bluuebunny/crossref_metadata_2025 huggingface dataset:
Fire Safety Aspects of Wood as a Renewable Energy Source
Authors: Galla Stefan , Majlingová Andrea , Suchomel Jozef
Published: August 2014

In the paper we introduce the results of dendromass quantification in Presov region to be used as a renewable energy source for heating purposes in this region. To map and quantify the dendromass volume we used the tools provided by ArcGIS environment. This study is completed with investigation of dendromass basic fire parameters – heat of combustion, calorific capacity that are directly related to its energetic potential to be used as a renewable energy source.
Hazards of Explosibility Dust from Wood Pellets
Authors: Horváth Jozef , Balog Karol , Scarafilo Domenico
Published: August 2014

The main purpose of this publication is to determine minimal ignition temperature of dust cloud. The flammable and explosive dust is formed during the production, transport, storage and usage of the wood pallets. The examined samples in experimental part of the work were made from different kind of pallets. Contribution deals with analysis of fire and explosion hazards of dust particles generated during transportation and handling of wood pellets. Minimum ignition temperature of dust cloud were performed according to STN EN 50281-2-1. In terms of forensic approach, by using of selected methods, the conditions in which initiation and explosion of dust can be occurred were simulated the exposibility for wood pellets dust was tested under different condition using various pressures and various weight to samples. Defining the conditions in which the risk of formation of dangerous situation exists, helps to predict the fire and explosion in the premises where the pellets are used.
Specific Knowledge in Assessment of Local Fire for Design of Building Structures
Authors: Pokorný Jiří , Kučera Petr , Vlček Vladimír
Published: August 2014

The development of designing building structures exposed to fire is solved not only on the basis of data obtained by standardized tabular values from the fire tests, but also by calculations or their combination with standard values. Calculation methods are becoming more important for most types of building structures, especially for timber and steel building structures. One possibility how to define thermal load of building structures, which is usable especially immediately after the development of a fire, is local fire method. This paper summarizes the principles of calculation while using local fire, it evaluates its positive and negative characteristics, and especially its practical applicability.
The Study of Selected Fire-Technical Characteristics of Special Wood Products Surface Treatment by Environmentally Problematic Coatings
Authors: Ružinská Eva , Mitterová Iveta , Zachar Martin
Published: August 2014

The paper deals with the issues relating to the assessment of the possible behaviour of the surface treated wood prepared by application solvent based polyurethane coatings in realistic conditions of use it is important to assess the characteristics of thermal degradation of these materials in simulations of reaction (ignition test) to fire and add the other necessary criteria, allowing an overall assessment of fire-technical (due to valid standards from the point of the reaction to fire) and ecological characteristics.
Thermal Decomposition of Loose-Fill Cellulose Thermal Insulation
Authors: Zigo Jaroslav , Rantuch Peter , Balog Karol
Published: August 2014

This article deals with thermal degradation of cellulose insulation. The sample of commercially available loose-fill cellulose insulation was tested in electrically heated hot air furnace modified for thermogravimetric analysis. Weight loss, weight loss rate and CO/CO2 ratio was measured, while the sample was heated from room temperature to 530°C. Particular phases of the thermal degradation process of cellulose insulation were identified and explained. The most rapid changes caused by thermal decomposition of loose-fill cellulose insulation were reported in temperature range 270°C – 380°C. The weight loss rate reached its maximum in 308°C, which was equal to 0,198g.min-1. Two temperature ranges in which the yield of CO was higher than the yield of CO2 were detected.
Analysis of Human Factors Applied to Work Activities of a Welder in a Small Plant Oriented to Manufacture of Weldments from Recycled Materials
Authors: Szabova Zuzana , Balog Karol , Belcik Michal
Published: August 2014

The aim of contribution was to assess the activity of a welder in small enterprise oriented to manufacture of weldments from recycled materials from ergonomic viewpoint by application of two methods, namely Quick Exposure Check (QEC) and Strain Index (SI). Suitability of application of individual methods for the welder ́s works is compared, regarding the aspects of speed, analysis complexity and relevance of the results achieved. Measures for improving the workplace state from the viewpoint of ergonomics and preventing the occurrence of the work-related musculoskeletal disorders (WMSDs) are discussed.
Changes of Anthropometric Characteristics of the Adult Population in Slovakia and their Influence on Material Sources and Work Safety
Authors: Mračková Eva , Hitka Miloš , Sedmák Robert
Published: August 2014

In this work we deal with a change of selected anthropometric characteristics of the adult population in Slovakia and its effects on work safety. Slovak population was represented by a sample of students who studied at the Technical University in Zvolen in the years 2000-2014. Selected anthropometric attributes are important for the design of optimal arrangement and safe workplace. Standard quantile characteristics were calculated and compared to historical data. The results showed that an update is necessary older data because sizes of attributes of Slovak population were increased about 4.5-5%. Enlargement was confirmed at significance level greater than 1% in the categories of men and women.
Determination of Ammonia Evaporation Rates for MOPORI Project Model
Authors: Mózer Vladimír , Hollá Katarina , Buganová Katarina
Published: August 2014

