bluuebunny/crossref_metadata_2025 huggingface dataset:
Web Usage Mining and the Challenge of Big Data
Authors: Abdalla Abubakr Gafar , Ahmed Tarig Mohamed , Seliaman Mohamed Elhassan
Published: September 2015

The web is a rich data mining source which is dynamic and fast growing, providing great opportunities which are often not exploited. Web data represent a real challenge to traditional data mining techniques due to its huge amount and the unstructured nature. Web logs contain information about the interactions between visitors and the website. Analyzing these logs provides insights into visitors' behavior, usage patterns, and trends. Web usage mining, also known as web log mining, is the process of applying data mining techniques to discover useful information hidden in web server's logs. Web logs are primarily used by Web administrators to know how much traffic they get and to detect broken links and other types of errors. Web usage mining extracts useful information that can be beneficial to a number of application areas such as: web personalization, website restructuring, system performance improvement, and business intelligence. The Web usage mining process involves three main phases: pre-processing, pattern discovery, and pattern analysis. Various preprocessing techniques have been proposed to extract information from log files and group primitive data items into meaningful, lighter level abstractions that are suitable for mining, usually in forms of visitors' sessions. Major data mining techniques in web usage mining pattern discovery are: clustering, association analysis, classification, and sequential patterns discovery. This chapter discusses the process of web usage mining, its procedure, methods, and patterns discovery techniques. The chapter also presents a practical example using real web log data.
Optimisation of a PID Controller for an Inverted Pendulum Using the Bees Algorithm
Authors: Sen Muhammed Arif , Kalyoncu Mete
Published: September 2015

The inverted pendulum system is a challenging control problem in the control theory, which continually moves away from a stable state. The paper presents the design of a Proportional-Integral-Derivative (PID) controller for a single-input multi-output (SIMO) inverted pendulum system and using the Bees Algorithm (BA) to obtain optimal gains for PID controllers. The Bees Algorithm optimizes the gains so that the controller can move the cart to a desired position with the minimum amount of the change in the pendulum’s angle from the vertically upright position during the movement. The tuning aim is to minimize the control responses of the cart’s position and the pendulum’s angle in time domain. MATLAB/Simulink simulation has been performed to demonstrate that the effects on the system performance of PID controllers with optimal gains. The obtained results show that the tuning method by using the Bees Algorithm produced PID controllers successfully within the controller design criteria. Following a description of the inverted pendulum system and the Bees Algorithm, the paper gives the obtained simulation results for the system demonstrating the efficiency of the design.
Performance of Grouted Splice Sleeves with Tapered Bars under Axial Tension
Authors: Rahman Ahmad Baharuddin Abd , Yoon Loh Hsi , Ibrahim Izni Syahrizal , Mohamed Roslli Noor , Mohammad Shahrin , Saim A. Aziz
Published: September 2015

Many structural failures in precast concrete buildings are initiated by connection failures. To avoid such failures, the connections should have enough strength to join the reinforcement bars between precast concrete panels. This paper presents the structural performance and behaviour of a proposed splice sleeve connection using generic steel pipe. The connection consisted of steel bars with tapered nuts confined in grouted steel pipes. The connections were subjected to increasing axial tension until failure. The results show that the use of smaller pipes gives better confinement effects and provide higher bond strength. A short embedment length of about 10 times rebar diameter is able to provide full tensile strength of the connected rebars. As compared to long embedment length of conventional lapping of steel bars, the proposed connection is able to provide structural continuity with short embedment length.
The Manufacture of Molar and Dental Bridge through 3D Printing
Authors: Chang Shinn Liang , Lo Cheng Hsun , Jiang Cho Pei
Published: September 2015

The 3D printing method for the human tooth is a possible and good solution in the manufacture. However, the shrinkage is the most challenging problem to manufacture the tooth. In this paper, CAE analysis and experimental design are applied to predict the shrinkage of different dentures shape. Then the CAD model of the dentures can be reverse amplified before the sintering process. The product will be close to the patients’ requirements with precise dentures shape. It also avoids the complicated procedure of CNC machining and reduces dentists finishing time. The dental bridge is the main research objective investigated in this paper to verify the CAE simulation developed by the authors.
Surface Integrity in Micromilling of Hardened AISI D2 Tool Steel
Authors: Saedon J.B. , Soo S.L. , Aspinwall D.K. , Barnacle A. , Mohamad Nor Nor Hafiez
Published: September 2015

This paper presents workpiece surface integrity of micromilling hardened tool steel AISI D2. These include 3D mapping of surface texture, analysis of microstructure and microhardness variation. The results indicate no evidence of major surface damage such as microcracks, un-tempered/over-tempered martensite, phase transformations or white layer formation was detected in any of the specimens analysed. No discernible deformation of the material grain structure beneath the machined surface was observed. This was mainly attributed to the comparatively low levels of mechanical force and temperatures generated during the micro milling operation.
Optical Methods for Studying the Drying Dynamics of Fe2O3 Nanocolloid Droplets Depending on Variation of Substrate Temperature
Authors: Dmitriev Alexander , Makarov Petr
Published: September 2015

