bluuebunny/crossref_metadata_2025 huggingface dataset:
Micro Cryogenic Coolers With Mixed Refrigerants
Authors: Lewis Ryan , Wang Yunda , Schroeder Paul , Coolidge Collin , Radebaugh Ray , Lee Y. C.
Published: January 2014

A number of small electronic devices benefit from micro-scale low temperature operation. Recently we have developed micro cryogenic coolers (MCCs) using a low-pressure, mixed-refrigerant Joule-Thomson cycle. The cryocoolers utilizes a MEMS-enabled gas compressor coupled to a micro cold stage. Two cold stages have been developed: one which uses a fiber-enabled heat exchanger assembled to a micro-machined throttling valve, and another which uses a MEMS-based heat exchanger. A microcompressor has been developed which uses MEMS-based check valves coupled to a membrane, which is actuated with a mechanically amplified piezoelectric amplifier. The compressor measures a volume 15 mL, can generate a pressure ratio of 6:1 and a maximum flow-rate of 60 standard mL/min. The complete cryocooler has reached low temperatures of 177 K, although temperature instability has been an issue, due to 2-phase flow through the micro-channels. This paper will cover the development and testing of the micro cryogenic cooler, as well as an analysis of the micro channel flow. A proper understanding of the micro-channel flow allows us to design refrigerant mixtures to improve the cooling power, and modify the cooler to eliminate temperature instabilities.
An Experimental and Numerical Study of the Dynamic Fracture of Glass
Authors: Xue Liang , Niu Yuling , Lee Hohyung , Yu Da , Chaparala Satish , Park Seungbae
Published: January 2014

The needs of glass to resist the scratches, drops impact, and bump from everyday use lead to the importance of investigation of the glass fracture under dynamic impact loading. The strength of the glass under dynamic fracture conditions is significantly larger than that under quasi-static loading. There are several theoretic models. In this study, an accumulated damage model is implemented. The relation among the stress, loading rate, contact time and the fracture is investigated. The effect of impact area, impact energy and impact momentum on the glass fracture has been proved to further improve the dynamic fracture criterion of glass. For the experimental studies, the Digital Image Correlation (DIC) method enables one to obtain the first principal strain of the glass during the impact process. Moreover, the FEA model is developed in ANSYS/LS-DYNA™.
Resistance Spectroscopy Based Assessment of Degradation in Cu-Al Wire Bond Interconnects
Authors: Lall Pradeep , Luo Yihua
Published: January 2014

Escalation of the expense of gold has resulted in industry interest in use of copper as alternative wire bonds interconnect material. Copper wire has the advantage of lower price and comparable electrical resistance to gold wire. In this paper, 32-pin copper-aluminum wire bond chip scale packages are aged at three types of environment conditions separately. Environmental conditions included: 200°C for 10 days, 85°C and 85% RH for 8 weeks and −40°C to 125°C for 500 thermal cycles. The resistances of the wire bond are obtained every 24 hours for 200°C environment, every 7 days for 85C/85RH environment and every 5 days (50 thermal cycles) for the thermal cycling environment. A leading indicator has been developed in order to monitor the progression effect of the different thermal aging condition on the package and prognosticate remaining useful life based on the resistance spectroscopy. The Cu-Al wire bond resistance has been measured using a modified Wheatstone bridge. It has been shown previously that precise resistance spectroscopy is able to offer the failure of a leading indicator prior to the traditional definition of failure. The prognostic health management is qualified to be an efficient and accuracy tool for assessment of the remaining life of the wire bond. The ability to predict the remaining useful life of Cu-Al wire bond provides several advantages, including increasing safety by providing warning ahead of time before the failure.
Highly Manufacturable and Reliable CZT Detectors
Authors: Burdick Bill , Erlbaum Jeff , Nagarkar Kaustubh , Yanoff Brian , Yin Liang , Bahadur Raj , Heidari Esmaeil , Sherman Donna , Simpson James E.
Published: January 2014

Cadmium Zinc Telluride (CZT) based radiation detectors have been developed over the past decade and are, increasingly, being used in security and healthcare applications. Improvements in radiation detector performance, size, and cost have been achieved; however, the manufacturability and reliability of the individual CZT detector package continues to limit widespread use and new applications.

To date, most CZT detector packages are designed, manufactured, and tested to requirements defined by manufacturers, rather than military, commercial, or industry standards, as is common for semiconductor packages. The lack of test standards has led to use restrictions and/or complex detector system design, as required to mitigate unknown or low detector package reliability. CZT detector packaging, as was the case for semiconductor packaging, has reached the point in technology maturation where a focus on optimizing detector design for manufacturability and reliability is appropriate and necessary.

