Analysis of interlocking performances on non-oriented electrical steels

Science.gov (United States)

Liu, Li-Hsiang; Liu, Lee-Cheng

2018-05-01

In order to reduce energy loss in motor, applications of high-efficiency non-oriented electrical steel sheets and optimal laminating process are both important elements. The motor core loss deterioration is influenced by a number of factors, such as flux distribution, stress and strain, space harmonics, temperature, and short circuits between lamination. In conventional clamping method, steel sheets are laminated via interlocking or welding in general manner. The measured energy loss by welding was much larger than that by interlocking. Therefore, interlocking is well known and usually employed with benefit of easy conducting. The protuberance shapes affected the fastening strength. Generally, the intensity of rectangular type is stronger than the circular counterparts. However, the circular interlocking has better magnetic characteristics. To clarify the method effectiveness, interlocking performances regarding fastened strength and magnetic deterioration by lamination were investigated. The key parameters of protuberance shape and forming depth were designed. Precisely manufacturing operation was applied to avoid interlocking failure. Magnetic properties largely influenced by clamping method are crucial to minimizing the magnetic deterioration during laminating procedure. Several experiments for various processing conditions were undertaken, and the quantification results showed the rectangular interlocking had better fastened strength but worsened iron loss comparing with the circular arrangement. To acquire the comprehensive mechanical and electrical identities for electrical steel lamination, deliberate producing conditions regarding minimizing the magnetic deterioration should be adopted prudently.

Interlock system of electron beam machine GJ-2

International Nuclear Information System (INIS)

Marnada, Nada

1999-01-01

As an irradiation installation facility, the electron beam machine (EBM) irradiation facility which use radionuclide as radiation source. There are three safety aspects to be considered in the facility i.e the safeties for human, machines, and samples to be irradiated. The safety aspect for human is to the radiation hazard and the safety aspect for machine and sample is to the damage as the result of operating failure. In the EBM GJ-2 (made in China) twelve interlock system parameter are installed to keep all of the safety aspects. Each interlock system consist transducer that controls a certain switch, a magnetic relay, and visible and audible interlock indicators to improve the reliability of interlock systems a method called redundancy method is applied to the systems of operation of high voltage. (author)

Automated generation of formal safety conditions from railway interlocking tables

DEFF Research Database (Denmark)

Haxthausen, Anne Elisabeth

2014-01-01

This paper describes a tool for extracting formal safety conditions from interlocking tables for railway interlocking systems. The tool has been applied to generate safety conditions for the interlocking system at Stenstrup station in Denmark, and the SAL model checker tool has been used to check...

Applied Bounded Model Checking for Interlocking System Designs

DEFF Research Database (Denmark)

Haxthausen, Anne Elisabeth; Peleska, Jan; Pinger, Ralf

2014-01-01

In this paper the verification and validation of interlocking systems is investigated. Reviewing both geographical and route-related interlocking, the verification objectives can be structured from a perspective of computer science into (1) verification of static semantics, and (2) verification o...

Applied Bounded Model Checking for Interlocking System Designs

DEFF Research Database (Denmark)

Haxthausen, Anne Elisabeth; Peleska, Jan; Pinger, Ralf

2013-01-01

In this article the verification and validation of interlocking systems is investigated. Reviewing both geographical and route-related interlocking, the verification objectives can be structured from a perspective of computer science into (1) verification of static semantics, and (2) verification...

Formal modelling and verification of interlocking systems featuring sequential release

DEFF Research Database (Denmark)

Vu, Linh Hong; Haxthausen, Anne Elisabeth; Peleska, Jan

2017-01-01

In this article, we present a method and an associated toolchain for the formal verification of the new Danish railway interlocking systems that are compatible with the European Train Control System (ETCS) Level 2. We have made a generic and reconfigurable model of the system behaviour and generic...... safety properties. This model accommodates sequential release - a feature in the new Danish interlocking systems. To verify the safety of an interlocking system, first a domain-specific description of interlocking configuration data is constructed and validated. Then the generic model and safety...

Formal Verification of the Danish Railway Interlocking Systems

DEFF Research Database (Denmark)

Vu, Linh Hong; Haxthausen, Anne Elisabeth; Peleska, Jan

2014-01-01

in the new Danish interlocking systems. Instantiating the generic model with interlocking configuration data results in a concrete model and high-level safety properties. Using bounded model checking and inductive reasoning, we are able to verify safety properties for model instances corresponding to railway...

Enhancing the Use of Vehicle Alcohol Interlocks With Emerging Technology.

Science.gov (United States)

Voas, Robert B

2014-01-01

Among the earliest applications of health technologies to a safety program was the development of blood alcohol content (BAC) tests for use in impaired-driving enforcement. This led to the development of miniature, highly accurate devices that officers could carry in their pockets. A natural extension of this technology was the vehicle alcohol interlock, which is used to reduce recidivism among drivers convicted of driving under the influence (DUI) by requiring them to install the devices (which will not allow someone with a positive BAC to drive) on their vehicles. While on the vehicle, interlocks have been shown to reduce recidivism by two-thirds. Use of these devices has been growing at the rate of 10 to 15 percent a year, and there currently are more than 300,000 units in use. This expansion in the application of interlocks has benefited from the integration of other emerging technologies into interlock systems. Such technologies include data systems that record both driver actions and vehicle responses, miniature cameras and face recognition to identify the user, Wi-Fi systems to provide rapid reporting on offender performance and any attempt to circumvent the device, GPS tracking of the vehicle, and more rapid means for monitoring the integrity of the interlock system. This article describes how these health technologies are being applied in interlock programs and the outlook for new technologies and new court sanctioning programs that may influence the growth in the use of interlocks in the future.

A new interlock design for the TESLA RF system

International Nuclear Information System (INIS)

Leich, H.; Kahl, J.; Choroba, S.; Grevsmuehl, T.; Heidbrook, N.

2001-01-01

The RF system for TESLA requires a comprehensive interlock system. Usually interlock systems are organized in a hierarchical way. In order to react to different fault conditions in a fast and flexible manner a nonhierarchical organization seems to be the better solution. At the TESLA Test Facility (TTF) at DESY the authors will install a nonhierarchical interlock system that is based on user designed reprogrammable gate-arrays (FPGA's) which incorporate an embedded microcontroller system. This system could be used later for the TESLA linear collider replacing a strictly hierarchical design

PLC-based interlock system for superconducting magnets

International Nuclear Information System (INIS)

Agostini, R.C.; Barker, L.; Hodgers, J.; Reagan, D.; Walz, H.V.

1989-01-01

Conventional interlock systems rely heavily on hard-wired electromagnetic relays. Although this approach is well understood and has proven to be reliable, several drawbacks plague the designer as well as the repairman. If larger systems have to be implemented in relay logic, the complexity limit is soon reached; the systems become too bulky, and wiring expenses sky-rocket; moreover, the intelligence of those designs is limited in such a way that desirable features such as self-tests have to be left out. Additionally, relay interlocks are inherently inflexible: if the configuration of the system they protect has to change, a disproportional amount of time, work and money has to be invested in order to adapt the hard-wiring of the interlock system to the new requirements. Repair work is often unnecessarily delayed due to the lack of adequate documentation

Hardwired interlock system with fault latchability and annunciation panel for electron accelerators

International Nuclear Information System (INIS)

Mukesh Kumar; Roychoudhury, P.; Nimje, V.T.

2011-01-01

A hard-wired interlock system is designed, developed, installed and tested to ensure healthy status for interlock signals, coming from the various sub-systems of electron accelerators as digital inputs. Each electron accelerator has approximately ninety-six interlock signals. Hardwired Interlock system consists of twelve-channel 19 inches rack mountable hard-wired interlock module of 4U height. Digital inputs are fed to the hard-wired interlock module in the form of 24V dc for logic 'TRUE' and 0V for logic 'FALSE'. These signals are flow signals to ensure cooling of the various sub-systems, signals from the klystron modulator system in RF Linac to ensure its healthy state to start, signals from high voltage system of DC accelerator, vacuum signals from vacuum system to ensure proper vacuum in the electron accelerator, door interlock signals, air flow signals, and area search and secure signals. This hard-wired interlock system ensures the safe start-up, fault annunciation and alarm, fault latchablity, and fail-safe operation of the electron accelerators. Safe start-up feature ensures that beam generation system can be made ON only when cooling of all the electron accelerator sub-systems are confirmed, all the fault signals of high voltage generation system are attended, proper vacuum is achieved inside the beam transport system, all the doors are closed and various areas have been searched and secured manually. Fault annunciation and alarm feature ensures that during the start up and operation of the electron accelerators, if any fault is there, that fault signal window keeps on flashing with red colour and alarm is sounded till the operator acknowledges the fault. Once acknowledged, flashing and alarm stops but display of the window in red colour remains till the operator clears the fault. Fault latchability feature ensures that if any fault has happened, accelerator cannot be started again till the operator resets that interlock signal. Fail-safe feature ensures

JET neutral beam duct Optical Interlock

Energy Technology Data Exchange (ETDEWEB)

Ash, A.D.; Jones, T.T.C.; Surrey, E.; Ćirić, D.; Hall, S.I.; Young, D.; Afzal, M.; Hackett, L.; Day, I.E.; King, R.

2015-10-15

Highlights: • Optical Interlocks were installed on the JET NBI system as part of the EP2 upgrade. • The system protects the JET tokamak and NBI systems from thermal load damage. • Balmer-α beam emission is used to monitor the neutral beam-line pressure. • We demonstrate an improved trip delay of 2 ms compared to 50 ms before EP2. - Abstract: The JET Neutral Beam Injection (NBI) system is the most powerful neutral beam plasma heating system currently operating. Optical Interlocks were installed on the beam lines in 2011 for the JET Enhancement Project 2 (EP2), when the heating power was increased from 23 MW to 34 MW. JET NBI has two beam lines. Each has eight positive ion injectors operating in deuterium at 80 kV–125 kV (accelerator voltage) and up to 65 A (beam current). Heating power is delivered through two ducts where the central power density can be more than 100 MW/m{sup 2}. In order to deliver this safely, the beam line pressure should be below 2 × 10{sup −5} mbar otherwise the power load on the duct from the re-ionised fraction of the beam is excessive. The new Optical Interlock monitors the duct pressure by measuring the Balmer-α beam emission (656 nm). This is proportional to the instantaneous beam flux and the duct pressure. Light is collected from a diagnostic window and focused into 1-mm diameter fibres. The Doppler shifted signal is selected using an angle-tuned interference filter. The light is measured by a photo-multiplier module with a logarithmic amplifier. The interlock activation time of 2 ms is sufficient to protect the system from a fully re-ionised beam—a significant improvement on the previous interlock. The dynamic range is sufficient to see bremsstrahlung emission from JET plasma and not saturate during plasma disruptions. For high neutron flux operations the optical fibres within the biological shield can be annealed to 350 °C. A self-test is possible by illuminating the diagnostic window with a test lamp and measuring

Software Development for Auto-Generation of Interlocking Knowledge base using Artificial Intelligence Approach

Energy Technology Data Exchange (ETDEWEB)

Ko, Yun Seok [Nanseoul University (Korea); Kim, JOng Sun [Kwangwoon University (Korea)

1999-06-01

This paper proposes IIKBAG (Intelligent Interlocking Knowledge Base Generator) which can build automatically the interlocking knowledge base utilized as the real-time interlocking strategy of the electronic interlocking system in order to enhance it's reliability and expansion. The IIKBAG consists of the inference engine and the knowledge base. The former has an auto-learning function which searches all the train routes for the given station model based on heuristic search technique while dynamically searching the model, and then generates automatically the interlocking patterns obtained from the interlocking relations of signal facilities on the routes. The latter is designed as the structure which the real-time expert system embedded on IS (Interlocking System) can use directly in order to enhances the reliability and accuracy. The IIKBAG is implemented in C computer language for the purpose of the build and interface of the station structure database. And, a typical station model is simulated to prove the validity of the proposed IIKBAG. (author). 13 refs., 5 figs., 2 tabs.

49 CFR 236.340 - Electromechanical interlocking machine; locking between electrical and mechanical levers.

Science.gov (United States)

2010-10-01

... Electromechanical interlocking machine; locking between electrical and mechanical levers. In electro-mechanical interlocking machine, locking between electric and mechanical levers shall be maintained so that mechanical... 49 Transportation 4 2010-10-01 2010-10-01 false Electromechanical interlocking machine; locking...

49 CFR 236.312 - Movable bridge, interlocking of signal appliances with bridge devices.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Movable bridge, interlocking of signal appliances with bridge devices. 236.312 Section 236.312 Transportation Other Regulations Relating to... SYSTEMS, DEVICES, AND APPLIANCES Interlocking Standards § 236.312 Movable bridge, interlocking of signal...

Poly[n]catenanes: Synthesis of molecular interlocked chains

Science.gov (United States)

Wu, Qiong; Rauscher, Phillip M.; Lang, Xiaolong; Wojtecki, Rudy J.; de Pablo, Juan J.; Hore, Michael J. A.; Rowan, Stuart J.

2017-12-01

As the macromolecular version of mechanically interlocked molecules, mechanically interlocked polymers are promising candidates for the creation of sophisticated molecular machines and smart soft materials. Poly[n]catenanes, where the molecular chains consist solely of interlocked macrocycles, contain one of the highest concentrations of topological bonds. We report, herein, a synthetic approach toward this distinctive polymer architecture in high yield (~75%) via efficient ring closing of rationally designed metallosupramolecular polymers. Light-scattering, mass spectrometric, and nuclear magnetic resonance characterization of fractionated samples support assignment of the high-molar mass product (number-average molar mass ~21.4 kilograms per mole) to a mixture of linear poly[7-26]catenanes, branched poly[13-130]catenanes, and cyclic poly[4-7]catenanes. Increased hydrodynamic radius (in solution) and glass transition temperature (in bulk materials) were observed upon metallation with Zn2+.

30 CFR 75.819 - Motor-starter enclosures; barriers and interlocks.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Motor-starter enclosures; barriers and...-Voltage Distribution High-Voltage Longwalls § 75.819 Motor-starter enclosures; barriers and interlocks. Compartment separation and cover interlock switches for motor-starter enclosures must be maintained in...

Rheology of three-dimensional packings of aggregates: microstructure and effects of nonconvexity.

Science.gov (United States)

Azéma, Emilien; Radjaï, Farhang; Saint-Cyr, Baptiste; Delenne, Jean-Yves; Sornay, Philippe

2013-05-01

We use three-dimensional contact dynamics simulations to analyze the rheological properties of granular materials composed of rigid aggregates. The aggregates are made from four overlapping spheres and described by a nonconvexity parameter depending on the relative positions of the spheres. The macroscopic and microstructural properties of several sheared packings are analyzed as a function of the degree of nonconvexity of the aggregates. We find that the internal angle of friction increases with the nonconvexity. In contrast, the packing fraction first increases to a maximum value but declines as the nonconvexity increases further. At a high level of nonconvexity, the packings are looser but show a higher shear strength. At the microscopic scale, the fabric and force anisotropy, as well as the friction mobilization, are enhanced by multiple contacts between aggregates and interlocking, thus revealings the mechanical and geometrical origins of shear strength.

Homodyne reflectometer for NBI interlock on Large Helical Device

International Nuclear Information System (INIS)

Tanaka, Kenji; Ito, Yasuhiko; Kawahata, Kazuo; Tokuzawa, Tokihiko; Osakabe, Masaki; Takeiri, Yasuhiko; Ejiri, Akira

2001-01-01

Neutral Beam Injection (NBI) under low density causes serious damage on vacuum vessel wall. It is necessary to stop NBI when electron density becomes lower than 1x10 19 m -3 . This needs reliable density monitor for NBI interlock. A three-channel homodyne reflectometer was installed on Large Helical Device (LHD) and was used for NBI interlock. 28.5, 34.9 and 40.2 GHz Gunn oscillators were used with O mode injection. Their O mode cut off density correspond to 1x10 19 , 1.5x10 19 and 2x10 19 m -3 respectively. The simple homodyne detection is presently used. When the density reaches to the cutoff density, the reflected signals are detected. The reflected signal consists of DC signal due to local and reflected power, and AC signal due to position of cut off layer and density fluctuation. Since the change of DC signal at lower and higher than cut off density was very small, root mean square (RMS) value of AC signal were used for interlock signal. This interlock system is successfully working from the beginning of the NBI experiments campaign on LHD. (author)

Programmable controllers replace relays in MFTF-B personnel-safety interlocks

International Nuclear Information System (INIS)

Branum, J.D.

1981-01-01

This paper describes a new approach for implementing personnel safety interlocks logic using industrial-type programmable controllers. The logic for all personnel safety interlocks except those totally internal to a subsystem is implemented in two non-redundant controllers. A high degree of fail-safe reliability is achieved by augmenting the protective features intrinsic to each controller with those provided by a small amount of external support hardware. The controllers are interfaced to the host computer system via fiber optic data links to enable display of interlock and overall system status on the control room graphic displays. When fully implemented, the controllers will perform the equivalent of over 2000 discreet relay functions

Outcome of intramedullary interlocking SIGN nail in tibial diaphyseal fracture

International Nuclear Information System (INIS)

Khan, I.; Javed, S.; Khan, G.N.; Aziz, A.

2013-01-01

Objective: To determine the outcome of intramedullary interlocking surgical implant generation network (SIGN) nail in diaphyseal tibial fractures in terms of union and failure of implant (breakage of nail or interlocking screws). Study Design: Case series. Place and Duration of Study: Orthopaedics and Spinal Surgery, Ghurki Trust Teaching Hospital, Lahore Medical and Dental College, Lahore, from September 2008 to August 2009. Methodology: Fifty patients aged 14 - 60 years, of either gender were included, who had closed and Gustilo type I and II open fractures reported in 2 weeks, whose closed reduction was not possible or was unsatisfactory and fracture was located 7 cm below knee joint to 7 cm above ankle joint. Fractures previously treated with external fixator, infected fractures and unfit patients were excluded. All fractures were fixed with intramedullary interlocking SIGN nail and were followed clinically and radiographically for union and for any implant failure. Results: Forty one (88%) patients had united fracture within 6 months, 5 (10%) patients had delayed union while 4 (8%) patients had non-union. Mean duration for achieving union was 163 + 30.6 days. Interlocking screws were broken in 2 patients while no nail was broken in any patient. Conclusion: Intramedullary interlocking nailing is an effective measure in treating closed and grade I and II open tibial fractures. It provides a high rate of union less complications and early return to function. (author)

Outcome of intramedullary interlocking SIGN nail in tibial diaphyseal fracture.

Science.gov (United States)

Khan, Irfanullah; Javed, Shahzad; Khan, Gauhar Nawaz; Aziz, Amer

2013-03-01

To determine the outcome of intramedullary interlocking surgical implant generation network (SIGN) nail in diaphyseal tibial fractures in terms of union and failure of implant (breakage of nail or interlocking screws). Case series. Orthopaedics and Spinal Surgery, Ghurki Trust Teaching Hospital, Lahore Medical and Dental College, Lahore, from September 2008 to August 2009. Fifty patients aged 14 - 60 years, of either gender were included, who had closed and Gustilo type I and II open fractures reported in 2 weeks, whose closed reduction was not possible or was unsatisfactory and fracture was located 7 cm below knee joint to 7 cm above ankle joint. Fractures previously treated with external fixator, infected fractures and unfit patients were excluded. All fractures were fixed with intramedullary interlocking SIGN nail and were followed clinically and radiographically for union and for any implant failure. Forty one (88%) patients had united fracture within 6 months, 5 (10%) patients had delayed union while 4 (8%) patients had non-union. Mean duration for achieving union was 163 + 30.6 days. Interlocking screws were broken in 2 patients while no nail was broken in any patient. Intramedullary interlocking nailing is an effective measure in treating closed and grade I and II open tibial fractures. It provides a high rate of union less complications and early return to function.

Application software for new BEPC interlock system

International Nuclear Information System (INIS)

Tang Shuming; Na Xiangyin; Chen Jiansong; Yu Yulan

1997-01-01

New BEPC (Beijing electron Positron collider) interlock system has been built in order to improve the reliability of personnel safety and interlock functions. Moreover, the system updates BEPC operation message once every 6 seconds, which are displayed on TV screens at the major entrances. Since March of 1996, new BEPC interlock system has been operating reliably. The hardware of the system is based on Programmable Logic Controllers (PLC). A multimedia IBM/PC-586 as the host computer of the PLCs, monitors the PLC system via serial port COM2. The PC communicates with the central computer VAX-4500 of BEPC control system and gets operating massage of the accelerator through serial port COM3. The application software on the host computer has been developed. Visual C++ for MS-Windows 3.2 TM is selected as the work bench. It provides nice tools for building programs, such as APP STUDIO, CLASS WIZARD, APP WIZARD and debugger tool. The author describes the design idea and the structure of the application software. Error tolerance is taken into consideration. The author also presents a small database and its data structure for the application

The RF-Station Interlock for the European X-ray laser

CERN Document Server

Grevsmühl, T; Duval, P; Hensler, O; Kahl, J; Kaiser, F R; Kretzschmann, A; Rehlich, K; Schwendicke, U; Simrock, S; Weisse, S

2004-01-01

The RF-station interlock for the European X-ray laser will be based on a 19"- 3U crate incorporating a controller with the 32-bit RISC NIOS-processor (ALTERA). The main task of the interlock system is to prevent any damage from the components of the RF station and connected cavities. The interlock system must also guarantee a maximum time of operation of the RF stations which implies the implementation of self diagnostics and repair strategies on a module basis. Additional tasks are: collection and temporary storage of status information of the individual channels of the interlock system, transfer of this information to the control system, slow control functions (e.g. HV setting and monitoring) and control of inputs and outputs from and to other subsystems. In this paper we present the implementation using an ALTERA-FPGA running a 32-bit RISC NIOS-processor. Connection to the accelerator main control is provided by Ethernet using BSD-style socket routines based on ALTERA's plugs-library. The layout o...

Incorporation of safety interlocks in commercial robotics for handling of nuclear materials

International Nuclear Information System (INIS)

Moore, F.W.

1986-01-01

The adaptation of commercial robotic systems to applications in the manufacturing of nuclear fuel has required the addition of safety interlocks as to the handling and accountability of nuclear materials. Also, additional safety interlocks are required when the robots are operated in containment enclosures that are environmentally sealed. Interlocks have been incorporated in a commercial robot which was modified and with additional interlocks into the existing robotic control system. The robotic system has been installed in the containment enclosure as part of the pellet storage subsystem in the Secure Automated Fabrication facility currently being built by Westinghouse Hanford Company for the US Department of Energy. The system has been installed in the Fuel Cycle Plant and is scheduled for initial operational testing in 1986

CAMAC-based interlock system for power-supply-hardware protection on MFTF

International Nuclear Information System (INIS)

Strauch, M.S.

1981-01-01

This interlock module accepts 16 inputs and generates, in conjunction with an internal PROM map, 8 outputs. This decision process is autonomous of the CAMAC dataway and host computer. The map is generated, burned and verified by a user interactive program written to accept input/output equations in Boolean algebra. The interlock module requires the host computer to periodically interrogate it to verify proper operation of the module, host computer and date link; otherwise, permissives are dropped. An internal mask register may be used to override interlock inputs. This mask is perishable and must be constantly refreshed. Output drivers may be operated in a latch/no latch mode. This prevents outputs, once dropped, from being reasserted even if the proper input sequence is reestablished. A first-out register may be utilized to determine which input has dropped first in the event that chain reactions are developed among the interlock inputs

FRACTURE SHAFT HUMERUS: INTERLOCKING

Directory of Open Access Journals (Sweden)

Deepak Kaladagi

2014-12-01

Full Text Available BACKGROUND: The incidence of humeral fracture has significantly increased during the present years due to the population growth and road traffic, domestic, industrial, automobile accidents & disasters like tsunami, earthquakes, head-on collisions, polytrauma etc. In order to achieve a stable fixation followed by early mobilization, numerous surgical implants have been devised. PURPOSE: The purpose of this study is to analyze the results of intramedullary fixation of proximal 2/3rd humeral shaft fractures using an unreamed interlocking intramedullary nail. INTRODUCTION: In 40 skeletally matured patients with fracture shaft of humerus admitted in our hospital, we used unreamed antegrade interlocking nails. MATERIAL: We carried out a prospective analysis of 40 patients randomly selected between 2001 to 2014 who were operated at JNMC Belgaum, MMC Mysore & Navodaya Medical College, Raichur. All cases were either RTAs, Domestic, Industrial, automobile accidents & also other modes of injury. METHOD: Routine investigations with pre-anaesthetic check-up & good quality X-rays of both sides of humerus was taken. Time of surgery ranged from 5-10 days from the time of admission. Only upper 1/3rd & middle 1/3rd humeral shaft fractures were included in the study. In all the cases antegrade locked unreamed humeral nails were inserted under C-arm. Patient was placed in supine position & the shoulder was kept elevated by placing a sandbag under the scapula. In all patients incision taken from tip of acromion to 3cm over deltoid longitudinally. Postoperatively sling applied with wrist & shoulder movements started after 24 hours. All the patients ranged between the age of 21-50 years. RESULTS: Total 40 patients were operated. Maximum fracture site were in the middle third- 76%, 14% upper 1/3rd. All 40 patients achieved union. The average time of union was 8-10 weeks. All patients regained full range of movements except in few cases, where there was shoulder

Interlocking Boards and Firm Performance: Evidence from a New Panel Database

NARCIS (Netherlands)

M.C. Non (Marielle); Ph.H.B.F. Franses (Philip Hans)

2007-01-01

textabstractAn interlock between two firms occurs if the firms share one or more directors in their boards of directors. We explore the effect of interlocks on firm performance for 101 large Dutch firms using a large and new panel database. We use five different performance measures, and for each

Design of the interlock and protection system for the SPIDER experiment

International Nuclear Information System (INIS)

Pomaro, N.; Grando, L.; Luchetta, A.; Paolucci, F.; Sartori, F.

2013-01-01

Highlights: •A custom designed interlock and protection system for SPIDER experiment is described. •It includes two subsystems implementing slow and fast protection functions. •High reliability PLCs are adopted for slow protection. •Fiber-optic based, custom designed fast logic circuitry is proposed for fast protection. •Accelerators breakdown events are also managed by the fast subsystem. -- Abstract: Unprecedented levels of beam energy and power are required for ITER Neutral Beam Heating systems. SPIDER experiment is an experimental device aimed to test and optimize a full size beam source satisfying ITER requirements. SPIDER experiment operation involves high power, voltage, temperature, and gas pressure. All these critical conditions are present simultaneously, so that any failure if not properly detected and managed is likely to cause severe damage. The Interlock and Protection System is a high-reliability system devoted to the investment protection of SPIDER. Its main purpose is to manage abnormal events occurring in one or more plants in order to minimize adverse consequences. The Interlock System also manages the SPIDER Operating Modes, defining the set and status of the Plants used in the various possible experimental configurations. In addition, the Interlock and Protection System takes care of particular events occurring during normal SPIDER operation, i.e. electrical arcs between accelerator grids, named breakdowns. Their treatment is committed to the Interlock and Protection System, as they need to be managed timely and with absolute reliability like actual faults. To perform the required functions, the Interlock and Protection System is interfaced with most SPIDER plants and with the SPIDER Control and Data Acquisition System. The paper describes the rationale of the protection functions, their implementation in the design and the technical specifications of the system

A Retrospective View to the Magnet Interlock Systems at CERN

CERN Document Server

Romera, I; Mompo, R; Puccio, B; Zerlauth, M

2014-01-01

Several thousands of both, superconducting and normal conducting magnets are in charge of guiding the particle beams in CERN’s accelerator complex. In order to protect the magnet and powering equipment from damage, dedicated magnet interlock and protection systems are deployed throughout the various accelerators and transfer lines. These systems have worked extremely well during the first years of LHC operation, providing highly dependable interlocking of magnet powering based on industrial COTS components. This paper reviews the performance and experience with more than 70 individual installations during the first LHC running period and compares the operational experience with the initial expectations of dependability. Additional improvements required to address specific operational needs and observed shortcomings are presented. Finally, we review the existing magnet interlock infrastructure in the LHC injector complex and the ongoing renovation works during the first long shutdown.

Poly[ n ]catenanes: Synthesis of molecular interlocked chains

Energy Technology Data Exchange (ETDEWEB)

Wu, Qiong; Rauscher, Phillip M.; Lang, Xiaolong; Wojtecki, Rudy J.; de Pablo, Juan J.; Hore, Michael J. A.; Rowan, Stuart J.

2017-11-30

As the macromolecular version of mechanically interlocked molecules, mechanically interlocked polymers are promising candidates for the creation of sophisticated molecular machines and smart soft materials. Poly[n]catenanes, where the molecular chains consist solely of interlocked macrocycles, contain one of the highest concentrations of topological bonds. We report, herein, a synthetic approach toward this distinctive polymer architecture in high yield (similar to 75%) via efficient ring closing of rationally designed metallosupramolecular polymers. Light-scattering, mass spectrometric, and nuclear magnetic resonance characterization of fractionated samples support assignment of the high-molar mass product (number-average molar mass similar to 21.4 kilograms per mole) to a mixture of linear poly[7-26]catenanes, branched poly[13-130]catenanes, and cyclic poly[4-7]catenanes. Increased hydrodynamic radius (in solution) and glass transition temperature (in bulk materials) were observed upon metallation with Zn2+.

The Radiation Safety Interlock System for Top-Up Mode Operation at NSRRC

CERN Document Server

Chen Chien Rong; Kao, Sheau-Ping; Liu, Joseph; Sheu, Rong-Jiun; Wang, Jau-Ping

2005-01-01

The radiation safety interlock systems of NSRRC have been operated for more than a decade. Some modification actions have been implemented in the past to perfect the safe operation. The machine and its interlock system were originally designed to operate at the decay mode. Recently some improvement programs to make the machine injection from original decay mode to top-up mode at NSRRC has initiated. For users at experimental area the radiation dose resulted from top-up re-fill injections where safety shutters of beam-lines are opened will dominate. In addition to radiation safety action plans such as upgrading the shielding, enlarging the exclusion zones and improving the injection efficiency, the interlock system for top-up operation is the most important to make sure that injection efficiency is acceptable. To ensure the personnel radiation safety during the top-up mode, the safety interlock upgrade and action plans will be implemented. This paper will summarize the original design logic of the safety inter...

Design review report for the hydrogen interlock preliminary design

International Nuclear Information System (INIS)

Corbett, J.E.

1996-01-01

This report documents the completion of a preliminary design review for the hydrogen interlock. The hydrogen interlock, a proposed addition to the Rotary Mode Core Sampling (RMCS) system portable exhauster, is intended to support core sampling operations in waste tanks requiring flammable gas controls. The objective of this review was to validate basic design assumptions and concepts to support a path forward leading to a final design. The conclusion reached by the review committee was that the design was acceptable and efforts should continue toward a final design review

Influence of interlocked transactions on gum arabic production and marketing in Senegal

NARCIS (Netherlands)

Mujawamariya, G.; Haese, D' M.F.C.; Burger, C.P.J.

2010-01-01

Interlocked relationships are characterised by traders’ supply of inputs and cash to producers on credit, to be reimbursed at sale time based on a pre-defined price which is often lower than the prevailing market price. The study analyses determinants of choice of interlocking in the gum sector in

RF generator interlock by plasma grid bias current - An alternate to Hα interlock

Science.gov (United States)

Bandyopadhyay, M.; Gahlaut, A.; Yadav, R. K.; Pandya, K.; Tyagi, H.; Vupugalla, M.; Bhuyan, M.; Bhagora, J.; Chakraborty, A.

2017-08-01

ROBIN is inductively coupled plasma (ICP) based negative hydrogen ion source, operated with a 100kW, 1MHz Tetrode based RF generator (RFG). Inductive plasma ignition by the RFG in ROBIN is associated with electron seeding by a hot filament and a gas puff. RFG is triggered by the control system to deliver power just at the peak pressure of the gas puff. Once plasma is ignited due to proper impedance matching, a bright light, dominated by Hα (˜656nm wavelength) radiation is available inside RF driver which is used as a feedback signal to the RFG to continue its operation. If impedance matching is not correct, plasma is not produced due to lack of power coupling and bright light is not available. During such condition, reflected RF power may damage the RFG. Therefore, to protect the RFG, it needs to be switched off automatically within 200ms by the control system in such cases. This plasma light based RFG interlock is adopted from BATMAN ion source. However, in case of vacuum immersed RF ion source in reactor grade NBI system, such plasma light based interlock may not be feasible due to lack of adequate optical fiber interfaces. In reactor grade NBI system, neutron and gamma radiations have impact on materials which may lead to frequent maintenance and machine down time. The present demonstration of RFG interlock by Bias Current (BC) in ROBIN testbed gives an alternate option in this regard. In ROBIN, a bias plate (BP) is placed in the plasma chamber near the plasma grid (PG). BP is electrically connected to the plasma chamber wall of the ion source and PG is isolated from the wall. A high current ˜85 A direct current (DC) power supply of voltage in the range of 0 - 33V is connected between the PG and the BP in such a way that PG can be biased positively with respect to the BP or plasma chamber. This arrangement is actually made to absorb electrons and correspondingly reduce co-extracted electron current during beam extraction. However, in case of normal plasma

Vertical interlocks of executives and performance of affiliated firms in state owned Chinese business groups

DEFF Research Database (Denmark)

Arnoldi, Jakob; Chen, Xin; Na, Chaohong

. Further, the positive effects of vertically interlocking chairmen decrease as the number of pyramidal layers increases or regional marketization index improves. Such positive effects of interlocks, however, become greater as the divergence between cash flow rights and control rights of business groups...... increases. Our findings are consistent with the hypotheses that vertically interlocking executives can increase firm value by providing better protection against political interference and expropriation by the ultimate controllers of business groups. Our study sheds new light in the role and function...... of interlocks and adds to a small body of literature on the dynamics of state owned business groups in emerging markets generally and China particularly....

Development of Interlocking Masonry Bricks and its’ Structural Behaviour: A Review Paper

Science.gov (United States)

Al-Fakih, Amin; Mohammed, Bashar S.; Nuruddin, Fadhil; Nikbakht, Ehsan

2018-04-01

Conventional bricks are the most elementary building materials for houses construction. However, the rapid growth in today’s construction industry has obliged the civil engineers in searching for a new building technique that may result in even greater economy, more efficient and durable as an alternative for the conventional brick. Moreover, the high demands for having a speedy and less labour and cost building systems is one of the factor that cause the changes of the masonry conventional systems. These changes have led to improved constructability, performance, and cost as well. Several interlocking bricks has been developed and implemented in building constructions and a number of researches had studied the manufacturing of interlocking brick and its structural behaviour as load bearing and non-load bearing element. This technical paper aims to review the development of interlocking brick and its structural behaviour. In conclusion, the concept of interlocking system has been widely used as a replacement of the conventional system where it has been utilized either as load bearing or non-load bearing masonry system.

Experimental Investigation About Stamping Behaviour of 3D Warp Interlock Composite Preforms

Science.gov (United States)

Dufour, Clément; Wang, Peng; Boussu, François; Soulat, Damien

2014-10-01

Forming of continuous fibre reinforcements and thermoplastic resin commingled prepregs can be performed at room temperature due to its similar textile structure. The "cool" forming stage is better controlled and more economical. The increase of temperature and the resin consolidation phases after the forming can be carried out under the isothermal condition thanks to a closed system. It can avoid the manufacturing defects easily experienced in the non-isothermal thermoforming, in particular the wrinkling [1]. Glass/Polypropylene commingled yarns have been woven inside different three-dimensional (3D) warp interlock fabrics and then formed using a double-curved shape stamping tool. The present study investigates the in-plane and through-thickness behaviour of the 3D warp interlock fibrous reinforcements during forming with a hemispherical punch. Experimental data allow analysing the forming behaviour in the warp and weft directions and on the influence of warp interlock architectures. The results point out that the layer to layer warp interlock preform has a better stamping behaviour, in particular no forming defects and good homogeneity in thickness.

ROLES OF INTERLOCKING DIRECTORATES IN AN EMERGING COUNTRY: CONTROL AND COORDINATION IN FAMILY BUSINESS GROUPS

Directory of Open Access Journals (Sweden)

Aylin Ataay

2016-04-01

Full Text Available Maman (1999 proposed that, in countries in which business groups are dominant forms for organizing economic activities, the interlocking directorate is a managerial tool that can be prioritized to control and coordinate activities of their affiliated firms within the same groups and align their business objectives. This organizational connection appears to be an intentional strategy on the part of the groups‟ headquarters. In order to study the interlocking ties in Turkish family business groups (FBG, this study focused on interlocking directorates among listed firms in Turkey. The findings of preliminary study reveal that almost all of the interlocking ties were within the business groups (BG in our sample. This is the result of assignment of familyaffiliated and/or professional inside directors to the various boards of companies in the BG. We also found that compare to vertical ties; business groups are using more horizontal interlocking connections to bond their affiliated companies together.

Advanced interlocking systems to improve heavy-load-bearing characteristics of flexible intramedullary nailing

Energy Technology Data Exchange (ETDEWEB)

Berger, Leopold, E-mail: leopold.berger@tuwien.ac.at [Institute of Building Construction and Technology, TU Wien, Karlsplatz 13/206-4, 1040 Vienna (Austria); Eichler, Johannes [Department of Orthopedics and Orthopedic Surgery, Medical University of Graz, Auenbruggerplatz 5/6, 8036 Graz (Austria); Ryll, E. Jonathan S. [Department of Trauma-, Hand- and Reconstructive Surgery, University Hospital Muenster, Westphalian-Wilhelms University, Muenster (Germany); Fischerauer, Stefan [Department of Traumatology, Medical University of Graz, Auenbruggerplatz 5/6, 8036 Graz (Austria); Raschke, Michael J. [Department of Trauma-, Hand- and Reconstructive Surgery, University Hospital Muenster, Westphalian-Wilhelms University, Muenster (Germany); Kolbitsch, Andreas [Institute of Building Construction and Technology, TU Wien, Karlsplatz 13/206-4, 1040 Vienna (Austria); Castellani, Christoph [Department of Pediatric and Adolescence Surgery, Medical University of Graz, Auenbruggerplatz 34, 8036 Graz (Austria); Weinberg, Annelie-Martina [Department of Orthopedics and Orthopedic Surgery, Medical University of Graz, Auenbruggerplatz 5/6, 8036 Graz (Austria)

2016-11-01

Flexible intramedullary nailing (FIN) is a minimally invasive and widespread standard method for osteosynthesis of pediatric long bone fractures. In the case of unstable fractures of the lower extremity, interlocking systems need to be used to prevent axial shortening and subsequent perforation of the nail at its insertion site. In the present study, four different screw-fixed interlocking systems for FINs (Hofer TwinPlug with two 3-mm titanium interlocking screws, Hofer FixPlug with 3-mm titanium interlocking screw, Hofer Plug with 3.5-mm titanium interlocking screw, and Hofer Plug with 3-mm titanium interlocking screw) in comparison with the commonly used Ender stainless steel nails (locked with 3.5-mm screw) were experimentally investigated in cadaveric lamb tibiae, regarding their load characteristics and failure modes in the case of heavy loading. The specimens were subjected to sequential axial cyclic loading of 5000cycles with stepwise increase of the load amplitude until failure. Migration of locking screws and internal damage of bone tissue was quantified by micro-computed tomography (CT) imaging. Ender nails failed on average at a peak load of 800 N, TwinPlugs at 1367 N, FixPlugs at 1222 N, Plugs 3.5mm at 1225 N and Plugs 3.0mm at 971 N. TwinPlugs, FixPlugs, and Plugs 3.5mm failed in a slow manner over several hundred loading cycles, whereas Ender nails and Plugs 3.0mm exhibited abrupt failure without any prior indication. Our results confirm that axial stability of FIN can be further improved by screw-fixed plugs by simultaneously avoiding shortcomings of an eye-locked system, which the Ender nails are. Considering biomechanical results, plug interlocking systems with 3.5-mm screws should be favored over conventional Ender nails and plugs with 3-mm screws. - Highlights: • Locked flexible intramedullary nails in lamb tibiae were cyclically loaded. • Strongly different failure modes of locking systems were detected. • Novel screw-fixed plugs are

Incorporation of safety interlocks in commercial robotics for handling of nuclear materials

International Nuclear Information System (INIS)

Moore, F.W.

1986-01-01

Current robotic systems have been developed primarily for the automotive and electronic industry. The adaptation of these commercial robotic systems to applications in the manufacturing of nuclear fuel requires the addition of safety interlocks as to the handling and accountability of nuclear materials. Also, additional safety interlocks are required when the robots are operated in containment enclosures that are environmentally sealed. Interlocks have been incorporated into a commercial robot. The robotic system has been installed in the containment enclosure as part of the pellet storage subsystem into the Secure Automated Fabrication (SAF) facility currently being built by Westinghouse Hanford Company (WHC) for the US Department of Energy (DOE). The system has been installed in the Fuel Cycle Plant and is scheduled for initial operational testing in 1986

Comparing formal verification approaches of interlocking systems

DEFF Research Database (Denmark)

Haxthausen, Anne Elisabeth; Nguyen, Hoang Nga; Roggenbach, Markus

2016-01-01

these approaches. As a first step towards this, in this paper we suggest a way to compare different formal approaches for verifying designs of route-based interlocking systems and we demonstrate it on modelling and verification approaches developed within the research groups at DTU/Bremen and at Surrey......The verification of railway interlocking systems is a challenging task, and therefore several research groups have suggested to improve this task by using formal methods, but they use different modelling and verification approaches. To advance this research, there is a need to compare....../Swansea. The focus is on designs that are specified by so-called control tables. The paper can serve as a starting point for further comparative studies. The DTU/Bremen research has been funded by the RobustRailS project granted by Innovation Fund Denmark. The Surrey/Swansea research has been funded by the Safe...

Formal Modeling and Verification of Interlocking Systems Featuring Sequential Release

DEFF Research Database (Denmark)

Vu, Linh Hong; Haxthausen, Anne Elisabeth; Peleska, Jan

2015-01-01

In this paper, we present a method and an associated tool suite for formal verification of the new ETCS level 2 based Danish railway interlocking systems. We have made a generic and reconfigurable model of the system behavior and generic high-level safety properties. This model accommodates seque...... SMT based bounded model checking (BMC) and inductive reasoning, we are able to verify the properties for model instances corresponding to railway networks of industrial size. Experiments also show that BMC is efficient for finding bugs in the railway interlocking designs....

Formal Modeling and Verification of Interlocking Systems Featuring Sequential Release

DEFF Research Database (Denmark)

Vu, Linh Hong; Haxthausen, Anne Elisabeth; Peleska, Jan

2014-01-01

In this paper, we present a method and an associated tool suite for formal verification of the new ETCS level 2 based Danish railway interlocking systems. We have made a generic and reconfigurable model of the system behavior and generic high-level safety properties. This model accommodates seque...... SMT based bounded model checking (BMC) and inductive reasoning, we are able to verify the properties for model instances corresponding to railway networks of industrial size. Experiments also show that BMC is efficient for finding bugs in the railway interlocking designs....

Architecture for interlock systems: reliability analysis with regard to safety and availability

International Nuclear Information System (INIS)

Wagner, S.; Apollonio, A.; Schmidt, R.; Zerlauth, M.; Vergara-Fernandez, A.

2012-01-01

For particle accelerators like LHC and other large experimental physics facilities like ITER, the machine protection relies on complex interlock systems. In the design of interlock loops for the signal exchange in machine protection systems, the choice of the hardware architecture impacts on machine safety and availability. The reliable performance of a machine stop (leaving the machine in a safe state) in case of an emergency, is an inherent requirement. The constraints in terms of machine availability on the other hand may differ from one facility to another. Spurious machine stops, lowering machine availability, may to a certain extent be tolerated in facilities where they do not cause undue equipment wear-out. In order to compare various interlock loop architectures in terms of safety and availability, the occurrence frequencies of related scenarios have been calculated in a reliability analysis, using a generic analytical model. This paper presents the results and illustrates the potential of the analysis method for supporting the choice of interlock system architectures. The results show the advantages of a 2003 (3 redundant lines with 2-out-of-3 voting) over the 6 architectures under consideration for systems with high requirements in both safety and availability

El prestigi empresarial: Anàlisi a través de les conselleries creuades The business prestige: A preliminary study based on interlocks within companies The business prestige: A preliminary study based on interlocks within companies

Directory of Open Access Journals (Sweden)

David Gonzalez-Prieto

2011-11-01

Full Text Available Purpose: The literature on interlocked directorate or interlocks has proposed the presence of cross-directors as an influential factor in the prestige of a firm (Mizruchi, 1996. This theory is based on the fact that, by having multiple companies with interlocks within them, major stakeholders of the company ought to have a higher perception of prestige. The aim of this preliminary study is to present an exploratory study and suggest future research lines on this issue. Design/methodology/approach: In a first preliminary study, we evaluate the interlocks network comprising companies belonging to the ranking established by the MERCO report in Spain for the year 2010. This is a well-known ranking of corporate reputation in Spain used in recent articles (Luna & Fernandez, 2010. For further analysis, other variables are considered as being quoted in the Spanish market benchmark index, IBEX 35, and the location of the headquarters.Findings: Significant positive relationship was obtained between the number of directorships shared with other public companies and the perceived prestige that stakeholders perceive from the firm. Similarly, we obtain significant positive correlation between the prestige and being listed on the IBEX 35. Finally, we identified banking, construction and energy sectors as the ones that use interlocking directorates more intensively.Research limitations: The results of this preliminary study show the viability of future studies about prestige and interlocks (Mizruchi, 1996. For the validation of the theory described in this study, it should be replicated in different regions and, with larger samples, to observe the effect that interlocks have on the perception of prestige of the company.Practical implications / Originality/value: This is among the first studies showing the existence of a relationship between interlocks and business prestige. It highlights the importance of the composition of the boards for the perceived prestige

Modelling and Verification of Relay Interlocking Systems

DEFF Research Database (Denmark)

Haxthausen, Anne Elisabeth; Bliguet, Marie Le; Kjær, Andreas

2010-01-01

This paper describes how relay interlocking systems as used by the Danish railways can be formally modelled and verified. Such systems are documented by circuit diagrams describing their static layout. It is explained how to derive a state transition system model for the dynamic behaviour...

Winter Performance of Inter-Locking Pavers—Stormwater Quantity and Quality

Directory of Open Access Journals (Sweden)

Angus Chu

2012-12-01

Full Text Available This study examined the effectiveness of open-joint inter-locking pavers in a permeable pavement in cold (winter conditions. A field-scale inter-locking paver cell (UNI Eco-Optiloc® was built to evaluate the hydraulic performance and water quality improvements experienced during freeze-thaw and frozen conditions in Calgary, Alberta, Canada. Hydraulic performance was assessed using stormwater runoff reduction (peaks and volumes and surface infiltration capacity. Water quality performance for removal of total suspended solids (TSS, total nitrogen (TN, total phosphorous (TP and three heavy metals: copper, lead and zinc, was assessed. Results from the study demonstrated that the inter-locking pavers were effective in attenuating stormwater runoff peak volumes. The surface infiltration capacity decreased significantly due to the deposition of sanding and de-icing materials on the pavement surface during winter operation. Infiltrated stormwater was stored and treated within the pavement structure, which showed removal rates of 91% for TSS, 78% for TP, 6% for TN, 68% for zinc, 69% for copper and 55% for lead.

Metal-organic frameworks with dynamic interlocked components

Science.gov (United States)

Vukotic, V. Nicholas; Harris, Kristopher J.; Zhu, Kelong; Schurko, Robert W.; Loeb, Stephen J.

2012-06-01

The dynamics of mechanically interlocked molecules such as rotaxanes and catenanes have been studied in solution as examples of rudimentary molecular switches and machines, but in this medium, the molecules are randomly dispersed and their motion incoherent. As a strategy for achieving a higher level of molecular organization, we have constructed a metal-organic framework material using a [2]rotaxane as the organic linker and binuclear Cu(II) units as the nodes. Activation of the as-synthesized material creates a void space inside the rigid framework that allows the soft macrocyclic ring of the [2]rotaxane to rotate rapidly, unimpeded by neighbouring molecular components. Variable-temperature 13C and 2H solid-state NMR experiments are used to characterize the nature and rate of the dynamic processes occurring inside this unique material. These results provide a blueprint for the future creation of solid-state molecular switches and molecular machines based on mechanically interlocked molecules.

Formal Development of a Tool for Automated Modelling and Verification of Relay Interlocking Systems

DEFF Research Database (Denmark)

Haxthausen, Anne Elisabeth; Kjær, Andreas A.; Le Bliguet, Marie

2011-01-01

This paper describes a tool for formal modelling relay interlocking systems and explains how it has been stepwise, formally developed using the RAISE method. The developed tool takes the circuit diagrams of a relay interlocking system as input and gives as result a state transition system modelling...

Determinants of Board Interlocking in the Brazilian Capital Market

Directory of Open Access Journals (Sweden)

Flávio Ribeiro

2016-10-01

Full Text Available The objective in this article was to identify the main determinants of Board Interlocking in the Brazilian capital market. As the theoretical structure, the Agency theory and Corporate Governance, the Resource Dependence theory and the Board of Administrators and the Characteristics of Board Interlocking. The sample consists of 58 Brazilian companies that participate in the Bovespa Index (Ibovespa. An empirical analytic study was undertaken. With regard to the objectives, it is characterized as exploratory and, with regard to the procedures, a documentary research was undertaken. The data on the Boards of Administrators were collected from the Reference Forms available on the website of the São Paulo Stock Exchange (BM&FBOVESPA. The results found demonstrate the generalized presence of Board Interlocking in these companies, normally associated with four factors: (1 economic group formation; (2 governmental control; (3 formation of pension funds; and (4 presence of professionals with acknowledged market experience. The results also suggest that the first three factors give rise to long-lasting links and that these connections are hard to break. On the other hand, the links established through professionals with market experience tend to be more unstable because the presence of these professionals is highly demanded to serve on the board of different companies.

Achieving interlocking nails without using an image intensifier.

Science.gov (United States)

Ikem, Innocent C; Ogunlusi, Johnson D; Ine, Henry R

2007-08-01

Interlocking nails are commonly performed using an image intensifier. These are expensive and are not readily available in most resource-poor countries of the world. The aim of this study was to achieve interlocking nailing without the use of an image intensifier. This is a prospective descriptive analysis of 40 consecutive cases seen with shaft fractures of the humerus, femur, and tibia. Fracture fixation was done using Surgical Implant Generation Network (SIGN) nails. Forty limbs in 34 patients were studied. There were 12 females and 22 males, giving a ratio of 1:2. The mean age (years) was 35.75+/-13.16 and the range was 17-70 years. The studied bones were: humerus 10%, femur 65%, and tibia 25%. The fracture lines were: transverse 40%, oblique 15%, and communited 45%. Fracture grades were: closed 90%, grade I, 5%, grade II, 2.5%, and grade IIIA, 2.5%. Surgical approaches were: antegrade 62.5% and retrograde 37.5%. Indications for fixation were: recent fracture 92.5%, non-union 5%, and malunion 3%. Methods of reductions were: open 85% and closed 15%. The mean follow-up period (years) was 1.50+/-0.78. The union time averaged 3 months. Complication was mainly screw loosening due to severe osteoporoses in one case. It is, therefore, concluded that, with the aid of external jigs and slot finders, interlocking can be achieved without an image intensifier.

Communities detection as a tool to assess a reform of the Italian interlocking directorship network

Science.gov (United States)

Drago, Carlo; Ricciuti, Roberto

2017-01-01

Interlocking directorships are important communication channels among companies and may have anticompetitive effect. A corporate governance reform was introduced in 2011 to prevent interlocking directorships in the financial sector. We apply community detection techniques to the analysis of the networks in 2009 and 2012 to ascertain the effect of such reform on the Italian directorship network. We find that, although the number of interlocking directorships decreases in 2012, the reduction takes place mainly at the periphery of the network. The network core is stable, allowing the most connected companies to keep their strategic position.

Governance of pension funds: interlocking and compensation of Australian superannuation fund boards

OpenAIRE

Ooi, Elizabeth Meishan

2017-01-01

This thesis documents the incidence and determinants of board interlocking (where directors simultaneously sit on multiple boards) in pension funds and examines its effect on fund performance. It also investigates the determinants of pension fund director compensation. The motivation to examine these issues stems from the distinctive interlocking and compensation practices in pension funds. Data on a sample of 249 Australian pension funds from 2004 to 2011 is collected from fund documents ...

Bio-inspired design of geometrically interlocked 3D printed joints

Science.gov (United States)

Kumar, S.; Oliva, Noel; Kumar's Lab Team

The morphology of the adhesive-adherend interface significantly affects the mechanical behavior of adhesive joints. As seen in some biocomposites like human skull, or the nacre of some bivalve molluscs' shells, a geometrically interlocking architecture of interfaces creates toughening and strengthening mechanisms enhancing the mechanical properties of the joint. In an attempt to characterize this mechanical interlocking mechanism, this study is focused on computational and experimental investigation of a single-lap joint with a very simple geometrically interlocked interface design in which both adherends have a square waveform configuration of the joining surfaces. This square waveform configuration contains a positive and a negative rectangular teeth per cycle in such a way that the joint is symmetric about the mid-bondlength. Both physical tests performed on 3D printed prototypes of joints and computational results indicate that the joints with square waveform design have higher strength and damage tolerance than those of joints with flat interface. In order to identify an optimal design configuration of this interface, a systematic parametric study is conducted by varying the geometric and material properties of the non-flat interface. This work was supported by Lockheed Martin (Award No: 12NZZ1).

Control interlock and monitoring system for 80 KW IOT based RF power amplifier system at 505.812 MHz for Indus-2

International Nuclear Information System (INIS)

Kumar, Gautam; Deo, R.K.; Jain, M.K.; Bagre, Sunil; Hannurkar, P.R.

2013-01-01

For 80 kW inductive output tube (IOT) based RF power amplifier system at 505.812 MHz for Indus-2, a control, interlock and monitoring system is realized. This is to facilitate proper start-up and shutdown of the amplifier system, monitor various parameters to detect any malfunction during its operation and to bring the system in a safe stage, thereby assuring reliable operation of the amplifier system. This high power amplifier system incorporates interlocks such as cooling interlocks, various voltage and current interlocks and time critical RF interlocks. Processing of operation sequence, cooling interlocks and various voltage and current interlocks have been realized by using Siemens make S7-CPU-315-2DP (CPU) based programmable logic controller (PLC) system. While time critical or fast interlocks have been realized by using Siemens make FPGA based Boolean Co-processor FM-352-5 which operates in standalone mode. Siemens make operating panel OP277 6'' is being used as a human machine interface (HMI) device for command, data, alarm generation and process parameter monitoring. (author)

The vacuum interlock system for the CELSIUS ring

International Nuclear Information System (INIS)

Gajewski, K.

1990-01-01

A vacuum interlock system has been designed and built for the CELSIUS storage ring. The ultrahigh-vacuum system of CELSIUS has a design pressure of 10 -11 mbar. This is achieved by using vacuum-fired stainless-steel chambers, baking the whole ring to 300degC and running some 50 sputter ion and titanium sublimation pumps. The turbopumps, combined with roughing pumps, are used during the pump-down and the bake-out. The pressure is monitored by Penning vacuum gauges. There is a number of programmable pressure thresholds set to trigger various events (like closing the sector valves, disabling the bake-out, etc.). The interlock system is based on the Mitsubishi programmable logic controller (PLC). An IBM PC is used as an operator's console. The operation and performance of the system is described. On the basis of present experience an upgrading of the system is suggested. (orig.)

Binding of anions in triply interlocked coordination catenanes and dynamic allostery for dehalogenation reactions.

Science.gov (United States)

Yang, Linlin; Jing, Xu; An, Bowen; He, Cheng; Yang, Yang; Duan, Chunying

2018-01-28

By synergistic combination of multicomponent self-assembly and template-directed approaches, triply interlocked metal organic catenanes that consist of two isolated chirally identical tetrahedrons were constructed and stabilized as thermodynamic minima. In the presence of suitable template anions, the structural conversion from the isolated tetrahedral conformers into locked catenanes occurred via the cleavage of an intrinsically reversible coordination bond in each of the tetrahedrons, followed by the reengineering and interlocking of two fragments with the regeneration of the broken coordination bonds. The presence of several kinds of individual pocket that were attributed to the triply interlocked patterns enabled the possibility of encapsulating different anions, allowing the dynamic allostery between the unlocked/locked conformers to promote the dehalogenation reaction of 3-bromo-cyclohexene efficiently, as with the use of dehalogenase enzymes. The interlocked structures could be unlocked into two individual tetrahedrons through removal of the well-matched anion templates. The stability and reversibility of the locked/unlocked structures were further confirmed by the catching/releasing process that accompanied emission switching, providing opportunities for the system to be a dynamic molecular logic system.

Control and Interlocking System for Bending Magnet Front-end at Indus-2

Science.gov (United States)

Kane, Sanjeev R.; Garg, Chander Kant; Nandedkar, R. V.

2007-01-01

We present control and interlock system developed for Indus-2 bending magnet front-end. The paper describes in detail the control of various signals associated with the front-end and the interlocking scheme implemented for the installed front-end. The number of signals associated with each front-end is ˜ 75. A control system is designed for monitoring temperature, pressure, airflow, water flow and control of vacuum gauges, fast shutter, water cooled shutter, safety shutter, pneumatic gate valves, sputter ion pump power supplies, beam position monitor etc. Two independent signals are generated for critical components that are used for software interlock and hard-wired interlock. The front-end control system is VME based and window 2000/XP workstation as an operator console. The CPU used is Motorola 68000-processor board of the VME bus having OS-9 real time operating system. One VME crate serves a cluster of 2-3 front ends. The communication between the VME and the workstation is linked over RS232 serial communication. The sputter ion power supplies are connected over isolated RS485 network. Critical protection features are implemented so that no single failure can render the system unsafe. This is implemented by providing two independent chains of protection (1) Hard wired in which relay logic is used and (2) Software. A Graphical User Interface (GUI) is developed using Lab view Version 7.0.

Control and Interlocking System for Bending Magnet Front-end at Indus-2

International Nuclear Information System (INIS)

Kane, Sanjeev R.; Garg, Chander Kant; Nandedkar, R. V.

