bluuebunny/crossref_metadata_2025 huggingface dataset:
Multi-Perspectives’ Comparisons and Mitigating Implications for the COD and NH3-N Discharges into the Wastewater from the Industrial Sector of China
Authors: Jia Junsong , Jian Huiyong , Xie Dongming , Gu Zhongyu , Chen Chundi
Published: March 2017

Taking China as a case study, we analyzed the underlying driving forces of two discharges—chemical oxygen demand (COD) and ammonia nitrogen (NH3-N)—from both periodic and structural perspectives by the Logarithmic Mean Divisia Index (LMDI) method. Changes in the two discharges were decomposed into three effects: the economic output effect, the industrial structure effect and the discharge intensity effect. The discharge intensity effect could be further decomposed into the cleaner production (technologies’) effect and the pollution abatement (technologies’) effect. Results showed that the economic output effect was mainly responsible for the growth of the two discharges; the average annual contribution rates were 10.77% and 10.39%, respectively. Inversely, the pollution abatement (technologies’) effect presented the most obvious mitigating effects (−9.71% and −9.52%, respectively). Furthermore, the clean production (technologies’) effect followed it (−4.36% and −5.22%). So, we found that the discharge intensity effect played a crucial role in the reduction of the two discharges. Then, the mitigation effect of industrial structure adjustment was the weakest (−0.19% and 0.47%). However, we could still not ignore the potential impact of industrial structure optimization for reducing the absolute amount of discharges in the long run. In addition, to simultaneously reduce the COD and NH3-N discharges, the sub-sectors of “Processing of Food from Agricultural Products (I7)”, “Manufacture of Foods (I8)”, “Manufacture of Raw Chemical Materials and Chemical Products (I20)”, “Manufacture of Non-metallic Mineral Products (I24)” and “Smelting and Pressing of Non-ferrous Metals (I26)” were suggested to be given prior consideration for the design of related mitigation policies. Finally, some particular policy implications were also recommended for reducing the two discharges.
Climate Variability Structures Plant Community Dynamics in Mediterranean Restored and Reference Tidal Wetlands
Authors: Chapple Dylan , Faber Phyllis , Suding Katharine , Merenlender Adina
Published: March 2017

In Mediterranean regions and other areas with variable climates, interannual weather variability may impact ecosystem dynamics, and by extension ecological restoration projects. Conditions at reference sites, which are often used to evaluate restoration projects, may also be influenced by weather variability, confounding interpretations of restoration outcomes. To better understand the influence of weather variability on plant community dynamics, we explore change in a vegetation dataset collected between 1990 and 2005 at a historic tidal wetland reference site and a nearby tidal wetland restoration project initiated in 1976 in California’s San Francisco (SF) Bay. To determine the factors influencing reference and restoration trajectories, we examine changes in plant community identity in relation to annual salinity levels in the SF Bay, annual rainfall, and tidal channel structure. Over the entire study period, both sites experienced significant directional change away from the 1990 community. Community change was accelerated following low salinity conditions that resulted from strong El Niño events in 1994–1995 and 1997–1998. Overall rates of change were greater at the restoration site and driven by a combination of dominant and sub-dominant species, whereas change at the reference site was driven by sub-dominant species. Sub-dominant species first appeared at the restoration site in 1996 and incrementally increased during each subsequent year, whereas sub-dominant species cover at the reference site peaked in 1999 and subsequently declined. Our results show that frequent, long-term monitoring is needed to adequately capture plant community dynamics in variable Mediterranean ecosystems and demonstrate the need for expanding restoration monitoring and timing restoration actions to match weather conditions.
Determinants of Farmers’ Climate Risk Perceptions in Agriculture—A Rural Ghana Perspective
Authors: Ndamani Francis , Watanabe Tsunemi
Published: March 2017

This study evaluates the socio-economic predictors of farmers’ perceptions about climate risk in agriculture. The levels of risk perception among different farmers’ wealth groups are also investigated. A total of 100 farmers in the Lawra district of Ghana are randomly selected and interviewed. Data is obtained through the use of semi-structured questionnaires and focus group discussions. A climate risk perception index (CRPI) is derived and applied to assess the degree of perceived risk among different wealth groups of farmers. The linear regression model is also used to analyze the data. The results showed that 93% of farmers have perceived climate risk while 7% are not sure if they have perceived it. Results of the CRPI showed that resource-poor farmers are concerned about climate risk on agricultural production, while resource-moderate and resource-rich farmers are concerned about risk impacts on climatic variables, and health and socio-economy, respectively. Results of the regression model showed that education, age, a perceived increase in human disease and mortality, and a decrease in food security and incomes are predictors of risk perception. The policy implication of this study is that predictors of farmers’ climate risk perception should be factored into climate change risk communication in order to boost awareness and adaptation to climate change.
CryoSat-2 Altimetry Applications over Rivers and Lakes
Authors: Jiang Liguang , Schneider Raphael , Andersen Ole , Bauer-Gottwein Peter
Published: March 2017

