bluuebunny/crossref_metadata_2025 huggingface dataset:
An Android-Based Interactive Museum Exhibit System Using Wireless Sensing and Augmented Reality Technologies
Authors: Lin Cheng Min , Huang Ching Yuan , Yang Dun Yu , Lin Tzu Chi , Chung Chiu Chiao , Lin Jyh Horng
Published: April 2013

In recent years, making use of smart mobile devices to the tour is more important due to these devices are popular and people pay much attention to tourism. The purpose of this work is to integrate technologies, including Android, wireless sensor networks and augmented reality to design an interactive museum exhibit system. The main contributions of this paper are twofold: the integration framework of interactive museum exhibit system is provided and the integration of museum exhibit system and wireless sensor networks. Implementation of this work includes Android, wireless sensor networks and augmented reality to design an interactive museum exhibit system.
Mean Square Asymptotic Stability of Neutral Stochastic Neutral Networks with Multiple Time-Varying Delays
Authors: Shi Xiang Dong
Published: April 2013

The paper considers the problems of almost surely asymptotic stability for neutral stochastic neural networks with multiple time-varying delays. By applying Lyapunov functional method and differential inequality techniques, new sufficient conditions ensuring the existence and almost surely asymptotic stability of neutral stochastic neural networks with multiple time-varying delays are established. The results are shown to be generalizations of some previously published results and are less conservative than existing results.
A Geographic Flooding Scheme for Air-Dropping and Node-Assembling Applications Using MANETs
Authors: Shao Zong Ru , Shao Chao
Published: April 2013

The paper proposes a geographic flooding algorithm, maximum distance broadcasting, for a location sinking system within the local mobile ad hoc network (MANET) during parachutists’ airdropping and on-ground assembling procedure. A time division and geographic routing (TD-GR) protocol for this MANET application is presented. Simulations are conducted to verify the feasibility of maximum distance broadcasting and TD-GR protocol.
Modified Nafion Membranes by Catalytic Materials for Direct Methanol Fuel Cells Applications
Authors: Tian Ai Hua , Shen Dong Hui
Published: April 2013

Sodium dodecyl sulfate/Pt composites and sodium dodecyl sulfate/Pd composites have been synthesized and used to modify the surface of Nafion membrane. Modified Nafion membranes have been characterized by Fourier transform infrared spectroscopy (FTIR). The properties of the modified membranes, in terms of their conductivity and the performance of the membrane electrode assembly (MEA) in the direct methanol fuel cells (DMFCs), have been analyzed and compared with those of the bare Nafion. It is found that the DMFC performance of the membranes modified by two kinds of catalytic materials are better than that of the bare Nafion when operated with 2.0 M methanol. The good conductivity and high cell performance makes the modified Nafion interesting candidates for DMFCs applications.
Effect of Heat Treatment on Microstructure and Corrosion Behavior of Az91d Magnesium Alloy
Authors: Chye Lih.T , Zamzuri M.Z.M. , Norbahiyah S. , Ismail Khairul Azwan , Derman M.N.B. , Illias S.
Published: April 2013

An AZ91D ingot in the as-cast condition was homogenized by heat treatment process. Then, the microstructures produced and corrosion behaviour after heat treatment was studied in detail. As-cast AZ91D was recrystallize by solution treatment at 415°C and then aged at 175°C for various period of time. The corrosion resistance of all the different microstructures was studied in NaCl solution through weight loss measurement in immersion testing. The β phase was found to have a significant influence on the corrosion behaviour. In solution treatment, β phase dissolution decreased the cathode area leading to accelerated corrosion rate. After aging treatment, fine β phase precipitates between grain and microstructure recrystallize causing an increase in the corrosion resistances.
The Effect of Al2O3-SiC and B4 Cadditions on Mechanical Properties of Cusnmatrix Composites for Cutting Tools
Authors: Öksüz Kerim Emre , Bağirov Hanlar , Yilmaz Hasan , Silahşor Buket , Yildirim Vedat
Published: April 2013

Keywords: Boron Carbide; Silisium Carbide; Composite; Powder Metallurgy. Abstract : In this study, effect of boron carbide (B4C), aluminium oxide (Al2O3) and silisium carbide (SiC) addition on microstructure and mechanical properties of diamond cutting segments was investigated. The effects of reinforcement particle additions on characteristic of CuSn matrix composites have been investigated. For this purpose, Al2O3, SiC and B4C addition quantity was added as 2 wt.%. Samples of segments were processed by cold pressing at 550 MPa, followed by sintering at 850°C/30min. Micro-structural aspects were observed by optical microscope. Density, hardness and wear tests were also performed. Wear behaviour and hardness values of segments changed depending on aluminium oxide, silisium carbide and boron carbide addition. The alloy CuSn– 2 wt.%. B4C presented the best results, available for use in cutting tools.
Mechanical Properties of Polypropylene Based Composites Reinforced with B4C
Authors: Dike Ali Sinan , Mindivan Harun
Published: April 2013

The present work aims to compare the mechanical properties of Polypropylene (PP) based composites reinforced with B4C. Maleic Anhydride Modified Polypropylene (MAPP) was added to improve the B4C-matrix interphase. Processing has been carried out by twin-screw extrusion and injection molding. By adding the B4C particles to the PP and PP+MAPP matrix, the yield strength, shore D hardness, microhardness and relative scratch resistance increased gradually, but PP+MAPP/B4C composites showed better overall mechanical properties than the PP/B4C composites. However, elongation at break values occurred for all composites dropped with the B4C content, and PP+MAPP/B4C composites exhibited lower elongations at break than PP/B4C composites.
Dielectric Relaxation of Chitosan Films
Authors: Bobritskaya E.I. , Castro R.A. , Gorokhovatsky Yu.A. , Temnov D.E.
Published: April 2013

