bluuebunny/crossref_metadata_2025 huggingface dataset:
Fire Stations and Firehouses Deployment Modeling
Authors: Jurdík Juraj , Mikolai Imrich
Published: December 2013

Problem of planning fire units deployment need deeper analysis. It will be appropriate to define standards and risk assessment for improving assistance to citizens. Effective support is defined as the minimum number of firefighters and equipment which must arrive on scene in a defined time. When we specify the number of firefighters and the optimal fire stations deployment, it is necessary to consider various factors influencing development of damages, consequences of emergencies and also operational and tactical options of firefighting units. This article summarizes theoretical knowledge of fire stations and compares different types of mathematical models of fire stations deployment.
Comparison Measuring Methods of Sound Insulation of Double Transparent Facade - NBS Bratislava
Authors: Urbán Daniel , Zaťko Peter , Dlhý Dušan , Tomašovič Peter
Published: December 2013

Acoustic of double transparent facades (DTF) is globally resolved only marginally. This paper presents the procedure and results of one of the acoustic measurements of DTF, which were carried out on the territory of Bratislava city. Measured was facade of the headquarters of the National Bank of Slovakia. This analysis is aimed at measuring of sound insulation of DTF, and the impact of using different sources of noise on the standardized level difference D2m,nT. The research is supported by grant project VEGA no.1/0358/13.
Impact Sound Insulation Concept for Lightweight Timber Floor
Authors: Medveď Juraj , Ingeleare Bart , de Geetere Lieven
Published: December 2013

This paper is the second continuation of lightweight timber frame floor construction investigation with a respect to impact noise isolation. We will log on to previous article which dealt with mockup investigation of new LWTF floor conception. The main objectives of research is to design lightweight floor with good impact sound insulation performance to achieve low cost and reduce thickness of construction. In the following chapters well outline results of new floor model on lightweight timber frame construction implemented in laboratory conditions in Belgian Building Research Institute in Limelette, Belgium.
Degradation of PVC-P Membranes in Flat Roof Compositions
Authors: Šutliak Stanislav
Published: December 2013

The degradation of PVC-P membranes in direct contact with bituminous membranes is well known problem. There is also the degradation of PVC-P membranes connected with EPS polystyrene incompatibility. Both bituminous membranes and EPS polystyrene board have been used to determine the differences in signs of PVC-P degradation.
New Physical-Energy Quantification of Buildings in the Development of the Technology in Architecture for a Sustainable Society
Authors: Bielek Milan , Bielek Boris , Híreš Juraj
Published: December 2013

Renewable energy sources as a conditioning factor of fundamental concept changes of energy quantification of buildings. 1st generation of low energy buildings. 2nd generation of low energy buildings. Green buildings with zero heat balance of the network - buildings with nearly zero energy balance of the network. Sustainable buildings with zero energy balance of the network. Sustainable building with an active energy balance in relation to distribution networks.
Influence of Facade Colour on Yearly Energy Need
Authors: Jurík Dušan , Chmúrny Ivan
Published: December 2013

Energy prices are constantly rising and that ́s why people are always looking for new ways to reduce energy costs. The main trend is to eliminate heat losses to the maximum extent. The demands for more sophisticated outer insulation for building still envelope (roofs, floors, walls, doors, and windows) are growing. Increased demands are evident also in the standards used in this area. Buildings with nearly zero energy (nZEB) become not only a vision but reality. Several ways for reduction of the energy needs are offered. The application of various colour adjustments of the building facade is one of the options. The impact of colour on the demand for heating and cooling at different thermal insulation capability is analyzed from the thermo - technical point of view. However, the question is whether it is possible to influence the annual costs for heating and cooling through the selection of facade colour (respectively through the absorption of solar radiation). We can say that today's architecture tries to use the structure of the building as some kind of thermal radiation (or rather solar energy) accumulator. In such a way we can characterize the majority of the structural designs for energy low cost buildings, where the main aim of such a solution is to reduce the energy need for heating and cooling.
Renewal of Panel Residential Houses from the Point of View of Energy Criterion
Authors: Gašparovičová Viera , Menďan Rastislav
Published: December 2013

A complex renewal of residential houses is a renewal of flats and common areas of the house so that they meet effective regulations and standards. Most of the residential houses in Slovakia built during last sixty years fall into the category of panel systems. An important criterion for determination of the extent of renewal of panel residential houses is required specific energy need for heating (energy criterion) and proving of precondition of satisfaction of energy economy of a building (criterion of minimum requirement on energy economy of buildings). In connection with the effect of new standard STN 73 0540:2012, the requirements for building constructions and buildings changed. Therefore, the residential houses of panel systems were evaluated in this paper from the point of view of the energy criterion both in original state and after the renewal by adding thermal insulation on walls, roof and replacement of windows.
Experimental Study of Surface Roughness of Wood Plastic Composites after Turning
Authors: Hutyrová Zuzana , Harničarová Marta , Zajac Jozef , Valíček Jan , Mihok Jozef
Published: December 2013