Monitoring the variation of rivers and lakes is of great importance. Satellite radar altimetry is a promising technology to do this on a regional to global scale. Satellite radar altimetry data has been used successfully to observe water levels in lakes and (large) rivers, and has also been combined with hydrologic/hydrodynamic models. Except CryoSat-2, all radar altimetry missions have been operated in conventional low resolution mode with a short repeat orbit (35 days or less). CryoSat-2, carrying a Synthetic Aperture Radar (SAR) altimeter, has a 369-day repeat and a drifting ground track pattern and provides new opportunities for hydrologic research. The narrow inter-track distance (7.5 km at the equator) makes it possible to monitor many lakes and rivers and SAR mode provides a finer along-track resolution, higher return power and speckle reduction through multi-looks. However, CryoSat-2 challenges conventional ways of dealing with satellite inland water altimetry data because virtual station time series cannot be directly derived for rivers. We review the CryoSat-2 mission characteristics, data products, and its use and perspectives for inland water applications. We discuss all the important steps in the workflow for hydrologic analysis with CryoSat-2, and conclude with a discussion of promising future research directions.
Neutral Gas Properties of Extremely Isolated Early-type Galaxies
Authors: Ashley Trisha , Marcum Pamela M. , Fanelli Michael N.
Published: March 2017

We present the results of single-dish atomic hydrogen (H i) observations of six highly isolated early-type galaxies. These objects are a representative subset of galaxies previously studied at optical wavelengths and selected to be separated by at least 2.5 Mpc from companions brighter than M

V
 = −16.5 mag. Each galaxy was observed with a single pointing using the NRAO Green Bank Telescope L-band receiver. Five of these systems were strongly detected in H i. These five galaxies exhibit H i profiles with a range of properties: single Gaussian-like peaks, separate double peaks, and double horn-like profiles. The four bluest galaxies (B−V < 0.54) all contain significant gas with H i masses ranging from 1.1 × 108 to 1.4 × 109.
Optical Spectra of Candidate International Celestial Reference Frame (ICRF) Flat-spectrum Radio Sources. III.
Authors: Titov O. , Pursimo T. , Johnston Helen M. , Stanford Laura M. , Hunstead Richard W. , Jauncey David L. , Zenere Katrina A.
Published: March 2017

In extending our spectroscopic program, which targets sources drawn from the International Celestial Reference Frame (ICRF) Catalog, we have obtained spectra for ∼160 compact, flat-spectrum radio sources and determined redshifts for 112 quasars and radio galaxies. A further 14 sources with featureless spectra have been classified as BL Lac objects. Spectra were obtained at three telescopes: the 3.58 m European Southern Observatory New Technology Telescope, and the two 8.2 m Gemini telescopes in Hawaii and Chile. While most of the sources are powerful quasars, a significant fraction of radio galaxies is also included from the list of non-defining ICRF radio sources.
On the Redshift of TeV BL Lac Objects
Authors: Paiano Simona , Landoni Marco , Falomo Renato , Treves Aldo , Scarpa Riccardo , Righi Chiara
Published: March 2017

We report results of a spectroscopic campaign carried out at the 10 m Gran Telescopio Canarias for a sample of 22 BL Lac objects detected (or candidates) at TeV energies, aiming to determine or constrain their redshift. This is of fundamental importance for the interpretation of their emission models and for population studies and is also mandatory for studying the interaction of high-energy photons with the extragalactic background light using TeV sources.  Optical spectra with high signal-to-noise ratios in the range 4250–10000 Å were obtained to search for faint emission or absorption lines from both the host galaxy and the nucleus. We determine a new redshift for PKS 1424+240 (z = 0.604) and a tentative one for 1ES 0033+595 (z = 0.467). We are able to set new spectroscopic redshift lower limits for three other sources on the basis of Mg ii and Ca ii intervening absorption features: BZB J1243+3627 (z > 0.483), BZB J1540+8155 (z > 0.672), and BZB 0J2323+4210 (z > 0.267). We confirm previous redshift estimates for four blazars: S3 0218+357 (z = 0.944), 1ES 1215+303 (z = 0.129), W Comae (z = 0.102), and MS 1221.8+2452 (z = 0.218). For the remaining targets, in seven cases (S2 0109+22, 3C 66A, VER J0521+211, S4 0954+65, BZB J1120+4214, S3 1227+25, BZB J2323+4210), we do not validate the proposed redshift. Finally, for all sources of still-unknown redshift, we set a lower limit based on the minimum equivalent width of absorption features expected from the host galaxy.
The Shock Dynamics of Heterogeneous YSO Jets:3D Simulations Meet Multi-epoch Observations
Authors: Hansen E. C. , Frank A. , Hartigan P. , Lebedev S. V.
Published: March 2017

High-resolution observations of young stellar object (YSO) jets show them to be composed of many small-scale knots or clumps. In this paper, we report results of 3D numerical simulations designed to study how such clumps interact and create morphologies and kinematic patterns seen in emission line observations. Our simulations focus on clump scale dynamics by imposing velocity differences between spherical, over-dense regions, which then lead to the formation of bow shocks as faster clumps overtake slower material. We show that much of the spatial structure apparent in emission line images of jets arises from the dynamics and interactions of these bow shocks. Our simulations show a variety of time-dependent features, including bright knots associated with Mach stems where the shocks intersect, a “frothy” emission structure that arises from the presence of the Nonlinear Thin Shell Instability along the surfaces of the bow shocks, and the merging and fragmentation of clumps. Our simulations use a new non-equilibrium cooling method to produce synthetic emission maps in Hα and [S ii]. These are directly compared to multi-epoch Hubble Space Telescope observations of Herbig–Haro jets. We find excellent agreement between features seen in the simulations and the observations in terms of both proper motion and morphologies. Thus we conclude that YSO jets may be dominated by heterogeneous structures and that interactions between these structures and the shocks they produce can account for many details of YSO jet evolution.
Low-frequency Carbon Radio Recombination Lines. I. Calculations of Departure Coefficients
Authors: Salgado F. , Morabito L. K. , Oonk J. B. R. , Salas P. , Toribio M. C. , Röttgering H. J. A. , Tielens A. G. G. M.
Published: March 2017