Dielectric spectra of pure chitosan films and chitosan films with different fillers were obtained. Two relaxation processes in 200 – 500 K temperature intervals were observed: wide β - peak in the region of 290 K and  - peak in the region of 390 K. The first peak due to the presence of the polymer-bound water and/or acetic acid and disappears when filler injected into the polymer. The second peak may be associated with the activation of the nonohmic conductivity.
One-Pot Catalytic Epoxidation Reaction of Perfluoro-2-methyl-2-pentene with Tri-n-butylamine N-Oxide or N, N-Dimethylcyclohexylamine N-Oxide
Authors: Sha Min , Pan Ren Ming , Jiang Biao
Published: April 2013

Perfluoro epoxy compounds are important intermediates in organic chemistry, however, the methods for preparing them are scanty. We found that in situ generated tri-n-butylamine N-oxide and N,N-Dimethylcyclohexylamine N-oxide were found to be good reagents for the epoxidation of tri-substituted Perfluoro-2-methyl-2-pentene in good to excellent yields. Catalytic epoxidation methods were developed by coupling this reaction with the N-oxidation of tertiary amine by hydrogen peroxide or MCPBA. The advantages of these methods are easy work-up, mild reaction conditions, environmentally friendly and low cost. The reaction using MCPBA as a oxidant is better than hydrogen peroxide for it is fast and high yielding.
Fabrication and Characterisation of Powder Metallurgy Fe-Cr Matrix Composites Reinforced with Al2O3
Authors: Shamsuddin Saidatulakmar , Jamaludin Shamsul Baharin , Hussain Zuhailawati , Ahmad Zainal Arifin
Published: April 2013

Abstract. Sintered powder metallurgy Fe based composites with advanced mechanical properties have been proposed as substitutes for more expensive cemented carbide and wrought alloys in many applications, especially as inexpensive wear resistance parts. The aim of this work was to fabricate and characterize a composite made of Fe-Cr as the matrix and Al2O3 particles as reinforcement. The composite was made by powder metallurgy method. The effect of different amount of binder, mixing duration, compaction pressure and sintering temperature has been investigated. Densification, micro hardness, wear resistance and compressive strength were used to characterize the composite. Powder metallurgy parameters that satisfy the composites quality have been optimized and result showed that higher sintering temperatures promote good sintering in the composites which produced better densification, higher reading of micro hardness, better wear resistance and compressive strength.
Effect of Annealing Treatment on the Wear Properties of Ni Rich NiTi Alloy Coatings
Authors: Abubakar T. , Rahman Mahfujur , Stokes Joseph
Published: April 2013

In the present study, NiTi alloy coatings were deposited onto AISI 316L stainless steel substrates using the Closed Field Unbalanced Magnetron Sputtering (CFUBMS) system. The as-deposited NiTi alloy coating was Ni rich NiTi alloy with a composition of 44.1 at. % of Ti and 55.9 at. % of Ni and demonstrated an amorphous structure. The post-annealing treatment of the as-deposited Ni rich NiTi alloy coating was successfully produced a crystalline structure. The as-deposited and the annealed Ni rich NiTi alloy coatings were characterized to determine the effect of the annealing process on their wear properties. The Ni rich NiTi phases and structure were determined by XRD. Wear morphology was investigated using the pin-on-disk wear test. The existence of a TiO2 rutile layer with a combination of the Ni3Ti and NiTi B2 parent phases, that formed during the annealing process produced a significant improvement over the wear performance compared to the as-deposited Ni rich NiTi SMA coating. The post-sputtered annealing process at the annealing temperatures of 550°C for a period of 60 minutes and 600°C for a period of 30 minutes succeeded in increasing the adhesion and wear resistance of the Ni rich NiTi coating. The findings show the potential the post-sputtering annealing process in creating an excellent structure of NiTi coating which demonstrates significant wear resistance properties for tribological applications.
Interfacial Morphology Studies of Sn-3.8Ag-0.7Cu Alloy on Different Substrates
Authors: Tian Yee Kai , Wong Mee Chu
Published: April 2013

Since the ban of lead containing solders, eutectic SAC solders has been claimed to posses better properties compared to other series of lead free solders. As the technology trend for portable devices change over time, solder joints are continuously miniaturized. The VLSI in modern devices will subject the solder joints to repeated temperature cycling during both assembling and use due to higher I/O. These lead free solders are prone to excessive intermetallic compound (IMC) growth at the interface between the solder and the substrate due to the reasons cited earlier. The most common substrate used in electronic packaging is Cu while Au or its alloys are often used as metallization layer. In this study PCBs coated with both Cu and Au to study the interfacial morphology of Sn-3.8Ag-0.7Cu (SAC387) alloy with these metals. SEM imaging and EDX analysis were used to observe the interfacial layers and to confirm formation of IMCs. IMCs formed between Au-solder are more blocky-like compared to those formed between Cu-solder. Thus further studies must be conducted to resolve this issue as Au is a commonly used metallization materials.
Optimum Powder Loading of Feedstock Based on an Alumina-Zirconia Powder for Ceramic Injection Molding
Authors: Ani Sarizal Md , Muchtar Andanastuti , Muhamad Norhamidi , Ghani Jaharah A.
Published: April 2013

