bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermal Management for Chip-Scale Atomic Clocks
Authors: Laws Alexander , Chang Richard Y. J. , Bright Victor M. , Lee Y. C.
Published: April 2009

Power dissipation of chip-scale atomic clocks is one of the major design considerations. The largest power dissipation is for temperature control of the vertical-cavity surface-emitting laser (VCSEL) and cesium vapor cell. For example, the temperature of the VCSEL and Cs cell have to both be at 70±0.1°C or there will be frequency shift which will ruin the lock of the clock. These temperatures have to be maintained even under a large temperature variation such as −40°C to 50°C. There are three major thermal designs to consider: a) micro-heaters to fine-tune the temperatures of VCSEL and Cs cell, b) use of waste heat from other units to heat the system when outside temperature is low, and c) use of a thermal switch to release any extra waste heat when ambient temperatures are high. These three thermal designs have been incorporated in to a thermal test vehicle, which will be used to develop a thermal management design for the clock. This paper describes the proposed clock design, creation of the thermal test vehicle and development of a bimetallic snap based thermal conduction switch. The switch has been demonstrated to change thermal resistance from 52.9±2.8 K/W when the switch is open to 19.5±1.1 K/W with the switch closed.
Maintaining Datacom Rack Inlet Air Temperatures With Water Cooled Heat Exchanger
Authors: Schmidt Roger , Chu Richard C. , Ellsworth Mike , Iyengar Madhu , Porter Don , Kamath Vinod , Lehman Bret
Published: April 2009

The heat dissipated by electronic equipment continues to increase at a alarming rate. This has occurred for products covering a wide range of applications. Manufacturers of this equipment require that the equipment be maintained within an environmental envelope in order to guarantee proper operation. Achievement of these environmental conditions are becoming increasingly difficult given the increases in rack heat loads and the desire for customers of such equipment to cluster racks in a small region for increased performance. And with the increased heat load of the racks and correspondingly increased air flowrate the chilled air flow supplied either through data center raised floor perforated tiles or diffusers for non raised floors is not sufficient to match the air flow required by the datacom racks. In this case some of the hot air exhausting the rear of a rack can return to the front of the rack and be ingested into the air intake thereby reducing the reliability of the electronic equipment. This paper describes a method to reduce the effect of the hot air recirculation with a water cooled heat exchanger attached to the rear door of the rack. This heat exchanger removes a large portion of the heat from the rack as well as significantly lowering the air temperature exhausting the rear of the rack. This paper describes the hardware and presents the test results showing that a large portion of the heat is removed from the rack and the temperature exhausting the rear of the rack is significantly reduced. Finally the effectiveness of the solution is shown in modeling of this water cooled solution in a data center application.
Peltier Enhanced Heat Spreading for Localized Hot Spot Thermal Management
Authors: Solbrekken Gary L.
Published: April 2009

Localized areas of high heat flux on microprocessors are currently being identified as a dominant challenge for the thermal management community. Heat flux values up to 1 kW/cm2 prevailing over a fraction of the overall CPU surface area create local hot spots that need to be cooled. However, thermal solutions designed for the maximum heat flux overcool the rest of the CPU, wasting resources and creating large on-die temperature gradients. Wasting resources obviously has a negative economic and thermodynamic impact. However, it has been argued that large on-die temperature gradients reduce chip reliability and increase the difficulty in laying out the electric circuits. The current study proposes a strategy to reduce local hot spots by enhancing heat spreading through the use of the Peltier effect. The Peltier effect is most commonly associated with the operation of thermoelectric modules. In thermoelectric modules, heat is transported across the module by electrons. Ideally, the material used for the thermoelectric module would have a very low thermal conductivity to reduce the amount of back heat conduction through the thermoelectric elements, and the electric resistivity would be very low to minimize the Joule heating. Using today’s best commercially available thermoelectric materials, the thermal conductivity, electric resistivity, and Seebeck coefficient are such that the COP for the thermoelectric module is on the order of 1. This implies that in order to cool a processor dissipating 100W, an additional 100W of electric power must be supplied to the thermoelectric module. A total of 200W must then be rejected by the heat sink and any building HVAC system. A more pragmatic approach is to use the Peltier effect to not cool the entire CPU, but rather only the high heat flux region. This is accomplished by placing the thermoelectric elements laterally on the backside of the CPU. The cooling junction is placed in the proximity of the high flux region, while the heating junction is placed in contact with the CPU in low heat flux area that can tolerate the additional heat, effectively creating an active heat spreader. The Peltier enhanced heat spreading proposed here is shown to provide a reduction in the temperature of a localized hot spot relative to passive heat spreading. The amount of reduction in temperature depends on the thickness of the material as well as the thermal conductivity, but values up to 50% are illustrated.
Monte Carlo Simulation of the Thermal Conductivity and Phonon Transport in Nanocomposites
Authors: Jeng Ming-Shan , Yang Ronggui , Song David , Chen Gang
Published: April 2009