In the first paper of this series, we study the level population problem of recombining carbon ions. We focus our study on high quantum numbers, anticipating observations of carbon radio recombination lines to be carried out by the Low Frequency Array. We solve the level population equation including angular momentum levels with updated collision rates up to high principal quantum numbers. We derive departure coefficients by solving the level population equation in the hydrogenic approximation and including low-temperature dielectronic capture effects. Our results in the hydrogenic approximation agree well with those of previous works. When comparing our results including dielectronic capture, we find differences that we ascribe to updates in the atomic physics (e.g., collision rates) and to the approximate solution method of the statistical equilibrium equations adopted in previous studies. A comparison with observations is discussed in an accompanying article, as radiative transfer effects need to be considered.
A Submillimeter Perspective on the GOODS Fields (SUPER GOODS). I. An Ultradeep SCUBA-2 Survey of the GOODS-N*

†

‡

§
Authors: Cowie L. L. , Barger A. J. , Hsu L.-Y. , Chen Chian-Chou , Owen F. N. , Wang W.-H.
Published: March 2017

In this first paper in the SUPER GOODS series on powerfully star-forming galaxies in the two GOODS fields, we present a deep SCUBA-2 survey of the GOODS-N at both 850 and 450 μm (central rms noise of 0.28 mJy and 2.6 mJy, respectively). In the central region, the 850 μm observations cover the GOODS-N to near the confusion limit of ∼1.65 mJy, while over a wider 450 arcmin2 region—well complemented by Herschel far-infrared imaging—they have a median

limit of 3.5 mJy. We present

catalogs of 186 850 μm and 31 450 μm selected sources. We use interferometric observations from the Submillimeter Array (SMA) and the Karl G. Jansky Very Large Array (VLA) to obtain precise positions for 114 SCUBA-2 sources (28 from the SMA, all of which are also VLA sources). We present new spectroscopic redshifts and include all existing spectroscopic or photometric redshifts. We also compare redshifts estimated using the 20 cm/850 μm and the 250 cm/850 μm flux ratios. We show that the redshift distribution increases with increasing flux, and we parameterize the dependence. We compute the star formation history and the star formation rate (SFR) density distribution functions in various redshift intervals, finding that they reach a peak at

before dropping to higher redshifts. We show that the number density per unit volume of

galaxies measured from the SCUBA-2 sample does not change much relative to that of lower SFR galaxies from UV selected samples over

, suggesting that, apart from changes in the normalization, the shape in the number density as a function of SFR is invariant over this redshift interval.
Kennicutt-Schmidt Relation Variety and Star-forming Cloud Fraction
Authors: Morokuma-Matsui Kana , Muraoka Kazuyuki
Published: March 2017

The observationally derived Kennicutt-Schmidt (KS) relation slopes differ from study to study, ranging from sublinear to superlinear. We investigate the KS-relation variety (slope and normalization) as a function of integrated intensity ratio, R
31 = CO(J = 3–2)/CO(J = 1–0) using spatially resolved CO(J = 1–0), CO(J = 3–2), H i, Hα, and 24 μm data of three nearby spiral galaxies (NGC 3627, NGC 5055, and M83). We find that (1) the slopes for each subsample with a fixed R
31 are shallower, but the slope for all data sets combined becomes steeper, (2) normalizations for high R
31 subsamples tend to be high, (3) R
31 correlates with star formation efficiency, therefore the KS relation depends on the distribution in R
31–Σgas space of the samples: no Σgas dependence of R
31 results in a linear slope of the KS relation, whereas a positive correlation between Σgas and R
31 results in a superlinear slope of the KS relation, and (4) R
31–Σgas distributions are different from galaxy to galaxy and within a galaxy: galaxies with prominent galactic structure tend to have large R
31 and Σgas. Our results suggest that the formation efficiency of a star-forming cloud from molecular gas is different among galaxies as well as within a galaxy, and it is one of the key factors inducing the variety in galactic KS relation.
A Study of Oxide Etch Angle of Edge Termination Field Plate for Fabrication of SiC SBD
Authors: Kang Ey Goo
Published: March 2017

The silicon carbide (SiC) material is being spotlighted as a next-generation power semiconductor material due to the characteristic limitations of the existing silicon materials. SiC has a wider band gap, higher breakdown voltage, higher thermal conductivity, and higher saturation electron mobility than Si. However, actual SiC SBDs exhibit a lower dielectric breakdown voltage than the theoretical breakdown voltage that causes the electric field concentration, a phenomenon that occurs on the edge of the contact surface as in the conventional power semiconductor devices. In this paper, we designed an edge termination structure using a field plate structure through oxide etch angle control, and optimized the structure to obtain a high breakdown voltage. The experiment results indicated that oxide etch angle was 45° when the breakdown voltage characteristics of the SiC SBD were optimized and a breakdown voltage of 681V was obtained.
Cyclic Voltammetry Measurement for n-Type Cu2O Thin Film Using Copper Sulphate-Based Solution
Authors: Mohamad Fariza , Cheong Kah Hao , binti Zinal Nabiah , binti Mohamad Arifin Nurliyana , binti Mohd Hanif Asyikin Sasha , Muhd Nor Nik Hisyamudin , Izaki Masanobu
Published: March 2017

