bluuebunny/crossref_metadata_2025 huggingface dataset:
Microstructure and properties of hot-pressed molybdenum-alumina composites
Authors: Chmielewski M. , Dutkiewicz J. , Kalinski D. , Litynska-Dobrzynska L. , Pietrzak K. , Strojny-Nedza A.
Published: June 2015

Brittleness is the main technical limitation on a wide use of advanced ceramic materials. To overcome this problem, ceramic-metal composites are commonly applied. A principal advantage of ceramic-metal composite materials is their higher resistance to brittle fracture. An increase of fracture toughness depends on the type, amount, size and shape of a metallic component. The metallic phase can additionally modify physical, mechanical and thermal properties of materials.

The results of experiments concerning a manufacturing process of Mo-Al2O3 composite materials obtained by the hot pressing method were presented. Two powder mixtures with different volume fraction of aluminium oxide were prepared in a planetary ball mill. The hot pressing process allowed to obtain well-densified metal matrix composites (~99% of a theoretical density). Microstructural observations of sinters were conducted using scanning electron microscopy, energy-dispersive X-ray spectroscopy, and transmission electron microscopy. Very stable bonding between metal and ceramic grains was observed. Complex investigations of the physical and mechanical properties of obtained molybdenum-alumina composite materials seem to be very promising from an application point of view.
An influence of mechanical mixing and hot-pressing on properties of NiAl/Al2O3 composite
Authors: Kalinski D. , Chmielewski M. , Pietrzak K. , Choregiewicz K.
Published: June 2015

Intermetallic phases of the Ni-Al type belong to the group of modern constructional materials which have numerous advantageous properties such as high melting temperature, low density, high resistance to high-temperature oxidation (to about 1200°C), high mechanical strength, high fatigue strength, and high tensile and compressive strength (also at elevated temperatures). Intermetallic compounds have however also drawbacks in that they are quite brittle at room temperature which makes their mechanical processing very difficult and restricts their application range. These drawbacks can be obviated by modifying their chemical composition. Improving the properties of NiAl-based materials can be achieved by creating the composite with the matrix made of an intermetallic phase NiAl reinforced with ceramic (Al2O3) particles.

This paper is concerned with the mechanical and physical properties (bending strength, fracture toughness, hardness, and Young modulus) and also the microstructure of NiAl/Al2O3 composite. The composite materials were produced by the hot-pressed method using the NiAl/20%Al2O3 (vol.%) powder mixtures. The composite thus produced had a high density of about 99% of the theoretical value and a high bending strength. The bending strength of the NiAl/20vol.%Al2O3 composite was higher by about 80% (635 MPa) than that of the pure NiAl phase (345 MPa). The experiments included also the examination of the effect of the rotational speed of the mill and the duration of the mixing process upon the size and distribution of grains, the microstructure, and phase composition of the composite powder mixtures obtained.
Non-isothermal annealing of AA7075 aluminum alloy – structural and mechanical effects
Authors: Pieła K. , Błaz L. , Sierpinski Z. , Forys T.
Published: June 2015

Calorimetric and dilatometric tests were performed on AA7075 aluminum alloy annealed at constant heating rate of 15°C/min in temperature range 20-470°C and discussed in relation to the hardness test and structure observation results. The samples were machined from furnace cooled material (FC), furnace cooled and deformed (FCD) material, solution treated (ST) material and solution treated and deformed (STD) material. It was found that the nucleation and growth of transition η’ and stable η (MgZn2) phases caused remarkable reduction of thermal expansion coefficient t , whereas both the dissolution of η phase and formation of GP zones were accompanied by an increase of t value. While αi phase started to dissolve at 250°C, a widespread endothermic effect was observed on DSC curves. Dissolution of η particles at high annealing temperatures was accompanied by the solid solution hardening of the alloy. Mentioned hardening process was overlapped by expected material softening that was ascribed to recovery and recrystallization processes. Because of superposition the solution hardening and recrystallization softening, recrystallization temperature could not be precisely defined on the basis of simple hardness measurements.
Influence of the mechanical alloying process on the sintering behaviour of astaloy CrM powder mixture with silicon carbide addition
Authors: Hebda M. , Gadek S. , Kazior J.
Published: June 2015

Due to an excellent combination of toughness and strength, bainitic-austenitic dual phase steels with silicon addition have many applications in the industry. However, silicon has a high affinity to oxygen and, therefore, its introduction to the alloy is problematic during the classical sintering processes of mixing powders. Mechanical alloying (MA) offers one of the most attractive alternatives to the introduction of silicon to Astaloy CrM powders.

The aim of the present study was to determine the influence of the MA process on changes in particle size distribution, work hardening and sintering behaviour of the investigated powder mixture - Astaloy CrM powder with the addition of 2 wt.% stearic acid and 2 wt.% silicon carbide alloyed under different conditions. The practical aspect of this study was to develop and apply a common and inexpensive method of die-pressing to compact a powder mixture prepared by the MA process.
Effects of direct current field on powder-packed boriding process on martensitic stainless steel AISI 420
Authors: Angkurarach L. , Juijerm P.
Published: June 2015