This paper reviews the systematic approach, including design, process development, and testing, utilized in the development and demonstration of a highly manufacturable and reliable (95% reliability at 1000 cycles) CZT detector package. Finite Element Model (FEM) based design and material trade-off studies, development of highly manufacturable and reliable commercial electronic assembly processes, failure mode identification and mitigation, selection and use of reliability test standards, and analyses are detailed for a flip-chip-CZT-on-ceramic substrate, detector package targeted for field deployment. As well, the next steps in package and system design, manufacturing, and reliability testing are proposed.
Compact Modeling of Data Center Air Containment Systems
Authors: Zhang Xuanhang (Simon) , VanGilder James W. , Healey Christopher M. , Sheffer Zachary R.
Published: January 2014

The practice of ducting racks to a dropped ceiling or containing entire cold or hot aisles in data centers is being implemented with more frequency in an attempt to improve reliability and efficiency. While CFD and other numerical modeling tools are widely used to optimize data center cooling, they are not particularly effective at modeling containment systems; the performance of such systems is dominated by small and complex leakage paths (e.g., through, around, and under racks), which are difficult or impossible to include in a practical full-scale model. We propose a compact model which uses a flow network to determine airflow rates inside containment systems while the traditional “parent” numerical model continues to handle predictions in the rest of the facility. The two models are coupled at flow boundaries such as where ducting meets a dropped ceiling and leakage paths cross rack surfaces. The compact-model approach has the opportunity to be much faster and more robust than fully-explicit CFD models since leakage path resistances can be established through experimental measurements. We discuss the characterization of rack leakage paths and demonstrate the use of the compact model in a full data center simulation in which the role of parent numerical model is played by a potential flow model.
Geohazard Prevention and Pipeline Deformation Monitoring Using Distributed Optical Fiber Sensing
Authors: Ravet Fabien , Borda Carlos , Rochat Etienne , Niklès Marc
Published: January 2014

The present work introduces the technology background at the origin of FOPIMS (Fiber Optic Pipeline Integrity Monitoring Systems) with an emphasis on geotechnical monitoring. It shows how temperature sensing can be implemented to control soil erosion or dune migration through event localization and spatial quantification. Arctic pipeline monitoring project illustrates the application of soil erosion detection. Direct measurement of strain in soil also enhances environmental threat detection. Combined with temperature sensing, strain sensing composes the geotechnical monitoring system. Transandean pipeline monitoring examples are presented where the DITEST AIM was implemented for geohazard prevention. These study cases concern new pipeline installation as well as retrofit of existing lines. The technique successfully evidenced early events and allowed preventive measures to be taken.

In some applications actual pipeline deformation need to be monitored. Such operation is achieved by measuring distributed strain along sensing cables attached to the structure. We show how such measurements complement the geotechnical measurements. We also describe a real implementation in seismic active area.

As a whole, the work focuses on the technique principles, the installation and how the system is being implemented for pipeline preventive maintenance. We intend to present a comprehensive set of design guidelines based on real results and lessons learned from the various projects in what concerns geohazard detection and pipeline deformation monitoring.
Emergency Actions for Containing Side Slope to the Pipeline Range
Authors: Varanda Erica , Soares José Pereira , Leite Roberta Amorim
Published: January 2014

After a period of heavy rainfall, the landslide of a mass of residual soil in the side slope to the Pipeline Range of PETROBRAS occurred, in which two oil pipelines and gas pipeline connecting a terminal to a refinery.

On the day following the event in field inspection performed by the TRANSPETRO team, it was found that due to the landslide, the gas pipeline was exposed, with a Section of approximately 8.0 meters apparent in a slope at risk of undergoing deformations with the movement of unstable soil.

In the course of the inspection several indications soil movement were observed, such as cracks in the ground, breaks and located cracks in reinforced concrete structures of the drainage system. Surge flow of water or soil saturation was not found, despite the high rate of rainfall during the period. Thus one ruled out the possibility of the presence of a high water table which could have caused sliding. It is assumed that this may have begun on lower slopes due to deficiencies in the surface drainage system, which caused the accumulation of rainwater and its collapse. Hence, ruptures allegedly have occurred progressively upstream until it reaches the side of the pipeline range.

To ensure the integrity of the gas pipeline and operational safety and prevent the evolution of the incidents with more serious consequences, a contingency group responsible for coordinating emergency actions to contain the slope and protecting the pipeline exposed was called.

The first actions consisted of protecting the slope using a plastic tarpaulin to prevent the infiltration of more rainwater, metal profile riveting to contain side soil movement to the pipelines and finally to the implementation of contention with soil nailing technique with shotcrete on the surface of the slope where the pipeline was exposed found. Repairs to the surface drainage system of the range and slopes, which had been damaged during landslide were made.

In parallel to emergency actions, a campaign of geotechnical surveys using Standard Penetration Test (SPT) aiming at providing grounds for stability studies for the preparation of final stabilization project of the slope.
Integral Management of Risk: From a Corrective to a Preventive Approach
Authors: Oliveros Montes Edward Francisco , Leynaud Favian Gustavo Luis
Published: January 2014

The Camisea Pipeline Transmission System (PTS) in Peru consists of two parallel pipelines, a Natural Gas (NG) pipeline and a Natural Gas Liquids (NGL) pipeline. The NG pipeline is 834 km long, including a 105 km loop. The NGL pipeline is 557 km long.

