Our results show that both normo and hypermutable strains of Escherichia coli are able to develop resistance to drug dosages > 1,000-fold higher than the minimal inhibitory concentration for their ancestors. Interestingly, such level of resistance was often associated with changes in susceptibility to other antibiotics, most prominently with increased resistance to fosfomycin. Whole-genome sequencing revealed that all resistant derivatives presented diverse mutations in five common genetic elements: fhuA, fusA and the atpIBEFHAGDC, cyoABCDE, and potABCD operons. Despite the large number of mutations acquired, hypermutable strains did not pay, apparently, fitness cost. In contrast to recent studies, we found that the mutation supply rate mainly affected the speed (tempo but not the pattern (mode of evolution: both backgrounds acquired the mutations in the same order, although the hypermutator strain did it faster. This observation is compatible with the adaptive landscape for high-level gentamicin resistance being relatively smooth, with few local maxima; which might be a common feature among antibiotics for which resistance involves multiple loci.

Upgrade of the Level-1 muon trigger of the ATLAS detector in the barrel-endcap transition region with RPC chambers

CERN Document Server

Massa, L; The ATLAS collaboration

2014-01-01

This report presents a project for the upgrade of the Level-1 muon trigger in the barrel-endcap transition region (1.01) caused by charged particles originating from secondary interactions downstream of the interaction point. After the LHC phase-1 upgrade, forseen for 2018, the Level-1 muon trigger rate would saturate the allocated bandwidth unless new measures are adopted to improve the rejection of fake triggers. ATLAS is going to improve the trigger selectivity in the region |$\\eta$|>1.3 with the addition of the New Small Wheel detector as an inner trigger plane. To obtain a similar trigger selectivity in the barrel-endcap transition region 1.0<|$\\eta$|<1.3, it is proposed to add new RPC chambers at the edge of the inner layer of the barrel muon spectrometer. These chambers will be based on a three layer structure with thinner gas gaps and electrodes with respect to the ATLAS standard and a new low-profile light-weight mechanical structure that will allow the installation in the limited available spa...

Low- and High-Resistance Exercise: Long-Term Adherence and Motivation among Older Adults.

Science.gov (United States)

Van Roie, Evelien; Bautmans, Ivan; Coudyzer, Walter; Boen, Filip; Delecluse, Christophe

2015-01-01

In terms of motivation and long-term adherence, low-resistance exercise might be more suitable for older adults than high-resistance exercise. However, more data are needed to support this claim. The objective was to investigate the effect of low- and high-resistance exercise protocols on long-term adherence and motivation. This study was designed as an exploratory 24-week follow-up of a randomized 12-week resistance training intervention in older adults. Participants were free to decide whether or not they continued resistance training at their own expense following the intervention. Fifty-six older adults were randomly assigned to HIGH [2 × 10-15 repetitions at 80% of one repetition maximum (1RM)], LOW (1 × 80-100 repetitions at 20% of 1RM), or LOW+ (1 × 60 repetitions at 20% of 1RM + 1 × 10-20 repetitions at 40% 1RM). Motivation, self-efficacy and the perceived barriers for continuing resistance exercise were measured after cessation of each supervised intervention and at follow-up, while long-term adherence was probed retrospectively at follow-up. Participants reported high levels of self-determined motivation before, during, and after the supervised intervention, with no differences between groups (p > 0.05). Nevertheless, only few participants continued strength training after the intervention: 17% in HIGH, 21% in LOW+, and 11% in LOW (p > 0.05). The most commonly reported barriers for continuing resistance exercise were perceived lack of time (46%), being more interested in other physical activities (40%), seasonal reasons (40%), and financial cost (28%). The results suggest no difference in long-term adherence after the end of a supervised exercise intervention at high or low external resistances. Long-term adherence was limited despite high levels of self-determined motivation during the interventions. These findings highlight the importance of further research on developing strategies to overcome barriers of older adults to adhere to resistance

Performances of the ATLAS Level-1 Muon barrel trigger during the Run-II data taking

CERN Document Server

Sessa, Marco; The ATLAS collaboration

2017-01-01

The Level-1 Muon Barrel Trigger is one of the main elements of the event selection of the ATLAS experiment at the Large Hadron Collider. It exploits the Resistive Plate Chambers (RPC) detectors to generate the trigger signal. The RPCs are placed in the barrel region of the ATLAS experiment: they are arranged in three concentric double layers and operate in a strong magnetic toroidal field. RPC detectors cover the pseudo-rapidity range $|\\eta|<1.05$ for a total surface of more than $4000\\ m^2$ and about 3600 gas volumes. The Level-1 Muon Trigger in the barrel region allows to select muon candidates with respect to their transverse momentum and associates them with the correct bunch-crossing number. The trigger system is able to take a decision within a latency of about 2 $\\mu s$. The detailed measurement of the RPC detector efficiencies and of the trigger performance during the ATLAS Run-II data taking is here presented.

Performance of the ATLAS Level-1 muon barrel trigger during the Run 2 data taking

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00404546; The ATLAS collaboration

2018-01-01

The Level-1 Muon Barrel Trigger is one of the main elements of the event selection of the ATLAS experiment at the Large Hadron Collider. It exploits the Resistive Plate Chambers (RPC) detectors to generate the trigger signal. The RPCs are placed in the barrel region of the ATLAS experiment: they are arranged in three concentric double layers and operate in a strong magnetic toroidal field. RPC detectors cover the pseudo-rapidity range |η| < 1.05 for a total surface of more than 4000 m 2 and about 3600 gas volumes. The Level-1 Muon Trigger in the barrel region allows to select muon candidates according to their transverse momentum and associates them with the correct bunch-crossing. The trigger system is able to take a decision within a latency of about 2 μs. The measurement of the RPC detector efficiencies and the trigger performance during the ATLAS Run-II data taking are here presented.

Evaluation of prevalence of low and high level mupirocin resistance in methicillin resistant staphylococcus aureus isolates at a tertiary care hospital

International Nuclear Information System (INIS)

Nizamuddin, S.; Irfan, S.; Zafar, A.

2011-01-01

To evaluate the trend of mupirocin resistance in MRSA, isolated at the Clinical Microbiology Laboratory of a tertiary care hospital. Methods: A total of 200 MRSA strains recovered over a 2 year period from various body sites were tested using the 5 and 200 mu g discs of mupirocin to detect its resistance. Results: High level and low level mupirocin resistance were detected in zero and 1 % of MRSA strains, respectively. Resistance to other non beta lactam antibiotics was also high. No MRSA strains were found to be resistant to vancomycin and tegicycline. Conclusion: Mupirocin resistance was found to be very low among local clinical isolates of MRSA. Its judicious use to decolonize nasal carriers should be promoted among hospitalized patients to avoid further transmission and infections due to prevalent endemic MRSA strains in any health care setting. Concomitantly, regular surveillance and effective infection control initiatives are desirable to reduce the incidence of health care associated infections due to MRSA and also of mupirocin resistance. (author)

Tokamaks with high-performance resistive magnets: advanced test reactors and prospects for commercial applications

International Nuclear Information System (INIS)

Bromberg, L.; Cohn, D.R.; Williams, J.E.C.; Becker, H.; Leclaire, R.; Yang, T.

1981-10-01

Scoping studies have been made of tokamak reactors with high performance resistive magnets which maximize advantages gained from high field operation and reduced shielding requirements, and minimize resistive power requirements. High field operation can provide very high values of fusion power density and n tau/sub e/ while the resistive power losses can be kept relatively small. Relatively high values of Q' = Fusion Power/Magnet Resistive Power can be obtained. The use of high field also facilitates operation in the DD-DT advanced fuel mode. The general engineering and operational features of machines with high performance magnets are discussed. Illustrative parameters are given for advanced test reactors and for possible commercial reactors. Commercial applications that are discussed are the production of fissile fuel, electricity generation with and without fissioning blankets and synthetic fuel production

High levels of macrolide-resistant Mycoplasma genitalium in Queensland, Australia.

Science.gov (United States)

Trembizki, Ella; Buckley, Cameron; Bletchly, Cheryl; Nimmo, Graeme R; Whiley, David M

2017-10-01

The macrolide azithromycin is recommended for treatment of Mycoplasma genitalium infection; however, M. genitalium strains possessing macrolide resistance-mediating mutations (MRMMs) are increasingly being reported. Here, we used the SpeeDx ResistancePlus MG kit, which provides simultaneous detection of M. genitalium and MRMMs, to assess MRMM carriage among M. genitalium infections in Queensland, Australia. Performance characteristics of the ResistancePlus MG kit for M. genitalium detection were compared to in-house PCR. Available M. genitalium PCR-positive (n=67) and negative (n=281) samples from the years 2011 to 2017 were tested using the SpeeDx ResistancePlus MG kit. In total, 63.6 % M. genitalium-positive samples were indicated to harbour MRMMs. The ResistancePlus MG method provided sensitivity and specificity of 97 and 99.6 % respectively compared to in-house PCR for M. genitalium detection. Such high levels of macrolide-resistant M. genitalium raise further concerns over future use of azithromycin for treatment of M. genitalium infection.

Directly patternable high refractive index ferroelectric sol–gel resist

Energy Technology Data Exchange (ETDEWEB)

Garoli, D., E-mail: denis.garoli@iit.it [Istituto Italiano di Tecnologia, Via Morego 16, 16136 Genova (Italy); Della Giustina, G. [Industrial Engineering Department, University of Padova and INSTM, Via Marzolo 9, 35131 Padova (Italy)

2015-08-15

The development of a ferroelectric negative tone sol–gel resist for Ultraviolet (UV) and Electron Beam (EB) lithography is presented. A new system based on Lead Zirconate Titanate (PZT, with formula PbZr{sub 0.52}Ti{sub 0.48}O{sub 3}) was synthesized by sol–gel method. The lithographic performances were investigated and several structures spanning from the micron range down to less than 50 nm have been achieved by UV and EB lithography. The system interaction with UV light and Electron beam was thoroughly characterized by FT-IT spectroscopy. The exposed PZT was annealed at high temperatures in order to study the crystalline phase evolution, the optical constants values and stability of patterned structures. After exposure and annealing, the refractive index of the material can vary from 1.68 up to 2.33 (@400 nm), while the ferroelectric behaviour seems to be maintained after high temperature annealing. These results suggest a possible application of PZT resist not only as ferroelectric but also as nanopatternable high refractive index material. Moreover, direct nanopatterning by means of Focused Ion Beam (FIB) lithography was verified and the potentiality for the preparation of high aspect ratio hollow nanostructures will be presented. - Highlights: • A new formula directly patternable PZT high refractive index resist is presented. • The gel is sensitive to both UV and electron beam exposure. • The refractive index can vary from 1.68 up to 2.33 (@400 nm). • Direct nanopatterning by means of Focused Ion Beam (FIB) lithography was verified. • High aspect ratio hollow nanostructures will be presented.

Effects of spinach nitrate on insulin resistance, endothelial dysfunction markers and inflammation in mice with high-fat and high-fructose consumption

Directory of Open Access Journals (Sweden)

Ting Li

2016-09-01

Full Text Available Background: Insulin resistance, which is associated with an increased risk of cardiovascular morbidity and mortality, has become a leading nutrition problem. Inorganic nitrate enriched in spinach has been demonstrated to reverse the pathological features of insulin resistance and endothelial dysfunction. However, the effects of a direct intake of nitrate-enriched spinach on insulin resistance and endothelial dysfunction have not been studied. Objective: To investigate the effects of spinach nitrate on insulin resistance, lipid metabolism, endothelial function, and inflammation in mice fed with a high-fat and high-fructose diet. Design: A diet intervention of spinach with or without nitrate was performed in mice. A high-fat and high-fructose diet was used to cause insulin resistance, endothelial dysfunction, and inflammation in mice. The impacts of spinach nitrate on lipid profile, insulin resistance, markers of endothelial function, and inflammation were determined in mice. Results: Spinach nitrate improved the vascular endothelial function of the mice with high-fat and high-fructose consumption, as evidenced by the elevated plasma nitrite level, increased serum nitric oxide (NO level and decreased serum ET-1 level after spinach nitrate intervention. Spinach nitrate also reduced serum triglycerides, total cholesterol, and low-density lipoprotein-cholesterol levels and elevated serum high-density lipoprotein-cholesterol levels in the mice fed with a high-fat and high-fructose diet. Mice receiving spinach with 60 mg/kg of nitrate (1.02±0.34 showed a significantly low homeostasis model assessment-insulin resistance index as compared with the model mice (2.05±0.58, which is indicating that spinach nitrate could effectively improve the insulin resistance. In addition, spinach nitrate remarkably decreased the elevated serum C-reactive protein, tumor necrosis factor α, and interleukin-6 levels induced by a high-fat and high-fructose diet

Consumption of a liquid high-fat meal increases triglycerides but decreases high-density lipoprotein cholesterol in abdominally obese subjects with high postprandial insulin resistance.

Science.gov (United States)

Wang, Feng; Lu, Huixia; Liu, Fukang; Cai, Huizhen; Xia, Hui; Guo, Fei; Xie, Yulan; Huang, Guiling; Miao, Miao; Shu, Guofang; Sun, Guiju

2017-07-01

Abdominal obesity is associated with an increased risk of insulin resistance, which may be a potential contributor to dyslipidemia. However, the relationship between postprandial insulin resistance and lipid metabolism in abdominally obese subjects remains unknown. We hypothesized that postprandial dyslipidemia would be exaggerated in abdominally obese subjects with high postprandial insulin resistance. To test this hypothesis, serum glucose, insulin, triglycerides, total cholesterol, high-density lipoprotein cholesterol, and apolipoprotein B were measured at baseline and postprandial state at 0.5, 1, 2, 4, 6, and 8 hours after a liquid high-fat meal in non-abdominally obese controls (n=44) and abdominally obese subjects with low (AO-LPIR, n=40), middle (n=40), and high postprandial insulin resistance (AO-HPIR, n=40) based on the tertiles ratio of the insulin to glucose areas under the curve (AUC). Their serum adipokines were tested at baseline only. Fasting serum leptin was higher (Pinsulin resistance and controls. The present study indicated that the higher degree of postprandial insulin resistance, the more adverse lipid profiles in abdominally obese subjects, which provides insight into opportunity for screening in health. Copyright © 2017 Elsevier Inc. All rights reserved.

Solving the Rational Polynomial Coefficients Based on L Curve

Science.gov (United States)

Zhou, G.; Li, X.; Yue, T.; Huang, W.; He, C.; Huang, Y.

2018-05-01

The rational polynomial coefficients (RPC) model is a generalized sensor model, which can achieve high approximation accuracy. And it is widely used in the field of photogrammetry and remote sensing. Least square method is usually used to determine the optimal parameter solution of the rational function model. However the distribution of control points is not uniform or the model is over-parameterized, which leads to the singularity of the coefficient matrix of the normal equation. So the normal equation becomes ill conditioned equation. The obtained solutions are extremely unstable and even wrong. The Tikhonov regularization can effectively improve and solve the ill conditioned equation. In this paper, we calculate pathological equations by regularization method, and determine the regularization parameters by L curve. The results of the experiments on aerial format photos show that the accuracy of the first-order RPC with the equal denominators has the highest accuracy. The high order RPC model is not necessary in the processing of dealing with frame images, as the RPC model and the projective model are almost the same. The result shows that the first-order RPC model is basically consistent with the strict sensor model of photogrammetry. Orthorectification results both the firstorder RPC model and Camera Model (ERDAS9.2 platform) are similar to each other, and the maximum residuals of X and Y are 0.8174 feet and 0.9272 feet respectively. This result shows that RPC model can be used in the aerial photographic compensation replacement sensor model.

Effect of some structural parameters on high-temperature crack resistance of tungsten

International Nuclear Information System (INIS)

Babak, A.V.; Uskov, E.I.

1984-01-01

The paper presents results of physicomechanical studied in high-temperature crack resistance of tungsten produced by powder metallurgy methods. It is shown that at high temperatures (>2000 deg C) a structure is formed in the material and fails at stresses independent of temperature. It is found that high-temperature tungsten crack resistance is affected neighter by changes in the effictive grain size, nor by appearance of grain-boundary microcraks in the material under high-temperature action

Improving UV Resistance of High Performance Fibers

Science.gov (United States)

Hassanin, Ahmed

High performance fibers are characterized by their superior properties compared to the traditional textile fibers. High strength fibers have high modules, high strength to weight ratio, high chemical resistance, and usually high temperature resistance. It is used in application where superior properties are needed such as bulletproof vests, ropes and cables, cut resistant products, load tendons for giant scientific balloons, fishing rods, tennis racket strings, parachute cords, adhesives and sealants, protective apparel and tire cords. Unfortunately, Ultraviolet (UV) radiation causes serious degradation to the most of high performance fibers. UV lights, either natural or artificial, cause organic compounds to decompose and degrade, because the energy of the photons of UV light is high enough to break chemical bonds causing chain scission. This work is aiming at achieving maximum protection of high performance fibers using sheathing approaches. The sheaths proposed are of lightweight to maintain the advantage of the high performance fiber that is the high strength to weight ratio. This study involves developing three different types of sheathing. The product of interest that need be protected from UV is braid from PBO. First approach is extruding a sheath from Low Density Polyethylene (LDPE) loaded with different rutile TiO2 % nanoparticles around the braid from the PBO. The results of this approach showed that LDPE sheath loaded with 10% TiO2 by weight achieved the highest protection compare to 0% and 5% TiO2. The protection here is judged by strength loss of PBO. This trend noticed in different weathering environments, where the sheathed samples were exposed to UV-VIS radiations in different weatheromter equipments as well as exposure to high altitude environment using NASA BRDL balloon. The second approach is focusing in developing a protective porous membrane from polyurethane loaded with rutile TiO2 nanoparticles. Membrane from polyurethane loaded with 4

Study on the high temperature crack resistance of tungsten

International Nuclear Information System (INIS)

Uskov, E.I.; Babak, A.V.

1983-01-01

The possibility of a multiple use of tungsten specimens in crack resistance tests in the temperature range of 600-2000 deg C is studied. It is established experimentally that the minimum length of growth of a main crack is 1x10 -4 m for the most effective repeated use of specimens. A flow diagram of mechanical tests is suggested for investigating high temperature tungsten crack resistance and estimating the degree of weakening the grain-boundary bond

Method for making low-resistivity contacts to high T/sub c/ superconductors

International Nuclear Information System (INIS)

Ekin, J.W.; Panson, A.J.; Blankenship, B.A.

1988-01-01

A method for making low-resistivity contacts to high T/sub c/ superconductors has been developed, which has achieved contact surface resistivities less than 10 μΩ cm 2 at 76 K and does not require sample heating above ∼150 0 C. This is an upper limit for the contact resistivity obtained at high current densities up to 10 2 --10 3 A/cm 2 across the contact interface. At lower measuring current densities the contact resistivities were lower and the voltage-current curve was nonlinear, having a superconducting transition character. On cooling from 295 to 76 K, the contact resistivity decreased several times, in contrast to indium solder contacts where the resistivity increased on cooling. The contacts showed consistently low resistivity and little degradation when exposed to dry air over a four-month period and when repeatedly cycled between room temperature and 76 K. The contacts are formed by sputter depositing a layer of a noble metal-silver and gold were used-on a clean superconductor surface to protect the surface and serve as a contact pad. External connections to the contact pads have been made using both solder and wire-bonding techniques

Incidence of high-level evernimicin resistance in Enterococcus faecium among food animals and humans

DEFF Research Database (Denmark)

Aarestrup, Frank Møller; McNicholas, P. M.

2002-01-01

Six high-level evernimicin-resistant Enterococcus faecium isolates were identified among 304 avilarnycin-resistant E. faecium isolates from animals and 404 stool samples from humans with diarrhea. All four animal isolates, and one of the human isolates, were able to transfer resistance...... to a susceptible E. faecium strain. The resulting transconjugants all tested positive for the presence of emtA, a gene encoding a methyltransferase previously linked with high-level evernimicin resistance. The four transconjugants derived from animal isolates all carried the same plasmid, while a differently sized...... plasmid was found in the isolate from humans. This study demonstrated a low incidence of high-level evernimicin resistance mediated by the emtA gene in different E. faecium isolates of animal and human origin....