In this study, surface characteristics of the samples of experimentally manufactured woodplastic composites (WPC) were determined. Turning process was used to produce surfaces by removing material from a rotating workpiece. For turning, the rotation speed, feed, and depth of cut determine the rate of material removal and resulting surface quality. The surface roughness is one of the most important factor affecting coating performance of the WPCs. Parameters of surface roughness (final micro-geometric characteristics Ra, Rz) of the samples was determined using a stylus-type profilometer Surftest SJ 401. This information will provide baseline data on the quality of WPC samples after turning.
Biosurfactant Producing Bacteria with Tensoactive and Emulsifying Properties Isolated from Palm Oil Mill Effluent
Authors: Marajan Caroline , Ramasamy Kalavathy , Abdul Talib Suhaimi
Published: December 2013

This study introduces potential biosurfactant producing bacteria found in agro-based wastewater generated by palm oil mills. A total of 38 potential biosurfactant producing bacteria isolated from palm oil mill effluent were qualitatively screened for its tensoactive properties using drop collapse and oil spreading tests. Eleven of the 38 isolates exhibited high surface activity through the drop collapse test. The 11 isolates also exhibited clear zones ranging between diameters 2 to 3 cm through oil spreading test which indicated biosurfactant production. Further evaluations were performed quantitatively for all the 11 isolates in relation to their ability in reducing surface tension and emulsifying capability. Results from Du Nouy ring test demonstrated that the isolates successfully reduced surface tension of water from 72 mNm-1 to below 40 mNm-1. When tested for emulsifying properties, these isolates displayed high emulsifying activity indicating the presence of biosurfactant production. These 11 isolates namely R06, R07, R08, R10, S08, S09, S10, S11, S12, S15 and S17 were selected and identified using 16S rDNA gene sequence analysis. The results suggested that the isolates belong to the genus Bacillus.
Enhanced Adsorption of Pb(II) on Chemically Treated Neem (Azadirachta indica) Leaf Powder
Authors: Hanafiah Megat Ahmad Kamal Megat , Alias Munirah , Khalir Wan Khaima Azira Wan Mat , Zakaria Haslizaidi
Published: December 2013

Neem (Azadirachta indica) leaf powder was treated with hydrogen peroxide followed by sodium hydroxide and its performance in Pb (II) removal was investigated. The characteristic of chemically treated neem leaf powder (CTNLP) was studied using Attenuated Total Reflectance Infra-red (ATR-IR) spectrometer and CHNOS Analyzer. The amount of Pb (II) adsorbed increased with increasing pH, concentration and contact time. The kinetic study indicated that adsorption equilibrium time was dependent on initial Pb (II) concentrations. The adsorption kinetic data fitted the pseudo-second-order model. The maximum adsorption capacity calculated from the Langmuir isotherm model was 227.3 mg/g. This study suggests suitable use of CTNLP as an adsorbent for treating wastewater containing Pb (II).
Validation of Nitinol SMA Characteristics Using Finite Element Analysis and Closed Form Solutions
Authors: Adarsh S.H. , Mallikarjun U.S.
Published: December 2013

Shape Memory Alloys (SMA) are promising materials for actuation in space applications, because of the relatively large deformations and forces that they offer. However, their complex behaviour and interaction of several physical domains (electrical, thermal and mechanical), the study of SMA behaviour is a challenging field. Present work aims at correlating the Finite Element (FE) analysis of SMA with closed form solutions and experimental data. Though sufficient literature is available on closed form solution of SMA, not much detail is available on the Finite element Analysis. In the present work an attempt is made for characterization of SMA through solving the governing equations by established closed form solution, and finally correlating FE results with these data. Extensive experiments were conducted on 0.3mm diameter NiTinol SMA wire at various temperatures and stress conditions and these results were compared with FE analysis conducted using MSC.Marc. A comparison of results from finite element analysis with the experimental data exhibits fairly good agreement.
Researches Concerning the Phenomena at the Interface for the Sintered Compacts of Titan-Hydroxyapatite
Authors: Băilă Diana Irinel
Published: December 2013

The behaviour of metallic powders is very important for manufacturing parts and for realize the prototypes. Manufacturing of the orthopaedic implants by selective laser sintering process can be used in medicine.
The powders necessary for SLS process are biomaterials who must assure a good osteointegration of endobone implants like the Ti powder (Ti-6Al-4V) and the hydroxyapatite powder. The conditioned powders is a very important process and is necessary in SLS to obtain medical prothesis and influence the final properties of prothesis. Materials must present a gradient for porosity and one for composition (presents of a bioactive phase in titan matrix).
The exterior porosity, in the contact zones with the bone tissue, favors the incipient cellular processes (the adhesion and attachment of osteoblastes, proliferation and cellular differentiation and nucleation of mineral bone). The pores must be open and with a specific surface more great. Its preferred the exterior intercommunicating porosity. The presence of phosphates of calcium in the contact zone of the implant with bone favors the mineral kernel on bone. The report Ca/P of phosphates mineral bone has an ascending evolution towards 10/6 according to hydroxyapatite.
Numerical Investigation of the SiGe/Si Heterostructure Including Interfacial Defects for Photovoltaic Applications
Authors: Kacha K. , Djeffal F. , Bentrcia T. , Arar D. , Meguellati M. , Chahdi M.
Published: December 2013