Cuprous oxide (Cu2O) is a promising material for solar cell application. Due to its various advantages over silicon material, it has been exploited extensively to be use in photovoltaic cell. Cu2O thin films were electrodeposited in sulfate-based solution. Cyclic voltammorgram (CV) measurement was used to investigate the reduction process under controlled parameters. Deposition potential of-0.1V vs. Ag/AgCl was used for the fabrication of Cu2O thin film based on the CV measurement. CV also revealed that the deposition speed was dependent on the bath pH and the temperature. X-ray diffraction (XRD) measurement, Field Emission Scanning-Electron Microscopy (FE-SEM) and Ultraviolet-visible spectroscopy (UV-Vis) were performed to characterize the deposited thin films. The n-Cu2O was successfully fabricated on FTO glass substrate with (111)-prefered orientation. Surface morphology of the thin films were observed to be in flower-like shape combination with pyramidal and triangular shape.
Different Molecular Weight Chitosans Prepared via the Ionic Liquid Hydrolysis and their Antibacterial Activity
Authors: Fu Ran Ran , Ji Xiu Jie , Ren Yan Fei , Wang Gang , Cheng Bo Wen
Published: March 2017

The hydrolysis effect of ionic liquid glycine chloride [Gly]Cl aqueous system without any catalyst on the degradation for chitosan were studied. The molecular weight (Mw) and degree of deacetylation (DD) of degraded products were tested via the viscometric method and the titration method, respectively. The structure of the raw and degraded chitosans were assessed through Fourier transform infrared spectroscopy (FTIR) and X-ray powder diffraction (XRD). Besides, the antibacterial effects of different Mw chitosans to Escherichia coli and Staphylococcus aureus were evaluated. The results showed that [Gly]Cl aqueous solution was of good assistant degradation effect for chitosan and different molecular weight (300-800 kDa) chitosans were obtained with different processing time via the ionic liquid hydrolysis method. The DD of degraded chitosans tested from titration method was almost unchanged by the treatment. The FTIR and XRD results showed that the ionic liquid degradation had no obvious effect on the molecular structure of chitosan. Besides, the antibacterial activity was closely relevant to the chitosan concentration and Mw. When the concentration was greater than 0.005% (w/v), chitosan began to show strong antibacterial activity. Molecular weight of 636 kDa exhibited commendable antimicrobial properties to E. coli and S. aureus simultaneously.
Metal Ion Release and Cytotoxicity of Titanium Orthodontic Miniscrews
Authors: Kosayadiloka Katha , Tangjit Nathaphon , Luppanapornlarp Suwannee , Santiwong Peerapong
Published: March 2017

The aim of this study was to investigate the metal ion release and cytotoxicity of MU orthodontic miniscrews as well as two other brands of orthodontic miniscrews over time. Twenty-four orthodontic miniscrews were tested, divided into three groups of eight. Each sample extraction was performed following the ISO 10993-12:2012 method. Solutions were collected after 1, 7, and 30 days (T1, T2, and T3). The supernatants extracted from these three groups were added and exposed to mouse L929 fibroblastic cell line using an MTT cytotoxicity test. They were also tested for ion release by inductively coupled plasma-mass spectrometry (ICP-MS). Element analysis by energy-dispersive X-ray spectroscopy (EDS) was used to analyze the surfaces of the miniscrews. The quantification of three elements, namely, titanium (Ti), aluminum (Al), and vanadium (V) were assessed. The results indicated that there were no statistical differences between the self-made orthodontic miniscrews and those from two commercial groups (p<0.05). Throughout the testing period, the quantity of ions increased from T1 to T3. After 24 h, vanadium was the first to appear on the surface in small quantities in other two commercial groups. The self-made orthodontic miniscrews exhibited no toxic effects on living cells.
Loading and Unloading Forces Following Addition of 5% Cu in Nickel-Titanium Alloy Used for Orthodontics
Authors: Phukaoluan Aphinan , Dechkunakorn Surachai , Anuwongnukroh Niwat , Khantachawana Anak , Kaewtatip Pongpan , Kajornchaiyakul Julathep , Wichai Wassana
Published: March 2017

