bluuebunny/crossref_metadata_2025 huggingface dataset:
THF Removal from Polluted Air in Aerobic Biotrickling Filter Inoculated with Microbactrium oxydans DDH-1
Authors: Shen Dong Shen , Huang Huan Lin , Wang Mei Zhen , Zhou Yu Yang
Published: August 2014

The performance of biotrickling filter (BTF) inoculated Microbactriumoxydans DDH-1 removing tetrahydrofuran (THF) was investigated. The biotrickling filter exhibited good performance with short start-up of 3 days and easily recovery from the fluctuations. During stable THF loading at concentrations of 520 mg·m-3 or lower and EBRT of 31, 24 and 18 s, the reactor exhibited high removal efficiencies up to 99%. The mass ratio of carbon dioxide produced to the THF removed was 2.01, which confirmed complete degradation of THF.
The Effect of the Winding Materials on the Compression and Bending Properties of GFRP Bars
Authors: Liu Hai Shuang , Zhao Ke , Liu Ze
Published: August 2014

Several kinds of Glass Fiber Reinforced Polymer (GFRP) bars with different winding materials were manufactured through modifying the production process. Based on the experiments, compression and bending properties were tested. Through the observation of experiment phenomenon and the analysis of test date, the influence and mechanism from different winding materials are discussed. The test results that winding materials affect the compressive strength and bending strength of GFRP bars to a certain extent.
Study on Piezoelectric Effect and Magnetic Properties of Tourmalines
Authors: Zhang Xiao Hui , Ma Hong Wen
Published: August 2014

The piezoelectric effect was determined and the magnetization testing of diverse tourmalines was carried out in this paper. The results show that static voltage on both ends of tourmaline crystal enhances gradually with pressure enhancing, but there is no linear function between each other. At the very time when crystal breaks, the static voltage can reach a maximum value. The direction of the static voltage is reverse when giving and losing pressure. The performances of piezoelectric strength are as follows: Elbaite>Schorl>Dravite. The piezoelectricity on both ends of tourmaline crystal is stronger than that on cylinder surface, which is 3 ~ 4 times of the cylindrical surface. The piezoelectric strength of tourmaline crystal has nothing to do with its crystal volume but has something to do with the crystal surface streak. The performance is that the more limpid of the crystal surface streak is, the more obvious of the piezoelectric effect is. The overall tourmaline magnetization is weak. Magnetic susceptibility is a linear function of the refractive index and Fe-contents. Magnetic susceptibility of Schorl is greater than that of Elbaite. Saturation magnetization and remanence magnetic of Schorl are greater perpendicular to than parallel to C axis.
Seafloor Polymetallic Sulfides Mechanical Property Test
Authors: Huang Zhong Hua , Liu Shao Jun , Xu Ying Guang , Hu Wang
Published: August 2014

Seafloor polymetallic sulfide specimens were developed according to engineering rock test method standard (GB/T 50266-2013). Seafloor polymetallic sulfide wet density and dry density were tested. Uniaxial compressive strength and triaxial compression strength of seafloor polymetallic sulfide were tested using rock mechanics test system MTS 815. Elasticity modulus and Poisson's ratio of seafloor polymetallic sulfide were calculated based on specimens stress-strain curves. Cohesion and internal friction angle were calculated based on specimens triaxial test Mohr stress circle. Test results show that seafloor polymetallic sulfide dry density average value is 2.6 g/cm3, wet density average value is 2.94 g/cm3. Uniaxial compressive strength and triaxial compression strength of seafloor polymetallic sulfide are unstable. Average value of the uniaxial compressive strength is 10.243MPa. Average value of triaxial compression strength test peak load is 47.166KN. Cohesion is 2.447MPa and internal friction angle is 38.04o.
Facile Biomimetic Fabrication of Hollow Hydroxyapatite with Hierarchically Porous Microstructure Using Hyperbranched Gemini Surfactant as Template
Authors: Li Shan , Wu Hua Hong , Xu Guo Jie , Xiao Xiu Feng
Published: August 2014

We successfully developed a facile synthetic way to 3D hollow HAp microspheres. We used Ca (NO3)2and (NH4)3PO4as materials, hyperbranched Gemini surfactant (PCD) as template.We used some techniques to characterize the products,such as X-ray powder diffraction (XRD), Fourier transform infrared spectroscope (FT-IR), Scanning electron microscopy (SEM) and Thermal gravimetric analysis (TG).The effects of the Gemini surfactant concentration on the morphology and crystal degree of the samples were analyzed.We proposed a possible growth of mechanism.The product morphology could vary from rod to hollow sphere by adjusting the template concentration.When the template concentration was low,ball-like hydroxyapatite preliminary formed.With increasing the template concentration,the crystal degree of products declined. While the spherical cluster composed of numbers of flake or needle architectures were appeared. The results show that when the mass fraction of template is 0.01%,we can product uniform well-defined hollow spherical hydroxyapatite with semidiameter about 1.5μm.
Synthesis of Graft Copolymer of Starch-Acrylamid-Propylene Hydroxamic Acid and Capability of Trapping Pb2+
Authors: Song Chang You , Wu Ai Bing
Published: August 2014

