WorldWideScience

Sample records for technology verifi cation

  1. Verifying disarmament: scientific, technological and political challenges

    Energy Technology Data Exchange (ETDEWEB)

    Pilat, Joseph R [Los Alamos National Laboratory

    2011-01-25

    There is growing interest in, and hopes for, nuclear disarmament in governments and nongovernmental organizations (NGOs) around the world. If a nuclear-weapon-free world is to be achievable, verification and compliance will be critical. VerifYing disarmament would have unprecedented scientific, technological and political challenges. Verification would have to address warheads, components, materials, testing, facilities, delivery capabilities, virtual capabilities from existing or shutdown nuclear weapon and existing nuclear energy programs and material and weapon production and related capabilities. Moreover, it would likely have far more stringent requirements. The verification of dismantlement or elimination of nuclear warheads and components is widely recognized as the most pressing problem. There has been considerable research and development done in the United States and elsewhere on warhead and dismantlement transparency and verification since the early 1990s. However, we do not today know how to verifY low numbers or zero. We need to develop the needed verification tools and systems approaches that would allow us to meet this complex set of challenges. There is a real opportunity to explore verification options and, given any realistic time frame for disarmament, there is considerable scope to invest resources at the national and international levels to undertake research, development and demonstrations in an effort to address the anticipated and perhaps unanticipated verification challenges of disarmament now andfor the next decades. Cooperative approaches have the greatest possibility for success.

  2. Synergistic effect of divalent cations in improving technological properties of cross-linked alginate beads.

    Science.gov (United States)

    Cerciello, Andrea; Del Gaudio, Pasquale; Granata, Veronica; Sala, Marina; Aquino, Rita P; Russo, Paola

    2017-08-01

    Gelling solution parameters are some of the most important variables in ionotropic gelation and consequently influence the technological characteristics of the product. To date, only a few studies have focused on the simultaneous use of multiple cations as gelling agents. With the aim to deeply explore this possibility, in this research we investigated the effect of two divalent cations (Ca 2+ and Zn 2+ ) on alginate beads formation and properties. Alginate beads containing prednisolone (P) as model drug were prepared by prilling technique. The main critical variables of the ionotropic gelation process i.e. composition of the aqueous feed solutions (sodium alginate and prednisolone concentration) and cross-linking conditions (Ca 2+ , Zn 2+ or Ca 2+ +Zn 2+ ), were studied. The obtained beads were characterized and their in vitro release performances were assessed in conditions simulating the gastrointestinal environment. Results evidenced a synergistic effect of the two cations, affecting positively both the encapsulation efficiency and the ability of the alginate polymeric matrix to control the drug release. A Ca 2+ /Zn 2+ ratio of 4:1, in fact, exploited the Ca 2+ ability of establish quicker electrostatic interactions with guluronic groups of alginate and the Zn 2+ ability to establish covalent-like bonds with carboxylate groups of both guluronic and mannuronic moieties of alginate. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Verifying versus falsifying banknotes

    Science.gov (United States)

    van Renesse, Rudolf L.

    1998-04-01

    A series of counterfeit Dutch, German, English, and U.S. banknotes was examined with respect to the various modi operandi to imitate paper based, printed and post-printed security features. These features provide positive evidence (verifiability) as well as negative evidence (falsifiability). It appears that the positive evidence provided in most cases is insufficiently convincing: banknote inspection mainly rests on negative evidence. The act of falsifying (to prove to be false), however, is an inefficacious procedure. Ergonomic verificatory security features are demanded. This demand is increasingly met by security features based on nano- technology. The potential of nano-security has a twofold base: (1) the unique optical effects displayed allow simple, fast and unambiguous inspection, and (2) the nano-technology they are based on, makes successful counterfeit or simulation extremely improbable.

  4. Concentration and Purifi cation of Yacon (Smallanthus sonchifolius Root Fructooligosaccharides Using Membrane Technology

    Directory of Open Access Journals (Sweden)

    Isabel Cristina Tessaro

    2015-01-01

    Full Text Available Yacon is a perennial plant originating from the Andean region whose roots have been receiving increased att ention due to their high content of prebiotic fructooligosaccharides (FOS. Apart from many health benefi ts, FOS have interesting characteristics as food ingredients, so are used as sugar substitute, and their extraction from yacon roots may be an alternative to commercially available FOS. This work evaluates membrane technology for concentration and purifi cation of FOS from yacon root extract, combining ultrafiltration (UF with nanofi ltration (NF, with and without the use of discontinuous diafi ltration (DF. After UF, 63.75 % of the saccharides from the initial feed were recovered in total permeate. DF did not largely infl uence FOS retention during NF (it increased from 68.78 % without DF to 70.48 % with DF, but decreased glucose and fructose retentions, from 40.63 to 31.61 % and 25.64 to 18.69 %, respectively, which was desirable, allowing greater purification of FOS in the retentate. The yield of total saccharides in the final retentate after combined UF and NF processes was 50.89 % and of FOS was 51.85 %, with 19.75 % purity. The results indicate that the combined UF and NF is a promising technique for concentrating yacon saccharides, but more diafi ltration steps are required for the improvement of FOS purity.

  5. Verified scientific findings

    International Nuclear Information System (INIS)

    Bullinger, M.G.

    1982-01-01

    In this essay, the author attempts to enlighten the reader as to the meaning of the term ''verified scientific findings'' in section 13, sub-section 1, sentence 2 of the new Chemicals Control Law. The examples given here are the generally accepted regulations in regards to technology (that is sections 7a and 18b of the WHG (law on water economy), section 3, sub-section 1 of the machine- and engine protection laws) and to the status of technology (section 3, sub-section 6 of the BImSchG (Fed. law on prevention of air-borne pollution)), and to the status of science (section 5, sub-section 2 of the AMG (drug legislation). The ''status of science and technology'' as defined in sections 4 ff of the Atomic Energy Law (AtomG) and in sections 3, 4, 12, 2) of the First Radiation Protection Ordinance (1.StrlSch. VO), is also being discussed. The author defines the in his opinion ''dynamic term'' as the generally recognized result of scientific research, and the respective possibilities of practical utilization of technology. (orig.) [de

  6. Verifiable Quantum Computing

    Science.gov (United States)

    Kashefi, Elham

    Over the next five to ten years we will see a state of flux as quantum devices become part of the mainstream computing landscape. However adopting and applying such a highly variable and novel technology is both costly and risky as this quantum approach has an acute verification and validation problem: On the one hand, since classical computations cannot scale up to the computational power of quantum mechanics, verifying the correctness of a quantum-mediated computation is challenging; on the other hand, the underlying quantum structure resists classical certification analysis. Our grand aim is to settle these key milestones to make the translation from theory to practice possible. Currently the most efficient ways to verify a quantum computation is to employ cryptographic methods. I will present the current state of the art of various existing protocols where generally there exists a trade-off between the practicality of the scheme versus their generality, trust assumptions and security level. EK gratefully acknowledges funding through EPSRC Grants EP/N003829/1 and EP/M013243/1.

  7. Externally Verifiable Oblivious RAM

    Directory of Open Access Journals (Sweden)

    Gancher Joshua

    2017-04-01

    Full Text Available We present the idea of externally verifiable oblivious RAM (ORAM. Our goal is to allow a client and server carrying out an ORAM protocol to have disputes adjudicated by a third party, allowing for the enforcement of penalties against an unreliable or malicious server. We give a security definition that guarantees protection not only against a malicious server but also against a client making false accusations. We then give modifications of the Path ORAM [15] and Ring ORAM [9] protocols that meet this security definition. These protocols both have the same asymptotic runtimes as the semi-honest original versions and require the external verifier to be involved only when the client or server deviates from the protocol. Finally, we implement externally verified ORAM, along with an automated cryptocurrency contract to use as the external verifier.

  8. Verifiably Truthful Mechanisms

    DEFF Research Database (Denmark)

    Branzei, Simina; Procaccia, Ariel D.

    2015-01-01

    It is typically expected that if a mechanism is truthful, then the agents would, indeed, truthfully report their private information. But why would an agent believe that the mechanism is truthful? We wish to design truthful mechanisms, whose truthfulness can be verified efficiently (in...... the computational sense). Our approach involves three steps: (i) specifying the structure of mechanisms, (ii) constructing a verification algorithm, and (iii) measuring the quality of verifiably truthful mechanisms. We demonstrate this approach using a case study: approximate mechanism design without money...

  9. Actinide cation-cation complexes

    International Nuclear Information System (INIS)

    Stoyer, N.J.; Seaborg, G.T.

    1994-12-01

    The +5 oxidation state of U, Np, Pu, and Am is a linear dioxo cation (AnO 2 + ) with a formal charge of +1. These cations form complexes with a variety of other cations, including actinide cations. Other oxidation states of actinides do not form these cation-cation complexes with any cation other than AnO 2 + ; therefore, cation-cation complexes indicate something unique about AnO 2 + cations compared to actinide cations in general. The first cation-cation complex, NpO 2 + ·UO 2 2+ , was reported by Sullivan, Hindman, and Zielen in 1961. Of the four actinides that form AnO 2 + species, the cation-cation complexes of NpO 2 + have been studied most extensively while the other actinides have not. The only PuO 2 + cation-cation complexes that have been studied are with Fe 3+ and Cr 3+ and neither one has had its equilibrium constant measured. Actinides have small molar absorptivities and cation-cation complexes have small equilibrium constants; therefore, to overcome these obstacles a sensitive technique is required. Spectroscopic techniques are used most often to study cation-cation complexes. Laser-Induced Photacoustic Spectroscopy equilibrium constants for the complexes NpO 2 + ·UO 2 2+ , NpO 2 + ·Th 4+ , PuO 2 + ·UO 2 2+ , and PuO 2 + ·Th 4+ at an ionic strength of 6 M using LIPAS are 2.4 ± 0.2, 1.8 ± 0.9, 2.2 ± 1.5, and ∼0.8 M -1

  10. THE BROOKHAVEN NATIONAL LABORATORY PERFLUOROCARBON TRACER TECHNOLOGY: A PROVEN AND COST EFFECTIVE METHOD TO VERIFY INTEGRITY AND MONITOR LONG TERM PERFORMANCE OF WALLS, FLOORS, CAPS, AND COVER SYSTEMS.

    Energy Technology Data Exchange (ETDEWEB)

    HEISER, J.; SULLIVAN, T.

    2002-03-11

    Currently, containment system failures are detected by monitoring wells downstream of the waste site. Clearly this approach is inefficient, as the contaminants will have migrated from the disposal area before they are detected. Methods that indicate early cover failure (prior to contaminant release) or predict impending cover failure are needed. The Brookhaven National Laboratory (BNL) Perfluorocarbon Tracer (PFT) technology can measure performance changes and integrity losses as the cover ages. This allows early detection of cover failure or pending failure so that repair or replacement can be made before contaminants leave the disposal cell. The PFT technology has been successfully applied to four subsurface barrier problems, one leak detection problem from underground ducts, and one surface cover problem. Testing has demonstrated that the PFTs are capable of accurately detecting and locating leaks down to fractions of an inch. The PFT technology has several advantages over competing approaches. The ability to simultaneously use multiple PFTs separates it from other gas tracer technologies. Using multiple tracers provides independent confirmation of flaw location, helps to clearly define transport pathways, and can be used for confirmatory testing (e.g., repeat the test using a new tracer). The PFT tests provide a direct measure of flaws in a barrier, whereas other measurements (pressure, moisture content, temperature, subsidence) provide indirect measures that need interpretation. The focus of the six PFT demonstrations has been on engineering aspects of the technology with the intent of finding if a flaw existed in the barrier. Work remains to be done on the scientific basis for this technology. This includes determining PFT diffusion rates through various materials (soils and barrier) as a function of moisture content, determining the effects of barometric pumping on PFT flow for cover systems, and determining wind effects on side slopes of cover systems and

  11. HHF test with 80x80x1 Be/Cu/SS Mock-ups for verifying the joining technology of the ITER blanket First Wall

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dong Won; Bae, Young Dug; Kim, Suk Kwon; Hong, Bong Guen; Jeong, Yong Hwan; Park, Jeong Yong; Choi, Byung Kwon; Jung, Hyun Kyu

    2008-11-15

    Through the fabrication of the Cu/SS and Be/Cu joint specimens, fabrication procedure such as material preparation, canning, degassing, HIP (Hot Isostatic Pressing), PHHT (Post HIP heat treatment) was established. The HIP conditions (1050 .deg. C, 100 MPa 2 hr for Cu/SS, 580 .deg. C 100 MPa 2 hr for Be/Cu) were developed through the investigation on joint specimen fabricated with the various HIP conditions; the destructive tests of joint include the microstructure observation of the interface with the examination of the elemental distribution, tension test, bend test, Charpy impact test and fracture toughness test. However, since the joint should be tested under the High Heat Flux (HHF) conditions like the ITER operation for verifying its joint integrity, several HHF tests were performed like the previous HHF test with the Cu/SS, Be/Cu, Be/Cu/SS Mock-ups. In the present study, the HHF test with Be/Cu/SS Mock-ups, which have 80 mm x 80 mm single Be tile and each material depths were kept to be the same as the ITER blanket FW. The Mock-ups fabricated with three kinds of interlayers such as Cr/Ti/Cu, Ti/Cr/Cu, Ti/Cu, which were different from the developed interlayer (Cr/Cu), total 6 Mock-ups were fabricated. Preliminary analysis were performed to decide the test conditions; they were tested with up to 2.5 MW/m2 of heat fluxes and 20 cycles for each Mock-up in a given heat flux. They were tested with JUDITH-1 at FZJ in Germany. During tests, all Mock-ups showed delamination or full detachment of Be tile and it can be concluded that the joints with these interlayers have a bad joining but it can be used as a good data for developing the Be/Cu joint with HIP.

  12. What is the IAEA? Programmes and activities that maximize the contribution of nuclear technology to society, while verifying its peaceful use

    International Nuclear Information System (INIS)

    2001-01-01

    The International Atomic Energy Agency (IAEA) serves as the world's foremost international governmental forum for scientific and technical co-operation in the peaceful use of nuclear technology. Established as an autonomous organization under the United Nations (UN) in 1957, the IAEA represents the culmination of international efforts to make a reality of US President Eisenhower's proposal in his 'Atoms for Peace' speech to the UN General Assembly in 1953. He envisioned the creation of an international body to control and develop the use of atomic energy. Today, the Agency's broad spectrum of services, programmes, and activities is based on the needs of its 130 Member States

  13. Status of personnel identity verifiers

    International Nuclear Information System (INIS)

    Maxwell, R.L.

    1985-01-01

    Identity verification devices based on the interrogation of six different human biometric features or actions now exist and in general have been in development for about ten years. The capability of these devices to meet the cost and operational requirements of speed, accuracy, ease of use and reliability has generally increased although the verifier industry is still immature. Sandia Laboratories makes a continuing effort to stay abreast of identity verifier developments and to assess the capabilities and improvements of each device. Operating environment and procedures more typical of field use can often reveal performance results substantially different from laboratory tests. An evaluation of several recently available verifiers is herein reported

  14. End-to-end verifiability

    OpenAIRE

    Benaloh, Josh; Rivest, Ronald; Ryan, Peter Y. A.; Stark, Philip; Teague, Vanessa; Vora, Poorvi

    2015-01-01

    This pamphlet describes end-to-end election verifiability (E2E-V) for a nontechnical audience: election officials, public policymakers, and anyone else interested in secure, transparent, evidence - based electronic elections. This work is part of the Overseas Vote Foundation’s End-to-End Verifiable Internet Voting: Specification and Feasibility Assessment Study (E2E VIV Project), funded by the Democracy Fund.

  15. Micronutrient Fortification of Foods

    African Journals Online (AJOL)

    Micronutrient Fortification of Foods: Developing A Program. Mahshid Lotti, M.G. Venkatesh Manar, Richard J. H. M. .... Develop the fortification technology. 11. Perform studies on interactions, potency, stability, ... Fortification with vitamin A is a long-term strategy capable of maintaining adequate vitamin A status over time.

  16. Radical cations in condensed phases

    Energy Technology Data Exchange (ETDEWEB)

    Symons, M.C.R. (Leicester Univ. (UK). Dept. of Chemistry)

    The subject is covered in sections, entitled: introduction (scope of present Review); preparative procedures; alkane and cycloalkane cations; alkene and cyclic alkene cations; alkyl-halide cations; alcohol and ether cations; carbonyl cations (aldehyde, ketone and ester cations); sulphur-centred cations; selenium-centred cations; nitrogen-centred cations; phosphorus-centred cations; tin- and lead-centred cations; aromatic cations; five membered hetero-aromatic cations; vinyl cations; inorganic cations.

  17. Verifying the Hanging Chain Model

    Science.gov (United States)

    Karls, Michael A.

    2013-01-01

    The wave equation with variable tension is a classic partial differential equation that can be used to describe the horizontal displacements of a vertical hanging chain with one end fixed and the other end free to move. Using a web camera and TRACKER software to record displacement data from a vibrating hanging chain, we verify a modified version…

  18. Verified Separate Compilation for C

    Science.gov (United States)

    2015-06-01

    Bibliography [AAV02] Amal Ahmed, Andrew W. Appel, and Roberto Virga. A strat- ified semantics of general references embeddable in higher- order logic. In...Annual Ieee Symp. on Logic in Computer Science, pages 75–86, June 2002. [AB11] Amal Ahmed and Matthias Blume. An equivalence- preserving CPS translation...333, 2006. [PA14] James T. Perconti and Amal Ahmed. Verifying an open com- piler using multi-language semantics. In Proceedings of the European

  19. Optimised resource construction for verifiable quantum computation

    International Nuclear Information System (INIS)

    Kashefi, Elham; Wallden, Petros

    2017-01-01

    Recent developments have brought the possibility of achieving scalable quantum networks and quantum devices closer. From the computational point of view these emerging technologies become relevant when they are no longer classically simulatable. Hence a pressing challenge is the construction of practical methods to verify the correctness of the outcome produced by universal or non-universal quantum devices. A promising approach that has been extensively explored is the scheme of verification via encryption through blind quantum computation. We present here a new construction that simplifies the required resources for any such verifiable protocol. We obtain an overhead that is linear in the size of the input (computation), while the security parameter remains independent of the size of the computation and can be made exponentially small (with a small extra cost). Furthermore our construction is generic and could be applied to any universal or non-universal scheme with a given underlying graph. (paper)

  20. Unconditionally verifiable blind quantum computation

    Science.gov (United States)

    Fitzsimons, Joseph F.; Kashefi, Elham

    2017-07-01

    Blind quantum computing (BQC) allows a client to have a server carry out a quantum computation for them such that the client's input, output, and computation remain private. A desirable property for any BQC protocol is verification, whereby the client can verify with high probability whether the server has followed the instructions of the protocol or if there has been some deviation resulting in a corrupted output state. A verifiable BQC protocol can be viewed as an interactive proof system leading to consequences for complexity theory. We previously proposed [A. Broadbent, J. Fitzsimons, and E. Kashefi, in Proceedings of the 50th Annual Symposium on Foundations of Computer Science, Atlanta, 2009 (IEEE, Piscataway, 2009), p. 517] a universal and unconditionally secure BQC scheme where the client only needs to be able to prepare single qubits in separable states randomly chosen from a finite set and send them to the server, who has the balance of the required quantum computational resources. In this paper we extend that protocol with additional functionality allowing blind computational basis measurements, which we use to construct another verifiable BQC protocol based on a different class of resource states. We rigorously prove that the probability of failing to detect an incorrect output is exponentially small in a security parameter, while resource overhead remains polynomial in this parameter. This resource state allows entangling gates to be performed between arbitrary pairs of logical qubits with only constant overhead. This is a significant improvement on the original scheme, which required that all computations to be performed must first be put into a nearest-neighbor form, incurring linear overhead in the number of qubits. Such an improvement has important consequences for efficiency and fault-tolerance thresholds.

  1. Learn About SmartWay Verified Aerodynamic Devices

    Science.gov (United States)

    Installing EPA-verified aerodynamic technologies on your trailer can help fleet and truck owners save fuel. Options include gap reducers, skirts, or tails and can be installed individually or in combination.

  2. Verify MesoNAM Performance

    Science.gov (United States)

    Bauman, William H., III

    2010-01-01

    The AMU conducted an objective analysis of the MesoNAM forecasts compared to observed values from sensors at specified KSC/CCAFS wind towers by calculating the following statistics to verify the performance of the model: 1) Bias (mean difference), 2) Standard deviation of Bias, 3) Root Mean Square Error (RMSE), and 4) Hypothesis test for Bias = O. The 45 WS LWOs use the MesoNAM to support launch weather operations. However, the actual performance of the model at KSC and CCAFS had not been measured objectively. The analysis compared the MesoNAM forecast winds, temperature and dew point to the observed values from the sensors on wind towers. The data were stratified by tower sensor, month and onshore/offshore wind direction based on the orientation of the coastline to each tower's location. The model's performance statistics were then calculated for each wind tower based on sensor height and model initialization time. The period of record for the data used in this task was based on the operational start of the current MesoNAM in mid-August 2006 and so the task began with the first full month of data, September 2006, through May 2010. The analysis of model performance indicated: a) The accuracy decreased as the forecast valid time from the model initialization increased, b) There was a diurnal signal in T with a cool bias during the late night and a warm bias during the afternoon, c) There was a diurnal signal in Td with a low bias during the afternoon and a high bias during the late night, and d) The model parameters at each vertical level most closely matched the observed parameters at heights closest to those vertical levels. The AMU developed a GUI that consists of a multi-level drop-down menu written in JavaScript embedded within the HTML code. This tool allows the LWO to easily and efficiently navigate among the charts and spreadsheet files containing the model performance statistics. The objective statistics give the LWOs knowledge of the model's strengths and

  3. Isomerization of propargyl cation to cyclopropenyl cation ...

    Indian Academy of Sciences (India)

    step) for isomerization of the linear propargyl cation to the aromatic cyclopropenyl cation, also probing the phenomenon of solvation of this reaction by simple lone pair donors (NH3, H2O, H2S and HF) which bind to the substrate at two sites.

  4. USCIS E-Verify Program Reports

    Data.gov (United States)

    Department of Homeland Security — The report builds on the last comprehensive evaluation of the E-Verify Program and demonstrates that E-Verify produces accurate results and that accuracy rates have...

  5. Verifying design patterns in Hoare Type Theory

    DEFF Research Database (Denmark)

    Svendsen, Kasper; Buisse, Alexandre; Birkedal, Lars

    In this technical report we document our experiments formally verifying three design patterns in Hoare Type Theory.......In this technical report we document our experiments formally verifying three design patterns in Hoare Type Theory....

  6. Crypto-Verifying Protocol Implementations in ML

    NARCIS (Netherlands)

    Bhargavan, K.; Corin, R.J.; Fournet, C.

    2007-01-01

    We intend to narrow the gap between concrete implementations and verified models of cryptographic protocols. We consider protocols implemented in F#, a variant of ML, and verified using CryptoVerif, Blanchet's protocol verifier for computational cryptography. We experiment with compilers from F#

  7. Verifying FreeRTOS; a feasibility study

    OpenAIRE

    Pronk, C.

    2010-01-01

    This paper presents a study on modeling and verifying the kernel of Real-Time Operating Systems (RTOS). The study will show advances in formally verifying such an RTOS both by refinement and by model checking approaches. This work fits in the context of Hoare’s verification challenge. Several real-time operating systems will be discussed including some commercial ones. The focus of the latter part of the paper will be on verifying FreeRTOS. The paper investigates a number of ways to verify th...

  8. Verifying FreeRTOS; a feasibility study

    NARCIS (Netherlands)

    Pronk, C.

    2010-01-01

    This paper presents a study on modeling and verifying the kernel of Real-Time Operating Systems (RTOS). The study will show advances in formally verifying such an RTOS both by refinement and by model checking approaches. This work fits in the context of Hoare’s verification challenge. Several

  9. Verifying parallel loops with separation logic

    NARCIS (Netherlands)

    Blom, Stefan; Darabi, Saeed; Huisman, Marieke

    2014-01-01

    This paper proposes a technique to specify and verify whether a loop can be parallelised. Our approach can be used as an additional step in a parallelising compiler to verify user annotations about loop dependences. Essentially, our technique requires each loop iteration to be specified with the

  10. Cycloaliphatic epoxide resins for cationic UV - cure

    International Nuclear Information System (INIS)

    Verschueren, K.; Balwant Kaur

    1999-01-01

    This paper introduces the cyclo - aliphatic epoxide resins used for the various applications of radiation curing and their comparison with acrylate chemistry. Radiation curable coatings and inks are pre - dominantly based on acrylate chemistry but over the last few years, cationic chemistry has emerged successfully with the unique properties inherent with cyclo - aliphatic epoxide ring structures. Wide variety of cationic resins and diluents, the formulation techniques to achieve the desired properties greatly contributes to the advancement of UV - curing technology

  11. The status of personnel identity verifiers

    International Nuclear Information System (INIS)

    Maxwell, R.L.

    1985-01-01

    Identity verification devices based on the interrogation of six different human biometric features or actions now exist and in general have been in development for about ten years. The capability of these devices to meet the cost and operational requirements of speed, accuracy, ease of use and reliability has generally increased although the verifier industry is still immature. Sandia Laboratories makes a continuing effort to stay abreast of identity verifier developments and to assess the capabilities and improvements of each device. Operating environment and procedures more typical of field use can often reveal performance results substantially different from laboratory tests. An evaluation of several recently available verifiers is herein reported

  12. USCIS E-Verify Self-Check

    Data.gov (United States)

    Department of Homeland Security — E-Verify is an internet based system that contains datasets to compare information from an employee's Form I-9, Employment Eligibility Verification, to data from the...

  13. Isomerization of propargyl cation to cyclopropenyl cation ...

    Indian Academy of Sciences (India)

    step) for isomeri- zation of the linear propargyl cation to ..... C3, C4 and C5. The ZPE corrections in each case are derived from the. B3LYP calculations. ..... the converse of which gives the relative capacity of the. LPD's to stabilize TS6 with respect ...

  14. Cation siting in low-silica zeolites with potential applications in pressure swing adsorption technology and structural studies of novel tectosilicates

    Science.gov (United States)

    Burton, Allen Wayne

    Adsorption and catalytic phenomena in zeolites are influenced by coulombic interactions within zeolite structure as well as by size restrictions imposed by zeolitic micropores. In the first part of this thesis, we investigate materials with potential applications in the selective adsorption of nitrogen. Studies have indicated the performance of LiX adsorbents correlates with the number of accessible lithium cations in the zeolite. However, in zeolite LiX only one-third of the lithium cations interact with adsorbed molecules. This prompted our investigation of other low-silica zeolites. The first zeolite examined was a cancrinite prepared in the presence of 1,3-butanediol. Neutron diffraction studies on the lithium-exchanged cancrinite suggest most of the lithium cations are ideally positioned within the micropores. However, our experiments show that carbonate anions are occluded within the micropores of this cancrinite. Another material examined in this study was zeolite (Ba,K)-GL. Neutron diffraction experiments show that 49 of the extraframework charges are located in the micropores. Unfortunately, less than 20% of these cations are replaced after lithium-exchange. We also attempted to directly synthesize a (Ba,Li)-GL. However, diffraction experiments and chemical analyses show that most of the extraframework charge is compensated by barium. Because of molecular size restrictions imposed by currently known zeolites, there is continued interest in the synthesis of materials that can be used for processing large molecules. This motivated our investigation of two tectosilicates MCM-61 and MCM-47. MCM-61 is an aluminosilicate made in the presence of the potassium-18-Crown-6 complex. Our structure solution shows MCM-61 is formed from novel [610412] polyhedral cage units that connect to form 18-membered-ring cages. The structure of MCM-61 suggests that crown ethers, azamacrocycles, and cryptands may be useful for the syntheses of extra-large pore zeolites. MCM-47 is

  15. An IBM 370 assembly language program verifier

    Science.gov (United States)

    Maurer, W. D.

    1977-01-01

    The paper describes a program written in SNOBOL which verifies the correctness of programs written in assembly language for the IBM 360 and 370 series of computers. The motivation for using assembly language as a source language for a program verifier was the realization that many errors in programs are caused by misunderstanding or ignorance of the characteristics of specific computers. The proof of correctness of a program written in assembly language must take these characteristics into account. The program has been compiled and is currently running at the Center for Academic and Administrative Computing of The George Washington University.

  16. Cation Exchange Water Softeners

    Science.gov (United States)

    WaterSense released a notice of intent to develop a specification for cation exchange water softeners. The program has made the decision not to move forward with a spec at this time, but is making this information available.

  17. A Verifiable Secret Shuffle of Homomorphic Encryptions

    DEFF Research Database (Denmark)

    Groth, Jens

    2003-01-01

    We show how to prove in honest verifier zero-knowledge the correctness of a shuffle of homomorphic encryptions (or homomorphic commitments.) A shuffle consists in a rearrangement of the input ciphertexts and a reencryption of them so that the permutation is not revealed....

  18. Verifiable Task Assignment and Scheduling Controller

    Science.gov (United States)

    2017-07-01

    AFRL-RH-WP-TR-2017-0045 Verifiable Task Assignment and Scheduling Controller Clayton Rothwell Infoscitex Corporation...Chief, Supervisory Control Cognition Branch Supervisory Control and Cognition Branch Warfighter Interface Division //signed// KRISTOFFER A...information if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1. REPORT DATE (DD-MM

  19. Unary self-verifying symmetric difference automata

    CSIR Research Space (South Africa)

    Marais, Laurette

    2016-07-01

    Full Text Available We investigate self-verifying nondeterministic finite automata, in the case of unary symmetric difference nondeterministic finite automata (SV-XNFA). We show that there is a family of languages Ln=2 which can always be represented non...

  20. Classroom Experiment to verify the Lorentz Force

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 8; Issue 3. Classroom Experiment to Verify the Lorentz Force. Somnath Basu Anindita Bose Sumit Kumar Sinha Pankaj Vishe S Chatterjee. Classroom Volume 8 Issue 3 March 2003 pp 81-86 ...

  1. Cation-cation interaction in neptunyl(V) compounds

    Energy Technology Data Exchange (ETDEWEB)

    Krot, N.N. [Russian Academy of Sciences, Institute of Physical Chemistry (Russian Federation); Saeki, Masakatsu [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2003-03-01

    The original manuscript was prepared by Professor N.N. Krot of Institute of Physical Chemistry, Russian Academy of Sciences, in 1997. Saeki tried to translate that into Japanese and to add some new data since 1997. The contents include the whole picture of cation-cation interactions mainly in 5-valence neptunium compounds. Firstly, characteristic structures of neptunium are summarized of the cation-cation bonding in compounds. Secondly, it is mentioned how the cation-cation bonding affects physical and chemical properties of the compounds. Then, characterization-methods for the cation-cation bonding in the compounds are discussed. Finally, the cation-cation interactions in compounds of other actinide-ions are shortly reviewed. (author)

  2. A performance evaluation of personnel identity verifiers

    International Nuclear Information System (INIS)

    Maxwell, R.L.; Wright, L.J.

    1987-01-01

    Personnel identity verification devices, which are based on the examination and assessment of a body feature or a unique repeatable personal action, are steadily improving. These biometric devices are becoming more practical with respect to accuracy, speed, user compatibility, reliability and cost, but more development is necessary to satisfy the varied and sometimes ill-defined future requirements of the security industry. In an attempt to maintain an awareness of the availability and the capabilities of identity verifiers for the DOE security community, Sandia Laboratories continues to comparatively evaluate the capabilities and improvements of developing devices. An evaluation of several recently available verifiers is discussed in this paper. Operating environments and procedures more typical of physical access control use can reveal performance substantially different from the basic laboratory tests

  3. Verified Subtyping with Traits and Mixins

    Directory of Open Access Journals (Sweden)

    Asankhaya Sharma

    2014-07-01

    Full Text Available Traits allow decomposing programs into smaller parts and mixins are a form of composition that resemble multiple inheritance. Unfortunately, in the presence of traits, programming languages like Scala give up on subtyping relation between objects. In this paper, we present a method to check subtyping between objects based on entailment in separation logic. We implement our method as a domain specific language in Scala and apply it on the Scala standard library. We have verified that 67% of mixins used in the Scala standard library do indeed conform to subtyping between the traits that are used to build them.

  4. Long-term verifiability of the electronic healthcare records' authenticity.

    Science.gov (United States)

    Lekkas, Dimitrios; Gritzalis, Dimitris

    2007-01-01

    To investigate whether the long-term preservation of the authenticity of electronic healthcare records (EHR) is possible. To propose a mechanism that enables the secure validation of an EHR for long periods, far beyond the lifespan of a digital signature and at least as long as the lifetime of a patient. The study is based on the fact that although the attributes of data authenticity, i.e. integrity and origin verifiability, can be preserved by digital signatures, the necessary period for the retention of EHRs is far beyond the lifespan of a simple digital signature. It is identified that the lifespan of signed data is restricted by the validity period of the relevant keys and the digital certificates, by the future unavailability of signature-verification data, and by suppression of trust relationships. In this paper, the notarization paradigm is exploited, and a mechanism for cumulative notarization of signed EHR is proposed. The proposed mechanism implements a successive trust transition towards new entities, modern technologies, and refreshed data, eliminating any dependency of the relying party on ceased entities, obsolete data, or weak old technologies. The mechanism also exhibits strength against various threat scenarios. A future relying party will have to trust only the fresh technology and information provided by the last notary, in order to verify the authenticity of an old signed EHR. A Cumulatively Notarized Signature is strong even in the case of the compromise of a notary in the chain.

  5. Identifi cation of Sectarianism

    Directory of Open Access Journals (Sweden)

    Martinovich Vladimir

    2016-03-01

    Full Text Available «New religious movements and society» is traditionally one of the most sophisticated topics in the area of new religions studies. Its problem field is so huge that up to now by far not all important research themes where even touched by scientists from all over the world. The problem of the process of the identification of sectarianism by diff erent societal institutions is one of such untouched themes that is taken as the main subject of this article. This process by itself is an inseparable part of the every societal deliberate reaction to the very existence of unconventional religiosity, its unstructured and mainly structured types. The focal point of the article is step-by-step analysis of the general structure elements of the process of the identification of sectarianism without any reference to the specific time and place of its flow. Special attention is paid to the analysis of the subjects of the identification of sectarianism, to the criteria for religious groups to be qualified as new religious movements, and to the specific features of the process of documents filtration. The causes of selective perception of sectarianism are disclosed. Some main consequences and unpredictable outcomes of the process of the identification of sectarianism are described.

  6. Testing Library Specifications by Verifying Conformance Tests

    DEFF Research Database (Denmark)

    Kiniry, Joseph Roland; Zimmerman, Daniel; Hyland, Ralph

    2012-01-01

    Formal specifications of standard libraries are necessary when statically verifying software that uses those libraries. Library specifications must be both correct, accurately reflecting library behavior, and useful, describing library behavior in sufficient detail to allow static verification...... of client programs. Specication and verification researchers regularly face the question of whether the library specications we use are correct and useful, and we have collectively provided no good answers. Over the past few years we have created and refined a software engineering process, which we call...... the Formal CTD Process (FCTD), to address this problem. Although FCTD is primarily targeted toward those who write Java libraries (or specifications for existing Java libraries) using the Java Modeling Language (JML), its techniques are broadly applicable. The key to FCTD is its novel usage of library...

  7. Verifiable process monitoring through enhanced data authentication

    International Nuclear Information System (INIS)

    Goncalves, Joao G.M.; Schwalbach, Peter; Schoeneman, Barry Dale; Ross, Troy D.; Baldwin, George Thomas

    2010-01-01

    To ensure the peaceful intent for production and processing of nuclear fuel, verifiable process monitoring of the fuel production cycle is required. As part of a U.S. Department of Energy (DOE)-EURATOM collaboration in the field of international nuclear safeguards, the DOE Sandia National Laboratories (SNL), the European Commission Joint Research Centre (JRC) and Directorate General-Energy (DG-ENER) developed and demonstrated a new concept in process monitoring, enabling the use of operator process information by branching a second, authenticated data stream to the Safeguards inspectorate. This information would be complementary to independent safeguards data, improving the understanding of the plant's operation. The concept is called the Enhanced Data Authentication System (EDAS). EDAS transparently captures, authenticates, and encrypts communication data that is transmitted between operator control computers and connected analytical equipment utilized in nuclear processes controls. The intent is to capture information as close to the sensor point as possible to assure the highest possible confidence in the branched data. Data must be collected transparently by the EDAS: Operator processes should not be altered or disrupted by the insertion of the EDAS as a monitoring system for safeguards. EDAS employs public key authentication providing 'jointly verifiable' data and private key encryption for confidentiality. Timestamps and data source are also added to the collected data for analysis. The core of the system hardware is in a security enclosure with both active and passive tamper indication. Further, the system has the ability to monitor seals or other security devices in close proximity. This paper will discuss the EDAS concept, recent technical developments, intended application philosophy and the planned future progression of this system.

  8. New Horizons in Cationic Photopolymerization

    Directory of Open Access Journals (Sweden)

    Marco Sangermano

    2018-01-01

    Full Text Available In this review, we report some recent advances and new horizons in UV-induced cationic photopolymerization. In particular, after a brief introduction on the discovery and affirmation of the cationic photopolymerization process, new efforts in the synthesis of cationic photoinitiators are reported. Subsequently, an interesting and absolutely new application is reported, related to the combination of Radical-Induced Cationic Photopolymerization with Frontal Polymerization, achieving the cross-linking of epoxy composites.

  9. VISION: Verifiable Fuel Cycle Simulation Model

    Energy Technology Data Exchange (ETDEWEB)

    Jacob J. Jacobson; Abdellatif M. Yacout; Gretchen E. Matthern; Steven J. Piet; David E. Shropshire

    2009-04-01

    The nuclear fuel cycle is a very complex system that includes considerable dynamic complexity as well as detail complexity. In the nuclear power realm, there are experts and considerable research and development in nuclear fuel development, separations technology, reactor physics and waste management. What is lacking is an overall understanding of the entire nuclear fuel cycle and how the deployment of new fuel cycle technologies affects the overall performance of the fuel cycle. The Advanced Fuel Cycle Initiative’s systems analysis group is developing a dynamic simulation model, VISION, to capture the relationships, timing and delays in and among the fuel cycle components to help develop an understanding of how the overall fuel cycle works and can transition as technologies are changed. This paper is an overview of the philosophy and development strategy behind VISION. The paper includes some descriptions of the model and some examples of how to use VISION.

  10. Paperless reporting and electronically verifying clinical investigations.

    Science.gov (United States)

    Sun, Cheng Hung; Lew, Thomas; Tan, Doris; Hoi, Shu Yin; Khandan, Raj; Poi, Choo Hwee; Surender, Reddy; Tay, Shirley; Wan, Gervais; Lee, Y S; Lim, Lee Lee; Solikin, Handi; Yeak, Samuel

    2014-01-01

    The purpose of this paper is to outline considerations and steps taken to introduce electronic reporting and verification from systems design and multidisciplinary collaborations to gap analysis and devising solutions. It also evaluates carefully placed forcing functions' impact on verification rates. A multidisciplinary workgroup was formed to stop print and establish electronic reporting. The electronic verification's success was assessed by weekly activity analysis. Introducing a verification forcing function markedly improved verification activity. Thereafter, non-verified results stabilized at 7 percent up to 75 weeks post-implementation. This paper illustrates how results reporting and verification could be implemented in a tertiary hospital using a mixed electronic and paper record. Factors that were critical to success include stakeholder engagement and applying systems design that focussed on patient safety as a key priority. The electronic reporting system was augmented by strategically inserted forcing functions, clear clinical-responsibility lines and ancillary alert systems. The systems design method's value in managing non-critical but abnormal results appears to have been under-appreciated. This paper describes how systems design could be used to improve health information delivery and management.

  11. A Verified Algebra for Linked Data

    Directory of Open Access Journals (Sweden)

    Ross Horne

    2011-07-01

    Full Text Available A foundation is investigated for the application of loosely structured data on the Web. This area is often referred to as Linked Data, due to the use of URIs in data to establish links. This work focuses on emerging W3C standards which specify query languages for Linked Data. The approach is to provide an abstract syntax to capture Linked Data structures and queries, which are then internalised in a process calculus. An operational semantics for the calculus specifies how queries, data and processes interact. A labelled transition system is shown to be sound with respect to the operational semantics. Bisimulation over the labelled transition system is used to verify an algebra over queries. The derived algebra is a contribution to the application domain. For instance, the algebra may be used to rewrite a query to optimise its distribution across a cluster of servers. The framework used to provide the operational semantics is powerful enough to model related calculi for the Web.

  12. Analyser Framework to Verify Software Components

    Directory of Open Access Journals (Sweden)

    Rolf Andreas Rasenack

    2009-01-01

    Full Text Available Today, it is important for software companies to build software systems in a short time-interval, to reduce costs and to have a good market position. Therefore well organized and systematic development approaches are required. Reusing software components, which are well tested, can be a good solution to develop software applications in effective manner. The reuse of software components is less expensive and less time consuming than a development from scratch. But it is dangerous to think that software components can be match together without any problems. Software components itself are well tested, of course, but even if they composed together problems occur. Most problems are based on interaction respectively communication. Avoiding such errors a framework has to be developed for analysing software components. That framework determines the compatibility of corresponding software components. The promising approach discussed here, presents a novel technique for analysing software components by applying an Abstract Syntax Language Tree (ASLT. A supportive environment will be designed that checks the compatibility of black-box software components. This article is concerned to the question how can be coupled software components verified by using an analyzer framework and determines the usage of the ASLT. Black-box Software Components and Abstract Syntax Language Tree are the basis for developing the proposed framework and are discussed here to provide the background knowledge. The practical implementation of this framework is discussed and shows the result by using a test environment.

  13. A control system verifier using automated reasoning software

    International Nuclear Information System (INIS)

    Smith, D.E.; Seeman, S.E.

    1985-08-01

    An on-line, automated reasoning software system for verifying the actions of other software or human control systems has been developed. It was demonstrated by verifying the actions of an automated procedure generation system. The verifier uses an interactive theorem prover as its inference engine with the rules included as logical axioms. Operation of the verifier is generally transparent except when the verifier disagrees with the actions of the monitored software. Testing with an automated procedure generation system demonstrates the successful application of automated reasoning software for verification of logical actions in a diverse, redundant manner. A higher degree of confidence may be placed in the verified actions of the combined system

  14. Election Verifiability: Cryptographic Definitions and an Analysis of Helios and JCJ

    Science.gov (United States)

    2015-08-06

    Election Verifiability: Cryptographic Definitions and an Analysis of Helios and JCJ (Technical Report) August 6, 2015 Ben Smyth Huawei Technologies...Cornell University Ithaca, NY, US clarkson@cs.cornell.edu Abstract—Definitions of election verifiability in the compu- tational model of cryptography...only eligible voters vote. The Helios (Adida et al., 2009) and JCJ (Juels et al., 2010) election schemes are analyzed using these definitions. Helios

  15. Sorption by cation exchange

    International Nuclear Information System (INIS)

    Bradbury, M.H.; Baeyens, B.

    1994-04-01

    A procedure for introducing exchange into geochemical/surface complexation codes is described. Beginning with selectivity coefficients, K c , defined in terms of equivalent fractional ion occupancies, a general expression for the molar based exchange code input parameters, K ex , is derived. In natural systems the uptake of nuclides onto complex sorbents often occurs by more than one mechanism. The incorporation of cation exchange and surface complexation into a geochemical code therefore enables sorption by both mechanisms to be calculated simultaneously. The code and model concepts are tested against sets of experimental data from widely different sorption studies. A proposal is made to set up a data base of selectivity coefficients. Such a data base would form part of a more general one consisting of sorption mechanism specific parameters to be used in conjunction with geochemical/sorption codes to model and predict sorption. (author) 6 figs., 6 tabs., 26 refs

  16. USCIS E-Verify Customer Satisfaction Survey, January 2013

    Data.gov (United States)

    Department of Homeland Security — This report focuses on the customer satisfaction of companies currently enrolled in the E-Verify program. Satisfaction with E-Verify remains high and follows up a...

  17. New concepts in nuclear arms control: verified cutoff and verified disposal

    International Nuclear Information System (INIS)

    Donnelly, W.H.

    1990-01-01

    Limiting the numbers of nuclear warheads by reducing military production and stockpiles of fissionable materials has been a constant item on the nuclear arms control agenda for the last 45 years. It has become more salient recently, however, because of two events: the enforced closure for safety reasons of the current United States military plutonium production facilities; and the possibility that the US and USSR may soon conclude an agreement providing for the verified destruction of significant numbers of nuclear warheads and the recovery of the fissionable material they contain with the option of transferring these materials to peaceful uses. A study has been made of the practical problems of verifying the cut off of fissionable material production for military purposes in the nuclear weapon states, as well as providing assurance that material recovered from warheads is not re-used for proscribed military purposes and facilitating its transfer to civil uses. Implementation of such measures would have important implications for non-proliferation. The resultant paper was presented to a meeting of the PPNN Core Group held in Baden, close to Vienna, over the weekend of 18/19th November 1989 and is reprinted in this booklet. (author)

  18. 28 CFR 802.13 - Verifying your identity.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Verifying your identity. 802.13 Section... COLUMBIA DISCLOSURE OF RECORDS Privacy Act § 802.13 Verifying your identity. (a) Requests for your own records. When you make a request for access to records about yourself, you must verify your identity. You...

  19. Verified Interval Orbit Propagation in Satellite Collision Avoidance

    NARCIS (Netherlands)

    Römgens, B.A.; Mooij, E.; Naeije, M.C.

    2011-01-01

    Verified interval integration methods enclose a solution set corresponding to interval initial values and parameters, and bound integration and rounding errors. Verified methods suffer from overestimation of the solution, i.e., non-solutions are also included in the solution enclosure. Two verified

  20. Cationic polymers and porous materials

    KAUST Repository

    Han, Yu

    2017-04-27

    According to one or more embodiments, cationic polymers may be produced which include one or more monomers containing cations. Such cationic polymers may be utilized as structure directing agents to form mesoporous zeolites. The mesoporous zeolites may include micropores as well as mesopores, and may have a surface area of greater than 350 m2/g and a pore volume of greater than 0.3 cm3/g. Also described are core/shell zeolites, where at least the shell portion includes a mesoporous zeolite material.

  1. A Finite Equivalence of Verifiable Multi-secret Sharing

    Directory of Open Access Journals (Sweden)

    Hui Zhao

    2012-02-01

    Full Text Available We give an abstraction of verifiable multi-secret sharing schemes that is accessible to a fully mechanized analysis. This abstraction is formalized within the applied pi-calculus by using an equational theory which characterizes the cryptographic semantics of secret share. We also present an encoding from the equational theory into a convergent rewriting system, which is suitable for the automated protocol verifier ProVerif. Based on that, we verify the threshold certificate protocol in ProVerif.

  2. Scenarios for exercising technical approaches to verified nuclear reductions

    International Nuclear Information System (INIS)

    Doyle, James

    2010-01-01

    Presidents Obama and Medvedev in April 2009 committed to a continuing process of step-by-step nuclear arms reductions beyond the new START treaty that was signed April 8, 2010 and to the eventual goal of a world free of nuclear weapons. In addition, the US Nuclear Posture review released April 6, 2010 commits the US to initiate a comprehensive national research and development program to support continued progress toward a world free of nuclear weapons, including expanded work on verification technologies and the development of transparency measures. It is impossible to predict the specific directions that US-RU nuclear arms reductions will take over the 5-10 years. Additional bilateral treaties could be reached requiring effective verification as indicated by statements made by the Obama administration. There could also be transparency agreements or other initiatives (unilateral, bilateral or multilateral) that require monitoring with a standard of verification lower than formal arms control, but still needing to establish confidence to domestic, bilateral and multilateral audiences that declared actions are implemented. The US Nuclear Posture Review and other statements give some indication of the kinds of actions and declarations that may need to be confirmed in a bilateral or multilateral setting. Several new elements of the nuclear arsenals could be directly limited. For example, it is likely that both strategic and nonstrategic nuclear warheads (deployed and in storage), warhead components, and aggregate stocks of such items could be accountable under a future treaty or transparency agreement. In addition, new initiatives or agreements may require the verified dismantlement of a certain number of nuclear warheads over a specified time period. Eventually procedures for confirming the elimination of nuclear warheads, components and fissile materials from military stocks will need to be established. This paper is intended to provide useful background information

  3. Identity-Based Verifiably Encrypted Signatures without Random Oracles

    Science.gov (United States)

    Zhang, Lei; Wu, Qianhong; Qin, Bo

    Fair exchange protocol plays an important role in electronic commerce in the case of exchanging digital contracts. Verifiably encrypted signatures provide an optimistic solution to these scenarios with an off-line trusted third party. In this paper, we propose an identity-based verifiably encrypted signature scheme. The scheme is non-interactive to generate verifiably encrypted signatures and the resulting encrypted signature consists of only four group elements. Based on the computational Diffie-Hellman assumption, our scheme is proven secure without using random oracles. To the best of our knowledge, this is the first identity-based verifiably encrypted signature scheme provably secure in the standard model.

  4. Asymmetric cation-binding catalysis

    DEFF Research Database (Denmark)

    Oliveira, Maria Teresa; Lee, Jiwoong

    2017-01-01

    solvents, thus increasing their applicability in synthesis. The expansion of this concept to chiral polyethers led to the emergence of asymmetric cation-binding catalysis, where chiral counter anions are generated from metal salts, particularly using BINOL-based polyethers. Alkali metal salts, namely KF...... and KCN, are selectively bound to the catalyst, providing exceptionally high enantioselectivities for kinetic resolutions, elimination reactions (fluoride base), and Strecker synthesis (cyanide nucleophile). Asymmetric cation-binding catalysis was recently expanded to silicon-based reagents, enabling...

  5. VerifyThis 2012 - A Program Verification Competition

    NARCIS (Netherlands)

    Huisman, Marieke; Klebanov, Vladimir; Monahan, Rosemary

    2015-01-01

    VerifyThis 2012 was a two-day verification competition taking place as part of the International Symposium on Formal Methods (FM 2012) on August 30-31, 2012 in Paris, France. It was the second installment in the VerifyThis series. After the competition, an open call solicited contributions related

  6. 20 CFR 401.45 - Verifying your identity.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Verifying your identity. 401.45 Section 401.45 Employees' Benefits SOCIAL SECURITY ADMINISTRATION PRIVACY AND DISCLOSURE OF OFFICIAL RECORDS AND... electronic means, e.g., over the Internet, we require you to verify your identity by using identity...

  7. Liquid-solid extraction of cationic metals by cationic amphiphiles

    International Nuclear Information System (INIS)

    Muller, W.

    2010-01-01

    In the field of selective separation for recycling of spent nuclear fuel, liquid-liquid extraction processes are widely used (PUREX, DIAMEX..) in industrial scale. In order to guarantee a sustainable nuclear energy for the forthcoming generations, alternative reprocessing techniques are under development. One of them bases on the studies from Heckmann et al in the 80's and consists in selectively precipitating actinides from aqueous waste solutions by cationic surfactants (liquid-solid extraction). This technique has some interesting advantages over liquid-liquid extraction techniques, because several steps are omitted like stripping or solvent washing. Moreover, the amount of waste is decreased considerably, since no contaminated organic solvent is produced. In this thesis, we have carried out a physico-chemical study to understand the specific interactions between the metallic cations with the cationic surfactant. First, we have analysed the specific effect of the different counter-ions (Cl - , NO 3 - , C 2 O 4 2- ) and then the effect of alkaline cations on the structural properties of the surfactant aggregation in varying thermodynamical conditions. Finally, different multivalent cations (Cu 2+ , Zn 2+ , UO 2 2+ , Fe 3+ , Nd 3+ , Eu 3+ , Th 4+ ) were considered; we have concluded that depending on the anionic complex of these metals formed in acidic media, we can observe either an adsorption at the micellar interface or not. This adsorption has a large influence of the surfactant aggregation properties and determines the limits of the application in term of ionic strength, temperature and surfactant concentration. (author) [fr

  8. Appraising the value of independent EIA follow-up verifiers

    Energy Technology Data Exchange (ETDEWEB)

    Wessels, Jan-Albert, E-mail: janalbert.wessels@nwu.ac.za [School of Geo and Spatial Sciences, Department of Geography and Environmental Management, North-West University, C/O Hoffman and Borcherd Street, Potchefstroom, 2520 (South Africa); Retief, Francois, E-mail: francois.retief@nwu.ac.za [School of Geo and Spatial Sciences, Department of Geography and Environmental Management, North-West University, C/O Hoffman and Borcherd Street, Potchefstroom, 2520 (South Africa); Morrison-Saunders, Angus, E-mail: A.Morrison-Saunders@murdoch.edu.au [School of Geo and Spatial Sciences, Department of Geography and Environmental Management, North-West University, C/O Hoffman and Borcherd Street, Potchefstroom, 2520 (South Africa); Environmental Assessment, School of Environmental Science, Murdoch University, Australia. (Australia)

    2015-01-15

    Independent Environmental Impact Assessment (EIA) follow-up verifiers such as monitoring agencies, checkers, supervisors and control officers are active on various construction sites across the world. There are, however, differing views on the value that these verifiers add and very limited learning in EIA has been drawn from independent verifiers. This paper aims to appraise how and to what extent independent EIA follow-up verifiers add value in major construction projects in the developing country context of South Africa. A framework for appraising the role of independent verifiers was established and four South African case studies were examined through a mixture of site visits, project document analysis, and interviews. Appraisal results were documented in the performance areas of: planning, doing, checking, acting, public participating and integration with other programs. The results indicate that independent verifiers add most value to major construction projects when involved with screening EIA requirements of new projects, allocation of financial and human resources, checking legal compliance, influencing implementation, reporting conformance results, community and stakeholder engagement, integration with self-responsibility programs such as environmental management systems (EMS), and controlling records. It was apparent that verifiers could be more creatively utilized in pre-construction preparation, providing feedback of knowledge into assessment of new projects, giving input to the planning and design phase of projects, and performance evaluation. The study confirms the benefits of proponent and regulator follow-up, specifically in having independent verifiers that disclose information, facilitate discussion among stakeholders, are adaptable and proactive, aid in the integration of EIA with other programs, and instill trust in EIA enforcement by conformance evaluation. Overall, the study provides insight on how to harness the learning opportunities

  9. Appraising the value of independent EIA follow-up verifiers

    International Nuclear Information System (INIS)

    Wessels, Jan-Albert; Retief, Francois; Morrison-Saunders, Angus

    2015-01-01

    Independent Environmental Impact Assessment (EIA) follow-up verifiers such as monitoring agencies, checkers, supervisors and control officers are active on various construction sites across the world. There are, however, differing views on the value that these verifiers add and very limited learning in EIA has been drawn from independent verifiers. This paper aims to appraise how and to what extent independent EIA follow-up verifiers add value in major construction projects in the developing country context of South Africa. A framework for appraising the role of independent verifiers was established and four South African case studies were examined through a mixture of site visits, project document analysis, and interviews. Appraisal results were documented in the performance areas of: planning, doing, checking, acting, public participating and integration with other programs. The results indicate that independent verifiers add most value to major construction projects when involved with screening EIA requirements of new projects, allocation of financial and human resources, checking legal compliance, influencing implementation, reporting conformance results, community and stakeholder engagement, integration with self-responsibility programs such as environmental management systems (EMS), and controlling records. It was apparent that verifiers could be more creatively utilized in pre-construction preparation, providing feedback of knowledge into assessment of new projects, giving input to the planning and design phase of projects, and performance evaluation. The study confirms the benefits of proponent and regulator follow-up, specifically in having independent verifiers that disclose information, facilitate discussion among stakeholders, are adaptable and proactive, aid in the integration of EIA with other programs, and instill trust in EIA enforcement by conformance evaluation. Overall, the study provides insight on how to harness the learning opportunities

  10. Cation-Pi Interaction: A Key Force for Sorption of Fluoroquinolone Antibiotics on Pyrogenic Carbonaceous Materials.

    Science.gov (United States)

    Zhao, Qing; Zhang, Siyu; Zhang, Xuejiao; Lei, Lei; Ma, Wei; Ma, Chuanxin; Song, Lei; Chen, Jingwen; Pan, Bo; Xing, Baoshan

    2017-12-05

    Cation-pi attraction is a major force that determines macromolecular structures and drug-receptor interactions. However, the role of the cation-pi interaction in sorption of fluoroquinolone antibiotics by pyrogenic carbonaceous materials (PCMs) has not been addressed. We studied sorption of ciprofloxacin (CIP) on graphite to quantify the contribution of the cation-pi interaction. Through competition experiments, the decreased amount of sorbed CIP by sequential treatment with hexadecane, phenanthrene and benzylamine represents the contribution of hydrophobic, pi-pi and cation-pi interactions, respectively. Benzylamine competed more strongly with CIP than n-hexadecane and phenanthrene, indicating that cation-pi is a major force. Cation-pi interactions accounted for up to 72.6% of the total sorption at an initial CIP concentration of 0.000015 mmol/L. Importantly, species transformation (CIP(0) captures H + from water to form CIP(+1)) induced by cation-pi interactions was verified both experimentally and theoretically and can be used to explain the environmental behavior of other fluoroquinolone antibiotics and biochemical processes of amino acids that interact with aromatic moieties. Because of the significant role of cation-pi interactions, CIP desorption increased up to 2.32 times when Na + increased from 0.01 mM to 0.45 mM, which is an environmentally relevant scenario at river estuaries. Hence, behaviors of fluoroquinolone antibiotics that are affected by ionic strength changes need to be carefully evaluated, especially in river estuaries.

  11. NOS CO-OPS Water Level Data, Verified, Hourly

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset has verified (quality-controlled), hourly, water level (tide) data from NOAA NOS Center for Operational Oceanographic Products and Services (CO-OPS)....

  12. NOS CO-OPS Water Level Data, Verified, High Low

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset has verified (quality-controlled), daily, high low water level (tide) data from NOAA NOS Center for Operational Oceanographic Products and Services...

  13. NOS CO-OPS Water Level Data, Verified, 6-Minute

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset has verified (quality-controlled), 6-minute, water level (tide) data from NOAA NOS Center for Operational Oceanographic Products and Services (CO-OPS)....

  14. Verifiable Distribution of Material Goods Based on Cryptology

    Directory of Open Access Journals (Sweden)

    Radomír Palovský

    2015-12-01

    Full Text Available Counterfeiting of material goods is a general problem. In this paper an architecture for verifiable distribution of material goods is presented. This distribution is based on printing such a QR code on goods, which would contain digitally signed serial number of the product, and validity of this digital signature could be verifiable by a customer. Extension consisting of adding digital signatures to revenue stamps used for state-controlled goods is also presented. Discussion on possibilities in making copies leads to conclusion that cryptographic security needs to be completed by technical difficulties of copying.

  15. Cationic electrodepositable coating composition comprising lignin

    Science.gov (United States)

    Fenn, David; Bowman, Mark P; Zawacky, Steven R; Van Buskirk, Ellor J; Kamarchik, Peter

    2013-07-30

    A cationic electrodepositable coating composition is disclosed. The present invention in directed to a cationic electrodepositable coating composition comprising a lignin-containing cationic salt resin, that comprises (A) the reaction product of: lignin, an amine, and a carbonyl compound; (B) the reaction product of lignin, epichlorohydrin, and an amine; or (C) combinations thereof.

  16. Analyzing Interaction Patterns to Verify a Simulation/Game Model

    Science.gov (United States)

    Myers, Rodney Dean

    2012-01-01

    In order for simulations and games to be effective for learning, instructional designers must verify that the underlying computational models being used have an appropriate degree of fidelity to the conceptual models of their real-world counterparts. A simulation/game that provides incorrect feedback is likely to promote misunderstanding and…

  17. An intruder model for verifying liveness in security protocols

    NARCIS (Netherlands)

    Cederquist, J.G.; Dashti, Muhammad Torabi

    2006-01-01

    We present a process algebraic intruder model for verifying a class of liveness properties of security protocols. For this class, the proposed intruder model is proved to be equivalent to a Dolev-Yao intruder that does not delay indefinitely the delivery of messages. In order to prove the

  18. Software Requirements Specification Verifiable Fuel Cycle Simulation (VISION) Model

    International Nuclear Information System (INIS)

    D. E. Shropshire; W. H. West

    2005-01-01

    The purpose of this Software Requirements Specification (SRS) is to define the top-level requirements for a Verifiable Fuel Cycle Simulation Model (VISION) of the Advanced Fuel Cycle (AFC). This simulation model is intended to serve a broad systems analysis and study tool applicable to work conducted as part of the AFCI (including costs estimates) and Generation IV reactor development studies

  19. Making Digital Artifacts on the Web Verifiable and Reliable

    NARCIS (Netherlands)

    Kuhn, T.; Dumontier, M.

    2015-01-01

    The current Web has no general mechanisms to make digital artifacts - such as datasets, code, texts, and images - verifiable and permanent. For digital artifacts that are supposed to be immutable, there is moreover no commonly accepted method to enforce this immutability. These shortcomings have a

  20. Elements of a system for verifying a Comprehensive Test Ban

    International Nuclear Information System (INIS)

    Hannon, W.J.