This study aims to address the amount of force delivered by a fabricated NiTiCu orthodontic wire with a ternary composition ratio of 46.0 Ni: 49.0 Ti: 5.0 Cu and to compare the results with a commercial NiTiCu35oC orthodontic archwire. Nickel (purity 99.9%), Titanium (purity 99.8%), and Copper (purity 99.9%) were used in this study with the atomic weight ratio 46.0 Ni: 49.0 Ti: 5.0 Cu. The elements were melted to form an alloy using an electrolytic arc furnace in argon gas atmosphere and homogenized at 800oC for 1 hr. The alloys were subsequently sliced into thin plates (1.5mm) by EDM wire cutting machine to obtain the specimens and were cold-rolled with 30% reduction followed by heat treatment in a furnace at 400oC for 1 hour. Then, the three newly fabricated NiTiCu specimens were cut in nearly identical wire sizes of 0.016 inch x0.022 inch. Commercial preformed Ormco NiTiCu35oC archwire with size 0.016 inch x 0.022 inches were used for comparative purposes. Three-point bending test was performed using a Universal Testing Machine to investigate the force of the load-deflection curve at oral temperature (36oC+ 1) with deflection points at 0.25, 0.5, 0.75, 1.0, 1.25, and 1.5 mm. Descriptive statistics was used to evaluate each variable and independent t-test was used to analyze the differences between the groups. It was found that both NiTiCu wires presented typical superelastic properties as observed from the load-deflection curve. The average force was 341.70 g for loading, and 264.18 g for unloading for 46.0 Ni: 49.0 Ti: 5.0 Cu wire. Similarly, the values were 299.88 g for loading, and 201.96 g for unloading for Ormco NiTiCu35oC. There were significant differences (p<0.05) in mean loading and unloading forces between the two NiTiCu wires. The deflection forces in loading and unloading force for Ormco NiTiCu at each point were less than 46.0 Ni: 49.0 Ti: 5.0 Cu wire, except at the deflection point of 0.25 mm. Regarding the force difference between each deflection point of loading and unloading force, Ormco NiTiCu35oC exerted less force than 46.0 Ni: 49.0 Ti: 5.0 Cu wire, except at difference deflection at 1.5-1.25 mm of unloading force. However, there were still within the acceptable limits for orthodontic use. It is concluded that the fabricated ternary alloy of 46.0 Ni: 49.0 Ti: 5.0 Cu (atomic weight) with 30% reduction and heat treatment at 400oC for 1 hr. and Ormco 35oC NiTiCu presented the characteristics of both superelastic and shape memory in their wire form. The unloading forces of both NiTiCu wires were in the range of orthodontic use. This should be a good foundation for further studies towards development of new orthodontic NiTiCu archwires.
Preparation, Characterization and Applications of Enzyme-Free Glucose Sensors
Authors: Hong Jing Chao , Qin Gu
Published: March 2017

With the continuous development of science and technology, the function of the electrochemical biosensor is becoming more and more diversified. The fourth generation of enzyme-free glucose sensor because of its particular advantages has become one of research focuses in glucose sensor now. For all sorts of optimization also are not enzyme glucose as the new material was born has made great progress. Enzyme-free glucose sensors are becoming more and more an integral part of electrochemical research. This article summarizes the characteristics of all kinds of conventional materials of enzyme-free glucose sensor, the domestic and foreign general preparation methods of enzyme-free glucose sensors, the specific characterization of the electrode, its application fields, and prospects for future development.
Facile Preparation of Gold Nanoparticle Modified Pencil Graphite Electrode
Authors: Puttharugsa Chokchai , Limnonthakul Puenisara
Published: March 2017

The purpose of this research was to prepare gold nanoparticle (AuNP) modified disposable pencil graphite electrode (PGE). The AuNP was prepared using trisodium citrate reduced gold ion solution. The PGE surface modification was carried out by immersing a bare PGE in poly (diallyldimethylammonium chloride) (PDDA) and then in AuNP solution at room temperature. The characterization of the bare and modified PGE surfaces was carried out using field emission scanning electron microscopy (FESEM) and cyclic voltammetry in the presence of 0.1 M NaOH. The electrochemical behavior of the modified PGE electrode was investigated using cyclic voltammetry, and impedance spectroscopy in the presence of 5 mM [Fe (CN)6]3-/4- redox probe solution. The obtained result indicated that the modification of AuNP on the PGE surface provided a good electrochemical signal. In order to obtain more sensitive electrochemical signals, the effect of adsorbed AuNP on the PGE surface was also studied.
Characteristics and Properties of Absorption Materials for Mercury Removal at High Temperature
Authors: Cheng Han Wen , Yu Ching Tsung
Published: March 2017

In this study, some metal-M/aluminum carbonate absorption materials with molar ratio of M:Al=3:1 were manufactured. There was Cu–Al, Mn–Al, Fe–Al three kinds of sorbents synthesized by co-precipitate method. The physicochemical structures during mercury removal were analyzed by a surface area and pore structure analyzer (BET), an X-ray diffraction (XRD), a scanning electron microscope coupled with an electron detection scanning (SEM/EDS), and X-ray fluorescence (XRF). The results showed that surface areas for metal-M/aluminum carbonate sorbents were only about 11~12 m2/g and the metal ratio loaded was more than 80%. Lab-scale tests mercury removal efficiency in the temperature range of 200–300 oC indicated that there was an improvement in the performance of mercury removal by increasing reaction temperature. Cu–Al, Fe–Al and Mn–Al all three sorbents reached their absorption equivalent of 256.6, 253.3 and 247.0 μg/g under 300 oC operating temperature and 19736 h-1 gas hourly space velocity. Additionally, the presence of transition metals can significantly improve the efficiency of mercury removal of the absorption materials.
Characterization of Vinyl Ester/Jute Fiber Bio-Composites in the Presence of Multi-Walled Carbon Nanotubes
Authors: Bassyouni Mohamed , Abdel-Hamid Shereen M.S. , Abdel-Aziz Mohamed H. , Zoromba M.Sh.
Published: March 2017

In this study, vinyl ester –Jute fiber biocomposites were prepared using vacuum-assisted resin infusion (VARI) process. Woven Jute fibers were used with mass fraction 0.68. Multi-walled carbon nanotubes (MWCNTs) are added to the resin with weight ratio 0.5: 99.5 to investigate the thermo-mechanical properties of bio-composites. Storage and loss modulus of vinyl ester bio-composites were investigated in the presence MWCNTs over a range of temperature (25 to 160 oC) to measure the capacity of bio-composite to store and dissipate energy. Damping properties of vinyl ester bio-composites were studied in terms of tan (d). Viscoelastic test using dynamic mechanical analysis (DMA) showed that the glass transition temperature increases with the addition of MWCNTs up to 112.4 oC. Addition of jute fiber reinforcements improves the storage modulus value of vinyl ester more than 65% at room temperature. Significant improvement in storage modulus was found in the presence of MWCNTs.
The Effect of pH on Bioleaching of Deerni Pyrite Roasting Residues as Magnetic Materials
Authors: Cui Xing Lan , Zuo Hao En , Wen Jian Kang
Published: March 2017