2007-01-01

We present control and interlock system developed for Indus-2 bending magnet front-end. The paper describes in detail the control of various signals associated with the front-end and the interlocking scheme implemented for the installed front-end. The number of signals associated with each front-end is ∼ 75. A control system is designed for monitoring temperature, pressure, airflow, water flow and control of vacuum gauges, fast shutter, water cooled shutter, safety shutter, pneumatic gate valves, sputter ion pump power supplies, beam position monitor etc. Two independent signals are generated for critical components that are used for software interlock and hard-wired interlock. The front-end control system is VME based and window 2000/XP workstation as an operator console. The CPU used is Motorola 68000-processor board of the VME bus having OS-9 real time operating system. One VME crate serves a cluster of 2-3 front ends. The communication between the VME and the workstation is linked over RS232 serial communication. The sputter ion power supplies are connected over isolated RS485 network. Critical protection features are implemented so that no single failure can render the system unsafe. This is implemented by providing two independent chains of protection (1) Hard wired in which relay logic is used and (2) Software. A Graphical User Interface (GUI) is developed using Lab view Version 7.0

The Impact of Board Interlocks on Auditor Choice and Audit Fees

DEFF Research Database (Denmark)

Riise Johansen, Thomas; Pettersson, Kim

2013-01-01

Research Question/Issue This paper uses unique Danish data to examine whether non-executive directors draw on both direct and indirect ties in the network of interlocking directorates to impact auditor choice, and whether this impact has consequences for audit fees. Research Findings/Insight The ......Research Question/Issue This paper uses unique Danish data to examine whether non-executive directors draw on both direct and indirect ties in the network of interlocking directorates to impact auditor choice, and whether this impact has consequences for audit fees. Research Findings....../Insight The paper finds clear evidence that non-executive directors draw on their networks to impact auditor choice, and evidence that clients pay an audit fee premium when non-executive directors are connected to audit firms outside the focal company. The relationship between non-executive directors and auditors...... of the non-executive director–auditor relationship and the role that board networks have in governing auditor choice decisions. The study identifies interlocks as an infrastructure for differentiation in the audit market and determines that such differentiation is associated with an audit fee premium...

Design of test JIG for centralized interlock and protection module of ITER-India Gyrotron Test Facility

International Nuclear Information System (INIS)

Rathod, Vipal; Rao, S.L.; Edappala, Praveenlal; Rajpal, Rachana

2017-01-01

Fast Interlock and protection system plays very crucial role in ensuring the safe and reliable operation of high power RF sources such as a Gyrotron system. Critical Protection Interlocks are generally implemented using hardwired components and are required to have a response time as fast as < 10 μs. In this context, an Industrial grade prototype Centralized Interlock and Protection Module (CIM) based on ITER-India design has been developed successfully with the help of local industry. This paper presents the complete requirements, approach, detailed design concept and current status of Test JIG in detail

An analytical hierarchical model explaining the robustness and flaw-tolerance of the interlocking barb-barbule structure of bird feathers

Science.gov (United States)

Chen, Qiang; Gorb, Stanislav; Kovalev, Alexander; Li, Zhiyong; Pugno, Nicola

2016-10-01

Feathers can fulfill their aerodynamic function only if the pennaceous vane forms an airfoil stabilized by robust interlocking between barbules. Thus, revealing the robustness of the interlocking mechanical behavior of the barbules is very important to understand the function and long-term resilience of bird feathers. This paper, basing on the small- and large-beam deflection solutions, presents a hierarchical mechanical model for deriving the critical delamination conditions of the interlocking barbules between two adjacent barbs in bird feathers. The results indicate a high robustness and flaw-tolerant design of the structure. This work contributes to the understanding of the mechanical behavior of the robust interlocking barb-barbule structure of the bird feather, and provides a basis for design of feather-inspired materials with robust interlocking mechanism, such as advanced bio-inspired micro-zipping devices.

Innovative monitoring of 3D warp interlock fabric during forming process

Science.gov (United States)

Dufour, C.; Jerkovic, I.; Wang, P.; Boussu, F.; Koncar, V.; Soulat, D.; Grancaric, A. M.; Pineau, P.

2017-10-01

The final geometry of 3D warp interlock fabric needs to be check during the 3D forming step to ensure the right locations of warp and weft yarns inside the final structure. Thus, a new monitoring approach has been proposed based on sensor yarns located in the fabric thickness. To ensure the accuracy of measurements, the observation of the surface deformation of the 3D warp interlock fabric has been joined to the sensor yarns measurements. At the end, it has been revealed a good correlation between strain measurement done globally by camera and locally performed by sensor yarns.

Refining the maintenance techniques for Interlocking Concrete Paver GIs

Science.gov (United States)

Surface clogging adversely affects the performance of Interlocking Concrete Pavements (ICP) by reducing their ability to infiltrate stormwater runoff. The clogging rate is a function of pavement type, traffic loading, surrounding physical environment and maintenance treatments. ...

National synchrotron light source medical personnel protection interlock

International Nuclear Information System (INIS)

Buda, S.; Gmur, N.F.; Larson, R.; Thomlinson, W.

1998-01-01

This report is founded on reports written in April 1987 by Robert Hettel for angiography operations at the Stanford Synchrotron Research Laboratory (SSRL) and a subsequent report covering angiography operations at the National Synchrotron Light Source (NSLS); BNL Informal Report 47681, June 1992. The latter report has now been rewritten in order to accurately reflect the design and installation of a new medical safety system at the NSLS X17B2 beamline Synchrotron Medical Research Facility (SMERF). Known originally as the Angiography Personnel Protection Interlock (APPI), this system has been modified to incorporate other medical imaging research programs on the same beamline and thus the name has been changed to the more generic Medical Personnel Protection Interlock (MPPI). This report will deal almost exclusively with the human imaging (angiography, bronchography, mammography) aspects of the safety system, but will briefly explain the modular aspects of the system allowing other medical experiments to be incorporated

NATIONAL SYNCHROTRON LIGHT SOURCE MEDICAL PERSONNEL PROTECTION INTERLOCK

Energy Technology Data Exchange (ETDEWEB)

BUDA,S.; GMUR,N.F.; LARSON,R.; THOMLINSON,W.

1998-11-03

This report is founded on reports written in April 1987 by Robert Hettel for angiography operations at the Stanford Synchrotron Research Laboratory (SSRL) and a subsequent report covering angiography operations at the National Synchrotron Light Source (NSLS); BNL Informal Report 47681, June 1992. The latter report has now been rewritten in order to accurately reflect the design and installation of a new medical safety system at the NSLS X17B2 beamline Synchrotron Medical Research Facility (SMERF). Known originally as the Angiography Personnel Protection Interlock (APPI), this system has been modified to incorporate other medical imaging research programs on the same beamline and thus the name has been changed to the more generic Medical Personnel Protection Interlock (MPPI). This report will deal almost exclusively with the human imaging (angiography, bronchography, mammography) aspects of the safety system, but will briefly explain the modular aspects of the system allowing other medical experiments to be incorporated.

Design of responsive materials using topologically interlocked elements

International Nuclear Information System (INIS)

Molotnikov, A; Gerbrand, R; Qi, Y; Simon, G P; Estrin, Y

2015-01-01

In this work we present a novel approach to designing responsive structures by segmentation of monolithic plates into an assembly of topologically interlocked building blocks. The particular example considered is an assembly of interlocking osteomorphic blocks. The results of this study demonstrate that the constraining force, which is required to hold the blocks together, can be viewed as a design parameter that governs the bending stiffness and the load bearing capacity of the segmented structure. In the case where the constraining forces are provided laterally using an external frame, the maximum load the assembly can sustain and its stiffness increase linearly with the magnitude of the lateral load applied. Furthermore, we show that the segmented plate with integrated shape memory wires employed as tensioning cables can act as a smart structure that changes its flexural stiffness and load bearing capacity in response to external stimuli, such as heat generated by the switching on and off an electric current. (paper)

National Synchrotron Light Source angiography personnel protection interlock

International Nuclear Information System (INIS)

Gmuer, N.; Larson, R.; Thomlinson, W.

1992-06-01

This document has been written to describe the safety system operation at the NSLS X17B2 beamline Synchrotron Medical Research Facility (SMERF). The angiography exposure process involves scanning a patient up and down through dual fixed-position x-ray beams; exposure is controlled by opening and closing a fast-acting Safety Shutter mechanism at precise times in relation to the up and down motion of the scan chair. The fast-acting Safety Shutter mechanism is the primary radiation-stopping element protecting the patient while the chair is at rest and while it is reversing directions during the scan. Its fail-safe and fast operation is essential for the safety of the patient. Operation of X17B2 as a human subject angiography station necessitates the implementation of a personnel protection interlock system that, in conjunction with the Safety Shutters: permits safe access to the patient exposure area while the synchrotron radiation beam is illuminating the upstream dual energy monochromator; allows a patient to be imaged by the monochromatized beam under the supervision of a Responsible Physician, with scan chair motion and precision shutter actuation regulated by an angiography control computer, while providing a suitable number of safeguards against accidental radiation exposure; has different modes of operation to accommodate equipment set-up, test, and calibration; and patient exposure; and ensures the quick extinction of the beam if a potentially unsafe condition is detected. The interlock system which performs these safety functions is called the Angiography Personnel Protection Interlock (APPI). The APPI Document is organized such that the level of detail changes from a general overview to detailed engineering drawings of the hardware system

National Synchrotron Light Source angiography personnel protection interlock

Energy Technology Data Exchange (ETDEWEB)

Gmuer, N.; Larson, R.; Thomlinson, W.

1992-06-01

This document has been written to describe the safety system operation at the NSLS X17B2 beamline Synchrotron Medical Research Facility (SMERF). The angiography exposure process involves scanning a patient up and down through dual fixed-position x-ray beams; exposure is controlled by opening and closing a fast-acting Safety Shutter mechanism at precise times in relation to the up and down motion of the scan chair. The fast-acting Safety Shutter mechanism is the primary radiation-stopping element protecting the patient while the chair is at rest and while it is reversing directions during the scan. Its fail-safe and fast operation is essential for the safety of the patient. Operation of X17B2 as a human subject angiography station necessitates the implementation of a personnel protection interlock system that, in conjunction with the Safety Shutters: permits safe access to the patient exposure area while the synchrotron radiation beam is illuminating the upstream dual energy monochromator; allows a patient to be imaged by the monochromatized beam under the supervision of a Responsible Physician, with scan chair motion and precision shutter actuation regulated by an angiography control computer, while providing a suitable number of safeguards against accidental radiation exposure; has different modes of operation to accommodate equipment set-up, test, and calibration; and patient exposure; and ensures the quick extinction of the beam if a potentially unsafe condition is detected. The interlock system which performs these safety functions is called the Angiography Personnel Protection Interlock (APPI). The APPI Document is organized such that the level of detail changes from a general overview to detailed engineering drawings of the hardware system.

National Synchrotron Light Source medical personnel protection interlock

Energy Technology Data Exchange (ETDEWEB)

Buda, S.; Gmuer, N.F.; Larson, R.; Thomlinson, W.

1998-11-01

This report is founded on reports written in April 1987 by Robert Hettel for angiography operations at the Stanford Synchrotron Research Laboratory (SSRL) and a subsequent report covering angiography operations at the National Synchrotron Light Source (NSLS); BNL Informal Report 47681, June 1992. The latter report has now been rewritten in order to accurately reflect the design and installation of a new medical safety system at the NSLS X17B2 beamline Synchrotron Medical Research Facility (SMERF). Known originally as the Angiography Personnel Protection Interlock (APPI), this system has been modified to incorporate other medical imaging research programs on the same beamline and thus the name has been changed to the more generic Medical Personnel Protection Interlock (MPPI). This report will deal almost exclusively with the human imaging (angiography, bronchography, mammography) aspects of the safety system, but will briefly explain the modular aspects of the system allowing other medical experiments to be incorporated. This MPPI report is organized such that the level of detail changes from a general overview to detailed engineering drawings of the hardware system. The general overview is presented in Section 1.0, MPPI Operational Mode and Procedures. The various MPPI components are described in detail in Section 2.0. Section 3.0 presents some simplified logic diagrams and accompanying text. This section was written to allow readers to become familiar with the logic system without having to work through the entire set of detailed engineering drawings listed in the Appendix. Detailed logic specifications are given in Section 4.0. The Appendix also contains copies of the current MPPI interlock test procedures for Setup and Patient Modes.

PLC-based search and secure interlock system for the personnel safety in folded tandem ion accelerator

International Nuclear Information System (INIS)

Padmakumar, Sapna; Subramanyum, N.B.V.; Bhatt, Jignesh P.; Ware, Shailaja V.; Kansara, M.J.; Gupta, S.K.; Singh, P.

2006-01-01

Safety of the personnel is one of the key issues addressed in any accelerator project. The FOTIA facility at BARC is capable of operating under standard operation conditions without any radiation hazard. Even then for a safe and reliable operation of FOTIA a PLC (Programmable logic controller) based interlock system has been implemented. This interlocking system is compact, modular, flexible, robust and easy for troubleshooting. These advantages led to the popularity of PLC rather than using a relay-based system. This paper highlights the salient features of the search and secure interlock for the personal safety of FOTIA. (author)

49 CFR 1242.17 - Signals and interlockers (accounts XX-17-19 and XX-18-19).

Science.gov (United States)

2010-10-01

... 49 Transportation 9 2010-10-01 2010-10-01 false Signals and interlockers (accounts XX-17-19 and XX... RAILROADS 1 Operating Expenses-Way and Structures § 1242.17 Signals and interlockers (accounts XX-17-19 and XX-18-19). Separate common expenses on the basis of the total train-hours in running service, and/or...

Control Logic for the Interlock system of the ATLAS Insertable B-Layer

CERN Document Server

Riegel, Christian

Part of the first upgrade program of the ATLAS detector is the installation of the Insertable B-Layer (IBL) as a fourth and innermost detector layer of the ATLAS pixel detector to prepare the tracking system for the expected increase of pile-up events. As with every sub-detector, the IBL and its components have to be monitored and controlled via a Detector Control System (DCS). A hardware-based interlock system is installed on-site to prevent detector and people working at the detector from serious harm and damage. For the IBL, the logical processing of interlock signals is realised in Interlock Matrix Crates (IMCs) using Complex Programmable Logic Devices (CPLD). One part of this master thesis is the automatic implementation of the logical assignments from database information. A script was developed to generate the needed file to program the CPLD. The second part of this thesis is the design of a test setup to verify the functionality of the electrical components of each IMC and to confirm the correct proce...

Effects of Interlocking and Supporting Conditions on Concrete Block Pavements

Science.gov (United States)

Mahapatra, Geetimukta; Kalita, Kuldeep

2018-02-01

Concrete Block Paving (CBP) is widely used as wearing course in flexible pavements, preferably under light and medium vehicular loadings. Construction of CBP at site is quick and easy in quality control. Usually, flexible pavement design philosophy is followed in CBP construction, though it is structurally different in terms of small block elements with high strength concrete and their interlocking aspects, frequent joints and discontinuity, restrained edge etc. Analytical solution for such group action of concrete blocks under loading in a three dimensional multilayer structure is complex and thus, the need of conducting experimental studies is necessitated for extensive understanding of the load—deformation characteristics and behavior of concrete blocks in pavement. The present paper focuses on the experimental studies for load transfer characteristics of CBP under different interlocking and supporting conditions. It is observed that both interlocking and supporting conditions affect significantly on the load transfer behavior in CBP structures. Coro-lock block exhibits better performance in terms of load carrying capacity and distortion behavior under static loads. Plate load tests are performed over subgrade, granular sub-base (GSB), CBP with and without GSB using different block shapes. For an example case, the comparison of CBP with conventional flexible pavement section is also presented and it is found that CBP provides considerable benefit in terms of construction cost of the road structure.

COMPARATIVE STUDY OF KUNTSCHER’S NAIL VS. INTERLOCKING NAILING FOR FEMORAL ISTHMUS FRACTURES

Directory of Open Access Journals (Sweden)

Rajeev Kumar Roy

2017-05-01

Full Text Available BACKGROUND Interlocking intramedullary nailing is suitable for comminuted femoral isthmus fractures, but for non-comminuted fractures its benefit over unlocked nailing is debatable. This study was undertaken to compare outcomes of interlocking nailing versus k-nail in such fractures. MATERIALS AND METHODS 40 cases of noncomminuted femoral isthmus fractures treated with interlocking nailing and K-nail from April 1, 2015, to December 1, 2016, were reviewed. Radiological and clinical union rates, bony alignment, complication and knee function were investigated. RESULTS There was no statistical significant difference with regard to union rate, implant failure, infection and fracture alignment in both study groups. Open fixation with K-nail is technically less demanding and requires less operating time; additionally, there is no exposure to radiation and cost of the implant is cheaper. CONCLUSION We therefore conclude that unlocked nailing is still useful for the management of noncomminuted isthmus fractures of the femur.

Novel Repair Concept for Composite Materials by Repetitive Geometrical Interlock Elements

Directory of Open Access Journals (Sweden)

David Zaremba

2011-12-01

Full Text Available Material adapted repair technologies for fiber-reinforced polymers with thermosetting matrix systems are currently characterized by requiring major efforts for repair preparation and accomplishment in all industrial areas of application. In order to allow for a uniform distribution of material and geometrical parameters over the repair zone, a novel composite interlock repair concept is introduced, which is based on a repair zone with undercuts prepared by water-jet technology. The presented numerical and experimental sensitivity analyses make a contribution to the systematic development of the interlock repair technology with respect to material and geometrical factors of influence. The results show the ability of the novel concept for a reproducible and automatable composite repair.

Fracture Union in Closed Interlocking Nail in Humeral Shaft Fractures

Directory of Open Access Journals (Sweden)

Ramji Lal Sahu

2015-01-01

Conclusions: The results of the present study indicates that in the presence of proper indications, reamed antegrade intramedullary interlocked nailing appears to be a method of choice for internal fixation of osteoporotic and pathologic fractures.

Analysis of operator support method based on intelligent dynamic interlock in lead-cooled fast reactor simulator

International Nuclear Information System (INIS)

Xu, Peng; Wang, Jianye; Yang, Minghan; Wang, Weitian; Bai, Yunqing; Song, Yong

2017-01-01

Highlights: • We development an operator support method based on intelligent dynamic interlock. • We offer an integrated aid system to reduce the working strength of operators. • The method can help operators avoid dangerous, irreversible operation. • This method can be used in the fusion research reactor in the further. - Abstract: In nuclear systems, operators have to carry out corrective actions when abnormal situations occur. However, operators might make mistakes under pressure. In order to avoid serious consequences of the human errors, a new method for operators support based on intelligent dynamic interlock was proposed. The new method based on full digital instrumentation and control system, contains real-time alarm analysis process, decision support process and automatic safety interlock process. Once abnormal conditions occur, necessary safety interlock parameter based on analysis of real-time alarm and decision support process can be loaded into human-machine interfaces and controllers automatically, and avoid human errors effectively. Furthermore, the new method can make recommendations for further use and development of this technique in nuclear power plant or fusion research reactor.

Central system of Interlock of ITER, high integrity architecture

International Nuclear Information System (INIS)

Prieto, I.; Martinez, G.; Lopez, C.

2014-01-01

The CIS (Central Interlock System), along with the CODAC system and CSS (Central Safety System), form the central I and C systems of ITER. The CIS is responsible for implementing the core functions of protection (Central Interlock Functions) through different systems of plant (Plant Systems) within the overall strategy of investment protection for ITER. IBERDROLA supports engineering to define and develop the control architecture of CIS according to the stringent requirements of integrity, availability and response time. For functions with response times of the order of half a second is selected PLC High availability of industrial range. However, due to the nature of the machine itself, certain functions must be able to act under the millisecond, so it has had to develop a solution based on FPGA (Field Programmable Gate Array) capable of meeting the requirements architecture. In this article CIS architecture is described, as well as the process for the development and validation of the selected platforms. (Author)

Cloning Nacre's 3D Interlocking Skeleton in Engineering Composites to Achieve Exceptional Mechanical Properties.

Science.gov (United States)

Zhao, Hewei; Yue, Yonghai; Guo, Lin; Wu, Juntao; Zhang, Youwei; Li, Xiaodong; Mao, Shengcheng; Han, Xiaodong

2016-07-01

Ceramic/polymer composite equipped with 3D interlocking skeleton (3D IL) is developed through a simple freeze-casting method, exhibiting exceptionally light weight, high strength, toughness, and shock resistance. Long-range crack energy dissipation enabled by 3D interlocking structure is considered as the primary reinforcing mechanism for such superior properties. The smart composite design strategy should hold a place in developing future structural engineering materials. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Experimental and numerical analysis of interlocking rib formation at sheet metal blanking

Science.gov (United States)

Bolka, Špela; Bratuš, Vitoslav; Starman, Bojan; Mole, Nikolaj

2018-05-01

Cores for electrical motors are typically produced by blanking of laminations and then stacking them together, with, for instance, interlocking ribs or welding. Strict geometrical tolerances, both on the lamination and on the stack, combined with complex part geometry and harder steel strip material, call for use of predictive methods to optimize the process before actual blanking to reduce the costs and speed up the process. One of the major influences on the final stack geometry is the quality of the interlocking ribs. A rib is formed in one step and joined with the rib of the preceding lamination in the next. The quality of the joint determines the firmness of the stack and also influences its. The geometrical and positional accuracy is thus crucial in rib formation process. In this study, a complex experimental and numerical analysis of interlocking rib formation has been performed. The aim of the analysis is to numerically predict the shape of the rib in order to perform a numerical simulation of the stack formation in the next step of the process. A detailed experimental research has been performed in order to characterize influential parameters on the rib formation and the geometry of the ribs itself, using classical and 3D laser microscopy. The formation of the interlocking rib is then simulated using Abaqus Explicit. The Hilll 48 constitutive material model is based on extensive and novel material characterization process, combining data from in-plane and out-of-plane material tests to perform a 3D analysis of both, rib formation and rib joining. The study shows good correlation between the experimental and numerical results.

A comparative study of interlocking directorates at the end of the import-substituting industrialization period in Argentina and Chile

Directory of Open Access Journals (Sweden)

Erica Salvaj, Andrea Lluch

2012-12-01

Full Text Available Research on interlocking directorates has been conducted primarily in the United States and European countries. Little work of either theoretical or empirical nature has been done to study the characteristics and the factors that affect this important business network in peripheral and turbulent economies. In this comparative and historical study, we focus on the effect of the political and economic turbulence and the ownership composition of the largest firms on shaping the structure of interlocking directorates in Argentina and Chile by the end of the sixties. Four main findings result from this analysis: 1 the interlocking directorate in Argentina is more fragmented than in Chile; 2 most relevant actors in the directorship interlock in Argentina are firms in industries considered strategic by the government; 3 multinational subsidiaries occupy a central position in Argentina; 4 banks and firms owned by local business groups played a central role in the interlocking directorates in Chile. This study shows how the institutional and economic factors shape the structure of relations between companies.

Evaluation of a fast PLC module in prospect of the LHC beam interlock system

CERN Document Server

Zaera-Sanz, Manuel

2005-01-01

The LHC Beam Interlock system requires a controller performing a simple matrix function to collect the different beam dump requests. To satisfy the expected safety level of the Interlock, the system should be robust and reliable. The PLC is a promising candidate to fulfil both aspects but too slow to meet the expected response time which is of the order of mseconds. Siemens has introduced a “so called” fast module (FM352-5 Boolean Processor) that provides independent and extremely fast control of a process within a larger control system using an onboard processor, a Field Programmable Gate Array (FPGA), to execute code in parallel which results in extremely fast scan times. It is interesting to investigate its features and to evaluate it as a possible candidate for the beam interlock system. This note publishes the results of this study. As well, this note could be useful for other applications requiring fast processing using a PLC.

Comparative Study on the Cost of Building Public House Construction Using Red Brick and Interlock Brick Building Material in the City of Banda Aceh

Science.gov (United States)

Malahayati, Nurul; Hayati, Yulia; Nursaniah, Cut; Firsa, T.; Fachrurrazi; Munandar, Aris

2018-05-01

Red brick and interlocking brick are the building materials that are often used for wall installation work on houses construction. In the development of building materials technology and cost savings, interlocking brick can be alternative to replace red bricks. In Aceh Province, the use of interlocking bricks is less popular compared to other big cities in Indonesia. Interlocking brick is made from a mixture of clay, concrete sand and compacted cement and one of the environmentally friendly materials because it does not burn the process like red brick material. It is named interlocking brick because the installation method is locked together and it serves as a structural and partition wall of residential buildings. The aims of this study are to compare the cost of building a house in Banda Aceh City using red brick and interlock brick building materials. The data were obtained from interviews and questionnaires distributed to respondents who had built houses in Banda Aceh City. The results concluded that the house construction cost using interlock brick offer lower construction cost at comparable quality rather than using red brick.

Board interlocking in Brazil: Director participation in multiple companies and its effect on the value of firms

Directory of Open Access Journals (Sweden)

Alexandre Di Miceli da Silveira

2007-12-01

Full Text Available This paper investigates the simultaneous participation of directors in different companies from 320 Brazilian listed firms in 2003 and 2005. We identify which firms are connected through a network of directors, which corporate characteristics contribute to this phenomenon, and if board interlocking influences firm value and operational performance. The results show that interlocking directorates are a common practice in Brazil. Besides, larger boards, more dispersed ownership structures, and larger firm size are factors associated with a high level of board interlocking. Moreover, we find that firm value is, on average, negatively impacted by higher levels of board interlocking, especially on firms with board of directors considered too busy (those in which a majority of directors hold three or more directorships or on firms where their CEO hold directorships in other companies. Besides being a pioneer work on this field in Latin America, the paper provides subsides for the preparation of good corporate governance practices from regulators regarding the effectiveness of multiple directorships and its consequences for corporate value.

Bunker door interlock limit issues of K-130 cyclotron, VECC

International Nuclear Information System (INIS)

Srihari, K.; Ravishankar, R.; Mitra, M.S.; Mishra, S.K.; Bandyopadhyay, T.; Sarkar, P.K.

2011-01-01

The K-130 cyclotron is in operation at VECC, Kolkata. Recently modernization of the cyclotron has taken place. Central region modification has increased reasonable internal beam current. During the tuning of the projectiles, loss of beam is unavoidable and projectiles hitting different parts of the machine inside the vacuum chamber . These interactions produce prompt radiation comprising neutron and gamma. However machine bunker is not accessible during the operation of the machine. The induced activity produced because of interactions of the primary and secondary radiation a radiation hazardous environment during the shut down for the related maintenance work. Area radiation monitors placed at machine bunker room have the interlock with massive shield door of the bunker. Area radiation monitors are set to specified limiting value, lower than that will allow to open the shield door in normal condition. As, the internal beam current being increased and the probability of beam spread being more. Consequently generation of induced activity is also high leading to delay in machine bunker door opening because of the interlock settings. Radiation dose mapping after a long operation of the machine was done for the different strategic points (The locations mainly people access immediate after shut down). Different consequences and remedial measures being presented in paper to raise the dose rate limit level for the interlocks between the area radiation monitors with machine bunker door, keeping in mind of the regulatory requirements. Raising the limit of dose rate limiting value will minimize the waiting time to access the machine bunker which will increase the duty factor of the machine. (author)

Preliminary design of safety and interlock system for indian test facility of diagnostic neutral beam

International Nuclear Information System (INIS)

Tyagi, Himanshu; Soni, Jignesh; Yadav, Ratnakar; Bandyopadhyay, Mainak; Rotti, Chandramouli; Gahlaut, Agrajit; Joshi, Jaydeep; Parmar, Deepak; Bansal, Gourab; Pandya, Kaushal; Chakraborty, Arun

2016-01-01

Highlights: • Indian Test Facility being built to characterize DNB for ITER delivery. • Interlock system required to safeguard the investment incurred in building the facility and protecting ITER deliverable components. • Interlock levels upto 3IL-3 identified. • Safety instrumented system for occupational safety being designed. Safety I&C functions of SIL-2 identified. • The systems are based on ITER PIS and PSS design guidelines. - Abstract: Indian Test Facility (INTF) is being built in Institute For Plasma Research to characterize Diagnostic Neutral Beam in co-operation with ITER Organization. INTF is a complex system which consists of several plant systems like beam source, gas feed, vacuum, cryogenics, high voltage power supplies, high power RF generators, mechanical systems and diagnostics systems. Out of these, several INTF components are ITER deliverable, that is, beam source, beam line components and power supplies. To ensure successful operation of INTF involving integrated operation of all the constituent plant systems a matured Data Acquisition and Control System (DACS) is required. The INTF DACS is based on CODAC platform following on PCDH (Plant Control Design Handbook) guidelines. The experimental phases involve application of HV power supplies (100 KV) and High RF power (∼800 KW) which will produce energetic beam of maximum power 6MW within the facility for longer durations. Hence the entire facility will be exposed tohigh heat fluxes and RF radiations. To ensure investment protection and to provide occupational safety for working personnel a matured Safety and Interlock system is required for INTF. The Safety and Interlock systems are high-reliability I&C systems devoted completely to the specific functions. These systems will be separate from the conventional DACS of INTF which will handle the conventional control and acquisition functions. Both, the Safety and Interlock systems are based on IEC 61511 and IEC 61508 standards as

Preliminary design of safety and interlock system for indian test facility of diagnostic neutral beam

Energy Technology Data Exchange (ETDEWEB)

Tyagi, Himanshu, E-mail: htyagi@iter-india.org [ITER-India, Institute For Plasma Research, Bhat, Gandhinagar, Gujarat (India); Soni, Jignesh [Institute For Plasma Research, Bhat, Gandhinagar, Gujarat (India); Yadav, Ratnakar; Bandyopadhyay, Mainak; Rotti, Chandramouli [ITER-India, Institute For Plasma Research, Bhat, Gandhinagar, Gujarat (India); Gahlaut, Agrajit [Institute For Plasma Research, Bhat, Gandhinagar, Gujarat (India); Joshi, Jaydeep; Parmar, Deepak [ITER-India, Institute For Plasma Research, Bhat, Gandhinagar, Gujarat (India); Bansal, Gourab; Pandya, Kaushal; Chakraborty, Arun [Institute For Plasma Research, Bhat, Gandhinagar, Gujarat (India)

2016-11-15

Highlights: • Indian Test Facility being built to characterize DNB for ITER delivery. • Interlock system required to safeguard the investment incurred in building the facility and protecting ITER deliverable components. • Interlock levels upto 3IL-3 identified. • Safety instrumented system for occupational safety being designed. Safety I&C functions of SIL-2 identified. • The systems are based on ITER PIS and PSS design guidelines. - Abstract: Indian Test Facility (INTF) is being built in Institute For Plasma Research to characterize Diagnostic Neutral Beam in co-operation with ITER Organization. INTF is a complex system which consists of several plant systems like beam source, gas feed, vacuum, cryogenics, high voltage power supplies, high power RF generators, mechanical systems and diagnostics systems. Out of these, several INTF components are ITER deliverable, that is, beam source, beam line components and power supplies. To ensure successful operation of INTF involving integrated operation of all the constituent plant systems a matured Data Acquisition and Control System (DACS) is required. The INTF DACS is based on CODAC platform following on PCDH (Plant Control Design Handbook) guidelines. The experimental phases involve application of HV power supplies (100 KV) and High RF power (∼800 KW) which will produce energetic beam of maximum power 6MW within the facility for longer durations. Hence the entire facility will be exposed tohigh heat fluxes and RF radiations. To ensure investment protection and to provide occupational safety for working personnel a matured Safety and Interlock system is required for INTF. The Safety and Interlock systems are high-reliability I&C systems devoted completely to the specific functions. These systems will be separate from the conventional DACS of INTF which will handle the conventional control and acquisition functions. Both, the Safety and Interlock systems are based on IEC 61511 and IEC 61508 standards as

An overview of process instrumentation, protective safety interlocks and alarm system at the JET facilities active gas handling system

International Nuclear Information System (INIS)

Skinner, N.; Brennan, P.; Brown, K.; Gibbons, C.; Jones, G.; Knipe, S.; Manning, C.; Perevezentsev, A.; Stagg, R.; Thomas, R.; Yorkshades, J.

2003-01-01

The Joint European Torus (JET) Facilities Active Gas Handling System (AGHS) comprises ten interconnected processing sub-systems that supply, process and recover tritium from gases used in the JET Machine. Operations require a diverse range of process instrumentation to carry out a multiplicity of monitoring and control tasks and approximately 500 process variables are measured. The different types and application of process instruments are presented with specially adapted or custom-built versions highlighted. Forming part of the Safety Case for tritium operations, a dedicated hardwired interlock and alarm system provides an essential safety function. In the event of failure modes, each hardwired interlock will back-up software interlocks and shutdown areas of plant to a failsafe condition. Design of the interlock and alarm system is outlined and general methodology described. Practical experience gained during plant operations is summarised and the methods employed for routine functional testing of essential instrument systems explained

Board and auditor interlocks and voluntary disclosure in annual reports

NARCIS (Netherlands)

Braam, G.J.M.; Borghans, L.

2014-01-01

Purpose – The purpose of this study is to explore whether interlock ties between the board of directors and the external auditors facilitate the cross-firm diffusion of voluntary disclosures in annual reports. Design/methodology/approach – Using a sample of 149 non-financial companies publicly

From the LHC Reference Database to the Powering Interlock System

CERN Document Server

Dehavay, C; Schmidt, R; Veyrunes, E; Zerlauth, M

2003-01-01

The protection of the magnet powering system for the Large Hadron Collider (LHC) currently being built at CERN is a major challenge due to the unprecedented complexity of the accelerator. The Powering Interlock System of the LHC will have to manage more than 1600 DC circuits for magnet powering, different in their structure, complexity and importance to the accelerator. For the coherent description of such complex system, a Reference Database as unique source of the parameters of the electrical circuits has been developed. The information, introduced via a generic circuit description language, is first used for installing the accelerator and making all electrical connections. The data is then used for tests and commissioning. During operation, the Powering Interlock System manages all critical functions. It consists of 36 PLC based controllers dis tributed around the machine and requires a flexible and transparent way of configuration, since each controller manages different numbers and types of electrical ci...

NSTX Protection And Interlock Systems For Coil And Powers Supply Systems

International Nuclear Information System (INIS)

Zhao, X.; Ramakrishnan, S.; Lawson, J.; Neumeyer, C.; Marsala, R.; Schneider, H.

2009-01-01

NSTX at Princeton Plasma Physics Laboratory (PPPL) requires sophisticated plasma positioning control system for stable plasma operation. TF magnetic coils and PF magnetic coils provide electromagnetic fields to position and shape the plasma vertically and horizontally respectively. NSTX utilizes twenty six coil power supplies to establish and initiate electromagnetic fields through the coil system for plasma control. A power protection and interlock system is utilized to detect power system faults and protect the TF coils and PF coils against excessive electromechanical forces, overheating, and over current. Upon detecting any fault condition the power system is restricted, and it is either prevented from initializing or suppressed to de-energize coil power during pulsing. Power fault status is immediately reported to the computer system. This paper describes the design and operation of NSTX's protection and interlocking system and possible future expansion.

Evaluation and application of a fast module in a PLC based interlock and control system

International Nuclear Information System (INIS)

Zaera-Sanz, M

2009-01-01

The LHC Beam Interlock system requires a controller performing a simple matrix function to collect the different beam dump requests. To satisfy the expected safety level of the Interlock, the system should be robust and reliable. The PLC is a promising candidate to fulfil both aspects but too slow to meet the expected response time which is of the order of μseconds. Siemens has introduced a 'so called' fast module (FM352-5 Boolean Processor). It provides independent and extremely fast control of a process within a larger control system using an onboard processor, a Field Programmable Gate Array (FPGA), to execute code in parallel which results in extremely fast scan times. It is interesting to investigate its features and to evaluate it as a possible candidate for the beam interlock system. This paper publishes the results of this study. As well, this paper could be useful for other applications requiring fast processing using a PLC.

A DUAL NETWORK MODEL OF INTERLOCKING DIRECTORATES

Directory of Open Access Journals (Sweden)

Humphry Hung

2003-01-01

Full Text Available The article proposes an integrative framework for the study of interlocking directorates by using an approach that encompasses the concepts of multiple networks and resource endowment. This serves to integrate the traditional views of interorganizational linkages and intra-class cohesion. Through appropriate strategic analysis of relevant resource endowment of internal environment and external networks of organizations and corporate elites, this article argues that the selection of directors, if used effectively, can be adopted as a strategic device to enhance the corporation's overall performance.

A Focus on Triazolium as a Multipurpose Molecular Station for pH-Sensitive Interlocked Crown-Ether-Based Molecular Machines.

Science.gov (United States)

Coutrot, Frédéric

2015-10-01

The control of motion of one element with respect to others in an interlocked architecture allows for different co-conformational states of a molecule. This can result in variations of physical or chemical properties. The increase of knowledge in the field of molecular interactions led to the design, the synthesis, and the study of various systems of molecular machinery in a wide range of interlocked architectures. In this field, the discovery of new molecular stations for macrocycles is an attractive way to conceive original molecular machines. In the very recent past, the triazolium moiety proved to interact with crown ethers in interlocked molecules, so that it could be used as an ideal molecular station. It also served as a molecular barrier in order to lock interlaced structures or to compartmentalize interlocked molecular machines. This review describes the recently reported examples of pH-sensitive triazolium-containing molecular machines and their peculiar features.

The engineering project and reliability research of the safety interlock slow control system in BESIII

International Nuclear Information System (INIS)

Zhang Yinhong; Zhao Jingwei; Li Xiaonan; Xie Xiaoxi; Gao Cuishan; Bai Jingzhi; Chen Xihui; Min Jian; Nie Zhendong

2008-01-01

The new safety interlock slow control system of BESIII is designed to ensure that the BESIII interior equipments and the accelerator control center to work in coordination, and to guarantee the safety of the operating staff and all the important equipments at the same time. This paper introduces the hardware and software design of safety interlock system from the engineering requirements angle, including a detailed research on the software implementation technique of the state machine on PLC and the reliability of the system. (authors)

Automatic Verification of Railway Interlocking Systems: A Case Study

DEFF Research Database (Denmark)

Petersen, Jakob Lyng

1998-01-01

This paper presents experiences in applying formal verification to a large industrial piece of software. The are of application is railway interlocking systems. We try to prove requirements of the program controlling the Swedish railway Station Alingsås by using the decision procedure which...... express thoughts on what is needed in order to be able to successfully verify large real-life systems....

Outcomes in closed reamed interlocking nail in fractures of shaft of femur

International Nuclear Information System (INIS)

Mohammad, T.; Sawati, A.; Ahmed, A.

2015-01-01

Femoral shaft fracture is one of the common fractures seen in accident and emergency department of our hospital. Violent forces are required to break this and strongest of human bones. There are various treatment modalities for femoral shaft fractures in adults like traction, brace, platting, intramedullary nail (IMN), external fixators and inter locking nails. The study was done with an objective to evaluate the results of closed reamed interlocking nail in fractures of shaft of femur. Methods: A prospective study of 114 cases of femoral shaft fractures was carried out at orthopaedic unit of Ayub Teaching Hospital Abbottabad during 1 year. All these cases were treated with statically locked nails under spinal or general anaesthesia. These cases were followed up for up to one year and Results of the interlocking nail were observed in terms of union and complications. Results: Out of 114 patients, 95 underwent union in 90-150 days with a mean of 110.68 days. Ten patients had dynamization within six weeks because of obvious fracture gap in radiograph. There were 3 patients who had non-union, and 6 patients had delayed union which was treated with dynamization. Conclusion: Close reamed interlocking intramedullary nail in femoral shaft fractures is the treatment of choice. Patient rehabilitation is early, hospitalization is short, and fracture healing response is good. (author)

The Layer of Kevlar Angle-interlock Woven Fabric Effect on the Tensile Properties of Composite Materials

Science.gov (United States)

Xie, Wan-Chen; Guo, Xu-Yi; Yan, Tao; Zhang, Shang-Yong

2017-09-01

This article is based on the structure of three-dimensional angle-interlock longitudinal.The 3-layer, 5-layer, 7-layer and 9-layer of angle-interlock 3D fabrics are woven on sample weaving machine respectively with the 1500D Kevlar fiber twist filament produced by United States DuPont. At the same time, Kevlar plain weave fabric is woven, and three, five, seven and nine layers’ fabric are to be compared. In the process of VARTM composite technology, epoxy resin is matrix material, acetone is diluent, triethylene tetramine is curing agent and the five different fabrics are the reinforced materials respectively. Finally, eight different three-dimensional woven fabric composites were prepared. In this paper, the tensile properties of eight kinds of three-dimensional woven fabric composites were tested respectively.Finally, it is concluded that the five-layer angle-interlock woven fabric prepared by Kevlar fiber shows the best tensile property.

Towards a Framework for Modelling and Verification of Relay Interlocking Systems

DEFF Research Database (Denmark)

Haxthausen, Anne Elisabeth

2011-01-01

This paper describes a framework currently under development for modelling, simulation, and verification of relay interlocking systems as used by the Danish railways. The framework is centred around a domain-specific language (DSL) for describing such systems, and provides (1) a graphical editor...

Compositional Model Checking of Interlocking Systems for Lines with Multiple Stations

DEFF Research Database (Denmark)

Macedo, Hugo Daniel dos Santos; Fantechi, Alessandro; Haxthausen, Anne Elisabeth

2017-01-01

In the railway domain safety is guaranteed by an interlocking system which translates operational decisions into commands leading to field operations. Such a system is safety critical and demands thorough formal verification during its development process. Within this context, our work has focused...

Towards a Framework for Modelling and Verification of Relay Interlocking Systems

DEFF Research Database (Denmark)

Haxthausen, Anne Elisabeth

2010-01-01

This paper describes a framework currently under development for modelling, simulation, and verification of relay interlocking systems as used by the Danish railways. The framework is centred around a domain-specific language (DSL) for describing such systems, and provides (1) a graphical editor ...

Fracture Union in Closed Interlocking Nail in Femoral Fracture

Directory of Open Access Journals (Sweden)

R L Sahu

2010-09-01

Full Text Available INTRODUCTION: Fractures shaft femur is a major cause of morbidity and mortality in patients with lower extremity injuries. The objective of this study was to find out the outcome of Interlocking nail in fracture femur. METHODS: This study was conducted in the Department of Orthopaedic surgery in M. M. Medical College from July 2006 to November 2008. Seventy eight patients were recruited from Emergency and out patient department having closed fracture of femoral shaft. All patients were operated under general or spinal anesthesia. All patients were followed for nine months. RESULTS: Out of seventy eight patients, sixty nine patients underwent union in 90 to 150 days with a mean of 110.68 days. Touch down weight bearing was started on 2nd post-operative day. Complications found in four patients who had non-union, and five patients had delayed union which was treated with dynamization and bone graft. The results were excellent in 88.46% and good in 6.41% patients. CONCLUSIONS: We concluded that this technique is advantageous because of early mobilization (early weight bearing, less complication with good results and is economical. Keywords: close reamed interlocking nail, dynamization, femoral shaft fractures, union

Efficacy and Safety of Interlocked Intramedullary Nailing for Open Fracture Shaft of Tibia

International Nuclear Information System (INIS)

Ahmad, N.; Awan, A. S.; Sultan, S.; Saifullah, K.; Afridi, S. A.; Afridi, S. K.; Lodhi, F. S.

2016-01-01

Background: Due to increasing population and changing human habits the number of accidents and high energy trauma is rising. Management of open fracture tibia is a complex problem and is a challenge for both orthopaedic and plastic surgeons. The study was carried out to ascertain the efficacy and safety of interlocked intra-medullary nailing for open shaft tibial fractures in patients presenting at or after 24 hr of injury. Methods: In this descriptive case series, over a period of 6 moths, 163 consecutive cases of open fracture of tibial shaft were reviewed in terms of clinical profile, time of presentation, and gender distribution. Results: In this study mean age was 30±0.02 years. Males comprised 85 percent of study population while 15 percent were females. Gustilo-I type fracture and Gustilo-II type fracture was diagnosed in 90 percent and 10 percent patients respectively. Thirty three percent patients had wound infection while fracture union was found in 15 percent cases. Moreover interlocked intramedullary nailing for open fracture shaft of tibia was safe in 80 percent patients while this procedure was effective in 85 percent. Conclusion: Un-reamed, interlocked intra-medullary nailing may be considered as a suitable option for treatment of open fractures of tibia. (author)

Availability Analysis of the Ventilation Stack CAM Interlock System

CERN Document Server

Young, J

2000-01-01

Ventilation Stack Continuous Air Monitor (CAM) Interlock System failure modes, failure frequencies, and system availability have been evaluated for the RPP. The evaluation concludes that CAM availability is as high as assumed in the safety analysis and that the current routine system surveillance is adequate to maintain this availability credited in the safety analysis, nor is such an arrangement predicted to significantly improve system availability.

Automatic generation and verification of railway interlocking control tables using FSM and NuSMV

Directory of Open Access Journals (Sweden)

Mohammad B. YAZDI

2009-01-01

Full Text Available Due to their important role in providing safe conditions for train movements, railway interlocking systems are considered as safety critical systems. The reliability, safety and integrity of these systems, relies on reliability and integrity of all stages in their lifecycle including the design, verification, manufacture, test, operation and maintenance.In this paper, the Automatic generation and verification of interlocking control tables, as one of the most important stages in the interlocking design process has been focused on, by the safety critical research group in the School of Railway Engineering, SRE. Three different subsystems including a graphical signalling layout planner, a Control table generator and a Control table verifier, have been introduced. Using NuSMV model checker, the control table verifier analyses the contents of control table besides the safe train movement conditions and checks for any conflicting settings in the table. This includes settings for conflicting routes, signals, points and also settings for route isolation and single and multiple overlap situations. The latest two settings, as route isolation and multiple overlap situations are from new outcomes of the work comparing to works represented on the subject recently.

Replacement of Fine Aggregate by using Recyclable Materials in Paving Blocks

Science.gov (United States)

Koganti, Shyam Prakash; Hemanthraja, Kommineni; Sajja, Satish

2017-08-01

Cement concrete paving blocks are precast hard products complete out of cement concrete. The product is made in various sizes and shapes like square, round and rectangular blocks of different dimensions with designs for interlocking of adjacent tiles blocks. Several Research Works have been carried out in the past to study the possibility of utilizing waste materials and industrial byproducts in the manufacturing of paver blocks. Various industrial waste materials like quarry dust, glass powder, ceramic dust and coal dust are used as partial replacement of fine aggregate and assessed the strength parameters and compared the profit percentages after replacement with waste materials. Quarry dust can be replaced by 20% and beyond that the difference in strength is not much higher but considering cost we can replace upto 40% so that we can get a profit of almost 10%. Similarly we can replace glass powder and ceramic dust by 20% only beyond that there is decrement in strength and even with 20% replacement we can get 1.34 % and 2.42% of profit. Coal dust is not suitable for alternative material as fine aggregate as it reduces the strength.

External jig in the placement of distal interlocking screws | Ikem ...

African Journals Online (AJOL)

Retrograde (52.2%) was the commonest surgical approach used for femur. The main indication for SIGN interlocking surgery was recent fracture 77.8%. Open reduction 97.8% was the commonest method of reduction used. The mean±SD bone union time was 3.58±0.56 months and range 3-5 months. Distal screw insertion ...

Online visual inspection of self-piercing riveting to determine the quality of the mechanical interlock

International Nuclear Information System (INIS)

Johnson, P; Cullen, J D; Al-Shamma'a, A I; Shaw, A

2007-01-01

Self-piercing riveting (SPR) has become a significant joining technique for the automotive applications of aluminium sheets. Quality control in this locale has progressed at an altogether more leisurely rate than other areas of mechanical joining (e.g. spotweld) and is underdeveloped. Testing the quality mechanical interlock is often achieved by destructive testing, which results in material and time wastage. The solution is online monitoring of the self-piercing riveting process to provide non-destructive testing of the mechanical interlock. Introducing sensors into the process facilitates real time data acquisition, which can be used to determine the quality of the joint

Custom sectional impression trays with interlocking type handle for microstomia patients

Directory of Open Access Journals (Sweden)

Fernandes Aquaviva

2009-01-01

Full Text Available Making impressions in microstomia patients is often cumbersome. A modification of standard impression procedure is often necessary while treating such patients. This article describes the fabrication of a custom sectional impression tray with interlocking type of a handle for definitive impression procedures in a microstomia patient.

78 FR 26849 - Model Specifications for Breath Alcohol Ignition Interlock Devices (BAIIDs)

Science.gov (United States)

2013-05-08

... requirements, and asked whether the Model Specifications should limit sensor technology to alcohol-specific sensors (such as fuel cell technology based on electrochemical oxidation of alcohol) or other emerging... have demanded alcohol- specific sensor technology. [Interlocks that] are not alcohol-specific...

Synthesis of interlocked molecules by olefin metathesis

Science.gov (United States)

Clark, Paul Gregory

A large body of work in the Grubbs group has focused on the development of functional-group tolerant ruthenium alkylidene catalysts that perform a number of olefin metathesis reactions. These catalysts have seen application in a wide range of fields, including classic total synthesis as well as polymer and materials chemistry. One particular family of compounds, interlocked molecules, has benefitted greatly from these advances in catalyst stability and activity. This thesis describes several elusive and challenging interlocked architectures whose syntheses have been realized through the utilization of different types of ruthenium-catalyzed olefin metathesis reactions. Ring-closing olefin metathesis has enabled the synthesis of a [c2]daisy-chain dimer with the ammonium binding site near the cap of the dimer. A deprotonated DCD possessing such a structural attribute will more forcefully seek to restore coordinating interactions upon reprotonation, enhancing its utility as a synthetic molecular actuator. Dimer functionalization facilitated incorporation into linear polymers, with a 48% size increase of an unbound, extended analogue of the polymer demonstrating slippage of the dimer units. Ongoing work is directed at further materials studies, in particular, exploring the synthesis of macroscopic networks containing the DCD units and analyzing the correlation between molecular-scale extension-contraction manipulations and resulting macro-scale changes. A "clipping" approach to a polycatenated cyclic polymer, a structure that resembles a molecular "charm bracelet", has been described. The use of ring-opening metathesis polymerization of a carbamate monomer in the presence of a chain transfer agent allowed for the synthesis of a linear polymer that was subsequently functionalized and cyclized to the corresponding cyclic analogue. This cyclic polymer was characterized through a variety of techniques, and subjected to further functionalization reactions, affording a cyclic

Composites reinforced via mechanical interlocking of surface-roughened microplatelets within ductile and brittle matrices.

Science.gov (United States)

Libanori, R; Carnelli, D; Rothfuchs, N; Binelli, M R; Zanini, M; Nicoleau, L; Feichtenschlager, B; Albrecht, G; Studart, A R

2016-04-12

Load-bearing reinforcing elements in a continuous matrix allow for improved mechanical properties and can reduce the weight of structural composites. As the mechanical performance of composite systems are heavily affected by the interfacial properties, tailoring the interactions between matrices and reinforcing elements is a crucial problem. Recently, several studies using bio-inspired model systems suggested that interfacial mechanical interlocking is an efficient mechanism for energy dissipation in platelet-reinforced composites. While cheap and effective solutions are available at the macroscale, the modification of surface topography in micron-sized reinforcing elements still represents a challenging task. Here, we report a simple method to create nanoasperities with tailored sizes and densities on the surface of alumina platelets and investigate their micromechanical effect on the energy dissipation mechanisms of nacre-like materials. Composites reinforced with roughened platelets exhibit improved mechanical properties for both organic ductile epoxy and inorganic brittle cement matrices. Mechanical interlocking increases the modulus of toughness (area under the stress-strain curve) by 110% and 56% in epoxy and cement matrices, respectively, as compared to those reinforced with flat platelets. This interlocking mechanism can potentially lead to a significant reduction in the weight of mechanical components while retaining the structural performance required in the application field.

Economic aspects of interlocking hollow brick system designed for industrialized building system

Science.gov (United States)

Tahir, Mahmood Md.; Saggaff, Anis; Ngian, Shek Poi; Sulaiman, Arizu

2017-11-01

Construction industry has moved forward into a technology driven where a transition is in progress from conventional method to a more advanced and mechanised system known as the Industrialised Building System (IBS). However, the need to implement the IBS should be well understood by all construction players such as designer, architect, contraction, erectors and construction workers. Therefore, there is a need to educate all these construction players which should be spearheaded by authorities such as Construction Industrial Development Board where enforcement trough building by laws as well as initiative to those that adopt the IBS in their construction. This paper reports on economic aspects of using interlocking hollow brick system in construction as an alternative method offered for Industrialized Building System. The main objective is to address the economic aspects of using interlocking block system in terms of time, costs, and utilization of manpower and to present some of the experimental tests results related to Interlocking Hollow Brick System (IHBS). Example of savings from the use of IHBS is presented in this paper by comparing the construction of two storey terrace house with build-up area of about 200 square meter with conventional construction method of typical reinforced concrete construction (RCC) compared to IHBS. The comparison shows that the implementation of IHBS can reduce construction time, cost, and utilization of man power up to 26.6% compared to the conventional method. Moreover, the construction time using IHBS can also be reduced by up to 50% as compared to the conventional construction.

Photovoltaic module and interlocked stack of photovoltaic modules

Science.gov (United States)

Wares, Brian S.

2014-09-02

One embodiment relates to an arrangement of photovoltaic modules configured for transportation. The arrangement includes a plurality of photovoltaic modules, each photovoltaic module including a frame. A plurality of individual male alignment features and a plurality of individual female alignment features are included on each frame. Adjacent photovoltaic modules are interlocked by multiple individual male alignment features on a first module of the adjacent photovoltaic modules fitting into and being surrounded by corresponding individual female alignment features on a second module of the adjacent photovoltaic modules. Other embodiments, features and aspects are also disclosed.

A STUDY OF THE MANAGEMENT OF OPEN FRACTURES OF TIBIA BY UNREAMED INTERLOCKING NAIL

Directory of Open Access Journals (Sweden)

Kuppa Srinivas

2015-01-01

Full Text Available AIMS AND OBJECTIVES: To evaluate the results of closed interlocking intramedullary nailing without reaming in the treatment of open fractures of t he tibial shaft and study the difficulties (complications encountered during the operative study. To compare the efficacy of interlocking intramedullary nailing without reaming in treating open fractures of tibia, Time required for the union of fracture, Range of motion of ankle and knee joint, Rate of malunion and mal rotation and Pain at the knee joint. RESULTS: The average age of patient is 32 years,83.33% are males, road traffic accidents account for majority(79.16%,right side involved in 58.33%,gustillo type II and type I compound fractures are common, full range of movements is seen in 66.67% by 12 weeks and union occurred in 95.83% by 9 months. Thirteen (54.17% patients had excellent results, six (25% patients had good results, four (1 6.67% patients had fair results and one (4.16 patient had poor result. CONCLUSION: Unreamed interlocking intramedullary nailing with the help of image intensifier seems feasible in open diaphyseal fractures of tibia with the advantages of minimal blood l oss, low risk of infection, early mobilisation , earlier soft tissue coverage , Promotes early union , minimal hospital stay and early returns to activities

On the Use of Static Checking in the Verification of Interlocking Systems

DEFF Research Database (Denmark)

Haxthausen, Anne Elisabeth; Østergaard, Peter H.

2016-01-01

In the formal methods community, the correctness of interlocking tables is typically verified by model checking. This paper suggests to use a static checker for this purpose and it demonstrates for the RobustRailS verification tool set that the execution time and memory usage of its static checker...

Modular safety interlock system for high energy physics experiments

International Nuclear Information System (INIS)

Kieffer, J.; Golceff, B.V.

1980-10-01

A frequent problem in electronics systems for high energy physics experiments is to provide protection for personnel and equipment. Interlock systems are typically designed as an afterthought and as a result, the working environment around complex experiments with many independent high voltages or hazardous gas subsystems, and many different kinds of people involved, can be particularly dangerous. A set of modular hardware has been designed which makes possible a standardized, intergrated, hierarchical system's approach and which can be easily tailored to custom requirements

Reinforcing the role of the conventional C-arm - a novel method for simplified distal interlocking

Directory of Open Access Journals (Sweden)

Windolf Markus

2012-01-01

Full Text Available Abstract Background The common practice for insertion of distal locking screws of intramedullary nails is a freehand technique under fluoroscopic control. The process is technically demanding, time-consuming and afflicted to considerable radiation exposure of the patient and the surgical personnel. A new concept is introduced utilizing information from within conventional radiographic images to help accurately guide the surgeon to place the interlocking bolt into the interlocking hole. The newly developed technique was compared to conventional freehand in an operating room (OR like setting on human cadaveric lower legs in terms of operating time and radiation exposure. Methods The proposed concept (guided freehand, generally based on the freehand gold standard, additionally guides the surgeon by means of visible landmarks projected into the C-arm image. A computer program plans the correct drilling trajectory by processing the lens-shaped hole projections of the interlocking holes from a single image. Holes can be drilled by visually aligning the drill to the planned trajectory. Besides a conventional C-arm, no additional tracking or navigation equipment is required. Ten fresh frozen human below-knee specimens were instrumented with an Expert Tibial Nail (Synthes GmbH, Switzerland. The implants were distally locked by performing the newly proposed technique as well as the conventional freehand technique on each specimen. An orthopedic resident surgeon inserted four distal screws per procedure. Operating time, number of images and radiation time were recorded and statistically compared between interlocking techniques using non-parametric tests. Results A 58% reduction in number of taken images per screw was found for the guided freehand technique (7.4 ± 3.4 (mean ± SD compared to the freehand technique (17.6 ± 10.3 (p p = 0.001. Operating time per screw (from first shot to screw tightened was on average 22% reduced by guided freehand (p = 0

Reinforcing the role of the conventional C-arm--a novel method for simplified distal interlocking.