In this paper, graft copolymer of starch-acrylamid-propylene hydroxamic acid was synthesized by inverse emulsion polymerization. Effects of the dosage of the graft copolymer, pH value and reaction time on the capability of trapping heavy metal ion Pb2+ were investigated. The results showed that the optimum conditions for treating lead-containing wastewater were: pH=7-9, reaction time≧30min , the dosage of polymeric ferric sulfate and graft copolymer in wastewater were 10mg·L-1 and 250-300mg·L-1, respectively. The Pb2+ removal rate is not less than 99.8% and meanwhile the copolymer possess good removal performance of turbidity.
Phase Equilibria of the Aqueous Lithium-Containing Carbonate Systems
Authors: Zhao Mei Ling , Han Xu Nian , Li Fei , Guo Ya Fei , Wang Shi Qiang
Published: August 2014

It is well known that the phase diagram plays an important role in exploitation and utilization of salt lake resources. To effectively employ the systems containing lithium and carbonate, the study on phase equilibrium is essential to the comprehensive utilization of the salt lake resources. In this paper, progresses on phase equilibria of salt-water systems containing lithium and carbonate were presented.
The Ammonia Leaching Method of Recycling the Spent Copper-Chromium Oxide Catalysts
Authors: Li Zeng Xin , Kuang Tang Bin , Zhou Xu Yi , Liang Qiang , Liu Sheng Peng
Published: August 2014

The spent copper chromium oxide catalyst of furfural hydrogenation was recycled.by ammonia leaching method. This method not only has the characteristics of simple process, low cost, quick effect, but also avoids the use of various oxidants increasing the security of the experimental operation and the generation of carcinogen hexavalent chromium.The experimental results show that the optimum process conditions of ammonia leaching is: the concentration of ammonia 15mol / L, the leaching temperature is at 180 °C, leaching time for 4h, the optimal dosage of (NH4)2SO40.6g/10g. The copper leaching rate can reach more than 80% of the maximum.
The Influence of Materials Properties on the LSPR Strength of Nanoshell Particles
Authors: Zhang Xing Fang , Yan Xin , Liu Feng Shou , Lv Yi Ying
Published: August 2014

The influence of the optical properties of the core and shell materials on the LSPR strength for nanoshell particles are calculated based on the quasi-static functions. The results show that for particles with the metallic shell and gained core, the desired real and imaginary parts of dielectric function are positive and negative respectively, and both the absolute values increase as the volume fraction of shell material increases while the LSPR strength is strongest. For particles with metallic material core and gained material shell, in order to produce the maximum LSPR strength, gain medium can have two kinds of choices, one is that the real part of the dielectric function is positive and the imaginary part is negative and both the absolute values are relatively large, the other is the real part and imaginary part of gained dielectric function are negative and their absolute values are relatively small, which small change may lead to mobile resonance wavelength greatly.
Study on Preparation of RGB Tricolor Up-Conversion Fluorescent Powder
Authors: Niu Chun Hui , Lv Yong , Li Xiao Ying , Chen Qing Shan
Published: August 2014

For producing RGB tricolor luminescence, three kinds of components of rare-earth ions is chosen, which are Er3+doping, Er3+-Yb3+co-doping and Tm3+-Yb3+co-doping, respectively. Three kinds of rare-earth doped up-conversion fluoride material are prepared based on high temperature solid-state method. Under being excited by 980nm laser, three materials emit red, green and blue light, whose peak wavelengths are 660nm, 550nm and 480nm, respectively. Through analysis of luminescence process, it can be concluded that red and green luminescence are belong to two-photon absorption transversion, and blue luminescence is three-photon absorption transversion.
Isotope Analysis on the Recharge Source of the Leakage Water behind the Right Dam of Suzhi Hydroelectric Station
Authors: Ba Jin Fu , Zhan Lu Cheng , Zhang Bo
Published: August 2014

In order to find out the recharge source of the leakage water that appears behind the right dam of Suzhi hydroelectric station located in Qinghai province of China, water samples of the leakage water, groundwater in the seepage observation wells, reservoir water and local precipitation are taken for isotopic composition analysis. Stable isotopes of the leakage water behind the dam have significant differences with local precipitation, indicating that the leakage water should not be recharged by precipitation. Isotopes of water in the seepage observation wells and reservoir water scatter around the same evaporation line, which implies that well water comes from reservoir water recharge. Leakage water behind the dam probably originates from the leakage of reservoir water as the stable isotopes of leakage water approximate those of well water and reservoir water.
The Analysis of Nano SiO2 Impacting on the Frost Resistance of EPS Lightweight Concrete
Authors: Cui Jian
Published: August 2014

Styrofoam (EPS) lightweight concrete, a new type of lightweight aggregate concrete, whose superior thermal performance and remarkable economic benefit earns more and more attention from the engineering. Adding nanoSiO2into it can improve the frost resistance of EPS lightweight concrete, so that it can improve the microstructure and mechanical properties of concrete. The research on the nanomaterials has the vital significance to the frost resistance of EPS lightweight concrete. The wide application of this technology will greatly promote the development of construction industry, and has very important engineering practical value and social economic benefits.
Synthesis and Optimization of Trimethylolpropane Rapeseed Oil Ester
Authors: Wang Ying , Zhou Cun , Zheng Guo , Sun Yu
Published: August 2014