The paper is aimed to provide key input for an analysis forming part of industrial process risk assessment and management in a selected enterprise. The analysis is a feature of the Complex model for industrial process risk assessment and management developed in the APVV 0043-10 project. As part of the evaluation of model application, a risk assessment is undertaken in selected enterprises. This risk assessment also involves modelling of a hazardous substance (ammonia water) spillage. To be able to predict the amount of ammonia released and its distribution in time, the evaporation rate must be known. This paper describes laboratory-scale experimental determination of the evaporation rate of ammonia from ammonia water provided by the enterprise for which the risk assessment is being undertaken. The results of the experiment show the dependence of the evaporation rate on the ambient temperature and solution concentration and may be applied directly in a toxic cloud movement model.
Determining of CBR Values of Pavement Construction Layers Based on Renewable Material Sources Using Non-Destructive Method
Authors: Pepucha Lubomír , Zgútová Katarína , Ďureková Dominika , Danišovič Peter , Šrámek Juraj
Published: August 2014

In the contribution, there are presented the newest issues of experimental activities of the authors. The Clegg Impact Soil Tester type CIST/882 provides a means for measuring and controlling soil strength and consolidation levels during trench reinstatement. It is also used to confirm uniform compaction over wide areas of ground, identifying poorly compacted areas and ineffective rolling of materials.
Evaluation of the Security Situation Abroad by the FMEA Method and Impact of Natural or Technical Threats on the Environment
Authors: Stefankova Jarmila , Balog Karol , Raksany Peter
Published: August 2014

The purpose of the project is the electronization of services provided to employees of the Ministry of Foreign and European Affairs of the Slovak Republic (MZVaEZ SR), as well as improvement of the information quality necessary for the operation of the situation centre (SITCEN) and the operating centre for the purpose of prevention (OPCEN) of the MZVaEZ with aim to prevent and solve crisis situations in the areas of residence of our citizens abroad. An electronic system supports the collection, evaluation, presentation and risk management. Regular monitoring of the security situation belongs to everyday activities of the Slovak representations [1]. The evaluated system in this process is the environment in which the specific representative office and its staff are located. Keywords: Threat, risk, crisis planning, Failure Mode and Effects Analysis (FMEA)
The Assessment of Population Safety in the Vicinity of Unclassified Risk Sources
Authors: Mäkká Katarína , Sventeková Eva
Published: August 2014

Act on the Prevention of Major Industrial Accidents defines the threshold quantities of hazardous substances in companies. Businesses that have exceeded their limits assess risks under this act. For smaller establishments where dangerous substances are present in quantities subliminal, risk assessment in terms of the occurrence and effects of the accident is not required. Nevertheless, these objects can represent a source of danger of a major accident, especially given its location, nature of the threat and synergy due to several adverse circumstances. Aim of this paper is to design a model for assessing the degree of threat or safety margin so unclassified sources of risks, for example refrigeration equipment, winter stadium, gas reservoirs and to apply the algorithm for the risk assessment of such objects. Unclassified sources of risk may also be a threat to critical transport infrastructure or its elements. The result is a consistent multi-step methodological approach to the assessment of risk sources and validation of selected operations involving dangerous substances, not reaching the threshold of this Act.
Geothermal Power Plant in Conditions of Geological and Hydrological Characteristics
Authors: Cehlár Michal , Jurkasová Zuzana , Kudelas Dušan , Tutko Róbert , Mendel Ján
Published: August 2014

The East Slovak Basin Area is from genetic viewpoint area which represents longitudinal intramount depression filled by Neogene sediments and volcanics. This basin morphologically represents north-eastern promontory of Pannonian Basins System. During more than 50 years of systematic oil-geological exploration a quantity of knowledge was gathered here, as on geological structure and hydrocarbon fields as on thermal setting and geothermal waters. It is a case of nearly 20 000 analysed water samples and temperature measurements in the depth span from surface up to 4200m what enables us to distinguish in this region several prospective geothermal areas.
Material Potential of End-of-Life Photovoltaic Panels in Slovak Republic
Authors: Moravec Marek , Badida Miroslav , Liptai Pavol
Published: August 2014

Solar power is one of the fastest growing sources of renewable power in the world today.The word “photovoltaic” is a combination of two words “photo”, meaning light, and “voltaic”, meaning electricity. Therefore photovoltaic technology, the scientific term used to describe solar energy, involves the generation of electricity from light. During the last years rapidly increased the number of photovoltaic sources in Slovak republic. By the increasing numbers of photovoltaic sources also increased the numbers of installed photovoltaic panels in Slovak republic. Photovoltaic panels contents valuable materials. These valuable materials will become interesting at the life end of photovoltaic panels [9].
Study on Luminescent Properties of YAG:Ce3+, Gd3+/La3+ Prepared by Co-Precipitation Method
Authors: Guan Rong Feng , You Ya Jun , Song Juan , Hou Gui Hua
Published: August 2014