Science.gov (United States)

Windolf, Markus; Schroeder, Josh; Fliri, Ladina; Dicht, Benno; Liebergall, Meir; Richards, R Geoff

2012-01-25

The common practice for insertion of distal locking screws of intramedullary nails is a freehand technique under fluoroscopic control. The process is technically demanding, time-consuming and afflicted to considerable radiation exposure of the patient and the surgical personnel. A new concept is introduced utilizing information from within conventional radiographic images to help accurately guide the surgeon to place the interlocking bolt into the interlocking hole. The newly developed technique was compared to conventional freehand in an operating room (OR) like setting on human cadaveric lower legs in terms of operating time and radiation exposure. The proposed concept (guided freehand), generally based on the freehand gold standard, additionally guides the surgeon by means of visible landmarks projected into the C-arm image. A computer program plans the correct drilling trajectory by processing the lens-shaped hole projections of the interlocking holes from a single image. Holes can be drilled by visually aligning the drill to the planned trajectory. Besides a conventional C-arm, no additional tracking or navigation equipment is required.Ten fresh frozen human below-knee specimens were instrumented with an Expert Tibial Nail (Synthes GmbH, Switzerland). The implants were distally locked by performing the newly proposed technique as well as the conventional freehand technique on each specimen. An orthopedic resident surgeon inserted four distal screws per procedure. Operating time, number of images and radiation time were recorded and statistically compared between interlocking techniques using non-parametric tests. A 58% reduction in number of taken images per screw was found for the guided freehand technique (7.4 ± 3.4) (mean ± SD) compared to the freehand technique (17.6 ± 10.3) (p < 0.001). Total radiation time (all 4 screws) was 55% lower for the guided freehand technique compared to conventional freehand (p = 0.001). Operating time per screw (from first

Patología de pavimentos articulados Pathology of interlocking pavements

Directory of Open Access Journals (Sweden)

Carlos Hernando Higuera Sandoval

2010-07-01

Full Text Available Este artículo presenta los resultados de un proyecto de grado sobre patología de pavimentos articulados, el cual fue elaborado con el propósito de hacer una recolección de los deterioros típicos de los pavimentos articulados construidos con adoquines de concreto o de ladrillo; y de esta forma, elaborar un catálogo de deterioros para este tipo de estructuras que facilitará la identificación y cuantificación de los deterioros en una inspección visual. El segundo propósito de este proyecto, es la formulación para Colombia de una metodología que permita determinar el Índice de Condición de las estructuras de pavimentos articulados.This article presents the results of a thesis on pathology of interlocking pavements, which objective was to make a compilation of typical damages of interlocking pavements constructed with concrete or brick pavers and, in this way, to elaborate a catalogue of damages for this kind of structures which will make the identification and quantification of deteriorations possible in a visual inspection. The second purpose of this project is the formulation of a methodology which allows determining the Index of pavement conditions for Colombia.

Engineering Task Plan for Hepa Filter Differential Pressure (DP) Fan Interlock Upgrades

International Nuclear Information System (INIS)

SIMONS, S.R.

2000-01-01

This document provides a plan for installation of Differential Pressure (DP) fan interlocks on the primary ventilation systems in selected Tank Farm facilities. This plan contains the engineering tasks required for installation and is summarized by the Acceptance for Beneficial Use list. Individuals responsible for each task are identified and scheduled accordingly

Access control and interlock system at the Advanced Photon Source

International Nuclear Information System (INIS)

Forrestal, J.; Hogrefe, R.; Knott, M.; McDowell, W.; Reigle, D.; Solita, L.; Koldenhoven, R.; Haid, D.

1997-01-01

The Advanced Photon Source (APS) consists of a linac, position accumulator ring (PAR), booster synchrotron, storage ring, and up to 70 experimental beamlines. The Access Control and Interlock System (ACIS) utilizes redundant programmable logic controllers (PLCs) and a third hard-wired chain to protect personnel from prompt radiation generated by the linac, PAR, synchrotron, and storage ring. This paper describes the ACIS's design philosophy, configuration, hardware, functionality, validation requirements, and operational experience

Three-dimensional Interlocking Professional Management Mechanism of Agricultural Family-Owned Enterprise

OpenAIRE

Zhong-ming, Shen; Cheng-jun, Zhang

2010-01-01

The establishment of the three-dimensional interlocking professional management mechanism of agricultural family-owned enterprise was studied through the following three mechanisms; the stimulation and restriction mechanism within the agricultural family-owned enterprises, the credit mechanism of professional manager and the social environment mechanism. The relationship between the agricultural family-owned enterprise, professional manager and the society was studied. In the first place, the...

Extending DIII-D Neutral Beam Modulated Operations with a Camac Based Total on Time Interlock

International Nuclear Information System (INIS)

Baggest, D.S.; Broesch, J.D.; Phillips, J.C.

1999-01-01

A new total-on-time interlock has increased the operational time limits of the Neutral Beam systems at DIII-D. The interlock, called the Neutral Beam On-Time-Limiter (NBOTL), is a custom built CAMAC module utilizing a Xilinx 9572 Complex Programmable Logic Device (CPLD) as its primary circuit. The Neutral Beam Injection Systems are the primary source of auxiliary heating for DIII-D plasma discharges and contain eight sources capable of delivering 20MW of power. The delivered power is typically limited to 3.5 s per source to protect beam-line components, while a DIII-D plasma discharge usually exceeds 5 s. Implemented as a hardware interlock within the neutral beam power supplies, the NBOTL limits the beam injection time. With a continuing emphasis on modulated beam injections, the NBOTL guards against command faults and allows the beam injection to be safely spread over a longer plasma discharge time. The NBOTL design is an example of incorporating modern circuit design techniques (CPLD) within an established format (CAMAC). The CPLD is the heart of the NBOTL and contains 90% of the circuitry, including a loadable, 1 MHz, 28 bit, BCD count down timer, buffers, and CAMAC communication circuitry. This paper discusses the circuit design and implementation. Of particular interest is the melding of flexible modern programmable logic devices with the CAMAC format

Photovoltaic module and interlocked stack of photovoltaic modules

Science.gov (United States)

Wares, Brian S.

2012-09-04

One embodiment relates to an arrangement of photovoltaic modules configured for transportation. The arrangement includes a plurality of photovoltaic modules, each photovoltaic module including a frame having at least a top member and a bottom member. A plurality of alignment features are included on the top member of each frame, and a plurality of alignment features are included on the bottom member of each frame. Adjacent photovoltaic modules are interlocked by the alignment features on the top member of a lower module fitting together with the alignment features on the bottom member of an upper module. Other embodiments, features and aspects are also disclosed.

Shutdown channels and fitted interlocks in atomic reactors

International Nuclear Information System (INIS)

Furet, J.; Landauer, C.

1968-01-01

This catalogue consists of tables (one per reactor) giving the following information: number and type of detectors, range of the shutdown channels, nature of the associated electronics, thresholds setting off the alarms, fitted interlocks. These cards have been drawn up with a view to an examination of the reactors safety by the 'Reactor Safety Sub-Commission', they take into account the latest decisions. The reactors involved in this review are: Azur, Cabri, Castor-Pollux, Cesar-Marius-2, Edf-2, EL3, EL4, Eole, G1, G2-G3, Harmonie, Isis, Masurca, Melusine, Minerve, Osiris, Pegase, Peggy, PAT, Rapsodie, SENA, Siloe, Siloette, Triton-Nereide, and Ulysse. (authors) [fr

Ground-state kinetics of bistable redox-active donor-acceptor mechanically interlocked molecules.

Science.gov (United States)

Fahrenbach, Albert C; Bruns, Carson J; Li, Hao; Trabolsi, Ali; Coskun, Ali; Stoddart, J Fraser

2014-02-18

The ability to design and confer control over the kinetics of theprocesses involved in the mechanisms of artificial molecular machines is at the heart of the challenge to create ones that can carry out useful work on their environment, just as Nature is wont to do. As one of the more promising forerunners of prototypical artificial molecular machines, chemists have developed bistable redox-active donor-acceptor mechanically interlocked molecules (MIMs) over the past couple of decades. These bistable MIMs generally come in the form of [2]rotaxanes, molecular compounds that constitute a ring mechanically interlocked around a dumbbell-shaped component, or [2]catenanes, which are composed of two mechanically interlocked rings. As a result of their interlocked nature, bistable MIMs possess the inherent propensity to express controllable intramolecular, large-amplitude, and reversible motions in response to redox stimuli. In this Account, we rationalize the kinetic behavior in the ground state for a large assortment of these types of bistable MIMs, including both rotaxanes and catenanes. These structures have proven useful in a variety of applications ranging from drug delivery to molecular electronic devices. These bistable donor-acceptor MIMs can switch between two different isomeric states. The favored isomer, known as the ground-state co-conformation (GSCC) is in equilibrium with the less favored metastable state co-conformation (MSCC). The forward (kf) and backward (kb) rate constants associated with this ground-state equilibrium are intimately connected to each other through the ground-state distribution constant, KGS. Knowing the rate constants that govern the kinetics and bring about the equilibration between the MSCC and GSCC, allows researchers to understand the operation of these bistable MIMs in a device setting and apply them toward the construction of artificial molecular machines. The three biggest influences on the ground-state rate constants arise from

Early Conversion of External Fixation to Interlocked Nailing in Open Fractures of Both Bone Leg Assisted with Vacuum Closure (VAC) - Final Outcome.

Science.gov (United States)

Gill, Simrat Pal Singh; Raj, Manish; Kumar, Sunil; Singh, Pulkesh; Kumar, Dinesh; Singh, Jasveer; Deep, Akash

2016-02-01

Management of compound grade III fractures of both bone leg includes external stabilization for long period, followed by various soft tissue coverage procedures. Primary interlocking of tibia had been also done with variable results. External fixation for long time without any bone loss often leads to infected nonunion, loss of reduction, pin tract infection and failure of fixation, primary interlocking in compound grade III fractures had shown high medullary infection rate. We managed all cases of compound grade III A/B fractures with primary external fixation, simultaneous wound management using vacuum assisted closure (VAC) followed by early conversion to interlocking within 2 weeks of fixator application. To determine the effectiveness of vacuum assisted closure (VAC) for the early conversion of external fixator to definitive interlocking in open fractures of the both bone leg. In current study we selected 84 cases of compound grade IIIA/B diaphyseal fractures of both bone leg during period of May 2010 to September 2013. We managed these cases by immediate debridement and application of external fixation followed by repeated debridement, application of vacuum assisted closure (VAC) and conversion to interlocking within two weeks. Out of 84 cases union was achieved in 80(95%) of cases with definitive tibial interlocking. Excellent to good result were obtained in 77(91.8%) of cases and fair to poor result seen in rest of 7(8.2%) of cases according to modified Ketenjian's criteria. 5 out of these 7 poor result group cases were from Compound Grade III B group to start with. Deep infection rate in our series were 7% i.e. total 6 cases and 4 out of these were from compound Grade III B group to start with. Vacuum assisted closure (VAC) give a good help for rapid closure of the wound and help in early conversion to definitive intramedullary nailing. Reamed nail could well be used in compound grade IIIA/B fractures without increasing the risk of infection. It gives

Three-dimensional iron sulfide-carbon interlocked graphene composites for high-performance sodium-ion storage

DEFF Research Database (Denmark)

Huang, Wei; Sun, Hongyu; Shangguan, Huihui

2018-01-01

Three-dimensional (3D) carbon-wrapped iron sulfide interlocked graphene (Fe7S8@C-G) composites for high-performance sodium-ion storage are designed and produced through electrostatic interactions and subsequent sulfurization. The iron-based metal–organic frameworks (MOFs, MIL-88-Fe) interact with...

Interlock system for the COMPASS tokamak

Czech Academy of Sciences Publication Activity Database

Hron, Martin; Sova, J.; Šíba, J.; Kovář, J.; Adámek, Jiří; Pánek, Radomír; Havlíček, Josef; Písačka, Jan; Mlynář, Jan; Stöckel, Jan

2010-01-01

Roč. 85, 3-4 (2010), s. 505-508 ISSN 0920-3796. [IAEA Technical Meeting on Control, Data Acquisition and Remote Participation for Fusion Research/7th./. Aix – en – Provence, 15.06.2009-19.06.2009] R&D Projects: GA MŠk 7G09042; GA ČR GD202/08/H057 Institutional research plan: CEZ:AV0Z20430508 Keywords : Tokamak operation * Interlock * Personnel safety Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.143, year: 2010 http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V3C-5003BXW-1&_user=6542793&_coverDate=07%2F31%2F2010&_rdoc=1&_fmt=high&_orig=search&_origin=search&_sort=d&_docanchor=&view=c&_acct=C000070123&_version=1&_urlVersion=0&_userid=6542793&md5=ef5794d05cc6530a905d1de43aa0ac6a&searchtype=a

The use of interlocking prostheses for both temporary and definitive management of infected periprosthetic femoral fractures.

Science.gov (United States)

Konan, Sujith; Rayan, Faizal; Manketelow, Andrew R J; Haddad, Fares S

2011-12-01

Infected periprosthetic fractures around total hip arthroplasties are an extremely challenging problem. We describe our experience of managing infected periprosthetic femoral fractures using interlocking long-stem femoral prostheses either as temporary functional spacers or as definitive implants. The Cannulock (Orthodesign, Christchurch, United Kingdom) uncoated stem was used in 12 cases, and the Kent hip prosthesis (Biomet Merck, Bridgend, United Kingdom), in 5 cases. Satisfactory outcome was noted in all cases, and in 11 cases, revision to a definitive stem has been undertaken after successful control of infection and fracture union. The use of interlocking stems offers a relatively appealing solution for a complex problem and avoids the complications that would be associated with resection of the entire femur or the use of large quantities of bone cement. Copyright © 2011 Elsevier Inc. All rights reserved.

Interlocked graphene-Prussian blue hybrid composites enable multifunctional electrochemical applications

DEFF Research Database (Denmark)

Zhang, Minwei; Hou, Chengyi; Halder, Arnab

2017-01-01

There has been increasing interest recently in mixed-valence inorganic nanostructure functionalized graphene composites, represented by Prussian blue, because they can cost-effectively apply to biosensors and energy devices. In this work, we present a one-pot green method to synthesize interlocked...... graphene-Prussian Blue hybrid composites as high-performance materials for biosensors and supercapacitor electrodes. Given the fact that graphene oxide (GO) can act as an electron acceptor, we used iron(II) and glucose as co-reducing agents to reduce GO under mild reaction conditions without introducing...

Finite Element Analysis of Absorbable Sheath to Prevent Stress Shielding of Tibial Interlocking Intramedullary Nail

Science.gov (United States)

Dong, Yansheng; Wang, Yongqing; Dong, Limin; Jia, Peng; Lu, Fengcheng

2017-07-01

The nail with absorbable sheath (AS nail) is designed to reduce the stress shielding effect of internal fixation with interlocking intramedullary nail. In order to verify its feasibility, two types of the finite element models of internal fixation of tibia with the AS nail and the common metal nail (CM nail) are established using the Softwares of Mimics, Geomagic, SolidWorks and ANSYS according to the CT scanning data of tibia. The result of the finite element analysis shows that the AS nail has great advantages compared with the CM nail in reducing the stress shielding effect in different periods of fracture healing. The conclusion is that the AS nail can realize the static fixation to the dynamic fixation from the early to the later automatically to shorten the time of fracture healing, which also provides a new technique to the interlocking intramedullary nail.

Casein Aggregates Built Step-by-Step on Charged Polyelectrolyte Film Surfaces Are Calcium Phosphate-cemented*

Science.gov (United States)

Nagy, Krisztina; Pilbat, Ana-Maria; Groma, Géza; Szalontai, Balázs; Cuisinier, Frédéric J. G.

2010-01-01

The possible mechanism of casein aggregation and micelle buildup was studied in a new approach by letting α-casein adsorb from low concentration (0.1 mg·ml−1) solutions onto the charged surfaces of polyelectrolyte films. It was found that α-casein could adsorb onto both positively and negatively charged surfaces. However, only when its negative phosphoseryl clusters remained free, i.e. when it adsorbed onto a negative surface, could calcium phosphate (CaP) nanoclusters bind to the casein molecules. Once the CaP clusters were in place, step-by-step building of multilayered casein architectures became possible. The presence of CaP was essential; neither Ca2+ nor phosphate could alone facilitate casein aggregation. Thus, it seems that CaP is the organizing motive in the casein micelle formation. Atomic force microscopy revealed that even a single adsorbed casein layer was composed of very small (in the range of tens of nanometers) spherical forms. The stiffness of the adsorbed casein layer largely increased in the presence of CaP. On this basis, we can imagine that casein micelles emerge according to the following scheme. The amphipathic casein monomers aggregate into oligomers via hydrophobic interactions even in the absence of CaP. Full scale, CaP-carrying micelles could materialize by interlocking these casein oligomers with CaP nanoclusters. Such a mechanism would not contradict former experimental results and could offer a synthesis between the submicelle and the block copolymer models of casein micelles. PMID:20921229

Peri-Implant Distribution of Polyethylene Debris in Postmortem-Retrieved Knee Arthroplasties: Can Polyethylene Debris Explain Loss of Cement-Bone Interlock in Successful Total Knee Arthroplasties?

Science.gov (United States)

Cyndari, Karen I; Goodheart, Jacklyn R; Miller, Mark A; Oest, Megan E; Damron, Timothy A; Mann, Kenneth A

2017-07-01

Loss of mechanical interlock between cement and bone with in vivo service has been recently quantified for functioning, nonrevised, cemented total knee arthroplasties (TKAs). The cause of interlocking trabecular resorption is not known. The goal of this study is to quantify the distribution of PE debris at the cement-bone interface and determine if polyethylene (PE) debris is locally associated with loss of interlock. Fresh, nonrevised, postmortem-retrieved TKAs (n = 8) were obtained en bloc. Laboratory-prepared constructs (n = 2) served as negative controls. The intact cement-bone interface of each proximal tibia was embedded in Spurr's resin, sectioned, and imaged under polarized light to identify birefringent PE particles. PE wear particle number density was quantified at the cement-bone interface and distal to the interface, and then compared with local loss of cement-bone interlock. The average PE particle number density for postmortem-retrieved TKAs ranged from 8.6 (1.3) to 24.9 (3.1) particles/mm 2 (standard error) but was weakly correlated with years in service. The average particle number density was twice as high as distal (>5mm) to the interface compared to at the interface. The local loss of interlock at the interface was not related to the presence, absence, or particle density of PE. PE debris can migrate extensively along the cement-bone interface of well-fixed tibial components. However, the amount of local bone loss at the cement-bone interface was not correlated with the amount of PE debris at the interface, suggesting that the observed loss of trabecular interlock in these well-fixed TKAs may be due to alternative factors. Copyright © 2017 Elsevier Inc. All rights reserved.

Compositional Verification of Multi-Station Interlocking Systems

DEFF Research Database (Denmark)

Macedo, Hugo Daniel dos Santos; Fantechi, Alessandro; Haxthausen, Anne Elisabeth

2016-01-01

pose a big challenge to current verification methodologies, due to the explosion of state space size as soon as large, if not medium sized, multi-station systems have to be controlled. For these reasons, verification techniques that exploit locality principles related to the topological layout...... of the controlled system to split in different ways the state space have been investigated. In particular, compositional approaches divide the controlled track network in regions that can be verified separately, once proper assumptions are considered on the way the pieces are glued together. Basing on a successful...... method to verify the size of rather large networks, we propose a compositional approach that is particularly suitable to address multi-station interlocking systems which control a whole line composed of stations linked by mainline tracks. Indeed, it turns out that for such networks, and for the adopted...

The multi-interlock and check of logical system for 5 MW low power reactor automatic rod

International Nuclear Information System (INIS)

Li Guangjian; Zhao Zengqiao

1992-01-01

The safety and reliability of the logical system for 5 MW LPR automatic rod are improved, because of using multi-interlock and manual check on line. The design character and function of the logical system are introduced

Bacterial carbonate precipitation improves water absorption of interlocking compressed earth block (ICEB)

Science.gov (United States)

Zamer, M. M.; Irwan, J. M.; Othman, N.; Faisal, S. K.; Anneza, L. H.; Alshalif, A. F.; Teddy, T.

2017-11-01

Interlocking compressed earth blocks (ICEB) are soil based blocks that allows for mortarless construction. The addition of many alternative materials into interlocking block in order to improve the durability has been reported. However there are currently lack of report and evidence on the application of biocalcification or microbiologically induced calcite precipitation (MICP) in improving the engineering properties of ICEB. This paper evaluate the effect of UB in improving the water absorption properties of ICEB. This paper also provide the results on SEM analysis of addition of 1%, 3% and 5% UB in ICEB. The bacteria were added as partial replacement of limestone water in ICEB. The results showed the reduction of 14.72% with 5% UB on initial water absorption followed by the results for water absorption by 24-hour soaking which also indicates reduction of 14.68% with 5% UB on 28th days of testing compared to control specimen. It was expected that the reduction of water absorption was due to the plugging of pores by the bacterial calcite which prevent ingression of water in ICEB samples. Therefore this study hopes that the positive results from the UB as improving in water absorption of ICEB will lead to improve others ICEB properties and others construction materials.

Design lessons from using programmable controllers in the MFTF-B personnel safety and interlocks system

International Nuclear Information System (INIS)

Branum, J.D.

1983-01-01

Applying programmable controllers in critical applications such as personnel safety and interlocks systems requires special considerations in the design of both hardware and software. All modern programmable controller systems feature extensive internal diagnostic capabilities to protect against problems such as program memory errors; however most, if not all present designs lack an intrinsic capability for detecting and countering failures on the field-side of their I/O modules. Many of the most common styles of I/O modules can also introduce potentially dangerous sneak circuits, even without component failure. This paper presents the most significant lessons learned to date in the design of the MFTF-B Personnel Safety and Interlocks System, which utilizes two non-redundant programmable controllers with over 800 I/O points each. Specific problems recognized during the design process as well as those discovered during initial testing and operation are discussed along with their specific solutions in hardware and software

A review on past and present development on the interlocking loadbearing hollow block (ILHB) system

Science.gov (United States)

Bosro, M. Z. M.; Samad, A. A. A.; Mohamad, N.; Goh, W. I.; Tambichik, M. A.; Iman, M. A.

2018-04-01

Massive migration and increasing population in Malaysia has contributed to the increasing demand of quality and affordable housing. Over the past 50 years, the Malaysian housing industry has seen the growth of using conventional construction system such as reinforced concrete frame structures and bricks. The conventional system, as agreed by many researchers, causes delays and other disadvantages in some of the construction projects. Thus, the utilization of interlocking loadbearing hollow block (ILHB) system is needed to address these issues. This system has been identified as an alternative and sustainable building system for the construction industry in Malaysia which the PUTRA block system is the latest example of the ILHB developed. The system offers various advantages in terms of speed and cost in construction, strength, environmentally friendly and aesthetic qualities. Despite these advantages, this system has not been practically applied and develop in Malaysia. Therefore, this paper aims to review the past and present development of the interlocking loadbearing hollow block (ILHB) system that available locally and globally.

Abating coal tar seepage into surface water bodies using sheet piles with sealed interlocks

International Nuclear Information System (INIS)

Collingwood, B.I.; Boscardin, M.D.; Murdock, R.F.

1995-01-01

A former coal tar processing facility processed crude coal tar supplied from manufactured gas plants in the area. Coal-tar-contaminated ground water from the site was observed seeping through an existing timber bulkhead along a tidal river and producing a multicolored sheen on the surface of the river. As part of a short-term measure to abate the seepage into the river, 64-m long anchored sheet pile wall with sheet pile wing walls at each end was constructed inland of the of the timber bulkhead. The sheet piles extended to low-permeability soils at depth and the interlocks of the sheet piles were provided with polyurethane rubber seals. Based on postconstruction observations for leakage and sheens related to leakage, the steel sheet piles with polyurethane rubber interlock seals appeared to provide a successful seal and abate coal-tar-contaminated ground water seepage into the river. The tie rod penetration sealing proved to be a more problematic detail, but through several postconstruction grouting episodes, an effective seal was produced

Production and Testing of Kiln-cast Glass Components for an Interlocking, Dry-assembled Transparent Bridge

NARCIS (Netherlands)

Bristogianni, T.; Oikonomopoulou, F.; Veer, F.A.; Snijder, A.H.; Nijsse, R.

A pedestrian glass bridge, located at the TU Delft campus site, is being designed by the TU Delft Glass & Transparency Lab. Specifically, the arch-formed bridge consists of cast glass, dry-assembled, interlocking components. To validate the shape of the components, glass mock-ups in 1:2 scale

Software Verification and Validation Test Report for the HEPA filter Differential Pressure Fan Interlock System

International Nuclear Information System (INIS)

ERMI, A.M.

2000-01-01

The HEPA Filter Differential Pressure Fan Interlock System PLC ladder logic software was tested using a Software Verification and Validation (VandV) Test Plan as required by the ''Computer Software Quality Assurance Requirements''. The purpose of his document is to report on the results of the software qualification

Machine interlock and protection system based on PLC for the SSRF linac

International Nuclear Information System (INIS)

Chou Wenjun; Zhou Dayong; Chen Jianfeng; Shen Liren; Liu Yajuan

2008-01-01

This paper describes a machine interlock and protection system used for accelerators based on EPICS (Experimental physics and industrial control system). The system is composed of a front-end computer and an FM-3R logic controller PLC. The alarm signal is passed by the hardware directly, and would be deal with PLC. The reporting, recording and analyst of the event are accomplished by EPICS control software. And PLC is linked to the EPICS by Internet. (authors)

49 CFR 236.401 - Automatic block signal system and interlocking standards applicable to traffic control systems.

Science.gov (United States)

2010-10-01

... TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Traffic Control Systems Standards § 236.401 Automatic... 49 Transportation 4 2010-10-01 2010-10-01 false Automatic block signal system and interlocking standards applicable to traffic control systems. 236.401 Section 236.401 Transportation Other Regulations...

PLC based development of control, monitoring and interlock for 100 kW, 45.6 MHz ICRH system

International Nuclear Information System (INIS)

Jadav, Hiralal; Joshi, Rameshkumar; Mali, Aniruddh K.; Kadia; Bhavesh; Parmar; Maganbhai, Kiritkumar; Kulkarni, S.V.

2015-01-01

This paper presents details of PLC based system development for 100KW at the rate 45.6 MHz. Presently in ICRH RF DAC (Data acquisition and control) system existing based on real time VME and linux operating system. The ICRH system consists of 1.5 MW RF generator operating at 22- 40MHz which is used for second harmonic heating and pre-ionization experiments on SST-1 Tokamak at 1.5T and 3T magnetic field operation respectively. The task of PLC system in RF ICRH is to control, monitoring and interlocks HVDC power supply signal. Voltage and current signal of 2 kW, 20 kW, tetrode for 100 kW RF tube electrode like Filament, Control grid, Plate, Screen grid, signal monitor and voltage set raised by PLC analog IO module. Acknowledgement of the HVDC supply Filament, Control grid, Plate, Screen grid power supply is monitor and interlocks by PLC Digital IO module to interlocks stop the RF pulse and off HV power supply. The RF pulse(shot) to trigger signal generator (5mw) RF power output feed to LPA then chain of 2 KW, 20 KW, 100 KW at the rate 45.6 MHz. The programming logic controller (PLC) software is written in ladder language for AH500 Delta make using ISP Soft 2.04 and GUI is in the table form to control and monitor the parameters. Communication of PLC to PC by ethernet LAN network. (author)

The Use of UML to Development of a Railway Interlocking System

Directory of Open Access Journals (Sweden)

Karol Rastocny

2003-01-01

Full Text Available The paper deals with problems of using the Unifield Modeling Lanfuage (UML in developmentt of new railway interlocking and signalling systems. A simplifield example of the control circuit of a point machine is used to demonstrate an object-oriented approach to specifying the functional safety requirements. An informal specification given by the relevant technical standart is used as a starting point and results in semi-formal specification based on UML model. Advantages of the presented approach are discussed and new trends of increasing formality of UML models are indicated within conclusions.

D0 Central Tracking Solenoid Energization, Controls, Interlocks and Quench Protection Operating Procedures

International Nuclear Information System (INIS)

Hance, R.

1998-01-01

This procedure is used when it is necessary to operate the solenoid energization, controls, interlocks and quench detection system. Note that a separate procedure exists for operating the solenoid 'cryogenic' systems. Only D0 Control Room Operators or the Project Electrical Engineer are qualified to execute these procedures or operate the solenoid system. This procedure assumes that the operator is familiar with using the Distributed Manufacturing Automation and Control Software (DMACS).

Plastic Bottles Waste Utilization as Modifier for Asphalt Mixture Production

Directory of Open Access Journals (Sweden)

Jan Hakeem

2017-01-01

Full Text Available Plastic Bottles was used as the polymeric waste to investigate performance of asphalt mixture Aggregates obtained from Margalla, Burhan and Karak quarries. 12 samples were prepared for conventional asphalt mixtures and 48 samples were prepared for PB modified asphalt mixture of each quarries at various proportions of PB waste. The PB used for modification according to wet process are 15%, 20%, 25% and 30% by weight of Optimum Bitumen Content (OBC. OBC of 4.2 % was concluded for conventional asphalt mixtures. The stability and flow values of the conventional and modified Asphalt Mixture were compared. The average Stability of the modified Margalla asphalt mixtures when 15% PB was used was much higher as compared to conventional asphalt mixtures. But when PB was used beyond 15%, the Marshall stability showed a decreasing trend for Margalla aggregates, increasing trend for Karak aggregates and decreasing trend for Burhan aggregates. This decline in stability is attributed to a decline in interlocking of aggregates due to lubricating effect. The corresponding flow for the Modified asphalt mixtures first showed a decreasing trend for Margalla aggregates at 15% PB modification but beyond 15%, an increasing trend in flow as compared to conventional asphalt mixtures The decrease in flow or increase in Marshall Stability is attributed to improvement in interlocking and decline in flow or stability is attributed to a decline in interlocking offered by binder and PB coated aggregate particles in modified asphalt.

Coalescence of 3-phenyl-propynenitrile on Cu(111) into interlocking pinwheel chains

Science.gov (United States)

Luo, Miaomiao; Lu, Wenhao; Kim, Daeho; Chu, Eric; Wyrick, Jon; Holzke, Connor; Salib, Daniel; Cohen, Kamelia D.; Cheng, Zhihai; Sun, Dezheng; Zhu, Yeming; Einstein, T. L.; Bartels, Ludwig

2011-10-01

3-phenyl-propynenitrile (PPN) adsorbs on Cu(111) in a hexagonal network of molecular trimers formed through intermolecular interaction of the cyano group of one molecule with the aromatic ring of its neighbor. Heptamers of trimers coalesce into interlocking pinwheel-shaped structures that, by percolating across islands of the original trimer coverage, create the appearance of gear chains. Density functional theory aids in identifying substrate stress associated with the chemisorption of PPN's acetylene group as the cause of this transition.

Controls and interlocks for a prototype 1MHz beam chopper

International Nuclear Information System (INIS)

Waters, G.; Bishop, D.; Barnes, M.J.; Wait, G.D.

1991-05-01

A prototype 1 MHz beam chopper for the proposed KAON Factory at TRIUMF has been constructed. The chopper is an electric field device, driven by a tetrode based pulser, for deflecting a charged particle beam. Associated with the tetrode used in the prototype design are high voltage power supplies for the electrodes. We use an FET based grid pulser and a sequencer capable of accurate digital control of pulse timing to 0.4 ns. A safety interlock and control system using a programmable controller with fibre optic links has been built. This has given us the versatility required in a prototype system. (Author) 4 refs., 5 figs

Structural damage monitoring of harbor caissons with interlocking condition

Energy Technology Data Exchange (ETDEWEB)

Huynh, Thanh Canh; Lee, So Young; Nauyen, Khac Duy; Kim, Jeong Tae [Pukyong National Univ., Busan (Korea, Republic of)

2012-12-15

The objective of this study is to monitor the health status of harbor caissons which have potential foundation damage. To obtain the objective, the following approaches are performed. Firstly, a structural damage monitoring(SDM) method is designed for interlocked multiple caisson structures. The SDM method utilizes the change in modal strain energy to monitor the foundation damage in a target caisson unit. Secondly, a finite element model of a caisson system which consists of three caisson units is established to verify the feasibility of the proposed method. In the finite element simulation, the caisson units are constrained each other by shear key connections. The health status of the caisson system against various levels of foundation damage is monitored by measuring relative modal displacements between the adjacent caissons.

Structural damage monitoring of harbor caissons with interlocking condition

International Nuclear Information System (INIS)

Huynh, Thanh Canh; Lee, So Young; Nauyen, Khac Duy; Kim, Jeong Tae

2012-01-01

The objective of this study is to monitor the health status of harbor caissons which have potential foundation damage. To obtain the objective, the following approaches are performed. Firstly, a structural damage monitoring(SDM) method is designed for interlocked multiple caisson structures. The SDM method utilizes the change in modal strain energy to monitor the foundation damage in a target caisson unit. Secondly, a finite element model of a caisson system which consists of three caisson units is established to verify the feasibility of the proposed method. In the finite element simulation, the caisson units are constrained each other by shear key connections. The health status of the caisson system against various levels of foundation damage is monitored by measuring relative modal displacements between the adjacent caissons

Artificial nanomachines based on interlocked molecules

International Nuclear Information System (INIS)

Credi, Alberto

2006-01-01

The extension of the concept of machine to the molecular level is of great interest for the growth of nanoscience and the development of nanotechnology. A molecular machine can be defined as an assembly of a discrete number of molecular components (that is, a supramolecular structure) designed to perform a function through the mechanical movements of its components, which occur under appropriate external stimulation. Hence, molecular machines contain a motor part, that is a device capable of converting energy into mechanical work. Molecular motors and machines operate via nuclear rearrangements and, like their macroscopic counterparts, are characterized by the kind of energy input supplied to make them work, the manner in which their operation can be monitored, the possibility to repeat the operation at will, i.e., establishing a cyclic process, the timescale needed to complete a cycle of operation, and the performed function. Owing to the progresses made in several branches of chemistry, and to the better understanding of the operation mechanisms of molecular machines of the biological world, it has become possible to design and construct simple prototypes of artificial molecular motors and machines. Some examples based on rotaxanes, catenanes, and related interlocked molecules will be described

Interlocking Toy Building Blocks as Hands-On Learning Modules for Blind and Visually Impaired Chemistry Students

Science.gov (United States)

Melaku, Samuel; Schreck, James O.; Griffin, Kameron; Dabke, Rajeev B.

2016-01-01

Interlocking toy building blocks (e.g., Lego) as chemistry learning modules for blind and visually impaired (BVI) students in high school and undergraduate introductory or general chemistry courses are presented. Building blocks were assembled on a baseplate to depict the relative changes in the periodic properties of elements. Modules depicting…

A comparative study of intramedullary interlocking nailing and minimally invasive plate osteosynthesis in extra articular distal tibial fractures.

Science.gov (United States)

Daolagupu, Arup K; Mudgal, Ashwani; Agarwala, Vikash; Dutta, Kaushik K

2017-01-01

Extraarticular distal tibial fractures are among the most challenging fractures encountered by an orthopedician for treatment because of its subcutaneous location, poor blood supply and decreased muscular cover anteriorly, complications such as delayed union, nonunion, wound infection, and wound dehiscence are often seen as a great challenge to the surgeon. Minimally invasive plate osteosynthesis (MIPO) and intramedullary interlocking nail (IMLN) are two well-accepted and effective methods, but each has been historically related to complications. This study compares clinical and radiological outcome in extraarticular distal tibia fractures treated by intramedullary interlocking nail (IMLN) and minimally invasive plate osteosynthesis (MIPO). 42 patients included in this study, 21 underwent IMLN and 21 were treated with MIPO who met the inclusion criteria and operated between June 2014 and May 2015. Patients were followed up for clinical and radiological evaluation. In IMLN group, average union time was 18.26 weeks compared to 21.70 weeks in plating group which was significant ( P ankle stiffness, and infection, were seen in interlocking group as compared to plating group. Average functional outcome according to American Orthopedic Foot and Ankle Society score was measured which came out to be 96.67. IMLN group was associated with lesser duration of surgery, earlier weight bearing and union rate, lesser incidence of infection and implant irritation which makes it a preferable choice for fixation of extra-articular distal tibial fractures. However, larger randomized controlled trials are required for confirming the results.

[Clinical application of blocking screws and rooting technique in the treatment of distal tibial fracture with interlocking intramedullary nail].

Science.gov (United States)

Zhu, Hai-Bing; Wu, Li-Guo; Fang, Zhi-Song; Luo, Cong-Feng; Wang, Qing-Feng; Ma, Yi-Ping; Gao, Hong; Fu, Guo-Hai; Hu, Cheng-Ting

2012-07-01

To introduce the clinical method of blocking screws and rooting technique in the treatment of distal tibial fracture with interlocking intramedullary nails. From June 2006 to March 2011, 26 patients with distal tibial fracture were treated with interlocking intramedullary nails using blocking screws and rooting technique, included 18 males and 8 females with an average age of 46.2 years old ranging from 24 to 64 years. According to AO classification: 10 cases of type A1, 4 cases of type A2, 8 cases of type B1, 4 cases of type B2. The average distance of the fractures end to the ankle joint was 85 mm ranging from 55 to 125 mm, the mean time between injured and operation was 4.5 days. The patients were evaluated with pain, range of motion, walking. All cases were followed-up for 6 to 22 months (averaged 15 months). According to Iowa ankle joint grading system,the score was improved from preoperative (66.8 +/- 8.2) to postoperative (94.6 +/- 4.8). All fractures had united, and got satisfactory reduction and stable fixation with no complications had happen such as breakage of screw. Fixation with interlocking intramedullary nail using blocking screws and rooting technique in treating distal tibial fracture, is a safe and effective technique for the improvement of stability.

"Fabrication of arbitrarily shaped carbonate apatite foam based on the interlocking process of dicalcium hydrogen phosphate dihydrate".

Science.gov (United States)

Sugiura, Yuki; Tsuru, Kanji; Ishikawa, Kunio

2017-08-01

Carbonate apatite (CO 3 Ap) foam with an interconnected porous structure is highly attractive as a scaffold for bone replacement. In this study, arbitrarily shaped CO 3 Ap foam was formed from α-tricalcium phosphate (α-TCP) foam granules via a two-step process involving treatment with acidic calcium phosphate solution followed by hydrothermal treatment with NaHCO 3 . The treatment with acidic calcium phosphate solution, which is key to fabricating arbitrarily shaped CO 3 Ap foam, enables dicalcium hydrogen phosphate dihydrate (DCPD) crystals to form on the α-TCP foam granules. The generated DCPD crystals cause the α-TCP granules to interlock with each other, inducing an α-TCP/DCPD foam. The interlocking structure containing DCPD crystals can survive hydrothermal treatment with NaHCO 3 . The arbitrarily shaped CO 3 Ap foam was fabricated from the α-TCP/DCPD foam via hydrothermal treatment at 200 °C for 24 h in the presence of a large amount of NaHCO 3 .

Macro-Micro Interlocked Simulator

International Nuclear Information System (INIS)

Sato, Tetsuya

2005-01-01

Simulation Science is now standing on a turning point. After the appearance of the Earth Simulator, HEC is struggling with several severe difficulties due to the physical limit of LSI technologies and the so-called latency problem. In this paper I would like to propose one clever way to overcome these difficulties from the simulation algorithm viewpoint. Nature and artificial products are usually organized with several nearly autonomously working internal systems (organizations, or layers). The Earth Simulator has gifted us with a really useful scientific tool that can deal with the entire evolution of one internal system with a sufficient soundness. In order to make a leap jump of Simulation Science, therefore, it is desired to design an innovative simulator that enables us to deal with simultaneously and as consistently as possible a real system that evolves cooperatively with several internal autonomous systems. Three years experience of the Earth Simulator Project has stimulated to come up with one innovative simulation algorithm to get rid of the technological barrier standing in front of us, which I would like to call 'Macro-Micro Interlocked Algorithm', or 'Macro-Micro Multiplying Algorithm', and present a couple of such examples to validate the proposed algorithm. The first example is an aurora-arc formation as a result of the mutual interaction between the macroscopic magnetosphere-ionosphere system and the microscopic field-aligned electron and ion system. The second example is the local heavy rain fall resulting from the interaction between the global climate evolution and the microscopic raindrop growth process. Based on this innovative feasible algorithm, I came up with a Macro-Micro Multiplying Simulator

Removal torque of nail interlocking screws is related to screw proximity to the fracture and screw breakage.

Science.gov (United States)

White, Alexander A; Kubacki, Meghan R; Samona, Jason; Telehowski, Paul; Atkinson, Patrick J

2016-06-01

Studies have shown that titanium implants can be challenging to explant due to the material's excellent biocompatibility and resulting osseointegration. Clinically, titanium alloy nail interlocking screws may require removal to dynamize a construct or revise the nail due to nonunion, infection, pain, or periprosthetic fracture. This study was designed to determine what variables influence the removal torque for titanium alloy interlocking screws. An intramedullary nail with four interlocking screws was used to stabilize a 1-cm segmental femoral defect in a canine model for 16 weeks. The animals were observed to be active following a several-day recovery after surgery. In six animals, the femora and implanted nail/screws were first tested to failure in torsion to simulate periprosthetic fracture of an implant after which the screws were then removed. In four additional animals, the screws were removed without mechanical testing. Both intraoperative insertional and extraction torques were recorded for all screws. Mechanical testing to failure broke 10/24 screws. On average, the intact screws required 70% of the insertional torque during removal while broken screws only required 16% of the insertional torque (p torque than the outboard distal screw (p torque was ∼80°. The peak axial load did not significantly correlate with the torque required to remove the screws. On average, the removal torque was lower than at the time of insertion, and less torque was required to remove broken screws and screws remote to the fracture. However, broken screws will require additional time to retrieve the remaining screw fragment. This study suggests that broken screws and screws in prematurely active patients will require less torque to remove. © IMechE 2016.

Beam interlock system and safe machine parameters system 2010 and beyond

CERN Document Server

Todd, B

2010-01-01

The Beam Interlock System (BIS) and Safe Machine Parameters (SMP) system are central to the protection of the Large Hadron Collider (LHC) machine. The BIS has been critical for the safe operation of LHC from the first day of operation. It has been installed and commissioned, only minor enhancements are required in order to accommodate all future LHC machine protection requirements. At reduced intensity, the SMP system is less critical for LHC operation. As such, the current system satisfies the 2010 operational requirements. Further developments are required, both at the SMP Controller level, and at the system level, in order to accommodate the requirements of the LHC beyond 2010.

Testing the permeability and corrosion resistance of micro-mechanically interlocked joints

DEFF Research Database (Denmark)

Byskov-Nielsen, Jeppe; Holm, Allan Hjarbæk; Højsholt, Rune

2011-01-01

Micro-mechanical interlocking (MMI) can be applied to create new and interesting composite materials. We have employed laser structuring to achieve MMI between stainless steel and plastic with extremely high joint strength. However, the water permeability and corrosion resistance of the joint must...... is conducted. The permeability seems to be consistent with the Hagen–Poiseuille equation independent of the laser structuring technique and is orders of magnitudes larger than the diffusion rate through the plastic. Two different types of corrosion tests have been undertaken, and we show that care must...... be taken in order not to degrade the corrosion resistance of the sample to an unacceptable level....

Interlocking Corporate Directorates and the Global City Hierarchy

Directory of Open Access Journals (Sweden)

Jeffrey Kentor

2015-08-01

Full Text Available This paper examines the direct and indirect economic linkages of the most prominent cities in the world, those commonly referred to as “global cities”, in terms of the direct and indirect linkages of the boards of directors of Fortune Global 500 firms headquartered in a given city with boards of directors of other firms. Specifically, we identify the interlocks of corporate boards located within these major cities with other Fortune 500 boards of directors by degrees of separation, and present a new ranking for selected global cities based upon these direct and indirect ties. We find that New York clearly dominates these economic linkages, followed by London and Paris. This is most pronounced for financial companies. Contrary to other global city rankings, we locate Tokyo below Frankfurt and Chicago on this dimension. We argue that these multiple levels of indirect relationships reflect a significant, and until now unexplored, dimension of what it means to be a “global” city.

An SEU-hardened latch with a triple-interlocked structure

International Nuclear Information System (INIS)

Li Yuanqing; Yao Suying; Xu Jiangtao; Gao Jing

2012-01-01

A single event upset (SEU) tolerant latch with a triple-interlocked structure is presented. Its self-recovery mechanism is implemented by using three pairs of guard-gates and inverters to construct feedback lines inside the structure. This latch effectively suppresses the effects of charge deposition at any single internal node caused by particle strikes. Three recently reported SEU-hardened latches are chosen and compared with this latch in terms of reliability. The potential problems that these three latches could still get flipped due to single event effects or single event effects plus crosstalk coupling are pointed out, which can be mitigated by this proposed latch. The SEU tolerance of each latch design is evaluated through circuit-level SEU injection simulation. Furthermore, discussions on the crosstalk robustness and some other characteristics of these latches are also presented. (semiconductor integrated circuits)

Interlocking-induced stiffness in stochastically microcracked materials beyond the transport percolation threshold

Science.gov (United States)

Picu, R. C.; Pal, A.; Lupulescu, M. V.

2016-04-01

We study the mechanical behavior of two-dimensional, stochastically microcracked continua in the range of crack densities close to, and above, the transport percolation threshold. We show that these materials retain stiffness up to crack densities much larger than the transport percolation threshold due to topological interlocking of sample subdomains. Even with a linear constitutive law for the continuum, the mechanical behavior becomes nonlinear in the range of crack densities bounded by the transport and stiffness percolation thresholds. The effect is due to the fractal nature of the fragmentation process and is not linked to the roughness of individual cracks.

Bio-inspired ``jigsaw''-like interlocking sutures: Modeling, optimization, 3D printing and testing

Science.gov (United States)

Malik, I. A.; Mirkhalaf, M.; Barthelat, F.

2017-05-01

Structural biological materials such as bone, teeth or mollusk shells draw their remarkable performance from a sophisticated interplay of architectures and weak interfaces. Pushed to the extreme, this concept leads to sutured materials, which contain thin lines with complex geometries. Sutured materials are prominent in nature, and have recently served as bioinspiration for toughened ceramics and glasses. Sutures can generate large deformations, toughness and damping in otherwise all brittle systems and materials. In this study we examine the design and optimization of sutures with a jigsaw puzzle-like geometry, focusing on the non-linear traction behavior generated by the frictional pullout of the jigsaw tabs. We present analytical models which accurately predict the entire pullout response. Pullout strength and energy absorption increase with higher interlocking angles and for higher coefficients of friction, but the associated high stresses in the solid may fracture the tabs. Systematic optimization reveals a counter-intuitive result: the best pullout performance is achieved with interfaces with low coefficient of friction and high interlocking angle. We finally use 3D printing and mechanical testing to verify the accuracy of the models and of the optimization. The models and guidelines we present here can be extended to other types of geometries and sutured materials subjected to other loading/boundary conditions. The nonlinear responses of sutures are particularly attractive to augment the properties and functionalities of inherently brittle materials such as ceramics and glasses.

Do biodegradable magnesium alloy intramedullary interlocking nails prematurely lose fixation stability in the treatment of tibial fracture? A numerical simulation.

Science.gov (United States)

Wang, Haosen; Hao, Zhixiu; Wen, Shizhu

2017-01-01

Intramedullary interlocking nailing is an effective technique used to treat long bone fractures. Recently, biodegradable metals have drawn increased attention as an intramedullary interlocking nailing material. In this study, numerical simulations were implemented to determine whether the degradation rate of magnesium alloy makes it a suitable material for manufacturing biodegradable intramedullary interlocking nails. Mechano-regulatory and bone-remodeling models were used to simulate the fracture healing process, and a surface corrosion model was used to simulate intramedullary rod degradation. The results showed that magnesium alloy intramedullary rods exhibited a satisfactory degradation rate; the fracture healed and callus enhancement was observed before complete dissolution of the intramedullary rod. Delayed magnesium degradation (using surface coating techniques) did not confer a significant advantage over the non-delayed degradation process; immediate degradation also achieved satisfactory healing outcomes. However, delayed degradation had no negative effect on callus enhancement, as it did not cause signs of stress shielding. To avoid risks of individual differences such as delayed union, delayed degradation is recommended. Although the magnesium intramedullary rod did not demonstrate rapid degradation, its ability to provide high fixation stiffness to achieve earlier load bearing was inferior to that of the conventional titanium alloy and stainless steel rods. Therefore, light physiological loads should be ensured during the early stages of healing to achieve bony healing; otherwise, with increased loading and degraded intramedullary rods, the fracture may ultimately fail to heal. Copyright © 2016 Elsevier Ltd. All rights reserved.

Availability Analysis of the Ventilation Stack CAM Interlock System

International Nuclear Information System (INIS)

YOUNG, J.

2000-01-01

Ventilation Stack Continuous Air Monitor (CAM) Interlock System failure modes, failure frequencies and system availability have been evaluated for the RPP. The evaluation concludes that CAM availability is as high as assumed in the safety analysis and that the current routine system surveillance is adequate to maintain this availability. Further, requiring an alarm to actuate upon CAM failure is not necessary to maintain the availability credited in the safety analysis, nor is such an arrangement predicted to significantly improve system availability. However, if CAM failures were only detected by the 92-day functional tests required in the Authorization Basis (AB), CAM availability would be much less than that credited in the safety analysis. Therefore it is recommended that the current surveillance practice of daily simple system checks, 30-day source checks and 92-day functional tests be continued in order to maintain CAM availability

I: Hydrodynamic-focusing microreactor II: Mechanically interlocked molecules for functional materials

Science.gov (United States)

Coti, Karla Karina

I: Microreactors, a class of microfluidics, offer numerous benefits -- such as small sample requirement, short analysis times and automations -- and have been used to study reactions of chemical and biological reagents. In order to understand the relationship between fast mixing, product regioselectivity, as well as the ability to separate, in time and space, the nanoparticle (NP) formation stages, a microreactor capable of fast and controllable mixing was developed (Chapter 1) based on multi-lamination and hydrodynamic-focusing. By taking advantage of the fast and controllable mixing properties of this novel microreactor one can control the time when chemical reactions commence inside the microchannels. These properties of the microreactor can be exploited to improve the product regioselectivity of a diazo-coupling reaction to attain a product distribution of monoazo to diazo product of ˜1:99, a selectivity unprecedented in both conventional, macroscopic reactors and other microfluidic systems. Additionally, the ability to separate different stages during the NP formation process inside the microreactor, allowed us to study the aggregation of polypyrrole NPs. II: Supramolecular actuators and molecular interlocked molecules, such as catenanes and rotaxanes, have attracted considerable attention because of their sophisticated topology and their application in functional molecular devices. The blending of supramolecular and mechanostereochemistry with mesoporous silica NPs has proven to be a powerful combination, leading to the development of a new class of materials -- mechanized silica nanoparticles ( Chapter 2). These new hybrid materials are designed to release their content in response to an external stimuli and their development is being driven by the need to improve current drug delivery technologies. In an effort to explore how the stimuli-controlled mechanical movement of switchable, bistable [2]rotaxanes -- based on a cyclobis(paraquat-p-phenylene) ring

Unidirectional splitting and uniting of rays in the cambium of Platanus accompanying the formation of interlocked grain in wood

Directory of Open Access Journals (Sweden)

J. Krawczyszyn

2015-01-01

Full Text Available Developmental changes in the cambium producing interlocked grain wood of Platanus, were determined by an analysis of successive late xylem layers (TLX at the borders of the annual rings. Intensive splitting and uniting of rays were observed. These occured by intrusion of fusiform cells into the rays and by loss of the fusiform initials which formed the strands separating the rays, respectively. Uniting of rays was unidirectional within the large areas of cambium (domain, so was the splitting, too. There were domains of Z and S-type. Orientation of splitting and uniting of rays at a particular locality of the cambium was reversed at irregular time intervals. It appears that the reason for these reversals was slow movement of domain pattern. The occurrence of alternating Z and S domains brought about the alternation of the grain inclination from right to left and back again in the interlocked-grained wood.

A Nonfullerene Small Molecule Acceptor with 3D Interlocking Geometry Enabling Efficient Organic Solar Cells.

Science.gov (United States)

Lee, Jaewon; Singh, Ranbir; Sin, Dong Hun; Kim, Heung Gyu; Song, Kyu Chan; Cho, Kilwon

2016-01-06

A new 3D nonfullerene small-molecule acceptor is reported. The 3D interlocking geometry of the small-molecule acceptor enables uniform molecular conformation and strong intermolecular connectivity, facilitating favorable nanoscale phase separation and electron charge transfer. By employing both a novel polymer donor and a nonfullerene small-molecule acceptor in the solution-processed organic solar cells, a high-power conversion efficiency of close to 6% is demonstrated. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Breath Alcohol Ignition Interlock Devices : Policy and Implementing Implications [Mobile .MP4 (480x320/29.97fps/13.9MB)

Science.gov (United States)

2011-01-01

The goal of this project is to perform a systematic review of breath alcohol ignition interlock devices (BAIID or IID) to understand how other states have integrated such systems into administrative and judicial practice and to make recommendations f...

Breath Alcohol Ignition Interlock Devices : Policy and Implementing Implications [SD .MP4 (640x424/29.97fps/22.6MB)

Science.gov (United States)

2011-01-01

The goal of this project is to perform a systematic review of breath alcohol ignition interlock devices (BAIID or IID) to understand how other states have integrated such systems into administrative and judicial practice and to make recommendations f...

Complications of close interlock nailing in the management of close tibial fracture

International Nuclear Information System (INIS)

Saeed, M.; Inam, M.; Khan, I.; Satar, A.; Arif, M.

2015-01-01

Objective: The objective of this study is to find out the frequency of complications of locally made interlock nailing in tibia after nine months of surgery. Material and Method:. This case series study was done from March 2004 to February 14 in the Department of Orthopedic and Trauma Postgraduate Medical Institute Hayatabad Medical Complex Peshawar. A total of 58 adults ( after the closure of epiphysis) patients were randomly selected provided that they have; Close diaphysial fracture of tibia which is located 7 cm below the knee joint and 4 cm above the ankle joint and fracture less than one week old. Results: Total numbers of patients were 58. Anterior Knee pain was observed in 14(24.1%), delayed union in 10(17.2%), external of 100 rotation in 4(6.9%) and internal rotation of 50 in 1(1.7%), non union in 4(6.9%), intramedullay infection in 3(5.2%), shortening of 1 centimeter (cm) in 2(3.4), 2 cm in 1(1.7%) and 1.5 cm in 3(5.2%) cases, distal screw broken in 2(3.4%), proximal screw broken in 1(1.7%), Nail broken in 2(3.4), infection at proximal screw in 2(3.4%) and at distal screw was 2(3.4%), Restriction of knee flexion in 1(1.7%), Restricted ankle movements in 1(1.7%), varus angulation of 100 in 1(1.7%), valgus angulation of 100 in 1(1.7%), Ankle pain in 1(1.7%) and deep vein thrombosis in 1(1.7%). Conclusion: interlocking nail is considered to be the gold standard for management of tibial fracture but it is not free of complication especially knee pain and angular rotation. (author)

Rydberg aggregates

Science.gov (United States)

Wüster, S.; Rost, J.-M.

2018-02-01

We review Rydberg aggregates, assemblies of a few Rydberg atoms exhibiting energy transport through collective eigenstates, considering isolated atoms or assemblies embedded within clouds of cold ground-state atoms. We classify Rydberg aggregates, and provide an overview of their possible applications as quantum simulators for phenomena from chemical or biological physics. Our main focus is on flexible Rydberg aggregates, in which atomic motion is an essential feature. In these, simultaneous control over Rydberg-Rydberg interactions, external trapping and electronic energies, allows Born-Oppenheimer surfaces for the motion of the entire aggregate to be tailored as desired. This is illustrated with theory proposals towards the demonstration of joint motion and excitation transport, conical intersections and non-adiabatic effects. Additional flexibility for quantum simulations is enabled by the use of dressed dipole-dipole interactions or the embedding of the aggregate in a cold gas or Bose-Einstein condensate environment. Finally we provide some guidance regarding the parameter regimes that are most suitable for the realization of either static or flexible Rydberg aggregates based on Li or Rb atoms. The current status of experimental progress towards enabling Rydberg aggregates is also reviewed.

An active interlock system for the NSLS x-ray ring insertion devices

International Nuclear Information System (INIS)

Nawrocky, R.J.; Biscardi, R.; Dabrowski, J.; Flannigan, J.; Ramamoorthy, S.; Rothman, J.; Smith, J.; So, I.; Thomas, M.; Decker, G.

1991-01-01

This paper describes the design and operation of an active interlock system which has been installed in the NSLS X-ray electron storage ing to protect the vacuum chamber from thermal damage by mis-steered high power photon beams from insertion devices (IDs). the system employs active beam position detectors to monitor beam motion in the ID straight sections and solid state logic circuitry to ''dump'' the stored beam in the event of a fault condition by interrupting the rf. To ensure a high degree of reliability, redundancy and continuous automatic checking has been incorporated into the design. Overall system integrity is checked periodically with beam at safe levels of beam current. 2 refs., 3 figs

Implementation of a Direct Link between the LHC Beam Interlock System and the LHC Beam Dumping System Re-Triggering Lines

CERN Document Server

Gabourin, S; Denz, R; Magnin, N; Uythoven, J; Wollmann, D; Zerlauth, M; Vatansever, V; Bartholdt, M; Bertsche, B; Zeiler, P

2014-01-01

To avoid damage of accelerator equipment due to impacting beam, the controlled removal of the LHC beams from the collider rings towards the dump blocks must be guaranteed at all times. When a beam dump is demanded, the Beam Interlock System communicates this request to the Trigger Synchronisation and Distribution System of the LHC Beam Dumping System. Both systems were built according to high reliability standards. To further reduce the risk of incapability to dump the beams in case of correlated failures in the Trigger Synchronisation and Distribution System, a new direct link from the Beam Interlock System to the re-triggering lines of the LHC Beam Dumping System will be implemented for the start-up with beam in 2015. The link represents a diverse redundancy to the current implementation, which should neither significantly increase the risk for so-called asynchronous beam dumps nor compromise machine availability. This paper describes the implementation choices of this link. Furthermore the results of a rel...

Feasibility of a fast optical pressure interlock for the ITER neutral beam injectors

International Nuclear Information System (INIS)

Ash, Andrew; Surrey, Elizabeth

2009-01-01

The feasibility of using Balmer-α emission for a high-speed pressure diagnostic and beam interlock for the ITER neutral beam heating system is investigated. An interlock is needed to prevent excessive re-ionisation of the neutral beam when rapid excursions of pressure occur in either the electrostatic residual ion dump (ERID), or the neutral beam duct (NBD). The re-ionised fraction of the beam, will be deflected by stray tokamak fields, potentially causing excessive thermal loads on beam line components. Experience from JET indicates that a response time of order 100 μs is required in order to prevent fast pressure excursions. Fast penning gauges have a time response of around 30-50 ms, however, a faster response (around 1 μs) is possible by monitoring the H α (656.3 nm)/D α (656.1 nm) emission from collisional excitation of the background gas and neutral beam. Published total cross-sections are used to calculate a signal of 3.5x10 13 -3.0x10 17 photons s -1 m -2 sr -1 for normal conditions. This signal must be distinguished from the background light of the tokamak plasma (line emission and bremsstrahlung). The beam emission is Doppler shifted by up to 21 nm (D operation) and up to 27 nm (H operation) depending on angle of observation and this can be used to help distinguish against background line emission. The distribution of background light along the beam line is calculated with a two-dimensional radiosity code, solving the equilibrium energy balance within the beam line enclosure. The Balmer-α signal and background signal due to bremsstrahlung are compared for a 500-MW reference plasma.