Lubricant base oil is an environmentally friendly lubricant with good lubricity and biodegradability. The thermostability and stability of rapeseed oil get improved through chemical modification. Fatty acid methyl ester (FAME),prepared by rapeseed oil as starting material with methanol by transesterification,the composition of FAME was detected by gas chromatograph-mass spectrometer (GC-MS).Trimethylolpropane (TMP) esters of fatty acids were synthesized by transesterifying FAME with TMP using zinc oxide as catalyst. The structures of products were characterized by mean of FTIR. The reaction conditions were studied and optimized, the optimum conditions were as follows: the temperature at 140°C~150°C, the reactant mass ratio of 1:9, the reaction time for 6 h, the mass content of catalyst of 0.5%.The thermal stability of product was conducted by thermogravimetry (TG) .It could be concluded that TMP esters of fatty acids possess better thermal stability.
Preparation and Characterization of the Rejuvenator Seal Materials with Fluid Catalytic Cracking Flurry
Authors: Zhang Hua , Shi Zhan Bin
Published: August 2014

Fluid catalytic cracking (FCC) slurry has a high content of aromatics. This research use three methods to prepare rejuvenator seal materials with FCC slurry and study their performance. The results showed that rejuvenator seal materials can improve the fatigue and low-temperature cracking resistance of the pavement. In addition, material 2# exhibit better performance as it has more aromatic content.
Intestinal Absorption, Pharmacokinetics and Tissue Distribution of Gossypol Nanosuspensions
Authors: Yang Si Tao , Ying Xue , Tang Hui , Wang Jian Chen , Wu Bing Bing
Published: August 2014

Gossypol (GP) is a kind of poorly water-soluble polyphenolic compounds. In this study, gossypol nanosuspensions (GP-NS) were prepared. The ability of intestinal absorption was evaluated. The result indicated that GP-NS could be absorbed in whole intestinal sections and permeated across the intestine, the process of gossypol nanosuspensions were not affected by P-gp efflux.The pharmacokinetics and tissue distribution of GP-NS after intravenous administration to mice was studied. GP-NS resulted in a higher plasma concentration and lower clearance.The tissue distribution study indicated that GP-NS showed a high uptake in reticuloendothelial system organs. In conclusion, the nanosuspensions system is a promising approach for gossypol.
Influence of Loading Conditions during Tensile Testing on Acoustic Emission
Authors: Chuluunbat Turbadrakh , Lu Cheng , Kostryzhev Andrii , Tieu Kiet
Published: August 2014

The Acoustic Emission (AE) monitoring technique is widely used in mechanical and material research for detection of plastic deformation, fracture initiation and crack growth. However, the influence of AE features (such as signal amplitude, frequency, rise time and duration) on the fracture parameters (such as brittle or ductile mode of propagation and fracture propagation speed) is not completely understood. In this paper, the effect of loading conditions on fracture behavior was studied using AE monitoring during tensile testing of an aluminum alloy specimen. The fracture development was observed using a high speed video camera and was analyzed using the finite element method. The hardware and software produced by Physical Acoustics Corporation (USA) was used. Variations in AE parameters were analyzed and correlated to the stress-strain curves obtained during testing. It is shown that the strain rate and the presence of a crack (modeled by a notch on the sample), affect the fracture mode (brittle or ductile) and a relative amount of the mode dependent AE signatures.
Key Performance Indicators of Tubes Used as Energy Absorbers
Authors: Yu T.X. , Xiang Yan Fei , Wang Min , Yang Li Ming
Published: August 2014

Based on our extensive studies on the experimental, theoretical and numerical results on various tubes under axial compression/impact in the last few years, we propose a set of Key Performance Indicators (KPIs) to assess and compare the energy absorbing performance of tubular structures with various configurations, so as to guide the design of energy absorbers whilst to archive a certain degree of optimization. The KPIs have five factors: Effective stroke ratio (ESR), Non-dimensional Load-carrying capacity (NLC), Effectiveness of energy absorption (EEA), Specific energy absorption capacity (SEA), Stableness of load-carrying capacity (SLC).The paper presents a series of diagrams to compare the energy absorbing performance of various tubes in terms of the four KPIs as described above. The work is valuable to engineering designs and applications, as well as to the further studies of the topic.
Effect of Plastic Anisotropy on the Strain Rate Intensity Factor: A Simple Analytic Solution
Authors: Alexandrov Sergei , Lyamina Elena , Tuan Hguyen Minh , Kalenova Natalia
Published: August 2014

Solutions for many rigid/plastic models are singular in the vicinity of maximum friction surfaces. In particular, the magnitude of the equivalent strain rate near such surfaces is controlled by the strain rate intensity factor. This factor is the coefficient of the leading singular term is a series expansion of the equivalent strain rate in the vicinity of maximum friction surfaces. Since the equivalent strain rate has a great effect of material properties, it is of important to reveal the dependence of the strain rate intensity factor on parameters characterizing material models. In the present paper, quite a general model of anisotropic plasticity under plane strain conditions is adopted. Then, using an analytic solution for instantaneous compression of a layer of plastic material between two parallel plates the effect of the shape of the yield locus on the asymptotic behavior of the equivalent strain rate in the vicinity of the friction surface is demonstrated.
Study for Sheared Edge Quality of High Strength Steel Sheet
Authors: Han Soo Sik
Published: August 2014