This work is devoted to investigation of the way light transmittance of drying drop of Fe2O3 nanocolloid deposited on flat surface changes as liquid evaporates. According to results of transmitted light intensity measuring it is assumed that drying process can be divided into separate stages each being characterized by particular quality level of ability to transmit light because of different behavior and, thus, density of suspended nanoparticles inside the droplet. The last stage ends by forming of a ring-shaped pattern (known as “coffee ring”). Temperature of the surface was being changed by applying a varying potential difference to lower layer of transparent substrate made of ITO. Time dependences of integral transmitted light intensity for every single temperature are represented in graphs. They are compared with dependences for water drops of the same volume.
Synthesis and Characterization of La10Si6O27 and Ce0.9Gd0.1O1.95 Solid Oxide Fuel Cell Electrolyte Material
Authors: Setsoafia Daniel , Hing Peter , Jung Andrew , Islam Aminul , Azad Abul Kalam , Lim Lim Chee
Published: September 2015

A Composite oxide ionic conductor consisting of La10Si6O27 (LASIO) and Ce0.9Gd0.1O1.95 (GDC) was synthesized by a modified sol-gel method. The La10Si6O27 powders prepared by modified sol-gel synthesis were coated with GDC gel and latter calcined to form a La10Si6O27 - Ce0.9Gd0.1O1.95 composite material. The structural and microstructural properties of the composite were investigated using powder XRD, SEM and TMA. EIS was conducted in air on the sintered pellets to evaluate the electrochemical performance of the pellets. The conductivity of the composite electrolyte at 973 K was 26 mS /cm which is two orders of magnitudes higher than that for the pure LASIO but lower than that of the GDC (30 mS/cm). The thermal expansion of the composite electrolyte is similar to that obtained for the LASIO.
ANSYS Analysis on Thermal Structure of Bionic Brake Discs
Authors: Wang Li Xin , Gao Ya Yan , Peng Li Qiang , Zhai Li Gang
Published: September 2015

The failure of brake performance, which is caused by thermal recession under the emergency brake, results in traffic accident frequently. Based on excellent wear-resisting properties of locust’s non-smooth surface structure, bionic brake disc with special surface micro-structure was designed. According to the thermal analysis theory, transient temperature field analysis of the bionic brake disc during the braking process under different initial velocity was analyzed. The results showed that bionic brake disc has excellent heat dissipation ability, which is beneficial to improve the brake performance. The non-smooth surface can store air and dissipate heat, thus reducing the thermal fatigue and thermal wear caused by temperature rise. This research provides a theoretical basis for designing bionic brake discs with excellent heat dissipation performance.
Application of PTFE Heat Exchanger in Low Temperature Waste Heat of Big Coal-Fired Power Plants
Authors: Hong Wen Peng , Zhang Hui
Published: September 2015

With the rapid development of the national economy, the use of low-temperature heat in thermal power plant boiler can not be ignored.Although low temperature economizer is widely used in low-temperature waste heat recovery of thermal power plant boiler, the problems of corrosion and fouling are very significant.New type PTFE heat exchanger filled with high thermal conductivity properties can replace the existing metal heat exchanger, fundamentally solve the problems of corrosion and fouling, meet the future development of the thermal power plant, and realize the energy recycling to maximize the benefit of energy.
Stress-Strain Behaviour of Dielectric Elastomer for Actuators
Authors: Sahu Raj Kumar , Patra K. , Bhaumik S. , Pandey A.K. , Setua D.K.
Published: September 2015

Dielectric elastomer (DE) is gaining importance for potential strategic and commercial application as actuators. This paper reports the experimental investigation on different mechanical phenomena at large deformation of a commercially available acrylic dielectric elastomer material, VHB 4910 (3M) which is widely used for dielectric elastomer actuator (DEA) research. Attempts are made for accurate and precise experimental determination of nonlinear stress-strain, strain rate dependent hysteresis behaviour and cyclic softening of this material. It is observed that with the increase in strain rate maximum stress at a particular strain increases whereas hysteresis loss decreases. In the cyclic loading case after a particular number of cycles almost the hysteresis loss and maximum stress becomes constant. These experimental results are likely to be interesting for the designers for proper designing and characterization of the actuators fabricated with this material.
Characteristics of a System in a Package with Silver Wires
Authors: Lai Yeong Lin , Chiang Wen Jung
Published: September 2015

The system in a package (SiP) including of a system on a chip (SoC) and a double-data-rate-three synchronous dynamic random access memory (DDR3 SDRAM) were studied with respect to the high-speed characteristics. The SiP was the multi-chip-module thin-profile fine-pitch ball grid array (MCM TFBGA) package with four-layer substrate. The high-speed 1600-Mbps data rate DDR3 signals were used in the signal integrity (SI) analysis. The SiP with low-cost silver (Ag) wires displayed a 500.18-ps aperture width in the eye diagram, which was successfully achieved signal integrity (SI) performance requirement. This work demonstrated the SiP with the Ag wires was the great potential solution for the advanced high-speed product applications.
A Plasma Spray Coating for Titanium Particles Using Software Simulation
Authors: Li Tse Chang , Lin Jen Fin
Published: September 2015