To improve the electrical performance and reduce the fabrication cost of the solar cell, thin-film solar-cell concepts are widely explored. In this context, many studies have been carried out to study the impact of the thin thickness of the material on the solar cell behavior. Recently, the Si1-xGex/Si heterostructure is considered as attractive alternative for photovoltaic applications due to their band structures, which allow getting an additional gain in the device efficiency. However, the growth of this material is not totally controlled, and the presence of interfacial defects is more than estimated after a growth run of this material. Therefore, new experimental and numerical investigations which capture the Si1-xGex/Si heterostructure behavior should be developed in order to build a complete Si1-xGex/Si-based solar cell model for photovoltaic applications. In this paper, we aim at highlighting the immunity of the Si1-xGex/Si heterostructure against the defects degradation effect at nanoscale level (thin films). The effect of interface defect on the heterostructure has been carried out by extensive simulation using Atlas 3-D simulator, including the device dimension and the Ge Mole fraction effects.
Investigation on the Structural Properties of a New Prepared 0.2PZS-0.8PLZT Ceramics
Authors: Sakri Adel , Boutarfaia Ahmed
Published: December 2013

View of the importance that has the development in the field of advanced technology transmission in human life, smart materials draws the attention of many researchers. In this contribution, we are interested in synthesizing a new smart material of the ceramic type based on Pb, Zr, Ti (PZT) doped La in the site A, and Sb, Zn in site B from a solid solution of pure oxides. The synthesized samples are thermally treated at 800°C. The techniques of x-ray diffraction (XRD) and SEM (scanning electron microscopy) are used to characterize the microstructure (the crystallographic phase), and the densities of the obtained samples were determined from their weights and volumes. The effect of sintering temperature on the microstructure properties was studied.
Residual Stress and Microstructures Characterization in Welded Al-Si-12Cu Alloy
Authors: Boumerzoug Zakaria , Bouremel Chérifa , Ji Vincent
Published: December 2013

X-ray diffraction method has been used to analyze the residual stress distribution across the joint of Al-Si-12Cu alloy just after welding process. On the other hand, isothermal heat treatments have been applied in order to study the residual stress evolution in this material. Optical microscope observation and Vickers hardness measurement have been carried out as complementary microstructure techniques. The different zones of welded joint have been analyzed, where the fusion zone was characterized by dendritic structure and different to heat affected zone. We have found a softening phenomenon in welded joint after heat according to microhardness results.
Steady State Conduction Behaviour of Liquid Crystalline Polyurethane
Authors: Quamara Jitender Kumar , Mahna Satish Kumar , Lal Sohan , Raj Pushkar
Published: December 2013

The steady state measurements in Liquid crystalline polyurethane (LCPU) have been investigated for different fields (4 - 45 kV/cm) and temperatures (50°-220°C). The nature of conduction processes has been determined by estimating ion jump distances (a) and Schottky coefficients. The order of magnitude of a in the temperature region 150°C and below does not seem to support an ionic conduction. However the magnitude of a at higher temperatures (180°C and above) indicates the possibility of ionic conduction. There is a definite possibility of a Schottky type conduction at lower temperature and a Poole Frankel type conduction at higher temperature (100°C). The activation energy associated with the high temperature region lies between 0.26 eV and 0.65 eV depending on the field whereas in the low temperature region the activation energy lies between 0.82 eV and 0.95 eV depending on the applied electric field. The dual slopes in the log I versus 1/T curves indicate the presence of more than one type of trapping levels.
Effect of Gate Dielectrics on the Performance of P-Type Cu2O TFTs Processed at Room Temperature
Authors: Al-Jawhari Hala , Caraveo-Frescsa J.A.
Published: December 2013

Single-phase Cu2O films with p-type semiconducting properties were successfully deposited by reactive DC magnetron sputtering at room temperature followed by post annealing process at 200°C. Subsequently, such films were used to fabricate bottom gate p-channel Cu2O thin film transistors (TFTs). The effect of using high-κ SrTiO3 (STO) as a gate dielectric on the Cu2O TFT performance was investigated. The results were then compared to our baseline process which uses a 220 nm aluminum titanium oxide (ATO) dielectric deposited on a glass substrate coated with a 200 nm indium tin oxide (ITO) gate electrode. We found that with a 150 nm thick STO, the Cu2O TFTs exhibited a p-type behavior with a field-effect mobility of 0.54 cm2.V-1.s-1, an on/off ratio of around 44, threshold voltage equaling-0.62 V and a sub threshold swing of 1.64 V/dec. These values were obtained at a low operating voltage of-2V. The advantages of using STO as a gate dielectric relative to ATO are discussed.
CFD Study on the Role of Gas Friction on the Molten Layer Shape and Melt Removal Mechanism in Laser Cutting Process of Steel
Authors: Kheloufi Karim , Amara El Hachemi
Published: December 2013

A numerical analysis of the role of the gas friction force on the shape of the melt surface in laser cutting process is carried out. The liquid film shape is analyzed in the central plane of cutting for both cases with the pressure gradient force only and for the case of gas friction force contribution. It is shown that, the gas friction force has a significant role in the formation of humps in the central kerf zone and the transition from the smooth melt ejection regime to a wavy structure characterized by humps formation.
Effect of Melt Cooling Rate on Microstructure of Sn - Bi and Sn - Pb Eutectic Alloys
Authors: Gusakova Olga , Shepelevich Vasiliy , Scherbachenko Lilia
Published: December 2013