The experiment focused on the Deerni pyrite roasting residues mainly made of magnetic materials such as hematite and magnetite in Qinghai Deerni Copper Deposit. The method of bioleaching sulfuric acid residue by bacteria was proposed for roasting residues desulfurization and valuable metal extraction. First of all, the study systematically performed multi-elements analysis, which provided scientific and technique basis for extraction of valuable metals. Subsequently, the effect of the pH value on the bacterial growth was investigated. The data revealed that pH at 1.2 was the optimum culture condition for the bacteria. The concentration of the bacteria at the best culture condition reached 8.5×107 cells/mL. Finally, the bioleaching experiments were performed to explore the ability of the NB bacteria to oxidize the Deerni pyrite roasting residues. The study demonstrated that the microorganism was able to effectively extract valuable metals such as copper and zinc. The total Fe and sulfur contents of the bioleaching residues account for 68.38% and 0.39%, respectively. The desulfurization effects are evident and bioleaching residues meet the requirements as magnetic materials in steel making industry.
Research on Water-Based Drilling Fluid for Super Depth and Ultra-High-Temperature Horizontal Wells in Tarim Basin
Authors: Wang Yue Zhi , Luo Chun Zhi , Wang Yi Di
Published: March 2017

One area of northern Tarim Basin in China is carbonate reservoir, and the reservoir is between 6600 ~ 6900 m. The bottom hole static temperature is close to 170°C, the ECD of pore pressure is 1.1 ~ 1.15 g/cm3. In order to improve the development economic benefit, reservoir need to adopt horizontal well development. Water-based drilling fluid is required to resistant high temperatures and high salt, prevent leakage of limestone reservoir fracture, control the density, protect the reservoir from damage, and has good rheological properties. For old poly-sulfide drilling fluid system, through the indoor evaluation system of various treatment agent and temperature resistance, authors found that by using polymer viscosities, loss of water and temperature resistance of lubricant can reach 140°C. Therefore authors developed the temperature stability agent and high temperature resistant lubricants. This paper introduces the mechanism of the treatment, and evaluates the performance of synthetic products. Aiming at the shortage of the lubricant, authors develop a blister, crosslinking, good environmental protection and maintain water-based lubricant characteristics of resistance to high temperature lubricant. It has good environmental protection ability. Through the evaluation, it has good lubricity and temperature resistance. By introducing the resistance temperature resistance to high temperature drilling fluid system, and after the application in well H9-10H, new drilling fluid system was carried out, well meet the requirements of drilling engineering.
Cylindrical Pin Embossment on A5083 Aluminum Alloy Substrate Fabricated by Friction Stir Forming
Authors: Ohashi Takahiro , Tabatabaei Hamed Mofidi , Nishihara Tadashi
Published: March 2017

This paper reports friction-stir forming (FSF) of cylindrical pin embossments on JIS A5083 aluminum alloy medium gauge plate. A substrate material was put on an emboss die and conducted friction stirring on its back surface. The die has 1mm diameter and 0.5mm deep fine holes at 1.5mm pitch on its top, and the material successfully filled them due to high pressure and heat caused by friction stirring. Three tools having different shoulder diameter were utilized to investigate the deformable area with a single pass. As a consequence, faster spindle speed, slower tool feed rate, and larger tool shoulder contribute to a wider range of completely formed pins. Extrusion of the material to the die cavity seemed to be mostly limited under the area of the shoulder. The ratios of the band width of the complete pins to the shoulder diameter were increased with the larger diameter of the shoulder of the FSF tool. Therefore, a larger shoulder was more effective for wide-range embossing with a single pass. In addition, we evaluated the shape of formed pins with a non-contact 3D measurement system. Accuracy of the height of the completely formed pins was within ±0.013mm, which was comparable with machining.
Use of Deep Cryogenic Treatment to Reduce Particle Contamination Induced Problem in Hard Disk Drive
Authors: Laksanasittiphan Somchai , Tuchinda Karuna , Manonukul Anchalee , Suranuntchai Surasak
Published: March 2017

In this study, the effect of deep cryogenic treatment on the generation of stainless steel particles in screw tightening process in hard disc drive assembly was investigated. During the cryogenic treatment, the specimens of both stainless steel screw and contacting tool (called as “bit”) material were quenched in a chamber containing liquid nitrogen at-196 oC with the soaking times of 33 hr. The specimens were then subjected to sliding wear tests under normal loading conditions. The experiments used for simulating dry sliding wear mechanisms were carried out by TriboGear machine. The machine consists of a stationary bit loaded against the plate containing screw. The screws used were made of martensitic 410 stainless steel and the bit was made of S2 tool steel. The experiments were carried out under both under single and multiple loading cycles under the normal load corresponding to the effective stresses higher and lower than the yield strength of screw material. The results showed that the deep cryogenic treatment led to more homogeneous distribution of fine size carbide particles in both martensitic 410 stainless steel and S2 tool steel. This lead to different failure mechanism of the stainless steel resulting in smaller and slender stainless steel particles generated. This was expected due to the effect of the change in the dimension of carbide, the stress distribution in the material and the crack propagation path.
Thermodynamic Research of S-H2O System in Sodium Aluminate Solution
Authors: Zheng Li Cong , Liu Zhan Wei , Xie Ke Qiang , Ma Wen Hui , Wei Kui Xian
Published: March 2017