Resistive internal kink modes in a tokamak with high-pressure plasma

International Nuclear Information System (INIS)

Kuvshinov, B.N.; Mikhajlovskij, A.B.; Tatarinov, E.G.

1988-01-01

Theory of resistive internal kink modes in a tokamak with high-pressure plasma is developed. Equation for Fourie-image of disturbed displacment in a resistive layer ie derived with regard to effects of the fourth order by plasma pressure within the framework of single-liquid approach. In its structure this equation coincides with a similar equation for resistive balloon modes and has an exact solution expressed by degenerated hypergeometric function. A general dispersion equation for resistive kink modes is derived with regard to the effects indicated. It is shown that plasma pressure finiteness leads to the reduction of reconnection and tyring-mode increments

Rugged Low-Resistance Contacts To High-Tc Superconductors

Science.gov (United States)

Caton, Randall; Selim, Raouf; Byvik, Charles E.; Buoncristiani, A. Martin

1992-01-01

Newly developed technique involving use of gold makes possible to fabricate low-resistance contacts with rugged connections to high-Tc superconductors. Gold diffused into specimen of superconducting material by melting gold beads onto surface of specimen, making strong mechanical contacts. Shear strength of gold bead contacts greater than epoxy or silver paste. Practical use in high-current-carrying applications of new high-Tc materials, including superconducting magnets, long-wavelength sensors, electrical ground planes at low temperatures, and efficient transmission of power.

Analysis and Comparison of Modular Railway Power Conditioner for High-Speed Railway Traction System

DEFF Research Database (Denmark)

Xu, Qianming; Ma, Fujun; He, Zhixing

2017-01-01

, IPOSIM calculation as well as PSIM simulation. These calculations are validated via simulations results in PSIM. The main conclusion is that presented modular RPCs can be divided into general purpose RPC and special purpose RPC in terms of the behavior and efficiency. It is helpful to choose......, voltage stress and current stress of power switch, numbers of the power switches and capacitor are derived by analytical methods. Moreover, the numerical comparison of operating controllers is completed for modular RPCs. In addition, power losses of five modular RPCs are obtained by theoretical analysis...

No seasonal accumulation of resistant P. falciparum when high-dose chloroquine is used

DEFF Research Database (Denmark)

Ursing, Johan; Kofoed, Poul-Erik; Rodrigues, Amabelia

2009-01-01

increase of pfcrt 76T if the high doses of CQ commonly used are effective. METHODS AND FINDINGS: P. falciparum parasite density, age, sex, the proportion of chloroquine resistance associated haplotypes pfcrt 76T and P. falciparum multidrug resistance gene 1 86Y were assessed in 988 samples collected from...... to become the dominant P.falciparum type in Guinea-Bissau. This is most likely due to the efficacy of high-dose chloroquine as used in Guinea-Bissau, combined with a loss of fitness associated with pfcrt 76T.......BACKGROUND: Potentially chloroquine resistant P. falciparum, identified by the 76T haplotype in the chloroquine resistance transporter (pfcrt 76T), are highly prevalent throughout Africa. In Guinea-Bissau, normal and double dose chloroquine have respective efficacies of 34% and 78% against P...

Analysis and interpretation of the performance degradation of glass Resistive Plate Chambers operated in streamer mode

CERN Document Server

Calcaterra, A; Patteri, P; Piccolo, M; Della Mea, G; Restello, S; Ferri, F; Musella, P; Redaelli, N; Tabarelli de Fatis, T; Tinti, G; Mannocchi, G; Trinchero, G

2007-01-01

The long-term stability of Resistive Plate Chambers (RPCs) with glass electrodes was studied for one year with a dedicated test station hosting about 10 m2 of detectors. RPCs were operated in streamer mode with a ternary gas mixture containing argon (27%), isobutane (9%) and tetrafluoroethane (64%). Environmental conditions were kept under control and, in particular, the water pollution in the gas, deemed responsible for the degradation of glass RPC performance, was monitored never to exceed 30 ppm in the exhaust line. Evidence for a substantial aging of the detectors was observed, resulting in a loss of efficiency correlated to an increased rate of spurious streamers. This can be ascribed to the chemical attack of the glass surface by hydrofluoric acid formed in the streamer process, as confirmed by detailed morphological and chemical analyses of the electrode surface. Our results strengthen the indication that the instability of glass RPCs in the long term is related to the use of fluorocarbons as quenching...

High Rate of Resistance to Quinupristin-Dalfopristin in Enterococcus faecium Clinical Isolates from Korea

Science.gov (United States)

Oh, Won Sup; Ko, Kwan Soo; Song, Jae-Hoon; Lee, Mi Young; Park, Sulhee; Peck, Kyong Ran; Lee, Nam Yong; Kim, Choon-Kwan; Lee, Hyuck; Kim, Shin-Woo; Chang, Hyun-Ha; Kim, Yeon-Sook; Jung, Sook-In; Son, Jun Seong; Yeom, Joon-Sup; Ki, Hyun Kyun; Woo, Gun-Jo

2005-01-01

We tested the in vitro susceptibilities of 603 enterococcal isolates from eight tertiary-care hospitals in Korea. The quinupristin-dalfopristin resistance rate in Enterococcus faecium was very high (25 isolates, 10.0%). It was suggested that both clonal spread and the sporadic emergence of quinupristin-dalfopristin-resistant isolates may explain the high prevalence of quinupristin-dalfopristin resistance in Korea. PMID:16304198

Virtual Parts Engineering Research Center

Science.gov (United States)

2010-05-20

engineering 10 materials. High strength alloys , composites (polymer composites and metallic composites), and the like cannot merely be replaced by...ceramics, smart materials, shape memory alloys , super plastic materials and nano- structured materials may be more appropriate substitutes in a reverse...molding process using thermosetting Bakelite. For remanufacturing the part in small quantities, machining has been identified as the most economical

Title: High-level cefotaxime-resistant Proteus mirabilis strain isolated ...

African Journals Online (AJOL)

oaca

High-level cefotaxime-resistant Proteus mirabilis strain isolated from a Tunisian .... UV- visible) at 37°C. Specific activity is calculated on depending of. Ross and ..... Performance standards for antimicrobial susceptibility testing;. Seventeenth ...

Resistance against Schistosoma mansoni induced by highly irradiated infections: studies on species specificity of immunization and attempts to transfer resistance

International Nuclear Information System (INIS)

Bickle, Q.D.; Andrews, B.J.; Doenhoff, M.J.; Ford, M.J.; Taylor, M.G.

1985-01-01

Significant levels of resistance against Schistosoma mansoni challenge were developed by mice exposed to highly irradiated (20 krad.) cercariae of the homologous species (53-67%), whereas vaccination with S. bovis, S. haematobium or S. japonicum failed to confer significant levels of resistance (-5-12%), thus confirming the specificity of the immunizing procedure. Attempts to transfer resistance to naive recipients by injection of serum and of spleen or lymph node cells from donor mice vaccinated with highly irradiated cercariae were largely unsuccessful. However, significant levels of resistance could be transferred to mice by injection of serum from rabbits exposed to irradiated cercariae. Comparable levels of resistance were conferred by injection of serum at the time of challenge (34-69%) or 5-6 days later (31-56%). In contrast, sera from rabbits injected with soluble egg antigen or homogenized cercariae failed to confer protection upon recipient mice. Sera from vaccinated mice, vaccinated rabbits and antigen-injected rabbits all caused cell adherence to skin-transformed schistosomula but neither the level of adherence nor the serum titre correlated with the ability to confer protection to mice. (author)

The use of high-throughput sequencing to investigate an outbreak of glycopeptide-resistant Enterococcus faecium with a novel quinupristin-dalfopristin resistance mechanism.

Science.gov (United States)

Shaw, Timothy D; Fairley, D J; Schneiders, T; Pathiraja, M; Hill, R L R; Werner, G; Elborn, J S; McMullan, R

2018-02-24

High-throughput sequencing (HTS) has successfully identified novel resistance genes in enterococci and determined clonal relatedness in outbreak analysis. We report the use of HTS to investigate two concurrent outbreaks of glycopeptide-resistant Enterococcus faecium (GRE) with an uncharacterised resistance mechanism to quinupristin-dalfopristin (QD). Seven QD-resistant and five QD-susceptible GRE isolates from a two-centre outbreak were studied. HTS was performed to identify genes or predicted proteins that were associated with the QD-resistant phenotype. MLST and SNP typing on HTS data was used to determine clonal relatedness. Comparative genomic analysis confirmed this GRE outbreak involved two distinct clones (ST80 and ST192). HTS confirmed the absence of known QD resistance genes, suggesting a novel mechanism was conferring resistance. Genomic analysis identified two significant genetic determinants with explanatory power for the high level of QD resistance in the ST80 QD-resistant clone: an additional 56aa leader sequence at the N-terminus of the lsaE gene and a transposon containing seven genes encoding proteins with possible drug or drug-target modification activities. However, HTS was unable to conclusively determine the QD resistance mechanism and did not reveal any genetic basis for QD resistance in the ST192 clone. This study highlights the usefulness of HTS in deciphering the degree of relatedness in two concurrent GRE outbreaks. Although HTS was able to reveal some genetic candidates for uncharacterised QD resistance, this study demonstrates the limitations of HTS as a tool for identifying putative determinants of resistance to QD.

High dietary zinc feeding promotes persistence of multi-resistant E. coli in the swine gut.

Science.gov (United States)

Ciesinski, Lisa; Guenther, Sebastian; Pieper, Robert; Kalisch, Martin; Bednorz, Carmen; Wieler, Lothar H

2018-01-01

High levels of zinc oxide are used frequently as feed additive in pigs to improve gut health and growth performance and are still suggested as an alternative to antimicrobial growth promoters. However, we have recently described an increase of multi-resistant E. coli in association to zinc feeding in piglets. This previous study focused on clonal diversity of E. coli, observing the effect on multi-resistant strains by chance. To shed further light into this highly important topic and falsify our previous findings, we performed a zinc pig feeding trial where we specifically focused on in-depth analysis of antimicrobial resistant E. coli. Under controlled experimental conditions, piglets were randomly allocated to a high dietary zinc (zinc group) and a background zinc feeding group (control group). At different ages samples were taken from feces, digesta, and mucosa and absolute E. coli numbers were determined. A total of 2665 E. coli isolates were than phenotypically tested for antimicrobial resistance and results were confirmed by minimum inhibitory concentration testing for random samples. In piglets fed with high dietary zinc, we detected a substantial increase of multi-resistant E. coli in all gut habitats tested, ranging from 28.9-30.2% multi-resistant E. coli compared to 5.8-14.0% in the control group. This increase was independent of the total number of E. coli. Interestingly, the total amount of the E. coli population decreased over time. Thus, the increase of the multi-resistant E. coli populations seems to be linked with persistence of the resistant population, caused by the influence of high dietary zinc feeding. In conclusion, these findings corroborate our previous report linking high dietary zinc feeding of piglets with the occurrence of antimicrobial resistant E. coli and therefore question the feeding of high dietary zinc oxide as alternative to antimicrobial growth promoters.

Screen for soil fungi highly resistant to dichloroaniline uncovers mostly Fusarium species.

Science.gov (United States)

Chan Ho Tong, Laetitia; Dairou, Julien; Bui, Linh-Chi; Bouillon, Julien; Rodrigues-Lima, Fernando; Dupret, Jean-Marie; Silar, Philippe

2015-08-01

Arylamines are frequent pollutants in soils. Fungi have proven to be efficient in detoxifying these chemicals by acetylating them using arylamine N-acetyl transferase enzymes. Here, we selected from natural soils fungi highly resistant to 3,4-dichloroaniline (DCA). Fusarium species were the most frequently isolated species, especially Fusarium solani. The sequenced strain of F. solani contains five NAT genes, as did all the DCA-resistant isolates. RT-PCR analysis showed that the five genes were expressed in F. solani. Expression of the F. solani genes in Podospora anserina and analysis of acetylation directly in F. solani showed that only the NhNAT2B gene conferred significant resistance to DCA and that F. solani likely uses pathways different from acetylation to resist high doses of DCA, as observed previously for Trichoderma. Copyright © 2015 Elsevier Inc. All rights reserved.

Development of leak detection system using high temperature-resistant microphones

International Nuclear Information System (INIS)

Morishita, Yoshitsugu; Mochizuki, Hiroyasu; Watanabe, Kenshiu; Nakamura, Takahisa; Nakazima, Yoshiaki; Yamauchi, Tatsuya

1995-01-01

This report describes the development and testing of a coolant leak detection system for an inlet feeder pipe of an advanced thermal reactor (ATR) using high temperature-resistant microphones. Such microphones must be resistant to both high temperatures and high radiation doses. Leakage sound characteristics, attenuation of the sound level in a heat insulating box for the inlet feeder pipes, and background noise were investigated using the experimental facility and the prototype ATR 'FUGEN'. The optimum frequency ranges for the microphone were then determined based on the observed leakage sound and background noise. The ability of the microphone to discriminate between leaks and other burst-type noises was also investigated by statistical analyses. Finally, it was confirmed that the present method could detect a leak within a couple of seconds. (author)

Mechanisms of Evolution in High-Consequence Drug Resistance Plasmids.

Science.gov (United States)

He, Susu; Chandler, Michael; Varani, Alessandro M; Hickman, Alison B; Dekker, John P; Dyda, Fred

2016-12-06

The dissemination of resistance among bacteria has been facilitated by the fact that resistance genes are usually located on a diverse and evolving set of transmissible plasmids. However, the mechanisms generating diversity and enabling adaptation within highly successful resistance plasmids have remained obscure, despite their profound clinical significance. To understand these mechanisms, we have performed a detailed analysis of the mobilome (the entire mobile genetic element content) of a set of previously sequenced carbapenemase-producing Enterobacteriaceae (CPE) from the National Institutes of Health Clinical Center. This analysis revealed that plasmid reorganizations occurring in the natural context of colonization of human hosts were overwhelmingly driven by genetic rearrangements carried out by replicative transposons working in concert with the process of homologous recombination. A more complete understanding of the molecular mechanisms and evolutionary forces driving rearrangements in resistance plasmids may lead to fundamentally new strategies to address the problem of antibiotic resistance. The spread of antibiotic resistance among Gram-negative bacteria is a serious public health threat, as it can critically limit the types of drugs that can be used to treat infected patients. In particular, carbapenem-resistant members of the Enterobacteriaceae family are responsible for a significant and growing burden of morbidity and mortality. Here, we report on the mechanisms underlying the evolution of several plasmids carried by previously sequenced clinical Enterobacteriaceae isolates from the National Institutes of Health Clinical Center (NIH CC). Our ability to track genetic rearrangements that occurred within resistance plasmids was dependent on accurate annotation of the mobile genetic elements within the plasmids, which was greatly aided by access to long-read DNA sequencing data and knowledge of their mechanisms. Mobile genetic elements such as

High hardness and superlative oxidation resistance in a pseudo-icosahehdral Cr-Al binary

Science.gov (United States)

Simonson, J. W.; Rosa, R.; Antonacci, A. K.; He, H.; Bender, A. D.; Pabla, J.; Adrip, W.; McNally, D. E.; Zebro, A.; Kamenov, P.; Geschwind, G.; Ghose, S.; Dooryhee, E.; Ibrahim, A.; Aronson, M. C.

Improving the efficiency of fossil fuel plants is a practical option for decreasing carbon dioxide emissions from electrical power generation. Present limits on the operating temperatures of exposed steel components, however, restrict steam temperatures and therefore energy efficiency. Even as a new generation of creep-resistant, high strength steels retain long term structural stability to temperatures as high as ~ 973 K, the low Cr-content of these alloys hinders their oxidation resistance, necessitating the development of new corrosion resistant coatings. We report here the nearly ideal properties of potential coating material Cr55Al229, which exhibits high hardness at room temperature as well as low thermal conductivity and superlative oxidation resistance at 973 K, with an oxidation rate at least three times smaller than those of benchmark materials. These properties originate from a pseudo-icosahedral crystal structure, suggesting new criteria for future research.

[From the discovery of antibiotics to emerging highly drug-resistant bacteria].

Science.gov (United States)

Meunier, Olivier

2015-01-01

The discovery of antibiotics has enabled serious infections to be treated. However, bacteria resistant to several families of antibiotics and the emergence of new highly drug-resistant bacteria constitute a public health issue in France and across the world. Actions to prevent their transmission are being put in place. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Differential Effects of High-Carbohydrate and High-Fat Diet Composition on Metabolic Control and Insulin Resistance in Normal Rats

Science.gov (United States)

Ble-Castillo, Jorge L.; Aparicio-Trapala, María A.; Juárez-Rojop, Isela E.; Torres-Lopez, Jorge E.; Mendez, Jose D.; Aguilar-Mariscal, Hidemi; Olvera-Hernández, Viridiana; Palma-Cordova, Leydi C.; Diaz-Zagoya, Juan C.

2012-01-01

The macronutrient component of diets is critical for metabolic control and insulin action. The aim of this study was to compare the effects of high fat diets (HFDs) vs. high carbohydrate diets (HCDs) on metabolic control and insulin resistance in Wistar rats. Thirty animals divided into five groups (n = 6) were fed: (1) Control diet (CD); (2) High-saturated fat diet (HSFD); (3) High-unsaturated fat diet (HUFD); (4) High-digestible starch diet, (HDSD); and (5) High-resistant starch diet (HRSD) during eight weeks. HFDs and HCDs reduced weight gain in comparison with CD, however no statistical significance was reached. Calorie intake was similar in both HFDs and CD, but rats receiving HCDs showed higher calorie consumption than other groups, (p < 0.01). HRSD showed the lowest levels of serum and hepatic lipids. The HUFD induced the lowest fasting glycemia levels and HOMA-IR values. The HDSD group exhibited the highest insulin resistance and hepatic cholesterol content. In conclusion, HUFD exhibited the most beneficial effects on glycemic control meanwhile HRSD induced the highest reduction on lipid content and did not modify insulin sensitivity. In both groups, HFDs and HCDs, the diet constituents were more important factors than caloric intake for metabolic disturbance and insulin resistance. PMID:22754464

High-pressure resistivity technique for quasi-hydrostatic compression experiments.

Science.gov (United States)

Rotundu, C R; Ćuk, T; Greene, R L; Shen, Z-X; Hemley, Russell J; Struzhkin, V V

2013-06-01

Diamond anvil cell techniques are now well established and powerful methods for measuring materials properties to very high pressure. However, high pressure resistivity measurements are challenging because the electrical contacts attached to the sample have to survive to extreme stress conditions. Until recently, experiments in a diamond anvil cell were mostly limited to non-hydrostatic or quasi-hydrostatic pressure media other than inert gases. We present here a solution to the problem by using focused ion beam ultrathin lithography for a diamond anvil cell loaded with inert gas (Ne) and show typical resistivity data. These ultrathin leads are deposited on the culet of the diamond and are attaching the sample to the anvil mechanically, therefore allowing for measurements in hydrostatic or nearly hydrostatic conditions of pressure using noble gases like Ne or He as pressure transmitting media.

Primary drug resistance in a region with high burden of tuberculosis. A critical problem.

Science.gov (United States)

Villa-Rosas, Cecilia; Laniado-Laborín, Rafael; Oceguera-Palao, Lorena

2015-01-01

To determine rates of drug resistance in new cases of pulmonary tuberculosis in a region with a high burden of the disease. New case suspects were referred for drug susceptibility testing. 28.9% of new cases were resistant to at least one first line drug; 3.9% had a multidrug-resistant strain, 15.6% a monoresistant strain and 9.4% a polyresistant strain. Our rate of drug resistant tuberculosis in new cases is very high; this has important clinical implications, since even monoresistance can have a negative impact on the outcome of new cases treated empirically with a six month regimen.