The optimum powder loading of feedstock based on an alumina–zirconia powder was investigated. The optimum powder loading were important to avoid any problems that may arise during the ceramic injection molding (CIM) process. The optimum powder loading is determined based on the critical powder loading and the characterization of the material rheological properties. The critical powder loading was determined using an oil absorption method, and the rheological studies were conducted using a capillary rheometer machine. The results showed that a 57 vol.% powder loading is the most suitable and optimal for the CIM process.
The Structural Properties of Carbon Nanotubes Grown on Porous Silicon-Based Materials by Thermal Chemical Vapor Deposition Method
Authors: Husairi Fadzilah Suhaimi , Zobir S.A.M. , Rusop Mohamad , Abdullah Saifolah
Published: April 2013

In this paper, carbon nanotubes on porous silicon substrate were developed in order to get high quality nanotubes for various kind of application. CNTs were deposited on porous silicon nanostructures (PSiN) at 750 0C on porous silicon by using double-furnace thermal chemical vapor deposition technique. Align carbon nanotubes with diameters of 15 to 30 nm were successfully synthesized on a porous silicon substrate. In this system, carbon nanotubes were grown directly on the p-type porous silicon surface at 750 0C for a total time of 30 minutes. The samples were characterized using field emission scanning electron microscopy and micro-Raman spectroscopy. Align carbon nanotubes (ACNTs) bundle with uniform diameter (~20 nm) were found grown on porous silicon at certain area. Based on micro-Raman spectroscopy result, the peak of silicon at ~520 nm and peak of carbon nanotube (around 1 300 to 1 600 nm) was detected.
Physical Properties of the Amorphous Silica Encapsulated Fluorescence Dye
Authors: Nor Dyana Zakaria , Khairunisak Abdul Razak , Azlan Abdul Aziz
Published: April 2013

Amorphous nanosilica entrapped fluorescence dye intended to be used as tracing agent for imaging of cell or tissue in human cell was prepared using micelle entrapment approach. Micelles were produced by mixing a surfactant in water with additives such as butanol and ammonia in a preheated bioreactor. Then, 1,1%-dioctadecyl-3,3,3%,3% tetramethylindocarbocyanine perchlorate (DiI) dye tracing agent was added into the mixture followed by the addition of silica precursor. The parameters studied including effect of surfactant amount, effect of temperature and amount of Si precursor. Silica encapsulated DiI produced were then characterized using Transmission Electron Microscope (TEM), X-ray diffraction (XRD) and UV-Vis NIR spectrophotometer. Dynamic light scattering (DLS) showed that tunable size of nanoparticles in the range of 30-150 nm can be produced by varying synthesis parameters. The results showed that the silica encapsulated DiI became bigger and uniform in size with the increase of temperature and amount of surfactant. The silica encapsulated with DiI is photostable which the intensity of fluorescence value is 279.12 after 90 minutes exposure to halogen lamp (200W) compared to bare DiI that degraded to 100.61.
Sintering of HA/Zirconia Composite for Biomedical and Dental Applications: A Review
Authors: Lim Kok Fong , Andanastuti Muchtar , Mustaffa Rusnah , Tan Chou Yong
Published: April 2013

Hydroxyapatite is a calcium phosphate product that being widely use in medical application due to its excellence biocompatibility. However its application has being limited due to the inferior mechanical properties, many researcher attempted to improve its mechanical properties. HA-ZrO2 composites have great potential because of their advantages from both constituent materials, such as the excellent biocompatibility of HA and the considerable mechanical strength and toughness of ZrO2. The synergy of the two materials provides a new possibility for developing a composite material with better properties than monolithic ZrO2 and HA. In this work, the stages of development, as well as the different sintering and processing methods of HA and ZrO2 such as conventional sintering, solid-state reaction, microwave sintering and hot isostatic pressing were discussed. It can be concluded that hot isostatic pressing processing yield the most satisfying result amount above method, however the use of nano structured material maybe able to provide alternative processing method and yield better result.
Nanoclay-Supported Zero-Valent Iron as an Efficient Adsorbent Material for Arsenic
Authors: Dela Cruz Michael Leo , Araño Khryslyn , Dela Pena Eden May , Diaz Leslie Joy L.
Published: April 2013

The release of arsenic to aqueous environment imposes threats to human health. Montmorillonite supported zero-valent iron (ZVI-MMT) is a material with capability of immobilizing arsenic from aqueous environment. The arsenic adsorption efficiency of ZVI-MMT was obtained. In addition, adsorption kinetics of arsenic contaminated water on the material was determined. Arsenic and iron content was quantified by an inductively coupled plasma mass spectrometer (ICP-MS), interplanar distance of the adsorbent was measured by x-ray diffractometer (XRD), and the morphology of the adsorbent was obtained from a transmission electron microscope (TEM). Isotherm data were analyzed using the Langmuir and Freundlich isotherms. The data fitted well to Langmuir isotherm with derived adsorption capacity of 20.1 mg/g. Kinetics data were analyzed using intra-particle model, Elovich equation, pseudo first-, and pseudo second-order models. Elovich equation and pseudo second-order equation fitted the experimental data with pseudo second-order rate constant of 61.2 x 10-4 g/mg-min.
Production of Herbal Nanopowders: Effect of Milling Time
Authors: Borhan M.Z. , Norhidayah A. , Ahmad R. , Rusop Mohamad , Abdullah Saifollah
Published: April 2013