    1987-01-01

    The paper discusses the goals of a monitoring system for a CTB, its functions, the challenges to verification, discrimination techniques, and some recent developments. It is concluded technical, military and political efforts are required to establish and verify test ban treaties which will contribute to stability in the long term. It currently appears there will be a significant number of unidentified events

  1. The hysterosalpingography examination verified by laparoscopy; Laparoskopowa weryfikacja obrazow histerosalpingograficznych

    Energy Technology Data Exchange (ETDEWEB)

    Popiela, A.; Kasiak, J.; Heimrath, T.; Cislo, M. [Akademia Medyczna, Wroclaw (Poland)

    1993-12-31

    The authors discuss 47 cases in which the hysterosalpingography (HSG) examination showed secondary tubar unpatency, then verified by laparoscopy. In the opinion of the authors supported by the results the HSG examination may be considered only as a preliminary element of tubar patency examination. In case of planned microsurgery the only qualifying or disqualifying examination is the laparoscopy with introduction of color contrast. (author)

  2. ORIGINAL ARTICLE Accuracy of bone assessments for verifying ...

    African Journals Online (AJOL)

    for stature and mass were calculated for these data for the ages of the subjects in this study. Accuracy of bone assessments for verifying age in adolescents – application in sport. S C Braude,. L M Henning,. M I Lambert,. MRC/UCT Research Unit for Exercise Science and Sports Medicine,. Department of Human Biology, ...

  3. Methods for verifying compliance with low-level radioactive waste acceptance criteria

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1993-09-01

    This report summarizes the methods that are currently employed and those that can be used to verify compliance with low-level radioactive waste (LLW) disposal facility waste acceptance criteria (WAC). This report presents the applicable regulations representing the Federal, State, and site-specific criteria for accepting LLW. Typical LLW generators are summarized, along with descriptions of their waste streams and final waste forms. General procedures and methods used by the LLW generators to verify compliance with the disposal facility WAC are presented. The report was written to provide an understanding of how a regulator could verify compliance with a LLW disposal facility`s WAC. A comprehensive study of the methodology used to verify waste generator compliance with the disposal facility WAC is presented in this report. The study involved compiling the relevant regulations to define the WAC, reviewing regulatory agency inspection programs, and summarizing waste verification technology and equipment. The results of the study indicate that waste generators conduct verification programs that include packaging, classification, characterization, and stabilization elements. The current LLW disposal facilities perform waste verification steps on incoming shipments. A model inspection and verification program, which includes an emphasis on the generator`s waste application documentation of their waste verification program, is recommended. The disposal facility verification procedures primarily involve the use of portable radiological survey instrumentation. The actual verification of generator compliance to the LLW disposal facility WAC is performed through a combination of incoming shipment checks and generator site audits.

  4. Methods for verifying compliance with low-level radioactive waste acceptance criteria

    International Nuclear Information System (INIS)

    1993-09-01

    This report summarizes the methods that are currently employed and those that can be used to verify compliance with low-level radioactive waste (LLW) disposal facility waste acceptance criteria (WAC). This report presents the applicable regulations representing the Federal, State, and site-specific criteria for accepting LLW. Typical LLW generators are summarized, along with descriptions of their waste streams and final waste forms. General procedures and methods used by the LLW generators to verify compliance with the disposal facility WAC are presented. The report was written to provide an understanding of how a regulator could verify compliance with a LLW disposal facility's WAC. A comprehensive study of the methodology used to verify waste generator compliance with the disposal facility WAC is presented in this report. The study involved compiling the relevant regulations to define the WAC, reviewing regulatory agency inspection programs, and summarizing waste verification technology and equipment. The results of the study indicate that waste generators conduct verification programs that include packaging, classification, characterization, and stabilization elements. The current LLW disposal facilities perform waste verification steps on incoming shipments. A model inspection and verification program, which includes an emphasis on the generator's waste application documentation of their waste verification program, is recommended. The disposal facility verification procedures primarily involve the use of portable radiological survey instrumentation. The actual verification of generator compliance to the LLW disposal facility WAC is performed through a combination of incoming shipment checks and generator site audits

  5. Verifiable Measurement-Only Blind Quantum Computing with Stabilizer Testing.

    Science.gov (United States)

    Hayashi, Masahito; Morimae, Tomoyuki

    2015-11-27

    We introduce a simple protocol for verifiable measurement-only blind quantum computing. Alice, a client, can perform only single-qubit measurements, whereas Bob, a server, can generate and store entangled many-qubit states. Bob generates copies of a graph state, which is a universal resource state for measurement-based quantum computing, and sends Alice each qubit of them one by one. Alice adaptively measures each qubit according to her program. If Bob is honest, he generates the correct graph state, and, therefore, Alice can obtain the correct computation result. Regarding the security, whatever Bob does, Bob cannot get any information about Alice's computation because of the no-signaling principle. Furthermore, malicious Bob does not necessarily send the copies of the correct graph state, but Alice can check the correctness of Bob's state by directly verifying the stabilizers of some copies.

  6. Software Platform Evaluation - Verifiable Fuel Cycle Simulation (VISION) Model

    International Nuclear Information System (INIS)

    J. J. Jacobson; D. E. Shropshire; W. B. West

    2005-01-01

    The purpose of this Software Platform Evaluation (SPE) is to document the top-level evaluation of potential software platforms on which to construct a simulation model that satisfies the requirements for a Verifiable Fuel Cycle Simulation Model (VISION) of the Advanced Fuel Cycle (AFC). See the Software Requirements Specification for Verifiable Fuel Cycle Simulation (VISION) Model (INEEL/EXT-05-02643, Rev. 0) for a discussion of the objective and scope of the VISION model. VISION is intended to serve as a broad systems analysis and study tool applicable to work conducted as part of the AFCI (including costs estimates) and Generation IV reactor development studies. This document will serve as a guide for selecting the most appropriate software platform for VISION. This is a ''living document'' that will be modified over the course of the execution of this work

  7. Verifying non-Abelian statistics by numerical braiding Majorana fermions

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Qiu-Bo [Department of Physics, Beijing Normal University, Beijing, 100875 (China); He, Jing [Department of Physics, Hebei Normal University, Hebei, 050024 (China); Kou, Su-Peng, E-mail: spkou@bnu.edu.cn [Department of Physics, Beijing Normal University, Beijing, 100875 (China)

    2016-02-15

    Recently, Majorana fermions have attracted intensive attention because of their possible non-Abelian statistics and potential applications in topological quantum computation. This paper describes an approach to verify the non-Abelian statistics of Majorana fermions in topological superconductors. From the relationship between the braiding operator of Majorana fermions and that of Bogoliubov–de Gennes states, we determine that Majorana fermions in one-dimensional and two-dimensional topological superconductors both obey non-Abelian statistics. - Highlights: • The braiding of Majorana fermions is an adiabatic evolution. • The approach to calculate Berry phase in the braiding is proposed. • Verifying non-Abelian statistics of Majorara Fermions induced in different systems.

  8. Verifying Anonymous Credential Systems in Applied Pi Calculus

    Science.gov (United States)

    Li, Xiangxi; Zhang, Yu; Deng, Yuxin

    Anonymous credentials are widely used to certify properties of a credential owner or to support the owner to demand valuable services, while hiding the user's identity at the same time. A credential system (a.k.a. pseudonym system) usually consists of multiple interactive procedures between users and organizations, including generating pseudonyms, issuing credentials and verifying credentials, which are required to meet various security properties. We propose a general symbolic model (based on the applied pi calculus) for anonymous credential systems and give formal definitions of a few important security properties, including pseudonym and credential unforgeability, credential safety, pseudonym untraceability. We specialize the general formalization and apply it to the verification of a concrete anonymous credential system proposed by Camenisch and Lysyanskaya. The analysis is done automatically with the tool ProVerif and several security properties have been verified.

  9. Verifying a nuclear weapon`s response to radiation environments

    Energy Technology Data Exchange (ETDEWEB)

    Dean, F.F.; Barrett, W.H.

    1998-05-01

    The process described in the paper is being applied as part of the design verification of a replacement component designed for a nuclear weapon currently in the active stockpile. This process is an adaptation of the process successfully used in nuclear weapon development programs. The verification process concentrates on evaluating system response to radiation environments, verifying system performance during and after exposure to radiation environments, and assessing system survivability.

  10. Verifying the gravitational shift due to the earth's rotation

    International Nuclear Information System (INIS)

    Briatore, L.; Leschiutta, S.

    1976-01-01

    Data on various independent time scales kept in different laboratories are elaborated in order to verify the gravitational shift due to the earth's rotation. It is shown that the state of the art in the measurement of time is just now resulting in the possibility to make measurement of Δ t/t approximately 10 -13 . Moreover it is shown an experimental evidence of the earth's rotation relativistic effects

  11. Robustness and device independence of verifiable blind quantum computing

    International Nuclear Information System (INIS)

    Gheorghiu, Alexandru; Kashefi, Elham; Wallden, Petros

    2015-01-01

    Recent advances in theoretical and experimental quantum computing bring us closer to scalable quantum computing devices. This makes the need for protocols that verify the correct functionality of quantum operations timely and has led to the field of quantum verification. In this paper we address key challenges to make quantum verification protocols applicable to experimental implementations. We prove the robustness of the single server verifiable universal blind quantum computing protocol of Fitzsimons and Kashefi (2012 arXiv:1203.5217) in the most general scenario. This includes the case where the purification of the deviated input state is in the hands of an adversarial server. The proved robustness property allows the composition of this protocol with a device-independent state tomography protocol that we give, which is based on the rigidity of CHSH games as proposed by Reichardt et al (2013 Nature 496 456–60). The resulting composite protocol has lower round complexity for the verification of entangled quantum servers with a classical verifier and, as we show, can be made fault tolerant. (paper)

  12. Verifiable fault tolerance in measurement-based quantum computation

    Science.gov (United States)

    Fujii, Keisuke; Hayashi, Masahito

    2017-09-01

    Quantum systems, in general, cannot be simulated efficiently by a classical computer, and hence are useful for solving certain mathematical problems and simulating quantum many-body systems. This also implies, unfortunately, that verification of the output of the quantum systems is not so trivial, since predicting the output is exponentially hard. As another problem, the quantum system is very delicate for noise and thus needs an error correction. Here, we propose a framework for verification of the output of fault-tolerant quantum computation in a measurement-based model. In contrast to existing analyses on fault tolerance, we do not assume any noise model on the resource state, but an arbitrary resource state is tested by using only single-qubit measurements to verify whether or not the output of measurement-based quantum computation on it is correct. Verifiability is equipped by a constant time repetition of the original measurement-based quantum computation in appropriate measurement bases. Since full characterization of quantum noise is exponentially hard for large-scale quantum computing systems, our framework provides an efficient way to practically verify the experimental quantum error correction.

  13. Proving Correctness for Pointer Programs in a Verifying Compiler

    Science.gov (United States)

    Kulczycki, Gregory; Singh, Amrinder

    2008-01-01

    This research describes a component-based approach to proving the correctness of programs involving pointer behavior. The approach supports modular reasoning and is designed to be used within the larger context of a verifying compiler. The approach consists of two parts. When a system component requires the direct manipulation of pointer operations in its implementation, we implement it using a built-in component specifically designed to capture the functional and performance behavior of pointers. When a system component requires pointer behavior via a linked data structure, we ensure that the complexities of the pointer operations are encapsulated within the data structure and are hidden to the client component. In this way, programs that rely on pointers can be verified modularly, without requiring special rules for pointers. The ultimate objective of a verifying compiler is to prove-with as little human intervention as possible-that proposed program code is correct with respect to a full behavioral specification. Full verification for software is especially important for an agency like NASA that is routinely involved in the development of mission critical systems.

  14. Cation-Coupled Bicarbonate Transporters

    OpenAIRE

    Aalkjaer, Christian; Boedtkjer, Ebbe; Choi, Inyeong; Lee, Soojung

    2014-01-01

    Cation-coupled HCO3− transport was initially identified in the mid-1970s when pioneering studies showed that acid extrusion from cells is stimulated by CO2/HCO3− and associated with Na+ and Cl− movement. The first Na+-coupled bicarbonate transporter (NCBT) was expression-cloned in the late 1990s. There are currently five mammalian NCBTs in the SLC4-family: the electrogenic Na,HCO3-cotransporters NBCe1 and NBCe2 (SLC4A4 and SLC4A5 gene products); the electroneutral Na,HCO3-cotransporter NBCn1 ...

  15. The Free Tricoordinated Silyl Cation Problem

    Directory of Open Access Journals (Sweden)

    Čičak, H.

    2010-03-01

    Full Text Available As the importance and abundance of silicon in our environment is large, it has been thought that silicon might take the place of carbon in forming a host of similar compounds and silicon-based life. However, until today there is no experimental evidence for such a hypothesis and carbon is still unique among the elements in the vast number and variety of compounds it can form. Also, the corresponding derivatives of the two elements show considerable differences in their chemical properties.The essential debate concerning organosilicon chemistry relates to the existence of the free planar tricoordinated silyl cations in condensed phase (R3Si+, in analogy to carbocations (R3C+ which have been known and characterized as free species. Although silyl cations are thermodynamically more stable than their carbon analogs, they are very reactive due to their high inherent electrophilicity and the ability of hypervalent coordination. On the other hand, stabilization by inductive and hyperconjugative effects and larger steric effects of carbocations make them less sensitive to solvation or other environmental effects than silyl cations. Hence, observation of free silyl cations in the condensed phase proved extremely difficult and the actual problem is the question of the degree of the (remaining silyl cation character.The first free silyl cation, trimesitylsilyl cation, and in analogy with it tridurylsilyl cation, were synthesized by Lambert et al. Free silyl cations based on analogy to aromatic ions (homocyclopropenylium and tropylium have also been prepared. However, in these silyl cations the cationic character is reduced by internal π -conjugation. Čičak et al. prepared some silyl-cationic intermediates (Me3Si--CH≡CR+in solid state. With the help of quantum-mechanical calculations it was concluded that these adducts have much more silyl cation than carbocation character.

  16. Relative solubility of cations in Class F fly ash.

    Science.gov (United States)

    Kim, Ann G; Kazonich, George; Dahlberg, Michael

    2003-10-01

    Coal utilization byproducts (CUB), such as fly ash, contain cations that may be released during exposure to fluids such as acid rain or acid mine drainage. Researchers at the Department of Energy's National Energy Technology Laboratory (DOE/NETL) have conducted a long-term column leaching study of 32 Class F fly ash samples from pulverized coal (PC) combustion, and quantified the release of 19 cations in four leachants with a pH between 1.2 and 12. The relative solubility (M(L/T)) of each cation was defined as the total mass leached (M(L)) relative to the concentration (M(T)) of that element in the fly ash sample. A frequency distribution of relative solubility values was computed with ranges defined as insoluble, slightly soluble, moderately soluble, and very soluble. On the basis of this sample set, Ba, Cd, Fe, Pb, Sb, and Se in PC fly ash are insoluble. The elements Al, Be, Ca, Co, Cr, Cu, K, Mg, Mn, Na, Ni, and Zn are slightly to moderately acid soluble. Only Ca and Na are water soluble; As and Ca are soluble in the basic solution, The results of this study indicate that the extent to which cations in Class F PC fly ash can be leached by naturally occurring fluids is very limited.

  17. A New Alkali-Stable Phosphonium Cation Based on Fundamental Understanding of Degradation Mechanisms.

    Science.gov (United States)

    Zhang, Bingzi; Kaspar, Robert B; Gu, Shuang; Wang, Junhua; Zhuang, Zhongbin; Yan, Yushan

    2016-09-08

    Highly alkali-stable cationic groups are a critical component of hydroxide exchange membranes (HEMs). To search for such cations, we studied the degradation kinetics and mechanisms of a series of quaternary phosphonium (QP) cations. Benzyl tris(2,4,6-trimethoxyphenyl)phosphonium [BTPP-(2,4,6-MeO)] was determined to have higher alkaline stability than the benchmark cation, benzyl trimethylammonium (BTMA). A multi-step methoxy-triggered degradation mechanism for BTPP-(2,4,6-MeO) was proposed and verified. By replacing methoxy substituents with methyl groups, a superior QP cation, methyl tris(2,4,6-trimethylphenyl)phosphonium [MTPP-(2,4,6-Me)] was developed. MTPP-(2,4,6-Me) is one of the most stable cations reported to date, with <20 % degradation after 5000 h at 80 °C in a 1 m KOD in CD3 OD/D2 O (5:1 v/v) solution. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. An alternative test for verifying electronic balance linearity

    International Nuclear Information System (INIS)

    Thomas, I.R.

    1998-02-01

    This paper presents an alternative method for verifying electronic balance linearity and accuracy. This method is being developed for safeguards weighings (weighings for the control and accountability of nuclear material) at the Idaho National Engineering and Environmental Laboratory (INEEL). With regard to balance linearity and accuracy, DOE Order 5633.3B, Control and Accountability of Nuclear Materials, Paragraph 2, 4, e, (1), (a) Scales and Balances Program, states: ''All scales and balances used for accountability purposes shall be maintained in good working condition, recalibrated according to an established schedule, and checked for accuracy and linearity on each day that the scale or balance is used for accountability purposes.'' Various tests have been proposed for testing accuracy and linearity. In the 1991 Measurement Science Conference, Dr. Walter E. Kupper presented a paper entitled: ''Validation of High Accuracy Weighing Equipment.'' Dr. Kupper emphasized that tolerance checks for calibrated, state-of-the-art electronic equipment need not be complicated, and he presented four easy steps for verifying that a calibrated balance is operating correctly. These tests evaluate the standard deviation of successive weighings (of the same load), the off-center error, the calibration error, and the error due to nonlinearity. This method of balance validation is undoubtedly an authoritative means of ensuring balance operability, yet it could have two drawbacks: one, the test for linearity is not intuitively obvious, especially from a statistical viewpoint; and two, there is an absence of definitively defined testing limits. Hence, this paper describes an alternative means of verifying electronic balance linearity and accuracy that is being developed for safeguards measurements at the INEEL

  19. The Guided System Development Framework: Modeling and Verifying Communication Systems

    DEFF Research Database (Denmark)

    Carvalho Quaresma, Jose Nuno; Probst, Christian W.; Nielson, Flemming

    2014-01-01

    . The Guided System Development framework contributes to more secure communication systems by aiding the development of such systems. The framework features a simple modelling language, step-wise refinement from models to implementation, interfaces to security verification tools, and code generation from...... the verified specification. The refinement process carries thus security properties from the model to the implementation. Our approach also supports verification of systems previously developed and deployed. Internally, the reasoning in our framework is based on the Beliefs and Knowledge tool, a verification...

  20. ASTUS system for verifying the transport seal TITUS 1

    International Nuclear Information System (INIS)

    Barillaux; Monteil, D.; Destain, G.D.

    1991-01-01

    ASTUS, a system for acquisition and processing ultrasonic signatures of TITUS 1 seals has been developed. TITUS seals are used to verify the integrity of the fissile material's container sealing after transport. An autonomous portable reading case permit to take seals signatures at the starting point and to transmit these reference signatures to a central safeguards computer by phonic modem. Then, at the terminal point with a similar reading case, an authority takes again the signature of seals and immediately transmit these signatures to the central safeguards computer. The central computer processes the data in real time by autocorrelation and return its verdict to the terminal point

  1. Lucid dreaming verified by volitional communication during REM sleep.

    Science.gov (United States)

    La Berge, S P; Nagel, L E; Dement, W C; Zarcone, V P

    1981-06-01

    The occurrence of lucid dreaming (dreaming while being conscious that one is dreaming) has been verified for 5 selected subjects who signaled that they knew they were dreaming while continuing to dream during unequivocal REM sleep. The signals consisted of particular dream actions having observable concomitants and were performed in accordance with pre-sleep agreement. The ability of proficient lucid dreamers to signal in this manner makes possible a new approach to dream research--such subjects, while lucid, could carry out diverse dream experiments marking the exact time of particular dream events, allowing derivation of of precise psychophysiological correlations and methodical testing of hypotheses.

  2. Verifying Architectural Design Rules of the Flight Software Product Line

    Science.gov (United States)

    Ganesan, Dharmalingam; Lindvall, Mikael; Ackermann, Chris; McComas, David; Bartholomew, Maureen

    2009-01-01

    This paper presents experiences of verifying architectural design rules of the NASA Core Flight Software (CFS) product line implementation. The goal of the verification is to check whether the implementation is consistent with the CFS architectural rules derived from the developer's guide. The results indicate that consistency checking helps a) identifying architecturally significant deviations that were eluded during code reviews, b) clarifying the design rules to the team, and c) assessing the overall implementation quality. Furthermore, it helps connecting business goals to architectural principles, and to the implementation. This paper is the first step in the definition of a method for analyzing and evaluating product line implementations from an architecture-centric perspective.

  3. Psychological and social aspects verified after the Goiania's radioactive accident

    International Nuclear Information System (INIS)

    Helou, Suzana

    1995-01-01

    Psychological and social aspects verified after the radioactive accident occurred in 1987 in Goiania - brazilian city - are discussed. With this goal was going presented a public opinion research in order to retract the Goiania's radioactive accident residual psychological effects. They were going consolidated data obtained in 1.126 interviews. Four involvement different levels groups with the accident are compared with regard to the event. The research allowed to conclude that the accident affected psychologically somehow all Goiania's population. Besides, the research allowed to analyze the professionals performance quality standard in terms of the accident

  4. Cation distribution of Ni 0.5 Zn 0.5 Fe 2 O 4 nanoparticles | Singh ...

    African Journals Online (AJOL)

    ... normal preference at a temperature around 675 °C. It has been found that size onset for having the bulk cation configuration exclusively depends on the composition. Keywords: Mössbauer Spectroscopy; Ferrite; Nanoparticles, Cationic distribution. International Journal of Engineering, Science and Technology, Vol. 2, No.

  5. ADSORPTION METHOD FOR SEPARATING METAL CATIONS

    Science.gov (United States)

    Khym, J.X.

    1959-03-10

    The chromatographic separation of fission product cations is discussed. By use of this method a mixture of metal cations containing Zr, Cb, Ce, Y, Ba, and Sr may be separated from one another. Mentioned as preferred exchange adsorbents are resins containing free sulfonic acid groups. Various eluants, such as tartaric acid, HCl, and citric acid, used at various acidities, are employed to effect the selective elution and separation of the various fission product cations.

  6. Computerized approach to verifying study population data in occupational epidemiology.

    Science.gov (United States)

    Marsh, G M

    1982-08-01

    IN a previous paper a method was presented for verifying the completeness of occupational study populations independently of company-held records. The basis for the verification scheme was the Employers Quarterly Report on Earnings (Internal Revenue Service Form 941) that is submitted to the IRS each quarter of every year for all employees on a company payroll. In employing the verification scheme two approaches can be taken in determining how many and which quarterly reports are selected: (1) If the work force is large and/or many years are surveyed, a probability sample of years and quarters within years can be selected, allowing inferences to be made with respect to the entire study population. (2) If the number of survey years and/or the size of the work force is sufficiently small, copies of all quarterly returns for each survey year can be requested thus allowing a comprehensive check for completeness to be conducted. Te verification method described in the previous paper concentrated primarily on the first-mentioned approach. The second approach is herein being dealt with as well as a computerized method for verifying the completeness of study populations. In addition a new computerized method is described that utilizes the quarterly reports as an unbiased data base for checking the accuracy of certain work history data as developed from company records. An application of the computerized methods is given using data from a recent historical-prospective study of chemical production workers.

  7. Verifying competence of operations personnel in nuclear power plants

    International Nuclear Information System (INIS)

    Farber, G.H.

    1986-01-01

    To ensure that only competent people are authorized to fill positions in a nuclear power plant, both the initial competence of personnel and the continuous maintenance of competence have to be verified. Two main methods are normally used for verifying competence, namely evaluation of a person's performance over a period of time, and evaluation of his knowledge and skills at a particular time by means of an examination. Both methods have limitations, and in practice they are often used together to give different and to some extent complementary evaluations of a person's competence. Verification of competence itself is a problem area, because objective judging of human competence is extremely difficult. Formal verification methods, such as tests and examinations, are particularly or exclusively applied for the direct operating personnel in the control room (very rarely for management personnel). Out of the many elements contributing to a person's competence, the knowledge which is needed and the intellectual skills are the main subjects of the formal verification methods. Therefore the presentation will concentrate on the proof of the technical qualification of operators by means of examinations. The examination process in the Federal Republic of Germany for the proof of knowledge and skills will serve as an example to describe and analyze the important aspects. From that recommendations are derived regarding standardization of the procedure as well as validation. (orig./GL)

  8. People consider reliability and cost when verifying their autobiographical memories.

    Science.gov (United States)

    Wade, Kimberley A; Nash, Robert A; Garry, Maryanne

    2014-02-01

    Because memories are not always accurate, people rely on a variety of strategies to verify whether the events that they remember really did occur. Several studies have examined which strategies people tend to use, but none to date has asked why people opt for certain strategies over others. Here we examined the extent to which people's beliefs about the reliability and the cost of different strategies would determine their strategy selection. Subjects described a childhood memory and then suggested strategies they might use to verify the accuracy of that memory. Next, they rated the reliability and cost of each strategy, and the likelihood that they might use it. Reliability and cost each predicted strategy selection, but a combination of the two ratings provided even greater predictive value. Cost was significantly more influential than reliability, which suggests that a tendency to seek and to value "cheap" information more than reliable information could underlie many real-world memory errors. Copyright © 2013 Elsevier B.V. All rights reserved.

  9. Verifiable Rational Secret Sharing Scheme in Mobile Networks

    Directory of Open Access Journals (Sweden)

    En Zhang

    2015-01-01

    Full Text Available With the development of mobile network, lots of people now have access to mobile phones and the mobile networks give users ubiquitous connectivity. However, smart phones and tablets are poor in computational resources such as memory size, processor speed, and disk capacity. So far, all existing rational secret sharing schemes cannot be suitable for mobile networks. In this paper, we propose a verifiable rational secret sharing scheme in mobile networks. The scheme provides a noninteractively verifiable proof for the correctness of participants’ share and handshake protocol is not necessary; there is no need for certificate generation, propagation, and storage in the scheme, which is more suitable for devices with limited size and processing power; in the scheme, every participant uses her encryption on number of each round as the secret share and the dealer does not have to distribute any secret share; every participant cannot gain more by deviating the protocol, so rational participant has an incentive to abide by the protocol; finally, every participant can obtain the secret fairly (means that either everyone receives the secret, or else no one does in mobile networks. The scheme is coalition-resilient and the security of our scheme relies on a computational assumption.

  10. The Guide-based Automatic Creation of Verified Test Scenarious

    Directory of Open Access Journals (Sweden)

    P. D. Drobintsev

    2013-01-01

    Full Text Available This paper presents an overview of technology of the automated generation of test scenarios based on guides. The usage of this technology can significantly improve the quality of the developed program products. In order to ground the technology creation, the main problems that occur during the development and testing of the large industrial systems, are described, as well as the methodologies of software verification on conformity to product requirements. The potentialities of tools for automatic and semi-automatic generation of a test suite by using a formal model in UCM notation are demonstrated, as well as tools for verification and automation of testing.

  11. Afrikaans Syllabification Patterns

    Directory of Open Access Journals (Sweden)

    Tilla Fick

    2010-01-01

    Full Text Available In contrast to English, automatic hyphenation by computer of Afrikaans words is a problem that still needs to be addressed, since errors are still often encountered in printed text. An initial step in this task is the ability to automatically syllabify words. Since new words are created continuously by joining words, it is necessary to develop an “intelligent” technique for syllabification. As a first phase of the research, we consider only the orthographic information of words, and disregard both syntactic and morphological information. This approach allows us to use machine-learning techniques such as artificial neural networks and decision trees that are known for their pattern recognition abilities. Both these techniques are trained with isolated patterns consisting of input patterns and corresponding outputs (or targets that indicate whether the input pattern should be split at a certain position, or not. In the process of compiling a list of syllabified words from which to generate training data for the  syllabification problem, irregular patterns were identified. The same letter patterns are split differently in different words and complete words that are spelled identically are split differently due to meaning. We also identified irregularities in and between  the different dictionaries that we used. We examined the influence range of letters that are involved in irregularities. For example, for their in agter-ente and vaste-rente we have to consider three letters to the left of r to be certain where the hyphen should be inserted. The influence range of the k in verstek-waarde and kleinste-kwadrate is four to the left and three to the right. In an analysis of letter patterns in Afrikaans words we found that the letter e has the highest frequency overall (16,2% of all letters in the word list. The frequency of words starting with s is the highest, while the frequency of words ending with e is the highest. It is important to

  12. Calling Out Cheaters : Covert Security with Public VerifiabilitySecurity

    DEFF Research Database (Denmark)

    Asharov, Gilad; Orlandi, Claudio

    2012-01-01

    We introduce the notion of covert security with public verifiability, building on the covert security model introduced by Aumann and Lindell (TCC 2007). Protocols that satisfy covert security guarantee that the honest parties involved in the protocol will notice any cheating attempt with some...... constant probability ε. The idea behind the model is that the fear of being caught cheating will be enough of a deterrent to prevent any cheating attempt. However, in the basic covert security model, the honest parties are not able to persuade any third party (say, a judge) that a cheating occurred. We...... propose (and formally define) an extension of the model where, when an honest party detects cheating, it also receives a certificate that can be published and used to persuade other parties, without revealing any information about the honest party’s input. In addition, malicious parties cannot create fake...

  13. How to Verify and Manage the Translational Plagiarism?

    Science.gov (United States)

    Wiwanitkit, Viroj

    2016-01-01

    The use of Google translator as a tool for determining translational plagiarism is a big challenge. As noted, plagiarism of the original papers written in Macedonian and translated into other languages can be verified after computerised translation in other languages. Attempts to screen the translational plagiarism should be supported. The use of Google Translate tool might be helpful. Special focus should be on any non-English reference that might be the source of plagiarised material and non-English article that might translate from an original English article, which cannot be detected by simple plagiarism screening tool. It is a hard job for any journal to detect the complex translational plagiarism but the harder job might be how to effectively manage the case. PMID:27703588

  14. Modelling and Verifying Communication Failure of Hybrid Systems in HCSP

    DEFF Research Database (Denmark)

    Wang, Shuling; Nielson, Flemming; Nielson, Hanne Riis

    2016-01-01

    Hybrid systems are dynamic systems with interacting discrete computation and continuous physical processes. They have become ubiquitous in our daily life, e.g. automotive, aerospace and medical systems, and in particular, many of them are safety-critical. For a safety-critical hybrid system......, in the presence of communication failure, the expected control from the controller will get lost and as a consequence the physical process cannot behave as expected. In this paper, we mainly consider the communication failure caused by the non-engagement of one party in communication action, i.......e. the communication itself fails to occur. To address this issue, this paper proposes a formal framework by extending HCSP, a formal modeling language for hybrid systems, for modeling and verifying hybrid systems in the absence of receiving messages due to communication failure. We present two inference systems...

  15. A Formally Verified Conflict Detection Algorithm for Polynomial Trajectories

    Science.gov (United States)

    Narkawicz, Anthony; Munoz, Cesar

    2015-01-01

    In air traffic management, conflict detection algorithms are used to determine whether or not aircraft are predicted to lose horizontal and vertical separation minima within a time interval assuming a trajectory model. In the case of linear trajectories, conflict detection algorithms have been proposed that are both sound, i.e., they detect all conflicts, and complete, i.e., they do not present false alarms. In general, for arbitrary nonlinear trajectory models, it is possible to define detection algorithms that are either sound or complete, but not both. This paper considers the case of nonlinear aircraft trajectory models based on polynomial functions. In particular, it proposes a conflict detection algorithm that precisely determines whether, given a lookahead time, two aircraft flying polynomial trajectories are in conflict. That is, it has been formally verified that, assuming that the aircraft trajectories are modeled as polynomial functions, the proposed algorithm is both sound and complete.

  16. Leveraging Parallel Data Processing Frameworks with Verified Lifting

    Directory of Open Access Journals (Sweden)

    Maaz Bin Safeer Ahmad

    2016-11-01

    Full Text Available Many parallel data frameworks have been proposed in recent years that let sequential programs access parallel processing. To capitalize on the benefits of such frameworks, existing code must often be rewritten to the domain-specific languages that each framework supports. This rewriting–tedious and error-prone–also requires developers to choose the framework that best optimizes performance given a specific workload. This paper describes Casper, a novel compiler that automatically retargets sequential Java code for execution on Hadoop, a parallel data processing framework that implements the MapReduce paradigm. Given a sequential code fragment, Casper uses verified lifting to infer a high-level summary expressed in our program specification language that is then compiled for execution on Hadoop. We demonstrate that Casper automatically translates Java benchmarks into Hadoop. The translated results execute on average 3.3x faster than the sequential implementations and scale better, as well, to larger datasets.

  17. VERIFYING OF BETA CONVERGENCE FOR SOUTH EAST COUNTRIES OF ASIA

    Directory of Open Access Journals (Sweden)

    Michaela Blaško

    2017-05-01

    Full Text Available The convergence means the process of balancing disparities in chosen indicators of homogeneous economic groups. β-convergence and is based on the assumption, where less developed economy grows faster than advanced ones, so GDP per capita has higher speed in less developed economy. In this article is verified β convergence based on dependency between the growth of real GDP per capita and the initial level of real GDP per capita (in PPP and by modifications of this relationship by using of Least Squares Method for 9 countries of South East Asia in different samples since 2000 till 2015. For completely explanation of dependency and calculation of consistent, minimal estimator are used dummies and created a structural parameter, which eliminate shocks and possible disparities between chosen countries. Based on reached results was proved convergence just in sample since 2004 till 2008 between chosen nine countries of South East Countries of Asia.

  18. A detailed and verified wind resource atlas for Denmark

    Energy Technology Data Exchange (ETDEWEB)

    Mortensen, N.G.; Landberg, L.; Rathmann, O.; Nielsen, M.N. [Risoe National Lab., Roskilde (Denmark); Nielsen, P. [Energy and Environmental Data, Aalberg (Denmark)

    1999-03-01

    A detailed and reliable wind resource atlas covering the entire land area of Denmark has been established. Key words of the methodology are wind atlas analysis, interpolation of wind atlas data sets, automated generation of digital terrain descriptions and modelling of local wind climates. The atlas contains wind speed and direction distributions, as well as mean energy densities of the wind, for 12 sectors and four heights above ground level: 25, 45, 70 and 100 m. The spatial resolution is 200 meters in the horizontal. The atlas has been verified by comparison with actual wind turbine power productions from over 1200 turbines. More than 80% of these turbines were predicted to within 10%. The atlas will become available on CD-ROM and on the Internet. (au)

  19. Verifying reciprocal relations for experimental diffusion coefficients in multicomponent mixtures

    DEFF Research Database (Denmark)

    Medvedev, Oleg; Shapiro, Alexander

    2003-01-01

    into Onsager coefficients and a subsequent symmetry check make it possible to evaluate different thermodynamic models with regard to their possibility of being used for prediction of the transport properties. We performed several checks of this kind for ternary mixtures of hydrocarbons and alcohols, where......The goal of the present study is to verify the agreement of the available data on diffusion in ternary mixtures with the theoretical requirement of linear non-equilibrium thermodynamics consisting in symmetry of the matrix of the phenomenological coefficients. A common set of measured diffusion...... diffusion coefficients into Onsager coefficients for a non-ideal mixture involves derivatives of the chemical potentials and, thus, should be based on a certain thermodynamic model (cubic equation of state (EoS), an activity coefficient model, etc.). Transformation of the Fickian diffusion coefficients...

  20. Technology.

    Science.gov (United States)

    Online-Offline, 1998

    1998-01-01

    Focuses on technology, on advances in such areas as aeronautics, electronics, physics, the space sciences, as well as computers and the attendant progress in medicine, robotics, and artificial intelligence. Describes educational resources for elementary and middle school students, including Web sites, CD-ROMs and software, videotapes, books,…

  1. Optimization of divalent cation in Saccharomyces pastorianus ...

    African Journals Online (AJOL)

    Cassava starch fermentations were conducted in batch cultures to optimize the effect of divalent cations on ethanol production with Saccharomyces pastorianus using the central composite rotatable response surface design. Divalent cations used were magnesium (Mg2+), zinc (Zn2+) and calcium (Ca2+). Maximum ethanol ...

  2. Lightweight ECC based RFID authentication integrated with an ID verifier transfer protocol.

    Science.gov (United States)

    He, Debiao; Kumar, Neeraj; Chilamkurti, Naveen; Lee, Jong-Hyouk

    2014-10-01

    The radio frequency identification (RFID) technology has been widely adopted and being deployed as a dominant identification technology in a health care domain such as medical information authentication, patient tracking, blood transfusion medicine, etc. With more and more stringent security and privacy requirements to RFID based authentication schemes, elliptic curve cryptography (ECC) based RFID authentication schemes have been proposed to meet the requirements. However, many recently published ECC based RFID authentication schemes have serious security weaknesses. In this paper, we propose a new ECC based RFID authentication integrated with an ID verifier transfer protocol that overcomes the weaknesses of the existing schemes. A comprehensive security analysis has been conducted to show strong security properties that are provided from the proposed authentication scheme. Moreover, the performance of the proposed authentication scheme is analyzed in terms of computational cost, communicational cost, and storage requirement.

  3. Exploring backbone-cation alkyl spacers for multi-cation side chain anion exchange membranes

    Science.gov (United States)

    Zhu, Liang; Yu, Xuedi; Hickner, Michael A.

    2018-01-01

    In order to systematically study how the arrangement of cations on the side chain and length of alkyl spacers between cations impact the performance of multi-cation AEMs for alkaline fuel cells, a series of polyphenylene oxide (PPO)-based AEMs with different cationic side chains were synthesized. This work resulted in samples with two or three cations in a side chain pendant to the PPO backbone. More importantly, the length of the spacer between cations varied from 3 methylene (-CH2-) (C3) groups to 8 methylene (C8) groups. The highest conductivity, up to 99 mS/cm in liquid water at room temperature, was observed for the triple-cation side chain AEM with pentyl (C5) or hexyl (C6) spacers. The multi-cation AEMs were found to have decreased water uptake and ionic conductivity when the spacer chains between cations were lengthened from pentyl (C5) or hexyl (C6) to octyl (C8) linking groups. The triple-cation membranes with pentyl (C5) or hexyl (C6) groups between cations showed greatest stability after immersion in 1 M NaOH at 80 °C for 500 h.

  4. Intracellular trafficking mechanism of cationic phospholipids including cationic liposomes in HeLa cells.

    Science.gov (United States)

    Un, K; Sakai-Kato, K; Goda, Y

    2014-07-01

    The development of gene delivery methods is essential for the achievement of effective gene therapy. Elucidation of the intracellular transfer mechanism for cationic carriers is in progress, but there are few reports regarding the intracellular trafficking processes of the cationic phospholipids taken up into cells. In the present work, the trafficking processes of a cationic phospholipid (1,2-dioleoyl-3-trimethylammonium-propane, DOTAP) were investigated from intracellular uptake to extracellular efflux using cationic liposomes in vitro. Following intracellular transport of liposomes via endocytosis, DOTAP was localized in the endoplasmic reticulum, Golgi apparatus, and mitochondria. Moreover, the proteins involved in DOTAP intracellular trafficking and extracellular efflux were identified. In addition, helper lipids of cationic liposomes were found to partially affect this intracellulartrafficking. These findings might provide valuable information for designing cationic carriers and avoiding unexpected toxic side effects derived from cationic liposomal components.

  5. VDVR: verifiable visualization of projection-based data.

    Science.gov (United States)

    Zheng, Ziyi; Xu, Wei; Mueller, Klaus

    2010-01-01

    Practical volume visualization pipelines are never without compromises and errors. A delicate and often-studied component is the interpolation of off-grid samples, where aliasing can lead to misleading artifacts and blurring, potentially hiding fine details of critical importance. The verifiable visualization framework we describe aims to account for these errors directly in the volume generation stage, and we specifically target volumetric data obtained via computed tomography (CT) reconstruction. In this case the raw data are the X-ray projections obtained from the scanner and the volume data generation process is the CT algorithm. Our framework informs the CT reconstruction process of the specific filter intended for interpolation in the subsequent visualization process, and this in turn ensures an accurate interpolation there at a set tolerance. Here, we focus on fast trilinear interpolation in conjunction with an octree-type mixed resolution volume representation without T-junctions. Efficient rendering is achieved by a space-efficient and locality-optimized representation, which can straightforwardly exploit fast fixed-function pipelines on GPUs.

  6. Garbage collection can be made real-time and verifiable

    Science.gov (United States)

    Hino, James H.; Ross, Charles L.

    1988-01-01

    An efficient means of memory reclamation (also known as Garbage Collection) is essential for Machine Intelligence applications where dynamic storage allocation is desired or required. Solutions for real-time systems must introduce very small processing overhead and must also provide for the verification of the software in order to meet the application time budgets and to verify the correctness of the software. Garbage Collection (GC) techniques are proposed for symbolic processing systems which may simultaneously meet both real-time requirements and verification requirements. The proposed memory reclamation technique takes advantage of the strong points of both the earlier Mark and Sweep technique and the more recent Copy Collection approaches. At least one practical implementation of these new GC techniques has already been developed and tested on a very-high performance symbolic computing system. Complete GC processing of all generated garbage has been demonstrated to require as little as a few milliseconds to perform. This speed enables the effective operation of the GC function as either a background task or as an actual part of the application task itself.

  7. AUTOMATIC ESTIMATION OF SIZE PARAMETERS USING VERIFIED COMPUTERIZED STEREOANALYSIS

    Directory of Open Access Journals (Sweden)

    Peter R Mouton

    2011-05-01

    Full Text Available State-of-the-art computerized stereology systems combine high-resolution video microscopy and hardwaresoftware integration with stereological methods to assist users in quantifying multidimensional parameters of importance to biomedical research, including volume, surface area, length, number, their variation and spatial distribution. The requirement for constant interactions between a trained, non-expert user and the targeted features of interest currently limits the throughput efficiency of these systems. To address this issue we developed a novel approach for automatic stereological analysis of 2-D images, Verified Computerized Stereoanalysis (VCS. The VCS approach minimizes the need for user interactions with high contrast [high signal-to-noise ratio (S:N] biological objects of interest. Performance testing of the VCS approach confirmed dramatic increases in the efficiency of total object volume (size estimation, without a loss of accuracy or precision compared to conventional computerized stereology. The broad application of high efficiency VCS to high-contrast biological objects on tissue sections could reduce labor costs, enhance hypothesis testing, and accelerate the progress of biomedical research focused on improvements in health and the management of disease.

  8. Verifying the Simulation Hypothesis via Infinite Nested Universe Simulacrum Loops

    Science.gov (United States)

    Sharma, Vikrant

    2017-01-01

    The simulation hypothesis proposes that local reality exists as a simulacrum within a hypothetical computer's dimension. More specifically, Bostrom's trilemma proposes that the number of simulations an advanced 'posthuman' civilization could produce makes the proposition very likely. In this paper a hypothetical method to verify the simulation hypothesis is discussed using infinite regression applied to a new type of infinite loop. Assign dimension n to any computer in our present reality, where dimension signifies the hierarchical level in nested simulations our reality exists in. A computer simulating known reality would be dimension (n-1), and likewise a computer simulating an artificial reality, such as a video game, would be dimension (n +1). In this method, among others, four key assumptions are made about the nature of the original computer dimension n. Summations show that regressing such a reality infinitely will create convergence, implying that the verification of whether local reality is a grand simulation is feasible to detect with adequate compute capability. The action of reaching said convergence point halts the simulation of local reality. Sensitivities to the four assumptions and implications are discussed.

  9. A credit card verifier structure using diffraction and spectroscopy concepts

    Science.gov (United States)

    Sumriddetchkajorn, Sarun; Intaravanne, Yuttana

    2008-04-01

    We propose and experimentally demonstrate an angle-multiplexing based optical structure for verifying a credit card. Our key idea comes from the fact that the fine detail of the embossed hologram stamped on the credit card is hard to duplicate and therefore its key color features can be used for distinguishing between the real and counterfeit ones. As the embossed hologram is a diffractive optical element, we choose to shine one at a time a number of broadband lightsources, each at different incident angle, on the embossed hologram of the credit card in such a way that different color spectra per incident angle beam is diffracted and separated in space. In this way, the number of pixels of each color plane is investigated. Then we apply a feed forward back propagation neural network configuration to separate the counterfeit credit card from the real one. Our experimental demonstration using two off-the-shelf broadband white light emitting diodes, one digital camera, a 3-layer neural network, and a notebook computer can identify all 69 counterfeit credit cards from eight real credit cards.

  10. Technology

    Directory of Open Access Journals (Sweden)

    Xu Jing

    2016-01-01

    Full Text Available The traditional answer card reading method using OMR (Optical Mark Reader, most commonly, OMR special card special use, less versatile, high cost, aiming at the existing problems proposed a method based on pattern recognition of the answer card identification method. Using the method based on Line Segment Detector to detect the tilt of the image, the existence of tilt image rotation correction, and eventually achieve positioning and detection of answers to the answer sheet .Pattern recognition technology for automatic reading, high accuracy, detect faster

  11. Cation transport in isomeric pentanes

    International Nuclear Information System (INIS)

    Gyoergy, Istvan; Gee, Norman; Freeman, G.R.

    1985-01-01

    The cation mobility μsub(+) is measured in n-pentane, isopentane, neo-pentane, and mixtures of n- and neo-pentane over conditions from the normal liquid, through the critical fluid, to the low density gas. Most of the liquid data correlate with the reduced temperature T/Tsub(c). The T/Tsub(c) reflects free volume and viscosity changes. Comparison is made to neutral molecule diffusion. The transition from viscosity control of mobility in the liquid to density control in the dilute gas occurs over the reduced viscosity region 3 > eta/etasub(c) > 0.6, which corresponds to the reduced density region 1.9 > eta/etasub(c) > 0.5. In the saturated gas etaμsub(+) is similar in all pentanes, but iso- approximately> n- > neo-pentane. At constant density dμsub(+)/dT >= 0 for gases. The average gas nμsub(+) is similar in all pentanes, but iso- approximately> n- > neo-pentane. At constant density dμsub(+)/dT >= 0 for gases. The average momentum transfer cross sections in the n-/neo-pentane mixtures are similar to those in neo-pentane at low T but similar to those in n-pentane at high T. The present findings are combined with previous electron mobility data in addressing the effect of hydrocarbon molecular (external) shape on the electric breakdown strength of gases

  12. Cationic Bolaamphiphiles for Gene Delivery

    Science.gov (United States)

    Tan, Amelia Li Min; Lim, Alisa Xue Ling; Zhu, Yiting; Yang, Yi Yan; Khan, Majad

    2014-05-01

    Advances in medical research have shed light on the genetic cause of many human diseases. Gene therapy is a promising approach which can be used to deliver therapeutic genes to treat genetic diseases at its most fundamental level. In general, nonviral vectors are preferred due to reduced risk of immune response, but they are also commonly associated with low transfection efficiency and high cytotoxicity. In contrast to viral vectors, nonviral vectors do not have a natural mechanism to overcome extra- and intracellular barriers when delivering the therapeutic gene into cell. Hence, its design has been increasingly complex to meet challenges faced in targeting of, penetration of and expression in a specific host cell in achieving more satisfactory transfection efficiency. Flexibility in design of the vector is desirable, to enable a careful and controlled manipulation of its properties and functions. This can be met by the use of bolaamphiphile, a special class of lipid. Unlike conventional lipids, bolaamphiphiles can form asymmetric complexes with the therapeutic gene. The advantage of having an asymmetric complex lies in the different purposes served by the interior and exterior of the complex. More effective gene encapsulation within the interior of the complex can be achieved without triggering greater aggregation of serum proteins with the exterior, potentially overcoming one of the great hurdles faced by conventional single-head cationic lipids. In this review, we will look into the physiochemical considerations as well as the biological aspects of a bolaamphiphile-based gene delivery system.

  13. Metabolic changes in ruminant calves fed cation-anion diets with different proportions of roughage and concentrate

    Directory of Open Access Journals (Sweden)

    Márcia Saladini Vieira Salles

    2012-02-01

    Full Text Available Two experiments were carried out with twenty-four male weaned Holstein calves to verify the influence of different dietary cation-anion concentrate and roughage proportions on calves metabolism. In the first experiment, calves were fed rations with -100, +200 and +400 mEq cation-anion balance/kg of dry matter, containing 60% of roughage and 40% of concentrate. In the second experiment, calves (117.6±20.8 kg average weight received rations with similar dietary cation-anion balance but in diets of 40% roughage and 60% concentrate. As the dietary cation-anion balance became more positive, there was a quadratic response of blood pH in both diets with 60 and 40% roughage. A linear increase following increased dietary cation-anion balance was observed on bicarbonate concentration, carbon dioxide tension, carbon dioxide partial pressure and urine pH on both experiments, while anion gap decreased linearly. Blood urea nitrogen and base excess increased quadratically according to increased dietary cation-anion balance on 60% roughage, whereas those same parameters showed a linear increase on 40% roughage. Growing ruminant metabolism both in cationic and anionic diets was modified when the roughage:concentrate ratio was altered.

  14. Canada and international safeguards. Verifying nuclear non-proliferation

    International Nuclear Information System (INIS)

    1990-01-01

    The Non-Proliferation Treaty (NPT) came into force in 1970 and now has about 140 signatory nations. By creating legal barriers against proliferation and by promoting an international non-proliferation ethic, the NPT has promoted international peace and security. A key ingredient has been the confidence generated through verification by IAEA safeguards. By the end of 1988 IAEA safeguards agreements had been concluded with about 100 countries, including Canada. Over 500 nuclear facilities worldwide are under safeguards or contain safeguarded nuclear material. The existence of this credible and effective safeguards system makes international trade in nuclear equipment and materials possible, monitoring the transfer of nuclear technology to developing countries as well as between industrial countries. Canada is committed to non-proliferation and IAEA safeguards. Canadian non-proliferation policy is among the strictest in the world, even though opportunities have been lost to sell Canadian technology abroad as a result

  15. Spectrophotometric studies on cation-cation interactions between Np(V) and Th(IV) cations in nitric acid medium

    International Nuclear Information System (INIS)

    Verma, P.K.; Pathak, P.N.; Bhattacharyya, A.; Prabhu, D.R.; Mohapatra, P.K.

    2014-01-01

    The higher-valent actinide cations exhibit fascinating coordination chemistry essentially due to the flexibility in their electronic structures. This is particularly applicable for the dioxo penta- and hexavalent lighter actinides such as U, Np, Pu, and Am. Even though the oxo moiety is assumed to be chemically inert in these cations, there are several studies which show that pentavalent Np cation (NpO 2 + ) displays a tendency of bonding with charged metal ions. This class of weak bond formation has been classified as cation-cation interactions (CCI). Initial studies suggested that these types of interactions of Np(V) with polyvalent metal ions are more probable in non complexing perchloric acid solutions. Majority of these studies have been performed in perchlorate media and the stability constant values have been calculated. On the other hand, these studies in nitric acid medium are rather few. Our recent spectrophotometric study has shown that Np(V) cation undergoes disproportionation reaction and the tendency for CCI becomes less favorable at elevated temperature in nitric acid media. This study has been extended for understanding possible CCI between Np(V)O 2 + and Th 4 + ions under varying conditions such as nitric acid (1-6 M HNO 3 ). Th concentration (up to 0.86 M), and temperature (293-343K). An attempt has been made to calculate the stability constant values and compare with those reported in other media

  16. Cationization of heparin for film applications

    Czech Academy of Sciences Publication Activity Database

    Šimkovic, I.; Mendichi, R.; Kelnar, Ivan; Filip, J.; Hricovíni, M.

    2015-01-01

    Roč. 115, 22 January (2015), s. 551-558 ISSN 0144-8617 Institutional support: RVO:61389013 Keywords : heparin * cationization * NMR Subject RIV: CD - Macromolecular Chemistry Impact factor: 4.219, year: 2015

  17. VISION User Guide - VISION (Verifiable Fuel Cycle Simulation) Model

    Energy Technology Data Exchange (ETDEWEB)

    Jacob J. Jacobson; Robert F. Jeffers; Gretchen E. Matthern; Steven J. Piet; Benjamin A. Baker; Joseph Grimm

    2009-08-01

    The purpose of this document is to provide a guide for using the current version of the Verifiable Fuel Cycle Simulation (VISION) model. This is a complex model with many parameters; the user is strongly encouraged to read this user guide before attempting to run the model. This model is an R&D work in progress and may contain errors and omissions. It is based upon numerous assumptions. This model is intended to assist in evaluating “what if” scenarios and in comparing fuel, reactor, and fuel processing alternatives at a systems level for U.S. nuclear power. The model is not intended as a tool for process flow and design modeling of specific facilities nor for tracking individual units of fuel or other material through the system. The model is intended to examine the interactions among the components of a fuel system as a function of time varying system parameters; this model represents a dynamic rather than steady-state approximation of the nuclear fuel system. VISION models the nuclear cycle at the system level, not individual facilities, e.g., “reactor types” not individual reactors and “separation types” not individual separation plants. Natural uranium can be enriched, which produces enriched uranium, which goes into fuel fabrication, and depleted uranium (DU), which goes into storage. Fuel is transformed (transmuted) in reactors and then goes into a storage buffer. Used fuel can be pulled from storage into either separation of disposal. If sent to separations, fuel is transformed (partitioned) into fuel products, recovered uranium, and various categories of waste. Recycled material is stored until used by its assigned reactor type. Note that recovered uranium is itself often partitioned: some RU flows with recycled transuranic elements, some flows with wastes, and the rest is designated RU. RU comes out of storage if needed to correct the U/TRU ratio in new recycled fuel. Neither RU nor DU are designated as wastes. VISION is comprised of several

  18. VISION User Guide - VISION (Verifiable Fuel Cycle Simulation) Model

    International Nuclear Information System (INIS)

    Jacobson, Jacob J.; Jeffers, Robert F.; Matthern, Gretchen E.; Piet, Steven J.; Baker, Benjamin A.; Grimm, Joseph

    2009-01-01

    The purpose of this document is to provide a guide for using the current version of the Verifiable Fuel Cycle Simulation (VISION) model. This is a complex model with many parameters; the user is strongly encouraged to read this user guide before attempting to run the model. This model is an R and D work in progress and may contain errors and omissions. It is based upon numerous assumptions. This model is intended to assist in evaluating 'what if' scenarios and in comparing fuel, reactor, and fuel processing alternatives at a systems level for U.S. nuclear power. The model is not intended as a tool for process flow and design modeling of specific facilities nor for tracking individual units of fuel or other material through the system. The model is intended to examine the interactions among the components of a fuel system as a function of time varying system parameters; this model represents a dynamic rather than steady-state approximation of the nuclear fuel system. VISION models the nuclear cycle at the system level, not individual facilities, e.g., 'reactor types' not individual reactors and 'separation types' not individual separation plants. Natural uranium can be enriched, which produces enriched uranium, which goes into fuel fabrication, and depleted uranium (DU), which goes into storage. Fuel is transformed (transmuted) in reactors and then goes into a storage buffer. Used fuel can be pulled from storage into either separation of disposal. If sent to separations, fuel is transformed (partitioned) into fuel products, recovered uranium, and various categories of waste. Recycled material is stored until used by its assigned reactor type. Note that recovered uranium is itself often partitioned: some RU flows with recycled transuranic elements, some flows with wastes, and the rest is designated RU. RU comes out of storage if needed to correct the U/TRU ratio in new recycled fuel. Neither RU nor DU are designated as wastes. VISION is comprised of several Microsoft

  19. Verifying cell loss requirements in high-speed communication networks

    Directory of Open Access Journals (Sweden)

    Kerry W. Fendick

    1998-01-01

    Full Text Available In high-speed communication networks it is common to have requirements of very small cell loss probabilities due to buffer overflow. Losses are measured to verify that the cell loss requirements are being met, but it is not clear how to interpret such measurements. We propose methods for determining whether or not cell loss requirements are being met. A key idea is to look at the stream of losses as successive clusters of losses. Often clusters of losses, rather than individual losses, should be regarded as the important “loss events”. Thus we propose modeling the cell loss process by a batch Poisson stochastic process. Successive clusters of losses are assumed to arrive according to a Poisson process. Within each cluster, cell losses do not occur at a single time, but the distance between losses within a cluster should be negligible compared to the distance between clusters. Thus, for the purpose of estimating the cell loss probability, we ignore the spaces between successive cell losses in a cluster of losses. Asymptotic theory suggests that the counting process of losses initiating clusters often should be approximately a Poisson process even though the cell arrival process is not nearly Poisson. The batch Poisson model is relatively easy to test statistically and fit; e.g., the batch-size distribution and the batch arrival rate can readily be estimated from cell loss data. Since batch (cluster sizes may be highly variable, it may be useful to focus on the number of batches instead of the number of cells in a measurement interval. We also propose a method for approximately determining the parameters of a special batch Poisson cell loss with geometric batch-size distribution from a queueing model of the buffer content. For this step, we use a reflected Brownian motion (RBM approximation of a G/D/1/C queueing model. We also use the RBM model to estimate the input burstiness given the cell loss rate. In addition, we use the RBM model to

  20. Test procedure for cation exchange chromatography

    International Nuclear Information System (INIS)

    Cooper, T.D.

    1994-01-01

    The purpose of this test plan is to demonstrate the synthesis of inorganic antimonate ion exchangers and compare their performance against the standard organic cation exchangers. Of particular interest is the degradation rate of both inorganic and organic cation exchangers. This degradation rate will be tracked by determining the ion exchange capacity and thermal stability as a function of time, radiation dose, and chemical reaction

  1. Cationic surfactants as the hydrolytic micellar catalysts

    OpenAIRE

    Janošcová, Petra

    2013-01-01

    Cationic surfactants as the hydrolytic micellar catalysts Petra Janošcová The effectiveness of hydrolytic cleavage of the pesticide fenitrothionin cationic surfactants micellar media has been tested. All used surfactants increased the rate of fenitrothionhydrolysis, which was the evidence of micellar catalysis. For some surfactants decreases has been evident at the highest rate of hydrolysis concentrations. It has been the result of a phenomenon called the effect of empty micelles. High hydro...

  2. Asymmetric Aminalization via Cation-Binding Catalysis

    DEFF Research Database (Denmark)

    Park, Sang Yeon; Liu, Yidong; Oh, Joong Suk

    2018-01-01

    Asymmetric cation-binding catalysis, in principle, can generate "chiral" anionic nucleophiles, where the counter cations are coordinated within chiral environments. Nitrogen-nucleophiles are intrinsically basic, therefore, its use as nucleophiles is often challenging and limiting the scope...... of the reaction. Particularly, a formation of configurationally labile aminal centers with alkyl substituents has been a formidable challenge due to the enamine/imine equilibrium of electrophilic substrates. Herein, we report enantioselective nucleophilic addition reactions of potassium phthalimides to Boc-protected...

  3. Cationized Carbohydrate Gas-Phase Fragmentation Chemistry

    Science.gov (United States)

    Bythell, Benjamin J.; Abutokaikah, Maha T.; Wagoner, Ashley R.; Guan, Shanshan; Rabus, Jordan M.

    2017-04-01

    We investigate the fragmentation chemistry of cationized carbohydrates using a combination of tandem mass spectrometry, regioselective labeling, and computational methods. Our model system is D-lactose. Barriers to the fundamental glyosidic bond cleavage reactions, neutral loss pathways, and structurally informative cross-ring cleavages are investigated. The most energetically favorable conformations of cationized D-lactose were found to be similar. In agreement with the literature, larger group I cations result in structures with increased cation coordination number which require greater collision energy to dissociate. In contrast with earlier proposals, the B n -Y m fragmentation pathways of both protonated and sodium-cationized analytes proceed via protonation of the glycosidic oxygen with concerted glycosidic bond cleavage. Additionally, for the sodiated congeners our calculations support sodiated 1,6-anhydrogalactose B n ion structures, unlike the preceding literature. This affects the subsequent propensity of formation and prediction of B n /Y m branching ratio. The nature of the anomeric center (α/β) affects the relative energies of these processes, but not the overall ranking. Low-energy cross-ring cleavages are observed for the metal-cationized analytes with a retro-aldol mechanism producing the 0,2 A 2 ion from the sodiated forms . Theory and experiment support the importance of consecutive fragmentation processes, particularly for the protonated congeners at higher collision energies.