Since 8 years ago and as a part of the current operation of the system, maintenance activities are being carried which, within its objectives for improvement, seek to establish a preventive approach instead a corrective approach. The involved areas in this new Management approach are geo-technics, pipelines, environment, communities and integrity.

This paper describes the process named Integral Plan for Operating Risks. This process is a result of the updating of the geological-geotechnical base-line, in relation to the environmental and social context, allowing a comprehensive analysis of the status of the relation between the works and its environment, as well as planning prevention tasks able to guarantee the stability of the right of way (RoW) and the pipeline Integrity. This job is performed by both desk work (remote interpretation) and field work conducted by multidisciplinary teams, which ensures a transverse communication flow. All of this is backed by a digital database and a geographical information system (GIS). A Technical Atlas is constructed as a graphic document containing a series of cartographic and text cards regarding the sector under study as a useful instrument of preventive management for intervention in a given area.

To date, a comprehensive remote analysis of the RoW has been completed and an in-site field analysis has started, upon which strategies are being developed in order to control items such as geological hazards, geological architecture, vegetation architecture, RoW stability, etc. Jobs were competed along the first 12 km as a pilot experience, which is being replicated all along the RoW.
Protection of Pipelines Uncovered in Crossing River: A Case Study
Authors: Teixeira Priscila Pereira , Russo Wanderley Camargo , Torralbo Quintana João Luiz , Hoff Ricardo
Published: January 2014

To ensure the integrity of pipelines in failure mode Geotechnical, TRANSPETRO and the TBG perform underwater inspections of pipelines in the main crossings of rivers, lakes, dams, canals and permanently flooded areas. The inspections are designed to locate guideline and measure the covering the pipelines from the margins and underwater depth, identify any exposure of the pipelines, map the occurrences of blocks of rock or debris on the channel and evaluate the anthropic influence on stability of the sections inspected. Among the crossings rivers inspected, in the Atibaia V, with approximately 27.3 m in length, was observed a high erosive potential, which resulted in the loss cover of 3 (three) pipelines of crossing river, besides the fiber optic cable. The lengths uncovered resulted in approximately 33.0 m, with suspended pipes, damage in the concrete jacket and presence of blocks of rocks in the channel. The pipeline in the most critical situation went vain of 6.0 m, with gap up to 0,2 m in relation the background. The crossing river was studied with bathymetric survey and designed cover the pipelines with mechanical protection and anti-erosive. The pipes were supported with sacks of granular material, sequentially, the margins and pipelines were protected with geotextile filled with concrete, installed with the help of divers. The working conditions of 4.0 m depth, currents of up to 0.8 m/s, temperature and low visibility waters were challenges overcome during execution, in which the divers took turns in short periods. Due to the characteristics of the bedrock, the blankets went stylized and stitched on the field by the team, with dimensions taken on site. After positioning the blankets in the background began the underwater concreting, which occurred in stages monitored by the volume pumped and divers strategically placed. The crossing river was re-inspected approximately 1 (one) year after their stabilization and was found in good conditions. The occurrence improved the procedures for geotechnical monitoring and treatment of pipelines uncovered in crossings rivers, being who the efficiency and safety of the work performed currently serve as a reference for the design of similar works.
Web-Based Virtual Seismic Monitoring for Pipelines
Authors: Nyman Douglas J. , Nigbor Robert L.
Published: January 2014

Strong motion seismic monitoring systems are often installed at critical industrial facilities located in areas of moderate to high seismicity. The objective of seismic monitoring is to facilitate post-earthquake evaluation and emergency action by providing rapid detection of seismic events and associated data, alarms, and information. Seismic monitoring can play a similar role for pipelines, especially considering the added geohazard risks along right-of-ways that might include landslides, fault crossings, and liquefaction hazard areas. Because of spatial distribution, seismic monitoring for pipelines is more complex than that required for a site-specific facility.

In recent years, graphical software known as “ShakeMap,” developed by U.S. Geological Survey (USGS), has been used to rapidly estimate and distribute the distribution and intensity of earthquake ground motions from an earthquake. The ShakeMap solution for ground motions takes into account the distance from the earthquake source, the rock and soil conditions at sites, and variations in the propagation of seismic waves due to complexities in the structure of the Earth’s crust. ShakeMap ground motion data is available for automatic download from the USGS for potentially damaging earthquakes, e.g., Magnitude 5 and greater, within minutes after the event.

USGS’ ShakeMap provides the opportunity to implement web-based systems to conduct automatic seismic monitoring for cross-county pipelines or networks of pipelines. A monitoring website can be equipped with a seismic database of fragilities that characterize geohazard vulnerabilities along pipeline right-of-ways as well as support facilities. Website software can be used to process the ground motion data to assess the threat to the pipeline system, advise pipeline controllers on the need for shutdown, and guide post-earthquake inspection on a prioritized basis.