The empirical approach was adopted to investigate the process parameters that effect on the quality of high strength steel sheet sheared edge. As a result of study, the quality of sheared edge that can be represented as the ratio of the shiny burnished surface to the sheared surface was not under influence of die clearance, lubrication and cutting line direction but under influence of the material strength and the usage of lower pad. The roll-over and burr height is highly affected by the die clearance and the usage of lower pad. The lower pad underneath of blank is of help to reduce the amount of roll-over and burr even at large die clearance.
Dynamic Behaviors of Aluminium Foam Analyzed Using Digital Image Processing Technology
Authors: Hu Ling Ling , Xiong Li Wen , Yu T.X.
Published: August 2014

A numerical model of the aluminium foam with voronoi cells is built and uni-directionally crushed with various velocities from 1m/s to 110m/s. It is shown that the foam deforms homogeneously within the whole specimen and the stress in the foam increases gradually with the strain without an obvious plateau stage under the low-velocity compression, while the deformation is concentrated within a zone near the impact end and an obvious plateau stage can be found in the stress-strain curves of the foams under the high-velocity crushing. By analyzing the distribution of the density within the foams using the digital image processing technology, the densification strain of the foams under dynamic crushing can be determined. Then combining the foam’s stress-strain curve under the low-velocity compression, the dynamic plateau stress of the foams can be predicted. It is shown that both the densification strain and the plateau stress of the foams under the high-velocity crushing predicted by employing the digital image process technology are in good agreement with the numerical simulations. The results show that both the plateau stress and the densification strain of the foams increase with the impact velocity, which is essentially caused by the localization of the foam’s deformation under dynamic crushing.
Effect of Texture on Plastic Flow Localization of FCC Polycrystals Using Homogenization-Based Polycrystalline Plasticity
Authors: Tadano Yuichi , Kuwashiro Naoki , Hagihara Seiya
Published: August 2014

In this study, a framework to predict the onset of plastic flow localization is introduced. The Marciniak-Kuczyński type approach, which is a classical method to predict the strain localization, and a crystal plasticity model with a homogenization-based finite element method are combined, and forming limit strains that are defined as the onset of plastic flow localization for FCC polycrystals are computed. The forming limit strains with several kinds of textures are evaluated with the present approach, and the results are compared with those obtained by the Taylor model, which is a widely used conventional polycrystalline model. Within the present application, the present method and the classical Taylor model give similar forming limit strains for FCC polycrystal sheets. According to the present results, the use of the Taylor model in the sheet necking analysis might be justified, at least for FCC polycrystal sheets with various textures.
An Experimental Study of Square Aluminium Tubes with Honeycomb Core Subjected to Quasi-Static Compressive Loads
Authors: Hussein Rafea Dakhil , Ruan Dong , Yoon Jeong Whan
Published: August 2014

Thin-walled honeycombs have been extensively investigated and they are often used as sandwich panels to enhance the energy absorption in many applications including vehicles. In this study, axial compressive tests at three different velocities (3, 30 and 300 mm/min, respectively) by using an MTS machine were conducted with both empty and hybrid aluminium tubes filled with aluminium honeycomb. The aim of this work is to study the contribution of aluminium honeycomb in square hybrid tubes in terms of the deformation mode and energy absorption. Square aluminium tubes made of AA 6060-T5 with two different side lengths, 40 and 50 mm, were used. Two types of honeycombs made of AA 5052 with different cell wall thicknesses were used in this study. The force and displacement of the tubes were recorded during the test. The specific energy absorption (SEA) of honeycomb-filled tubes was compared with the sum of the SEA of an empty tube and honeycomb. It was noticed that the SEA of the hybrid tubes depended on the honeycomb density and the loading velocity within the velocity range studied.
Synthesis and Characterization of Layered-Double Hydroxide 3-(4-Hydroxyphenyl) Propionate Nanocomposite
Authors: Siti Nurasikin Ahmad , Norhayati Hashim , Yusri Nur Hidayah , Md Isa Illyas , Kamari Azlan , Mohamed Azmi , Mohd Damanhuri Muhammad Ibrahim
Published: August 2014

A new layered-double hydroxide-3-(4-hydroxyphenyl) propionate (LDH-HPP) has been synthesized by intercalation of 3-(4-hydroxyphenyl) propionic acid (HPP) into Zn-Al-layered double hydroxide (LDH) by ion-exchange method. PXRD, FTIR, TGA/DTG, compositional studies and FESEM were used to characterize the synthesized nanocomposite. The intercalation of HPP into the interlayer gallery space of LDH was characterized by x-ray diffractogram showed expanded basal spacing of the value of 17.1 Å. The FTIR spectra of LDH-HPP nanocomposite synthesis by 0.025M HPP resembled a mixture of both FTIR spectra of HPP and LDH. Thermal analysis of LDH-HPP nanocomposite shows a better thermal stability as compared to the pure HPP, which proved that the intercalation of HPP into LDH interlayer enhanced the thermal stability of the HPP.
Bio-Reductive Synthesis and Characterization of Plant Protein Coated Magnetite Nanoparticles
Authors: Kumar Das Amlan , Marwal Avinash , Verma Ruchi
Published: August 2014