Several clinical studies have proved the triterpenes in this herb have therapeutic properties and posses significant to health such as antitumor and wound healing. Centella asiatica nanopowders (CANPs) have been produced via top down approach using Planetary Ball Mill (PBM) at 0.5, 4 and 8 hours of milling in optimized condition. CANPs have been characterized using Photo Correlation Spectroscopy (PCS), Field Emission Scanning Electron Microscope (FESEM) and High Performance Liquid Chromatography (HPLC). As a result significant reduction on size was observed as increased a milling time by comparing their z-Average (nm) and the morphology of CANPs exist in the agglomerated form. The HPLC results showed significant increase in concentration of asiatic acid by comparing the concentration of asiatic acid in extract of CANPs and coarse powders whereby the asiaticoside completely disappeared after milling. Thus, nanoherbal can be said as improving the extraction ratio of asiatic acid compared to the coarse powders due to the smaller particle size and larger surface area and the disappearance of asiaticoside still not completely understood.
Qualitative Analysis of the Effect of Polymer Solution and Suspension Properties on the Electrospinning of Nanocomposite Fibers
Authors: Araño Khryslyn , Dela Cruz Michael Leo , Dela Pena Eden May , Diaz Leslie Joy L.
Published: April 2013

Nanocomposite fibers produced via electrospinning have very large surface area by virtue of their nanometer diameter sizes thereby making them very attractive for various applications such as for adsorption of contaminants from wastewater. In this study, a highly adsorbing nanoparticle, iron-modified montmorillonite was used as filler in the nanocomposite. The effects of polymer solution and suspension properties such as polymer concentration, clay loading, and filler type on the electrospinning of the nanocomposite were investigated using a 2k factorial design of experiment. The types of montmorillonite used were zero valent iron-MMT (ZVIMMT) and iron (III)-MMT (FeMMT). It was found from the SEM images that finer fibers were generated from suspensions with lower polymer concentration in the solution specifically at 5 wt% and from suspensions with ZVIMMT particles as filler. However, a common defect in nanofibers called beads was also observed in the fibers produced from 5 wt% polymer concentration. TEM micrographs confirmed that the ZVIMMT fibers have smaller diameter than the FeMMT fibers. In addition, it was recognized that the layered structure of the clay is still intact after the electrospinning process. The XRD pattern of the fibers revealed that the clay particles were intercalated with the polymer molecules based on the calculated d-spacing. Furthermore, elemental analysis on the bead and string regions of the electrospun fibers confirmed the presence of polymer and montmorillonite particles in both regions.
Experimental Behaviour of Polyvinyl-Alcohol Modified Concrete
Authors: Sclofani Domenico Aurelio Salvatore , Contrafatto Loredana
Published: April 2013

This paper reports the results of experimental tests on Polyvinyl-Alcohol modified concrete. The mechanical properties, such as uniaxial compression strength and elastic modulus, and the influence of a cross-linking agent are investigated. Uniaxial tests under displacement control both monotonic and cyclic are performed to study the ductility properties of the new composite material and the degradation evolution of the secant stiffness. Moreover, SEM observations and EDX spectroscopy analyses are carried out. In some cases a really significant reduction of the compressive strength is observed due to a pronounced air entrapment in the mixture. Nevertheless, the presence of the polymer introduces a considerable improvement in the ductility of the material, drastically reduces the surface cracking, which is prerequisite for increasing the durability and for reducing stiffness damage.
Properties of Polyacrylic Ester Latex Modified Cement Mortar
Authors: Sun Zhen Ping , Ye Dan Mei , Fu Le Feng , Zheng Bo Cun , Feng Zhong Jun , Chen Ming
Published: April 2013

The water reducing performance, retarding effect, air entrainment, flexural and compressive strength of polyacrylic ester (PAE) latex modified cement mortar were investigated with fixed flow values. The research shows that PAE latex has water-reducing performance. The amount of water used in modified cement mortar decreases with increasing dosage of PAE latex. Because of the retarding effect, PAE latex delays the hydration process of cement. PAE latex has a strong effect of air entraining, and the air content of fresh mortar can be controlled by suitable dosage of defoamer. With the same air content of fresh mortar, PAE latex can obviously improve the flexural strength of cement mortar, and has no adverse effect on its compressive strength.
Study on the Load-Deformation Behavior of Modified Cement Concrete
Authors: Flohr Alexander , Dimmig-Osburg Andrea
Published: April 2013

The results of experimental investigations of unreinforced and reinforced modified concrete under monotonically increasing load until fracture, simple short-term load at the limit of capacity and repeated load with continuous loading and release rate should be presented. The modification of the concretes was approached in two ways: the variation of the aggregates and the modification of the binder phase with thermoplastic polymers. Of particular interest were the effects of the modifications on the strength properties and the deformation behavior under short-term load. The observed changes in the hardened concrete properties and the non-linear relation between the elastic and inelastic proportions of deformation indicate that such modifications affect the deformation and fracture behavior of concrete significantly. Therefore they have to be accounted for the analysis of capacity and suitability. In addition to the evaluation of the load-dependent deformation behavior, the established approaches to describe the structural state areas are developed further. Therewith, the transitions between the areas can be determined accurately and the dimension of the areas can be quantified. As a result the changes caused by modifications could be compared more precisely.
The Engineering Properties of Unsaturated Polyester Polymer Concrete Used the Spherical Steel Slag Fine Aggregate
Authors: Kim Jin Man , Kwak Eun Gu , Lee Choul Ho , Lee Seung Kye
Published: April 2013

