bluuebunny/crossref_metadata_2025 huggingface dataset:
Umbral: ingreso a La nueva novela de Juan Luis Martínez
Authors: Polanco Salinas Jorge
Published: December 2015

El siguiente ensayo aborda la dificultad de ingresar a los "textos" del complejo poeta chileno Juan Luis Martínez (1942-1993), en particular a su primer libro La nueva novela (1977). La intención consiste en exhibir el estado "vestibular" de su escritura; es decir, la imposibilidad de ingresar desde la apropiación hermenéutica, como usualmente ocurre en los estudios literarios, considerando la "extrañeza" de su trabajo. Como muestra de este ejercicio, abordaremos la consecuencia de una lectura "fallida" de La nueva novela y las formas de exclusión que ésta suscita.
Las vidas que transcurren (una lectura de la performance “Campo de Mayo” de Félix Bruzzone)
Authors: Keizman Betina
Published: December 2015

Este trabajo indaga los alcances estéticos y políticos de la performance “Campo de Mayo”, en que el escritor argentino Félix Bruzzone explora la topografía, vida e historia cotidiana del lugar en donde estuvo detenida su madre, desaparecida por la dictadura militar que gobernó Argentina entre 1976 y 1983. La utilización de materiales visuales y sonoros –la presencia del escritor, las voces de las entrevistas y las imágenes– contribuyen a una representación de lo real cuya discontinuidad y volumen re-produce la tensión entre la elisión, la saturación y la experiencia. La experiencia personal se vuelve evocable en la medida en que su substancia actual se desintegra en formas intersubjetivas, en otros circuitos de vida, en el pasado, en los proyectos a futuro. De ese modo, se abandona la lógica de la hermenéutica a favor de un sistema de correspondencias que busca revelar una relación de conjunto. Nuestra lectura propone, entonces, la necesidad de relativizar las categorías habituales de autofiguración y de referencialidad para considerar el trabajo de Bruzzone como una indagación estética que redefine la experiencia bajo una perspectiva holística, en la que el sujeto dislocado del escritor se sabe parte –y cada vez menos condición– de existencias más amplias que lo incluyen y lo exceden en su devenir.
Study on the Effect of Porous Silicon Sizes for Potential Visible Photodetector
Authors: Abd Rahim Alhan Farhanah , Sah N.M. , Hamzah I.H. , Sulaiman Siti Noraini , Zahidi Musa Mohamed
Published: December 2015

In this work, the characterization of porous silicon (PS) for potential visible light emission was investigated by simulation. SILVACO TCAD simulator was used to simulate PS by using process simulator, ATHENA and device simulator, ATLAS. Different pore diameter sizes of the PS structures were constructed. The structural, optical and electrical characteristics of the structures PS were investigated by current-voltage (I-V), current gain, spectral response and the energy band gap. It was observed that PS enhances the current gain compare to bulk Si and exhibited photo emission in the visible spectrum which constitutes to the quantum confinement effect of the Si in the PS structures.
Multi-Layer Microstructure of Sol-Gel Barium Titanate Thin Films for Optical Waveguide Applications
Authors: Najamudin S.H. , Yusof H.Mohd , Saif Ala’eddin A. , Osman R.A. , Poopalan P.
Published: December 2015

— Barium titanate (BaTiO3) thin films are suitable for many application especially photonics. BaTiO3 thin films are deposited using spin coating with an optimum spin speed of 4500rpm. The samples are then characterized using XRD, AFM and SEM. The results of the XRD analysis showed that both the 5-and 10-coated layers are polycrystalline BaTiO3 with differences in terms of diffraction intensity, due to the number of layers. As for optical application, the surface roughness is the most crucial part. The number of layers of 5 and 10 have thickness of 2.927nm and 4.456nm RMS.
High Throughput Graphene Oxide in Modified Hummers Method and Annealing Effect on Different Deposition Method
Authors: Muda M.R. , Hanim K.N. , Mat Isa Siti Salwa , Ramli Muhammad Mahyiddin , Jamlos M.F.
Published: December 2015