In the present study, a plasma spray coating for titanium particles was studied using software simulations. The governing equations to solve the velocity and temperature distributions of plasma flow and titanium particles considered the effects of electric/magnetic inductions. Seven controlling factors were included in order to investigate their effects on the velocity and temperature of titanium particles colliding with the specimen substrate and the colliding scope of the effective particle depositions. The velocity and temperature distributions of the plasma flow predicted in the present study were expressed in a power form. The results predicted by the present governing equations were thus trustworthy. In general, either a small particle diameter in collaboration with a low electric potential or a large particle diameter in collaboration with a high electric potential is advantageous for a high melting and boiling points.
Manufacturing of a Linear Variable Filter for Spectral Order Sorting
Authors: Ko Cheng Hao , Chang Kuei Ying , Huang You Min , Tsai Jih Run , Wang Bang Ji
Published: September 2015

An analytical thin film thickness model based on the geometry of a commercial vacuum coating system is proposed. This model can calculate the profiles of linear variable filters (LVFs), which are used to eliminate overlapping orders of spectra due to the use of a diffraction grating and which are fabricated using a local mask, producing a linearly variable thickness. While the filter transmits the first-order wavelength and blocks the second-order wavelength. The 75% and 25% relative thicknesses deviation between the evaporated film and the theoretical model is less than 5%, indicating good suitability for LVF design and fabrication.
Development of a Single Pulse Micro EDM System and to Manufacture Micro Spherical Probe Used in Micro CMM
Authors: Chu Chih Liang , Chen Hung Chi
Published: September 2015

The focus of this research is the development of a single pulse micro EDM system and to manufacture micro spherical probe used in micro CMM. In the single pulse micro EDM system contain unsteady-state multi-degree oscillation circuits to control the transistors’ switches. This configuration is to achieve the adjustment of pulse-off time of the micro-electrical discharge machining system. Investigating the effect of pulse voltages on the critical discharge gaps, the experimental results show that maximum discharge gaps are linearly proportional to the pulse voltages. This tendency serves as the basis for the machine processing parameters. And used of the single pulse micro EDM system to machining micro spherical probe.The micro spherical probe with a diameter smaller than 100 μm, is made by a single pulse micro EDM system with the method of wire electro discharge grinding (WEDG). The current study uses tungsten carbide (WC) as the material for the stylus. Experimental results show that, the micro spherical probe roundness could amount to 2 μm.
Polymer-Based Capacity Micromachined Ultrasonic Transducer for Surface Roughness Measurement
Authors: Bui Gia Thinh , Chen Yi Ze , Pang Da-Chen
Published: September 2015

A polymer-based capacitive micromachined ultrasonic transducer (CMUT) is developed to measure surface roughness. The transducer is designed with two groups in a ratio of two to one. By using air-coupled ultrasound, the transducer can evaluate surface roughness in five modes: full transmission/ full reception, majority transmission/ majority reception, majority transmission/ minority reception, minority transmission/ majority reception, and minority transmission/ minority reception. Experimentation shows the CMUT can identify the surface roughness using a sample of sandpaper with surface roughness Rrms ranging from 11.4μm to 179.8μm. The results indicate that the full transmission/ full reception mode has maximum signal output and the minority transmission/ majority reception mode can obtain a good signal output with a better energy efficiency rating.
Stress Analysis of Forging Dies for Inverse Extrusion
Authors: Chang Kao Hua , Shih Ching Wei , Tzou Gow Yi
Published: September 2015

This study intended to investigate the longitudinal crack on the tungsten carbide alloy die core that caused by the influence of receiving the hoop tensile stress in the process of inverse extrusion. Therefore, the shrink fit is adopted to design the die core and stress ring, and assemble the die case, in order to yield the hoop compressive stress in advance, which can be used to resist the tensile hoop stress yielded from the forging process. It also applied the FEM simulation software and Taguchi Method L9(34) in this study to simulate various combinations of different shrink fits, in order to obtain the best combination of die. Moreover, it focused on the compressive strength of material characteristics for the tungsten carbide alloy steel die core, and properly adjusted the shrink fit to prevent an early crack on the die core that caused by the hoop compressive stress in advance, in order to achieve the best result.
Effect of Grain Size on Micro Deep Drawing of SUS304 Stainless Steel Square Cup
Authors: Chang Chao Cheng , Chen Han Sheng
Published: September 2015

The study investigated the effect of grain size on the micro deep drawing of SUS304 stainless steel squares. Three stainless steel sheets with different thicknesses of 0.05 mm, 0.1 mm and 0.2 mm were treated by annealing processes at 1100 °C in which the holding times were varied in order to adjust the grain size. The sheets were used in the micro deep drawing processes for producing the square cups with 3 mm side length and 1.8 mm height. According to the design rules from references, the dimensions of the blank were determined to reduce the variation on the rim height of the square cup. The results showed that two peak values appeared on the load curves and the as-received sheet with the smallest grain size led to the largest load. Moreover, the cases of the as-received sheet with smaller grains had smoother surface textures than those of the annealed sheets with larger grains.
Finite Element Modeling of Grain Size Effect on the Mechanical Properties and Deformability of Titanium Alloy in Equal Channel Angular Pressure
Authors: Jiang Cho-Pei , Huang Zong Han
Published: September 2015