This paper presents a Monte Carlo simulation scheme to study the phonon transport and thermal conductivity of nanocomposites. Special attention has been paid to the implementation of periodic boundary condition in Monte Carlo simulation. The scheme is applied to study the thermal conductivity of silicon germanium (Si-Ge) nanocomposites, which are of great interest for high efficiency thermoelectric material development. The Monte Carlo simulation was first validated by successfully reproducing the results of (two dimensional) nanowire composites using the deterministic solution of the phonon Boltzmann transport equation and the experimental thermal conductivity of bulk germanium, and then the validated simulation method was used to study (three dimensional) nanoparticle composites, where Si nanoparticles are embedded in Ge host. The size effects of phonon transport in nanoparticle composites were studied and the results show that the thermal conductivity of nanoparticle composites can be lower than alloy value. It was found that randomly distributed nanopaticles in nanocomposites rendered the thermal conductivity values close to that of periodic aligned patterns.
Understanding the Spreading Patterns of Mobile Phone Viruses
Authors: Wang Pu , González Marta C. , Hidalgo César A. , Barabási Albert-László
Published: April 2009

Viruses and Mobile Phones

While traditional cellphones have been relatively immune to viruses, smartphones (like Palm, Blackberry, iPhone, and many Nokia brands) that can share programs and data with each other could potentially be vulnerable to virus epidemics. Why then haven't we experienced any major mobile virus outbreak so far?Wanget al.(p. 1071; published online 2 April; see the Perspective byHavlin) believe that the answer is related to the spreading patterns possible in the current mobile phone systems. They studied the anonymized billing record of a mobile phone company, representing the calling patterns and the coordinates of the closest mobile phone tower each time a group of 6.2 million mobile phone subscribers used their phone. While a Bluetooth virus could reach all susceptible users given sufficient time, its spread, limited by human mobility, was relatively slow. In contrast, MMS viruses would have an explosive spreading pattern, but could only reach the group of individuals that know each other and carry the same phone. Thus, no major virus outbreak is likely until one operating system encompasses a larger fraction of the total smartphone market.
Quantification of Human Polyomaviruses JC Virus and BK Virus by TaqMan Quantitative PCR and Comparison to Other Water Quality Indicators in Water and Fecal Samples
Authors: McQuaig Shannon M. , Scott Troy M. , Lukasik Jerzy O. , Paul John H. , Harwood Valerie J.
Published: April 2009

In the United States, total maximum daily load standards for bodies of water that do not meet bacterial water quality standards are set by each state. The presence of human polyomaviruses (HPyVs) can be used as an indicator of human-associated sewage pollution in these waters. We have developed and optimized a TaqMan quantitative PCR (QPCR) assay based on the conserved T antigen to both quantify and simultaneously detect two HPyVs; JC virus and BK virus. The QPCR assay was able to consistently quantify ≥10 gene copies per reaction and is linear over 5 orders of magnitude. HPyVs were consistently detected in human waste samples (57 of 64) and environmental waters with known human fecal contamination (5 of 5) and were not amplified in DNA extracted from 127 animal waste samples from 14 species. HPyV concentrations in sewage decreased 81.2 and 84.2% over 28 days incubation at 25 and 35°C, respectively. HPyVs results were compared to
Escherichia coli
, fecal coliform, and enterococci concentrations and the presence of three other human-associated microbes:
Bacteroidetes
,
Methanobrevibacter smithii
, and adenovirus. HPyVs were the most frequently detected of these in human and contaminated environmental samples and were more human specific than the
Bacteroidetes
(HF183) or
M. smithii
. HPyVs and
M. smithii
more closely mimicked the persistence of adenovirus in sewage than the other microbes. The use of this rapid and quantitative assay in water quality research could help regulatory agencies to identify sources of water pollution for improved remediation of contaminated waters and ultimately protect humans from exposure to pathogens.
Pedestrian injuries in school-attending children: a comparison of injury data sources in a low-income setting
Authors: Lee P P S , Mihailovic A , Rothman L , Mutto M , Nakitto M , Howard A W
Published: April 2009

Objective:

To estimate and compare the rate of pedestrian injuries in primary school-attending children of urban Uganda using different data sources.

Design:

Data collection from a hospital-based trauma registry, police data, teacher reports, and a cross-sectional community-based survey.

Setting:

Kawempe, the largest urban district in the capital Kampala, Uganda.

Patients or subjects:

Primary school-attending children aged 4–12 from 39 randomly selected schools were included in the trauma registry, police data, and teacher reports. 1828 households randomly selected from the 39 schools were interviewed for the community survey.

Main outcome measure:

A pedestrian injury. For the trauma registry—defined as a pedestrian injury resulting in a visit to the hospital. For the police data—defined as a pedestrian injury reported to the police. For the teacher reports and survey—defined as a pedestrian injury resulting in at least a day off school.

Results:

The estimated pedestrian injury rates per 100 000 person-years were 54.0 (95% CI 25.3 to 117.4), <53.97 (95% CI 23.8 to 125.9), 1878.8 (95% CI 1513.1 to 2322.4), and 764.0 (95% CI 523.3 to 1117.2) from the trauma registry, police data, teacher reports, and community survey, respectively.