Over the past two decades, there have been increased emphases on the topic of green chemistry and chemical processes. Utilization of non toxic chemicals, environmentally benign solvents, and renewable materials are some of the key issues that merit important consideration in a green synthetic strategy. The Datura Inoxia leaves possesses biomolecules such as cardiac glycosides, proteins, phenolic compounds, flavonoids and sugar, which could be used as reducing agent to react with ferrous and ferric ions and as scaffolds to direct the formation of Fe3O4 NPs in solution. To the best of our knowledge, the use of Dhatura innoxia plant extract at room temperature for the bio-reductive synthesis of Fe3O4 nanoparticles has not been reported. The formation of the Fe3O4 magnetic nanoparticles was first monitored using UV-Vis absorption spectroscopy. FT-IR spectroscopy and TGA/DTG analysis further confirms the formation of plant protein coated magnetite nanobio hybrid. The dried form of synthesized nanoparticles was further characterized using XRD, TEM.
Determination of Flexural Properties of Rigid PUR Foams Using Digital Image Correlation
Authors: Voiconi Tudor , Linul Emanoil , Marşavina Liviu , Sadowski Tomasz , Kneć Marcin
Published: August 2014

Cellular materials represent a new class of materials; main parameters that characterize the cellular structure are relative density, shape of the cell (open or closed), wall thickness and cell diameter. The purpose of this paper is to investigate the microstructure of foams materials and also to determine the flexural properties of this rigid PUR foams using Digital Image Correlation (DIC). The rigid PUR foams cells morphology and pore distribution for three densities (100, 145 and 300 kg/m3) were studied before testing through scanning electron microscopy. Determination of flexural properties was carried out on rectangular beam samples using ARAMIS 2D system. This method provides a substantial increase in accuracy for measuring strain and is based on the calculation of surface deformation using a set of digital images from undeformed stage to different deformed stages. The specimens were subjected to static three points bending tests with loading rate of 2 mm/min, at room temperature and loading was applied in rise direction of the foam. Experimental results show that main mechanical properties such as flexural modulus and flexural strength values increases with increasing of density.
A competency framework for the business rescue practitioner profession
Authors: Pretorius Marius
Published: August 2014

Orientation: Business Rescue Practitioner (BRP) tasks are complex and involve a wide range of knowledge, tacit skills and experience not accessible to novices.Research purpose: Competencies required by business rescue practitioners (BRPs) to navigate a distressed venture were investigated. What BRPs actually ‘do’ during a rescue guided the development of a competency framework to inform future qualification guidelines for BRP education and accreditation.Motivation for the study: To investigate the research question: ‘What are the competencies that underlie the activities of a business rescue practitioner?’.Research design, approach and method: A modified ‘interview to the double’ (ITTD) process was used to elicit instructions that a BRP would give to an imaginary ‘double’. These instructions were analysed and rated for importance, transferability, knowledge requirement and skills requirement; in conclusion, these instructions were ranked and subjected to a content analysis.Main findings: Based on the main activities that were derived from the practices and praxis, one assignment and four supra (higher-level) competencies were consequent to the analysis. A BRP able to successfully navigate a distressed venture towards normal operations should demonstrate a high level of competency in sense-making, decision making and integration, achieved through collaboration as the central competency.Practical implications: Firstly, the study addresses educators’ need for a framework of competencies to guide education. Secondly, it paves the way for the Regulator to develop a qualifications framework for accreditation.Contribution: The findings gave structure to the competencies underlying the activities of a BRP to navigate a rescue. Pre-business and financial acumen appears limited without these competencies containing insight, experience, intuition, heuristics, tacit knowledge, perceptive induction and more.
Communicating amidst reality: Ezekiel�s communication as a response to his reality
Authors: Serfontein Johan , Wessels Wilhelm J.
Published: August 2014

The reality of exile was the backdrop of Ezekiel�s prophecies (communication). He respondedto this reality with a word that he claimed he received from YHWH. This word he crafted intoa powerful piece of communication that appealed, with the help of metaphors and images, tothe imaginations of his audience. These imaginations of the future in the end seed the newpossibilities that became their new reality. The question would be if Ezekiel�s communicationprocess could be helpful to leaders who find themselves in a new modern-day reality wherethey are struggling to lead.Intradisciplinary and/or interdisciplinary implications: Prophetic criticism usually staysclear of practical issues like leadership, communication and change. This article attempts toconstruct a communication model from the prophet Ezekiel�s communication that can helpmodern-day leaders to communicate amidst their reality. It aids in bridging the divide thatexists between Practical Theology and Old Testament Biblical Studies.
Assessment Lumboperitoneal or Ventriculoperitoneal Shunt Patency by Radionuclide Technique: A Review Experience Cases
Authors: Chiewvit Sunanta , Nuntaaree Sarun , Kanchaanapiboon Potjanee , Chiewvit Pipat
Published: August 2014

Hydrocephalus-related symptoms that worsen after shunt placement may indicate a malfunctioning or obstructed shunt. The assessment of shunt patency and site of obstruction is important for planning of treatment. The radionuclide cerebrospinal fluid (CSF) shunt study provides a simple, effective, and low-radiation-dose method of assessing CSF shunt patency. The radionuclide CSF shuntography is a useful tool in the management of patients presenting with shunt-related problems not elucidated by conventional radiological examination. This article described the imaging technique of ventriculoperitoneal (VP) shunt and lumbar puncture (LP) shunt. The normal finding, abnormal finding of completed obstruction and partial obstruction is present by our cases experience. The radiopharmaceutical (Tc-99m diethylenetriaminepentaacetic acid) was injected via the reservoir for VP shunt and via lumbar puncture needle in subarachnoid space for LP shunt, then serial image in the head and abdominal area.