The YAG:Ce3+, Gd3+/La3+ yellow phosphors were prepared by co-precipitation method with 0.1mol/L ammonium bicarbonate and aqueous ammonia as precipitants, and the crystal structure, morphology, luminescent properties were investigated. The results indicated that the emission peaks of the YAG:Ce3+, Gd3+/La3+ were redshifted from 535nm to 545.5nm /547nm, and the relative emission intensity declined from 330nm to 145/132 with doping content of Gd3+ /La3+ increased from 0 to 0.9mol at room temperature. Compared with Gd-doping phosphors, the redshift of La3+-doping phosphor was larger and the relative emission intensity declined more quickly. Compared with YAG:Ce3+, the thermal quenching characteristics of YAG:Ce,Gd and YAG:Ce,La were noticeably worse when the temperature increased, but the extents of peak wavelength redshifts were almost the same, about is 7-8nm in the experimental temperature range (50-200°C), have little relation with the doping concentration change. Doping concentrations of Gd or La couldn't be too high, and the suitable concentration was less than 0.6mol at the regulating color temperature and color index.
Ag2S-Ag Nanorod as Multifunctional SERS Substrate for Degradation and Detection of Dye Molecules
Authors: Shi Wei , Lin Ju Qiang , Chen Rong , Wang Jing , Lu Peng
Published: August 2014

Multifunctional Ag2S-Ag heterogeneous porous nanorods were synthesised by the irradiation of microwave in 210s .The nanorods were characterized by scanning electron microscopic (SEM) and X-ray diffraction (XRD). The photocatalytic activity for degradation of crystal violet and the lowest detectable limit of crystal violet are tested. Results show that the degradation rate of crystal violet can reach almost 100% within 50 min, the detection limit of crystal violet as low as 1×10-6 M. They indicate that the Ag2S-Ag heterogeneous porous nanorods would be a promising material for environmental protection.
The Study on Evolutive Model of Heavy Metal Pollution in Urban Surface Soil and Design of Time-Series Database
Authors: Yang Yuan Hui , Lu Jing Juan , Shi Yi Xiang
Published: August 2014

In order to study how the heavy metal pollution disseminates in urban surface soil and to recognize its evolutive pattern, this paper provides a model with time variable based on Euler method which could avoid the shortcoming of the traditional constant time assumption. We establish a set of spatial-temporal equations and derive their analytical solutions by 3-order Fourier transform.
Antioxidant and Free Radical Scavenging Activities of Chitosan Materials
Authors: Xu Qing , Zhong Tian , Li Hui Li
Published: August 2014

Chitosan and its derivatives, which are known to possess multiple functional properties, have captured considerable interest due to their biological activities and potential applications in food, pharmaceutical, agricultural and environmental industries. This paper focuses on the antioxidant and free radical scavenging activities of various chitosan materials based on our and others’ latest research results, including scaffold, film, tablet, nanoparticle, and so on. The free radical scavenging mechanisms are summarized. This work may provide more insights into the antioxidant ability of chitosan and its derivatives and potentially enable them to use as natural antioxidant materials for application in food, agriculture, cosmetic and biomedical science.
Antioxidant and Free Radical Scavenging Activities of N-Modified Chitosans
Authors: Xu Qing , Zhong Tian , Li Hui Li
Published: August 2014

Recently, the search for effective natural antioxidants use in food and medicinal fields to replace synthetic ones has attracted the most attention. Chitosan, a natural nontoxic biopolymer, is known to possess antioxidant property, which is attributed that NH2 and OH attached in the pyranose ring react with unstable free radicals to form stable macromolecule radicals. It has been observed that the antioxidant activity of chitosan is closely related to the form of nitrogen atom in the molecules. This review focuses on the antioxidant and free radical scavenging activities of various nitrogen atom of chitosan, including N-acylated chitosans, Schiff bases of chitosan, N-alkyl chitosan, and N-quaternized chitosan. The free radical scavenging mechanisms are summarized and the effects on free radical scavenging activity of N-modified chitosan are discussed. This work may provide more insights into the antioxidant ability of N-modified chitosans and potentially enable them to be used as natural antioxidants for application in food, agriculture, cosmetic and biomedical science.
Keywords: N-modified chitosan, Sythesis, Antioxidant, Free radical scavenging
Material Removal, Correction and Laboratory X-Ray Diffraction
Authors: Wasniewski Eric , Honnart Baptiste , Lefebvre Fabien , Usmial Eric
Published: August 2014

Laboratory X-ray diffraction is commonly used for surface residual stresses determination. Nevertheless, the in-depth residual stress gradient also needs to be known. Chemical or electro-polishing method is generally used for material removal. However, material removal may seek a new equilibrium and stress field may change in such a way that experimental residual stress values must be corrected. Different methods exist to account for the residual stress relaxation associated with the material removal operation and will be discussed in this paper.
MYTHEN Detector – Perspectives in Residual Stress Measurements
Authors: Jung Dubravka Sisak , Suominen Lasse , Parantainen Jari , Hoermann Christoph
Published: August 2014

MYTHEN is a single-photon-counting strip detector. Its main features are high spatial resolution, zero noise, fluorescence suppression, fast readout, high dynamic range, radiation-hard and maintenance-free design. Perspectives of such a detector in residual stress measurements involve: (i) Measurements of absorbing/thick materials (ii) Well resolved peaks (iii) excellent signal-to-noise ratio (iv) Analysis of alloys (v) Fast data collection (vi) Accurate low content retained austenite measurements (vii) in situ measurements and mapping (viii) infinite life cycle. Technical details and application in synchrotron and laboratory diffractometers will be presented.
Assessing Shot-Peening Residual Stresses by Using the Incremental Hole-Drilling Technique and Laser Interferometry (DSPI)
Authors: Nobre João P. , Oliveira Miguel , Albertazzi Armando , Viotti Matias , Batista António Castanhola , Coelho Luís , Marques Maria J.
Published: August 2014