Graphene sheets offer extraordinary thermal, electronic and mechanical properties which could enhance the performance of the device for various applications. However, a large quantity production and the direct dispersion of graphene or graphite sheets in water without the assistance of dispersing agent has been considered to be a challenging issue. In this study, we reported that by introducing the functional group on the graphene basal plane started from natural graphite can readily form stable graphene oxide (GO) solution in a large quantity through modified hummers method. Structural and physiochemical properties of the GO were investigated with help of Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR). The effects of the annealing treatment on a GO surface were analyzed using a Semiconductor Parameter Analyzer (SPA) in order to obtain the electrical resistance measurement. Based on the thermal reduction results, the resistance of drop casting is greater than spray coating which indicates that, the drop casting method is more reliable to be used in any application.
Rapid Indicators in Detecting Variation of Fly Ash for Making HVFA Concrete
Authors: Antoni Antoni , Gunawan Rianto , Hardjito Djwantoro
Published: December 2015

The use of fly ash as an alternative material for cement substitute in concrete mix already a common practice nowadays. However, as a waste material, fly ash varies in quality and condition, as shown by variation of its fineness, specific gravity, Loss on Ignition (LOI) and also on its chemical composition. By measuring the acidity (pH) of the fly ash in water solution, percentage of mass retained on 45 μm sieve, and superplasticizer demand of the fly ash, we can develop a quick estimation of the quality of fly ash. This study aims to investigate a quick method to estimate the quality of fly ash by measuring the physical and chemical pointers, as indicator for its properties and the effect on the setting time and compressive strength of mortar. Fly ash content was varied from 0-70% of the total mass of cementitious materials to make HVFA mortar. Fly ashes were obtained from four power plants in Indonesia. Tests conducted were material characterization, setting time, temperature rise, and compressive strength of mortar at different ages. Different fly ash quality can be shown by the fast pointers; namely pH, superplasticizer demand and % retained on 45 μm sieve. Setting time and strength development were affected by the different properties of fly ash.
Flood Mud as Geopolymer Precursor Materials: Effect of Curing Regime on Compressive Strength
Authors: Al Bakri A.M. Mustafa , Mohtar Mukridz Md , Liew Yun Ming , Mohd Tahir Muhammad Faheem , Husin Kamarudin , Ekaputri Januarti Jaya
Published: December 2015

This paper studies the effect of curing temperature and curing duration to the flood mud based geopolymer on compressive strength properties. Flood mud was used as a raw material for geopolymer and geopolymer samples were synthesized by using sodium silicate and sodium hydroxide 14M solution. These samples were cured at different temperature (100°C, 150°C, 200°C and 250°) for different curing duration (6h, 12h and 24h) respectively. Compressive strength tests were carried out at after 28 days. The compressive strength and SEM analysis of geopolymer products were evaluated. Result showed that the maximum compressive strength was 24 MPa at temperature of 150°C for 24 hours. With increasing ageing day, densification of geopolymer gel was observed.
Correlation of Impact Energy from Instrumented Charpy Impact
Authors: Ali M.B. , Zakaria Kamarul Ariffin , Abdullah Shahrum , Alkhari M.R.
Published: December 2015

This paper proposes the correlation of absorbed energy with calculated energy using the power spectrum density (PSD) method. The total absorbed energy was obtained using the dial/encoder system may significantly vary depending on the strength and ductility of the material. In addition, according to ASTM E23, over 80% of absorbed energy is inaccurate and approximate. For this reason, we determined the energy collected from the dial/encoder Charpy impact test using the signal processing approach. Strain gauges were connected to the Charpy impact striker and the high frequency data acquisition system in order to capture the dynamic impact strain response. Specimens of an aluminium alloy of 6061-T6 and carbon steel 1050 with different velocities and thicknesses were used in the experiment. The specimens are prepared based on the ASTM E23. A collection of signal was converted from the time domain to the frequency domain by means of PSD method and the area under its plot was used to calculate strain energy. The comparison between energy absorbed during the experiment with PSD peak and the strain energy were performed using different materials, velocities and thicknesses. The total energy absorbed for both material with the PSD peak and the strain energy using the dial/encoder system can be linked by a power law equation with R2 96% and R2 94 %. Thus, the effects of the strain signal pattern and impact duration with different parameters were correlated with the PSD peak and the strain energy. This correlation using PSD can be used as an alternative for the charpy impact test and solve the problem of inaccurate absorbed energy.
Performance of Concrete by Using Palm Oil Fuel Ash (POFA) as a Cement Replacement Material
Authors: Sofri Liyana Ahmad , Mohd Zahid Mohd Zulham Affandi , Isa Nur Fitriah , Azizi Azizan Muhammad , Ahmad Muhammad Munsif , Ab Manaf Mohd Badrul Hisyam , Abdul Rahim Mustaqqim , Md Ghazaly Zuhayr , Abu Bakar Juraida , Ahmran Muhammad Shafiq Aiman
Published: December 2015