Institutional Conflict of Interest: The Role of Interlocking Directorates in the Scientific Relationships between Universities and the Corporate Sector

Science.gov (United States)

Slaughter, Sheila; Thomas, Scott L.; Johnson, David R.; Barringer, Sondra N.

2014-01-01

We examined the potential for institutional conflict of interest between the 26 private universities belonging to the Association of American Universities and the corporations to which they are tied through their boards of trustees. We were interested in the degree to which interlocks may have tightened over three points across an 11-year period…

Strength properties of interlocking compressed earth brick units

Science.gov (United States)

Saari, S.; Bakar, B. H. Abu; Surip, N. A.

2017-10-01

This study presents a laboratory investigation on the properties of interlocking compressed earth brick (ICEB) units. Compressive strength, which is one of the most important properties in masonry structures, is used to determine masonry performance. The compressive strength of the ICEB units was determined by applying a compressive strength test for 340 units from four types of ICEB. To analyze the strength of the ICEB units, each unit was capped by a steel plate at the top and bottom to create a flat surface, and then ICEB was loaded until failure. The average compressive strength of the corresponding ICEB units are as follows: wall brick, 19.15 N/mm2; beam brick, 16.99 N/mm2; column brick, 13.18 N/mm2; and half brick, 11.79 N/mm2. All the ICEB units had compressive strength of over 5 N/mm2, which is the minimum strength for a load-bearing brick. This study proves that ICEB units may be used as load-bearing bricks. The strength of ICEBs is equal to that of other common bricks and blocks that are currently available in the market.

Influence of Fabric Parameters on Thermal Comfort Performance of Double Layer Knitted Interlock Fabrics

Directory of Open Access Journals (Sweden)

Afzal Ali

2017-03-01

Full Text Available The aim of this study was to analyse the effects of various fabric parameters on the thermal resistance, thermal conductivity, thermal transmittance, thermal absorptivity and thermal insulation of polyester/cotton double layer knitted interlock fabrics. It was found that by increasing fibre content with higher specific heat increases the thermal insulation while decreases the thermal transmittance and absorptivity of the fabric. It was concluded that double layer knitted fabrics developed with higher specific heat fibres, coarser yarn linear densities, higher knitting loop length and fabric thickness could be adequately used for winter clothing purposes.

Close Intramedullary Interlocking Nailing Versus Locking Compression Plating In the Treatment of Closed Fracture Shaft of the Tibia.

Science.gov (United States)

Kundu, I K; Datta, N K; Chowdhury, A Z; Das, K P; Tarik, M M; Faisal, M A

2016-07-01

Fracture of tibial shaft is the commonest site of long bone fractures due to its superficial location involving young or middle-age people. Proper management is an important issue regarding the future effective movements. In this study patients were grouped in closed Intra medullary interlocking nailing and locking compression plating. Post-operative follow up at 2 weeks, 6 weeks, 12 weeks and 3 months thereafter up to 6 months were done. Each of the patients was evaluated clinically and radiologically by tucker criteria of Tuker et al. Patients were assessed for pain on full weight bearing and kneeling, shortening and range of motion of knee and ankle joints. Radiological assessment for union of fracture, alignment of fracture and angulations and position of nail and screws and infection were observed during follow up. A total number of 32 patients were selected but only 27 patients were available for follow up for a period of 6 months. They were grouped into Group A, consisting of 15 patients who took the treatment in the form of closed intramedullary interlocking nailing and Group B, consisting of 12 patients those underwent ORIF with locking compression plating. In both of the groups Motor Vehicle Accident was the main mechanism of trauma. Fracture involving the middle 3rd of the tibia is common in both the groups. During post-operative follow up, four patients in Group A complained anterior knee pain, one patient in Group B had superficial infection, most of the patients had no restriction of movement in the ankle and knee joints and a single patient in Group B showed 1.5cm shortening of the lower limb. Period of hospital stay and fracture union time were less in Group A, which was statistically significant. Both groups showed excellent result with minimum complications. So this study permits to conclude that close IM interlocking nailing and open reduction and internal fixation by locking compression plating is equally effective for the management of close

Reuse of mining dams waste for the processing of interlocking blocks for paving

International Nuclear Information System (INIS)

Machado, Raissa Ribeiro Lima; Ribeiro, Guilherme Borges; Silva, Sidney Nicodemos da

2014-01-01

The environmental impact of mining dam residues can be mitigated by their reuse in the production of interlocking blocks for pavements with a mechanical strength greater than 50 MPa. From the mixture of cement CPV-ARI, sand and gravel, the characterization of the mechanical and physicochemical properties was performed by the following procedures: SEM, FRX, XRD, compression tests and thermal analysis (DSC). These blocks produced from these residues can be considered an economical alternative for the mining depletion cycle in the State of Minas Gerais. This work sought to improve the traces with the replacement the sand of the rivers bed by residues of mining dams that can represent an opportunity for generation of employment and income

Marine Synechococcus Aggregation

Science.gov (United States)

Neuer, S.; Deng, W.; Cruz, B. N.; Monks, L.

2016-02-01

Cyanobacteria are considered to play an important role in the oceanic biological carbon pump, especially in oligotrophic regions. But as single cells are too small to sink, their carbon export has to be mediated by aggregate formation and possible consumption by zooplankton producing sinking fecal pellets. Here we report results on the aggregation of the ubiquitous marine pico-cyanobacterium Synechococcus as a model organism. We first investigated the mechanism behind such aggregation by studying the potential role of transparent exopolymeric particles (TEP) and the effects of nutrient (nitrogen or phosphorus) limitation on the TEP production and aggregate formation of these pico-cyanobacteria. We further studied the aggregation and subsequent settling in roller tanks and investigated the effects of the clays kaolinite and bentonite in a series of concentrations. Our results show that despite of the lowered growth rates, Synechococcus in nutrient limited cultures had larger cell-normalized TEP production, formed a greater volume of aggregates, and resulted in higher settling velocities compared to results from replete cultures. In addition, we found that despite their small size and lack of natural ballasting minerals, Synechococcus cells could still form aggregates and sink at measureable velocities in seawater. Clay minerals increased the number and reduced the size of aggregates, and their ballasting effects increased the sinking velocity and carbon export potential of aggregates. In comparison with the Synechococcus, we will also present results of the aggregation of the pico-cyanobacterium Prochlorococcus in roller tanks. These results contribute to our understanding in the physiology of marine Synechococcus as well as their role in the ecology and biogeochemistry in oligotrophic oceans.

Metal-organic and supramolecular architectures based on mechanically interlocked molecules

Science.gov (United States)

Fernando, Isurika Rosini

The focus of this work is on mechanically interlocked molecules (MIMs), which have unusual physicochemical and mechanical properties with potential applications in nano-scale/molecular devices and high strength materials. Rotaxanes, for example, consist of an axle-like molecule threaded through a wheel-like molecule, with bulky groups at the two ends of the axle preventing the wheel from dissociating. The position of the wheel along the axle can be switched in a controllable and reversible manner by applying external stimuli, a feature that might lead to the next generation of computers. Molecularly woven materials (MWMs), another example of molecules with mechanically interlocked features, are predicted to be unprecedentedly strong while being lightweight and flexible. With the ultimate goal of achieving control over the functioning of molecular devices in the solid state, a variety of pseudorotaxane building blocks were prepared and characterized, including a novel, rare blue-colored motif. The temperature-dependent assembly/disassembly of pseudorotaxanes was exploited for the construction of single-wavelength colorimetric temperature sensors over a 100 °C window. Pseudorotaxanes based on aromatic crown ether wheels and disubstituted 4,4'-bipyridinium axles were converted into rotaxanes upon binding to metal complexes (zinc, cadmium, mercury, copper, cobalt), and the formation of ordered crystalline arrays was studied in the solid state. The columnar organization of pseudorotaxanes by Hg2X6 2-- complexes (X = Cl, Br, I), leading to unprecedented dichroic (blue/red) rotaxane crystals, was demonstrated for the first time. From the crystal structures studied it became apparent that negatively charged metal complexes are needed for successful assembly with the positively charged pseudorotaxane units. To be able to use the more common, positively charged metal ions for rotaxane framework construction, neutral and negatively charged pseudorotaxanes were synthesized

Defining and systematic analyses of aggregation indices to evaluate degree of calcium oxalate crystal aggregation

Science.gov (United States)

Chaiyarit, Sakdithep; Thongboonkerd, Visith

2017-12-01

Crystal aggregation is one of the most crucial steps in kidney stone pathogenesis. However, previous studies of crystal aggregation were rarely done and quantitative analysis of aggregation degree was handicapped by a lack of the standard measurement. We thus performed an in vitro assay to generate aggregation of calcium oxalate monohydrate (COM) crystals with various concentrations (25-800 µg/ml) in saturated aggregation buffer. The crystal aggregates were analyzed by microscopic examination, UV-visible spectrophotometry, and GraphPad Prism6 software to define a total of 12 aggregation indices (including number of aggregates, aggregated mass index, optical density, aggregation coefficient, span, number of aggregates at plateau time-point, aggregated area index, aggregated diameter index, aggregated symmetry index, time constant, half-life, and rate constant). The data showed linear correlation between crystal concentration and almost all of these indices, except only for rate constant. Among these, number of aggregates provided the greatest regression coefficient (r=0.997; pr=0.993; pr=‑0.993; pr=0.991; p<0.001 for both). These five indices are thus recommended as the most appropriate indices for quantitative analysis of COM crystal aggregation in vitro.

[Treatment of multi-segment fracture of complex femoral shaft with instrument-assisted reduction combined with intramedullary interlocking nail fixation].

Science.gov (United States)

Fan, Ke-Jie; Chen, Ke; Ma, Wen-Long; Tian, Ke-Wei; Ye, Ye; Chen, Hong-Gan; Tang, Yan-Feng; Cai, Hong-Min

2018-05-25

To investigate the effect of minimally invasive mini-incision and instrumented reduction combined with interlocking intramedullary nailing in the treatment of patients with multi-segment fracture of complex femoral shaft. From January 2013 to January 2016, 32 patients with multiple fractures segments of femoral shaft were treated with instrumentation-assisted reduction combined with interlocking intramedullary nailing, including 22 males and 10 females with an average age of 45 years old ranging 17 to 68 years old. The time from injured to operation was 5 to 10 days with an average of 7 days. After admission, routine tibial tubercle or supracondylar bone traction was performed. The patient's general condition was evaluated, the operation time and intraoperative blood loss were recorded. According to Thorsen femoral fracture morphology evaluation criteria and Hohl knee function evaluation of postoperative efficacy, postoperative fracture healing, complications and postoperative recovery of limb function were observed. All patients were followed up for 6 to 24 months with an average of 12 months. The operative time ranged from 48 to 76 minutes with an average of 67 min. The intraoperative blood loss was 150 to 400 ml with an average of 220 ml. The surgical incisions all achieved grade A healing. The fractures reached the clinical standard of healing. The fracture healing time ranged from 4.2 to 10.8 months with an average of 5.7 months. There were no nonunion, incision infection and internal fixation fracture, failure and other complications. According to Thorsen femoral fracture morphology evaluation criteria, the result was excellent in 28 cases, good in 3 cases, fair in 1 case. According to Hohl knee function evaluation criteria, the result was excellent in 30 cases, good in 2 cases. Instrument-assisted reduction combined with interlocking intramedullary nail fixation is a safe and effective method for the treatment of complex femoral shaft fractures. It has

Sustainable aggregates production : green applications for aggregate by-products.

Science.gov (United States)

2015-06-01

Increased emphasis in the construction industry on sustainability and recycling requires production of : aggregate gradations with lower dust (cleaner aggregates) and smaller maximum sizeshence, increased : amount of quarry by-products (QBs). QBs ...

Influence of Aggregate Wettability with Different Lithology Aggregates on Concrete Drying Shrinkage

Directory of Open Access Journals (Sweden)

Yuanchen Guo

2015-01-01

Full Text Available The correlation of the wettability of different lithology aggregates and the drying shrinkage of concrete materials is studied, and some influential factors such as wettability and wetting angle are analyzed. A mercury porosimeter is used to measure the porosities of different lithology aggregates accurately, and the pore size ranges that significantly affect the drying shrinkage of different lithology aggregate concretes are confirmed. The pore distribution curve of the different coarse aggregates is also measured through a statistical method, and the contact angle of different coarse aggregates and concrete is calculated according to the linear fitting relationship. Research shows that concrete strength is determined by aggregate strength. Aggregate wettability is not directly correlated with concrete strength, but wettability significantly affects concrete drying shrinkage. In all types’ pores, the greatest impacts on wettability are capillary pores and gel pores, especially for the pores of the size locating 2.5–50 nm and 50–100 nm two ranges.

RELATIONSHIPS BETWEEN SOIL MICROBIAL BIOMASS, AGGREGATE STABILITY AND AGGREGATE ASSOCIATED-C: A MECHANISTIC APPROACH

Directory of Open Access Journals (Sweden)

Patrizia Guidi

2014-01-01

Full Text Available For the identification of C pools involved in soil aggregation, a physically-based aggregate fractionation was proposed, and  additional pretreatments were used in the measurement of the 1-2 mm aggregate stability in order to elucidate the relevance of the role of soil microorganisms with respect to the different aggregate breakdown mechanisms. The study was carried out on three clay loam Regosols, developed on calcareous shales, known history of organic cultivation.Our results showed that the soil C pool controlling the process of stabilisation of aggregates was related to the microbial community. We identified the resistance to fast wetting as the major mechanism of aggregate stability driven by microorganims. The plausible hypothesis is that organic farming promotes fungi growth, improving water repellency of soil aggregates by fungal hydrophobic substances. By contrast, we failed in the identification of C pools controlling the formation of aggregates, probably because of the disturbance of mechanical tillage which contributes to the breakdown of soil aggregates.The physically-based aggregate fractionation proposed in this study resulted useful in the  mechanistically understanding of the role of microorganisms in soil aggregation and it might be suggested for studying the impact of management on C pools, aggregates properties and their relationships in agricultural soils.

Patterns of [PSI+] aggregation allow insights into cellular organization of yeast prion aggregates

Science.gov (United States)

Tyedmers, Jens

2012-01-01

The yeast prion phenomenon is very widespread and mounting evidence suggests that it has an impact on cellular regulatory mechanisms related to phenotypic responses to changing environments. Studying the aggregation patterns of prion amyloids during different stages of the prion life cycle is a first key step to understand major principles of how and where cells generate, organize and turn-over prion aggregates. The induction of the [PSI+] state involves the actin cytoskeleton and quality control compartments such as the Insoluble Protein Deposit (IPOD). An initially unstable transitional induction state can be visualized by overexpression of the prion determinant and displays characteristic large ring- and ribbon-shaped aggregates consisting of poorly fragmented bundles of very long prion fibrils. In the mature prion state, the aggregation pattern is characterized by highly fragmented, shorter prion fibrils that form aggregates, which can be visualized through tagging with fluorescent proteins. The number of aggregates formed varies, ranging from a single large aggregate at the IPOD to multiple smaller ones, depending on several parameters discussed. Aggregate units below the resolution of light microscopy that are detectable by fluorescence correlation spectroscopy are in equilibrium with larger aggregates in this stage and can mediate faithful inheritance of the prion state. Loss of the prion state is often characterized by reduced fragmentation of prion fibrils and fewer, larger aggregates. PMID:22449721

Metacarpophalangeal joint of the thumb arthrodesis using intramedullary interlocking screws XMCP™.

Science.gov (United States)

Novoa-Parra, C N; Montaner-Alonso, D; Morales-Rodríguez, J

2017-09-04

The study objective was to assess the results of a thumb metacarpophalangeal joint (MCPJ) arthrodesis using intramedullary interlocking screws at 25°, XMCP ™ (Extremity Medical, Parsippany, NJ). Radiographs evaluated the angle of arthrodesis, time of fusion and fixation of the implant. Clinical and functional outcomes were assessed using the DASH questionnaire and the VAS scale. Any complications found during surgery or the follow-up period were noted. We studied 9 patients. The mean follow-up was 27.6 months. Patients showed clinical and radiological evidence of fusion in an average of 8 weeks, the angle of fusion was 25°. There were no complications and no implant had to be removed. The XMCP™ system provides a reliable method for MCPJ arthrodesis for several indications and can be used with other procedures in the complex hand. Copyright © 2017 SECOT. Publicado por Elsevier España, S.L.U. All rights reserved.

The use of microprocessors at TRIUMF in the control of radiation safety interlock systems

International Nuclear Information System (INIS)

King, L.

1988-01-01

At TRIUMF the cyclotron vault, all primary beam lines, and each experimental area has a dedicated control unit to manage the safety interlock control of the area lockup sequence, beam blocker drive and area access. Typically each area has 24 devices which are monitored to control 16 outputs. These control units (Area Safety Units) were first implemented through the use of relay logic. The relay logic was reliable but difficult to modify to incorporate changes to the areas. In 1979 it was decided to use microprocessors in the form of single board computers to control the Area Safety Units. The details of the hardware and software is discussed as well as the advantages of microprocessor control

Topological interlocking provides stiffness to stochastically micro-cracked materials beyond the transport percolation limit

Science.gov (United States)

Pal, Anirban; Picu, Catalin; Lupulescu, Marian V.

We study the mechanical behavior of two-dimensional, stochastically microcracked continua in the range of crack densities close to, and above the transport percolation threshold. We show that these materials retain stiffness up to crack densities much larger than the transport percolation threshold, due to topological interlocking of sample sub-domains. Even with a linear constitutive law for the continuum, the mechanical behavior becomes non-linear in the range of crack densities bounded by the transport and stiffness percolation thresholds. The effect is due to the fractal nature of the fragmentation process and is not linked to the roughness of individual cracks. We associate this behavior to that of itacolumite, a sandstone that exhibits unusual flexibility.

Interlocking multi-material components made of structured steel sheets and high-pressure die cast aluminium

Science.gov (United States)

Senge, S.; Brachmann, J.; Hirt, G.; Bührig-Polaczek, A.

2017-10-01

Lightweight design is a major driving force of innovation, especially in the automotive industry. Using hybrid components made of two or more different materials is one approach to reduce the vehicles weight and decrease fuel consumption. As a possible way to increase the stiffness of multi-material components, this paper presents a process chain to produce such components made of steel sheets and high-pressure die cast aluminium. Prior to the casting sequence the steel sheets are structured in a modified rolling process which enables continuous interlocking with the aluminium. Two structures manufactured by this rolling process are tested. The first one is a channel like structure and the second one is a channel like structure with undercuts. These undercuts enable the formation of small anchors when the molten aluminium fills them. The correlation between thickness reduction during rolling and the shape of the resulting structure was evaluated for both structures. It can be stated that channels with a depth of up to 0.5 mm and a width of 1 mm could be created. Undercuts with different size depending on the thickness reduction could be realised. Subsequent aluminium high-pressure die casting experiments were performed to determine if the surface structure can be filled gap-free with molten aluminium during the casting sequence and if a gap-free connection can be achieved after contraction of the aluminium. The casting experiments showed that both structures could be filled during the high-pressure die casting. The channel like structure results in a gap between steel and aluminium after contraction of the cast metal whereas the structure with undercuts leads to a good interlocking resulting in a gap-free connection.

Effect of aggregate graining compositions on skid resistance of Exposed Aggregate Concrete pavement

Science.gov (United States)

Wasilewska, Marta; Gardziejczyk, Wladysław; Gierasimiuk, Pawel

2018-05-01

The paper presents the evaluation of skid resistance of EAC (Exposed Aggregate Concrete) pavements which differ in aggregate graining compositions. The tests were carried out on concrete mixes with a maximum aggregate size of 8 mm. Three types of coarse aggregates were selected depending on their resistance to polishing which was determined on the basis of the PSV (Polished Stone Value). Basalt (PSV 48), gabbro (PSV 50) and trachybasalt (PSV 52) aggregates were chosen. For each type of aggregate three graining compositions were designed, which differed in the content of coarse aggregate > 4mm. Their content for each series was as follows: A - 38%, B - 50% and C - 68%. Evaluation of the skid resistance has been performed using the FAP (Friction After Polishing) test equipment also known as the Wehner/Schulze machine. Laboratory method enables to compare the skid resistance of different types of wearing course under specified conditions simulating polishing processes. In addition, macrotexture measurements were made on the surface of each specimen using the Elatexure laser profile. Analysis of variance showed that at significance level α = 0.05, aggregate graining compositions as well as the PSV have a significant influence on the obtained values of the friction coefficient μm of the tested EAC pavements. The highest values of the μm have been obtained for EAC with the lowest amount of coarse aggregates (compositions A). In these cases the resistance to polishing of the aggregate does not significantly affect the friction coefficients. This is related to the large areas of cement mortar between the exposed coarse grains. Based on the analysis of microscope images, it was observed that the coarse aggregates were not sufficiently exposed. It has been proved that PSV significantly affected the coefficient of friction in the case of compositions B and C. This is caused by large areas of exposed coarse aggregate. The best parameters were achieved for the EAC pavements

Concrete produced with recycled aggregates

Directory of Open Access Journals (Sweden)

J. J. L. Tenório

Full Text Available This paper presents the analysis of the mechanical and durable properties of recycled aggregate concrete (RAC for using in concrete. The porosity of recycled coarse aggregates is known to influence the fresh and hardened concrete properties and these properties are related to the specific mass of the recycled coarse aggregates, which directly influences the mechanical properties of the concrete. The recycled aggregates were obtained from construction and demolition wastes (CDW, which were divided into recycled sand (fine and coarse aggregates. Besides this, a recycled coarse aggregate of a specific mass with a greater density was obtained by mixing the recycled aggregates of the CDW with the recycled aggregates of concrete wastes (CW. The concrete was produced in laboratory by combining three water-cement ratios, the ratios were used in agreement with NBR 6118 for structural concretes, with each recycled coarse aggregates and recycled sand or river sand, and the reference concrete was produced with natural aggregates. It was observed that recycled aggregates can be used in concrete with properties for structural concrete. In general, the use of recycled coarse aggregate in combination with recycled sand did not provide good results; but when the less porous was used, or the recycled coarse aggregate of a specific mass with a greater density, the properties of the concrete showed better results. Some RAC reached bigger strengths than the reference concrete.

Graph Aggregation

NARCIS (Netherlands)

Endriss, U.; Grandi, U.

Graph aggregation is the process of computing a single output graph that constitutes a good compromise between several input graphs, each provided by a different source. One needs to perform graph aggregation in a wide variety of situations, e.g., when applying a voting rule (graphs as preference

Residual Heat Removal System qualitative probabilistic safety analysis before and after auto closure interlock removal

International Nuclear Information System (INIS)

Mikulicic, V.; Simic, Z.

1992-01-01

The analysis evaluates the consequences of the removal of the auto closure interlock (ACI) on the Residual Heat Removal System (RHRS) suction/isolation valves at the nuclear power plant. The deletion of the RHRS ACI is in part based on a probabilistic safety analysis (PSA) which justifies the removal based on a criterion of increased availability and reliability. Three different areas to be examined in PSA: the likelihood of an interfacing system LOCA; RHRS availability and reliability; and low temperature overpressurization control. The paper emphasizes particularly the RHRS unavailability and reliability evaluation utilizing the current control circuitry configuration and then with the proposed modification to the control circuitry. (author)

p53 Aggregates penetrate cells and induce the co-aggregation of intracellular p53.

Directory of Open Access Journals (Sweden)

Karolyn J Forget

Full Text Available Prion diseases are unique pathologies in which the infectious particles are prions, a protein aggregate. The prion protein has many particular features, such as spontaneous aggregation, conformation transmission to other native PrP proteins and transmission from an individual to another. Protein aggregation is now frequently associated to many human diseases, for example Alzheimer's disease, Parkinson's disease or type 2 diabetes. A few proteins associated to these conformational diseases are part of a new category of proteins, called prionoids: proteins that share some, but not all, of the characteristics associated with prions. The p53 protein, a transcription factor that plays a major role in cancer, has recently been suggested to be a possible prionoid. The protein has been shown to accumulate in multiple cancer cell types, and its aggregation has also been reproduced in vitro by many independent groups. These observations suggest a role for p53 aggregates in cancer development. This study aims to test the «prion-like» features of p53. Our results show in vitro aggregation of the full length and N-terminally truncated protein (p53C, and penetration of these aggregates into cells. According to our findings, the aggregates enter cells using macropinocytosis, a non-specific pathway of entry. Lastly, we also show that once internalized by the cell, p53C aggregates can co-aggregate with endogenous p53 protein. Together, these findings suggest prion-like characteristics for p53 protein, based on the fact that p53 can spontaneously aggregate, these aggregates can penetrate cells and co-aggregate with cellular p53.

An extreme-halophile archaebacterium possesses the interlock type of prephenate dehydratase characteristic of the Gram-positive eubacteria

Science.gov (United States)

Jensen, R. A.; d'Amato, T. A.; Hochstein, L. I.

1988-01-01

The focal point of phenylalanine biosynthesis is a dehydratase reaction which in different organisms may be prephenate dehydratase, arogenate dehydratase, or cyclohexadienyl dehydratase. Gram-positive, Gram-negative, and cyanobacterial divisions of the eubacterial kingdom exhibit different dehydratase patterns. A new extreme-halophile isolate, which grows on defined medium and is tentatively designated as Halobacterium vallismortis CH-1, possesses the interlock type of prephenate dehydratase present in Gram-positive bacteria. In addition to the conventional sensitivity to feedback inhibition by L-phenylalanine, the phenomenon of metabolic interlock was exemplified by the sensitivity of prephenate dehydratase to allosteric effects produced by extra-pathway (remote) effectors. Thus, L-tryptophan inhibited activity while L-tyrosine, L-methionine, L-leucine and L-isoleucine activated the enzyme. L-Isoleucine and L-phenylalanine were effective at micromolar levels; other effectors operated at mM levels. A regulatory mutant selected for resistance to growth inhibition caused by beta-2-thienylalanine possessed an altered prephenate dehydratase in which a phenomenon of disproportionately low activity at low enzyme concentration was abolished. Inhibition by L-tryptophan was also lost, and activation by allosteric activators was diminished. Not only was sensitivity to feedback inhibition by L-phenylalanine lost, but the mutant enzyme was now activated by this amino acid (a mutation type previously observed in Bacillus subtilis). It remains to be seen whether this type of prephenate dehydratase will prove to be characteristic of all archaebacteria or of some archaebacterial subgroup cluster.

Radiation interlocks - The choice between conventional hard-wired logic and computer-based systems

International Nuclear Information System (INIS)

Crook, K.F.

1987-01-01

During the past few years, the use of computers in radiation safety systems has become more widespread. This is not surprising given the ubiquitous nature of computers in the modern technological world. But is a computer a good choice for the central logic element of a personnel safety system? Recent accidents at computer controlled medical accelerators would indicate that extreme care must be exercised if malfunctions are to be avoided. The Department of Energy (DOE) has recently established a sub-committee to formulate recommendations on the use of computers in safety systems for accelerators. This paper reviews the status of the committee's recommendations, and describes radiation protection interlock systems as applied to both accelerators and to irradiation facilities. Comparisons are made between the conventional (relay) approach and designs using computers

Radiation interlocks: The choice between conventional hard-wired logic and computer-based systems

International Nuclear Information System (INIS)

Crook, K.F.

1986-11-01

During the past few years, the use of computers in radiation safety systems has become more widespread. This is not surprising given the ubiquitous nature of computers in the modern technological world. But is a computer a good choice for the central logic element of a personnel safety system. Recent accidents at computer controlled medical accelerators would indicate that extreme care must be exercised if malfunctions are to be avoided. The Department of Energy has recently established a sub-committee to formulate recommendations on the use of computers in safety systems for accelerators. This paper will review the status of the committee's recommendations, and describe radiation protection interlock systems as applied to both accelerators and to irradiation facilities. Comparisons are made between the conventional relay approach and designs using computers. 6 refs., 6 figs

Information Aggregation in Organizations

OpenAIRE

Schulte, Elisabeth

2006-01-01

This dissertation contributes to the analysis of information aggregation procedures within organizations. Facing uncertainty about the consequences of a collective decision, information has to be aggregated before making a choice. Two main questions are addressed. Firstly, how well is an organization suited for the aggregation of decision-relevant information? Secondly, how should an organization be designed in order to aggregate information efficiently? The main part deals with information a...

A Novel Method to Quantify Soil Aggregate Stability by Measuring Aggregate Bond Energies

Science.gov (United States)

Efrat, Rachel; Rawlins, Barry G.; Quinton, John N.; Watts, Chris W.; Whitmore, Andy P.

2016-04-01

Soil aggregate stability is a key indicator of soil quality because it controls physical, biological and chemical functions important in cultivated soils. Micro-aggregates are responsible for the long term sequestration of carbon in soil, therefore determine soils role in the carbon cycle. It is thus vital that techniques to measure aggregate stability are accurate, consistent and reliable, in order to appropriately manage and monitor soil quality, and to develop our understanding and estimates of soil as a carbon store to appropriately incorporate in carbon cycle models. Practices used to assess the stability of aggregates vary in sample preparation, operational technique and unit of results. They use proxies and lack quantification. Conflicting results are therefore drawn between projects that do not provide methodological or resultant comparability. Typical modern stability tests suspend aggregates in water and monitor fragmentation upon exposure to an un-quantified amount of ultrasonic energy, utilising a laser granulometer to measure the change in mean weight diameter. In this project a novel approach has been developed based on that of Zhu et al., (2009), to accurately quantify the stability of aggregates by specifically measuring their bond energies. The bond energies are measured operating a combination of calorimetry and a high powered ultrasonic probe, with computable output function. Temperature change during sonication is monitored by an array of probes which enables calculation of the energy spent heating the system (Ph). Our novel technique suspends aggregates in heavy liquid lithium heteropolytungstate, as opposed to water, to avoid exposing aggregates to an immeasurable disruptive energy source, due to cavitation, collisions and clay swelling. Mean weight diameter is measured by a laser granulometer to monitor aggregate breakdown after successive periods of calculated ultrasonic energy input (Pi), until complete dispersion is achieved and bond

Curcumin Attenuates Amyloid-β Aggregate Toxicity and Modulates Amyloid-β Aggregation Pathway.

Science.gov (United States)

Thapa, Arjun; Jett, Stephen D; Chi, Eva Y

2016-01-20

The abnormal misfolding and aggregation of amyloid-β (Aβ) peptides into β-sheet enriched insoluble deposits initiates a cascade of events leading to pathological processes and culminating in cognitive decline in Alzheimer's disease (AD). In particular, soluble oligomeric/prefibrillar Aβ have been shown to be potent neurotoxins. The naturally occurring polyphenol curcumin has been shown to exert a neuroprotective effect against age-related neurodegenerative diseases such as AD. However, its protective mechanism remains unclear. In this study, we investigated the effects of curcumin on the aggregation of Aβ40 as well as Aβ40 aggregate induced neurotoxicity. Our results show that the curcumin does not inhibit Aβ fibril formation, but rather enriches the population of "off-pathway" soluble oligomers and prefibrillar aggregates that were nontoxic. Curcumin also exerted a nonspecific neuroprotective effect, reducing toxicities induced by a range of Aβ conformers, including monomeric, oligomeric, prefibrillar, and fibrillar Aβ. The neuroprotective effect is possibly membrane-mediated, as curcumin reduced the extent of cell membrane permeabilization induced by Aβ aggregates. Taken together, our study shows that curcumin exerts its neuroprotective effect against Aβ induced toxicity through at least two concerted pathways, modifying the Aβ aggregation pathway toward the formation of nontoxic aggregates and ameliorating Aβ-induced toxicity possibly through a nonspecific pathway.

Recycled aggregates concrete: aggregate and mix properties

Directory of Open Access Journals (Sweden)

González-Fonteboa, B.

2005-09-01

Full Text Available This study of structural concrete made with recycled concrete aggregate focuses on two issues: 1. The characterization of such aggregate on the Spanish market. This involved conducting standard tests to determine density, water absorption, grading, shape, flakiness and hardness. The results obtained show that, despite the considerable differences with respect to density and water absorption between these and natural aggregates, on the whole recycled aggregate is apt for use in concrete production. 2. Testing to determine the values of basic concrete properties: mix design parameters were established for structural concrete in non-aggressive environments. These parameters were used to produce conventional concrete, and then adjusted to manufacture recycled concrete aggregate (RCA concrete, in which 50% of the coarse aggregate was replaced by the recycled material. Tests were conducted to determine the physical (density of the fresh and hardened material, water absorption and mechanical (compressive strength, splitting tensile strength and modulus of elasticity properties. The results showed that, from the standpoint of its physical and mechanical properties, concrete in which RCA accounted for 50% of the coarse aggregate compared favourably to conventional concrete.

Se aborda el estudio de hormigones estructurales fabricados con áridos reciclados procedentes de hormigón, incidiéndose en dos aspectos: 1. Caracterización de tales áridos, procedentes del mercado español. Para ello se llevan a cabo ensayos de densidad, absorción, granulometría, coeficiente de forma, índice de lajas y dureza. Los resultados obtenidos han puesto de manifiesto que, a pesar de que existen diferencias notables (sobre todo en cuanto a densidad y absorción con los áridos naturales, las características de los áridos hacen posible la fabricación de hormigones. 2. Ensayos sobre propiedades básicas de los hormigones: se establecen parámetros de dosificaci

Towards General Temporal Aggregation

DEFF Research Database (Denmark)

Boehlen, Michael H.; Gamper, Johann; Jensen, Christian Søndergaard

2008-01-01

associated with the management of temporal data. Indeed, temporal aggregation is complex and among the most difficult, and thus interesting, temporal functionality to support. This paper presents a general framework for temporal aggregation that accommodates existing kinds of aggregation, and it identifies...

D0 Central Tracking Solenoid Energization, Controls, Interlocks and Quench Protection Initial Validation Procedures

International Nuclear Information System (INIS)

Jaskierny, W.; Hance, R.

1998-01-01

This note presents the inspection and tests to be performed on the DZERO solenoid energization, controls, interlocks and quench protection system before it is energized for the first time. This test is to be performed with a 5000A jumper at the end of the bus instead of the solenoid. This system is based in DZERO room 511. A copy of this note shall be annotated, signed and dated by the person coordinating the procedure; and filed with the system maintenance records. Annotations shall include comments about any aspect of the procedure that is abnormal or unsuccessful. The following inspections and tests shall be performed by persons knowledgeable about the system. Each individual test step should be reviewed and understood before proceeding with that step.

Heavy vehicle simulator (HVS) evaluation of load transfer efficiency and continuously reinforced concrete inlays on the N3 near Pietermartizburg

CSIR Research Space (South Africa)

Du Plessis, L

2006-07-01

Full Text Available The paper addresses two different heavy Vehicle Simulator (HVS) studies conducted on concrete: Load transfer through aggregate interlock and the use of dowels and the evaluation of the performance of an in-service continuously reinforced concrete...

Modeling of hot-mix asphalt compaction : a thermodynamics-based compressible viscoelastic model

Science.gov (United States)

2010-12-01

Compaction is the process of reducing the volume of hot-mix asphalt (HMA) by the application of external forces. As a result of compaction, the volume of air voids decreases, aggregate interlock increases, and interparticle friction increases. The qu...

Proteins aggregation and human diseases

International Nuclear Information System (INIS)

Hu, Chin-Kun

2015-01-01

Many human diseases and the death of most supercentenarians are related to protein aggregation. Neurodegenerative diseases include Alzheimer's disease (AD), Huntington's disease (HD), Parkinson's disease (PD), frontotemporallobar degeneration, etc. Such diseases are due to progressive loss of structure or function of neurons caused by protein aggregation. For example, AD is considered to be related to aggregation of Aβ40 (peptide with 40 amino acids) and Aβ42 (peptide with 42 amino acids) and HD is considered to be related to aggregation of polyQ (polyglutamine) peptides. In this paper, we briefly review our recent discovery of key factors for protein aggregation. We used a lattice model to study the aggregation rates of proteins and found that the probability for a protein sequence to appear in the conformation of the aggregated state can be used to determine the temperature at which proteins can aggregate most quickly. We used molecular dynamics and simple models of polymer chains to study relaxation and aggregation of proteins under various conditions and found that when the bending-angle dependent and torsion-angle dependent interactions are zero or very small, then protein chains tend to aggregate at lower temperatures. All atom models were used to identify a key peptide chain for the aggregation of insulin chains and to find that two polyQ chains prefer anti-parallel conformation. It is pointed out that in many cases, protein aggregation does not result from protein mis-folding. A potential drug from Chinese medicine was found for Alzheimer's disease. (paper)

Proteins aggregation and human diseases

Science.gov (United States)

Hu, Chin-Kun

2015-04-01

Many human diseases and the death of most supercentenarians are related to protein aggregation. Neurodegenerative diseases include Alzheimer's disease (AD), Huntington's disease (HD), Parkinson's disease (PD), frontotemporallobar degeneration, etc. Such diseases are due to progressive loss of structure or function of neurons caused by protein aggregation. For example, AD is considered to be related to aggregation of Aβ40 (peptide with 40 amino acids) and Aβ42 (peptide with 42 amino acids) and HD is considered to be related to aggregation of polyQ (polyglutamine) peptides. In this paper, we briefly review our recent discovery of key factors for protein aggregation. We used a lattice model to study the aggregation rates of proteins and found that the probability for a protein sequence to appear in the conformation of the aggregated state can be used to determine the temperature at which proteins can aggregate most quickly. We used molecular dynamics and simple models of polymer chains to study relaxation and aggregation of proteins under various conditions and found that when the bending-angle dependent and torsion-angle dependent interactions are zero or very small, then protein chains tend to aggregate at lower temperatures. All atom models were used to identify a key peptide chain for the aggregation of insulin chains and to find that two polyQ chains prefer anti-parallel conformation. It is pointed out that in many cases, protein aggregation does not result from protein mis-folding. A potential drug from Chinese medicine was found for Alzheimer's disease.

[The monorail system--bone segment transport over unreamed interlocking nails].

Science.gov (United States)

Oedekoven, G; Jansen, D; Raschke, M; Claudi, B F

1996-11-01

A treatment protocol is demonstrated, consisting of an osteotomy, either proximal or distal, of the bone defect with subsequent segmental transport via an anteromedially (tibia) or laterally (femur) mounted AO external fixation over an unreamed interlocking nail (monorail system). Twenty patients were treated by this method with indications as follows: 13 had a segmental bone defect of the tibia, 3 of the femur. Three patients showed post-traumatic and postinfectious leg-length discrepancies and one was treated for hypertrophic non-union of the femur. Defect distance varied between 5 and 18.5 cm and average time for transport was 19,42 days/ cm for the tibial shaft, 15,93 days/cm for the femur. Two patients developed deep infection, which required change of treatment, removing the monorail system and application of an Ilizarov apparatus. Despite complications using the monorail system, all patients healed and no amputations were required. The monorail system can be used as an alternative to the Ilizarov method under certain criteria of patient selection; these criteria are shown by an algorithm for segmental bone defects without infection, respecting the soft-tissue status with or without neurovascular compromise.

Shielding of the patient's gonads during intramedullary interlocking femoral nailing.

Science.gov (United States)

Kwong, L M; Johanson, P H; Zinar, D M; Lenihan, M R; Herman, M W

1990-12-01

Levels of exposure to radiation were recorded at sixty sites in fifteen patients during intramedullary interlocking femoral nailing. Radiation film dosimeters were placed at four gonadal sites on each subject. A standard male-gonad cup or a pelvic drape of 0.5-millimeter-thick lead-equivalent was put in place to shield the gonads. A second set of four dosimeters was placed external to the shield to approximate unprotected exposure. The total duration of the fluoroscopy averaged five minutes (range, thirty seconds to fourteen minutes). The total exposure to radiation external to the shield was 35 +/- 34 millirems at the male gonadal sites and 17 +/- 11 millirems at the female gonadal sites. With use of the gonadal shield, exposure to radiation was not measurable in thirteen of the fifteen patients. The differences between the exposures of the shielded and unshielded sites to radiation were statistically significant (p less than 0.001). The highest level of gonadal exposure was found with the treatment of proximal femoral fractures and with the use of statically locked nails. Regardless of the conditions, and for all types of fractures and locations, our results demonstrated that gonadal shielding is justified.

Shielding of the patient's gonads during intramedullary interlocking femoral nailing

International Nuclear Information System (INIS)

Kwong, L.M.; Johanson, P.H.; Zinar, D.M.; Lenihan, M.R.; Herman, M.W.

1990-01-01

Levels of exposure to radiation were recorded at sixty sites in fifteen patients during intramedullary interlocking femoral nailing. Radiation film dosimeters were placed at four gonadal sites on each subject. A standard male-gonad cup or a pelvic drape of 0.5-millimeter-thick lead-equivalent was put in place to shield the gonads. A second set of four dosimeters was placed external to the shield to approximate unprotected exposure. The total duration of the fluoroscopy averaged five minutes (range, thirty seconds to fourteen minutes). The total exposure to radiation external to the shield was 35 +/- 34 millirems at the male gonadal sites and 17 +/- 11 millirems at the female gonadal sites. With use of the gonadal shield, exposure to radiation was not measurable in thirteen of the fifteen patients. The differences between the exposures of the shielded and unshielded sites to radiation were statistically significant (p less than 0.001). The highest level of gonadal exposure was found with the treatment of proximal femoral fractures and with the use of statically locked nails. Regardless of the conditions, and for all types of fractures and locations, our results demonstrated that gonadal shielding is justified

Tibiotalocalcaneal arthrodesis with a curved, interlocking, intramedullary nail.

Science.gov (United States)

Budnar, Vijaya M; Hepple, Steve; Harries, William G; Livingstone, James A; Winson, Ian

2010-12-01

Tibiotalocalcaneal fusion with a straight rod has a risk of damaging the lateral plantar neurovascular structures and may interfere with maintaining normal heel valgus position.We report the results of a prospective study of tibiotalocalcaneal (TTC) arthrodesis with a short, anatomically curved interlocking, intramedullary nail. Forty-five arthrodesis in 42 patients, performed between Jan 2003 and Oct 2008, were prospectively followed. The mean followup was 48 (range, 10 to 74) months. The main indications for the procedure were failed ankle arthrodesis with progressive subtalar arthritis, failed ankle arthroplasty and complex hindfoot deformity. The outcome was measured by a combination of pre and postoperative clinical examination, AOFAS hindfoot scores, SF-12 scores and radiological assessment. Union rate was 89% (40/45). Eighty-two percent (37/45) reported improvement in pain and 73% (33/45) had improved foot function. Satisfactory hindfoot alignment was achieved in 84% (38/45). Postoperatively there was a mean improvement in the AOFAS score of 37. Complications included a below knee amputation for persistent deep infection, five nonunions, and three delayed unions. Four nails, six proximal and six distal locking screws were removed for various causes. Other complications included two perioperative fractures, four superficial wound infections and one case of lateral plantar nerve irritation. With a short, anatomically curved intramedullary nail, we had a high rate of tibiotalocalcaneal fusion with minimal plantar neurovascular complications. We believe a short, curved intramedullary nail, with its more lateral entry point, helped maintain hindfoot alignment.

Control/interlock/display system for EBT-P using commercially-available hardware and firmware

International Nuclear Information System (INIS)

Schmitt, R.J.

1983-01-01

For the EBT-P project, alternative commercially-available hardware, software and firmware have been employed for control, interlock and data display functions. This paper describes the criteria and rationale used to select that commercial equipment and discusses the important features of the equipment chosen, especially programmable controllers. Additional discussion is centered on interface problems which are encountered upon attempts to integrate equipment from several vendors. Some solutions to these problems are discussed. Details of software and hardware performance during tests are presented. The extent to which the EBT-P hardware and software configuration addresses and resolves various issues is discussed. Several areas have been uncovered in which relatively slight improvements/modifications of commercial programmable controller firmware would significantly improve the capability of this type of hardware in fusion control applications. These improvements are discussed in detail

Denitrification in Soil Aggregate Analogues-Effect of Aggregate Size and Oxygen Diffusion

Directory of Open Access Journals (Sweden)

Steffen Schlüter

2018-04-01

Full Text Available Soil-borne nitrous oxide (N2O emissions have a high spatial and temporal variability which is commonly attributed to the occurrence of hotspots and hot moments for microbial activity in aggregated soil. Yet there is only limited information about the biophysical processes that regulate the production and consumption of N2O on microscopic scales in undisturbed soil. In this study, we introduce an experimental framework relying on simplified porous media that circumvents some of the complexities occuring in natural soils while fully accounting for physical constraints believed to control microbial activity in general and denitrification in particular. We used this framework to explore the impact of aggregate size and external oxygen concentration on the kinetics of O2 consumption, as well as CO2 and N2O production. Model aggregates of different sizes (3.5 vs. 7 mm diameter composed of porous, sintered glass were saturated with a defined growth medium containing roughly 109 cells ml−1 of the facultative anaerobic, nosZ-deficient denitrifier Agrobacterium tumefaciens with N2O as final denitrification product and incubated at five different oxygen levels (0–13 vol-%. We demonstrate that the onset of denitrification depends on the amount of external oxygen and the size of aggregates. Smaller aggregates were better supplied with oxygen due to a larger surface-to-volume ratio, which resulted in faster growth and an earlier onset of denitrification. In larger aggregates, the onset of denitrification was more gradual, but with comparably higher N2O production rates once the anoxic aggregate centers were fully developed. The normalized electron flow from the reduced carbon substrate to N-oxyanions (edenit-/etotal- ratio could be solely described as a function of initial oxygen concentration in the headspace with a simple, hyperbolic model, for which the two empirical parameters changed with aggregate size in a consistent way. These findings confirm the

Utilização de agregados reciclados em pavimentos intertravados

OpenAIRE

Daniel Simieli; Camilo Mizumoto; Antônio Anderson da Silva Segantini; Flávio Moreira Salles

2007-01-01

The destination of the construction waste is a problem that becomes worse as the time goes by, and that affects the environmental conditions, with consequences for whole society. In this work, aiming to minimize the environmental impact caused by these residues, it was studied the use of recycled aggregates in the composition of interlocking pavement. Laboratory rehearsals were performed to evaluate the behavior of this concrete manufactured with recycled aggregates...

Measurement of the ground-state distributions in bistable mechanically interlocked molecules using slow scan rate cyclic voltammetry.

Science.gov (United States)

Fahrenbach, Albert C; Barnes, Jonathan C; Li, Hao; Benítez, Diego; Basuray, Ashish N; Fang, Lei; Sue, Chi-Hau; Barin, Gokhan; Dey, Sanjeev K; Goddard, William A; Stoddart, J Fraser

2011-12-20

In donor-acceptor mechanically interlocked molecules that exhibit bistability, the relative populations of the translational isomers--present, for example, in a bistable [2]rotaxane, as well as in a couple of bistable [2]catenanes of the donor-acceptor vintage--can be elucidated by slow scan rate cyclic voltammetry. The practice of transitioning from a fast scan rate regime to a slow one permits the measurement of an intermediate redox couple that is a function of the equilibrium that exists between the two translational isomers in the case of all three mechanically interlocked molecules investigated. These intermediate redox potentials can be used to calculate the ground-state distribution constants, K. Whereas, (i) in the case of the bistable [2]rotaxane, composed of a dumbbell component containing π-electron-rich tetrathiafulvalene and dioxynaphthalene recognition sites for the ring component (namely, a tetracationic cyclophane, containing two π-electron-deficient bipyridinium units), a value for K of 10 ± 2 is calculated, (ii) in the case of the two bistable [2]catenanes--one containing a crown ether with tetrathiafulvalene and dioxynaphthalene recognition sites for the tetracationic cyclophane, and the other, tetrathiafulvalene and butadiyne recognition sites--the values for K are orders (one and three, respectively) of magnitude greater. This observation, which has also been probed by theoretical calculations, supports the hypothesis that the extra stability of one translational isomer over the other is because of the influence of the enforced side-on donor-acceptor interactions brought about by both π-electron-rich recognition sites being part of a macrocyclic polyether.

Effect of the Aggregate Size on Strength Properties of Recycled Aggregate Concrete

Directory of Open Access Journals (Sweden)

Ma Kang

2018-01-01

Full Text Available The study on preparation technology of recycled concrete with economical and technical feasibility has gained more serious attention in each country due to its involvement and effect on the environment protection and the sustainable development of human society. In this study, we conducted a control variable test to investigate and assess the influence of the aggregate size on the strength characteristics of concrete with different diameters of recycled aggregates. Concrete with recycled aggregates of 5∼15 mm (A, 15∼20 mm (B, 20∼30 mm (C, and their combinations were subjected to a series of unconfined pressure tests after curing for 28 days. Based on the results obtained from the tests, an effort was made to study the relationship between the mechanical characteristics of recycled aggregate concrete and aggregate particle size. Also, a regression model of recycled concrete was proposed to predict the elasticity modulus and to adjust the design of mixture proportion. It is believed that these experiment results would contribute to adjust the remediation mixture for recycling plants by considering the influence of recycled aggregate size.

Oil-Price Shocks: Beyond Standard Aggregate Demand/Aggregate Supply Analysis.

Science.gov (United States)

Elwood, S. Kirk

2001-01-01

Explores the problems of portraying oil-price shocks using the aggregate demand/aggregate supply model. Presents a simple modification of the model that differentiates between production and absorption of goods, which enables it to better reflect the effects of oil-price shocks on open economies. (RLH)

A bio-inspired swellable microneedle adhesive for mechanical interlocking with tissue

Science.gov (United States)

Yang, Seung Yun; O'Cearbhaill, Eoin D.; Sisk, Geoffroy C.; Park, Kyeng Min; Cho, Woo Kyung; Villiger, Martin; Bouma, Brett E.; Pomahac, Bohdan; Karp, Jeffrey M.

2013-04-01

Achieving significant adhesion to soft tissues while minimizing tissue damage poses a considerable clinical challenge. Chemical-based adhesives require tissue-specific reactive chemistry, typically inducing a significant inflammatory response. Staples are fraught with limitations including high-localized tissue stress and increased risk of infection, and nerve and blood vessel damage. Here inspired by the endoparasite Pomphorhynchus laevis, which swells its proboscis to attach to its host’s intestinal wall, we have developed a biphasic microneedle array that mechanically interlocks with tissue through swellable microneedle tips, achieving ~3.5-fold increase in adhesion strength compared with staples in skin graft fixation, and removal force of ~4.5 N cm-2 from intestinal mucosal tissue. Comprising a poly(styrene)-block-poly(acrylic acid) swellable tip and non-swellable polystyrene core, conical microneedles penetrate tissue with minimal insertion force and depth, yet high adhesion strength in their swollen state. Uniquely, this design provides universal soft tissue adhesion with minimal damage, less traumatic removal, reduced risk of infection and delivery of bioactive therapeutics.

The community structure of the European network of interlocking directorates 2005-2010.

Directory of Open Access Journals (Sweden)

Eelke M Heemskerk

Full Text Available The boards of directors at large European companies overlap with each other to a sizable extent both within and across national borders. This could have important economic, political and management consequences. In this work we study in detail the topological structure of the networks that arise from this phenomenon. Using a comprehensive information database, we reconstruct the implicit networks of shared directorates among the top 300 European firms in 2005 and 2010, and suggest a number of novel ways to explore the trans-nationality of such business elite networks. Powerful community detection heuristics indicate that geography still plays an important role: there exist clear communities and they have a distinct national character. Nonetheless, from 2005 to 2010 we observe a densification of the boards interlocks network and a larger transnational orientation in its communities. Together with central actors and assortativity analyses, we provide statistical evidence that, at the level of corporate governance, Europe is getting closer.

The community structure of the European network of interlocking directorates 2005-2010.

Science.gov (United States)

Heemskerk, Eelke M; Daolio, Fabio; Tomassini, Marco

2013-01-01

The boards of directors at large European companies overlap with each other to a sizable extent both within and across national borders. This could have important economic, political and management consequences. In this work we study in detail the topological structure of the networks that arise from this phenomenon. Using a comprehensive information database, we reconstruct the implicit networks of shared directorates among the top 300 European firms in 2005 and 2010, and suggest a number of novel ways to explore the trans-nationality of such business elite networks. Powerful community detection heuristics indicate that geography still plays an important role: there exist clear communities and they have a distinct national character. Nonetheless, from 2005 to 2010 we observe a densification of the boards interlocks network and a larger transnational orientation in its communities. Together with central actors and assortativity analyses, we provide statistical evidence that, at the level of corporate governance, Europe is getting closer.

The New Control and Interlock System for the SPS Main Power Converters

CERN Document Server

Denis, B; Mugnier, C; Varas, J

1999-01-01

The Control and Interlock System (CIS) of the SPS main power converters was designed in the mid-70s and became increasingly difficult to maintain. A new system based on Programmable Logic Controllers has been developed by an external contractor in close collaboration with CERN. The system is now operational and fully integrated in the SPS/LEP control infrastructure. The CIS is the first major contracted industrial solution used to control accelerator equipment directly involved in the production of particle beams at CERN. This paper gives an overview of the SPS main power converter installation and describes both the contractual and technical solution adopted for the CIS. It first explains how the system was specified and how the contractual relationship was defined to respect CERN’s purchasing rules and the operational requirements of the SPS accelerator. The architectural design of the new system is presented with special emphasis on how the conflict between safety and availability has been addressed.

Photo-induced reorganization of molecular packing of amphi-PIC J-aggregates (single J-aggregate spectroscopy)

International Nuclear Information System (INIS)

Malyukin, Yu.V.; Sorokin, A.V.; Yefimova, S.L.; Lebedenko, A.N.

2005-01-01

Confocal luminescence microscopy has been used to excite and collect luminescence from single amphi-PIC J-aggregate. Two types of J-aggregates have been revealed in the luminescence image: bead-like J-aggregates, which diameter is less than 1 μm and rod-like ones, which length is about 3 μm and diameter is less than 1 μm. It has been found that single rod-like and bead-like J-aggregates exhibit different luminescence bands with different decay parameters. At the off-resonance blue tail excitation, the J-aggregate exciton luminescence disappeared within a certain time period and a new band appeared, which cannot be attributed to the monomer emission. The luminescence image shows that the J-aggregate is not destroyed. However, J-aggregate storage in darkness does not recover its exciton luminescence

Studies on recycled aggregates-based concrete.

Science.gov (United States)

Rakshvir, Major; Barai, Sudhirkumar V

2006-06-01

Reduced extraction of raw materials, reduced transportation cost, improved profits, reduced environmental impact and fast-depleting reserves of conventional natural aggregates has necessitated the use of recycling, in order to be able to conserve conventional natural aggregate. In this study various physical and mechanical properties of recycled concrete aggregates were examined. Recycled concrete aggregates are different from natural aggregates and concrete made from them has specific properties. The percentages of recycled concrete aggregates were varied and it was observed that properties such as compressive strength showed a decrease of up to 10% as the percentage of recycled concrete aggregates increased. Water absorption of recycled aggregates was found to be greater than natural aggregates, and this needs to be compensated during mix design.

An exact approach for aggregated formulations

DEFF Research Database (Denmark)

Gamst, Mette; Spoorendonk, Simon; Røpke, Stefan

Aggregating formulations is a powerful approach for problems to take on tractable forms. Aggregation may lead to loss of information, i.e. the aggregated formulation may be an approximation of the original problem. In branch-and-bound context, aggregation can also complicate branching, e.g. when...... optimality cannot be guaranteed by branching on aggregated variables. We present a generic exact solution method to remedy the drawbacks of aggregation. It combines the original and aggregated formulations and applies Benders' decomposition. We apply the method to the Split Delivery Vehicle Routing Problem....

Theoretical Review on Corporate Governance and Performance of Interlocking Director%连锁董事对公司治理与企业绩效影响的理论综述

Institute of Scientific and Technical Information of China (English)

宋晓琳

2013-01-01

同时在两家或多家企业的董事会中任职的同一名董事被称为连锁董事。这一现象在我国公司中极为普遍，然而，我国学术界对其展开的研究却极其匮乏。在我国转型时期经济环境背景下，以公司间的连锁董事现象为线索，通过对连锁董事的公司治理与绩效影响进行理论和实证研究，验证和拓展了公司治理理论。%A director working for two or more enterprises is referred to as an interlocking director. This phenomenon is very common in China,however,academic studies on this can hardly be found. Based on the economic environment in China’s transition period,taking the phenomenon of interlocking director among companies as a clue,the paper studies the corporate governance and performance impact of interlocking director by theoretical and empirical research,validates and expands the corporate governance theory.

Properties of Concrete with Tire Derived Aggregate Partially Replacing Coarse Aggregates.

Science.gov (United States)

Siringi, Gideon; Abolmaali, Ali; Aswath, Pranesh B

2015-01-01

Tire derived aggregate (TDA) has been proposed as a possible lightweight replacement for mineral aggregate in concrete. The role played by the amount of TDA replacing coarse aggregate as well as different treatment and additives in concrete on its properties is examined. Conventional concrete (without TDA) and concrete containing TDA are compared by examining their compressive strength based on ASTM C39, workability based on ASTM C143, splitting tensile strength based on ASTM C496, modulus of rupture (flexural strength) based on ASTM C78, and bond stress based on ASTM C234. Results indicate that while replacement of coarse aggregates with TDA results in reduction in strength, it may be mitigated with addition of silica fume to obtain the desired strength. The greatest benefit of using TDA is in the development of a higher ductile product while utilizing recycled TDA.

Protein aggregate turbidity: Simulation of turbidity profiles for mixed-aggregation reactions.

Science.gov (United States)

Hall, Damien; Zhao, Ran; Dehlsen, Ian; Bloomfield, Nathaniel; Williams, Steven R; Arisaka, Fumio; Goto, Yuji; Carver, John A

2016-04-01

Due to their colloidal nature, all protein aggregates scatter light in the visible wavelength region when formed in aqueous solution. This phenomenon makes solution turbidity, a quantity proportional to the relative loss in forward intensity of scattered light, a convenient method for monitoring protein aggregation in biochemical assays. Although turbidity is often taken to be a linear descriptor of the progress of aggregation reactions, this assumption is usually made without performing the necessary checks to provide it with a firm underlying basis. In this article, we outline utilitarian methods for simulating the turbidity generated by homogeneous and mixed-protein aggregation reactions containing fibrous, amorphous, and crystalline structures. The approach is based on a combination of Rayleigh-Gans-Debye theory and approximate forms of the Mie scattering equations. Crown Copyright © 2015. Published by Elsevier Inc. All rights reserved.