The aim of this research is to investigate the effect of grain size on the mechanical properties and deformability of titanium alloy in equal channel and cross-sectional reduction channel angular pressing process. Specimens made of grade 2 titanium alloy with diameter 5 mm are annealed to temperature of 500 °C to 1000 °C resulting in different initial grain sizes, thus underwent tensile test for obtaining mechanical properties. Molds for both processes are designed to carry out serve plastic deformation. Finite element models are created and simulated the deformation behavior according to the mechanical properties of tensile test. Experimental results show that small α-phase grain starts to form in 700 °C homogenization treatment and its grain size increases as an increasing of annealing temperature. The β-phase microstructure precipitates resulting in brittle behavior in 850 °C annealing treatment. Simulation result show that squeeze load of ECAP is larger than 100 ton but it can be reduced when exit angle of channel is larger than entrance. Outer corner of ECAP with 90 ̊ generate lower squeeze pressure than that of 40 ̊.
Cold Bending a Ni-Ti Shape Memory Alloy Wire
Authors: Fann Kuang-Jau , Huang Pao Min
Published: September 2015

Because of being in possession of shape memory effect and superelasticity, Ni-Ti shape memory alloys have earned more intense gaze on the next generation applications. Conventionally, Ni-Ti shape memory alloys are manufactured by hot forming and constraint aging, which need a capital-intensive investment. To have a cost benefit getting rid of plenty of die sets, this study is aimed to form Ni-Ti shape memory alloys at room temperature and to age them at elevated temperature without any die sets. In this study, starting with solution treatments at various temperatures, which served as annealing process, Ni-rich Ni-Ti shape memory alloy wires were bent by V-shaped punches in different curvatures at room temperature. Subsequently, the wires were aged at different temperatures to have shape memory effect. As a result, springback was found after withdrawing the bending punch and further after the aging treatment as well. A higher solution treatment temperature or a smaller bending radius leads to a smaller springback, while a higher aging treatment temperature made a larger springback. This springback may be compensated by bending the wires in further larger curvatures to keep the shape accuracy as designed. To explore the shape memory effect, a reverse bending test was performed. It shows that all bent wires after aging had a shape recovery rate above 96.3% on average.
Stratigraphy of Duval Corporation Potash Shaft No 1, Saskatoon, Saskatchewan
Authors: Price L L , Ball N L
Published: September 2015

From l ate 1967 to early 1969, the Duval Corporation sank two s hafts, 20 feet in diameter and 3, 500 feet deep, near Saskatoon, Saskatchewan. The object was to recover the sylvite ore of potash from the Middle Devonian Prairie Evaporite Formation, a unit within
the Middle and Upper Devonian carbonate sequence. The Devonian succession is overlain unconformably by elastic Cretaceous strata which, in turn, are overlain by Pleistocene till.
The thick Prairie Evaporite salt represents the culmination of an early cycle in a success ion of clastic-carbonate-evaporite cycles that become successively thinner upward in the sequence and disappear entirely at the end of Middle Devonian time.
The overlying Dawson Bay Formation comprises a second cycle. The formation consists of basal dolomitic red beds, a middle marine limestone, and an upper evaporite composed of anhydrite with a trace of halite.
The Souris River Formation, composed of three members, overlies the Dawson Bay. The lower or Davidson Member consists of a basal elastic unit ("First Red Beds"), a middle argillaceous limestone unit, and an upper intertidal and supratidal sequence preceding the final beds of halite. The overlying
Harris and Hatfield Members each contain several incomplete cycles interrupted by evaporitic supratidal phases. An anhydrite in the lower part of the Hatfield Member contains inclusions of chert.
The Upper Devonian Duperow Formation is distinguished by alternating argillaceous and non-argillaceous limestones that form the basis for subdivision into the Saskatoon, Elstow, Wymark and Seward Members. A solution cavity occurs in interbedded carbonate and elastic strata of the Wymark Member. The
Birdbear Formation, at the top of the Devonian is truncated by the sub-Cretaceous unconformity.
The Cretaceous sequence evolves, in ascending order, from the aggrading nonmarine, basal (Cantuar Formation) sandstones above the unconformity; through transgressive intertidal and subtidal (Pense Formation) shaly sandstones; to shallow marine (Ashville) shale; and, in the basal part of the Upper
Cretaceous, kerogenous ("white-speckled") oil s hales. Cordilleran silt and fine sand modify the overlying thick Upper Cretaceous (Lea P ark) shale sequence and dominate the youngest beds composed of non-marine sandstones of the Belly River Formation.
Unoxidized till is covered by a mantle of outwash material.
A detailed lithologic log (Appendix I) of the succession in the shaft above the Prairie Evaporite is keyed to fossil localities as well as to induction, radiation and sonic wireline logs. Appendix II illustrates the mineralogy of the insoluble components of the upper part of the evaporite as
determined by X-ray diffraction. The stratigraphic summary suggests new interpretations of contact relationships, structure and sedimentation, and contains reports on paleontology including correlations and age determinations.
Abstracts of publications in scientific journals by officers of the Geological Survey of Canada, April 1970 to March 1971
Authors:   Geological Survey of Canada
Published: September 2015