The results of microstructure investigation of eutectic alloys Sn Bi and Sn Pb, obtained at cooling rates of the melt 10-2 K/s, 1 K/s and 105 K/s are represented. Various cooling rates are achieved by graphite mold casting and by ultra fast quenching from the melt. Microstructure and grain structure are investigated by scanning electron microscopy and the electron backscatter diffraction technique. It has found that the melt cooling rate increasing at rapid quenching leads to microcrystalline structure and to a change of the solidification mechanism. The reasons for the transition from lamellar to the microcrystalline structure are discussed.
The Effect of Intercritical Deformation on Microstructure Development in Thermomechanically-Processed Low-Silicon TRIP-Assisted Steels
Authors: Kazem Hosseini Seyed Mohammad , Zarei-Hanzaki Abbass , Yue Stephen
Published: December 2013

The effect of intercritical deformation on development of microstructure in low-silicon contents multiphase TRIP-assisted steels were investigated by laboratory simulation of controlled-thermomechanical processing in an automated hot compression testing machine. A typical multiple cooling stages TMP program was applied and samples were deformed in intercritical region to different strains. Microstructures of samples were characterized by optical and scanning electron microscopy, XRD and Mössbauer. The result indicated that intercritical straining increases volume fraction of polygonal ferrite and granular-type retained austenite particles, but reduces fraction of bainite. The increase in retained austenite volume fraction is attributed to strain-assisted diffusion of carbon and to refinement of retained austenite particles.
Evaluation of the Physical and Mechanical Properties of Ceramic Tiles Processed Using Steel Slag
Authors: Chukwudi Benneth C. , Okorie Boniface A.
Published: December 2013

This present study has evaluated the physical and mechanical properties of ceramic tiles processed from steel slag. The chemical compositions of both samples were conducted using atomic absorption spectrophotometer (AAS). Steel slag in the range of 0-100wt% was added to kaolinite clay. The blended samples were hydraulic pressed into rectangular moulds, oven dried and sintered within the temperature range of 1100°C - 1200°C. Surface appearance and colouration of sintered products were observed. Linear shrinkage, apparent porosity, water absorption, bulk density, apparent specific gravity and modulus of rupture of sintered samples were examined. Phases present were identified using X-ray diffraction (XRD), while microstructural examination was conducted using scanning electron microscopy (SEM). Phases like quartz, wollastonite, enstatite, were identified. SEM showed considerable degree of vetrification at both temperatures. Results obtained showed that samples containing 25-75wt% steel slag have very good usable ceramic tile properties.
Significant Atomic Displacement at Isostructural Transition in Li0.99Cu0.01CrO2 and its Effects
Authors: Karmakar Arindam , Dey Koushik , Giri Saurav , Majumdar Subham
Published: December 2013

LiCrO2 is a triangular lattice antiferromagnetic compound exhibiting geometrically frustrated two dimensional arrangement of Cr ions with TN = 62 K at which an isostructural transition occurs. We show, using temperature dependent high energy synchrotron X-ray diffraction studies, that upon a nominal 1% Cu doping at the Li site, there are large changes in structural parameters and the (coupled) magnetic and dielectric properties.
AFM Studies of Thin Films as Nanobiosensor for Early Detection of Prostate Cancer
Authors: Ani Najeeb Mansoor , Chavali Murthy
Published: December 2013

India has the highest incidences of prostate cancer in the world. The elevated occurrence of prostate cancer in India has long been linked with the lifestyle and family history. The survival rate of prostate cancer is 6080% when detected during its early stages; however, this number drops to 3040% when the cancer is diagnosed during the advanced stages. A sol-gel based nanobio sensor can be developed for the detection of prostate cancer from blood using Prostate Specific Antigen (PSA), a prostate cancer marker. Solgel-derived materials can be exploited for the manufacturing of various optoelectronic devices, including sensors optodes and their protective layers, as well as other kinds of coatings. One of the objectives of present study is to explicate the changes in the internal environment of the sol-gel.
Ultrafine Solid State Polymerized PA66 Nanofibers Fabrication via Air-Sealed Centrifuge Electrospinning (ASCES)
Authors: Valipouri Afsaneh , Hosseini Seyed Abdolkarim , Pishevar Ahmadreza
Published: December 2013

This study presents a method for the fabrication of ultrafine polymeric nanofibers utilizing centrifugal and electrostatic forces simultaneously. To reduce the diameter and variability of nanofibers produced from solid state polymerized PA66 (SSP PA66), a unique electro-centrifuge spinning device was designed using rotating nozzle and collector, whereas the fabrication process (spinning head) was skillfully sealed from ambient airflow. An electric field is applied between the nozzle containing the polymer solution and cylindrical collector. Due to centrifugal force, polymer solution is ejected from the nozzle tip and extended by centrifugal force as well as electrical force. The diameters of nanofibers were controlled by adjusting the selected affecting parameters such as solution concentration, rotational speed of spinning head, syringe content as well as applied voltage. With this new technique, nanofibers were electrospun from SSP PA66 solutions. Field emission scanning electron microscope (FESEM) results demonstrated that ASCES has the unique ability to produce high quality ultrafine nanofibers from SSP PA66 polymer. Well control of parameters was tended to produce the thinnest fibers with mean diameter of 63 nm.
Structure and Magnetism of Fe/Al Nanostructures Grown by Ion-Beam Sputtering
Authors: Vyas A. , Shripathi T. , Lakshmi N. , Seeck O.H. , Vij A. , Brajpuriya R.
Published: December 2013