Aggregates from mineral wastes

Directory of Open Access Journals (Sweden)

Baic Ireneusz

2016-01-01

Full Text Available The problem concerning the growing demand for natural aggregates and the need to limit costs, including transportation from remote deposits, cause the increase in growth of interest in aggregates from mineral wastes as well as in technologies of their production and recovery. The paper presents the issue related to the group of aggregates other than natural. A common name is proposed for such material: “alternative aggregates”. The name seems to be fully justified due to adequacy of this term because of this raw materials origin and role, in comparison to the meaning of natural aggregates based on gravel and sand as well as crushed stones. The paper presents characteristics of the market and basic application of aggregates produced from mineral wastes, generated in the mining, power and metallurgical industries as well as material from demolished objects.

Aggregated Computational Toxicology Online Resource

Data.gov (United States)

U.S. Environmental Protection Agency — Aggregated Computational Toxicology Online Resource (AcTOR) is EPA's online aggregator of all the public sources of chemical toxicity data. ACToR aggregates data...

Aggregation and pH-temperature phase behavior for aggregates of an IgG2 antibody.

Science.gov (United States)

Sahin, Erinc; Weiss, William F; Kroetsch, Andrew M; King, Kevin R; Kessler, R Kendall; Das, Tapan K; Roberts, Christopher J

2012-05-01

Monomer unfolding and thermally accelerated aggregation kinetics to produce soluble oligomers or insoluble macroscopic aggregates were characterized as a function of pH for an IgG2 antibody using differential scanning calorimetry (DSC) and size-exclusion chromatography (SEC). Aggregate size was quantified via laser light scattering, and aggregate solubility via turbidity and visual inspection. Interestingly, nonnative oligomers were soluble at pH 5.5 above approximately 15°C, but converted reversibly to visible/insoluble particles at lower temperatures. Lower pH values yielded only soluble aggregates, whereas higher pH resulted in insoluble aggregates, regardless of the solution temperature. Unlike the growing body of literature that supports the three-endotherm model of IgG1 unfolding in DSC, the results here also illustrate limitations of that model for other monoclonal antibodies. Comparison of DSC with monomer loss (via SEC) from samples during thermal scanning indicates that the least conformationally stable domain is not the most aggregation prone, and that a number of the domains remain intact within the constituent monomers of the resulting aggregates. This highlights continued challenges with predicting a priori which domain(s) or thermal transition(s) is(are) most relevant for product stability with respect to aggregation. Copyright © 2012 Wiley Periodicals, Inc.

Combined Non-destructive Testing (NDT) methods for evaluating concrete quality

International Nuclear Information System (INIS)

Mohamad Pauzi Ismail; Noor Azreen Masenwat; Suhairy Sani; Nasharuddin Isa; Mohamad Haniza Mahmud

2014-01-01

This paper described the results of combining Non-destructive measurements on concrete. Local crushed granite and hematite were used as coarse aggregates; mining sand and river sand were used as fine aggregates to produce various density and strength of concrete. Concrete samples (150 mm cubes and interlocked blocks) were prepared by changing mix ratio, water to cement ratio (w/c) and types of aggregates. Density, rebound number(N) and ultrasonic pulse velocity (UPV) of the samples were taken before compressed to failure. The measurement results are explained and discussed. (author)

Ground-state thermodynamics of bistable redox-active donor-acceptor mechanically interlocked molecules.

Science.gov (United States)

Fahrenbach, Albert C; Bruns, Carson J; Cao, Dennis; Stoddart, J Fraser

2012-09-18

Fashioned through billions of years of evolution, biological molecular machines, such as ATP synthase, myosin, and kinesin, use the intricate relative motions of their components to drive some of life's most essential processes. Having control over the motions in molecules is imperative for life to function, and many chemists have designed, synthesized, and investigated artificial molecular systems that also express controllable motions within molecules. Using bistable mechanically interlocked molecules (MIMs), based on donor-acceptor recognition motifs, we have sought to imitate the sophisticated nanoscale machines present in living systems. In this Account, we analyze the thermodynamic characteristics of a series of redox-switchable [2]rotaxanes and [2]catenanes. Control and understanding of the relative intramolecular movements of components in MIMs have been vital in the development of a variety of applications of these compounds ranging from molecular electronic devices to drug delivery systems. These bistable donor-acceptor MIMs undergo redox-activated switching between two isomeric states. Under ambient conditions, the dominant translational isomer, the ground-state coconformation (GSCC), is in equilibrium with the less favored translational isomer, the metastable-state coconformation (MSCC). By manipulating the redox state of the recognition site associated with the GSCC, we can stimulate the relative movements of the components in these bistable MIMs. The thermodynamic parameters of model host-guest complexes provide a good starting point to rationalize the ratio of GSCC to MSCC at equilibrium. The bistable [2]rotaxanes show a strong correlation between the relative free energies of model complexes and the ground-state distribution constants (K(GS)). This relationship does not always hold for bistable [2]catenanes, most likely because of the additional steric and electronic constraints present when the two rings are mechanically interlocked with each other

Properties of Concrete with Tire Derived Aggregate Partially Replacing Coarse Aggregates

Science.gov (United States)

Siringi, Gideon; Abolmaali, Ali; Aswath, Pranesh B.

2015-01-01

Tire derived aggregate (TDA) has been proposed as a possible lightweight replacement for mineral aggregate in concrete. The role played by the amount of TDA replacing coarse aggregate as well as different treatment and additives in concrete on its properties is examined. Conventional concrete (without TDA) and concrete containing TDA are compared by examining their compressive strength based on ASTM C39, workability based on ASTM C143, splitting tensile strength based on ASTM C496, modulus of rupture (flexural strength) based on ASTM C78, and bond stress based on ASTM C234. Results indicate that while replacement of coarse aggregates with TDA results in reduction in strength, it may be mitigated with addition of silica fume to obtain the desired strength. The greatest benefit of using TDA is in the development of a higher ductile product while utilizing recycled TDA. PMID:26161440

Properties of Concrete with Tire Derived Aggregate Partially Replacing Coarse Aggregates

Directory of Open Access Journals (Sweden)

Gideon Siringi

2015-01-01

Full Text Available Tire derived aggregate (TDA has been proposed as a possible lightweight replacement for mineral aggregate in concrete. The role played by the amount of TDA replacing coarse aggregate as well as different treatment and additives in concrete on its properties is examined. Conventional concrete (without TDA and concrete containing TDA are compared by examining their compressive strength based on ASTM C39, workability based on ASTM C143, splitting tensile strength based on ASTM C496, modulus of rupture (flexural strength based on ASTM C78, and bond stress based on ASTM C234. Results indicate that while replacement of coarse aggregates with TDA results in reduction in strength, it may be mitigated with addition of silica fume to obtain the desired strength. The greatest benefit of using TDA is in the development of a higher ductile product while utilizing recycled TDA.

Interlocked chiral/polar domain walls and large optical rotation in Ni3TeO6

Directory of Open Access Journals (Sweden)

Xueyun Wang

2015-07-01

Full Text Available Chirality, i.e., handedness, pervades much of modern science from elementary particles, DNA-based biology to molecular chemistry; however, most of the chirality-relevant materials have been based on complex molecules. Here, we report inorganic single-crystalline Ni3TeO6, forming in a corundum-related R3 structure with both chirality and polarity. These chiral Ni3TeO6 single crystals exhibit a large optical specific rotation (α—1355° dm−1 cm3 g−1. We demonstrate, for the first time, that in Ni3TeO6, chiral and polar domains form an intriguing domain pattern, resembling a radiation warning sign, which stems from interlocked chiral and polar domain walls through lowering of the wall energy.

Kinetics of aggregation with choice.

Science.gov (United States)

Ben-Naim, E; Krapivsky, P L

2016-12-01

We generalize the ordinary aggregation process to allow for choice. In ordinary aggregation, two random clusters merge and form a larger aggregate. In our implementation of choice, a target cluster and two candidate clusters are randomly selected and the target cluster merges with the larger of the two candidate clusters. We study the long-time asymptotic behavior and find that as in ordinary aggregation, the size density adheres to the standard scaling form. However, aggregation with choice exhibits a number of different features. First, the density of the smallest clusters exhibits anomalous scaling. Second, both the small-size and the large-size tails of the density are overpopulated, at the expense of the density of moderate-size clusters. We also study the complementary case where the smaller candidate cluster participates in the aggregation process and find an abundance of moderate clusters at the expense of small and large clusters. Additionally, we investigate aggregation processes with choice among multiple candidate clusters and a symmetric implementation where the choice is between two pairs of clusters.

Kinetic Behaviors of Catalysis-Driven Growth of Three-Species Aggregates on Base of Exchange-Driven Aggregations

International Nuclear Information System (INIS)

Sun Yunfei; Chen Dan; Lin Zhenquan; Ke Jianhong

2009-01-01

We propose a solvable aggregation model to mimic the evolution of population A, asset B, and the quantifiable resource C in a society. In this system, the population and asset aggregates themselves grow through self-exchanges with the rate kernels K 1 (k, j) = K 1 kj and K 2 (k, j) = K 2 kj, respectively. The actions of the population and asset aggregations on the aggregation evolution of resource aggregates are described by the population-catalyzed monomer death of resource aggregates and asset-catalyzed monomer birth of resource aggregates with the rate kernels J 1 (k, j) = J 1 k and J 2 (k, j) = J 2 k, respectively. Meanwhile, the asset and resource aggregates conjunctly catalyze the monomer birth of population aggregates with the rate kernel I 1 (k, i, j) = I 1 ki μ j η , and population and resource aggregates conjunctly catalyze the monomer birth of asset aggregates with the rate kernel I 2 (k, i, j) = I 2 ki v j η . The kinetic behaviors of species A, B, and C are investigated by means of the mean-field rate equation approach. The effects of the population-catalyzed death and asset-catalyzed birth on the evolution of resource aggregates based on the self-exchanges of population and asset appear in effective forms. The coefficients of the effective population-catalyzed death and the asset-catalyzed birth are expressed as J 1e = J 1 /K 1 and J 2e = J 2 /K 2 , respectively. The aggregate size distribution of C species is found to be crucially dominated by the competition between the effective death and the effective birth. It satisfies the conventional scaling form, generalized scaling form, and modified scaling form in the cases of J 1e 2e , J 1e = J 2e , and J 1e > J 2e , respectively. Meanwhile, we also find the aggregate size distributions of populations and assets both fall into two distinct categories for different parameters μ, ν, and η: (i) When μ = ν = η = 0 and μ = ν = 0, η = 1, the population and asset aggregates obey the generalized

Efficiency analysis and assessment of interlocking PVC sheet piling walls

International Nuclear Information System (INIS)

Emam, A.A.

2005-01-01

The use of PVC sheet piling in marine environments offers a number of unique advantages that include weight saving, corrosion resistance and environmentally safe material. In this study, one of the widely used classical methods as well as a finite element analysis are used to analyze such sheet piling walls. The analysis focuses on the effect of some important parameters on the wall global behavior, bending moments, stresses and deflections. The parameters include wall cross-section, wall height, embedment depth, number and spacing of anchor rods, and type of soil and loading conditions. Furthermore, the effect of the shape of the wall cross-section and the location of the interlocking joints has been studied by using plane frame and arch-like models. Results indicate that the finite element modeling is an effective tool for numerical approximation of soil-structure interaction problems. The required theoretical embedment depth is nearly 30 % of the clear wall height. Also, the modulus of subgrade reaction has a minor effect on both cantilever wall and one anchor sheet-pile wall. Finally, lateral (horizontal) action shows that deep sections tend to behave like an arch under radial loading which might increase normal stresses at some critical sections

Research on Judgment Aggregation Based on Logic

Directory of Open Access Journals (Sweden)

Li Dai

2014-05-01

Full Text Available Preference aggregation and judgment aggregation are two basic research models of group decision making. And preference aggregation has been deeply studied in social choice theory. However, researches of social choice theory gradually focus on judgment aggregation which appears recently. Judgment aggregation focuses on how to aggregate many consistent logical formulas into one, from the perspective of logic. We try to start with judgment aggregation model based on logic and then explore different solutions to problem of judgment aggregation.

Análise experimental de blocos intertravados de concreto com adição de resíduos do processo de recauchutagem de pneus = Analysis of experimental interlocking blocks of concrete with addition of residues of process the tires retreading production

Directory of Open Access Journals (Sweden)

Cesar Fabiano Fioriti

2010-07-01

of concrete with residues tires. We accomplished tests of compression strength, water absorption and resistance to impact. Through the preliminary results, we verified that are satisfactory, confirming the possibility of applying this type of interlocking block in environments with low demand, which would bring the economy of natural sources of aggregates, beyond ecological benefits through the reuse of residues from retreading of tires.

Definition and means of maintaining the process vacuum liquid detection interlock systems portion of the PFP safety envelope

International Nuclear Information System (INIS)

THOMAS, R.J.

1999-01-01

The Process Vacuum Liquid Detection interlock systems prevent intrusion of process liquids into the HEPA filters downstream of demisters No.6 and No.7 during Process Vacuum System operation. This prevents liquid intrusion into the filters, which could cause a criticality. The Safety Envelope (SE) includes the equipment, which detects the presence of liquids in the vacuum headers; isolates the filters; shuts down the vacuum pumps; and alarms the condition. This report identifies the equipment in the SE operating, maintenance, and surveillance procedures needed to maintain the SE equipment; and rationale for exclusion of some equipment and testing from the SE

Heating of Porous Icy Dust Aggregates

Energy Technology Data Exchange (ETDEWEB)

Sirono, Sin-iti [Earth and Environmental Sciences, Nagoya University, Tikusa-ku, Furo-cho, Nagoya 464-8601 (Japan)

2017-06-10

At the beginning of planetary formation, highly porous dust aggregates are formed through coagulation of dust grains. Outside the snowline, the main component of an aggregate is H{sub 2}O ice. Because H{sub 2}O ice is formed in amorphous form, its thermal conductivity is extremely small. Therefore, the thermal conductivity of an icy dust aggregate is low. There is a possibility of heating inside an aggregate owing to the decay of radionuclides. It is shown that the temperature increases substantially inside an aggregate, leading to crystallization of amorphous ice. During the crystallization, the temperature further increases sufficiently to continue sintering. The mechanical properties of icy dust aggregates change, and the collisional evolution of dust aggregates is affected by the sintering.

GENERAL: Kinetic Behaviors of Catalysis-Driven Growth of Three-Species Aggregates on Base of Exchange-Driven Aggregations

Science.gov (United States)

Sun, Yun-Fei; Chen, Dan; Lin, Zhen-Quan; Ke, Jian-Hong

2009-06-01

We propose a solvable aggregation model to mimic the evolution of population A, asset B, and the quantifiable resource C in a society. In this system, the population and asset aggregates themselves grow through self-exchanges with the rate kernels K1(k, j) = K1kj and K2(k, j) = K2kj, respectively. The actions of the population and asset aggregations on the aggregation evolution of resource aggregates are described by the population-catalyzed monomer death of resource aggregates and asset-catalyzed monomer birth of resource aggregates with the rate kernels J1(k, j) = J1k and J2(k, j) = J2k, respectively. Meanwhile, the asset and resource aggregates conjunctly catalyze the monomer birth of population aggregates with the rate kernel I1(k, i, j) = I1kiμjη, and population and resource aggregates conjunctly catalyze the monomer birth of asset aggregates with the rate kernel I2(k, i, j) = I2kivjη. The kinetic behaviors of species A, B, and C are investigated by means of the mean-field rate equation approach. The effects of the population-catalyzed death and asset-catalyzed birth on the evolution of resource aggregates based on the self-exchanges of population and asset appear in effective forms. The coefficients of the effective population-catalyzed death and the asset-catalyzed birth are expressed as J1e = J1/K1 and J2e = J2/K2, respectively. The aggregate size distribution of C species is found to be crucially dominated by the competition between the effective death and the effective birth. It satisfies the conventional scaling form, generalized scaling form, and modified scaling form in the cases of J1e J2e, respectively. Meanwhile, we also find the aggregate size distributions of populations and assets both fall into two distinct categories for different parameters μ, ν, and η: (i) When μ = ν = η = 0 and μ = ν = 0, η = 1, the population and asset aggregates obey the generalized scaling forms; and (ii) When μ = ν = 1, η = 0, and μ = ν = η = 1, the

The Community Structure of the European Network of Interlocking Directorates 2005–2010

Science.gov (United States)

Heemskerk, Eelke M.; Daolio, Fabio; Tomassini, Marco

2013-01-01

The boards of directors at large European companies overlap with each other to a sizable extent both within and across national borders. This could have important economic, political and management consequences. In this work we study in detail the topological structure of the networks that arise from this phenomenon. Using a comprehensive information database, we reconstruct the implicit networks of shared directorates among the top 300 European firms in 2005 and 2010, and suggest a number of novel ways to explore the trans-nationality of such business elite networks. Powerful community detection heuristics indicate that geography still plays an important role: there exist clear communities and they have a distinct national character. Nonetheless, from 2005 to 2010 we observe a densification of the boards interlocks network and a larger transnational orientation in its communities. Together with central actors and assortativity analyses, we provide statistical evidence that, at the level of corporate governance, Europe is getting closer. PMID:23894318

Model for amorphous aggregation processes

Science.gov (United States)

Stranks, Samuel D.; Ecroyd, Heath; van Sluyter, Steven; Waters, Elizabeth J.; Carver, John A.; von Smekal, Lorenz

2009-11-01

The amorphous aggregation of proteins is associated with many phenomena, ranging from the formation of protein wine haze to the development of cataract in the eye lens and the precipitation of recombinant proteins during their expression and purification. While much literature exists describing models for linear protein aggregation, such as amyloid fibril formation, there are few reports of models which address amorphous aggregation. Here, we propose a model to describe the amorphous aggregation of proteins which is also more widely applicable to other situations where a similar process occurs, such as in the formation of colloids and nanoclusters. As first applications of the model, we have tested it against experimental turbidimetry data of three proteins relevant to the wine industry and biochemistry, namely, thaumatin, a thaumatinlike protein, and α -lactalbumin. The model is very robust and describes amorphous experimental data to a high degree of accuracy. Details about the aggregation process, such as shape parameters of the aggregates and rate constants, can also be extracted.

A comparative study on the aggregating effects of guanidine thiocyanate, guanidine hydrochloride and urea on lysozyme aggregation

Energy Technology Data Exchange (ETDEWEB)

Emadi, Saeed, E-mail: emadi@iasbs.ac.ir; Behzadi, Maliheh

2014-08-08

Highlights: • Lysozyme aggregated in guanidine thiocyanate (1.0 and 2.0 M). • Lysozyme aggregated in guanidine hydrochloride (4 and 5 M). • Lysozyme did not aggregated at any concentration (0.5–5 M) of urea. • Unfolding pathway is more important than unfolding per se in aggregation. - Abstract: Protein aggregation and its subsequent deposition in different tissues culminate in a diverse range of diseases collectively known as amyloidoses. Aggregation of hen or human lysozyme depends on certain conditions, namely acidic pH or the presence of additives. In the present study, the effects on the aggregation of hen egg-white lysozyme via incubation in concentrated solutions of three different chaotropic agents namely guanidine thiocyanate, guanidine hydrochloride and urea were investigated. Here we used three different methods for the detection of the aggregates, thioflavin T fluorescence, circular dichroism spectroscopy and atomic force microscopy. Our results showed that upon incubation with different concentrations (0.5, 1.0, 2.0, 3.0, 4.0, 5.0 M) of the chemical denaturants, lysozyme was aggregated at low concentrations of guanidine thiocyanate (1.0 and 2.0 M) and at high concentrations of guanidine hydrochloride (4 and 5 M), although no fibril formation was detected. In the case of urea, no aggregation was observed at any concentration.

Water absorption characteristic of interlocking compressed earth brick units

Science.gov (United States)

Bakar, B. H. Abu; Saari, S.; Surip, N. A.

2017-10-01

This study aims to investigate the water absorption characteristic of interlocking compressed earth brick (ICEB) units. Apart from compressive strength, water absorption is an important property in masonry. This property can affect the quality of the brick itself and the bond strength between the brick and mortar in masonry structures and can result in reducing its strength properties. The units were tested for 24 h water absorption and 5 h boiling water absorption. A total of 170 ICEB units from four ICEB types underwent both tests. For the 24 h water absorption, the ICEB units were dried in the oven for 24 h and then cooled before being weighed. Thereafter, each brick was immersed in water for 24 h and weighed. The same specimens used for the 24 h water absorption test were re-used for the 5 h boiling water absorption test. After completing the 24 h water absorption test, the brick was boiled for 5-hours and weighed. The highest water absorption for the ICEBs in the 24-hour water absorption and 5 h boiling water absorption tests are 15.09% and 17.18%, respectively. The half brick has the highest water absorption (15.87%), whereas the beam brick has the lowest (13.20%). The water absorption of an ICEB unit is higher than that of normal bricks, although the water absorption of the former remains below the maximum rate of the brick water absorption (21%).

Influence of granitic aggregates from Northeast Brazil on the alkali-aggregate reaction

Energy Technology Data Exchange (ETDEWEB)

Gomes Neto, David de Paiva; Santana, Rodrigo Soares de; Barreto, Ledjane Silva, E-mail: pvgomes@uol.com.br [Universidade Federal de Sergipe (UFS), Sao Cristovao, SE (Brazil). Dept. de Ciencias dos Materiais e Engenharia; Conceicao, Herbert; Lisboa, Vinicios Anselmo Carvalho [Universidade Federal de Sergipe (UFS), Sao Cristovao, SE (Brazil). Dept. de Geologia

2014-08-15

The alkali-aggregate reaction (AAR) in concrete structures is a problem that has concerned engineers and researchers for decades. This reaction occurs when silicates in the aggregates react with the alkalis, forming an expanded gel that can cause cracks in the concrete and reduce its lifespan. The aim of this study was to characterize three coarse granitic aggregates employed in concrete production in northeastern Brazil, correlating petrographic analysis with the kinetics of silica dissolution and the evolution of expansions in mortar bars, assisted by SEM/EDS, XRD, and EDX. The presence of grains showing recrystallization into individual microcrystalline quartz subgrains was associated with faster dissolution of silica and greater expansion in mortar bars. Aggregates showing substantial deformation, such as stretched grains of quartz with strong undulatory extinction, experienced slower dissolution, with reaction and expansion occurring over longer periods that could not be detected using accelerated tests with mortar bars. (author)

Interlock System for the COMPASS Tokamak

Energy Technology Data Exchange (ETDEWEB)

Hron, M.; Adamek, J.; Pisacka, J.; Panek, R. [Institute of Plasma Physics AS CR, Association EURATOM/IPP.CR, Prague (Czech Republic); Sova, J.; Siba, J.; Kovarj, J. [Department of Control Engineering, Faculty of Electrical Engineering, Prague (Czech Republic)

2009-07-01

Full text of publication follows: The COMPASS tokamak (R=0.56 m, a=0.18 - 0.23 m) is starting operation presently at Institute of Plasma Physics AS CR in Prague. An important issue of the operation is the safety of the personnel and machine protection against faults, presented in this contribution. The personnel protection is based on a restricted access into the experimental hall during the operation of potentially dangerous systems. A tokamak hall access system, based on Honeywell WIN-PAK (tm) 2005, allows to set the status of the experimental area (open/closed) and to control the in and out movement of persons using access cards. On top of this, a check of the whole experimental area by the operator is enforced before the hall enclosure. A hardware interlock then interprets the experimental hall status and controls the operation of key systems accordingly. The permit for operation is granted and the real status of the systems is reported by hard wired potential less contacts. The control procedure is based on a PLC MicroPEL M66. This PLC provides HW interface between Actuators (Relays and switches) and it is connected on PESNET bus. Its programming is done using language Simple v.2 in Winstudio IDE. Second site of personnel protection system is created on PC where runs a .NET application on MSWindows XP or 2000. This PC is connected with PLC via PESNET bus (on RS485 layer) and it generates all control signals to PLC from the operator. Simultaneously, the PC receives all warning and alarm signals from the PLC. This signals are displayed on a screen of the PC in real-time, this way the GUI provides visualization of the controlled process. Except for this fact the operator is informed about the status of the system and individual subsystems on a PC via an operator's panel. Further we will describe the machine protection which uses similar system for checking conditions for the start of a shot. Fast key processes which have to be checked during the shot are

Fractal Aggregates in Tennis Ball Systems

Science.gov (United States)

Sabin, J.; Bandin, M.; Prieto, G.; Sarmiento, F.

2009-01-01

We present a new practical exercise to explain the mechanisms of aggregation of some colloids which are otherwise not easy to understand. We have used tennis balls to simulate, in a visual way, the aggregation of colloids under reaction-limited colloid aggregation (RLCA) and diffusion-limited colloid aggregation (DLCA) regimes. We have used the…

A Functional Reference Architecture for Aggregators

DEFF Research Database (Denmark)

Bondy, Daniel Esteban Morales; Heussen, Kai; Gehrke, Oliver

2015-01-01

Aggregators are considered to be a key enabling technology for harvesting power system services from distributed energy resources (DER). As a precondition for more widespread use of aggregators in power systems, methods for comparing and validating aggregator designs must be established. This paper...... proposes a functional reference architecture for aggregators to address this requirement....

Aggregation server for grid-integrated vehicles

Science.gov (United States)

Kempton, Willett

2015-05-26

Methods, systems, and apparatus for aggregating electric power flow between an electric grid and electric vehicles are disclosed. An apparatus for aggregating power flow may include a memory and a processor coupled to the memory to receive electric vehicle equipment (EVE) attributes from a plurality of EVEs, aggregate EVE attributes, predict total available capacity based on the EVE attributes, and dispatch at least a portion of the total available capacity to the grid. Power flow may be aggregated by receiving EVE operational parameters from each EVE, aggregating the received EVE operational parameters, predicting total available capacity based on the aggregated EVE operational parameters, and dispatching at least a portion of the total available capacity to the grid.

Sand Cement Brick Containing Recycled Concrete Aggregate as Fine-Aggregate Replacement

Directory of Open Access Journals (Sweden)

Sheikh Khalid Faisal

2017-01-01

Full Text Available Nowadays, the usage amount of the concrete is increasing drastically. The construction industry is a huge consumer of natural consumer. It is also producing the huge wastage products. The usage of concrete has been charged to be not environmentally friendly due to depletion of reserve natural resources, high energy consumption and disposal issues. The conservation of natural resources and reduction of disposal site by reuse and recycling waste material was interest possibilites. The aim of this study is to determine the physical and mechanical properties of sand cement brick containing recycled concrete aggregate and to determine the optimum mix ratio containing recycled concrete aggregate. An experiment done by comparing the result of control specimen using 100% natural sand with recycled concrete aggregate replacement specimen by weight for 55%, 65%, and 75%. The sample was tested under density, compressive strength, flexural strength and water absorption to study the effect of using recycled concrete aggregate on the physical and mechanical properties of bricks. The result shows that the replacement of natural sand by recycled concrete aggregate at the level of 55% provide the highest compressive and flexural strength compared to other percentage and control specimen. However, if the replacement higher than 55%, the strength of brick was decreased for compressive and flexural strength, respectively. The relationship of compressive-flexural strength is determined from statistical analysis and the predicted result can be obtained by using equation ff,RCA = 0.5375 (fc0.3272.

Binding of anions in triply interlocked coordination catenanes and dynamic allostery for dehalogenation reactions† †Electronic supplementary information (ESI) available: Characterization data and additional tables and figures. CCDC 1515722 and 1515723. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c7sc04070a

Science.gov (United States)

Yang, Linlin; Jing, Xu; An, Bowen; Yang, Yang

2017-01-01

By synergistic combination of multicomponent self-assembly and template-directed approaches, triply interlocked metal organic catenanes that consist of two isolated chirally identical tetrahedrons were constructed and stabilized as thermodynamic minima. In the presence of suitable template anions, the structural conversion from the isolated tetrahedral conformers into locked catenanes occurred via the cleavage of an intrinsically reversible coordination bond in each of the tetrahedrons, followed by the reengineering and interlocking of two fragments with the regeneration of the broken coordination bonds. The presence of several kinds of individual pocket that were attributed to the triply interlocked patterns enabled the possibility of encapsulating different anions, allowing the dynamic allostery between the unlocked/locked conformers to promote the dehalogenation reaction of 3-bromo-cyclohexene efficiently, as with the use of dehalogenase enzymes. The interlocked structures could be unlocked into two individual tetrahedrons through removal of the well-matched anion templates. The stability and reversibility of the locked/unlocked structures were further confirmed by the catching/releasing process that accompanied emission switching, providing opportunities for the system to be a dynamic molecular logic system. PMID:29675152

Observing Convective Aggregation

Science.gov (United States)

Holloway, Christopher E.; Wing, Allison A.; Bony, Sandrine; Muller, Caroline; Masunaga, Hirohiko; L'Ecuyer, Tristan S.; Turner, David D.; Zuidema, Paquita

2017-11-01

Convective self-aggregation, the spontaneous organization of initially scattered convection into isolated convective clusters despite spatially homogeneous boundary conditions and forcing, was first recognized and studied in idealized numerical simulations. While there is a rich history of observational work on convective clustering and organization, there have been only a few studies that have analyzed observations to look specifically for processes related to self-aggregation in models. Here we review observational work in both of these categories and motivate the need for more of this work. We acknowledge that self-aggregation may appear to be far-removed from observed convective organization in terms of time scales, initial conditions, initiation processes, and mean state extremes, but we argue that these differences vary greatly across the diverse range of model simulations in the literature and that these comparisons are already offering important insights into real tropical phenomena. Some preliminary new findings are presented, including results showing that a self-aggregation simulation with square geometry has too broad distribution of humidity and is too dry in the driest regions when compared with radiosonde records from Nauru, while an elongated channel simulation has realistic representations of atmospheric humidity and its variability. We discuss recent work increasing our understanding of how organized convection and climate change may interact, and how model discrepancies related to this question are prompting interest in observational comparisons. We also propose possible future directions for observational work related to convective aggregation, including novel satellite approaches and a ground-based observational network.

What favors convective aggregation and why?

Science.gov (United States)

Muller, Caroline; Bony, Sandrine

2015-07-01

The organization of convection is ubiquitous, but its physical understanding remains limited. One particular type of organization is the spatial self-aggregation of convection, taking the form of cloud clusters, or tropical cyclones in the presence of rotation. We show that several physical processes can give rise to self-aggregation and highlight the key features responsible for it, using idealized simulations. Longwave radiative feedbacks yield a "radiative aggregation." In that case, sufficient spatial variability of radiative cooling rates yields a low-level circulation, which induces the upgradient energy transport and radiative-convective instability. Not only do vertically integrated radiative budgets matter but the vertical profile of cooling is also crucial. Convective aggregation is facilitated when downdrafts below clouds are weak ("moisture-memory aggregation"), and this is sufficient to trigger aggregation in the absence of longwave radiative feedbacks. These results shed some light on the sensitivity of self-aggregation to various parameters, including resolution or domain size.

Curcumin inhibits aggregation of alpha-synuclein.

Science.gov (United States)

Pandey, Neeraj; Strider, Jeffrey; Nolan, William C; Yan, Sherry X; Galvin, James E

2008-04-01

Aggregation of amyloid-beta protein (Abeta) is a key pathogenic event in Alzheimer's disease (AD). Curcumin, a constituent of the Indian spice Turmeric is structurally similar to Congo Red and has been demonstrated to bind Abeta amyloid and prevent further oligomerization of Abeta monomers onto growing amyloid beta-sheets. Reasoning that oligomerization kinetics and mechanism of amyloid formation are similar in Parkinson's disease (PD) and AD, we investigated the effect of curcumin on alpha-synuclein (AS) protein aggregation. In vitro model of AS aggregation was developed by treatment of purified AS protein (wild-type) with 1 mM Fe3+ (Fenton reaction). It was observed that the addition of curcumin inhibited aggregation in a dose-dependent manner and increased AS solubility. The aggregation-inhibiting effect of curcumin was next investigated in cell culture utilizing catecholaminergic SH-SY5Y cell line. A model system was developed in which the red fluorescent protein (DsRed2) was fused with A53T mutant of AS and its aggregation examined under different concentrations of curcumin. To estimate aggregation in an unbiased manner, a protocol was developed in which the images were captured automatically through a high-throughput cell-based screening microscope. The obtained images were processed automatically for aggregates within a defined dimension of 1-6 microm. Greater than 32% decrease in mutant alpha-synuclein aggregation was observed within 48 h subsequent to curcumin addition. Our data suggest that curcumin inhibits AS oligomerization into higher molecular weight aggregates and therefore should be further explored as a potential therapeutic compound for PD and related disorders.

Platelet activation and aggregation

DEFF Research Database (Denmark)

Jensen, Maria Sander; Larsen, O H; Christiansen, Kirsten

2013-01-01

This study introduces a new laboratory model of whole blood platelet aggregation stimulated by endogenously generated thrombin, and explores this aspect in haemophilia A in which impaired thrombin generation is a major hallmark. The method was established to measure platelet aggregation initiated...

Role of Multicellular Aggregates in Biofilm Formation

Directory of Open Access Journals (Sweden)

Kasper N. Kragh

2016-03-01

Full Text Available In traditional models of in vitro biofilm development, individual bacterial cells seed a surface, multiply, and mature into multicellular, three-dimensional structures. Much research has been devoted to elucidating the mechanisms governing the initial attachment of single cells to surfaces. However, in natural environments and during infection, bacterial cells tend to clump as multicellular aggregates, and biofilms can also slough off aggregates as a part of the dispersal process. This makes it likely that biofilms are often seeded by aggregates and single cells, yet how these aggregates impact biofilm initiation and development is not known. Here we use a combination of experimental and computational approaches to determine the relative fitness of single cells and preformed aggregates during early development of Pseudomonas aeruginosa biofilms. We find that the relative fitness of aggregates depends markedly on the density of surrounding single cells, i.e., the level of competition for growth resources. When competition between aggregates and single cells is low, an aggregate has a growth disadvantage because the aggregate interior has poor access to growth resources. However, if competition is high, aggregates exhibit higher fitness, because extending vertically above the surface gives cells at the top of aggregates better access to growth resources. Other advantages of seeding by aggregates, such as earlier switching to a biofilm-like phenotype and enhanced resilience toward antibiotics and immune response, may add to this ecological benefit. Our findings suggest that current models of biofilm formation should be reconsidered to incorporate the role of aggregates in biofilm initiation.

Pre-aggregation for Probability Distributions

DEFF Research Database (Denmark)

Timko, Igor; Dyreson, Curtis E.; Pedersen, Torben Bach

Motivated by the increasing need to analyze complex uncertain multidimensional data (e.g., in order to optimize and personalize location-based services), this paper proposes novel types of {\\em probabilistic} OLAP queries that operate on aggregate values that are probability distributions...... and the techniques to process these queries. The paper also presents the methods for computing the probability distributions, which enables pre-aggregation, and for using the pre-aggregated distributions for further aggregation. In order to achieve good time and space efficiency, the methods perform approximate...... multidimensional data analysis that is considered in this paper (i.e., approximate processing of probabilistic OLAP queries over probability distributions)....

Discrete stochastic charging of aggregate grains

Science.gov (United States)

Matthews, Lorin S.; Shotorban, Babak; Hyde, Truell W.

2018-05-01

Dust particles immersed in a plasma environment become charged through the collection of electrons and ions at random times, causing the dust charge to fluctuate about an equilibrium value. Small grains (with radii less than 1 μm) or grains in a tenuous plasma environment are sensitive to single additions of electrons or ions. Here we present a numerical model that allows examination of discrete stochastic charge fluctuations on the surface of aggregate grains and determines the effect of these fluctuations on the dynamics of grain aggregation. We show that the mean and standard deviation of charge on aggregate grains follow the same trends as those predicted for spheres having an equivalent radius, though aggregates exhibit larger variations from the predicted values. In some plasma environments, these charge fluctuations occur on timescales which are relevant for dynamics of aggregate growth. Coupled dynamics and charging models show that charge fluctuations tend to produce aggregates which are much more linear or filamentary than aggregates formed in an environment where the charge is stationary.

Prediction of the aggregation propensity of proteins from the primary sequence: aggregation properties of proteomes.

Science.gov (United States)

Castillo, Virginia; Graña-Montes, Ricardo; Sabate, Raimon; Ventura, Salvador

2011-06-01

In the cell, protein folding into stable globular conformations is in competition with aggregation into non-functional and usually toxic structures, since the biophysical properties that promote folding also tend to favor intermolecular contacts, leading to the formation of β-sheet-enriched insoluble assemblies. The formation of protein deposits is linked to at least 20 different human disorders, ranging from dementia to diabetes. Furthermore, protein deposition inside cells represents a major obstacle for the biotechnological production of polypeptides. Importantly, the aggregation behavior of polypeptides appears to be strongly influenced by the intrinsic properties encoded in their sequences and specifically by the presence of selective short regions with high aggregation propensity. This allows computational methods to be used to analyze the aggregation properties of proteins without the previous requirement for structural information. Applications range from the identification of individual amyloidogenic regions in disease-linked polypeptides to the analysis of the aggregation properties of complete proteomes. Herein, we review these theoretical approaches and illustrate how they have become important and useful tools in understanding the molecular mechanisms underlying protein aggregation. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Understanding curcumin-induced modulation of protein aggregation.

Science.gov (United States)

Ahmad, Basir; Borana, Mohanish S; Chaudhary, Ankur P

2017-07-01

Curcumin, a diarylheptanoid compound, found in spice turmeric is known to alter the aggregation of proteins and reduce the toxicity of the aggregates. This review looks at the molecular basis of modulating protein aggregation and toxicity of the aggregates. Foremost, we identify the interaction of curcumin and its derivatives with proteins/peptides and the effect of their interaction on the conformational stability and unfolding/folding pathway(s). The unfolding/folding processes generate partially folded/unfolded intermediate, which serve as aggregation precursor state. Secondly, we discuss the effect of curcumin binding on the kinetics parameters of the aggregation process, which give information about the mechanism of the aggregation inhibition. We describe, in addition, that curcumin can accelerate/promote fibril formation by binding to oligomeric intermediate(s) accumulated in the aggregation pathway. Finally, we discuss the correlation of curcumin-induced monomeric and/or oligomeric precursor states with aggregate structure and toxicity. On the basis of these discussions, we propose a model describing curcumin-induced inhibition/promotion of formation of amyloid-like fibrils. Copyright © 2016 Elsevier B.V. All rights reserved.

Customer Aggregation: An Opportunity for Green Power?

Energy Technology Data Exchange (ETDEWEB)

Holt, E.; Bird, L.

2001-02-26

We undertook research into the experience of aggregation groups to determine whether customer aggregation offers an opportunity to bring green power choices to more customers. The objectives of this report, therefore, are to (1) identify the different types of aggregation that are occurring today, (2) learn whether aggregation offers an opportunity to advance sales of green power, and (3) share these concepts and approaches with potential aggregators and green power advocates.

Transportation and utilization of aggregates for road construction

Science.gov (United States)

Fladvad, Marit; Wigum, Børge Johannes; Aurstad, Joralf

2017-04-01

Road construction relies on non-renewable aggregate resources as the main construction material. Sources for high-quality aggregate resources are scattered, and requirements for aggregate quality can cause long transport distances between quarry and road construction site. In European countries, the average aggregate consumption per capita is 5 tonnes per year (European Aggregates Association, 2016), while the corresponding figure for Norway is 11 tonnes (Neeb, 2015). Half the Norwegian aggregate production (sand, gravel and crushed rock) is used for road construction. In Norway, aggregate resources have been considered abundant. However, stricter requirement for aggregate quality, and increased concern for sustainability and environmental issues have spurred focus on reduction of transport lengths through better utilization of local aggregate materials. In this research project, information about pavement design and aggregate quality requirements were gathered from a questionnaire sent to selected experts from the World Road Organization (PIARC), European Committee for Standardization (CEN), and Nordic Road Association (NVF). The gathered data was compared to identify differences and similarities for aggregate use in the participating countries. Further, the data was compared to known data from Norway regarding: - amount of aggregates required for a road structure - aggregate transport lengths and related costs A total of 18 countries participated in the survey, represented by either road authorities, research institutions, or contractors. There are large variations in practice for aggregate use among the represented countries, and the selection of countries is sufficient to illustrate a variety in pavement designs, aggregate sizes, and quality requirements for road construction. There are considerable differences in both pavement thickness and aggregate sizes used in the studied countries. Total thicknesses for pavement structures varies from 220 mm to 2400 mm

Reusing recycled aggregates in structural concrete

Science.gov (United States)

Kou, Shicong

The utilization of recycled aggregates in concrete can minimize environmental impact and reduce the consumption of natural resources in concrete applications. The aim of this thesis is to provide a scientific basis for the possible use of recycled aggregates in structure concrete by conducting a comprehensive programme of laboratory study to gain a better understanding of the mechanical, microstructure and durability properties of concrete produced with recycled aggregates. The study also explored possible techniques to of improve the properties of recycled aggregate concrete that is produced with high percentages (≧ 50%) of recycled aggregates. These techniques included: (a) using lower water-to-cement ratios in the concrete mix design; (b) using fly ash as a cement replacement or as an additional mineral admixture in the concrete mixes, and (c) precasting recycled aggregate concrete with steam curing regimes. The characteristics of the recycled aggregates produced both from laboratory and a commercially operated pilot construction and demolition (C&D) waste recycling plant were first studied. A mix proportioning procedure was then established to produce six series of concrete mixtures using different percentages of recycled coarse aggregates with and without the use of fly ash. The water-to-cement (binder) ratios of 0.55, 0.50, 0.45 and 0.40 were used. The fresh properties (including slump and bleeding) of recycled aggregate concrete (RAC) were then quantified. The effects of fly ash on the fresh and hardened properties of RAC were then studied and compared with those RAC prepared with no fly ash addition. Furthermore, the effects of steam curing on the hardened properties of RAC were investigated. For micro-structural properties, the interfacial transition zones of the aggregates and the mortar/cement paste were analyzed by SEM and EDX-mapping. Moreover, a detailed set of results on the fracture properties for RAC were obtained. Based on the experimental

Aggregated particles caused by instrument artifact

Science.gov (United States)

Pierce, Ashley M.; Loría-Salazar, S. Marcela; Arnott, W. Patrick; Edwards, Grant C.; Miller, Matthieu B.; Gustin, Mae S.

2018-04-01

Previous studies have indicated that superaggregates, clusters of aggregates of soot primary particles, can be formed in large-scale turbulent fires. Due to lower effective densities, higher porosity, and lower aerodynamic diameters, superaggregates may pass through inlets designed to remove particles 2.5 µm in aerodynamic diameter were collected on 36 out of 158 sample days. On preliminary analysis, it was thought that these aggregated particles were superaggregates, depositing past PM10 (particles wind speeds, as well as the use of generators on site. Samples with aggregated particles, referred to as aggregates, were analyzed using a scanning electron microscope for size and shape and energy dispersive X-ray spectroscopy was used for elemental analysis. It was determined, based on the high amounts of aluminum present in the aggregate samples, that a sampling artifact associated with the sample inlet and prolonged, high wind events was the probable reason for the observed aggregates.

Biocalcification using Ureolytic Bacteria (UB) for strengthening Interlocking Compressed Earth Blocks (ICEB)

Science.gov (United States)

Zamer, M. M.; Irwan, J. M.; Othman, N.; Faisal, S. K.; Anneza, L. H.; Alshalif, A. F.; Teddy, T.

2018-02-01

Interlocking compressed earth blocks (ICEB) are soil based blocks that allows for mortarless construction. This characteristic resulted to faster the process of building walls and required less skilled labor as the blocks are laid dry and lock into place. Recently, implementation in using bacteria as construction material improvement is vigorously used in research in order pursuit the sustainable construction works. This paper provide the results of ureolytic bacteria (UB) throughout enrichment process in soil condition to acclimatize the ICEB environment, compressive strength of 1%, 3% and 5% UB and SEM analysis of ICEB. The bacteria were added as partial replacement of limestone water in ICEB. The results showed the optimal growth achieved based on the days and absorbance from optical density (OD) test which are in 12th days with absorbance of 0.55 whereas the results for strength shows the increment of 15.25% with 5% UB on 28th days of testing compared to control specimen. Therefore this study hopes that positive results from the UB as improving in strength of ICEB which will lead to improve others ICEB properties and others construction materials.

Shielding of the patient's gonads during intramedullary interlocking femoral nailing

Energy Technology Data Exchange (ETDEWEB)

Kwong, L.M.; Johanson, P.H.; Zinar, D.M.; Lenihan, M.R.; Herman, M.W. (Harbor/Univ. of California, Los Angeles Medical Center, Torrance (USA))

1990-12-01

Levels of exposure to radiation were recorded at sixty sites in fifteen patients during intramedullary interlocking femoral nailing. Radiation film dosimeters were placed at four gonadal sites on each subject. A standard male-gonad cup or a pelvic drape of 0.5-millimeter-thick lead-equivalent was put in place to shield the gonads. A second set of four dosimeters was placed external to the shield to approximate unprotected exposure. The total duration of the fluoroscopy averaged five minutes (range, thirty seconds to fourteen minutes). The total exposure to radiation external to the shield was 35 +/- 34 millirems at the male gonadal sites and 17 +/- 11 millirems at the female gonadal sites. With use of the gonadal shield, exposure to radiation was not measurable in thirteen of the fifteen patients. The differences between the exposures of the shielded and unshielded sites to radiation were statistically significant (p less than 0.001). The highest level of gonadal exposure was found with the treatment of proximal femoral fractures and with the use of statically locked nails. Regardless of the conditions, and for all types of fractures and locations, our results demonstrated that gonadal shielding is justified.

The alkali–aggregate reaction for various aggregates used in concrete

Directory of Open Access Journals (Sweden)

Calderón, V.

2010-09-01

Full Text Available The aim of this work is to contribute to the knowledge of the interactions between aggregates and the components of the interstitial phase of concrete and to determine whether those aggregates that are subsequently used in the manufacture of concrete are reagents and are therefore likely to undergo a progressive deterioration of their initial properties. An initial petrographic study of each aggregate is performed in order to be able to determine its subsequent behaviour and reactivity under the influence of various factors. The potential reactivity of different silicaceous aggregates (slates, gneiss, hornfels, granites, quartzite and serpentine is then determined by a chemical method for evaluating the potential reactivity of aggregates and an accelerated method in mortar specimens, and finally the surface reactivity is investigated. The results of these studies suggest that some aggregates are able to react with the components of the interstitial phase of concrete. The existence of this kind of interaction is confirmed by the results of the surface investigations before and after the basic reaction.

Este trabajo pretende contribuir al conocimiento de las reacciones de interacción entre los áridos y los componentes de la fase intersticial del hormigón y determinar si estos áridos, empleados posteriormente en la fabricación del hormigón, son reactivos y por tanto susceptibles de provocar una disminución progresiva de sus propiedades iniciales. Para la caracterización de cada árido se ha realizado un estudio petrográfico, fundamental a la hora de determinar su posterior comportamiento en términos de reactividad frente a diversos factores. Seguidamente, se ha analizado la reactividad potencial de diferentes áridos silicatados (pizarras, gneis, corneanas, granitos, cuarcita y serpentina mediante los dos métodos normalizados existentes: el método químico para la determinación de la reactividad potencial de áridos y

Tune resonance phenomena in the SPS and machine protection via fast position interlocking

CERN Document Server

Baer, T; Bogey, T; Wenninger, J

2010-01-01

The Super Proton Synchrotron (SPS) at CERN with a peak energy of 450GeV is at the top of the LHC preaccelerator-complex. Apart from LHC, SPS is with Tevatron the accelerator with the largest stored beam energy, up to 2.5MJ. The SPS has a known vulnerability to fast equipment failures that led to an uncontrolled loss of a high intensity beam in 2008, which resulted in major damage of a main dipole. The beam loss was caused by a fast tune decrease towards an integer resonance. Simulations and distinct experimental studies provide clear understanding of the beam dynamics at different SPS tune resonances. Diverging closed orbit oscillations, dispersion explosion and abrupt increased beta-beating are the driving effects leading to a complete beam loss in as little as 3 turns (70us). Dedicated experiments of fast failures of the main power converters reveal that the current interlock systems are much too slow for an adequate machine protection. To counteract the vulnerability of the SPS, current research focuses on...

Development of Remote Control and Interlock System for the PEFP Microwave Ion Source

International Nuclear Information System (INIS)

Song, Young Gi; Seol, Kyung Tae; Kwon, Hyeok Jung; Jang, Ji Ho; Cho, Yong Sub

2011-01-01

The control system for a microwave ion source as an isolated high voltage device is a main part of the PEFP distributed control system. The system is used to control two sets of microwave ion sources, the remote control and the interlock system. A VME system with an embedded Power PC CPU is used as main computer. The VME system is dedicated to control and monitoring of the ion source operation. An isolated control system has been designed and developed for remote control and monitoring of a microwave generator and various power supplies. As the source is placed on high voltage platform, optical fiber isolation has been used between the serial to optical fiber VME I/O board and the control system on the high voltage platform. These are connected through RS232 serial interface. A fast Ethernet is used to communicate between the microwave ion source control system and other control stations in the PEFP control system. EPICS toolkit is adopted to provide network programming and user interface by using EPICS Channel Access (CA)

Information Aggregation and Investment Decisions

OpenAIRE

Christian Hellwig; Aleh Tsyvinski; Elias Albagli

2010-01-01

This paper studies an environment in which information aggregation interacts with investment decisions. The first contribution of the paper is to develop a tractable model of such interactions. The second contribution is to solve the model in closed form and derive a series of implications that result from the interplay between information aggregation and the value of market information for the firms' decision problem. We show that the model generates an information aggregation wedge between ...

Production of lightweight aggregates from washing aggregate sludge and fly ash

Science.gov (United States)

González-Corrochano, Beatriz; Alonso-Azcárate, Jacinto; Rodas, Magdalena

2010-05-01

Increasing generation of wastes is one of the main environmental problems in industrialised countries. Heat treatment at high temperatures can convert some types of wastes into ceramic products with a wide range of microstructural features and properties (Bethanis et al., 2004). A lightweight aggregate (LWA) is a granular material with a bulk density (bd) not exceeding 1.20 g/cm3 or with a particle density not exceeding 2.00 g/cm3 (UNE-EN-13055-1, 2003). They have become a focus of interest because the low particle density and the low bulk density entail a decrease in the load transmitted to the ground, and less work and effort are required to transport them (De' Gennaro et al., 2004). The benefits associated with these low densities, which are due to the formation of voids and pores, are very good thermal and acoustic insulation and materials with a good resistance to fire (Benbow, 1987; Fakhfakh et al., 2007). The objective was to recycle fly ash, used motor oil from cars and mineral wastes from washing aggregate sludge, in order to obtain a usable material such as lightweight aggregates, and also to ensure that they are of good quality for different applications. Raw materials have been physically, chemically and mineralogically characterized. On the basis of the results obtained, they were mixed, milled to a grain size of less than 200 μm (Yasuda, 1991), formed into pellets, pre-heated for 5 min and sintered in a rotary kiln at 1150°C, 1175°C, 1200°C and 1225°C for 10 and 15 min at each temperature (Theating). Effects of raw material characteristics, heating temperature and dwell time on the following LWAs properties were determined: loss on ignition (LOI), bloating index (BI), loose bulk density (bd), apparent and dry particle density (ad, dd), voids (H), water absorption (WA24h) and compressive strength (S). The products obtained were lightweight aggregates in accordance with norm UNE-EN-13055-1 (bd ≤1.20 g/cm3 or particle density ≤2.00 g/cm3). LWAs

Internal water curing with Liapor aggregates

DEFF Research Database (Denmark)

Lura, Pietro

2005-01-01

Internal water curing is a very efficient way to counteract self-desiccation and autogenous shrinkage in high performance concrete, thereby reducing the likelihood of early-age cracking. This paper deals with early-age volume changes and moisture transport in lightweight aggregate concrete realized...... with wet lightweight aggregates. Lightweight aggregate concrete mixtures with different degree of saturation and different particle size of the lightweight aggregates were studied and compared to normal weight concrete. Autogenous deformations, selfinduced stresses in fully restrained conditions, elastic...

Fly ash aggregates. Vliegaskunstgrind

Energy Technology Data Exchange (ETDEWEB)

1983-03-01

A study has been carried out into artificial aggregates made from fly ash, 'fly ash aggregates'. Attention has been drawn to the production of fly ash aggregates in the Netherlands as a way to obviate the need of disposal of fly ash. Typical process steps for the manufacturing of fly ash aggregates are the agglomeration and the bonding of fly ash particles. Agglomeration techniques are subdivided into agitation and compaction, bonding methods into sintering, hydrothermal and 'cold' bonding. In sintering no bonding agent is used. The fly ash particles are more or less welded together. Sintering in general is performed at a temperature higher than 900 deg C. In hydrothermal processes lime reacts with fly ash to a crystalline hydrate at temperatures between 100 and 250 deg C at saturated steam pressure. As a lime source not only lime as such, but also portland cement can be used. Cold bonding processes rely on reaction of fly ash with lime or cement at temperatures between 0 and 100 deg C. The pozzolanic properties of fly ash are used. Where cement is applied, this bonding agent itself contributes also to the strength development of the artificial aggregate. Besides the use of lime and cement, several processes are known which make use of lime containing wastes such as spray dry absorption desulfurization residues or fluid bed coal combustion residues. (In Dutch)

Macrophage triggering by aggregated immunoglobulins. II. Comparison of IgE and IgG aggregates or immune complexes.

Science.gov (United States)

Pestel, J; Dessaint, J P; Joseph, M; Bazin, H; Capron, A

1984-01-01

Macrophages incubated with complexed or aggregated IgE released beta-glucuronidase (beta-G) within 30 min. In contrast in the presence of aggregated or complexed IgG, macrophages liberated equivalent amount of beta-G only after 6 h incubation. In addition the rapid macrophage stimulation induced by aggregated IgE was also followed by a faster 3H-glucosamine incorporation when compared to the delayed activation caused by aggregated IgG. However, macrophages stimulated either by IgG or by IgE oligomers produced the same percentage of plasminogen activator at 24 h. In contrast, while the interaction between macrophages and aggregated IgE was only followed by a peak of cyclic GMP and a beta-G release during the first 30 min of incubation, the interaction between macrophages and IgG oligomers was accompanied by a simultaneous increase of cyclic GMP and AMP nucleotides and by an absence of beta-G exocytosis. Moreover, the beta-G release induced by aggregated IgE was increased when macrophages were preincubated with aggregated IgG. This additive effect was not observed in the reverse situation. Finally macrophages activated by IgG oligomers were demonstrated to exert a cytotoxic effect on tumour cells and to kill schistosomula in the presence of a low level of complement. Taken together these results underline the peculiar ability of aggregated or complexed IgE to trigger rapidly the macrophage activation compared to aggregated IgG and can explain the important role of complexed IgE in some macrophage dependent cytotoxicity mechanisms (i.e. in parasitic diseases). PMID:6088135

Microfluidic magnetic switching valves based on aggregates of magnetic nanoparticles: Effects of aggregate length and nanoparticle sizes

Energy Technology Data Exchange (ETDEWEB)

Jiemsakul, Thanakorn [National Nanotechnology Center (NANOTEC), National Science and Technology Development Agency (NSTDA), 111 Thailand Science Park, Thanon Phahonyothin, Tambon Khlong Nueng, Amphoe Khlong Luang, Pathum Thani 12120 (Thailand); Manakasettharn, Supone, E-mail: supone@nanotec.or.th [National Nanotechnology Center (NANOTEC), National Science and Technology Development Agency (NSTDA), 111 Thailand Science Park, Thanon Phahonyothin, Tambon Khlong Nueng, Amphoe Khlong Luang, Pathum Thani 12120 (Thailand); Kanharattanachai, Sivakorn; Wanna, Yongyuth [College of Nanotechnology, King Mongkut' s Institute of Technology Ladkrabang, Chalongkrung Road, Bangkok 10520 (Thailand); Wangsuya, Sujint [College of Nanotechnology, King Mongkut' s Institute of Technology Ladkrabang, Chalongkrung Road, Bangkok 10520 (Thailand); Faculty of Science, Mahidol University, 272 Rama VI Road, Ratchathewi District, Bangkok 10400 (Thailand); Pratontep, Sirapat [College of Nanotechnology, King Mongkut' s Institute of Technology Ladkrabang, Chalongkrung Road, Bangkok 10520 (Thailand)

2017-01-15

We demonstrate microfluidic switching valves using magnetic nanoparticles blended within the working fluid as an alternative microfluidic flow control in microchannels. Y-shaped microchannels have been fabricated by using a CO{sub 2} laser cutter to pattern microchannels on transparent poly(methyl methacrylate) (PMMA) sheets covered with thermally bonded transparent polyvinyl chloride (PVC) sheets. To examine the performance of the microfluidic magnetic switching valves, an aqueous magnetic nanoparticle suspension was injected into the microchannels by a syringe pump. Neodymium magnets were then employed to attract magnetic nanoparticles and form an aggregate that blocked the microchannels at a required position. We have found that the maximum volumetric flow rate of the syringe pump that the magnetic nanoparticle aggregate can withstand scales with the square of the external magnetic flux density. The viscosity of the fluid exhibits dependent on the aggregate length and the size of the magnetic nanoparticles. This microfluidic switching valve based on aggregates of magnetic nanoparticles has strong potentials as an on-demand flow control, which may help simplifying microfluidic channel designs. - Highlights: • We demonstrate microfluidic switching valves based on aggregates of magnetic particles. • Maximum flow rate that the aggregate can withstand scales with the square of the external magnetic flux density. • Aggregates with smaller magnetic nanoparticle size can withstand higher flow rate. • Aggregate length exhibits a linear dependence with flow resistance of a viscous fluid.

Macroeconomic susceptibility, inflation, and aggregate supply

Science.gov (United States)

Hawkins, Raymond J.

2017-03-01

We unify aggregate-supply dynamics as a time-dependent susceptibility-mediated relationship between inflation and aggregate economic output. In addition to representing well various observations of inflation-output dynamics this parsimonious formalism provides a straightforward derivation of popular representations of aggregate-supply dynamics and a natural basis for economic-agent expectations as an element of inflation formation. Our formalism also illuminates questions of causality and time-correlation that challenge central banks for whom aggregate-supply dynamics is a key constraint in their goal of achieving macroeconomic stability.