This report contains titles, and in most cases abstracts, of 103 papers by officers of the Geological Survey of Canada which were published in scientific journals and books during the period 1 April, 1970 to 31 March, 1971. Most of these papers included abstracts
and these have been reproduced from the published text. The abstracts are arranged alphabetically according to author. The papers published in scientific journals together with the various reports of the Geological Survey (memoirs, bulletins, papers, economic geology reports, miscellaneous reports,
maps and open file items) which are listed in the Index of Publications (GSC Paper 71-1) represent most of the published scientific output of the Geological Survey for fiscal year 1970-71.
Revised catalogue of the National Meteorite Collection of Canada listing acquisitions to August 31, 1970
Authors: Douglas J A V
Published: September 2015

A catalogue of the National Meteorite Collection of Canada, published in 1963 listed 242 different meteorite specimens. Since then specimens from 50 additional meteorites have been added to the collection and several more specimens have been added to the tektite
collection. This report describes all specimens in the collection.
Parathyroidectomy Ameliorates Glucose and Blood Pressure Control in a Patient with Primary Hyperparathyroidism, Type 2 Diabetes, and Hypertension
Authors: Kumar Alok , Singh Sunita
Published: September 2015

Effect of parathyroidectomy on glucose control and hypertension is controversial. Here, we report a case of a patient with primary hyperparathyroidism, type 2 diabetes mellitus, and hypertension in whom parathyroidectomy ameliorated both glucose control and blood pressure. Once high serum calcium levels were noticed, ultrasonography of neck confirmed a well-defined oval hypoechoic mass posterior to the right lobe of the thyroid, confirmed by scintiscan. Parathyroidectomy resulted in improvement of blood pressure and blood glucose. We could stop insulin and antihypertensive medications. We conclude that in patients with type 2 diabetes with vague complaints like fatigue, body ache, and refractory hypertension, as a part of the diagnostic workup, clinicians should also check serum calcium levels and parathyroid hormone to rule out hyperparathyroidism. Correction of hyperparathyroidism may result in improvement of hypertension and glucose control.
Effect of Vitamin E Administration on Learning of the Young Male Rats
Authors: Dolu Nazan , Khan Azizuddin , Dokutan Şule
Published: September 2015

The effect of vitamin E intake on spatial learning and working memory performances of young rats has been investigated in the Morris water maze and locomotor activity has been assessed by an open-field test. A total of 45 young male Wistar albino rats aged two months were divided into three equal groups: control, olive oil, and vitamin E groups. These groups were treated for 30 days with a once daily intraperitoneal injection. The rats were then tested for their ability to find the location of the platform (spatial learning). The results revealed that there was no statistically significant difference between the time spent to find the platform and the time spent in half area of the tank, including the platform among the group, while the time spent to find the platform was found to have increased from the first day to the fourth day in all the groups. In the open-field test, the locomotor activity quite significantly increased in the peripheral area in the olive oil group. The supplementation with vitamin E for a short period had not improved the learning performance of the healthy young rats. It was concluded that the beneficial effect of vitamin E intake on learning is related to the beginning time and the duration of vitamin E intake.
Strong Asymptotics of Hermite-Padé
Approximants for Angelesco Systems
Authors: Yattselev Maxim L.
Published: September 2015

In this work type II Hermite-Padé approximants for a vector of Cauchy transforms of smooth Jacobi-type densities are considered. It is assumed that densities are supported on mutually disjoint intervals (an Angelesco system with complex weights). The formulae of strong asymptotics are derived for any ray sequence of multi-indices.
Uncertainty Principles on Weighted Spheres, Balls, and Simplexes
Authors: Feng Han
Published: September 2015

This paper studies the uncertainty principle for spherical h-harmonic expansions on the unit sphere of ℝ
d
associated with a weight function invariant under a general finite reflection group, which is in full analogy with the classical Heisenberg inequality. Our proof is motivated by a new decomposition of the Dunkl–Laplace–Beltrami operator on the weighted sphere.
Differences in milk fat composition from four old sheep breeds
Authors: Viturro E. , Schlattl M. , Kienberger H. , Rychlik M. , Pfaffl M. W. , Frölich K.
Published: September 2015

Abstract. The present short communication presents a comparison between the milk fat composition of four old sheep breeds. All animals were fed the same diet and a milk sample was obtained at the same lactation day and analyzed for its major components, cholesterol concentration and a complete fatty acid profile. From all studied candidates, the Walachian breed (also when compared with modern breeds employed in the dairy industry) was determined to have the most suitable milk composition for human health.
Is there a solar signal in lower stratospheric water vapour?
Authors: Schieferdecker T. , Lossow S. , Stiller G. P. , von Clarmann T.
Published: September 2015