The effects of direct current field on a powder-packed boriding process on a martensitic stainless steel AISI 420 have been investigated at a temperature of 900°C for about 2–6 hr. A powder-packed boriding process without direct current field (conventional powder-packed boriding process, PB) is a reference as compared to the powder-packed boriding process with applied current densities (PB-DC) of 60-170 mA/cm2. The microstructure and the presence of boride layers of PB and PB-DC were characterized using optical microscope and X-ray diffraction (XRD). The hardness values of the boride layer were measured by Vickers microhardness tester. Experimental results show that the direct current filed can enhance the decomposition and chemical reaction in the boriding agent and also drive active free boron ions as well as atoms to diffuse toward the cathode. Therefore, a boron concentration around the specimen at the cathode of PB-DC is higher than that at the anode as well as PB (as a reference). As a consequence, higher boride layer thickness of PB-DC was detected. The double-phase boride layer (FeB and Fe2B) on borided martensitic stainless steel AISI 420 was found both PB and PB-DC. The hardness of the boride layer of about 1800–2000 HV can be observed.
Inaccuracy in self-synchronisation of vibrators of two-drive vibratory machines caused by insufficient stiffness of vibrators mounting
Authors: Michalczyk J.
Published: June 2015

The influence of an insufficient stiffness of inertial vibrators mounting to a vibratory machine body on phase angles of unbalanced masses and on a machine motion was analysed in the paper.

The mathematical model of the effect was developed and the analytical dependencies determining the influence of the mounting elasticity on the synchronisation and machine movement - useful in engineering practice - were obtained.
Mechanical behaviour of ultrafine grained Al-Mg alloys obtained by different processing routes
Authors: Bazarnik P. , Lewandowska M. , Kurzydłowski K.J.
Published: June 2015

The subject of the study were microstructure and mechanical properties of two commercial 5xxx aluminium alloys obtained by Plastic Consolidation (PC) of nanopowders and Hydrostatic extrusion (HE). It has been observed that HE samples exhibit a higher strength whereas PC samples higher ductility. The two types of samples also differ in the type and intensity of serrations on stress-strain curves. The microstructures of samples processed were found to differ significantly in terms of size and shape of grains, grain boundary characteristics, second phase particles content and density of dislocations. The results are discussed in terms of the influence of microstructure on mechanical behaviour of 5xxx aluminium alloys processed by severe plastic deformation.
The Equal Channel Angular Extrusion Process of Multiphase High Strength Aluminium Bronze / Proces Równokanałowego Wyciskania Kątowego Wysokowytrzymałych Wielofazowych Brązów Aluminiowych
Authors: Gronostajski Z. , Hawryluk M. , Kuziak R. , Radwański K. , Skubiszewski T. , Zwierzchowski M.
Published: June 2015

The aim of the research was to determine the deformation condition of ECAP process of multiphase high strength aluminium bronze BA1032. The studies have indicated that it is possible to deform multiphase aluminium bronze BA1032 in the ECAP process at a temperature of 400°C and die angle Φ =110°. The deformation of the bronzes at lower temperatures encounters some difficulties - cracks appear which make repeated ECAP impossible. The cracks appear on the top surface of the samples where it contacts the surface of the outlet channel. FEM simulations show that the largest plastic strains occur in this area. The proposed ECAP method of large plastic deformations as applied to the investigated aluminium bronzes makes it possible to obtain very strong refinement especially of eutectoid α + γ2.
Elimination of Aluminum During the Process of Ti-6Al-4V Alloy, Smelting in a Vacuum Induction Furnace / Eliminacja Aluminium W Procesie Wytopu Stopu Ti-6Al-4V W Indukcyjnym Piecu Próżniowym
Authors: Siwiec G.
Published: June 2015

In the paper, results of the study on kinetics of aluminum evaporation from a liquid Ti-6Al-4V alloy during its smelting in a vacuum induction furnace are presented. The experiments were performed with the use of a VIM 20-50 furnace (manufactured by SECO-WARWICK) at 1973 K and 5-1000 Pa. Based on the values of changes in aluminum concentration in a liquid alloy, overall mass transfer coefficients were estimated. Within the analysed pressure range, the coefficient values changed from 0.97·10-5 ms-1 to 1.93·10-5 ms-1 for 1000 Pa and 5 Pa, respectively
Analysis of Selected Liquid Steel Viscosity / Analiza Lepkosci Wybranych Gatunków Stali W Stanie Ciekłym
Authors: Korolczuk-Hejnak M. , Migas P.
Published: June 2015

This paper presents the results of the rheological analysis of selected grades of steel: 90CrV6, DHQ3, 34CrNiMo. In metallurgical processes, gradient of the dynamic viscosity parameter is an important indicator characterizing the behavior of liquid metal in the industrial aggregates. It affects the processes of heat exchange and mass transport occurring in the existing liquid, solid and gaseous phases. Only a small number of high temperature viscosity measurements is available. This is due to the fact that the experiments are difficult to conduct and due to the general assumption that the molten steel is a liquid exhibiting similarities to Newtonian liquids body.

In general liquid metal processes are affected by dynamic forces. Values of the parameters which could be treated as rheological in those real processes are very difficult to measure therefore the influence of the following factors: time of shearing, force value, force direction and shear rate are neglected.