There are many different types of valence of sufur in aluminate sodium solution during the process of the bauxite dissolution, which mainly including S2-, S22-, S, S2O32-, SO32-, SO42- and it may have an effect on the mineral dissolution process. Therefore, it is necessary that the thermodynamic properties of S-H2O system were investigated in sodium aluminate solution. In this paper, the reactions between different valence states of sulfur and lye (with or without oxygen participation) were studied in sodium aluminate solution. The thermodynamic software Factsage 7.0 was carried out to calculate the standard reaction Gibbs free energy (ΔGTθ). The results showed that S2- and SO42- are the most stability in terms of the autoreactive reaction of different valence states at 298-573 K, and that the stability of different valence states of sufur order is “S22- >(S2O32-, SO32-) >S”. At 523 K, SO32- is more stable than S2O32-. On the other hand, the low-valent sulfur was more likely to be oxidized into SO42- under oxidizing conditions at 298-573 K. Besides, it was also found that S22- is most susceptible to oxidation because of the lowest stability. Finally, the stability of the other valence states of sulfur under oxidizing conditions order is “SO32- >S2O32- >S2- >S”.
Chips Morphology Analysis under Graphene Oxide Suspension with Tungsten Carbide Tool in Drilling Ti-6Al-4V
Authors: Yi Shuang , Li Guang Xian , Ding Song Lin , Mo John
Published: March 2017

Recently, titanium alloys have been widely used in industry owing to their excellent physical and mechanical properties. However, the severe cutting conditions such as abrasion, adhesion and high temperature accelerate the rate of chip formation and strongly affect the quality of machined surface. This paper investigates that the effect of the conventional coolant (CC) and graphene oxide suspended (GO) on the drilling process of titanium alloy Ti-6Al-4V using tungsten carbide tools. Here are two main chip formation could be found that zigzag chips and spiral chips. Through the analysis of chip morphology, it was found that under graphene oxide suspended fluid. It can be found that using conventional coolant would form the zigzag chips, while it formed spiral chips when graphene oxide suspended fluid applied. In addition, by analysing the chip free surfaces, the chip lamella stuck and chip flaw happened when conventional fluid used. While the back surfaces could be found that less chip stuck and crack occurred when graphene oxide suspended coolant applied. Finally, chip thickness were investigated that thinner chip thickness was found when graphene oxide suspended fluid used.
Flexural Performance Evaluation of Hybrid Concrete Filled Fiber Reinforced Polymer Plastic (FRP) Tube Connection
Authors: Seo Jae Hun , Cheon Jin Uk , Shin Kwang Yeoul , Kim Sun Hee , Yoon Soon Jong
Published: March 2017

In the construction industries, in order to compensate material disadvantages of existing construction material (concrete, steel, wood, etc.) and satisfy requirements of the structural performance, research on durable and outstanding corrosion resistant fiber reinforced polymeric plastic (FRP) is actively underway. In general, a pile cannot be produced with unlimited lengths because of the size of the manufacturing machine and transportation to construction site. Therefore, the connection of pile and structural integrity of connection should be considered in the pile design. In this paper, hybrid FRP-concrete composite pile (HCFFT) was investigated by focusing on the connection of HCFFT members. The connection capacity of HCFFT was evaluated by the experiment and the finite element analysis. From the results appropriate connection method of HCFFT is discussed.
Soil-Cement Ratio and Curing Conditions as the Factors of Soil-Concrete Strength
Authors: Kharun Makhmud , Svintsov Alexander P.
Published: March 2017

Soil-concrete is widely used to strengthen the foundation footings, in the construction of roads and railways, as well as for the production of bricks and pavement tiles. One of the most important physical and mechanical properties of soil-concrete is the compressive strength. We carried out a study of soil-concrete strength depending on its curing conditions and percentage of cement. For our study we used loam soil with the plasticity index of Ip = 12.3, Portland cement of type I, ground limestone with the specific surface of 4500 cm2/g, polycarboxylate based superplasticizer and water for mixing. Curing of samples was carried out in air-humid condition in wet sawdust and also with the thermal humid treatment in a steam chamber. It is experimentally established that the strength of soil-concrete depends not only on the ratio of clay aggregate and mineral binder, but also on the temperature and humidity conditions of curing. Additives of ground limestone and superplasticizer contribute to increase the compressive strength of soil-concrete. A mathematical model for determining the compressive strength of soil-concrete depending on the percentage of cement and the curing period is developed. This proposed mathematical model is advisable to apply for assessment of the compressive strength of soil-cement massive layer after the urgent repair of under-road pipelines.
The Effect of Interface Agent on Bonding Strength between Rock Wool Belt and Adhesive Mortar
Authors: Sun Shi Bing , Du Tao , Chen Bo Ru
Published: March 2017