Synchrotron based X-ray diffraction (XRD) and X-ray reflectivity (XRR) were used to study the structural and magnetic properties of ion beam sputtered Fe/Al multilayer sample (MLS) as a function of annealing temperature. The structural studies show substantial intermixing between the layers which results in multilayer of complicated structures i.e. formation of thin intermixed FeAl layer at the interface during deposition, the nucleation and precipitation of disordered FeAl layer, and its subsequent growth to Fe3Al at higher temperature. The results were also supported by TEM measurements. Magnetization decreases with increase in temperature and Curie temperature (Tc) is found to be much less than that of bulk bcc Fe.
Enhancement in Thermal Property of Phase Change Microcapsule with Modified Carbon Nanotube
Authors: Li Min , Wu Zhi Shen
Published: December 2013

Carbon nanotubes grafted with stearyl alcohol (CNTs-SA) was used to enhance the thermal conductivities of the microcapsules. Differential Scanning Calorimeter (DSC) and thermogravimetry (TG) analysis method are employed to measure thermal properties of the prepared MicroPCM containing the grafted CNTs (MicroPCM/CNTs-SA). The results indicated the phase change temperature and latent heat of MicroPCM/CNTs-SA was 26.2°C and 47.7J/g. An increase in thermal conductivity, thermal stability of MicroPCM/CNTs-SA was observed. After 100 heating and cooling cycles, MicroPCM/CNTs-SA still had better durability and thermal stability.
Biogas Production from Napier Grass (Pak Chong 1) (Pennisetum purpureum × Pennisetum americanum)
Authors: Janejadkarn Apiwaj , Chavalparit Orathai
Published: December 2013

The objective of this research was to evaluate the quantity of biogas production from napier grass (Pak Chong 1) (Pennisetum purpureum × Pennisetum americanum) in three identical continuously stirred tank reactor (CSTRs) at room temperature. The volatile solids feed was varied at 1.5, 2 and 3%, respectively. The organic loading rate was altered at 0.43, 0.57 and 0.86 kg VS/m3.d in CSTR 1, 2 and 3, respectively. Three laboratory scale CSTRs with working volume of 5 l were carried out. The results showed that the optimum volatile solids fraction was 2% VS with maximum biogas production of 0.529 m3/kg VS added. The methane production was achieved at 0.242 m3/kg VS added. Under this condition, the soluble chemical oxygen demand (SCOD) of the hydrolysate was increased by 74% and the SCOD and VS removal efficiency were obtained 52.52% and 55.98%, respectively. The highest total volatile fatty acid was obtained on day 12, which was 5.51 g/l and the highest concentration of HAc was 4.33 g/l. The results indicated that volatile solids fraction was 2% VS achieves a maximum biogas yield and can be successfully converted using anaerobic digestion and was investigated into economical and scalable.
Study on the Performance of the Organic Rankine Cycle System with Internal Heat Exchanger under Vehicle Engine Various Operating Conditions
Authors: Yang Kai , Zhang Hong Guang , Wang Zhen , Zhang Jian , Yang Fu Bin , Wang En Hua , Yao Bao Feng
Published: December 2013

Through experiment, the variation of the exhaust energy of the vehicle diesel engine is studied, a set of vehicle diesel engine-organic Rankine cycle (ORC) combined system with internal heat exchanger (IHE) is designed, the zeotropic mixtures R416A is used as the working fluids for the ORC system with IHE, by theoretical analysis and numerical calculation, the variation of the vehicle diesel engine-ORC combined system with IHE under entire operating conditions of the diesel engine is studied, the calculation results show that, when engine is operating at high speed and high torque, the performance of the vehicle diesel engine-ORC combined system with IHE is higher.
VPP Processed Variable Phase Controller for Array Antenna Scanning
Authors: Zafar J. , Zafar H. , Gibson A.A.P.
Published: December 2013

An appropriate configuration of the magnetic bias geometry used in waveguide based phase control sections can help to reduce size, bulk and energy utilization. In this paper ferrite inserts for a toroidal phase controller are fabricated using a viscous plastic processing method. This technique has been exploited to produce a low reluctance magnetic geometry that avoids machining. The magnetostatic result for the bias geometry has been computed and used to analyze the phase control characteristics of a twin toroid phase controller. The microwave response in terms of S-Parameter over 8-12 GHz for various magnetization levels has been measured. The insertion loss of less than 1.1 dB has been achieved. The reflection coefficient (<22 dB) has been experimentally verified.
Numerical Simulation of the Mechanical Structure of a Helmet Motorcyclist
Authors: Naïma Bessai , Fatiha Boudjemaa , Mourad Lounis , Danie Baumgartner
Published: December 2013

Road safety is of high importance in our modern life in terms of social and economic. The helmet is the head protective system the most common used. Their main function is to reduce or prevent damage that may occur during an impact due to an accident. The head will be better protected if the more important quantity of the energy caused by the kinetic energy of the impact is absorbed by the helmet. The greater part of the impact energy should be absorbed by the deformations of the different layers of the helmet. The analytic equations of the model of the helmet parts show a realistic dynamic reaction of the different layers after the shock impact. These results will permit a better comprehension of the helmet behaviour to violent impact and the energy distribution in the different layers so a better optimisation of the head helmet in the future.
The Chip in the Up and Down Milling Process
Authors: Fečová Veronika , Michalik Peter , Zajac Jozef , Mihok Jozef , Berthoty Jozef
Published: December 2013