The significance of these dynamic parameters seems to be particularly important in the steel continuous casting and thixoforming process. In this work authors analyzed, from the rheological point of view, chosen representative types of steel produced in electric arc furnace. Measurements were taken using a high temperature viscometer FRS1600 in the range of liquidus temperatures as well as above the liquidus for variable shear rates and different time of shearing.
Welded Joint Cracking in Martensitic Stainless Steel Precipitation-Sthregthened with Copper / Pękanie Złącz Spawanych Stali Nierdzewnej Martenzytycznej Utwardzanej Wydzieleniowo Miedzią
Authors: Ziewiec A. , Czech J. , Tasak E.
Published: June 2015

Problem of welded joint cracking in the HAZ of Cu strengthened 17-4PH grade precipitation hardening martensitic stainless steel is presented. Hypothesis concerning hydrogen embrittlement origin of the cracks is opposed. It was concluded that the cracks located in the high-temperature zone of the HAZ exhibit characteristics of hot cracks which originated as a result of steel embrittlement in the presence of Cu rich liquid phase. The mechanism of steel surface enrichment in Cu is proposed. Practical methods of cracks elimination are presented.
Enthalpy of Formation of Intermetallic Phases from Fe-Ni-Ti System. Comparative Studies / Entalpia Tworzenia Faz Międzymetalicznych Z Układu Fe-Ni-Ti. Studia Porównawcze
Authors: Gąsior W. , Dębski A.
Published: June 2015

The solution calorimetric method was used for the measurement of the formation enthalpy of the binary FeTi and Fe2Ti intermetallic phases and of the FeNiTi2 phase from the region of the ternary B2 one.

The FeNi and FeNiTi2 phases were prepared by levitation melting and the Fe2Ti phase - by melting the metals in a glove-box under high purity argon. The alloys obtained were identified by the X-ray diffraction analysis. The structural study of the alloys with the composition equal to the FeTi and Fe2Ti phase confirmed the mentioned phases mainly in the samples. In the case of the ternary alloy of the composition of the FeNiTi2 phase, a slight amount of iron was also found. The obtained values of the formation enthalpy equal as follows: -27.2±1.3 kJ/mole of atoms, -22.5±1.4 kJ/mole of atoms and -34.2±1.3 kJ/mole of atoms for the Fe2Ti, FeTi and FeNiTi2 phase, respectively.
Analysis of Plastic Strain Localization on the Basis of Strain and Temperature Fields / Analiza Lokalizacji Odkształcenia Plastycznego Na Podstawie Pola Odkształceń I Pola Temperatury
Authors: Maj M. , Oliferuk W.
Published: June 2015

In the present paper the onset of plastic strain localization was determined using two independent methods based on strain and temperature field analysis. The strain field was obtained from markers displacement recorded using visible light camera. In the same time, on the other side of the specimen, the temperature field was determined by means of infrared camera. The objective of this work was to specify the conditions when the non-uniform temperature distribution can be properly used as the indicator of plastic strain localization. In order to attain the objective an analysis of strain and temperature fields for different deformation rates were performed. It has been shown, that for given experimental conditions, the displacement rate 2000 mm/min is a threshold, above which the non-uniform temperature distribution can be used as the indicator of plastic strain localization.
Fabrication, Properties and Microstructures of High Strength and High Conductivity Copper-Silver Wires / Otrzymywanie Oraz Własności I Mikrostruktura Wysokowytrzymałych I Wysoko Przewodzących Drutów Ze Stopów Cu-Ag
Authors: Kawecki A. , Knych T. , Sieja-Smaga E. , Mamala A. , Kwaśniewski P. , Kiesiewicz G. , Smyrak B. , Pacewicz A.
Published: June 2015

Research results of manufacturing composite filamentary nanostructure Cu-Ag alloys with silver addition from 5 to 15% wt. are presented in the paper. Manufacturing technology of these composites and variable solubility of silver in copper and copper in silver in the range of solid solutions. Suitable quantity and processing sequences of high deformation plastic working and heat treatment allows to obtain wires constituted from Cu and Ag fibres with nanometric transverse dimensions and in consequence provide to optimum superposition of high mechanical strength, high electrical conductivity and sufficient ductility of Cu-Ag alloys.

The paper presents the method of continuous casting of alloys, selected physico-chemical properties and degree of deformation. Influence of chosen heat treatment method over electrical and mechanical properties of both casts and micro wires on mechanical and electrical properties of cast materials during converting them into micro wires with tensile strength higher than 1200 MPa and electrical conductivity higher than 40 MS/m are presented too.

Research results of optical and scanning microscopy structure analysis were presented for casts and wires submitted to various thermo-mechanical strengthening.
Effects of Therapeutic Physical Agents on Achilles Tendon Microcirculation
Authors: Chang Yi-Ping , Chiang Hongsen , Shih Kao-Shang , Ma Hsiao-Li , Lin Leou-Chyr , Hsu Wei-Li , Huang Yung-Cheng , Wang Hsing-Kuo
Published: June 2015

Study Design

Controlled laboratory study.

Objectives

To measure Achilles tendon microcirculation (total hemoglobin [THb] and oxygen saturation [StO2]) before and after the application of a physical agent in asymptomatic participants, and to compare differences between application location and physical agent dosage.

Background

Tendon microcirculation can be altered by superficial heating or cryotherapy.

Methods

Fifty-one healthy adults (median age, 22 years; range, 20–34 years) were recruited and randomly assigned into 1 of 4 groups. Participants in each group received an intervention consisting of 1 of the following 4 physical agents: ultrasound (n = 12), interferential current (n = 14), low-level laser (n = 11), or vibration massage (n = 14). In each group, the selected intervention was applied at 2 different doses (ultrasound, 0.8 or 1.2 W/cm2; laser, 5.4 or 18 J) or target locations (vibration and electrostimulation, calf muscle or Achilles tendon). For each participant, each dose or target location was randomly applied to 1 randomly selected lower leg (each leg receiving only 1 of the 2 options).