ICFA Instrumentation Bulletin, Volume 23, Fall 2001 Issue (SLAC-J-ICFA-023)

Energy Technology Data Exchange (ETDEWEB)

Va' Vra, J.

2003-10-21

The publication of the ICFA Instrumentation Bulletin is an activity of the Panel on Future Innovation and Development of ICFA (International Committee for Future Accelerators). The Bulletin reports on research and progress in the field of instrumentation with emphasis on application in the field of high-energy physics. It encourages issues of generic instrumentation. This issue has the following articles: (1) ''A Large Area Timing RPC''; (2) ''Applications and New Developments in Resistive Plate Chambers''; and (3) ''Advanced Study of Silicon Photomultipliers''.

Fluoride production in RPCs operated with F-compound gases

International Nuclear Information System (INIS)

Aielli, G.; Camarri, P.; Cardarelli, R.; Di Ciaccio, A.; Di Simone, A.; Liberti, B.; Palummo, L.; Santonico, R.

2006-01-01

The Resistive Plate Chambers (RPC) are gaseous detectors widely used in LCH experiments for muon trigger systems and time of flight measurement due to their very good time resolution. Gas mixtures with a prevalence of HFC components are generally adjoint used to achieve a lower charge per count an consequently an higher rate capability. The decomposition of HFC under electrical discharge produces a significant concentration of fluorine ions F - that can be detected in the RPC exhausted gas. Due to the high chemical reactivity, this pollutant represents a possible cause of the inner surface damaging if it not quickly removed by the gas flow. In this paper various aspects of this phenomenology are investigated. We measured the F - production rate as a function of the detector counting rate and the working point (both in streamer and avalanche mode). The effect of the addition of 0.5% of SF 6 to the test mixture is also shown. We also extensively investigated the ratio between the F - production associated to a the time integral of the working current

Technical Design Report for the Phase-II Upgrade of the ATLAS Muon Spectrometer

CERN Document Server

Collaboration, ATLAS

2017-01-01

The muon spectrometer of the ATLAS detector will be significantly upgraded during the Phase-II upgrade in LS3 in order to cope with the operational conditions at the HL-LHC in Run 4 and beyond. A large fraction of the frontend and on- and off-detector readout and trigger electronics for the Resistive Plate Chambers (RPC), Thin Gap Chambers (TGC), and Monitored Drift Tube (MDT) chambers will be replaced to make them compatible with the higher trigger rates and longer latencies necessary for the new level-0 trigger. The MDT chambers will be integrated into the level-0 trigger in order to sharpen the momentum threshold. Additional RPC chambers will be installed in the inner barrel layer to increase the acceptance and robustness of the trigger, and some chambers in high-rate regions will be refurbished. Some of the MDT chambers in the inner barrel layer will be replaced with new small-diameter MDTs. New TGC triplet chambers in the barrel-endcap transition region will replace the current TGC doublets to suppress t...

Characterization of active CMOS pixel sensors on high resistive substrate

Energy Technology Data Exchange (ETDEWEB)

Hirono, Toko; Hemperek, Tomasz; Huegging, Fabian; Krueger, Hans; Rymaszewski, Piotr; Wermes, Norbert [Physikalisches Institut, Universitaet Bonn, Bonn (Germany)

2016-07-01

Active CMOS pixel sensors are very attractive as radiation imaging pixel detector because they do not need cost-intensive fine pitch bump bonding. High radiation tolerance and time resolution are required to apply those sensors to upcoming particle physics experiments. To achieve these requirements, the active CMOS pixel sensors were developed on high resistive substrates. Signal charges are collected faster by drift in high resistive substrates than in standard low resistive substrates yielding also a higher radiation tolerance. A prototype of the active CMOS pixel sensor has been fabricated in the LFoundry 150 nm CMOS process on 2 kΩcm substrate. This prototype chip was thinned down to 300 μm and the backside has been processed and can contacted by an aluminum contact. The breakdown voltage is around -115 V, and the depletion width has been measured to be as large as 180 μm at a bias voltage of -110 V. Gain and noise of the readout circuitry agree with the designed values. Performance tests in the lab and test beam have been done before and after irradiation with X-rays and neutrons. In this presentation, the measurement results of the active CMOS prototype sensors are shown.

30 CFR 75.803 - Fail safe ground check circuits on high-voltage resistance grounded systems.

Science.gov (United States)

2010-07-01

... High-Voltage Distribution § 75.803 Fail safe ground check circuits on high-voltage resistance grounded systems. [Statutory Provisions] On and after September 30, 1970, high-voltage, resistance grounded systems... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Fail safe ground check circuits on high-voltage...

Tailoring Cytotoxicity of Antimicrobial Peptidomimetics with High Activity against Multidrug-Resistant Escherichia coli

DEFF Research Database (Denmark)

Jahnsen, Rasmus D; Sandberg-Schaal, Anne; Vissing, Karina Juul

2014-01-01

Infections with multidrug-resistant pathogens are an increasing concern for public health. Recently, subtypes of peptide-peptoid hybrids were demonstrated to display potent activity against multidrug-resistant Gram-negative bacteria. Here, structural variation of these antibacterial peptidomimetics...... cells. Thus, lead compounds with a high selectivity toward killing of clinically important multidrug-resistant E. coli were identified....

Development of High Temperature/High Sensitivity Novel Chemical Resistive Sensor

Energy Technology Data Exchange (ETDEWEB)

Ma, Chunrui [Univ. of Texas, San Antonio, TX (United States); Enriquez, Erik [Univ. of Texas, San Antonio, TX (United States); Wang, Haibing [Univ. of Texas, San Antonio, TX (United States); Xu, Xing [Univ. of Texas, San Antonio, TX (United States); Bao, Shangyong [Univ. of Texas, San Antonio, TX (United States); Collins, Gregory [Univ. of Texas, San Antonio, TX (United States)

2013-08-13

The research has been focused to design, fabricate, and develop high temperature/high sensitivity novel multifunctional chemical sensors for the selective detection of fossil energy gases used in power and fuel systems. By systematically studying the physical properties of the LnBaCo₂O_5+d (LBCO) [Ln=Pr or La] thin-films, a new concept chemical sensor based high temperature chemical resistant change has been developed for the application for the next generation highly efficient and near zero emission power generation technologies. We also discovered that the superfast chemical dynamic behavior and an ultrafast surface exchange kinetics in the highly epitaxial LBCO thin films. Furthermore, our research indicates that hydrogen can superfast diffuse in the ordered oxygen vacancy structures in the highly epitaxial LBCO thin films, which suggest that the LBCO thin film not only can be an excellent candidate for the fabrication of high temperature ultra sensitive chemical sensors and control systems for power and fuel monitoring systems, but also can be an excellent candidate for the low temperature solid oxide fuel cell anode and cathode materials.

Halogen effect for improving high temperature oxidation resistance of Ti-50Al by anodization

Science.gov (United States)

Mo, Min-Hua; Wu, Lian-Kui; Cao, Hua-Zhen; Lin, Jun-Pin; Zheng, Guo-Qu

2017-06-01

The high temperature oxidation resistance of Ti-50Al was significantly improved via halogen effect which was achieved by anodizing in an ethylene glycol solution containing with fluorine ion. The anodized Ti-50Al with holes and micro-cracks could be self-repaired during oxidation at 1000 °C. The thickness of the oxide scale increases with the prolonging of oxidation time. On the basis of halogen effect for improving the high temperature oxidation resistance of Ti-50Al by anodization, only fluorine addition into the electrolyte can effectively improve the high temperature oxidation resistance of Ti-50Al.

Monitoring of high temperature zone by resistivity tomography during in-situ heater test in sedimentary soft rocks

International Nuclear Information System (INIS)

Kubota, Kenji; Suzuki, Koichi; Ikenoya, Takafumi; Takakura, Nozomu; Tani, Kazuo

2008-01-01

In-situ heater test has been conducted to evaluate the influence of high temperature in an underground facility at a depth of 50 m. Resistivity monitoring is thought to be effective to map the extent of the high temperature zone. So we have conducted resistivity tomography during the heater test. As a result, low resistivity zone was appeared near the heated area as starting the heating, and the zone was expanded. Resistivity of rock is proportional to resistivity of pore water. It is known that pore water resistivity decreases as the temperature rise. This suggests that high temperature zone is detected and spatial distribution of temperature can be mapped by resistivity tomography. (author)

Effects of high-intensity interval cycling performed after resistance training on muscle strength and hypertrophy.

Science.gov (United States)

Tsitkanou, S; Spengos, K; Stasinaki, A-N; Zaras, N; Bogdanis, G; Papadimas, G; Terzis, G

2017-11-01

Aim of the study was to investigate whether high-intensity interval cycling performed immediately after resistance training would inhibit muscle strength increase and hypertrophy expected from resistance training per se. Twenty-two young men were assigned into either resistance training (RE; N = 11) or resistance training plus high-intensity interval cycling (REC; N = 11). Lower body muscle strength and rate of force development (RFD), quadriceps cross-sectional area (CSA) and vastus lateralis muscle architecture, muscle fiber type composition and capillarization, and estimated aerobic capacity were evaluated before and after 8 weeks of training (2 times per week). Muscle strength and quadriceps CSA were significantly and similarly increased after both interventions. Fiber CSA increased significantly and similarly after both RE (type I: 13.6 ± 3.7%, type IIA: 17.6 ± 4.4%, type IIX: 23.2 ± 5.7%, P high-intensity interval cycling performed after heavy-resistance exercise may not inhibit resistance exercise-induced muscle strength/hypertrophy after 2 months of training, while it prompts aerobic capacity and muscle capillarization. The addition of high-intensity cycling after heavy-resistance exercise may decrease RFD partly due to muscle architectural changes. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Breeding of new variety Yangfumai 4 with high resistance to wheat yellow mosaic disease

International Nuclear Information System (INIS)

He Zhentian; Chen Xiulan; Zhang Rong; Wang Jianhua; Wang Jinrong; Liu Jian

2011-01-01

To control the infection of wheat yellow mosaic disease,new wheat variety with high-yield, disease-resistant was selected. Ningmai 9, which carries yellow mosaic disease resistant genes, was used as original material. Combination of conventional breeding technique and radiation methods, a new wheat variety Yangfumai 4 was developed during 1996-2007, and registered in 2008. The new wheat variety with high yield and resistance to yellow mosaic disease is suitable to plant in the Yangtze River region. (authors)

The high temperature resistivity of Ba2YCu3O7-chi

International Nuclear Information System (INIS)

Xingkui, Z.; Shining, Z.; Hao, W.; Shiyuan, Z.; Ningshen, Z.; Ziran, X.

1988-01-01

The high temperature resistivity (rho), thermogravimetry (TG) and derivative thermogravimetric (DTG) have been used to characterize superconductor Ba 2 YCu 3 O 7-chi (BYCO) in O 2 , air and N 2 . The resistivity is linear from room temperature at 350 0 C and then deviate from linearity with oxygen evolution, the derivative of resistivity drho/dT increases abruptly near orthorhombic to tetragonal phase transition. These phenomena can give good explanations for a two-band Drude model

The High Temperature Resistivity of Ba2YCu3O7-x

Science.gov (United States)

Xingkui, Zhang; Shining, Zhu; Hao, Wang; Shiyuan, Zhang; Su, Ye; Ningshen, Zhou; Ziran, Xu

The high temperature resistivity (ρ), thermogravimetry (TG) and derivative thermogravimetry (DTG) have been used to characterize superconductor Ba2YCu3O7-x (BYCO) in O2, air and N2. The resistivity is linear from room temperature to 350°C and then deviate from linearity with oxygen evolution, the derivative of resistivity dρ/dT increases abruptly near orthorhombic to tetragonal phase transition. These phenomena can give good explanations for a two-band Drude model.

Primary drug resistance in a region with high burden of tuberculosis. A critical problem

Directory of Open Access Journals (Sweden)

Cecilia Villa-Rosas

2015-03-01

Full Text Available Objective. To determine rates of drug resistance in new cases of pulmonary tuberculosis in a region with a high burden of the disease. Materials and methods. New case suspects were referred for drug susceptibility testing. Results. 28.9% of new cases were resistant to at least one first line drug; 3.9% had a multidrug-resistant strain, 15.6% a monoresistant strain and 9.4% a polyresistant strain. Conclusion. Our rate of drug resistant tuberculosis in new cases is very high; this has important clinical implications, since even monoresistance can have a negative impact on the outcome of new cases treated empirically with a six month regimen.

The effects of varying resistance-training loads on intermediate- and high-velocity-specific adaptations.

Science.gov (United States)

Jones, K; Bishop, P; Hunter, G; Fleisig, G

2001-08-01

The purpose of this study was to compare changes in velocity-specific adaptations in moderately resistance-trained athletes who trained with either low or high resistances. The study used tests of sport-specific skills across an intermediate- to high-velocity spectrum. Thirty NCAA Division I baseball players were randomly assigned to either a low-resistance (40-60% 1 repetition maximum [1RM]) training group or a high-resistance (70-90% 1RM) training group. Both of the training groups intended to maximallv accelerate each repetition during the concentric phase (IMCA). The 10 weeks of training consisted of 4 training sessions a week using basic core exercises. Peak force, velocity, and power were evaluated during set angle and depth jumps as well as weighted jumps using 30 and 50% 1RM. Squat 1RMs were also tested. Although no interactions for any of the jump tests were found, trends supported the hypothesis of velocity-specific training. Percentage gains suggest that the combined use of heavier training loads (70-90% 1RM) and IMCA tend to increase peak force in the lower-body leg and hip extensors. Trends also show that the combined use of lighter training loads (40-60% 1RM) and IMCA tend to increase peak power and peak velocity in the lower-body leg and hip extensors. The high-resistance group improved squats more than the low-resistance group (p training loads and IMCA to increase 1RM strength in the lower bodies of resistance-trained athletes.

Breeding of a new potato variety 'Nagasaki Kogane' with high eating quality, high carotenoid content, and resistance to diseases and pests.

Science.gov (United States)

Sakamoto, Yu; Mori, Kazuyuki; Matsuo, Yuuki; Mukojima, Nobuhiro; Watanabe, Wataru; Sobaru, Norio; Tamiya, Seiji; Nakao, Takashi; Hayashi, Kazuya; Watanuki, Hitomi; Nara, Kazuhiro; Yamazaki, Kaoru; Chaya, Masataka

2017-06-01

'Nagasaki Kogane' is a new potato variety bred from a cross between 'Saikai 35' as a female parent and 'Saikai 33' as a male. 'Saikai 35' is resistant to bacterial wilt, contains the H1 and Ry chc genes for resistance to the potato cyst nematode (PCN) and potato virus Y (PVY), respectively, and has high carotenoid content, while 'Saikai 33' has large and high-yielding tubers and is resistant to both bacterial wilt and PCN. The carotenoid content of 'Nagasaki Kogane' is higher than that of 'Dejima', a common double cropping variety. The taste quality of steamed 'Nagasaki Kogane' is comparable to that of 'Inca-no-mezame' tubers, which has high levels of carotenoid, and superior to 'Nishiyutaka', another popular double cropping variety. 'Nagasaki Kogane' is suitable for French fries, because its tuber has high starch content. The marketable yield of 'Nagasaki Kogane' was higher than that of 'Inca-no-mezame' in spring cropping, although it was lower than that of 'Nishiyutaka' in double cropping regions. 'Nagasaki Kogane' tubers are larger on average than 'Inca-no-mezame' tubers in spring cropping. Moreover, the 'Nagasaki Kogane' variety is resistant to PCN and PVY, and exhibits a high level of resistance to bacterial wilt.

SU-E-P-02: Imaging and Radiation Oncology Core (IROC) Houston QA Center (RPC) Credentialing

International Nuclear Information System (INIS)

Amador, C; Keith, T; Nguyen, T; Molineu, A; Followill, D

2014-01-01

Purpose: To provide information pertaining to IROC Houston QA Center's (RPC) credentialing process for institutions participating in NCI-sponsored clinical trials. Methods: IROC Houston issues credentials for NCI sponsored study groups. Requirements for credentialing might include any combination of questionnaires, knowledge assessment forms, benchmarks, or phantom irradiations. Credentialing requirements for specific protocols can be found on IROC Houston's website (irochouston.mdanderson.org). The website also houses the credentialing status inquiry (CSI) form. Once an institution has reviewed the protocol's credentialing requirements, a CSI form should be completed and submitted to IROC Houston. This form is used both to request whether requirements have been met as well as to notify IROC Houston that the institution requests credentialing for a specific protocol. IROC Houston will contact the institution to discuss any delinquent requirements. Once the institution has met all requirements IROC Houston issues a credentialing letter to the institution and will inform study groups and other IROC offices of the credentials. Institutions can all phone the IROC Houston office to initiate credentialing or ask any credentialing related questions. Results: Since 2010 IROC has received 1313 credentialing status inquiry forms. We received 317 in 2010, 266 in 2011, 324 in 2012, and 406 in 2013. On average we receive 35 phone calls per week with multiple types of credentialing questions. Decisions regarding credentialing status are based on the protocol specifications and previous completed credentialing by the institution. In some cases, such as for general IMRT credentialing, up to 5 sites may be credentialed based on the credentialing of one main center. Each of these situations is handled individually. Conclusion: IROC Houston will issue radiation therapy credentials for the NCI trials in the National Clinical Trials Network. Credentialing requirements and the CSI form

Diffusion barrier coatings for high temperature corrosion resistance of advanced carbon/carbon composites

International Nuclear Information System (INIS)

Singh Raman, K.S.

2000-01-01

Carbon possesses an excellent combination of mechanical and thermal properties, viz., excellent creep resistance at temperatures up to 2400 deg C in non-oxidizing environment and a low thermal expansion coefficient. These properties make carbon a potential material for very high temperature applications. However, the use of carbon materials at high temperatures is considerably restricted due to their extremely poor oxidation resistance at temperatures above 400 deg C. The obvious choice for improving high temperature oxidation resistance of such materials is a suitable diffusion barrier coating. This paper presents an overview of recent developments in advanced diffusion- and thermal-barrier coatings for ceramic composites, with particular reference to C/C composites. The paper discusses the development of multiphase and multi-component ceramic coatings, and recent investigations on the oxidation resistance of the coated C/C composites. The paper also discusses the cases of innovative engineering solutions for traditional problems with the ceramic coatings, and the scope of intelligent processing in developing coatings for the C/C composites. Copyright (2000) AD-TECH - International Foundation for the Advancement of Technology Ltd

30 CFR 77.803 - Fail safe ground check circuits on high-voltage resistance grounded systems.

Science.gov (United States)

2010-07-01

... circuits on high-voltage resistance grounded systems. On and after September 30, 1971, all high-voltage... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Fail safe ground check circuits on high-voltage resistance grounded systems. 77.803 Section 77.803 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION...

RNAi validation of resistance genes and their interactions in the highly DDT-resistant 91-R strain of Drosophila melanogaster.

Science.gov (United States)

Gellatly, Kyle J; Yoon, Kyong Sup; Doherty, Jeffery J; Sun, Weilin; Pittendrigh, Barry R; Clark, J Marshall

2015-06-01

4,4'-dichlorodiphenyltrichloroethane (DDT) has been re-recommended by the World Health Organization for malaria mosquito control. Previous DDT use has resulted in resistance, and with continued use resistance will increase in terms of level and extent. Drosophila melanogaster is a model dipteran that has many available genetic tools, numerous studies done on insecticide resistance mechanisms, and is related to malaria mosquitoes allowing for extrapolation. The 91-R strain of D. melanogaster is highly resistant to DDT (>1500-fold), however, there is no mechanistic scheme that accounts for this level of resistance. Recently, reduced penetration, increased detoxification, and direct excretion have been identified as resistance mechanisms in the 91-R strain. Their interactions, however, remain unclear. Use of UAS-RNAi transgenic lines of D. melanogaster allowed for the targeted knockdown of genes putatively involved in DDT resistance and has validated the role of several cuticular proteins (Cyp4g1 and Lcp1), cytochrome P450 monooxygenases (Cyp6g1 and Cyp12d1), and ATP binding cassette transporters (Mdr50, Mdr65, and Mrp1) involved in DDT resistance. Further, increased sensitivity to DDT in the 91-R strain after intra-abdominal dsRNA injection for Mdr50, Mdr65, and Mrp1 was determined by a DDT contact bioassay, directly implicating these genes in DDT efflux and resistance. Copyright © 2015 Elsevier Inc. All rights reserved.