Aggregated recommendation through random forests.

Science.gov (United States)

Zhang, Heng-Ru; Min, Fan; He, Xu

2014-01-01

Aggregated recommendation refers to the process of suggesting one kind of items to a group of users. Compared to user-oriented or item-oriented approaches, it is more general and, therefore, more appropriate for cold-start recommendation. In this paper, we propose a random forest approach to create aggregated recommender systems. The approach is used to predict the rating of a group of users to a kind of items. In the preprocessing stage, we merge user, item, and rating information to construct an aggregated decision table, where rating information serves as the decision attribute. We also model the data conversion process corresponding to the new user, new item, and both new problems. In the training stage, a forest is built for the aggregated training set, where each leaf is assigned a distribution of discrete rating. In the testing stage, we present four predicting approaches to compute evaluation values based on the distribution of each tree. Experiments results on the well-known MovieLens dataset show that the aggregated approach maintains an acceptable level of accuracy.

Microbial properties of soil aggregates created by earthworms and other factors: spherical and prismatic soil aggregates from unreclaimed post-mining sites

Energy Technology Data Exchange (ETDEWEB)

Frouz, J.; Kristufek, V.; Liveckova, M.; van Loo, D.; Jacobs, P.; Van Hoorebeke, L. [Charles University of Prague, Prague (Czech Republic). Inst. of Environmental Studies

2011-01-15

Soil aggregates between 2 and 5 mm from 35- and 45-year-old unreclaimed post-mining sites near Sokolov (Czech Republic) were divided into two groups: spherical and prismatic. X-ray tomography indicated that prismatic aggregates consisted of fragments of claystone bonded together by amorphous clay and roots while spherical aggregates consisted of a clay matrix and organic fragments of various sizes. Prismatic aggregates were presumed to be formed by plant roots and physical processes during weathering of Tertiary mudstone, while earthworms were presumed to contribute to the formation of spherical aggregates. The effects of drying and rewetting and glucose addition on microbial respiration, microbial biomass, and counts of bacteria in these aggregates were determined. Spherical aggregates contained a greater percentage of C and N and a higher C-to-N ratio than prismatic ones. The C content of the particulate organic matter was also higher in the spherical than in the prismatic aggregates. Although spherical aggregates had a higher microbial respiration and biomass, the growth of microbial biomass in spherical aggregates was negatively correlated with initial microbial biomass, indicating competition between bacteria. Specific respiration was negatively correlated with microbial biomass. Direct counts of bacteria were higher in spherical than in prismatic aggregates. Bacterial numbers were more stable in the center than in the surface layers of the aggregates. Transmission electron microscopy indicated that bacteria often occurred as individual cells in prismatic aggregates but as small clusters of cells in spherical aggregates. Ratios of colony forming units (cultivatable bacteria) to direct counts were higher in spherical than in prismatic aggregates. Spherical aggregates also contained faster growing bacteria.

Glycation precedes lens crystallin aggregation

International Nuclear Information System (INIS)

Swamy, M.S.; Perry, R.E.; Abraham, E.C.

1987-01-01

Non-enzymatic glycosylation (glycation) seems to have the potential to alter the structure of crystallins and make them susceptible to thiol oxidation leading to disulfide-linked high molecular weight (HMW) aggregate formation. They used streptozotocin diabetic rats during precataract and cataract stages and long-term cell-free glycation of bovine lens crystallins to study the relationship between glycation and lens crystallin aggregation. HMW aggregates and other protein components of the water-soluble (WS) and urea-soluble (US) fractions were separated by molecular sieve high performance liquid chromatography. Glycation was estimated by both [ 3 H]NaBH 4 reduction and phenylboronate agarose affinity chromatography. Levels of total glycated protein (GP) in the US fractions were about 2-fold higher than in the WS fractions and there was a linear increase in GP in both WS and US fractions. This increase was parallelled by a corresponding increase in HMW aggregates. Total GP extracted by the affinity method from the US fraction showed a predominance of HMW aggregates and vice versa. Cell-free glycation studies with bovine crystallins confirmed the results of the animals studies. Increasing glycation caused a corresponding increase in protein insolubilization and the insoluble fraction thus formed also contained more glycated protein. It appears that lens protein glycation, HMW aggregate formation, and protein insolubilization are interrelated

Reuse of industrial sludge as construction aggregates.

Science.gov (United States)

Tay, J H; Show, K Y; Hong, S Y

2001-01-01

Industrial wastewater sludge and dredged marine clay are high volume wastes that needed enormous space at landfill disposal sites. Due to the limitation of land space, there is an urgent need for alternative disposal methods for these two wastes. This study investigates the possibility of using the industrial sludge in combination with marine clay as construction aggregates. Different proportions of sludge and clay were made into round and angular aggregates. It was found that certain mix proportions could provide aggregates of adequate strength, comparable to that of conventional aggregates. Concrete samples cast from the sludge-clay aggregates yield compressive strengths in the range of 31.0 to 39.0 N/mm2. The results showed that the round aggregates of 100% sludge and the crush aggregates of sludge with up to 20% clay produced concrete of compressive strengths which are superior to that of 38.0 N/mm2 for conventional aggregate. The study indicates that the conversion of high volume wastes into construction materials is a potential option for waste management.

Silt-clay aggregates on Mars

International Nuclear Information System (INIS)

Greeley, R.

1979-01-01

Viking observations suggest abundant silt and clay particles on Mars. It is proposed that some of these particles agglomerate to form sand size aggregates that are redeposited as sandlike features such as drifts and dunes. Although the binding for the aggregates could include salt cementation or other mechanisms, electrostatic bonding is considered to be a primary force holding the aggregates together. Various laboratory experiments conducted since the 19th century, and as reported here for simulated Martian conditions, show that both the magnitude and sign of electrical charges on windblown particles are functions of particle velocity, shape and composition, atmospheric pressure, atmospheric composition, and other factors. Electrical charges have been measured for saltating particles in the wind tunnel and in the field, on the surfaces of sand dunes, and within dust clouds on earth. Similar, and perhaps even greater, charges are proposed to occur on Mars, which could form aggregates of silt and clay size particles. Electrification is proposed to occur within Martian dust clouds, generating silt-clay aggregates which would settle to the surface where they may be deposited in the form of sandlike structures. By analog, silt-clay dunes are known in many parts of the earth where silt-clay aggregated were transported by saltation and deposited as 'sand.' In these structures the binding forces were later destroyed, and the particles reassumed the physical properties of silt and clay, but the sandlike bedding structure within the 'dunes' was preserved. The bedding observed in drifts at the Viking landing site is suggested to result from a similar process involving silt-clay aggregates on Mars

Aggregating and Disaggregating Flexibility Objects

DEFF Research Database (Denmark)

Siksnys, Laurynas; Valsomatzis, Emmanouil; Hose, Katja

2015-01-01

In many scientific and commercial domains we encounter flexibility objects, i.e., objects with explicit flexibilities in a time and an amount dimension (e.g., energy or product amount). Applications of flexibility objects require novel and efficient techniques capable of handling large amounts...... and aiming at energy balancing during aggregation. In more detail, this paper considers the complete life cycle of flex-objects: aggregation, disaggregation, associated requirements, efficient incremental computation, and balance aggregation techniques. Extensive experiments based on real-world data from...

CPAD, Curated Protein Aggregation Database: A Repository of Manually Curated Experimental Data on Protein and Peptide Aggregation.

Science.gov (United States)

Thangakani, A Mary; Nagarajan, R; Kumar, Sandeep; Sakthivel, R; Velmurugan, D; Gromiha, M Michael

2016-01-01

Accurate distinction between peptide sequences that can form amyloid-fibrils or amorphous β-aggregates, identification of potential aggregation prone regions in proteins, and prediction of change in aggregation rate of a protein upon mutation(s) are critical to research on protein misfolding diseases, such as Alzheimer's and Parkinson's, as well as biotechnological production of protein based therapeutics. We have developed a Curated Protein Aggregation Database (CPAD), which has collected results from experimental studies performed by scientific community aimed at understanding protein/peptide aggregation. CPAD contains more than 2300 experimentally observed aggregation rates upon mutations in known amyloidogenic proteins. Each entry includes numerical values for the following parameters: change in rate of aggregation as measured by fluorescence intensity or turbidity, name and source of the protein, Uniprot and Protein Data Bank codes, single point as well as multiple mutations, and literature citation. The data in CPAD has been supplemented with five different types of additional information: (i) Amyloid fibril forming hexa-peptides, (ii) Amorphous β-aggregating hexa-peptides, (iii) Amyloid fibril forming peptides of different lengths, (iv) Amyloid fibril forming hexa-peptides whose crystal structures are available in the Protein Data Bank (PDB) and (v) Experimentally validated aggregation prone regions found in amyloidogenic proteins. Furthermore, CPAD is linked to other related databases and resources, such as Uniprot, Protein Data Bank, PUBMED, GAP, TANGO, WALTZ etc. We have set up a web interface with different search and display options so that users have the ability to get the data in multiple ways. CPAD is freely available at http://www.iitm.ac.in/bioinfo/CPAD/. The potential applications of CPAD have also been discussed.

Contrasting self-aggregation over land and ocean surfaces

Science.gov (United States)

Inda Diaz, H. A.; O'Brien, T. A.

2017-12-01

The spontaneous organization of convection into clusters, or self-aggregation, demonstrably changes the nature and statistics of precipitation. While there has been much recent progress in this area, the processes that control self-aggregation are still poorly understood. Most of the work to date has focused on self-aggregation over ocean-like surfaces, but it is particularly pressing to understand what controls convective aggregation over land, since the associated change in precipitation statistics—between non-aggregated and aggregated convection—could have huge impacts on society and infrastructure. Radiative-convective equilibrium (RCE), has been extensively used as an idealized framework to study the tropical atmosphere. Self-aggregation manifests in numerous numerical models of RCE, nevertheless, there is still a lack of understanding in how it relates to convective organization in the observed world. Numerous studies have examined self-aggregation using idealized Cloud Resolving Models (CRMs) and General Circulation Models over the ocean, however very little work has been done on RCE and self-aggregation over land. Idealized models of RCE over ocean have shown that aggregation is sensitive to sea surface temperature (SST), more intense precipitation occurs in aggregated systems, and a variety of feedbacks—such as surface flux, cloud radiative, and upgradient moisture transport— contribute to the maintenance of aggregation, however it is not clear if these results apply over land. Progress in this area could help relate understanding of self-aggregation in idealized simulations to observations. In order to explore the behavior of self-aggregation over land, we use a CRM to simulate idealized RCE over land. In particular, we examine the aggregation of convection and how it compares with aggregation over ocean. Based on previous studies, where a variety of different CRMs exhibit a SST threshold below which self-aggregation does not occur, we hypothesize

Light-induced aggregation of microbial exopolymeric substances.

Science.gov (United States)

Sun, Luni; Xu, Chen; Zhang, Saijin; Lin, Peng; Schwehr, Kathleen A; Quigg, Antonietta; Chiu, Meng-Hsuen; Chin, Wei-Chun; Santschi, Peter H

2017-08-01

Sunlight can inhibit or disrupt the aggregation process of marine colloids via cleavage of high molecular weight compounds into smaller, less stable fragments. In contrast, some biomolecules, such as proteins excreted from bacteria can form aggregates via cross-linking due to photo-oxidation. To examine whether light-induced aggregation can occur in the marine environment, we conducted irradiation experiments on a well-characterized protein-containing exopolymeric substance (EPS) from the marine bacterium Sagitulla stellata. Our results show that after 1 h sunlight irradiation, the turbidity level of soluble EPS was 60% higher than in the dark control. Flow cytometry also confirmed that more particles of larger sized were formed by sunlight. In addition, we determined a higher mass of aggregates collected on filter in the irradiated samples. This suggests light can induce aggregation of this bacterial EPS. Reactive oxygen species hydroxyl radical and peroxide played critical roles in the photo-oxidation process, and salts assisted the aggregation process. The observation that Sagitulla stellata EPS with relatively high protein content promoted aggregation, was in contrast to the case where no significant differences were found in the aggregation of a non-protein containing phytoplankton EPS between the dark and light conditions. This, together with the evidence that protein-to-carbohydrate ratio of aggregates formed under light condition is significantly higher than that formed under dark condition suggest that proteins are likely the important component for aggregate formation. Light-induced aggregation provides new insights into polymer assembly, marine snow formation, and the fate/transport of organic carbon and nitrogen in the ocean. Copyright © 2017 Elsevier Ltd. All rights reserved.

The effect of electrolytes on the aggregation kinetics of titanium dioxide nanoparticle aggregates

International Nuclear Information System (INIS)

Shih Yanghsin; Zhuang Chengming; Tso Chihping; Lin Chenghan

2012-01-01

Metal oxide nanoparticles (NPs) are receiving increasing attention due to their increased industrial production and potential hazardous effect. The process of aggregation plays a key role in the fate of NPs in the environment and the resultant health risk. The aggregation of commercial titanium dioxide NP powder (25 nm) was investigated with various environmentally relevant solution chemistries containing different concentrations of monovalent (Na + , K + ) and divalent (Ca 2+ ) electrolytes. Titanium dioxide particle size increased with the increase in ion concentration. The stability of titanium dioxide also depended on the ionic composition. Titanium dioxide aggregated to a higher degree in the presence of divalent cations than monovalent ones. The attachment efficiency of NPs was constructed through aggregation kinetics data, from which the critical coagulation concentrations for the various electrolytes are determined (80, 19, and 1 meq/L for Na + , K + , and Ca 2+ , respectively). Our results suggest that titanium dioxide NP powders are relatively unstable in water and could easily be removed by adding multivalent cations so hazardous potentials decrease in aquatic environment.

Aggregated particles caused by instrument artifact

Directory of Open Access Journals (Sweden)

A. M. Pierce

2018-04-01

Full Text Available Previous studies have indicated that superaggregates, clusters of aggregates of soot primary particles, can be formed in large-scale turbulent fires. Due to lower effective densities, higher porosity, and lower aerodynamic diameters, superaggregates may pass through inlets designed to remove particles  <  2.5 µm in aerodynamic diameter (PM2.5. Ambient particulate matter samples were collected at Peavine Peak, NV, USA (2515 m northwest of Reno, NV, USA from June to November 2014. The Teledyne Advanced Pollution Instrumentation (TAPI 602 BetaPlus particulate monitor was used to collect PM2.5 on two filter types. During this time, aggregated particles  >  2.5 µm in aerodynamic diameter were collected on 36 out of 158 sample days. On preliminary analysis, it was thought that these aggregated particles were superaggregates, depositing past PM10 (particles  <  10 µm in aerodynamic diameter pre-impactors and PM2.5 cyclones. However, further analysis revealed that these aggregated particles were dissimilar to superaggregates observed in previous studies, both in morphology and in elemental composition. To determine if the aggregated particles were superaggregates or an instrument artifact, samples were investigated for the presence of certain elements, the occurrence of fires, high relative humidity and wind speeds, as well as the use of generators on site. Samples with aggregated particles, referred to as aggregates, were analyzed using a scanning electron microscope for size and shape and energy dispersive X-ray spectroscopy was used for elemental analysis. It was determined, based on the high amounts of aluminum present in the aggregate samples, that a sampling artifact associated with the sample inlet and prolonged, high wind events was the probable reason for the observed aggregates.

Concrete Waste Recycling Process for High Quality Aggregate

International Nuclear Information System (INIS)

Ishikura, Takeshi; Fujii, Shin-ichi

2008-01-01

Large amount of concrete waste generates during nuclear power plant (NPP) dismantling. Non-contaminated concrete waste is assumed to be disposed in a landfill site, but that will not be the solution especially in the future, because of decreasing tendency of the site availability and natural resources. Concerning concrete recycling, demand for roadbeds and backfill tends to be less than the amount of dismantled concrete generated in a single rural site, and conventional recycled aggregate is limited of its use to non-structural concrete, because of its inferior quality to ordinary natural aggregate. Therefore, it is vital to develop high quality recycled aggregate for general uses of dismantled concrete. If recycled aggregate is available for high structural concrete, the dismantling concrete is recyclable as aggregate for industry including nuclear field. Authors developed techniques on high quality aggregate reclamation for large amount of concrete generated during NPP decommissioning. Concrete of NPP buildings has good features for recycling aggregate; large quantity of high quality aggregate from same origin, record keeping of the aggregate origin, and little impurities in dismantled concrete such as wood and plastics. The target of recycled aggregate in this development is to meet the quality criteria for NPP concrete as prescribed in JASS 5N 'Specification for Nuclear Power Facility Reinforced Concrete' and JASS 5 'Specification for Reinforced Concrete Work'. The target of recycled aggregate concrete is to be comparable performance with ordinary aggregate concrete. The high quality recycled aggregate production techniques are assumed to apply for recycling for large amount of non-contaminated concrete. These techniques can also be applied for slightly contaminated concrete dismantled from radiological control area (RCA), together with free release survey. In conclusion: a technology on dismantled concrete recycling for high quality aggregate was developed

Cholesterol impairment contributes to neuroserpin aggregation

Science.gov (United States)

Giampietro, Costanza; Lionetti, Maria Chiara; Costantini, Giulio; Mutti, Federico; Zapperi, Stefano; La Porta, Caterina A. M.

2017-03-01

Intraneural accumulation of misfolded proteins is a common feature of several neurodegenerative pathologies including Alzheimer’s and Parkinson’s diseases, and Familial Encephalopathy with Neuroserpin Inclusion Bodies (FENIB). FENIB is a rare disease due to a point mutation in neuroserpin which accelerates protein aggregation in the endoplasmic reticulum (ER). Here we show that cholesterol depletion induced either by prolonged exposure to statins or by inhibiting the sterol reg-ulatory binding-element protein (SREBP) pathway also enhances aggregation of neuroserpin proteins. These findings can be explained considering a computational model of protein aggregation under non-equilibrium conditions, where a decrease in the rate of protein clearance improves aggregation. Decreasing cholesterol in cell membranes affects their biophysical properties, including their ability to form the vesicles needed for protein clearance, as we illustrate by a simple mathematical model. Taken together, these results suggest that cholesterol reduction induces neuroserpin aggregation, even in absence of specific neuroserpin mutations. The new mechanism we uncover could be relevant also for other neurodegenerative diseases associated with protein aggregation.

Reliability Analysis of the new Link between the Beam Interlock System and the LHC Beam Dumping System Zuverlässigkeitsanalyse der neuen Verbindung zwischen dem Beam Interlock System und dem LHC Beam Dumping System

CERN Document Server

Vatansever, Volkan

The nominal stored energy in each LHC beam is 360 MJ, surpassing the beam energy of other accelerators by orders of magnitude. This energy threatens to damage accelerator components in case of uncontrolled beam losses To avoid damage of accelerator equipment due to impacting beam, the controlled removal of the LHC beams from the collider rings towards the dump block must be guaranteed at all times. Therefore, the LHC Beam Dumping System was built according to high reliability standards. To further reduce the risk of incapability to dump the beams in case of correlated failures in the redundant system, a new direct link from the LHC Beam Interlock System to the Re-triggering Lines of the LHC Beam Dumping System will be implemented for the startup with beam in 2015. This link represents a diverse redundancy to the current implementation, which should neither significantly increase the risk for so-called Asynchronous Beam Dumps nor compromise machine availability. Therefore, a reliability analysis down to the co...

Mechanical properties of recycled concrete with demolished waste concrete aggregate and clay brick aggregate

Science.gov (United States)

Zheng, Chaocan; Lou, Cong; Du, Geng; Li, Xiaozhen; Liu, Zhiwu; Li, Liqin

2018-06-01

This paper presents an experimental investigation on the effect of the replacement of natural coarse aggregate (NCA) with either recycled concrete aggregate (RCA) or recycled clay brick aggregate (RBA) on the compressive strengths of the hardened concrete. Two grades (C25 and C50) of concrete were investigated, which were achieved by using different water-to-cement ratios. In each grade concrete five different replacement rates, 0%, 25%, 50%, 75% and 100% were considered. In order to improve the performance of the recycled aggregates in the concrete mixes, the RCA and RBA were carefully sieved by using the optimal degradation. In this way the largest reduction in the 28-day compressive strength was found to be only 7.2% and 9.6% for C25 and C50 recycled concrete when the NCA was replaced 100% by RCA, and 11% and 13% for C25 and C50 recycled concrete when the NCA was replaced 100% by RBA. In general, the concrete with RCA has better performance than the concrete with RBA. The comparison of the present experimental results with those reported in literature for hardened concrete with either RCA or RBA demonstrates the effectiveness in improving the compressive strength by using the optimal gradation of recycled aggregates.

Compressive strength improvement for recycled concrete aggregate

Directory of Open Access Journals (Sweden)

Mohammed Dhiyaa

2018-01-01

Full Text Available Increasing amount of construction waste and, concrete remnants, in particular pose a serious problem. Concrete waste exist in large amounts, do not decay and need long time for disintegration. Therefore, in this work old demolished concrete is crashed and recycled to produce recycled concrete aggregate which can be reused in new concrete production. The effect of using recycled aggregate on concrete compressive strength has been experimentally investigated; silica fume admixture also is used to improve recycled concrete aggregate compressive strength. The main parameters in this study are recycled aggregate and silica fume admixture. The percent of recycled aggregate ranged from (0-100 %. While the silica fume ranged from (0-10 %. The experimental results show that the average concrete compressive strength decreases from 30.85 MPa to 17.58 MPa when the recycled aggregate percentage increased from 0% to 100%. While, when silica fume is used the concrete compressive strength increase again to 29.2 MPa for samples with 100% of recycled aggregate.

Pore structure of natural and regenerated soil aggregates

DEFF Research Database (Denmark)

Naveed, Muhammad; Arthur, Emmanuel; de Jonge, Lis Wollesen

2014-01-01

Quantitative characterization of aggregate pore structure can reveal the evolution of aggregates under different land use and management practices and their effects on soil processes and functions. Advances in X-ray Computed Tomography (CT) provide powerful means to conduct such characterization....... This study examined aggregate pore structure of three differently managed same textured Danish soils (mixed forage cropping, MFC; mixed cash cropping, MCC; cereal cash cropping, CCC) for (i) natural aggregates, and (ii) aggregates regenerated after 20 months of incubation. In total, 27 aggregates (8-16 mm...... pore diameter of 200 and 170 Hm, respectively. Pore shape analysis indicated that CCC and MFC aggregates had an abundance of rounded and elongated pores, respectively, and those of MCC were in-between CCC and MFC. Aggregate pore structure development in the lysimeters was nearly similar irrespective...

Ratio-Based Gradual Aggregation of Data

DEFF Research Database (Denmark)

Iftikhar, Nadeem

2012-01-01

cause data management and data storage issues. However, non-flexible and ineffective means of data aggregation not only reduce performance of database queries but also lead to erroneous reporting. This paper presents flexible and effective ratio-based methods for gradual data aggregation in databases....... Gradual data aggregation is a process that reduces data volume by converting the detailed data into multiple levels of summarized data as the data gets older. This paper also describes implementation strategies of the proposed methods based on standard database technology.......Majority of databases contain large amounts of data, gathered over long intervals of time. In most cases, the data is aggregated so that it can be used for analysis and reporting purposes. The other reason of data aggregation is to reduce data volume in order to avoid over-sized databases that may...

Aggregation of flexible polyelectrolytes: Phase diagram and dynamics.

Science.gov (United States)

Tom, Anvy Moly; Rajesh, R; Vemparala, Satyavani

2017-10-14

Similarly charged polymers in solution, known as polyelectrolytes, are known to form aggregated structures in the presence of oppositely charged counterions. Understanding the dependence of the equilibrium phases and the dynamics of the process of aggregation on parameters such as backbone flexibility and charge density of such polymers is crucial for insights into various biological processes which involve biological polyelectrolytes such as protein, DNA, etc. Here, we use large-scale coarse-grained molecular dynamics simulations to obtain the phase diagram of the aggregated structures of flexible charged polymers and characterize the morphology of the aggregates as well as the aggregation dynamics, in the presence of trivalent counterions. Three different phases are observed depending on the charge density: no aggregation, a finite bundle phase where multiple small aggregates coexist with a large aggregate and a fully phase separated phase. We show that the flexibility of the polymer backbone causes strong entanglement between charged polymers leading to additional time scales in the aggregation process. Such slowing down of the aggregation dynamics results in the exponent, characterizing the power law decay of the number of aggregates with time, to be dependent on the charge density of the polymers. These results are contrary to those obtained for rigid polyelectrolytes, emphasizing the role of backbone flexibility.

Nickel aggregates produced by radiolysis

International Nuclear Information System (INIS)

Marignier, J.L.; Belloni, J.

1988-01-01

Nickel aggregates with subcolloidal size and stable in water have been synthesized by inhibiting the corrosion by the medium. The protective effect of the surfactant is discussed in relation with the characteristics of various types of polyvinyl alcohol studied. The reactivity of aggregates towards oxidizing compounds, nitro blue tetrazolium, methylene blue, silver ions, oxygen, methylviologen, enables an estimation of the redox potential of nickel aggregates (E = - 04 ± 0.05 V). It has been applied to quantitative analysis of the particles in presence of nickel ions. 55 refs [fr

Aggregation Algorithms in Heterogeneous Tables

Directory of Open Access Journals (Sweden)

Titus Felix FURTUNA

2006-01-01

Full Text Available The heterogeneous tables are most used in the problem of aggregation. A solution for this problem is to standardize these tables of figures. In this paper, we proposed some methods of aggregation based on the hierarchical algorithms.

Small file aggregation in a parallel computing system

Science.gov (United States)

Faibish, Sorin; Bent, John M.; Tzelnic, Percy; Grider, Gary; Zhang, Jingwang

2014-09-02

Techniques are provided for small file aggregation in a parallel computing system. An exemplary method for storing a plurality of files generated by a plurality of processes in a parallel computing system comprises aggregating the plurality of files into a single aggregated file; and generating metadata for the single aggregated file. The metadata comprises an offset and a length of each of the plurality of files in the single aggregated file. The metadata can be used to unpack one or more of the files from the single aggregated file.

ALPHA-SYNUCLEIN STRUCTURE, AGGREGATION AND MODULATORS

Directory of Open Access Journals (Sweden)

Pinakin K. Makwana

2016-06-01

Full Text Available Alpha-synuclein is an intrinsically unstructured protein, involved in various neurodegenerative disorders. In vitro/in vivo experiments, as well as genetic mutation studies establish a direct link between alphasynuclein and synucleinopathies. Due to its natively unfolded state, alpha synuclein can adopt numerous conformations upon interaction with its partners and cellular factors, offering explanation for its diverse interactions. Aggregated form of alpha-synuclein has been observed in the brain of patients with synucleinopathies, a hallmark of neurodegeneration, and cell death has been attributed to aggregation induced toxicity. The process of aggregation involves nucleation, followed by intermediate oligomeric states, and finally the fibrillar amyloids. Of the various conformations/species that alpha-synuclein assumes before it transforms into mature amyloid fibrils, the oligomeric species is the most toxic. Thus, an effective way to limit disease progression is by modifying/slowing down protein aggregation/deposition in the brain. Various small natural products, synthetic chemicals, peptides and antibodies specific to alpha-synuclein have been designed/identified to reduce its rate of aggregation. Unfortunately, not even a handful of the molecules have cleared the clinical trials. Even today, medications available for Parkinson’s patients are mostly the drugs that adjust for loss of dopamine in the brain, and hence do not stop the progression of the disease or cure the symptoms. Thus, more molecular level studies are warranted to fully elucidate the process of alpha-synuclein aggregation, which in turn could help in identifying novel therapeutics and preventives. The present review summarizes the insights gained into the structure, in vitro aggregation and inhibitors/modulators of alpha-synuclein aggregation, that can be used to design better and effective inhibitors against the diseases.

Supervision Software for the Integration of the Beam Interlock System with the CERN Accelerator Complex

CERN Document Server

Audrain, M; Dragu, M; Fuchsberger, K; Garnier, JC; Gorzawski, AA; Koza, M; Krol, K; Moscatelli, A; Puccio, B; Stamos, K; Zerlauth, M

2014-01-01

The Accelerator complex at the European Organisation for Nuclear Research (CERN) is composed of many systems which are required to function in a valid state to ensure safe beam operation. One key component of machine protection, the Beam Interlock System (BIS), was designed to interface critical systems around the accelerator chain, provide fast and reliable transmission of beam dump requests and trigger beam extraction in case of malfunctioning of equipment systems or beam losses. Numerous upgrades of accelerator and controls components during the Long Shutdown 1 (LS1) are followed by subsequent software updates that need to be thoroughly validated before the restart of beam operation in 2015. In parallel, the ongoing deployments of the BIS hardware in the PS booster (PSB) and the future LINAC4 give rise to new requirements for the related controls and monitoring software due to their fast cycle times. This paper describes the current status and ongoing work as well as the long-term vision for the integratio...

Septum magnet MNP-23 for the CERN PS experimental area and its fast interlock system

CERN Document Server

Borburgh, J; Prost, A; Zickler, T

2004-01-01

Two MNP-23 septum-like magnets are installed at CERN in the transfer line from the Proton Synchrotron (PS) to the East Hall Experimental Area. They are exposed to extremely high doses of ionizing radiation. In the past, the magnets experienced two catastrophic failures due to overheating of its coils and cannot be repaired. The magnets of improved design which is subject of this article are built as replacements for the magnets presently installed. The MNP-23 is a resistive C shaped iron-dominated magnet made of solid low carbon steel blocks. The excitation windings consist of two water-cooled coils wound from hollow copper conductor. The septum design of these magnets implies a high current density which requires an efficient water cooling system. The newly designed cooling circuit provides better cooling performance and more reliability. To avoid failures due to coil overheating, an elaborate interlock system was developed and installed. It consists of two parts: firstly a slow, more classic sensor, to dete...

Mechanical Dissociation of Platelet Aggregates in Blood Stream

Science.gov (United States)

Hoore, Masoud; Fedosov, Dmitry A.; Gompper, Gerhard; Complex; Biological Fluids Group Team

2017-11-01

von Willebrand factor (VWF) and platelet aggregation is a key phenomenon in blood clotting. These aggregates form critically in high shear rates and dissolve reversibly in low shear rates. The emergence of a critical shear rate, beyond which aggregates form and below which they dissolve, has an interesting impact on aggregation in blood flow. As red blood cells (RBCs) migrate to the center of the vessel in blood flow, a RBC free layer (RBC-FL) is left close to the walls into which the platelets and VWFs are pushed back from the bulk flow. This margination process provides maximal VWF-platelet aggregation probability in the RBC-FL. Using mesoscale hydrodynamic simulations of aggregate dynamics in blood flow, it is shown that the aggregates form and grow in RBC-FL wherein shear rate is high for VWF stretching. By growing, the aggregates penetrate to the bulk flow and get under order of magnitude lower shear rates. Consequently, they dissolve and get back into the RBC-FL. This mechanical limitation for aggregates prohibits undesired thrombosis and vessel blockage by aggregates, while letting the VWFs and platelets to aggregate close to the walls where they are actually needed. The support by the DFG Research Unit FOR 1543 SHENC and CPU time Grant by the Julich Supercomputing Center are acknowledged.

Learning about individuals' health from aggregate data.

Science.gov (United States)

Colbaugh, Rich; Glass, Kristin

2017-07-01

There is growing awareness that user-generated social media content contains valuable health-related information and is more convenient to collect than typical health data. For example, Twitter has been employed to predict aggregate-level outcomes, such as regional rates of diabetes and child poverty, and to identify individual cases of depression and food poisoning. Models which make aggregate-level inferences can be induced from aggregate data, and consequently are straightforward to build. In contrast, learning models that produce individual-level (IL) predictions, which are more informative, usually requires a large number of difficult-to-acquire labeled IL examples. This paper presents a new machine learning method which achieves the best of both worlds, enabling IL models to be learned from aggregate labels. The algorithm makes predictions by combining unsupervised feature extraction, aggregate-based modeling, and optimal integration of aggregate-level and IL information. Two case studies illustrate how to learn health-relevant IL prediction models using only aggregate labels, and show that these models perform as well as state-of-the-art models trained on hundreds or thousands of labeled individuals.

Efficient clustering aggregation based on data fragments.

Science.gov (United States)

Wu, Ou; Hu, Weiming; Maybank, Stephen J; Zhu, Mingliang; Li, Bing

2012-06-01

Clustering aggregation, known as clustering ensembles, has emerged as a powerful technique for combining different clustering results to obtain a single better clustering. Existing clustering aggregation algorithms are applied directly to data points, in what is referred to as the point-based approach. The algorithms are inefficient if the number of data points is large. We define an efficient approach for clustering aggregation based on data fragments. In this fragment-based approach, a data fragment is any subset of the data that is not split by any of the clustering results. To establish the theoretical bases of the proposed approach, we prove that clustering aggregation can be performed directly on data fragments under two widely used goodness measures for clustering aggregation taken from the literature. Three new clustering aggregation algorithms are described. The experimental results obtained using several public data sets show that the new algorithms have lower computational complexity than three well-known existing point-based clustering aggregation algorithms (Agglomerative, Furthest, and LocalSearch); nevertheless, the new algorithms do not sacrifice the accuracy.

Customer Aggregation: An Opportunity for Green Power?; TOPICAL

International Nuclear Information System (INIS)

Holt, E.; Bird, L.

2001-01-01

We undertook research into the experience of aggregation groups to determine whether customer aggregation offers an opportunity to bring green power choices to more customers. The objectives of this report, therefore, are to (1) identify the different types of aggregation that are occurring today, (2) learn whether aggregation offers an opportunity to advance sales of green power, and (3) share these concepts and approaches with potential aggregators and green power advocates

Concrete manufacture with un-graded recycled aggregates

OpenAIRE

Richardson, Alan; Coventry, Kathryn; Graham, Sue

2009-01-01

Purpose – The purpose of this paper is to investigate whether concrete that includes un-graded recycled aggregates can be manufactured to a comparable strength to concrete manufactured from virgin aggregates. \\ud \\ud Design/methodology/approach – A paired comparison test was used to evaluate the difference between concrete made with virgin aggregates (plain control) and concrete including recycled waste. Un-graded construction demolition waste and un-graded ground glass were used as aggregate...

Coupling of aggregation and immunogenicity in biotherapeutics: T- and B-cell immune epitopes may contain aggregation-prone regions.

Science.gov (United States)

Kumar, Sandeep; Singh, Satish K; Wang, Xiaoling; Rup, Bonita; Gill, Davinder

2011-05-01

Biotherapeutics, including recombinant or plasma-derived human proteins and antibody-based molecules, have emerged as an important class of pharmaceuticals. Aggregation and immunogenicity are among the major bottlenecks during discovery and development of biotherapeutics. Computational tools that can predict aggregation prone regions as well as T- and B-cell immune epitopes from protein sequence and structure have become available recently. Here, we describe a potential coupling between aggregation and immunogenicity: T-cell and B-cell immune epitopes in therapeutic proteins may contain aggregation-prone regions. The details of biological mechanisms behind this observation remain to be understood. However, our observation opens up an exciting potential for rational design of de-immunized novel, as well as follow on biotherapeutics with reduced aggregation propensity.

em pavimentos intertravados

Directory of Open Access Journals (Sweden)

Daniel Simieli

2007-01-01

Full Text Available The destination of the construction waste is a problem that becomes worse as the time goes by, and that affects the environmental conditions, with consequences for whole society. In this work, aiming to minimize the environmental impact caused by these residues, it was studied the use of recycled aggregates in the composition of interlocking pavement. Laboratory rehearsals were performed to evaluate the behavior of this concrete manufactured with recycled aggregates. Analyses of the mechanical resistance parameters were made and, the defined standards according to the Brazilian norms, considered.

Detection of ubiquitinated huntingtin species in intracellular aggregates

Directory of Open Access Journals (Sweden)

Katrin eJuenemann

2015-01-01

Full Text Available Protein conformation diseases, including polyglutamine diseases, result from the accumulation and aggregation of misfolded proteins. Huntington’s disease is one of nine diseases caused by an expanded polyglutamine repeat within the affected protein and is hallmarked by intracellular inclusion bodies composed of aggregated N-terminal huntingtin fragments and other sequestered proteins. Fluorescence microscopy and filter trap assay are conventional methods to study protein aggregates, but cannot be used to analyze the presence and levels of post-translational modifications of aggregated huntingtin such as ubiquitination. Ubiquitination of proteins can be a signal for degradation and intracellular localization, but also affects protein activity and protein-protein interactions. The function of ubiquitination relies on its mono- and polymeric isoforms attached to protein substrates. Studying the ubiquitination pattern of aggregated huntingtin fragments offers an important possibility to understand huntingtin degradation and aggregation processes within the cell. For the identification of aggregated huntingtin and its ubiquitinated species, solubilization of the cellular aggregates is mandatory. Here we describe methods to identify post-translational modifications such as ubiquitination of aggregated mutant huntingtin. This approach is specifically described for use with mammalian cell culture and is suitable to study other disease-related proteins prone to aggregate.

Microstructural characterization of concrete prepared with recycled aggregates.

Science.gov (United States)

Guedes, Mafalda; Evangelista, Luís; de Brito, Jorge; Ferro, Alberto C

2013-10-01

Several authors have reported the workability, mechanical properties, and durability of concrete produced with construction waste replacing the natural aggregate. However, a systematic microstructural characterization of recycled aggregate concrete has not been reported. This work studies the use of fine recycled aggregate to replace fine natural aggregate in the production of concrete and reports the resulting microstructures. The used raw materials were natural aggregate, recycled aggregate obtained from a standard concrete, and Portland cement. The substitution extent was 0, 10, 50, and 100 vol%; hydration was stopped at 9, 24, and 96 h and 28 days. Microscopy was focused on the cement/aggregate interfacial transition zone, enlightening the effect of incorporating recycled aggregate on the formation and morphology of the different concrete hydration products. The results show that concretes with recycled aggregates exhibit typical microstructural features of the transition zone in normal strength concrete. Although overall porosity increases with increasing replacement, the interfacial bond is apparently stronger when recycled aggregates are used. An addition of 10 vol% results in a decrease in porosity at the interface with a corresponding increase of the material hardness. This provides an opportunity for development of increased strength Portland cement concretes using controlled amounts of concrete waste.

The alkali-aggregate reaction - concrete microstructure evolution

International Nuclear Information System (INIS)

Regourd, M.; Hornain, H.; Poitevin, P.

1981-01-01

The alkali-aggregate reaction has been studied by scanning electron microscopy and energy dispersive X-ray analysis, electron probe microanalysis, and X-ray diffraction in concretes containing glass aggregates or hornfels and greywacke aggregates. The surface reaction of the natural aggregates in alkaline solutions has been analysed by X-ray photo-electron spectrometry. The study of concretes with glass aggregates stored at 20 degrees Celcius and 100 percent relative humidity has revealed, irrespective of alkali content and type of cement, the formation of a gel containing SiO 2 , Na 2 O, CaO, MgO and Al 2 O 3 . Under heat and pressure (210 degrees Celcius at MPa for 48 hours), the gel crystallizes and yields silicates not very different from tobermorite found in autoclaved normal concretes but cotaining Na and K in solid solutions. The alkali reaction in two natural aggregate concretes, is also shown by the formation of gels and silicate crystals. The progressive structuring of the gels in silicate crystals is promoted by an increase in temperature. Ettringite and Ca(OH) 2 reinforce the alkali-aggregate reaction which may be looked upon as a hydration reaction, partially of the pozzolanic type

Collective Rationality in Graph Aggregation

NARCIS (Netherlands)

Endriss, U.; Grandi, U.; Schaub, T.; Friedrich, G.; O'Sullivan, B.

2014-01-01

Suppose a number of agents each provide us with a directed graph over a common set of vertices. Graph aggregation is the problem of computing a single “collective” graph that best represents the information inherent in this profile of individual graphs. We consider this aggregation problem from the

Sequence dependent aggregation of peptides and fibril formation

Science.gov (United States)

Hung, Nguyen Ba; Le, Duy-Manh; Hoang, Trinh X.

2017-09-01

Deciphering the links between amino acid sequence and amyloid fibril formation is key for understanding protein misfolding diseases. Here we use Monte Carlo simulations to study the aggregation of short peptides in a coarse-grained model with hydrophobic-polar (HP) amino acid sequences and correlated side chain orientations for hydrophobic contacts. A significant heterogeneity is observed in the aggregate structures and in the thermodynamics of aggregation for systems of different HP sequences and different numbers of peptides. Fibril-like ordered aggregates are found for several sequences that contain the common HPH pattern, while other sequences may form helix bundles or disordered aggregates. A wide variation of the aggregation transition temperatures among sequences, even among those of the same hydrophobic fraction, indicates that not all sequences undergo aggregation at a presumable physiological temperature. The transition is found to be the most cooperative for sequences forming fibril-like structures. For a fibril-prone sequence, it is shown that fibril formation follows the nucleation and growth mechanism. Interestingly, a binary mixture of peptides of an aggregation-prone and a non-aggregation-prone sequence shows the association and conversion of the latter to the fibrillar structure. Our study highlights the role of a sequence in selecting fibril-like aggregates and also the impact of a structural template on fibril formation by peptides of unrelated sequences.

21 CFR 1303.11 - Aggregate production quotas.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 9 2010-04-01 2010-04-01 false Aggregate production quotas. 1303.11 Section 1303.11 Food and Drugs DRUG ENFORCEMENT ADMINISTRATION, DEPARTMENT OF JUSTICE QUOTAS Aggregate Production and Procurement Quotas § 1303.11 Aggregate production quotas. (a) The Administrator shall determine...

Mechanical properties of concrete containing recycled concrete aggregate (RCA) and ceramic waste as coarse aggregate replacement

Science.gov (United States)

Khalid, Faisal Sheikh; Azmi, Nurul Bazilah; Sumandi, Khairul Azwa Syafiq Mohd; Mazenan, Puteri Natasya

2017-10-01

Many construction and development activities today consume large amounts of concrete. The amount of construction waste is also increasing because of the demolition process. Much of this waste can be recycled to produce new products and increase the sustainability of construction projects. As recyclable construction wastes, concrete and ceramic can replace the natural aggregate in concrete because of their hard and strong physical properties. This research used 25%, 35%, and 45% recycled concrete aggregate (RCA) and ceramic waste as coarse aggregate in producing concrete. Several tests, such as concrete cube compression and splitting tensile tests, were also performed to determine and compare the mechanical properties of the recycled concrete with those of the normal concrete that contains 100% natural aggregate. The concrete containing 35% RCA and 35% ceramic waste showed the best properties compared with the normal concrete.

Logic-based aggregation methods for ranking student applicants

Directory of Open Access Journals (Sweden)

Milošević Pavle

2017-01-01

Full Text Available In this paper, we present logic-based aggregation models used for ranking student applicants and we compare them with a number of existing aggregation methods, each more complex than the previous one. The proposed models aim to include depen- dencies in the data using Logical aggregation (LA. LA is a aggregation method based on interpolative Boolean algebra (IBA, a consistent multi-valued realization of Boolean algebra. This technique is used for a Boolean consistent aggregation of attributes that are logically dependent. The comparison is performed in the case of student applicants for master programs at the University of Belgrade. We have shown that LA has some advantages over other presented aggregation methods. The software realization of all applied aggregation methods is also provided. This paper may be of interest not only for student ranking, but also for similar problems of ranking people e.g. employees, team members, etc.

Topics in Probabilistic Judgment Aggregation

Science.gov (United States)

Wang, Guanchun

2011-01-01

This dissertation is a compilation of several studies that are united by their relevance to probabilistic judgment aggregation. In the face of complex and uncertain events, panels of judges are frequently consulted to provide probabilistic forecasts, and aggregation of such estimates in groups often yield better results than could have been made…

Thermophoretic aggregation of particles in a protoplanetary disc

Science.gov (United States)

Smith, Francis J.

2018-04-01

Thermophoresis causes particles to move down a temperature gradient to a cooler region of a neutral gas. An example is the temperature gradient in the gas around a large cold object, such as an aggregate of particles, cooled by radiation in a protoplanetary disc. Particles near this aggregate move down the temperature gradient to the aggregate, equivalent to the particles being attracted to it by an inter-particle thermophoretic force. This force is proportional to the temperature difference between gas and aggregate, to the gas density and to the cross-section of the aggregate. The force can be large. For example, calculations based on the equations of motion of the interacting particles show that it can be large enough in an optically thin environment to increase the rate of aggregation by up to six orders of magnitude when an aggregate radius lies between 0.1 μm and 1 mm. From 1 mm to about 10 cm aggregates drift inwards through the gas too quickly for the thermophoretic attraction to increase aggregation significantly; so they grow slowly, causing an observed accumulation of particles at these sizes. Particles above 10 cm move more quickly, causing aggregation due to collisions, but also causing fragmentation. However, calculations show that fragmenting particles and bouncing particles in inelastic collisions often have low enough relative velocities that thermophoresis brings them together again. This allows particles to grow above 1 m, which is otherwise difficult to explain.

Aggregates in monoclonal antibody manufacturing processes.

Science.gov (United States)

Vázquez-Rey, María; Lang, Dietmar A

2011-07-01

Monoclonal antibodies have proved to be a highly successful class of therapeutic products. Large-scale manufacturing of pharmaceutical antibodies is a complex activity that requires considerable effort in both process and analytical development. If a therapeutic protein cannot be stabilized adequately, it will lose partially or totally its therapeutic properties or even cause immunogenic reactions thus potentially further endangering the patients' health. The phenomenon of protein aggregation is a common issue that compromises the quality, safety, and efficacy of antibodies and can happen at different steps of the manufacturing process, including fermentation, purification, final formulation, and storage. Aggregate levels in drug substance and final drug product are a key factor when assessing quality attributes of the molecule, since aggregation might impact biological activity of the biopharmaceutical. In this review it is analyzed how aggregates are formed during monoclonal antibody industrial production, why they have to be removed and the manufacturing process steps that are designed to either minimize or remove aggregates in the final product. Copyright © 2011 Wiley Periodicals, Inc.

Towards constraint-based aggregation of energy flexibilities

DEFF Research Database (Denmark)

Valsomatzis, Emmanouil; Pedersen, Torben Bach; Abello, Alberto

2016-01-01

present the problem of aggregating energy flexibilities taking into account grid capacity limitations and introduce a heuristic aggregation technique. We show through an experimental setup that our proposed technique, compared to a baseline approach, not only leads to a valid unit commitment result......The aggregation of energy flexibilities enables individual producers and/or consumers with small loads to directly participate in the emerging energy markets. On the other hand, aggregation of such flexibilities might also create problems to the operation of the electrical grid. In this paper, we...

Aspects Concerning the Use of Recycled Concrete Aggregates

Science.gov (United States)

Robu, I.; Mazilu, C.; Deju, R.

2016-11-01

Natural aggregates (gravel and crushed) are essential non-renewable resources which are used for infrastructure works and civil engineering. Using recycled concrete aggregates (RCA) is a matter of high priority in the construction industry worldwide. This paper presents a study on the use of recycled aggregates, from a concrete of specified class, to acquire new cement concrete with different percentages of recycled aggregates.

Sustainable normal and high strength recycled aggregate concretes using crushed tested cylinders as coarse aggregates

Directory of Open Access Journals (Sweden)

Bilal S. Hamad

2017-12-01

Full Text Available The paper reports on a research program that was designed at the American University of Beirut (AUB to investigate the fresh and hardened mechanical properties of a high performance concrete mix produced with partial or full substitution of crushed natural lime-stone aggregates with recycled aggregates from crushed tested cylinders in batching plants. Choosing crushed cylinders as source of recycling would result in reusing portion of the waste products of the concrete production industry. An extensive concrete batching and testing program was conducted to achieve two optimum normal and high strength concrete mixes. The variables were the nominal concrete strength (28 or 60 MPa and the percentage replacement of natural coarse aggregates with recycled aggregates from crushed tested cylinders (0, 20, 40, 60, 80, or 100%. Normal strength tested cylinders were used as source of the recycled aggregates for the normal strength concrete (NSC mix and high strength tested cylinders were used for the high strength concrete (HSC mix. Tests on the trial batches included plastic state slump and hardened state mechanical properties including cylinder compressive strength, cylinder splitting tensile strength, modulus of elasticity, and standard beams flexural strength. The results indicated no significant effect on the slump and around 10% average reduction in the hardened mechanical properties for both investigated levels of concrete compressive strength.

SHAPE CHARACTERIZATION OF CONCRETE AGGREGATE

Directory of Open Access Journals (Sweden)

Jing Hu

2011-05-01

Full Text Available As a composite material, the performance of concrete materials can be expected to depend on the properties of the interfaces between its two major components, aggregate and cement paste. The microstructure at the interfacial transition zone (ITZ is assumed to be different from the bulk material. In general, properties of conventional concrete have been found favoured by optimum packing density of the aggregate. Particle size is a common denominator in such studies. Size segregation in the ITZ among the binder particles in the fresh state, observed in simulation studies by concurrent algorithm-based SPACE system, additionally governs density as well as physical bonding capacity inside these shell-like zones around aggregate particles. These characteristics have been demonstrated qualitatively pertaining also after maturation of the concrete. Such properties of the ITZs have direct impact on composite properties. Despite experimental approaches revealed effects of aggregate grain shape on different features of material structure (among which density, and as a consequence on mechanical properties, it is still an underrated factor in laboratory studies, probably due to the general feeling that a suitable methodology for shape characterization is not available. A scientific argument hindering progress is the interconnected nature of size and shape. Presently, a practical problem preventing shape effects to be emphasized is the limitation of most computer simulation systems in concrete technology to spherical particles. New developments at Delft University of Technology will make it possible in the near future to generate jammed states, or other high-density fresh particle mixtures of non-spherical particles, which thereupon can be subjected to hydration algorithms. This paper will sketch the outlines of a methodological approach for shape assessment of loose (non-embedded aggregate grains, and demonstrate its use for two types of aggregate, allowing

An exact approach for aggregated formulations

DEFF Research Database (Denmark)

Gamst, Mette; Spoorendonk, Simon

Aggregating formulations is a powerful approach for transforming problems into taking more tractable forms. Aggregated formulations can, though, have drawbacks: some information may get lost in the aggregation and { put in a branch-and-bound context { branching may become very di_cult and even....... The paper includes general considerations on types of problems for which the method is of particular interest. Furthermore, we prove the correctness of the procedure and consider how to include extensions such as cutting planes and advanced branching strategies....

Single particle detection and characterization of synuclein co-aggregation

International Nuclear Information System (INIS)

Giese, Armin; Bader, Benedikt; Bieschke, Jan; Schaffar, Gregor; Odoy, Sabine; Kahle, Philipp J.; Haass, Christian; Kretzschmar, Hans

2005-01-01

Protein aggregation is the key event in a number of human diseases such as Alzheimer's and Parkinson's disease. We present a general method to quantify and characterize protein aggregates by dual-colour scanning for intensely fluorescent targets (SIFT). In addition to high sensitivity, this approach offers a unique opportunity to study co-aggregation processes. As the ratio of two fluorescently labelled components can be analysed for each aggregate separately in a homogeneous assay, the molecular composition of aggregates can be studied even in samples containing a mixture of different types of aggregates. Using this method, we could show that wild-type α-synuclein forms co-aggregates with a mutant variant found in familial Parkinson's disease. Moreover, we found a striking increase in aggregate formation at non-equimolar mixing ratios, which may have important therapeutic implications, as lowering the relative amount of aberrant protein may cause an increase of protein aggregation leading to adverse effects

Live Cell Characterization of DNA Aggregation Delivered through Lipofection.

Science.gov (United States)

Mieruszynski, Stephen; Briggs, Candida; Digman, Michelle A; Gratton, Enrico; Jones, Mark R

2015-05-27

DNA trafficking phenomena, such as information on where and to what extent DNA aggregation occurs, have yet to be fully characterised in the live cell. Here we characterise the aggregation of DNA when delivered through lipofection by applying the Number and Brightness (N&B) approach. The N&B analysis demonstrates extensive aggregation throughout the live cell with DNA clusters in the extremity of the cell and peri-nuclear areas. Once within the nucleus aggregation had decreased 3-fold. In addition, we show that increasing serum concentration of cell media results in greater cytoplasmic aggregation. Further, the effects of the DNA fragment size on aggregation was explored, where larger DNA constructs exhibited less aggregation. This study demonstrates the first quantification of DNA aggregation when delivered through lipofection in live cells. In addition, this study has presents a model for alternative uses of this imaging approach, which was originally developed to study protein oligomerization and aggregation.

Retiring the Short-Run Aggregate Supply Curve

Science.gov (United States)

Elwood, S. Kirk

2010-01-01

The author argues that the aggregate demand/aggregate supply (AD/AS) model is significantly improved--although certainly not perfected--by trimming it of the short-run aggregate supply (SRAS) curve. Problems with the SRAS curve are shown first for the AD/AS model that casts the AD curve as identifying the equilibrium level of output associated…

Measurement of platelet aggregation, independently of patient platelet count

DEFF Research Database (Denmark)

Vinholt, P J; Frederiksen, H; Hvas, A-M

2017-01-01

with collagen-related peptide). Platelet aggregation had a negative predictive value of 100% for a bleeding tendency among patients. Conclusion The established platelet aggregation assay was applicable for thrombocytopenic patients, and improved the identification of bleeding risk.......Essentials •Platelet function may influence bleeding risk in thrombocytopenia, but useful tests are needed. •A flow cytometric platelet aggregation test independent of the patient platelet count was made. •Platelet aggregation was reduced in thrombocytopenic patients with hematological cancer....... •High platelet aggregation ruled out bleeding tendency in thrombocytopenic patients. Summary Background Methods for testing platelet aggregation in thrombocytopenia are lacking. Objective To establish a flow-cytometric test of in vitro platelet aggregation independently of the patient's platelet count...

Environmentalism and natural aggregate mining

Science.gov (United States)

Drew, L.J.; Langer, W.H.; Sachs, J.S.

2002-01-01

Sustaining a developed economy and expanding a developing one require the use of large volumes of natural aggregate. Almost all human activity (commercial, recreational, or leisure) is transacted in or on facilities constructed from natural aggregate. In our urban and suburban worlds, we are almost totally dependent on supplies of water collected behind dams and transported through aqueducts made from concrete. Natural aggregate is essential to the facilities that produce energy-hydroelectric dams and coal-fired powerplants. Ironically, the utility created for mankind by the use of natural aggregate is rarely compared favorably with the environmental impacts of mining it. Instead, the empty quarries and pits are seen as large negative environmental consequences. At the root of this disassociation is the philosophy of environmentalism, which flavors our perceptions of the excavation, processing, and distribution of natural aggregate. The two end-member ideas in this philosophy are ecocentrism and anthropocentrism. Ecocentrism takes the position that the natural world is a organism whose arteries are the rivers-their flow must not be altered. The soil is another vital organ and must not be covered with concrete and asphalt. The motto of the ecocentrist is "man must live more lightly on the land." The anthropocentrist wants clean water and air and an uncluttered landscape for human use. Mining is allowed and even encouraged, but dust and noise from quarry and pit operations must be minimized. The large volume of truck traffic is viewed as a real menace to human life and should be regulated and isolated. The environmental problems that the producers of natural aggregate (crushed stone and sand and gravel) face today are mostly difficult social and political concerns associated with the large holes dug in the ground and the large volume of heavy truck traffic associated with quarry and pit operations. These concerns have increased in recent years as society's demand for

Evaluation of Colemanite Waste as Aggregate Hot Mix Asphalt Concrete

Directory of Open Access Journals (Sweden)

Nihat MOROVA

2015-09-01

Full Text Available In this study usability of waste colemanite which is obtained after cutting block colemanite for giving proper shape to blocks as an aggregate in hot mix asphalt. For this aim asphalt concrete samples were prepared with four different aggregate groups and optimum bitumen content was determined. First of all only limestone was used as an aggregate. After that, only colemanite aggregate was used with same aggregate gradation. Then, the next step of the study, Marshall samples were produced by changing coarse and fine aggregate gradation as limestone and colemanite and Marshall test were conducted. When evaluated the results samples which produced with only limestone aggregate gave the maximum Marshall Stability value. When handled other mixture groups (Only colemanite, colemanite as coarse aggregate-limestone as fine aggregate, colemanite as fine aggregate-limestone as coarse aggregate all groups were verified specification limits. As a result, especially in areas where there is widespread colemanite waste, if transportation costs did not exceed the cost of limestone, colemanite stone waste could be used instead of limestone in asphalt concrete mixtures as fine aggregate

Effects of vegetation restoration on the aggregate stability and distribution of aggregate-associated organic carbon in a typical karst gorge region

Science.gov (United States)

Tang, F. K.; Cui, M.; Lu, Q.; Liu, Y. G.; Guo, H. Y.; Zhou, J. X.

2015-08-01

Changes in soil utilization significantly affect aggregate stability and aggregate-associated soil organic carbon (SOC). A field investigation and indoor analysis were conducted in order to study the soil aggregate stability and organic carbon distribution in the water-stable aggregates (WSA) of the bare land (BL), grassland (GL), shrubland (SL), and woodland (WL) in a typical karst gorge region. The results indicated that the BL, GL, SL, and WL were dominated by particles with sizes > 5 mm under dry sieving treatment, and that the soil aggregate contents of various sizes decreased as the particle size decreased. In addition, the BL, GL, SL, and WL were predominantly comprised of WSA sieving treatment, and that the WSA contents initially increased, then decreased, and then increased again as the particle size decreased. Furthermore, at a soil depth of 0-60 cm, the mean weight diameter (MWD), geometrical mean diameter (GMD), and fractal dimensions (D) of the dry aggregates and water-stable aggregates in the different types of land were ranked, in descending order, as WL > GL > SL > BL. The contents of WSA > 0.25 mm, MWD and GMD increased significantly, in that order, and the percentage of aggregate destruction (PAD) and fractal dimensions decreased significantly as the soil aggregate stability improved. The results of this study indicated that, as the SOC contents increased after vegetation restoration, the average SOC content of WL was 2.35, 1.37, and 1.26 times greater than that in the BL, GL, and SL, respectively. The total SOC and SOC associated in WSA of various sizes were the highest at a soil depth of 0-20 cm. In addition, the SOC contents of the WSA increased as the soil aggregate sizes decreased. The SOC contents of the WSA aggregates aggregate SOC contents. The woodland and grassland facilitated WSA stability and SOC protection, thus, promoting the natural restoration of vegetation by reducing artificial disturbances could effectively restore the ecology

The Mechanisms of Aberrant Protein Aggregation

Science.gov (United States)

Cohen, Samuel; Vendruscolo, Michele; Dobson, Chris; Knowles, Tuomas

2012-02-01

We discuss the development of a kinetic theory for understanding the aberrant loss of solubility of proteins. The failure to maintain protein solubility results often in the assembly of organized linear structures, commonly known as amyloid fibrils, the formation of which is associated with over 50 clinical disorders including Alzheimer's and Parkinson's diseases. A true microscopic understanding of the mechanisms that drive these aggregation processes has proved difficult to achieve. To address this challenge, we apply the methodologies of chemical kinetics to the biomolecular self-assembly pathways related to protein aggregation. We discuss the relevant master equation and analytical approaches to studying it. In particular, we derive the underlying rate laws in closed-form using a self-consistent solution scheme; the solutions that we obtain reveal scaling behaviors that are very generally present in systems of growing linear aggregates, and, moreover, provide a general route through which to relate experimental measurements to mechanistic information. We conclude by outlining a study of the aggregation of the Alzheimer's amyloid-beta peptide. The study identifies the dominant microscopic mechanism of aggregation and reveals previously unidentified therapeutic strategies.