Drawing from the authors’ recent seismic monitoring experience for the Trans-Alaska Pipeline and other lifeline facilities, a conceptual plan for web-based seismic monitoring for pipelines is presented. The choice of a software platform can range from the use of open-source software available from USGS (ShakeCast) to custom software making direct use of gridded data downloads. Regardless of implementation strategy, the most convincing point to be made is that a seismic monitoring system need not require the installation of seismic instruments and the associated commitment to maintenance and hands-on seismology; instead it makes use of publicly available scientific data for rapid post-earthquake assessment.
The Challenge of Crossing the Andes: A Data Base Analysis and Peru LNG Project Description
Authors: Cardenas Ariel Gasca , Gutierrez Edilberto
Published: January 2014

As of the date this paper is written pipelines in South America comprises 113000 kms of transmission lines including Oil, Gas, Condensates, and refined products from which approximately 17% (19400 kms) crosses the Andes reaching elevations up to near 5000mts. Rugged terrain combined with the geology, weather conditions (especially rain intensity) and continuous pipe ruptures in the past impose serious challenges for the pipeline industry that makes the design, construction and operation substantially different from other pipelines in the world. The records have shown that the threat of Ground movement/weather-related pipeline ruptures in the Andes plays a significant role since the percentage of the risk associated with geotechnical causes is substantially higher than any other parts such as Europe or United States. Thus the rate of pipeline failures due to natural forces is significant higher than the average industry. Peru LNG is a 406km × 34in gas pipeline transporting natural gas from the jungle side of Peru to the Pacific Coast where a LNG terminal has been installed. Peru LNG’s pipeline currently holds the record of being the highest Gas Pipeline of the world with a maximum elevation of 4901 meters above sea level. Project completion was done in May 2010 and lessons learnt from similar projects were taken into account since project designs. This paper is divided in two parts. First, it compares pipeline ruptures frequencies due to natural forces in the Andes with other pipelines in different terrains based on historical cases compiled by the authors. Secondly, it explains the different phases of Pipeline Project in rugged terrain from the conceptual design until the operations stage and the role of Pipeline Geotechnical Engineers in this process based on PERU LNG’s pipeline experience. It also describes some of the main features of the PLNG pipeline project. A comprehensive flow chart provides general guidance for future pipeline projects in similar conditions.
Asset Integrity Management: Geohazards
Authors: Pedraza Acuña René , Moncada Saavedra Daniel Mauricio , Rojas S. Holman Fernando , De Los Ríos Ibáñez Pablo , Caipa R. John Freddy
Published: January 2014

TECNICONTROL S.A. and TECHNICAL QUALIFIED PERSONNEL have jointly developed an Assets Integrity Management solution specialized on GEOHAZARDS, conceived with the vision of completely implementing the continuous improvement process during all stages of the asset’s life cycle.

This process is based on the implementation of technical-administrative management controls, by optimizing, planning and appropriately allocating investment resources and following a cost-benefit analysis philosophy, to all operations and processes in which hazardous materials are involved and have the potential of generating high level risks. The aim is that these risks are identified, assessed, understood and publicized so that mitigate, control or minimize, and prevent personal injury, irreversible damage to health, fatalities, environmental impact, loss of production, quality, image and profitability of processes and production facilities and treatment of hazardous fluids.

The integration of the main processes of asset integrity management, focused on hazardous fluids pipelines exposed to geohazards, was divided into four main steps are Risk Identification, Remote Monitoring, Risk Management and Consulting, in which runs from the identification, description and classification of all natural phenomena by external forces that may affect the integrity of pipelines, along with real-time measurement and remotely adequate instruments of the major variables that cause likelihood of injury, by shifting to the associated risk management, by implementing methodologies and continuous improvement processes and focused to evaluate, assess and manage risk, and ending the process with recommendations consultancy studies for assessing threat mitigation alternative civil works or similar.

Tecnicontrol S.A. has implemented this Asset Integrity Management process taking advantage of the experience gained over 20 years of involvement in the field of Integrity, working with several operators and customers.
Geotechnical Aspects of the Norandino Pipeline at Mal Paso
Authors: Bustinza Juan A. , Rocca Ricardo J. , Ponce José M. , Reale Rodolfo
Published: January 2014

The Norandino pipeline, build between 1998 and 1999, begins at the town of Pichanal nearby Orán in Argentina where it is connected to Argentinean Gas Transport System, It runs towards west crossing the Yunga in Salta province, climbs the Sierras Subandinas and the Cordillera Oriental through highly erosive environment, descends to Humahuaca city in Jujuy Province, crosses the Altiplano plateau, and reaches Chile through Paso de Jama then climbs up to 4.980 mas, crosses the Atacama desert to finally arrives at Tocopilla, Mejillones and Coloso cities. With 1070 km long and 20″ diameter, it’s capable to carry 4,6 million cubic meters per day expandable up to 8.

The most hazardous part of the alignment is the Sierras Subandinas area, due mainly to geology and heavy rains. The east slope of the Cordillera Oriental, where the risk arises from the intense geodynamic and strong erosions in river crossings and landslides because of heavy rains that reach 1.500mm in four month, from December to March.