Photo-induced current transient spectroscopy for high-resistivity neutron-transmutation-doped silicon

International Nuclear Information System (INIS)

Tokuda, Yutaka; Inoue, Yajiro; Usami, Akira

1987-01-01

Defects in high-resistivity neutron-transmutation-doped (NTD) silicon prior to annealing were studied by photo-induced current transient spectroscopy (PICTS). The thermal-neutron fluence was 9.5 x 10 17 cm -2 to give a resistivity of about 30 Ω after annealing, and the fast-neutron fluence was 9.5 x 10 16 cm -2 . Four traps with thermal emission activation energies of 0.15, 0.41. 0.47 and 0.50 eV were observed in NTD silicon. A trap with the thermal emission activation energy of 0.15 eV was considered to correspond to the divacancy. Although the clustered nature of the defects was observed, PICTS measurements suggest that the material state of high-resistivity NTD silicon is still crystalline and not amorphous. (author)

Adaptation to high current using low external resistances eliminates power overshoot in microbial fuel cells

KAUST Repository

Hong, Yiying; Call, Douglas F.; Werner, Craig M.; Logan, Bruce E.

2011-01-01

. Acclimation of the high external resistance reactors for a few cycles to low external resistance (5. Ω), and therefore higher current densities, eliminated power overshoot. MFCs initially acclimated to low external resistances exhibited both higher current

Status of insecticide resistance in high-risk malaria provinces in Afghanistan.

Science.gov (United States)

Ahmad, Mushtaq; Buhler, Cyril; Pignatelli, Patricia; Ranson, Hilary; Nahzat, Sami Mohammad; Naseem, Mohammad; Sabawoon, Muhammad Farooq; Siddiqi, Abdul Majeed; Vink, Martijn

2016-02-18

Insecticide resistance seriously threatens the efficacy of vector control interventions in malaria endemic countries. In Afghanistan, the status of insecticide resistance is largely unknown while distribution of long-lasting insecticidal nets has intensified in recent years. The main objective of this study was thus to measure the level of resistance to four classes of insecticides in provinces with medium to high risk of malaria transmission. Adult female mosquitoes were reared from larvae successively collected in the provinces of Nangarhar, Kunar, Badakhshan, Ghazni and Laghman from August to October 2014. WHO insecticide susceptibility tests were performed with DDT (4 %), malathion (5 %), bendiocarb (0.1 %), permethrin (0.75 %) and deltamethrin (0.05 %). In addition, the presence of kdr mutations was investigated in deltamethrin resistant and susceptible Anopheles stephensi mosquitoes collected in the eastern provinces of Nangarhar and Kunar. Analyses of mortality rates revealed emerging resistance against all four classes of insecticides in the provinces located east and south of the Hindu Kush mountain range. Resistance is observed in both An. stephensi and Anopheles culicifacies, the two dominant malaria vectors in these provinces. Anopheles superpictus in the northern province of Badakhshan shows a different pattern of susceptibility with suspected resistance observed only for deltamethrin and bendiocarb. Genotype analysis of knock down resistance (kdr) mutations at the voltage-gated channel gene from An. stephensi mosquitoes shows the presence of the known resistant alleles L1014S and L1014F. However, a significant fraction of deltamethrin-resistant mosquitoes were homozygous for the 1014L wild type allele indicating that other mechanisms must be considered to account for the observed pyrethroid resistance. This study confirms the importance of monitoring insecticide resistance for the development of an integrated vector management in Afghanistan. The

High Radiation Resistance IMM Solar Cell

Science.gov (United States)

Pan, Noren

2015-01-01

Due to high launch costs, weight reduction is a key driver for the development of new solar cell technologies suitable for space applications. This project is developing a unique triple-junction inverted metamorphic multijunction (IMM) technology that enables the manufacture of very lightweight, low-cost InGaAsP-based multijunction solar cells. This IMM technology consists of indium (In) and phosphorous (P) solar cell active materials, which are designed to improve the radiation-resistant properties of the triple-junction solar cell while maintaining high efficiency. The intrinsic radiation hardness of InP materials makes them of great interest for building solar cells suitable for deployment in harsh radiation environments, such as medium Earth orbit and missions to the outer planets. NASA Glenn's recently developed epitaxial lift-off (ELO) process also will be applied to this new structure, which will enable the fabrication of the IMM structure without the substrate.

Development of a leak detection system using high temperature-resistant microphones

International Nuclear Information System (INIS)

Morishita, Yoshitsugu; Mochizuki, Hiroyasu; Watanabe, Kenshiu; Nakamura, Takahisa; Nakajima, Yoshiaki; Yamauchi, Tatsuya

1991-01-01

This report describes the development of a detection system of coolant leak from an inlet feeder pipe of an Advanced Thermal Reactor (ATR) with high temperature-resistant microphones. A microphone having resistance to both high temperature and high radiation dose has been developed at first. The characteristics with regard to leakage sound, attenuation of sound level in a heat insulating box for the inlet feeder pipes and background noise were clarified by laboratory experiments and measurements in the prototype ATR 'Fugen'. On the basis of these experimental findings, appropriate frequency ranges were surveyed to detect the leakage sound with a high S/N ratio under the background noise. Reliability of the system to a malfunction caused by burst-type noises observed in the plant was also investigated by statistical analyses. Finally, it was confirmed that the present method could detect a leak within a couple of seconds. (author)

IncA/C plasmids conferring high azithromycin resistance in vibrio cholerae.

Science.gov (United States)

Wang, Ruibai; Liu, Haican; Zhao, Xiuqin; Li, Jie; Wan, Kanglin

2018-01-01

Azithromycin (AZM) is a clinically important antibiotic against Vibrio cholerae, especially for inhibiting V. cholerae colonisation of the intestine and for the treatment of severe cholera in children and pregnant women. An IncA/C plasmid was isolated from two high minimum inhibitory concentration (MIC) AZM-resistant V. cholerae strains of the two mainly pathogenic serogroups (O1 and O139) isolated in China. In the 172 predicted open reading frames (ORFs), 16 genes were related to antibiotic resistance, of which 5 were well-defined genes associated with macrolide resistance. The five macrolide resistance genes distributed in two clusters, mphR-mrx-mph(K) and mel-mph2, flanked by insertion sequence elements and involving two kinds of resistance mechanism. Deletion of the complete region of the two clusters deceased the AZM MIC from ≥64 µg/mL to ≤0.5 µg/mL. This IncA/C plasmid shows great ability to accumulate antibiotic resistance genes. In addition to 11 resistance genes to other antibiotics, 5 macrolide resistance genes with different function were gathered repeatedly through transposition on one plasmid. This genotype could not be simply explained by antibiotic stress applied on the host from the environment or treatment. These phosphorylases and transmembrane transporters might be involved in the transport and metabolism of other non-antibiotic substances, enabling this kind of plasmid to propagate better in the host. Copyright © 2017 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

The High-Temperature Resistance Properties of Polysiloxane/Al Coatings with Low Infrared Emissivity

Directory of Open Access Journals (Sweden)

Jun Zhao

2018-03-01

Full Text Available High-temperature-resistant coatings with low infrared emissivity were prepared using polysiloxane resin and flake aluminum as the adhesive and pigment, respectively. The heat resistance mechanisms of the polysiloxane/Al coating were systematically investigated. The composition, surface morphology, infrared reflectance spectra, and thermal expansion dimension (ΔL of the coatings were characterized by X-ray photoelectron spectroscopy (XPS, field emission scanning electron microscopy (FE-SEM, Fourier transform infrared spectroscopy, and thermal mechanical analysis (TMA, respectively. The results show that thermal decomposition of the resin and mismatch of ΔL between the coating and the substrate facilitate the high temperature failure of the coating. A suitable amount of flake aluminum pigments could restrain the thermal decomposition of the resin and could increase the match degree of ΔL between the coating and substrate, leading to an enhanced thermal resistance of the coating. Our results find that a coating with a pigment to binder ratio (P/B ratio of 1.0 could maintain integrity until 600 °C, and the infrared emissivity was as low as 0.27. Hence, a coating with high-temperature resistance and low emissivity was obtained. Such coatings can be used for infrared stealth technology or energy savings in high-temperature equipment.

Analysis of RE4 Construction Cosmic Muon Test Data and Comparison with 2015 Collision Calibration Run Data for the Newly Installed RPC Chambers in the 4th Muon Endcap Station of the CMS Detector

CERN Document Server

Iqbal, Muhammad Ansar

2015-01-01

RPC are the heart of the muon system of CMS experiment at LHC, CERN. Recently a new endcap layer, RE4, was added to increase redundancy. These added chambers were tested during the construction period with cosmic muons in the 904 lab at Prevessin, CERN. This study analyzes the HV scan from those tests and compares them with the first 2015 collision data taken at Point-5. The analysis showed that most of the chambers were producing more than 90% efficiency and were in good agreement with the Point-5 results. Those which did not give good results were reported. Other variables like working point and maximum efficiency were also studied.

Summer freezing resistance: a critical filter for plant community assemblies in Mediterranean high mountains

Directory of Open Access Journals (Sweden)

David Sánchez Pescador

2016-02-01

Full Text Available Assessing freezing community response and whether freezing resistance is related to other functional traits is essential for understanding alpine community assemblages, particularly in Mediterranean environments where plants are exposed to freezing temperatures and summer droughts. Thus, we characterized the leaf freezing resistance of 42 plant species in 38 plots at Sierra de Guadarrama (Spain by measuring their ice nucleation temperature, freezing point (FP, and low-temperature damage (LT50, as well as determining their freezing resistance mechanisms (i.e., tolerance or avoidance. The community response to freezing was estimated for each plot as community weighted means (CWMs and functional diversity, and we assessed their relative importance with altitude. We established the relationships between freezing resistance, growth forms, and four key plant functional traits (i.e., plant height, specific leaf area, leaf dry matter content, and seed mass. There was a wide range of freezing resistance responses and more than in other alpine habitats. At the community level, the CWMs of FP and LT50 responded negatively to altitude, whereas the functional diversity of both traits increased with altitude. The proportion of freezing-tolerant species also increased with altitude. The ranges of FP and LT50 varied among growth forms, and only the leaf dry matter content correlated negatively with freezing-resistance traits. Summer freezing events represent important abiotic filters for assemblies of Mediterranean high mountain communities, as suggested by the CWMs. However, a concomitant summer drought constraint may also explain the high freezing resistance of species that thrive in these areas and the lower functional diversity of freezing resistance traits at lower altitudes. Leaves with high dry matter contents may maintain turgor at lower water potential and enhance drought tolerance in parallel to freezing resistance. This adaptation to drought seems to

Development of a Long-Life-Cycle, Highly Water-Resistant Solar Reflective Retrofit Roof Coating

Energy Technology Data Exchange (ETDEWEB)

Polyzos, Georgios [ORNL; Hunter, Scott Robert [ORNL; Sharma, Jaswinder K [ORNL; Cheng, Mengdawn [ORNL; Chen, Sharon S [Lawrence Berkeley National Laboratory (LBNL); Demarest, Victoria [Dow Chemical Company; Fabiny, William [Dow Chemical Company; Destaillats, Hugo [Lawrence Berkeley National Laboratory (LBNL); Levinson, Ronnen [Lawrence Berkeley National Laboratory (LBNL)

2016-03-04

Highly water-resistant and solar-reflective coatings for low-slope roofs are potentially among the most economical retrofit approaches to thermal management of the building envelope. Therefore, they represent a key building technology research program within the Department of Energy. Research efforts in industry and the Department of Energy are currently under way to increase long-term solar reflectance on a number of fronts. These include new polymer coatings technologies to provide longer-lasting solar reflectivity and improved test methodologies to predict long-term soiling and microbial performance. The focus on long-term improvements in soiling and microbial resistance for maximum reflectance does not address the single most important factor impacting the long-term sustainability of low-slope roof coatings: excellent water resistance. The hydrophobic character of asphaltic roof products makes them uniquely suitable for water resistance, but their low albedo and poor exterior durability are disadvantages. A reflective coating that maintains very high water resistance with increased long-term resistance to soiling and microbial activity would provide additional energy savings and extend roof service life.

Development and implementation of a remote audit tool for high dose rate (HDR) Ir-192 brachytherapy using optically stimulated luminescence dosimetry

International Nuclear Information System (INIS)

Casey, Kevin E.; Kry, Stephen F.; Howell, Rebecca M.; Followill, David; Alvarez, Paola; Lawyer, Ann

2013-01-01

Purpose: The aim of this work was to create a mailable phantom with measurement accuracy suitable for Radiological Physics Center (RPC) audits of high dose-rate (HDR) brachytherapy sources at institutions participating in National Cancer Institute-funded cooperative clinical trials. Optically stimulated luminescence dosimeters (OSLDs) were chosen as the dosimeter to be used with the phantom.Methods: The authors designed and built an 8 × 8 × 10 cm 3 prototype phantom that had two slots capable of holding Al 2 O 3 :C OSLDs (nanoDots; Landauer, Glenwood, IL) and a single channel capable of accepting all 192 Ir HDR brachytherapy sources in current clinical use in the United States. The authors irradiated the phantom with Nucletron and Varian 192 Ir HDR sources in order to determine correction factors for linearity with dose and the combined effects of irradiation energy and phantom characteristics. The phantom was then sent to eight institutions which volunteered to perform trial remote audits.Results: The linearity correction factor was k L = (−9.43 × 10 −5 × dose) + 1.009, where dose is in cGy, which differed from that determined by the RPC for the same batch of dosimeters using 60 Co irradiation. Separate block correction factors were determined for current versions of both Nucletron and Varian 192 Ir HDR sources and these vendor-specific correction factors differed by almost 2.6%. For the Nucletron source, the correction factor was 1.026 [95% confidence interval (CI) = 1.023–1.028], and for the Varian source, it was 1.000 (95% CI = 0.995–1.005). Variations in lateral source positioning up to 0.8 mm and distal/proximal source positioning up to 10 mm had minimal effect on dose measurement accuracy. The overall dose measurement uncertainty of the system was estimated to be 2.4% and 2.5% for the Nucletron and Varian sources, respectively (95% CI). This uncertainty was sufficient to establish a ±5% acceptance criterion for source strength audits under a

Development and implementation of a remote audit tool for high dose rate (HDR) Ir-192 brachytherapy using optically stimulated luminescence dosimetry

Energy Technology Data Exchange (ETDEWEB)

Casey, Kevin E.; Kry, Stephen F.; Howell, Rebecca M.; Followill, David [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 and The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, Texas 77030 (United States); Alvarez, Paola; Lawyer, Ann [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States)

2013-11-15

Purpose: The aim of this work was to create a mailable phantom with measurement accuracy suitable for Radiological Physics Center (RPC) audits of high dose-rate (HDR) brachytherapy sources at institutions participating in National Cancer Institute-funded cooperative clinical trials. Optically stimulated luminescence dosimeters (OSLDs) were chosen as the dosimeter to be used with the phantom.Methods: The authors designed and built an 8 × 8 × 10 cm{sup 3} prototype phantom that had two slots capable of holding Al{sub 2}O{sub 3}:C OSLDs (nanoDots; Landauer, Glenwood, IL) and a single channel capable of accepting all {sup 192}Ir HDR brachytherapy sources in current clinical use in the United States. The authors irradiated the phantom with Nucletron and Varian {sup 192}Ir HDR sources in order to determine correction factors for linearity with dose and the combined effects of irradiation energy and phantom characteristics. The phantom was then sent to eight institutions which volunteered to perform trial remote audits.Results: The linearity correction factor was k{sub L}= (−9.43 × 10{sup −5}× dose) + 1.009, where dose is in cGy, which differed from that determined by the RPC for the same batch of dosimeters using {sup 60}Co irradiation. Separate block correction factors were determined for current versions of both Nucletron and Varian {sup 192}Ir HDR sources and these vendor-specific correction factors differed by almost 2.6%. For the Nucletron source, the correction factor was 1.026 [95% confidence interval (CI) = 1.023–1.028], and for the Varian source, it was 1.000 (95% CI = 0.995–1.005). Variations in lateral source positioning up to 0.8 mm and distal/proximal source positioning up to 10 mm had minimal effect on dose measurement accuracy. The overall dose measurement uncertainty of the system was estimated to be 2.4% and 2.5% for the Nucletron and Varian sources, respectively (95% CI). This uncertainty was sufficient to establish a ±5% acceptance

Exceptionally high cavitation erosion and corrosion resistance of a high entropy alloy.

Science.gov (United States)

Nair, R B; Arora, H S; Mukherjee, Sundeep; Singh, S; Singh, H; Grewal, H S

2018-03-01

Cavitation erosion and corrosion of structural materials are serious concerns for marine and offshore industries. Durability and performance of marine components are severely impaired due to degradation from erosion and corrosion. Utilization of advanced structural materials can play a vital role in limiting such degradation. High entropy alloys (HEAs) are a relatively new class of advanced structural materials with exceptional properties. In the present work, we report on the cavitation erosion behavior of Al 0.1 CoCrFeNi HEA in two different media: distilled water with and without 3.5wt% NaCl. For comparison, conventionally used stainless steel SS316L was also evaluated in identical test conditions. Despite lower hardness and yield strength, the HEA showed significantly longer incubation period and lower erosion-corrosion rate (nearly 1/4th) compared to SS316L steel. Enhanced erosion resistance of HEA was attributed to its high work-hardening behavior and stable passivation film on the surface. The Al 0.1 CoCrFeNi HEA showed lower corrosion current density, high pitting resistance and protection potential compared to SS316L steel. Further, HEA showed no evidence of intergranular corrosion likely due to the absence of secondary precipitates. Although, the degradation mechanisms (formation of pits and fatigue cracks) were similar for both the materials, the damage severity was found to be much higher for SS316L steel compared to HEA. Copyright © 2017 Elsevier B.V. All rights reserved.

Output pulse-shapes of position-sensitive proportional counters using high resistance single wire

International Nuclear Information System (INIS)

Iwatani, Kazuo; Nishiyama, Fumitaka; Hasai, Hiromi

1980-01-01

The measurements and model analysis of the output pulse-shapes from a single wire proportional counter (SWPC) which has a high resistance anode are described. The characteristics of the observed pulse-shapes are determined by only one parameter which is a function of anode resistance and load resistance and they are reproduced by a simple model. Using this model, the methods for position read-out are discussed in a systematical way. (author)

High alkali-resistant basalt fiber for reinforcing concrete

International Nuclear Information System (INIS)

Lipatov, Ya.V.; Gutnikov, S.I.; Manylov, M.S.; Zhukovskaya, E.S.; Lazoryak, B.I.