Conclusions:

Pedestrian injury rates differed significantly between different data sources. Users must be aware of the different target populations, definitions, and limitations of the data sources before direct comparisons are made. Injury reports by volunteer teachers may be a feasible source of injury data in other low/middle-income countries.
Unintentional injuries in school-aged children and adolescents: lessons from a systematic review of cohort studies
Authors: Mytton J , Towner E , Brussoni M , Gray S
Published: April 2009

Objectives:

To critically synthesise current knowledge of the patterns of injuries and risk factors for injury in school-aged children, to summarise the evidence and support effective child injury prevention initiatives.

Design:

Systematic review.

Selection criteria and methods:

Prospective cohort studies reporting unintentional injuries in healthy children aged 5–18 years were identified by searching 15 electronic databases and additional grey literature sources. A narrative synthesis was conducted of papers meeting quality criteria, with risk factors analysed at individual, family and environmental levels. Limitations of existing evidence were considered.

Results:

44 papers from 18 different cohort studies met the inclusion criteria. There were broad and consistent patterns of injury across time and place. Male sex, psychological, behavioural and risk-taking behaviour problems, having a large number of siblings, and a young mother were all associated with increased injury occurrence across more than one cohort and setting.

Conclusions:

Descriptive epidemiology and risk factors for injury were derived from prospective cohort studies, but few studies used the full potential of their design. Opportunities to use repeated measures to assess temporal changes in injury occurrence, and the exploration of risk factors, particularly those related to the child’s environment, have rarely been undertaken. Few studies were conducted in low/middle-income countries where the burden of injury is greatest. These findings should be considered when planning future research and prevention initiatives.
Substance use among road traffic casualties admitted to emergency departments
Authors: Santamariña-Rubio E , Pérez K , Ricart I , Rodríguez-Sanz M , Rodríguez-Martos A , Brugal M T , Borrell C , Ariza C , Díez E , Beneyto V M , Nebot M , Ramos P , Suelves J M
Published: April 2009

Objective:

To describe the prevalence of recent psychoactive substance use and associated factors among road traffic casualties admitted to emergency departments.

Methods:

A cross-sectional study was carried out, including adults injured in road traffic crashes admitted to the emergency department (ED) of eight hospitals in Catalonia (Spain), during three cross-sections, each of 4 days duration (2005–2006). Information sources were an interview, an oral fluid specimen and the patient’s clinical record. Dependent variables were presence of alcohol, cannabis, cocaine, ecstasy, opiates or benzodiazepines. Independent variables were socioeconomic characteristics and circumstances of the injuries and admission. Prevalence and exact 95% confidence intervals were estimated for men and women. Bivariate analyses and multivariate binomial regression modelling were carried out to study factors associated with substance use in male drivers and pedestrians.

Results:

The prevalence of substance use was higher in men (n = 226) than in women (n = 161) for any substance (34.4% and 16.2%), any illegal substance (19.3% and 7.6%), alcohol (18.5% and 9.2%) and cannabis (17.0% and 3.8%), respectively. In male drivers and pedestrians, alcohol use was associated with being in the 25–30-year age group, being injured at night and the weekend, and arriving at the ED by ambulance; cannabis use was only associated with being in the 18–30-year age group.

Conclusions:

A high prevalence of recent psychoactive substance use, especially alcohol, cannabis and cocaine, was observed in all age groups. The results indicate the need to screen for substance use and to give simple advice to casualties at EDs.
Evaluation of an emergency department-based injury surveillance project in China using WHO guidelines
Authors: Liu X , Li L , Cui H , Liu X , Jackson V W
Published: April 2009

Objectives:

To assess an emergency department-based injury surveillance project (S-EDISP) in China using WHO evaluation guidelines. To identify problems and make suggestions for improvement.

Methods:

According to the methods provided by the WHO injury surveillance guidelines, retrospective evaluation, process evaluation and system environment evaluations were implemented monthly from 1 April 2006 to 31 March 2007.

Results:

Results were collected in the three categories provided by WHO. (1)Retrospective evaluation. The injury rate from all emergency department (ED) logs was 40.4%, with no significant difference between weekends and weekdays. The accuracy of S-EDISP (percentage of injuries reported by the project) was 53.7%, and the accuracy rate (percentage of injuries accurately coded) was 79.3%. The differences between weekdays and weekends were significant for the accuracy of S-EDISP (59.0% vs 49.0%, respectively; p<0.05) and the accuracy rate (75.1% vs 88.7%, respectively; p = 0.03). The predictive value of the system was 100%. (2)Process evaluation. 87.0% of surveillance forms were filled out, and the mean (SD) completion time was 29.5 (4.0) min. Rates of incompletion of the forms were 31.6%, 40.0%, 23.8% and 50.0%, respectively, for every 6 h from 00:00 onwards (p = 0.051). (3)System environment evaluation. The staff included doctors (45.8%), interns (20.8%) and students (29.2%). Most of the staff (87.5%) had completed the S-EDISP training, and 41.7% of them reported difficulties with injury surveillance.