  4. Luminescent sulfides of monovalent and trivalent cations

    International Nuclear Information System (INIS)

    1975-01-01

    The invention discloses a family of luminescent materials or phosphors having a rhombohedral crystal structure and consisting essentially of a mixed host sulfide of at least one monovalent host cation and at least one trivalent host cation, and containing, for each mole of phosphor, 0.0005 to 0.05 mole of at least one activating cation. The monovalent host cations may be Na, K or Rb and Cs. The trivalent host cations may be Gd, La, Lu, Sc and Y. The activating cations may be one or more of trivalent As, Bi, Ce, Dy, Er, Pr, Sb, Sm, Tb and Tm; divalent Lu, Mn, Pb and Sn; and monovalent Ag, Cu and Tl. The novel phosphors may be used in devices to convert electron-beam, ultraviolet or x-ray energy to light in the visible spectrum. Such energy conversion can be employed for example in fluoroscopic screens, and in viewing screens of cathode-ray tubes and other electron tubes

  5. Verifying the Dependence of Fractal Coefficients on Different Spatial Distributions

    International Nuclear Information System (INIS)

    Gospodinov, Dragomir; Marekova, Elisaveta; Marinov, Alexander

    2010-01-01

    : - Simple way to quantify scale-invariant distributions of complex objects or phenomena by a small number of parameters. - It is becoming evident that the applicability of fractal distributions to geological problems could have a more fundamental basis. Chaotic behaviour could underlay the geotectonic processes and the applicable statistics could often be fractal.The application of fractal distribution analysis has, however, some specific aspects. It is usually difficult to present an adequate interpretation of the obtained values of fractal coefficients for earthquake epicenter or hypocenter distributions. That is why in this paper we aimed at other goals - to verify how a fractal coefficient depends on different spatial distributions. We simulated earthquake spatial data by generating randomly points first in a 3D space - cube, then in a parallelepiped, diminishing one of its sides. We then continued this procedure in 2D and 1D space. For each simulated data set we calculated the points' fractal coefficient (correlation fractal dimension of epicentres) and then checked for correlation between the coefficients values and the type of spatial distribution.In that way one can obtain a set of standard fractal coefficients' values for varying spatial distributions. These then can be used when real earthquake data is analyzed by comparing the real data coefficients values to the standard fractal coefficients. Such an approach can help in interpreting the fractal analysis results through different types of spatial distributions.

  6. Verified by Visa and MasterCard SecureCode: Or, How Not to Design Authentication

    Science.gov (United States)

    Murdoch, Steven J.; Anderson, Ross

    Banks worldwide are starting to authenticate online card transactions using the '3-D Secure' protocol, which is branded as Verified by Visa and MasterCard SecureCode. This has been partly driven by the sharp increase in online fraud that followed the deployment of EMV smart cards for cardholder-present payments in Europe and elsewhere. 3-D Secure has so far escaped academic scrutiny; yet it might be a textbook example of how not to design an authentication protocol. It ignores good design principles and has significant vulnerabilities, some of which are already being exploited. Also, it provides a fascinating lesson in security economics. While other single sign-on schemes such as OpenID, InfoCard and Liberty came up with decent technology they got the economics wrong, and their schemes have not been adopted. 3-D Secure has lousy technology, but got the economics right (at least for banks and merchants); it now boasts hundreds of millions of accounts. We suggest a path towards more robust authentication that is technologically sound and where the economics would work for banks, merchants and customers - given a gentle regulatory nudge.

  7. Cation Exchange in the Presence of Oil in Porous Media

    NARCIS (Netherlands)

    Farajzadeh, R.; Guo, H.; van Winden, J.L.; Bruining, J.

    2017-01-01

    Cation exchange is an interfacial process during which cations on a clay surface are replaced by other cations. This study investigates the effect of oil type and composition on cation exchange on rock surfaces, relevant for a variety of oil-recovery processes. We perform experiments in which brine

  8. Non-destructive technique to verify clearance of pipes

    Directory of Open Access Journals (Sweden)

    Savidou Anastasia

    2010-01-01

    Full Text Available A semi-empirical, non-destructive technique to evaluate the activity of gamma ray emitters in contaminated pipes is discussed. The technique is based on in-situ measurements by a portable NaI gamma ray spectrometer. The efficiency of the detector for the pipe and detector configuration was evaluated by Monte Carlo calculations performed using the MCNP code. Gamma ray detector full-energy peak efficiency was predicted assuming a homogeneous activity distribution over the internal surface of the pipe for 344 keV, 614 keV, 662 keV, and 1332 keV photons, representing Eu-152, Ag-118m, Cs-137, and Co-60 contamination, respectively. The effect of inhomogeneity on the accuracy of the technique was also examined. The model was validated against experimental measurements performed using a Cs-137 volume calibration source representing a contaminated pipe and good agreement was found between the calculated and experimental results. The technique represents a sensitive and cost-effective technology for calibrating portable gamma ray spectrometry systems and can be applied in a range of radiation protection and waste management applications.

  9. Digital models: How can dental arch form be verified chairside?

    Science.gov (United States)

    Tavares, Alana; Braga, Emanuel; de Araújo, Telma Martins

    2017-01-01

    ABSTRACT Introduction: Plaster dental casts are routinely used during clinical practice to access maxillary dental arch form and assist on fabrication of individualized orthodontic archwires. Recently introduced, digital model technology may offer a limitation for the obtainment of a dental physical record. In this context, a tool for dental arch form assessment for chairside use is necessary when employing digital models. In this regard, paper print of the dental arch seems thus to be useful. Methods: In the present study, 37 lower arch models were used. Intercanine and intermolar widths and dental arch length measurements were performed and compared using plaster dental casts, digital models and paper print image of the models. Ortho Insight 3D scanner was employed for model digitalization. Results: No statistically significant differences were noted regarding the measurements performed on the plaster or digital models (p> 0.05). Paper print images, however, showed subestimated values for intercanine and intermolar widths and overestimated values for dental arch length. Despite being statistically significant (p< 0.001), the differences were considered clinically negligible. Conclusion: The present study suggests that paper print images obtained from digital models are clinically accurate and can be used as a tool for dental arch form assessment for fabrication of individualized orthodontic archwires. PMID:29364382

  10. Digital models: How can dental arch form be verified chairside?

    Directory of Open Access Journals (Sweden)

    Alana Tavares

    Full Text Available ABSTRACT Introduction: Plaster dental casts are routinely used during clinical practice to access maxillary dental arch form and assist on fabrication of individualized orthodontic archwires. Recently introduced, digital model technology may offer a limitation for the obtainment of a dental physical record. In this context, a tool for dental arch form assessment for chairside use is necessary when employing digital models. In this regard, paper print of the dental arch seems thus to be useful. Methods: In the present study, 37 lower arch models were used. Intercanine and intermolar widths and dental arch length measurements were performed and compared using plaster dental casts, digital models and paper print image of the models. Ortho Insight 3D scanner was employed for model digitalization. Results: No statistically significant differences were noted regarding the measurements performed on the plaster or digital models (p> 0.05. Paper print images, however, showed subestimated values for intercanine and intermolar widths and overestimated values for dental arch length. Despite being statistically significant (p< 0.001, the differences were considered clinically negligible. Conclusion: The present study suggests that paper print images obtained from digital models are clinically accurate and can be used as a tool for dental arch form assessment for fabrication of individualized orthodontic archwires.

  11. Exchangeable cations-mediated photodegradation of polycyclic aromatic hydrocarbons (PAHs) on smectite surface under visible light

    International Nuclear Information System (INIS)

    Jia, Hanzhong; Li, Li; Chen, Hongxia; Zhao, Yue; Li, Xiyou; Wang, Chuanyi

    2015-01-01

    Graphical abstract: Roles of exchangeable cations in PAHs photodegradation on clay surafces under visible light. - Highlights: • Photolysis rate are strongly dependent on the type of cations on clay surface. • The strength of “cation–π” interactions governs the photodegradation rate of PAHs. • Several exchangeable cations could cause a shift in the absorption spectrum of PAHs. • Exchangeable cations influence the type and amount of reactive intermediates. - Abstract: Clay minerals saturated with different exchangeable cations are expected to play various roles in photodegradation of polycyclic aromatic hydrocarbons (PAHs) via direct and/or indirect pathways on clay surfaces. In the present study, anthracene and phenanthrene were selected as molecule probes to investigate the roles of exchangeable cations on their photodegradation under visible light irradiation. For five types of cation-modified smectite clays, the photodegradation rate of anthracene and phenanthrene follows the order: Fe 3+ > Al 3+ > Cu 2+ >> Ca 2+ > K + > Na + , which is consistent with the binding energy of cation–π interactions between PAHs and exchangeable cations. The result suggests that PAHs photolysis rate depends on cation–π interactions on clay surfaces. Meanwhile, the deposition of anthracene at the Na + -smectite and K + -smectite surface favors solar light absorption, resulting in enhanced direct photodecomposition of PAHs. On the other hand, smectite clays saturated with Fe 3+ , Al 3+ , and Cu 2+ are highly photoreactive and can act as potential catalysts giving rise to oxidative radicals such as O 2 − · , which initiate the transformation of PAHs. The present work provides valuable insights into understanding the transformation and fate of PAHs in the natural soil environment and sheds light on the development of technologies for contaminated land remediation

  12. Exchangeable cations-mediated photodegradation of polycyclic aromatic hydrocarbons (PAHs) on smectite surface under visible light

    Energy Technology Data Exchange (ETDEWEB)

    Jia, Hanzhong, E-mail: jiahz@ms.xjb.ac.cn [Laboratory of Environmental Sciences and Technology, Xinjiang Technical Institute of Physics & Chemistry, Key Laboratory of Functional Materials and Devices for Special Environments, Chinese Academy of Sciences, Urumqi 830011 (China); Li, Li [Laboratory of Environmental Sciences and Technology, Xinjiang Technical Institute of Physics & Chemistry, Key Laboratory of Functional Materials and Devices for Special Environments, Chinese Academy of Sciences, Urumqi 830011 (China); Chen, Hongxia; Zhao, Yue [Laboratory of Environmental Sciences and Technology, Xinjiang Technical Institute of Physics & Chemistry, Key Laboratory of Functional Materials and Devices for Special Environments, Chinese Academy of Sciences, Urumqi 830011 (China); School of Geology and Mining Engineering, Xinjiang University, Urumqi 830046 (China); Li, Xiyou [Laboratory of Environmental Sciences and Technology, Xinjiang Technical Institute of Physics & Chemistry, Key Laboratory of Functional Materials and Devices for Special Environments, Chinese Academy of Sciences, Urumqi 830011 (China); Wang, Chuanyi, E-mail: cywang@ms.xjb.ac.cn [Laboratory of Environmental Sciences and Technology, Xinjiang Technical Institute of Physics & Chemistry, Key Laboratory of Functional Materials and Devices for Special Environments, Chinese Academy of Sciences, Urumqi 830011 (China)

    2015-04-28

    Graphical abstract: Roles of exchangeable cations in PAHs photodegradation on clay surafces under visible light. - Highlights: • Photolysis rate are strongly dependent on the type of cations on clay surface. • The strength of “cation–π” interactions governs the photodegradation rate of PAHs. • Several exchangeable cations could cause a shift in the absorption spectrum of PAHs. • Exchangeable cations influence the type and amount of reactive intermediates. - Abstract: Clay minerals saturated with different exchangeable cations are expected to play various roles in photodegradation of polycyclic aromatic hydrocarbons (PAHs) via direct and/or indirect pathways on clay surfaces. In the present study, anthracene and phenanthrene were selected as molecule probes to investigate the roles of exchangeable cations on their photodegradation under visible light irradiation. For five types of cation-modified smectite clays, the photodegradation rate of anthracene and phenanthrene follows the order: Fe{sup 3+} > Al{sup 3+} > Cu{sup 2+} >> Ca{sup 2+} > K{sup +} > Na{sup +}, which is consistent with the binding energy of cation–π interactions between PAHs and exchangeable cations. The result suggests that PAHs photolysis rate depends on cation–π interactions on clay surfaces. Meanwhile, the deposition of anthracene at the Na{sup +}-smectite and K{sup +}-smectite surface favors solar light absorption, resulting in enhanced direct photodecomposition of PAHs. On the other hand, smectite clays saturated with Fe{sup 3+}, Al{sup 3+}, and Cu{sup 2+} are highly photoreactive and can act as potential catalysts giving rise to oxidative radicals such as O{sub 2}{sup −}· , which initiate the transformation of PAHs. The present work provides valuable insights into understanding the transformation and fate of PAHs in the natural soil environment and sheds light on the development of technologies for contaminated land remediation.

  13. Thermal Stability of RNA Structures with Bulky Cations in Mixed Aqueous Solutions.

    Science.gov (United States)

    Nakano, Shu-Ichi; Tanino, Yuichi; Hirayama, Hidenobu; Sugimoto, Naoki

    2016-10-04

    Bulky cations are used to develop nucleic-acid-based technologies for medical and technological applications in which nucleic acids function under nonaqueous conditions. In this study, the thermal stability of RNA structures was measured in the presence of various bulky cations in aqueous mixtures with organic solvents or polymer additives. The stability of oligonucleotide, transfer RNA, and polynucleotide structures was decreased in the presence of salts of tetrabutylammonium and tetrapentylammonium ions, and the stability and salt concentration dependences were dependent on cation sizes. The degree to which stability was dependent on salt concentration was correlated with reciprocals of the dielectric constants of mixed solutions, regardless of interactions between the cosolutes and RNA. Our results show that organic solvents affect the strength of electrostatic interactions between RNA and cations. Analysis of ion binding to RNA indicated greater enhancement of cation binding to RNA single strands than to duplexes in media with low dielectric constants. Furthermore, background bulky ions changed the dependence of RNA duplex stability on the concentration of metal ion salts. These unique properties of large tetraalkylammonium ions are useful for controlling the stability of RNA structures and its sensitivity to metal ion salts. Copyright © 2016 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  14. Privacy-Preserving Verifiability: A Case for an Electronic Exam Protocol

    DEFF Research Database (Denmark)

    Giustolisi, Rosario; Iovino, Vincenzo; Lenzini, Gabriele

    2017-01-01

    We introduce the notion of privacy-preserving verifiability for security protocols. It holds when a protocol admits a verifiability test that does not reveal, to the verifier that runs it, more pieces of information about the protocol’s execution than those required to run the test. Our definition...... of privacy-preserving verifiability is general and applies to cryptographic protocols as well as to human security protocols. In this paper we exemplify it in the domain of e-exams. We prove that the notion is meaningful by studying an existing exam protocol that is verifiable but whose verifiability tests...... are not privacy-preserving. We prove that the notion is applicable: we review the protocol using functional encryption so that it admits a verifiability test that preserves privacy according to our definition. We analyse, in ProVerif, that the verifiability holds despite malicious parties and that the new...

  15. 31 CFR 363.14 - How will you verify my identity?

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false How will you verify my identity? 363... you verify my identity? (a) Individual. When you establish an account, we may use a verification service to verify your identity using information you provide about yourself on the online application. At...

  16. 13 CFR 127.403 - What happens if SBA verifies the concern's eligibility?

    Science.gov (United States)

    2010-01-01

    ....403 What happens if SBA verifies the concern's eligibility? If SBA verifies that the concern satisfies... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false What happens if SBA verifies the concern's eligibility? 127.403 Section 127.403 Business Credit and Assistance SMALL BUSINESS...

  17. Mechanism of bacterial inactivation by cationic surfactants

    Energy Technology Data Exchange (ETDEWEB)

    Pavlova, I.B.; Samoylenko, I.I.

    1985-03-01

    The mechanism of bacteriocidal action of the cationic surfactant dimethylbenzylammonium chloride was studied on exposure of Staphylococcus aureus, Streptococcus faecium, Bacillus subtilis and Escherichia coli to different concentrations of the agent and determinations of survival plots. The data showed that the surfactant was bacteriocidal for all the bacteria tested at a concentration of 0.0001%, but more efficient in the case of the gram positives. Electron microscopy showed considerable damage and dissarrangement of the cytoplasmic membrane, indicating that the killing mechanism involved this organelle. It appears that cationic surfactants may constitute effective disinfectant preparations. 9 references, 2 figures.

  18. An RFID solution for enhancing inpatient medication safety with real-time verifiable grouping-proof.

    Science.gov (United States)

    Chen, Yu-Yi; Tsai, Meng-Lin

    2014-01-01

    The occurrence of a medication error can threaten patient safety. The medication administration process is complex and cumbersome, and nursing staffs are prone to error when they are tired. Proper Information Technology (IT) can assist the nurse in correct medication administration. We review a recent proposal regarding a leading-edge solution to enhance inpatient medication safety by using RFID technology. The proof mechanism is the kernel concept in their design and worth studying to develop a well-designed grouping-proof scheme. Other RFID grouping-proof protocols could be similarly applied in administering physician orders. We improve on the weaknesses of previous works and develop a reading-order independent RFID grouping-proof scheme in this paper. In our scheme, tags are queried and verified under the direct control of the authorized reader without connecting to the back-end database server. Immediate verification in our design makes this application more portable and efficient and critical security issues have been analyzed by the threat model. Our scheme is suitable for the safe drug administration scenario and the drug package scenario in a hospital environment to enhance inpatient medication safety. It automatically checks for correct drug unit-dose and appropriate inpatient treatments. Copyright © 2013. Published by Elsevier Ireland Ltd.

  19. Sample Acquisition and Analytical Chemistry Challenges to Verifying Compliance to Aviators Breathing Oxygen (ABO) Purity Specification

    Science.gov (United States)

    Graf, John

    2015-01-01

    NASA has been developing and testing two different types of oxygen separation systems. One type of oxygen separation system uses pressure swing technology, the other type uses a solid electrolyte electrochemical oxygen separation cell. Both development systems have been subjected to long term testing, and performance testing under a variety of environmental and operational conditions. Testing these two systems revealed that measuring the product purity of oxygen, and determining if an oxygen separation device meets Aviator's Breathing Oxygen (ABO) specifications is a subtle and sometimes difficult analytical chemistry job. Verifying product purity of cryogenically produced oxygen presents a different set of analytical chemistry challenges. This presentation will describe some of the sample acquisition and analytical chemistry challenges presented by verifying oxygen produced by an oxygen separator - and verifying oxygen produced by cryogenic separation processes. The primary contaminant that causes gas samples to fail to meet ABO requirements is water. The maximum amount of water vapor allowed is 7 ppmv. The principal challenge of verifying oxygen produced by an oxygen separator is that it is produced relatively slowly, and at comparatively low temperatures. A short term failure that occurs for just a few minutes in the course of a 1 week run could cause an entire tank to be rejected. Continuous monitoring of oxygen purity and water vapor could identify problems as soon as they occur. Long term oxygen separator tests were instrumented with an oxygen analyzer and with an hygrometer: a GE Moisture Monitor Series 35. This hygrometer uses an aluminum oxide sensor. The user's manual does not report this, but long term exposure to pure oxygen causes the aluminum oxide sensor head to bias dry. Oxygen product that exceeded the 7 ppm specification was improperly accepted, because the sensor had biased. The bias is permanent - exposure to air does not cause the sensor to

  20. Measuring reporting verifying. A primer on MRV for nationally appropriate mitigation actions

    Energy Technology Data Exchange (ETDEWEB)

    Hinostroza, M. (ed.); Luetken, S.; Holm Olsen, K. (Technical Univ. of Denmark. UNEP Risoe Centre, Roskilde (Denmark)); Aalders, E.; Pretlove, B.; Peters, N. (Det Norske Veritas, Hellerup (Denmark))

    2012-03-15

    The requirements for measurement, reporting and verification (MRV) of nationally appropriate mitigation actions (NAMAs) are one of the crucial topics on the agenda of international negotiations to address climate change mitigation. According to agreements so far, the general guidelines for domestic MRV are to be developed by Subsidiary Body for Scientific and Technological Advice (SBSTA)1. Further, the Subsidiary Body for Implementation (SBI) will be conducting international consultations and analysis (ICA) of biennial update reports (BUR) to improve transparency of mitigation actions, which should be measured, reported and verified. 2. What is clear from undergoing discussions both at SBSTA and at SBI is that MRV for NAMAs should not be a burden for controlling greenhouse gas (GHG) emissions connected to economic activities. Instead, the MRV process should facilitate mitigation actions; encourage the redirection of investments and address concerns regarding carbon content of emission intensive operations of private and public companies and enterprises worldwide. While MRV requirements are being shaped within the Convention, there are a number of initiatives supporting developing countries moving forward with NAMA development and demonstration activities. How these actions shall be measured, reported and verified, however, remain unanswered. MRV is not new. It is present in most existing policies and frameworks related to climate change mitigation. With an aim to contribute to international debate and capacity building on this crucial issue, the UNEP Risoe Centre in cooperation with UNDP, are pleased to present this publication that through the direct collaboration with Det Norske Veritas (DNV) builds on existing MRV practices in current carbon markets; provides insights on how MRV for NAMAs can be performed and identifies elements and drivers to be considered when designing adequate MRV systems for NAMAs in developing countries. This primer is the second

  1. Formally verifying human-automation interaction as part of a system model: limitations and tradeoffs.

    Science.gov (United States)

    Bolton, Matthew L; Bass, Ellen J

    2010-03-25

    Both the human factors engineering (HFE) and formal methods communities are concerned with improving the design of safety-critical systems. This work discusses a modeling effort that leveraged methods from both fields to perform formal verification of human-automation interaction with a programmable device. This effort utilizes a system architecture composed of independent models of the human mission, human task behavior, human-device interface, device automation, and operational environment. The goals of this architecture were to allow HFE practitioners to perform formal verifications of realistic systems that depend on human-automation interaction in a reasonable amount of time using representative models, intuitive modeling constructs, and decoupled models of system components that could be easily changed to support multiple analyses. This framework was instantiated using a patient controlled analgesia pump in a two phased process where models in each phase were verified using a common set of specifications. The first phase focused on the mission, human-device interface, and device automation; and included a simple, unconstrained human task behavior model. The second phase replaced the unconstrained task model with one representing normative pump programming behavior. Because models produced in the first phase were too large for the model checker to verify, a number of model revisions were undertaken that affected the goals of the effort. While the use of human task behavior models in the second phase helped mitigate model complexity, verification time increased. Additional modeling tools and technological developments are necessary for model checking to become a more usable technique for HFE.

  2. Electromagnetic Signature Technique as a Promising Tool to Verify Nuclear Weapons Storage and Dismantlement under a Nuclear Arms Control Regime

    Energy Technology Data Exchange (ETDEWEB)

    Bunch, Kyle J.; Williams, Laura S.; Jones, Anthony M.; Ramuhalli, Pradeep

    2012-08-01

    The 2010 ratification of the New START Treaty has been widely regarded as a noteworthy national security achievement for both the Obama administration and the Medvedev-Putin regime, but deeper cuts are envisioned under future arms control regimes. Future verification needs will include monitoring the storage of warhead components and fissile materials and verifying dismantlement of warheads, pits, secondaries, and other materials. From both the diplomatic and technical perspectives, verification under future arms control regimes will pose new challenges. Since acceptable verification technology must protect sensitive design information and attributes, non-nuclear non-sensitive signatures may provide a significant verification tool without the use of additional information barriers. The use of electromagnetic signatures to monitor nuclear material storage containers is a promising technology with the potential to fulfill these challenging requirements. Research performed at Pacific Northwest National Laboratory (PNNL) has demonstrated that low frequency electromagnetic signatures of sealed metallic containers can be used to confirm the presence of specific components on a “yes/no” basis without revealing classified information. Arms control inspectors might use this technique to verify the presence or absence of monitored items, including both nuclear and non-nuclear materials. Although additional research is needed to study signature aspects such as uniqueness and investigate container-specific scenarios, the technique potentially offers a rapid and cost-effective tool to verify reduction and dismantlement of U.S. and Russian nuclear weapons.

  3. Effect of cations on the hydrated proton.

    Science.gov (United States)

    Ottosson, Niklas; Hunger, Johannes; Bakker, Huib J

    2014-09-17

    We report on a strong nonadditive effect of protons and other cations on the structural dynamics of liquid water, which is revealed using dielectric relaxation spectroscopy in the frequency range of 1-50 GHz. For pure acid solutions, protons are known to have a strong structuring effect on water, leading to a pronounced decrease of the dielectric response. We observe that this structuring is reduced when protons are cosolvated with salts. This reduction is exclusively observed for combinations of protons with other ions; for all studied solutions of cosolvated salts, the effect on the structural dynamics of water is observed to be purely additive, even up to high concentrations. We derive an empirical model that quantitatively describes the nonadditive effect of cosolvated protons and cations. We argue that the effect can be explained from the special character of the proton in water and that Coulomb fields exerted by other cations, in particular doubly charged cations like Mg(2+)aq and Ca(2+)aq, induce a localization of the H(+)aq hydration structures.

  4. NMR studies of cation transport across membranes

    Energy Technology Data Exchange (ETDEWEB)

    Shochet, N.R.

    1985-01-01

    /sup 23/Na NMR Studies of cation transport across membranes were conducted both on model and biological membranes. Two ionophores, the carrier monensin and the channel-former gramicidin, were chosen to induce cation transport in large unilamellar phosphatidylcholine vesicles. The distinction between the NMR signals arising from the two sides of the membrane was achieved by the addition of an anionic paramagnetic shift reagent to the outer solution. The kinetics of the cation transport across the membrane was observed simultaneously monitoring the changes in the /sup 23/Na NMR signals of both compartments. Two mathematical models were developed for the estimation of the transport parameters of the monensin- and gramicidin-induced cation transport. The models were able to fit the experimental data very well. A new method for the estimation of the volume trapped inside the vesicles was developed. The method uses the relative areas of the intra- and extravesicular NMR signals arising from a suspension of vesicles bathed in the same medium they contain, as a measure for the relative volumes of these compartments. Sodium transport across biological membranes was studied by /sup 23/ NMR, using suspensions of cultured nerve cells. The sodium influx through voltage-gated channels was studied using the channel modifier batrachotoxin in combination with scorpion toxin.

  5. Mixed cation effect in sodium aluminosilicate glasses

    DEFF Research Database (Denmark)

    Kjeldsen, Jonas; Smedskjær, Morten Mattrup; Mauro, John C.

    , network structure, and the resistances associated with the deformation processes in mixed cation glasses by partially substituting magnesium for calcium and calcium for lithium in sodium aluminosilicate glasses. We use Raman and 27Al NMR spectroscopies to obtain insights into the structural...

  6. Resonance raman studies of phenylcyclopropane radical cations

    NARCIS (Netherlands)

    Godbout, J.T.; Zuilhof, H.; Heim, G.; Gould, I.R.; Goodman, J.L.; Dinnocenzo, J.P.; Myers Kelley, A.

    2000-01-01

    Resonance Raman spectra of the radical cations of phenylcyclopropane and trans-1-phenyl-2-methylcyclopropane are reported. A near-UV pump pulse excites a photosensitizer which oxidizes the species of interest, and a visible probe pulse delayed by 35 ns obtains the spectrum of the radical ion. The

  7. Water Adsorption on Free Cobalt Cluster Cations

    NARCIS (Netherlands)

    Kiawi, Denis M.; Bakker, Joost M.; Oomens, Jos; Buma, Wybren Jan; Jamshidi, Zahra; Visscher, Lucas; Waters, L. B. F. M.

    2015-01-01

    Cationic cobalt clusters complexed with water Con+–H2O (n = 6–20) are produced through laser ablation and investigated via infrared multiple photon dissociation (IR-MPD) spectroscopy in the 200–1700 cm–1 spectral range. All spectra exhibit a resonance close to the 1595 cm–1 frequency of the free

  8. Water adsorption on free cobalt cluster cations

    NARCIS (Netherlands)

    Kiawi, D.M.; Bakker, J.M.; Oomens, J.; Buma, W.J.; Jamshidi, Z.; Visscher, L.; Waters, L.B.F.M.

    2015-01-01

    Cationic cobalt clusters complexed with water Con+-​H2O (n = 6-​20) are produced through laser ablation and investigated via IR multiple photon dissocn. (IR-​MPD) spectroscopy in the 200-​1700 cm-​1 spectral range. All spectra exhibit a resonance close to the 1595 cm-​1 frequency of the free water

  9. Simultaneous anion and cation mobility in polypyrrole

    DEFF Research Database (Denmark)

    Skaarup, Steen; Bay, Lasse; Vidanapathirana, K.

    2003-01-01

    Polypyrrole (PPy) polymer films permanently doped with large, immobile anion dodecyl benzene sulfonate (DBS) have been characterized by cyclic voltammetry in order to clarify the roles of cations and anions in the aqueous electrolyte as mobile ions in the film. Aqueous solutions of 0.05-0.1 M...

  10. Cationic flotation of some lithium ores

    International Nuclear Information System (INIS)

    Valadao, G.E.S.; Peres, A.E.C.; Silva, H.C. da

    1984-01-01

    The cationic flotation of some lithium ores (spodumene, amblygonite, petalite, lepidolite) is studied by the measure of zeta potential and micro-flotation tests in Hallimond tube. The effect of some modifier agents (corn starch, meta sodium silicate) on the lithium flotation is studied. (M.A.C.) [pt

  11. Selective crystallization of cations with crown ethers

    International Nuclear Information System (INIS)

    Heffels, Dennis Egidius

    2014-01-01

    The aim of this work was to study the selectivity and preferences of the incorporation of differently sized cations in the cavities of various crown ethers and the characterization of the resulting compounds. The coordination preferences of crown ethers with different cavities have long been known, and the impact of other effects on the structure formation have increasingly become the focus of attention. In this work a comparative overview of the coordination preferences depending on various factors was undertaken. The focus was mainly on the variation of the cavity of the crown ether in the presence of differently sized cations. In addition, the effects of the solvent and differently coordinating anions have been investigated. Within the framework of this work, basic coordination preferences could be detected with rare earth nitrates, which are affected particularly by the choice of the solvent. The formation of different types of structures could be controlled by varying the conditions such that the incorporation of the cation in the cavity of the crown ether was influenced and the formation of a particular type of structure can be influenced partly by the choice of solvent. In this case no direct preferences for the incorporation into the cavity of the crown ether in relation to the cation size were observed for rare earth cations. However, the coordination of the crown ether leads in each case - for lanthanides - to rather high coordination numbers. A total of five new rare earth complexes and two structural variants could be observed with crown ethers. In the study of the selectivity of the incorporation into the cavity, known structures were also reproduced and further structures were characterized but the crystal structures not entirely solved. With the use of monovalent cations such as potassium, lithium or silver a total of nine new compounds could be synthesized, while no clear preferences for the incorporation of certain cations were detected. The

  12. Verified Gaming

    DEFF Research Database (Denmark)

    Kiniry, Joseph Roland; Zimmerman, Daniel

    2011-01-01

    In recent years, several Grand Challenges (GCs) of computing have been identified and expounded upon by various professional organizations in the U.S. and England. These GCs are typically very difficult problems that will take many hundreds, or perhaps thousands, of man-years to solve. Researchers...... involved in identifying these problems are not going to solve them. That task will fall to our students, and our students' students. Unfortunately for GC6, the Grand Challenge focusing on Dependable Systems Evolution, interest in formal methods---both by students and within computer science faculties...

  13. Verified Gaming

    DEFF Research Database (Denmark)

    Kiniry, Joseph Roland; Zimmerman, Daniel

    2011-01-01

    ---falls every year and any mention of mathematics in the classroom seems to frighten students away. So the question is: How do we attract new students in computing to the area of dependable software systems? Over the past several years at three universities we have experimented with the use of computer games...... as a target domain for software engineering project courses that focus on reliable systems engineering. This position paper summarizes our experiences in incorporating rigorous software engineering into courses whose projects include computer games....

  14. Risks of Using Bedside Tests to Verify Nasogastric Tube Position in Adult Patients

    Directory of Open Access Journals (Sweden)

    Melody Ni

    2014-12-01

    Full Text Available Nasogastric (NG tubes are commonly used for enteral feeding. Complications of feeding tube misplacement include malnutrition, pulmonary aspiration, and even death. We built a Bayesian network (BN to analyse the risks associated with available bedside tests to verify tube position. Evidence on test validity (sensitivity and specificity was retrieved from a systematic review. Likelihood ratios were used to select the best tests for detecting tubes misplaced in the lung or oesophagus. Five bedside tests were analysed including magnetic guidance, aspirate pH, auscultation, aspirate appearance, and capnography/colourimetry. Among these, auscultation and appearance are non-diagnostic towards lung or oesophagus placements. Capnography/ colourimetry can confirm but cannot rule out lung placement. Magnetic guidance can rule out both lung and oesophageal placement. However, as a relatively new technology, further validation studies are needed. The pH test with a cut-off at 5.5 or lower can rule out lung intubation. Lowering the cut-off to 4 not only minimises oesophageal intubation but also provides extra safety as the sensitivity of pH measurement is reduced by feeding, antacid medication, or the use of less accurate pH paper. BN is an effective tool for representing and analysing multi-layered uncertainties in test validity and reliability for the verification of NG tube position. Aspirate pH with a cut-off of 4 is the safest bedside method to minimise lung and oesophageal misplacement.

  15. Unmaking the bomb: Verifying limits on the stockpiles of nuclear weapons

    Science.gov (United States)

    Glaser, Alexander

    2017-11-01

    Verifying limits on the stockpiles of nuclear weapons may require the ability for international in-spectors to account for individual warheads, even when non-deployed, and to confirm the authenticity of nuclear warheads prior to dismantlement. These are fundamentally new challenges for nuclear verification, and they have been known for some time; unfortunately, due to a lack of sense of urgency, research in this area has not made substantial progress over the past 20 years. This chapter explores the central outstanding issues and offers a number of possible paths forward. In the case of confirming numerical limits, these in-clude innovative tagging techniques and approaches solely based on declarations using modern crypto-graphic escrow schemes; with regard to warhead confirmation, there has recently been increasing interest in developing fundamentally new measurement approaches where, in one form or another, sensitive infor-mation is not acquired in the first place. Overall, new international R&D efforts could more usefully focus on non-intrusive technologies and approaches, which may show more promise for early demonstration and adoption. In the meantime, while warhead dismantlements remain unverified, nuclear weapon states ought to begin to document warhead assembly, refurbishment, and dismantlement activities and movements of warheads and warhead components through the weapons complex in ways that international inspectors will find credible at a later time. Again, such a process could be enabled by modern cryptographic techniques such as blockchaining. Finally, and perhaps most importantly, it is important to recognize that the main reason for the complexity of technologies and approaches needed for nuclear disarmament verification is the requirement to protect information that nuclear weapon states consider sensitive. Ultimately, if information security concerns cannot be resolved to the satisfaction of all stakeholders, an alternative would be to "reveal the

  16. Evaluation of verifiability in HAL/S. [programming language for aerospace computers

    Science.gov (United States)

    Young, W. D.; Tripathi, A. R.; Good, D. I.; Browne, J. C.

    1979-01-01

    The ability of HAL/S to write verifiable programs, a characteristic which is highly desirable in aerospace applications, is lacking since many of the features of HAL/S do not lend themselves to existing verification techniques. The methods of language evaluation are described along with the means in which language features are evaluated for verifiability. These methods are applied in this study to various features of HAL/S to identify specific areas in which the language fails with respect to verifiability. Some conclusions are drawn for the design of programming languages for aerospace applications and ongoing work to identify a verifiable subset of HAL/S is described.

  17. The adjuvant mechanism of cationic dimethyldioctadecylammonium liposomes

    DEFF Research Database (Denmark)

    Korsholm, Karen Smith; Agger, Else Marie; Foged, Camilla

    2007-01-01

    Cationic liposomes are being used increasingly as efficient adjuvants for subunit vaccines but their precise mechanism of action is still unknown. Here, we investigated the adjuvant mechanism of cationic liposomes based on the synthetic amphiphile dimethyldioctadecylammonium (DDA). The liposomes...... concentrations. This efficient adsorption onto the liposomes led to an enhanced uptake of OVA by BM-DCs as assessed by flow cytometry and confocal fluorescence laser-scanning microscopy. This was an active process, which was arrested at 4 degrees and by an inhibitor of actin-dependent endocytosis, cytochalasin D....... In vivo studies confirmed the observed effect because adsorption of OVA onto DDA liposomes enhanced the uptake of the antigen by peritoneal exudate cells after intraperitoneal injection. The liposomes targeted antigen preferentially to antigen-presenting cells because we only observed a minimal uptake...

  18. Regulation of Cation Balance in Saccharomyces cerevisiae

    Science.gov (United States)

    Cyert, Martha S.; Philpott, Caroline C.

    2013-01-01

    All living organisms require nutrient minerals for growth and have developed mechanisms to acquire, utilize, and store nutrient minerals effectively. In the aqueous cellular environment, these elements exist as charged ions that, together with protons and hydroxide ions, facilitate biochemical reactions and establish the electrochemical gradients across membranes that drive cellular processes such as transport and ATP synthesis. Metal ions serve as essential enzyme cofactors and perform both structural and signaling roles within cells. However, because these ions can also be toxic, cells have developed sophisticated homeostatic mechanisms to regulate their levels and avoid toxicity. Studies in Saccharomyces cerevisiae have characterized many of the gene products and processes responsible for acquiring, utilizing, storing, and regulating levels of these ions. Findings in this model organism have often allowed the corresponding machinery in humans to be identified and have provided insights into diseases that result from defects in ion homeostasis. This review summarizes our current understanding of how cation balance is achieved and modulated in baker’s yeast. Control of intracellular pH is discussed, as well as uptake, storage, and efflux mechanisms for the alkali metal cations, Na+ and K+, the divalent cations, Ca2+ and Mg2+, and the trace metal ions, Fe2+, Zn2+, Cu2+, and Mn2+. Signal transduction pathways that are regulated by pH and Ca2+ are reviewed, as well as the mechanisms that allow cells to maintain appropriate intracellular cation concentrations when challenged by extreme conditions, i.e., either limited availability or toxic levels in the environment. PMID:23463800

  19. Mechanism of metal cationization in organic SIMS

    International Nuclear Information System (INIS)

    Wojciechowski, I.; Delcorte, A.; Gonze, X.; Bertrand, P.

    2003-01-01

    A scenario of metal cationization in which the organic molecule combines with a neutral excited metal atom is proposed. Ionization of the nascent complex occurs via ejection of an electron during the association process. Electron structure calculations for the model systems C 6 H 6 +Me (Me=Ag, Cu, Au) using the density functional theory give a strong argument in favor of the proposed mechanism

  20. Proton dynamics investigation for dimethyl ammonium cation

    International Nuclear Information System (INIS)

    Pislewski, N.; Tritt-Goc, J.; Jakubas, R.

    1995-01-01

    Proton dynamics in dimethyl ammonium cation has been investigated by means of NMR and spin echo methods in polycrystalline salts [NH 2 (CH 3 ) 2 ] + Bi 2 J 9 - and [NH 2 (CH 3 ) 2 ] + SbJ 9 - . Spin-lattice relaxation time as well as second moment of NMR line have been measured for influence study of crystal structure changes on proton dynamics

  1. Reducible cationic lipids for gene transfer.

    Science.gov (United States)

    Wetzer, B; Byk, G; Frederic, M; Airiau, M; Blanche, F; Pitard, B; Scherman, D

    2001-01-01

    One of the main challenges of gene therapy remains the increase of gene delivery into eukaryotic cells. We tested whether intracellular DNA release, an essential step for gene transfer, could be facilitated by using reducible cationic DNA-delivery vectors. For this purpose, plasmid DNA was complexed with cationic lipids bearing a disulphide bond. This reduction-sensitive linker is expected to be reduced and cleaved in the reducing milieu of the cytoplasm, thus potentially improving DNA release and consequently transfection. The DNA--disulphide-lipid complexation was monitored by ethidium bromide exclusion, and the size of complexes was determined by dynamic light scattering. It was found that the reduction kinetics of disulphide groups in DNA--lipid complexes depended on the position of the disulphide linker within the lipid molecule. Furthermore, the internal structure of DNA--lipid particles was examined by small-angle X-ray scattering before and after lipid reduction. DNA release from lipid complexes was observed after the reduction of disulphide bonds of several lipids. Cell-transfection experiments suggested that complexes formed with selected reducible lipids resulted in up to 1000-fold higher reporter-gene activity, when compared with their analogues without disulphide bonds. In conclusion, reduction-sensitive groups introduced into cationic lipid backbones potentially allow enhanced DNA release from DNA--lipid complexes after intracellular reduction and represent a tool for improved vectorization. PMID:11389682

  2. Defining and Verifying Research Grade Airborne Laser Swath Mapping (ALSM) Observations

    Science.gov (United States)

    Carter, W. E.; Shrestha, R. L.; Slatton, C. C.

    2004-12-01

    The first and primary goal of the National Science Foundation (NSF) supported Center for Airborne Laser Mapping (NCALM), operated jointly by the University of Florida and the University of California, Berkeley, is to make "research grade" ALSM data widely available at affordable cost to the national scientific community. Cost aside, researchers need to know what NCALM considers research grade data and how the quality of the data is verified, to be able to determine the likelihood that the data they receive will meet their project specific requirements. Given the current state of the technology it is reasonable to expect a well planned and executed survey to produce surface elevations with uncertainties less than 10 centimeters and horizontal uncertainties of a few decimeters. Various components of the total error are generally associated with the aircraft trajectory, aircraft orientation, or laser vectors. Aircraft trajectory error is dependent largely on the Global Positioning System (GPS) observations, aircraft orientation on Inertial Measurement Unit (IMU) observations, and laser vectors on the scanning and ranging instrumentation. In addition to the issue of the precision or accuracy of the coordinates of the surface points, consideration must also be given to the point-to-point spacing and voids in the coverage. The major sources of error produce distinct artifacts in the data set. For example, aircraft trajectory errors tend to change slowly as the satellite constellation geometry varies, producing slopes within swaths and offsets between swaths. Roll, pitch and yaw biases in the IMU observations tend to persist through whole flights, and created distinctive artifacts in the swath overlap areas. Errors in the zero-point and scale of the laser scanner cause the edges of swaths to turn up or down. Range walk errors cause offsets between bright and dark surfaces, causing paint stripes to float above the dark surfaces of roads. The three keys to producing

  3. [Antioxidant activity of cationic whey protein isolate].

    Science.gov (United States)

    titova, M E; Komolov, S A; Tikhomirova, N A

    2012-01-01

    The process of lipid peroxidation (LPO) in biological membranes of cells is carried out by free radical mechanism, a feature of which is the interaction of radicals with other molecules. In this work we investigated the antioxidant activity of cationic whey protein isolate, obtained by the cation-exchange chromatography on KM-cellulose from raw cow's milk, in vitro and in vivo. In biological liquids, which are milk, blood serum, fetal fluids, contains a complex of biologically active substances with a unique multifunctional properties, and which are carrying out a protective, antimicrobial, regenerating, antioxidant, immunomodulatory, regulatory and others functions. Contents of the isolate were determined electrophoretically and by its biological activity. Cationic whey protein isolate included lactoperoxidase, lactoferrin, pancreatic RNase, lysozyme and angeogenin. The given isolate significantly has an antioxidant effect in model experimental systems in vitro and therefore may be considered as a factor that can adjust the intensity of lipid oxidation. In model solutions products of lipid oxidation were obtained by oxidation of phosphatidylcholine by hydrogen peroxide in the presence of a source of iron. The composition of the reaction mixture: 0,4 mM H2O2; 50 mcM of hemin; 2 mg/ml L-alpha-phosphatidylcholine from soybean (Sigma, German). Lipid peroxidation products were formed during the incubation of the reaction mixture for two hours at 37 degrees C. In our studies rats in the adaptation period immediately after isolation from the nest obtained from food given orally native cationic whey protein isolate at the concentration three times higher than in fresh cow's milk. On the manifestation of the antioxidant activity of cationic whey protein isolate in vivo evidence decrease of lipid peroxidation products concentration in the blood of rats from the experimental group receipt whey protein isolate in dos 0,6 mg/g for more than 20% (pisolate has an antioxidant

  4. Identity Based Strong Designated Verifier Parallel Multi-Proxy Signature Scheme

    OpenAIRE

    Lal, Sunder; Verma, Vandani

    2009-01-01

    This paper presents a new identity based strong designated verifier parallel multi-proxy signature scheme. Multi-Proxy signatures allow the original signer to delegate his signing power to a group of proxy signers. In our scheme, the designated verifier can only validate proxy signatures created by a group of proxy signer.

  5. An approach for verifying biogenic greenhouse gas emissions inventories with atmospheric CO2 concentration data

    Science.gov (United States)

    Stephen M Ogle; Kenneth Davis; Thomas Lauvaux; Andrew Schuh; Dan Cooley; Tristram O West; Linda S Heath; Natasha L Miles; Scott Richardson; F Jay Breidt; James E Smith; Jessica L McCarty; Kevin R Gurney; Pieter Tans; A Scott. Denning

    2015-01-01

    Verifying national greenhouse gas (GHG) emissions inventories is a critical step to ensure that reported emissions data to the United Nations Framework Convention on Climate Change (UNFCCC) are accurate and representative of a country's contribution to GHG concentrations in the atmosphere. Furthermore, verifying biogenic fluxes provides a check on estimated...

  6. Comparative analysis of cation/proton antiporter superfamily in plants

    Energy Technology Data Exchange (ETDEWEB)

    Ye, Chuyu [ORNL; Yang, Xiaohan [ORNL; Xia, Xinli [Beijing Forestry University, China; Yin, Weilun [Beijing Forestry University, China

    2013-01-01

    The cation/proton antiporter superfamily is associated with the transport of monovalent cations across membranes. This superfamily was annotated in the Arabidopsis genome and some members were functionally characterized. In the present study, a systematic analysis of the cation/proton antiporter genes in diverse plant specieswas reported.We identified 240 cation/proton antiporters in alga, moss, and angiosperm. A phylogenetic tree was constructed showing these 240members are separated into three families, i.e., Na+/H+ exchangers, K+ efflux antiporters, and cation/H+ exchangers. Our analysis revealed that tandem and/or segmental duplications contribute to the expansion of cation/H+ exchangers in the examined angiospermspecies. Sliding windowanalysis of the nonsynonymous/synonymous substitution ratios showed some differences in the evolutionary fate of cation/proton antiporter paralogs. Furthermore, we identified over-represented motifs among these 240 proteins and foundmostmotifs are family specific, demonstrating diverse evolution of the cation/proton antiporters among three families. In addition, we investigated the co-expressed genes of the cation/proton antiporters in Arabidopsis thaliana. The results showed some biological processes are enriched in the co-expressed genes, suggesting the cation/proton antiporters may be involved in these biological processes. Taken together, this study furthers our knowledge on cation/proton antiporters in plants.

  7. Cationic niosomes an effective gene carrier composed of novel spermine-derivative cationic lipids: effect of central core structures.

    Science.gov (United States)

    Opanasopit, Praneet; Leksantikul, Lalita; Niyomtham, Nattisa; Rojanarata, Theerasak; Ngawhirunpat, Tanasait; Yingyongnarongkul, Boon-Ek

    2017-05-01

    Cationic niosomes formulated from Span 20, cholesterol (Chol) and novel spermine-based cationic lipids of multiple central core structures (di(oxyethyl)amino, di(oxyethyl)amino carboxy, 3-amino-1,2-dioxypropyl and 2-amino-1,3-dioxypropyl) were successfully prepared for improving transfection efficiency in vitro. The niosomes composed of spermine cationic lipid with central core structure of di(oxyethyl)amino revealed the highest gene transfection efficiency. To investigate the factors affecting gene transfection and cell viability including differences in the central core structures of cationic lipids, the composition of vesicles, molar ratio of cationic lipids in formulations and the weight ratio of niosomes to DNA. Cationic niosomes composed of nonionic surfactants (Span20), cholesterol and spermine-based cationic lipids of multiple central core structures were formulated. Gene transfection and cell viability were evaluated on a human cervical carcinoma cell line (HeLa cells) using pDNA encoding green fluorescent protein (pEGFP-C2). The morphology, size and charge were also characterized. High transfection efficiency was obtained from cationic niosomes composed of Span20:Chol:cationic lipid at the molar ratio of 2.5:2.5:0.5 mM. Cationic lipids with di(oxyethyl)amino as a central core structure exhibited highest transfection efficiency. In addition, there was also no serum effect on transfection efficiency. These novel cationic niosomes may constitute a good alternative carrier for gene transfection.

  8. Cationic surfactants for control of fresh- and saltwater mollusks in nuclear cooling systems

    International Nuclear Information System (INIS)

    Post, R.M.; Mallen, E.; Lehmann, F.

    1991-01-01

    One result of the release of the US Nuclear Regulatory Commission's Generic Letter 89-13, Service Water Problems Affecting Safety-Related Equipment, was the heightened awareness of the nuclear industry to the problems of macrofouling in heat exchange systems. The principal mollusk species that contribute to freshwater macrofouling problems are Asiatic Clam (southern United States) and Zebra Mussel (Great Lakes). The predominant saltwater fouling mollusks are the Blue Mussel (Pacific, northern Atlantic), Ribbed Mussel (southern Atlantic, Gulf Coast), and American Oyster (Atlantic, Gulf Coast). The nuclear community's awareness of macrofouling problems and the ineffectiveness of intermittent chlorination programs have led to the development of several chemical control technologies for eliminating macrofouling organism infestation. One technology that has proven effective for the control of macrofouling organisms is the periodic addition of a combination of two cationic charged surfactants, specifically, alkyldimethylbenzylammonium chloride (QUAT) and dodecyl guanidine hydrochloride (DGH). Experience with the cationic surfactants at several nuclear power plants is reported

  9. Complex Macromolecular Architectures by Living Cationic Polymerization

    KAUST Repository

    Alghamdi, Reem D.

    2015-05-01

    Poly (vinyl ether)-based graft polymers have been synthesized by the combination of living cationic polymerization of vinyl ethers with other living or controlled/ living polymerization techniques (anionic and ATRP). The process involves the synthesis of well-defined homopolymers (PnBVE) and co/terpolymers [PnBVE-b-PCEVE-b-PSiDEGVE (ABC type) and PSiDEGVE-b-PnBVE-b-PSiDEGVE (CAC type)] by sequential living cationic polymerization of n-butyl vinyl ether (nBVE), 2-chloroethyl vinyl ether (CEVE) and tert-butyldimethylsilyl ethylene glycol vinyl ether (SiDEGVE), using mono-functional {[n-butoxyethyl acetate (nBEA)], [1-(2-chloroethoxy) ethyl acetate (CEEA)], [1-(2-(2-(t-butyldimethylsilyloxy)ethoxy) ethoxy) ethyl acetate (SiDEGEA)]} or di-functional [1,4-cyclohexanedimethanol di(1-ethyl acetate) (cHMDEA), (VEMOA)] initiators. The living cationic polymerizations of those monomers were conducted in hexane at -20 0C using Et3Al2Cl3 (catalyst) in the presence of 1 M AcOEt base.[1] The PCEVE segments of the synthesized block terpolymers were then used to react with living macroanions (PS-DPE-Li; poly styrene diphenyl ethylene lithium) to afford graft polymers. The quantitative desilylation of PSiDEGVE segments by n-Bu4N+F- in THF at 0 °C led to graft co- and terpolymers in which the polyalcohol is the outer block. These co-/terpolymers were subsequently subjected to “grafting-from” reactions by atom transfer radical polymerization (ATRP) of styrene to afford more complex macromolecular architectures. The base assisted living cationic polymerization of vinyl ethers were also used to synthesize well-defined α-hydroxyl polyvinylether (PnBVE-OH). The resulting polymers were then modified into an ATRP macro-initiator for the synthesis of well-defined block copolymers (PnBVE-b-PS). Bifunctional PnBVE with terminal malonate groups was also synthesized and used as a precursor for more complex architectures such as H-shaped block copolymer by “grafting-from” or

  10. Complexes of natural carbohydrates with metal cations

    International Nuclear Information System (INIS)

    Alekseev, Yurii E; Garnovskii, Alexander D; Zhdanov, Yu A

    1998-01-01

    Data on the interaction of natural carbohydrates (mono-, oligo-, and poly-saccharides, amino sugars, and natural organic acids of carbohydrate origin) with metal cations are surveyed and described systematically. The structural diversity of carbohydrate metal complexes, caused by some specific features of carbohydrates as ligands, is demonstrated. The influence of complex formation on the chemical properties of carbohydrates is discussed. It is shown that the formation of metal complexes plays an important role in the configurational and conformational analysis of carbohydrates. The practical significance of the coordination interaction in the series of carbohydrate ligands is demonstrated. The bibliography includes 571 references.

  11. Homogeneous cation exchange membrane by radiation grafting

    International Nuclear Information System (INIS)

    Kolhe, Shailesh M.; G, Agathian; Ashok Kumar

    2001-01-01

    Preparation of a strong cation exchange membrane by radiation grafting of styrene on to polyethylene (LDPE) film by mutual irradiation technique in the presence of air followed by sulfonation is described. The grafting has been carried out in the presence of air and without any additive. Low dose rate has been seen to facilitate the grafting. Further higher the grafting percentage more is the exchange capacity. The addition of a swelling agent during the sulfonation helped in achieving the high exchange capacity. The TGA-MASS analysis confirmed the grafting and the sulfonation. (author)

  12. New technology and application in UV curing

    International Nuclear Information System (INIS)

    Loutz, J.M.

    1999-01-01

    Overview of radcure technology was presented. Its included this following subjects, radiation curable powder coatings, UV curable water based polyurethanes, photo-initiators, fire retardancy, aqueous systems, cationic, ceramic and optical grade material

  13. Alkali Metal Cation versus Proton and Methyl Cation Affinities: Structure and Bonding Mechanism.

    Science.gov (United States)

    Boughlala, Zakaria; Fonseca Guerra, Célia; Bickelhaupt, F Matthias

    2016-06-01

    We have analyzed the structure and bonding of gas-phase Cl-X and [HCl-X](+) complexes for X(+)= H(+), CH3 (+), Li(+), and Na(+), using relativistic density functional theory (DFT). We wish to establish a quantitative trend in affinities of the anionic and neutral Lewis bases Cl(-) and HCl for the various cations. The Cl-X bond becomes longer and weaker along X(+) = H(+), CH3 (+), Li(+), and Na(+). Our main purpose is to understand the heterolytic bonding mechanism behind the intrinsic (i.e., in the absence of solvent) alkali metal cation affinities (AMCA) and how this compares with and differs from those of the proton affinity (PA) and methyl cation affinity (MCA). Our analyses are based on Kohn-Sham molecular orbital (KS-MO) theory in combination with a quantitative energy decomposition analysis (EDA) that pinpoints the importance of the different features in the bonding mechanism. Orbital overlap appears to play an important role in determining the trend in cation affinities.

  14. Cationic Antimicrobial Polymers and Their Assemblies

    Science.gov (United States)

    Carmona-Ribeiro, Ana Maria; de Melo Carrasco, Letícia Dias

    2013-01-01

    Cationic compounds are promising candidates for development of antimicrobial agents. Positive charges attached to surfaces, particles, polymers, peptides or bilayers have been used as antimicrobial agents by themselves or in sophisticated formulations. The main positively charged moieties in these natural or synthetic structures are quaternary ammonium groups, resulting in quaternary ammonium compounds (QACs). The advantage of amphiphilic cationic polymers when compared to small amphiphilic molecules is their enhanced microbicidal activity. Besides, many of these polymeric structures also show low toxicity to human cells; a major requirement for biomedical applications. Determination of the specific elements in polymers, which affect their antimicrobial activity, has been previously difficult due to broad molecular weight distributions and random sequences characteristic of radical polymerization. With the advances in polymerization control, selection of well defined polymers and structures are allowing greater insight into their structure-antimicrobial activity relationship. On the other hand, antimicrobial polymers grafted or self-assembled to inert or non inert vehicles can yield hybrid antimicrobial nanostructures or films, which can act as antimicrobials by themselves or deliver bioactive molecules for a variety of applications, such as wound dressing, photodynamic antimicrobial therapy, food packing and preservation and antifouling applications. PMID:23665898

  15. Cobalt 60 cation exchange with mexican clays

    International Nuclear Information System (INIS)

    Nava Galve, R.G.

    1993-01-01

    Mexican clays can be used to remove radioactive elements from contaminated aqueous solutions. Cation exchange experiments were performed with 60 Co radioactive solution. In the present work the effect of contact time on the sorption of Co 2+ was studied. The contact time in hydrated montmorillonite was from 5 to 120 minutes and in dehydrated montmorillonite 5 to 1400 minutes. The Co 2+ uptake value was, in hydrated montmorillonite, between 0.3 to 0.85 m eq/g and in dehydrated montmorillonite, between 0.6 to 1.40 m eq/g. The experiments were done in a pH 5.1 to 5.7 and normal conditions. XRD patterns were used to characterize the samples. The crystallinity was determined by X-ray Diffraction and it was maintained before and after the cation exchange. DTA thermo grams showed the temperatures of the lost humidity and crystallization water. Finally, was observed that dehydrated montmorillonite adsorb more cobalt than hydrated montmorillonite. (Author)

  16. Cationic Antimicrobial Polymers and Their Assemblies

    Directory of Open Access Journals (Sweden)

    Ana Maria Carmona-Ribeiro

    2013-05-01

    Full Text Available Cationic compounds are promising candidates for development of antimicrobial agents. Positive charges attached to surfaces, particles, polymers, peptides or bilayers have been used as antimicrobial agents by themselves or in sophisticated formulations. The main positively charged moieties in these natural or synthetic structures are quaternary ammonium groups, resulting in quaternary ammonium compounds (QACs. The advantage of amphiphilic cationic polymers when compared to small amphiphilic molecules is their enhanced microbicidal activity. Besides, many of these polymeric structures also show low toxicity to human cells; a major requirement for biomedical applications. Determination of the specific elements in polymers, which affect their antimicrobial activity, has been previously difficult due to broad molecular weight distributions and random sequences characteristic of radical polymerization. With the advances in polymerization control, selection of well defined polymers and structures are allowing greater insight into their structure-antimicrobial activity relationship. On the other hand, antimicrobial polymers grafted or self-assembled to inert or non inert vehicles can yield hybrid antimicrobial nanostructures or films, which can act as antimicrobials by themselves or deliver bioactive molecules for a variety of applications, such as wound dressing, photodynamic antimicrobial therapy, food packing and preservation and antifouling applications.

  17. Noncovalent cation-π interactions – their role in nature

    Directory of Open Access Journals (Sweden)

    Krzysztof Fink

    2014-11-01

    Full Text Available Non-covalent interactions play an extremely important role in organisms. The main non-covalent interactions in nature are: ion-ion interactions, dipole-dipole interactions, hydrogen bonds, and van der Waals interactions. A new kind of intermolecular interactions – cation-π interactions – is gaining increasing attention. These interactions occur between a cation and a π system. The main contributors to cation-π interactions are electrostatic, polarization and, to a lesser extent, dispersion interactions. At first, cation-π interactions were studied in a gas phase, with metal cation–aromatic system complexes. The characteristics of these complexes are as follows: an increase of cation atomic number leads to a decrease of interaction energy, and an increase of cation charge leads to an increase of interaction energy. Aromatic amino acids bind with metal cations mainly through interactions with their main chain. Nevertheless, cation-π interaction with a hydrophobic side chain significantly enhances binding energy. In water solutions most cations preferentially interact with water molecules rather than aromatic systems. Cation-π interactions occur in environments with lower accessibility to a polar solvent. Cation-π interactions can have a stabilizing role on the secondary, tertiary and quaternary structure of proteins. These interactions play an important role in substrate or ligand binding sites in many proteins, which should be taken into consideration when the screening of effective inhibitors for these proteins is carried out. Cation-π interactions are abundant and play an important role in many biological processes.

  18. Stability and recovery of DNA origami structure with cation concentration

    Science.gov (United States)

    Chen, Yi; Wang, Ping; Liu, Yang; Liu, Ting; Xu, Yan; Zhu, Shanshan; Zhu, Jun; Ye, Kai; Huang, Guang; Dannong, He

    2018-01-01

    We synthesized triangular and rectangular DNA origami nanostructures and investigated the stability and recovery of them under low cation concentration. Our results demonstrated that the origami nanostructures would melt when incubated in low cation concentration, and recover whilst kept in the concentration for less than 10 min. However, extending the incubation time would lead to irreversible melting. Our results show the possibility of application of DNA origami nanostructures for things such as a sensor for cation concentration response, etc.

  19. The formation of singly and doubly cationized oligomers in SIMS

    International Nuclear Information System (INIS)

    Delcorte, A.; Wojciechowski, I.; Gonze, X.; Garrison, B.J.; Bertrand, P.

    2003-01-01

    The cationization of sputtered organic species via metal particle adduction is investigated using poly-4-methylstyrene molecules in combination with Cu, Pd, Ag and Au substrates. Metal-cationization occurs for these four substrates. The cationized molecule yields vary with the considered substrate and they are not correlated with the metal ion yields. In addition, double cationization with two metal particles is observed with a very significant intensity for Cu, Ag and Au supports. We interpret the results with an emission scheme in which excited molecules and metal atoms recombine above the surface and decay via electron emission, thereby locking the complex in the ionic state

  20. Hydration Structure of the Quaternary Ammonium Cations

    KAUST Repository

    Babiaczyk, Wojtek Iwo

    2010-11-25

    Two indicators of the hydropathicity of small solutes are introduced and tested by molecular dynamics simulations. These indicators are defined as probabilities of the orientation of water molecules\\' dipoles and hydrogen bond vectors, conditional on a generalized distance from the solute suitable for arbitrarily shaped molecules. Using conditional probabilities, it is possible to distinguish features of the distributions in close proximity of the solute. These regions contain the most significant information on the hydration structure but cannot be adequately represented by using, as is usually done, joint distance-angle probability densities. Our calculations show that using our indicators a relative hydropathicity scale for the interesting test set of the quaternary ammonium cations can be roughly determined. © 2010 American Chemical Society.

  1. Use of a material conducting hydrogen cations

    International Nuclear Information System (INIS)

    Howe, A.T.; Shilton, M.G.