2015-01-01

Highlights: • Doping of basalt fiber with ZrSiO 4 increased its alkali resistance. • Alkali treatment results in formation of protective surface layer on fibers. • Morphology and chemical composition of surface layer were investigated. • Mechanical properties of fibers were analyzed by a Weibull distribution. • Zirconia doped basalt fibers demonstrate high performance in concrete. - Abstract: Basalt glasses and fibers with zirconia content in the range from 0 to 7 wt% were obtained using ZrSiO 4 as a zirconium source. Weight loss and tensile strength loss of fibers after refluxing in alkali solution were determined. Basalt fiber with 5.7 wt% ZrO 2 had the best alkali resistance properties. Alkali treatment results in formation of protective surface layer on fibers. Morphology and chemical composition of surface layer were investigated. It was shown that alkali resistance of zirconia doped basalt fibers is caused by insoluble compounds of Zr 4+ , Fe 3+ and Mg 2+ in corrosion layer. Mechanical properties of initial and leached fibers were evaluated by a Weibull distribution. The properties of basalt fibers with ZrSiO 4 were compared with AR-glass fibers. The performance of concrete with obtained fibers was investigated

Proposal for the RPC muon detector of LHCb

CERN Document Server

Adinolfi, M; Calvetti, M; Carboni, G; Iacopini, E; Messi, R; Pacciani, L; Passaleva, G; Santovetti, E; Santovetti, Emanuele

2000-01-01

2000-053 We propose to use RPCs to equip a substantial part of the muon detector stations M2-M5. RPCs made of phenolic plates of low resistivity (9 10^9 ohm-cm) and operated in avalanche mode offer very good performance and several advantages in region IV of M2-M5 and in region III of M4-M5. Using this technique it is possible to cover 75 % of the total area behind the calorimeters at moderate cost.

Analysis of clinical isolates of Helicobacter pylori in Pakistan reveals high degrees of pathogenicity and high frequencies of antibiotic resistance.

Science.gov (United States)

Rasheed, Faisal; Campbell, Barry James; Alfizah, Hanafiah; Varro, Andrea; Zahra, Rabaab; Yamaoka, Yoshio; Pritchard, David Mark

2014-10-01

Antibiotic resistance in Helicobacter pylori contributes to failure in eradicating the infection and is most often due to point and missense mutations in a few key genes. The antibiotic susceptibility profiles of H. pylori isolates from 46 Pakistani patients were determined by Etest. Resistance and pathogenicity genes were amplified, and sequences were analyzed to determine the presence of mutations. A high percentage of isolates (73.9%) were resistant to metronidazole (MTZ), with considerable resistance to clarithromycin (CLR; 47.8%) and amoxicillin (AML; 54.3%) also observed. Relatively few isolates were resistant to tetracycline (TET; 4.3%) or to ciprofloxacin (CIP; 13%). However, most isolates (n = 43) exhibited resistance to one or more antibiotics. MTZ-resistant isolates contained missense mutations in oxygen-independent NADPH nitroreductase (RdxA; 8 mutations found) and NADH flavin oxidoreductase (FrxA; 4 mutations found). In the 23S rRNA gene, responsible for CLR resistance, a new point mutation (A2181G) and 4 previously reported mutations were identified. Pathogenicity genes cagA, dupA, and vacA s1a/m1 were detected frequently in isolates which were also found to be resistant to MTZ, CLR, and AML. A high percentage of CagA and VacA seropositivity was also observed in these patients. Phylogenetic analysis of partial sequences showed uniform distribution of the 3' region of cagA throughout the tree. We have identified H. pylori isolates in Pakistan which harbor pathogenicity genes and worrying antibiotic resistance profiles as a result of having acquired multiple point and missense mutations. H. pylori eradication regimens should therefore be reevaluated in this setting. © 2014 John Wiley & Sons Ltd.

High hydrostatic pressure resistance of Campylobacter jejuni after different sublethal stresses.

Science.gov (United States)

Sagarzazu, N; Cebrián, G; Condón, S; Mackey, B; Mañas, P

2010-07-01

To study the development of resistance responses in Campylobacter jejuni to high hydrostatic pressure (HHP) treatments after the exposure to different stressful conditions that may be encountered in food-processing environments, such as acid pH, elevated temperatures and cold storage. Campylobacter jejuni cells in exponential and stationary growth phase were exposed to different sublethal stresses (acid, heat and cold shocks) prior to evaluate the development of resistance responses to HHP. For exponential-phase cells, neither of the conditions tested increased nor decreased HHP resistance of C. jejuni. For stationary-phase cells, acid and heat adaptation-sensitized C. jejuni cells to the subsequent pressure treatment. On the contrary, cold-adapted stationary-phase cells developed resistance to HHP. Whereas C. jejuni can be classified as a stress sensitive micro-organism, our findings have demonstrated that it can develop resistance responses under different stressing conditions. The resistance of stationary phase C. jejuni to HHP was increased after cells were exposed to cold temperatures. The results of this study contribute to a better knowledge of the physiology of C. jejuni and its survival to food preservation agents. Results here presented may help in the design of combined processes for food preservation based on HHP technology. © 2009 The Authors. Journal compilation © 2009 The Society for Applied Microbiology.

High-resolution and high-conductive electrode fabrication on a low thermal resistance flexible substrate

International Nuclear Information System (INIS)

Kang, Bongchul; Kno, Jinsung; Yang, Minyang

2011-01-01

Processes based on the liquid-state pattern transfer, like inkjet printing, have critical limitations including low resolution and low electrical conductivity when fabricating electrodes on low thermal resistance flexible substrates such as polyethylene terephthalate (PET). Those are due to the nonlinear transfer mechanism and the limit of the sintering temperature. Although the laser direct curing (LDC) of metallic inks is an alternative process to improve the resolution, it is also associated with the disadvantages of causing thermal damage to the polymer substrate. This paper suggests the laser induced pattern adhesion transfer method to fabricate electrodes of both high electrical conductivity and high resolution on a PET substrate. First, solid patterns are cost-effectively created by the LDC of the organometallic silver ink on a glass that is optically and thermally stable. The solid patterns sintered on the glass are transferred to the PET substrate by the photo-thermally generated adhesion force of the substrate. Therefore, we achieved electrodes with a minimum line width of 10 µm and a specific resistance of 3.6 μΩcm on the PET substrate. The patterns also showed high mechanical reliability

High-resolution and high-conductive electrode fabrication on a low thermal resistance flexible substrate

Science.gov (United States)

Kang, Bongchul; Kno, Jinsung; Yang, Minyang

2011-07-01

Processes based on the liquid-state pattern transfer, like inkjet printing, have critical limitations including low resolution and low electrical conductivity when fabricating electrodes on low thermal resistance flexible substrates such as polyethylene terephthalate (PET). Those are due to the nonlinear transfer mechanism and the limit of the sintering temperature. Although the laser direct curing (LDC) of metallic inks is an alternative process to improve the resolution, it is also associated with the disadvantages of causing thermal damage to the polymer substrate. This paper suggests the laser induced pattern adhesion transfer method to fabricate electrodes of both high electrical conductivity and high resolution on a PET substrate. First, solid patterns are cost-effectively created by the LDC of the organometallic silver ink on a glass that is optically and thermally stable. The solid patterns sintered on the glass are transferred to the PET substrate by the photo-thermally generated adhesion force of the substrate. Therefore, we achieved electrodes with a minimum line width of 10 µm and a specific resistance of 3.6 μΩcm on the PET substrate. The patterns also showed high mechanical reliability.

New approach to increasing rice lodging resistance and biomass yield through the use of high gibberellin producing varieties.

Science.gov (United States)

Okuno, Ayako; Hirano, Ko; Asano, Kenji; Takase, Wakana; Masuda, Reiko; Morinaka, Yoichi; Ueguchi-Tanaka, Miyako; Kitano, Hidemi; Matsuoka, Makoto

2014-01-01

Traditional breeding for high-yielding rice has been dependent on the widespread use of fertilizers and the cultivation of gibberellin (GA)-deficient semi-dwarf varieties. The use of semi-dwarf plants facilitates high grain yield since these varieties possess high levels of lodging resistance, and thus could support the high grain weight. Although this approach has been successful in increasing grain yield, it is desirable to further improve grain production and also to breed for high biomass. In this study, we re-examined the effect of GA on rice lodging resistance and biomass yield using several GA-deficient mutants (e.g. having defects in the biosynthesis or perception of GA), and high-GA producing line or mutant. GA-deficient mutants displayed improved bending-type lodging resistance due to their short stature; however they showed reduced breaking-type lodging resistance and reduced total biomass. In plants producing high amounts of GA, the bending-type lodging resistance was inferior to the original cultivars. The breaking-type lodging resistance was improved due to increased lignin accumulation and/or larger culm diameters. Further, these lines had an increase in total biomass weight. These results show that the use of rice cultivars producing high levels of GA would be a novel approach to create higher lodging resistance and biomass.

MUON DETECTORS: RPC

CERN Multimedia

Giuseppe Iaselli

Major interventions have been completed on the plus-side endcap. Two faulty chambers have been replaced, the gas circuit for six sectors has been modified from serial to parallel, the leaking cooling circuits have been fixed, and a few high voltage connectors have been replaced. The minus-side endcap has been fully commissioned and the link board electronics put into operation. A preliminary attempt to synchronize the minus endcap has also been attempted during the global run data taking. Some additional improvement of the grounding connections has been done on the W+2/W-2 barrel wheels. A preliminary observation of the monitoring data shows this has had a positive effect on the noise level. Significant improvement in our understanding of the CCR ring instabilities has been achieved. Additional filters will be installed on the cables to protect against noise pick-up. The implementation of the TTU technical trigger was completed and the system was debugged. The TTU now has to be integrated into the overal...

A simple identification method for spore-forming bacteria showing high resistance against γ-rays

International Nuclear Information System (INIS)

Koshikawa, Tomihiko; Sone, Koji; Kobayashi, Toshikazu

1993-01-01

A simple identification method was developed for spore-forming bacteria which are highly resistant against γ-rays. Among 23 species of Bacillus studied, the spores of Bacillus megaterium, B. cereus, B. thuringiensis, B. pumilus and B. aneurinolyticus showed high resistance against γ-rays as compared with other spores of Bacillus species. Combination of the seven kinds of biochemical tests, namely, the citrate utilization test, nitrate reduction test, starch hydrolysis test, Voges-Proskauer reaction test, gelatine hydrolysis test, mannitol utilization test and xylose utilization test showed a characteristic pattern for each species of Bacillus. The combination pattern of each the above tests with a few supplementary test, if necessary, was useful to identify Bacillus species showing high radiation resistance against γ-rays. The method is specific for B. megaterium, B. thuringiensis and B. pumilus, and highly selective for B. aneurinolyticus and B. cereus. (author)

Intermittent dynamics of nonlinear resistive tearing modes at extremely high magnetic Reynolds number

International Nuclear Information System (INIS)

Miyoshi, Takahiro; Becchaku, Masahiro; Kusano, Kanya

2008-01-01

Nonlinear dynamics of the resistive tearing instability in high magnetic Reynolds number (R m ) plasmas is studied by newly developing an accurate and robust resistive magnetohydrodynamic (MHD) scheme. The results show that reconnection processes strongly depend on R m . Particularly, in a high R m case, small-scale plasmoids induced by a secondary instability are intermittently generated and ejected accompanied by fast shocks. According to the intermittent processes, the reconnection rate increases intermittently at a later nonlinear stage. (author)

Crack-resistant polyimide coating for high-capacity battery anodes

Science.gov (United States)

Li, Yingshun; Wang, Shuo; Lee, Pui-Kit; He, Jieqing; Yu, Denis Y. W.

2017-10-01

Electrode cracking is a serious problem that hinders the application of many next-generation high-capacity anode materials for lithium-ion batteries. Even though nano-sizing the material can reduce fracturing of individual particles, capacity fading is still observed due to large volume change and loss of contact in the electrode during lithium insertion and extraction. In this study, we design a crack-resistant high-modulus polyimide coating with high compressive strength which can hold multiple particles together during charge and discharge to maintain contact. The effectiveness of the coating is demonstrated on tin dioxide, a high-capacity large-volume-change material that undergoes both alloy and conversion reactions. The polyimide coating improves capacity retention of SnO2 from 80% to 100% after 80 cycles at 250 mA g-1. Stable capacity of 585 mAh g-1 can be obtained even at 500 mA g-1 after 300 cycles. Scanning electron microscopy and in-situ dilatometry confirm that electrode cracking is suppressed and thickness change is reduced with the coating. In addition, the chemically-stable polyimide film can separate the surface from direct contact with electrolyte, improving coulombic efficiency to ∼100%. We expect the novel strategy of suppressing electrode degradation with a crack-resistant coating can also be used for other alloy and conversion-based anodes.

Estimation of interface resistivity in bonded Si for the development of high performance radiation detectors

International Nuclear Information System (INIS)

Kanno, Ikuo; Yamashita, Makoto; Nomiya, Seiichiro; Onabe, Hideaki

2007-01-01

For the development of high performance radiation detectors, direct bonding of Si wafers would be an useful method. Previously, p-n bonded Si were fabricated and they showed diode characteristics. The interface resistivity was, however, not investigated in detail. For the study of interface resistivity, n-type Si wafers with different resistivities were bonded. The resistivity of bonded Si wafers were measured and the interface resistivity was estimated by comparing with the results of model calculations. (author)

Implementation of the AAPM Task Group 21 protocol by the Radiological Physics Center and its implications

International Nuclear Information System (INIS)

Gastorf, R.J.; Hanson, W.F.; Shalek, R.J.; Berkley, L.W.

1984-01-01

The Radiation Therapy Committee of the American Association of Physicists in Medicine appointed Task Group 21 to write a new protocol for the calibration of high-energy photon and electron therapy beams. This protocol updates the physical parameters used in the calculations and is intended to account for differences in ionization chamber design and some differences between phantom materials that were not considered in previous protocols. This paper discusses how the Radiological Physics Center (RPC) intends to implement the new protocol, the changes required in the RPC calibration techniques, and the magnitude of the change in the RPC calculations of absorbed dose resulting from the implementation of the new protocol. Although the change in the RPC absorbed-dose calculations will be only 0%-2% over the range of photon and electron energies of interest, some institutions using specific dosimetry systems may find their absorbed-dose calculations changing by 4% or more

Methicillin-susceptible and -resistant Staphylococcus aureus with high-level antiseptic and low-level mupirocin resistance in Malaysia.

Science.gov (United States)

Ghasemzadeh-Moghaddam, Hamed; van Belkum, Alex; Hamat, Rukman Awang; van Wamel, Willem; Neela, Vasanthakumari

2014-10-01

The prevalence and spread of mupirocin and antiseptic resistance among colonizing and infectious Staphylococcus aureus were determined. S. aureus isolated from anterior nares and infection sites of patients hospitalized in the largest tertiary care referral hospital in Malaysia was investigated for mupirocin and antiseptic susceptibility testing, and for PCR detection of mupA, qacA/B, and smr genes. Twelve isolates showed resistance to mupirocin by disk diffusion, of which 10 (3.8%) harbored the mupA gene. Minimum inhibitory concentrations (MICs) ranged from 64 to 768 μg/ml for mupA positive and below 46 μg/ml for negative isolates. The mupA was more common among ST239 isolates (70%). The qacA/B was carried in 67 out of 95 methicillin-resistant Staphylococcus aureus (MRSA) (70.5%) and 3 out of 164 methicillin-susceptible Staphylococcus aureus (MSSA) (1.8%), while smr was carried in 6 out of 95 MRSA (6.3%) strains. MICs ranged from 3.9 to 15.6 μg/ml for benzethonium chloride (BTC) and benzalkonium chloride (BKC), and from 10.3 to 20.7 μg/ml for chlorhexidine digluconate (CHG). Isolates with qacA/B and smr or qacA/B alone showed higher MIC (20.7 μg/ml for CHG and 15.6 μg/ml for BTC and BKC) than the isolates that lacked antiseptic resistance genes (10.3 μg/ml for CHG and 3.9 μg/ml for BTC and BKC). In 16 cases, ST239 was isolated from the infection site and the nares simultaneously, and shared identical resistance patterns (qacAB or qacAB+smr), suggesting possible endogenous infection. Spread of low-level mupirocin resistance expressing ST239 MRSA and high-level resistance expressing emerging ST1, co-existing with antiseptic-resistant genes showing elevated MICs, should be monitored for effective infection control.

RNA-Seq analysis reveals insight into enhanced rice Xa7-mediated bacterial blight resistance at high temperature.

Directory of Open Access Journals (Sweden)

Stephen P Cohen

Full Text Available Plant disease is a major challenge to agriculture worldwide, and it is exacerbated by abiotic environmental factors. During some plant-pathogen interactions, heat stress allows pathogens to overcome host resistance, a phenomenon which could severely impact crop productivity considering the global warming trends associated with climate change. Despite the importance of this phenomenon, little is known about the underlying molecular mechanisms. To better understand host plant responses during simultaneous heat and pathogen stress, we conducted a transcriptomics experiment for rice plants (cultivar IRBB61 containing Xa7, a bacterial blight disease resistance (R gene, that were infected with Xanthomonas oryzae, the bacterial blight pathogen of rice, during high temperature stress. Xa7-mediated resistance is unusual relative to resistance mediated by other R genes in that it functions better at high temperatures. Using RNA-Seq technology, we identified 8,499 differentially expressed genes as temperature responsive in rice cultivar IRBB61 experiencing susceptible and resistant interactions across three time points. Notably, genes in the plant hormone abscisic acid biosynthesis and response pathways were up-regulated by high temperature in both mock-treated plants and plants experiencing a susceptible interaction and were suppressed by high temperature in plants exhibiting Xa7-mediated resistance. Genes responsive to salicylic acid, an important plant hormone for disease resistance, were down-regulated by high temperature during both the susceptible and resistant interactions, suggesting that enhanced Xa7-mediated resistance at high temperature is not dependent on salicylic acid signaling. A DNA sequence motif similar to known abscisic acid-responsive cis-regulatory elements was identified in the promoter region upstream of genes up-regulated in susceptible but down-regulated in resistant interactions. The results of our study suggest that the plant

Comparison of two highly granular hadronic calorimeter concepts

International Nuclear Information System (INIS)

Neubueser, Coralie

2016-11-01

The CALICE collaboration develops hadron calorimeter technologies with high granularity for future electron-positron linear colliders. These technologies differ in active material, granularity and their readout and thus their energy reconstruction schemes. The Analogue Hadron Calorimeter (AHCAL), based on scintillator tiles with Silicon Photomultiplier readout, measures the signal amplitude of the energy deposition in the cells of at most 3 x 3 cm"2 size. The Digital, Resistive Plate Chamber (RPC) based, HCAL (DHCAL) detects hits above a certain threshold by firing pad sensors of 1 x 1 cm"2. A 2 bit readout is provided by the, also RPC based, Semi-Digital HCAL (SDHCAL), which counts hits above three different thresholds per 1 x 1 cm"2 pad. All three calorimeter concepts have been realised in 1 m"3 prototypes with interleaved steel absorber and tested at various test beams. The differences in active medium, granularity and readout have different impacts on the energy resolution and need to be studied independently. This analysis concentrates on the comparison between these technologies by investigating the impact of the different energy reconstruction schemes on the energy resolution of the AHCAL testbeam data and simulation. Additionally, a so-called software compensation algorithm is developed to weight hits dependent on their energy content and correct for the difference in the response to the electromagnetic and hadronic sub-showers (e/h≠1) and thus reduce the influence of fluctuations in the π"0 generation. The comparison of the energy resolutions revealed that it is mandatory for the AHCAL with 3 x 3 cm"2 cell size to have analogue signal readout, to apply the software compensation algorithm and thus achieve the best possible energy resolution. The effect of the granularity is studied with a simulation of the AHCAL with 1 x 1 cm"2 cell size, and it has been found that to achieve the best possible energy resolution the semi-digital energy reconstruction is

Laser beam joining of non-oxidic ceramics for ultra high temperature resistant joints

International Nuclear Information System (INIS)

Lippmann, W.; Knorr, J.; Wolf, R.; Reinecke, A.M.; Rasper, R.