Salt-induced aggregation of stiff polyelectrolytes

International Nuclear Information System (INIS)

Fazli, Hossein; Mohammadinejad, Sarah; Golestanian, Ramin

2009-01-01

Molecular dynamics simulation techniques are used to study the process of aggregation of highly charged stiff polyelectrolytes due to the presence of multivalent salt. The dominant kinetic mode of aggregation is found to be the case of one end of one polyelectrolyte meeting others at right angles, and the kinetic pathway to bundle formation is found to be similar to that of flocculation dynamics of colloids as described by Smoluchowski. The aggregation process is found to favor the formation of finite bundles of 10-11 filaments at long times. Comparing the distribution of the cluster sizes with the Smoluchowski formula suggests that the energy barrier for the aggregation process is negligible. Also, the formation of long-lived metastable structures with similarities to the raft-like structures of actin filaments is observed within a range of salt concentration.

Suspensions of colloidal particles and aggregates

CERN Document Server

Babick, Frank

2016-01-01

This book addresses the properties of particles in colloidal suspensions. It has a focus on particle aggregates and the dependency of their physical behaviour on morphological parameters. For this purpose, relevant theories and methodological tools are reviewed and applied to selected examples. The book is divided into four main chapters. The first of them introduces important measurement techniques for the determination of particle size and interfacial properties in colloidal suspensions. A further chapter is devoted to the physico-chemical properties of colloidal particles—highlighting the interfacial phenomena and the corresponding interactions between particles. The book’s central chapter examines the structure-property relations of colloidal aggregates. This comprises concepts to quantify size and structure of aggregates, models and numerical tools for calculating the (light) scattering and hydrodynamic properties of aggregates, and a discussion on van-der-Waals and double layer interactions between ...

Path coupling and aggregate path coupling

CERN Document Server

Kovchegov, Yevgeniy

2018-01-01

This book describes and characterizes an extension to the classical path coupling method applied to statistical mechanical models, referred to as aggregate path coupling. In conjunction with large deviations estimates, the aggregate path coupling method is used to prove rapid mixing of Glauber dynamics for a large class of statistical mechanical models, including models that exhibit discontinuous phase transitions which have traditionally been more difficult to analyze rigorously. The book shows how the parameter regions for rapid mixing for several classes of statistical mechanical models are derived using the aggregate path coupling method.

Entanglement dynamics of J-aggregate systems

Energy Technology Data Exchange (ETDEWEB)

Thilagam, A, E-mail: Thilagam.Lohe@unisa.edu.au [Information Technology, Engineering and the Environment, Mawson Institute, University of South Australia, South Australia 5095 (Australia)

2011-04-01

The entanglement dynamics of one-dimensional J-aggregate systems are examined using entanglement measures such as the von Neumann entropy and Wootters concurrence. The effect of dispersion and resonance terms associated with the exciton-phonon interaction are analyzed using Green's function formalism. A probability propagator term, derived using the Markovian approximation, presents J-aggregate systems as potential channels for large scale energy propagation for a select range of parameters. We highlight the role of a critical number of coherently coupled monomer sites and two-exciton states in determining superradiance in J-aggregate systems.

Strain-dependent profile of misfolded prion protein aggregates.

Science.gov (United States)

Morales, Rodrigo; Hu, Ping Ping; Duran-Aniotz, Claudia; Moda, Fabio; Diaz-Espinoza, Rodrigo; Chen, Baian; Bravo-Alegria, Javiera; Makarava, Natallia; Baskakov, Ilia V; Soto, Claudio

2016-02-15

Prions are composed of the misfolded prion protein (PrP(Sc)) organized in a variety of aggregates. An important question in the prion field has been to determine the identity of functional PrP(Sc) aggregates. In this study, we used equilibrium sedimentation in sucrose density gradients to separate PrP(Sc) aggregates from three hamster prion strains (Hyper, Drowsy, SSLOW) subjected to minimal manipulations. We show that PrP(Sc) aggregates distribute in a wide range of arrangements and the relative proportion of each species depends on the prion strain. We observed a direct correlation between the density of the predominant PrP(Sc) aggregates and the incubation periods for the strains studied. The relative presence of PrP(Sc) in fractions of different sucrose densities was indicative of the protein deposits present in the brain as analyzed by histology. Interestingly, no association was found between sensitivity to proteolytic degradation and aggregation profiles. Therefore, the organization of PrP molecules in terms of the density of aggregates generated may determine some of the particular strain properties, whereas others are independent from it. Our findings may contribute to understand the mechanisms of strain variation and the role of PrP(Sc) aggregates in prion-induced neurodegeneration.

Balancing energy flexibilities through aggregation

DEFF Research Database (Denmark)

Valsomatzis, Emmanouil; Hose, Katja; Pedersen, Torben Bach

2014-01-01

One of the main goals of recent developments in the Smart Grid area is to increase the use of renewable energy sources. These sources are characterized by energy fluctuations that might lead to energy imbalances and congestions in the electricity grid. Exploiting inherent flexibilities, which exist...... in both energy production and consumption, is the key to solving these problems. Flexibilities can be expressed as flex-offers, which due to their high number need to be aggregated to reduce the complexity of energy scheduling. In this paper, we discuss balance aggregation techniques that already during...... aggregation aim at balancing flexibilities in production and consumption to reduce the probability of congestions and reduce the complexity of scheduling. We present results of our extensive experiments....

Recycled Concrete as Aggregate for Structural Concrete Production

Directory of Open Access Journals (Sweden)

Mirjana Malešev

2010-04-01

Full Text Available A comparative analysis of the experimental results of the properties of fresh and hardened concrete with different replacement ratios of natural with recycled coarse aggregate is presented in the paper. Recycled aggregate was made by crushing the waste concrete of laboratory test cubes and precast concrete columns. Three types of concrete mixtures were tested: concrete made entirely with natural aggregate (NAC as a control concrete and two types of concrete made with natural fine and recycled coarse aggregate (50% and 100% replacement of coarse recycled aggregate. Ninety-nine specimens were made for the testing of the basic properties of hardened concrete. Load testing of reinforced concrete beams made of the investigated concrete types is also presented in the paper. Regardless of the replacement ratio, recycled aggregate concrete (RAC had a satisfactory performance, which did not differ significantly from the performance of control concrete in this experimental research. However, for this to be fulfilled, it is necessary to use quality recycled concrete coarse aggregate and to follow the specific rules for design and production of this new concrete type.

SHAPE ANALYSIS OF FINE AGGREGATES USED FOR CONCRETE

Directory of Open Access Journals (Sweden)

Huan He

2016-12-01

Full Text Available Fine aggregate is one of the essential components in concrete and significantly influences the material properties. As parts of natures, physical characteristics of fine aggregate are highly relevant to its behaviors in concrete. The most of previous studies are mainly focused on the physical properties of coarse aggregate due to the equipment limitations. In this paper, two typical fine aggregates, i.e. river sand and crushed rock, are selected for shape characterization. The new developed digital image analysis systems are employed as the main approaches for the purpose. Some other technical methods, e.g. sieve test, laser diffraction method are also used for the comparable references. Shape characteristics of fine aggregates with different origins but in similar size ranges are revealed by this study. Compared with coarse aggregate, fine grains of different origins generally have similar shape differences. These differences are more significant in surface texture properties, which can be easily identified by an advanced shape parameter: bluntness. The new image analysis method is then approved to be efficient for the shape characterization of fine aggregate in concrete.

Self-aggregation of magnetic semiconductor EuS nanocrystals

International Nuclear Information System (INIS)

Tanaka, Atsushi; Hasegawa, Yasuchika; Kamikubo, Hironari; Kataoka, Mikio; Kawai, Tsuyoshi

2009-01-01

Controlled formation of aggregates having organized structure of cube-shaped EuS nanocrystals is reported. The EuS aggregates in liquid media (methanol) were obtained by means of van der Waals interaction between EuS nanocrystals. The packing structure of the EuS aggregates is characterized with transmission electron microscopy (TEM) and small angle X-ray scattering measurements (SAXS). TEM image indicates the EuS nanocrystals form self-aggregated 2D orthogonal lattice structure. The diffraction peak of (111) of SAXS profile shows that the cube-shaped EuS form 3D cubic superlattice. We successfully demonstrated that the aggregates of cube-shaped EuS nanocrystals formed cubic stacking structure.

Modelling The Effects of Aggregate Size on Alkali Aggregate Reaction Expansion

Directory of Open Access Journals (Sweden)

N. Z. Sekrane

2014-06-01

Full Text Available This work aims at developing models to predict the potential expansion of concrete containing alkali-reactive aggregates. The paper gives measurements in order to provide experimental data concerning the effect of particle size of an alkali-reactive siliceous limestone on mortar expansion. Results show that no expansion was measured on the mortars using small particles (0.5-1.0 mm while the particles (1.0–2.0 mm gave the largest expansions (0.217%. Two models are proposed, the first one studies the correlations between the measured expansions and the size of aggregates, the second one calculates the thickness of the porous zone necessary to take again all the volume of the gel created.

Model of fractal aggregates induced by shear

Directory of Open Access Journals (Sweden)

Wan Zhanhong

2013-01-01

Full Text Available It is an undoubted fact that particle aggregates from marine, aerosol, and engineering systems have fractal structures. In this study, fractal geometry is used to describe the morphology of irregular aggregates. The mean-field theory is employed to solve coagulation kinetic equation of aggregates. The Taylor-expansion method of moments in conjunction with the self-similar fractal characteristics is used to represent the particulate field. The effect of the target fractal dimensions on zeroth-order moment, second-order moment, and geometric standard deviation of the aggregates is explored. Results show that the developed moment method is an efficient and powerful approach to solving such evolution equations.

Towards Better Understanding of Concrete Containing Recycled Concrete Aggregate

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Hisham Qasrawi

2013-01-01

Full Text Available The effect of using recycled concrete aggregates (RCA on the basic properties of normal concrete is studied. First, recycled aggregate properties have been determined and compared to those of normal aggregates. Except for absorption, there was not a significant difference between the two. Later, recycled aggregates were introduced in concrete mixes. In these mixes, natural coarse aggregate was partly or totally replaced by recycled aggregates. Results show that the use of recycled aggregates has an adverse effect on the workability and air content of fresh concrete. Depending on the water/cement ratio and on the percent of the normal aggregate replaced by RCA, the concrete strength is reduced by 5% to 25%, while the tensile strength is reduced by 4% to 14%. All results are compared with previous research. As new in this research, the paper introduces a simple formula for the prediction of the modulus of elasticity of RCA concrete. Furthermore, the paper shows the variation of the air content of RAC.

Microbial Ecology of Soil Aggregation in Agroecosystems

Science.gov (United States)

Hofmockel, K. S.; Bell, S.; Tfailly, M.; Thompson, A.; Callister, S.

2017-12-01

Crop selection and soil texture influence the physicochemical attributes of the soil, which structures microbial communities and influences soil C cycling storage. At the molecular scale, microbial metabolites and necromass alter the soil environment, which creates feedbacks that influence ecosystem functions, including soil C accumulation. By integrating lab to field studies we aim to identify the molecules, organisms and metabolic pathways that control carbon cycling and stabilization in bioenergy soils. We investigated the relative influence of plants, microbes, and minerals on soil aggregate ecology at the Great Lakes Bioenergy Research experiment. Sites in WI and MI, USA have been in corn and switchgrass cropping systems for a decade. By comparing soil aggregate ecology across sites and cropping systems we are able to test the relative importance of plant, microbe, mineral influences on soil aggregate dynamics. Soil microbial communities (16S) differ in diversity and phylogeny among sites and cropping systems. FT-ICR MS revealed differences in the molecular composition of water-soluble fraction of soil organic matter for cropping systems and soil origin for both relative abundance of assigned formulas and biogeochemical classes of compounds. We found the degree of aggregation, measured by mean weighted diameter of aggregate fractions, is influenced by plant-soil interactions. Similarly, the proportion of soil aggregate fractions varied by both soil and plant factors. Differences in aggregation were reflected in differences in bacterial, but not fungal community composition across aggregate fractions, within each soil. Scanning electron microscopy revealed stark differences in mineral-organic interactions that influence the microbial niche and the accessibility of substrates within the soil. The clay soils show greater surface heterogeneity, enabling interactions with organic fraction of the soil. This is consistent with molecular data that reveal differences

Cooperative structural transitions in amyloid-like aggregation

Science.gov (United States)

Steckmann, Timothy; Bhandari, Yuba R.; Chapagain, Prem P.; Gerstman, Bernard S.

2017-04-01

Amyloid fibril aggregation is associated with several horrific diseases such as Alzheimer's, Creutzfeld-Jacob, diabetes, Parkinson's, and others. Although proteins that undergo aggregation vary widely in their primary structure, they all produce a cross-β motif with the proteins in β-strand conformations perpendicular to the fibril axis. The process of amyloid aggregation involves forming myriad different metastable intermediate aggregates. To better understand the molecular basis of the protein structural transitions and aggregation, we report on molecular dynamics (MD) computational studies on the formation of amyloid protofibrillar structures in the small model protein ccβ, which undergoes many of the structural transitions of the larger, naturally occurring amyloid forming proteins. Two different structural transition processes involving hydrogen bonds are observed for aggregation into fibrils: the breaking of intrachain hydrogen bonds to allow β-hairpin proteins to straighten, and the subsequent formation of interchain H-bonds during aggregation into amyloid fibrils. For our MD simulations, we found that the temperature dependence of these two different structural transition processes results in the existence of a temperature window that the ccβ protein experiences during the process of forming protofibrillar structures. This temperature dependence allows us to investigate the dynamics on a molecular level. We report on the thermodynamics and cooperativity of the transformations. The structural transitions that occurred in a specific temperature window for ccβ in our investigations may also occur in other amyloid forming proteins but with biochemical parameters controlling the dynamics rather than temperature.

Aggregate formation in 3D turbulent-like flows

NARCIS (Netherlands)

Dominguez, A.; Aartrijk, van M.; Castello, Del L.; Clercx, H.J.H.; Geurts, B.; Clercx, H

2006-01-01

Aggregate formation is an important process in industrial and environ mental turbulent flows. Two examples in the environmental area, where turbulent aggregate formation takes place, are raindrop formation in clouds and Marine Snow (aggregate) formation in the upper layer in the oceans. The

Engineering Performance of Polyurethane Bonded Aggregates

Directory of Open Access Journals (Sweden)

Haimin WU

2017-08-01

Full Text Available In this paper the engineering performance of polyurethane (PUR bonded aggregate were studied. The engineering performance, including compressive and flexural mechanical properties, void ratio, and coefficient of permeability were determined through laboratory tests. Moreover, the effects of two different curing conditions on the compressive strength properties of a PUR bonded aggregate were also evaluated. The compressive strengths of PUR bonded aggregates were found to be lower than that of conventional porous concrete, which is a commonly used cushion material. However, experimental results indicated a higher void ratio and coefficient of permeability, lower elasticity modulus, better toughness, and stronger adaptability to flexural deformation compared to porous concrete. Consequently, PUR bonded aggregate is a better solution than porous concrete when used as the cushion material of a geomembrane surface barrier for a high rock-fill dam.DOI: http://dx.doi.org/10.5755/j01.ms.23.2.15798

SHAPE ANALYSIS OF FINE AGGREGATES USED FOR CONCRETE

OpenAIRE

HE, Huan; Courard, Luc; Pirard, Eric; Michel, Frédéric

2016-01-01

Fine aggregate is one of the essential components in concrete and significantly influences the material properties. As parts of natures, physical characteristics of fine aggregate are highly relevant to its behaviors in concrete. The most of previous studies are mainly focused on the physical properties of coarse aggregate due to the equipment limitations. In this paper, two typical fine aggregates, i.e. river sand and crushed rock, are selected for shape characterization. The new developed d...

Probabilistic Analysis of Structural Member from Recycled Aggregate Concrete

Science.gov (United States)

Broukalová, I.; Šeps, K.

2017-09-01

The paper aims at the topic of sustainable building concerning recycling of waste rubble concrete from demolition. Considering demands of maximising recycled aggregate use and minimising of cement consumption, composite from recycled concrete aggregate was proposed. The objective of the presented investigations was to verify feasibility of the recycled aggregate cement based fibre reinforced composite in a structural member. Reliability of wall from recycled aggregate fibre reinforced composite was assessed in a probabilistic analysis of a load-bearing capacity of the wall. The applicability of recycled aggregate fibre reinforced concrete in structural applications was demonstrated. The outcomes refer to issue of high scatter of material parameters of recycled aggregate concretes.

Liver tissue engineering based on aggregate assembly: efficient formation of endothelialized rat hepatocyte aggregates and their immobilization with biodegradable fibres

International Nuclear Information System (INIS)

Pang, Y; Shinohara, M; Komori, K; Sakai, Y; Montagne, K

2012-01-01

To realize long-term in vitro culture of hepatocytes at a high density while maintaining a high hepatic function for aggregate-based liver tissue engineering, we report here a novel culture method whereby endothelialized rat hepatocyte aggregates were formed using a PDMS microwell device and cultured in a perfusion bioreactor by introducing spacers between aggregates to improve oxygen and nutrient supply. Primary rat hepatocyte aggregates around 100 µm in diameter coated with human umbilical vein endothelial cells were spontaneously and quickly formed after 12 h of incubation, thanks to the continuous supply of oxygen by diffusion through the PDMS honeycomb microwell device. Then, the recovered endothelialized rat hepatocyte aggregates were mixed with biodegradable poly-l-lactic acid fibres in suspension and packed into a PDMS-based bioreactor. Perfusion culture of 7 days was successfully achieved with more than 73.8% cells retained in the bioreactor. As expected, the fibres acted as spacers between aggregates, which was evidenced from the enhanced albumin production and more spherical morphology compared with fibre-free packing. In summary, this study shows the advantages of using PDMS-based microwells to form heterotypic aggregates and also demonstrates the feasibility of spacing tissue elements for improving oxygen and nutrient supply to tissue engineering based on modular assembly. (paper)

Aggregate formation in 3D turbulent-like flows

NARCIS (Netherlands)

Dominguez, A.; Clercx, H.J.H.

2006-01-01

Aggregate formation is an important process in industrial and environmental turbulent flows. In oceans turbulence play an important role on Marine Snow (aggregate) formation. For a proper description, the study of aggregate formation in turbulent flows requires a particle based model i.e. following

The proteome of neurofilament-containing protein aggregates in blood

Directory of Open Access Journals (Sweden)

Rocco Adiutori

2018-07-01

Full Text Available Protein aggregation in biofluids is a poorly understood phenomenon. Under normal physiological conditions, fluid-borne aggregates may contain plasma or cell proteins prone to aggregation. Recent observations suggest that neurofilaments (Nf, the building blocks of neurons and a biomarker of neurodegeneration, are included in high molecular weight complexes in circulation. The composition of these Nf-containing hetero-aggregates (NCH may change in systemic or organ-specific pathologies, providing the basis to develop novel disease biomarkers. We have tested ultracentrifugation (UC and a commercially available protein aggregate binder, Seprion PAD-Beads (SEP, for the enrichment of NCH from plasma of healthy individuals, and then characterised the Nf content of the aggregate fractions using gel electrophoresis and their proteome by mass spectrometry (MS. Western blot analysis of fractions obtained by UC showed that among Nf isoforms, neurofilament heavy chain (NfH was found within SDS-stable high molecular weight aggregates. Shotgun proteomics of aggregates obtained with both extraction techniques identified mostly cell structural and to a lesser extent extra-cellular matrix proteins, while functional analysis revealed pathways involved in inflammatory response, phagosome and prion-like protein behaviour. UC aggregates were specifically enriched with proteins involved in endocrine, metabolic and cell-signalling regulation. We describe the proteome of neurofilament-containing aggregates isolated from healthy individuals biofluids using different extraction methods.

Influence of velocity gradient on optimisation of the aggregation process and properties of formed aggregates. Part 2. Quantification of the influence of agitation intensity and time on the properties of formed aggregates

Czech Academy of Sciences Publication Activity Database

Polášek, Pavel

2011-01-01

Roč. 59, č. 3 (2011), s. 196-205 ISSN 0042-790X R&D Projects: GA ČR GA103/07/1016 Institutional research plan: CEZ:AV0Z20600510 Keywords : inline high density suspension (IHDS) formation process * aggregation phases * aggregate properties * compactness * relative density of aggregates Subject RIV: BK - Fluid Dynamics Impact factor: 0.340, year: 2011

Soil aggregation under different management systems

Directory of Open Access Journals (Sweden)

Cibele Mascioli Rebello Portella

2012-12-01

Full Text Available Considering that the soil aggregation reflects the interaction of chemical, physical and biological soil factors, the aim of this study was evaluate alterations in aggregation, in an Oxisol under no-tillage (NT and conventional tillage (CT, since over 20 years, using as reference a native forest soil in natural state. After analysis of the soil profile (cultural profile in areas under forest management, samples were collected from the layers 0-5, 5-10, 10-20 and 20-40 cm, with six repetitions. These samples were analyzed for the aggregate stability index (ASI, mean weighted diameter (MWD, mean geometric diameter (MGD in the classes > 8, 8-4, 4-2, 2-1, 1-0.5, 0.5-0.25, and < 0.25 mm, and for physical properties (soil texture, water dispersible clay (WDC, flocculation index (FI and bulk density (Bd and chemical properties (total organic carbon - COT, total nitrogen - N, exchangeable calcium - Ca2+, and pH. The results indicated that more intense soil preparation (M < NT < PC resulted in a decrease in soil stability, confirmed by all stability indicators analyzed: MWD, MGD, ASI, aggregate class distribution, WDC and FI, indicating the validity of these indicators in aggregation analyses of the studied soil.

Aggregation of natively folded proteins: a theoretical approach

International Nuclear Information System (INIS)

Trovato, Antonio; Maritan, Amos; Seno, Flavio

2007-01-01

The reliable identification of β-aggregating stretches in protein sequences is essential for the development of therapeutic agents for Alzheimer's and Parkinson's diseases, as well as other pathological conditions associated with protein deposition. While the list of aggregation related diseases is growing, it has also been shown that many proteins that are normally well behaved can be induced to aggregate in vitro. This fact suggests the existence of a unified framework that could explain both folding and aggregation. By assuming this universal behaviour, we have recently introduced an algorithm (PASTA: prediction of amyloid structure aggregation), which is based on a sequence-specific energy function derived from the propensity of two residue types to be found paired in neighbouring strands within β-sheets in globular proteins. The algorithm is able to predict the most aggregation-prone portions of several proteins initially unfolded, in excellent agreement with experimental results. Here, we apply the method to a set of proteins which are known to aggregate, but which are natively folded. The quality of the prediction is again very high, corroborating the hypothesis that the amyloid structure is stabilized by the same physico-chemical determinants as those operating in folded proteins

Protein aggregation and misfolding: good or evil?

Science.gov (United States)

Pastore, Annalisa; Temussi, Pierandrea

2012-06-01

Protein aggregation and misfolding have important implications in an increasing number of fields ranging from medicine to biology to nanotechnology and material science. The interest in understanding this field has accordingly increased steadily over the last two decades. During this time the number of publications that have been dedicated to protein aggregation has increased exponentially, tackling the problem from several different and sometime contradictory perspectives. This review is meant to summarize some of the highlights that come from these studies and introduce this topical issue on the subject. The factors that make a protein aggregate and the cellular strategies that defend from aggregation are discussed together with the perspectives that the accumulated knowledge may open.

Protein aggregation and misfolding: good or evil?

International Nuclear Information System (INIS)

Pastore, Annalisa; Temussi, Pierandrea

2012-01-01

Protein aggregation and misfolding have important implications in an increasing number of fields ranging from medicine to biology to nanotechnology and material science. The interest in understanding this field has accordingly increased steadily over the last two decades. During this time the number of publications that have been dedicated to protein aggregation has increased exponentially, tackling the problem from several different and sometime contradictory perspectives. This review is meant to summarize some of the highlights that come from these studies and introduce this topical issue on the subject. The factors that make a protein aggregate and the cellular strategies that defend from aggregation are discussed together with the perspectives that the accumulated knowledge may open. (topical review)

Characterization of fine aggregates in concrete by different experimental approaches

OpenAIRE

He, Huan; Courard, Luc; Pirard, Eric; Michel, Frédéric

2011-01-01

Being its major component, aggregate can occupy up to three-quarter of the volume of concrete. The structure of aggregate formed in hardened state impacts largely on mechanical and durability properties of concrete. On another hand, physical characteristics of aggregate are primarily assumed to be relevant to granular behavior of aggregate. Therefore, characterization of aggregate is of high relevance to concrete studies. In this study, different types of fine aggregate used in concrete, name...

Efficient external memory structures for range-aggregate queries

DEFF Research Database (Denmark)

Agarwal, P.K.; Yang, J.; Arge, L.

2013-01-01

We present external memory data structures for efficiently answering range-aggregate queries. The range-aggregate problem is defined as follows: Given a set of weighted points in Rd, compute the aggregate of the weights of the points that lie inside a d-dimensional orthogonal query rectangle. The...

Effect of fly ash on the strength of porous concrete using recycled coarse aggregate to replace low-quality natural coarse aggregate

Science.gov (United States)

Arifi, Eva; Cahya, Evi Nur; Christin Remayanti, N.

2017-09-01

The performance of porous concrete made of recycled coarse aggregate was investigated. Fly ash was used as cement partial replacement. In this study, the strength of recycled aggregate was coMPared to low quality natural coarse aggregate which has high water absorption. Compression strength and tensile splitting strength test were conducted to evaluate the performance of porous concrete using fly ash as cement replacement. Results have shown that the utilization of recycled coarse aggregate up to 75% to replace low quality natural coarse aggregate with high water absorption increases compressive strength and splitting tensile strength of porous concrete. Using fly ash up to 25% as cement replacement improves compressive strength and splitting tensile strength of porous concrete.

Cellular Handling of Protein Aggregates by Disaggregation Machines.

Science.gov (United States)

Mogk, Axel; Bukau, Bernd; Kampinga, Harm H

2018-01-18

Both acute proteotoxic stresses that unfold proteins and expression of disease-causing mutant proteins that expose aggregation-prone regions can promote protein aggregation. Protein aggregates can interfere with cellular processes and deplete factors crucial for protein homeostasis. To cope with these challenges, cells are equipped with diverse folding and degradation activities to rescue or eliminate aggregated proteins. Here, we review the different chaperone disaggregation machines and their mechanisms of action. In all these machines, the coating of protein aggregates by Hsp70 chaperones represents the conserved, initializing step. In bacteria, fungi, and plants, Hsp70 recruits and activates Hsp100 disaggregases to extract aggregated proteins. In the cytosol of metazoa, Hsp70 is empowered by a specific cast of J-protein and Hsp110 co-chaperones allowing for standalone disaggregation activity. Both types of disaggregation machines are supported by small Hsps that sequester misfolded proteins. Copyright © 2018 Elsevier Inc. All rights reserved.

Signature of an aggregation-prone conformation of tau

Science.gov (United States)

Eschmann, Neil A.; Georgieva, Elka R.; Ganguly, Pritam; Borbat, Peter P.; Rappaport, Maxime D.; Akdogan, Yasar; Freed, Jack H.; Shea, Joan-Emma; Han, Songi

2017-03-01

The self-assembly of the microtubule associated tau protein into fibrillar cell inclusions is linked to a number of devastating neurodegenerative disorders collectively known as tauopathies. The mechanism by which tau self-assembles into pathological entities is a matter of much debate, largely due to the lack of direct experimental insights into the earliest stages of aggregation. We present pulsed double electron-electron resonance measurements of two key fibril-forming regions of tau, PHF6 and PHF6*, in transient as aggregation happens. By monitoring the end-to-end distance distribution of these segments as a function of aggregation time, we show that the PHF6(*) regions dramatically extend to distances commensurate with extended β-strand structures within the earliest stages of aggregation, well before fibril formation. Combined with simulations, our experiments show that the extended β-strand conformational state of PHF6(*) is readily populated under aggregating conditions, constituting a defining signature of aggregation-prone tau, and as such, a possible target for therapeutic interventions.

Growth hormone aggregates in the rat adenohypophysis

Science.gov (United States)

Farrington, M.; Hymer, W. C.

1990-01-01

Although it has been known for some time that GH aggregates are contained within the rat anterior pituitary gland, the role that they might play in pituitary function is unknown. The present study examines this issue using the technique of Western blotting, which permitted visualization of 11 GH variants with apparent mol wt ranging from 14-88K. Electroelution of the higher mol wt variants from gels followed by their chemical reduction with beta-mercaptoethanol increased GH immunoassayability by about 5-fold. With the blot procedure we found 1) that GH aggregates greater than 44K were associated with a 40,000 x g sedimentable fraction; 2) that GH aggregates were not present in glands from thyroidectomized rats, but were in glands from the thyroidectomized rats injected with T4; 3) that GH aggregates were uniquely associated with a heavily granulated somatotroph subpopulation isolated by density gradient centrifugation; and 4) that high mol wt GH forms were released from the dense somatotrophs in culture, since treatment of the culture medium with beta-mercaptoethanol increased GH immunoassayability by about 5-fold. Taken together, the results show that high mol wt GH aggregates are contained in secretory granules of certain somatotrophs and are also released in aggregate form from these cells in vitro.

Aggregate Supply and Potential Output

OpenAIRE

Razin, Assaf

2004-01-01

The New-Keynesian aggregate supply derives from micro-foundations an inflation-dynamics model very much like the tradition in the monetary literature. Inflation is primarily affected by: (i) economic slack; (ii) expectations; (iii) supply shocks; and (iv) inflation persistence. This paper extends the New Keynesian aggregate supply relationship to include also fluctuations in potential output, as an additional determinant of the relationship. Implications for monetary rules and to the estimati...

Targeting Protein Aggregation for the Treatment of Degenerative Diseases

Science.gov (United States)

Eisele, Yvonne S.; Monteiro, Cecilia; Fearns, Colleen; Encalada, Sandra E.; Wiseman, R. Luke; Powers, Evan T.; Kelly, Jeffery W.

2015-01-01

The aggregation of specific proteins is hypothesized to underlie several degenerative diseases, collectively called amyloid disorders. However, the mechanistic connection between the process of protein aggregation and tissue degeneration is not yet fully understood. Here, we review current and emerging strategies to ameliorate aggregation-associated degenerative disorders, with a focus on disease-modifying strategies that prevent the formation of and/or eliminate protein aggregates. Persuasive pharmacologic and genetic evidence now support protein aggregation as the cause of post-mitotic tissue dysfunction or loss. However, a more detailed understanding of the factors that trigger and sustain aggregate formation, as well as the structure-activity relationships underlying proteotoxicity are needed to develop future disease-modifying therapies. PMID:26338154

Extending Practical Pre-Aggregation in On-Line Analytical Processing

DEFF Research Database (Denmark)

Pedersen, Torben Bach; Jensen, Christian Søndergaard; Dyreson, Curtis E.

On-Line Analytical Processing (OLAP) based on a dimensional view of data is being used increasingly in traditional business applications as well as in applications such as health care for the purpose of analyzing very large amounts of data. Pre-aggregation, the prior materialization of aggregate...... select combinations of aggregates and then re-use these for efficiently computing other aggregates. However, this re-use of aggregates is contingent on the dimension hierarchies and the relationships between facts and dimensions satisfying stringent constraints. This severely limits the scope...

Aggregate assessments support improved operational decision making

International Nuclear Information System (INIS)

Bauer, R.

2003-01-01

At Darlington Nuclear aggregate assessment of plant conditions is carried out in support of Operational Decision Making. This paper discusses how aggregate assessments have been applied to Operator Workarounds leading to improved prioritisation and alignment of work programs in different departments. As well, aggregate assessment of plant and human performance factors has been carried out to identify criteria which support conservative decision making in the main control room during unit transients. (author)

Aggregated nanoplatelets: optical properties and optically induced deaggregation

International Nuclear Information System (INIS)

Jayabalan, J; Singh, Asha; Chari, Rama; Srivastava, Himanshu; Srivastava, A K; Mukhopadhyay, P K; Oak, S M

2008-01-01

A study of aggregation and laser-induced deaggregation of silver nanospheres and nanoplatelets in colloidal form is presented. Changes in the extinction spectrum caused by aggregation are explained using a two-particle approximation. In the case of platelets, controlled laser irradiation is shown to reverse the aggregation process.

Aggregated nanoplatelets: optical properties and optically induced deaggregation

Energy Technology Data Exchange (ETDEWEB)

Jayabalan, J; Singh, Asha; Chari, Rama [Laser Physics Application Division, Raja Ramanna Centre for Advanced Technology, Indore 452013 (India); Srivastava, Himanshu; Srivastava, A K [Indus Synchrotrons Utilization Division, Raja Ramanna Centre for Advanced Technology, Indore 452013 (India); Mukhopadhyay, P K; Oak, S M [Solid State Laser Division, Raja Ramanna Centre for Advanced Technology, Indore 452013 (India)], E-mail: jjaya@cat.ernet.in

2008-11-05

A study of aggregation and laser-induced deaggregation of silver nanospheres and nanoplatelets in colloidal form is presented. Changes in the extinction spectrum caused by aggregation are explained using a two-particle approximation. In the case of platelets, controlled laser irradiation is shown to reverse the aggregation process.

Viral Aggregation: Impact on Virus Behavior in the Environment.

Science.gov (United States)

Gerba, Charles P; Betancourt, Walter Q

2017-07-05

Aggregates of viruses can have a significant impact on quantification and behavior of viruses in the environment. Viral aggregates may be formed in numerous ways. Viruses may form crystal like structures and aggregates in the host cell during replication or may form due to changes in environmental conditions after virus particles are released from the host cells. Aggregates tend to form near the isoelectric point of the virus, under the influence of certain salts and salt concentrations in solution, cationic polymers, and suspended organic matter. The given conditions under which aggregates form in the environment are highly dependent on the type of virus, type of salts in solution (cation, anion. monovalent, divalent) and pH. However, virus type greatly influences the conditions when aggregation/disaggregation will occur, making predictions difficult under any given set of water quality conditions. Most studies have shown that viral aggregates increase the survival of viruses in the environment and resistance to disinfectants, especially with more reactive disinfectants. The presence of viral aggregates may also result in overestimation of removal by filtration processes. Virus aggregation-disaggregation is a complex process and predicting the behavior of any individual virus is difficult under a given set of environmental circumstances without actual experimental data.

A brief review of the construction aggregates market

Science.gov (United States)

Willett, Jason Christopher

2012-01-01

The U.S. Geological Survey defines the construction aggregates industry as those companies that mine and process crushed stone and/or construction sand and gravel. Aggregates have been used from the earliest times of our civilization for a variety of purposes - construction being the major use. As construction aggregates, crushed stone and construction sand and gravel are the basic raw materials used to build the foundation for modern society. The widespread use of construction aggregates is the result of their general availability throughout the country and around the world along with their relatively low cost. Although construction aggregates have a low unit value, their widespread use makes them major contributors to, and indicators of, the economic well-being of the nation.

PE859, a novel tau aggregation inhibitor, reduces aggregated tau and prevents onset and progression of neural dysfunction in vivo.

Directory of Open Access Journals (Sweden)

Michiaki Okuda

Full Text Available In tauopathies, a neural microtubule-associated protein tau (MAPT is abnormally aggregated and forms neurofibrillary tangle. Therefore, inhibition of the tau aggregation is one of the key approaches for the treatment of these diseases. Here, we have identified a novel tau aggregation inhibitor, PE859. An oral administration of PE859 resulted in the significant reduction of sarkosyl-insoluble aggregated tau along with the prevention of onset and progression of the motor dysfunction in JNPL3 P301L-mutated human tau transgenic mice. These results suggest that PE859 is useful for the treatment of tauopathies.

Strength of masonry blocks made with recycled concrete aggregates

Science.gov (United States)

Matar, Pierre; Dalati, Rouba El

The idea of recycling concrete of demolished buildings aims at preserving the environment. Indeed, the reuse of concrete as aggregate in new concrete mixes helped to reduce the expenses related to construction and demolition (C&D) waste management and, especially, to protect the environment by reducing the development rate of new quarries. This paper presents the results of an experimental study conducted on masonry blocks containing aggregates resulting from concrete recycling. The purpose of this study is to investigate the effect of recycled aggregates on compressive strength of concrete blocks. Tests were performed on series of concrete blocks: five series each made of different proportions of recycled aggregates, and one series of reference blocks exclusively composed of natural aggregates. Tests showed that using recycled aggregates with addition of cement allows the production of concrete blocks with compressive strengths comparable to those obtained on concrete blocks made exclusively of natural aggregates.

Do chemical gradients within soil aggregates reflect plant/soil interactions?

Science.gov (United States)

Krüger, Jaane; Hallas, Till; Kinsch, Lena; Stahr, Simon; Prietzel, Jörg; Lang, Friederike

2016-04-01

As roots and hyphae often accumulate at the surface of soil aggregates, their formation and turnover might be related to the bioavailability especially of immobile nutrients like phosphorus. Several methods have been developed to obtain specific samples from aggregate surfaces and aggregate cores and thus to investigate differences between aggregate shell and core. However, these methods are often complex and time-consuming; therefore most common methods of soil analysis neglect the distribution of nutrients within aggregates and yield bulk soil concentrations. We developed a new sequential aggregate peeling method to analyze the distribution of different nutrients within soil aggregates (4-20 mm) from four forest sites (Germany) differing in concentrations of easily available mineral P. Aggregates from three soil depths (Ah, BwAh, Bw) were isolated, air-dried, and peeled with a sieving machine performing four sieving levels with increasing sieving intensity. This procedure was repeated in quadruplicate, and fractions of the same sample and sieving level were pooled. Carbon and N concentration, citric acid-extractable PO4 and P, as well as total element concentrations (P, K, Mg, Ca, Al, Fe) were analyzed. Additionally, synchrotron-based P K-edge XANES spectroscopy was applied on selected samples to detect P speciation changes within the aggregates. The results reveal for most samples a significantly higher C and N concentration at the surface compared to the interior of the aggregates. Carbon and N gradients get more pronounced with increasing soil depth and decreasing P status of study sites. This might be explained by lower aggregate turnover rates of subsoil horizons and intense bioturbation on P-rich sites. This assumption is also confirmed by concentrations of citric acid-extractable PO4 and P: gradients within aggregates are getting more pronounced with increasing soil depth and decreasing P status. However, the direction of these gradients is site

Procedure for Validation of Aggregators Providing Demand Response

DEFF Research Database (Denmark)

Bondy, Daniel Esteban Morales; Gehrke, Oliver; Thavlov, Anders

2016-01-01

of small heterogeneous resources that are geographically distributed. Therefore, a new test procedure must be designed for the aggregator validation. This work proposes such a procedure and exemplifies is with a study case. The validation of aggregators is essential if aggregators are to be integrated...... succesfully into the power system....

Compressive strength performance of OPS lightweight aggregate concrete containing coal bottom ash as partial fine aggregate replacement

Science.gov (United States)

Muthusamy, K.; Mohamad Hafizuddin, R.; Mat Yahaya, F.; Sulaiman, M. A.; Syed Mohsin, S. M.; Tukimat, N. N.; Omar, R.; Chin, S. C.

2018-04-01

Concerns regarding the negative impact towards environment due to the increasing use of natural sand in construction industry and dumping of industrial solid wastes namely coal bottom ash (CBA) and oil palm shell (OPS) has resulted in the development of environmental friendly lightweight concrete. The present study investigates the effect of coal bottom ash as partial fine aggregate replacement towards workability and compressive strength of oil palm shell lightweight aggregate concrete (OPS LWAC). The fresh and mechanical properties of this concrete containing various percentage of coal bottom ash as partial fine aggregate replacement were investigated. The result was compared to OPS LWAC with 100 % sand as a control specimen. The concrete workability investigated by conducting slump test. All specimens were cast in form of cubes and water cured until the testing age. The compressive strength test was carried out at 7 and 28 days. The finding shows that integration of coal bottom ash at suitable proportion enhances the strength of oil palm shell lightweight aggregate concrete.

Turbulent breakage of ductile aggregates.

Science.gov (United States)

Marchioli, Cristian; Soldati, Alfredo

2015-05-01

In this paper we study breakage rate statistics of small colloidal aggregates in nonhomogeneous anisotropic turbulence. We use pseudospectral direct numerical simulation of turbulent channel flow and Lagrangian tracking to follow the motion of the aggregates, modeled as sub-Kolmogorov massless particles. We focus specifically on the effects produced by ductile rupture: This rupture is initially activated when fluctuating hydrodynamic stresses exceed a critical value, σ>σ(cr), and is brought to completion when the energy absorbed by the aggregate meets the critical breakage value. We show that ductile rupture breakage rates are significantly reduced with respect to the case of instantaneous brittle rupture (i.e., breakage occurs as soon as σ>σ(cr)). These discrepancies are due to the different energy values at play as well as to the statistical features of energy distribution in the anisotropic turbulence case examined.

Temporal aggregation in first order cointegrated vector autoregressive

DEFF Research Database (Denmark)

la Cour, Lisbeth Funding; Milhøj, Anders

2006-01-01

We study aggregation - or sample frequencies - of time series, e.g. aggregation from weekly to monthly or quarterly time series. Aggregation usually gives shorter time series but spurious phenomena, in e.g. daily observations, can on the other hand be avoided. An important issue is the effect of ...... of aggregation on the adjustment coefficient in cointegrated systems. We study only first order vector autoregressive processes for n dimensional time series Xt, and we illustrate the theory by a two dimensional and a four dimensional model for prices of various grades of gasoline....

Recycled aggregates in concrete production: engineering properties and environmental impact

Directory of Open Access Journals (Sweden)

Seddik Meddah Mohammed

2017-01-01

Full Text Available Recycled concrete aggregate is considered as the most abundant and used secondary aggregate in concrete production, other types of solid waste are also being used in concrete for specific purposes and to achieve some desired properties. Recycled aggregates and particularly, recycled concrete aggregate substantially affect the properties and mix design of concrete both at fresh and hardened states since it is known by high porosity due to the adhered layer of old mortar on the aggregate which results in a high water absorption of the recycled secondary aggregate. This leads to lower density and strength, and other durability related properties. The use of most recycled aggregate in concrete structures is still limited to low strength and non-structural applications due to important drop in strength and durability performances generated. Embedding recycled aggregates in concrete is now a current practice in many countries to enhance sustainability of concrete industry and reduce its environmental impacts. The present paper discusses the various possible recycled aggregates used in concrete production, their effect on both fresh and hardened properties as well as durability performances. The economic and environmental impacts of partially or fully substituting natural aggregates by secondary recycled aggregates are also discussed.

Partitioning of red blood cell aggregates in bifurcating microscale flows

Science.gov (United States)

Kaliviotis, E.; Sherwood, J. M.; Balabani, S.

2017-03-01

Microvascular flows are often considered to be free of red blood cell aggregates, however, recent studies have demonstrated that aggregates are present throughout the microvasculature, affecting cell distribution and blood perfusion. This work reports on the spatial distribution of red blood cell aggregates in a T-shaped bifurcation on the scale of a large microvessel. Non-aggregating and aggregating human red blood cell suspensions were studied for a range of flow splits in the daughter branches of the bifurcation. Aggregate sizes were determined using image processing. The mean aggregate size was marginally increased in the daughter branches for a range of flow rates, mainly due to the lower shear conditions and the close cell and aggregate proximity therein. A counterintuitive decrease in the mean aggregate size was apparent in the lower flow rate branches. This was attributed to the existence of regions depleted by aggregates of certain sizes in the parent branch, and to the change in the exact flow split location in the T-junction with flow ratio. The findings of the present investigation may have significant implications for microvascular flows and may help explain why the effects of physiological RBC aggregation are not deleterious in terms of in vivo vascular resistance.

Molecular origin of polyglutamine aggregation in neurodegenerative diseases.

Directory of Open Access Journals (Sweden)

2005-08-01

Full Text Available Expansion of polyglutamine (polyQ tracts in proteins results in protein aggregation and is associated with cell death in at least nine neurodegenerative diseases. Disease age of onset is correlated with the polyQ insert length above a critical value of 35-40 glutamines. The aggregation kinetics of isolated polyQ peptides in vitro also shows a similar critical-length dependence. While recent experimental work has provided considerable insights into polyQ aggregation, the molecular mechanism of aggregation is not well understood. Here, using computer simulations of isolated polyQ peptides, we show that a mechanism of aggregation is the conformational transition in a single polyQ peptide chain from random coil to a parallel beta-helix. This transition occurs selectively in peptides longer than 37 glutamines. In the beta-helices observed in simulations, all residues adopt beta-strand backbone dihedral angles, and the polypeptide chain coils around a central helical axis with 18.5 +/- 2 residues per turn. We also find that mutant polyQ peptides with proline-glycine inserts show formation of antiparallel beta-hairpins in their ground state, in agreement with experiments. The lower stability of mutant beta-helices explains their lower aggregation rates compared to wild type. Our results provide a molecular mechanism for polyQ-mediated aggregation.

Acid resistance of quaternary blended recycled aggregate concrete

Directory of Open Access Journals (Sweden)

K Jagannadha Rao

2018-06-01

Full Text Available The possibility of reusing the aggregate from demolished structures in fresh concrete, in order to reduce the CO2 impact on the environment [23] and to preserve natural resources, was explored worldwide and it is established that recycled aggregates can be used as a partial replacement of natural aggregates. Due to its potential to be used in eco-friendly structures and shortage of supply of natural aggregates in some parts of the world, there is an increasing interest in using the recycled aggregate. The durability aspects are also of equal concern along with the strength and economy of any material to be used in the construction. Studies reveal that the behaviour of ternary and quaternary blended concretes is superior from durability point of view compared to conventional concrete. Therefore a study is conducted to assess the acid resistance of recycled aggregate based Quaternary Blended Cement Concrete (QBCC of two grades M40 and M60. Fly ash and silica fume are fixed at 20% and 10% respectively from the previous studies while two percentages of Nano silica (2 and 3% were used along with the cement to obtain QBCC. Three percentages of recycled aggregates as partial replacement of conventional aggregate (0%, 50% and 75% were used in this study. Two different acids (HCL and H2SO4 with different concentrations (3 and 5% were used in this study. Acid resistance of QBCC with Recycled Concrete Aggregate (RCA is assessed in terms of visual appearance, weight loss, and compressive strength loss by destructive and non-destructive tests at regular intervals for a period of 56 days. The test results showed marginal weight loss and strength loss in both M40 and M60 grades of concretes. The Ultrasonic Pulse Velocity (UPV results show that the quality of QBCC is good even after being subjected to acid exposure. Keywords: Recycled concrete aggregate (RCA, Quaternary blended cement concrete (QBCC, Acid resistance, Ultrasonic pulse velocity (UPV, Mineral

Product Aggregation Bias as a Specification Error in Demand Systems

OpenAIRE

George C. Davis

1997-01-01

Inherent in all demand studies is some form of product aggregation which can lead to product aggregation bias. This article develops a simple procedure for incorporating product aggregation bias in demand systems that permits testing of product aggregation bias with a standard likelihood ratio test. An empirical illustration of the procedure demonstrates the importance of proper product aggregation. Copyright 1997, Oxford University Press.

Piecewise Polynomial Aggregation as Preprocessing for Data Numerical Modeling

Science.gov (United States)

Dobronets, B. S.; Popova, O. A.

2018-05-01

Data aggregation issues for numerical modeling are reviewed in the present study. The authors discuss data aggregation procedures as preprocessing for subsequent numerical modeling. To calculate the data aggregation, the authors propose using numerical probabilistic analysis (NPA). An important feature of this study is how the authors represent the aggregated data. The study shows that the offered approach to data aggregation can be interpreted as the frequency distribution of a variable. To study its properties, the density function is used. For this purpose, the authors propose using the piecewise polynomial models. A suitable example of such approach is the spline. The authors show that their approach to data aggregation allows reducing the level of data uncertainty and significantly increasing the efficiency of numerical calculations. To demonstrate the degree of the correspondence of the proposed methods to reality, the authors developed a theoretical framework and considered numerical examples devoted to time series aggregation.

H- and J-aggregate behavior in polymeric semiconductors.

Science.gov (United States)

Spano, Frank C; Silva, Carlos

2014-01-01

Aggregates of conjugated polymers exhibit two classes of fundamental electronic interactions: those occurring within a given chain and those occurring between chains. The impact of such excitonic interactions on the photophysics of polymer films can be understood using concepts of J- and H-aggregation originally developed by Kasha and coworkers to treat aggregates of small molecules. In polymer assemblies, intrachain through-bond interactions lead to J-aggregate behavior, whereas interchain Coulombic interactions lead to H-aggregate behavior. The photophysics of common emissive conjugated polymer films are determined by a competition between intrachain, J-favoring interactions and interchain, H-favoring interactions. We review formalisms describing absorption and photoluminescence lineshapes, based on intra- and intermolecular excitonic coupling, electron-vibrational coupling, and correlated energetic disorder. Examples include regioregular polythiophenes, pheneylene-vinylenes, and polydiacetylene.

Effect of protein-surfactant interactions on aggregation of β-lactoglobulin.

Science.gov (United States)

Hansted, Jon G; Wejse, Peter L; Bertelsen, Hans; Otzen, Daniel E

2011-05-01

The milk protein β-lactoglobulin (βLG) dominates the properties of whey aggregates in food products. Here we use spectroscopic and calorimetric techniques to elucidate how anionic, cationic and non-ionic surfactants interact with bovine βLG and modulate its heat-induced aggregation. Alkyl trimethyl ammonium chlorides (xTAC) strongly promote aggregation, while sodium alkyl sulfates (SxS) and alkyl maltopyranosides (xM) reduce aggregation. Sodium dodecyl sulfate (SDS) binds to non-aggregated βLG in several steps, but reduction of aggregation was associated with the first binding step, which occurs far below the critical micelle concentration. In contrast, micellar concentrations of xMs are required to reduce aggregation. The ranking order for reduction of aggregation (normalized to their tendency to self-associate) was C10-C12>C8>C14 for SxS and C8>C10>C12>C14>C16 for xM. xTAC promote aggregation in the same ranking order as xM reduce it. We conclude that SxS reduce aggregation by stabilizing the protein's ligand-bound state (the melting temperature t(m) increases by up to 10°C) and altering its charge potential. xM monomers also stabilize the protein's ligand-bound state (increasing t(m) up to 6°C) but in the absence of charged head groups this is not sufficient by itself to prevent aggregation. Although micelles of both anionic and non-ionic surfactants destabilize βLG, they also solubilize unfolded protein monomers, leaving them unavailable for protein-protein association and thus inhibiting aggregation. Cationic surfactants promote aggregation by a combination of destabilization and charge neutralization. The food compatible surfactant sodium dodecanoate also inhibited aggregation well below the cmc, suggesting that surfactants may be a practical way to modulate whey protein properties. Copyright © 2011 Elsevier B.V. All rights reserved.

Aggregate complexes of HIV-1 induced by multimeric antibodies.

Science.gov (United States)

Stieh, Daniel J; King, Deborah F; Klein, Katja; Liu, Pinghuang; Shen, Xiaoying; Hwang, Kwan Ki; Ferrari, Guido; Montefiori, David C; Haynes, Barton; Pitisuttithum, Punnee; Kaewkungwal, Jaranit; Nitayaphan, Sorachai; Rerks-Ngarm, Supachai; Michael, Nelson L; Robb, Merlin L; Kim, Jerome H; Denny, Thomas N; Tomaras, Georgia D; Shattock, Robin J

2014-10-02

Antibody mediated viral aggregation may impede viral transfer across mucosal surfaces by hindering viral movement in mucus, preventing transcytosis, or reducing inter-cellular penetration of epithelia thereby limiting access to susceptible mucosal CD4 T cells and dendritic cells. These functions may work together to provide effective immune exclusion of virus from mucosal tissue; however little is known about the antibody characteristics required to induce HIV aggregation. Such knowledge may be critical to the design of successful immunization strategies to facilitate viral immune exclusion at the mucosal portals of entry. The potential of neutralizing and non-neutralizing IgG and IgA monoclonals (mAbs) to induce HIV-1 aggregation was assessed by Dynamic light scattering (DLS). Although neutralizing and non-neutralizing IgG mAbs and polyclonal HIV-Ig efficiently aggregated soluble Env trimers, they were not capable of forming viral aggregates. In contrast, dimeric (but not monomeric) IgA mAbs induced stable viral aggregate populations that could be separated from uncomplexed virions. Epitope specificity influenced both the degree of aggregation and formation of higher order complexes by dIgA. IgA purified from serum of uninfected RV144 vaccine trial responders were able to efficiently opsonize viral particles in the absence of significant aggregation, reflective of monomeric IgA. These results collectively demonstrate that dIgA is capable of forming stable viral aggregates providing a plausible basis for testing the effectiveness of aggregation as a potential protection mechanism at the mucosal portals of viral entry.

Optimal policies for aggregate recycling from decommissioned forest roads.

Science.gov (United States)

Thompson, Matthew; Sessions, John

2008-08-01

To mitigate the adverse environmental impact of forest roads, especially degradation of endangered salmonid habitat, many public and private land managers in the western United States are actively decommissioning roads where practical and affordable. Road decommissioning is associated with reduced long-term environmental impact. When decommissioning a road, it may be possible to recover some aggregate (crushed rock) from the road surface. Aggregate is used on many low volume forest roads to reduce wheel stresses transferred to the subgrade, reduce erosion, reduce maintenance costs, and improve driver comfort. Previous studies have demonstrated the potential for aggregate to be recovered and used elsewhere on the road network, at a reduced cost compared to purchasing aggregate from a quarry. This article investigates the potential for aggregate recycling to provide an economic incentive to decommission additional roads by reducing transport distance and aggregate procurement costs for other actively used roads. Decommissioning additional roads may, in turn, result in improved aquatic habitat. We present real-world examples of aggregate recycling and discuss the advantages of doing so. Further, we present mixed integer formulations to determine optimal levels of aggregate recycling under economic and environmental objectives. Tested on an example road network, incorporation of aggregate recycling demonstrates substantial cost-savings relative to a baseline scenario without recycling, increasing the likelihood of road decommissioning and reduced habitat degradation. We find that aggregate recycling can result in up to 24% in cost savings (economic objective) and up to 890% in additional length of roads decommissioned (environmental objective).

Teaching Aggregate Demand and Supply Models

Science.gov (United States)

Wells, Graeme

2010-01-01

The author analyzes the inflation-targeting model that underlies recent textbook expositions of the aggregate demand-aggregate supply approach used in introductory courses in macroeconomics. He shows how numerical simulations of a model with inflation inertia can be used as a tool to help students understand adjustments in response to demand and…

Outsourcing the development of specific application software using the ESA software engineering standards the SPS software Interlock System

CERN Document Server

Denis, B

1995-01-01

CERN is considering outsourcing as a solution to the reduction of staff. To need to re-engineer the SPS Software Interlock System provided an opportunity to explore the applicability of outsourcing to our specific controls environment and the ESA PSS-05 standards were selected for the requirements specification, the development, the control and monitoring and the project management. The software produced by the contractor is now fully operational. After outlining the scope and the complexity of the project, a discussion on the ESA PSS-05 will be presented: the choice, the way these standards improve the outsourcing process, the quality induced but also the need to adapt them and their limitation in the definition of the customer-supplier relationship. The success factors and the difficulties of development under contract will also be discussed. The maintenance aspect and the impact on in-house developments will finally be addressed.

Kinetics of a Migration-Driven Aggregation-Fragmentation Process

Institute of Scientific and Technical Information of China (English)

ZHUANG You-Yi; LIN Zhen-Quan; KE Jian-Hong

2003-01-01

We propose a reversible model of the migration-driven aggregation-fragmentation process with the sym-metric migration rate kernels K(k;j) = K'(k;j) = λkjv and the constant aggregation rates I1, I2 and fragmentationrates J1, J2. Based on the mean-field theory, we investigate the evolution behavior of the aggregate size distributions inseveral cases with different values of index v. We find that the fragmentation reaction plays a more important role in the kinetic behaviors of the system than the aggregation and migration. When J1 = 0 and J2 = 0, the aggregate sizedistributions ak(t) and bk(t) obey the conventional scaling law, while when J1 ＞ 0 and J2 ＞ 0, they obey the modifiedscaling law with an exponential scaling function. The total mass of either species remains conserved.