The incremental hole-drilling technique was applied to determine residual stress profiles in shot-peened steel layers. The accuracy of using an enhanced Digital Speckle Pattern Interferometry technique for measuring the strain relaxation arising around the drilled holes and, consequently, the in-depth residual stress distribution induced by shot-peening, was evaluated. The experimental results were systematically compared with those determined using standard electric strain-gauges. The X-ray diffraction technique was chosen as reference due to its high accuracy to determine shot-peening residual stresses.
Residual Stress Measurement on Large Shafts
Authors: Václavík Jaroslav , Weinberg Otakar
Published: August 2014

The review and some experiences are given from measurement and evaluations of residual stresses on large shaft forgings and rail axles using the hole-drilling and ring-core strain-gauge methods, provided by Pilsner Research and Testing Institute, Czech Republic.
Estimation of Residual Stress Field Uniformity when Using the Ring-Core Method
Authors: Menda František , Šarga Patrik , Trebuňa František
Published: August 2014

The evaluation of residual stresses using Ring-Core method requires complex analysis of the acquired strain values. The development is based on ASTM Standard E837-08 for hole-drilling method, but the specific approach for Ring-Core is needed. The input data sets obtained from strain gage rosette are categorized by proposed uniformity test. The influence of geometric parameters of the specimen on this test and subsequently on the both uniform and nonuniform calculations is considered.
Plasticity in the Contour Method of Residual Stress Measurement
Authors: Traoré Yéli , Hosseinzadeh Foroogh , Bouchard Peter John
Published: August 2014

The contour method is a powerful measurement technique that can provide two-dimensional maps of residual stress in engineering components. However, like most strain relief techniques, it can lose accuracy owing to plasticity when residual stresses have high magnitude relative to the yield strength of the material being measured. Finite element analysis is utilised to provide an insight into how plasticity introduced by material removal can influence the accuracy of the contour method. In addition the effect of component restraint during the cut is investigated and the results discussed with respect to published experimental measurements.
Residual Stress Measurement Methods Comparison in High-Strength Steel for Naval Application
Authors: Levieil Bruno , Calloch Sylvain , Doudard Cédric , Thévenet David , Leblé Bruno
Published: August 2014

Residual stresses can be beneficial or detrimental to mechanical structures. In this work, a rectangular plate specimen with a cold expanded hole was designed to study the influence of these stresses on low cycle fatigue of high-strength steel. Three separated measurements of the stresses were made using different techniques: indentation method, X-ray diffraction method and contour method. The results show good agreement with finite element modelling of the cold-expanded hole problem.
Residual Stress Measurements on a Metal Matrix Composite Using the Contour Method with Brittle Fracture
Authors: Araujo de Oliveira Jeferson , Fitzpatrick Michael E. , Kowal Jan
Published: August 2014

In this work we evaluate the application of the contour method to fatigue and fracture surfaces. Residual stress measurements were made on quenched and aged AA2124-SiCp composite using neutron diffraction, the contour method with wire EDM, and the contour method on a fatigue crack surface including brittle failure. The contour method successfully measured residual stresses from a wire electro-discharge cut surface, but the fracture method results suggest that residual stress information is lost due to plasticity during fatigue crack growth.
X-Ray Line Profile Study on Shot/Laser-Peened Stainless Steel
Authors: Kumagai Masayoshi , Akita Koichi , Imafuku Muneyuki , Ohya Shinichi
Published: August 2014

Microstructure and residual stress in AISI316 stainless steels processed via shot peening (SP) and laser peening (LP) were evaluated using X-ray line profile analysis and residual stress measurements. Although both specimens exhibited similar compressive residual stress profiles in the depth direction, the dislocation density in the SP specimen was greater than that in the LP specimen, while the crystallite size in the SP specimen was less than that of the LP specimen. Thus, the variation in the microstructural features in the samples subjected to the two processes differed.
Nondestructive Identification of Inhomogeneous Residual Stress State in Deformable Bodies on the Basis of the Acoustic Sounding Method
Authors: Dudarev Vladimir Vladimirovich , Nedin Rostislav Dmitrievich , Vatulyan Alexander Ovanesovich
Published: August 2014

Analysis of inhomogeneous residual stress (RS) fields in bodies is one of the major problems of the mechanics of deformable solid bodies. In the present research the new techniques of identification of inhomogeneous RS in bodies are developed on the basis of surface displacement measurement in a set of points under vibrating sounding load. Corresponding nonlinear ill-posed inverse problems (IP) are formulated and solved numerically by means of iterative regularization. Based on computational experiments, the most advantageous sounding load types and frequency ranges providing the best reconstruction accuracy are revealed. The examples for a cantilever, a plate, a layer, and a cylindrical tube are presented.
In Situ Observation of Stress Accumulation during Sub-Merged Arc Welding
Authors: Kromm Arne , Kannengiesser Thomas
Published: August 2014