Rock wool belt is one form of rock wool products used in external thermal insulation composite system. However, a related and important problem is how to improve bonding strength between rock wool belt and adhesive mortar. The present work studies the effect of interface agent on bonding strength. After interface agent was applied on the surface of rock wool belt, the original strength and water-resistance strength increased remarkably with the increasing of the concentration of interface agent, and the maximum value was almost 7 times over that without interface agent. It was believed that the significant increasing of bonding strength was related to fiber structure of rock wool belt, correspondingly, the interface agent could improve effective bonding area and increase the bonding depth. Moreover, it is worth noticing that the drying time of the interface agent had little effect on original strength and water-resistance strength, so it needn't a strict time requirement for rock wool bonding construction after applying interface agent.
Influence of the Nanomaterials of Kaolin Content on the Chloride Permeability of Cement Mortar
Authors: Guo Xiao Yu , Fan Ying Fang , Yang Kun
Published: March 2017

This study investigated the influence of nanokaolin content on the behavior of cement mortar at various curing ages. The fluidity, chloride permeability, bending and compressive strength of cement mortar with various nanokaolin additives were examined. The addition of 0%, 1%, 2%, 3%, 4%, 5% and 6% nanokaolin were taken into consideration. The results showed that the addition of nanokaolin decreases the fluidity of cement mortar, and the fluidity the cement mortar decreases with the increase of nanokaolin additives. It is obtained that the addition of nanokaolin increases both the bending and compressive strength of cement mortar, and with the increase of nanokaolin additives, the bending and compressive strength of cement mortar increase. The addition of 4% nanokaolin can result in a significant low chloride permeability of cement mortar among the seven dosages. The chloride diffusion coefficient of the mortar with the addition of 4% nanokaolin was decreased by 18.93%, 12.68% and 31.05% at 7, 14 and 28 curing days, respectively.
Effect of Span-to-Depth Ratio on the Fracture Energy of Foam Concrete
Authors: Abd Rahman Norashidah , Jaini Zainorizuan Mohd , Muhammed Rum Rahmat Hidayat , Khairuddin Siti Amirah Azra , Zamri Mohd Naqiuddin
Published: March 2017

The use of foam concrete as an alternative material in the construction industry has become popular in structure industries due to the low density range, good strength, high serviceability, and lightness of this material. Several studies have been conducted to determine the mechanical properties and strength of foam concrete. However, research on fracture energy is still ongoing. Therefore, these studies aim to experimentally investigate the effect of span-to-depth (S/W) ratio on the fracture energy of foam concrete using beam specimens with V-notches through a three-point bending test. Beam specimens were encased and prepared at a density of 1600 kg/m3. Moreover, three different S/W ratios (4, 5, and 6) with a notch height of 20 mm were adopted. Fracture energy was determined using the Hillerborg, Bazant, and Comite Euro-International du Beton models. From the experiment, results showed that S/W ratio affected fracture energy.
The Potential of Recycled Locally-Sourced Waste Materials for Green Roof Soil Mixtures
Authors: Kasmin Hartini , Munir Siti Nur Ummiah , Razak Nur Syafira , Yusoff Nor Azizi , Kassim Rosniza , Ahmad Hanim , Sayuti Zulhazmi
Published: March 2017

The increase in surface runoff has become a serious environmental problem and concern in Malaysia. Hence, promoting the use of green roofs in urban areas will potentially allow some storage area and time attenuation for any rainfall. Initial studies on a few substrate mixtures were done in order to find out the properties of green roof media. These included vermiculite (V), perlite (P) and peat moss (PM) together with locally-sourced waste materials such as empty fruit bunches (EFB) and wet diaper gel (D) which are expected to potentially retain more storm water runoff. A test on the substrate mixture properties and evaporation tests were conducted on seven types of soil mixtures. The results show that a basic substrate mixture of PVPM3,5,2 has a maximum water capacity of 50%. The modification and addition of diaper gel in DVPM1,3,2 and empty fruit bunch (EFB) in PEFBPM1,0.3,2 show an increment in both mixtures’ water holding capacity (54%). All the proposed mixtures have shown permeability values larger than 0.0005 cm/s. To investigate the maximum water storage availability, the evaporation tests show that both mixtures could provide 60 - 62 mm of water storage after 34 days without rainfall under ambient climatic condition (32 ̊ to 34 ̊) whereas under extreme heat temperatures (50 ̊), both mixtures took only 1 day to provide the same storage as the ambient condition. Therefore, this study has provided an initial understanding of the properties of the substrate mixture as well as the evaporation rate of the materials tested. This information can be used to demonstrate the relationship between soil characteristics and local climatic factors (temperature).
Performance Test of Swage Anchorage According to the Insert of CFRP Tendon
Authors: Keum Moon Seoung , Kang Jae Yoon , Park Jong Sup , Jung Woo Tai
Published: March 2017

Despite of the numerous advantages offered by the CFRP tendon, there are still problems to be solved. Among them, finding an effective anchoring method considering the material properties of CFRP constitutes a typically pending problem. Being an orthotropic material, the CFRP tendon presents risk of breakage under forces acting perpendicularly to the direction of the fibers. This implies that a new type of anchor should be developed for the CFRP tendon since the anchorages used for conventional steel strands cannot be readily applied. Moreover, following the growing interest given to the CFRP tendon, research is being relentlessly conducted to develop dedicated anchorages with improved performance. Accordingly, this paper presents an experimental study on the anchor performance of the swage anchorage known to be the most compact among the various types of anchor. The tests revealed that the swage anchor without insert developed about 92% of the tensile strength of the CFRP tendon whereas the swage anchor with metallic winding insert developed 100% of the tensile strength. From these results, it appears that the anchorage with outer diameter of 24 mm develops anchor performance higher than 95% of the tensile performance of the CFRP tendon and can potentially be exploited for post-tensioning.