In Cuesta de Mal Paso site, in front of San Andrés village in Salta Province, the pipeline should be laid along the hillside on a slope formed by the anticline limb, whose exposure to heavy erosion of the San Andres river at the base of the slope, the bedding to the river and seismic conditions of the region, constitute a geological and geotechnical risk to the pipeline integrity.

The evaluation of deformation measurements of the slope, measured along several years, provided the necessary arguments to undertake the construction of tunnel in rock of 750 meters long and 2.5 meters wide and high, allowing the pipeline to pass below the main slip surface and therefore protecting it from a possible slide of the superficial layers of the slope.

This paper describes the geological conditions, the geostructural situation of Cuesta de Mal Paso, the deformation monitoring system, the evaluation of the auscultation measurements, the design of the tunnel, the meaningful geological and geotechnical aspects of the tunnel construction and, finally, criteria for definition the auscultation system to monitoring the behavior of the tunnel and the Cuesta de Mal Paso slope.
The Assessment of Pipeline Integrity in Geohazard Areas Using ILI Data
Authors: Young Andy , Lockey Aaron
Published: January 2014

In-line inspection by inertial mapping techniques is an essential tool for pipeline operators in areas susceptible to geohazards. The detection of previously unknown movements can provide early warning of the presence of a hazard. Positional change and the nature of the loading process can be monitored using the results of multiple inspections over time. Structural modelling is required to fully evaluate the integrity of the pipeline and whether a failure condition is being approached. Finite element techniques can be used, including the effects of soil-pipe interaction, axial forces and operational loads. This enables the prediction of future performance, based on trends from multiple inspections, so that mitigation or intervention methods are efficiently designed and scheduled.

This paper considers some key aspects of the analysis process. The use of ILI mapping data to detect small movements below the tool measurement tolerance is examined. The importance of structural analysis is demonstrated by consideration of the axial force component. The inherent variability of the soil surrounding the pipe and its influence on the load transfer effects is illustrated, together with the issues of significant interaction within the transition zones of landslides or faults.
Lower-Extremity Electromyography Measures During Walking With Ankle-Destabilization Devices
Authors: Donovan Luke , Hart Joseph M. , Hertel Jay
Published: January 2014

Context:

Ankle-destabilization devices are rehabilitation tools that may improve neuromuscular control by increasing lower-extremity muscle activation. Their effects should be tested in healthy individuals before being implemented in rehabilitation programs.

Objective:

To compare EMG activation of lower-extremity muscles during walking while wearing 2 different ankle-destabilization devices.

Design:

Crossover.

Setting:

Laboratory.

Participants:

15 healthy young adults (5 men, 10 women).

Intervention:

Surface EMG activity was recorded from the anterior tibialis, peroneus longus, lateral gastrocnemius, rectus femoris, biceps femoris, and gluteus medius as subjects walked on a treadmill shod, with an ankle-destabilization boot (ADB), and an ankle-destabilization sandal (ADS).

Main Outcome Measures:

Normalized amplitudes 100 ms before and 200 ms after initial heel contact, time of onset activation relative to initial contact, and percent of activation time across the stride cycle were calculated for each muscle in each condition.

Results:

The precontact amplitudes of the peroneus longus and lateral gastrocnemius and the postcontact amplitudes of the lateral gastrocnemius were significantly greater in the ADB and ADS conditions. In the ADB condition, the rectus femoris and biceps femoris postcontact amplitudes were significantly greater than shod. The peroneus longus and lateral gastrocnemius were activated significantly earlier, and the anterior tibialis, lateral gastrocnemius, and rectus femoris were activated significantly longer across the stride cycle in the ADB and the ADS conditions. In addition, the peroneus longus was activated significantly longer in the ADB condition when compared with shod.

Conclusions:

Both ankle-destabilization devices caused an alteration in muscle activity during walking, which may be favorable to an injured patient. Therefore, implementing these devices in rehabilitation programs may be beneficial to improving neuromuscular control.
Anatomical aberrations in root canals of maxillary first and second molar teeth: an endodontic challenge
Authors: Shah Manish , Patel Pathik , Desai Parth , Patel Jayanti R
Published: January 2014

Root canal anatomy variations present a constant challenge in successful diagnosis and endodontic treatment, especially the multirooted teeth. Maxillary first molar is the most commonly treated tooth yet with frequent failures because of undetected canals, especially the mesiobuccal second canal (MB2) with more frequency and distobuccal second canal (DB2) with quite a less frequency. Also, there are limited chances to find MB2 in maxillary second molars. We present two such cases, each of maxillary first and second molar with extra distobuccal and mesiobuccal canals, respectively.
Resolution of neurological deficits secondary to spontaneous intracranial haemorrhage and posterior reversible encephalopathy syndrome (PRES) in a patient with hepatitis C-associated cryoglobulinaemia: a role for plasmapheresis
Authors: Ahmad Delshad , Ilias Basha Haseeb , Towfiq Basim , Bachuwa Ghassan
Published: January 2014