    1986-01-01

    The invention concerns a separator conducting hydrogenous for electrical devices, which contains at least one compound with the formula H(UO 2 )PO 4 x nH 2 O, H(UO 2 )AsO 4 x nH 2 O or H(UO 2 )IO 4 (OH) 2 x nH 2 O, where not more than 50% by weight of the H + is replaced by one or more cations, such as Li + , Na + , K + , NH 4 + , Cu 2+ , Mg 2+ , Ca 2+ , Ba 2+ , Sr 2+ , Pb 2+ , Fe 2+ , Co 2+ , Ni 2+ , Mn 2+ or Al 3+ . The electrical device having the separator can be an electrolysis cell, for example, an electro chromium cell. (H x WO 3 ), a hydrogen isotope enrichment device, a proton-sensitive electrode (eg for a pH meter), a battery or a fuel cell. (orig./MM) [de

  2. An investigation of mixed cation oxide glasses

    International Nuclear Information System (INIS)

    Brook, H.C.

    1999-02-01

    This study has been undertaken with several purposes in mind. Firstly, the author wished to ascertain whether EXAFS would show the mixed alkali (MAE) in a mixed alkali glass in shell parameters other than those for the first shell, as well as being a structural probe. Secondly, it was desired to see whether borate glasses show the MAE in EXAFS. Thirdly, the author attempted to ascertain whether cations of different charges would show an effect similar to the MAE. Fourthly, to use NMR as a second structure probe in an attempt to gain a better understanding of the structure. Fifthly, to perform electrical conductivity experiments to try to link the conductivity behaviour with structural changes. Finally, to attempt to develop a generalised explanation of the origins of the MAE and the variations in physical properties in glasses. (author)

  3. Retention of Cationic Starch onto Cellulose Fibres

    Science.gov (United States)

    Missaoui, Mohamed; Mauret, Evelyne; Belgacem, Mohamed Naceur

    2008-08-01

    Three methods of cationic starch titration were used to quantify its retention on cellulose fibres, namely: (i) the complexation of CS with iodine and measurement of the absorbency of the ensuing blue solution by UV-vis spectroscopy; (ii) hydrolysis of the starch macromolecules followed by the conversion of the resulting sugars to furan-based molecules and quantifying the ensuing mixture by measuring their absorbance at a Ι of 490 nm, using the same technique as previous one and; finally (iii) hydrolysis of starch macromolecules by trifluoro-acetic acid and quantification of the sugars in the resulting hydrolysates by high performance liquid chromatography. The three methods were found to give similar results within the range of CS addition from 0 to 50 mg per g of cellulose fibres.

  4. Altered erythrocyte cation permeability in familial pseudohyperkalaemia.

    Science.gov (United States)

    Dagher, G; Vantyghem, M C; Doise, B; Lallau, G; Racadot, A; Lefebvre, J

    1989-08-01

    1. Erythrocyte cation transport pathways have been investigated in a family with pseudohyperkalaemia. 2. Ouabain- and bumetanide-resistant Na+ and K+ effluxes in three pseudohyperkalaemic patients were not different from those of control subjects when assessed at 37 degrees C. 3. When the temperature was decreased to 20 degrees C and 9 degrees C, K+ passive permeability markedly increased and Na+ permeability remained unchanged in these patients. In contrast, in control subjects a reduction in temperature caused a marked reduction in Na+ and K+ passive permeability. 4. These findings could account for the marked increase in plasma K+ concentration observed at subphysiological temperatures. 5. The Na+-K+ co-transport pathway was reduced in all members of the family, but the Na+-K+ pump was reduced in only two of them. These alterations were independent from the pseudohyperkalaemic state.

  5. A Cationic Smart Copolymer for DNA Binding

    Directory of Open Access Journals (Sweden)

    Tânia Ribeiro

    2017-11-01

    Full Text Available A new block copolymer with a temperature-responsive block and a cationic block was prepared by reversible addition-fragmentation chain transfer (RAFT polymerization, with good control of its size and composition. The first block is composed by di(ethylene glycol methyl ether methacrylate (DEGMA and oligo(ethylene glycol methyl ether methacrylate (OEGMA, with the ratio DEGMA/OEGMA being used to choose the volume phase transition temperature of the polymer in water, tunable from ca. 25 to above 90 °C. The second block, of trimethyl-2-methacroyloxyethylammonium chloride (TMEC, is positively charged at physiological pH values and is used for DNA binding. The coacervate complexes between the block copolymer and a model single strand DNA are characterized by fluorescence correlation spectroscopy and fluorescence spectroscopy. The new materials offer good prospects for biomedical application, for example in controlled gene delivery.

  6. Cell Penetrating Peptides and Cationic Antibacterial Peptides

    Science.gov (United States)

    Rodriguez Plaza, Jonathan G.; Morales-Nava, Rosmarbel; Diener, Christian; Schreiber, Gabriele; Gonzalez, Zyanya D.; Lara Ortiz, Maria Teresa; Ortega Blake, Ivan; Pantoja, Omar; Volkmer, Rudolf; Klipp, Edda; Herrmann, Andreas; Del Rio, Gabriel

    2014-01-01

    Cell penetrating peptides (CPP) and cationic antibacterial peptides (CAP) have similar physicochemical properties and yet it is not understood how such similar peptides display different activities. To address this question, we used Iztli peptide 1 (IP-1) because it has both CPP and CAP activities. Combining experimental and computational modeling of the internalization of IP-1, we show it is not internalized by receptor-mediated endocytosis, yet it permeates into many different cell types, including fungi and human cells. We also show that IP-1 makes pores in the presence of high electrical potential at the membrane, such as those found in bacteria and mitochondria. These results provide the basis to understand the functional redundancy of CPPs and CAPs. PMID:24706763

  7. The Method of a Standalone Functional Verifying Operability of Sonar Control Systems

    Directory of Open Access Journals (Sweden)

    A. A. Sotnikov

    2014-01-01

    Full Text Available This article describes a method of standalone verifying sonar control system, which is based on functional checking of control system operability.The main features of realized method are a development of the valid mathematic model for simulation of sonar signals at the point of hydroacoustic antenna, a valid representation of the sonar control system modes as a discrete Markov model, providing functional object verification in real time mode.Some ways are proposed to control computational complexity in case of insufficient computing resources of the simulation equipment, namely the way of model functionality reduction and the way of adequacy reduction.Experiments were made using testing equipment, which was developed by department of Research Institute of Information Control System at Bauman Moscow State Technical University to verify technical validity of industrial sonar complexes.On-board software was artificially changed to create malfunctions in functionality of sonar control systems during the verifying process in order to estimate verifying system performances.The method efficiency was proved by the theory and experiment results in comparison with the basic methodology of verifying technical systems.This method could be also used in debugging of on-board software of sonar complexes and in development of new promising algorithms of sonar signal processing.

  8. Analyzing Solutions High in Total Dissolved Solids for Rare Earth Elements (REEs) Using Cation Exchange and Online Pre-Concentration with the seaFAST2 Unit; NETL-TRS-7-2017; NETL Technical Report Series; U.S. Department of Energy, National Energy Technology Laboratory: Albany, OR, 2017; p 32

    Energy Technology Data Exchange (ETDEWEB)

    Yang, J. [National Energy Technology Lab. (NETL), Albany, OR (United States); Oregon State Univ., Corvallis, OR (United States). College of Earth, Ocean, and Atmospheric Science; Torres, M. [Oregon State Univ., Corvallis, OR (United States). College of Earth, Ocean, and Atmospheric Science; Verba, C. [National Energy Technology Lab. (NETL), Albany, OR (United States); Oregon State Univ., Corvallis, OR (United States); Hakala, A. [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States)

    2017-08-01

    The accurate quantification of the rare earth element (REE) dissolved concentrations in natural waters are often inhibited by their low abundances in relation to other dissolved constituents such as alkali, alkaline earth elements, and dissolved solids. The high abundance of these constituents can suppress the overall analytical signal as well as create isobaric interferences on the REEs during analysis. Waters associated with natural gas operations on black shale plays are characterized by high salinities and high total dissolved solids (TDS) contents >150,000 mg/L. Methods used to isolate and quantify dissolved REEs in seawater were adapted in order to develop the capability of analyzing REEs in waters that are high in TDS. First, a synthetic fluid based on geochemical modelling of natural brine formation fluids was created within the Marcellus black shale with a TDS loading of 153,000 mg/L. To this solution, 1,000 ng/mL of REE standards was added based on preliminary analyses of experimental fluids reacted at high pressure and temperature with Marcellus black shale. These synthetic fluids were then run at three different dilution levels of 10, 100, and 1,000–fold dilutions through cation exchange columns using AG50-X8 exchange resin from Eichrom Industries. The eluent from the cation columns were then sent through a seaFAST2 unit directly connected to an inductively coupled plasma mass spectrometer (ICP-MS) to analyze the REEs. Percent recoveries of the REEs ranged from 80–110% and fell within error for the external reference standard used and no signal suppression or isobaric interferences on the REEs were observed. These results demonstrate that a combined use of cation exchange columns and seaFAST2 instrumentation are effective in accurately quantifying the dissolved REEs in fluids that are >150,000 mg/L in TDS and have Ba:Eu ratios in excess of 380,000.

  9. How mobile are sorbed cations in clays and clay rocks?

    Science.gov (United States)

    Gimmi, T; Kosakowski, G

    2011-02-15

    Diffusion of cations and other contaminants through clays is of central interest, because clays and clay rocks are widely considered as barrier materials for waste disposal sites. An intriguing experimental observation has been made in this context: Often, the diffusive flux of cations at trace concentrations is much larger and the retardation smaller than expected based on their sorption coefficients. So-called surface diffusion of sorbed cations has been invoked to explain the observations but remains a controversial issue. Moreover, the corresponding surface diffusion coefficients are largely unknown. Here we show that, by an appropriate scaling, published diffusion data covering a broad range of cations, clays, and chemical conditions can all be modeled satisfactorily by a surface diffusion model. The average mobility of sorbed cations seems to be primarily an intrinsic property of each cation that follows inversely its sorption affinity. With these surface mobilities, cation diffusion coefficients can now be estimated from those of water tracers. In pure clays at low salinities, surface diffusion can reduce the cation retardation by a factor of more than 1000.

  10. In vivo toxicity of cationic micelles and liposomes

    DEFF Research Database (Denmark)

    Knudsen, Kristina Bram; Northeved, Helle; Ek, Pramod Kumar

    2015-01-01

    This study investigated toxicity of nanocarriers comprised of cationic polymer and lipid components often used in gene and drug delivery, formulated as cationic micelles and liposomes. Rats were injected intravenously with 10, 25 or 100 mg/kg and sacrificed after 24 or 48 h, or 24 h after the las...

  11. Synthesis of Cationic Core-Shell Latex Particles

    NARCIS (Netherlands)

    Dziomkina, N.; Hempenius, Mark A.; Vancso, Gyula J.

    2006-01-01

    Surfactant-free seeded (core-shell) polymerization of cationic polymer colloids is presented. Polystyrene core particles with sizes between 200 nm and 500 nm were synthesized. The number average diameter of the colloidal core particles increased with increasing monomer concentration. Cationic shells

  12. Effects of metallic cations in the beryl flotation

    International Nuclear Information System (INIS)

    Lima Leonel, C.M. de; Peres, A.E.C.

    1984-01-01

    The beryl zeta potential in microelectrophoretic cell is studied in the presence of neutral electrolyte, cations of calcium, magnesium and iron. The petroleum sulfonate is used how collector in Hallimond tube. Hydroxy complex of metallic cations seems activate the ore and precipitates of colloidal metallic hidroxies seems lower him when added to the mixture. (M.A.C.) [pt

  13. Does alkali cation binding to aromatic ring retard the fluxional ...

    Indian Academy of Sciences (India)

    A Kalpana

    2017-11-10

    Nov 10, 2017 ... the role of cation on haptotropic migration. Cation binding not only enhances the complex interaction energy but also delicately affects the fluxionality in the molecule by increasing the barrier to haptotropic shift of Cr(CO)3. The competing nature of the bifacial acids with sandwiched aromatic ring is ...

  14. Membrane potential change effects on cationic and neutral drug ...

    African Journals Online (AJOL)

    Membrane potential change effects on cationic and neutral drug - induced erythrocyte shape change and cellular uptake of drugs. A Nwafor, WT Coakley. Abstract. The effect of membrane potential change of the human erythrocytes on cationic drugs tetracaine and chlorpromazine and neutral drug benzyl alcohol induced ...

  15. Cation substitution induced blue-shift of optical band gap

    Indian Academy of Sciences (India)

    Cation substitution induced blue-shift of optical band gap in nanocrystalline Zn ( 1 − x ) Ca x O thin films deposited by sol–gel dip coating technique ... thin films giving 13.03% enhancement in theenergy gap value due to the electronic perturbation caused by cation substitution as well as deterioration in crystallinity.

  16. Base Cation Leaching From the Canopy of a Rubber ( Hevea ...

    African Journals Online (AJOL)

    Base cations are essential to the sustainability of forest ecosystems. They are important for neutralizing the acidifying effects of atmospheric deposition. There is the need for in-depth understanding of base cation depletion and leaching from forest canopy. This is important particularly due to the increasing acidification and ...

  17. Cationic Antimicrobial Peptides Inactivate Shiga Toxin-Encoding Bacteriophages

    Directory of Open Access Journals (Sweden)

    Manuel E. Del Cogliano

    2017-12-01

    Full Text Available Shiga toxin (Stx is the principal virulence factor during Shiga toxin-producing Escherichia coli (STEC infections. We have previously reported the inactivation of bacteriophage encoding Stx after treatment with chitosan, a linear polysaccharide polymer with cationic properties. Cationic antimicrobial peptides (cAMPs are short linear aminoacidic sequences, with a positive net charge, which display bactericidal or bacteriostatic activity against a wide range of bacterial species. They are promising novel antibiotics since they have shown bactericidal effects against multiresistant bacteria. To evaluate whether cationic properties are responsible for bacteriophage inactivation, we tested seven cationic peptides with proven antimicrobial activity as anti-bacteriophage agents, and one random sequence cationic peptide with no antimicrobial activity as a control. We observed bacteriophage inactivation after incubation with five cAMPs, but no inactivating activity was observed with the random sequence cationic peptide or with the non-alpha helical cAMP Omiganan. Finally, to confirm peptide-bacteriophage interaction, zeta potential was analyzed by following changes on bacteriophage surface charges after peptide incubation. According to our results we could propose that: (1 direct interaction of peptides with phage is a necessary step for bacteriophage inactivation, (2 cationic properties are necessary but not sufficient for bacteriophage inactivation, and (3 inactivation by cationic peptides could be sequence (or structure specific. Overall our data suggest that these peptides could be considered a new family of molecules potentially useful to decrease bacteriophage replication and Stx expression.

  18. Verifying Quality of Service of ARCnet Based ATOMOS Communication System for Integrated Ship Control

    DEFF Research Database (Denmark)

    Nielsen, N.N.; Nielsen, Jens Frederik Dalsgaard; Schiøler, Henrik

    1999-01-01

    As part of the ATOMOS project (Funded by EU, DG VII) a reliable communication system with predictable behaviour has been designed. The selected solution is a network based on redundant ARCnet segments extended with an EN50170 compliant fieldbus based layer on top of an ARCnet SAP (service access...... point) layer. An important characteristic of the communication system is that the functionality and timing must be verifiable in order to satisfy requirements from classification companies like Lloyds and Norsk Veritas. By including Service Categories, Traffic Descriptors and Quality of Service concepts...... in the system it is made possible to measure network performance and hereby obtain verifiable methods for traffic planning and network surveillance. This paper describes the design of a simulation system to be used for testing and verifying the communication on a single ARCnet segment throughout the development...

  19. Dynamic Symmetric Key Mobile Commerce Scheme Based on Self-Verified Mechanism

    Directory of Open Access Journals (Sweden)

    Jiachen Yang

    2014-01-01

    Full Text Available In terms of the security and efficiency of mobile e-commerce, the authors summarized the advantages and disadvantages of several related schemes, especially the self-verified mobile payment scheme based on the elliptic curve cryptosystem (ECC and then proposed a new type of dynamic symmetric key mobile commerce scheme based on self-verified mechanism. The authors analyzed the basic algorithm based on self-verified mechanisms and detailed the complete transaction process of the proposed scheme. The authors analyzed the payment scheme based on the security and high efficiency index. The analysis shows that the proposed scheme not only meets the high efficiency of mobile electronic payment premise, but also takes the security into account. The user confirmation mechanism at the end of the proposed scheme further strengthens the security of the proposed scheme. In brief, the proposed scheme is more efficient and practical than most of the existing schemes.

  20. A Formal Approach to Verify Parameterized Protocols in Mobile Cyber-Physical Systems

    Directory of Open Access Journals (Sweden)

    Long Zhang

    2017-01-01

    Full Text Available Mobile cyber-physical systems (CPSs are very hard to verify, because of asynchronous communication and the arbitrary number of components. Verification via model checking typically becomes impracticable due to the state space explosion caused by the system parameters and concurrency. In this paper, we propose a formal approach to verify the safety properties of parameterized protocols in mobile CPS. By using counter abstraction, the protocol is modeled as a Petri net. Then, a novel algorithm, which uses IC3 (the state-of-the-art model checking algorithm as the back-end engine, is presented to verify the Petri net model. The experimental results show that our new approach can greatly scale the verification capabilities compared favorably against several recently published approaches. In addition to solving the instances fast, our method is significant for its lower memory consumption.

  1. Evolution of optically nondestructive and data-non-intrusive credit card verifiers

    Science.gov (United States)

    Sumriddetchkajorn, Sarun; Intaravanne, Yuttana

    2010-04-01

    Since the deployment of the credit card, the number of credit card fraud cases has grown rapidly with a huge amount of loss in millions of US dollars. Instead of asking more information from the credit card's holder or taking risk through payment approval, a nondestructive and data-non-intrusive credit card verifier is highly desirable before transaction begins. In this paper, we review optical techniques that have been proposed and invented in order to make the genuine credit card more distinguishable than the counterfeit credit card. Several optical approaches for the implementation of credit card verifiers are also included. In particular, we highlight our invention on a hyperspectral-imaging based portable credit card verifier structure that offers a very low false error rate of 0.79%. Other key features include low cost, simplicity in design and implementation, no moving part, no need of an additional decoding key, and adaptive learning.

  2. What are the ultimate limits to computational techniques: verifier theory and unverifiability

    International Nuclear Information System (INIS)

    Yampolskiy, Roman V

    2017-01-01

    Despite significant developments in proof theory, surprisingly little attention has been devoted to the concept of proof verifiers. In particular, the mathematical community may be interested in studying different types of proof verifiers (people, programs, oracles, communities, superintelligences) as mathematical objects. Such an effort could reveal their properties, their powers and limitations (particularly in human mathematicians), minimum and maximum complexity, as well as self-verification and self-reference issues. We propose an initial classification system for verifiers and provide some rudimentary analysis of solved and open problems in this important domain. Our main contribution is a formal introduction of the notion of unverifiability, for which the paper could serve as a general citation in domains of theorem proving, as well as software and AI verification. (invited comment)

  3. What are the ultimate limits to computational techniques: verifier theory and unverifiability

    Science.gov (United States)

    Yampolskiy, Roman V.

    2017-09-01

    Despite significant developments in proof theory, surprisingly little attention has been devoted to the concept of proof verifiers. In particular, the mathematical community may be interested in studying different types of proof verifiers (people, programs, oracles, communities, superintelligences) as mathematical objects. Such an effort could reveal their properties, their powers and limitations (particularly in human mathematicians), minimum and maximum complexity, as well as self-verification and self-reference issues. We propose an initial classification system for verifiers and provide some rudimentary analysis of solved and open problems in this important domain. Our main contribution is a formal introduction of the notion of unverifiability, for which the paper could serve as a general citation in domains of theorem proving, as well as software and AI verification.

  4. Cation-cation "attraction": when London dispersion attraction wins over Coulomb repulsion.

    Science.gov (United States)

    Grimme, Stefan; Djukic, Jean-Pierre

    2011-03-21

    London forces are omnipresent in nature and relevant to molecular engineering. Proper tuning of their energetic contribution may stabilize molecular aggregates, which would be otherwise highly unstable by virtue of other overwhelming repulsive terms. The literature contains a number of such noncovalently bonded molecular aggregates, of which the "binding mode" has never been thoroughly settled. Among those are the emblematic cationic complexes of tetrakis(isonitrile)rhodium(I) studied by a number of researchers. The propensity of these complexes to spontaneously produce oligomers has been an "open case" for years. For the dimer [(PhNC)(4)Rh](2)(2+), one of the archetypes of such oligomers, density functional theory methods (DFT-D3) and wave function based spin-component-scaled second-order Møller-Plesset perturbation theory (SCS-MP2) quantum chemical calculations indicate that when the eight isonitrile ligands arrange spatially in an optimal π-stacked fashion, the energy due to dispersion not only overcomes coulombic repulsion but also the entropy penalty of complex formation. This central role of long-range electron correlation explains such cation-cation attractive interactions. Furthermore, the present findings relativize the role of the metal-metal "d(8)-d(8)" interactions, which are present on a relatively small scale compared to the effects of the ligands; d(8)-d(8) interactions represent about 10-15% of the total dispersion contribution to the binding energy.

  5. Cooling of PAH cations studied with an electrostatic storage ring

    Science.gov (United States)

    Bernard, Jérôme; Chen, Li; Brédy, Richard; Ji, Mingchao; Ortéga, Céline; Matsumoto, Jun; Martin, Serge

    2017-10-01

    In this paper we discuss the production of molecular PAH cations using an ECR ion source and their subsequent cooling studied with an electrostatic storage ring, the Mini-Ring on a time range up to 10 ms. We show that the ECR ion source can produce high currents of small PAH cation, here naphthalene and anthracene cations. Then, we report experimental result for the cooling of three PAH cations (anthracene, naphthalene and pyrene) stored in our compact electrostatic storage ring (the Mini-Ring). We show that the Poincaré recurrent fluorescence plays a major role in the cooling process of those PAH cations. We show that for a given internal energy, the cooling rate is much smaller for pyrene than for anthracene and naphthalene. We conclude that the Poincaré recurrent fluorescence is less efficient due to smaller oscillator strength of the D2-D0 electronic transition for pyrene.

  6. Thermochemical stability of Soviet macroporous sulfonated cation-exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Rukhlyada, N.N.; Plotnikova, V.P.; Roginskaya, B.S.; Znamenskii, Yu.P.; Zavodovskaya, A.S.; Dobrova, E.I.

    1988-10-20

    The purpose of this work was to study the influence of macroporosity on the thermochemical stability of sulfonated cation-exchangers. The investigations were carried out on commercial macroporous sulfonated cation-exchangers based on styrene-divinylbenzene copolymers. Study of the thermochemical stability of macroporous sulfonated cation-exchangers in dilute hydrogen peroxide solutions showed that the type of macroporosity has virtually no influence on their stability. The determining factor in thermal stability of macroporous cation-exchangers, as of the gel type, is the degree of cross-linking of the polymer matrix. The capacity loss of macroporous cation-exchangers during oxidative thermolysis is caused by destruction of the macromolecular skeleton and elution of fragments of polar chains containing sulfo groups into the solution.

  7. Development of material measures for performance verifying surface topography measuring instruments

    International Nuclear Information System (INIS)

    Leach, Richard; Giusca, Claudiu; Rickens, Kai; Riemer, Oltmann; Rubert, Paul

    2014-01-01

    The development of two irregular-geometry material measures for performance verifying surface topography measuring instruments is described. The material measures are designed to be used to performance verify tactile and optical areal surface topography measuring instruments. The manufacture of the material measures using diamond turning followed by nickel electroforming is described in detail. Measurement results are then obtained using a traceable stylus instrument and a commercial coherence scanning interferometer, and the results are shown to agree to within the measurement uncertainties. The material measures are now commercially available as part of a suite of material measures aimed at the calibration and performance verification of areal surface topography measuring instruments

  8. Association between cotinine-verified smoking status and hypertension in 167,868 Korean adults.

    Science.gov (United States)

    Kim, Byung Jin; Han, Ji Min; Kang, Jung Gyu; Kim, Bum Soo; Kang, Jin Ho

    2017-10-01

    Previous studies showed inconsistent results concerning the relationship between chronic smoking and blood pressure. Most of the studies involved self-reported smoking status. This study was performed to evaluate the association of urinary cotinine or self-reported smoking status with hypertension and blood pressure in Korean adults. Among individuals enrolled in the Kangbuk Samsung Health Study and Kangbuk Samsung Cohort Study, 167,868 participants (men, 55.7%; age, 37.5 ± 6.9 years) between 2011 and 2013 who had urinary cotinine measurements were included. Individuals with urinary cotinine levels ≥50 ng/mL were defined as cotinine-verified current smokers. The prevalence of hypertension and cotinine-verified current smokers in the overall population was 6.8% and 22.7%, respectively (10.0% in men and 2.8% in women for hypertension: 37.7% in men and 3.9% in women for cotinine-verified current smokers). In a multivariate regression analysis adjusted for age, sex, body mass index, waist circumference, alcohol drinking, vigorous exercise, and diabetes, cotinine-verified current smoking was associated with lower prevalence of hypertension compared with cotinine-verified never smoking (OR[95% CI], 0.79 [0.75, 0.84]). Log-transformed cotinine levels and unobserved smoking were negatively associated with hypertension, respectively (0.96 [0.96, 0.97] and 0.55 [0.39, 0.79]). In a multivariate linear regression analysis, the cotinine-verified current smoking was inversely associated with systolic and diastolic blood pressure (BP) (regression coefficient[95% CI], -1.23[-1.39, -1.07] for systolic BP and -0.71 [-0.84, -0.58] for diastolic BP). In subgroup analyses according to sex, the inverse associations between cotinine-verified current smoking and hypertension were observed only in men. This large observational study showed that cotinine-verified current smoking and unobserved smoking were inversely associated with hypertension in Korean adults, especially only in

  9. Automatic Estimation of Verified Floating-Point Round-Off Errors via Static Analysis

    Science.gov (United States)

    Moscato, Mariano; Titolo, Laura; Dutle, Aaron; Munoz, Cesar A.

    2017-01-01

    This paper introduces a static analysis technique for computing formally verified round-off error bounds of floating-point functional expressions. The technique is based on a denotational semantics that computes a symbolic estimation of floating-point round-o errors along with a proof certificate that ensures its correctness. The symbolic estimation can be evaluated on concrete inputs using rigorous enclosure methods to produce formally verified numerical error bounds. The proposed technique is implemented in the prototype research tool PRECiSA (Program Round-o Error Certifier via Static Analysis) and used in the verification of floating-point programs of interest to NASA.

  10. Increasing Base Cations in Streams: Another Legacy of Deicing Salts?

    Science.gov (United States)

    Helton, A. M.; Barclay, J. R.; Bellucci, C.; Rittenhouse, C.

    2017-12-01

    Elevated use of deicing salts directly increases sodium chloride inputs to watersheds. Sodium can accumulate in soils over time and has the potential to leach other cations (e.g., calcium, magnesium, and potassium) from the soil through cation exchange. We hypothesize that increased use of deicing salts results in a legacy of soils depleted in non-sodium base cations with loss of cations to receiving waters. The goal of this project is to quantify temporal trends in base cations and chloride in streams and rivers across the United States. We used Weighted Regressions on Time, Discharge, and Season (WRTDS) to analyze trends in base cations. Our preliminary analysis of 10 rivers in Connecticut with chemical periods of record ranging from 24 - 64 years (median = 55 years), shows that the flux of base cations is increasing in all sites (25 - 366 103 meq ha-1 yr-1 yr-1), driven largely by increases in sodium (23 - 222 103 meq ha-1 yr-1 yr-1), the dominant cation in 7 of the sites. Chloride is also increasing at all sites (26 - 261 103 meq ha-1 yr-1 yr-1), which, in combination with salt use trends, suggests a road salt source for the increased sodium. Non-sodium cations are also increasing in 9 of the sites (8 - 54 103 meq ha-1 yr-1 yr-1), though they are not directly added with most deicing salts. We will compare these trends to other long-term sites across the United States, and quantify relationships between cation trends and land cover, road density, and snowfall.

  11. IRMPD Action Spectroscopy of Alkali Metal Cation-Cytosine Complexes: Effects of Alkali Metal Cation Size on Gas Phase Conformation

    NARCIS (Netherlands)

    Yang, B.; Wu, R.R.; Polfer, N.C.; Berden, G.; Oomens, J.; Rodgers, M.T.

    2013-01-01

    The gas-phase structures of alkali metal cation-cytosine complexes generated by electrospray ionization are probed via infrared multiple photon dissociation (IRMPD) action spectroscopy and theoretical calculations. IRMPD action spectra of five alkali metal cation-cytosine complexes exhibit both

  12. Anaerobic toxicity of cationic silver nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Gitipour, Alireza; Thiel, Stephen W. [Biomedical, Chemical, and Environmental Engineering, University of Cincinnati, Cincinnati, OH (United States); Scheckel, Kirk G. [USEPA, Office of Research and Development, Cincinnati, OH (United States); Tolaymat, Thabet, E-mail: tolaymat.thabet@epa.gov [USEPA, Office of Research and Development, Cincinnati, OH (United States)

    2016-07-01

    The microbial toxicity of silver nanoparticles (AgNPs) stabilized with different capping agents was compared to that of Ag{sup +} under anaerobic conditions. Three AgNPs were investigated: (1) negatively charged citrate-coated AgNPs (citrate-AgNPs), (2) minimally charged polyvinylpyrrolidone coated AgNPs (PVP-AgNPs) and (3) positively charged branched polyethyleneimine coated AgNPs (BPEI-AgNPs). The AgNPs investigated in this experiment were similar in size (10–15 nm), spherical in shape, but varied in surface charge which ranged from highly negative to highly positive. While, at AgNPs concentrations lower than 5 mg L{sup −1}, the anaerobic decomposition process was not influenced by the presence of the nanoparticles, there was an observed impact on the diversity of the microbial community. At elevated concentrations (100 mg L{sup −1} as silver), only the cationic BPEI-AgNPs demonstrated toxicity similar in magnitude to that of Ag{sup +}. Both citrate and PVP-AgNPs did not exhibit toxicity at the 100 mg L{sup −1} as measured by biogas evolution. These findings further indicate the varying modes of action for nanoparticle toxicity and represent one of the few studies that evaluate end-of-life management concerns with regards to the increasing use of nanomaterials in our everyday life. These findings also highlight some of the concerns with a one size fits all approach to the evaluation of environmental health and safety concerns associated with the use of nanoparticles. - Highlights: • At concentrations -1 the anaerobic decomposition process was not impacted. • An impact on the microbial community at concentrations -1 were observed. • At high concentrations (100 mg L{sup −1}), the cationic BPEI-AgNPs demonstrated toxicity. • Toxicity was demonstrated without the presence of oxidative dissolution of silver. • A one size fits all approach for the evaluation of NPs may not be accurate.

  13. Investigation of a model to verify software for 3-D static force calculation

    OpenAIRE

    Takahashi, Norio; Nakata, Takayoshi; Morishige, H.

    1994-01-01

    Requirements for a model to verify software for 3-D static force calculation are examined, and a 3-D model for static force calculation is proposed. Some factors affecting the analysis and experiments are investigated in order to obtain accurate and reproducible results

  14. Regressive transgressive cycle of Devonian sea in Uruguay verified by Palynology

    International Nuclear Information System (INIS)

    Da Silva, J.

    1990-01-01

    This work is about the results and conclusions of the populations palinomorphs study, carried out in Devonian formations in the center of Uruguay. The existence of a regressive transgressive cycle is verified by analyzing the vertical distribution of palinomorphs as well as is mentioned the presence of chintziest for the section studied - hoesphaeridium Cyathochitina kinds

  15. 25 CFR 20.602 - How does the Bureau verify eligibility for social services?

    Science.gov (United States)

    2010-04-01

    ... verify eligibility for social services? (a) You, the applicant, are the primary source of information used to determine eligibility and need. If it is necessary to secure information such as medical records from other sources, you must authorize the release of information. (b) You must immediately report...

  16. Successful conservative treatment of patients with MRI-verified meniscal lesions

    DEFF Research Database (Denmark)

    Rathleff, Camilla Rams; Cavallius, Christian; Jensen, Hans Peter

    2015-01-01

    suspected of meniscal lesion were referred to the regional orthopaedic division and subjected to MRI and clinical examination by an experienced surgeon. Patients with MRI-verified meniscal lesions were treated according to an arthroscopy restrictive strategy meaning that treatment was initiated...

  17. Combined Analysis of Stable Isotope, (1)H NMR, and Fatty Acid To Verify Sesame Oil Authenticity.

    Science.gov (United States)

    Kim, Jeongeun; Jin, Gyungsu; Lee, Yunhee; Chun, Hyang Sook; Ahn, Sangdoo; Kim, Byung Hee

    2015-10-14

    The aim of this study was to verify the authenticity of sesame oils using combined analysis of stable isotope ratio, (1)H NMR spectroscopy, and fatty acid profiles of the oils. Analytical data were obtained from 35 samples of authentic sesame oils and 29 samples of adulterated sesame oils currently distributed in Korea. The orthogonal projection to latent structure discriminant analysis technique was used to select variables that most effectively verify the sesame oil authenticity. The variables include δ(13)C value, integration values of NMR peaks that signify the CH3 of n-3 fatty acids, CH2 between two C═C, protons from sesamin/sesamolin, and 18:1n-9, 18:3n-3, 18:2t, and 18:3t content values. The authenticity of 65 of 70 blind samples was correctly verified by applying the range of the eight variables found in the authentic sesame oil samples, suggesting that triple analysis is a useful approach to verify sesame oil authenticity.

  18. Die verifiëring, verfyning en toepassing van leksikografiese liniale ...

    African Journals Online (AJOL)

    rbr

    been expressed against the ruler for Afrikaans and this is followed up in this article by an effort to verify the existing ruler and a recalculation or refinement of the Afrikaans Ruler. For verification ..... FICTION: ADVENTURE (29 texts). SKILLS AND HOBBIES (36 texts). FICTION: ROMANCE (29 texts). POPULAR LORE (48 texts).

  19. Die verifiëring, verfyning en toepassing van leksikografiese liniale ...

    African Journals Online (AJOL)

    Leksikografiese liniale vir Afrikaans en die Afrikatale is 'n dekade oud en word algemeen gebruik in die samestelling van woordeboeke. Die samestellers het dit tot dusver nie nodig geag om hierdie liniale te verifieer of te verfyn nie. Kritiek is egter uitgespreek op die samestelling van die Afrikaanse Liniaal en dit word in ...

  20. 40 CFR 8.9 - Measures to assess and verify environmental impacts.

    Science.gov (United States)

    2010-07-01

    ... environmental impacts. 8.9 Section 8.9 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GENERAL ENVIRONMENTAL IMPACT ASSESSMENT OF NONGOVERNMENTAL ACTIVITIES IN ANTARCTICA § 8.9 Measures to assess and verify environmental impacts. (a) The operator shall conduct appropriate monitoring of key environmental indicators as...

  1. Eddy-Current Testing of Welded Stainless Steel Storage Containers to Verify Integrity and Identity

    International Nuclear Information System (INIS)

    Tolk, Keith M.; Stoker, Gerald C.

    1999-01-01

    An eddy-current scanning system is being developed to allow the International Atomic Energy Agency (IAEA) to verify the integrity of nuclear material storage containers. Such a system is necessary to detect attempts to remove material from the containers in facilities where continuous surveillance of the containers is not practical. Initial tests have shown that the eddy-current system is also capable of verifying the identity of each container using the electromagnetic signature of its welds. The DOE-3013 containers proposed for use in some US facilities are made of an austenitic stainless steel alloy, which is nonmagnetic in its normal condition. When the material is cold worked by forming or by local stresses experienced in welding, it loses its austenitic grain structure and its magnetic permeability increases. This change in magnetic permeability can be measured using an eddy-current probe specifically designed for this purpose. Initial tests have shown that variations of magnetic permeability and material conductivity in and around welds can be detected, and form a pattern unique to the container. The changes in conductivity that are present around a mechanically inserted plug can also be detected. Further development of the system is currently underway to adapt the system to verifying the integrity and identity of sealable, tamper-indicating enclosures designed to prevent unauthorized access to measurement equipment used to verify international agreements

  2. Methodology for Rewetting Drained Tropical Peatlands. Approved Verified Carbon Standard (VCS) Methodology VM0027

    NARCIS (Netherlands)

    Hoffer, S.; Laer, Y.; Navrátil, R.; Wosten, J.H.M.

    2014-01-01

    The first methodology to address the rewetting of drained peatlands "Methodology for rewetting Drained Tropical Peatlands" has been approved by the Verified Carbon Standard (VCS) Program. As the methodology is the first of its kind, it will provide unique guidance for other projects that aim at

  3. Developing a corpus to verify the performance of a tone labelling algorithm

    CSIR Research Space (South Africa)

    Raborife, M

    2011-11-01

    Full Text Available The authors report on a study that involved the development of a corpus used to verify the performance of two tone labelling algorithms, with one algorithm being an improvement on the other. These algorithms were developed for speech synthesis...

  4. 76 FR 1620 - Trials to Verify and Describe Clinical Benefit of Midodrine Hydrochloride; Establishment of...

    Science.gov (United States)

    2011-01-11

    ... HUMAN SERVICES Food and Drug Administration Trials to Verify and Describe Clinical Benefit of Midodrine... the clinical benefit of midodrine hydrochloride (HCl) when used to treat symptomatic orthostatic... . SUPPLEMENTARY INFORMATION: FDA approved PROAMATINE (midodrine HCl) for marketing under its accelerated approval...

  5. Business rescue decision making through verifier determinants – ask the specialists

    Directory of Open Access Journals (Sweden)

    Marius Pretorius

    2013-11-01

    Full Text Available Orientation: Business rescue has become a critical part of business strategy decision making, especially during economic downturns and recessions. Past legislation has generally supported creditor-friendly regimes, and its mind-set still applies which increases the difficulty of such turnarounds. There are many questions and critical issues faced by those involved in rescue. Despite extensive theory in the literature on failure, there is a void regarding practical verifiers of the signs and causes of venture decline, as specialists are not forthcoming about what they regard as their “competitive advantage”. Research purpose: This article introduces the concept and role of “verifier determinants” of early warning signs, as a tool to confirm the causes of decline in order to direct rescue strategies and, most importantly, reduce time between the first observation and the implementation of the rescue. Motivation for the study: Knowing how specialist practitioners confirm causes of business decline could assist in deciding on strategies for the rescue earlier than can be done using traditional due diligence which is time consuming. Reducing time is a crucial element of a successful rescue. Research design and approach: The researchers interviewed specialist practitioners with extensive experience in rescue and turnaround. An experimental design was used to ensure the specialists evaluated the same real cases to extract their experiences and base their decisions on. Main findings: The specialists confirmed the use of verifier determinants and identified such determinants as they personally used them to confirm causes of decline. These verifier determinants were classified into five categories; namely, management, finance, strategic, banking and operations and marketing of the ventures under investigation. The verifier determinants and their use often depend heavily on subconscious (non-factual information based on previous experiences

  6. Cation immobilization in pyrolyzed simulated spent ion exchange resins

    Energy Technology Data Exchange (ETDEWEB)

    Luca, Vittorio, E-mail: vluca@cnea.gov.ar [Programa Nacional de Gestion de Residuos Radiactivos, Centro Atomico Constituyentes, Comision Nacional de Energia Atomica, Av. General, Paz 1499, 1650 San Martin, Provincia de Buenos Aires (Argentina); Bianchi, Hugo L. [Gerencia de Quimica, Centro Atomico Constituyentes, Comision Nacional de Energia Atomica, Av. General, Paz 1499, 1650 San Martin, Provincia de Buenos Aires (Argentina); ECyT, Universidad Nacional de General San Martin, Campus Miguelete, Ed. Tornavias, Martin de Irigoyen 3100, 1650 San Martin (Argentina); Conicet, Av. Rivadavia 1917, 1033 Buenos Aires (Argentina); Manzini, Alberto C. [Programa Nacional de Gestion de Residuos Radiactivos, Comision Nacional de Energia Atomica, Av. Del Libertador 8250, CP 1429, Ciudad Autonoma de Buenos Aires (Argentina)

    2012-05-15

    Significant quantities of spent ion exchange resins that are contaminated by an assortment of radioactive elements are produced by the nuclear industry each year. The baseline technology for the conditioning of these spent resins is encapsulation in ordinary Portland cement which has various shortcomings none the least of which is the relatively low loading of resin in the cement and the poor immobilization of highly mobile elements such as cesium. The present study was conducted with cationic resin samples (Lewatit S100) loaded with Cs{sup +}, Sr{sup 2+}, Co{sup 2+}, Ni{sup 2+} in roughly equimolar proportions at levels at or below 30% of the total cation exchange capacity. Low temperature thermal treatment of the resins was conducted in inert (Ar), or reducing (CH{sub 4}) gas atmospheres, or supercritical ethanol to convert the hydrated polymeric resin beads into carbonaceous materials that contained no water. This pyrolytic treatment resulted in at least a 50% volume reduction to give mechanically robust spherical materials. Scanning electron microscope investigations of cross-sections of the beads combined with energy dispersive analysis showed that initially all elements were uniformly distributed through the resin matrix but that at higher temperatures the distribution of Cs became inhomogeneous. Although Cs was found in the entire cross-section, a significant proportion of the Cs occurred within internal rings while a proportion migrated toward the outer surfaces to form a crustal deposit. Leaching experiments conducted in water at 25 Degree-Sign C showed that the divalent contaminant elements were very difficult to leach from the beads heated in inert atmospheres in the range 200-600 Degree-Sign C. Cumulative fractional loses of the order of 0.001 were observed for these divalent elements for temperatures below 500 Degree-Sign C. Regardless of the processing temperature, the cumulative fractional loss of Cs in water at 25 Degree-Sign C reached a plateau or

  7. Cation immobilization in pyrolyzed simulated spent ion exchange resins

    International Nuclear Information System (INIS)

    Luca, Vittorio; Bianchi, Hugo L.; Manzini, Alberto C.

    2012-01-01

    Significant quantities of spent ion exchange resins that are contaminated by an assortment of radioactive elements are produced by the nuclear industry each year. The baseline technology for the conditioning of these spent resins is encapsulation in ordinary Portland cement which has various shortcomings none the least of which is the relatively low loading of resin in the cement and the poor immobilization of highly mobile elements such as cesium. The present study was conducted with cationic resin samples (Lewatit S100) loaded with Cs + , Sr 2+ , Co 2+ , Ni 2+ in roughly equimolar proportions at levels at or below 30% of the total cation exchange capacity. Low temperature thermal treatment of the resins was conducted in inert (Ar), or reducing (CH 4 ) gas atmospheres, or supercritical ethanol to convert the hydrated polymeric resin beads into carbonaceous materials that contained no water. This pyrolytic treatment resulted in at least a 50% volume reduction to give mechanically robust spherical materials. Scanning electron microscope investigations of cross-sections of the beads combined with energy dispersive analysis showed that initially all elements were uniformly distributed through the resin matrix but that at higher temperatures the distribution of Cs became inhomogeneous. Although Cs was found in the entire cross-section, a significant proportion of the Cs occurred within internal rings while a proportion migrated toward the outer surfaces to form a crustal deposit. Leaching experiments conducted in water at 25 °C showed that the divalent contaminant elements were very difficult to leach from the beads heated in inert atmospheres in the range 200–600 °C. Cumulative fractional loses of the order of 0.001 were observed for these divalent elements for temperatures below 500 °C. Regardless of the processing temperature, the cumulative fractional loss of Cs in water at 25 °C reached a plateau or steady-state within the first 24 h increasing only

  8. An approach for verifying biogenic greenhouse gas emissions inventories with atmospheric CO2 concentration data

    International Nuclear Information System (INIS)

    Ogle, Stephen M; Davis, Kenneth; Lauvaux, Thomas; Miles, Natasha L; Richardson, Scott; Schuh, Andrew; Cooley, Dan; Breidt, F Jay; West, Tristram O; Heath, Linda S; Smith, James E; McCarty, Jessica L; Gurney, Kevin R; Tans, Pieter; Denning, A Scott

    2015-01-01

    Verifying national greenhouse gas (GHG) emissions inventories is a critical step to ensure that reported emissions data to the United Nations Framework Convention on Climate Change (UNFCCC) are accurate and representative of a country’s contribution to GHG concentrations in the atmosphere. Furthermore, verifying biogenic fluxes provides a check on estimated emissions associated with managing lands for carbon sequestration and other activities, which often have large uncertainties. We report here on the challenges and results associated with a case study using atmospheric measurements of CO 2 concentrations and inverse modeling to verify nationally-reported biogenic CO 2 emissions. The biogenic CO 2 emissions inventory was compiled for the Mid-Continent region of United States based on methods and data used by the US government for reporting to the UNFCCC, along with additional sources and sinks to produce a full carbon balance. The biogenic emissions inventory produced an estimated flux of −408 ± 136 Tg CO 2 for the entire study region, which was not statistically different from the biogenic flux of −478 ± 146 Tg CO 2 that was estimated using the atmospheric CO 2 concentration data. At sub-regional scales, the spatial density of atmospheric observations did not appear sufficient to verify emissions in general. However, a difference between the inventory and inversion results was found in one isolated area of West-central Wisconsin. This part of the region is dominated by forestlands, suggesting that further investigation may be warranted into the forest C stock or harvested wood product data from this portion of the study area. The results suggest that observations of atmospheric CO 2 concentration data and inverse modeling could be used to verify biogenic emissions, and provide more confidence in biogenic GHG emissions reporting to the UNFCCC. (letter)

  9. Radical Cations and Acid Protection during Radiolysis

    International Nuclear Information System (INIS)

    Mincher, Bruce J.; Zarzana, Christopher A.; Mezyk, Stephen P.

    2016-01-01

    Ligand molecules for used nuclear fuel separation schemes are exposed to high radiation fields and high concentrations of acid. Thus, an understanding of the complex interactions between extraction ligands, diluent, and acid is critical to understanding the performance of a separation process. The diglycolamides are ligands with important structural similarities to CMPO; however, previous work has shown that their radiolytic degradation has important mechanistic differences from CMPO. The DGAs do not enjoy radioprotection by HNO3 and the kinetics of DGA radiolytic degradation are different. CMPO degrades with pseudo-zero-order kinetics in linear fashion with absorbed dose while the DGAs degrade in pseudo-first-order, exponential fashion. This suggests that the DGAs degrade by simple reaction with some product of direct diluent radiolysis, while CMPO degradation is probably multi-step, with a slow step that is not dependent on the CMPO concentration, and mitigated by HNO 3 . It is thus believed that radio-protection and the zero-order radiolytic degradation kinetics are related, and that these phenomena are a function of either the formation of strong acid complexes with CMPO and/or to the presence of the CMPO phenyl ring. Experiments to test both these hypotheses have been designed and partially conducted. This report summarizes findings related to these phenomena for FY16, in satisfaction of milestone M3FT-16IN030104053. It also reports continued kinetic measurements for the reactions of the dodecane radical cation with solvent extraction ligands.

  10. Antiviral activity of cationic amphiphilic drugs.

    Science.gov (United States)

    Salata, Cristiano; Calistri, Arianna; Parolin, Cristina; Baritussio, Aldo; Palù, Giorgio

    2017-05-01

    Emerging and reemerging viral infections represent a major concern for human and veterinary public health and there is an urgent need for the development of broad-spectrum antivirals. Areas covered: A recent strategy in antiviral research is based on the identification of molecules targeting host functions required for infection of multiple viruses. A number of FDA-approved drugs used to treat several human diseases are cationic amphiphilic drugs (CADs) that have the ability to accumulate inside cells affecting several structures/functions hijacked by viruses during infection. In this review we summarized the CADs' chemical properties and effects on the cells and reported the main FDA-approved CADs that have been identified so far as potential antivirals in drug repurposing studies. Expert commentary: Although there have been concerns regarding the efficacy and the possible side effects of the off-label use of CADs as antivirals, they seem to represent a promising starting point for the development of broad-spectrum antiviral strategies. Further knowledge about their mechanism of action is required to improve their antiviral activity and to reduce the risk of side effects.

  11. Radical Cations and Acid Protection during Radiolysis

    Energy Technology Data Exchange (ETDEWEB)

    Mincher, Bruce J. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Zarzana, Christopher A. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Mezyk, Stephen P. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-09-09

    Ligand molecules for used nuclear fuel separation schemes are exposed to high radiation fields and high concentrations of acid. Thus, an understanding of the complex interactions between extraction ligands, diluent, and acid is critical to understanding the performance of a separation process. The diglycolamides are ligands with important structural similarities to CMPO; however, previous work has shown that their radiolytic degradation has important mechanistic differences from CMPO. The DGAs do not enjoy radioprotection by HNO3 and the kinetics of DGA radiolytic degradation are different. CMPO degrades with pseudo-zero-order kinetics in linear fashion with absorbed dose while the DGAs degrade in pseudo-first-order, exponential fashion. This suggests that the DGAs degrade by simple reaction with some product of direct diluent radiolysis, while CMPO degradation is probably multi-step, with a slow step that is not dependent on the CMPO concentration, and mitigated by HNO3. It is thus believed that radio-protection and the zero-order radiolytic degradation kinetics are related, and that these phenomena are a function of either the formation of strong acid complexes with CMPO and/or to the presence of the CMPO phenyl ring. Experiments to test both these hypotheses have been designed and partially conducted. This report summarizes findings related to these phenomena for FY16, in satisfaction of milestone M3FT-16IN030104053. It also reports continued kinetic measurements for the reactions of the dodecane radical cation with solvent extraction ligands.

  12. Interaction of cationic drugs with liposomes.

    Science.gov (United States)

    Howell, Brett A; Chauhan, Anuj

    2009-10-20

    Interactions between cationic drugs and anionic liposomes were studied by measuring binding of drugs and the effect of binding on liposome permeability. The measurements were analyzed in the context of a continuum model based on electrostatic interactions and a Langmuir isotherm. Experiments and modeling indicate that, although electrostatic interactions are important, the fraction of drug sequestered in the double-layer is negligible. The majority of drug enters the bilayer with the charged regions interacting with the charged lipid head groups and the lipophilic regions associated with the bilayer. The partitioning of the drug can be described by a Langmuir isotherm with the electrostatic interactions increasing the sublayer concentration of the drug. The binding isotherms are similar for all tricyclic antidepressants (TCA). Bupivacaine (BUP) binds significantly less compared to TCA because its structure is such that the charged region has minimal interactions with the lipid heads once the BUP molecule partitions inside the bilayer. Conversely, the TCAs are linear with distinct hydrophilic and lipophilic regions, allowing the lipophilic regions to lie inside the bilayer and the hydrophilic regions to protrude out. This conformation maximizes the permeability of the bilayer, leading to an increased release of a hydrophilic fluorescent dye from liposomes.

  13. Water Adsorption on Free Cobalt Cluster Cations.

    Science.gov (United States)

    Kiawi, Denis M; Bakker, Joost M; Oomens, Jos; Buma, Wybren Jan; Jamshidi, Zahra; Visscher, Lucas; Waters, L B F M

    2015-11-05

    Cationic cobalt clusters complexed with water Con(+)-H2O (n = 6-20) are produced through laser ablation and investigated via infrared multiple photon dissociation (IR-MPD) spectroscopy in the 200-1700 cm(-1) spectral range. All spectra exhibit a resonance close to the 1595 cm(-1) frequency of the free water bending vibration, indicating that the water molecule remains intact upon adsorption. For n = 6, the frequency of this band is blue-shifted, but it gradually converges to the free water value with increasing cluster size. In the lower-frequency range (200-650 cm(-1)) the spectra contain several bands which show a very regular frequency evolution, suggesting that the exact cluster geometry has little effect on the water-surface interaction. Density functional theory (DFT) calculations are carried out at the OPBE/TZP level for three representative sizes (n = 6, 9, 13) and indicate that the vibrations responsible for the resonances correspond to bending and torsional modes between the cluster and water moieties. The potential energy surfaces describing these interactions are very shallow, making the calculated harmonic frequencies and IR intensities very sensitive to small geometrical perturbations. We conclude that harmonic frequency calculations on (local) minima structures provide insufficient information for these types of cluster complexes and need to be complemented with calculations that provide a more extensive sampling of the potential energy surface.

  14. Repurposing Cationic Amphiphilic Antihistamines for Cancer Treatment

    Directory of Open Access Journals (Sweden)

    Anne-Marie Ellegaard

    2016-07-01

    Full Text Available Non-small cell lung cancer (NSCLC is one of the deadliest cancers worldwide. In search for new NSCLC treatment options, we screened a cationic amphiphilic drug (CAD library for cytotoxicity against NSCLC cells and identified several CAD antihistamines as inducers of lysosomal cell death. We then performed a cohort study on the effect of CAD antihistamine use on mortality of patients diagnosed with non-localized cancer in Denmark between 1995 and 2011. The use of the most commonly prescribed CAD antihistamine, loratadine, was associated with significantly reduced all-cause mortality among patients with non-localized NSCLC or any non-localized cancer when compared with use of non-CAD antihistamines and adjusted for potential confounders. Of the less frequently described CAD antihistamines, astemizole showed a similar significant association with reduced mortality as loratadine among patients with any non-localized cancer, and ebastine use showed a similar tendency. The association between CAD antihistamine use and reduced mortality was stronger among patients with records of concurrent chemotherapy than among those without such records. In line with this, sub-micromolar concentrations of loratadine, astemizole and ebastine sensitized NSCLC cells to chemotherapy and reverted multidrug resistance in NSCLC, breast and prostate cancer cells. Thus, CAD antihistamines may improve the efficacy of cancer chemotherapy.

  15. Repurposing Cationic Amphiphilic Antihistamines for Cancer Treatment.

    Science.gov (United States)

    Ellegaard, Anne-Marie; Dehlendorff, Christian; Vind, Anna C; Anand, Atul; Cederkvist, Luise; Petersen, Nikolaj H T; Nylandsted, Jesper; Stenvang, Jan; Mellemgaard, Anders; Østerlind, Kell; Friis, Søren; Jäättelä, Marja

    2016-07-01

    Non-small cell lung cancer (NSCLC) is one of the deadliest cancers worldwide. In search for new NSCLC treatment options, we screened a cationic amphiphilic drug (CAD) library for cytotoxicity against NSCLC cells and identified several CAD antihistamines as inducers of lysosomal cell death. We then performed a cohort study on the effect of CAD antihistamine use on mortality of patients diagnosed with non-localized cancer in Denmark between 1995 and 2011. The use of the most commonly prescribed CAD antihistamine, loratadine, was associated with significantly reduced all-cause mortality among patients with non-localized NSCLC or any non-localized cancer when compared with use of non-CAD antihistamines and adjusted for potential confounders. Of the less frequently described CAD antihistamines, astemizole showed a similar significant association with reduced mortality as loratadine among patients with any non-localized cancer, and ebastine use showed a similar tendency. The association between CAD antihistamine use and reduced mortality was stronger among patients with records of concurrent chemotherapy than among those without such records. In line with this, sub-micromolar concentrations of loratadine, astemizole and ebastine sensitized NSCLC cells to chemotherapy and reverted multidrug resistance in NSCLC, breast and prostate cancer cells. Thus, CAD antihistamines may improve the efficacy of cancer chemotherapy. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  16. Tuning the solution organization of cationic polymers through interactions with bovine serum albumin.

    Science.gov (United States)

    Papagiannopoulos, Aristeidis; Vlassi, Eleni; Pispas, Stergios; Jafta, Charl J

    2017-07-19

    The interactions of bovine serum albumin (BSA) with aggregates of cationic polymers, i.e. quaternized poly(chloromethyl styrene) chains (QIm-PCMS), in aqueous solutions are investigated using small angle neutron scattering on length scales relevant to the size of BSA. The arrangement of the macromolecular chains within their aggregates is consistent with a blob description of overlapping chains that contain hydrophobic domains. The local conformations depend on the salt content as in typical linear polyelectrolytes. Although the hydrophobic content of the cationic polymers does not cause measurable local morphology differences, the interactions with BSA are enhanced in the case of the not fully quaternized polymer. The secondary structure of BSA is critically compromised by the interaction with the quaternized polymers as the signature of the alpha helix conformation is lost. The complexation with BSA and the resulting enhancement of interchain associations on higher length scales are verified using dynamic light scattering experiments. This study demonstrates the ability to tune the polyelectrolyte/protein interactions and polyelectrolyte chain-chain associations by modifying the hydrophobic content of the polyelectrolytes.

  17. User Guide for VISION 3.4.7 (Verifiable Fuel Cycle Simulation) Model

    Energy Technology Data Exchange (ETDEWEB)

    Jacob J. Jacobson; Robert F. Jeffers; Gretchen E. Matthern; Steven J. Piet; Wendell D. Hintze

    2011-07-01

    The purpose of this document is to provide a guide for using the current version of the Verifiable Fuel Cycle Simulation (VISION) model. This is a complex model with many parameters and options; the user is strongly encouraged to read this user guide before attempting to run the model. This model is an R&D work in progress and may contain errors and omissions. It is based upon numerous assumptions. This model is intended to assist in evaluating 'what if' scenarios and in comparing fuel, reactor, and fuel processing alternatives at a systems level. The model is not intended as a tool for process flow and design modeling of specific facilities nor for tracking individual units of fuel or other material through the system. The model is intended to examine the interactions among the components of a fuel system as a function of time varying system parameters; this model represents a dynamic rather than steady-state approximation of the nuclear fuel system. VISION models the nuclear cycle at the system level, not individual facilities, e.g., 'reactor types' not individual reactors and 'separation types' not individual separation plants. Natural uranium can be enriched, which produces enriched uranium, which goes into fuel fabrication, and depleted uranium (DU), which goes into storage. Fuel is transformed (transmuted) in reactors and then goes into a storage buffer. Used fuel can be pulled from storage into either separation or disposal. If sent to separations, fuel is transformed (partitioned) into fuel products, recovered uranium, and various categories of waste. Recycled material is stored until used by its assigned reactor type. VISION is comprised of several Microsoft Excel input files, a Powersim Studio core, and several Microsoft Excel output files. All must be co-located in the same folder on a PC to function. You must use Powersim Studio 8 or better. We have tested VISION with the Studio 8 Expert, Executive, and Education versions

  18. Preparation, characterization, and efficient transfection of cationic liposomes and nanomagnetic cationic liposomes

    Directory of Open Access Journals (Sweden)

    Samadikhah HR

    2011-10-01

    Full Text Available Hamid Reza Samadikhah1,*, Asia Majidi2,*, Maryam Nikkhah2, Saman Hosseinkhani11Department of Biochemistry, 2Department of Nanobiotechnology, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran *These authors contributed equally to this work Purpose: Cationic liposomes (CLs are composed of phospholipid bilayers. One of the most important applications of these particles is in drug and gene delivery. However, using CLs to deliver therapeutic nucleic acids and drugs to target organs has some problems, including low transfection efficiency in vivo. The aim of this study was to develop novel CLs containing magnetite to overcome the deficiencies. Patients and methods: CLs and magnetic cationic liposomes (MCLs were prepared using the freeze-dried empty liposome method. Luciferase-harboring vectors (pGL3 were transferred into liposomes and the transfection efficiencies were determined by luciferase assay. Firefly luciferase is one of most popular reporter genes often used to measure the efficiency of gene transfer in vivo and in vitro. Different formulations of liposomes have been used for delivery of different kinds of gene reporters. Lipoplex (liposome–plasmid DNA complexes formation was monitored by gel retardation assay. Size and charge of lipoplexes were determined using particle size analysis. Chinese hamster ovary cells were transfected by lipoplexes (liposome-pGL3; transfection efficiency and gene expression level was evaluated by luciferase assay. Results: High transfection efficiency of plasmid by CLs and novel nanomagnetic CLs was achieved. Moreover, lipoplexes showed less cytotoxicity than polyethyleneimine and Lipofectamine™. Conclusion: Novel liposome compositions (1,2-dipalmitoyl-sn-glycero-3-phosphocholine [DPPC]/dioctadecyldimethylammonium bromide [DOAB] and DPPC/cholesterol/DOAB with high transfection efficiency can be useful in gene delivery in vitro. MCLs can also be used for targeted gene delivery, due to

  19. Evaluation of phenomena affecting diffusion of cations in compacted bentonite

    International Nuclear Information System (INIS)

    Muurinen, A.; Lehikoinen, J.

    1995-04-01

    In a number of diffusion studies, contradictions between the apparent diffusivities of cations and their distribution coefficients in bentonite have been found. Two principal reasons have been offered as explanations for this discrepancy; diffusion of the sorbed cations, often called surface diffusion, and the decrease of sorption in compacted clay compared to a sorption value obtained from a batch experiment. In the study the information available from the literature on sorption-diffusion mechanisms of cations in bentonite has been compiled and re-interpreted in order to improve the understanding of the diffusion process. (103 refs., 23 figs., 8 tabs.)

  20. Alkali Metal Cation versus Proton and Methyl Cation Affinities: Structure and Bonding Mechanism

    OpenAIRE

    Boughlala, Z.; Guerra, C.F.; Bickelhaupt, F.M.

    2016-01-01

    Abstract We have analyzed the structure and bonding of gas?phase Cl?X and [HCl?X]+ complexes for X+=?H+, CH3 +, Li+, and Na+, using relativistic density functional theory (DFT). We wish to establish a quantitative trend in affinities of the anionic and neutral Lewis bases Cl? and HCl for the various cations. The Cl?X bond becomes longer and weaker along X+?=?H+, CH3 +, Li+, and Na+. Our main purpose is to understand the heterolytic bonding mechanism behind the intrinsic (i.e., in the absence ...