Platelet aggregation following trauma

DEFF Research Database (Denmark)

Windeløv, Nis A; Sørensen, Anne M; Perner, Anders

2014-01-01

We aimed to elucidate platelet function in trauma patients, as it is pivotal for hemostasis yet remains scarcely investigated in this population. We conducted a prospective observational study of platelet aggregation capacity in 213 adult trauma patients on admission to an emergency department (ED...... severity score (ISS) was 17; 14 (7%) patients received 10 or more units of red blood cells in the ED (massive transfusion); 24 (11%) patients died within 28 days of trauma: 17 due to cerebral injuries, four due to exsanguination, and three from other causes. No significant association was found between...... aggregation response and ISS. Higher TRAP values were associated with death due to cerebral injuries (P 

Utilization of unbound aggregates for road construction

OpenAIRE

Fladvad, Marit

2017-01-01

Crushed rock aggregate is a non-renewable resource of great interest in road construction and other branches of the construction industry. To prevent resource scarcity, utilization of aggregates should be considered carefully. © 2016 Norsk Bergforening

Discontinuous Residue and Theme in Higher-Order Semiotic: A Case for Interlocking Systems

Directory of Open Access Journals (Sweden)

Ali Akbar Farahani

2008-11-01

Full Text Available The fallacy persists in discourse analysis research to explore lexicogrammatical phenomena detached from any adjacent plane of the meaning potential. In an attempt to dispel this and toss out some preconceived notions about what a modern SFG vantage point should involve, this study homes in on one aspect of SFG within prose fiction in particular, which is very revealing in terms of how separate system networks are actually in synergistic simultaneity, and how SFG allows one , phenomenally well, to bring such synergies out, getting to the heart of the fact that language pervasively operates on multiple planes of textuality simultaneously. Thus, building upon Halliday’s 2004 work, the quest is if it is interpersonally significant when the Residue is split into two parts; more importantly, if it is also laced with some lexicogrammatical quality on the textual plane, in light of the fairly well-entrenched assumption that there is always Theme at work when the Residue is split. Halliday is the only scholar to touch upon the topic of Discontinuous Residue and its relationship to Marked Theme in the culmination of his groundbreaking career, i.e. his 2004 work. Having driven home the proposal to make into a watchword the ubiquity of interlocking macro-semantic system networks, some pedagogical and research implications and suggestions flowing from this are brought up.

Active interlock system for high power insertion devices in the x-ray ring

International Nuclear Information System (INIS)

Anon.

1991-01-01

In modern synchrotron radiation rings photon beams generated by high power insertion devices (IDs) may be sufficiently intense to cause severe thermal damage to the machine vacuum chamber if mis-steered. Thus when operating a storage ring with the IDs, great care must be exercised to prevent mis-steering of the electron beam orbit. At present, the X-ray ring operates with three IDs, namely two hybrid wigglers (HBW) at X-21 and X-25,a nd a 5-Tesla superconducting wiggler at X-17. All wigglers are located in low-beta straight sections. In the straight sections. In the straight sections, beam orbit may be deflected by as much as ±8 mrad without scraping the chamber wall. For various reasons it was not possible to design the X-ray ring vacuum chamber to be safe under all possible operating conditions, however, the chamber is safe for i < 7 mA, all horizontal beam deflection angles and for vertical angles < ± 2.5 mrad. To protect the machine vacuum chamber from damage due to mis-steered beams, and interlock system has been developed and installed. This system utilizes active beam position detectors which continuously monitor beam motion in each of the ID straight sections and logic circuitry which interrupts the RF and dumps the stored beam in the case of a fault

Comparative environmental assessment of natural and recycled aggregate concrete.

Science.gov (United States)

Marinković, S; Radonjanin, V; Malešev, M; Ignjatović, I

2010-11-01

Constant and rapid increase in construction and demolition (C&D) waste generation and consumption of natural aggregate for concrete production became one of the biggest environmental problems in the construction industry. Recycling of C&D waste represents one way to convert a waste product into a resource but the environment benefits through energy consumption, emissions and fallouts reductions are not certain. The main purpose of this study is to determine the potentials of recycled aggregate concrete (concrete made with recycled concrete aggregate) for structural applications and to compare the environmental impact of the production of two types of ready-mixed concrete: natural aggregate concrete (NAC) made entirely with river aggregate and recycled aggregate concrete (RAC) made with natural fine and recycled coarse aggregate. Based on the analysis of up-to-date experimental evidence, including own tests results, it is concluded that utilization of RAC for low-to-middle strength structural concrete and non-aggressive exposure conditions is technically feasible. The Life Cycle Assessment (LCA) is performed for raw material extraction and material production part of the concrete life cycle including transport. Assessment is based on local LCI data and on typical conditions in Serbia. Results of this specific case study show that impacts of aggregate and cement production phases are slightly larger for RAC than for NAC but the total environmental impacts depend on the natural and recycled aggregates transport distances and on transport types. Limit natural aggregate transport distances above which the environmental impacts of RAC can be equal or even lower than the impacts of NAC are calculated for the specific case study. Copyright © 2010 Elsevier Ltd. All rights reserved.

An overview of aggregate resources in the United States

Science.gov (United States)

Langer, William H.; Scott, P.W.; Bristow, C.M.

2002-01-01

In 2000 the USA produced about 2.7 billion tonnes of aggregate worth about $13.7 billion. Both crushed stone and sand and gravel are produced in virtually every State, although limited quantities are available in the Gulf Coastal Plain, the Colorado Plateau , the Wyoming Basin and the Great Plains. Prices vary depending on the product and location. Most aggregates are transported by road, and minor amounts by railroad, barge on navigable inland channels, and through the Great Lake ports. Imports and exports of aggregates are very minor. A major amount f crushed stone aggregates is consumed by concrete aggregate. Recycled aggregates account for about 8% of total demand, although the amount recycled is thought to be increasing. Current issues facing the inductry unclude the differences in quality specifications between States, adjusting to the increasing concern for the impact of aggregate mining on the environmentm, health issues from particulate matter and crystalline silica, and the complexity of obtaining permits for extraction. Redcustion in the number od companies extracting aggregrates is likely to occur through acquisitions.

Implications Of Aggregate Demand Elasticity For The Phillips Curve

OpenAIRE

Ben L. Kyer; Gary E. Maggs

2004-01-01

While the general relationship between the aggregate supply curve and the Phillips curve is recognized, the importance of aggregate demand and, in particular, aggregate demand elasticity, for the inflation-unemployment relationship has been untreated. We believe, however, that the elasticity of aggregate demand with respect to the general price level does have some significance for the short-run Phillips curve since, on a general level, the economy's equilibrium price level, inflation rate, r...

Being present in action: a theoretical model about the interlocking between intentions and environmental affordances

Directory of Open Access Journals (Sweden)

Stefano eTriberti

2016-01-01

Full Text Available Recent neuropsychological evidence suggest that a key role in linking perceptions and intentions is played by sense of presence. Despite this phenomenon having been studied primarily in the field of virtual reality (conceived as the illusion of being in the virtual space, recent research highlighted that it is a fundamental feature of everyday experience. Specifically, the function of presence as a cognitive process is to locate the Self in a physical space or situation, based on the perceived possibility to act in it; so, the variations in sense of presence allow one to continuously adapt his own action to the external environment. Indeed intentions, as the cognitive antecedents of action, are not static representations of the desired outcomes, but dynamic processes able to adjust their own representational content according to the opportunities/restrictions emerging in the environment. Focusing on the peculiar context of action mediated by interactive technologies, we here propose a theoretical model showing how each level of an intentional hierarchy (future-directed; present directed; and motor intentions can interlock with environmental affordances in order to promote a continuous stream of action and activity.

The Tight-interlocked Rhythm Section: Production and Perception of Synchronisation in Jazz Trio Performance.

Science.gov (United States)

Hofmann, Alex; Wesolowski, Brian C; Goebl, Werner

2017-01-01

This study investigates the production and perception of timing, synchronisation and dynamics in jazz trio performances. In a production experiment, six trio combinations of one saxophonist, two bassists, and three drummers were recorded while they performed three popular jazz songs. Onset timing and dynamics of each performer were extracted and analysed. Results showed that the tempo was significantly influenced by the timing of the drummers and all performers showed higher temporal precision on the backbeats. The drummers demonstrated individual swing-ratios, accentuations of beats and intrapersonal asynchronies between simultaneous hi-hat and ride cymbal onsets, which resulted in a hi-hat played 2-26 ms ahead of the pulse of the music. In a subsequent perception test, participants ([Formula: see text]) rated 12 excerpts of the jazz recordings. They selected their preferred version from a pool of stimuli containing the original version, but also manipulations with artificially increased or reduced asynchronies. Stimuli with reduced asynchronies smaller than 19 ms were preferred by the listeners over the original or the fully quantised timing. This suggests that listeners endorse a 'tight-interlocked' jazz rhythm section, with asynchronies smaller than the perceptual threshold (temporal masking), but with natural timing variabilities that makes it distinguishable from a computer-generated playback.

Scalable privacy-preserving big data aggregation mechanism

Directory of Open Access Journals (Sweden)

Dapeng Wu

2016-08-01

Full Text Available As the massive sensor data generated by large-scale Wireless Sensor Networks (WSNs recently become an indispensable part of ‘Big Data’, the collection, storage, transmission and analysis of the big sensor data attract considerable attention from researchers. Targeting the privacy requirements of large-scale WSNs and focusing on the energy-efficient collection of big sensor data, a Scalable Privacy-preserving Big Data Aggregation (Sca-PBDA method is proposed in this paper. Firstly, according to the pre-established gradient topology structure, sensor nodes in the network are divided into clusters. Secondly, sensor data is modified by each node according to the privacy-preserving configuration message received from the sink. Subsequently, intra- and inter-cluster data aggregation is employed during the big sensor data reporting phase to reduce energy consumption. Lastly, aggregated results are recovered by the sink to complete the privacy-preserving big data aggregation. Simulation results validate the efficacy and scalability of Sca-PBDA and show that the big sensor data generated by large-scale WSNs is efficiently aggregated to reduce network resource consumption and the sensor data privacy is effectively protected to meet the ever-growing application requirements.

Effect of natural antioxidants on the aggregation and disaggregation ...

African Journals Online (AJOL)

Conclusion: High antioxidant activities were positively correlated with the inhibition of Aβ aggregation, although not with the disaggregation of pre-formed Aβ aggregates. Nevertheless, potent antioxidants may be helpful in treating Alzheimer's disease. Keywords: Alzheimer's disease, β-Amyloid, Aggregation, Disaggregation ...

Acceleration of tropical cyclogenesis by self-aggregation feedbacks.

Science.gov (United States)

Muller, Caroline J; Romps, David M

2018-03-20

Idealized simulations of tropical moist convection have revealed that clouds can spontaneously clump together in a process called self-aggregation. This results in a state where a moist cloudy region with intense deep convection is surrounded by extremely dry subsiding air devoid of deep convection. Because of the idealized settings of the simulations where it was discovered, the relevance of self-aggregation to the real world is still debated. Here, we show that self-aggregation feedbacks play a leading-order role in the spontaneous genesis of tropical cyclones in cloud-resolving simulations. Those feedbacks accelerate the cyclogenesis process by a factor of 2, and the feedbacks contributing to the cyclone formation show qualitative and quantitative agreement with the self-aggregation process. Once the cyclone is formed, wind-induced surface heat exchange (WISHE) effects dominate, although we find that self-aggregation feedbacks have a small but nonnegligible contribution to the maintenance of the mature cyclone. Our results suggest that self-aggregation, and the framework developed for its study, can help shed more light into the physical processes leading to cyclogenesis and cyclone intensification. In particular, our results point out the importance of the longwave radiative cooling outside the cyclone.

Green frame aggregation scheme for Wi-Fi networks

KAUST Repository

Alaslani, Maha S.

2015-07-01

Frame aggregation is a major enhancement in the IEEE 802.11 family to boost the network performance. The increasing awareness about energy efficiency motivates the re-think of frame aggregation design. In this paper, we propose a novel Green Frame Aggregation (GFA) scheduling scheme that optimizes the aggregate size based on channel quality in order to minimize the consumed energy. GFA selects an optimal sub-frame size that satisfies the loss constraint for real-time applications as well as the energy budget of the ideal channel. This scheme is implemented and evaluated using a testbed deployment. The experimental analysis shows that GFA outperforms the conventional frame aggregation methodology in terms of energy efficiency by about 6x in the presence of severe interference conditions. Moreover, GFA outperforms the static frame sizing method in terms of network goodput while maintaining the same end-to-end latency.

Programming spiders, bots, and aggregators in Java

CERN Document Server

Heaton, Jeff

2006-01-01

The content and services available on the web continue to be accessed mostly through direct human control. But this is changing. Increasingly, users rely on automated agents that save them time and effort by programmatically retrieving content, performing complex interactions, and aggregating data from diverse sources. Programming Spiders, Bots, and Aggregators in Java teaches you how to build and deploy a wide variety of these agents-from single-purpose bots to exploratory spiders to aggregators that present a unified view of information from multiple user accounts. You will quickly build on

Recycled concrete aggregate in portland cement concrete.

Science.gov (United States)

2013-01-01

Aggregates can be produced by crushing hydraulic cement concrete and are known as recycled concrete : aggregates (RCA). This report provides results from a New Jersey Department of Transportation study to identify : barriers to the use of RCA in new ...

Determination of the dynamic elastic constants of recycled aggregate concrete

Science.gov (United States)

Tsoumani, A. A.; Barkoula, N.-M.; Matikas, T. E.

2015-03-01

Nowadays, construction and demolition waste constitutes a major portion of the total solid waste production in the world. Due to both environmental and economical reasons, an increasing interest concerning the use of recycled aggregate to replace aggregate from natural sources is generated. This paper presents an investigation on the properties of recycled aggregate concrete. Concrete mixes are prepared using recycled aggregates at a substitution level between 0 and 100% of the total coarse aggregate. The influence of this replacement on strengthened concrete's properties is being investigated. The properties estimated are: density and dynamic modulus of elasticity at the age of both 7 and 28 days. Also, flexural strength of 28 days specimens is estimated. The determination of the dynamic elastic modulus was made using the ultrasonic pulse velocity method. The results reveal that the existence of recycled aggregates affects the properties of concrete negatively; however, in low levels of substitution the influence of using recycled aggregates is almost negligible. Concluding, the controlled use of recycled aggregates in concrete production may help solve a vital environmental issue apart from being a solution to the problem of inadequate concrete aggregates.

Recycled aggregates in concrete production: engineering properties and environmental impact

OpenAIRE

Seddik Meddah Mohammed

2017-01-01

Recycled concrete aggregate is considered as the most abundant and used secondary aggregate in concrete production, other types of solid waste are also being used in concrete for specific purposes and to achieve some desired properties. Recycled aggregates and particularly, recycled concrete aggregate substantially affect the properties and mix design of concrete both at fresh and hardened states since it is known by high porosity due to the adhered layer of old mortar on the aggregate which ...

Linkages between aggregate formation, porosity and soil chemical properties

NARCIS (Netherlands)

Regelink, I.C.; Stoof, C.R.; Rousseva, S.; Weng, L.; Lair, G.J.; Kram, P.; Nikolaidis, N.P.; Kercheva, M.; Banwart, S.; Comans, R.N.J.

2015-01-01

Linkages between soil structure and physical–chemical soil properties are still poorly understood due to the wide size-range at which aggregation occurs and the variety of aggregation factors involved. To improve understanding of these processes, we collected data on aggregate fractions, soil

Development of advanced, non-toxic, synthetic radiation shielding aggregate

Energy Technology Data Exchange (ETDEWEB)

Mudgal, Manish; Chouhan, Ramesh Kumar; Verma, Sarika; Amritphale, Sudhir Sitaram; Das, Satyabrata [CSIR-Advanced Materials and Processes Research Institute, Bhopal (India); Shrivastva, Arvind [Nuclear Power Corporation of India Ltd. (NPCIL), Mumbai (India)

2018-04-01

For the first time in the world, the capability of red mud waste has been explored for the development of advanced synthetic radiation shielding aggregate. Red mud, an aluminium industry waste consists of multi component, multi elemental characteristics. In this study, red mud from two different sources have been utilized. Chemical formulation and mineralogical designing of the red mud has been done by ceramic processing using appropriate reducing agent and additives. The chemical analysis, SEM microphotographs and XRD analysis confirms the presence of multi-component, multi shielding and multi-layered phases in both the different developed advance synthetic radiation shielding aggregate. The mechanical properties, namely aggregate impact value, aggregate crushing value and aggregate abrasion value have also been evaluated and was compared with hematite ore aggregate and found to be an excellent material useful for making advanced radiation shielding concrete for the construction of nuclear power plants and other radiation installations.

Familial Aggregation of Insomnia.

Science.gov (United States)

Jarrin, Denise C; Morin, Charles M; Rochefort, Amélie; Ivers, Hans; Dauvilliers, Yves A; Savard, Josée; LeBlanc, Mélanie; Merette, Chantal

2017-02-01

There is little information about familial aggregation of insomnia; however, this type of information is important to (1) improve our understanding of insomnia risk factors and (2) to design more effective treatment and prevention programs. This study aimed to investigate evidence of familial aggregation of insomnia among first-degree relatives of probands with and without insomnia. Cases (n = 134) and controls (n = 145) enrolled in a larger epidemiological study were solicited to invite their first-degree relatives and spouses to complete a standardized sleep/insomnia survey. In total, 371 first-degree relatives (Mage = 51.9 years, SD = 18.0; 34.3% male) and 138 spouses (Mage = 55.5 years, SD = 12.2; 68.1% male) completed the survey assessing the nature, severity, and frequency of sleep disturbances. The dependent variable was insomnia in first-degree relatives and spouses. Familial aggregation was claimed if the risk of insomnia was significantly higher in the exposed (relatives of cases) compared to the unexposed cohort (relatives of controls). The risk of insomnia was also compared between spouses in the exposed (spouses of cases) and unexposed cohort (spouses of controls). The risk of insomnia in exposed and unexposed biological relatives was 18.6% and 10.4%, respectively, yielding a relative risk (RR) of 1.80 (p = .04) after controlling for age and sex. The risk of insomnia in exposed and unexposed spouses was 9.1% and 4.2%, respectively; however, corresponding RR of 2.13 (p = .28) did not differ significantly. Results demonstrate evidence of strong familial aggregation of insomnia. Additional research is warranted to further clarify and disentangle the relative contribution of genetic and environmental factors in insomnia. © Sleep Research Society 2016. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.

Effect of shear rate on aggregate size and structure in the process of aggregation and at steady state

Czech Academy of Sciences Publication Activity Database

Bubáková, Petra; Pivokonský, Martin; Filip, Petr

2013-01-01

Roč. 235, February (2013), s. 540-549 ISSN 0032-5910 R&D Projects: GA ČR GAP105/11/0247 Institutional support: RVO:67985874 Keywords : aggregation * aggregate size * fractal dimension * shear rate * steady state * time evolution Subject RIV: BK - Fluid Dynamics Impact factor: 2.269, year: 2013

Building Representative-Based Data Aggregation Tree in Wireless Sensor Networks

Directory of Open Access Journals (Sweden)

Yanfei Zheng

2010-01-01

Full Text Available Data aggregation is an essential operation to reduce energy consumption in large-scale wireless sensor networks (WSNs. A compromised node may forge an aggregation result and mislead base station into trusting a false reading. Efficient and secure aggregation scheme is critical in WSN applications due to the stringent resource constraints. In this paper, we propose a method to build up the representative-based aggregation tree in the WSNs such that the sensing data are aggregated along the route from the leaf cell to the root of the tree. In the cinema of large-scale and high-density sensor nodes, representative-based aggregation tree can reduce the data transmission overhead greatly by directed aggregation and cell-by-cell communications. It also provides security services including the integrity, freshness, and authentication, via detection mechanism in the cells.

Performance of Uplink Carrier Aggregation in LTE-Advanced Systems

DEFF Research Database (Denmark)

Wang, Hua; Rosa, Claudio; Pedersen, Klaus

2010-01-01

Carrier aggregation (CA) has been proposed to aggregate two or more component carriers (CCs) to support a much wider transmission bandwidth for LTE-Advanced systems. With carrier aggregation, it is possible to schedule a user equipment (UE) on multiple component carriers simultaneously. In this p...

Aggregation and fibrillation of bovine serum albumin

DEFF Research Database (Denmark)

Holm, NK; Jespersen, SK; Thomassen, LV

2007-01-01

The all-alpha helix multi-domain protein bovine serum albumin (BSA) aggregates at elevated temperatures. Here we show that these thermal aggregates have amyloid properties. They bind the fibril-specific dyes Thioflavin T and Congo Red, show elongated although somewhat worm-like morphology...

Characterization and modeling of thermal diffusion and aggregation in nanofluids.

Energy Technology Data Exchange (ETDEWEB)

Gharagozloo, Patricia E.; Goodson, Kenneth E. (Stanford University, Stanford, CA)

2010-05-01

Fluids with higher thermal conductivities are sought for fluidic cooling systems in applications including microprocessors and high-power lasers. By adding high thermal conductivity nanoscale metal and metal oxide particles to a fluid the thermal conductivity of the fluid is enhanced. While particle aggregates play a central role in recent models for the thermal conductivity of nanofluids, the effect of particle diffusion in a temperature field on the aggregation and transport has yet to be studied in depth. The present work separates the effects of particle aggregation and diffusion using parallel plate experiments, infrared microscopy, light scattering, Monte Carlo simulations, and rate equations for particle and heat transport in a well dispersed nanofluid. Experimental data show non-uniform temporal increases in thermal conductivity above effective medium theory and can be well described through simulation of the combination of particle aggregation and diffusion. The simulation shows large concentration distributions due to thermal diffusion causing variations in aggregation, thermal conductivity and viscosity. Static light scattering shows aggregates form more quickly at higher concentrations and temperatures, which explains the increased enhancement with temperature reported by other research groups. The permanent aggregates in the nanofluid are found to have a fractal dimension of 2.4 and the aggregate formations that grow over time are found to have a fractal dimension of 1.8, which is consistent with diffusion limited aggregation. Calculations show as aggregates grow the viscosity increases at a faster rate than thermal conductivity making the highly aggregated nanofluids unfavorable, especially at the low fractal dimension of 1.8. An optimum nanoparticle diameter for these particular fluid properties is calculated to be 130 nm to optimize the fluid stability by reducing settling, thermal diffusion and aggregation.

Temperature dependence of erythrocyte aggregation in vitro by backscattering nephelometry

Science.gov (United States)

Sirko, Igor V.; Firsov, Nikolai N.; Ryaboshapka, Olga M.; Priezzhev, Alexander V.

1997-05-01

We apply backscattering nephelometry technique to register the alterations of the scattering signal from a whole blood sample due to appearance or disappearance of different types of erythrocyte aggregates in stasis and under controlled shear stress. The measured parameters are: the characteristic times of linear and 3D aggregates formation, and the strength of aggregates of different types. These parameters depend on the sample temperature in the range of 2 divided by 50 degrees C. Temporal parameters of the aggregation process strongly increase at temperature 45 degrees C. For samples of normal blood the aggregates strength parameters do not significantly depend on the sample temperature, whereas for blood samples from patients suffering Sjogren syndrome we observe high increase of the strength of 3D and linear aggregates and decrease of time of linear aggregates formation at low temperature of the sample. This combination of parameters is opposite to that observed in the samples of pathological blood at room temperature. Possible reasons of this behavior of aggregation state of blood and explanation of the observed effects will be discussed.

Biogenic silica dissolution in diatom aggregates: insights from reactive transport modelling

KAUST Repository

Moriceau, B

2014-12-15

© Inter-Research 2014. Diatom aggregates contribute significantly to the vertical sinking flux of particulate matter in the ocean. These fragile structures form a specific microhabitat for the aggregated cells, but their internal chemical and physical characteristics remain largely unknown. Studies on the impact of aggregation on the Si cycle led to apparent inconsistency. Despite a lower biogenic silica (bSiO2) dissolution rate and diffusion of the silicic acid (dSi) being similar in aggregates and in sea-water, dSi surprisingly accumulates in aggregates. A reaction-diffusion model helps to clarify this incoherence by reconstructing dSi accumulation measured during batch experiments with aggregated and non-aggregated Skeletonema marinoi and Chaetoceros decipiens. The model calculates the effective bSiO2 dissolution rate as opposed to the experimental apparent bSiO2 dissolution rate, which is the results of the effective dissolution of bSiO2 and transport of dSi out of the aggregate. In the model, dSi transport out of the aggregate is modulated by alternatively considering retention (decrease of the dSi diffusion constant) and adsorption (reversible chemical bonds between dSi and the aggregate matrix) processes. Modelled bSiO2 dissolution is modulated by the impact of dSi concentration inside aggregates and diatom viability, as enhanced persistence of metabolically active diatoms has been observed in aggregates. Adsorption better explains dSi accumulation within and outside aggregates, raising the possible importance of dSi travelling within aggregates to the deep sea (potentially representing 20% of the total silica flux). The model indicates that bSiO2 dissolution is effectively decreased in aggregates mainly due to higher diatom viability but also to other parameters discussed herein.

The Effect of Zeolite on Aggregate Stability Indices

Directory of Open Access Journals (Sweden)

F. Sohrab

2016-02-01

Full Text Available Introduction: Soil structural stability affects the profitability and sustainability of agricultural systems. Particle size distribution (PSD and aggregate stability are the important characteristics of soil. Aggregate stability has a significant impact on the development of the root system, water and carbon cycle and soil resistance against soil erosion. Soil aggregate stability, defined as the ability of the aggregates to remain intact when subject to a given stress, is an important soil property that affects the movement and storage of water, aeration, erosion, biological activity and growth of crops. Dry soil aggregate stability (Mean Weight Diameter (MWD, Geometric Mean Diameter (GMD and Wet Aggregate Stability (WAS are important indices for evaluating soil aggregate stability.To improve soil physical properties, including modifying aggregate, using various additives (organic, inorganic and chemicals, zeolites are among what has been studied.According to traditional definition, zeolites are hydratealuminosilicates of alkaline and alkaline-earth minerals. Their structure is made up of a framework of[SiO4]−4 and [AlO4]−5 tetrahedron linked to each other's cornersby sharing oxygen atoms. The substitution of Si+4 by Al+3 intetrahedral sites results inmore negative charges and a high cation exchange capacity.Zeolites, as natural cation exchangers, are suitable substitutes to remove toxic cations. Among the natural zeolites,Clinoptilolite seems to be the most efficient ion exchanger and ion-selective material forremoving and stabilizing heavy metals.Due to theexisting insufficient technical information on the effects of using different levels of zeolite on physical properties of different types of soils in Iran, the aim of this research was to assess the effects of two different types of zeolite (Clinoptilolite natural zeolite, Z4, and Synthetic zeolite, A4 on aggregate stability indicesof soil. Materials and Methods: In this study at first

21 CFR 1303.13 - Adjustments of aggregate production quotas.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 9 2010-04-01 2010-04-01 false Adjustments of aggregate production quotas. 1303.13 Section 1303.13 Food and Drugs DRUG ENFORCEMENT ADMINISTRATION, DEPARTMENT OF JUSTICE QUOTAS Aggregate Production and Procurement Quotas § 1303.13 Adjustments of aggregate production quotas. (a) The...

Measuring the Pros and Cons of What It Means to Be a Black Man: Development and Validation of the Black Men?s Experiences Scale (BMES)

OpenAIRE

Bowleg, Lisa; English, Devin; del Rio-Gonzalez, Ana Maria; Burkholder, Gary J.; Teti, Michelle; Tschann, Jeanne M.

2016-01-01

Although extensive research documents that Black people in the U.S. frequently experience social discrimination, most of this research aggregates these experiences primarily or exclusively by race. Consequently, empirical gaps exist about the psychosocial costs and benefits of Black men?s experiences at the intersection of race and gender. Informed by intersectionality, a theoretical framework that highlights how multiple social identities intersect to reflect interlocking social-structural i...

Commercial Building Tenant Energy Usage Aggregation and Privacy

Energy Technology Data Exchange (ETDEWEB)

Livingston, Olga V.; Pulsipher, Trenton C.; Anderson, David M.; Wang, Na

2014-10-31

A growing number of building owners are benchmarking their building energy use. This requires the building owner to acquire monthly whole-building energy usage information, which can be challenging for buildings in which individual tenants have their own utility meters and accounts with the utility. Some utilities and utility regulators have turned to aggregation of customer energy use data (CEUD) as a way to give building owners whole-building energy usage data while protecting customer privacy. Meter profile aggregation adds a layer of protection that decreases the risk of revealing CEUD as the number of meters aggregated increases. The report statistically characterizes the similarity between individual energy usage patterns and whole-building totals at various levels of meter aggregation.

Multivalent scaffolds induce galectin-3 aggregation into nanoparticles

Directory of Open Access Journals (Sweden)

Candace K. Goodman

2014-07-01

Full Text Available Galectin-3 meditates cell surface glycoprotein clustering, cross linking, and lattice formation. In cancer biology, galectin-3 has been reported to play a role in aggregation processes that lead to tumor embolization and survival. Here, we show that lactose-functionalized dendrimers interact with galectin-3 in a multivalent fashion to form aggregates. The glycodendrimer–galectin aggregates were characterized by dynamic light scattering and fluorescence microscopy methodologies and were found to be discrete particles that increased in size as the dendrimer generation was increased. These results show that nucleated aggregation of galectin-3 can be regulated by the nucleating polymer and provide insights that improve the general understanding of the binding and function of sugar-binding proteins.

Determinants of Aggregate Agricultural Productivity among High ...

African Journals Online (AJOL)

African Journal of Food, Agriculture, Nutrition and Development ... Determinants of Aggregate Agricultural Productivity among High External Input Technology Farms in a ... of aggregate agricultural productivity in an environment where policy on ... to increase the farm sizes through re-examination of the existing land laws.

Monitoring the Aggregation of Dansyl Chloride in Acetone through Fluorescence Measurements

Institute of Scientific and Technical Information of China (English)

FANG，Yu; YIN，Yi－Qing; 等

2002-01-01

The aggregation of dansyl chloride (DNS-Cl) in acetone has been studied in detail by steady-state fluorescence techniques.It has been demonstrated that DNS-Cl is stable in acetone during purification and aggregation study processes.The aggregates are not solvolyzed in acetone,and do not take part n any chemical reactions either.It has been found that DNS-Cl tends to aggregate even when its concentration is much lower than its solubility in acetone.The aggregation is reversible,and both the aggregation and the deaggregation are very slow processes.Introduction of SDS has a positive effect upon the formation and stabilization of the aggregates.

Monitoring the Aggregation of Dansyl Chloride in Acetone through Fluorescence Measurements

Institute of Scientific and Technical Information of China (English)

FANG,Yu(房喻); YIN,Yi-Qing(尹艺青); HU,Dao-Dao(胡道道); GAO,Gai-Ling(高改玲)

2002-01-01

The aggregation of dansyl chloride (DNS-Cl) in acetone has been studied in detail by steady-state fluorescence techniques. It has been demonstrated that DNS-Cl is stable in acetone during purification and aggregation study processes. The aggregates are not solvolyzed in acetone, and do not take part in any chemical reactions either. It has been found that DNS-Cl tends to aggregate even when its concentration is much lower than its solubility in acetone. The aggregation is reversible, and both the aggregation and the deaggregation are very slow processes.Introduction of SDS has a positive effect upon the formation and stabilization of the aggregates.

Nano-aggregates: emerging delivery tools for tumor therapy.

Science.gov (United States)

Sharma, Vinod Kumar; Jain, Ankit; Soni, Vandana

2013-01-01

A plethora of formulation techniques have been reported in the literature for site-specific targeting of water-soluble and -insoluble anticancer drugs. Along with other vesicular and particulate carrier systems, nano-aggregates have recently emerged as a novel supramolecular colloidal carrier with promise for using poorly water-soluble drugs in molecular targeted therapies. Nano-aggregates possess some inherent properties such as size in the nanometers, high loading efficiency, and in vivo stability. Nano-aggregates can provide site-specific drug delivery via either a passive or active targeting mechanism. Nano-aggregates are formed from a polymer-drug conjugated amphiphilic block copolymer. They are suitable for encapsulation of poorly water-soluble drugs by covalent conjugation as well as physical encapsulation. Because of physical encapsulation, a maximum amount of drug can be loaded in nano-aggregates, which helps to achieve a sufficiently high drug concentration at the target site. Active transport can be achieved by conjugating a drug with vectors or ligands that bind specifically to receptors being overexpressed in the tumor cells. In this review, we explore synthesis and tumor targeting potential of nano-aggregates with active and passive mechanisms, and we discuss various characterization parameters, ex vivo studies, biodistribution studies, clinical trials, and patents.

Entrapment of Aβ1-40 peptide in unstructured aggregates

International Nuclear Information System (INIS)

Corsale, C; Carrotta, R; Mangione, M R; Vilasi, S; Provenzano, A; Bulone, D; San Biagio, P L; Cavallaro, G

2012-01-01

Recognizing the complexity of the fibrillogenesis process provides a solid ground for the development of therapeutic strategies aimed at preventing or inhibiting protein-protein aggregation. Under this perspective, it is meaningful to identify the possible aggregation pathways and their relative products. We found that Aβ-peptide dissolved in a pH 7.4 solution at small peptide concentration and low ionic strength forms globular aggregates without typical amyloid β-conformation. ThT binding kinetics was used to monitor aggregate formation. Circular dichroism spectroscopy, AFM imaging, static and dynamic light scattering were used for structural and morphological characterization of the aggregates. They appear stable or at least metastable with respect to fiber growth, therefore appearing as an incidental product in the pathway of fibrillogenesis. (paper)

A study of concrete properties using phyllite as coarse aggregates

International Nuclear Information System (INIS)

Adom-Asamoah, Mark; Afrifa, Russell Owusu

2010-01-01

Nowadays, industrial activities generate a huge amount of waste. One such activity is underground mining which generates phyllite wastes that are recycled as coarse aggregates for use in concrete production. Aggregate use in concrete is dependent on availability. This paper reports of an experimental study on some of the physical and mechanical properties of phyllite aggregate concrete as compared to granite (conventional) aggregate concrete. The obtained physical and mechanical properties of both aggregates for specific gravity, water absorption (%), dry density, aggregate impact value (%), aggregate crushing value (%), 10% fines, elongation index (%), flakiness index (%) and Los Angeles abrasion values satisfied minimum requirements for aggregates suitable for concrete production. Five mixes of concrete mix proportions designated M1, M2, M3, M4 and M5 were cast using phyllite and granite aggregates. A total of 400 concrete cubes and 210 modulus of rupture beams were cast and cured by total submerging in water for ages 3, 7, 14, 28, 56, 90, 180 and 360 days before compression and bending tests were performed. The results show that the trends in the development of compressive and bending strengths of plain phyllite concrete were similar to those in granite (conventional) aggregate concrete. However the compressive and bending strengths of phyllite concrete mixes were on the average 15-20% lower than those of the corresponding granite concrete mixes at all ages. The same concrete mix proportions gave lower concrete classes for phyllite compared to granite with the exception of the lowest grade. This was probably because the flakiness and elongation properties coupled with reactive materials in phyllite aggregates affect the absorption and bond characteristics of its concrete.

40 CFR 63.1408 - Aggregate batch vent stream provisions.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 11 2010-07-01 2010-07-01 true Aggregate batch vent stream provisions... § 63.1408 Aggregate batch vent stream provisions. (a) Emission standards. Owners or operators of aggregate batch vent streams at a new or existing affected source shall comply with either paragraph (a)(1...

Biomass round bales infield aggregation logistic scenarios

Science.gov (United States)

Biomass bales often need to be aggregated (collected into groups and transported) to a field-edge stack for temporary storage for feedlots or processing facilities. Aggregating the bales with the least total distance involved is a goal of producers and bale handlers. Several logistics scenarios for ...

Trust-aware recommendation for improving aggregate diversity

Science.gov (United States)

Liu, Haifeng; Bai, Xiaomei; Yang, Zhuo; Tolba, Amr; Xia, Feng

2015-10-01

Recommender systems are becoming increasingly important and prevalent because of the ability of solving information overload. In recent years, researchers are paying increasing attention to aggregate diversity as a key metric beyond accuracy, because improving aggregate recommendation diversity may increase long tails and sales diversity. Trust is often used to improve recommendation accuracy. However, how to utilize trust to improve aggregate recommendation diversity is unexplored. In this paper, we focus on solving this problem and propose a novel trust-aware recommendation method by incorporating time factor into similarity computation. The rationale underlying the proposed method is that, trustees with later creation time of trust relation can bring more diverse items to recommend to their trustors than other trustees with earlier creation time of trust relation. Through relevant experiments on publicly available dataset, we demonstrate that the proposed method outperforms the baseline method in terms of aggregate diversity while maintaining almost the same recall.

Stay connected: Electrical conductivity of microbial aggregates.

Science.gov (United States)

Li, Cheng; Lesnik, Keaton Larson; Liu, Hong

2017-11-01

The discovery of direct extracellular electron transfer offers an alternative to the traditional understanding of diffusional electron exchange via small molecules. The establishment of electronic connections between electron donors and acceptors in microbial communities is critical to electron transfer via electrical currents. These connections are facilitated through conductivity associated with various microbial aggregates. However, examination of conductivity in microbial samples is still in its relative infancy and conceptual models in terms of conductive mechanisms are still being developed and debated. The present review summarizes the fundamental understanding of electrical conductivity in microbial aggregates (e.g. biofilms, granules, consortia, and multicellular filaments) highlighting recent findings and key discoveries. A greater understanding of electrical conductivity in microbial aggregates could facilitate the survey for additional microbial communities that rely on direct extracellular electron transfer for survival, inform rational design towards the aggregates-based production of bioenergy/bioproducts, and inspire the construction of new synthetic conductive polymers. Copyright © 2017 Elsevier Inc. All rights reserved.

Compressive strength and resistance to chloride ion penetration and carbonation of recycled aggregate concrete with varying amount of fly ash and fine recycled aggregate.

Science.gov (United States)

Sim, Jongsung; Park, Cheolwoo

2011-11-01

Construction and demolition waste has been dramatically increased in the last decade, and social and environmental concerns on the recycling have consequently been increased. Recent technology has greatly improved the recycling process for waste concrete. This study investigates the fundamental characteristics of concrete using recycled concrete aggregate (RCA) for its application to structural concrete members. The specimens used 100% coarse RCA, various replacement levels of natural aggregate with fine RCA, and several levels of fly ash addition. Compressive strength of mortar and concrete which used RCA gradually decreased as the amount of the recycled materials increased. Regardless of curing conditions and fly ash addition, the 28 days strength of the recycled aggregate concrete was greater than the design strength, 40 MPa, with a complete replacement of coarse aggregate and a replacement level of natural fine aggregate by fine RCA up to 60%. The recycled aggregate concrete achieved sufficient resistance to the chloride ion penetration. The measured carbonation depth did not indicate a clear relationship to the fine RCA replacement ratio but the recycled aggregate concrete could also attain adequate carbonation resistance. Based on the results from the experimental investigations, it is believed that the recycled aggregate concrete can be successfully applied to structural concrete members. Copyright © 2011 Elsevier Ltd. All rights reserved.

Temporal aggregation in first order cointegrated vector autoregressive models

DEFF Research Database (Denmark)

La Cour, Lisbeth Funding; Milhøj, Anders

We study aggregation - or sample frequencies - of time series, e.g. aggregation from weekly to monthly or quarterly time series. Aggregation usually gives shorter time series but spurious phenomena, in e.g. daily observations, can on the other hand be avoided. An important issue is the effect of ...... of aggregation on the adjustment coefficient in cointegrated systems. We study only first order vector autoregressive processes for n dimensional time series Xt, and we illustrate the theory by a two dimensional and a four dimensional model for prices of various grades of gasoline...

Automatic analysis of microscopic images of red blood cell aggregates

Science.gov (United States)

Menichini, Pablo A.; Larese, Mónica G.; Riquelme, Bibiana D.

2015-06-01

Red blood cell aggregation is one of the most important factors in blood viscosity at stasis or at very low rates of flow. The basic structure of aggregates is a linear array of cell commonly termed as rouleaux. Enhanced or abnormal aggregation is seen in clinical conditions, such as diabetes and hypertension, producing alterations in the microcirculation, some of which can be analyzed through the characterization of aggregated cells. Frequently, image processing and analysis for the characterization of RBC aggregation were done manually or semi-automatically using interactive tools. We propose a system that processes images of RBC aggregation and automatically obtains the characterization and quantification of the different types of RBC aggregates. Present technique could be interesting to perform the adaptation as a routine used in hemorheological and Clinical Biochemistry Laboratories because this automatic method is rapid, efficient and economical, and at the same time independent of the user performing the analysis (repeatability of the analysis).

Feasibility Study on Manufacturing Lightweight Aggregates from Water Purification Sludge

Science.gov (United States)

Peng, Ching-Fang; Chen, How-Ji

2018-02-01

This study mainly discussed the feasibility of manufacturing lightweight aggregates from water purification sludge in Taiwan. They were analysed for the physical and chemical composition before the sintering test for lightweight aggregates in a laboratory. Then the physical and mechanical properties of the synthesized aggregates were assessed. The result showed that the chemical composition of sludge in the water purification plants was within the appropriate range for manufacturing lightweight aggregate as proposed in the literature. The sintering test demonstrated that the particle density of aggregates from the ten types of water purification sludge were mostly less than 1.8 g/cm3. In addition, the dry unit weight, the organic impurity, the ignition loss, and other characteristics of synthesized aggregates met the requirement of CNS standards, while its water absorption and crushing strength also fulfilled the general commercial specifications. Therefore, reclamation of water purification sludge for production of lightweight aggregate is indeed feasible.

Engineering a fibrocartilage spectrum through modulation of aggregate redifferentiation.

Science.gov (United States)

Murphy, Meghan K; Masters, Taylor E; Hu, Jerry C; Athanasiou, Kyriacos A

2015-01-01

Expanded costochondral cells provide a clinically relevant cell source for engineering both fibrous and hyaline articular cartilage. Expanding chondrocytes in a monolayer results in a shift toward a proliferative, fibroblastic phenotype. Three-dimensional aggregate culture may, however, be used to recover chondrogenic matrix production. This study sought to engineer a spectrum of fibrous to hyaline neocartilage from a single cell source by varying the duration of three-dimensional culture following expansion. In third passage porcine costochondral cells, the effects of aggregate culture duration were assessed after 0, 8, 11, 14, and 21 days of aggregate culture and after 4 subsequent weeks of neocartilage formation. Varying the duration of aggregate redifferentiation generated a spectrum of fibrous to hyaline neocartilage. Within 8 days of aggregation, proliferation ceased, and collagen and glycosaminoglycan production increased, compared with monolayer cells. In self-assembled neocartilage, type II-to-I collagen ratio increased with increasing aggregate duration, yet glycosaminoglycan content varied minimally. Notably, 14 days of aggregate redifferentiation increased collagen content by 25%, tensile modulus by over 110%, and compressive moduli by over 50%, compared with tissue formed in the absence of redifferentiation. A spectrum of fibrous to hyaline cartilage was generated using a single, clinically relevant cell source, improving the translational potential of engineered cartilage.

Vocal Fold Mucus Aggregation in Persons with Voice Disorders

Science.gov (United States)

Bonilha, Heather Shaw; White, Lisa; Kuckhahn, Kelsey; Gerlach, Terri Treman; Deliyski, Dimitar D.

2012-01-01

Mucus aggregation on the vocal folds is a common finding from laryngeal endoscopy. Patients with voice disorders report the presence of mucus aggregation. Patients also report that mucus aggregation causes them to clear their throat, a behavior believed to be harmful to vocal fold mucosa. Even though clinicians and patients report and discuss…

A model for bacterial colonization of sinking aggregates.

Science.gov (United States)

Bearon, R N

2007-01-01

Sinking aggregates provide important nutrient-rich environments for marine bacteria. Quantifying the rate at which motile bacteria colonize such aggregations is important in understanding the microbial loop in the pelagic food web. In this paper, a simple analytical model is presented to predict the rate at which bacteria undergoing a random walk encounter a sinking aggregate. The model incorporates the flow field generated by the sinking aggregate, the swimming behavior of the bacteria, and the interaction of the flow with the swimming behavior. An expression for the encounter rate is computed in the limit of large Péclet number when the random walk can be approximated by a diffusion process. Comparison with an individual-based numerical simulation is also given.

Convective Self-Aggregation in Numerical Simulations: A Review

Science.gov (United States)

Wing, Allison A.; Emanuel, Kerry; Holloway, Christopher E.; Muller, Caroline

Organized convection in the tropics occurs across a range of spatial and temporal scales and strongly influences cloud cover and humidity. One mode of organization found is ``self-aggregation,'' in which moist convection spontaneously organizes into one or several isolated clusters despite spatially homogeneous boundary conditions and forcing. Self-aggregation is driven by interactions between clouds, moisture, radiation, surface fluxes, and circulation, and occurs in a wide variety of idealized simulations of radiative-convective equilibrium. Here we provide a review of convective self-aggregation in numerical simulations, including its character, causes, and effects. We describe the evolution of self-aggregation including its time and length scales and the physical mechanisms leading to its triggering and maintenance, and we also discuss possible links to climate and climate change.

Rules for aggregated satisfaction with work commutes

NARCIS (Netherlands)

Suzuki, Haruna; Fujii, Satoshi; Gärling, Tommy; Ettema, Dick|info:eu-repo/dai/nl/114422729; Olsson, Lars E.; Friman, Margareta

In general trips frequently entail several stages varying in mode, duration, and other factors. In some way travelers aggregate their satisfaction with the stages to satisfaction with the whole trip. In this paper we address the question of how this aggregation is made. We use data from a Swedish

Recycled Concrete as Aggregate for Structural Concrete Production

OpenAIRE

Mirjana Malešev; Vlastimir Radonjanin; Snežana Marinković

2010-01-01

A comparative analysis of the experimental results of the properties of fresh and hardened concrete with different replacement ratios of natural with recycled coarse aggregate is presented in the paper. Recycled aggregate was made by crushing the waste concrete of laboratory test cubes and precast concrete columns. Three types of concrete mixtures were tested: concrete made entirely with natural aggregate (NAC) as a control concrete and two types of concrete made with natural fine and recycle...

An Outline of Data Aggregation Security in Heterogeneous Wireless Sensor Networks.

Science.gov (United States)

Boubiche, Sabrina; Boubiche, Djallel Eddine; Bilami, Azzedine; Toral-Cruz, Homero

2016-04-12

Data aggregation processes aim to reduce the amount of exchanged data in wireless sensor networks and consequently minimize the packet overhead and optimize energy efficiency. Securing the data aggregation process is a real challenge since the aggregation nodes must access the relayed data to apply the aggregation functions. The data aggregation security problem has been widely addressed in classical homogeneous wireless sensor networks, however, most of the proposed security protocols cannot guarantee a high level of security since the sensor node resources are limited. Heterogeneous wireless sensor networks have recently emerged as a new wireless sensor network category which expands the sensor nodes' resources and capabilities. These new kinds of WSNs have opened new research opportunities where security represents a most attractive area. Indeed, robust and high security level algorithms can be used to secure the data aggregation at the heterogeneous aggregation nodes which is impossible in classical homogeneous WSNs. Contrary to the homogeneous sensor networks, the data aggregation security problem is still not sufficiently covered and the proposed data aggregation security protocols are numberless. To address this recent research area, this paper describes the data aggregation security problem in heterogeneous wireless sensor networks and surveys a few proposed security protocols. A classification and evaluation of the existing protocols is also introduced based on the adopted data aggregation security approach.

An Outline of Data Aggregation Security in Heterogeneous Wireless Sensor Networks

Directory of Open Access Journals (Sweden)

Sabrina Boubiche

2016-04-01

Full Text Available Data aggregation processes aim to reduce the amount of exchanged data in wireless sensor networks and consequently minimize the packet overhead and optimize energy efficiency. Securing the data aggregation process is a real challenge since the aggregation nodes must access the relayed data to apply the aggregation functions. The data aggregation security problem has been widely addressed in classical homogeneous wireless sensor networks, however, most of the proposed security protocols cannot guarantee a high level of security since the sensor node resources are limited. Heterogeneous wireless sensor networks have recently emerged as a new wireless sensor network category which expands the sensor nodes’ resources and capabilities. These new kinds of WSNs have opened new research opportunities where security represents a most attractive area. Indeed, robust and high security level algorithms can be used to secure the data aggregation at the heterogeneous aggregation nodes which is impossible in classical homogeneous WSNs. Contrary to the homogeneous sensor networks, the data aggregation security problem is still not sufficiently covered and the proposed data aggregation security protocols are numberless. To address this recent research area, this paper describes the data aggregation security problem in heterogeneous wireless sensor networks and surveys a few proposed security protocols. A classification and evaluation of the existing protocols is also introduced based on the adopted data aggregation security approach.

An Outline of Data Aggregation Security in Heterogeneous Wireless Sensor Networks

Science.gov (United States)

Boubiche, Sabrina; Boubiche, Djallel Eddine; Bilami, Azzedine; Toral-Cruz, Homero

2016-01-01

Data aggregation processes aim to reduce the amount of exchanged data in wireless sensor networks and consequently minimize the packet overhead and optimize energy efficiency. Securing the data aggregation process is a real challenge since the aggregation nodes must access the relayed data to apply the aggregation functions. The data aggregation security problem has been widely addressed in classical homogeneous wireless sensor networks, however, most of the proposed security protocols cannot guarantee a high level of security since the sensor node resources are limited. Heterogeneous wireless sensor networks have recently emerged as a new wireless sensor network category which expands the sensor nodes’ resources and capabilities. These new kinds of WSNs have opened new research opportunities where security represents a most attractive area. Indeed, robust and high security level algorithms can be used to secure the data aggregation at the heterogeneous aggregation nodes which is impossible in classical homogeneous WSNs. Contrary to the homogeneous sensor networks, the data aggregation security problem is still not sufficiently covered and the proposed data aggregation security protocols are numberless. To address this recent research area, this paper describes the data aggregation security problem in heterogeneous wireless sensor networks and surveys a few proposed security protocols. A classification and evaluation of the existing protocols is also introduced based on the adopted data aggregation security approach. PMID:27077866

The structure of microbial community in aggregates of a typical chernozem aggregates under contrasting variants of its agricultural use

Science.gov (United States)

Ivanova, E. A.; Kutovaya, O. V.; Tkhakakhova, A. K.; Chernov, T. I.; Pershina, E. V.; Markina, L. G.; Andronov, E. E.; Kogut, B. M.

2015-11-01

The taxonomic structure of microbiomes in aggregates of different sizes from typical chernozems was investigated using sequencing of the 16S rRNA gene. The aggregate fractions of 7 mm obtained by sieving of the soil samples at natural moisture were used for analysis. The highest prokaryote biomass (bacteria, archaea) was determined in the fractions permanent black fallow > permanent winter wheat. The greatest number of fungi was recorded in the fraction wheat. The system of agricultural use affected more significantly the structure of the prokaryote community in the chernozem than the size of aggregate fractions did. The most diverse microbial community was recorded in the soil samples of the fallow; the statistically significant maximums of the Shannon diversity indices and indices of phylogenetic diversity (PD) were recorded in the fractions <0.25 and 2-5 mm from the fallow soil. On the whole, the fine soil fractions (<0.25 mm) were characterized by higher diversity indices in comparison with those of the coarser aggregate fractions.

Experimental research on durability of recycled aggregate concrete under freeze- thaw cycles

Science.gov (United States)

Cheng, Yanqiu; Shang, Xiaoyu; Zhang, Youjia

2017-07-01

The freeze-thaw durability of recycled aggregate concrete has significance for the concrete buildings in the cold region. In this paper, the rapid freezing and thawing cycles experience on recycle aggregate concrete was conducted to study on the effects of recycle aggregate amount, water-binder ratio and fly ash on freeze-thaw durability of recycle aggregate concrete. The results indicates that recycle aggregate amount makes the significant influence on the freeze-thaw durability. With the increase of recycled aggregates amount, the freeze-thaw resistance for recycled aggregate concrete decreases. Recycled aggregate concrete with lower water cement ratio demonstrates better performance of freeze-thaw durability. It is advised that the amount of fly ash is less than 30% for admixture of recycled aggregates in the cold region.

Two-Step Amyloid Aggregation: Sequential Lag Phase Intermediates

Science.gov (United States)

Castello, Fabio; Paredes, Jose M.; Ruedas-Rama, Maria J.; Martin, Miguel; Roldan, Mar; Casares, Salvador; Orte, Angel

2017-01-01

The self-assembly of proteins into fibrillar structures called amyloid fibrils underlies the onset and symptoms of neurodegenerative diseases, such as Alzheimer’s and Parkinson’s. However, the molecular basis and mechanism of amyloid aggregation are not completely understood. For many amyloidogenic proteins, certain oligomeric intermediates that form in the early aggregation phase appear to be the principal cause of cellular toxicity. Recent computational studies have suggested the importance of nonspecific interactions for the initiation of the oligomerization process prior to the structural conversion steps and template seeding, particularly at low protein concentrations. Here, using advanced single-molecule fluorescence spectroscopy and imaging of a model SH3 domain, we obtained direct evidence that nonspecific aggregates are required in a two-step nucleation mechanism of amyloid aggregation. We identified three different oligomeric types according to their sizes and compactness and performed a full mechanistic study that revealed a mandatory rate-limiting conformational conversion step. We also identified the most cytotoxic species, which may be possible targets for inhibiting and preventing amyloid aggregation.

Aggregation in charged nanoparticles solutions induced by different interactions

Energy Technology Data Exchange (ETDEWEB)

Abbas, S.; Kumar, Sugam; Aswal, V. K., E-mail: vkaswal@barc.gov.in [Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Kohlbrecher, J. [Laboratory for Neutron Scattering, Paul Scherrer Institut, CH-5232 PSI Villigen (Switzerland)

2016-05-23

Small-angle neutron scattering (SANS) has been used to study the aggregation of anionic silica nanoparticles as induced through different interactions. The nanoparticle aggregation is induced by addition of salt (NaCl), cationic protein (lysozyme) and non-ionic surfactant (C12E10) employing different kind of interactions. The results show that the interaction in presence of salt can be explained using DLVO theory whereas non-DLVO forces play important role for interaction of nanoparticles with protein and surfactant. The presence of salt screens the repulsion between charged nanoparticles giving rise to a net attraction in the DLVO potential. On the other hand, strong electrostatic attraction between nanoparticle and oppositely charged protein leads to protein-mediated nanoparticle aggregation. In case of non-ionic surfactant, the relatively long-range attractive depletion interaction is found to be responsible for the particle aggregation. Interestingly, the completely different interactions lead to similar kind of aggregate morphology. The nanoparticle aggregates formed are found to have mass fractal nature having a fractal dimension (~2.5) consistent with diffusion limited type of fractal morphology in all three cases.

Acetylcholinesterase triggers the aggregation of PrP 106-126

International Nuclear Information System (INIS)

Pera, M.; Roman, S.; Ratia, M.; Camps, P.; Munoz-Torrero, D.; Colombo, L.; Manzoni, C.; Salmona, M.; Badia, A.; Clos, M.V.

2006-01-01

Acetylcholinesterase (AChE), a senile plaque component, promotes amyloid-β-protein (Aβ) fibril formation in vitro. The presence of prion protein (PrP) in Alzheimer's disease (AD) senile plaques prompted us to assess if AChE could trigger the PrP peptides aggregation as well. Consequently, the efficacy of AChE on the PrP peptide spanning-residues 106-126 aggregation containing a coumarin fluorescence probe (coumarin-PrP 106-126) was studied. Kinetics of coumarin-PrP 106-126 aggregation showed a significant increase of maximum size of aggregates (MSA), which was dependent on AChE concentration. AChE-PrP 106-126 aggregates showed the tinctorial and optical amyloid properties as determined by polarized light and electronic microscopy analysis. A remarkable inhibition of MSA was obtained with propidium iodide, suggesting that AChE triggers PrP 106-126 and Aβ aggregation through a similar mechanism. Huprines (AChE inhibitors) also significantly decreased MSA induced by AChE as well, unveiling the potential interest for some AChE inhibitors as a novel class of potential anti-prion drugs

Aggregation of Frenkel defects under irradiation: a mesoscopic approach

International Nuclear Information System (INIS)

Soppe, W.; Kotomin, E.

1993-08-01

The radiation-induced aggregation of Frenkel defects in solids is studied in terms of a mesoscopic approach. The asymmetry in elastic interactions between mobile interstitials (I-I) and between interstitials and vacancies (I-V) plays a decisive role in the aggregation of similar defects. The conditions for defect aggregation are studied in detail for NaCl crystals. The critical dose rate for aggregation has been calculated as a function of the temperature as well as the aggregation rate as a function of temperature and dose rate. Furthermore, the role of deep traps (like impurities and di-vacancies), reducing the mobility of interstitials, and the role of dislocations serving as sinks for interstitials, are studied. The aggregation appears to reach a maximum at a distinct temperature which is in agreement both with experiment and the Jain-Lidiard theory. The model also predicts a shift of this maximum towards lower temperatures if the dose rate is decreased. The consequences of the model for the disposal of nuclear waste in rock salt formations, are briefly discussed. (orig.)

[Composition and stability of soil aggregates in hedgerow-crop slope land].

Science.gov (United States)

Pu, Yu-Lin; Lin, Chao-Wen; Xie, De-Ti; Wei, Chao-Fu; Ni, Jiu-Pai

2013-01-01

Based on a long-term experiment of using hedgerow to control soil and water loss, this paper studied the composition and stability of soil aggregates in a hedgerow-crop slope land. Compared with those under routine contour cropping, the contents of > 0.25 mm soil mechanical-stable and water-stable aggregates under the complex mode hedgerow-crop increased significantly by 13.3%-16.1% and 37.8% -55.6%, respectively. Under the complex mode, the contents of > 0.25 mm soil water-stable aggregates on each slope position increased obviously, and the status of > 0.25 mm soil water-stable aggregates being relatively rich at low slope and poor at top slope was improved. Planting hedgerow could significantly increase the mean mass diameter and geometric mean diameter of soil aggregates, decrease the fractal dimension of soil aggregates and the destruction rate of > 0.25 mm soil aggregates, and thus, increase the stability and erosion-resistance of soil aggregates in slope cropland. No significant effects of slope and hedgerow types were observed on the composition, stability and distribution of soil aggregates.

Protein aggregation studied by forward light scattering and light transmission analysis

Science.gov (United States)

Penzkofer, A.; Shirdel, J.; Zirak, P.; Breitkreuz, H.; Wolf, E.

2007-12-01

The aggregation of the circadian blue-light photo-receptor cryptochrome from Drosophila melanogaster (dCry) is studied by transmission and forward light scattering measurement in the protein transparent wavelength region. The light scattering in forward direction is caused by Rayleigh scattering which is proportional to the degree of aggregation. The light transmission through the samples in the transparent region is reduced by Mie light scattering in all directions. It depends on the degree of aggregation and the monomer volume fill factor of the aggregates (less total scattering with decreasing monomer volume fill factor of protein globule) allowing a distinction between tightly packed protein aggregation (monomer volume fill factor 1) and loosely packed protein aggregation (monomer volume fill factor less than 1). An increase in aggregation with temperature, concentration, and blue-light exposure is observed. At a temperature of 4 °C and a protein concentration of less than 0.135 mM no dCry aggregation was observed, while at 24 °C and 0.327 mM gelation occurred (loosely packed aggregates occupying the whole solution volume).