The milling is the most used technology in engineering. The shape of chip is important for its transport and for economical aspect of this technology. The volumetric coefficient of chip represents the shape of chip. The small chip has a lower volumetric coefficient, but the very small chip is not very desired in the machining, because it can damage the machine. The main aim of this contribution was monitoring of chip in the milling process by high-speed camera and consequently the evaluation of this chip by the volumetric coefficient of chip. This coefficient was monitoring in the peripheral up and down milling with the different radial cutting depth.
Effect of Silver Nanoparticles on the Mechanical and Physical Properties of Epoxy Based Silane Coupling Agent
Authors: Balakrishnan Vengadaesvaran , Arun N. , Chanthiriga R. , Bushroa A.R. , Rau S. Ramis , Kasi Ramesh , Alshabeeb G.H.E. , Subramaniam Ramesh T. , Arof A.K.
Published: December 2013

In this work, silver nanoparticles were synthesized using the precipitation method at room temperature. The size of the silver nanoparticle was analyzed using transmission electron microscope and found to be in the range of 20 to 40 nm. The multi-functional transparent film on glass substrate was prepared using silver nanoparticle solutions and 3-Glycidyloxypropyltrimethoxy silane (GLYMO) by dip coating method. Ultraviolet visible spectroscopy measurement shows low absorbance thus confirming high transparency level. The critical load obtained from the micro-scratch test showed an increase from 3000 mN to 3319 mN.
Use of Cellular Automata for Modelling of the Carbon Nanolayer Growth on a Light Alloy Substrate
Authors: Golabczak Marcin , Konstantynowicz Andrzej , Golabczak Andrzej
Published: December 2013

Carbon deposition forming a nanolayer on a light alloy substrate is a physico-chemical process of the discrete type in all of its aspects. Thus, use of cellular automata, intrinsic discrete, as a mathematical tool for modelling, is fully justified. We adopted two-dimensional (i.e. surface), two-layer automation with Moore vicinity of a cell, for modelling of the carbon deposition process, starting from bonding to the light alloy substrate, leading through layer growth and finishing at the phase transition process, converting graphite into diamond form. To achieve this, we related the transition probabilities of the automaton with the Lennard-Jones potentials for carbon and metal atoms, as well as the physico-chemical conditions in the reaction environment gaseous hydrocarbons density and their particles energy distribution (Maxwell). Taking it into account allowed us to establish an automation time scale of about 1s per calculations run, which has resulted in a simulated layer thickness growth rate well matched with observed results. Using of the two-layer automation allowed us to make some survey into the mechanism of the graphite/diamond transition in the real environmental conditions we met. This demanded further thorough investigations to properly model the spatial structure of mutually interleaved areas of the graphite and diamond type carbon, giving not only a flat-surface but also a vertical structure. The overall surface morphology of the simulated nanolayer we have compared with those of AFM survey performed on real samples, observing relatively good matching in terms of statistical parameters of the surface.
Diffusion Processes in the Sintering of Zirconia-Based Nanomaterials
Authors: Melikhova Oksana , Čížek Jakub , Procházka Ivan , Anwand Wolfgang , Konstantinova Tetyana E. , Danilenko Igor A.
Published: December 2013

In the present work, zirconia-based nanomaterials with various stabilizers were prepared by a co-precipitation technique. Defects in these nanomaterials were characterized by positron annihilation spectroscopy which is a non-destructive technique with a high sensitivity to open volume defects and atomic scale resolution. It was found that zirconia-based nanomaterials contain vacancies and also nanoscale and meso-scale pores. Diffusion processes which occur in the nanomaterials sintered at elevated temperatures were investigated by depth sensitive positron annihilation studies on a variable energy slow positron beam. It was found that sintering causes intensive grain growth and residual porosity is removed from samples by diffusion to the surface.
Effect of Annealing Temperature of Magnesium Doped Zinc Oxide Nanorods Growth on Silicon Substrate
Authors: Mohamed Ruziana , Khusaimi Zuraida , Abdullah Nurul Afaah , Aziz Aadila , Mamat Mohamad Hafiz , Rusop Mohamad
Published: December 2013

Magnesium (Mg)-doped zinc oxides (ZnO) have been prepared on a silicon substrate by using the solution-immersion method. The nanorods films were annealed at different temperature 0°C, 250°C, 500°C respectively for 1 hour. The XRD diffraction indicated that the Mg-doped ZnO nanorods have good crystallinity with a hexagonal wurzite structure preferentially oriented along the (002) direction. PL spectroscopy at room temperature shows strong UV peaks appearing at 383 nm when annealed at 250°C. The intensity of broad emission peaks increases with increasing annealing temperature to 500°C which is possibility attributed to intrinsic defects.
Effect of SiC Particles Dispersion on the Grain Size and Mechanical Properties of Cu/SiC Metal Matrix Nanocomposites Produced via MFSP
Authors: Barmouz Mohsen , Araee A.
Published: December 2013