Results

The StO2 values significantly increased after ultrasound at both doses (P<.008), and the THb value significantly increased for the higher dose only (P<.008). Both THb and StO2 values also significantly increased in response to vibration massage targeting the Achilles tendon (P<.008), and these values were greater than those resulting from the vibration massage applied to the calf muscle (P = .003 and .002, respectively). No significant THb and StO2 differences were found after the application of interferential current or low-level laser.

Conclusion

Tendon microcirculation increases after ultrasound and vibration massage intervention concentrated on the Achilles tendon. These modalities may be considered for the purpose of temporarily increasing microcirculation in the tendon. J Orthop Sports Phys Ther 2015;45(7):563–569. Epub 3 Jun 2015. doi:10.2519/jospt.2015.5681
Use of ICT/Web Tools in ELT in Nepal
Authors: Acharya Chandra Prasad
Published: June 2015

Information and Communication Technology (ICT) has become the integral part of English Language Teaching (ELT) to meet the needs of the present day world. It has brought significant changes in the traditional teacher-centered lecturing methods. However, this emerging field of study has not been researched rigorously in the context of Nepal. Considering this, the research study carried out at the Department of English Education, Tribhuvan University, Kathmandu aimed to find out the commonly used ICT/Web tools in ELT and its positive impact on ELT practice. The sample size of the study consisted of 40 English teachers of private Secondary and Higher Secondary Schools of Kathmandu Valley. The informants were selected using judgmental non-random sampling from Kathmandu, Lalitpur and Bhaktapur districts in a proportionate way. A questionnaire consisting of both close-ended and open-ended questions was used as a data collection tool. The data were analyzed and interpreted descriptively and statistically. The result of the data obtained revealed that the ICT tools such as mobile phone, laptop, multimedia projector and web tools like YouTube, Facebook, wiki, email, blog are used in ELT and have positive impact on ELT.DOI: http://dx.doi.org/10.3126/nelta.v19i1-2.12076 Journal of NELTA, Vol 19 No. 1-2, December 2014: 1-16
Negotiating the Local and Global in Nepalese EAP: Inherent Ideological Tensions and Possible Pathways
Authors: Kafle Madhav
Published: June 2015

This article explores ideological tensions and possible directions to solutions in Nepalese EAP pedagogy in the context of increasingly interdependent world. Seventeen EAP professionals responded to a qualitative online survey disseminated through the Nepal English Language Teachers’ Association listserv, personal emails and other social networking sites. Data was analyzed from the perspective of language ideologies. The main ideological tensions as indicated by the teachers are grouped under three interrelated headings: top-down imposition, buying into Standard English as a panacea for all problems, and disconnect between policy and practice. Based on these findings, the article argues that whereas the top-down imposition is connected with the ideology of development, buying into Standard English with ideologies of linguistic fixity and purism, and the disconnect between policy and practice with the ideology of nationalism and language ownership. DOI: http://dx.doi.org/10.3126/nelta.v19i1-2.12082 Journal of NELTA, Vol 19 No. 1-2, December 2014: 77-87
Motivation and Learning English: A Study on Nepalese Public High School Learners
Authors: Laudari Suman
Published: June 2015

Motivation is long found to be an important factor to affect the task of learning an L2 as it provides the stimulus required to initiate and sustain the task of learning the L2. It is even argued that if learners are motivated, they are likely to succeed in the task of language learning regardless of other factors. The present study examined the Nepalese public high school learners’ motivation to learn English. Based on Dörnyei’s (2005; 2009) second language (L2) motivational Self System as the theoretical framework, this study employed a 64 item questionnaire to collect the data. Correlation and regression were carried out to establish that the main factors affecting learners’ English language learning motivation were attitude to learning English and ideal L2 self. However, ought-to L2 self did not contribute to learners’ motivation directly, which is on the contrary to the findings of the study done in Asian contexts previously. DOI: http://dx.doi.org/10.3126/nelta.v19i1-2.12084 Journal of NELTA, Vol 19 No. 1-2, December 2014: 99-116
Poems and Short Stories: Authentic Resources for English Language Learning
Authors: Yadav Praveen Kumar
Published: June 2015

Maley, A., Mukundan J. & Widodo H. P. (2014). Poems and Short Stories: Authentic Resources for English Language Learning: LINCOM GmbH.DOI: http://dx.doi.org/10.3126/nelta.v19i1-2.12090 Journal of NELTA, Vol 19 No. 1-2, December 2014: 169-171
Advances and New Concepts in Alcohol-Induced Organelle Stress, Unfolded Protein Responses and Organ Damage
Authors: Ji Cheng
Published: June 2015