Polymer concrete has high durability, high abrasion resistance, and high strength, compared to ordinary Portland cement concrete. However, because of high cost of binder, it has not been used in construction field generally. The properties of unsaturated polyester polymer concrete used the steel slag fine aggregate of spherical type as an aggregate for polymer concrete in fresh and hardened state were studied. This research shows that the unsaturated polyester polymer concrete have high workability, high strength and low cost due to decreasing the polymer content, when steel slag fine aggregate of spherical type was used.
Evaluation of Rut Resistance of Polymer-Modified Asphalt Concretes
Authors: Kim Sun Gun , Lee Sung Jin , Lee Soon Jae , Kim Kwang W.
Published: April 2013

The rutting is a significant damage mechanism showing longitudinal furrows along with both wheel paths on asphalt pavement surface. To prevent the rutting under heavy traffic condition, polymer-modified asphalt (PMA) concretes were introduced in asphalt pavement industry. To measure rut resistance of asphalt concretes, the asphalt pavement analyzer (APA) and the deformation strength, SD, were used in this study. The SD was measured by Kim Test, a simple static-loading test, on the 150 mm-diameter cylindrical specimens at 60oC and APA test was performed for the same material. The PMA concretes were found to show improvement in SD and APA rut resistance by more than 50% and 60%, respectively. The SD and APA rut depth showed a relatively high correlation (R2 = 0.81) each other at 60°C. Therefore, it was possible to estimate rut tendency of normal asphalt and polymer-modified asphalt concretes by SD.
Development of Continuous-Type Mixer for Improvement of Workability and Quality of Polymer Cement Mortar
Authors: Bae Kee Sun , Choi Sung Min , Oh Sang Geun
Published: April 2013

This study aimed to develop a section repair system for concrete structures through the application of polymer cement mortar and improvement of the continuous-type mixer.
Jobs, Prosperity, and World Peace through Polymer Concrete
Authors: Gunasekaran Muthian
Published: April 2013

This paper gives an over-view of the many areas in which polymer concrete technology can create opportunities for developing and manufacturing products of immediate and local interest. It is postulated that such opportunities, if grasped and sensibly addressed will create sustainable employment which in turn will lead to prosperity throughout the world and the creation of world peace. An extensive Bibliography is provided to enable the interested reader to access further and more detailed information on the various application areas and also to study the state-of-the-art R&D in these areas involving various types of polymer concrete.
Current research part A
Authors:   Geological Survey of Canada
Published: April 2013

The northeast-striking Kapuskasing structural zone of high-grade metamorphic rocks is not present in the 60 km wide area between Kapuskasing and Fraserdale. Amphibolite-facies orÙwgneiss occurs between the southern Groundhog and the northern
Fraserdale-Moosonee high-grade metamorphic blacks. The River southern block consists of tonalite, mafic gneiss and paragneiss metamorphosed to the granulite and upper amphibolite facies. It is in fault contact with granite to the east and gneiss in the amphibolite facies to the west. To the north,
the Fraserdale-Moosonee Block is made up of anhydrous granulite of psammitic metasedimentary and intermediate igneous composition. A pseudotachylite zone separates the granulites from granitoid rocks and gneiss in major the amphibolite facies to the east; smaller fault zones within the block as well
as between and orthopyroxene-bearing occur metasedimentary gneiss of the Quetico belt to the west. it Within the 120 km long zone of granulites in the Quetico belt, the proportion and grain size of orthopyroxenes and garnet increases toward the east at the expense of biotite, suggesting that
metamorphic grade increases toward the anhydrous granulites of the Fraserdale­M oosonee Block. Although this apparent metamorphic pattern requires further study by geothermobarometry, appears to support the model of a tilted crustal section west of the Kapuskasing it
structure.
Aftercare to chemically addicted adolescents: An exploration of their needs
Authors: Van der  Westhuizen Marichen , Alpaslan Assim H. , De Jager Mariana
Published: April 2013