Palm Oil Fuel Ash (POFA) is one of the solid waste in Malaysia and had trouble with the ash removal. Therefore, the use of waste oil palm ash can overcome the problem of solid waste. POFA is a pozzolanic material and it can act as a replacement of cement (OPC) to produce concrete with higher strength and low cost. POFA quality will increase as the range made up to a medium level of fineness in the size of 50 microns. POFA used to replace OPC is 0%, 10%, 30% and 50% by weight percent of OPC. POFA concrete compressive strength will be tested after a curing process that concrete age of 7 days and 28 days. POFA concrete density is also tested and compared with OPC concrete. Results showed that compressive strength POFA lower than normal concrete. On the other hand, the replacement of cement by 10% POFA shows a record high in compressive strength compared with other POFA mixing at the age of 7 days and 28 days. Fineness pozzolanic POFA is the best material and can be used as a cement replacement alternative.
Designing a Low Cost Endoskeletal below Knee Prostheses with the Implementation of Appropriate Technology
Authors: Herdiman Lobes , Adiputra Nyoman , Tirtayasa Ketut , Manuaba I.B. Adnyana
Published: December 2015

The endoskeletal below knee prostheses was commercially available in Indonesia. More advanced products also available in the market but they come with expensive price and high maintenance cost. This paper presents a design concept of an affordable endoskeletal below knee prostheses for daily living with functional ankle joint. The design was developed through the application of appropriate technology approach from the total ergonomics framework which consists of 7 characteristics; technically feasible, ergonomic, energy saving, economical, socioculturally acceptable, environmental friendly, and trendy. The result is an endoskeletal below knee prostheses with multiaxis joint system and energy store-return components installed on its modular ankle joint.
Mega Floats: Floating Offshore Remote Terminal (FORT) towards Sustainability Life Cycle Assessment
Authors: Abdul Malik Asmawi , Ahmad Mohd Zamani , Radzi Azura Ahmad , Ahmad Fuad Ahmad Faizal , Azlan Nur Hanani Ahmad
Published: December 2015

The life cycle model of Mega Float: Floating offshore fishing terminal (FORT) for deep sea fishing industry is presented in this paper. FORT is a totally new concept of a mega float for deep sea fishing application. It is aimed at increasing productivity through reducing travelling time to fishing ground by providing critical support services such as loading and unloading and minor maintenance and repair of boat and equipment at sea close to the fishing ground. The immediate concern is surely on its life cycle cost and techno-economic viability. The system is huge and remotely located far offshore and hence the element of sustainability and environmental friendliness and safety are some of the major investment issues. Immediate cost consideration includes the relatively high initial/acquisition cost and operation and maintenance costs and the intention is to at least self-sufficient by generation income from the services offered. Therefore, hybrid algorithm of cash flow and life cost cycle is applied in FORT implementation. The new derivation of the mathematical model for FORT application is developed to life cycle assessment principle [1-3]. The algorithm requires data that could be best produced based on forecast demand and projected cost. For ease of use the lengthy algorithm will be presented in a computer-based package.
Mechanical and Thermal Properties of Polylactic Acid Filled Rice Straw
Authors: Hani Md Zubir Nurul , Ting Sam Sung , Kamarudin H. , Ragunathan S. , Noriman N.Z. , Abdullah Mohd Mustafa Al Bakri , Jing Wang
Published: December 2015