Alcohol is a simple and consumable biomolecule yet its excessive consumption disturbs numerous biological pathways damaging nearly all organs of the human body. One of the essential biological processes affected by the harmful effects of alcohol is proteostasis, which regulates the balance between biogenesis and turnover of proteins within and outside the cell. A significant amount of published evidence indicates that alcohol and its metabolites directly or indirectly interfere with protein homeostasis in the endoplasmic reticulum (ER) causing an accumulation of unfolded or misfolded proteins, which triggers the unfolded protein response (UPR) leading to either restoration of homeostasis or cell death, inflammation and other pathologies under severe and chronic alcohol conditions. The UPR senses the abnormal protein accumulation and activates transcription factors that regulate nuclear transcription of genes related to ER function. Similarly, this kind of protein stress response can occur in other cellular organelles, which is an evolving field of interest. Here, I review recent advances in the alcohol-induced ER stress response as well as discuss new concepts on alcohol-induced mitochondrial, Golgi and lysosomal stress responses and injuries.
Computational Recognition of RNA Splice Sites by Exact Algorithms for the Quadratic Traveling Salesman Problem
Authors: Fischer Anja , Fischer Frank , Jäger Gerold , Keilwagen Jens , Molitor Paul , Grosse Ivo
Published: June 2015

One fundamental problem of bioinformatics is the computational recognition of DNA and RNA binding sites. Given a set of short DNA or RNA sequences of equal length such as transcription factor binding sites or RNA splice sites, the task is to learn a pattern from this set that allows the recognition of similar sites in another set of DNA or RNA sequences. Permuted Markov (PM) models and permuted variable length Markov (PVLM) models are two powerful models for this task, but the problem of finding an optimal PM model or PVLM model is NP-hard. While the problem of finding an optimal PM model or PVLM model of order one is equivalent to the traveling salesman problem (TSP), the problem of finding an optimal PM model or PVLM model of order two is equivalent to the quadratic TSP (QTSP). Several exact algorithms exist for solving the QTSP, but it is unclear if these algorithms are capable of solving QTSP instances resulting from RNA splice sites of at least 150 base pairs in a reasonable time frame. Here, we investigate the performance of three exact algorithms for solving the QTSP for ten datasets of splice acceptor sites and splice donor sites of five different species and find that one of these algorithms is capable of solving QTSP instances of up to 200 base pairs with a running time of less than two days.
Nanotechnology, Inflammation and the Skin Barrier: Innovative Approaches for Skin Health and Cosmesis
Authors: Landriscina Angelo , Rosen Jamie , Friedman Adam
Published: June 2015

Dermatologic physiology and aesthetics are profoundly connected. Inflammatory stimuli abound in the environment, and have the potential to impact both the physiology and aesthetics of the integument. Inflammation results in a compromised epidermal barrier, impaired moisture retention, erythema, scale and pigment alteration. The advent of nanotechnology has introduced a variety of new approaches to preserving skin cosmesis in the face of inflammation. In this article, we review the architecture and physiology of the epidermal barrier, describe the pathological and aesthetic effects of inflammation, and report recent advances in the development of nanomaterials to offset the aesthetic impact of inflammation.
Medication Trials for Hyperphagia and Food-Related Behaviors in Prader–Willi Syndrome
Authors: Miller Jennifer , Strong Theresa , Heinemann Janalee
Published: June 2015

Prader-Willi syndrome (PWS) is a neurodevelopmental disorder caused by the absence of paternally expressed, imprinted genes on chromosome 15q11-13. Individuals with PWS characteristically have poor feeding and lack of appetite in infancy, followed by the development of weight gain and then uncontrolled appetite and lack of satiety, sometime after the age of two. The overwhelming drive to eat is coupled with reduced energy expenditure and decreased caloric requirements, thus, individuals with PWS will become severely obese unless their food intake is strictly controlled. The mechanisms underlying hyperphagia in PWS remain incompletely understood, and to date no drugs have proven effective in controlling appetite. However, clinical trials have started for several medications, which may provide therapeutic options for those with PWS. These medication trials may also provide insight into potential treatments for obesity in the general population. Ideally, these treatments will help alleviate the complex metabolic issues that are part of this syndrome.
Environmentally Sustainable Biogas? The Key Role of Manure Co-Digestion with Energy Crops
Authors: Agostini Alessandro , Battini Ferdinando , Giuntoli Jacopo , Tabaglio Vincenzo , Padella Monica , Baxter David , Marelli Luisa , Amaducci Stefano
Published: June 2015

We analysed the environmental impacts of three biogas systems based on dairy manure, sorghum and maize. The geographical scope of the analysis is the Po valley, in Italy. The anaerobic digestion of manure guarantees high GHG (Green House Gases) savings thanks to the avoided emissions from the traditional storage and management of raw manure as organic fertiliser. GHG emissions for maize and sorghum-based systems, on the other hand, are similar to those of the Italian electricity mix. In crop-based systems, the plants with open-tank storage of digestate emit 50% more GHG than those with gas-tight tanks. In all the environmental impact categories analysed (acidification, particulate matter emissions, and eutrophication), energy crops based systems have much higher impacts than the Italian electricity mix. Maize-based systems cause higher impacts than sorghum, due to more intensive cultivation. Manure-based pathways have always lower impacts than the energy crops based pathways, however, all biogas systems cause much higher impacts than the current Italian electricity mix. We conclude that manure digestion is the most efficient way to reduce GHG emissions; although there are trade-offs with other local environmental impacts. Biogas production from crops; although not providing environmental benefits per se; may be regarded as an option to facilitate the deployment of manure digestion.
A Medium-Scale 50 MWfuel Biomass Gasification Based Bio-SNG Plant: A Developed Gas Cleaning Process
Authors: Sadegh-Vaziri Ramiar , Amovic Marko , Ljunggren Rolf , Engvall Klas
Published: June 2015