Conclusions:

The accuracy of S-EDISP and completeness of the forms require improvement. Full-time, professional staff should be hired for monitoring injuries in order to provide a better work environment. The problems identified and suggestions provided should be useful in developing a national injury surveillance system for China and other low-resource regions.
Sedimentology of perennial ice-covered, meromictic Lake A, Ellesmere Island, at the northern extreme of CanadaPolar Continental Shelf Program Contribution 00109.
Authors: Tomkins Jessica D. , Lamoureux Scott F. , Antoniades Dermot , Vincent Warwick F.
Published: April 2009

The sedimentology of coastal, meromictic Lake A, Ellesmere Island (83°00′N, 75°30′W), was investigated to understand the linkages between the extreme lake environment and its sedimentary features. Four facies were identified within the sedimentary record that represent stages of the lake’s development from a marine embayment to a meromictic lake. Despite low ecosystem productivity, both clastic and biogenic materials contribute substantially, and highly seasonal sedimentation, pervasive ice cover, and anoxia in the saline bottom water (monimolimnion) act to preserve annual sedimentary units (varves) within the upper part of the sedimentary record. Sediment texture is predominantly silt and clay, but the irregular presence of sand indicates past episodes of higher energy stream discharge to the lake. Oxygen incursions into the chemocline likely cause bacteria mortality and provide elemental sulphur for iron sulphides that are deposited in the sediments. Millimetre-scale sedimentary pellets are also a conspicuous feature in the sediments and are interpreted to result from littoral sediment transport by ice-rafting. Many of Lake A’s notable sedimentary features are also evident in other High Arctic meromictic lakes, particularly those on the northern coast of Ellesmere Island. These similarities and the important biogenic component identified in Lake A suggest that processes in these sedimentary environments are more complex than previously thought.
The neutral hydrolysis of methyl acetate — Part 1. Kinetic experiments
Authors: Hsieh Yih-Huang , Weinberg Noham , Wolfe Saul
Published: April 2009

The neutral hydrolysis of methyl acetate and catalysis of the reaction by the acetic acid product have been studied in the temperature range 90–110 °C. Extrapolated to 25 °C, the rate constants are 0.17 × 10−8 s–1 for the uncatalyzed reaction and 1.4 × 10−4 (mol/L)–1s–1 for the catalyzed reaction. The acid catalysis is specific not general: at 90 °C the rate constants for hydrochloric acid catalysis and catalysis by ionized acetic acid are the same as the rate constant, kH = 1.4 × 10−2 (mol/L)–1s–1, determined in the neutral reaction.
Preparation and properties of thienyl and 2,2′-bithienyl substituted cobalt-bis(semiquinone) valence tautomers
Authors: O’Sullivan Thomas J. , Djukic Brandon , Dube Paul A. , Lemaire Martin T.
Published: April 2009

The synthesis and characterization of two new 2,2′-bipyridine ligands containing 3-ethynylthiophene and 3,3′-diethynyl-2,2′-bithiophene substituents is presented, along with the preparation, electronic, and magnetic properties of mono- and bimetallic cobalt-semiquinone valence tautomers containing these ligands.
LINEARIZATION OF 0-1 MULTI-QUADRATIC FRACTIONAL PROGRAMMING PROBLEM
Authors: KAPOOR R. , ARORA S. R.
Published: April 2009

The considered problem in this paper is a 0-1 Multi-Quadratic Fractional Programming Problem (0-1MQFP) without the restriction of positive denominators. The two important contributions of the paper are: (a) it proposes a linearization technique to solve any type of 0-1MQFP problem; and (b) when applied to the 0-1MQFP problem with the restriction of positive denominators, it requires less number of constraints and variables as compare with the available techniques in the literature. The problem is proved to be NP-hard. The linearization process is summarized with the help of an algorithm and flow chart, and further illustrated by examples. Codes for linearizing 0-1MQFPP is given in the APPENDIX.
EXPLORING THE DIMENSIONALITY OF SERVICE QUALITY: AN APPLICATION OF TOPSIS IN THE INDIAN BANKING INDUSTRY
Authors: PAL MANABENDRA N. , CHOUDHURY KOUSHIKI
Published: April 2009

The Indian banking industry is going through turbulent times. With the lowering of entry barriers and blurring product lines of banks and non-banks since the financial sector reforms, banks are functioning increasingly under competitive pressures. Hence, it is imperative that banks maintain a loyal customer base. In order to achieve this and improve their market positions, many retail banks are directing their strategies towards increasing customer satisfaction and loyalty through improved service quality. Moreover, with the advent of international banking and innovations in the marketplace, customers are having greater and greater difficulty in selecting one institution from another.

Hence, to gain and sustain competitive advantages in the fast changing retail banking industry in India, it is crucial for banks to understand in-depth what customers perceive to be the key dimensions of service quality and to evaluate banks on these dimensions. This is because if service quality dimensions can be identified, service managers should be able to improve the delivery of customer perceived quality during the service process and have greater control over the overall outcome.