Results obtained from laboratory tests mostly need to be verified under fabrication conditions in order to incorporate design specifics (joint configuration and restraint), which effect the residual stress state considerably. For this purpose, multi-pass sub merged arc welding was performed in a special large-scale testing facility. The impact of varying interpass temperatures could be proven in-situ by means of a pronounced stress accumulation during welding and subsequent heat treatment accompanied by stress determination using X-ray diffraction.
Evaluation of Weld Filler Alloying Concepts for Residual Stress Engineering by Means of Neutron and X-Ray Diffraction
Authors: Kromm Arne
Published: August 2014

Novel Low Transformation Temperature (LTT-) filler materials are specially designed for controlling residual stresses by means of adjusted martensite formation already during welding. Different alloying concepts compete for maximum stress reduction. Two newly developed LTT-alloys were evaluated concerning their potential for residual stress control. For this purpose residual stresses were determined in the surface and also in sub-surface areas of welded joints using X-ray diffraction and Neutron diffraction taking into account local variations of the unstrained lattice parameter.
Influence of Heat Control on Welding Stresses in Multilayer-Component Welds of High-Strength Steel S960QL
Authors: Schröpfer Dirk , Kannengiesser Thomas , Kromm Arne
Published: August 2014

Today high-strength structural steels (yield strength ≥ 960 MPa) are increasingly applied. Therefore, weldments have to achieve equal strength. Yet, high residual stresses in those welds diminish the components safety. Especially high restraint intensities can lead to crack-critical stress-levels. A special 2-MN-test facility allowed online-measurements of global reaction forces under defined restraint conditions during welding and cooling of multilayer-component MAG-welds. Local residual stresses were measured via X-ray diffraction before and after relief of the restraint. Local and global stresses were highly affected by heat control.
Residual Stress Distribution Caused by Laser Hardening and Conventional Quenching in Plain Carbon Steel
Authors: Filep Adám , Benke Márton , Mertinger Valéria , Buza Gábor
Published: August 2014

Heat transfer during laser hardening occurs from the surface towards the bulk in contrast to conventional quenching, where it occurs from the bulk towards the surrounding. The residual stress distributions due to laser hardening and conventional quenching of plain carbon steel samples were measured using X-ray diffraction. The effect of changing the treatment parameters, that is laser power and feed rate, was examined on the resulting stress distribution. The relationship between the measured stress distribution and the evolved microstructure is established.
Analysis of Thermal Effect on Residual Stresses of Broached Inconel 718
Authors: Chen Zhe , Peng Ru Lin , Avdovic Pajazit , Moverare Johan , Karlsson Fredrik , Zhou Jin Ming , Johansson Sten
Published: August 2014

Inconel 718 is a nickel based superalloy that is widely used as a turbine disc material in gas turbine industries. This study details the effect of thermal exposure on the residual stresses produced when broaching Inconel 718. The chosen parameters for broaching in this study are similar to those used when manufacturing turbine discs. The broaching operation produced a high level of tensile residual stresses at the broached surface. A layer with tensile residual stresses was formed in the sub-surface region, followed by a layer several times thicker with compressive residual stresses. Thermal exposure was conducted at 550 °C. The depth distributions of residual stresses after thermal exposure are presented and discussed in this paper. Complete relaxation of the surface tensile residual stresses was observed after 30 h thermal exposure, whereas the 3000 h thermal exposure influenced both the surface and sub-surface residual stress states.
Prediction and Measurement of Machining Distortion in Aluminium Alloy 7085
Authors: Zheng Zhang , Li Liang , Yang Yin Fei , He Ning , Zhao Wei
Published: August 2014

It is essential to accurately predict or model the residual stresses in a material resulting from various manufacturing operations. Numerical methods were used in this study to predict the residual stresses after quenching and cold compression of an Al 7085 forged block. Experimental verification was provided by comparing the measured distortions due to a relaxation of the residual stresses with the predictions obtained by using a simulated stress field. The validation was carried out on a simplified structural part. The measured and simulated distortions were found to be in good agreement with each other. The results indicated that part distortion is attributable to the relaxation of bulk residual stresses.
Residual Stresses in Different Heat Treated Workpieces after Turning
Authors: Lebsanft Markus , Tiffe Marcel , Zabel Andreas , Zinn Wolfgang , Biermann Dirk , Scholtes Berthold
Published: August 2014

The use of short process chains for the realization of complex and high performance components is a reasonable approach to achieve sustainable products and to reduce energy consumption. In the Collaborative Research Center SFB/TR TRR30 which is supported by the German Research Foundation DFG this approach is investigated applying thermo-mechanically forming processes. In this way, combining hot metal forming and heat treatment steps in a single process, tailored materials properties together with appropriate geometries are achieved [1, 2] . However, still additional machining operations, e. g. turning operations in case of shafts, are needed to achieve proper workpiece finish. Due to locally varying mechanical properties, undesired changings of the process conditions occur, leading to varying surface and subsurface properties, e.g. the residual stress state. It is well known that residual stresses have a major impact on the components properties during service [3]. In this paper, a survey is given about near surface residual stress states after exterior dry turning of differently heat treated cylindrical workpieces made of steel AISI 6150.
Residual Stress Evolution during the Manufacturing Process of Bearing Rings
Authors: Cseh Dávid , Benke Márton , Mertinger Valéria , Czibik Ádám
Published: August 2014