  1. Converting Hg-1212 to Tl-2212 via Tl-Hg cation exchange in combination with Tl cation intercalation

    International Nuclear Information System (INIS)

    Zhao Hua; Wu, Judy Z

    2007-01-01

    In a cation exchange process developed recently for epitaxy of HgBa 2 CaCu 2 O 6 (Hg-1212) thin films, TlBa 2 CaCu 2 O 7 (Tl-1212) or Tl 2 Ba 2 CaCu 2 O 9 (Tl-2212) precursor films were employed as the precursor matrices and Hg-1212 was obtained by replacing Tl cations on the precursor lattice with Hg cations. The reversibility of the cation exchange dictates directly the underlying mechanism. Following our recent success in demonstrating a complete reversibility within '1212' structure, we show the conversion from Hg-1212 to Tl-2212 can be achieved via two steps: conversion from Hg-1212 to Tl-1212 followed by Tl intercalation to form double Tl-O plans in each unit cell. The demonstrated reversibility of the cation exchange process has confirmed the process is a thermal perturbation of weakly bonded cations on the lattice and the direction of the process is determined by the population ratio between the replacing cations and that to be replaced

  2. Endomembrane Cation Transporters and Membrane Trafficking

    Energy Technology Data Exchange (ETDEWEB)

    Sze, Heven [Univ. of Maryland, College Park, MD (United States). Dept. of Cell Biology & Molecular Genetics

    2017-04-01

    Multicellular, as well as unicellular, organisms have evolved mechanisms to regulate ion and pH homeostasis in response to developmental cues and to a changing environment. The working hypothesis is that the balance of fluxes mediated by diverse transporters at the plasma membrane and in subcellular organelles determines ionic cellular distribution, which is critical for maintenance of membrane potential, pH control, osmolality, transport of nutrients, and protein activity. An emerging theme in plant cell biology is that cells respond and adapt to diverse cues through changes of the dynamic endomembrane system. Yet we know very little about the transporters that might influence the operation of the secretory system in plants. Here we focus on transporters that influence alkali cation and pH homeostasis, mainly in the endomembrane/ secretory system. The endomembrane system of eukaryote cells serves several major functions: i) sort cargo (e.g. enzymes, transporters or receptors) to specific destinations, ii) modulate the protein and lipid composition of membrane domains through remodeling, and iii) determine and alter the properties of the cell wall through synthesis and remodeling. We had uncovered a novel family of predicted cation/H+ exchangers (CHX) and K+ efflux antiporters (KEA) that are prevalent in higher plants, but rare in metazoans. We combined phylogenetic and transcriptomic analyses with molecular genetic, cell biological and biochemical studies, and have published the first reports on functions of plant CHXs and KEAs. CHX studied to date act at the endomembrane system where their actions are distinct from the better-studied NHX (Na/K-H+ exchangers). Arabidopsis thaliana CHX20 in guard cells modulate stomatal opening, and thus is significant for vegetative survival. Other CHXs ensure reproductive success on dry land, as they participate in organizing pollen walls, targeting of pollen tubes to the ovule or promoting

  3. Efficient Verifiable Range and Closest Point Queries in Zero-Knowledge

    Directory of Open Access Journals (Sweden)

    Ghosh Esha

    2016-10-01

    Full Text Available We present an efficient method for answering one-dimensional range and closest-point queries in a verifiable and privacy-preserving manner. We consider a model where a data owner outsources a dataset of key-value pairs to a server, who answers range and closest-point queries issued by a client and provides proofs of the answers. The client verifies the correctness of the answers while learning nothing about the dataset besides the answers to the current and previous queries. Our work yields for the first time a zero-knowledge privacy assurance to authenticated range and closest-point queries. Previous work leaked the size of the dataset and used an inefficient proof protocol. Our construction is based on hierarchical identity-based encryption. We prove its security and analyze its efficiency both theoretically and with experiments on synthetic and real data (Enron email and Boston taxi datasets.

  4. A Secure and Verifiable Outsourced Access Control Scheme in Fog-Cloud Computing.

    Science.gov (United States)

    Fan, Kai; Wang, Junxiong; Wang, Xin; Li, Hui; Yang, Yintang

    2017-07-24

    With the rapid development of big data and Internet of things (IOT), the number of networking devices and data volume are increasing dramatically. Fog computing, which extends cloud computing to the edge of the network can effectively solve the bottleneck problems of data transmission and data storage. However, security and privacy challenges are also arising in the fog-cloud computing environment. Ciphertext-policy attribute-based encryption (CP-ABE) can be adopted to realize data access control in fog-cloud computing systems. In this paper, we propose a verifiable outsourced multi-authority access control scheme, named VO-MAACS. In our construction, most encryption and decryption computations are outsourced to fog devices and the computation results can be verified by using our verification method. Meanwhile, to address the revocation issue, we design an efficient user and attribute revocation method for it. Finally, analysis and simulation results show that our scheme is both secure and highly efficient.

  5. An method of verify period signal based on data acquisition card

    International Nuclear Information System (INIS)

    Zeng Shaoli

    2005-01-01

    This paper introduces an method to verify index voltage of Period Signal Generator by using data acquisition card. which it's error is less 0.5%. A corresponding Win32's program, which use voluntarily developed VxD to control data acquisition card direct I/O and multi thread technique for gain the best time scale precision, has developed in Windows platform. The program will real time collect inda voltage data and auto measure period. (authors)

  6. Review of Ground Systems Development and Operations (GSDO) Tools for Verifying Command and Control Software

    Science.gov (United States)

    Aguilar, Michael L.; Bonanne, Kevin H.; Favretto, Jeffrey A.; Jackson, Maddalena M.; Jones, Stephanie L.; Mackey, Ryan M.; Sarrel, Marc A.; Simpson, Kimberly A.

    2014-01-01

    The Exploration Systems Development (ESD) Standing Review Board (SRB) requested the NASA Engineering and Safety Center (NESC) conduct an independent review of the plan developed by Ground Systems Development and Operations (GSDO) for identifying models and emulators to create a tool(s) to verify their command and control software. The NESC was requested to identify any issues or weaknesses in the GSDO plan. This document contains the outcome of the NESC review.

  7. Value elements of industrial maintenance: verifying the views of the customer and the service provider

    OpenAIRE

    Ali-Marttila, Maaren; Tynninen, Leena; Marttonen-Arola, Salla; Kärri, Timo

    2015-01-01

    To maximize the total value in a maintenance business relationship it is important to know what the partner values. The value of industrial maintenance service can be considered to consist of value elements, and the perceived total value for the customer and service provider is the sum of these value elements. The specific objectives of this paper are to verify the most important value elements for the maintenance service customer and provider and also to recognize where the value elements di...

  8. Successful conservative treatment of patients with MRI-verified meniscal lesions.

    Science.gov (United States)

    Rathleff, Camilla Rams; Cavallius, Christian; Jensen, Hans Peter; Simonsen, Ole Højgaard; Rasmussen, Sten; Kaalund, Søren; Østgaard, Svend Erik

    2015-01-01

    To follow a prospective cohort of consecutive patients with MRI-verified meniscal lesions to identify pre-treatment prognostic factors for long-term results following arthroscopic or conservative treatment. In the course of 1 year, 291 patients with knee pain and clinically suspected of meniscal lesion were referred to the regional orthopaedic division and subjected to MRI and clinical examination by an experienced surgeon. Patients with MRI-verified meniscal lesions were treated according to an arthroscopy restrictive strategy meaning that treatment was initiated by conservative treatment. Arthroscopy was only performed if satisfying pain relief was not obtained. The Lysholm score and Knee Injury and Osteoarthritis Outcome Score (KOOS) were obtained at baseline and after 12-24 months. A multiple linear regression model was used to investigate which pre-treatment prognostic factors were associated with improvement in the KOOS subscale pain from baseline to follow-up. An MRI-verified meniscal lesion was found in 185 patients (64%). Among these, 58% were treated successfully by conservative treatment. A high KOOS subscale pain score at baseline was associated with less improvement from baseline to follow-up. Bucket-handle lesions were associated with larger improvement from baseline to follow-up compared to flap-tear lesions. MRI findings and clinical status measured by KOOS subscale pain are prognostic for improvement among patients treated for MRI-verified meniscal lesions. Good results were observed for both operative and conservative treatment. The success rate for conservative treatment was 58%. Prospective cohort study, Level II.

  9. The AutoProof Verifier: Usability by Non-Experts and on Standard Code

    Directory of Open Access Journals (Sweden)

    Carlo A. Furia

    2015-08-01

    Full Text Available Formal verification tools are often developed by experts for experts; as a result, their usability by programmers with little formal methods experience may be severely limited. In this paper, we discuss this general phenomenon with reference to AutoProof: a tool that can verify the full functional correctness of object-oriented software. In particular, we present our experiences of using AutoProof in two contrasting contexts representative of non-expert usage. First, we discuss its usability by students in a graduate course on software verification, who were tasked with verifying implementations of various sorting algorithms. Second, we evaluate its usability in verifying code developed for programming assignments of an undergraduate course. The first scenario represents usability by serious non-experts; the second represents usability on "standard code", developed without full functional verification in mind. We report our experiences and lessons learnt, from which we derive some general suggestions for furthering the development of verification tools with respect to improving their usability.

  10. Biochemically verified smoking cessation and vaping beliefs among vape store customers.

    Science.gov (United States)

    Tackett, Alayna P; Lechner, William V; Meier, Ellen; Grant, DeMond M; Driskill, Leslie M; Tahirkheli, Noor N; Wagener, Theodore L

    2015-05-01

    To evaluate biochemically verified smoking status and electronic nicotine delivery systems (ENDS) use behaviors and beliefs among a sample of customers from vapor stores (stores specializing in ENDS). A cross-sectional survey of 215 adult vapor store customers at four retail locations in the Midwestern United States; a subset of participants (n = 181) also completed exhaled carbon monoxide (CO) testing to verify smoking status. Outcomes evaluated included ENDS preferences, harm beliefs, use behaviors, smoking history and current biochemically verified smoking status. Most customers reported starting ENDS as a means of smoking cessation (86%), using newer-generation devices (89%), vaping non-tobacco/non-menthol flavors (72%) and using e-liquid with nicotine strengths of ≤20 mg/ml (72%). There was a high rate of switching (91.4%) to newer-generation ENDS among those who started with a first-generation product. Exhaled CO readings confirmed that 66% of the tested sample had quit smoking. Among those who continued to smoke, mean cigarettes per day decreased from 22.1 to 7.5 (P customers in the United States who use electronic nicotine delivery devices to stop smoking, vaping longer, using newer-generation devices and using non-tobacco and non-menthol flavored e-liquid appear to be associated with higher rates of smoking cessation. © 2015 Society for the Study of Addiction.

  11. A robust preference for cheap-and-easy strategies over reliable strategies when verifying personal memories.

    Science.gov (United States)

    Nash, Robert A; Wade, Kimberley A; Garry, Maryanne; Adelman, James S

    2017-08-01

    People depend on various sources of information when trying to verify their autobiographical memories. Yet recent research shows that people prefer to use cheap-and-easy verification strategies, even when these strategies are not reliable. We examined the robustness of this cheap strategy bias, with scenarios designed to encourage greater emphasis on source reliability. In three experiments, subjects described real (Experiments 1 and 2) or hypothetical (Experiment 3) autobiographical events, and proposed strategies they might use to verify their memories of those events. Subjects also rated the reliability, cost, and the likelihood that they would use each strategy. In line with previous work, we found that the preference for cheap information held when people described how they would verify childhood or recent memories (Experiment 1), personally important or trivial memories (Experiment 2), and even when the consequences of relying on incorrect information could be significant (Experiment 3). Taken together, our findings fit with an account of source monitoring in which the tendency to trust one's own autobiographical memories can discourage people from systematically testing or accepting strong disconfirmatory evidence.

  12. Opposing effects of cationic antimicrobial peptides and divalent cations on bacterial lipopolysaccharides

    Science.gov (United States)

    Smart, Matthew; Rajagopal, Aruna; Liu, Wing-Ki; Ha, Bae-Yeun

    2017-10-01

    The permeability of the bacterial outer membrane, enclosing Gram-negative bacteria, depends on the interactions of the outer, lipopolysaccharide (LPS) layer, with surrounding ions and molecules. We present a coarse-grained model for describing how cationic amphiphilic molecules (e.g., antimicrobial peptides) interact with and perturb the LPS layer in a biologically relevant medium, containing monovalent and divalent salt ions (e.g., Mg2+). In our approach, peptide binding is driven by electrostatic and hydrophobic interactions and is assumed to expand the LPS layer, eventually priming it for disruption. Our results suggest that in parameter ranges of biological relevance (e.g., at micromolar concentrations) the antimicrobial peptide magainin 2 effectively disrupts the LPS layer, even though it has to compete with Mg2+ for the layer. They also show how the integrity of LPS is restored with an increasing concentration of Mg2+. Using the approach, we make a number of predictions relevant for optimizing peptide parameters against Gram-negative bacteria and for understanding bacterial strategies to develop resistance against cationic peptides.

  13. Removal of cesium ions from clays by cationic surfactant intercalation.

    Science.gov (United States)

    Park, Chan Woo; Kim, Bo Hyun; Yang, Hee-Man; Seo, Bum-Kyoung; Moon, Jei-Kwon; Lee, Kune-Woo

    2017-02-01

    We propose a new approach to remediate cesium-contaminated clays based on intercalation of the cationic surfactant dodecyltrimethylammonium bromide (DTAB) into clay interlayers. Intercalation of DTAB was found to occur very rapidly and involved exchanging interlayer cations. The reaction yielded efficient cesium desorption (∼97%), including of a large amount of otherwise non-desorbable cesium ions by cation exchange with ammonium ions. In addition, the intercalation of DTAB afforded an expansion of the interlayers, and an enhanced desorption of Cs by cation exchange with ammonium ions even at low concentrations of DTAB. Finally, the residual intercalated surfactants were easily removed by a decomposition reaction with hydrogen peroxide in the presence of Cu 2+ /Fe 2+ catalysts. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Chemical bonding and structural ordering of cations in silicate glasses

    International Nuclear Information System (INIS)

    Calas, G.; Cormier, L.; Galoisy, L.; Ramos, A.; Rossano, St.

    1997-01-01

    The specific surrounding of cations in multicomponent silicate glasses is briefly presented. Information about interatomic distances and site geometry may be gained by using spectroscopic methods among which x-ray absorption spectroscopy may be used for the largest number of glass components. Scattering of x-rays and neutrons may also be used to determine the importance of medium range order around specific cations. All the existing data show that cations occur in sites with a well-defined geometry, which are in most cases connected to the silicate polymeric network. Medium range order has been detected around cations such as Ti, Ca and Ni, indicating that these elements have an heterogeneous distribution within the glassy matrix. (authors)

  15. Significant role of cationic polymers in drug delivery systems.

    Science.gov (United States)

    Farshbaf, Masoud; Davaran, Soodabeh; Zarebkohan, Amir; Annabi, Nasim; Akbarzadeh, Abolfazl; Salehi, Roya

    2017-11-06

    Cationic polymers are characterized as the macromolecules that possess positive charges, which can be either inherently in the polymer side chains and/or its backbone. Based on their origins, cationic polymers are divided in two category including natural and synthetic, in which the possessed positive charges are as result of primary, secondary or tertiary amine functional groups that could be protonated in particular situations. Cationic polymers have been employed commonly as drug delivery agents due to their superior encapsulation efficacy, enhanced bioavailability, low toxicity and improved release profile. In this paper, we focus on the most prominent examples of cationic polymers which have been revealed to be applicable in drug delivery systems and we also discuss their general synthesis and surface modification methods as well as their controlled release profile in drug delivery.

  16. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT: EXEL INDUSTRIAL AIRMIX SPRAY GUN

    Science.gov (United States)

    The Environmental Technology Verification Program has partnered with Concurrent Technologies Corp. to verify innovative coatings and coating equipment technologies for reducing air emissions. This report describes the performance of EXEL Industrial's Kremlin Airmix high transfer ...

  17. Protective effect of divalent cations against aluminum toxicity in soybean

    OpenAIRE

    Silva,Ivo Ribeiro da; Corrêa,Tarcísio Fernando Côrtes; Novais,Roberto Ferreira; Gebrim,Fabrício de Oliveira; Nunes,Flancer Novais; Silva,Eulene Francisco da; Smyth,Thomas Jot

    2008-01-01

    A large proportion of soybean fields in Brazil are currently cultivated in the Cerrado region, where the area planted with this crop is growing considerably every year. Soybean cultivation in acid soils is also increasing worldwide. Since the levels of toxic aluminum (Al) in these acid soils is usually high it is important to understand how cations can reduce Al rhizotoxicity in soybean. In the present study we evaluated the ameliorative effect of nine divalent cations (Ca, Mg, Mn, Sr, Sn, Cu...

  18. Isomerizations of the Nitromethane Radical Cation in the Gas Phase

    DEFF Research Database (Denmark)

    Egsgaard, Helge; Carlsen, Lars; Elbel, Susanne

    1986-01-01

    The concurrent isomerizations of the nitromethane radical cation to its aci-nitromethane and methylnitrite isomers, respectively, has been established based on metastable ion studies and collision activation mass spectrometry. The energy diagram for the ionized nitromethane/aci-nitromethane tauto......The concurrent isomerizations of the nitromethane radical cation to its aci-nitromethane and methylnitrite isomers, respectively, has been established based on metastable ion studies and collision activation mass spectrometry. The energy diagram for the ionized nitromethane...

  19. Bithiophene radical cation: Resonance Raman spectroscopy and molecular orbital calculations

    DEFF Research Database (Denmark)

    Grage, M.M.-L.; Keszthelyi, T.; Offersgaard, J.F.

    1998-01-01

    The resonance Raman spectrum of the photogenerated radical cation of bithiophene is reported. The bithiophene radical cation was produced via a photoinduced electron transfer reaction between excited bithiophene and the electron acceptor fumaronitrile in a room temperature acetonitrile solution...... and the Raman spectrum excited in resonance with the absorption band at 425 nm. The spectrum was interpreted with the help of density functional theory calculations. (C) 1998 Elsevier Science B.V....

  20. Mercury release from deforested soils triggered by base cation enrichment

    International Nuclear Information System (INIS)

    Farella, N.; Lucotte, M.; Davidson, R.; Daigle, S.

    2006-01-01

    The Brazilian Amazon has experienced considerable colonization in the last few decades. Family agriculture based on slash-and-burn enables millions of people to live in that region. However, the poor nutrient content of most Amazonian soils requires cation-rich ashes from the burning of the vegetation biomass for cultivation to be successful, which leads to forest ecosystem degradation, soil erosion and mercury contamination. While recent studies have suggested that mercury present in soils was transferred towards rivers upon deforestation, little is known about the dynamics between agricultural land-use and mercury leaching. In this context, the present study proposes an explanation that illustrates how agricultural land-use triggers mercury loss from soils. This explanation lies in the competition between base cations and mercury in soils which are characterized by a low adsorption capacity. Since these soils are naturally very poor in base cations, the burning of the forest biomass suddenly brings high quantities of base cations to soils, destabilizing the previous equilibrium amongst cations. Base cation enrichment triggers mobility in soil cations, rapidly dislocating mercury atoms. This conclusion comes from principal component analyses illustrating that agricultural land-use was associated with base cation enrichment and mercury depletion. The overall conclusions highlight a pernicious cycle: while soil nutrient enrichment actually occurs through biomass burning, although on a temporary basis, there is a loss in Hg content, which is leached to rivers, entering the aquatic chain, and posing a potential health threat to local populations. Data presented here reflects three decades of deforestation activities, but little is known about the long-term impact of such a disequilibrium. These findings may have repercussions on our understanding of the complex dynamics of deforestation and agriculture worldwide

  1. Structure and performance of cationic assembly dispersed in amphoteric surfactants solution as a shampoo for hair damaged by coloring.

    Science.gov (United States)

    Nagahara, Yasuo; Nishida, Yuichi; Isoda, Masanori; Yamagata, Yoshifumi; Nishikawa, Naoki; Takada, Koji

    2007-01-01

    In recent years, hair coloring gains popularity as a trend of consumer's hair care. This coloring frequently damages hair. In response to this, a new shampoo-base was developed for repairing hair damaged by coloring. The new shampoo-base was prepared by dispersing cationic assembly in a solution of amphoteric surfactants. The mixture of behenyl trimethyl ammonium chloride (C22TAC) and behenyl alcohol (C22OH) was applied as the cationic assembly, which are dispersed in amido propyl betaine laurate (LPB) solution. LPB, which behaves as an amphoteric surfactant, was used as the wash-base. It was verified from the results on the measurements of DSC, calorimeter polarization, cryo-SEM and X-ray diffraction that the cationic assembly has a crystalline structure in the LPB solution. The new shampoo-base was highly efficient to change the color-damaged hair from hydrophilic to hydrophobic. The friction level of the hair washed with the new shampoo-base recovered to the same state as that of healthy hair. The exfoliation of cuticle was reduced after washing with the new shampoo-base.

  2. Characterization of gadolinia-doped ceria with manganese addition synthesized by the cation complexation technique; Caracterizacao de ceria-gadolinia e ceria-gadolinia-manganes sintetizados pelo metodo de complexacao de cations

    Energy Technology Data Exchange (ETDEWEB)

    Yang, J.D.; Muccillo, R.; Muccillo, E.N.S., E-mail: enavarro@usp.b [Instituto de Pesquisas Energeticas e Nucleares (CCTM/IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Ciencia e Tecnologia de Materiais; Rocha, R.A. [Universidade Federal do ABC (CEMCSA/UFABC), Santo Andre, SP (Brazil). Centro de Engenharia, Modelagem e Ciencias Sociais Aplicadas

    2010-07-01

    Ceria-based compounds may be used for several technological applications like catalysts, grinding media and materials for electrolyte and electrodes in solid oxide fuel cells. For most of these applications fine powders are required. In this work, nanostructured ceria powders containing 20 mol % gadolinia with and without manganese addition were synthesized by the cation complexation technique. The prepared powders were calcined at 600 deg C for thermal decomposition of the metal citrate precursors. Results of X-ray diffraction, scanning electron microscopy and specific surface area evidenced the role of manganese on physical characteristics of the nanostructured materials. The cation complexation technique revealed to be a promising method for obtaining nanostructured powders with high yield and suitable physical properties for several technological applications. (author)

  3. Sorption phenomena of modification of clinoptilolite tuffs by surfactant cations.

    Science.gov (United States)

    Rozić, M; Ivanec Sipusić, D; Sekovanić, L; Miljanić, S; Curković, L; Hrenović, J

    2009-03-15

    The sorption of cationic surfactant hexadecyltrimethylammonium (HDTMA) onto the solid/liquid interfaces of different clinoptilolite rich tuffs (CT) is examined. Examined were CT from Serbia with 75% clinoptilolite, CT from Turkey with 70% clinoptilolite, and CT from Croatia with 60% clinoptilolite. The sorption of HDTMA cations increased in the following order: CT from Serbia>CT from Turkey>CT from Croatia. The maximum amounts of sorbed HDTMA cations, normalized with regard to external cation exchange capacities of tuffs, were 1.79, 1.70, and 1.14 for Serbian, Turkish, and Croatian CT. FTIR analysis of samples with the maximum amount of sorbed HDTMA cations showed that HDTMA chains on Serbian CT adopt mainly a stretched all-trans conformation, while at the surfaces of CT from Turkey and Croatia the amount of gauche conformations increased. The zeta potentials of CT samples with the maximum amount of sorbed HDTMA cations and the sorption of benzoate anions on these samples increased in the following order: CT from Turkey>CT from Serbia>CT from Croatia. It can be assumed that on the surface of CT from Turkey iron (hydr)oxide clusters or nanoparticles with positive surface sites are present, due to which the isoelectric point is sifted toward lower and the zeta potential toward higher values. Therefore, the sorption of benzoate anions on modified CT from Turkey is also higher.

  4. On the mobility of exchangeable cations on clay surfaces

    International Nuclear Information System (INIS)

    Gimmi, T.; Kosakowski, G.; Glaus, M.A.

    2010-01-01

    Document available in extended abstract form only. The diffusive mobility of radionuclides in buffer materials and potential host rocks is an important topic in the safety analysis for underground waste repositories. Many of the radionuclides are cations. Accordingly, the diffusion and retention of cations in compacted clay minerals and clay rocks is of central interest. The retention properties of the clay minerals originate from their negative surface charges. These are compensated by un-specifically sorbed cations that are located on planar surfaces or in interlayers (exchangeable cations) and by cations that are more specifically sorbed for instance to edge sites. In general, sorbed cations are considered as immobile with respect to diffusive transport. Whereas this may be correct for specifically sorbed cations, this is probably not the case for un-specifically sorbed exchangeable cations. They can easily exchange with cations in the pore solution, even if they are located- at low hydration states-in very narrow interlayers. For such exchange a certain mobility in the sorbed state is required. This is in line with the observations that many experimentally derived cation diffusion coefficients are larger than expected when compared with those of water tracers. This and the dependence of effective diffusion coefficients on the external salt concentration can be explained with so-called surface diffusion, that is, a movement of sorbed cations. Unfortunately, no direct proof of this phenomenon is available, and parameters like surface diffusion coefficients or surface mobilities are largely unknown. We compiled a large number of published cation diffusion coefficients for various clay minerals and clay rocks. We showed that by an appropriate scaling of the cation diffusion coefficients, it is possible to estimate the average surface mobility of the cation in each experiment. We define the surface mobility as the surface diffusion coefficient of a cation on a flat

  5. Tunable states of interlayer cations in two-dimensional materials

    Energy Technology Data Exchange (ETDEWEB)

    Sato, K.; Numata, K. [Department of Environmental Sciences, Tokyo Gakugei University, Koganei, Tokyo 184-8501 (Japan); Dai, W. [Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), College of Chemistry, Nankai University, Tianjin 300071 (China); Hunger, M. [Institute of Chemical Technology, University of Stuttgart, 70550 Stuttgart (Germany)

    2014-03-31

    The local state of cations inside the Ångstrom-scale interlayer spaces is one of the controlling factors for designing sophisticated two-dimensional (2D) materials consisting of 2D nanosheets. In the present work, the molecular mechanism on how the interlayer cation states are induced by the local structures of the 2D nanosheets is highlighted. For this purpose, the local states of Na cations in inorganic 2D materials, in which the compositional fluctuations of a few percent are introduced in the tetrahedral and octahedral units of the 2D nanosheets, were systematically studied by means of {sup 23}Na magic-angle-spinning (MAS) nuclear magnetic resonance (NMR) and {sup 23}Na multiple-quantum MAS (MQMAS) NMR spectroscopy. In contrast with an uniform distribution of Na cations expected so far, various well-defined cation states sensitive to the local structures of the 2D nanosheets were identified. The tunability of the interlayer cation states along with the local structure of the 2D nanosheets, as the smallest structural unit of the 2D material, is discussed.

  6. Novel Reactivity Of The Cationic Complex

    International Nuclear Information System (INIS)

    Wang, J.; Dash, A.K.; Eisen, AM.; Berthet, J.C.; Ephritikhine, M.

    2002-01-01

    The catalytic chemistry of electrophilic d 0 /f organometallic complexes is nowadays under intense investigation, reaching a high level of sophistication. General aspects concerning these complexes are concentrated for most studies to the functionalization of unsaturated organic molecules. To cite an instance, the actinide-promoted oligomerization of terminal alkynes is of essential present concern since it may introduce to a diversity of organic enynes and oligoacetylene products that are valuable synthons for the synthesis of natural products. Enynes are the simplest oligomerization products of alkynes. We have demonstrated that organoactinides complexes of the type [Cp* 2 AnMe 2 AnMe 2 ] (Cp* = C 5 Me 5 ; An = U, Th) are active catalysts for the linear oligomerization of terminal alkynes and the extent of oligomerization was found to be strongly dependent on the electronic and steric properties of the alkyne substituents. Bulky alkynes were reacted with high regioselectivity toward dimer and/or trimers whereas for non-bulky alkynes, these compounds were transformed into oligomers with a total deficiency of regioselectivity. The addition of primary amines to the catalytic cycle, for An = Th, granted the chemoselective formation of dimers, chemoselectively, whereas for An = U, this control was not succeeded. In distinction to the neutral organoactinide complexes, homogeneous cationic d 0 /f n actinide complexes have been used as in the homogeneous polymerization of olefins as extremely active catalysts. Hence, the catalytic alkyne oligomerization is a opportune route to explore insertions and σ-bond metathesis reactivity of complexes. We have recently shown that the reaction of terminal alkynes (RC≡CH), promoted by [(Et 2 N) 3 U][BPh 4 ], in toluene, produces efficiently mostly the gem dimers (for R = Me, i Pr and n Bu) as the major products, whereas for bulky alkynes (R = t MS or t Bu) small amounts of the cis dimer was concomitantly obtained. A plausible

  7. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT - BAGHOUSE FILTRATION PRODUCTS - TETRATEC PTFE TECHNOLOGIES TETRATEX 8005

    Science.gov (United States)

    Baghouse filtration products (BFPs) were evaluated by the Air Pollution Control Technology (APCT) pilot of the Environmental Technology Verification (ETV) Program. The performance factor verified was the mean outlet particle concentration for the filter fabric as a function of th...

  8. Trends in the incidence rate, type and treatment of surgically verified endometriosis - a nationwide cohort study.

    Science.gov (United States)

    Saavalainen, Liisu; Tikka, Tuulia; But, Anna; Gissler, Mika; Haukka, Jari; Tiitinen, Aila; Härkki, Päivi; Heikinheimo, Oskari

    2018-01-01

    To study the trends in incidence rate, type and surgical treatment, and patient characteristics of surgically verified endometriosis during 1987-2012. This is a register-based cohort study. We identified women receiving their first diagnosis of endometriosis in surgery from the Finnish Hospital Discharge Register (FHDR). Quality of the FHDR records was assessed bidirectionally. The age-standardized incidence rates of the first surgically verified endometriosis was assessed by calendar year. The cohort comprises 49 956 women. The quality assessment suggested the FHDR data to be of good quality. The most common diagnosis, ovarian endometriosis (46%), was associated with highest median age 38.5 years (interquartile range 31.0-44.8) and the second most common diagnosis, peritoneal endometriosis (40%), with median age 34.9 years (28.6-41.7). Between 1987 and 2012, a decrease was observed in the median age, from 38.8 (32.3-43.6) to 34.0 (28.9-41.0) years, and in the age-standardized incidence rate from 116 [95% confidence interval (CI) 112-121] to 45 (42-48) per 100 000 women. The proportion of hysterectomy as a first surgical treatment decreased from 38 to 19%, whereas that of laparoscopy increased from 42 to 73% when comparing 1987-1995 with 1996-2012. This nationwide cohort of surgically verified endometriosis showed a decrease in the incidence rate and in the patient age at the time of first diagnosis, even though the proportion of laparoscopy has increased. The number of hysterectomies has decreased. These changes are likely to reflect the evolving diagnostics, increasing awareness of endometriosis, and effective use of medical treatment before surgery. © 2017 Nordic Federation of Societies of Obstetrics and Gynecology.

  9. Using NicAlert strips to verify smoking status among pregnant cigarette smokers.

    Science.gov (United States)

    Gaalema, Diann E; Higgins, Stephen T; Bradstreet, Matthew P; Heil, Sarah H; Bernstein, Ira M

    2011-12-01

    Decreasing smoking during pregnancy is an important public health priority. An important step towards decreasing smoking during pregnancy is wider dissemination of evidence-based smoking cessation interventions. One such intervention is contingency management wherein mothers earn vouchers exchangeable for retail items contingent on biochemically verified smoking abstinence. Wider dissemination may be possible by using smoking verification methods that require minimal training and equipment. One possibility is to use a cotinine-sensitive dipstick (NicAlert) rather than a bench-top cotinine analyzer, which is expensive and requires relatively extensive technician expertise, or breath carbon monoxide analysis, which is relatively nonspecific. The present study was conducted to begin examining the utility of cotinine-sensitive dipsticks for this purpose. Fifty urine samples from pregnant women enrolled in a smoking cessation program were analyzed to compare three different methods for verifying smoking status: NicAlert strips, a bench-top enzyme multiplied immunoassay technique (EMIT) analyzer, and gas chromatography (GC), the current gold standard for determining cotinine levels in urine. Agreement between GC and NicAlert results were high (96%) and comparable to agreement between GC and EMIT results (94%). Semi-quantitative measurements using NicAlert were low with only 30% of samples in agreement between GC and specific ranges given on the strips. NicAlert strips appear to be a valid measure of determining smoking status among pregnant smokers although not of absolute cotinine concentration. With minimal training and equipment required, NicAlert strips provide a potentially practical method for using urine cotinine to verify smoking status in community treatment settings. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  10. Verified reduction of dimensionality for an all-vanadium redox flow battery model

    Science.gov (United States)

    Sharma, A. K.; Ling, C. Y.; Birgersson, E.; Vynnycky, M.; Han, M.

    2015-04-01

    The computational cost for all-vanadium redox flow batteries (VRFB) models that seek to capture the transport phenomena usually increases with the number of spatial dimensions considered. In this context, we carry out scale analysis to derive a reduced zero-dimensional model. Two nondimensional numbers and their limits to support the model reduction are identified. We verify the reduced model by comparing its charge-discharge curve predictions with that of a full two-dimensional model. The proposed analysis leading to reduction in dimensionality is generic and can be employed for other types of redox flow batteries.

  11. Verifying the competition between haloperidol and biperiden in serum albumin through a model based on spectrofluorimetry

    Science.gov (United States)

    Muniz da Silva Fragoso, Viviane; Patrícia de Morais e Coura, Carla; Paulino, Erica Tex; Valdez, Ethel Celene Narvaez; Silva, Dilson; Cortez, Celia Martins

    2017-11-01

    The aim of this work was to apply mathematical-computational modeling to study the interactions of haloperidol (HLP) and biperiden (BPD) with human (HSA) and bovine (BSA) serum albumin in order to verify the competition of these drugs for binding sites in HSA, using intrinsic tryptophan fluorescence quenching data. The association constants estimated for HPD-HSA was 2.17(±0.05) × 107 M-1, BPD-HSA was 2.01(±0.03) × 108 M-1 at 37 °C. Results have shown that drugs do not compete for the same binding sites in albumin.

  12. Geant4 based Monte Carlo simulation for verifying the modified sum-peak method.

    Science.gov (United States)

    Aso, Tsukasa; Ogata, Yoshimune; Makino, Ryuta

    2018-04-01

    The modified sum-peak method can practically estimate radioactivity by using solely the peak and the sum peak count rate. In order to efficiently verify the method in various experimental conditions, a Geant4 based Monte Carlo simulation for a high-purity germanium detector system was applied. The energy spectra in the detector were simulated for a 60 Co point source in various source to detector distances. The calculated radioactivity shows good agreement with the number of decays in the simulation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. On the safe use of verify-and-record systems in external beam radiation therapy

    International Nuclear Information System (INIS)

    Seelantag, W.W.; Davis, J.B.

    1997-01-01

    Verify-and-record (V and R) systems are being used increasingly, not only for verification, but also for computer aided setup and chart printing. The close intercorrelation between V and R system and treatment routine requires new ideas for quality assurance (QA): pure ''machine checking'' as with treatment units is not sufficient anymore. The level of QA obviously depends on the tasks of the V and R system: the most advanced case of the system being used for computer aided setup and for chart printing is discussed -both are indispensable for an efficient use of V and R systems. Seven propositions are defined to make this not only efficient but safe. (author)

  14. RETRANS - A tool to verify the functional equivalence of automatically generated source code with its specification

    International Nuclear Information System (INIS)

    Miedl, H.

    1998-01-01

    Following the competent technical standards (e.g. IEC 880) it is necessary to verify each step in the development process of safety critical software. This holds also for the verification of automatically generated source code. To avoid human errors during this verification step and to limit the cost effort a tool should be used which is developed independently from the development of the code generator. For this purpose ISTec has developed the tool RETRANS which demonstrates the functional equivalence of automatically generated source code with its underlying specification. (author)

  15. Effect of glucocorticosteroid injections in tennis elbow verified on colour Doppler ultrasonography: evidence of inflammation

    DEFF Research Database (Denmark)

    Torp-Pedersen, T.E.; Torp-Pedersen, S.T.; Qvistgaard, E.

    2008-01-01

    -guided corticosteroid injection in patients with LE. DESIGN: Case-only, blinded intervention study. SETTING: Secondary care at a government hospital. PATIENTS: 62 patients with LE verified by colour Doppler US. INTERVENTION: One US-guided corticosteroid injection was given into the CEO. MAIN OUTCOME MEASURES: Patients...... fraction, Likert pain score, pain at rest, pain during activity, age, height, weight, disease in dominant versus nondominant arm. RESULTS: All but one patient experienced improvement of general elbow pain perception at follow-up at 2 weeks. In parallel, Doppler US showed significant reduction in colour...

  16. Force10 networks performance in world's first transcontinental 10 gigabit ethernet network verified by Ixia

    CERN Multimedia

    2003-01-01

    Force10 Networks, Inc., today announced that the performance of the Force10 E-Series switch/routers deployed in a transcontinental network has been verified as line-rate 10 GE throughput by Ixia, a leading provider of high-speed, network performance and conformance analysis systems. The network, the world's first transcontinental 10 GE wide area network, consists of a SURFnet OC-192 lambda between Geneva and the StarLight facility in Chicago via Amsterdam and another OC-192 lambda between this same facility in Chicago and Carleton University in Ottawa, Canada provided by CANARIE and ORANO (1/2 page).

  17. Cation Exchange in the Presence of Oil in Porous Media.

    Science.gov (United States)

    Farajzadeh, R; Guo, H; van Winden, J; Bruining, J

    2017-04-20

    Cation exchange is an interfacial process during which cations on a clay surface are replaced by other cations. This study investigates the effect of oil type and composition on cation exchange on rock surfaces, relevant for a variety of oil-recovery processes. We perform experiments in which brine with a different composition than that of the in situ brine is injected into cores with and without remaining oil saturation. The cation-exchange capacity (CEC) of the rocks was calculated using PHREEQC software (coupled to a multipurpose transport simulator) with the ionic composition of the effluent histories as input parameters. We observe that in the presence of crude oil, ion exchange is a kinetically controlled process and its rate depends on residence time of the oil in the pore, the temperature, and kinetic rate of adsorption of the polar groups on the rock surface. The cation-exchange process occurs in two stages during two phase flow in porous media. Initially, the charged sites of the internal surface of the clays establish a new equilibrium by exchanging cations with the aqueous phase. At later stages, the components of the aqueous and oleic phases compete for the charged sites on the external surface or edges of the clays. When there is sufficient time for crude oil to interact with the rock (i.e., when the core is aged with crude oil), a fraction of the charged sites are neutralized by the charged components stemming from crude oil. Moreover, the positively charged calcite and dolomite surfaces (at the prevailing pH environment of our experiments) are covered with the negatively charged components of the crude oil and therefore less mineral dissolution takes place when oil is present in porous media.

  18. Automatic data-processing equipment of moon mark of nail for verifying some experiential theory of Traditional Chinese Medicine.

    Science.gov (United States)

    Niu, Renjie; Fu, Chenyu; Xu, Zhiyong; Huang, Jianyuan

    2016-04-29

    Doctors who practice Traditional Chinese Medicine (TCM) diagnose using four methods - inspection, auscultation and olfaction, interrogation, and pulse feeling/palpation. The shape and shape changes of the moon marks on the nails are an important indication when judging the patient's health. There are a series of classical and experimental theories about moon marks in TCM, which does not have support from statistical data. To verify some experiential theories on moon mark in TCM by automatic data-processing equipment. This paper proposes the equipment that utilizes image processing technology to collect moon mark data of different target groups conveniently and quickly, building a database that combines this information with that gathered from the health and mental status questionnaire in each test. This equipment has a simple design, a low cost, and an optimized algorithm. The practice has been proven to quickly complete automatic acquisition and preservation of key data about moon marks. In the future, some conclusions will likely be obtained from these data; some changes of moon marks related to a special pathological change will be established with statistical methods.

  19. Characterization of an extrapolation chamber and radiochromic films for verifying the metrological coherence among beta radiation fields

    International Nuclear Information System (INIS)

    Castillo, Jhonny Antonio Benavente

    2011-01-01

    The metrological coherence among standard systems is a requirement for assuring the reliability of dosimetric quantities measurements in ionizing radiation field. Scientific and technologic improvements happened in beta radiation metrology with the installment of the new beta secondary standard BSS2 in Brazil and with the adoption of the internationally recommended beta reference radiations. The Dosimeter Calibration Laboratory of the Development Center for Nuclear Technology (LCD/CDTN), in Belo Horizonte, implemented the BSS2 and methodologies are investigated for characterizing the beta radiation fields by determining the field homogeneity, the accuracy and uncertainties in the absorbed dose in air measurements. In this work, a methodology to be used for verifying the metrological coherence among beta radiation fields in standard systems was investigated; an extrapolation chamber and radiochromic films were used and measurements were done in terms of absorbed dose in air. The reliability of both the extrapolation chamber and the radiochromic film was confirmed and their calibrations were done in the LCD/CDTN in 90 Sr/ 90 Y, 85 Kr and 147 Pm beta radiation fields. The angular coefficients of the extrapolation curves were determined with the chamber; the field mapping and homogeneity were obtained from dose profiles and isodose with the radiochromic films. A preliminary comparison between the LCD/CDTN and the Instrument Calibration Laboratory of the Nuclear and Energy Research Institute / Sao Paulo (LCI/IPEN) was carried out. Results with the extrapolation chamber measurements showed in terms of absorbed dose in air rates showed differences between both laboratories up to de -I % e 3%, for 90 Sr/ 90 Y, 85 Kr and 147 Pm beta radiation fields, respectively. Results with the EBT radiochromic films for 0.1, 0.3 and 0.15 Gy absorbed dose in air, for the same beta radiation fields, showed differences up to 3%, -9% and -53%. The beta radiation field mappings with

  20. Development of an integrated reporting system for verifying hemolysis, icterus, and lipemia in clinical chemistry results.

    Science.gov (United States)

    Shin, Dong Hoon; Kim, Juwon; Uh, Young; Lee, Se Il; Seo, Dong Min; Kim, Kab Seung; Jang, Jae Yun; Lee, Man Hee; Yoon, Kwang Ro; Yoon, Kap Jun

    2014-07-01

    Hemolysis, icterus, and lipemia (HIL) cause preanalytical interference and vary unpredictably with different analytical equipments and measurement methods. We developed an integrated reporting system for verifying HIL status in order to identify the extent of interference by HIL on clinical chemistry results. HIL interference data from 30 chemical analytes were provided by the manufacturers and were used to generate a table of clinically relevant interference values that indicated the extent of bias at specific index values (alert index values). The HIL results generated by the Vista 1500 system (Siemens Healthcare Diagnostics, USA), Advia 2400 system (Siemens Healthcare Diagnostics), and Modular DPE system (Roche Diagnostics, Switzerland) were analyzed and displayed on physicians' personal computers. Analytes 11 and 29 among the 30 chemical analytes were affected by interference due to hemolysis, when measured using the Vista and Modular systems, respectively. The hemolysis alert indices for the Vista and Modular systems were 0.1-25.8% and 0.1-64.7%, respectively. The alert indices for icterus and lipemia were integrated HIL reporting system provides an effective screening tool for verifying specimen quality with regard to HIL and simplifies the laboratory workflow.

  1. An improved system to verify CANDU spent fuel elements in dry storage silos

    International Nuclear Information System (INIS)

    Almeida, Gevaldo L. de; Soares, Milton G.; Filho, Anizio M.; Martorelli, Daniel S.; Fonseca, Manoel

    2000-01-01

    An improved system to verify CANDU spent fuel elements stored in dry storage silos was developed. It is constituted by a mechanical device which moves a semi-conductor detector along a vertical verification pipe incorporated to the silo, and a modified portable multi-channel analyzer. The mechanical device contains a winding drum accommodating a cable hanging the detector, in such a way that the drum rotates as the detector goes down due to its own weight. The detector is coupled to the multi-channel analyzer operating in the multi-scaler mode, generating therefore a spectrum of total counts against time. To assure a linear transformation of time into detector position, the mechanical device dictating the detector speed is controlled by the multi-channel analyzer. This control is performed via a clock type escapement device activated by a solenoid. Whenever the multi-channel analyzer shifts to the next channel, the associated pulse is amplified, powering the solenoid causing the drum to rotate a fixed angle. Spectra taken in laboratory, using radioactive sources, have shown a good reproducibility. This qualify the system to be used as an equipment to get a fingerprint of the overall distribution of the fuel elements along the silo axis, and hence, to verify possible diversion of the nuclear material by comparing spectra taken at consecutive safeguards inspections. All the system is battery operated, being thus capable to operate in the field where no power supply is available. (author)

  2. Study and survey of assembling parameters to a radioactive source production laboratory used to verify equipment

    International Nuclear Information System (INIS)

    Gauglitz, Erica

    2010-01-01

    This paper presents a survey of parameters for the proper and safe flooring, doors, windows, fume hoods and others, in a radiochemical laboratory. The layout of each item follows guidelines and national standards of the National Commission of Nuclear Energy (CNEN) and the International Atomic Energy Agency (IAEA), aiming to ensure the radiological protection of workers and environment. The adequate items arrangement in the radiochemical laboratory ensures quality and safety in the production of 57 Co 137 Cs and 133 Ba radioactive sealed sources, with activities 185, 9.3 and 5.4 MBq, respectively. These sources are used to verify meter activity equipment and should be available throughout the Nuclear Medicine Center, following the recommendations of CNEN-NN-3.05 standard R equirements for Radiation Protection and Safety Services for Nuclear Medicine , to verify the activity of radiopharmaceuticals that are administered in patients, for diagnosis and therapy. Verification of measuring activity equipment will be used to perform accuracy, reproducibility and linearity tests, which should show results within the limits specified in the standard CNEN-NN-3.05. (author)

  3. Using Integer Clocks to Verify the Timing-Sync Sensor Network Protocol

    Science.gov (United States)

    Huang, Xiaowan; Singh, Anu; Smolka, Scott A.

    2010-01-01

    We use the UPPAAL model checker for Timed Automata to verify the Timing-Sync time-synchronization protocol for sensor networks (TPSN). The TPSN protocol seeks to provide network-wide synchronization of the distributed clocks in a sensor network. Clock-synchronization algorithms for sensor networks such as TPSN must be able to perform arithmetic on clock values to calculate clock drift and network propagation delays. They must be able to read the value of a local clock and assign it to another local clock. Such operations are not directly supported by the theory of Timed Automata. To overcome this formal-modeling obstacle, we augment the UPPAAL specification language with the integer clock derived type. Integer clocks, which are essentially integer variables that are periodically incremented by a global pulse generator, greatly facilitate the encoding of the operations required to synchronize clocks as in the TPSN protocol. With this integer-clock-based model of TPSN in hand, we use UPPAAL to verify that the protocol achieves network-wide time synchronization and is devoid of deadlock. We also use the UPPAAL Tracer tool to illustrate how integer clocks can be used to capture clock drift and resynchronization during protocol execution

  4. Periodontal Disease and its Association with Angiographically Verified Coronary Artery Disease.

    Science.gov (United States)

    Vražić, Domagoj; Miovski, Zoran; Strozzi, Maja; Puhar, Ivan; Badovinac, Ana; Božić, Darko; Plančak, Darije

    2015-03-01

    The aim of this research was to investigate the association of chronic and aggressive periodontitis with the severity of coronary artery disease which was angiographically verified. Subjects were selected among the hospitalized patients at the University Hospital Centre Zagreb who had coronary angiography done because of the chest pain. Thorough clinical examination included periodontal indices and clinical and socio-demographic characteristics of participants. Subjects were divided in two test groups, acute coronary syndrome (ACS) and stable coronary artery disease (CAD), and the control group with no significant CAD. Data were analyzed using Kruskal-Wallis and Pearson's Chi-Square test. From 106 subjects, 66 (62.3%) were hospitalized for ACS, 22 (20.7%) had stable CAD and only 18 (17.0%) had no significant CAD. Only 26 (24.5%) out of 106 patients were never smokers (pperiodontitis was the most common finding with 68.2% in ACS group and 54.5% in stable CAD group, while healthy patients without periodontitis (72.6%) were dominant in the control group (pPeriodontitis was shown to be associated with angiographically verified coronary artery disease. Physical inactivity, poor oral hygiene and periodontal inflammation were observed in patients with ACS and stable CAD.

  5. Insurance based lie detection: Enhancing the verifiability approach with a model statement component.

    Science.gov (United States)

    Harvey, Adam C; Vrij, Aldert; Leal, Sharon; Lafferty, Marcus; Nahari, Galit

    2017-03-01

    The Verifiability Approach (VA) is verbal lie detection tool that has shown promise when applied to insurance claims settings. This study examined the effectiveness of incorporating a Model Statement comprised of checkable information to the VA protocol for enhancing the verbal differences between liars and truth tellers. The study experimentally manipulated supplementing (or withholding) the VA with a Model Statement. It was hypothesised that such a manipulation would (i) encourage truth tellers to provide more verifiable details than liars and (ii) encourage liars to report more unverifiable details than truth tellers (compared to the no model statement control). As a result, it was hypothesized that (iii) the model statement would improve classificatory accuracy of the VA. Participants reported 40 genuine and 40 fabricated insurance claim statements, in which half the liars and truth tellers where provided with a model statement as part of the VA procedure, and half where provide no model statement. All three hypotheses were supported. In terms of accuracy, the model statement increased classificatory rates by the VA considerably from 65.0% to 90.0%. Providing interviewee's with a model statement prime consisting of checkable detail appears to be a useful refinement to the VA procedure. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Independent technique of verifying high-dose rate (HDR) brachytherapy treatment plans

    International Nuclear Information System (INIS)

    Saw, Cheng B.; Korb, Leroy J.; Darnell, Brenda; Krishna, K. V.; Ulewicz, Dennis

    1998-01-01

    Purpose: An independent technique for verifying high-dose rate (HDR) brachytherapy treatment plans has been formulated and validated clinically. Methods and Materials: In HDR brachytherapy, dwell times at respective dwell positions are computed, using an optimization algorithm in a HDR treatment-planning system to deliver a specified dose to many target points simultaneously. Because of the variability of dwell times, concerns have been expressed regarding the ability of the algorithm to compute the correct dose. To address this concern, a commercially available low-dose rate (LDR) algorithm was used to compute the doses at defined distances, based on the dwell times obtained from the HDR treatment plans. The percent deviation between doses computed using the HDR and LDR algorithms were reviewed for HDR procedures performed over the last year. Results: In this retrospective study, the difference between computed doses using the HDR and LDR algorithms was found to be within 5% for about 80% of the HDR procedures. All of the reviewed procedures have dose differences of less than 10%. Conclusion: An independent technique for verifying HDR brachytherapy treatment plans has been validated based on clinical data. Provided both systems are available, this technique is universal in its applications and not limited to either a particular implant applicator, implant site, or implant type

  7. THERMODYNAMICS OF ETHANOLAMMONIUM CATIONES DISSOCIATION IN AQUEOUS SOLUTIONS

    Directory of Open Access Journals (Sweden)

    R. E. Khoma

    2017-03-01

    Full Text Available The literature data on the thermodynamics of ethanolamines onium cations dissociation have been systematized and generalized. The correlation between these cations dissociation thermodynamic functions (DH and DS and physicochemical properties (Tmp., Tbp, Pp, lgPow et al. has been revealed. There was a correlation between lipophilicity determined experimentally and calculated by QSAR. For monoethanolammonium, diethanolammonium, and their N-methyl and N-ethyl derivatives it was found dissociation thermodynamic functions to depend on bases lgPow. Acid-base dissociation of TRIS and triethanolamine onium cations does not correspond to said relationship because TRIS (primary amine, TEA (tertiary amine act differently on aqueous solutions of SO2. TEA, unlike MEA, DEA and MMEA, has a salting out effect towards sulfur dioxide because of competing hydration that promotes sulfite «onium» salts hydrolysis. TRIS promotes S(IV → S(VI sulphooxidation, in contrast to another ethanolamines. Enthalpy–enthropy compensation with isothermodynamic temperature 303 K has been recorded. The revealed correlations may be useful in developing of procedures for air sanitary cleaning from acidic gases; chemisorbents immobilized for gas and ion exchange chromatography; potentiometric methods for fluorocomplex acids determinations. The use of monoethanolamine is most promising to obtain chemisorbents because the thermodynamic functions of its onium cation acid-base dissociation are least dependent on temperature compared to other etanolammonium cations.

  8. Comparison contemporary methods of regeneration sodium-cationic filters

    Science.gov (United States)

    Burakov, I. A.; Burakov, A. Y.; Nikitina, I. S.; Verkhovsky, A. E.; Ilyushin, A. S.; Aladushkin, S. V.

    2017-11-01

    Regeneration plays a crucial role in the field of efficient application sodium-cationic filters for softening the water. Traditionally used as regenerant saline NaCl. However, due to the modern development of the energy industry and its close relationship with other industrial and academic sectors the opportunity to use in the regeneration of other solutions. The report estimated data and application possibilities as regenerant solution sodium-cationic filters brine wells a high mineral content, as both primary application and after balneotherapeutic use reverse osmosis and concentrates especially recycled regenerant water repeated. Comparison of the effectiveness of these solutions with the traditional use of NaCl. Developed and tested system for the processing of highly mineralized brines wells after balneological use. Recommendations for use as regeneration solutions for the sodium-cationic unit considered solutions and defined rules of brine for regeneration costs.

  9. Cationization of Alpha-Cellulose to Develop New Sustainable Products

    Directory of Open Access Journals (Sweden)

    Ana Moral

    2015-01-01

    Full Text Available Papermaking has been using high quantities of retention agents, mainly cationic substances and organic compounds such as polyamines. The addition of these agents is related to economic and environmental issues, increasing contamination of the effluents. The aim of this work is to develop a cationic polymer for papermaking purposes based on the utilization of alpha-cellulose. The cationization of mercerized alpha-cellulose with 3-chloro-2-hydroxypropyltrimethylammonium chloride (CHPTAC is governed by a pseudo-second-order reaction. The initial amorphous fraction of cellulose is reacted with CHPTAC until the equilibrium value of nitrogen substitution is reached. Nitrogen is incorporated as a quaternary ammonium group in the polymer. Also, the kinetic constant increased with decreasing crystallinity index, showing the importance of the previous alkalization stage. The use of modified natural polysaccharides is a sustainable alternative to synthetic, nonbiodegradable polyelectrolytes and thus is desirable with a view to developing new products and new processes.

  10. Structure and Intramolecular Proton Transfer of Alanine Radical Cations

    International Nuclear Information System (INIS)

    Lee, Gab Yong

    2012-01-01

    The structures of the four lowest alanine conformers, along with their radical cations and the effect of ionization on the intramolecular proton transfer process, are studied using the density functional theory and MP2 method. The energy order of the radical cations of alanine differs from that of the corresponding neutral conformers due to changes in the basicity of the NH 2 group upon ionization. Ionization favors the intramolecular proton transfer process, leading to a proton-transferred radical-cation structure, [NH 3 + -CHCH 3 -COO·], which contrasts with the fact that a proton-transferred zwitterionic conformer is not stable for a neutral alanine in the gas phase. The energy barrier during the proton transfer process is calculated to be about 6 kcal/mol

  11. Nanoscale encapsulation: the structure of cations in hydrophobic microporous aluminosilicates

    International Nuclear Information System (INIS)

    Wasserman, S.R.; Yuchs, S.E.; Giaquinta, D.; Soderholm, L.; Song, Kang.

    1996-01-01

    Hydrophobic microporous aluminosilicates, created by organic surface modification of inherently hydrophilic materials such as zeolites and clays, are currently being investigated as storage media for hazardous cations. Use of organic monolayers to modify the surface of an aluminosilicate after introducing an ion into the zeolite/clay reduces the interaction of water with the material. Resulting systems are about 20 times more resistant to leaching of stored ion. XAS spectra from the encapsulated ion demonstrate that byproducts from the organic modifier can complex with the stored cation. This complexation can result in a decreased affinity of the cation for the aluminosilicate matrix. Changing the organic modifier eliminates this problem. XAS spectra also indicate that the reactivity and speciation of the encapsulated ion may change upon application of the hydrophobic layer

  12. Vibronic and cation spectroscopy of 2,4-difluoroaniline

    Science.gov (United States)

    Huang, Wei Chih; Huang, Po Sheng; Hu, Ching Han; Tzeng, Wen Bih

    We applied the two-color resonant two-photon ionization and mass-analyzed threshold ionization techniques to record the vibronic and cation spectra of 2,4-difluoroaniline. The cation spectra were recorded by ionizing via the 00, X1, 6b1, and 11 levels of the electronically excited S1 state. Most of the observed active modes of this molecule in the S1 and cationic ground D0 states are related to the in-plane ring deformation vibrations. The band origin of the S1 ← S0 electronic excitation was found to appear at 33 294 ± 2 cm-1, whereas the adiabatic ionization energy was determined to be 63 935 ± 5 cm-1. Comparing the data of 2,4-difluoroaniline with those of aniline, 2-fluoroaniline, and 4-fluoroaniline, one can learn the effects of fluorine substitution on the electronic transition and molecular vibration.

  13. Changing of Cations Concentrations in Waters of Polluted Urban River

    Directory of Open Access Journals (Sweden)

    Andrianova Maria

    2016-01-01

    Full Text Available Water from urban river Okhta polluted with domestic and industrial wastewaters was investigated. Specific electric conductivity (k, molar concentrations of ions Na+, K+, Mg++ and Ca++, concentration of total nitrogen (TN were measured in water samples. Increasing of k happened together with increasing of molar fraction of sodium-ion (RNa among all studied cations (and correspondingly decreasing of molar fractions of other cations. Good correlations were found between RNa and TN (r = 0.67, k and TN (r = 0.84. The results support the idea of the leading role of wastewaters in changing of k and cations concentrations. Electric conductivity and RNa could be used to distinguish between polluted and not polluted waters in the Okhta.

  14. Energies and physicochemical properties of cation-π interactions in biological structures.

    Science.gov (United States)

    Du, Qi-Shi; Meng, Jian-Zong; Liao, Si-Ming; Huang, Ri-Bo

    2012-04-01

    The cation-π interactions occur frequently within or between proteins due to six (Phe, Tyr, Trp, Arg, Lys, and His) of the twenty natural amino acids potentially interacting with metallic cations via these interactions. In this study, quantum chemical calculations and molecular orbital (MO) theory are used to study the energies and properties of cation-π interactions in biological structures. The cation-π interactions of H⁺ and Li⁺ are similar to hydrogen bonds and lithium bonds, respectively, in which the small, naked cations H⁺ and Li⁺ are buried deep within the π-electron density of aromatic molecules, forming stable cation-π bonds that are much stronger than the cation-π interactions of other alkali metal cations. The cation-π interactions of metallic cations with atomic masses greater than that of Li⁺ arise mainly from the coordinate bond comprising empty valence atomic orbitals (AOs) of metallic cations and π-MOs of aromatic molecules, though electrostatic interactions may also contribute to the cation-π interaction. The binding strength of cation-π interactions is determined by the charge and types of AOs in the metallic cations. Cation-π interaction energies are distance- and orientation-dependent; energies decrease with the distance (r) and the orientation angle (θ). In solution, the cation-π energies decrease with the increase of the dielectric constant (ɛ) of the solvent; however, solvation has less influence on the H⁺-π and H₃O⁺-π interactions than on interactions with other cations. The conclusions from this study provide useful theoretical insights into the nature of cation-π interactions and may contribute to the development of better force field parameters for describing the molecular dynamics of cation-π interactions within and between proteins. Copyright © 2011 Elsevier Inc. All rights reserved.

  15. Cationic mobility in polystyrene sulfone exchangers - Application to the elution of a cation on an exchange column

    International Nuclear Information System (INIS)

    Menin, Jean-Pierre

    1969-01-01

    The aim of this work is to improve elutions and separations carried out on inorganic exchangers by selective electromigration of the ionic species to be displaced. To do this, it has been found indispensable to make a fundamental study of the mobility of cations in exchangers. As the field for this research we have chosen those organic exchangers whose structure and behaviour with respect to ion-exchange are much better known that in the case of their inorganic equivalents. We have related the idea of the equivalent conductivity to that of the cation mobility in the exchanger, and this has entailed determining the specific conductivity of the exchanger and the cation concentration in the resin. The results obtained have allowed us to draw up a hypothesis concerning the cation migration mechanism in the exchanger. The third part of our work has been the application of the preceding results to an operation on an ion-exchange column, viz. the elution by an acid solution of a single fixed ion, magnesium or strontium. This work has enabled us to show that the electromigration of a cation during its elution can markedly accelerate or retard this elution. (author) [fr

  16. Effect of cation exchange of major cation chemistry in the large scale redox experiment at Aespoe. Revision 1

    International Nuclear Information System (INIS)

    Viani, B.E.; Bruton, C.J.