Essential mixed cryoglobulinaemia or type II cryoglobulinaemia is an important extrahepatic manifestation of chronic hepatitis C. Cryoglobulinaemia results in the deposition of immune complexes in small or medium-sized blood vessels leading to palpable purpura, arthralgia, renal disease and peripheral neuropathy. Posterior reversible encephalopathy syndrome (PRES) is a distinct phenomenon characterised by vasogenic oedema in the posterior circulation of brain. Cryoglobulinaemic vasculitis leading to spontaneous intracranial haemorrhage and PRES syndrome is rarely reported in the medical literature. In this report, we present an unusual case of spontaneous intracranial haemorrhage and PRES secondary to hepatitis C-associated cryoglobulinaemia presenting as right dense hemiplegia. Prompt institution of plasmapheresis resulted in successful resolution of symptoms in our patient, followed by full neurological recovery. To the best of our knowledge, this case describes the first successful use of plasmapheresis in alleviating neurological complications resulting from cryoglobulinaemic vasculitis and PRES secondary to chronic hepatitis C.
Inferolateral ST-segment elevation associated with a gastric variceal bleed and the use of a Minnesota tube
Authors: Birse Duncan R B
Published: January 2014

The use of Minnesota and modified Sengstaken-Blakemore tubes for balloon tamponade in acute variceal haemorrhage has declined with the availability of modern endoscopic techniques. However, in massive uncontrolled haemorrhage their use may still be required. They are very effective in controlling acute bleeding, but are associated with a range of potentially serious complications. This case demonstrates an unusual complication of the use of a Minnesota tube in a gentleman with a large gastric variceal bleed. The patient developed inferolateral ST-segment elevation on a 12-lead ECG which resolved rapidly following aspiration of 2000 mL of blood from the gastric port of the Minnesota tube. It was thought that the distension of the stomach, along with the traction applied to the Minnesota tube, resulted in external compression of the diaphragmatic surface of the heart and the observed ECG changes.
Coastal movements of migrating sea lamprey (Petromyzon marinus) in response to a partial pheromone added to river water: implications for management of invasive populations
Authors: Meckley Trevor D. , Wagner C. Michael , Gurarie Eliezer
Published: January 2014

How sea lampreys (Petromyzon marinus) search for and select reproductive habitat is poorly understood. Manual tracking of acoustically tagged migrants confirms the hypothesis that sea lampreys transition from extensive search to intensive search upon encounter with river water and return to extensive search upon leaving the plume. In addition, we document a previously unknown search tactic used to localize river mouths termed coastal rebounding. Increased intensive search in the river plume and subsequent approach to the river mouth is hypothesized to occur as a consequence of detection of a pheromone released by river resident larvae that indicate the presence of high-quality reproductive habitat. Application of two synthesized pheromone components caused migrants to increase time spent searching a plume by 57%; applications did not increase the likelihood of river entry. These findings suggest that partial pheromones constitute information that facilitates the search for river entrances, but prove insufficient to affect the decision to select a habitat. Proposed management tactics that rely on luring migrants into rivers with larval odor may prove ineffective without a complete blend of pheromone components.
Temperature and bias dependence of hydrogenated amorphous silicon – crystalline silicon heterojunction capacitance: the link to band bending and band offsets
Authors: Maslova O. , Brézard-Oudot A. , Gueunier-Farret M.E. , Alvarez J. , Favre W. , Muñoz D. , Gudovskikh A.S. , Kleider J.-P.
Published: January 2014

The temperature dependence of the capacitance–voltage data (C–V–T) of very high efficiency silicon heterojunction solar cells in a wide temperature range, up to 400 K, is analyzed. We show that the temperature dependence of the capacitance exhibits an anomalously large increase with temperature that cannot be explained under the usual depletion approximation. Using the complete analytical calculation of the capacitance, where the contribution of both types of carriers is taken into account, this large increase of capacitance with temperature of p-type hydrogenated amorphous silicon – n-type crystalline silicon ((p) a-Si:H – (n) c-Si) heterojunctions observed experimentally is reproduced. This increase of the capacitance is due to a strong inversion layer at the c-Si surface, which is promoted as the temperature increases. Further we show that the temperature dependence of the 1/C2 versus applied reverse voltage (Va) plot is as well strongly affected by the strong inversion layer at the c-Si surface. Consequently, the intercept of the linear extrapolation of 1/C2 versus Va with the voltage axis (Vint) differs significantly from the total diffusion potential predicted by depletion capacitance theory. These underestimated values of the total diffusion potential can consequently lead to erroneous estimation of the band offsets. The temperature dependence of Vint is considerably enhanced for the case of the full analytical calculation when compared with the depletion approximation approach. These data, obtained directly on the final solar cell device, thus confirm the existence of a surface strong inversion layer that was previously revealed by measurements performed by other techniques on dedicated or precursor devices, allowing one to get information on the band diagram and the heterointerface.
Development of plasma-enhanced chemical vapor deposition microcrystalline silicon oxide as a replacement for N-type or back transparent conducting oxide layers in amorphous silicon single-junction solar cells
Authors: Liang Shin-Wei , Hsu Hung-Jung , Hsu Cheng-Hang , Tsai Chuang-Chuang
Published: January 2014