The normal function of VP and LP shunt usually rapid spillage of the radioactivity in the abdominal cavity diffusely. The patent proximal tube VP shunt demonstrates ventricular reflux. The early image of patent LP shunt reveals no activity in the ventricular system contrast to distal LP shunt reveals early reflux of activity in the ventricular system. The completed distal VP and LP shunt obstruction show absence of tracer in the peritoneal area or markedly delayed appearance of abdominal activity. The partial distal VP and LP shunt obstruction recognized by slow transit or accumulation of tracer at the distal end or focal tracer in the peritoneal cavity near the tip of distal shunt. The images of the normal and abnormal CSF shunt as describe before are present in the full paper. Radionuclide CSF shuntography is a reliable and simple procedure for assessment shunt patency.
The Anatomical Biological Value on Pretreatment 18 F-fluorodeoxyglucose Positron Emission Tomography Computed Tomography Predicts Response and Survival in Locally Advanced Head and Neck Cancer
Authors: Ashamalla Hani , Mattes Malcolm , Guirguis Adel , Zaidi Arifa , Mokhtar Bahaa , Tejwani Ajay
Published: August 2014

18 F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) has become increasingly relevant in the staging of head and neck cancers, but its prognostic value is controversial. The objective of this study was to evaluate different PET/CT parameters for their ability to predict response to therapy and survival in patients treated for head and neck cancer. A total of 28 consecutive patients with a variety of newly diagnosed head and neck cancers underwent PET/CT scanning at our institution before initiating definitive radiation therapy. All underwent a posttreatment PET/CT to gauge tumor response. Pretreatment PET/CT parameters calculated include the standardized uptake value (SUV) and the anatomical biological value (ABV), which is the product of SUV and greatest tumor diameter. Maximum and mean values were studied for both SUV and ABV, and correlated with response rate and survival. The mean pretreatment tumor ABV max decreased from 35.5 to 7.9 (P = 0.0001). Of the parameters tested, only pretreatment ABV max was significantly different among those patients with a complete response (CR) and incomplete response (22.8 vs. 65, respectively, P = 0.021). This difference was maximized at a cut-off ABV max of 30 and those patients with ABV max < 30 were significantly more likely to have a CR compared to those with ABV max of ≥ 30 (93.8% vs. 50%, respectively, P = 0.023). The 5-year overall survival was 80% compared to 36%, respectively, (P = 0.028). Multivariate analysis confirmed that ABV max was an independent prognostic factor. Our data supports the use of PET/CT, and specifically ABV max , as a prognostic factor in head and neck cancer. Patients who have an ABV max ≥ 30 were more likely to have a poor outcome with chemoradiation alone, and a more aggressive trimodality approach may be indicated in these patients.
Prevalence of Detecting Unknown Cerebral Metastases in Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography and its Potential Clinical Impact
Authors: Kung Boom , Auyong T , Tong C
Published: August 2014

To determine the prevalence of incidental finding of unknown cerebral metastases and explore the clinical impact of detecting unknown brain metastases among individuals underwent whole body fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) with brain included in field of view. A retrospective review of 1876 patients who underwent whole body PET/CT examination in our clinical PET center for oncological evaluation from January 2009 to September 2009 was performed. The total number and prevalence of unknown brain metastases detected by PET/CT were calculated. Patients diagnosed with cerebral metastases by PET/CT were further analyzed via the electronic patient record system for relevant clinical and radiological findings. Positive predictive value of PET/CT for the diagnosis of cerebral metastases was calculated with reference to contrast enhanced magnetic resonance imaging (MRI) or contrast enhanced CT. Of the 1876 subjects, 71 patients (3.8%) were diagnosed with cerebral metastases by PET/CT. 31 patients were already diagnosed with brain metastases before PET/CT. Among the 40 patients with unknown brain metastasis, 24 (60.0%) underwent either MRI (n = 5) or CT (n = 19) after PET/CT, of which 17 patients were confirmed with cerebral metastases. The true positive rate was 70.8% (17/24), while the false positive rate of PET/CT was 29.2% (7/24). Nearly 94.1% (16/17) patients with confirmed cerebral metastases on MRI or CT had subsequent change in management. Among the remaining 16 patients with positive findings of cerebral metastases without further radiological correlation, 43.8% (7/16) patients had change in management after PET/CT. A total of 57.5% (23/40) patients had change in management after PET/CT. The point prevalence of detecting unknown cerebral metastases by PET/CT was 2.1% (40/1876). 94.1% patients with newly diagnosed brain metastases confirmed with either MRI or CT received immediate treatment for cerebral metastasis in this retrospective study. PET/CT demonstrated significant clinical impact by identifying cerebral lesions with mass effect and hence that timely treatment was offered.
Differential susceptibility of cladoceran species to a saxitoxin-producer strain of Cylindrospermopsis raciborskii (cyanobacteria)
Authors: Ferrão-Filho Aloysio S. , Galvão Luiz Eduardo C. , Magalhães Valéria Freitas
Published: August 2014