The study suggests that customers distinguish four dimensions of service quality in the case of the retail banking industry in India, namely, customer-orientedness, competence, tangibles and convenience. A methodological innovation in this study has been in the use of TOPSIS in the field of customer-perceived service quality. TOPSIS has been used to evaluate and ranking the relative performance of the banks across the service quality dimensions. Identifying the underlying dimensions of the service quality construct and evaluating the performance of the banks across these factors is the first step in the definition and hence provision of quality service in the Indian retail banking industry.
TOPOLOGICAL DEFECT DISTRIBUTIONS AND THE SELF-ENERGY OF A CHARGED PARTICLE
Authors: CARVALHO ALEXANDRE M. DE M. , LIMA RIBEIRO C. A. DE , FURTADO CLAUDIO
Published: April 2009

We study a charged particle in a medium with different continuous distributions of topological defects in the approach of the geometric theory of defects. Those distributions allow us to evaluate the self-energy for a single charge in both the internal and external regions of each distribution.
MODELING USUAL AND UNUSUAL ANISOTROPIC SPHERES
Authors: VIAGGIU STEFANO
Published: April 2009

In this paper, we study anisotropic spheres built from known static spherical solutions. In particular, we are interested in the physical consequences of a "small" departure from a physically sensible configuration. The obtained solutions smoothly depend on free parameters. By setting these parameters to zero, the starting seed solution is regained. We apply our procedure in detail by taking as seed solutions the Florides metrics, and the Tolman IV solution. We show that the chosen Tolman IV solution, and also the Heint IIa and Durg IV,V perfect fluid solutions, can be used to generate a class of parametric solutions where the anisotropic factor has features recalling boson stars. This is an indication that boson stars could emerge by "perturbing" appropriately a perfect fluid solution (at least for the seed metrics considered). Finally, starting with the Tolman IV, Heint IIa and Durg IV,V solutions, we build anisotropic gravastar-like sources with the appropriate boundary conditions.
MAXWELL BRANE COSMOLOGY WITH HIGHER-ORDER STRING CURVATURE CORRECTIONS, A NONMINIMALLY COUPLED SCALAR FIELD, DARK MATTER–DARK ENERGY INTERACTION AND A VARYING SPEED OF LIGHT
Authors: EL-NABULSI R. A.
Published: April 2009

We investigate the cosmological effects of an alternative theory of gravity on the four-dimensional Randall–Sundrum braneworld of type II with a higher-order string curvature term added to the action. We discuss the possibility of a varying speed of light, which has recently attracted considerable attention, in the presence a Maxwell field and of a dynamically evolving bulk scalar field nonminimally coupled to scalar curvature in a quadratic form, together with a dark matter–dark energy interaction term. After deriving the modified Friedmann equation on the brane, as well as the scalar field equations, we then analyze the dynamical equations obtained so far. Special attention is paid to scaling solutions which could be important building blocks in constructing the models of dark energy. The constructed model exhibits several features of cosmological and astrophysical interest for both the early and the late universe, consistent with recent observations, in particular the ones concerned with celerity of light, four and five gravitational constants, black hole masses and entropies.
NONLINEAR EQUATION OF STATE, COSMIC ACCELERATION AND DECELERATION DURING PHANTOM DOMINANCE
Authors: SRIVASTAVA S. K. , DUTTA J.
Published: April 2009

In this paper, the RS-II model of brane gravity is considered for the phantom universe using a nonlinear equation of state. Phantom fluid is known to violate the weak energy condition. It is found that this characteristic of phantom energy is affected drastically by the negative brane tension λ of the RS-II model. It is interesting to see that up to a certain value of energy density ρ satisfying ρ/λ < 1, the weak energy condition is violated and the universe superaccelerates. But, as ρ increases more, only the strong energy condition is violated and the universe accelerates. When 1 < ρ/λ < 2, even the strong energy condition is not violated and the universe decelerates. Expansion of the universe stops when ρ = 2 λ. This is contrary to earlier results of the phantom universe exhibiting acceleration only.
IS THE EQUIVALENCE PRINCIPLE VIOLATED BY THE GENERALIZED UNCERTAINTY PRINCIPLE AND HOLOGRAPHY IN A BRANE-WORLD?
Authors: SCARDIGLI FABIO , CASADIO ROBERTO
Published: April 2009

It has recently been debated whether a class of generalized uncertainty principles that include gravitational sources of error is compatible with the holographic principle in models with extra spatial dimensions. We had in fact shown elsewhere that the holographic scaling is lost when more than four space–time dimensions are present. However, we shall show here that the validity of the holographic counting can be maintained also in models with extra spatial dimensions, but at than intriguing price — the equivalence principle for a pointlike source is violated and the inertial mass differs from the gravitational mass in a specific, nontrivial way.
CORROSION INITIATION TIME FOR REINFORCED CONCRETE MEMBERS ALONG INDIAN COASTS: EFFECTS OF TEMPERATURE AND RELATIVE HUMIDITY — A PROBABILISTIC APPROACH
Authors: ALLAMPALLEWAR SATISH B. , SRIVIDYA A.
Published: April 2009