Friction stir processing (FSP) has been found as a promising method for surface modification of materials such as grain refinement and hardness increment. FSP is also widely used for fabrication of in situ micro-and nanocomposites on the surface of materials. In this research FSP is used for inserting the nanosized SiC particles into the copper matrix. Subsequently, 4-pass FSP is applied to obtain good dispersion of SiC particles in copper matrix leading to improve the mechanical properties of the fabricated composite. The optical microscopy and scanning electron microscopy are used for microstructural evaluation. Results show that an increase in the number of FSP passes considerably enhances the dispersion of the SiC particles in the stir zone and also breaks down the SiC particles. These phenomena lead to reduction of the grain size and improvement of mechanical properties in 4-pass composite compared to that of fabricated by 1-pass FSP.
Optical Properties of Amorphous and Nanostructure Si/SiO2 Quantum Wells
Authors: Takeuchi Toshio , Kondo Minoru , Fujuta Miki , Kawaharazuka Atsushi , Horikoshi Yoshiji
Published: December 2013

Amorphous Si/SiO2 quantum wells have been obtained at room temperature with atomic precision using magnetron sputtering. The Si/SiO2 layer structure induces the higher optical transmittance at the visible wavelength region with increasing layer numbers. The tentative absorption coefficients are evaluated for integrated Si thicknesses. The absorption edge energy dependency on Si layer thickness E0 = 1.61 + 0.75d-2 is in accordance with effective mass theory for thicknesses 0.5 < d < 6nm. Quantum confinement effects of the Si/SiO2 nanostructure layer are confirmed from optical transmittance and reflectance spectra.
Application of ZnO Nanostructures in Improvement of Effective Surface Parameters in EOR Process
Authors: Esmaeilzadeh Pouriya , Fakhroueian Zahra , Nadafpour Mohammad , Bahramian Alireza
Published: December 2013

ZnO nanosphericals and nanorods have interesting potential applications in various fields such as antibacterial and enhanced oil recovery process. In this work, it was shown that 30 ml of a water-based solution containing 3% of ZnO nanofluids could significantly change the wettability of a carbonate reservoir rock from a strongly oil-wet alter to a strongly water-wet condition, after 3 days aging of the rock at 70°C in the designed solution. Moreover, we have studied air-water and oil-water interfacial tensions of system containing nanofluids. Fluids included ZnO nanoparticles and quantum dots nanostructures (QDOTs ZnO) could effectively decrease the n-decane/water interfacial tension and air/water surface tension. So their efficiency is much higher in comparison with distilled water.The stabilization of various aqueous ZnO nanostructured in mixtures of NaCl, CaCl2, MgCl2 and Na2SO4 salts were investigated, and 50000-163000 ppm transparent and stable nanosalt fluids were fabricated. Wettability of an oil-wet carbonate rock aged for 3 days at 70°C in the designed ZnO nanosalt fluids was studied by measuring the contact angles. The results show a strong change in wettability of carbonate rocks from oil-wet to more water-wet condition. These nanosalt fluids performed an excellent trend of surface tension and IFT reduction in comparison with distilled water too.
Evaluation five years after a Refinary Oil Spill in freshwater wetland - Paraná State, Southern of Brazil
Authors: Katsumiti Alberto , França Patricia P , Silva Costa G P , Zandoná E M , Benica Cristiane , Silva de Assis Helena , Cestari Marta , Maschio J , Randi M A , Silva C A , Roche H , Oliveira Ribeiro Ciro Alberto de
Published: December 2013

In order to evaluate the Getúlio Vargas refinery oil spill - 2000, Paraná State - Brazil the presence of PAHs in the sediment, PAHs bioavailability through bile chemical analysis and biochemical and morphological biomarkers were investigated in a native fish species Hyphessobrycon reticulates. The histophatological parameters were also considered to another native species Phalloceros caudimaculatus. Sediment analysis showed the presence of 5-6 rings PAHs on the surface layer and 2-3 rings PAHs in the deepest sediment showing that oil is still accumulated in sediment, and its bioavailability is confirmed by the accumulation of PAHs in bile. Lipid peroxidation, catalase (CAT), GST and cholinesterase activities indicated respectively oxidative stress in liver of H. reticulatus and neurotoxicity, also evidenced by genotoxic and histopathological damages. Despite of the occurrence of other pollutants not identified in the current study, the data presented here may suggest that 5 years after the accident animals as fish can be still affected by hydrocarbons and PAHs presented in the sediment. Concluding, studies must be done to confirm that with a more sophisticated chemical analysis, but this work is the only study realized after the accident. We strongly suggest a new study to compare and verify if still there is risk to biota.
Statistical analysis to characterize transport of nutrients in groundwater near an abandoned feedlot
Authors: Gbolo P. , Gerla P.
Published: December 2013

Abstract. Surface water from a lagoon and groundwater samples from 17 wells within and near an abandoned feedlot in northwestern Minnesota, USA, were analyzed for carbon, nutrients, and field parameters. The feedlot is surrounded by wetlands that act as receptors of nutrients from the feedlot. Q- and R-mode multivariate analyses performed on total carbon (TC), inorganic carbon (IC), total organic carbon (TOC), nitrite-nitrogen (NO2-N), nitrate-nitrogen (NO3-N), ammonium-nitrogen (NH4-N), soluble or dissolved reactive phosphorus (DRP), and total phosphorus (TP) indicated three groups of the chemical species, which reflected variability in groundwater chemistry. Factor analysis indicated approximately 82% of the variability in factor 1 was caused by TC, IC, TOC, and DRP, while in factor 2 approximately 79% of the variability was caused by NO2-N, NO3-N, and TP. In factor 3, only NH4-N contributed 31% of the variability. Groundwater isotope and spatial distribution analysis indicated reduced nitrate concentration from the source to the wetlands, with variation in NO2-N, NO3-N, and NH4-N concentrations attributed to the plant nutrient uptake, high rate of denitrification and/or the dissimilatory nitrate reduction to ammonium. This study indicated the value of multivariate analyses in characterizing variability in groundwater quality.
Examining the spatial and temporal variation of groundwater inflows to a valley-to-floodplain river using 222Rn, geochemistry and river discharge: the Ovens River, southeast Australia
Authors: Yu M. C. L. , Cartwright I. , Braden J. L. , de Bree S. T.
Published: December 2013