An innovative X-ray diffractometer was used to measure the residual stress being the source of a typical deformation failure called ovality on bearing rings. The equipment performs the measurements without sample cutting making it possible to measure the stress state of the same rings after each processing step. Thus, the stress state evolution during the complete manufacturing scenario was monitored on the same rings and the manufacturing process was revised.
Modification of Stress and Texture Distributions in Asymmetrically Rolled Titanium
Authors: Wronski Marcin , Wierzbanowski Krzysztof , Baczmański Andrzej , Wroński Sebastian , Bacroix Brigitte , Wróbel Mirosław , Lodini Alain
Published: August 2014

Asymmetric rolling can be used in order to modify material properties and to decrease forces and torques applied during deformation. This geometry of deformation is relatively easy to implement on existing industrial rolling mills and it can provide large volumes of a material. The study of microstructure, crystallographic texture and residual stress in asymmetrically rolled titanium (grade 2) is presented in this work. The above characteristics were examined using EBSD technique and X-ray diffraction. The rolling asymmetry was realized using two identical rolls, driven by independent motors, rotating with different angular velocities w1 and w2. It was found that asymmetric rolling leads to microstructure refinement, texture homogenization and lowering of residual stress.
High Pressure Interpass Rolling of Wire + Arc Additively Manufactured Titanium Components
Authors: Colegrove Paul A. , Martina Filomeno , Roy Matthew J. , Szost Blanka A. , Terzi Sofiane , Williams Stewart W. , Withers Philip J. , Jarvis David
Published: August 2014

Wire + Arc Additively Manufactured components contain significant residual stresses that manifest in distortion. Each layer of an additively manufactured wall was rolled with the aim of reducing the residual stress. Neutron diffraction and contour method measurements show that the residual stresses were reduced particularly at the boundary with the substrate. The process also reduced distortion, and refined the microstructure which may facilitate implementation on aerospace components.
Modeling of Stress and Strain Fields Induced during the Smart-Cut Process on Silicone - Influence of Different Couplings for Diffusion of Hydrogen at a Microscopic Scale
Authors: Zhao Yu Chen , Labergère Carl , Panicaud Benoit , Grosseau-Poussard Jean Luc , Goudeau Philippe
Published: August 2014

The Smart-Cut technology consists in the increasing of pressure imposed by the diffusion of hydrogen ions in the silicon substrate leading to a wafer splitting. In the present work, we studied the evolution of the stress field in the crystalline lattice of silicon, the diffusion of hydrogen ions as well as the growth and coalescence of cavities. Meanwhile, we test several models and simulate these phenomena by a numerical approach, in order to compare its results to experimental observations.
Effect of Surface Properties on the Fatigue Life of Manufactured Parts: Experimental Analysis and Multi-Axial Criteria
Authors: Sidhom Habib , Ben Moussa Naoufel , Ben Fathallah Brahim , Sidhom Naziha , Braham Chedly
Published: August 2014

The effects of machined and treated surface characteristics on the fatigue strength were analyzed on the basis of experimental results related to AISI D2 ground surface and AA 5083-H111 hammered surface. The fatigue strength improvement resulting from controlled grinding and mechanical surface treatment was discussed on the basis of the beneficial effect of the work hardening and the stabilized residual stress. A numerical procedure using F.E.M for calculating residual stress and work hardening evolution under cyclic loading has been developed. The validation of the numerical procedure was carried out by comparing the calculated residual stress profiles to those resulted from XRD measurements. The multi-axial criterion accounting for the work hardening and the residual stress was used to predict the fatigue life of notched samples.
Stress Relaxation in Shot-Peened Geometric Features Subjected to Fatigue: Experiments and Modelling
Authors: Achintha Mithila , You Chao , He Bin Yan , Soady Kath , Reed Philippa
Published: August 2014

This paper investigates experimentally and numerically the degree to which the stress relaxation in shot-peened simple geometric features of steel turbine materials can be modelled by using an understanding of simple eigenstrain distributions. The residual stress is determined as the elastic response of whole component when the plastic strains caused by shot peening is incorporated as an eigenstrain in an appropriate finite element (FE) model. The application of a subsequent live load is then modelled as an additional load step in the FE model which will superpose the effect of this loading on the residual stress field. The results show that the eigenstrain approach is particularly useful in predicting residual stress relaxation in shot-peened components.
Numerical Investigation of Welding Residual Stress Field and its Behaviour under Multiaxial Loading in Tubular Joints
Authors: Hemmesi Kimiya , Farajian Majid , Siegele Dieter
Published: August 2014

The lack of clarities in estimating the residual stress threat to the structural integrity has led to conservative assumptions in the current design of welds. The complexities become more in the case of multiaxial loading of welded structure, considering fracture or fatigue. To what extent the residual stresses influence the performance of a welded structure, depends on how stable they are under service loads. Finite element analyses are used here to describe the development of welding residual stresses in tubular joints and their relaxation under multiaxial loading. It is observed that the effect of the torsion load is more significant than the effect of tension load in releasing of the residual stresses. For pure tensile loading, the relaxation of the residual stresses are negligible as long as the applied load is lower than 50% of the yield strength of the material. For a combined tension-torsion loading of 75% of the yield strength, the residual stresses are almost completely released, and in the weld zone they become compressive.
Residual Stresses in Large Scale Structures Welded at Low Ambient Temperatures
Authors: Klassen Jakob , Nitschke-Pagel Thomas , Dilger Klaus
Published: August 2014