Corrosion initiation time of steel reinforcement for partially saturated concrete members subjected to chloride ingress is investigated at five places along Indian coasts using simplified probabilistic analysis and sensitivity of the parameters to reinforcement corrosion is studied. Previously proposed diffusion based chloride ingress model for constant surface chloride concentration and variable diffusion coefficient is used. Corrosion is initiated when the chloride concentration on steel reinforcement exceeds a threshold value. The various input parameters considered in the model are surface chloride concentration (Cs), chloride threshold value (Cth), Concrete cover (X), reference diffusion coefficient (Dref), age (t), reference age (tref), diffusion decay index (m) and monthly temperature and relative humidity correction factors f(T) and f(h) respectively; to reference diffusion coefficient. For prediction of corrosion initiation time temperature and relative humidity data collected by India metrological Department is used and all other parameters are assumed same. A large variation in corrosion initiation time is found and therefore it becomes necessary to consider the temperature and relative humidity data in a region. Life-365 considers fully saturated condition of concrete and thus underestimates the corrosion initiation time of a reinforced concrete member. The deterministic approach uses mean values of the parameters and provides a 50% probability of corrosion initiation but the probabilistic approach provides expected time of first corrosion for chosen risk of corrosion and also gives sensitivity of parameters to probability of corrosion. Corrosion initiation time in ascending order is found at Colaba, Kanyakumari, Santacruz, Chennai and Vishakhapatnam. Corrosion initiation time is useful for owner, designer, or to an organization to take decision in time of priority of repairs, repair strategy, corrosion protection in order to optimize maintenance planning and budgeting. Planned maintenance at the optimum time is the safest and most cost effective approach.
ATTRIBUTE SELECTION USING ROUGH SETS IN SOFTWARE QUALITY CLASSIFICATION
Authors: KHOSHGOFTAAR TAGHI M. , BULLARD LOFTON A. , GAO KEHAN
Published: April 2009

Finding techniques to reduce software developmental effort and produce highly reliable software is an extremely vital goal for software developers. One method that has proven quite useful is the application of software metrics-based classification models. Classification models can be constructed to identify faulty components in a software system with high accuracy. Significant research has been dedicated towards developing methods for improving the quality of software metrics-based classification models. It has been shown in several studies that the accuracy of these models improves when irrelevant attributes are identified and eliminated from the training data set.

This study presents a rough set theory approach, based on classical set theory, for identifying and eliminating irrelevant attributes from a training data set. Rough set theory is used to find small groups of attributes, determined by the relationships that exist between the objects in a data set, with comparable discernibility as larger sets of attributes. This allows for the development of simpler classification models that are easy for analyst to understand and explain to others.

We built case-based reasoning models in order to evaluate their classification performance on the smaller subsets of attributes selected using rough set theory. The empirical studies demonstrated that by applying a rough set approach to find small subsets of attributes we can build case-based reasoning models with an accuracy comparable to, and in some cases better than, a case-based reasoning model built with a complete set of attributes.
AN IMPROVED GENETIC-ALGORITHM-BASED NEURAL-TUNED NEURAL NETWORK
Authors: LEUNG F. H. F. , LING S. H. , LAM H. K.
Published: April 2009

This paper presents a neural-tuned neural network (NTNN), which is trained by an improved genetic algorithm (GA). The NTNN consists of a common neural network and a modified neural network (MNN). In the MNN, a neuron model with two activation functions is introduced. An improved GA is proposed to train the parameters of the proposed network. A set of improved genetic operations are presented, which show superior performance over the traditional GA. The proposed network structure can increase the search space of the network and offer better performance than the traditional feed-forward neural network. Two application examples are given to illustrate the merits of the proposed network and the improved GA.
HYBRID-NEURAL-NETWORK-BASED ESTIMATION OF LINE OVERLOADING
Authors: SHARMA SAVITA , SRIVASTAVA LAXMI
Published: April 2009

Since the modern power systems are being operated under heavily stressed conditions, the cases of voltage limit violation and power system line overloading are occurring frequently. These events are responsible for several incidents of major network collapses leading to partial or even complete blackouts. Alleviation of line overloads is the suitable corrective action in this regard and for this, fast and accurate identification of overloaded lines is essential along with the estimation of the overloading amount in these lines. In this paper, an approach based on hybrid neural network (HNN) is presented for identification and estimation of line overloading in an efficient manner. The effectiveness of the proposed HNN-based approach is demonstrated by estimation of line overloading for different loading conditions in IEEE 14-bus system. The developed HNN provides accurate and quick results for previously unseen operating condition during testing phase.
Stratigraphy, depositional environments and geodynamic significance of the Upper Bajocian–Bathonian Kashafrud Formation, NE Iran
Authors: Taheri Jafar , Fürsich Franz Theodor , Wilmsen Markus
Published: April 2009

A strongly subsiding rift basin in NE Iran, the Kashafrud Basin, opened in the Late Bajocian with the accumulation of more than 2000 m of Upper Bajocian–Upper Bathonian siliciclastic sediments. These sediments comprise the Kashafrud Formation, which crops out along a NW–SE stretch of more than 200 km and occupies a width of 50 km, situated between the Koppeh Dagh and the Binalud Mountains. Ten sections of the formation were logged. Sedimentary environments range from non-marine alluvial fans and braided rivers in the lowermost part of the succession to deltas, succeeded by storm-dominated shelf, slope and deep-marine basin. Monotonous mudstones and turbidites prevail in the deep-marine part of the basin. The thickness and facies of the Kashafrud Formation vary strongly between localities, and reflect distance from the rift margins as well as submarine topography, which was shaped by block tectonics. The Kashafrud Basin is interpreted as the eastern extension of the South Caspian Basin, which entered the rifting stage in the late Early Jurassic and the spreading stage in the Late Bajocian.
Subsidence and uplift mechanisms within the South Caspian Basin: insights from the onshore and offshore Azerbaijan region
Authors: Egan Stuart S. , Mosar Jon , Brunet Marie-Françoise , Kangarli Talat
Published: April 2009

A combination of fieldwork, basin analysis and modelling techniques has been used to try and understand the role, as well as the timing, of the subsidence–uplift mechanisms that have affected the Azerbaijan region of the South Caspian Basin (SCB) from Mesozoic to Recent.