Abstract. Radon (222Rn) and major ion geochemistry were used to define and quantify the catchment-scale groundwater-surface water interactions along the Ovens River in the southeast Murray–Darling Basin, Victoria, Australia, between September 2009 and October 2011. The Ovens River is characterized by the transition from a single channel within a mountain valley in the upper catchment to a multi-channel meandering river on flat alluvial plains in the lower catchment. Overall, the Ovens River is dominated by gaining reaches, receiving groundwater from both alluvial and basement aquifers. The distribution of gaining and losing reaches is governed by catchment morphology and lithology. In the upper catchment, rapid groundwater recharge through the permeable aquifers increases the water table. The rising water table, referred to as hydraulic loading, increases the hydraulic head gradient toward the river and hence causes high baseflow to the river during wet (high flow) periods. In the lower catchment, lower rainfall and finer-gained sediments reduce the magnitude and variability of hydraulic gradient between the aquifer and the river, producing lower but more constant groundwater inflows. The water table in the lower reaches has a shallow gradient, and small changes in river height or groundwater level can result in fluctuating gaining and losing behaviour. The middle catchment represents a transition in river-aquifer interactions from the upper to the lower catchment. High baseflow in some parts of the middle and lower catchments is caused by groundwater flowing over basement highs. Mass balance calculations based on 222Rn activities indicate that groundwater inflows are 2 to 17% of total flow with higher inflows occurring during high flow periods. In comparison to 222Rn activities, estimates of groundwater inflows from Cl concentrations are higher by up to 2000% in the upper and middle catchment but lower by 50 to 100% in the lower catchment. The high baseflow estimates using Cl concentrations may be due to the lack of sufficient difference between groundwater and surface water Cl concentrations. Both hydrograph separation and differential flow gauging yield far higher baseflow fluxes than 222Rn activities and Cl concentrations, probably indicating the input of other sources to the river in additional to regional groundwater, such as bank return flows.
Redefining the city through social software: Two examples of open source locative art in Italian urban space
Authors: Timeto Federica
Published: December 2013

In this paper, I compare the work of the Guerrilla Spam collective (GS), which works mainly with analog technologies such as b/w manifestos that they stick up on urban walls, and the work of Salvatore Iaconesi and Oriana Persico (Art is Open Source, aka AOS), who work with digital platforms and open source software production. I show how space can be localized and mobilized at the same time, and how space is conceived as situated and generative by different technologies which share a bottom–up approach that creates new forms of experience of the urban, resignifying its everyday codes. For this reason, I adopt an analytical framework that, drawing on actor-network theory and non–representational theory, underlines the performative aspects of both space and information and helps redefine concepts such as location and software in a processual and performative way. Comparing the actions of GS and AOS brings to the fore the importance of horizontal social practices and sociotechnical associations without which cities could not be intelligent nor could technologies be smart. Through their artistic interventions, urban space is recontextualized and activated by means of multi–authorial performances in which ordinary codes acquire shared meanings that allow for collaborative and open source practices.
Chicago World’s Fair of 1893: Marketing the modern imaginary of the city and urban everyday life through representation
Authors: Silla Cesare
Published: December 2013

Held in Chicago to celebrate the 400th anniversary of the discovery of America, the Chicago World’s Fair of 1893 has been one of the first events of a kind later defined as ‘media events’ (Susman, 1983). Set up in a liminal period for American life, this ‘event’ was a ‘rite of passage’ paving the road to modernity out of traditional life, as Henry Adams recognized when he defined the Fair as “the first expression of American thought as a unity.”I suggest the Columbian Exposition is a worthwhile case study for this special issue from a historical point of view. The Fair was indeed one of the first cases in which the interplay among urban planning, communication technologies and marketing strategies — a mark of the contemporary production of urban space (McQuire, 2008) — can be observed. I would also suggest it is important from a genealogical point of view because it contributes to unveil the conditions of emergence of such interplay as the outcome of a process of interactions among several social actors which had the task of marketing an imaginary of the city adequate to the new economic and social conditions of America (Harris, 1990).I will therefore attempt to show how the Chicago World’s Fair was both a place where to trace back the genesis of modern American urban life and an opérateur of such emergence, given the fact that the experience of its ideal city life contributed in shaping the imaginary at its foundation. Through a description of the Fair I show how the representation (a literal ‘staging’) of a temporary ideal city — a land of enchantment freed from pain and poverty, with beautiful marble–like buildings, basins, theatres, palaces of consumption, spectacles, entertainments and wonders — was strategically conceived to produce actual effects on the imaginary of the public. As Lewis Mumford (1934) and Louis Sullivan (1949) recognized, the ‘liminal’ characters of the fair became ‘permanent’ features of modern cities and their everyday life through the staging of illusory (but with real consequences) effects.