The n-type hydrogenated microcrystalline silicon oxide (μc-SiOx:H(n)) thin films with varied electrical and optical properties were prepared. We employed μc-SiOx:H(n) as a replacement for n-type hydrogenated amorphous silicon (a-Si:H(n)) or back transparent conducting oxide (TCO) layers in hydrogenated amorphous silicon (a-Si:H) single-junction solar cells. Compared to the standard cell with a-Si:H(n)/ITO/Ag back reflecting structure, the cell using a-Si:H(n)/μc-SiOx:H(n)/Ag or μc-SiOx:H(n)/Ag showed a similar or even better performance. This improvement of cell performance mainly arose from the increased short-circuit current density (JSC) that originated from the increased long wavelength (580–660 nm) absorption in the absorber confirmed by the quantum efficiency measurement. The “all plasma-enhanced chemical vapor deposition ” (if the front TCO and metal contact are disregarded) process without TCO (indium tin oxide, ITO) sputtering can simplify the fabrication and result in better interface quality. Compared to the standard cell, the conversion efficiency of a-Si:H cells using an 80 nm thick μc-SiOx:H(n)/Ag back reflecting structure was enhanced from 9.32% to 9.84%, with VOC = 0.90 V, JSC = 14.84 mA/cm2, and FF = 73.7%.
DUAL THRESHOLD VOLTAGE DOMINO ADDER DESIGN WITH PASS TRANSISTOR LOGIC USING STANDBY SWITCH FOR REDUCING SUB-THRESHOLD LEAKAGE CURRENT
Authors: YUAN SHOUCAI , LIU YAMEI
Published: January 2014

Standby switch can strongly turn off all the high threshold voltage transistors, which enhances the effectiveness of a dual threshold voltage CMOS technology to reduce sub-threshold leakage current. Sub-threshold leakage currents are especially important in burst mode type integrated circuits where the system is in an idle mode in the majority of the time. The standby switch allows a domino system to enter and leave a low leakage standby mode within a single clock cycle. In addition, we combine domino dynamic logic with pass transistor XNOR and pass transistor NAND gates to achieve logic 1 output during its precharge phase without affecting circuits operation in its evaluation and standby phase. The required process for dual threshold voltage circuit configuration involves only one additional ion implant step to provide an extra threshold voltage. SPICE simulation for our proposed circuits is made using a 0.18 μm CMOS processes from TSMC, with 10 fF capacitive loads in all output nodes, and parameters for typical process corner at 25°C. Layout is designed, wafer is fabricate and measured. The measurement results of fabricated chips are listed and verify that our designed 8-bit carry look-ahead adders (CLAs) reduced power consumption and propagation delay time by more than 15% and around 20%, respectively, when compared with the prior work.
Potential Benefits of Therapeutic Use ofβ2-Adrenergic Receptor Agonists in Neuroprotection and Parkinson’s Disease
Authors: Peterson Lynda , Ismond Kathleen P. , Chapman Elisha , Flood Patrick
Published: January 2014

Theβ2-adrenergic receptor (β2AR) is a seven-transmembrane (7TM) G-protein coupled receptor that is expressed on cells of the pulmonary, cardiac, skeletal muscle, and immune systems. Previous work has shown that stimulation of this receptor on immune cells has profound effects on the regulatory activity of both adaptive and innate immune cells. This review examines the functional dichotomy associated with stimulation ofβ2AR and microglial cells. As well, recent studies targeting these receptors with long-acting agonists are considered with respect to their therapeutic potential in management of Parkinson’s disease.
Influence of Fuel Moisture Content and Reactor Temperature on the Calorific Value of Syngas Resulted from Gasification of Oil Palm Fronds
Authors: Atnaw Samson Mekbib , Sulaiman Shaharin Anwar , Yusup Suzana
Published: January 2014

Biomass wastes produced from oil palm mills and plantations include empty fruit bunches (EFBs), shells, fibers, trunks, and oil palm fronds (OPF). EFBs and shells are partially utilized as boiler fuel while the rest of the biomass materials like OPF have not been utilized for energy generation. No previous study has been reported on gasification of oil palm fronds (OPF) biomass for the production of fuel gas. In this paper, the effect of moisture content of fuel and reactor temperature on downdraft gasification of OPF was experimentally investigated using a lab scale gasifier of capacity 50 kW. In addition, results obtained from equilibrium model of gasification that was developed for facilitating the prediction of syngas composition are compared with experimental data. Comparison of simulation results for predicting calorific value of syngas with the experimental results showed a satisfactory agreement with a mean error of 0.1 MJ/Nm3. For a biomass moisture content of 29%, the resulting calorific value for the syngas was found to be only 2.63 MJ/Nm3, as compared to nearly double (4.95 MJ/Nm3) for biomass moisture content of 22%. A calorific value as high as 5.57 MJ/Nm3was recorded for higher oxidation zone temperature values.
Model Selection Approach for Distributed Fault Detection in Wireless Sensor Networks
Authors: Nandi Mrinal , Dewanji Anup , Roy Bimal , Sarkar Santanu
Published: January 2014