Key outcrops have been studied in the eastern Greater Caucasus, and the region has been divided into several major tectonic zones that are diagnostic of different former sedimentary realms representing a complete traverse from a passive margin setting to slope and distal basin environments. Subsequent deformation has caused folds and thrusts that generally trend from NW–SE to WNW–ESE.

Offshore data has been analysed to provide insights into the regional structural and stratigraphic evolution of the SCB to the east of Azerbaijan. Several structural trends and subsidence patterns have been identified within the study area. In addition, burial history modelling suggests that there are at least three main components of subsidence, including a relatively short-lived basin-wide event at 6 Ma that is characterized by a rapid increase in the rate of subsidence.

Numerical modelling that includes structural, thermal, isostatic and surface processes has been applied to the SCB. Models that reconcile the observed amount of fault-controlled deformation with the magnitude of overall thinning of the crust generate a comparable amount of subsidence to that observed in the basin. In addition, model results support the tectonic scenario that SCB crust has a density that is compatible with an oceanic composition and is being under-thrust beneath the central Caspian region.
The Cimmerian evolution of the Nakhlak–Anarak area, Central Iran, and its bearing for the reconstruction of the history of the Eurasian margin
Authors: Zanchi Andrea , Zanchetta Stefano , Garzanti Eduardo , Balini Marco , Berra Fabrizio , Mattei Massimo , Muttoni Giovanni
Published: April 2009

New structural, sedimentological, petrological and palaeomagnetic data collected in the region of Nakhlak–Anarak provide important constraints on the Cimmerian evolution of Central Iran. The Olenekian–Upper Ladinian succession of Nakhlak was deposited in a forearc setting, and records the exhumation and erosion of an orogenic wedge, possibly located in the present-day Anarak region. The Triassic succession was deformed after Ladinian times and shows south-vergent folds and thrusts unconformably covered by Upper Cretaceous limestones following the Late Jurassic Neo-Cimmerian deformation. Palaeomagnetic data obtained in the Olenekian succession suggest a palaeoposition of the region close to Eurasia at a latitude around 20°N. In addition, the palaeopoles do not support large anticlockwise rotations around vertical axes for central Iran with respect to Eurasia since the Middle Triassic, as previously suggested.

The Anarak Metamorphic Complex (AMC) includes blueschist-facies metabasites associated with discontinuous slivers of serpentinized ultramafic rocks and Carboniferous greenschist-facies ‘Variscan’ metamorphic rocks, including widespread metacarbonates. The AMC was formed, at least partially, in the Triassic. Its erosion is recorded by the Middle Triassic Bāqoroq Formation at Nakhlak, which consists of conglomerates and sandstones rich in metamorphic detritus. The AMC was repeatedly deformed during post-Triassic times, giving origin to a complex structural setting characterized by strong tectonic fragmentation of previously formed tectonic units.

Based on these data, we suggest that the Nakhlak–Anarak units represent an arc–trench system developed during the Eo-Cimmerian orogenic cycle. Different tectonic scenarios that can account for the evolution of the region and for the occurrence of this orogenic wedge in its present position within Central Iran are critically discussed, as well as its relationships with a presumed ‘Variscan’ metamorphic event.
The Shanderman eclogites: a Late Carboniferous high-pressure event in the NW Talesh Mountains (NW Iran)
Authors: Zanchetta Stefano , Zanchi Andrea , Villa Igor , Poli Stefano , Muttoni Giovanni
Published: April 2009