Natural gas is becoming increasingly important as a primary energy source. A suitable replacement for fossil natural gas is bio-SNG, produced by biomass gasification, followed by methanation. A major challenge is efficient gas cleaning processes for removal of sulfur compounds and other impurities. The present study focuses on development of a gas cleaning step for a product gas produced in a 50 MWfuel gasification system. The developed gas cleaning washing process is basically a modification of the Rectisol process. Several different process configurations were evaluated using Aspen plus, including PC-SAFT for the thermodynamic modeling. The developed configuration takes advantage of only one methanol wash column, compared to two columns in a conventional Rectisol process. Results from modeling show the ability of the proposed configuration to remove impurities to a sufficiently low concentrations - almost zero concentration for H2S, CS2, HCl, NH3 and HCN, and approximately 0.01 mg/Nm3 for COS. These levels are acceptable for further upgrading of the gas in a methanation process. Simultaneously, up to 92% of the original CO2 is preserved in the final cleaned syngas stream. No process integration or economic consideration was performed within the scope of the present study, but will be investigated in future projects to improve the overall process.
Analysis of Cool Roof Coatings for Residential Demand Side Management in Tropical Australia
Authors: Miller Wendy , Crompton Glenn , Bell John
Published: June 2015

Cool roof coatings have a beneficial impact on reducing the heat load of a range of building types, resulting in reduced cooling energy loads. This study seeks to understand the extent to which cool roof coatings could be used as a residential demand side management (DSM) strategy for retrofitting existing housing in a constrained network area in tropical Australia where peak electrical demand is heavily influenced by residential cooling loads. In particular this study seeks to determine whether simulation software used for building regulation purposes can provide networks with the ‘impact certainty’ required by their DSM principles. The building simulation method is supported by a field experiment. Both numerical and experimental data confirm reductions in total consumption (kWh) and energy demand (kW). The nature of the regulated simulation software, combined with the diverse nature of residential buildings and their patterns of occupancy, however, mean that simulated results cannot be extrapolated to quantify benefits to a broader distribution network. The study suggests that building data gained from regulatory simulations could be a useful guide for potential impacts of widespread application of cool roof coatings in this region. The practical realization of these positive impacts, however, would require changes to the current business model for the evaluation of DSM strategies. The study provides seven key recommendations that encourage distribution networks to think beyond their infrastructure boundaries, recognising that the broader energy system also includes buildings, appliances and people.
Satellite-Based Derivation of High-Resolution Forest Information Layers for Operational Forest Management
Authors: Stoffels Johannes , Hill Joachim , Sachtleber Thomas , Mader Sebastian , Buddenbaum Henning , Stern Oksana , Langshausen Joachim , Dietz Jürgen , Ontrup Godehard
Published: June 2015

A key factor for operational forest management and forest monitoring is the availability of up-to-date spatial information on the state of forest resources. Earth observation can provide valuable contributions to these information needs. The German federal state of Rhineland-Palatinate transferred its inherited forest information system to a new architecture that is better able to serve the needs of centralized inventory and planning services, down to the level of forest districts. During this process, a spatially adaptive classification approach was developed to derive high-resolution forest information layers (e.g., forest type, tree species distribution, development stages) based on multi-temporal satellite data. This study covers the application of the developed approach to a regional scale (federal state level) and the further adaptation of the design to meet the information needs of the state forest service. The results confirm that the operational requirements for mapping accuracy can, in principle, be fulfilled. However, the state-wide mapping experiment also revealed that the ability to meet the required level of accuracy is largely dependent on the availability of satellite observations within the optimum phenological time-windows.
A Range-Wide Experiment to Investigate Nutrient and Soil Moisture Interactions in Loblolly Pine Plantations
Authors: Will Rodney , Fox Thomas , Akers Madison , Domec Jean-Christophe , González-Benecke Carlos , Jokela Eric , Kane Michael , Laviner Marshall , Lokuta Geoffrey , Markewitz Daniel , McGuire Mary , Meek Cassandra , Noormets Asko , Samuelson Lisa , Seiler John , Strahm Brian , Teskey Robert , Vogel Jason , Ward Eric , West Jason , Wilson Duncan , Martin Timothy
Published: June 2015

The future climate of the southeastern USA is predicted to be warmer, drier and more variable in rainfall, which may increase drought frequency and intensity. Loblolly pine (Pinus taeda) is the most important commercial tree species in the world and is planted on ~11 million ha within its native range in the southeastern USA. A regional study was installed to evaluate effects of decreased rainfall and nutrient additions on loblolly pine plantation productivity and physiology. Four locations were established to capture the range-wide variability of soil and climate. Treatments were initiated in 2012 and consisted of a factorial combination of throughfall reduction (approximate 30% reduction) and fertilization (complete suite of nutrients). Tree and stand growth were measured at each site. Results after two growing seasons indicate a positive but variable response of fertilization on stand volume increment at all four sites and a negative effect of throughfall reduction at two sites. Data will be used to produce robust process model parameterizations useful for simulating loblolly pine growth and function under future, novel climate and management scenarios. The resulting improved models will provide support for developing management strategies to increase pine plantation productivity and carbon sequestration under a changing climate.
SaDA: From Sampling to Data Analysis—An Extensible Open Source Infrastructure for Rapid, Robust and Automated Management and Analysis of Modern Ecological High-Throughput Microarray Data
Authors: Singh Kumar , Thual Dominique , Spurio Roberto , Cannata Nicola
Published: June 2015