    1996-06-01

    Geochemical modeling was used to test the hypothesis that cation exchange with fracture-lining clays during fluid mixing in the Aespoe Hard Rock Laboratory can significantly affect major element chemistry. Conservative mixing models do not adequately account for changes in Na, Ca and Mg concentrations during mixing. Mixing between relatively dilute shallow waters and more concentrated waters at depth along fracture zones was modeled using the EQ3/6 geochemical modeling package. A cation exchange model was added to the code to describe simultaneously aqueous speciation, mineral precipitation/dissolution, and equilibration between a fluid and a cation exchanger. Fluid chemistries predicted to result from mixing were compared with those monitored from boreholes intersecting the fracture zone. Modeling results suggest that less than 0.1 equivalent of a smectite exchanger per liter of groundwater is necessary to account for discrepancies between predictions from a conservative mixing model and measured Na and Ca concentrations. This quantity of exchanger equates to an effective fracture coating thickness of 20 microm or less given a fracture aperture width of 1,000 microm or less. Trends in cation ratios in the fluid cannot be used to predict trends in cation ratios on the exchanger because of the influence of ionic strength on heterovalent exchange equilibrium. It is expected that Na for Ca exchange will dominate when shallow waters such as HBHO2 are mixed with deeper waters. In contrast, Na for Mg exchange will dominate mixing between deeper waters

  17. Model Checking Artificial Intelligence Based Planners: Even the Best Laid Plans Must Be Verified

    Science.gov (United States)

    Smith, Margaret H.; Holzmann, Gerard J.; Cucullu, Gordon C., III; Smith, Benjamin D.

    2005-01-01

    Automated planning systems (APS) are gaining acceptance for use on NASA missions as evidenced by APS flown On missions such as Orbiter and Deep Space 1 both of which were commanded by onboard planning systems. The planning system takes high level goals and expands them onboard into a detailed of action fiat the spacecraft executes. The system must be verified to ensure that the automatically generated plans achieve the goals as expected and do not generate actions that would harm the spacecraft or mission. These systems are typically tested using empirical methods. Formal methods, such as model checking, offer exhaustive or measurable test coverage which leads to much greater confidence in correctness. This paper describes a formal method based on the SPIN model checker. This method guarantees that possible plans meet certain desirable properties. We express the input model in Promela, the language of SPIN and express the properties of desirable plans formally.

  18. Error prevention in radiotherapy treatments using a record and verify system

    International Nuclear Information System (INIS)

    Navarrete Campos, S.; Hernandez Vitoria, A.; Canellas Anoz, M.; Millan Cebrian, E.; Garcia Romero, A.

    2001-01-01

    Computerized record-and-verify systems (RVS) are being used increasingly to improve the precision of radiotherapy treatments. With the introduction of new treatment devices, such as multileaf or asymmetric collimators and virtual wedges, the responsibility to ensure correct treatment has increased. The purpose of this paper is to present the method that we are following to prevent some potential radiotherapy errors and to point out some errors that can be easily detected using a RVS, through a check of the daily recorded treatment information. We conclude that a RVS prevents the occurrence of many errors, when the settings of the treatment machine do not match the intended parameters within some maximal authorized deviation, and allows to detect easily other potential errors related with a incorrect selection of the treatment patient data. A quality assurance program, including a check of all beam data and a weekly control of the manual and electronic chart, has helped reduce errors. (author)

  19. Verifying the error bound of numerical computation implemented in computer systems

    Science.gov (United States)

    Sawada, Jun

    2013-03-12

    A verification tool receives a finite precision definition for an approximation of an infinite precision numerical function implemented in a processor in the form of a polynomial of bounded functions. The verification tool receives a domain for verifying outputs of segments associated with the infinite precision numerical function. The verification tool splits the domain into at least two segments, wherein each segment is non-overlapping with any other segment and converts, for each segment, a polynomial of bounded functions for the segment to a simplified formula comprising a polynomial, an inequality, and a constant for a selected segment. The verification tool calculates upper bounds of the polynomial for the at least two segments, beginning with the selected segment and reports the segments that violate a bounding condition.

  20. Verifying the interactive convergence clock synchronization algorithm using the Boyer-Moore theorem prover

    Science.gov (United States)

    Young, William D.

    1992-01-01

    The application of formal methods to the analysis of computing systems promises to provide higher and higher levels of assurance as the sophistication of our tools and techniques increases. Improvements in tools and techniques come about as we pit the current state of the art against new and challenging problems. A promising area for the application of formal methods is in real-time and distributed computing. Some of the algorithms in this area are both subtle and important. In response to this challenge and as part of an ongoing attempt to verify an implementation of the Interactive Convergence Clock Synchronization Algorithm (ICCSA), we decided to undertake a proof of the correctness of the algorithm using the Boyer-Moore theorem prover. This paper describes our approach to proving the ICCSA using the Boyer-Moore prover.

  1. Development of measurement standards for verifying functional performance of surface texture measuring instruments

    Energy Technology Data Exchange (ETDEWEB)

    Fujii, A [Life and Industrial Product Development Department Olympus Corporation, 2951 Ishikawa-machi, Hachiouji-shi, Tokyo (Japan); Suzuki, H [Industrial Marketing and Planning Department Olympus Corporation, Shinjyuku Monolith, 3-1 Nishi-Shinjyuku 2-chome, Tokyo (Japan); Yanagi, K, E-mail: a_fujii@ot.olympus.co.jp [Department of Mechanical Engineering, Nagaoka University of Technology, 1603-1 Kamitomioka-machi, Nagaoka-shi, Niigata (Japan)

    2011-08-19

    A new measurement standard is proposed for verifying overall functional performance of surface texture measuring instruments. Its surface is composed of sinusoidal surface waveforms of chirp signals along horizontal cross sections of the material measure. One of the notable features is that the amplitude of each cycle in the chirp signal form is geometrically modulated so that the maximum slope is kept constant. The maximum slope of the chirp-like signal is gradually decreased according to movement in the lateral direction. We fabricated the measurement standard by FIB processing, and it was calibrated by AFM. We tried to evaluate the functional performance of Laser Scanning Microscope by this standard in terms of amplitude response with varying slope angles. As a result, it was concluded that the proposed standard can easily evaluate the performance of surface texture measuring instruments.

  2. Computed Tomography--Verified Leukoaraiosis Is a Risk Factor for Post-thrombolytic Hemorrhage

    DEFF Research Database (Denmark)

    Willer, Lasse; Havsteen, Inger; Ovesen, Christian

    2015-01-01

    BACKGROUND: Is computed tomography (CT)-verified leukoaraiosis (LA) a risk factor for post-thrombolytic hemorrhagic transformation and symptomatic hemorrhage? METHODS: (1) Retrospective analysis based on a prospectively planned single-center registry of consecutive tissue plasminogen activator (t......PA)-treated patients within 4.5 hours from symptom onset. Standard work-up included baseline noncontrast CT and CT angiography and next day follow-up noncontrast CT. Baseline noncontrast CT LA was graded using Fazekas' score and dichotomized as the absence (Fazekas, 0) or the presence (Fazekas, 1-3). Hemorrhagic...... transformation was rated using European Cooperative Acute Stroke Study (ECASS) criteria. Symptomatic intracerebral hemorrhage was defined as hemorrhage and deterioration of National Institutes of Health Stroke Scale (NIHSS) of 4 or greater within 36 hours from symptom onset. Endovascularly treated patients were...

  3. Methods to verify absorbed dose of irradiated containers and evaluation of dosimeters

    International Nuclear Information System (INIS)

    Gao Meixu; Wang Chuanyao; Tang Zhangxong; Li Shurong

    2001-01-01

    The research on dose distribution in irradiated food containers and evaluation of several methods to verify absorbed dose were carried out. The minimum absorbed dose of treated five orange containers was in the top of the highest or in the bottom of lowest container. D max /D min in this study was 1.45 irradiated in a commercial 60 Co facility. The density of orange containers was about 0.391g/cm 3 . The evaluation of dosimeters showed that the PMMA-YL and clear PMMA dosimeters have linear relationship with dose response, and the word NOT in STERIN-125 and STERIN-300 indicators were covered completely at the dosage of 125 and 300 Gy respectively. (author)

  4. Getting What We Paid for: a Script to Verify Full Access to E-Resources

    Directory of Open Access Journals (Sweden)

    Kristina M. Spurgin

    2014-07-01

    Full Text Available Libraries regularly pay for packages of e-resources containing hundreds to thousands of individual titles. Ideally, library patrons could access the full content of all titles in such packages. In reality, library staff and patrons inevitably stumble across inaccessible titles, but no library has the resources to manually verify full access to all titles, and basic URL checkers cannot check for access. This article describes the E-Resource Access Checker—a script that automates the verification of full access. With the Access Checker, library staff can identify all inaccessible titles in a package and bring these problems to content providers’ attention to ensure we get what we pay for.

  5. A numerical simulation to verify the stress-free growth of silicon crystal ribbon

    Science.gov (United States)

    Ray, Sujit K.; Utku, Senol; Wada, Ben K.

    1987-01-01

    Thermal stresses developed during the growth of silicon crystal ribbon have been shown to be negligible, thus eliminating residual stresses and dislocations, if the temperature profile satisfies a second-order partial differential equation inside the ribbon. This has been numerically verified through a finite element model, an outline of which is presented here. This model shows that, for homogeneous isotropic material with temperature independent thermal expansion coefficients, thermal stresses will vanish if the temperature profile satisfies the Laplacian. A comparison of stresses due to uniform and nonuniform temperature gradients in the plane of the ribbon is also presented. The strategies employed to control the round-off error and to validate the computer model are discussed.

  6. The influence of immediate complete anterior guidance development technique on subjective symptoms in Myofascial pain patients: Verified using digital analysis of occlusion (Tek-scan) for analysing occlusion: A 3 years clinical observation

    OpenAIRE

    Prafulla Thumati

    2015-01-01

    Objectives: The purpose of this study is to evaluate the effect of occlusal equilibration using immediate complete anterior guidance development (ICAGD) technique by Kerstein and Farrell on the subjective symptoms of myofascial pain. This technique is the most advanced verifiable and measurable way of digitally analyzing the occlusion using T-scan technology. The primary objective is to reduce the anterior disclusion time to

  7. FDG-PET changes in brain glucose metabolism from normal cognition to pathologically verified Alzheimer's disease

    International Nuclear Information System (INIS)

    Mosconi, Lisa; Mistur, Rachel; Switalski, Remigiusz; Glodzik, Lidia; Li, Yi; Pirraglia, Elizabeth; De Santi, Susan; Reisberg, Barry; Tsui, Wai Hon; De Leon, Mony J.; Wisniewski, Thomas

    2009-01-01

    We report the first clinicopathological series of longitudinal FDG-PET scans in post-mortem (PM) verified cognitively normal elderly (NL) followed to the onset of Alzheimer's-type dementia (DAT), and in patients with mild DAT with progressive cognitive deterioration. Four NL subjects and three patients with mild DAT received longitudinal clinical, neuropsychological and dynamic FDG-PET examinations with arterial input functions. NL subjects were followed for 13 ± 5 years, received FDG-PET examinations over 7 ± 2 years, and autopsy 6 ± 3 years after the last FDG-PET. Two NL declined to mild cognitive impairment (MCI), and two developed probable DAT before death. DAT patients were followed for 9 ± 3 years, received FDG-PET examinations over 3 ± 2 years, and autopsy 7 ± 1 years after the last FDG-PET. Two DAT patients progressed to moderate-to-severe dementia and one developed vascular dementia. The two NL subjects who declined to DAT received a PM diagnosis of definite AD. Their FDG-PET scans indicated a progression of deficits in the cerebral metabolic rate for glucose (CMRglc) from the hippocampus to the parietotemporal and posterior cingulate cortices. One DAT patient showed AD with diffuse Lewy body disease (LBD) at PM, and her last in vivo PET was indicative of possible LBD for the presence of occipital as well as parietotemporal hypometabolism. Progressive CMRglc reductions on FDG-PET occur years in advance of clinical DAT symptoms in patients with pathologically verified disease. The FDG-PET profiles in life were consistent with the PM diagnosis. (orig.)

  8. Processes of cation migration in clay-rocks: Final Scientific Report of the CatClay European Project

    International Nuclear Information System (INIS)

    Altmann, S.; Aertsens, M.; Appelo, T.; Bruggeman, C.; Gaboreau, S.; Glaus, M.; Jacquier, P.; Kupcik, T.; Maes, N.; Montoya, V.; Rabung, T.; Robinet, J.-C.; Savoye, S.; Schaefer, T.; Tournassat, C.; Van Laer, L.; Van Loon, L.

    2015-07-01

    In the framework of the feasibility studies on the radioactive waste disposal in deep argillaceous formations, it is now well established that the transport properties of solutes in clay rocks, i.e. parameter values for Fick's law, are mainly governed by the negatively charged clay mineral surface. While a good understanding of the diffusive behaviour of non-reactive anionic and neutral species is now achieved, much effort has to be placed on improving understanding of coupled sorption/diffusion phenomena for sorbing cations. Indeed, several cations known to form highly stable surface complexes with sites on mineral surfaces migrate more deeply into clay rock than expected. Therefore, the overall objective of the EC CatClay project is to address this issue, using a 'bottom-up' approach, in which simpler, analogous systems (here a compacted clay, 'pure' illite) are experimentally studied and modelled, and then the transferability of these results to more complex materials, i.e. the clay rocks under consideration in France, Switzerland and Belgium for hosting radioactive waste disposal facilities, is verified. The cations of interest were chosen for covering a representative range of cations families: from a moderately sorbing cation, the strontium, to three strongly sorbing cations, Co(II), Zn(II) and Eu(III). For the 4 years of this project, much effort was devoted to developing and applying specific experimental methods needed for acquiring the high precision, reliable data needed to test the alternative hypotheses represented by different conceptual-numerical models. The enhanced diffusion of the sorbing cations of interest was confirmed both in the simpler analogous illite system for Sr 2+ , Co(II) and Zn(II), but also in the natural clay rocks, except for Eu(III). First modelling approach including diffusion in the diffuse double layer (DDL) promisingly succeeded in reproducing the experimental data under the various conditions both in

  9. Renaissance of cation-radicals in mass spectrometry.

    Science.gov (United States)

    Tureček, František

    2013-01-01

    This brief overview addresses the topic that was presented in the Thomson Medal Award session at the 19th International Mass Spectrometry Conference in Kyoto, Japan. Mass spectrometry of cation-radicals has enjoyed a remarkable renaissance thanks to the development of new methods for electron attachment to multiply charged peptide ions. The charge-reduced ions that are odd-electron species exhibit interesting reactivity that is useful for peptide and protein sequencing. The paper briefly reviews the fundamental aspects of the formation, energetics, and backbone dissociations of peptide cation-radicals.

  10. Inward Cationic Diffusion and Percolation Transition in Glass-Ceramics

    DEFF Research Database (Denmark)

    Smedsklaer, Morten Mattrup; Yue, Yuanzheng; Mørup, Steen

    2010-01-01

    We show the quantitative correlation between the degree of crystallization and the cationic diffusion extent in iron-containing diopside glass–ceramics at the glass transition temperature. We find a critical degree of crystallization, above which the diffusion extent sharply drops with the degree...... of crystallization. Below the critical value, the diffusion extent decreases only slightly with the degree of crystallization. No cationic diffusion is observed in the fully crystalline materials. The critical value might be associated with a percolation transition from an interconnected to a disconnected glass...

  11. Oxy-Allyl Cation Catalysis: An Enantioselective Electrophilic Activation Mode

    Science.gov (United States)

    Liu, Chun; Oblak, E. Zachary; Vander Wal, Mark N.; Dilger, Andrew K.; Almstead, Danielle K.; MacMillan, David W. C.

    2016-01-01

    A generic activation mode for asymmetric LUMO-lowering catalysis has been developed using the long-established principles of oxy-allyl cation chemistry. Here, the enantioselective conversion of racemic α-tosyloxy ketones to optically enriched α-indolic carbonyls has been accomplished using a new amino alcohol catalyst in the presence of electron-rich indole nucleophiles. Kinetic studies reveal that the rate-determining step in this SN1 pathway is the catalyst-mediated α-tosyloxy ketone deprotonation step to form an enantiodiscriminant oxy-allyl cation prior to the stereodefining nucleophilic addition event. PMID:26797012

  12. Use of the Rietveld technique for estimating cation distributions

    International Nuclear Information System (INIS)

    Nord, A.G.

    1984-01-01

    The use of the Rietveld full-profile refinement technique to estimate cation distributions is exemplifed by a neutron powder diffraction study of the farringtonite-type solid solution γ-(Znsub(0.70)Fesub(0.30)) 3 (PO 4 ) 2 , with five- and six-coordinated cation sites. A review of similar studies of phases with the farringtonite, sarcopside, Ni 2 P 4 O 12 or olivine structure is given. The accuracy is discussed in terms of Ksub(D) distribution coefficients and metal-oxygen distances. Some investigations of olivines based on X-ray single-crystal data are reviewed for comparison. (Auth.)

  13. Robust Approach to Verifying the Weak Form of the Efficient Market Hypothesis

    Science.gov (United States)

    Střelec, Luboš

    2011-09-01

    The weak form of the efficient markets hypothesis states that prices incorporate only past information about the asset. An implication of this form of the efficient markets hypothesis is that one cannot detect mispriced assets and consistently outperform the market through technical analysis of past prices. One of possible formulations of the efficient market hypothesis used for weak form tests is that share prices follow a random walk. It means that returns are realizations of IID sequence of random variables. Consequently, for verifying the weak form of the efficient market hypothesis, we can use distribution tests, among others, i.e. some tests of normality and/or some graphical methods. Many procedures for testing the normality of univariate samples have been proposed in the literature [7]. Today the most popular omnibus test of normality for a general use is the Shapiro-Wilk test. The Jarque-Bera test is the most widely adopted omnibus test of normality in econometrics and related fields. In particular, the Jarque-Bera test (i.e. test based on the classical measures of skewness and kurtosis) is frequently used when one is more concerned about heavy-tailed alternatives. As these measures are based on moments of the data, this test has a zero breakdown value [2]. In other words, a single outlier can make the test worthless. The reason so many classical procedures are nonrobust to outliers is that the parameters of the model are expressed in terms of moments, and their classical estimators are expressed in terms of sample moments, which are very sensitive to outliers. Another approach to robustness is to concentrate on the parameters of interest suggested by the problem under this study. Consequently, novel robust testing procedures of testing normality are presented in this paper to overcome shortcomings of classical normality tests in the field of financial data, which are typical with occurrence of remote data points and additional types of deviations from

  14. Study of ionic liquid cations transport in soil.

    Science.gov (United States)

    Studzińska, Sylwia; Kowalkowski, Tomasz; Buszewski, Bogusław

    2009-09-15

    Ionic liquids are a form of organic or inorganic molten salts consisting positive and negative ions. There have been several attempts of their utilization in industry. These substances can be released from industrial sites into water and soils thus causing contamination. The most significant chemical processes affecting the behavior of ionic liquid cations in soils are related to their transport. The major aim of this work was to investigate the transport process of imidazolium ionic liquids in soils by column leaching experiments. Five types of soil with varying total organic carbon (TOC) content (chlorides namely: 1-ethyl-3-methylimidazolium (EMIM), 1-n-butyl-3-methylimidazolium (BMIM), 1-n-hexyl-3-methylimidazolium (HMIM). The results obtained indicated significant ability to immobilize ionic liquid cations by soils with higher organic carbon content. The higher TOC value in soil results in lower amounts of solutes migrating through the soil. Factorial regression has been applied to modeling of the results. It relates soil and the ionic liquid cation properties to the retardation of this cation in soil profile.

  15. Cationic starches on cellulose surfaces : a study of polyelectrolyte adsorption

    NARCIS (Netherlands)

    Steeg, van de H.G.M.

    1992-01-01

    Cationic starches are used on a large scale in paper industry as wet-end additives. They improve dry strength. retention of fines and fillers, and drainage. Closure of the white water systems in the paper mills hase increased the concentration of detrimental substances. This might be the

  16. Solidification cracking in austenitic stainless steel welds

    Indian Academy of Sciences (India)

    Solidification cracking is a significant problem during the welding of austenitic stainless steels, particularly in fully austenitic and stabilized compositions. Hot cracking in stainless steel welds is caused by low-melting eutectics containing impurities such as S, P and alloy elements such as Ti, Nb. The WRC-92 diagram can be ...

  17. Cationic polymers for nuclaic acid delivery to tumors

    NARCIS (Netherlands)

    Wolf, H.K. de

    2007-01-01

    In the field of cancer gene therapy, the use of gene carrier systems is considered indispensable. Cationic polymers are able to effectively condense plasmid DNA to nano-sized particles, further referred to as polyplexes. Compared to free DNA, polyplexes have shown improved nuclease-resistance, a

  18. Dietary cation anion difference: Impact on productive and ...

    African Journals Online (AJOL)

    Various nutritional tools have been used to improve the productive and reproductive performance of animals, among which difference between certain minerals, called dietary cation anion difference (DCAD) plays a pivotal role. Low or negative DCAD diets reduce blood pH and HCO3- and animal becomes acidotic.

  19. Fabrication of Cationic Exchange Polystyrene Nanofibers for Drug ...

    African Journals Online (AJOL)

    Trop J Pharm Res, February 2014; 13(2): 192. Many polymers are used to produce nanofibers by electrospinning. Polystyrene (PS) is one of polymers used to produce cation exchange fibers. [9]. PS nanofibers were successfully produced using the electrospinning method and it has been demonstrated that electrospun PS.

  20. Tuning underwater adhesion with cation-π interactions

    Science.gov (United States)

    Gebbie, Matthew A.; Wei, Wei; Schrader, Alex M.; Cristiani, Thomas R.; Dobbs, Howard A.; Idso, Matthew; Chmelka, Bradley F.; Waite, J. Herbert; Israelachvili, Jacob N.

    2017-05-01

    Cation-π interactions drive the self-assembly and cohesion of many biological molecules, including the adhesion proteins of several marine organisms. Although the origin of cation-π bonds in isolated pairs has been extensively studied, the energetics of cation-π-driven self-assembly in molecular films remains uncharted. Here we use nanoscale force measurements in combination with solid-state NMR spectroscopy to show that the cohesive properties of simple aromatic- and lysine-rich peptides rival those of the strong reversible intermolecular cohesion exhibited by adhesion proteins of marine mussel. In particular, we show that peptides incorporating the amino acid phenylalanine, a functional group that is conspicuously sparing in the sequences of mussel proteins, exhibit reversible adhesion interactions significantly exceeding that of analogous mussel-mimetic peptides. More broadly, we demonstrate that interfacial confinement fundamentally alters the energetics of cation-π-mediated assembly: an insight that should prove relevant for diverse areas, which range from rationalizing biological assembly to engineering peptide-based biomaterials.

  1. Changes in Cations Distribution on Degraded Soils of Otamiri ...

    African Journals Online (AJOL)

    This study evaluated changes cations distribution in degraded soils Otamiri floodplain, having 4 easily idenfiable physiographic land units, namely Upland, Terrace, Levee and Backswamp. Results showed high degradation in Upland and Terrace soils. (Ca/Mg ≤ 3.0) when compared with Levee and Backswamp soils ...

  2. Cations Content And Membrane Properties Of Human Sickle Blood ...

    African Journals Online (AJOL)

    Human sickle blood was incubated with the drugs in vitro at their optimum sickling inhibitory concentration. Mean corpuscular volume (MCV), mean corpuscular haemoglobin concentration (MCHC), cations (Na+, K+ and Ca2+) contents and viscosity were measured. Tellurite and thiocyanate significantly increased (P 0.05) ...

  3. Selective oxidation of propane over cation exchanged zeolites

    NARCIS (Netherlands)

    Xu, J.

    2005-01-01

    This thesis focuses on investigation of the fundamental knowledge on a new method for selective oxidation of propane with O2 at low temperature (< 100°C). The relation between propane catalytic selective oxidation and physicochemical properties of cation exchanged Y zeolite has been studied. An

  4. Cation exchange interaction between antibiotic ciprofloxacin and montmorillonite

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Chih-Jen [Department of Earth Sciences, National Cheng Kung University, 1 University Road, Tainan 70101, Taiwan (China); Department of Geosciences, National Taiwan University, Taipei 10617, Taiwan (China); Li, Zhaohui, E-mail: li@uwp.edu [Department of Earth Sciences, National Cheng Kung University, 1 University Road, Tainan 70101, Taiwan (China); Department of Geosciences, University of Wisconsin - Parkside, Kenosha, WI 53144 (United States); Jiang, Wei-Teh, E-mail: atwtj@mail.ncku.edu.tw [Department of Earth Sciences, National Cheng Kung University, 1 University Road, Tainan 70101, Taiwan (China); Jean, Jiin-Shuh; Liu, Chia-Chuan [Department of Earth Sciences, National Cheng Kung University, 1 University Road, Tainan 70101, Taiwan (China)

    2010-11-15

    Exploring the interactions between antibiotics and soils/minerals is of great importance in resolving their fate, transport, and elimination in the environment due to their frequent detection in wastewater, river water, sewage sludge and soils. This study focused on determining the adsorption properties and mechanisms of interaction between antibiotic ciprofloxacin and montmorillonite (SAz-1), a swelling dioctahedral mineral with Ca{sup 2+} as the main interlayer cation. In acidic and neutral aqueous solutions, a stoichiometric exchange between ciprofloxacin and interlayer cations yielded an adsorption capacity as high as 330 mg/g, corresponding to 1.0 mmol/g. When solution pH was above its pK{sub a2} (8.7), adsorption of ciprofloxacin was greatly reduced due to the net repulsion between the negatively charged clay surfaces and the ciprofloxacin anion. The uptake of ciprofloxacin expanded the basal spacing (d{sub 001}) of montmorillonite from 15.04 to 17.23 A near its adsorption capacity, confirming cation exchange within the interlayers in addition to surface adsorption. Fourier transform infrared results further suggested that the protonated amine group of ciprofloxacin in its cationic form was electrostatically attracted to negatively charged sites of clay surfaces, and that the carboxylic acid group was hydrogen bonded to the basal oxygen atoms of the silicate layers. The results indicate that montmorillonite is an effective sorbent to remove ciprofloxacin from water.

  5. Fly ash adsorbents for multi-cation wastewater treatment

    Energy Technology Data Exchange (ETDEWEB)

    Visa, Maria, E-mail: maria.visa@unitbv.ro [Transilvania University of Brasov, Dept. Renewable Energy Systems and Recycling, Eroilor 29, 500036 Brasov (Romania); Isac, Luminita; Duta, Anca [Transilvania University of Brasov, Dept. Renewable Energy Systems and Recycling, Eroilor 29, 500036 Brasov (Romania)

    2012-06-15

    Class 'F' fly ash (FA), collected from the Central Heat and Power (CHP) Plant Brasov (Romania), with oxides composition SiO{sub 2}/Al{sub 2}O{sub 3} over 2.4 proved good adsorbent properties, and was further used for obtaining a new substrate with good adsorption capacity for heavy metals from multi-cation wastewater treatment. Firstly, the new adsorbent was characterized by AFM, XRD, DSC, FTIR and the surface energy was evaluated by contact angle measurements. The experimental data suggested that the new type of substrate is predominant crystalline with highly polar surface. The substrate was used for removing the Pb{sup 2+}, Cd{sup 2+} and Zn{sup 2+} cations from mixed solutions. The results show high efficiency and selective adsorption the Pb{sup 2+} and Zn{sup 2+} cations. The optimized adsorption parameters were further used in thermodynamic and kinetic studies of the adsorption processes. The Langmuir and Freundlich models were used to describe the processes. The pseudo-second order kinetics could well model all the processes, indicating a surface concentration of the adsorption sites with the same order of magnitude as the cation concentrations.

  6. Esterification of maleic acid and butanol using cationic exchange ...

    Indian Academy of Sciences (India)

    AARTI MULAY

    2017-11-15

    Nov 15, 2017 ... Abstract. Dibutyl maleate is a perfumery ester used as an intermediate in the production of paints, adhesives, and copolymers. Esterification of maleic acid and butanol was studied in presence of acidic cation exchange resin as a catalyst. The objective of this work was to test the suitability and efficacy of ...

  7. Coordination of lanthanide cation to an Anderson type ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 126; Issue 5. Coordination of lanthanide cation to an Anderson type polyoxometalate anion ... and spectroscopy. Vaddypally Shivaiah Tanmay Chatterjee Samar K Das. Special issue on Chemical Crystallography Volume 126 Issue 5 September 2014 pp 1525-1533 ...

  8. Stabilizing cations in the backbones of conjugated polymers

    NARCIS (Netherlands)

    Voortman, Thomas P.; de Gier, Hilde D.; Havenith, Remco W. A.; Chiechi, Ryan C.

    2014-01-01

    We synthesized a cross-conjugated polymer containing ketones in the backbone and converted it to a linearly conjugated, cationic polyarylmethine via a process we call "spinless doping" to create a new class of materials, conjugated polyions. This process involves activating the ketones with a Lewis

  9. Computer simulation of superionic conductors: II. Cationic conductors. Review

    International Nuclear Information System (INIS)

    Ivanov-Shitz, A. K.

    2007-01-01

    The state of the art of the molecular-dynamics simulation of superionic conductors is reviewed. The main studies devoted to the structural, dynamic, and transport properties of the basic classes of solid electrolytes with conductivity via silver, copper, lithium, sodium, and hydrogen cations are considered. The premelting effect in ionic crystals is discussed

  10. Two different cationic positions in Cu-SSZ-13?

    Energy Technology Data Exchange (ETDEWEB)

    Kwak, Ja Hun; Zhu, Haiyang; Lee, Jong H.; Peden, Charles HF; Szanyi, Janos

    2012-04-18

    H2-TPR and FTIR were used to characterize the Cu ions present in Cu-SSZ-13 zeolite at different ion exchange levels. The results obtained are consistent with the presence of Cu ions in two distinct cationic positions of the SSZ-13 framework.

  11. Weight gradient and physiological responses to cation-treatment by ...

    African Journals Online (AJOL)

    There was regular taking of body weight of the rabbits using a top- loading weighing balance, while feed consumption, rectal temperature, stool frequency, physical appearance and behavioural changes were noted. Weight gradient studies show gradual increase in body weight following cation treatment of rabbits, but after ...

  12. Metal Cations in G-Quadruplex Folding and Stability

    Science.gov (United States)

    Bhattacharyya, Debmalya; Mirihana Arachchilage, Gayan; Basu, Soumitra

    2016-09-01

    This review is focused on the structural and physico-chemical aspects of metal cation coordination to G-Quadruplexes (GQ) and their effects on GQ stability and conformation. G-Quadruplex structures are non-canonical secondary structures formed by both DNA and RNA. G-quadruplexes regulate a wide range of important biochemical processes. Besides the sequence requirements, the coordination of monovalent cations in the GQ is essential for its formation and determines the stability and polymorphism of GQ structures. The nature, location and dynamics of the cation coordination and their impact on the overall GQ stability are dependent on several factors such as the ionic radii, hydration energy and the bonding strength to the O6 of guanines. The intracellular monovalent cation concentration and the localized ion concentrations determine the formation of GQs and can potentially dictate their regulatory roles. A wide range of biochemical and biophysical studies on an array of GQ enabling sequences have generated at a minimum the knowledge base that allows us to often predict the stability of GQs in presence of the physiologically relevant metal ions, however, prediction of conformation of such GQs is still out of the realm.

  13. Aqueous solubility of ciprofloxacin in the presence of metal cations ...

    African Journals Online (AJOL)

    Purpose: Though the complexation of ciprofloxacin with metal cations has been extensively studied, the effect of this complexation on the aqueous solubility of ciprofloxacin which is an important factor affecting drug distribution has not been well documented. We have thus set out in this study to investigate the aqueous ...

  14. Micellization of a Cationic Surfactant in Mixed Aqueous and Non ...

    African Journals Online (AJOL)

    Reception

    surfactant molecules arrange themselves in bulk solutions into aggregates otherwise called micelles when the interface is fully saturated with the surfactant molecules. Micelle formation is driven by hydrophobic effect but opposed by electrostatic repulsion of the ionic head group (Jiang et al., 2009). Cationic surfactants like ...

  15. Small angle neutron scattering studies on the interaction of cationic

    Indian Academy of Sciences (India)

    The structure of the protein–surfactant complex of bovine serum albumin (BSA) and cationic surfactants has been studied by small angle neutron scattering. At low concentrations, the CTAB monomers are observed to bind to the protein leading to an increase in its size. On the other hand at high concentrations, surfactant ...

  16. Structure and Reactivity of the Cysteine Methyl Ester Radical Cation

    NARCIS (Netherlands)

    Osburn, S.; Steill, J. D.; Oomens, J.; O' Hair, R. A. J.; Van Stipdonk, M.; Ryzhov, V.

    2011-01-01

    The structure and reactivity of the cysteine methyl ester radical cation, CysOMe(center dot+), have been examined in the gas phase using a combination of experiment and density functional theory (DFT) calculations. CysOMe(center dot+) undergoes rapid ion molecule reactions with dimethyl disulfide,

  17. Dipicolinate complexes of main group metals with hydrazinium cation

    Indian Academy of Sciences (India)

    Unknown

    Some new coordination complexes of hydrazinium main group metal dipicolinate hydrates of formulae ... dipicolinate dianions and non-coordinating hydrazinium cations. Conductance measurements ... group metals, and the ability of dip2– to function as a tridentate ligand, we expect to find anionic complexes of the type ...

  18. A tetrakis (amido) phosphonium cation containing 2-pyridyl (2 Py ...

    Indian Academy of Sciences (India)

    amido)phosphonium cation containing 2-pyridyl (2Py) substituents,[P(NH2Py)4]+ and its reactivity studies with Ag(I) salts ... Abstract. Poly-imido analogues of various phosphorus oxo anions have gained recent attention in inorganic chemistry.

  19. Cation exchange applications of synthetic tobermorite for the ...

    Indian Academy of Sciences (India)

    Immobilization and solidification of hazardous cations like Cs137 and Sr90 are required while handling the radioactive waste of nuclear power plants. Efforts are on to find a fail proof method of safe disposal of nuclear wastes. In this context, various materials like borosilicate glass, zeolites, cements and synthetic rocks have ...

  20. Esterification of maleic acid and butanol using cationic exchange ...

    Indian Academy of Sciences (India)

    AARTI MULAY

    2017-11-15

    Nov 15, 2017 ... Special Issue on Recent Trends in the Design and Development of Catalysts and their Applications. Esterification of maleic acid and butanol using cationic exchange resin as ..... Thus, the mole ratio of maleic acid to n-butanol was also varied as 1:3, 1:4, and 1:5 keeping other parameters at a constant value ...

  1. membrane potential change effects on cationic and neutral drug

    African Journals Online (AJOL)

    USER

    NWAFOR A AND COAKLEY W. T. 1Department of Human Physiology, College of Health Sciences University Of Port Harcourt,. Nigeria. 2School of Pure and Applied Biology University of Wales, College of Cardiff, Cathay's Park,. Cardiff, U.K.. The effect of membrane potential change of the human erythrocytes on cationic ...

  2. The exchangeable cations in soils flooded with sea water

    NARCIS (Netherlands)

    Molen, van der W.H.

    1958-01-01

    The changes in the exchangeable cations of soils flooded with sea-water were extensively studied in the Netherlands after the inundations of 1940, 1945 and 1953. A synopsis of the results was given, both from a theoretical and a practical viewpoint.

    Current formulae for ion-exchange tested in the

  3. Adaptive resistance to cationic compounds in Pseudomonas aeruginosa.

    Science.gov (United States)

    Skiada, Anna; Markogiannakis, Antonis; Plachouras, Diamantis; Daikos, George L

    2011-03-01

    Adaptive resistance is an autoregulated phenomenon characterised by induction of resistance in the presence of drug and reversal to the sensitive phenotype in its absence. This type of resistance is well documented for polycationic antibiotics, including aminoglycosides and polymyxins, in Pseudomonas aeruginosa and other aerobic Gram-negative bacilli. It is not caused by selection of resistant mutants but rather by phenotypic alterations in order to survive the lethal drug effect. Adaptive resistance to aminoglycosides is mainly mediated by the MexXY-OprM efflux pump that is rapidly upregulated in bacteria surviving the first exposure to aminoglycosides and is downregulated when bacteria are no longer in contact with the drug. A two-component regulatory system designated ParR-ParS plays a major role in adaptive resistance induced by cationic peptides. In the presence of cationic peptides, ParR-ParS activates the lipopolysaccharide modification operon (arnBCADTEF) leading to increased resistance in polymyxins and aminoglycosides. The bactericidal kinetics related to adaptive resistance have important clinical implications and provide a rationale for administering cationic antibiotics in larger initial and longer interval bolus dosing. A better understanding of this phenomenon and the molecular mechanisms responsible will be essential not only for optimum use of cationic antibiotics but also for developing new agents with ability to counteract the detrimental effects of adaptive resistance and thus enhance the therapeutic efficacy of polycationic compounds. Copyright © 2010 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

  4. Fusion Pore Diameter Regulation by Cations Modulating Local Membrane Anisotropy

    Directory of Open Access Journals (Sweden)

    Doron Kabaso

    2012-01-01

    Full Text Available The fusion pore is an aqueous channel that is formed upon the fusion of the vesicle membrane with the plasma membrane. Once the pore is open, it may close again (transient fusion or widen completely (full fusion to permit vesicle cargo discharge. While repetitive transient fusion pore openings of the vesicle with the plasma membrane have been observed in the absence of stimulation, their frequency can be further increased using a cAMP-increasing agent that drives the opening of nonspecific cation channels. Our model hypothesis is that the openings and closings of the fusion pore are driven by changes in the local concentration of cations in the connected vesicle. The proposed mechanism of fusion pore dynamics is considered as follows: when the fusion pore is closed or is extremely narrow, the accumulation of cations in the vesicle (increased cation concentration likely leads to lipid demixing at the fusion pore. This process may affect local membrane anisotropy, which reduces the spontaneous curvature and thus leads to the opening of the fusion pore. Based on the theory of membrane elasticity, we used a continuum model to explain the rhythmic opening and closing of the fusion pore.

  5. Molecular determinants of permeation through the cation channel TRPM6.

    NARCIS (Netherlands)

    Topala, C.N.; Groenestege, W.T.; Thebault, S.C.; Berg, D. Van den; Nilius, B.; Hoenderop, J.G.J.; Bindels, R.J.M.

    2007-01-01

    TRPM6 and its closest relative TRPM7 are members of the Transient Receptor Potential Melastatin (TRPM) subfamily of cation channels and are known to be Mg2+ permeable. By aligning the sequence of the putative TRPM6 pore with the pore sequences of the other subfamily members, we located in the loop

  6. Cation exchange interaction between antibiotic ciprofloxacin and montmorillonite.

    Science.gov (United States)

    Wang, Chih-Jen; Li, Zhaohui; Jiang, Wei-Teh; Jean, Jiin-Shuh; Liu, Chia-Chuan

    2010-11-15

    Exploring the interactions between antibiotics and soils/minerals is of great importance in resolving their fate, transport, and elimination in the environment due to their frequent detection in wastewater, river water, sewage sludge and soils. This study focused on determining the adsorption properties and mechanisms of interaction between antibiotic ciprofloxacin and montmorillonite (SAz-1), a swelling dioctahedral mineral with Ca(2+) as the main interlayer cation. In acidic and neutral aqueous solutions, a stoichiometric exchange between ciprofloxacin and interlayer cations yielded an adsorption capacity as high as 330 mg/g, corresponding to 1.0 mmol/g. When solution pH was above its pK(a2) (8.7), adsorption of ciprofloxacin was greatly reduced due to the net repulsion between the negatively charged clay surfaces and the ciprofloxacin anion. The uptake of ciprofloxacin expanded the basal spacing (d(001)) of montmorillonite from 15.04 to 17.23 A near its adsorption capacity, confirming cation exchange within the interlayers in addition to surface adsorption. Fourier transform infrared results further suggested that the protonated amine group of ciprofloxacin in its cationic form was electrostatically attracted to negatively charged sites of clay surfaces, and that the carboxylic acid group was hydrogen bonded to the basal oxygen atoms of the silicate layers. The results indicate that montmorillonite is an effective sorbent to remove ciprofloxacin from water. Copyright © 2010 Elsevier B.V. All rights reserved.

  7. Electrodeposition properties of modified cational epoxy resin-type photoresist

    International Nuclear Information System (INIS)

    Yong He; Yunlong Zhang; Feipeng Wu; Miaozhen Li; Erjian Wang

    1999-01-01

    Multi-component cationic epoxy and acrylic resin system for ED photoresist was used in this work, since they can provide better storage stability for ED emulsion and better physical and chemical properties of deposited film than one-component system. The cationic main resin (AE) was prepared from amine modified epoxy resins and then treated with acetic acid. The amination degree was controlled as required. The synthetic procedure of cationic main resins is described in scheme I. The ED photoresist (AME) is composed of cationic main resin (AE) and nonionic multifunctional acrylic crosslinkers (PETA), in combination with suitable photo-initiator. They can easily be dispersed in deionized water to form a stable ED emulsion. The exposed part of deposited film upon UV irradiation occurs crosslinking to produce an insoluble semi-penetrating network and the unexposed part remains good solubility in the acidic water solution. It is readily utilized for fabrication of fine micropattern. The electrodeposition are carried out on Cu plate at room temperature. To evaluate the electrodeposition properties of ED photoresist (AME), the different influences are examined

  8. Verifying the polymer drawing model of melt blowing using factory production data

    Directory of Open Access Journals (Sweden)

    Wu Li-Li

    2015-01-01

    Full Text Available Non-woven samples were collected from four non-woven factories. The fiber diameters of the non-woven samples were measured, which agree tally well with the predicted ones by the polymer drawing model. The paper concludes that the model can be effectively applied to the melt blowing technology.

  9. 78 FR 13369 - Agency Information Collection Activities: E-Verify Program; Revision of a Currently Approved...

    Science.gov (United States)

    2013-02-27

    ... Coordination Division, 20 Massachusetts Avenue NW., Washington, DC 20529-2140. Comments may also be submitted... techniques or other forms of information technology, e.g., permitting electronic submission of responses... signing of the MOU, registration, new user training, and review of the user guides); plus 425,000, the...

  10. Verifying Heisenberg's error-disturbance relation using a single trapped ion.

    Science.gov (United States)

    Zhou, Fei; Yan, Leilei; Gong, Shijie; Ma, Zhihao; He, Jiuzhou; Xiong, Taiping; Chen, Liang; Yang, Wanli; Feng, Mang; Vedral, Vlatko

    2016-10-01

    Heisenberg's uncertainty relations have played an essential role in quantum physics since its very beginning. The uncertainty relations in the modern quantum formalism have become a fundamental limitation on the joint measurements of general quantum mechanical observables, going much beyond the original discussion of the trade-off between knowing a particle's position and momentum. Recently, the uncertainty relations have generated a considerable amount of lively debate as a result of the new inequalities proposed as extensions of the original uncertainty relations. We report an experimental test of one of the new Heisenberg's uncertainty relations using a single 40 Ca + ion trapped in a harmonic potential. By performing unitary operations under carrier transitions, we verify the uncertainty relation proposed by Busch, Lahti, and Werner (BLW) based on a general error-trade-off relation for joint measurements on two compatible observables. The positive operator-valued measure, required by the compatible observables, is constructed by single-qubit operations, and the lower bound of the uncertainty, as observed, is satisfied in a state-independent manner. Our results provide the first evidence confirming the BLW-formulated uncertainty at a single-spin level and will stimulate broad interests in various fields associated with quantum mechanics.

  11. Verifying Heisenberg’s error-disturbance relation using a single trapped ion

    Science.gov (United States)

    Zhou, Fei; Yan, Leilei; Gong, Shijie; Ma, Zhihao; He, Jiuzhou; Xiong, Taiping; Chen, Liang; Yang, Wanli; Feng, Mang; Vedral, Vlatko

    2016-01-01

    Heisenberg’s uncertainty relations have played an essential role in quantum physics since its very beginning. The uncertainty relations in the modern quantum formalism have become a fundamental limitation on the joint measurements of general quantum mechanical observables, going much beyond the original discussion of the trade-off between knowing a particle’s position and momentum. Recently, the uncertainty relations have generated a considerable amount of lively debate as a result of the new inequalities proposed as extensions of the original uncertainty relations. We report an experimental test of one of the new Heisenberg’s uncertainty relations using a single 40Ca+ ion trapped in a harmonic potential. By performing unitary operations under carrier transitions, we verify the uncertainty relation proposed by Busch, Lahti, and Werner (BLW) based on a general error–trade-off relation for joint measurements on two compatible observables. The positive operator-valued measure, required by the compatible observables, is constructed by single-qubit operations, and the lower bound of the uncertainty, as observed, is satisfied in a state-independent manner. Our results provide the first evidence confirming the BLW-formulated uncertainty at a single-spin level and will stimulate broad interests in various fields associated with quantum mechanics. PMID:28861461

  12. Experimentally verified inductance extraction and parameter study for superconductive integrated circuit wires crossing ground plane holes

    International Nuclear Information System (INIS)

    Fourie, Coenrad J; Wetzstein, Olaf; Kunert, Juergen; Meyer, Hans-Georg; Toepfer, Hannes

    2013-01-01

    As the complexity of rapid single flux quantum (RSFQ) circuits increases, both current and power consumption of the circuits become important design criteria. Various new concepts such as inductive biasing for energy efficient RSFQ circuits and inductively coupled RSFQ cells for current recycling have been proposed to overcome increasingly severe design problems. Both of these techniques use ground plane holes to increase the inductance or coupling factor of superconducting integrated circuit wires. New design tools are consequently required to handle the new topographies. One important issue in such circuit design is the accurate calculation of networks of inductances even in the presence of finite holes in the ground plane. We show how a fast network extraction method using InductEx, which is a pre- and post-processor for the magnetoquasistatic field solver FastHenry, is used to calculate the inductances of a set of SQUIDs (superconducting quantum interference devices) with ground plane holes of different sizes. The results are compared to measurements of physical structures fabricated with the IPHT Jena 1 kA cm −2 RSFQ niobium process to verify accuracy. We then do a parameter study and derive empirical equations for fast and useful estimation of the inductance of wires surrounded by ground plane holes. We also investigate practical circuits and show excellent accuracy. (paper)

  13. Verifying three-dimensional skull model reconstruction using cranial index of symmetry.

    Science.gov (United States)

    Kung, Woon-Man; Chen, Shuo-Tsung; Lin, Chung-Hsiang; Lu, Yu-Mei; Chen, Tzu-Hsuan; Lin, Muh-Shi

    2013-01-01

    Difficulty exists in scalp adaptation for cranioplasty with customized computer-assisted design/manufacturing (CAD/CAM) implant in situations of excessive wound tension and sub-cranioplasty dead space. To solve this clinical problem, the CAD/CAM technique should include algorithms to reconstruct a depressed contour to cover the skull defect. Satisfactory CAM-derived alloplastic implants are based on highly accurate three-dimensional (3-D) CAD modeling. Thus, it is quite important to establish a symmetrically regular CAD/CAM reconstruction prior to depressing the contour. The purpose of this study is to verify the aesthetic outcomes of CAD models with regular contours using cranial index of symmetry (CIS). From January 2011 to June 2012, decompressive craniectomy (DC) was performed for 15 consecutive patients in our institute. 3-D CAD models of skull defects were reconstructed using commercial software. These models were checked in terms of symmetry by CIS scores. CIS scores of CAD reconstructions were 99.24±0.004% (range 98.47-99.84). CIS scores of these CAD models were statistically significantly greater than 95%, identical to 99.5%, but lower than 99.6% (ppairs signed rank test). These data evidenced the highly accurate symmetry of these CAD models with regular contours. CIS calculation is beneficial to assess aesthetic outcomes of CAD-reconstructed skulls in terms of cranial symmetry. This enables further accurate CAD models and CAM cranial implants with depressed contours, which are essential in patients with difficult scalp adaptation.

  14. A provably secure identity-based strong designated verifier proxy signature scheme from bilinear pairings

    Directory of Open Access Journals (Sweden)

    SK Hafizul Islam

    2014-01-01

    Full Text Available The proxy signature, a variant of the ordinary digital signature, has been an active research topic in recent years; it has many useful applications, including distributed systems and grid computing. Although many identity-based proxy signature schemes have been proposed in the literature, only a few proposals for identity-based strong designated verifier proxy signature (ID-SDVPS schemes are available. However, it has been found that most of the ID-SDVPS schemes that have been proposed to date are not efficient in terms of computation and security, and a computationally efficient and secured ID-SDVPS scheme using elliptic curve bilinear pairing has been proposed in this paper. The security of the scheme is mainly based on the hardness assumption of CDH and GBDH problems in the random oracle model, which is existentially unforgeable against different types of adversaries. Furthermore, the security of our scheme is simulated in the AVISPA (Automated Validation of Internet Security Protocols and Applications software, a widely used automated internet protocol validation tool, and the simulation results confirm strong security against both active and passive attacks. In addition, because of a high processing capability and supporting additional security features, the scheme is suitable for the environments in which less computational cost with strong security is required.

  15. POSSIBILITIES TO EVALUATE THE QUALITY OF EDUCATION BY VERIFYING THE DISTRIBUTION OF MARKS

    Directory of Open Access Journals (Sweden)

    Alexandru BOROIU

    2015-05-01

    Full Text Available In the higher education, for the evaluation of education process it is of high interest to use some numeric indicators obtained from the database with the final results realized by the students on exams session. For this purpose could be used the following numeric indicators: proportion of students absent on final evaluation, proportion of non-promoted students, normality degree of passing marks distribution. In order to do this we realized an Excel calculation program that could be applied to each discipline. The inputs are concrete (students total, students present to final evaluation, marks absolute frequency and the outputs for the three indicators are binary (competent or noncompetent, in the last situation the verdict being: “Give explanations. Propose an action plan, with actions, responsible and terms”. To verify the imposed normality degree we elaborate a calculation program based on Kolmogorov-Smirnov concordance test. So, it was realized the increase of analyze objectivity and it was created the opportunity to apply corrective measures in order to improve the education process.

  16. On verifying magnetic dipole moment of a magnetic torquer by experiments

    Science.gov (United States)

    Kuyyakanont, Aekjira; Kuntanapreeda, Suwat; Fuengwarodsakul, Nisai H.

    2018-01-01

    Magnetic torquers are used for the attitude control of small satellites, such as CubeSats with Low Earth Orbit (LEO). During the design of magnetic torquers, it is necessary to confirm if its magnetic dipole moment is enough to control the satellite attitude. The magnetic dipole moment can affect the detumbling time and the satellite rotation time. In addition, it is also necessary to understand how to design the magnetic torquer for operation in a CubeSat under the space environment at LEO. This paper reports an investigation of the magnetic dipole moment and the magnetic field generated by a circular air-coil magnetic torquer using experimental measurements. The experiment testbed was built on an air-bearing under a magnetic field generated by a Helmholtz coil. This paper also describes the procedure to determine and verify the magnetic dipole moment value of the designed circular air-core magnetic torquer. The experimental results are compared with the design calculations. According to the comparison results, the designed magnetic torquer reaches the required magnetic dipole moment. This designed magnetic torquer will be applied to the attitude control systems of a 1U CubeSat satellite in the project “KNACKSAT.”

  17. Acute shear stress direction dictates adherent cell remodeling and verifies shear profile of spinning disk assays

    International Nuclear Information System (INIS)

    Fuhrmann, Alexander; Engler, Adam J

    2015-01-01

    Several methods have been developed to quantify population level changes in cell attachment strength given its large heterogeneity. One such method is the rotating disk chamber or ‘spinning disk’ in which a range of shear forces are applied to attached cells to quantify detachment force, i.e. attachment strength, which can be heterogeneous within cell populations. However, computing the exact force vectors that act upon cells is complicated by complex flow fields and variable cell morphologies. Recent observations suggest that cells may remodel their morphology and align during acute shear exposure, but contrary to intuition, shear is not orthogonal to the radial direction. Here we theoretically derive the magnitude and direction of applied shear and demonstrate that cells, under certain physiological conditions, align in this direction within minutes. Shear force magnitude is also experimentally verified which validates that for spread cells shear forces and not torque or drag dominate in this assay, and demonstrates that the applied force per cell area is largely independent of initial morphology. These findings suggest that direct quantified comparison of the effects of shear on a wide array of cell types and conditions can be made with confidence using this assay without the need for computational or numerical modeling. (paper)

  18. Cationic liposomes as non-viral vector for RNA delivery in cancer immunotherapy.

    Science.gov (United States)

    Vitor, Micaela T; Bergami-Santos, Patrícia C; Barbuto, José A M; de la Torre, Lucimara G

    2013-08-01

    This review presents the current status in the use of liposomes as non-viral vector for nucleic acid delivery in cancer immunotherapy. Currently, cancer treatment uses surgery, radiotherapy and/or chemotherapy. The search for new strategies to improve the efficiency of conventional treatments is a challenge, and biological therapy has emerged as a promising technique. Immunotherapy is a branch of biological therapy that uses the body's immune system to detect and destroy cancer cells. One immunotherapy approach is the activation of T lymphocytes from cancer patients by dendritic cells (DCs) loaded with tumor antigens. Among different antigens, mRNA coding the tumor antigens is advantageous due to its capability to be amplified from small amounts of tumor tissue, its safety because it is easily degraded without integrating into the host genome, and it does not need to cross the nuclear barrier to exert its biological activity. Nanotechnology is an approach to deliver tumor antigens into DCs. Specially; we review the use of nanoliposomes in the field of cancer therapy because cationic liposomes can be used as non-viral vectors for mRNA delivery. Aside from the promise of liposomes, the development of scalable processes and facilities to the use this individualized therapy is still a challenge. Thus, we also present the recent techniques used for liposome production. In this context, the integration between technological knowledge in the production of cationic liposomes and immunotherapy using mRNA may contribute to the development of new strategies for cancer therapy.

  19. Layer-Tunable Phosphorene Modulated by the Cation Insertion Rate as a Sodium-Storage Anode.

    Science.gov (United States)

    Huang, Zhaodong; Hou, Hongshuai; Zhang, Yan; Wang, Chao; Qiu, Xiaoqing; Ji, Xiaobo

    2017-09-01

    Liquid phase exfoliation of few-layer phosphorene (FL-P) is extensively explored in recent years. Nevertheless, their deficiencies such as ultralong sonication time, limited flake size distribution, and uncontrollable thicknesses are major hurdles for the development of phosphorene-based materials. Herein, electrochemical cationic intercalation has been introduced to prepare phosphorene, through which large-area FL-P without surface functional groups can be efficiently attained (less than 1 h). More importantly, its layer number (from 2 to 11 layers) can be manipulated by changing the applied potential. The as-obtained phosphorene delivers superior sodium-storage performances when directly utilized as an anode material in sodium-ion batteries. This electrochemical cation insertion method to prepare phosphorene should greatly facilitate the development of phosphorene-based technologies. Moreover, this work provides the possibility for the scalable preparation of monolayer 2D materials by exploring intercalation ions. Additionally, the successful electrochemical exfoliation of phosphorene can promote the application of electrochemical exfoliation in other 2D materials. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Binding CO2from Air by a Bulky Organometallic Cation Containing Primary Amines.

    Science.gov (United States)

    Luo, Yang-Hui; Chen, Chen; Hong, Dan-Li; He, Xiao-Tong; Wang, Jing-Wen; Ding, Ting; Wang, Bo-Jun; Sun, Bai-Wang

    2018-03-21

    The organometallic cation 1 (Fe(bipy-NH 2 ) 3 2+ , bipy-NH 2 = 4,4'-diamino-2,2'-bipyridine), which was constructed in situ in solution, can bind CO 2 from air effectively with a stoichiometric ratio of 1:4 (1/CO 2 ), through the formation of "H-bonded CO 2 " species: [CO 2 -OH-CO 2 ] - and [CO 2 -CO 2 -OH] - . These two species, along with the captured individual CO 2 molecules, connected 1 into a novel 3D (three-dimensional) architecture, that was crystal 1·2(OH - )·4(CO 2 ). The adsorption isotherms, recycling investigations, and the heat capacity of 1 have been investigated; the results revealed that the organometallic cation 1 can be recycled at least 10 times for the real-world CO 2 capture applications. The strategies presented here may provide new hints for the development of new alkanolamine-related absorbents or technologies for CO 2 capture and sequestration.

  1. Cation-pi interaction of the univalent silver cation with meso-octamethylcalix[4]pyrrole: Experimental and theoretical study

    Czech Academy of Sciences Publication Activity Database

    Polášek, Miroslav; Kvíčala, J.; Makrlík, E.; Křížová, Věra; Vaňura, P.

    2017-01-01

    Roč. 1130, FEB 2017 (2017), s. 408-413 ISSN 0022-2860 Grant - others:GA MŠk(CZ) 20/2015; GA MŠk(CZ) LM2010005 Institutional support: RVO:61388955 Keywords : silver cation * meso-octamethylcalix[4]pyrrole * complexation Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry Impact factor: 1.753, year: 2016

  2. Voltammetry of Lead Cations on a New Type of Silver Composite Electrode in the Presence of Other Cations

    Czech Academy of Sciences Publication Activity Database

    Navrátil, Tomáš; Šebková, Světlana; Kopanica, M.

    2004-01-01

    Roč. 379, - (2004), s. 294-301 ISSN 1618-2642 Grant - others:GIT(AR) 101/02/U111/CZ Institutional research plan: CEZ:AV0Z4040901 Keywords : voltammetry * silver composite electrode * lead cations Subject RIV: CG - Electrochemistry Impact factor: 2.098, year: 2004

  3. IR spectroscopy of cationized aliphatic amino acids: Stability of charge-solvated structure increases with metal cation size

    NARCIS (Netherlands)

    Drayss, M. K.; Armentrout, P. B.; Oomens, J.; Schaefer, M.

    2010-01-01

    Gas-phase structures of alkali metal cationized (Li+, Na+,K+, Rb+, and Cs+) proline (Pro) and N-methyl alanine have been investigated using infrared multiple photon dissociation (IRMPD) spectroscopy utilizing light generated by a free electron laser and computational modeling. Measured IRMPD spectra

  4. IR spectroscopy of cationized aliphatic amino acids: Stability of charge-solvated structure increases with metal cation size

    NARCIS (Netherlands)

    Drayß, M.K.; Armentrout, P.B.; Oomens, J.; Schäfer, M.

    2010-01-01

    Gas-phase structures of alkali metal cationized (Li+, Na+, K+, Rb+, and Cs+) proline (Pro) and N-methyl alanine have been investigated using infrared multiple photon dissociation (IRMPD) spectroscopy utilizing light generated by a free electron laser and computational modeling. Measured IRMPD

  5. Effect of cation competition on cadmium uptake from solution by the earthworm Eisenia fetida.

    NARCIS (Netherlands)

    Li, L.-Z.; Zhou, D.-M.; Wang, P.; Jin, S.-Y.; Peijnenburg, W.J.G.M.; Reinecke, A.J.; van Gestel, C.A.M.

    2009-01-01

    Metal speciation alone is insufficient to predict metal accumulation in aquatic and terrestrial organisms, because competition between cations can play an important role. In the present study, the effects of competing cations (Ca

  6. Verifiable Fuel Cycle Simulation Model (VISION): A Tool for Analyzing Nuclear Fuel Cycle Futures

    International Nuclear Information System (INIS)

    Jacobson, Jacob J.; Piet, Steven J.; Matthern, Gretchen E.; Shropshire, David E.; Jeffers, Robert F.; Yacout, A.M.; Schweitzer, Tyler

    2010-01-01

    The nuclear fuel cycle consists of a set of complex components that are intended to work together. To support the nuclear renaissance, it is necessary to understand the impacts of changes and timing of events in any part of the fuel cycle system such as how the system would respond to each technological change, a series of which moves the fuel cycle from where it is to a postulated future state. The system analysis working group of the United States research program on advanced fuel cycles (formerly called the Advanced Fuel Cycle Initiative) is developing a dynamic simulation model, VISION, to capture the relationships, timing, and changes in and among the fuel cycle components to help develop an understanding of how the overall fuel cycle works. This paper is an overview of the philosophy and development strategy behind VISION. The paper includes some descriptions of the model components and some examples of how to use VISION. For example, VISION users can now change yearly the selection of separation or reactor technologies, the performance characteristics of those technologies, and/or the routing of material among separation and reactor types - with the model still operating on a PC in <5 min.

  7. Use of models and mockups in verifying man-machine interfaces

    International Nuclear Information System (INIS)

    Seminara, J.L.