Treatment of chemical addiction includes preparation for treatment, formal treatment and aftercare. The latter appears to be a neglected area in service delivery to chemically addicted adolescents, contributing to the high relapse potential following treatment. The current qualitative study aimed at both exploring and describing the aftercare needs of chemically addicted adolescents. The chemically addicted adolescents included in this study received in-patient treatment as well as aftercare, but nonetheless experienced a relapse; necessitating further in-patient treatment. Purposive sampling was implemented to recruit 31 participants between the ages of 14 and 20 years. The sample size was determined by data saturation. Data for this exploratory, descriptive and contextual study were collected by means of narrative inquiry. Tesch’s framework for qualitative data analysis was employed and data verification was conducted through Guba’s model. The findings illustrated a need to attend to adolescents intrapersonal and interpersonal as well as environmental needs following treatment. The results can provide service providers with focus areas to be included in aftercare services to these adolescents.Die behandeling van chemiese afhanklikheid sluit die voorbereiding vir behandeling, formele behandeling en nasorg in. Laasgenoemde blyk ‘n afgeskeepte area te wees in die lewering van dienste aan chemies-afhanklike adolessente, wat bydra tot die hoë terugvalpotensiaal wat op die behandeling volg. Hierdie kwalitatiewe studie was daarop gerig om die nasorgbehoeftes van chemies-afhanklike adolessente te verken, sowel as te beskryf. Die chemies-afhanklike adolessente wat by hierdie studie ingesluit was het vantevore beide binnepasiëntbehandeling en nasorg ontvang, maar ten spyte hiervan teruggeval; wat verdere binnepasiëntbehandeling genoodsaak het. Doelbewuste steekproefneming is geïmplementeer om 31 deelnemers tussen die ouderdomme van 14 en 20 jaar te werf. Die steekproefgrootte was deur middel van data versadiging bepaal. Data vir hierdie verkennende, beskrywende en kontektuele studie is versamel deur middel van narratiewe ondersoek. Tesch se raamwerk vir kwalitatiewe data-analise is toegepas en dataverifikasie is uitgevoer aan die hand van Guba se model. Die bevindings illustreer ‘n behoefte om intrapersoonlike en interpersoonlike, asook omgewingsbehoeftes wat op behandeling volg, aan te spreek as deel van nasorg. Die resultate kan diensleweraars van fokusareas voorsien wat ingesluit kan word in nasorgdienste aan hierdie adolessente.
Isotopic (δ13C, Δ14C) analysis of organic acids in marine samples using wet chemical oxidation
Authors: Lang Susan Q. , Früh‐Green Gretchen L. , Bernasconi Stefano M. , Wacker Lukas
Published: April 2013

We present a method for the isolation and off‐line isotope analysis of formate and acetate in marine samples. Organic acids are separated by high performance liquid chromatography and collected in glass Exetainer® screw‐capped vials that have been prespiked with an oxidant and flushed with helium. The vials are subsequently heated to convert the organic compounds to CO2 for radiocarbon and δ13C analysis. Small aliquots are sampled for measurement of δ13C by isotope ratio mass spectrometry, whereas the majority of the CO2 is saved for radiocarbon analysis by accelerator mass spectrometry using a gas ion source. Accurate δ13C and radiocarbon values were obtained for formate and acetate standards spiked into deep seawater and saline Milli‐Q water at concentrations of 25 to 1000 µM C. The process blank associated with the isolation of formate for radiocarbon analysis was ~1.5 µg C and stable over time. Accurate results could be obtained for marine samples with only 25 µM formate. The radiocarbon analysis of acetate showed significantly higher and more variable extraneous carbon contributions, particularly for samples spiked into seawater. Potential improvements that may make the method appropriate for the radiocarbon analysis of acetate in seawater are discussed. The blanks associated with the wet chemical oxidation were assessed independently and found to be small and consistent (<0.3 µg C), potentially making this approach feasible for a broader set of compounds separated by HPLC for radiocarbon analysis.
A competência em informação e o bibliotecário mediador da leitura em Biblioteca Pública
Authors: Cavalcante Lidia Eugenia , Rasteli Alessandro
Published: April 2013

A competência em informação (information literacy) está no núcleo do aprendizado ao longo da vida. Seu conceito veicula-se à necessidade de se exercer o domínio sobre o sempre crescente universo informacional, abrangendo-se em três dimensões: conhecimento, habilidades e atitudes. Como mediadores de leitura, os bibliotecários devem buscar o aprendizado contínuo e a melhoria de suas qualificações e competências, envolvendo-se e colaborando com a crescente demanda evidenciada nos diversos segmentos da sociedade, a exemplo da escola e da biblioteca pública. Na função de agente socializador da informação, o bibliotecário contribuirá no processo de aprendizagem dos indivíduos através das mais diversas formas de leituras e suportes, como também em suas práticas, ajudando o leitor a atingir nível elevado de complexidade no processo de leitura/escrita e na produção de sentidos. Refletir o papel do bibliotecário como agente educacional e a biblioteca pública enquanto equipamento multicultural, pluralista e aprendente, tornam-se a base dessa transformação, demonstrando que a biblioteca pública não é lugar de estoques estanques, mas sim, espaços de possibilidades de transformação, esse, portanto, é do que trata esse estudo.
Resistência à mudança na educação superior: design e operacionalização de um instrumento de medida para o MEES
Authors: Corrêa Angela Cristina , Bortolotti Silvana Ligia Vincenzi , Sousa Júnior Afonso Farias de , Andrade Dalton Francisco de , Moreira Junior Fernando de Jesus , Flores Raquel Dalvit
Published: April 2013

A autonomia científica e tecnológica de um país pressupõe que o mesmo tenha uma educação de qualidade. O objetivo deste artigo é apresentar um instrumento de medida de avaliação da resistência à mudança na administração da educação superior. Propõe-se um desenho e operacionalização para o projeto Mapa Estratégico da Educação Superior (MEES) fundamentado em um sistema de gestão integrado. O MEES se constitui em uma proposta metodológica para a operacionalização do Plano de Desenvolvimento Institucional (PDI) em Instituições de Ensino Superior (IES). O instrumento de medida  de avaliação da resistência à mudança na administração da educação superior (RAMES) se fundamenta na seguinte base conceitual: teoria de resposta ao ítem (TRI),  teoria psicometrica e no estudo sobre gestão da mudança. A RAMES compõe-se de cinco etapas: 1. elaboração do instrumento de coleta de dados; 2. definição do tamanho amostra representativa da comunidade acadêmica das IES; 3. coleta de dados – conjunto de itens; 4. estimação dos parâmetros dos itens; 5. definição da escala de medida A RAMES tem como expectativa de resultados contribuir para  a eficácia na implementação do MEES. Visa também identificar os principais indicadores de resistência a mudança na administração da educação superior.
The mathematical principles and design of the NAIS – a spectrometer for the measurement of cluster ion and nanometer aerosol size distributions
Authors: Mirme S. , Mirme A.
Published: April 2013