Abstract. A merged time series of stratospheric water vapour built from the Halogen Occultation Instrument (HALOE) and the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) data between 60° S and 60° N and 15 to 30 km and covering the years 1992 to 2012 was analysed by multivariate linear regression, including an 11-year solar cycle proxy. Lower stratospheric water vapour was found to reveal a phase-shifted anti-correlation with the solar cycle, with lowest water vapour after solar maximum. The phase shift is composed of an inherent constant time lag of about 2 years and a second component following the stratospheric age of air. The amplitudes of the water vapour response are largest close to the tropical tropopause (up to 0.35 ppmv) and decrease with altitude and latitude. Including the solar cycle proxy in the regression results in linear trends of water vapour being negative over the full altitude/latitude range, while without the solar proxy, positive water vapour trends in the lower stratosphere were found. We conclude from these results that a solar signal seems to be generated at the tropical tropopause which is most likely imprinted on the stratospheric water vapour abundances and transported to higher altitudes and latitudes via the Brewer–Dobson circulation. Hence it is concluded that the tropical tropopause temperature at the final dehydration point of air may also be governed to some degree by the solar cycle. The negative water vapour trends obtained when considering the solar cycle impact on water vapour abundances can possibly solve the "water vapour conundrum" of increasing stratospheric water vapour abundances despite constant or even decreasing tropopause temperatures.
Observation of ozone enhancement in the lower troposphere over East Asia from a space-borne ultraviolet spectrometer
Authors: Hayashida S. , Liu X. , Ono A. , Yang K. , Chance K.
Published: September 2015

Abstract. We report observations from space using ultraviolet (UV) radiance for significant enhancement of ozone in the lower troposphere over central and eastern China (CEC). The recent retrieval products of the Ozone Monitoring Instrument (OMI) onboard the Earth Observing System (EOS) Aura satellite revealed the spatial and temporal variation of ozone distributions in multiple layers in the troposphere. We compared the OMI-derived ozone over Beijing with airborne measurements by the Measurement of Ozone and Water Vapor by Airbus In-Service Aircraft (MOZAIC) program. The correlation between OMI and MOZAIC ozone in the lower troposphere was reasonable, which assured the reliability of OMI ozone retrievals in the lower troposphere under enhanced ozone conditions. The ozone enhancement was clearly observed over CEC, with Shandong Province as its center, and was most notable in June in any given year. Similar seasonal variations were observed throughout the 9-year OMI measurement period of 2005 to 2013. A considerable part of this ozone enhancement could be attributed to the emissions of ozone precursors from industrial activities and automobiles, and possibly from open crop residue burning (OCRB) after the winter wheat harvest. The ozone distribution presented in this study is also consistent with some model studies. The lower tropospheric ozone distribution is first shown from OMI retrieval in this study, and the results will be useful in clarifying any unknown factors that influence ozone distribution by comparison with model simulations.
Meteor radar quasi 2-day wave observations over 10 years at Collm (51.3° N, 13.0° E)
Authors: Lilienthal F. , Jacobi Ch.
Published: September 2015

Abstract. The quasi 2-day wave (QTDW) at 82–97 km altitude over Collm (51° N, 13° E) has been observed using a VHF meteor radar. The long-term mean amplitudes calculated using data between September 2004 and August 2014 show a strong summer maximum and a much weaker winter maximum. In summer, the meridional amplitude is slightly larger than the zonal one with about 15 m s−1 at 91 km height. Phase differences are slightly greater than 90° on an average. The periods of the summer QTDW vary between 43 and 52 h during strong bursts, while in winter the periods tend to be more diffuse. On average, the summer QTDW is amplified after a maximum of zonal wind shear which is connected with the summer mesospheric jet and there is a possible correlation of the summer mean amplitudes with the background wind shear. QTDW amplitudes exhibit considerable inter-annual variability; however, a relationship between the 11-year solar cycle and the QTDW is not found.
Nitrogen fixation in sediments along a depth transect through the Peruvian oxygen minimum zone
Authors: Gier J. , Sommer S. , Löscher C. R. , Dale A. W. , Schmitz R. A. , Treude T.
Published: September 2015

Abstract. Benthic nitrogen (N2) fixation and sulfate reduction (SR) were investigated in the Peruvian oxygen minimum zone (OMZ). Sediment samples, retrieved by a multiple corer were taken at six stations (70–1025 m) along a depth transect at 12° S, covering anoxic and hypoxic bottom water conditions. Benthic N2 fixation was detected at all sites, with high rates measured in OMZ mid-waters between the 70 and 253 m and lowest N2 fixation rates below 253 m down to 1025 m water depth. SR rates were decreasing with increasing water depth, with highest rates at the shallow site. Benthic N2 fixation depth profiles largely overlapped with SR depth profiles, suggesting that both processes are coupled. The potential of N2 fixation by SR bacteria was verified by the molecular analysis of nifH genes. Detected nifH sequences clustered with SR bacteria that have been demonstrated to fix N2 in other benthic environments. Depth-integrated rates of N2 fixation and SR showed no direct correlation along the 12° S transect, suggesting that the benthic diazotrophs in the Peruvian OMZ are being controlled by additional various environmental factors. The organic matter availability and the presence of sulfide appear to be major drivers for benthic diazotrophy. It was further found that N2 fixation was not inhibited by high ammonium concentrations. N2 fixation rates in OMZ sediments were similar to rates measured in other organic-rich sediments. Overall, this work improves our knowledge on N sources in marine sediments and contributes to a better understanding of N cycling in OMZ sediments.
Biogeochemical characteristics of a long-lived anticyclonic eddy in the eastern South Pacific Ocean
Authors: Cornejo M. , Bravo L. , Ramos M. , Pizarro O. , Karstensen J. , Gallegos M. , Correa-Ramirez M. , Silva N. , Farias L. , Karp-Boss L.
Published: September 2015