Toxic cyanobacteria can affect several organisms, including herbivorous zooplankton, as cladocerans. In this study we tested the hypothesis that cladoceran species of different body size, origin and degree of exposure to toxic cyanobacteria would respond differently to a saxitoxin(STX)-producing strain of the cyanobacterium Cylindrospermopsis raciborskii (CYRF-01). Newborns were exposed to increasing concentrations of the strain CYRF-01 mixed to a fixed proportion of green algae for 14 days and survivorship, age at first reproduction, clutch size, total offspring and the intrinsic rate of population increase (r), as a measure of fitness, were estimated. Different responses to the strain CYRF-01 were observed, with Daphnia similis (temperate, large size) being more sensitive, followed by Moina micrura (tropical, small size), both presenting symptoms of decreased fitness and paralysis. While Ceriodaphnia richardi (tropical, small size) D. gessneri (tropical, medium size) and Diaphanosoma spinulosum (tropical, small size) showed neither of these symptoms, the later species showed even increased fitness in the cyanobacterial treatments relative to control with green algae, suggesting not only a greater resistance to this strain, but also that it can serve as a nutritional supplement for this cladoceran. In conclusion, the results showed that while some cladocerans species may be negatively affected in their fitness, others may be not affected at all or even utilize STX-producer cyanobacteria as a complementary resource. This suggests that responses of cladocerans to toxic cyanobacteria in nature may vary with species and that the presence of toxic cyanobacteria may shape zooplankton communities to the dominance of more tolerant herbivorous species.
Scattering and absorption properties of near-surface aerosol over Gangetic–Himalayan region: the role of boundary layer dynamics and long-range transport
Authors: Dumka U. C. , Kaskaoutis D. G. , Srivastava M. K. , Devara P. C. S.
Published: August 2014

Abstract. Knowledge of light scattering and absorption properties of atmospheric aerosols is of vital importance in evaluating their types, sources and radiative forcing. This is of particular interest over the Gangetic–Himalayan (GH) region due to large aerosol loading over the plains and the uplift over the Himalayan range causing serious effects on atmospheric heating, glaciology and monsoon circulation. In this respect, Ganges Valley Aerosol Experiment (GVAX) was initiated over the region aiming to examine the aerosol properties, source regions, uplift mechanisms and aerosol-cloud interactions. The present study examines the temporal (monthly, seasonal) evolution of scattering (σsp) and absorption (σap) coefficients, their wavelength dependence, and the role of the Indo-Gangetic plains (IGP), boundary-layer dynamics (BLD) and long-range transport (LRT) in the aerosol uplift over the Himalayas. The measurements are performed at the elevated site Nainital via the Atmospheric Radiation Measurement Mobile Facility including several instruments (Nephelometer, Particle Soot Absorption Photometer, etc.) during June 2011 to March 2012. The σsp and σap exhibit a pronounced seasonal variation with monsoon low and post-monsoon (November) high, while the scattering wavelength exponent exhibits higher values during monsoon, in contrast to the absorption Ångström exponent which maximizes in December–March. The analysis is performed separately for particles bellow 10 and 1μm in diameter in order to examine the influence of the particle size on optical properties. The elevated-background measuring site provides the advantage of examining the LRT of natural and anthropogenic aerosols from the IGP and southwest Asia and the role of BLD in the aerosol lifting processes, while the aerosols are found to be well-mixed and aged-type dominant.
Are C-loss rates from drained peatlands constant over time? The additive value of soil profile based and flux budget approach
Authors: Leifeld J. , Bader C. , Borraz E. , Hoffmann M. , Giebels M. , Sommer M. , Augustin J.
Published: August 2014

Abstract. Drained peatlands are CO2 hotspots and lose important soil functions over time. In contrast to mineral soils, their high carbon density induces long lasting and high emissions. These emissions can be estimated using various approaches which cover different system boundaries in time and space. Here we compare 5 years flux measurements from manual chambers with a soil profile based method to estimate carbon losses from two temperate fens under different management intensity drained at the end of the 19th century. According to the flux measurements, both grassland sites currently lose significant amounts of carbon as CO2 in the order of 7.1 and 9.1 t CO2-C ha−1a−1 when managed non-intensively or intensively, respectively. Profile based estimates, which make use of the difference in ash concentration along the soil profile, reveal a total of 284 and 619 t C ha−1 since the onset of drainage. These substantial losses are accompanied by a sharp decrease in peat quality as measured by NMR spectroscopy, confirming that a large part of former topsoil material is already mineralized. On average, the profile based estimate converts to smaller annual loss rates of 2.2 (non-intensive) and 4.8 t CO2−C ha−1a−1 (intensive) management. Our data, together with historical flux measurements at this site, provide evidence that peat decomposition rates increased over time, despite declining organic matter quality. We suggest that higher management intensities (i.e., higher fertilization and changes in carbon export from the field), including drainage, and increased mean annual temperature may be important factors for higher emissions today. These two methods are complementary in terms of time horizon and system boundary and, in conjunction, confirm the long-term emission potential of temperate drained organic grassland soils.
MOMBA 1.1 – a high-resolution Baltic Sea configuration of GFDL's Modular Ocean Model
Authors: Dietze H. , Löptien U. , Getzlaff K.
Published: August 2014

Abstract. We present a new coupled ocean-circulation–ice model configuration of the Baltic Sea. The model features, contrary to most existing configurations, a high horizontal resolution of ≈ 1 nautical mile (≈ 1.85 km), which is eddy-resolving over much of the domain. The vertical discretisation comprises a total of 47 vertical levels. Results from a 1987 to 1999 hindcast simulation show that the model's fidelity is competitive. As suggested by a comparison with sea surface temperatures observed from space, this applies especially to near-surface processes. Hence, the configuration is well suited to serve as a nucleus of a fully fledged coupled ocean-circulation–biogeochemical model (which is yet to be developed). A caveat is that the model fails to reproduce major inflow events. We trace this back to spurious vertical circulation patterns at the sills which may well be endemic to high-resolution models based on geopotential coordinates. Further, we present indications that – so far neglected – eddy/wind effects exert significant control on wind-induced up- and downwelling.
Geochemical controls on the partitioning and hydrological transport of metals in a non-acidic river system
Authors: Thorslund J. , Jarsjö J. , Wällstedt T. , Mörth C. M. , Lychagin M. Y. , Chalov S. R.
Published: August 2014