Abstract. The paper describes the Neutral cluster and Air Ion Spectrometer (NAIS) – a multichannel aerosol instrument capable of measuring the distribution of ions (charged particles and cluster ions) of both polarities in the electric mobility range from 3.2 to 0.0013 cm2 V−1 s−1 and the distribution of aerosol particles in the size range from 2.0 to 40 nm. We introduce the principles of design, data processing and spectrum deconvolution of the instrument.
Seasonal and spatial comparisons of phytoplankton growth and mortality rates due to microzooplankton grazing in the northern South China Sea
Authors: Chen B. , Zheng L. , Huang B. , Song S. , Liu H.
Published: April 2013

Abstract. We conducted a comprehensive investigation on the microzooplankton herbivory effect on phytoplankton in the northern South China Sea (SCS) using the seawater dilution technique at surface and deep chlorophyll maximum (DCM) layers on two cruises (July–August of 2009 and January of 2010). We compared vertical (surface vs. DCM), spatial (onshore vs. offshore), and seasonal (summer vs. winter) differences of phytoplankton growth (μ0) and microzooplankton grazing rates (m). During summer, both μ0 and m were significantly higher at the surface than at the DCM layer, which was below the mixed layer. During winter, surface μ0 was significantly higher than at the DCM, while m was not significantly different between the two layers, both of which were within the mixed layer. Surface μ0 was, on average, significantly higher in summer than in winter, while average surface m was not different between the two seasons. There were no cross-shelf gradients of μ0 in summer or winter surface waters. In surface waters, μ0 was not correlated with ambient nitrate concentrations, and the effect of nutrient enrichment on phytoplankton growth was not pronounced. There was a decreasing trend of m from shelf to basin surface waters in summer, but not in winter. Microzooplankton grazing effect on phytoplankton (m/μ0) was relatively small in the summer basin waters, indicating a decoupling of microzooplankton grazing and phytoplankton growth at this time. On average, microzooplankton grazed 73% and 65% of the daily primary production in summer and winter, respectively.
Water column distribution and carbon isotopic signal of cholesterol, brassicasterol and particulate organic carbon in the Atlantic sector of the Southern Ocean
Authors: Cavagna A.-J. , Dehairs F. , Bouillon S. , Woule-Ebongué V. , Planchon F. , Delille B. , Bouloubassi I.
Published: April 2013

Abstract. The combination of concentrations and δ13C signatures of Particulate Organic Carbon (POC) and sterols provides a powerful approach to study ecological and environmental changes in both the modern and ancient ocean. We applied this tool to study the biogeochemical changes in the modern ocean water column during the BONUS-GoodHope survey (February–March 2008) from Cape Basin to the northern part of the Weddell Gyre. Cholesterol and brassicasterol were chosen as ideal biomarkers of the heterotrophic and autotrophic carbon pools, respectively, because of their ubiquitous and relatively refractory nature. We document depth distributions of concentrations (relative to bulk POC) and δ13C signatures of cholesterol and brassicasterol combined with CO2 aq. surface concentration variation. While the relationship between CO2 aq. and δ13C of bulk POC and biomarkers have been reported by others for the surface water, our data show that this persists in mesopelagic and deep waters, suggesting that δ13C signatures of certain biomarkers in the water column could be applied as proxies for surface water CO2 aq. We observed a general increase in sterol δ13C signatures with depth, which is likely related to a combination of particle size effects, selective feeding on larger cells by zooplankton, and growth rate related effects. Our data suggest a key role of zooplankton fecal aggregates in carbon export for this part of the Southern Ocean (SO). Additionally, in the southern part of the transect south of the Polar Front (PF), the release of sea-ice algae during the ice demise in the Seasonal Ice Zone (SIZ) is hypothesized to influence the isotopic signature of sterols in the open ocean. Overall, the combined use of δ13C values and concentrations measurements of both bulk organic C and specific sterols throughout the water column offers the promising potential to explore the recent history of plankton and the fate of organic matter in the SO.
McMaster Mesonet soil moisture dataset: description and spatio-temporal variability analysis
Authors: Kornelsen K. C. , Coulibaly P.
Published: April 2013