2004-01-01

The excellent technical properties of silicon carbide (SiC) and silicon nitride (Si 3 N 4 ) ceramics, such as resistance to extreme temperatures, oxidation, mechanical wear, aggressive chemical substances and radioactive radiation and also its high thermal conductivity and good temperature-shock resistance, make these ceramics ideally suited for use in the field of nuclear technology. However, their practical use has been limited so far because of the unavailability of effective joining techniques for these ceramics, especially for high temperature applications. A new joining technology (CERALINK registered ) has been developed in a network project which allowed high temperature resistant and vacuum-tight joining of SiC or Si 3 N 4 ceramics. A power laser is used as heat source, which makes it possible to join ceramic components in free atmosphere in combination with a pure oxidic braze filler. As no furnace is necessary, there are no limitations on the component dimensions by the furnace-geometry. During the joining process, the heated area can be limited to the seam area so that this technology can also be used to encapsulate materials with a low melting point. The seam has a high mechanical strength, it is resistant to a wide range of chemicals and radiation and it is also vacuum-tight. The temperature resistance can be varied by variation of the braze filler composition - usually between 1,400 C and >1,600 C. Beside the optimum filler it is also important to select the suitable laser wavelength. The paper will demonstrate the influence of different wave lengths, i. e. various laser types, on the seam quality. Examples are chosen to illustrate the strengths and limitations of the new technology

Development of a large-area Multigap RPC with adequate spatial resolution for muon tomography

Science.gov (United States)

Wang, J.; Wang, Y.; Wang, X.; Zeng, M.; Xie, B.; Han, D.; Lyu, P.; Wang, F.; Li, Y.

2016-11-01

We study the performance of a large-area 2-D Multigap Resistive Plate Chamber (MRPC) designed for muon tomography with high spatial resolution. An efficiency up to 98% and a spatial resolution of around 270 μ m are obtained in cosmic ray and X-ray tests. The performance of the MRPC is also investigated for two working gases: standard gas and pure Freon. The result shows that the MRPC working in pure Freon can provide higher efficiency and better spatial resolution.

New approach to increasing rice lodging resistance and biomass yield through the use of high gibberellin producing varieties.

Directory of Open Access Journals (Sweden)

Ayako Okuno

Full Text Available Traditional breeding for high-yielding rice has been dependent on the widespread use of fertilizers and the cultivation of gibberellin (GA-deficient semi-dwarf varieties. The use of semi-dwarf plants facilitates high grain yield since these varieties possess high levels of lodging resistance, and thus could support the high grain weight. Although this approach has been successful in increasing grain yield, it is desirable to further improve grain production and also to breed for high biomass. In this study, we re-examined the effect of GA on rice lodging resistance and biomass yield using several GA-deficient mutants (e.g. having defects in the biosynthesis or perception of GA, and high-GA producing line or mutant. GA-deficient mutants displayed improved bending-type lodging resistance due to their short stature; however they showed reduced breaking-type lodging resistance and reduced total biomass. In plants producing high amounts of GA, the bending-type lodging resistance was inferior to the original cultivars. The breaking-type lodging resistance was improved due to increased lignin accumulation and/or larger culm diameters. Further, these lines had an increase in total biomass weight. These results show that the use of rice cultivars producing high levels of GA would be a novel approach to create higher lodging resistance and biomass.

High Thermal Conductivity and High Wear Resistance Tool Steels for cost-effective Hot Stamping Tools

Science.gov (United States)

Valls, I.; Hamasaiid, A.; Padré, A.

2017-09-01

In hot stamping/press hardening, in addition to its shaping function, the tool controls the cycle time, the quality of the stamped components through determining the cooling rate of the stamped blank, the production costs and the feasibility frontier for stamping a given component. During the stamping, heat is extracted from the stamped blank and transported through the tool to the cooling medium in the cooling lines. Hence, the tools’ thermal properties determine the cooling rate of the blank, the heat transport mechanism, stamping times and temperature distribution. The tool’s surface resistance to adhesive and abrasive wear is also an important cost factor, as it determines the tool durability and maintenance costs. Wear is influenced by many tool material parameters, such as the microstructure, composition, hardness level and distribution of strengthening phases, as well as the tool’s working temperature. A decade ago, Rovalma developed a hot work tool steel for hot stamping that features a thermal conductivity of more than double that of any conventional hot work tool steel. Since that time, many complimentary grades have been developed in order to provide tailored material solutions as a function of the production volume, degree of blank cooling and wear resistance requirements, tool geometries, tool manufacturing method, type and thickness of the blank material, etc. Recently, Rovalma has developed a new generation of high thermal conductivity, high wear resistance tool steel grades that enable the manufacture of cost effective tools for hot stamping to increase process productivity and reduce tool manufacturing costs and lead times. Both of these novel grades feature high wear resistance and high thermal conductivity to enhance tool durability and cut cycle times in the production process of hot stamped components. Furthermore, one of these new grades reduces tool manufacturing costs through low tool material cost and hardening through readily

Breeding of a new potato variety ‘Nagasaki Kogane’ with high eating quality, high carotenoid content, and resistance to diseases and pests

Science.gov (United States)

Sakamoto, Yu; Mori, Kazuyuki; Matsuo, Yuuki; Mukojima, Nobuhiro; Watanabe, Wataru; Sobaru, Norio; Tamiya, Seiji; Nakao, Takashi; Hayashi, Kazuya; Watanuki, Hitomi; Nara, Kazuhiro; Yamazaki, Kaoru; Chaya, Masataka

2017-01-01

‘Nagasaki Kogane’ is a new potato variety bred from a cross between ‘Saikai 35’ as a female parent and ‘Saikai 33’ as a male. ‘Saikai 35’ is resistant to bacterial wilt, contains the H1 and Rychc genes for resistance to the potato cyst nematode (PCN) and potato virus Y (PVY), respectively, and has high carotenoid content, while ‘Saikai 33’ has large and high-yielding tubers and is resistant to both bacterial wilt and PCN. The carotenoid content of ‘Nagasaki Kogane’ is higher than that of ‘Dejima’, a common double cropping variety. The taste quality of steamed ‘Nagasaki Kogane’ is comparable to that of ‘Inca-no-mezame’ tubers, which has high levels of carotenoid, and superior to ‘Nishiyutaka’, another popular double cropping variety. ‘Nagasaki Kogane’ is suitable for French fries, because its tuber has high starch content. The marketable yield of ‘Nagasaki Kogane’ was higher than that of ‘Inca-no-mezame’ in spring cropping, although it was lower than that of ‘Nishiyutaka’ in double cropping regions. ‘Nagasaki Kogane’ tubers are larger on average than ‘Inca-no-mezame’ tubers in spring cropping. Moreover, the ‘Nagasaki Kogane’ variety is resistant to PCN and PVY, and exhibits a high level of resistance to bacterial wilt. PMID:28744186

Metabolic responses to high protein diet in Korean elite bodybuilders with high-intensity resistance exercise

Directory of Open Access Journals (Sweden)

Choue Ryowon

2011-07-01

Full Text Available Abstract Background High protein diet has been known to cause metabolic acidosis, which is manifested by increased urinary excretion of nitrogen and calcium. Bodybuilders habitually consumed excessive dietary protein over the amounts recommended for them to promote muscle mass accretion. This study investigated the metabolic response to high protein consumption in the elite bodybuilders. Methods Eight elite Korean bodybuilders within the age from 18 to 25, mean age 21.5 ± 2.6. For data collection, anthropometry, blood and urinary analysis, and dietary assessment were conducted. Results They consumed large amounts of protein (4.3 ± 1.2 g/kg BW/day and calories (5,621.7 ± 1,354.7 kcal/day, as well as more than the recommended amounts of vitamins and minerals, including potassium and calcium. Serum creatinine (1.3 ± 0.1 mg/dl and potassium (5.9 ± 0.8 mmol/L, and urinary urea nitrogen (24.7 ± 9.5 mg/dl and creatinine (2.3 ± 0.7 mg/dl were observed to be higher than the normal reference ranges. Urinary calcium (0.3 ± 0.1 mg/dl, and phosphorus (1.3 ± 0.4 mg/dl were on the border of upper limit of the reference range and the urine pH was in normal range. Conclusions Increased urinary excretion of urea nitrogen and creatinine might be due to the high rates of protein metabolism that follow high protein intake and muscle turnover. The obvious evidence of metabolic acidosis in response to high protein diet in the subjects with high potassium intake and intensive resistance exercise were not shown in this study results. However, this study implied that resistance exercise with adequate mineral supplementation, such as potassium and calcium, could reduce or offset the negative effects of protein-generated metabolic changes. This study provides preliminary information of metabolic response to high protein intake in bodybuilders who engaged in high-intensity resistance exercise. Further studies will be needed to determine the effects of the intensity

Quasi-static puncture resistance behaviors of high-strength polyester fabric for soft body armor

Directory of Open Access Journals (Sweden)

Qiu-Shi Wang

Full Text Available A series of economical and flexible fabrics were prepared using high-strength polyester yarns with different fabric structures, weft density and number of layers. The effect of these factors on quasi-static puncture resistance was comparatively studied. The failure mode of the fabrics was analyzed with SEM photographs. Findings indicate that the structure and the weft density affected the quasi-static puncture resistance property of the fabrics, the plain fabrics had better puncture resistance property than twill and satin fabrics. The max puncture force and puncture energy of the plain fabrics with 160 yarn/10 cm reached the max values which were 107.43 N and 0.44 J, respectively. The number of layers had a linear relationship to quasi-static puncture resistance. The contact pressure and friction of the probe against the fibers were the main hindrance during the quasi-static puncture process and the breakage of the fibers during the penetration was caused by the bend and tensile deformation. Keywords: High-strength polyester fabrics, Fabric structure, Multiple-layer fabrics, Quasi-static puncture resistance

Performance, operation and detector studies with the ATLAS Resistive Plate Chambers

International Nuclear Information System (INIS)

Aielli, G; Bindi, M; Polini, A

2013-01-01

Resistive Plate Chambers provide the barrel region of the ATLAS detector with an independent muon trigger and a two-coordinate measurement. The chambers, arranged in three concentric double layers, are operated in a strong magnetic toroidal field and cover a surface area of about 4000 m 2 . During 2011 the LHC has provided proton-proton collisions at 7 TeV in the center-of-mass frame with a steady increase in instantaneous luminosity, summing up to about 5 fb −1 . The operational experience for this running period is presented along with studies of the detector performance as a function of luminosity, environmental conditions and working point settings. Non-event based information including in particular the large number of gas gap currents, individually monitored with nA accuracy, have been used to study the detector behavior with growing luminosity and beam currents. These data are shown to provide, when calibrated, an independent luminosity measurement and a crucial handle for understanding the ATLAS backgrounds well beyond the scope of muon triggering and detection. The measurements presented here allow to plan a strategy for the data taking in the next years and make some predictions about the detector performance at higher luminosities. They also improve the knowledge on RPC detector physics.

Highly corrosion resistant zirconium based alloy for reactor structural material

International Nuclear Information System (INIS)

Ito, Yoichi.

1996-01-01

The alloy of the present invention is a zirconium based alloy comprising tin (Sn), chromium (Cr), nickel (Ni) and iron (Fe) in zirconium (Zr). The amount of silicon (Si) as an impurity is not more than 60ppm. It is preferred that Sn is from 0.9 to 1.5wt%, that of Cr is from 0.05 to 0.15wt%, and (Fe + Ni) is from 0.17 to 0.5wt%. If not less than 0.12wt% of Fe is added, resistance against nodular corrosion is improved. The upper limit of Fe is preferably 0.40wt% from a view point of uniform suppression for the corrosion. The nodular corrosion can be suppressed by reducing the amount of Si-rich deposition product in the zirconium based alloy. Accordingly, a highly corrosion resistant zirconium based alloy improved for the corrosion resistance of zircaloy-2 and usable for a fuel cladding tube of a BWR type reactor can be obtained. (I.N.)

GREX/COVER-PLASTEX: an experiment to analyze the space-time structure of extensive air showers produced by primary cosmic rays of 1015 eV

International Nuclear Information System (INIS)

Agnetta, G.; Ambrosio, M.; Beaman, J.; Barbarino, G.C.; Biondo, B.; Catalano, O.; Colesanti, L.; Dali, G.; Guarino, F.; Lauro, A.; Lloyd-Evans, J.; Mangano, A.; Popova, L.; Watson, A.A.

1995-01-01

A novel experimental installation is described in which the traditional method of detecting extensive air showers with scintillation counters is significantly extended by the addition of limited streamer tube hodoscopes (LST) and layers of resistive plate counters (RPC). Runs with the scintillator array, GREX, at Haverah Park have demonstrated the power of the LST hodoscopes to determine the direction of arrival of muons, electrons and photons in air showers while the RPC system permits the relative arrival time of individual particles and the temporal thickness and structure of the shower disc to be obtained. The potential of these technical advances for studying the longitudinal profile of air showers produced by primaries of about 1000 TeV is briefly discussed. First measurements of thickness and time profile of EAS front are also reported. (orig.)

Pramana – Journal of Physics | Indian Academy of Sciences

Indian Academy of Sciences (India)

The India-based Neutrino Observatory Collaboration is planning to set up a magnetized 50 kt iron calorimeter (ICAL) with resistive plate chambers (RPC) as active detectors to study neutrino oscillations and precisely measure its parameters. A prototype detector stack is set up at TIFR (18°54'N, 72°48'E) to track cosmic ray ...

High-throughput phenotyping of plant resistance to aphids by automated video tracking.

Science.gov (United States)

Kloth, Karen J; Ten Broeke, Cindy Jm; Thoen, Manus Pm; Hanhart-van den Brink, Marianne; Wiegers, Gerrie L; Krips, Olga E; Noldus, Lucas Pjj; Dicke, Marcel; Jongsma, Maarten A

2015-01-01

Piercing-sucking insects are major vectors of plant viruses causing significant yield losses in crops. Functional genomics of plant resistance to these insects would greatly benefit from the availability of high-throughput, quantitative phenotyping methods. We have developed an automated video tracking platform that quantifies aphid feeding behaviour on leaf discs to assess the level of plant resistance. Through the analysis of aphid movement, the start and duration of plant penetrations by aphids were estimated. As a case study, video tracking confirmed the near-complete resistance of lettuce cultivar 'Corbana' against Nasonovia ribisnigri (Mosely), biotype Nr:0, and revealed quantitative resistance in Arabidopsis accession Co-2 against Myzus persicae (Sulzer). The video tracking platform was benchmarked against Electrical Penetration Graph (EPG) recordings and aphid population development assays. The use of leaf discs instead of intact plants reduced the intensity of the resistance effect in video tracking, but sufficiently replicated experiments resulted in similar conclusions as EPG recordings and aphid population assays. One video tracking platform could screen 100 samples in parallel. Automated video tracking can be used to screen large plant populations for resistance to aphids and other piercing-sucking insects.

Proliferation resistance assessment of high temperature gas reactors

Energy Technology Data Exchange (ETDEWEB)

Chikamatsu N, M. A. [Instituto Tecnologico y de Estudios Superiores de Monterrey, Campus Santa Fe, Av. Carlos Lazo No. 100, Santa Fe, 01389 Mexico D. F. (Mexico); Puente E, F., E-mail: midori.chika@gmail.com [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

2014-10-15

The Generation IV International Forum has established different objectives for the new generation of reactors to accomplish. These objectives are focused on sustain ability, safety, economics and proliferation resistance. This paper is focused on how the proliferation resistance of the High Temperature Gas Reactors (HTGR) is assessed and the advantages that these reactors present currently. In this paper, the focus will be on explaining why such reactors, HTGR, can achieve the goals established by the GIF and can present a viable option in terms of proliferation resistance, which is an issue of great importance in the field of nuclear energy generation. The reason why the HTGR are being targeted in this writing is that these reactors are versatile, and present different options from modular reactors to reactors with the same size as the ones that are being operated today. Besides their versatility, the HTGR has designed features that might improve on the overall sustain ability of the nuclear reactors. This is because the type of safety features and materials that are used open up options for industrial processes to be carried out; cogeneration for instance. There is a small section that mentions how HTGR s are being developed in the international sector in order to present the current world view in this type of technology and the further developments that are being sought. For the proliferation resistance section, the focus is on both the intrinsic and the extrinsic features of the nuclear systems. The paper presents a comparison between the features of Light Water Reactors (LWR) and the HTGR in order to be able to properly compare the most used technology today and one that is gaining international interest. (Author)

Proliferation resistance assessment of high temperature gas reactors

International Nuclear Information System (INIS)

Chikamatsu N, M. A.; Puente E, F.

2014-10-01

The Generation IV International Forum has established different objectives for the new generation of reactors to accomplish. These objectives are focused on sustain ability, safety, economics and proliferation resistance. This paper is focused on how the proliferation resistance of the High Temperature Gas Reactors (HTGR) is assessed and the advantages that these reactors present currently. In this paper, the focus will be on explaining why such reactors, HTGR, can achieve the goals established by the GIF and can present a viable option in terms of proliferation resistance, which is an issue of great importance in the field of nuclear energy generation. The reason why the HTGR are being targeted in this writing is that these reactors are versatile, and present different options from modular reactors to reactors with the same size as the ones that are being operated today. Besides their versatility, the HTGR has designed features that might improve on the overall sustain ability of the nuclear reactors. This is because the type of safety features and materials that are used open up options for industrial processes to be carried out; cogeneration for instance. There is a small section that mentions how HTGR s are being developed in the international sector in order to present the current world view in this type of technology and the further developments that are being sought. For the proliferation resistance section, the focus is on both the intrinsic and the extrinsic features of the nuclear systems. The paper presents a comparison between the features of Light Water Reactors (LWR) and the HTGR in order to be able to properly compare the most used technology today and one that is gaining international interest. (Author)

Resistance to Corrosion of Reinforcement of High Volume Fly Ash Concrete

International Nuclear Information System (INIS)

Kwon, S. O.; Bae, S. H.; Lee, H. J.; Lee, K. M.; Jung, S. H.

2014-01-01

Due to the increasing of interest about the eco-friendly concrete, it is increased to use concretes containing by-products of industry such as fly ash(FA), ground granulated blast furnace slag(GGBFS), silica fume(SF), and etc. Especially, these are well known for improving the resistances to reinforcement corrosion in concrete and decreasing chloride ion penetration. The purpose of this experimental research is to evaluate the resistance against corrosion of reinforcement of high volume fly ash(HVFA) concrete which is replaced with high volume fly ash for cement volume. For this purpose, the concrete test specimens were made for various strength level and replacement ratio of FA, and then the compressive strength and diffusion coefficient for chloride ion of them were measured for 28, 91, and 182 days, respectively. Also, corrosion monitoring by half cell potential method was carried out for the made lollypop concrete test specimens to detect the time of corrosion initiation for reinforcement in concrete. As a result, it was observed from the test results that the compressive strength of HVFA concrete was decreased with increasing replacement ratio of FA but long-term resistances against reinforcement corrosion and chloride ion penetration of that were increased

Odontella aurita-enriched diet prevents high fat diet-induced liver insulin resistance.

Science.gov (United States)

Amine, Hamza; Benomar, Yacir; Haimeur, Adil; Messaouri, Hafida; Meskini, Nadia; Taouis, Mohammed

2016-01-01

The beneficial effect of polyunsaturated omega-3 fatty acid (w-3 FA) consumption regarding cardiovascular diseases, insulin resistance and inflammation has been widely reported. Fish oil is considered as the main source of commercialized w-3 FAs, and other alternative sources have been reported such as linseed or microalgae. However, despite numerous reports, the underlying mechanisms of action of w-3 FAs on insulin resistance are still not clearly established, especially those from microalgae. Here, we report that Odontella aurita, a microalga rich in w-3 FAs eicosapentaenoic acid, prevents high fat diet-induced insulin resistance and inflammation in the liver of Wistar rats. Indeed, a high fat diet (HFD) increased plasma insulin levels associated with the impairment of insulin receptor signaling and the up-regulation of toll-like receptor 4 (TLR4) expressions. Importantly, Odontella aurita-enriched HFD (HFOA) reduces body weight and plasma insulin levels and maintains normal insulin receptor expression and responsiveness. Furthermore, HFOA decreased TLR4 expression, JNK/p38 phosphorylation and pro-inflammatory factors. In conclusion, we demonstrate for the first time, to our knowledge, that diet supplementation with whole Ondontella aurita overcomes HFD-induced insulin resistance through the inhibition of TLR4/JNK/p38 MAP kinase signaling pathways. © 2016 Society for Endocrinology.