One of the most crucial characteristics of day-to-day laboratory information management is the collection, storage and retrieval of information about research subjects and environmental or biomedical samples. An efficient link between sample data and experimental results is absolutely important for the successful outcome of a collaborative project. Currently available software solutions are largely limited to large scale, expensive commercial Laboratory Information Management Systems (LIMS). Acquiring such LIMS indeed can bring laboratory information management to a higher level, but most of the times this requires a sufficient investment of money, time and technical efforts. There is a clear need for a light weighted open source system which can easily be managed on local servers and handled by individual researchers. Here we present a software named SaDA for storing, retrieving and analyzing data originated from microorganism monitoring experiments. SaDA is fully integrated in the management of environmental samples, oligonucleotide sequences, microarray data and the subsequent downstream analysis procedures. It is simple and generic software, and can be extended and customized for various environmental and biomedical studies.
The Spatiotemporal Dynamics of Forest–Heathland Communities over 60 Years in Fontainebleau, France
Authors: Mobaied Samira , Machon Nathalie , Lalanne Arnault , Riera Bernard
Published: June 2015

According to the EU Habitats Directive, heathlands are “natural habitats of community interest”. Heathland management aims at conserving these habitats threatened by various changes, including successional processes leading to forest vegetation. We investigate the dynamics of woody species to the detriment of heathland over a period of 60 years in the Fontainebleau forest and we examine the effects of soil types, soil depth and topography parameters on heathland stability. We assess changes in forest cover between 1946 and 2003 by comparing vegetation maps derived from aerial photographs coupled to GIS analyses. The results show the loss of more than 75% of heathland during 1946–2003 due to tree colonisation of abandoned heathland. We detected differences in the dynamics of colonisation between coniferous and deciduous trees. The colonisation of heathland by coniferous species was faster over the last 20 years of our study period. Tree encroachment was faster in north-facing areas and in areas of acidic luvisols. While this dynamic was very slow in acid sandstone soils, heathland stability was more important in shallow soils on flat and south facing areas. Our study has the potential to assist land managers in selecting those heathland areas that will be easier to conserve and/or to restore by focusing on areas and spatial conditions that prevent forest colonisation and hence favour the long-term stability of heathland.
25-Hydroxyvitamin D3 Levels, BsmI Polymorphism and Insulin Resistance in Brazilian Amazonian Children
Authors: Cobayashi Fernanda , Lourenço Bárbara , Cardoso Marly
Published: June 2015

Vitamin D is associated with a wide range of other functions beyond bone development. We evaluated the factors associated with 25-hydroxyvitamin D levels in 974 children aged ≤10 years and the impact of BsmI polymorphism of the vitamin D receptor (VDR) gene (rs1544410) on metabolic parameters in a subsample (n: 430) with a follow-up 2 years later from the initial population-based cross-sectional study. Multiple linear regression models were used in the analyses. The prevalence (95% CI) of vitamin D deficiency, insufficiency and sufficiency of children was 11.1% (9.2–13.2), 21.8% (19.2–24.5) and 67.2% (64.1–70.1), respectively. Overall, 23% of the variation in serum 25-hydroxyvitamin D concentrations was accounted for by BsmI polymorphism β = −0.053 (95% CI) (−0.100, −0.006), maternal schooling (≥9 years) β = 0.100 (0.039, 0.161), serum vitamin E β = 0.478 (0.381, 0.574), total cholesterol concentration β = 0.232 (0.072, 0.393) and serum folate β = 0.064 (0.013, 0.115). BsmI polymorphism was positively associated with HOMA-IR β = 0.122 (0.002, 0.243) and fasting glucose concentration β = 1.696 (0.259, 3.133). In conclusion, variables related to socioeconomic level, the presence of the allele risk for BsmI and other nutrient concentrations were associated with serum 25-hydroxyvitamin D concentrations. Our results suggest that BsmI polymorphism is correlated with metabolic outcomes.
Hydrothermal Synthesis Au-Bi2Te3 Nanocomposite Thermoelectric Film with a Hierarchical Sub-Micron Antireflection Quasi-Periodic Structure
Authors: Tian Junlong , Zhang Wang , Zhang Yuan , Xue Ruiyang , Wang Yuhua , Zhang Zhijian , Zhang Di
Published: June 2015

In this work, Au-Bi2Te3 nanocomposite thermoelectric film with a hierarchical sub-micron antireflection quasi-periodic structure was synthesized via a low-temperature chemical route using Troides helena (Linnaeus) forewing (T_FW) as the biomimetic template. This method combines chemosynthesis with biomimetic techniques, without the requirement of expensive equipment and energy intensive processes. The microstructure and the morphology of the Au-Bi2Te3 nanocomposite thermoelectric film was analyzed by X-ray diffraction (XRD), field-emission scanning-electron microscopy (FESEM), and transmission electron microscopy (TEM). Coupled the plasmon resonances of the Au nanoparticles with the hierarchical sub-micron antireflection quasi-periodic structure, the Au-Bi2Te3 nanocomposite thermoelectric film possesses an effective infrared absorption and infrared photothermal conversion performance. Based on the finite difference time domain method and the Joule effect, the heat generation and the heat source density distribution of the Au-Bi2Te3 nanocomposite thermoelectric film were studied. The heterogeneity of heat source density distribution of the Au-Bi2Te3 nanocomposite thermoelectric film opens up a novel promising technique for generating thermoelectric power under illumination.
Homocysteine Triggers Inflammatory Responses in Macrophages through Inhibiting CSE-H2S Signaling via DNA Hypermethylation of CSE Promoter
Authors: Li Jiao-Jiao , Li Qian , Du Hua-Ping , Wang Ya-Li , You Shou-Jiang , Wang Fen , Xu Xing-Shun , Cheng Jian , Cao Yong-Jun , Liu Chun-Feng , Hu Li-Fang
Published: June 2015