Sensor networks aim at monitoring their surroundings for event detection and object tracking. But, due to failure or death of sensors, false signal can be transmitted. In this paper, we consider the problems of distributed fault detection in wireless sensor network (WSN). In particular, we consider how to take decision regarding fault detection in a noisy environment as a result of false detection or false response of event by some sensors, where the sensors are placed at the center of regular hexagons and the event can occur at only one hexagon. We propose fault detection schemes that explicitly introduce the error probabilities into the optimal event detection process. We introduce two types of detection probabilities, one for the center node, where the event occurs, and the other one for the adjacent nodes. This second type of detection probability is new in sensor network literature. We develop schemes under the model selection procedure and multiple model selection procedure and use the concept of Bayesian model averaging to identify a set of likely fault sensors and obtain an average predictive error.
Parametric Optimization of Squeeze Cast AC2A-Ni CoatedSiCpComposite Using Taguchi Technique
Authors: Ravikumar A. R. , Amirthagadeswaran K. S. , Senthil P.
Published: January 2014

This paper mainly focusses on parametric optimization of squeeze cast AC2A Ni coatedSiCpcomposite through Taguchi technique. Composite samples have been cast through squeeze casting for each experimental trial based on L16 orthogonal array. From analysis of variance (ANOVA), it has been found that reinforcement percentage, squeeze pressure, and pressure duration were the casting parameters making significant improvement in the mechanical properties such as hardness and ultimate tensile strength. Reinforcement percentage and squeeze pressure have been identified as the most influencing parameters from the percentage contribution analysis. The optimum parametric setting has been determined through Taguchi technique. It has been confirmed that AC2A-Ni coatedSiCpcomposite obtained for the optimum parametric setting has exhibited better mechanical properties compared to the experimental trials.
A Modified Nonlinear Damage Accumulation Model for Fatigue Life Prediction Considering Load Interaction Effects
Authors: Gao Huiying , Huang Hong-Zhong , Zhu Shun-Peng , Li Yan-Feng , Yuan Rong
Published: January 2014

Many structures are subjected to variable amplitude loading in engineering practice. The foundation of fatigue life prediction under variable amplitude loading is how to deal with the fatigue damage accumulation. A nonlinear fatigue damage accumulation model to consider the effects of load sequences was proposed in earlier literature, but the model cannot consider the load interaction effects, and sometimes it makes a major error. A modified nonlinear damage accumulation model is proposed in this paper to account for the load interaction effects. Experimental data of two metallic materials are used to validate the proposed model. The agreement between the model prediction and experimental data is observed, and the predictions by proposed model are more possibly in accordance with experimental data than that by primary model and Miner’s rule. Comparison between the predicted cumulative damage by the proposed model and an existing model shows that the proposed model predictions can meet the accuracy requirement of the engineering project and it can be used to predict the fatigue life of welded aluminum alloy joint of Electric Multiple Units (EMU); meanwhile, the accuracy of approximation can be obtained from the proposed model though more simple computing process and less material parameters calling for extensive testing than the existing model.
A Cooperative Model for IS Security Risk Management in Distributed Environment
Authors: Feng Nan , Zheng Chundong
Published: January 2014

Given the increasing cooperation between organizations, the flexible exchange of security information across the allied organizations is critical to effectively manage information systems (IS) security in a distributed environment. In this paper, we develop a cooperative model for IS security risk management in a distributed environment. In the proposed model, the exchange of security information among the interconnected IS under distributed environment is supported by Bayesian networks (BNs). In addition, for an organization’s IS, a BN is utilized to represent its security environment and dynamically predict its security risk level, by which the security manager can select an optimal action to safeguard the firm’s information resources. The actual case studied illustrates the cooperative model presented in this paper and how it can be exploited to manage the distributed IS security risk effectively.
The Effect of Hydroxyapatite Nanocrystals on Osseointegration of Titanium Implants: AnIn VivoRabbit Study
Authors: Breding Karin , Jimbo Ryo , Hayashi Mariko , Xue Ying , Mustafa Kamal , Andersson Martin
Published: January 2014

Osseointegration is dependent on implant surface characteristics, including surface chemistry and topography. The presence of nanosized calcium phosphates on the implant surface is interesting to investigate since they affect both the nanotopography and surface chemistry, forming a bone mineral resembling surface. In this work, the osseointegration of titanium implants with and without the presence of hydroxyapatite (HA) nanocrystals has been evaluatedin vivo. The integration was examined using removal torque measurements and real-time polymerase chain reaction (RT-PCR) analysis. The study was performed using two healing time points, 3 and 12 weeks. The results showed that the torque needed to remove the implants was insignificant between the non- and HA-coated implants, both at weeks 3 and 12. The RT-PCR, however, showed significant differences for osteoblast, osteoclast, and proinflammation markers when HA nanocrystals were present.