Slice Test Results of the ATLAS Barrel Muon Level-1 Trigger

CERN Document Server

Aielli, G; Alviggi, M G; Bocci, V; Brambilla, Elena; Canale, V; Caprio, M A; Cardarelli, R; Cataldi, G; De Asmundis, R; Della Volpe, D; Di Ciaccio, A; Di Simone, A; Distante, L; Gorini, E; Grancagnolo, F; Iengo, P; Nisati, A; Pastore, F; Patricelli, S; Perrino, R; Petrolo, E; Primavera, M; Salamon, A; Santonico, R; Sekhniaidze, G; Severi, M; Spagnolo, S; Vari, R; Veneziano, Stefano; 9th Workshop On Electronics For LHC Experiments - LECC 2003

2003-01-01

The muon spectrometer of the ATLAS experiment makes use of the Resistive Plate Chambers detectors for particle tracking in the barrel region. The level-1 muon trigger system has to measure and discriminate muon transverse momentum, perform a fast and coarse tracking of the muon candidates, associate them to the bunch crossing corresponding to the event of interest, measure the second coordinate in the non-bending projection. The on-detector electronics first collects front-end signals coming from the two inner RPC stations on the low-pT PAD boards, each one covering a region of DetaxDphi=0.2x0.2, and hosting four Coincidence Matrix ASICs. Each CMA performs the low-pT trigger algorithm and data readout on a region of DetaxDphi=0.2x0.1. Data coming from the four CMAs are assembled by the low-pT PAD logic. Each low-pT PAD board sends data to the corresponding high-pT PAD boards, located on the outer RPC station. Four CMA on each board make use of the low-pT trigger result and of the front-end signals coming from...

Inexpensive system protects megawatt resistance-heating furnace against high-voltage surges

Science.gov (United States)

Stearns, E. J.

1971-01-01

Coolant gas extinguishes arcing across the break in a heater element. Air-gap shunt which bypasses high voltage impressed across the circuit prevents damage if the resistance elements break and open the inductive circuit.

A study on the improvement of oxidation resistance of OAE-added stainless steels for high temperature applications

International Nuclear Information System (INIS)

Kim, Dae Hwan; Kim, Gil Moo

1996-01-01

Since the manufacturing temperature of stainless steels is relatively high, oxidation at the elevated temperature becomes important. The chemical and physical properties of the protective oxide film which was formed on the stainless steels at high temperature for the oxidation resistance are important in determining the rate of oxidation and the life of equipment exposed to high temperature oxidizing environments. In this study, the oxidation behavior of STS 309S and STS 409L added by a small amount of oxygen active element(each + 0.5wt% Hf and Y) was studied to improve oxidation resistance. In the cyclic oxidation, while OAE-free specimens showed relatively poor oxidation resistance due to spallations and cracks of Cr-rich oxide layer, OAE-added specimens improved cyclic oxidation resistance assumably due to constant oxidation rate with stable oxide layers at high temperature. Especially Hf improved cyclic oxidation resistance by forming Cr-rich oxide layer preventing internal oxidation in STS 309S. (author)

HIGH TEMPERATURE CORROSION RESISTANCE OF METALLIC MATERIALS IN HARSH CONDITIONS

OpenAIRE

Novello, Frederic; Dedry, Olivier; De Noose, Vincent; Lecomte-Beckers, Jacqueline

2014-01-01

Highly efficient energy recovery from renewable sources and from waste incineration causes new problems of corrosion at high temperature. A similar situation exists for new recycling processes and new energy storage units. These corrosions are generally considered to be caused by ashes or molten salts, the composition of which differs considerably from one plant to another. Therefore, for the assessment of corrosion-resistance of advanced materials, it is essential to precisely evaluate the c...

Superconducting fault current limiter using high-resistive YBCO tapes

Energy Technology Data Exchange (ETDEWEB)

Yazawa, T. [Power and Industrial System R and D Center, Toshiba Corporation, 2-4 Suehiro, Tsurumi, Yokohama 230-0045 (Japan)], E-mail: takashi.yazawa@toshiba.co.jp; Koyanagi, K.; Takahashi, M.; Ono, M.; Toba, K.; Takigami, H.; Urata, M. [Power and Industrial System R and D Center, Toshiba Corporation, 2-4 Suehiro, Tsurumi, Yokohama 230-0045 (Japan); Iijima, Y.; Saito, T. [Fujikura Ltd., 1-5-1 Kiba, Koto, Tokyo 135-0042 (Japan); Ameniya, N. [Yokohama National University, 79-1 Tokiwadai, Hodogaya, Yokohama 240-8501 (Japan); Shiohara, Y. [Superconductivity Research Laboratory, ISTEC, 1-10-13 Shinonome, Koto, Tokyo 135-0062 (Japan)

2008-09-15

One of the programs in the Ministry of Economy and Trade and Industry (METI) project regarding R and D on YBCO conductor is to evaluate the applicability of the developed conductor toward several applications. This paper focuses on a fault current limiter (FCL) as one of the expected power applications. YBCO tape conductors with ion beam assisted deposition (IBAD) substrate are used in this work. In order to obtain high resistance of the conductor, which is preferable to an FCL, the thickness of the protecting layer made of silver was decreased as possible. Then high-resistive metal stabilizing layer is attached on the silver layer to improve stability. Obtaining the relevant current limiting performance on short sample experiments, model coils were developed to aim the 6.6 kV-class FCL. Short circuit experiments were implemented with a short circuit generator. The coil successfully restricted the short circuit current over 17 kA to about 700 A by the applied voltage of 3.8 kV, which is nominal phase-to-ground voltage. The experimental results show good agreement with computer analyses and show promising toward the application.

SU-E-P-02: Imaging and Radiation Oncology Core (IROC) Houston QA Center (RPC) Credentialing

Energy Technology Data Exchange (ETDEWEB)

Amador, C; Keith, T; Nguyen, T; Molineu, A; Followill, D [UT MD Anderson Cancer Center, Houston, TX (United States)

2014-06-01

Purpose: To provide information pertaining to IROC Houston QA Center's (RPC) credentialing process for institutions participating in NCI-sponsored clinical trials. Methods: IROC Houston issues credentials for NCI sponsored study groups. Requirements for credentialing might include any combination of questionnaires, knowledge assessment forms, benchmarks, or phantom irradiations. Credentialing requirements for specific protocols can be found on IROC Houston's website (irochouston.mdanderson.org). The website also houses the credentialing status inquiry (CSI) form. Once an institution has reviewed the protocol's credentialing requirements, a CSI form should be completed and submitted to IROC Houston. This form is used both to request whether requirements have been met as well as to notify IROC Houston that the institution requests credentialing for a specific protocol. IROC Houston will contact the institution to discuss any delinquent requirements. Once the institution has met all requirements IROC Houston issues a credentialing letter to the institution and will inform study groups and other IROC offices of the credentials. Institutions can all phone the IROC Houston office to initiate credentialing or ask any credentialing related questions. Results: Since 2010 IROC has received 1313 credentialing status inquiry forms. We received 317 in 2010, 266 in 2011, 324 in 2012, and 406 in 2013. On average we receive 35 phone calls per week with multiple types of credentialing questions. Decisions regarding credentialing status are based on the protocol specifications and previous completed credentialing by the institution. In some cases, such as for general IMRT credentialing, up to 5 sites may be credentialed based on the credentialing of one main center. Each of these situations is handled individually. Conclusion: IROC Houston will issue radiation therapy credentials for the NCI trials in the National Clinical Trials Network. Credentialing requirements

High-Performance Corrosion-Resistant Materials: Iron-Based Amorphous-Metal Thermal-Spray Coatings

International Nuclear Information System (INIS)

Farmer, J C; Haslam, J J; Wong, F; Ji, X; Day, S D; Branagan, D J; Marshall, M C; Meacham, B E; Buffa, E J; Blue, C A; Rivard, J K; Beardsley, M B; Weaver, D T; Aprigliano, L F; Kohler, L; Bayles, R; Lemieux, E J; Wolejsza, T M; Martin, F J; Yang, N; Lucadamo, G; Perepezko, J H; Hildal, K; Kaufman, L; Heuer, A H; Ernst, F; Michal, G M; Kahn, H; Lavernia, E J

2004-01-01

The multi-institutional High Performance Corrosion Resistant Materials (HPCRM) Team is cosponsored by the Defense Advanced Projects Agency (DARPA) Defense Science Office (DSO) and the Department of Energy (DOE) Office of Civilian Radioactive Waste Management (OCRWM), and has developed new corrosion-resistant, iron-based amorphous metals that can be applied as coatings with advanced thermal spray technology. Two compositions have corrosion resistance superior to wrought nickel-based Alloy C-22 (UNS No. N06022) in very aggressive environments, including concentrated calcium-chloride brines at elevated temperature. Corrosion costs the Department of Defense billions of dollars every year, with an immense quantity of material in various structures undergoing corrosion. For example, in addition to fluid and seawater piping, ballast tanks, and propulsions systems, approximately 345 million square feet of structure aboard naval ships and crafts require costly corrosion control measures. The use of advanced corrosion-resistant materials to prevent the continuous degradation of this massive surface area would be extremely beneficial. The Fe-based corrosion-resistant, amorphous-metal coatings under development may prove of importance for applications on ships. Such coatings could be used as an ''integral drip shield'' on spent fuel containers, as well as protective coatings that could be applied over welds, thereby preventing exposure to environments that might cause stress corrosion cracking. In the future, such new high-performance iron-based materials could be substituted for more-expensive nickel-based alloys, thereby enabling a reduction in the $58-billion life cycle cost for the long-term storage of the Nation's spent nuclear fuel by tens of percent

Investigation on the effect of thermal resistances on a highly concentrated photovoltaic-thermoelectric hybrid system

International Nuclear Information System (INIS)

Zhang, Jin; Xuan, Yimin

2016-01-01

Highlights: • The highly concentrated PV-TE hybrid system is studied. • The performances of different cooling systems are analyzed and compared. • Sandwiching a copper plate between the PV and TE can improve the efficiency. • Four thermal design principles of the system are proposed. - Abstract: A thermal analysis of a highly concentrated photovoltaic-thermoelectric (PV-TE) hybrid system is carried out in this paper. Both the output power and the temperature distribution in the hybrid system are calculated by means of a three-dimensional numerical model. Three possible approaches for designing the highly concentrated PV-TE hybrid system are presented by analyzing the thermal resistance of the whole system. First, the sensitivity analysis shows that the thermal resistance between the TE module and the environment has a more great effect on the output power than the thermal resistance between the PV and the TE. The influence of the natural convection and the radiation can be ignored for the highly concentrated PV-TE hybrid system. Second, it is necessary to sandwich a copper plate between the PV and the TE for decreasing the thermal resistance between the PV and the TE. The role of the copper plate is to improve the temperature uniformity. Third, decreasing the area of PV cells can improve the efficiency of the highly concentrated PV-TE hybrid system. It should be pointed out that decreasing the area of PV cells also increases the total thermal resistance, but the raise of the efficiency is caused by the reduction of the heat transfer rate of the system. Therefore, the principle of minimizing the total thermal resistance may not be suitable for optimizing the area of PV cells.

Development of Steel Fiber-Reinforced Expanded-Shale Lightweight Concrete with High Freeze-Thaw Resistance

Directory of Open Access Journals (Sweden)

Mingshuang Zhao

2018-01-01

Full Text Available For the popularized structural application, steel fiber-reinforced expanded-shale lightweight concrete (SFRELC with high freeze-thaw resistance was developed. The experimental study of this paper figured out the effects of air-entraining content, volume fraction of steel fibers, and fine aggregate type. Results showed that while the less change of mass loss rate was taken place for SFRELC after 300 freeze-thaw cycles, the relative dynamic modulus of elasticity and the relative flexural strength presented clear trends of freeze-thaw resistance of SFRELC. The compound effect of the air-entraining agent and the steel fibers was found to support the SFRELC with high freeze-thaw resistance, and the mechanisms were explored with the aid of the test results of water penetration of SFRELC. The beneficial effect was appeared from the replacement of lightweight sand with manufactured sand. Based on the test results, suggestions are given out for the optimal mix proportion of SFRELC to satisfy the durability requirement of freeze-thaw resistance.

Developmental acclimation to low or high humidity conditions affect starvation and heat resistance of Drosophila melanogaster.

Science.gov (United States)

Parkash, Ravi; Ranga, Poonam; Aggarwal, Dau Dayal

2014-09-01

Several Drosophila species originating from tropical humid localities are more resistant to starvation and heat stress than populations from high latitudes but mechanistic bases of such physiological changes are largely unknown. In order to test whether humidity levels affect starvation and heat resistance, we investigated developmental acclimation effects of low to high humidity conditions on the storage and utilization of energy resources, body mass, starvation survival, heat knockdown and heat survival of D. melanogaster. Isofemale lines reared under higher humidity (85% RH) stored significantly higher level of lipids and showed greater starvation survival hours but smaller in body size. In contrast, lines reared at low humidity evidenced reduced levels of body lipids and starvation resistance. Starvation resistance and lipid storage level were higher in females than males. However, the rate of utilization of lipids under starvation stress was lower for lines reared under higher humidity. Adult flies of lines reared at 65% RH and acclimated under high or low humidity condition for 200 hours also showed changes in resistance to starvation and heat but such effects were significantly lower as compared with developmental acclimation. Isofemale lines reared under higher humidity showed greater heat knockdown time and heat-shock survival. These laboratory observations on developmental and adult acclimation effects of low versus high humidity conditions have helped in explaining seasonal changes in resistance to starvation and heat of the wild-caught flies of D. melanogaster. Thus, we may suggest that wet versus drier conditions significantly affect starvation and heat resistance of D. melanogaster. Copyright © 2014 Elsevier Inc. All rights reserved.

Study on microstructure and high temperature wear resistance of laser cladded nuclear valve clack

International Nuclear Information System (INIS)

Zhang Chunliang; Chen Zichen

2002-01-01

Laser cladding of Co-base alloy on the nuclear valve-sealing surface are performed with a 5 kW CO 2 transverse flowing laser. The microstructure and the high temperature impact-slide wear resistance of the laser cladded coating and the plasma cladded coating are studied. The results show that the microstructure, the dilution rate and the high temperature impact-slide wear resistance of the laser cladded coating have obvious advantages over the spurt cladding processing

Bipolar one diode-one resistor integration for high-density resistive memory applications.

Science.gov (United States)

Li, Yingtao; Lv, Hangbing; Liu, Qi; Long, Shibing; Wang, Ming; Xie, Hongwei; Zhang, Kangwei; Huo, Zongliang; Liu, Ming

2013-06-07

Different from conventional unipolar-type 1D-1R RRAM devices, a bipolar-type 1D-1R memory device concept is proposed and successfully demonstrated by the integration of Ni/TiOx/Ti diode and Pt/HfO2/Cu bipolar RRAM cell to suppress the undesired sneak current in a cross-point array. The bipolar 1D-1R memory device not only achieves self-compliance resistive switching characteristics by the reverse bias current of the Ni/TiOx/Ti diode, but also exhibits excellent bipolar resistive switching characteristics such as uniform switching, satisfactory data retention, and excellent scalability, which give it high potentiality for high-density integrated nonvolatile memory applications.

Electrical resistance and magnetoresistance of UCoAl under high pressure

Czech Academy of Sciences Publication Activity Database

Honda, F.; Oomi, G.; Andreev, Alexander V.; Sechovský, V.; Shiokawa, Y.

--, - (2002), s. 126-128 ISSN 0022-3131 R&D Projects: GA ČR GP202/01/D045 Institutional research plan: CEZ:AV0Z1010914 Keywords : UCoAl * non-Fermi liquid * itinerant metamagnetism * electrical resistance * high pressure Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.572, year: 2002

Effects of rumen-protected Capsicum oleoresin on productivity and responses to a glucose tolerance test in lactating dairy cows.

Science.gov (United States)

Oh, J; Harper, M; Giallongo, F; Bravo, D M; Wall, E H; Hristov, A N

2017-03-01

The objective of this experiment was to investigate the effects of rumen-protected Capsicum oleoresin (RPC) supplementation on feed intake, milk yield and composition, nutrient utilization, fecal microbial ecology, and responses to a glucose tolerance test in lactating dairy cows. Nine multiparous Holstein cows were used in a replicated 3 × 3 Latin square design balanced for residual effects with three 28-d periods. Each period consisted of 14 d for adaptation and 14 d for data collection and sampling. Treatments were 0 (control), 100, and 200 mg of RPC/cow per day. They were mixed with a small portion of the total mixed ration and top-dressed. Glucose tolerance test was conducted once during each experimental period by intravenous administration of glucose at a rate of 0.3 g/kg of body weight. Dry matter intake was not affected by RPC. Milk yield tended to increase for RPC treatments compared to the control. Feed efficiency was linearly increased by RPC supplementation. Concentrations of fat, true protein, and lactose in milk were not affected by RPC. Apparent total-tract digestibility of dry matter, organic matter, and crude protein was linearly increased, and fecal nitrogen excretion was linearly decreased by RPC supplementation. Rumen-protected Capsicum oleoresin did not affect the composition of fecal bacteria. Glucose concentration in serum was not affected by RPC supplementation post glucose challenge. However, compared to the control, RPC decreased serum insulin concentration at 5, 10, and 40 min post glucose challenge. The area under the insulin concentration curve was also decreased 25% by RPC. Concentration of nonesterified fatty acids and β-hydroxybutyrate in serum were not affected by RPC following glucose administration. In this study, RPC tended to increase milk production and increased feed efficiency in dairy cows. In addition, RPC decreased serum insulin concentration during the glucose tolerance test, but glucose concentration was not affected

High temperature chemically resistant polymer concrete

Science.gov (United States)

Sugama, T.; Kukacka, L.E.

High temperature chemically resistant, non-aqueous polymer concrete composites consist of about 12 to 20% by weight of a water-insoluble polymer binder. The binder is polymerized in situ from a liquid vinyl-type monomer or mixture of vinyl containing monomers such as triallylcyanurate, styrene, acrylonitrile, acrylamide, methacrylamide, methyl-methacrylate, trimethylolpropane trimethacrylate and divinyl benzene. About 5 to 40% by weight of a reactive inorganic filler selected from the group consisting of tricalcium silicate and dicalcium silicate and mixtures containing less than 2% free lime, and about 48 to 83% by weight of silica sand/ and a free radical initiator such as di-tert-butyl peroxide, azobisisobutyronitrile, benzoyl peroxide, lauryl peroxide, other orgaic peroxides and combinations to initiate polymerization of the monomer in the presence of the inorganic filers are used.

In-beam measurements of the HADES-TOF RPC wall

Czech Academy of Sciences Publication Activity Database

Blanco, A.; Cabanelas, P.; Belver, D.; Castro, E.; Díaz, J.; Fonte, P.; Gil, A.; Garzón, J.A.; Gonzalez-Diaz, D.; Heinz, T.; Koenig, W.; Lopes, L.; Muentz, C.; Palka, M.; Pietraszko, J.; Rustamov, A.; Schwab, E.; Sobolev, Yuri, G.; Tarantola, A.; Teilab, K.; Traxler, M.; Trebacz, R.; Wuestenfeld, J.; Yurevich, S.