Hyperhomocysteinemia (HHcy) is an independent risk factor of atherosclerosis and other cardiovascular diseases. Unfortunately, Hcy-lowering strategies were found to have limited effects in reducing cardiovascular events. The underlying mechanisms remain unclear. Increasing evidence reveals a role of inflammation in the pathogenesis of HHcy. Homocysteine (Hcy) is a precursor of hydrogen sulfide (H2S), which is formed via the transsulfuration pathway catalyzed by cystathionine β-synthase and cystathionine γ-lyase (CSE) and serves as a novel modulator of inflammation. In the present study, we showed that methionine supplementation induced mild HHcy in mice, associated with the elevations of TNF-α and IL-1β in the plasma and reductions of plasma H2S level and CSE expression in the peritoneal macrophages. H2S-releasing compound GYY4137 attenuated the increases of TNF-α and IL-1β in the plasma of HHcy mice and Hcy-treated raw264.7 cells while CSE inhibitor PAG exacerbated it. Moreover, the in vitro study showed that Hcy inhibited CSE expression and H2S production in macrophages, accompanied by the increases of DNA methyltransferase (DNMT) expression and DNA hypermethylation in cse promoter region. DNMT inhibition or knockdown reversed the decrease of CSE transcription induced by Hcy in macrophages. In sum, our findings demonstrate that Hcy may trigger inflammation through inhibiting CSE-H2S signaling, associated with increased promoter DNA methylation and transcriptional repression of cse in macrophages.
Preliminary Observations on Zelus obscuridorsis (Stål) (Hemiptera: Reduviidae) as Predator of the Corn Leafhopper (Hemiptera: Cicadellidae) in Argentina
Authors: Virla Eduardo , Melo Cecilia , Speranza Stefano
Published: June 2015

The corn leafhopper Dalbulus maidis (Hemiptera: Cicadellidae), is an important corn pest in most of tropical and subtropical America. This leafhopper has a rich natural enemy complex of which parasitoids and pathogens are the most studied; knowledge on its predators is limited. We noted the presence of the native assassin bug Zelus obscuridorsis (Hemiptera: Reduviidae) predating diverse motile insects, including the corn leafhopper, on corn plants cultivated in household vegetable gardens in San Miguel de Tucumán (Argentina); in order to verify its predatory actions, we exposed lab-bred individuals of D. maidis to adults of Z. obscuridorsis. The predators were starved for 24 h before trials in which the corn leafhopper in different developmental stages were exposed. Zelus obscuridorsis is highly skilled in catching specimens in motion, but it was not able to prey on eggs. The predator was capable to catch and prey on nymphs and adults.
Cutaneous Squamous Cell Carcinomas in Organ Transplant Recipients
Authors: Chockalingam Ramya , Downing Christopher , Tyring Stephen
Published: June 2015

Non-melanoma skin cancers represent a major cause of morbidity after organ transplantation. Squamous cell carcinomas (SCC) are the most common cutaneous malignancies seen in this population, with a 65–100 fold greater incidence in organ transplant recipients compared to the general population. In recent years, human papillomaviruses (HPV) of the beta genus have been implicated in the pathogenesis of post-transplant SCCs. The underlying mechanism of carcinogenesis has been attributed to the E6 and E7 proteins of HPV. Specific immunosuppressive medications, such as the calcineurin inhibitors and azathioprine, are associated with a higher incidence of post-transplant SCCs compared to other immunosuppressive agents. Compared to other immunosuppressives, mTOR inhibitors and mycophenolate mofetil have been associated with a decreased risk of developing post-transplant non-melanoma skin cancers. As a result, they may represent ideal immunosuppressive medications in organ transplant recipients. Treatment options for post-transplant SCCs include surgical excision, Mohs micrographic surgery, systemic retinoid therapy, adjunct topical therapy, electrodessication and curettage, and radiation therapy. This review will discuss the epidemiology, risk factors, and management options of post-transplant SCCs. In addition, the underlying mechanisms of beta-HPV mediated carcinogenesis will be discussed.
A Survey of Image Security in Wireless Sensor Networks
Authors: Gonçalves Danilo , Costa Daniel
Published: June 2015

Wireless sensor networks are increasingly gaining attention. In recent years, a great deal of monitoring, control and tracking applications have been designed for different scenarios. For such networks, camera-enabled sensors can retrieve visual data from a monitored field, providing valuable information for many applications. In general, those networks have resource constraints of processing, memory, energy and transmission bandwidth, imposing many design challenges. Nevertheless, a group of applications may also have security requirements, which bring additional complexity to be handled. Most traditional security mechanisms for popular networks, like the Internet, are not suitable for wireless sensor networks, demanding proper investigation in this area. In this paper, we survey recent developments in encryption and privacy in wireless sensor networks deployed for transmissions of image snapshots, reviewing innovative approaches to provide different levels of security. Promising research directions are also discussed.