Abstract. Eastern boundary upwelling systems are characterized by high productivity that often leads to subsurface hypoxia on the shelf. Mesoscale eddies are important, frequent, and persistent features of circulation in these regions, transporting physical, chemical and biological properties from shelves to the open ocean. In austral fall of 2011, during the Tara Oceans expedition, a subsurface layer (200–400 m) in which the concentration of oxygen was very low (< 2 μmol kg−1 of O2) was observed in the eastern South Pacific, ~ 900 km offshore (30° S, 81° W). Satellite altimetry combined with CTD observations associated the local oxygen anomaly with an intrathermocline, anticyclonic, mesoscale eddy with a diameter of about 150 km. The eddy contained Equatorial Subsurface Water (ESSW) that at this latitude is normally restricted near the coast. Undersaturation (44 %) of nitrous oxide (N2O) and nitrite accumulation (> 0.5 μM) gave evidence for denitrification in this water mass. Based on satellite altimetry, we tracked the eddy back to its region of formation on the coast of central Chile (36.1° S, 74.6° W). We estimate that the eddy formed in April 2010. Field studies conducted on the Chilean shelf in June 2010 provided approximate information on initial O2 and N2O concentrations of "source water" in the region at the time of eddy formation. Concentrations of both O2 and N2O in the oxygen minimum zone (OMZ) of the offshore eddy were lower than its surroundings or "source water" on the shelf, suggesting that these chemical species were consumed as the eddy moved offshore. Estimates of apparent oxygen utilization rates at the OMZ of the eddy ranged from 0.29 to 44 nmol L−1 d−1 and the rate of N2O consumption was 3.92 nmol L−1 d−1. Our results show that mesoscale eddies in the ESP not only transport physical properties of the ESSW from the coast to the ocean interior, but also export and transform biogeochemical properties, creating suboxic environments in the oligotrophic region of the eastern South Pacific. Suboxic water masses that are advected by eddies act as hotspots for denitrification and loss of fixed nitrogen from the system.
Selective deposition response to aeolian–fluvial sediment supply in the desert braided channel of the upper Yellow River, China
Authors: Wang H. , Jia X. , Li Y. , Peng W.
Published: September 2015

Abstract. Rivers flow across aeolian dunes and develop braided stream channels. Both aeolian and fluvial sediment supplies regulate sediment transport and deposition in such cross-dune braided rivers. Here we show a significant selective deposition in response to both aeolian and fluvial sediment supplies in the Ulan Buh desert braided channel. The Ulan Buh desert is the main coarse sediment source for this desert braided channel, and the mean percentage of the coarser (> 0.08 mm) grains on the aeolian dunes surface is 95.34 %. The lateral selective deposition process is developed by the interaction between the flows and the aeolian–fluvial sediment supplies, causing the coarser sediments (> 0.08 mm) from aeolian sand supply and bank erosion to accumulate in the channel centre and the finer fluvial sediments (< 0.08 mm) to be deposited on the bar and floodplain surfaces, forming a coarser-grained thalweg bed bounded by finer-grained floodplain surfaces. This lateral selective deposition reduces the downstream sediment transport and is a primary reason for the formation of an "above-ground" river in the braided reach of the upper Yellow River in response to aeolian and fluvial sediment supplies.
The role of vertical shear on the horizontal oceanic dispersion
Authors: Lanotte A. S. , Corrado R. , Lacorata G. , Palatella L. , Pizzigalli C. , Schipa I. , Santoleri R.
Published: September 2015

Abstract. The effect of vertical shear on the horizontal dispersion properties of passive tracer particles on the continental shelf of South Mediterranean is investigated by means of observative and model data. In-situ current measurements reveal that vertical velocity gradients in the upper mixed layer decorrelate quite fast (∼ 1 day), whereas basin-scale ocean circulation models tend to overestimate such decorrelation time because of finite resolution effects. Horizontal dispersion simulated by an eddy-permitting ocean model, like, e.g., the Mediterranean Forecasting System, is mosty affected by: (1) unresolved scale motions, and mesoscale motions that are largely smoothed out; (2) poorly resolved time variability of vertical velocity profiles in the upper layer. For the case study we have analysed, we show that a suitable use of kinematic parameterisations is helpful to implement realistic statistical features of tracer dispersion in two and three dimensions. The approach here suggested provides a functional tool to control the horizontal spreading of small organisms or substance concentrations, and is thus relevant for marine biology, pollutant dispersion as well as oil spill applications.
Experimental study on the electrical conductivity of quartz andesite at high temperature and high pressure: evidence of grain boundary transport
Authors: Hui K. S. , Zhang H. , Li H. P. , Dai L. D. , Hu H. Y. , Jiang J. J. , Sun W. Q.
Published: September 2015