The Shanderman Metamorphic Complex, exposed along the Caspian foothills of the Talesh Mountain, western Alborz, Iran, has always been interpreted as an ophiolitic fragment of the Palaeotethys Ocean. According to our new data, this unit consists of metamorphic rocks mainly represented by garnet–staurolite micaschists with large bodies of metabasites containing well-preserved eclogitic-phase assemblages. The Shanderman Complex (SC) was later intruded at middle crustal levels by intermediate–basic intrusive bodies. New Ar/Ar ages of paragonitic white micas in equilibrium with the high-pressure assemblages have given a Late Carboniferous age (315±9 Ma). Our new data suggest that the SC was equilibrated in high-pressure conditions during an orogenic event that predates the Eo-Cimmerian orogeny by more than 100 Ma and that may be tentatively ascribed to the Variscan orogeny
sensu latu
. We suggest that the Shanderman Complex represents a fragment of the Upper Palaeozoic European continental crust. The occurrence of eclogites in these regions can be explained by two different hypotheses: (1) the SC high-pressure rocks can be related to the accretion of Gondwana-related Transcauscasian–Moesian microplate to the southern margin of Eurasia; or (2) the SC eclogites can represent a fragment of the Late Palaeozoic ‘Variscan belt’
sensu latu
of central Europe, which has been translated eastwards during Permian along a dextral megashear zone taking from a Pangea-B to a Pangea-A plate configuration. This metamorphic unit was stacked southwards on the northern edge of the Iran Plate during the Eo-Cimmerian events occurring at the end of the Triassic. The eclogite-bearing basement of the SC was finally exhumed at the end of the Eo-Cimmerian orogeny, as suggested by the composition of the basal layers of the Shemshak Group dated here Middle Jurassic, that cover the crystalline rocks of the SC along a regional non-conformity. The SC was probably displaced further southwards during the Mesozoic opening of the South Caspian Basin and the Tertiary thrust stacking and dextral shearing accompanying the formation of the Alborz intracontinental belt.
Apelin decreases myocardial injury and improves right ventricular function in monocrotaline-induced pulmonary hypertension
Authors: Falcão-Pires Inês , Gonçalves Nádia , Henriques-Coelho Tiago , Moreira-Gonçalves Daniel , Roncon-Albuquerque Roberto , Leite-Moreira Adelino F.
Published: April 2009

We investigated the endogenous production of apelin and the cardiac and pulmonary effects of its chronic administration in monocrotaline (MCT)-induced pulmonary hypertension (PH). Male Wistar rats were injected with MCT (60 mg/kg sc) or vehicle ( day 0). One week later, these animals were randomly treated during 17 days with pyroglutamylated apelin-13 (Pyr-AP13; 200 μg·kg−1·day−1 ip) or a similar volume of saline, resulting in four groups: sham ( n = 11), sham-AP ( n = 11), MCT ( n = 16), and MCT-AP ( n = 13). On day 25, right ventricular (RV) and left ventricular (LV) hemodynamic and morphometric parameters were assessed. Tissue and plasma samples were collected for histological and molecular analysis. When compared with sham, the MCT group presented a significant increase of RV mass (166 ± 38%), diameter of cardiomyocyte (40 ± 10%), myocardial fibrosis (95 ± 20%), peak systolic pressure (99 ± 22%), peak rate of ventricular pressure rise (dP/d tmax; 74 ± 24%), peak rate of ventricular pressure decline (dP/d tmin; 73 ± 19%), and time constant τ (55 ± 16%). In these animals, RV expression of apelin (−73 ± 10%) and its receptor APJ (−61 ± 20%) was downregulated, whereas mRNA expression of type B natriuretic peptide (9,606 ± 713%), angiotensinogen (191 ± 147%), endothelin-1 (RV, 497 ± 156%; and LV, 799 ± 309%), plasmatic levels of apelin (104 ± 48%), and angiotensin 1-7 (161 ± 151%) were increased. Chronic treatment with Pyr-AP13 significantly attenuated or normalized these changes, preventing apelin-APJ mRNA downregulation and PH-induced neurohumoral activation of several vasoconstrictors, which exacerbates apelin-APJ vasodilator effects. Therefore, apelin delayed the progression of RV hypertrophy and diastolic dysfunction. Together, these observations suggest that the apelin-APJ system may play an important role in the pathophysiology of PH, representing a potential therapeutic target since it significantly attenuates RV overload and PH-induced neurohumoral activation.
Initiation and maturation of cilia-generated flow in newborn and postnatal mouse airway
Authors: Francis Richard J. B. , Chatterjee Bishwanath , Loges Niki T. , Zentgraf Hanswalter , Omran Heymut , Lo Cecilia W.
Published: April 2009

Mucociliary clearance in the adult trachea is well characterized, but there are limited data in newborns. Cilia-generated flow was quantified across longitudinal sections of mouse trachea from birth through postnatal day (PND) 28 by tracking fluorescent microsphere speed and directionality. The percentage of ciliated tracheal epithelial cells, as determined by immunohistochemistry, was shown to increase linearly between PND 0 and PND 21 ( R2 = 0.94). While directionality measurements detected patches of flow starting at PND 3, uniform flow across the epithelia was not observed until PND 7 at a ∼35% ciliated cell density. Flow became established at a maximal rate at PND 9 and beyond. A linear correlation was observed between the percentage of ciliated cells versus flow speed ( R2 = 0.495) and directionality ( R2 = 0.975) between PND 0 and PND 9. Cilia beat frequency (CBF) was higher at PND 0 than at all subsequent time points, but cilia beat waveform was not noticeably different. Tracheal epithelia from a mouse model of primary ciliary dyskinesia (PCD) harboring a Mdnah5 mutation showed that ciliated cell density was unaffected, but no cilia-generated flow was detected. Cilia in mutant airways were either immotile or with slow dyssynchronous beat and abnormal ciliary waveform. Overall, our studies showed that the initiation of cilia-generated flow is directly correlated with an increase in epithelial ciliation, with the measurement of directionality being more sensitive than speed for detecting flow. The higher CBF observed in newborn epithelia suggests unique physiology in the newborn trachea, indicating possible clinical relevance to the pathophysiology of respiratory distress seen in newborn PCD patients.