    1985-01-01

    The objective of Human Factors Engineering is to tailor the design of facilities and equipment systems to match the capabilities and limitations of the personnel who will operate and maintain the system. This optimization of the man-machine interface is undertaken to enhance the prospects for safe, reliable, timely, and error-free human performance in meeting system objectives. To ensure the eventual success of a complex man-machine system it is important to systematically and progressively test and verify the adequacy of man-machine interfaces from initial design concepts to system operation. Human factors specialists employ a variety of methods to evaluate the quality of the human-system interface. These methods include: (1) Reviews of two-dimensional drawings using appropriately scaled transparent overlays of personnel spanning the anthropometric range, considering clothing and protective gear encumbrances (2) Use of articulated, scaled, plastic templates or manikins that are overlayed on equipment or facility drawings (3) Development of computerized manikins in computer aided design approaches (4) Use of three-dimensional scale models to better conceptualize work stations, control rooms or maintenance facilities (5) Full or half-scale mockups of system components to evaluate operator/maintainer interfaces (6) Part of full-task dynamic simulation of operator or maintainer tasks and interactive system responses (7) Laboratory and field research to establish human performance capabilities with alternative system design concepts or configurations. Of the design verification methods listed above, this paper will only consider the use of models and mockups in the design process

  8. Applying the Water Vapor Radiometer to Verify the Precipitable Water Vapor Measured by GPS

    Directory of Open Access Journals (Sweden)

    Ta-Kang Yeh

    2014-01-01

    Full Text Available Taiwan is located at the land-sea interface in a subtropical region. Because the climate is warm and moist year round, there is a large and highly variable amount of water vapor in the atmosphere. In this study, we calculated the Zenith Wet Delay (ZWD of the troposphere using the ground-based Global Positioning System (GPS. The ZWD measured by two Water Vapor Radiometers (WVRs was then used to verify the ZWD that had been calculated using GPS. We also analyzed the correlation between the ZWD and the precipitation data of these two types of station. Moreover, we used the observational data from 14 GPS and rainfall stations to evaluate three cases. The offset between the GPS-ZWD and the WVR-ZWD ranged from 1.31 to 2.57 cm. The correlation coefficient ranged from 0.89 to 0.93. The results calculated from GPS and those measured using the WVR were very similar. Moreover, when there was no rain, light rain, moderate rain, or heavy rain, the flatland station ZWD was 0.31, 0.36, 0.38, or 0.40 m, respectively. The mountain station ZWD exhibited the same trend. Therefore, these results have demonstrated that the potential and strength of precipitation in a region can be estimated according to its ZWD values. Now that the precision of GPS-ZWD has been confirmed, this method can eventually be expanded to the more than 400 GPS stations in Taiwan and its surrounding islands. The near real-time ZWD data with improved spatial and temporal resolution can be provided to the city and countryside weather-forecasting system that is currently under development. Such an exchange would fundamentally improve the resources used to generate weather forecasts.

  9. Verifying of endocrine disruptor chemical affect to the mouse testes: can raman spectroscopy support histology study?

    Science.gov (United States)

    Andriana, Bibin B.; Oshima, Yusuke; Takanezawa, Sota; Tay, Tat W.; Rosawati Soeratman, Catherine Linda; Alam, Mohammad S.; Mitsuoka, Hiroki; Zhu, Xiao B.; Suzuki, Toshiaki; Yamamoto, Yuko S.; Tsunekawa, Naoki; Kanai, Yoshiakira; Kurohmaru, Masamichi; Sato, Hidetoshi

    2009-02-01

    One of suspect environmental endocrine disruptors that affect mouse male reproduction by altering the morphology of Sertoli cells and spermatogenic cells is phthalate. The effects of mono(2-ethylhexyl)phthalate (MEHP), one of metabolites of di(2-ethylhexyl)phthalate , on immature mouse testes in vivo were examined. We have recently shown that MEHP induced Sertoli cells necrosis and spermatogenic cells apoptosis in mice by TUNEL method, F-actin staining, and ultrastructural study, but there is no data for biochemical changing of testes due to those methods could not explore. To verify in detail of it, we conducted Raman spectroscopy study with 785 nm wavelength laser line, 50mW of laser power and 3 minutes of exposure time to analysis the MEHP-treated testicular tissue, which has been fixatived by 4% paraformaldehyde (PFA). Five weeks old (5 w.o) male mice were used in this experiment. As the results, the alterations were observed by Raman spectroscopy that there are significantly differences of DNA, actin filament, type IV collagen and amide I between control group (0 μM MEHP) and treatment group (100 μM MEHP). These results significantly support histology staining observation (such as the apoptotic spermatogenic cells which is associated with DNA fragmentation and F-actin disruption) and ultrastructural observation (such as mitochondria rupture and disintegration of nucleus membrane). Raman spectroscopy can be used for 4% PFA-fixatived tissue observation. However, we recommend that Raman spectroscopy may be able to be expanded as an armamentarium not just for the clarification of histology staining and ultrastructural study, but furthermore, it may be as a non-invasion assessment for screening animal tissue toxicity of chemical in future.

  10. Trust, but verify - Accuracy of clinical commercial radiation Treatment Planning Systems

    Science.gov (United States)

    Lehmann, J.; Kenny, J.; Lye, J.; Dunn, L.; Williams, I.

    2014-03-01

    Computer based Treatment Planning Systems (TPS) are used worldwide to design and calculate treatment plans for treating radiation therapy patients. TPS are generally well designed and thoroughly tested by their developers and local physicists prior to clinical use. However, the wide-reaching impact of their accuracy warrants ongoing vigilance. This work reviews the findings of the Australian national audit system and provides recommendations for checks of TPS. The Australian Clinical Dosimetry Service (ACDS) has designed and implemented a national system of audits, currently in a three year test phase. The Level III audits verify the accuracy of a beam model of a facility's TPS through a comparison of measurements with calculation at selected points in an anthropomorphic phantom. The plans are prescribed by the ACDS and all measurement equipment is brought in for independent onsite measurements. In this first version of audits, plans are comparatively simple, involving asymmetric fields, wedges and inhomogeneities. The ACDS has performed 14 Level III audits to-date. Six audits returned at least one measurement at Action Level, indicating that the measured dose differed more than 3.3% (but less than 5%) from the planned dose. Two audits failed (difference >5%). One fail was caused by a data transmission error coupled with quality assurance (QA) not being performed. The second fail was investigated and reduced to Action Level with the onsite audit team finding phantom setup at treatment a contributing factor. The Action Level results are attributed to small dose calculation deviations within the TPS, which are investigated and corrected by the facilities. Small deviations exist in clinical TPS which can add up and can combine with output variations to result in unacceptable variations. Ongoing checks and independent audits are recommended.

  11. Trust, but verify – accuracy of clinical commercial radiation treatment planning systems

    International Nuclear Information System (INIS)

    Lehmann, J; Kenny, J; Lye, J; Dunn, L; Williams, I

    2014-01-01

    Computer based Treatment Planning Systems (TPS) are used worldwide to design and calculate treatment plans for treating radiation therapy patients. TPS are generally well designed and thoroughly tested by their developers and local physicists prior to clinical use. However, the wide-reaching impact of their accuracy warrants ongoing vigilance. This work reviews the findings of the Australian national audit system and provides recommendations for checks of TPS. The Australian Clinical Dosimetry Service (ACDS) has designed and implemented a national system of audits, currently in a three year test phase. The Level III audits verify the accuracy of a beam model of a facility's TPS through a comparison of measurements with calculation at selected points in an anthropomorphic phantom. The plans are prescribed by the ACDS and all measurement equipment is brought in for independent onsite measurements. In this first version of audits, plans are comparatively simple, involving asymmetric fields, wedges and inhomogeneities. The ACDS has performed 14 Level III audits to-date. Six audits returned at least one measurement at Action Level, indicating that the measured dose differed more than 3.3% (but less than 5%) from the planned dose. Two audits failed (difference >5%). One fail was caused by a data transmission error coupled with quality assurance (QA) not being performed. The second fail was investigated and reduced to Action Level with the onsite audit team finding phantom setup at treatment a contributing factor. The Action Level results are attributed to small dose calculation deviations within the TPS, which are investigated and corrected by the facilities. Small deviations exist in clinical TPS which can add up and can combine with output variations to result in unacceptable variations. Ongoing checks and independent audits are recommended.

  12. Development of a New Cardiac and Torso Phantom for Verifying the Accuracy of Myocardial Perfusion SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto; Tomoaki [Dept. of Radiological Science, School of Health Science, International University of Health and Welfare, Otawara(Japan); Kim, Jung Min; Lee, Ki Sung [Dept. of Radiological Science, College of Health Science, Korea University, Seoul (Korea, Republic of); Takayama, Teruhiko [Dept. of Clinical Laboratory Science, Graduate School of Medicine, Kanazawa University, Kanazawa (Japan); Kitashi, Kitahara [Dept. of Radiology, Fujigaoka Hospital, Showa University, Tokyo (Korea, Republic of)

    2008-12-15

    Corrections of attenuation, scatter and resolution are important in order to improve the accuracy of single photon emission computed tomography (SPECT) image reconstruction. Especially, the heart movement by respiration and beating cause the errors in the corrections. Myocardial phantom is used to verify the correction methods, but there are many different parts in the current phantoms in actual human body. Therefore the results using a phantom are often considered apart from the clinical data. We developed a new phantom that implements the human body structure around the thorax more faithfully. The new phantom has the small mediastinum which can simulate the structure in which the lung adjoins anterior, lateral and apex of myocardium. The container was made of acrylic and water-equivalent material was used for mediastinum. In addition, solidified polyurethane foam in epoxy resin was used for lung. Five different sizes of myocardium were developed for the quantitative gated SPECT (QGS). The septa of all different cardiac phantoms were designed so that they can be located at the same position. The proposed phantom was attached with liver and gallbladder, the adjustment was respectively possible for the height of them. The volumes of five cardiac ventricles were 150.0, 137.3, 83.1, 42.7 and 38.6 ml respectively. The SPECT were performed for the new phantom, and the differences between the images were examined after the correction methods were applied. The three-dimensional tomography of myocardium was well reconstructed, and the subjective evaluations were done to show the difference among the various corrections. We developed the new cardiac and torso phantom, and the difference of various corrections was shown on SPECT images and QGS results.

  13. Verifying three-dimensional skull model reconstruction using cranial index of symmetry.

    Directory of Open Access Journals (Sweden)

    Woon-Man Kung

    Full Text Available BACKGROUND: Difficulty exists in scalp adaptation for cranioplasty with customized computer-assisted design/manufacturing (CAD/CAM implant in situations of excessive wound tension and sub-cranioplasty dead space. To solve this clinical problem, the CAD/CAM technique should include algorithms to reconstruct a depressed contour to cover the skull defect. Satisfactory CAM-derived alloplastic implants are based on highly accurate three-dimensional (3-D CAD modeling. Thus, it is quite important to establish a symmetrically regular CAD/CAM reconstruction prior to depressing the contour. The purpose of this study is to verify the aesthetic outcomes of CAD models with regular contours using cranial index of symmetry (CIS. MATERIALS AND METHODS: From January 2011 to June 2012, decompressive craniectomy (DC was performed for 15 consecutive patients in our institute. 3-D CAD models of skull defects were reconstructed using commercial software. These models were checked in terms of symmetry by CIS scores. RESULTS: CIS scores of CAD reconstructions were 99.24±0.004% (range 98.47-99.84. CIS scores of these CAD models were statistically significantly greater than 95%, identical to 99.5%, but lower than 99.6% (p<0.001, p = 0.064, p = 0.021 respectively, Wilcoxon matched pairs signed rank test. These data evidenced the highly accurate symmetry of these CAD models with regular contours. CONCLUSIONS: CIS calculation is beneficial to assess aesthetic outcomes of CAD-reconstructed skulls in terms of cranial symmetry. This enables further accurate CAD models and CAM cranial implants with depressed contours, which are essential in patients with difficult scalp adaptation.

  14. Exploration of overloaded cation exchange chromatography for monoclonal antibody purification.

    Science.gov (United States)

    Liu, Hui F; McCooey, Beth; Duarte, Tiago; Myers, Deanna E; Hudson, Terry; Amanullah, Ashraf; van Reis, Robert; Kelley, Brian D

    2011-09-28

    Cation exchange chromatography using conventional resins, having either diffusive or perfusive flow paths, operated in bind-elute mode has been commonly employed in monoclonal antibody (MAb) purification processes. In this study, the performance of diffusive and perfusive cation exchange resins (SP-Sepharose FF (SPSFF) and Poros 50HS) and a convective cation exchange membrane (Mustang S) and monolith (SO(3) Monolith) were compared. All matrices were utilized in an isocratic state under typical binding conditions with an antibody load of up to 1000 g/L of chromatographic matrix. The dynamic binding capacity of the cation exchange resins is typically below 100 g/L resin, so they were loaded beyond the point of anticipated MAb break through. All of the matrices performed similarly in that they effectively retained host cell protein and DNA during the loading and wash steps, while antibody flowed through each matrix after its dynamic binding capacity was reached. The matrices differed, though, in that conventional diffusive and perfusive chromatographic resins (SPSFF and Poros 50HS) demonstrated a higher binding capacity for high molecular weight species (HMW) than convective flow matrices (membrane and monolith); Poros 50HS displayed the highest HMW binding capacity. Further exploration of the conventional chromatographic resins in an isocratic overloaded mode demonstrated that the impurity binding capacity was well maintained on Poros 50HS, but not on SPSFF, when the operating flow rate was as high as 36 column volumes per hour. Host cell protein and HMW removal by Poros 50HS was affected by altering the loading conductivity. A higher percentage of host cell protein removal was achieved at a low conductivity of 3 mS/cm. HMW binding capacity was optimized at 5 mS/cm. Our data from runs on Poros 50HS resin also showed that leached protein A and cell culture additive such as gentamicin were able to be removed under the isocratic overloaded condition. Lastly, a MAb

  15. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT - BAGHOUSE FILTRATION PRODUCTS - ALBANY INTERNATIONAL CORP. INDUSTRIAL PROCESS TECHNOLOGIES PRIMATEX PLUS I FILTER SAMPLE

    Science.gov (United States)

    Baghouse filtration products (BFPs) were evaluated by the Air Pollution Control Technology (APCT) pilot of the Environmental Technology Verification (ETV) Program. The performance factor verified was the mean outlet particle concentration for the filter fabric as a function of th...

  16. Discovery of a Novel Cationic Surfactant: Tributyltetradecyl-Phosphonium Chloride for Iron Ore Flotation: From Prediction to Experimental Verification

    Directory of Open Access Journals (Sweden)

    Pan Chen

    2017-12-01

    Full Text Available In this work, tributyltetradecyl-phosphonium chloride (TTPC, has been first introduced to be a novel and efficient cationic surfactant for cationic reverse flotation separation of quartz from magnetite. The first-principles density functional theory calculations, Zeta potential measurements and adsorption isotherm measurements consistently predict that TTPC may be a promising collector that is better than dodecyl triethyl ammonium chloride (DTAC, based on the facts that TTPC and DTAC both prefer to physically adsorb on the quartz surface owing to electrostatic force, but the active part (P+(C4H93 of TTPC takes much more positive charges than that (N+(CH33 of DTAC. The micro-flotation and Bench-scale flotation results further verify that TTPC presents a stronger collecting power and much better selectivity for iron ore reverse flotation in comparison to the conventional collector DTAC. Furthermore, the corresponding adsorption mechanism of TTPC on the quartz have also been investigated in detail. This work might show a good example to discover a potential candidate collector by analogy with a known excellent collector based on reasonable prediction.

  17. JPRS Report, Science & Technology, China

    Science.gov (United States)

    1991-12-23

    Petrochemical Corp. Completes First Integrated Network [JISUANJI SHIJIE, 18 Sep 91] ............ 27 Shanghai To Build FTTH CATV Network [Xiao Qiang; JISUANJI...long-wave fiber optic communi- cations. Shanghai To Build FTTH CATV Network 92P60054D Beijing JISUANJI SHIJIE [CHINA First 60-km Unrepeatered Bundle...technology is now moving into Cable Operational"] the home ( FTTH , or fiber-to-the-home), with the upcoming construction in the Shanghai area’s Jiading [Summary

  18. Spectroscopic and computer modelling studies of mixed-cation superionic fluorites

    CSIR Research Space (South Africa)

    Netshisaulu, TT

    2005-10-19

    Full Text Available into the local environments of the Cd and Pb cations (as a function of composition and temperature) in CdF2 (xPbF(2)) mixed-cation superionic fluorites. A high degree of disorder is shown around both cations. However, the extent of disorder is even larger around...

  19. Gene vectors based on DOEPC/DOPE mixed cationic liposomes : a physicochemical study

    NARCIS (Netherlands)

    Munoz-Ubeda, Monica; Rodriguez-Pulido, Alberto; Nogales, Aurora; Llorca, Oscar; Quesada-Perez, Manuel; Martin-Molina, Alberto; Aicart, Emilio; Junquera, Elena

    2011-01-01

    A double approach, experimental and theoretical, has been followed to characterize from a physicochemical standpoint the compaction process of DNA by means of cationic colloidal aggregates. The colloidal vectors are cationic liposomes constituted by a mixture of a novel cationic lipid,

  20. 21 CFR 872.3480 - Polyacrylamide polymer (modified cationic) denture adhesive.

    Science.gov (United States)

    2010-04-01

    ... adhesive. 872.3480 Section 872.3480 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND... polymer (modified cationic) denture adhesive. (a) Identification. A polyacrylamide polymer (modified cationic) denture adhesive is a device composed of polyacrylamide polymer (modified cationic) intended to...

  1. Baselining the New GSFC Information Systems Center: The Foundation for Verifiable Software Process Improvement

    Science.gov (United States)

    Parra, A.; Schultz, D.; Boger, J.; Condon, S.; Webby, R.; Morisio, M.; Yakimovich, D.; Carver, J.; Stark, M.; Basili, V.; hide

    1999-01-01

    This paper describes a study performed at the Information System Center (ISC) in NASA Goddard Space Flight Center. The ISC was set up in 1998 as a core competence center in information technology. The study aims at characterizing people, processes and products of the new center, to provide a basis for proposing improvement actions and comparing the center before and after these actions have been performed. The paper presents the ISC, goals and methods of the study, results and suggestions for improvement, through the branch-level portion of this baselining effort.

  2. Ultrasound-guided fluoroscopic-verified lumbar transforaminal epidural injection: A clinical evaluation of technique

    Directory of Open Access Journals (Sweden)

    Dinesh Kumar Sahu

    2016-01-01

    Full Text Available Background: Fluoroscope guidance method is the gold standard for performing lumbar transforaminal epidural steroid injections (TFESIs, but it is not devoid of adverse effects such as exposure to radiation and need to wear heavy lead aprons. Ultrasound (US-guided techniques are being evaluated recently but methodological acceptability and reproducibility remain unknown. So after reviewing literatures, studing the us scan of lumber region, we have performed these injection safely and methodologial manner and describing in this study. Duration of Study: The duration of this study was six months, from May 01, 2016, to November 31, 2016. Study Design: This was a prospective, open-label, clinical, pilot study. Materials and Methods: A total of twenty patients with low back pain and radiculopathy were enrolled in this study. A US-guided novel technique was used to perform TFESI. A needle was placed under the guidance of US, and then verified with fluoroscope for dye spread. Then, predecided mixture of drugs were injected. Patients were monitored for number of attempts for localization of transforaminal space, number of adjustment, time taken for needle insertion in transforaminal space, radiation dosage, if the cortex of bone touched by the needle, and whether any complication occurred. Results: The number of attempts for localization of transforaminal space in 85% was one and two in 15% of the patients, number of adjustment per attempt was 5.3, and the average time taken for TFESI in patients in one-attempt group was 973 ± 93 s and 1506 ± 65 s in two-attempt group. Average exposure time of fluoroscope per person was 17.5 ± 2.5 s only. Bone was contacted in 75% of cases and no complications were noted. Conclusion: Lumbar TFESI can be safely and effectively performed under US guidance but fluoroscopic confirmation is required to rule out intravascular and intrathecal spread of the contrast at this stage. However, US guidance has reduced radiation

  3. Verifying Digital Components of Physical Systems: Experimental Evaluation of Test Quality

    Science.gov (United States)

    Laputenko, A. V.; López, J. E.; Yevtushenko, N. V.

    2018-03-01

    This paper continues the study of high quality test derivation for verifying digital components which are used in various physical systems; those are sensors, data transfer components, etc. We have used logic circuits b01-b010 of the package of ITC'99 benchmarks (Second Release) for experimental evaluation which as stated before, describe digital components of physical systems designed for various applications. Test sequences are derived for detecting the most known faults of the reference logic circuit using three different approaches to test derivation. Three widely used fault types such as stuck-at-faults, bridges, and faults which slightly modify the behavior of one gate are considered as possible faults of the reference behavior. The most interesting test sequences are short test sequences that can provide appropriate guarantees after testing, and thus, we experimentally study various approaches to the derivation of the so-called complete test suites which detect all fault types. In the first series of experiments, we compare two approaches for deriving complete test suites. In the first approach, a shortest test sequence is derived for testing each fault. In the second approach, a test sequence is pseudo-randomly generated by the use of an appropriate software for logic synthesis and verification (ABC system in our study) and thus, can be longer. However, after deleting sequences detecting the same set of faults, a test suite returned by the second approach is shorter. The latter underlines the fact that in many cases it is useless to spend `time and efforts' for deriving a shortest distinguishing sequence; it is better to use the test minimization afterwards. The performed experiments also show that the use of only randomly generated test sequences is not very efficient since such sequences do not detect all the faults of any type. After reaching the fault coverage around 70%, saturation is observed, and the fault coverage cannot be increased anymore. For

  4. Verifying interpretive criteria for bioaerosol data using (bootstrap) Monte Carlo techniques.

    Science.gov (United States)

    Spicer, R Christopher; Gangloff, Harry

    2008-02-01

    A number of interpretive descriptors have been proposed for bioaerosol data due to the lack of health-based numerical standards, but very few have been verified as to their ability to describe a suspect indoor environment. Culturable and nonculturable (spore trap) sampling using the bootstrap version of Monte Carlo simulation (BMC) at several sites during 2003-2006 served as a source of indoor and outdoor data to test various criteria with regard to their variability in characterizing an indoor or outdoor environment. The purpose was to gain some insight for the reliability of some of the interpretive criteria in use as well as to demonstrate the utility of BMC methods as a generalized technique for validation of various interpretive criteria for bioaerosols. The ratio of nonphylloplane (NP) fungi (total of Aspergillus and Penicillium) to phylloplane (P) fungi (total of Cladosporium, Alternaria, and Epicoccum), or NP/P, is a descriptor that has been used to identify "dominance" of nonphylloplane fungi (NP/P > 1.0), assumed to be indicative of a problematic indoor environment. However, BMC analysis of spore trap and culturable bioaerosol data using the NP/P ratio identified frequent dominance by nonphylloplane fungi in outdoor air. Similarly, the NP/P descriptor indicated dominance of nonphylloplane fungi in buildings with visible mold growth and/or known water intrusion with a frequency often in the range of 0.5 Fixed numerical criteria for spore trap data of 900 and 1300 spores/m(3) for total spores and 750 Aspergillus/Penicillium spores/m(3) exhibited similar variability, as did ratios of nonphylloplane to total fungi, phylloplane to total fungi, and indoor/outdoor ratios for total fungal spores. Analysis of bioaerosol data by BMC indicates that numerical levels or descriptors based on dominance of certain fungi are unreliable as criteria for characterizing a given environment. The utility of BMC analysis lies in its generalized application to test mathematically

  5. Protic Cationic Oligomeric Ionic Liquids of the Urethane Type

    DEFF Research Database (Denmark)

    Shevchenko, V. V.; Stryutsky, A. V.; Klymenko, N. S.

    2014-01-01

    temperature, but ethanesulfonate imidazolium and pyridinium oligomeric ionic liquids form a low melting crystalline phase. The proton conductivities of the oligomeric ionic liquids are determined by the type of cation in the temperature range 80-120 degrees C under anhydrous conditions and vary within five......Protic oligomeric cationic ionic liquids of the oligo(ether urethane) type are synthesized via the reaction of an isocyanate prepolymer based on oligo(oxy ethylene)glycol with M = 1000 with hexamethylene-diisocyanate followed by blocking of the terminal isocyanate groups with the use of amine...... derivatives of imidazole, pyridine, and 3-methylpyridine and neutralization of heterocycles with ethanesulfonic acid and p-toluenesulfonic acid. The structures and properties of the synthesized oligomeric ionic liquids substantially depend on the structures of the ionic groups. They are amorphous at room...

  6. High-dynamic-range cationic two-photon photopolymerization

    Science.gov (United States)

    Boiko, Yuri B.; Costa, Joannes M.; Wang, Mark M.; Esener, Sadik C.

    2001-06-01

    Cationic-induced two-photon photopolymerization is demonstrated at 710 nm, using an isopropylthioxanthone/diarylidonium salt initiating system for the cationic polymerization of an epoxide. The polymerization threshold J2th is found to be approximately 1 GW/cm2, with a dynamic range of > 100, i.e. the material can be fully polymerized at intensities > 100 times the threshold level without damage. The polymerization rate R is found to be proportional to the m equals 1.7 power of the intensity, or R equals [C (J-J2th)]m equals [C (J-J2th)]1.7, which implies a significantly stronger localization of the photochemical response than that of free radical photoinitiators. R and J2th significantly improve when the concentration z of the initiator (onium salt) increases.

  7. Mass analyzed threshold ionization spectroscopy of 1-methylindole cation

    Science.gov (United States)

    Lin, Jung Lee; Tzeng, Wen Bih

    2003-08-01

    The vibrationally resolved mass analyzed threshold ionization spectra of jet-cooled 1-methylindole (1MI) have been recorded by ionizing via four vibronic levels. The adiabatic ionization energy of this molecule is determined to be 60 749 ± 5 cm -1, which is less than that of indole by 1842 cm -1. This indicates that the N-methyl substitution causes a greater extent of the lowering in the zero energy level of the cationic ground state than that of the neutral. A few characteristic vibrations of the 1MI cation are observed, where the frequencies of the out-of-plane, in-plane bending and stretching vibrations of the N-CH 3 part are found to be 124, 251, and 1492 cm -1, respectively.

  8. Exchangeable cations in some soils of Mt. Stara planina

    Directory of Open Access Journals (Sweden)

    Belanović Snežana

    2005-01-01

    Full Text Available Land use in forest and pasture ecosystems requires the respecting of ecological and economic interactions between the individual components of these ecosystems. The content of nutrition elements in the soil solution depends on soil types, climate conditions and vegetation species, i.e., it is conditioned by their cycling in the ecosystem. This paper studies the cation exchange capacity in pasture and forest soils of Mt. Stara Planina.

  9. Cation-Exchanged Zeolitic Chalcogenides for CO2 Adsorption.

    Science.gov (United States)

    Yang, Huajun; Luo, Min; Chen, Xitong; Zhao, Xiang; Lin, Jian; Hu, Dandan; Li, Dongsheng; Bu, Xianhui; Feng, Pingyun; Wu, Tao

    2017-12-18

    We report here the intrinsic advantages of a special family of porous chalcogenides for CO 2 adsorption in terms of high selectivity of CO 2 /N 2 , large uptake capacity, and robust structure due to their first-ever unique integration of the chalcogen-soft surface, high porosity, all-inorganic crystalline framework, and the tunable charge-to-volume ratio of exchangeable cations. Although tuning the CO 2 adsorption properties via the type of exchangeable cations has been well-studied in oxides and MOFs, little is known about the effects of inorganic exchangeable cations in porous chalcogenides, in part because ion exchange in chalcogenides can be very sluggish and incomplete due to their soft character. We have demonstrated that, through a methodological change to progressively tune the host-guest interactions, both facile and nearly complete ion exchange can be accomplished. Herein, a series of cation-exchanged zeolitic chalcogenides (denoted as M@RWY) were studied for the first time for CO 2 adsorption. Samples were prepared through a sequential ion-exchange strategy, and Cs + -, Rb + -, and K + -exchanged samples demonstrated excellent CO 2 adsorption performance. Particularly, K@RWY has the superior CO 2 /N 2 selectivity with the N 2 adsorption even undetected at either 298 or 273 K. It also has the large uptake of 6.3 mmol/g (141 cm 3 /g) at 273 K and 1 atm with an isosteric heat of 35-41 kJ mol -1 , the best among known porous chalcogenides. Moreover, it permits a facile regeneration and exhibits an excellent recyclability, as shown by the multicycling adsorption experiments. Notably, K@RWY also demonstrates a strong tolerance toward water.

  10. Renaissance of Cation-Radicals in Mass Spectrometry

    OpenAIRE

    Tureček, František

    2013-01-01

    This brief overview addresses the topic that was presented in the Thomson Medal Award session at the 19th International Mass Spectrometry Conference in Kyoto, Japan. Mass spectrometry of cation-radicals has enjoyed a remarkable renaissance thanks to the development of new methods for electron attachment to multiply charged peptide ions. The charge-reduced ions that are odd-electron species exhibit interesting reactivity that is useful for peptide and protein sequencing. The paper briefly revi...

  11. Nitrogen heteroaromatic cations by [2+2+2] cycloaddition

    Czech Academy of Sciences Publication Activity Database

    Čížková, Martina; Kolivoška, Viliam; Císařová, I.; Šaman, David; Pospíšil, Lubomír; Teplý, Filip

    2011-01-01

    Roč. 9, č. 2 (2011), s. 450-462 ISSN 1477-0520 R&D Projects: GA ČR GA203/09/1614; GA ČR GA203/09/0705; GA MŠk OC 140 Institutional research plan: CEZ:AV0Z40550506; CEZ:AV0Z40400503 Keywords : modular synthesis * N-heteroaromatic cation * [2+2+2] cycloaddition Subject RIV: CC - Organic Chemistry Impact factor: 3.696, year: 2011

  12. The complex nature of calcium cation interactions with phospholipid bilayers

    Czech Academy of Sciences Publication Activity Database

    Melcrová, Adéla; Pokorná, Šárka; Pullanchery, S.; Kohagen, Miriam; Jurkiewicz, Piotr; Hof, Martin; Jungwirth, Pavel; Cremer, P. S.; Cwiklik, Lukasz

    2016-01-01

    Roč. 6, DEC 2016 (2016), č. článku 38035. ISSN 2045-2322 R&D Projects: GA ČR(CZ) GBP208/12/G016; GA ČR(CZ) GA16-01074S Institutional support: RVO:61388955 ; RVO:61388963 Keywords : FLUORESCENCE SOLVENT RELAXATION * MOLECULAR-DYNAMICS SIMULATIONS * ALKALINE-EARTH CATIONS Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 4.259, year: 2016

  13. Coordination of lanthanide cation to an Anderson type ...

    Indian Academy of Sciences (India)

    For correspondence lanthanide cations. In 2002, we reported a prelimi- nary result14 on “a polyoxometalate chain formed from heteropolyanion building blocks and rare earth metal ion linkers: [La(H2O)7Al(OH)6Mo6O18]n · 4nH2O”, in which we mentioned that “this material provides an opportunity to synthesize a new class ...

  14. Temporal Deductive Verification of Basic ASM Models

    OpenAIRE

    Daho, Hocine El-Habib; University of Oran; Benhamamouch, Djillali; University of Oran

    2010-01-01

    Abstract State Machines (ASMs, for short) provide a practical new computational model which has been applied in the area of software engineering for systems design and analysis. However, reasoning about ASM models occurs, not within a formal deductive system, but basically in the classical informal proofs style of mathematics. Several formal verification approaches for proving correctness of ASM models have been investigated. In this paper we consider the use of the TLA+logic for the deductive...

  15. Effect of hydroxide polymenrs on cation exchange of montmorillonite

    NARCIS (Netherlands)

    Janssen, R.P.T.; Bruggenwert, M.G.M.; Riemsdijk, van W.H.

    2003-01-01

    Al hydroxide polymers (AlHO) can significantly influence the cation exchange behaviour of clays. We have determined the effect of synthesized AlHO on Ca¿Na, Zn¿Na and Pb¿Na exchange for a series of exchanger compositions and two Al loadings at pH 6.0 and an ionic strength of 0.01 m. The preference

  16. Insertion of cations into WO3 investigated by QCM techniques

    Czech Academy of Sciences Publication Activity Database

    Vondrák, Jiří; Sedlaříková, M.; Velická, Jana; Špičák, P.; Svoboda, V.; Kazelle, J.

    2007-01-01

    Roč. 11, č. 10 (2007), s. 1459-1462 ISSN 1432-8488 R&D Projects: GA MŽP SN/3/171/05; GA AV ČR(CZ) KJB208130604; GA ČR(CZ) GA104/06/1471 Institutional research plan: CEZ:AV0Z40320502 Keywords : tungsten trioxide * insertion of cations * quartz crystal microbalance Subject RIV: CG - Electrochemistry Impact factor: 1.535, year: 2007

  17. Hematocrit alters VerifyNow P2Y12 assay results independently of intrinsic platelet reactivity and clopidogrel responsiveness.

    Science.gov (United States)

    Kakouros, N; Kickler, T S; Laws, K M; Rade, J J

    2013-10-01

    The VerifyNow P2Y12 assay assesses the adequacy of clopidogrel therapy by measuring ADP-induced platelet activation in whole blood. Low hematocrit is associated with high clopidogrel on-treatment platelet reactivity (HTPR) defined by this assay. To characterize the effect of hematocrit on VerifyNow values and determine if it is due to hematocrit-dependent changes in intrinsic platelet reactivity or an in vitro assay phenomenon. Adenosine diphosphate-induced platelet activation was measured using the VerifyNow P2Y12 assay, whole blood impedance and light transmission platelet aggregometry (LTA) before and after clopidogrel loading in 113 patients undergoing elective cardiac catheterization. Iso-TRAP-induced platelet activation was additionally measured using the VerifyNow device. Multivariate modeling employing clinical and laboratory variables was used to investigate the association between hematocrit and VerifyNow values. VerifyNow P2Y12 reaction units (PRU) and iso-TRAP Base units before and after clopidogrel loading, but not their relative change, exhibited strong negative correlation with hematocrit (P ≤ 0.0005 for both). While hematocrit remained a strong predictor of post-clopidogrel PRU (P = 0.001) in multivariate modeling, it was independent of post-clopidogrel ADP-induced platelet reactivity as measured by LTA (P = 0.001). Correcting for the effects of hematocrit resulted in a 15-39% reduction in the prevalence of HTPR defined by thresholds of 208-236 PRU. The effect of hematocrit on VerifyNow PRU values is an in vitro phenomenon that is independent of intrinsic change in ADP-induced platelet reactivity and clopidogrel responsiveness. Correcting for hematocrit when using this assay may more accurately identify patients with HTPR that may benefit from alternative antiplatelet therapy. © 2013 International Society on Thrombosis and Haemostasis.

  18. Procedures for measuring and verifying gastric tube placement in newborns: an integrative review.

    Science.gov (United States)

    Dias, Flávia de Souza Barbosa; Emidio, Suellen Cristina Dias; Lopes, Maria Helena Baena de Moraes; Shimo, Antonieta Keiko Kakuda; Beck, Ana Raquel Medeiros; Carmona, Elenice Valentim

    2017-07-10

    to investigate evidence in the literature on procedures for measuring gastric tube insertion in newborns and verifying its placement, using alternative procedures to radiological examination. an integrative review of the literature carried out in the Cochrane, LILACS, CINAHL, EMBASE, MEDLINE and Scopus databases using the descriptors "Intubation, gastrointestinal" and "newborns" in original articles. seventeen publications were included and categorized as "measuring method" or "technique for verifying placement". Regarding measuring methods, the measurements of two morphological distances and the application of two formulas, one based on weight and another based on height, were found. Regarding the techniques for assessing placement, the following were found: electromagnetic tracing, diaphragm electrical activity, CO2 detection, indigo carmine solution, epigastrium auscultation, gastric secretion aspiration, color inspection, and evaluation of pH, enzymes and bilirubin. the measuring method using nose to earlobe to a point midway between the xiphoid process and the umbilicus measurement presents the best evidence. Equations based on weight and height need to be experimentally tested. The return of secretion into the tube aspiration, color assessment and secretion pH are reliable indicators to identify gastric tube placement, and are the currently indicated techniques. investigar, na literatura, evidências sobre procedimentos de mensuração da sonda gástrica em recém-nascidos e de verificação do seu posicionamento, procedimentos alternativos ao exame radiológico. revisão integrativa da literatura nas bases Biblioteca Cochrane, LILACS, CINAHL, EMBASE, MEDLINE e Scopus, utilizando os descritores "intubação gastrointestinal" e "recém-nascido" em artigos originais. dezessete publicações foram incluídas e categorizadas em "método de mensuração" ou "técnica de verificação do posicionamento". Como métodos de mensuração, foram encontrados os de tomada

  19. An Investigation into the Effect of Cation-exchange on the Adsorption Performance of Indium-based Sodalite-ZMOF

    KAUST Repository

    Samin, Umer A.

    2016-04-13

    There is a pressing need for advanced solid-state materials that can be implemented in industrial gas separation processes to achieve separations with a significantly reduced energy input compared to what is typically required from current technologies. Although certain porous materials like zeolites bear some commercial significance for gas separation; their inherent lack of tunability limits the extent to which these materials may be exploited in industry. Zeolite-like Metal-Organic Frameworks (ZMOFs) are a sub-class of Metal-Organic Framework materials (MOFs) that show a structural semblance to zeolites while possessing the tunability advantages of MOF materials. ZMOFs which are topologically similar to certain zeolites can be functionalised and tuned in numerous ways to improve their gas separation properties. In this work, indium-based sod-ZMOF was tuned by cation-exchange and then characterised by different experimental tools such as single-crystal x-ray diffraction, elemental analysis and gas adsorption. It was found that various parameters like the choice of cation, the concentration of salt solution and the choice of solvent had a significant bearing on the cation-exchange of sod-ZMOF and its subsequent adsorption properties.

  20. A Review on Adsorption of Cationic Dyes using Activated Carbon

    Directory of Open Access Journals (Sweden)

    Corda Nikita Chrishel

    2018-01-01

    Full Text Available In this article efficiency of activated carbon as a potent adsorbent of cationic dyes has been reviewed. Non-biodegradable nature of pollutants and their removal in the present generation is a great challenge. Therefore, extensive study on adsorption of these classes of pollutants from water bodies is being carried out. Methylene blue (majorly a dye seen in the effluent streams of textile, printing, paper industries along with some of the commonly used cationic dyes in process industries and their sorption on activated carbon are reviewed here. High cost of commercially activated carbon which is a limitation to its extensive use have paved way for study of adsorption by naturally obtained and extracted activated carbon from agricultural wastes and various other sources. The purpose of this review paper is to summarize the available information on the removal of cationic dyes using naturally extracted and commercially obtained activated carbon. Various parameters such as temperature, initial dye concentration, pH, contact time, adsorbent dosage, particle size, stirring, agitation etc. were studied and the optimum parameters were determined based on the experimental outcomes. Equilibrium data was examined using Langmuir, Freundlich, Temkin and Dubinin–Radushkevich and few other isotherm models. Kinetic studies also have been carried out to find the most suitable way of expressing the adsorption process.

  1. The mechanochemical production of phenyl cations through heterolytic bond scission.

    Science.gov (United States)

    Shiraki, Tomohiro; Diesendruck, Charles E; Moore, Jeffrey S

    2014-01-01

    High mechanical forces applied to polymeric materials typically induce unselective chain scission. For the last decade, mechanoresponsive molecules, mechanophores, have been designed to harness the mechanical energy applied to polymers and provide a productive chemical response. The selective homolysis of chemical bonds was achieved by incorporating peroxide and azo mechanophores into polymer backbones. However, selective heterolysis in polymer mechanochemistry is still mostly unachieved. We hypothesized that highly polarized bonds in ionic species are likely to undergo heterolytic bond scission. To test this, we examined a triarylsulfonium salt (TAS) as a mechanophore. Poly(methyl acrylate) possessing TAS at the center of the chain (PMA-TAS) is synthesized by a single electron transfer living radical polymerization (SET-LRP) method. Computational and experimental studies in solution reveal the mechanochemical production of phenyl cations from PMA-TAS. Interestingly, the generated phenyl cation reacts with its counter-anion (trifluoromethanesulfonate) to produce a terminal trifluoromethyl benzene structure that, to the best of our knowledge, is not observed in the photolysis of TAS. Moreover, the phenyl cation can be trapped by the addition of a nucleophile. These findings emphasize the interesting reaction pathways that become available by mechanical activation.

  2. From cation to oxide: hydroxylation and condensation of aqueous complexes

    International Nuclear Information System (INIS)

    Jolivet, J.P.

    1997-01-01

    Hydroxylation, condensation and precipitation of metal cations in aqueous solution are briefly reviewed. Hydroxylation of aqueous complexes essentially depends on the format charge (oxidation state), the size and the pH of the medium. It is the step allowing the condensation reaction. Depending on the nature of complexes (aqua-hydroxo, oxo-hydroxo), the. mechanism of condensation is different, olation or ox-olation respectively. The first one leads to poly-cations or hydroxides more or less stable against dehydration. The second one leads to poly-anions or oxides. Oligomeric species (poly-cations, poly-anions) are form from charged monomer complexes while the formation of solid phases requires non-charged precursors. Because of their high lability, charged oligomers are never the precursors of solids phases. The main routes for the formation of solid phases from solution are studied with two important and representative elements, Al and Si. For Al 3+ ions, different methods (base addition in solution, thermo-hydrolysis, hydrothermal synthesis) are discussed in relation to the crystal structure of the solid phase obtained. For silicic species condensing by ox-olation, the role of acid or base catalysis on the morphology of gels is studied. The influence of complexing ligands on the processes and on the characteristics of solids (morphology of particles, basic salts and polymetallic oxides formation) is studied. (author)

  3. Metal cation uptake and reduction kinetics in microalgal cell culture

    Science.gov (United States)

    Kare, Anudeep

    This work was conducted to create a bio synthetic process for production of sustainable Nano materials, such as Noble metal nanoparticles with the use of living organisms as catalysts. Dactylococcus, Coelastrella and Chlamydomonas reinhardtii are the different species of algae used through which the Au and Ag nanoparticles are extracted. Under the appropriate bioprocess conditions phototrophic algal cell cultures can catalyze the conversion of soluble metal cations, such as trivalent gold cation (Au+3), to metallic gold nanoparticles (Au0 NP) and silver cation (Ag+) to metallic silver nanoparticles (Ag0 NP). The primary objective of this experiment is to identify the rate-limiting kinetics such as, mixing, biological, pH and so forth to see whether a scalable process can be proposed for production of these high valued materials. It is proposed in the literature that the reducing power required to drive this reaction is derived from the electron flux produced in the algae's photosynthetic apparatus. However, due to the lack of fundamental knowledge about the transport and kinetics, and therefore the bottlenecks and key process parameters, there is currently no scalable, controllable phototrophic system has been developed for the production of metallic nanoparticles.

  4. Electronically Unsaturated Three-Coordinate Aluminum Hydride and Organoaluminum Cations.

    Science.gov (United States)

    Prashanth, Billa; Bhandari, Mamta; Ravi, Satyam; Shamasundar, K R; Singh, Sanjay

    2018-02-16

    New three-coordinate and electronically unsaturated aluminum hydride [LAlH] + [HB(C 6 F 5 ) 3 ] - (LH=[{(2,6-iPr 2 C 6 H 3 N)P(Ph 2 )} 2 N]H) and aluminum methyl [LAlMe] + [MeB(C 6 F 5 ) 3 ] - cations have been prepared. The quantitative estimation of Lewis acidity by Gutmann-Beckett method revealed [LAlH] + [HB(C 6 F 5 ) 3 ] - to be better Lewis acid than B(C 6 F 5 ) 3 and AlCl 3 making these compounds ideal catalysts for Lewis acid-mediated reactions. To highlight that the work is of fundamental importance, catalytic hydroboration of aliphatic and aromatic aldehydes and ketones have been demonstrated. Important steps of the catalytic cycle have been probed by using multinuclear NMR measurements, including successful characterization of the proposed aluminum benzyloxide cationic intermediate, [LAl-O-CH 2 Ph] + [HB(C 6 F 5 ) 3 ] - . The proposed catalytic cycle has been found to be consistent with experimental observations and computational studies clearly indicating the migration of hydride from cationic aluminum center to the carbonyl carbon is the rate-limiting step of the catalytic cycle. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. The chemistry of separations ligand degradation by organic radical cations

    International Nuclear Information System (INIS)

    Mezyk, S.P.; Horne, G.P.; Mincher, B.J.; Zalupski, P.R.; Cook, A.R.; Wishart, J.F.

    2016-01-01

    Solvent based extractions of used nuclear fuel use designer ligands in an organic phase extracting ligand complexed metal ions from an acidic aqueous phase. These extractions will be performed in highly radioactive environments, and the radiation chemistry of all these complexing agents and their diluents will play a major role in determining extraction efficiency, separation factors, and solvent-recycle longevity. Although there has been considerable effort in investigating ligand damage occurring in acidic water radiolysis conditions, only minimal fundamental kinetic and mechanistic data has been reported for the degradation of extraction ligands in the organic phase. Extraction solvent phases typically use normal alkanes such as dodecane, TPH, and kerosene as diluents. The radiolysis of such diluents produce a mixture of radical cations (R .+ ), carbon-centered radicals (R . ), solvated electrons, and molecular products such as hydrogen. Typically, the radical species will preferentially react with the dissolved oxygen present to produce relatively inert peroxyl radicals. This isolates the alkane radical cation species, R .+ as the major radiolytically-induced organic species that can react with, and degrade, extraction agents in this phase. Here we report on our recent studies of organic radical cation reactions with 2 ligands: CMPO and TODGA. Elucidating these parameters, and combining them with the known acidic aqueous phase chemistry, will allow a full, fundamental, understanding of the impact of radiation on solvent extraction based separation processes to be achieved. (authors)

  6. Modulation of Group I Ribozyme Activity by Cationic Porphyrins

    Directory of Open Access Journals (Sweden)

    Shigeyoshi Matsumura

    2015-03-01

    Full Text Available The effects of cationic porphyrins on the catalytic activities of four group I ribozymes were investigated. A cationic porphyrin possessing four pyridinium moieties (pPyP inhibited two group IC3 ribozymes (Syn Rz and Azo Rz and a group IC1 ribozyme (Tet Rz. In the case of a group IA2 ribozyme (Td Rz, however, pPyP served not only as an inhibitor but also as an activator, and the effects of pPyP were dependent on its concentration. To analyze the structural and electronic factors determining the effects of pPyP on group I ribozymes, three cationic porphyrins (pPyNCP, pPyF4P, and TMPyP were also examined. As interactions between small organic molecules and nucleic acids are attractive and important issues in biochemistry and biotechnology, this study contributes to the development of porphyrin-based molecules that can modulate functions of structured RNA molecules.

  7. Drug loading to lipid-based cationic nanoparticles

    International Nuclear Information System (INIS)

    Cavalcanti, Leide P.; Konovalov, Oleg; Torriani, Iris L.; Haas, Heinrich

    2005-01-01

    Lipid-based cationic nanoparticles are a new promising option for tumor therapy, because they display enhanced binding and uptake at the neo-angiogenic endothelial cells, which a tumor needs for its nutrition and growth. By loading suitable cytotoxic compounds to the cationic carrier, the tumor endothelial and consequently also the tumor itself can be destroyed. For the development of such novel anti-tumor agents, the control of drug loading and drug release from the carrier matrix is essential. We have studied the incorporation of the hydrophobic anti-cancer agent Paclitaxel (PXL) into a variety of lipid matrices by X-Ray reflectivity measurements. Liposome suspensions from cationic and zwitterionic lipids, comprising different molar fractions of Paclitaxel, were deposited on planar glass substrates. After drying at controlled humidity, well ordered, oriented multilayer stacks were obtained, as proven by the presence of bilayer Bragg peaks to several orders in the reflectivity curves. The presence of the drug induced a decrease of the lipid bilayer spacing, and with an excess of drug, also Bragg peaks of drug crystals could be observed. From the results, insight into the solubility of Paclitaxel in the model membranes was obtained and a structural model of the organization of the drug in the membrane was derived. Results from subsequent pressure/area-isotherm and grazing incidence diffraction (GID) measurements performed with drug/lipid Langmuir monolayers were in accordance with these conjectures

  8. Sorption and fixation of large cations by shale formations

    International Nuclear Information System (INIS)

    Brindley, G.W.

    1977-01-01

    Large cations such as Cs + are preferentially sorbed and partially fixed by fine-grained 2 : 1 type layer silicates such as micas, vermiculites, smectites and various mixed-layer minerals. Since these minerals are common constituents of many shale formations, these formations may provide suitable location for the burial of radioactive waste containers. However, the usual investigations of cation sorption and fixation must be extended to the conditions likely to develop in the vicinity of buried radioactive waste. Prior to possible leakage from buried containers, elevated temperatures around the burial site will develop leading to hydrothermal modification of the surrounding mineralogy. A range of temperature and of mineralogy must be envisaged. If and when leakage occurs, an outward diffusion of radioactive ions will occur by solvation in the fluids in the shale. The ratio of radioactive ions/normal ions will diminish outwards from the source. At near distances from the source high temperature modifications of the clay minerals and high concentrations of radioactive cations may lead to saturation of the fixation capacity. At greater distances, little or no thermal modification of the clay minerals and lower concentrations of ions will permit maximum sorption and fixation

  9. Synthesis of cationic star polymers by simplified electrochemically mediated ATRP

    Directory of Open Access Journals (Sweden)

    P. Chmielarz

    2016-10-01

    Full Text Available Cyclodextrin-based cationic star polymers were synthesized using β-cyclodextrin (β-CD core, and 2-(dimethylamino ethyl methacrylate (DMAEMA as hydrophilic arms. Star-shaped polymers were prepared via a simplified electrochemically mediated ATRP (seATRP under potentiostatic and galvanostatic conditions. The polymerization results showed molecular weight (MW evolution close to theoretical values, and maintained narrow molecular weight distribution (MWD of obtained stars. The rate of the polymerizations was controlled by applying more positive potential values thereby suppressing star-star coupling reactions. Successful chain extension of the ω-functional arms with a hydrophobic n-butyl acrylate (BA formed star block copolymers and confirmed the living nature of the β-CD-PDMAEMA star polymers prepared by seATRP. Novelty of this work is that the β-CD-PDMAEMA-b-PBA cationic star block copolymers were synthesized for the first time via seATRP procedure, utilizing only 40 ppm of catalyst complex. The results from 1H NMR spectral studies support the formation of cationic star (copolymers.

  10. Selective Facet Reactivity During Cation Exchange in Cadmium Sulfide Nanorods

    Energy Technology Data Exchange (ETDEWEB)

    Sadtler, Bryce; Demchenko, Denis; Zheng, Haimei; Hughes, Steven; Merkle, Maxwell; Dahmen, Ulrich; Wang, Lin-Wang; Alivisatos, A. Paul

    2008-12-18

    The partial transformation of ionic nanocrystals through cation exchange has been used to synthesize nanocrystal heterostructures. We demonstrate that the selectivity for cation exchange to take place at different facets of the nanocrystal plays an important role in determining the resulting morphology of the binary heterostructure. In the case of copper I (Cu+) cation exchange in cadmium sulfide (CdS) nanorods, the reaction starts preferentially at the ends of the nanorods such that copper sulfide (Cu2S) grows inwards from either end. The resulting morphology is very different from the striped pattern obtained in our previous studies of silver I (Ag+) exchange in CdS nanorods where non-selective nucleation of silver sulfide (Ag2S) occurs. From interface formation energies calculated for several models of epitaxialconnections between CdS and Cu2S or Ag2S, we infer the relative stability of each interface during the nucleation and growth of Cu2S or Ag2S within the CdS nanorods. The epitaxial connections of Cu2S to the end facets of CdS nanorods minimize the formation energy, making these interfaces stable throughout the exchange reaction. However, as the two end facets of wurtzite CdS nanorods are crystallographically nonequivalent, asymmetric heterostructures can be produced.

  11. Verifying the botanical authenticity of commercial tannins through sugars and simple phenols profiles.

    Science.gov (United States)

    Malacarne, Mario; Nardin, Tiziana; Bertoldi, Daniela; Nicolini, Giorgio; Larcher, Roberto

    2016-09-01

    Commercial tannins from several botanical sources and with different chemical and technological characteristics are used in the food and winemaking industries. Different ways to check their botanical authenticity have been studied in the last few years, through investigation of different analytical parameters. This work proposes a new, effective approach based on the quantification of 6 carbohydrates, 7 polyalcohols, and 55 phenols. 87 tannins from 12 different botanical sources were analysed following a very simple sample preparation procedure. Using Forward Stepwise Discriminant Analysis, 3 statistical models were created based on sugars content, phenols concentration and combination of the two classes of compounds for the 8 most abundant categories (i.e. oak, grape seed, grape skin, gall, chestnut, quebracho, tea and acacia). The last approach provided good results in attributing tannins to the correct botanical origin. Validation, repeated 3 times on subsets of 10% of samples, confirmed the reliability of this model. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Issues to be verified by IFMIF prototype accelerator for engineering validation

    CERN Document Server

    Sugimoto, M; Okumura, Y; Nakayama, K; Suzuki, S; Saigusa, M

    2002-01-01

    The validation of the accelerator technology providing the 250 mA/40 MeV continuous-wave (CW) deuteron beam with the required quality is a key issue to realize the international fusion materials irradiation facility (IFMIF). As the difficulty of high current accelerator generally comes from the low energy section due to space-charge effects, a prototype test of such a part is planned in the next development phase. The optimal choice of the prototype consists of a full-scale injector, a full-modelled radiofrequency quadrupole, and a short drift tube linear accelerator associated with a beam diagnostics/dump. Through prototype tests, the stable control of the CW accelerator at the various operational conditions will be addressed, and the technical risks of IFMIF accelerator construction can be significantly reduced.

  13. Qualification and training of the trainers, verifiers, licensors and upper management

    International Nuclear Information System (INIS)

    Recker, M.

    1986-01-01

    Within the scope of technology transfer, also the know-how transfer should be included. It is no longer sufficient to train once the operating personnel, retraining and training of new employees must be performed during all the time. For the performance of training, qualified trainers and instructors should be available. A suitable training program will be explained in detail. To operate a plant effectively, it is important to train the operating personnel, but of the same importance is also to have a well functioning management, which will be achieved by training methods and programs to be defined in detail. The adherence to rules and regulations has to be controlled by authorities. The duties and the respective training programs are shown in this report. (orig.)

  14. Ultrasonic dyeing of cationized cotton fabric with natural dye. Part 1: cationization of cotton using Solfix E.

    Science.gov (United States)

    Kamel, M M; El Zawahry, M M; Ahmed, N S E; Abdelghaffar, F

    2009-02-01

    The dyeing of cationized cotton fabric with Solfix E using colouring matter extracted from Cochineal dye has been studied using both conventional and ultrasonic techniques. Factors affecting dye extraction such as ultrasound power, particle size, extraction temperature and time were studied. The results indicated that the extraction by ultrasound at 300 W was more effective at lower temperature and time than conventional extraction. The effect of various factors of dye bath such as pH, salt concentration, ultrasound power, dyeing time and temperature were investigated. The colour strength values obtained were found to be higher with ultrasound than with conventional techniques. The results of fastness properties of the dyed fabrics were fair to good. The scanning electron microscope (SEM) images of the morphological and X-ray analyzes were measured for cationized cotton fabrics dyed with both conventional and ultrasound methods, thus showing the sonicator efficiency.

  15. Verifying compliance with nuclear non-proliferation undertakings: IAEA safeguards agreements and additional protocols

    International Nuclear Information System (INIS)

    2008-06-01

    commonly used, for instance, in shielding on radioactive sources used in hospitals. Other radioactive material, such as most radioactive sources and isotopes used in medicine, industry, agriculture, and water resource management, are not the subject of safeguards and need not be reported to the IAEA under safeguards agreements. Reporting depends on the level of nuclear activity in the country. Declarations pursuant to safeguards agreements and additional protocols for States that do not have nuclear facilities are expected to be short and simple. The IAEA has prepared a document, available upon request, which provides guidance on the reporting requirements for such States. More elaborate guidelines have been prepared for States that do have nuclear facilities subject to routine safeguards inspections. Through its activities in the field, the IAEA seeks to verify the correctness and completeness of States' reports and declarations regarding nuclear material. Each State with a comprehensive safeguards agreement is required to establish and maintain a State system of accounting for and control of nuclear material (SSAC), which is the national authority formally designated to keep track of nuclear material and activities in the country. For all States with safeguards agreements in force, the IAEA draws an annual conclusion on the non-diversion of nuclear material and other items placed under safeguard. The IAEA's focal point for the negotiation of safeguards agreements and additional protocols, and the amendment of SQPs, is the Office of External Relations and Policy Coordination. Once a State has decided to conclude such an agreement and/or protocol, or amend its SQP, the IAEA can help the country with the implementation of related legal and technical requirements. The appendix of this publication informs how to conclude a comprehensive Safeguards Agreement and/or an Additional Protocol and provides 3 model notification letters for (a) conclusion of a safeguards agreement, a

  16. Verifying the distributed temperature sensing Bowen ratio method for measuring evaporation

    Science.gov (United States)

    Schilperoort, Bart; Coenders-Gerrits, Miriam; Luxemburg, Willem; Cisneros Vaca, César; Ucer, Murat

    2016-04-01

    Evaporation is an important process in the hydrological cycle, therefore measuring evaporation accurately is essential for water resource management, hydrological management and climate change models. Current techniques to measure evaporation, like eddy covariance systems, scintillometers, or lysimeters, have their limitations and therefore cannot always be used to estimate evaporation correctly. Also the conventional Bowen ratio surface energy balance method has as drawback that two sensors are used, which results in large measuring errors. In Euser et al. (2014) a new method was introduced, the DTS-based Bowen ratio (BR-DTS), that overcomes this drawback. It uses a distributed temperature sensing technique (DTS) whereby a fibre optic cable is placed vertically, going up and down along a measurement tower. One stretch of the cable is dry, the other wrapped with cloth and kept wet, akin to a psychrometer. Using this, the wet and dry bulb temperatures are determined every 12.5 cm over the height, from which the Bowen ratio can be determined. As radiation and wind have an effect on the cooling and heating of the cable's sheath as well, the DTS cables do not necessarily always measure dry and wet bulb temperature of the air accurately. In this study the accuracy in representing the dry and wet bulb temperatures of the cable are verified, and evaporation observations of the BR-DTS method are compared to Eddy Covariance (EC) measurements. Two ways to correct for errors due to wind and solar radiation warming up the DTS cables are presented: one for the dry cable and one for the wet cable. The measurements were carried out in a pine forest near Garderen (The Netherlands), along a 46-meter tall scaffold tower (15 meters above the canopy). Both the wet (Twet) and dry (Tdry) temperature of the DTS cable were compared to temperature and humidity (from which Twet is derived) observations from sensors placed along the height of the tower. Underneath the canopy, where there was

  17. The combination between cations and sulfated polysaccharide from abalone gonad (Haliotis discus hannai Ino).

    Science.gov (United States)

    Guo, Yiming; Cong, Shuang; Zhao, Jun; Dong, Yingying; Li, Tingting; Zhu, Beiwei; Song, Shuang; Wen, Chengrong

    2018-05-15

    Effects of cations (Na + , K + , Ca 2+ , Mg 2+ ) on the structure of abalone gonad sulfated polysaccharide (AGSP) were studied by means of Congo red test, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM). The results showed that the local ordered helical conformation was observed in AGSP. The cations could combine with anionic groups in AGSP by ionic bonds, which caused the weakening of electrostatic repulsion and crosslinking of molecular chains. Furthermore, the effects of divalent cations on the conformation were more obvious than that of monovalent cations, and divalent cations led to the aggregation of AGSP due to the more interaction sites. In short, AGSP molecular chains were crosslinked through ionic bonds after adding cations, and, divalent cations could induce the aggregation of AGSP by electrostatic interactions. This study will provide valuable insights for the further research on AGSP conformation. Copyright © 2018 Elsevier Ltd. All rights reserved.

  18. Movement of metal cations through the soil to the plant root membrane. Final technical report, June 1, 1966--November 30, 1978

    International Nuclear Information System (INIS)

    Barber, S.A.

    1978-11-01

    This project concerns metal cation flux through the soil and into the plant. Some highlights resulting from this research are as follows. Effect of soil properties on relative adsorption of Ca, Sr, K, Rb, and Cs by soil was measured. A theoretically developed concept explained differences between Ca and Sr adsorption on inorganic and organic exchange sites. A convenient method was developed to characterize cation absorption kinetics of intact plant roots. Use of this method showed genotypic variation in effect of ion concentration on influx. Corn absorbed Ca and Sr and K and Rb indiscriminantly. A method, using Ca/Sr and K/Rb ratio of ion influx into the plant, was developed to determine the source of these ions absorbed from the soil. Uptake of these ions from soil by corn was in the ratio on exchange sites rather than that in solution. The method was also used to compare uptake of chelated with ionized cations. A simulation model was developed that described ion flux from the soil into the plant. Ten independently measured soil and plant parameters were used. A computer program was prepared to calculate uptake with time. The model was verified in both growth chamber and field experiments

  19. effectiveness of technological options for minimising production risks

    African Journals Online (AJOL)

    ACSS

    preferred technologies in reducing production risk related to climate variability in Eastern Uganda. Data for this study were ..... Set of technological options employed by farmers to reduce climate-induced production risk. Dummy = 1 if farmer. 0.71. 0.46 ..... cation exchange capacity for holding nutrients against leaching loss.