Abstract. The speciation of metals, i.e. in which chemical form they occur, controls their mobility, bioavailability and toxicity. The overall objective of this study is to extend the knowledge on the spreading of metals in non-acidic river systems; this knowledge is currently much more limited than the knowledge on metal behavior under acidic conditions that for instance are found in acid mine drainage systems. We combine novel measurements of metal spreading under distinctly high-pH conditions (up to 9.6) in the Tuul River at the Zaamar Goldfield mining site (Upper Lake Baikal Drainage Basin, Mongolia) with a geochemical modelling approach (Visual MINTEQ). Total mass flows of several metals (Al, Cd, Fe, Mn, Pb and V) showed net increases over the mining site, with metals in suspension generally dominating the total export from the site. Model results showed that a main difference from acid mine drainage geochemistry is that the prevailing high pH causes precipitation of ferrihydrite and gibbsite, which removed between 90 to 100% of Fe and Al from solution. This notably influenced the behavior of As, Pb and V since their solubilities are controlled by sorption onto ferrihydrite. The combined effects from such geochemical processes (precipitation, sorption) hence explain the high impact of suspended transport to total transport under high pH conditions. Arsenic furthermore showed dissolved concentrations above health risk-based guideline values in several locations and can thus be of main toxic concern in the upper Lake Baikal Drainage Basin. Moreover, present modelling showed that in particular the solubility of Fe, Pb and Zn can increase considerably as DOC concentrations increase due to metal-organic complexation. In high pH systems, seasonality of DOC concentrations can therefore have a major influence on the spreading and toxicity of these metals, as can DOC trends caused by land use change. Present results also suggest that the behavior of Cr, Cu and Mo would be much better understood if a dependable adsorption database for hydroxyapatite could be developed.
Glacier dynamics at Helheim and Kangerdlugssuaq glaciers, southeast Greenland, since the Little Ice Age
Authors: Khan S. A. , Kjeldsen K. K. , Kjær K. H. , Bevan S. , Luckman A. , Aschwanden A. , Bjørk A. A. , Korsgaard N. J. , Box J. E. , van den Broeke M. , van Dam T. M. , Fitzner A.
Published: August 2014

Abstract. Observations over the past decade show significant ice loss associated with the speed-up of glaciers in southeast Greenland from 2003, followed by a deceleration from 2006. These short-term, episodic, dynamic perturbations have a major impact on the mass balance on the decadal scale. To improve the projection of future sea level rise, a long-term data record that reveals the mass balance beyond such episodic events is required. Here, we extend the observational record of marginal thinning of Helheim and Kangerdlugssuaq glaciers from 10 to more than 80 years. We show that, although the frontal portion of Helheim Glacier thinned by more than 100 m between 2003 and 2006, it thickened by more than 50 m during the previous two decades. In contrast, Kangerdlugssuaq Glacier underwent minor thinning of 40–50 m from 1981 to 1998 and major thinning of more than 100 m after 2003. Extending the record back to the end of the Little Ice Age (prior to 1930) shows no thinning of Helheim Glacier from its maximum extent during the Little Ice Age to 1981, while Kangerdlugssuaq Glacier underwent substantial thinning of 230 to 265 m. Comparison of sub-surface water temperature anomalies and variations in air temperature to records of thickness and velocity change suggest that both glaciers are highly sensitive to short-term atmospheric and ocean forcing, and respond very quickly to small fluctuations. On century timescales, however, multiple external parameters (e.g. outlet glacier shape) may dominate the mass change. These findings suggest that special care must be taken in the projection of future dynamic ice loss.
Stable climate and surface mass balance in Svalbard over 1979–2013 despite the Arctic warming
Authors: Lang C. , Fettweis X. , Erpicum M.
Published: August 2014

Abstract. With the help of the regional climate model MAR forced by the ERA-Interim reanalysis (MARERA) and the MIROC5 global model (MARMIROC5) from the CMIP5 database, we have modelled the climate and surface mass balance of Svalbard at a 10 km resolution over 1979–2013. The integrated total SMB over Svalbard modelled by MARERA is negative (−1.6 Gt yr−1) with a large interannual variability (7.1 Gt) but, unlike over Greenland, there has been no acceleration of the surface melt over the past 35 years because of the recent change in atmospheric circulation bringing northerly flows in summer over Svalbard, contrasting the recent observed Arctic warming. However, in 2013, the atmospheric circulation changed to a southwesterly flow over Svalbard causing a record of melt, SMB (−20.4 Gt yr−1) and summer temperature. MIROC5 is significantly colder than ERA-Interim over 1980–2005 but MARMIROC5 is able to improve the near-surface MIROC5 results by simulating not significant SMB differences with MARERA over 1980–2005. On the other hand, MIROC5 does not represent the recent atmospheric circulation shift in summer and induces in MARMIROC5 a significant trend of decreasing SMB (−0.6 Gt yr−2) over 1980–2005.