Prefabricated components during final assembling on site may be exposed to ambient temperatures below freezing point. Thus high cooling rates induce local hardening and can, however, affect distortion and residual stresses. These effects are investigated here for large-scale specimens in a climatic chamber simulating different possible ambient temperatures (down to-10 °C). Hereby experimentally obtained welding distortions and residual stresses are compared to numerical welding simulations.
The Effect of Specimen Dimension on Residual Stress Relaxation of the Weldments
Authors: Qian Zhong Yuan , Chumbley Scott , Johnson Eric
Published: August 2014

The purpose of this study is to evaluate the residual stress relaxation behavior in weldments. The stress relaxation is studied while successively reducing the size of weld specimens. Finite-element modeling was used to simulate the stress relaxation, and then an empirical model was derived based on the experimental and modeling results. The results of this study shall encourage industry users to utilize more plentiful conventional X-ray diffractometers for residual stress measurement of large weld components.
Influence of Xe Ion-Bombardment on the Substrate Microstructure and the Residual Stresses of Tin Coatings Deposited by Plasma Reactive Sputtering onto AISI 4140 Steel
Authors: Miranda Thaís Helena Carvalho , Vales Sandra , Becerra Erika Ochoa , Droppa Roosevelt , Brito Pedro , Garcia Jose Luis , Alvarez Fernando , Pinto Haroldo
Published: August 2014

The seek for sustainability in the global economic scenario has led to the need for developing materials that provide higher productivity, greater speed of operation, extended lifetimes and enhanced surface finishing of engineering parts. To achieve these goals it is essential to modify the metal surface with respect to its behavior in situations of friction, wear and oxidation at high temperatures. In this work, we studied the impact of different surface treatment strategies involving atomic peening with Xe ions and low temperature plasma nitriding on the surface microstructure of AISI 4140steel and the consequences of those surface treatments on the residual stresses of TiN coatings deposited onto the pre-treated substrates. The results show that ion bombardment at 1000 eV leads to mainly sputtering of surface material and no appreciable surface activation could be obtained for the subsequent plasma nitriding treatment. In the sample subjected to simple plasma nitriding, the highest nitride content was found and a Ti-enriched transition zone deposition appears to build up during the coating deposition. Accordingly the residual stresses of the TiN coatings deposited onto the nitrided steel surface were significantly lower in comparison to those encountered in the coatings grown on the non-treated, only bombarded and bombarded followed by nitriding substrates.
Relaxation of Residual Stresses in Brush-Plated Gold and Silver Coatings on Copper and on Brass Substrates
Authors: Lille Harri , Kõo Jakub , Ryabchikov Alexander , Reitsnik Renno , Sergejev Fjodor , Dong Min Jie
Published: August 2014

The investigated brush-plated gold and silver coatings are used for repairing the commutators of generators and sliding contacts. Tensile residual stresses generated in the plated coatings were determined by the curvature method and by instrumented indentation testing of a thin-walled open ring substrate, as described in our earlier papers. These stresses relax over time and their dependence on relaxation time was approximated by a linear-fractional function. The Young ́s modulus and nanohardness of the coatings were determined. The surface structure and cross section of the coated substrates were studied.
Effect of Interlamellar Spacing on the Monotonic Behavior of C70 Pearlitic Steel
Authors: Yahyaoui Houda , Sidhom Habib , Braham Chedly , Baczmański Andrzej , François Manuel , Seiler Wilfrid
Published: August 2014

The effect of interlamellar spacing on monotonic behavior of C70 pearlitic steel was investigated. Tensile tests under X-ray diffraction coupled with self-consistent model have been used to identify the role of interlamellar spacing on the ferrite plasticity parameters and residual stresses. It has been established that yielding of pearlite is controlled by ferrite critical shear stresses ( τc 0α) which is higher for the smaller interlamellar spacing. Moreover, the residual stress level in ferrite is higher for the largest interlamellar spacing under the same imposed total strain. Lattice strains, measured by synchrotron X-ray diffraction, show an elastic and plastic anisotropy of ferrite crystallites and high stresses in cementite which confirm the self-consistent model calculation. Keywords: Pearlitic steel, X-ray diffraction, Synchrotron radiation, Self-consistent model, Critical shear stress, Lattice strains.
Influence of Interlayer Macrostress on Oxidation of Shell Tubes from Zr-Based Alloys
Authors: Isaenkova Margarita , Perlovich Yury , Medvedev Pavel , Krymskaya Olga , Thu Soe San
Published: August 2014

Shell tubes from Zr-based alloys are responsible construction elements of atomic reactors. Under exploitation these tubes undergo to oxidation, which can become a reason for their cracking. Inevitable texture layering arises by rolling of tubes due to different values of the Q-factor, calculated for inside and outside tube layers. Therefore these layers are characterized by different texture Kearns parameters and, correspondingly, by different thermal expansion. As a result, tensile tangential macrostress operates between layers and oxygen diffusion into tube intensifies.
Influence of the Residual Stresses Induced by Shot-Peening on the Oxidation of Zr Plates
Authors: Optasanu Virgil , Jacquinot Pierre , Montesin Tony
Published: August 2014