Abstract. In this study, the electrical conductivity of quartz andesite was measured in situ under conditions of 0.5–2.0 GPa and 723–973 K using a YJ-3000t multi-anvil press and a Solartron-1260 Impedance/Gain-Phase Analyzer. Experimental results indicate that grain interior transport controls the higher frequencies (102–106 Hz), whereas the grain boundary process dominates the lower frequencies (10−1–102 Hz). For a given pressure and temperature range, the relationship between Log σ and T−1 follows the Arrhenius relation. As temperature increased, both the grain boundary and grain interior conductivities of quartz andesite increased; however, with increasing pressure, both the grain boundary and grain interior conductivities of the sample decreased. By the virtue of the dependence of grain boundary conductivity on pressure, the activation enthalpy and the activation volume were calculated to be 0.87–0.92 eV and 0.56 ± 0.52 cm3 mol−1, respectively. The small polaron conduction mechanism for grain interior process and the ion conduction mechanism for grain boundary process are also discussed.
Pinch and swell structures: evidence for strain localisation by brittle–viscous behaviour in the middle crust
Authors: Gardner R. L. , Piazolo S. , Daczko N. R.
Published: September 2015

Abstract. The flow properties of middle crustal rocks are commonly represented by viscous flow. Examples of pinch and swell structures found in a high strain zone at St. Anne Point (Fiordland, New Zealand) and Wongwibinda (N.S.W., Australia) suggest pinch and swell structures may be initiated by brittle failure of the more competent layer in conjunction with subsequent material softening. On this basis we develop a numerical model where Mohr–Coulomb constitutive strain localising behaviour is utilised to initiate pinch and swell structure development. Results show that pinch and swell structures develop in a competent layer in both Newtonian and non-Newtonian flow, provided the competent layer has sufficient viscosity contrast and can localise strain to form shear bands. The flow regime and strain localising characteristics of the surrounding country rock appear not to impact pinch and swell structure formation. The degree of material softening after the initial strain localising behaviour is shown to impact pinch and swell characteristics, while extensive material softening causes the formation of thick necks between swells by limiting the focused localisation of strain into shear bands. To aid analysis of the structures and help derive the flow properties of rocks in the field, we define three stages of pinch and swell development and offer suggestions for measurements to be made in the field. Our study suggests that Mohr–Coulomb strain localising behaviour combined with viscous flow is a viable alternative representation of the heterogeneous rheological behaviour of rocks seen in the middle crust. This type of mid-crustal rheological behaviour can have significant influence on the localisation of strain at all scales. For example, inclusion of Mohr–Coulomb strain localising behaviour with viscous flow in just some mid-crustal layers within a crustal-scale model can result in significant strain localisation, extending from the upper crust into the middle crust. This localisation also influences the development of near-surface structures.
Global Cooperation or Rival Trade Blocs?
Authors: Junne Gerd
Published: September 2015

This paper examines the question of whether the world will continue to move toward a liberal, multi-lateral world trade system or whether it will fall apart into rival trade blocs. It starts with a short comparison of different scenarios for the development of the world economy. It then tries to illustrate the importance of developments inside the major trade blocs for the relationships between these blocs, taking as an examples (a) the impact of Gernam reunification, (b) the impact of a possible break-up of China, and (c) the impact of domestic polarization within the United States. It then discusses how different research avenues give rise to different expectations with regard to cooperation versus rivalry. For instance, from a long waves perspective increasing rivalry can be expected. However, an analysis of strategic alliances points in the direction of more cooperation and collective management of international economic relations. And finally, analyses that give more attention to the internal restructuring of companies lead to the hypothesis that new societal demands for a more active state will be articulated, implying more frictions at the international level. An analysis in terms of "concepts of control" points in the same direction. The tenative conclusion of this paper, meanwhile, is that "managed rivalry" will characterize future relations between the main trading blocs.
The Modern World-System and Evolution
Authors: Wallerstein Immanuel
Published: September 2015

The concept of evolution is ambiguous. Sometimes it only means those changes that have historically ocurred. In other cases it has a more teleological aspect, as in the claim that acorns evolve into oaks. In that meaning, the end result is the normal outcome of a pattern inscribed in the inner structure of the entity under discussion... I consider it important to distinguish three processes in the historical life of of any system: its genesis; its relatively long period of normal functioning; and its demise (the result of birfurcation), which can also be thought of as the period of transition to a new historical system or systems. It is only about the period of normal functioning that it seems useful to apply the term of evolution, and it is to this period that I shall restrict the discussion.
Three Logics of "Major Power Rivalry" in the World-System: A Footnote to a Pentagon study
Authors: Su Tieting
Published: September 2015

A vast body of social science literature on long waves and major power wars has greatly enriched our knowledge about the rhythms and violent transitions of the modern world-system. The correlations between long waves and major power clashes in the past has been established. What are the structural causal mechanisms between these two historical and cyclical movements? Using trade network patterns as an indicator of a deep structure, this article summarizes a longitudinial study attempted to construct one of the missing links between the two historical cycles. Based on a structural analysis of world trade networks in 1938, 1950, and 1990, and a quantitative study of U.S.--Japanese commercial rivalry in the Asia-Pacific region, this study considers three logics of "major power rivalry" in the past and its implication for the future: (1) the logic of rivalry over "life spaces"; (2) the logic of rivalry for global domination; and (3) the logic of imperial intervention. I contend that these three logics are related, and that changes in one logic result in changes in others.