  20. Development of a system to verify the programs used for planning of photon beams teletherapy

    International Nuclear Information System (INIS)

    Ocariz Ayala, Victor Daniel

    2004-12-01

    The main objective of radiotherapy is to deliver to the tumor the radiation dose prescribed by the physician, in the most possible accurate form, to save, as much as possible, the healthy tissues located in the neighborhood of the tumor. In order to reach these objectives, it is necessary to carry out a treatment planning and the more the used technologies and therapeutical procedures are sophisticated, the more the planning will be sophisticated. The most sophisticated planning systems use computer programs and are able to determine dose distributions in three dimensions. However, since they work using mathematical models, they may fail and it is necessary to evaluate their performances in order to be considered reliable. Therefore, the availability of a system capable to evaluate the performance of planning systems employed in oncological teletherapy, using ionizing radiation, becomes important. In this work, a data file to be used in radiotherapy planning system quality control (Algorithm accuracy and dose distribution) was developed and it is able to be sent by mail to the radiotherapy services that work with photon beams. (author)

  1. Cation-pi interaction of the univalent silver cation with racemic [6]helicene in the gas phase and in the solid state

    Czech Academy of Sciences Publication Activity Database

    Klepetářová, Blanka; Makrlík, E.; Sýkora, D.; Böhm, S.; Vaňura, P.

    2016-01-01

    Roč. 117, Oct 15 (2016), s. 1-6 ISSN 0277-5387 Institutional support: RVO:61388963 Keywords : univalent silver cation * [6]helicene * cation-pi interaction * DFT calculations * X-ray crystallography Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.926, year: 2016

  2. Anion and cation diffusion in barium titanate and strontium titanate

    International Nuclear Information System (INIS)

    Kessel, Markus Franz

    2012-01-01

    Perovskite oxides show various interesting properties providing several technical applications. In many cases the defect chemistry is the key to understand and influence the material's properties. In this work the defect chemistry of barium titanate and strontium titanate is analysed by anion and cation diffusion experiments and subsequent time-of-flight secondary ion mass spectrometry (ToF-SIMS). The reoxidation equation for barium titanate used in multi-layer ceramic capacitors (MLCCs) is found out by a combination of different isotope exchange experiments and the analysis of the resulting tracer diffusion profiles. It is shown that the incorporation of oxygen from water vapour is faster by orders of magnitude than from molecular oxygen. Chemical analysis shows the samples contain various dopants leading to a complex defect chemistry. Dysprosium is the most important dopant, acting partially as a donor and partially as an acceptor in this effectively acceptor-doped material. TEM and EELS analysis show the inhomogeneous distribution of Dy in a core-shell microstructure. The oxygen partial pressure and temperature dependence of the oxygen tracer diffusion coefficients is analysed and explained by the complex defect chemistry of Dy-doped barium titanate. Additional fast diffusion profiles are attributed to fast diffusion along grain boundaries. In addition to the barium titanate ceramics from an important technical application, oxygen diffusion in cubic, nominally undoped BaTiO 3 single crystals has been studied by means of 18 O 2 / 16 O 2 isotope exchange annealing and subsequent determination of the isotope profiles in the solid by ToF-SIMS. It is shown that a correct description of the diffusion profiles requires the analysis of the diffusion through the surface space-charge into the material's bulk. Surface exchange coefficients, space-charge potentials and bulk diffusion coefficients are analysed as a function of oxygen partial pressure and temperature. The

  3. 20 CFR 411.415 - Who will verify the establishment of agreements between ENs and State VR agencies?

    Science.gov (United States)

    2010-04-01

    ... agreements between ENs and State VR agencies? 411.415 Section 411.415 Employees' Benefits SOCIAL SECURITY ADMINISTRATION THE TICKET TO WORK AND SELF-SUFFICIENCY PROGRAM State Vocational Rehabilitation Agencies' Participation Agreements Between Employment Networks and State Vr Agencies § 411.415 Who will verify the...

  4. 30 CFR 253.27 - When I submit audited annual financial statements to verify my unencumbered assets, what...

    Science.gov (United States)

    2010-07-01

    ... Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR OFFSHORE OIL SPILL FINANCIAL... 30 Mineral Resources 2 2010-07-01 2010-07-01 false When I submit audited annual financial... financial statements to verify my unencumbered assets, what standards must they meet? Any audited annual...

  5. 49 CFR 40.137 - On what basis does the MRO verify test results involving marijuana, cocaine, amphetamines, or PCP?

    Science.gov (United States)

    2010-10-01

    ... involving marijuana, cocaine, amphetamines, or PCP? 40.137 Section 40.137 Transportation Office of the... results involving marijuana, cocaine, amphetamines, or PCP? (a) As the MRO, you must verify a confirmed positive test result for marijuana, cocaine, amphetamines, and/or PCP unless the employee presents a...

  6. Predictive value of soluble haemoglobin scavenger receptor CD163 serum levels for survival in verified tuberculosis patients

    DEFF Research Database (Denmark)

    Knudsen, T B; Gustafson, P; Kronborg, G

    2005-01-01

    Pre-treatment serum levels of sCD163 were measured in a cohort of 236 suspected tuberculosis (TB) cases from Guinea-Bissau, with a median follow-up period of 3.3 years (range 0-6.4 years). In 113 cases, the diagnosis of TB was verified by positive sputum microscopy and/or culture. Among the verif...

  7. 45 CFR 261.62 - What must a State do to verify the accuracy of its work participation information?

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 2 2010-10-01 2010-10-01 false What must a State do to verify the accuracy of its work participation information? 261.62 Section 261.62 Public Welfare Regulations Relating to Public Welfare OFFICE OF FAMILY ASSISTANCE (ASSISTANCE PROGRAMS), ADMINISTRATION FOR CHILDREN AND FAMILIES, DEPARTMENT OF HEALTH AND HUMAN SERVICES ENSURIN...

  8. 24 CFR 5.218 - Penalties for failing to disclose and verify Social Security and Employer Identification Numbers.

    Science.gov (United States)

    2010-04-01

    ... and verify Social Security and Employer Identification Numbers. 5.218 Section 5.218 Housing and Urban... REQUIREMENTS; WAIVERS Disclosure and Verification of Social Security Numbers and Employer Identification Numbers; Procedures for Obtaining Income Information Disclosure and Verification of Social Security...

  9. Cation-exchange high-performance liquid chromatography for variant hemoglobins and HbF/A2: What must hematopathologists know about methodology?

    OpenAIRE

    Sharma, Prashant; Das, Reena

    2016-01-01

    Cation-exchange high-performance liquid chromatography (CE-HPLC) is a widely used laboratory test to detect variant hemoglobins as well as quantify hemoglobins F and A2 for the diagnosis of thalassemia syndromes. It’s versatility, speed, reproducibility and convenience have made CE-HPLC the method of choice to initially screen for hemoglobin disorders. Despite its popularity, several methodological aspects of the technology remain obscure to pathologists and this may have consequences in spec...

  10. Efficient gene delivery to human umbilical cord mesenchymal stem cells by cationized Porphyra yezoensis polysaccharide nanoparticles

    Directory of Open Access Journals (Sweden)

    Yu Q

    2015-11-01

    Full Text Available Qingtong Yu,1,2 Jin Cao,2 Baoding Chen,3 Wenwen Deng,2 Xia Cao,2 Jingjing Chen,2 Yan Wang,2 Shicheng Wang,2 Jiangnan Yu,2 Ximing Xu,2 Xiangdong Gao1 1School of Life Science and Technology, China Pharmaceutical University, Nanjing, 2Department of Pharmaceutics, School of Pharmacy and Center for Drug/Gene Delivery and Tissue Engineering, Jiangsu University, 3Department of Medical Ultrasound, Affiliated Hospital of Jiangsu University, Zhenjiang, People’s Republic of China Abstract: This study centered on an innovative application of Porphyra yezoensis polysaccharide (PPS with cationic modification as a safe and efficient nonviral gene vector to deliver a plasmid encoding human Wnt3a (pWnt3a into human umbilical cord mesenchymal stem cells (HUMSCs. After modification with branched low-molecular-weight (1,200 Da polyethylenimine, the cationized PPS (CPPS was combined with pWnt3a to form spherical nanoscale particles (CPPS-pWnt3a nanoparticles. Particle size and distribution indicated that the CPPS-pWnt3a nanoparticles at a CPPS:pWnt3a weight ratio of 40:1 might be a potential candidate for DNA plasmid transfection. A cytotoxicity assay demonstrated that the nanoparticles prepared at a CPPS:pWnt3a weight ratio of 40:1 were nontoxic to HUMSCs compared to those of Lipofectamine 2000 and polyethylenimine (25 kDa. These nanoparticles were further transfected to HUMSCs. Western blotting demonstrated that the nanoparticles (CPPS:pWnt3a weight ratio 40:1 had the greatest transfection efficiency in HUMSCs, which was significantly higher than that of Lipofectamine 2000; however, when the CPPS:pWnt3a weight ratio was increased to 80:1, the nanoparticle-treated group showed no obvious improvement in translation efficiency over Lipofectamine 2000. Therefore, CPPS, a novel cationic polysaccharide derived from P. yezoensis, could be developed into a safe, efficient, nonviral gene vector in a gene-delivery system. Keywords: Porphyra yezoensis, nanoparticle

  11. [Effects of copper and zinc cations bound by gamma-globulin fraction in Staphylococcus aureus culture].

    Science.gov (United States)

    Cheknev, S B; Vostrova, E I; Piskovskaia, L S; Vostrov, A V

    2014-01-01

    AIM. Evaluation of Staphylococcus aureus culture growth dynamics in the presence of gamma-globulin: metal-complexes formed with copper and zinc cations as well as cations of metals used in isolation during the first 24 hours of exposition. . Samples of human gamma-globulin metal-complexes with copper or zinc cations at a final concentration of 0.5 microg/ml were introduced into S. aureus bacteria suspensions containing approximately 10(3) CFU/ml. Suspension at the volume of 5.0 ml was incubated at 37 degrees C for 24 hours with sampling and CFU calculation in the culture at various exposure periods. An accepted micromethod for determination of viability of bacteria was used. The protein transformed by copper cation binding realizes bacteriostatic activity in the logarithmic growth phase of S. aureus culture from 3.0 to 6.0 hours of incubation. Free copper cations inhibit bacterial reproduction at a higher degree than the metal-complex. The protein transformed by zinc cation binding realizes bacteriostatic activity at 1.5 hours of S. aureus incubation. Free zinc cations do not have bacteriostatic effect against S. aureus. Proteins of the gamma-globulin fraction in the range of physiological concentrations forming metal-complexes with copper and zinc cations may be factors that have cytostatic effect against S. aureus bacteria. Zinc cations realize bacteriostatic activity only in gamma-gloulin bound state whereas copper cations--also in the free state.

  12. Cationic and neutral copper (I) iodide cluster MOFs derived from ...

    Indian Academy of Sciences (India)

    By utilizing L¹, a cationic 2D-MOF {[(L¹) ₂ (Cu₆I₅)](OH) · 3DMF·4MeOH}n, 1 containing a rugby ball shaped discrete Cu₆I₅ cluster has been reported earlier. Formation of a new 3D-MOF {[(L²) ₂ (Cu₆I₄)](OH) ₂· 2DMF}n containing a Zintl type [(Cu₆I₄4) ² ⁺]n cluster chains is reported in this paper. A neutral cluster MOFs ...

  13. Spontaneous Superlattice Formation in Nanorods through PartialCation Exchange

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, Richard D.; Sadtler, Bryce; Demchenko, Denis O.; Erdonmez, Can K.; Wang, Lin-Wang; Alivisatos, A. Paul

    2007-03-14

    Lattice mismatch strains are widely known to controlnanoscale pattern formation in heteroepitaxy, but such effects have notbeen exploited in colloidal nanocrystal growth. We demonstrate acolloidal route to synthesizing CdS-Ag2S nanorod superlattices throughpartial cation exchange. Strain induces the spontaneous formation ofperiodic structures. Ab initio calculations of the interfacial energy andmodeling of strain energies show that these forces drive theself-organization. The nanorod superlattices exhibit high stabilityagainst ripening and phase mixing. These materials are tunablenear-infrared emitters with potential applications as nanometer-scaleoptoelectronic devices.

  14. Magnesium isotope fractionation in cation-exchange chromatography

    International Nuclear Information System (INIS)

    Oi, T.; Yanase, S.; Kakihana, H.

    1987-01-01

    Band displacement chromatography of magnesium has been carried out successfully for the purpose of magnesium isotope separation by using a strongly acidic cation-exchange resin and the strontium ion as the replacement ion. A small but definite accumulation of the heavier isotopes ( 25 Mg, 26 Mg) has been observed at the front parts of the magnesium chromatograms. The heavier isotopes have been fractionated preferentially into the solution phase. The single-stage separation factors have been calculated for the 25 Mg/ 24 Mg and 26 Mg/ 24 isotopic pairs at 25 0 C. The reduced partition function ratios of magnesium species involved in the present study have been estimated

  15. Detergent-like actions of linear amphipathic cationic antimicrobial peptides.

    Science.gov (United States)

    Bechinger, Burkhard; Lohner, Karl

    2006-09-01

    Antimicrobial peptides have raised much interest as pathogens become resistant against conventional antibiotics. We review biophysical studies that have been performed to better understand the interactions of linear amphipathic cationic peptides such as magainins, cecropins, dermaseptin, delta-lysin or melittin. The amphipathic character of these peptides and their interactions with membranes resemble the properties of detergent molecules and analogies between membrane-active peptide and detergents are presented. Several models have been suggested to explain the pore-forming, membrane-lytic and antibiotic activities of these peptides. Here we suggest that these might be 'special cases' within complicated phase diagrams describing the morphological plasticity of peptide/lipid supramolecular assemblies.

  16. Incorporation of Monovalent Cations in Sulfate Green Rust

    DEFF Research Database (Denmark)

    Christiansen, B. C.; Dideriksen, K.; Katz, A.

    2014-01-01

    with water showed that Na+ and K+ were structurally fixed in the interlayer, whereas Rb+ and Cs+ could be removed, resulting in a decrease in the basal layer spacing. The incorporation of cations in the interlayer opens up new possibilities for the use of sulfate green rust for exchange reactions with both......Green rust is a naturally occurring layered mixed-valent ferrous-ferric hydroxide, which can react with a range of redox-active compounds. Sulfate-bearing green rust is generally thought to have interlayers composed of sulfate and water. Here, we provide evidence that the interlayers also contain...

  17. Applications of pressurized cation exchange chromatography for fission yield determination

    International Nuclear Information System (INIS)

    Yan Shuheng; Lin Fa; Zhang Hongdi; Li Xueliang; Zhang Shulan

    1988-01-01

    In order to determine the fission yields of lanthanides precisely, lanthanides with carriers of 1-2 mg per element are separated from each other by means of pressurized cation exchange chromatography - αHIBA concentration gradient elution. The effect of initial loading technique, concentration gradient, flow rate, and temperature on separation were investigated in detail. Under the optimum conditions adapted according to the results given in this work, all the lanthanides can be completely separated within about 90 minutes with a recovery of more than 95% and purity higher than 99%. (author) 3 refs.; 6 figs

  18. Peak metamorphic temperatures from cation diffusion zoning in garnet

    DEFF Research Database (Denmark)

    Smit, Matthijs Arjen; Scherer, Erik; Mezger, Klaus

    2013-01-01

    is robust and provides a reliable means of estimating peak temperatures for different types of high-grade metamorphic rock. The tool could be of particular advantage in rocks where critical assemblages for conventional thermometry do not occur or have been replaced during retrogression.......) to develop a tool that uses the diffusion zoning of these cations in garnet to constrain peak temperature conditions for garnet-bearing rocks. The thermometric approach was externally tested by applying it to garnet crystals from various metamorphic terranes worldwide and comparing the results to published...

  19. Mass analyzed threshold ionization spectroscopy of indazole cation

    Science.gov (United States)

    Su, Huawei; Pradhan, Manik; Tzeng, Wen Bih

    2005-08-01

    We have recorded the two-color resonant two-photon mass analyzed threshold ionization (MATI) spectra of indazole via four intermediate states. The adiabatic ionization energy of this molecule is determined to be 67 534 ± 5 cm -1. The observed MATI bands include in-plane ring bending as well as out-of-plane ring twisting and bending vibrations of the indazole cation. Comparing the present data with those of indole and 7-azaindole leads to a better understanding about the influence of the nitrogen atom in the aza-aromatic bicyclic system.

  20. Elemental composition of some essential cations in human ocular tissue

    Energy Technology Data Exchange (ETDEWEB)

    Panessa-Warren, B.J.; Kraner, H.W.; Warren, J.B.

    1983-01-01

    To obtain data on the baseline elemental content in normal adult sensory retina, RPE and iris, normal non-diabetic eyes were analyzed and these results were used for comparison to similarly prepared samples from diabetic donor eyes. To determine if the concentrations of the cations, Ca, Ba and Zn were altered by the age, alimentation and exposure to light of the donor, tissue from children (from 25 weeks gestation to 8-1/2 years old) was also analyzed by x-ray fluorescence spectroscopy, proton induced x-ray emission spectroscopy, and light and electron (scanning and transmission) microscopy.

  1. Interaction of ethidium and tetraphenylphosphonium cations with Salmonella enterica cells

    Directory of Open Access Journals (Sweden)

    Valeryia Mikalayeva

    2017-01-01

    Conclusions: Results of our experiments indicate that ionic strength of the incubation medium influence the selectivity, the medium temperature and the assay conditions impact the kinetics of efflux. The lower accumulated amount and the weaker fluorescence of Et+ registered in slightly acidic medium indicate that ΔΨ plays a role in the accumulation of this indicator cation. The bound amount of Et+ to the de-energized or permeabilized cells considerably varies depending on the conditions and methods of de-energization or permeabilization of cells. Tris/EDTA permeabilization of the cells does not inhibit the efflux.

  2. Mars 2024/2026 Pathfinder Mission: Mars Architectures, Systems, & Technologies for Exploration and Resources

    Data.gov (United States)

    National Aeronautics and Space Administration — Integrate In Situ Resource Utilization (ISRU) sub-systems and examine advanced capabilities and technologies to verify Mars 2024 Forward architecture precursor...

  3. Zero-dipole molecular organic cations in mixed organic-inorganic halide perovskites: possible chemical solution for the reported anomalous hysteresis in the current-voltage curve measurements.

    Science.gov (United States)

    Giorgi, Giacomo; Yamashita, Koichi

    2015-11-06

    Starting from a brief description of the main architectures characterizing the novel solar technology of perovskite-based solar cells, we focus our attention on the anomalous hysteresis experimentally found to affect the measurement of the current-voltage curve of such devices. This detrimental effect, associated with slow dynamic reorganization processes, depends on several parameters; among them, the scan rate of the measurements, the architecture of the cell, and the perovskite deposition rate are crucial. Even if a conclusive explanation of the origin of the hysteresis has not been provided so far, several experimental findings ascribe its origin to ionic migration at an applied bias and dielectric polarization that occurs in the perovskite layer. Consistently, a dipole-moment-reduced cation such as formamidinium ion is experimentally reported to quantitatively reduce the hysteresis from perovskite-based devices. By means of a density-functional theory-based set of calculations, we have predicted and characterized guanidinium ion (GA = (+)[C(NH2)3], a zero-dipole moment cation by symmetry)-based organic-inorganic halide perovskite's structural and electronic properties, speculating that such a cation and the alloys it may form with other organic cations can represent a possible chemical solution for the puzzling issue of the hysteresis.

  4. Electrochemical investigations on cation-cation interaction between Np(V) and U(VI) in nitric acid medium

    International Nuclear Information System (INIS)

    Verma, P.K.; Murali, M.S.; Pathak, P.N.; Mohapatra, P.K.

    2014-01-01

    Ever since the first report on cation-cation interactions (CCIs) in 1961 by Sullivan et al., many researchers have worked on this using different techniques like optical spectroscopy and potentiometry. However, there is almost no report, in recent times, on this interesting subject using an electrochemical technique. In the present work, we set out to use simple cyclic voltammetry (CV) as a probe to study this phenomenon in the case of Np(V)-U(VI) in nitric acid medium. Accordingly, cyclic voltammograms were recorded individually for Np(V) , U(VI) in 4M HNO 3 and for solutions resulting from a titration of Np(V) with incremental additions of U(VI) in the same medium. These experiments were carried out using AutoLab 30 with three solid electrode system. Ag/AgCl was the reference electrode while Pt wires were used as working and counter electrode. The paper gives the part of CVs for successive additions of only U(VI) (1.4M) at fixed scan rate and room temperature. It can be seen that that the reduction peak shifts only slightly towards left with increased aliquots of U(VI). In contrast, the paper also gives the part of CVs for only U(VI) and for a titration mixture of fixed concentration of Np(V) and successive volume aliquot-additions of U(VI). It can be seen that there was no appreciable shift in the cathodic peak (∼ -0.15V) for additions of 1225μL of only U(VI) and 3225 μL of U(VI) in presence of Np. This showed that no change occurred till this composition. But with the addition of next aliquot of 4225μL of U(VI), there was an appreciable shift in the peak. This signified the formation of a new complex which can be attributed to the cation-cation interaction envisaged for Np(V)-U(VI). With further addition of an aliquot of 4725 μL of U(VI), it can be seen that again there was no appreciable shift in the cathodic peak position which probably underlined that the formation of the complex was complete

  5. Evidence for the Formation of Pyrimidine Cations from the Sequential Reactions of Hydrogen Cyanide with the Acetylene Radical Cation.

    Science.gov (United States)

    Hamid, Ahmed M; Bera, Partha P; Lee, Timothy J; Aziz, Saadullah G; Alyoubi, Abdulrahman O; El-Shall, M Samy

    2014-10-02

    Herein, we report the first direct evidence for the formation of pyrimidine ion isomers by sequential reactions of HCN with the acetylene radical cation in the gas phase at ambient temperature using the mass-selected variable temperature and pressure ion mobility technique. The formation and structures of the pyrimidine ion isomers are theoretically predicted via coupled cluster and density functional theory calculations. This ion-molecule synthesis may indicate that pyrimidine is produced in the gas phase in space environments before being incorporated into condensed-phase ices and transformed into nucleic acid bases such as uracil.

  6. PEMFC contamination model: Foreign cation exchange with ionomer protons

    Science.gov (United States)

    St-Pierre, Jean

    2011-08-01

    A generic, transient fuel cell ohmic loss mathematical model was developed for the case of contaminants that ion exchange with ionomer protons. The model was derived using step changes in contaminant concentration, constant operating conditions and foreign cation transport via liquid water droplets. In addition, the effect of ionomer cations redistribution within the ionomer on thermodynamic, kinetic and mass transport losses and migration were neglected. Thus, a simpler, ideal, ohmic loss case is defined and is applicable to uncharged contaminant species and gas phase contaminants. The closed form solutions were validated using contamination data from a membrane exposed to NH3. The model needs to be validated against contamination and recovery data sets including an NH4+ contaminated membrane exposed to a water stream. A method is proposed to determine model parameters and relies on the prior knowledge of the initial ionomer resistivity. The model expands the number of previously derived cases. Most models in this inventory, derived with the assumption that the reactant is absent, lead to different dimensionless current vs. time behaviors similar to a fingerprint. These model characteristics facilitate contaminant mechanism identification. Separation between membrane and catalyst (electroinactive contaminant) contamination is conceivably possible using additional indicative cell resistance measurements. Contamination is predicted to be significantly more severe under low relative humidity conditions.

  7. Crystal structure of the channelrhodopsin light-gated cation channel

    Science.gov (United States)

    Kato, Hideaki E.; Zhang, Feng; Yizhar, Ofer; Ramakrishnan, Charu; Nishizawa, Tomohiro; Hirata, Kunio; Ito, Jumpei; Aita, Yusuke; Tsukazaki, Tomoya; Hayashi, Shigehiko; Hegemann, Peter; Maturana, Andrés D.; Ishitani, Ryuichiro; Deisseroth, Karl; Nureki, Osamu

    2014-01-01

    Channelrhodopsins (ChRs) are light-gated cation channels derived from algae that have shown experimental utility in optogenetics; for example, neurons expressing ChRs can be optically controlled with high temporal precision within systems as complex as freely moving mammals. Although ChRs have been broadly applied to neuroscience research, little is known about the molecular mechanisms by which these unusual and powerful proteins operate. Here we present the crystal structure of a ChR (a C1C2 chimaera between ChR1 and ChR2 from Chlamydomonas reinhardtii) at 2.3 Å resolution. The structure reveals the essential molecular architecture of ChRs, including the retinal-binding pocket and cation conduction pathway. This integration of structural and electrophysiological analyses provides insight into the molecular basis for the remarkable function of ChRs, and paves the way for the precise and principled design of ChR variants with novel properties. PMID:22266941

  8. Crystal structures of the TRIC trimeric intracellular cation channel orthologues.

    Science.gov (United States)

    Kasuya, Go; Hiraizumi, Masahiro; Maturana, Andrés D; Kumazaki, Kaoru; Fujiwara, Yuichiro; Liu, Keihong; Nakada-Nakura, Yoshiko; Iwata, So; Tsukada, Keisuke; Komori, Tomotaka; Uemura, Sotaro; Goto, Yuhei; Nakane, Takanori; Takemoto, Mizuki; Kato, Hideaki E; Yamashita, Keitaro; Wada, Miki; Ito, Koichi; Ishitani, Ryuichiro; Hattori, Motoyuki; Nureki, Osamu

    2016-12-01

    Ca 2+ release from the sarcoplasmic reticulum (SR) and endoplasmic reticulum (ER) is crucial for muscle contraction, cell growth, apoptosis, learning and memory. The trimeric intracellular cation (TRIC) channels were recently identified as cation channels balancing the SR and ER membrane potentials, and are implicated in Ca 2+ signaling and homeostasis. Here we present the crystal structures of prokaryotic TRIC channels in the closed state and structure-based functional analyses of prokaryotic and eukaryotic TRIC channels. Each trimer subunit consists of seven transmembrane (TM) helices with two inverted repeated regions. The electrophysiological, biochemical and biophysical analyses revealed that TRIC channels possess an ion-conducting pore within each subunit, and that the trimer formation contributes to the stability of the protein. The symmetrically related TM2 and TM5 helices are kinked at the conserved glycine clusters, and these kinks are important for the channel activity. Furthermore, the kinks of the TM2 and TM5 helices generate lateral fenestrations at each subunit interface. Unexpectedly, these lateral fenestrations are occupied with lipid molecules. This study provides the structural and functional framework for the molecular mechanism of this ion channel superfamily.

  9. Source of Lake Vostok Cations Constrained with Strontium Isotopes

    Directory of Open Access Journals (Sweden)

    William Berry Lyons

    2016-08-01

    Full Text Available Lake Vostok is the largest sub-glacial lake in Antarctica. The primary source of our current knowledge regarding the geochemistry and biology of the lake comes from the analysis of refrozen lake water associated with ice core drilling. Several sources of dissolved ions and particulate matter to the lake have been proposed, including materials from the melted glacier ice, the weathering of underlying geological materials, hydrothermal activity and underlying, ancient evaporitic deposits. A sample of Lake Vostok Type 1 accretion ice has been analyzed for its 87Sr/86Sr signature as well as its major cation and anion and Sr concentrations. The strontium isotope ratio of 0.71655 and the Ca/Sr ratio in the sample strongly indicate that the major source of the Sr is from aluminosilicate minerals from the continental crust. These data imply that at least a portion of the other cations in the Type 1 ice also are derived from continental crustal materials and not hydrothermal activity, the melted glacier ice, or evaporitic sources.

  10. Characterization of cationic glycoporphyrins by electrospray tandem mass spectrometry.

    Science.gov (United States)

    Silva, Eduarda M P; Serra, Vanda Vaz; Ribeiro, Anderson O; Tomé, João P C; Domingues, Pedro; Faustino, M Amparo F; Neves, M Graça P M S; Tomé, Augusto C; Cavaleiro, José A S; Ferrer-Correia, António J; Iamamoto, Yassuko; Domingues, M Rosário M

    2006-01-01

    Novel cationic porphyrin derivatives having a galactose or a bis(isopropylidene)galactose unit linked directly to a pyridine or to an aminophenyl group were characterized by electrospray tandem mass spectrometry (ESI-MS/MS). The electrospray mass spectra (ESI-MS) show the M(+) ions, since these porphyrins are already monocharged in solution. The fragmentation of these ions under ESI-MS/MS conditions was studied and it was found that elimination of the sugar residue as a radical (-163 or -243 Da) is a common fragmentation pathway. Loss of the sugar unit as a neutral fragment (-162 or -242 Da) and cross-ring fragmentations typical of glyco-derivatives are also observed for the pyridinium glycoporphyrins, but they are absent in the case of ammonium glycoporphyrins. The cationic beta-pyridiniumvinyl porphyrins show an atypical fragmentation due to the cleavage of the C(5)-C(6) bond of the sugar unit. Overall, the different patterns of fragmentation observed in the ESI-MS/MS spectra of the sugar pyridinium porphyrins and of the sugar ammonium phenyl porphyrins can give important information about the type of spacer between the porphyrin and the sugar unit. Copyright (c) 2006 John Wiley & Sons, Ltd.

  11. Effects of cation concentration on photocatalytic performance over magnesium vanadates

    Energy Technology Data Exchange (ETDEWEB)

    Li, Peng [Catalytic Materials Group, Environmental Remediation Materials Unit, National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Zhou, Wei [Department of Physics, Tianjin University, 92 Weijin Road, Nankai District, Tianjin (China); Wang, Xin; Zhang, Yan; Wang, Defa [TU-NIMS Joint Research Center, School of Materials Science and Engineering, Tianjin University, 92 Weijin Road, Nankai District, Tianjin (China); Umezawa, Naoto, E-mail: UMEZAWA.Naoto@nims.go.jp, E-mail: ABE.Hideki@nims.go.jp; Abe, Hideki, E-mail: UMEZAWA.Naoto@nims.go.jp, E-mail: ABE.Hideki@nims.go.jp [Catalytic Materials Group, Environmental Remediation Materials Unit, National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); TU-NIMS Joint Research Center, School of Materials Science and Engineering, Tianjin University, 92 Weijin Road, Nankai District, Tianjin (China); PRESTO, Japan Science and Technology Agency (JST), 4-1-8 Honcho, Kawaguchi, Saitama 332-0012 (Japan); Ye, Jinhua [Catalytic Materials Group, Environmental Remediation Materials Unit, National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); TU-NIMS Joint Research Center, School of Materials Science and Engineering, Tianjin University, 92 Weijin Road, Nankai District, Tianjin (China); International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan)

    2015-10-01

    A series of magnesium vanadates (MgV {sub 2}O{sub 6}, Mg{sub 2}V {sub 2}O{sub 7}, and Mg{sub 3}V {sub 2}O{sub 8}) were synthesized to investigate the effect of cation concentration on photocatalytic performance. The samples were characterized by X-ray diffraction, field emission-scanning electron microscopy, UV-visible diffuse reflectance spectroscopy, and fluorescence spectroscopy. The photocatalytic O{sub 2} evolution experiments under visible light irradiation showed Mg{sub 2}V {sub 2}O{sub 7} exhibits the best performance, while Mg{sub 3}V {sub 2}O{sub 8} has the lowest activity. The density functional theory calculations indicated that the lowest unoccupied states of Mg{sub 3}V {sub 2}O{sub 8} are the mostly localized by the cation layers. The fluorescence spectra and fluorescence decay curves gave evident performances of excited states of magnesium vanadates and pointed out MgV {sub 2}O{sub 6} has a very short excited electron lift-time. Mg{sub 2}V {sub 2}O{sub 7} performs high photocatalytic activity because of its high electron mobility and long electron life-time.

  12. Correlation between cationic lipid-based transfection and cell division

    Energy Technology Data Exchange (ETDEWEB)

    Kirchenbuechler, Inka; Kirchenbuechler, David; Elbaum, Michael, E-mail: michael@elbaum.ac.il

    2016-07-01

    We evaluate the temporal relation between protein expression by cationic lipid-mediated transfection and cell division using time lapse fluorescence microscopy. Detailed image analysis provides new insights on the single cell level while simultaneously achieving appropriate statistics. Earlier evidence by less direct methods such as flow cytometry indicates a primary route for transfection involving nuclear envelope breakdown, but also suggests the existence of a pathway independent of mitosis. We confirm and quantify both mechanisms. We found the timing for successful transfection to be unexpectedly flexible, contrary to assertions of a narrow time window. Specifically, cells dividing more than 24 h after exposure to the transfection medium express the probed protein at a comparable level to cells in a mitotic state during or shortly after transfection. This finding can have a profound impact on the guidance and development of non-viral gene delivery materials. - Highlights: • Cationic lipid-based transfection supports protein expression without cell division. • Protein expression is unrelated to cell cycle status at the time of transfection. • Time-lapse imaging provides direct evaluation without statistical averaging. • Lipoplex dissociation is a likely target for improvement of transfection efficiency.

  13. Stretch-activated cation channel from larval bullfrog skin

    DEFF Research Database (Denmark)

    Hillyard, Stanley D; Willumsen, Niels J; Marrero, Mario B

    2010-01-01

    Cell-attached patches from isolated epithelial cells from larval bullfrog skin revealed a cation channel that was activated by applying suction (-1 kPa to -4.5 kPa) to the pipette. Activation was characterized by an initial large current spike that rapidly attenuated to a stable value and showed...... was markedly reduced with N-methyl-D-glucamide (NMDG)-Cl Ringer's solution in the pipette. Neither amiloride nor ATP, which are known to stimulate an apical cation channel in Ussing chamber preparations of larval frog skin, produced channel activation nor did these compounds affect the response to suction....... Stretch activation was not affected by varying the pipette concentrations of Ca(2+) between 0 mmol l(-1) and 4 mmol l(-1) or by varying pH between 6.8 and 8.0. However, conductance was reduced with 4 mmol l(-1) Ca(2+). Western blot analysis of membrane homogenates from larval bullfrog and larval toad skin...

  14. Coordination phenomena of cationic uranium(iv) complexes

    International Nuclear Information System (INIS)

    Rohwer, H.E.

    1974-12-01

    The coordination properties of the cationic uranium(IV) complexes UCl 3 + , UCl 2 2+ , UCl 3+ , and U 4+ were studied in a non-aqueous medium in the presence of perchlorate as counterion which, however, proved to coordinate to a much greater extent than expected. The strong neutral ligand, HMPA, could successively displace some of the perchlorates. An electrostatic model for the U(CIO 4 ) 4 -HMPA-acetone system compared favourably with the actual results. This emphasized the high ionic content in the bonding with actenoid cations, even with such a high charge as +4 . These conclusions are in agreement with studies 75 in which nitrate acts as counter ion. Correspondingly the uranium (IV) chemistry is characterized by the absence of typical 3d-organometallic chemistry, for example, strong bonding with CO, P(Phi) 3 etc, which strongly depends on covalent bonding. This stresses the fact that the d and f orbitals are not readily available for strong bond formation with the actenoids. 76

  15. Cation Dynamics Governed Thermal Properties of Lead Halide Perovskite Nanowires.

    Science.gov (United States)

    Wang, Yuxi; Lin, Renxing; Zhu, Pengchen; Zheng, Qinghui; Wang, Qianjin; Li, Deyu; Zhu, Jia

    2018-04-09

    Metal halide perovskite (MHP) nanowires such as hybrid organic-inorganic CH 3 NH 3 PbX 3 (X = Cl, Br, I) have drawn significant attention as promising building blocks for high-performance solar cells, light-emitting devices, and semiconductor lasers. However, the physics of thermal transport in MHP nanowires is still elusive even though it is highly relevant to the device thermal stability and optoelectronic performance. Through combined experimental measurements and theoretical analyses, here we disclose the underlying mechanisms governing thermal transport in three different kinds of lead halide perovskite nanowires (CH 3 NH 3 PbI 3 , CH 3 NH 3 PbBr 3 and CsPbBr 3 ). It is shown that the thermal conductivity of CH 3 NH 3 PbBr 3 nanowires is significantly suppressed as compared to that of CsPbBr 3 nanowires, which is attributed to the cation dynamic disorder. Furthermore, we observed different temperature-dependent thermal conductivities of hybrid perovskites CH 3 NH 3 PbBr 3 and CH 3 NH 3 PbI 3 , which can be attributed to accelerated cation dynamics in CH 3 NH 3 PbBr 3 at low temperature and the combined effects of lower phonon group velocity and higher Umklapp scattering rate in CH 3 NH 3 PbI 3 at high temperature. These data and understanding should shed light on the design of high-performance MHP based thermal and optoelectronic devices.

  16. Diffusion of anions and cations in compacted sodium bentonite

    International Nuclear Information System (INIS)

    Muurinen, A.

    1994-02-01

    The thesis presents the results of studies on the diffusion mechanisms of anions and cations in compacted sodium bentonite, which is planned to be used as a buffer material in nuclear waste disposal in Finland. The diffusivities and sorption factors were determined by tracer experiments. The pore volume accessible to chloride, here defined as effective porosity, was determined as a function of bentonite density and electrolyte concentration in water, and the Stern-Gouy double-layer model was used to explain the observed anion exclusion. The sorption of Cs + and Sr 2+ was studied in loose and compacted bentonite samples as a function of the electrolyte concentration in solution. In order to obtain evidence of the diffusion of exchangeable cations, defined as surface diffusion, the diffusivities of Cs + and Sr 2+ in compacted bentonite were studied as a function of the sorption factor, which was varied by electrolyte concentration in solution. The measurements were performed both by a non-steady state method and by a through-diffusion method. (89 refs., 35 fig., 4 tab.)

  17. Cationic two-photon induced polymerization with high dynamic range

    Science.gov (United States)

    Boiko, Yuri B.; Costa, Joannes; Wang, Mark M.; Esener, Sadik C.

    2001-05-01

    Cationic-induced two-photon photo-polymerization is demonstrated at 710 nm, using an isopropylthioxanthone / diarylidonium salt initiating system for the cationic polymerization of an epoxide. In-situ monitoring of the polymer conversion using interferometry allows for determination of the polymerization threshold J2th, polymerization rate R and its dependence of initiator's concentration z. Best J2th achieved is 1 GW/cm 2 , with a dynamic range of > 100, i.e. the material can be fully polymerized at intensities > 100 times the threshold level without damage. The R is found to be proportional to the m=1.7 power of the intensity, or R =[C(J-J2th)]m =[C(J-J2th)]1.7 , which implies a significantly stronger localization of the photochemical response than that of free radical photoinitiators. Both R and J2th significantly improve when the concentration z of the initiator (onium salt) increases, reduction of J2th exhibiting z -m trend.

  18. Column Chromatography To Obtain Organic Cation Sorption Isotherms.

    Science.gov (United States)

    Jolin, William C; Sullivan, James; Vasudevan, Dharni; MacKay, Allison A

    2016-08-02

    Column chromatography was evaluated as a method to obtain organic cation sorption isotherms for environmental solids while using the peak skewness to identify the linear range of the sorption isotherm. Custom packed HPLC columns and standard batch sorption techniques were used to intercompare sorption isotherms and solid-water sorption coefficients (Kd) for four organic cations (benzylamine, 2,4-dichlorobenzylamine, phenyltrimethylammonium, oxytetracycline) with two aluminosilicate clay minerals and one soil. A comparison of Freundlich isotherm parameters revealed isotherm linearity or nonlinearity was not significantly different between column chromatography and traditional batch experiments. Importantly, skewness (a metric of eluting peak symmetry) analysis of eluting peaks can establish isotherm linearity, thereby enabling a less labor intensive means to generate the extensive data sets of linear Kd values required for the development of predictive sorption models. Our findings clearly show that column chromatography can reproduce sorption measures from conventional batch experiments with the benefit of lower labor-intensity, faster analysis times, and allow for consistent sorption measures across laboratories with distinct chromatography instrumentation.

  19. Cationic Contrast Agent Diffusion Differs Between Cartilage and Meniscus.

    Science.gov (United States)

    Honkanen, Juuso T J; Turunen, Mikael J; Freedman, Jonathan D; Saarakkala, Simo; Grinstaff, Mark W; Ylärinne, Janne H; Jurvelin, Jukka S; Töyräs, Juha

    2016-10-01

    Contrast enhanced computed tomography (CECT) is a non-destructive imaging technique used for the assessment of composition and structure of articular cartilage and meniscus. Due to structural and compositional differences between these tissues, diffusion and distribution of contrast agents may differ in cartilage and meniscus. The aim of this study is to determine the diffusion kinematics of a novel iodine based cationic contrast agent (CA(2+)) in cartilage and meniscus. Cylindrical cartilage and meniscus samples (d = 6 mm, h ≈ 2 mm) were harvested from healthy bovine knee joints (n = 10), immersed in isotonic cationic contrast agent (20 mgI/mL), and imaged using a micro-CT scanner at 26 time points up to 48 h. Subsequently, normalized X-ray attenuation and contrast agent diffusion flux, as well as water, collagen and proteoglycan (PG) contents in the tissues were determined. The contrast agent distributions within cartilage and meniscus were different. In addition, the normalized attenuation and diffusion flux were higher (p meniscus. These tissue specific variations can affect the interpretation of CECT images and should be considered when cartilage and meniscus are assessed simultaneously.

  20. Methylene blue adsorption in clay mineral dealt with organic cation

    International Nuclear Information System (INIS)

    Silva, T.L.; Lemos, V.P.

    2011-01-01

    The interaction among organic cations, as the methylene blue (AM) and benzyltrimethylammonium (BTMA), and clay minerals of the group of the smectite they result in the formation of applied materials in the adsorption of organic pollutant presents in waters, soils and you cultivate. In this work they were prepared the adsorbents (organic-clays) smectite - AM and smectite-BTMA. The precursory sample of smectite was collected in Rio Branco-Acre. We were also used an smectite sample collected in Sena Madureira (SM)-Acre already characterized in previous work and a sample of standard smectite Swy-2-Na-Montmorillonite (SWy-2) of Wymong - USA. The organic agents selected for this study they were: Blue of Methylene, denominated AM and Benzyltrimethylammonium, denominated BTMA. They were appraised the capacities adsorptive of the treated samples with BTMA being used AM as adsorbate. The results of these evaluations detected that ran total adsorption of AM (concentrations varying from 1 to 10 ppm) for the treated samples with BTMA. The organic cation, BTMA, interacting with the surfaces of the natural clay was more efficient in the adsorption of AM than the clay without the previous treatment with this salt. (author)

  1. Effects of cation concentration on photocatalytic performance over magnesium vanadates

    Directory of Open Access Journals (Sweden)

    Peng Li

    2015-10-01

    Full Text Available A series of magnesium vanadates (MgV 2O6, Mg2V 2O7, and Mg3V 2O8 were synthesized to investigate the effect of cation concentration on photocatalytic performance. The samples were characterized by X-ray diffraction, field emission-scanning electron microscopy, UV-visible diffuse reflectance spectroscopy, and fluorescence spectroscopy. The photocatalytic O2 evolution experiments under visible light irradiation showed Mg2V 2O7 exhibits the best performance, while Mg3V 2O8 has the lowest activity. The density functional theory calculations indicated that the lowest unoccupied states of Mg3V 2O8 are the mostly localized by the cation layers. The fluorescence spectra and fluorescence decay curves gave evident performances of excited states of magnesium vanadates and pointed out MgV 2O6 has a very short excited electron lift-time. Mg2V 2O7 performs high photocatalytic activity because of its high electron mobility and long electron life-time.

  2. Cation incorporation into zirconium oxide in LiOH, NaOH, and KOH solutions

    International Nuclear Information System (INIS)

    Jeong, Y.H.; Kim, K.H.; Baek, J.H.

    1999-01-01

    To investigate the cation incorporation into zirconium oxide, SIMS analysis was performed on the specimens prepared to have an equal oxide thickness in LiOH, NaOH, and KOH solutions. Even though they have an equal oxide thickness in LiOH, NaOH, and KOH solutions, the penetration depth of cation into the oxide decreased with an increase in the ionic radius of cation. The cation is considered to control the corrosion in alkali hydroxide solutions and its effect is dependent on the concentration of alkali and the oxide thickness. The slight enhancement of the corrosion rate at a low concentration is thought to be caused by cation incorporation into oxide, while the significant acceleration at a high concentration is due to the transformation of oxide microstructures that would be also induced by cation incorporation into oxide. (orig.)

  3. Kinetics of styrene type radical cations generated by different ionization procedures

    International Nuclear Information System (INIS)

    Brede, O.; David, Frank

    1996-01-01

    In this paper the results from time-resolved experiments (pulse radiolysis, laser photolysis) on the formation of radical cations derived from styrene type olefins in solvents of different polarity are presented. The free olefin radical cations formed by charge transfer (in cyclohexane), two photon ionization or one electron oxidation (in aqueous solutions) dimerize to distonic radical cations or react with nucleophiles to produce benzyl type radicals. The decay of the dimer cation Ar-C·H-CH 2 -CH 2 -C + H-Ar seems to be determined by their ionic state: cationic polymerization in the case of free radical cations (one electron transfer ionization of styrenes), and intramolecular rearrangement to molecular dimer structures in the presence of counter ions [triplet sensitized electron transfer as reported by [Schepp and Johnston (1994) J. Am. Chem. Soc. 116, 6895]. (Author)

  4. Effect of alkyl length of cationic surfactants on desorption of Cs from contaminated clay

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Bo Hyun; Park, Chan Woo; Yang, Hee Man; Seo, Bum Kyoung; Lee, Kune Woo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Park, So Jin [Chungnam National University, Daejeon (Korea, Republic of)

    2017-03-15

    In this study, desorption characteristics of Cs from clay according to the hydrophobic alkyl chain length of the cationic surfactant were investigated. Alkyltrimethylammonium bromide was used as a cationic surfactant, and the length of the hydrophobic alkyl chain of the cationic surfactant was varied from –octyl to –cetyl. The adsorbed amount of the cationic surfactant on montmorillonite increased with the length of the hydrophobic alkyl chain, and intercalation of the cationic surfactant into the clay interlayer increased the interlayer distances. The Cs removal efficiency was also enhanced with increasing alkyl chain length, and the cationic surfactant with the cetyl group showed a maximum Cs removal efficiency of 99±2.9%.

  5. Structure and dynamics of olefin radical cation aggregates. Time-resolved fluorescence detected magnetic resonance

    International Nuclear Information System (INIS)

    Desrosiers, M.F.; Trifunac, A.D.

    1986-01-01

    The time-resolved EPR spectra and thus the structure and dynamics of transient hydrocarbon radical cations are obtained by the pulse radiolysis-fluorescence detected magnetic resonance (FDMR) technique. Here the authors report the observation of short-lived radical cations from olefins. FDMR-EPR spectra of radical cations from tetramethylethylene and cyclohexadiene are illustrated. The olefin radical cations, FDMR spectra are concentration-dependent, since dimerization with neutral molecules takes place at higher (>10 -2 M) olefin concentration. Rate constants for the dimerization reaction are derived and the effect of solvent viscosity on aggregate formation is demonstrated. By monitoring the further reactions of dimer cations the authors have obtained EPR evidence for previously unobserved higher-order (multimer) radical cation aggregates of olefins. 16 references, 5 figures

  6. Synergetic Influence of Alkali-Metal and Lone-Pair Cations on Frameworks of Tellurites.

    Science.gov (United States)

    Chen, Yi-Gang; Yang, Nan; Yao, Xiao-Ni; Li, Cheng-Bo; Guo, Yao; Zhang, Xian-Ming

    2018-04-11

    Four new tellurites were hydrothermally synthesized by the adjustment of different alkali-metal ions, and all of the compounds demonstrate 2D layer structures. Rb 2 Te 4 O 9 ·2H 2 O in centrosymmetric space group Pccn features a new [Te 4 O 9 ] ∞ 2- anion sheet consisting of rare [Te 8 O 22 ] 12- groups. RbNaTe 8 O 14 (OH) 6 ·8H 2 O in CS space group P1̅ exhibits a [Te 4 O 9 ] ∞ 2- anion layer by linkage of the TeO 3 and TeO 4 units. NaPb 4 Te 4 O 12 F located in CS space group P4/ n displays an unusual [PbTeO 3 ] ∞ neutral layer made up of PbO 3 and TeO 3 trigonal pyramids. RbK 3 Te 8 O 18 ·5H 2 O lying in noncentrosymmetric (NCS) space group Cc shows a [Te 4 O 9 ] ∞ 2- anion layer composed of the TeO 3 and TeO 4 units; its second-harmonic-generation response is about 0.2 times that of KH 2 PO 4 ; structure analysis and local dipole moment calculation verify that the weak polarization mostly from the [Te 4 O 9 ] ∞ 2- layer results from the inverse arrangement of TeO n units, and further theoretical calculation confirms that TeO n groups dominate the band gap of RbK 3 Te 8 O 18 ·5H 2 O and optical properties. Meanwhile, systematic analyses of a series of metal tellurites reveal that the alkali-metal cations exert a considerable impact on polarization of the crystal structures, which puts forward a feasible idea about the design of new NCS materials.

  7. Removal of metal cations from wastewater using recycled wool-based non-woven material

    Directory of Open Access Journals (Sweden)

    MAJA RADETIC

    2007-06-01

    Full Text Available In this study, the effect of low-temperature air plasma, biopolymer chitosan and hydrogen peroxide treatment of recycled wool-based non-woven material on metal cation uptake was investigated. Recycled wool-based material either as an untreated or modified material showed ability to bind all investigated metal cations in the following order: Pb2+>Cu2+>Zn2+>Co2+. Material performed good selectivity due to distinct sorption rates of studied metal cations.

  8. Acceptor ability of cations in reactions of donor-acceptor interaction

    International Nuclear Information System (INIS)

    Buchikhin, E.P.; Kuznetsov, A.Yu.; Chekmarev, A.M.; Bobyrenko, N.A.

    2007-01-01

    Analysis of literature data devoted to the problem of quantitative characteristics of cations in reactions of donor-acceptor interaction is represented. Relative acceptor numbers of Co 2+ , Mn 2+ , Ni 2+ , Al 3+ , Ga 3+ are determined by the method of polarography. Known relative acceptor numbers for 21 cations are systematized and linear dependence between ionization potentials and relative acceptor numbers of the rigid cations is determined [ru

  9. Early events following radiolytic and photogeneration of radical cations in hydrocarbons

    International Nuclear Information System (INIS)

    Werst, D.W.; Trifunac, A.D.

    1992-01-01

    Real-time studies in hydrocarbons have revealed a richness of chemistry involving the initial ionic species produced in radiolysis and photoionization. A modified radical cation mechanism patterned after the core mechanism for alkane radiolysis-formation of radical cations and their disappearance via ion-molecule reactions - is capable of explaining a wide range of observations in high-energy photochemistry, and thus unifies two high-energy regimes. Fundamental studies of radical cations suggest strategies for mitigating radiation effects in materials

  10. Interfacial Tryptophan Residues: A Role for the Cation-{pi} Effect?

    DEFF Research Database (Denmark)

    Petersen, Frederic Nicolas Rønne; Jensen, Morten Ø.; Helix Nielsen, Claus

    2005-01-01

    . Our criteria for cation-pi interactions are based on distance and angular requirements, and the results from our model suggest that cation-pi interactions are relevant for W(PE)(11), W(PE)(13), W(PE)(15), and, to some extent, W(PC)(11) and W(PC)(13). In our model, W(9)does not seem to engage in cation...

  11. Absorptive-mediated endocytosis of cationized albumin and a beta-endorphin-cationized albumin chimeric peptide by isolated brain capillaries. Model system of blood-brain barrier transport

    Energy Technology Data Exchange (ETDEWEB)

    Kumagai, A.K.; Eisenberg, J.B.; Pardridge, W.M.

    1987-11-05

    Cationized albumin (pI greater than 8), unlike native albumin (pI approximately 4), enters cerebrospinal fluid (CSF) rapidly from blood. This suggests that a specific uptake mechanism for cationized albumin may exist at the brain capillary wall, i.e. the blood-brain barrier. Isolated bovine brain capillaries rapidly bound cationized (/sup 3/H)albumin and approximately 70% of the bound radioactivity was resistant to mild acid wash, which is assumed to represent internalized peptide. Binding was saturable and a Scatchard plot gave a maximal binding capacity (Ro) = 5.5 +/- 0.7 micrograms/mgp (79 +/- 10 pmol/mgp), and a half-saturation constant (KD) = 55 +/- 8 micrograms/ml (0.8 +/- 0.1 microM). The binding of cationized (/sup 3/H)albumin (pI = 8.5-9) was inhibited by protamine, protamine sulfate, and polylysine (molecular weight = 70,000) with a Ki of approximately 3 micrograms/ml for all three proteins. The use of cationized albumin in directed delivery of peptides through the blood-brain barrier was examined by coupling (/sup 3/H)beta-endorphin to unlabeled cationized albumin (pI = 8.5-9) using the bifunctional reagent, N-succinimidyl 3-(2-pyridyldithio)proprionate. The (/sup 3/H)beta-endorphin-cationized albumin chimeric peptide was rapidly bound and endocytosed by isolated bovine brain capillaries, and this was inhibited by unlabeled cationized albumin but not by unconjugated beta-endorphin or native bovine albumin. Cationized albumin provides a new tool for studying absorptive-mediated endocytosis at the brain capillary and may also provide a vehicle for directed drug delivery through the blood-brain barrier.

  12. Verified Representations of Landau's "Grundlagen" in the lambda-delta Family and in the Calculus of Constructions

    Directory of Open Access Journals (Sweden)

    Ferruccio Guidi

    2016-01-01

    Full Text Available Landau's "Grundlagen der Analysis" formalized in the language Aut-QE, represents an early milestone in computer-checked mathematics and is the only non-trivial development finalized in the languages of the Automath family. Here we discuss an implemented procedure producing a faithful representation of the Grundlagen in the Calculus of Constructions, verified by the proof assistant Coq 8.4.3. The point at issue is distinguishing lambda-abstractions from pi-abstractions where the original text uses Automath unified binders, taking care of the cases in which a binder corresponds to both abstractions at one time. It is a fact that some binders can be disambiguated only by verifying the Grundlagen in a calculus accepting Aut-QE and the Calculus of Constructions. To this end, we rely on lambda-delta version 3, a system that the author is proposing here for the first time.

  13. Potential effect of cationic liposomes on interactions with oral bacterial cells and biofilms.

    Science.gov (United States)

    Sugano, Marika; Morisaki, Hirobumi; Negishi, Yoichi; Endo-Takahashi, Yoko; Kuwata, Hirotaka; Miyazaki, Takashi; Yamamoto, Matsuo

    2016-01-01

    Although oral infectious diseases have been attributed to bacteria, drug treatments remain ineffective because bacteria and their products exist as biofilms. Cationic liposomes have been suggested to electrostatically interact with the negative charge on the bacterial surface, thereby improving the effects of conventional drug therapies. However, the electrostatic interaction between oral bacteria and cationic liposomes has not yet been examined in detail. The aim of the present study was to examine the behavior of cationic liposomes and Streptococcus mutans in planktonic cells and biofilms. Liposomes with or without cationic lipid were prepared using a reverse-phase evaporation method. The zeta potentials of conventional liposomes (without cationic lipid) and cationic liposomes were -13 and 8 mV, respectively, and both had a mean particle size of approximately 180 nm. We first assessed the interaction between liposomes and planktonic bacterial cells with a flow cytometer. We then used a surface plasmon resonance method to examine the binding of liposomes to biofilms. We confirmed the binding behavior of liposomes with biofilms using confocal laser scanning microscopy. The interactions between cationic liposomes and S. mutans cells and biofilms were stronger than those of conventional liposomes. Microscopic observations revealed that many cationic liposomes interacted with the bacterial mass and penetrated the deep layers of biofilms. In this study, we demonstrated that cationic liposomes had higher affinity not only to oral bacterial cells, but also biofilms than conventional liposomes. This electrostatic interaction may be useful as a potential drug delivery system to biofilms.

  14. Disposal of heavy metal cations in aqueous media by adsorption on coal to Ghazni

    Directory of Open Access Journals (Sweden)

    О.М. Заславський

    2008-03-01

    Full Text Available  Adsorption of Pb and Cu cations and their mixture on the surface of modified and non-modified anti-gas coal trough different time intervals have been studied. The maximum adsorption capacity of coal relative to each cations have been determined. Absence  of concurrence between cations of Pb and Cu during adsorption from mixture is explained by difference of  types of their interaction with coal surface. The high effectiveness and perspectivities of application of anti-gas coal for neutralization of heavy metal cations in aqueous solution was shown.

  15. Resonance Raman and quantum chemical studies of short polyene radical cations

    DEFF Research Database (Denmark)

    Keszthelyi, T.; Wilbrandt, R.; Bally, T.

    1997-01-01

    The results of our investigations of the geometric and vibrational structures of some short conjugated polyene radical cations are reported. The radical cations of 1,3-butadiene and three of its deuterated isotopomers, trans- and cis-1,3-pentadiene, 2-methyl-1,3-butadiene, and E- and Z-1...... and to assist assignment of the resonance Raman spectra. A new and improved scaled quantum mechanical force field for the butadiene radical cation was also determined. The presence of more than one rotamer was observed in all the polyene radical cations we investigated. (C) 1997 Elsevier Science B.V....

  16. A Machine-Checked, Type-Safe Model of Java Concurrency : Language, Virtual Machine, Memory Model, and Verified Compiler

    OpenAIRE

    Lochbihler, Andreas

    2012-01-01

    The Java programming language provides safety and security guarantees such as type safety and its security architecture. They distinguish it from other mainstream programming languages like C and C++. In this work, we develop a machine-checked model of concurrent Java and the Java memory model and investigate the impact of concurrency on these guarantees. From the formal model, we automatically obtain an executable verified compiler to bytecode and a validated virtual machine.

  17. Socially Anxious Individuals’ Conflicted Emotional and Cognitive Responses to Self-Verifying and Self-Enhancing Others

    OpenAIRE

    Szpunar, Marlena M.

    2014-01-01

    This study investigated how individuals with social anxiety respond to others who provide them with positive (self-enhancing) or negative (self-verifying) feedback. The findings are based on data from 276 undergraduate students (74 males and 202 females). Participants completed a standardized measure of social anxiety and then answered questions about themselves in front of a one-way mirror. They received positive and negative written feedback on their social abilities supposedly from two stu...

  18. ENVIRONMENTAL TECHNOLOGY VERIFICATION COATINGS AND COATING EQUIPMENT PROGRAM (ETV CCEP), FINAL TECHNOLOGY APPLICATIONS GROUP TAGNITE--TESTING AND QUALITY ASSURANCE PLAN (T/QAP)

    Science.gov (United States)

    The overall objective of the Environmental Testing and Verification Coatings and Coating Equipment Program is to verify pollution prevention and performance characteristics of coating technologies and make the results of the testing available to prospective coating technology use...

  19. Kinetic Analyses of Cation Exchange Rates in Synthetic Birnessite Measured by Time- Resolved Synchrotron X-ray Diffraction

    Science.gov (United States)

    Lopano, C. L.; Heaney, P. J.; Post, J. E.; Bandstra, J.; Brantley, S. L.

    2006-05-01

    Birnessite is the most abundant and chemically important layer-structure Mn-oxide phase found in soils, desert varnishes, and ocean nodules. It also is industrially important for use in battery technology and octahedral sieves. Due to the poorly crystalline nature of natural birnessite, synthetic analogues typically have been employed in studies that explore the structural response of birnessite to variations in interlayer composition. For this work, we measured changes in unit-cell parameters over time to quantify the degree of cation exchange as a function of concentration. Aqueous K+, Cs+, and Ba2+ cations at varying concentrations at pH 7 were exchanged for interlayer Na+ in synthetic birnessite (Na0.58(Mn4+1.42,Mn3+0.58)O4·1.5H2O) using a simple flow- through cell, and the exchange products were monitored via time-resolved X-ray powder diffraction at the National Synchrotron Light Source. Powder X-ray diffraction patterns were collected every 2-3 minutes. Rietveld analyses of X-ray diffraction patterns for K- and Ba-exchanged birnessite revealed a decrease in unit- cell volume over time. In contrast, Cs+ substitution increased cell volume. For all three cations, the crystallographic data indicate that exchange occurred in two stages. A rapid and dramatic change in unit-cell volume was followed by a modest adjustment over longer timescales. Fourier electron difference syntheses revealed that the rapid, initial stage of exchange was marked by re-configuration of the interlayer species, whereas the second, protracted phase of substitution represented ordering into the newly established interlayer positions. For the first time, we have modeled the kinetics of interlayer substitution in Na-birnessite. For purposes of comparison, we have employed a simple one-stage reaction (i.e., Na-birnessite → K-birnessite) and a two stage reaction (i.e,. Na-birnessite → K-birnessitedisordered → K- birnessiteordered). For exchange with 0.01 M KCl solutions, the single

  20. Correlation between cationic lipid-based transfection and cell division.

    Science.gov (United States)

    Kirchenbuechler, Inka; Kirchenbuechler, David; Elbaum, Michael

    2016-07-01

    We evaluate the temporal relation between protein expression by cationic lipid-mediated transfection and cell division using time lapse fluorescence microscopy. Detailed image analysis provides new insights on the single cell level while simultaneously achieving appropriate statistics. Earlier evidence by less direct methods such as flow cytometry indicates a primary route for transfection involving nuclear envelope breakdown, but also suggests the existence of a pathway independent of mitosis. We confirm and quantify both mechanisms. We found the timing for successful transfection to be unexpectedly flexible, contrary to assertions of a narrow time window. Specifically, cells dividing more than 24h after exposure to the transfection medium express the probed protein at a comparable level to cells in a mitotic state during or shortly after transfection. This finding can have a profound impact on the guidance and development of non-viral gene delivery materials. Copyright © 2016. Published by Elsevier Inc.