The present study evaluates the influence of the residual stress on the oxidation rate of Zr at 650°C. It is shown that the oxidation rate can be substantially decreased by shot-peening. A systematic instigation of the various factors (such as the residual stress, the surface pollution and the chemical composition of the oxidation atmosphere) is realized to separate their influence on the oxidation. The influence of an annealing made after the shot-peening is also considered. One show that the pollution of the surface during the shot-peening process is not responsible for the oxidation rate decrease.
Experimental and Numerical Analysis of Mechanical Behaviour of AISI 316L Austenitic Stainless Steel: Two Level Homogenization – Neutron Diffraction
Authors: Fajoui Jamal , Gloaguen David , Legrand Vincent , Oum Guy , Kelleher Joe , Kockelmann Winfried
Published: August 2014

A two-level homogenization approach is adopted in order to predict the stress state of deformed polycrystals in correlation with the microstructure. This study is devoted to complex loading paths behaviour of cubic material. A mechanical description of the grain is developed through a micro-meso transition based on elastoplastic Kröner’s model. The meso-macro transition using a self-consistent approach is applied to deduce the global behaviour. Mechanical tests and neutron diffraction measurements are used to validate and assess the model.
Study on Solid-State Fermentation Tea Produced by Antrodia camphorate with Taizishen (Pseudostellariae heterophylla)
Authors: Guo Dan Zhao , Ma Hai Le , Wang Zhi Wu , Zhu Yi Hao , Yang Dan Dan , Gu Kai Hua , Han Bang Xing
Published: August 2014

Taizishen and A.camphorate were used respectively as primary medium and fermentation strain to obtain solid-fermentation tea in this paper. A.camphorate were inoculated into the optimal medium with Taizishen’s powder of 90%, glucose of 3 %, soybean flour of 6 % and gypsum powder for food of 1 %, and cultured at 26 °C. The fermentation procedure was ended on three days after the mycelia of A. camphorate growing all over the medium. The content of crude polysaccharides, total triterpenoids and amino acids were 12.03 %, 3.67 % and 4.6 % respectively in the solid-fermentation tea. The tea soup possessed good colour, special fruity from A. camphorate, mellow and full of taste.
The Influence Factors Study on Acid Corrosion Fracture Conductivity
Authors: He Shuang Xi , Wei Zi Chao , Liu Shuai , Chen Xing , Xia Sheng Miao , Hou Bo Heng
Published: August 2014

The influence factors of acid corrosion fracture conductivity included fracture width, acid type and concentration, close pressure, reaction temperature, acid injection rate, et al. The experiment was conducted to study the change of etched fracture conductivity with different acid type and close pressure. The results show that conventional acid tend to produce uniform etched fracture, gelled acid and self-diverting acid prefer to produce non-uniform etched fracture. Besides, conventional acid contributes to improve etched fracture conductivity, gelled acid and self-diverting acid contribute to stabilize fracture conductivity.
The Application and Synthesis of Dipolyethylene Glycol Maleate
Authors: Wang Bo , Ren Yun , Wang Sheng Li
Published: August 2014

Dipolyethylene glycol maleate was synthesized by decompression melting method, and the synthetic process was discussed. Five factors were optimized, including alcohol acid mole ratio, amount of catalyst, inhibitor dosage, reaction temperature and reaction time, designing L16(45) for orthogonal experiment. The best condition was determined: alcohol acid mole ratio is 2.1:1, the amount of catalyst is 4%,the inhibitor dosage is 3%, the reaction temperature is 120°C and the reaction time is 6h, the esterification rate reaches 96.46%. The macromonomer copolymerized with sodium allylsulfonate to produce polycarboxylate superplasticizer. The water consumption of Lithium ion battery slurry reduces 27% when the superplasticizer dosage is 0.6%. Slurry viscosity is 1786.6 MPa.s and 2680.3 MPa.s after 90min which meet requirements for coating technology.
Effects of Compound Probiotics on Growth Performance, Intestinal Microflora and Immune Function of Broilers
Authors: Wang Hong Ling , Yang Yu Hong , Wang Jia Qing , Wang Zhuo , Ma Shuang
Published: August 2014

This study aimed to investigate the efficacy of compound probiotics on broiler performance, intestinal microflora, immune function and serum biochemical indicators. Four hundred one-d-old female broiler chickens were randomly divided into 4 groups with 4 replicates in each group and 25 chickens per replication. The chickens in groupI(control group) were fed a basal diet, experimental groups II, III and IVwere fed the basal diet supplemented with 0.1%, 0.2% and 0.4% compound probiotics. The results of this work were as follows: (1) during the experimental period, compared with control group, the average daily in group III was significantly increased (P<0.05), the feed/gain and average daily feed intake were significantly lower (P<0.05); (2) at the age of 14 and 28 days, the number of cecal Lactic acid in group II and III were significantly higher than the control (P<0.05) and the content of E.coli has the opposite results. (3) the anti-body titer in group III was the highest, and significantly higher compared to the control (P<0.05), but there were no significantly differences between group IV and control group (P>0.05). (4) serum biochemical indexes of broilers in group III and IVwere significantly increased than that in control group (P<0.05). In conclusion, the supplementation of 0.2% compound probiotics could promote the growth performance, improve the cecal mico-ecosystem, enhance the anti-body titer and biochemical indexes in serum.