2009-01-01

Roč. 602, č. 3 (2009), s. 691-695 ISSN 0168-9002. [9th International Workshop on Resistive Plate Chambers and Related Detectors. Bombay, 13.02.2008-16.02.2008] R&D Projects: GA AV ČR IAA100480803; GA MŠk LC07050 Institutional research plan: CEZ:AV0Z10480505 Keywords : Gaseous detectors * Timing * TOF Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.317, year: 2009

Frequency-domain analysis of intrinsic neuronal properties using high-resistant electrodes

Directory of Open Access Journals (Sweden)

Christian Rössert

2009-08-01

Full Text Available Intrinsic cellular properties of neurons in culture or slices are usually studied by the whole cell clamp method using low-resistant patch pipettes. These electrodes allow detailed analyses with standard electrophysiological methods such as current- or voltage-clamp. However, in these preparations large parts of the network and dendritic structures may be removed, thus preventing an adequate study of synaptic signal processing. Therefore, intact in vivo preparations or isolated in vitro whole brains have been used in which intracellular recordings are usually made with sharp, high-resistant electrodes to optimize the impalement of neurons. The general non-linear resistance properties of these electrodes, however, severely limit accurate quantitative studies of membrane dynamics especially needed for precise modelling. Therefore, we have developed a frequency-domain analysis of membrane properties that uses a Piece-wise Non-linear Electrode Compensation (PNEC method. The technique was tested in second-order vestibular neurons and abducens motoneurons of isolated frog whole brain preparations using sharp potassium chloride- or potassium acetate-filled electrodes. All recordings were performed without online electrode compensation. The properties of each electrode were determined separately after the neuronal recordings and were used in the frequency-domain analysis of the combined measurement of electrode and cell. This allowed detailed analysis of membrane properties in the frequency-domain with high-resistant electrodes and provided quantitative data that can be further used to model channel kinetics. Thus, sharp electrodes can be used for the characterization of intrinsic properties and synaptic inputs of neurons in intact brains.

Electrical resistivity of liquid iron with high concentration of light element impurities

Science.gov (United States)

Wagle, F.; Steinle-Neumann, G.

2017-12-01

The Earth's outer core mainly consists of liquid iron, enriched with several weight percent of lighter elements, such as silicon, oxygen, sulfur or carbon. Electrical resistivities of alloys of this type determine the stability of the geodynamo. Both computational and experimental results show that resistivites of Fe-based alloys deviate significantly from values of pure Fe. Using optical conductivity values computed with the Kubo-Greenwood formalism for DFT-based molecular dynamics results, we analyze the high-P and T behavior of resitivities for Fe-alloys containing various concentrations of sulfur, oxygen and silicon. As the electron mean free path length in amorphous and liquid material becomes comparable to interatomic distances at high P and T, electron scattering is expected to be dominated by the short-range order, rather than T-dependent vibrational contributions, and we describe such correlations in our results. In analogy to macroscopic porous media, we further show that resistivity of a liquid metal-nonmetal alloy is determined to first order by the resistivity of the metallic matrix and the volume fraction of non-metallic impurities.

The cytochrome P450 CYP6P4 is responsible for the high pyrethroid resistance in knockdown resistance-free Anopheles arabiensis.

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Ibrahim, Sulaiman S; Riveron, Jacob M; Stott, Robert; Irving, Helen; Wondji, Charles S

2016-01-01

Pyrethroid insecticides are the front line vector control tools used in bed nets to reduce malaria transmission and its burden. However, resistance in major vectors such as Anopheles arabiensis is posing a serious challenge to the success of malaria control. Herein, we elucidated the molecular and biochemical basis of pyrethroid resistance in a knockdown resistance-free Anopheles arabiensis population from Chad, Central Africa. Using heterologous expression of P450s in Escherichia coli coupled with metabolism assays we established that the over-expressed P450 CYP6P4, located in the major pyrethroid resistance (rp1) quantitative trait locus (QTL), is responsible for resistance to Type I and Type II pyrethroid insecticides, with the exception of deltamethrin, in correlation with field resistance profile. However, CYP6P4 exhibited no metabolic activity towards non-pyrethroid insecticides, including DDT, bendiocarb, propoxur and malathion. Combining fluorescent probes inhibition assays with molecular docking simulation, we established that CYP6P4 can bind deltamethrin but cannot metabolise it. This is possibly due to steric hindrance because of the large vdW radius of bromine atoms of the dihalovinyl group of deltamethrin which docks into the heme catalytic centre. The establishment of CYP6P4 as a partial pyrethroid resistance gene explained the observed field resistance to permethrin, and its inability to metabolise deltamethrin probably explained the high mortality from deltamethrin exposure in the field populations of this Sudano-Sahelian An. arabiensis. These findings describe the heterogeneity in resistance towards insecticides, even from the same class, highlighting the need to thoroughly understand the molecular basis of resistance before implementing resistance management/control tools. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

High frequency of silver resistance genes in invasive isolates of Enterobacter and Klebsiella species.

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Sütterlin, S; Dahlö, M; Tellgren-Roth, C; Schaal, W; Melhus, Å

2017-07-01

Silver-based products have been marketed as an alternative to antibiotics, and their consumption has increased. Bacteria may, however, develop resistance to silver. To study the presence of genes encoding silver resistance (silE, silP, silS) over time in three clinically important Enterobacteriaceae genera. Using polymerase chain reaction (PCR), 752 bloodstream isolates from the years 1990-2010 were investigated. Age, gender, and ward of patients were registered, and the susceptibility to antibiotics and silver nitrate was tested. Clonality and single nucleotide polymorphism were assessed with repetitive element sequence-based PCR, multi-locus sequence typing, and whole-genome sequencing. Genes encoding silver resistance were detected most frequently in Enterobacter spp. (48%), followed by Klebsiella spp. (41%) and Escherichia coli 4%. Phenotypical resistance to silver nitrate was found in Enterobacter (13%) and Klebsiella (3%) isolates. The lowest carriage rate of sil genes was observed in blood isolates from the neonatology ward (24%), and the highest in blood isolates from the oncology/haematology wards (66%). Presence of sil genes was observed in international high-risk clones. Sequences of the sil and pco clusters indicated that a single mutational event in the silS gene could have caused the phenotypic resistance. Despite a restricted consumption of silver-based products in Swedish health care, silver resistance genes are widely represented in clinical isolates of Enterobacter and Klebsiella species. To avoid further selection and spread of silver-resistant bacteria with a high potential for healthcare-associated infections, the use of silver-based products needs to be controlled and the silver resistance monitored. Copyright © 2017 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

High-resolution analysis of a QTL for resistance to Stagonospora nodorum glume blotch in wheat reveals presence of two distinct resistance loci in the target interval.

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Shatalina, Margarita; Messmer, Monika; Feuillet, Catherine; Mascher, Fabio; Paux, Etienne; Choulet, Frédéric; Wicker, Thomas; Keller, Beat

2014-03-01

Stagonospora nodorum glume blotch (SNG), caused by the necrotrophic fungus Stagonospora nodorum, is one of the economically important diseases of bread wheat (Triticum aestivum L.). Resistance to SNG is known to be quantitative and previous studies of a recombinant inbred line (RIL) population identified a major quantitative trait locus (QTL) for resistance to SNG on the short arm of chromosome 3B. To localize this QTL (QSng.sfr-3BS) with high resolution, we constructed a genetic map for the QTL target region using information from sequenced flow-sorted chromosomes 3B of the two parental cultivars 'Arina' and 'Forno', the physical map of chromosome 3B of cultivar 'Chinese Spring' and BAC-clone sequences. The mapping population of near-isogenic lines (NIL) was evaluated for SNG resistance in field infection tests. NILs segregated for disease resistance as well as for plant height; additionally, we observed a high environmental influence on the trait. Our analysis detected a strong negative correlation of SNG resistance and plant height. Further analysis of the target region identified two linked loci associated with SNG resistance. One of them was also associated with plant height, revealing an effect of QSng.sfr-3BS on plant height that was hidden in the RIL population. This result demonstrates an unexpectedly high genetic complexity of resistance controlled by QSng.sfr-3BS and shows the importance of the study of QTL in mendelized form in NILs.

microRNAs in High and Low Responders to Resistance Training in Breast Cancer Survivors.

Science.gov (United States)

Hagstrom, Amanda D; Denham, Joshua

2018-04-26

Accounting for one in three cancer diagnoses, breast cancer is the second most commonly diagnosed cancer in women. Exercise has a well-accepted role in the multi-disciplinary approach to rehabilitating breast cancer survivors. Despite the many known benefits of resistance training on women recovering from breast cancer, the molecular mechanisms are poorly understood. MicroRNAs are small non-coding RNAs that have crucial roles in growth and development. Here, we analysed the abundance of 9 miRNAs, with known roles in muscle physiology and some linked to cancer, in serum samples from 24 breast cancer survivors before and after a 16-week resistance training or usual care intervention. The resistance training group completed supervised thrice-weekly training. miRNA abundance was assessed before and after the intervention period using qPCR. There were no statistically significant changes in any of the miRNAs between groups after the intervention period (all p>0.05). After assessing miRNA abundance in context with high and low responders to resistance training, we observed that relative to low responders, high responders exhibited increased miR-133a-3p and a borderline statistically significant increase in miR-370-3p. Findings from our controlled study indicate the diverse interindividual miRNA responses to resistance training and reveal a discordant regulation between high and low responders. © Georg Thieme Verlag KG Stuttgart · New York.

Effect of heat treatment conditions on stress corrosion cracking resistance of alloy X-750 in high temperature water

International Nuclear Information System (INIS)

Yonezawa, Toshio; Onimura, Kichiro; Sakamoto, Naruo; Sasaguri, Nobuya; Susukida, Hiroshi; Nakata, Hidenori.

1984-01-01

In order to improve the resistance of the Alloy X-750 in high temperature and high purity water, the authors investigated the influence of heat treatment condition on the stress corrosion cracking resistance of the alloy. This paper describes results of the stress corrosion cracking test and some discussion on the mechanism of the stress corrosion cracking of Alloy X-750 in deaerated high temperature water. The following results were obtained. (1) The stress corrosion cracking resistance of Alloy X-750 in deaerated high temperature water remarkably depended upon the heat treatment condition. The materials solution heat treated and aged within temperature ranges from 1065 to 1100 0 C and from 704 to 732 0 C, respectively, have a good resistance to the stress corrosion cracking in deaerated high temperature water. Especially, water cooling after the solution heat treatment gives an excellent resistance to the stress corrosion cracking in deaerated high temperature water. (2) Any correlations were not observed between the stress corrosion cracking susceptibility of Alloy X-750 in deaerated high temperature water and grain boundary chromium depleted zones, precipitate free zones and the grain boundary segregation of impurity elements and so on. It appears that there are good correlations between the stress corrosion cracking resistance of the alloy in the environment and the kinds, morphology and coherency of precipitates along the grain boundaries. (author)

Berberine improves insulin resistance induced by high fat diet in rats

International Nuclear Information System (INIS)

Zhou Libin; Yang Ying; Shang Wenbin; Li Fengying; Tang Jinfeng; Wang Xiao; Liu Shangquan; Yuan Guoyue; Chen Mingdao

2005-01-01

Objective: To observe the effect of berberine on insulin resistance induced by high fat diet in rats. Methods: Normal male SD rats (8 weeks old) were divided into two groups taking either normal chow (NC, n=9) or high fat diet (HF, n=20). After fourteen weeks, HF rats were divided into two groups. Ten rats continued to take high fat diet. Another ten rats took additional berberine gavage (HF+B, 150mg/kg weight once a day). Six weeks later, oral glucose tolerance test and insulin tolerance test were performed for estimating insulin sensitivity. Results: The body weight, liver weight and epididyaml fat pads weight of HF group were significantly higher than those of HF+B group and NC group (all P<0.01). Fasting plasma glucose, insulin and plasma glucose, insulin 2h after taking glucose in HF+B rats were significantly lower than those in HF rats (all P<0.01). Plasma glucose and insulin levels at all time points in HF rats were significantly higher than those in NC rats. Homa-IR of HF group was markedly higher than that of HF+B group (P<0.01). The glucose-lowering effects after the administration of insuin (0.5u/kg intrapenitoneally) at all time points in HF+B rats were stronger than those in HF rats with 23% and 7% reduction at 15min respectively. Conclusion: Long term high fat diet resulted in insulin resistance. Berberine was able to reverse insulin resistance through promoting peripheral tissue up taking of glucose and decreasing insulin, which would be quite ideal for the intervention of IGT. (authors)

Investigation on amorphous InGaZnO based resistive switching memory with low-power, high-speed, high reliability

Energy Technology Data Exchange (ETDEWEB)

Fan, Yang-Shun [Department of Photonics and Institute of Electro-Optical Engineering, National Chiao Tung University, Hsinchu 30010, Taiwan, ROC (China); Liu, Po-Tsun, E-mail: ptliu@mail.nctu.edu.tw [Department of Photonics and Display Institute, National Chiao Tung University, Hsinchu 30010, Taiwan, ROC (China); Hsu, Ching-Hui [Department of Photonics and Display Institute, National Chiao Tung University, Hsinchu 30010, Taiwan, ROC (China)

2013-12-31

Recently, non-volatile memory (NVM) has been widely used in electronic devices. Nowadays, the prevailing NVM is Flash memory. However, it is generally believed that the conventional Flash memory will approach its scaling limit within about a decade. The resistive random access memory (RRAM) is emerging as one of the potential candidates for future memory replacement because of its high storage density, low power consumption as well as simple structure. The purpose of this work is to develop a reliable a-InGaZnO based resistive switching memory. We investigate the resistive switching characteristics of TiN/Ti/IGZO/Pt structure and TiN/IGZO/Pt structure. The device with TiN/Ti/IGZO/Pt structure exhibits stable bipolar resistive switching. The impact of inserting a Ti interlayer is studied by material analyses. The device shows excellent resistive switching properties. For example, the DC sweep endurance can achieve over 1000 times; and the pulse induced switching cycles can reach at least 10,000 times. Furthermore, the impact of different sputtering ambience, the variable temperature measurement, and the conduction mechanisms are also investigated. According to our experiments, we propose a model to explain the resistive switching phenomenon observed in our devices.

High-damage-resistant tungsten disulfide saturable absorber mirror for passively Q-switched fiber laser.

Science.gov (United States)

Chen, Hao; Chen, YuShan; Yin, Jinde; Zhang, Xuejun; Guo, Tuan; Yan, Peiguang

2016-07-25

In this paper, we demonstrate a high-damage-resistant tungsten disulfide saturable absorber mirror (WS2-SAM) fabricated by magnetron sputtering technique. The WS2-SAM has an all-fiber-integrated configuration and high-damage-resistant merit because the WS2 layer is protected by gold film so as to avoid being oxidized and destroyed at high pump power. Employing the WS2-SAM in an Erbium-doped fiber laser (EDFL) with linear cavity, the stable Q-switching operation is achieved at central wavelength of 1560 nm, with the repetition rates ranging from 29.5 kHz to 367.8 kHz and the pulse duration ranging from 1.269 μs to 154.9 ns. For the condition of the maximum pump power of 600 mW, the WS2-SAM still works stably with an output power of 25.2 mW, pulse energy of 68.5 nJ, and signal-noise-ratio of 42 dB. The proposed WS2-SAM configuration provides a promising solution for advanced pulsed fiber lasers with the characteristics of high damage resistance, high output energy, and wide tunable frequency.

Comparison of multi-drug resistant environmental methicillin-resistant Staphylococcus aureus [MRSA] isolated from recreational beaches and high touch surfaces in built environments

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Marilyn C Roberts

2013-04-01

Full Text Available Over the last decade community-acquired methicillin-resistant Staphylococcus aureus [MRSA] has emerged as a major cause of disease in the general population with no health care exposure or known classical risk factors for MRSA infections. The potential community reservoirs have not been well defined though certain strains such as ST398 and USA300 have been well studied in some settings. MRSA has been isolated from recreational beaches, high-touch surfaces in homes, universities and other community environmental surfaces. However, in most cases the strains were not characterized to determine if they are related to community-acquired or hospital-acquired clinical strains. We compared 55 environmental MRSA from 805 samples including sand, fresh and marine water samples from local marine and fresh water recreational beaches (n=296, high touch surfaces on the University of Washington campus (n=294, surfaces in UW undergraduate housing (n=85, and the local community (n=130. Eleven USA300, representing 20% of the isolates, were found on the UW campus surfaces, student housing surfaces and on the community surfaces but not in the recreational beach samples from the Northwest USA. Similarly, the predominant animal ST133 was found in the recreational beach samples but not in the high touch surface samples. All USA300 isolates were multi-drug resistant carrying 2-6 different antibiotic resistance genes coding for kanamycin, macrolides and/or macrolides-lincosamides-streptogramin B and tetracycline, with the majority [72%] carrying 4-6 different antibiotic resistance genes. A surprising 98% of the 55 MRSA isolates were resistant to other classes of antibiotics and most likely represent reservoirs for these genes in the environment.

Corrosion resistance of high performance stainless steels in cooling water and other refinery environments

International Nuclear Information System (INIS)

Kovach, C.W.; Redmerski, L.S.

1984-01-01

The recent successful introduction of high performance stainless steels as tubing for seawater cooled electric utility condensers suggests that these alloys can also provide useful service in refinery heat exchanger applications. Since many of these applications involve higher temperature exposure than steam condensers, a study was conducted to evaluate crevice corrsion resistance over a range of cooling water temperature and chloride concentrations, and also to evaluate general corrosion resistance in some strong chemical and refinery environments. These stainless steels display excellent crevice corrosion resistance as well as good resistance to a variety of chemical environments that may be encountered in refinery, petrochemical and chemical plant service

Advanced Corrosion-Resistant Zr Alloys for High Burnup and Generation IV Application

International Nuclear Information System (INIS)

Jeong, Y. H.; Park, S. Y.; Lee, M. H.; Choi, B. K.; Baek, J. H.; Park, J. Y.; Kim, J. H.; Kim, H. G.; Jung, Y. H.; Bang, B. G.

2006-08-01

The systematic study was performed to develop the advanced corrosion-resistant Zr alloys for high burnup and Gen IV application. The corrosion behavior was significantly changed with the alloy composition and the corrosion environment. In general, the model alloys with a higher alloying elements showed a higher corrosion resistance. Among the model alloys tested in this study, Zr-10Cr-0.2Fe showed the best corrosion resistance regardless of the corrosion condition. The oxide on the higher corrosion-resistant alloy such as Zr-1.0Cr-0.2Fe consisted of mainly columnar grains, and it have a higher tetragonal phase stability. In comparison with other alloys being considered for the SCWR, the Zr alloys showed a lower corrosion rate than ferritic-martensitic steels. The results of this study imply that, at least from a corrosion standpoint, Zr alloys deserve consideration as potential cladding or structural materials in supercritical water cooled reactors

[Resistance risk, cross-resistance and biochemical resistance mechanism of Laodelphax striatellus to buprofezin].

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Mao, Xu-lian; Liu, Jin; Li, Xu-ke; Chi, Jia-jia; Liu, Yong-jie

2016-01-01

In order to investigate the resistance development law and biochemical resistance mechanism of Laodelphax striatellus to buprofezin, spraying rice seedlings was used to continuously screen resistant strains of L. striatellus and dipping rice seedlings was applied to determine the toxicity and cross-resistance of L. striatellus to insecticides. After 32-generation screening with buprofezin, L. striatellus developed 168.49 folds resistance and its reality heritability (h2) was 0.11. If the killing rate was 80%-90%, L. striatellus was expected to develop 10-fold resistance to buprofezin only after 5 to 6 generations breeding. Because the actual reality heritability of field populations was usually lower than that of the resistant strains, the production of field populations increasing with 10-fold resistance would need much longer time. The results of cross-resistance showed that resistant strain had high level cross-resistance with thiamethoxam and imidacloprid, low level cross-resistance with acetamiprid, and no cross-resistance with pymetrozine and chlorpyrifos. The activity of detoxification enzymes of different strains and the syergism of synergist were measured. The results showed that cytochrome P450 monooxygenase played a major role in the resistance of L. striatellus to buprofezin, the esterase played a minor role and the GSH-S-transferase had no effect. Therefore, L. striatellus would have high risk to develop resistance to buprofezin when used in the field and might be delayed by using pymetrozine and chlorpyrifos.

Oxidation resistance of nickel alloys at high temperature

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