Abstract. This paper introduces and describes the hourly, high-resolution soil moisture dataset continuously recorded by the McMaster Mesonet located in the Hamilton-Halton Watershed in Southern Ontario, Canada. The McMaster Mesonet consists of a network of time domain reflectometer (TDR) probes collecting hourly soil moisture data at six depths between 10 cm and 100 cm at nine locations per site, spread across four sites in the 1250 km2 watershed. The sites for the soil moisture arrays are designed to further improve understanding of soil moisture dynamics in a seasonal climate and to capture soil moisture transitions in areas that have different topography, soil and land cover. The McMaster Mesonet soil moisture constitutes a unique database in Canada because of its high spatio-temporal resolution. In order to provide some insight into the dominant processes at the McMaster Mesonet sites, a spatio-temporal and temporal stability analysis were conducted to identify spatio-temporal patterns in the data and to suggest some physical interpretation of soil moisture variability. It was found that the seasonal climate of the Great Lakes Basin causes a transition in soil moisture patterns at seasonal timescales. During winter and early spring months, and at the meadow sites, soil moisture distribution is governed by topographic redistribution, whereas following efflorescence in the spring and summer, soil moisture spatial distribution at the forested site was also controlled by vegetation canopy. Analysis of short-term temporal stability revealed that the relative difference between sites was maintained unless there was significant rainfall (> 20 mm) or wet conditions a priori. Following a disturbance in the spatial soil moisture distribution due to wetting, the relative soil moisture pattern re-emerged in 18 to 24 h. Access to the McMaster Mesonet data can be provided by visiting www.hydrology.mcmaster.ca/mesonet.
Estimation of surface energy fluxes under complex terrain of Mt. Qomolangma over the Tibetan Plateau
Authors: Chen X. , Su Z. , Ma Y. , Yang K. , Wang B.
Published: April 2013

Abstract. Surface solar radiation is an important parameter in surface energy balance models and in estimation of evapotranspiration. This study developed a DEM based radiation model to estimate instantaneous clear sky solar radiation for surface energy balance system to obtain accurate energy absorbed by the mountain surface. Efforts to improve spatial accuracy of satellite based surface energy budget in mountainous regions were made in this work. Based on eight scenes of Landsat TM/ETM+ (Thematic Mapper/Enhanced Thematic Mapper+) data and observations around the Qomolangma region of the Tibetan Plateau, the topographical enhanced surface energy balance system (TESEBS) was tested for deriving net radiation, ground heat flux, sensible heat flux and latent heat flux distributions over the heterogeneous land surface. The land surface energy fluxes over the study area showed a wide range in accordance with the surface features and their thermodynamic states. The model was validated by observations at QOMS/CAS site in the research area with a reasonable accuracy. The mean bias of net radiation, sensible heat flux, ground heat flux and latent heat flux is lower than 23.6 W m−2. The surface solar radiation estimated by the DEM based radiation model developed by this study has a mean bias as low as −9.6 W m−2. TESEBS has a decreased mean bias of about 5.9 W m−2 and 3.4 W m−2 for sensible heat and latent heat flux, respectively, compared to the Surface Energy Balance System (SEBS).
Spectral induced polarization measurements for environmental purposes and predicting the hydraulic conductivity in sandy aquifers
Authors: Attwa M. , Günther T.
Published: April 2013

Abstract. Low-frequency field and laboratory induced polarization measurements are carried out to characterize the hydrogeological conditions at Schillerslage test site in Germany. The laboratory spectral induced polarization (SIP) data are analyzed to derive an empirical relationship for predicting the hydraulic conductivity (K) in the field scale. On the other hand, the results from SIP sounding and profiling field data indicate that the method identifies the lithological layers with sufficient resolution to achieve our objectives. Two main Quaternary groundwater aquifers separated by a till layer can be well differentiated. Furthermore, the phase images are also capable of monitoring thin peat layers within the sandy groundwater aquifer. However, the field results show limitations of decreasing resolution with depth and/or low data coverage. Similarly, the SIP laboratory results show a certain shift in SIP response due to different compaction and sorting of the samples. The overall results obtained show that the integration of field and laboratory SIP measurements is an efficient tool to avoid a hydrogeological misinterpretation. In particular, two significant but weak correlations between individual real resistivities (ρ') and relaxation times (τ), based on a Debye decomposition (DD) model, with measured K are found for the upper groundwater aquifer. While the maximum relaxation time (τmax) and logarithmically weighted average relaxation time (τlw) show a better relation with K values than the median value τ50, however, the single relationships are weak. A combined power law relation between individual ρ' and/or τ with K is developed with an expression of A · (ρ')B · (τlw)C, where A, B and C are determined using a least-squares fit between the measured and predicted K. The suggested approach with the calculated coefficients of the first aquifer is applied for the second one. The results indicate a good correlation with the measured K and prove to be superior to single phase angle models as the Börner or Slater models.
Regional GRACE-based estimates of water mass variations over Australia: validation and interpretation
Authors: Seoane L. , Ramillien G. , Frappart F. , Leblanc M.
Published: April 2013

Abstract. Time series of regional 2°-by-2° GRACE solutions have been computed from 2003 to 2011 with a 10 day resolution by using an energy integral method over Australia [112° E 156° E; 44° S 10° S]. This approach uses the dynamical orbit analysis of GRACE Level 1 measurements, and specially accurate along-track K Band Range Rate (KBRR) residuals (1 μm s−1 level of error) to estimate the total water mass over continental regions. The advantages of regional solutions are a significant reduction of GRACE aliasing errors (i.e. north–south stripes) providing a more accurate estimation of water mass balance for hydrological applications. In this paper, the validation of these regional solutions over Australia is presented as well as their ability to describe water mass change as a reponse of climate forcings such as El Niño. Principal component analysis of GRACE-derived total water storage maps show spatial and temporal patterns that are consistent with independent datasets (e.g. rainfall, climate index and in-situ observations). Regional TWS show higher spatial correlations with in-situ water table measurements over Murray–Darling drainage basin (80–90%), and they offer a better localization of hydrological structures than classical GRACE global solutions (i.e. Level 2 GRGS products and 400 km ICA solutions as a linear combination of GFZ, CSR and JPL GRACE solutions).