Natural fiber reinforced polylactic acid based biocomposites are broadly considered by the researchers to compete with non-renewable petroleum based products. In this study, the biodegradable composites which are the polylactic acid, PLA and rice straw, RS were prepared by using heated two roll-mill at 180°C. Mechanical properties showed that the tensile strength and elongation at break, Eb decreased with the increasing of RS while the Young’s modulus had increased. The TGA results confirmed that thermal stability of PLA with RS composites decreased when the RS fiber loading increased.
Design and Analysis on Symmetric MEMS Inductor
Authors: Khalid N. , Nor N.I.M. , Norhaimi W.M.W. , Sauli Zaliman , Retnasamy Vithyacharan
Published: December 2015

This paper presents the design and analysis of new proposed topology micro-electro-mechanical system (MEMS) inductor. This new symmetric MEMS inductor is designed to reduce the total length of the conductor strip and hence reduce the resistance of the metal tracks. This results significant increases in the quality (Q) factor of the inductor. In this paper, the MEMS inductor is designed using CoventorWare®, which is powerful software for MEMS computer aided design (CAD), modeling and simulation. Results indicate that new symmetric inductor topology has thehighest Q-factor and it hasbeenimproved bytwo times compared to circular inductor. The analysis revealed that area of the symmetric inductor has reduced by37.5% compared to the circular inductor. Result has proved that the reduction of length of the conductor strip has reduced the resistance of the metal tracks and results in a high Q-factor inductor.
Extrinsic and Intrinsic Modeling of InGaAs/InAlAs pHEMT for Wireless Applications
Authors: Ahmad Norhawati , Jamuar S.S. , Isa Muammar Mohamad , Mat Isa Siti Salwa , Ramli Muhammad Mahyiddin , Khalid N. , Nor N.I.M. , Kasjoo Shahrir Rizal , Zainol Murad Sohiful Anuar , Missous M.
Published: December 2015

This paper presents the linear modelling of high breakdown InP pseudomorphic High Electron Mobility Transistors (pHEMT) that have been developed and fabricated at the University of Manchester (UoM) for low noise applications mainly for the Square Kilometre Array (SKA) project. The ultra-low leakage properties of a novel InGaAs/InAlAs/InP pHEMTs structure were used to fabricate a series of transistor with total gate width ranging from 0.2 mm to 1.2 mm. The measured DC and S-Parameters data from the fabricated devices were then used for the transistors’ modelling. The transistors demonstrated to operate up to frequencies of 25 GHz. These transistors models are used in the design of Low Noise Amplifiers (LNAs) using fully Monolithic Microwave Integrated Circuit (MMIC) technology.
Defect Segmentation of Semiconductor Wafer Image Using k-Means Clustering
Authors: Saad N.H. , Sabri N. Mohamad , Hasan A.F. , Ali Azuwa , Saleh Hariyanti Mohd
Published: December 2015

Nowadays, quality control becomes an important issue in semiconductor manufacturing industry. The rate of production with respect to time gives a lot of issues in the industry. In most semiconductor assemblies, a lot of defects generated from various processes in semiconductor wafer manufacturing need to be inspected manually using human experts and this process required full concentration of the operators. This human inspection procedure, however, is time consuming and highly subjective. In order to overcome this problem, implementation of machine vision will be the best solution. This paper presents defect segmentation of semiconductor wafer image based on colour features with k-Means clustering algorithm which can be adopted in machine vision system. In this work, the segmentation process is carried out in two stages. The first stage comprised of clustering the pixels in the image based on their colour and spatial features. Then the clustered pixels are merged to a specific number of regions. The proposed approach is being evaluated using defected wafer image. The experimental results show that it can be used to segment the defect correctly. By using this method, it is possible to increase the computational efficiency since it will avoid feature extraction for every pixel in the image.
The Development of Novel High Speed – Low Noise pHEMT Device for Lossless Underwater Optical Communication
Authors: Isa Muammar Mohamad , Ong Siok Lan , Charin Chanuri , Ahmad Norhawati , Mat Isa Siti Salwa , Ramli Muhammad Mahyiddin , Khalid N. , Nor N.I.M. , Kasjoo Shahrir Rizal , Missous M.
Published: December 2015

We report the development of two epilayers namely the baseline highly strained channel and enhanced low gate leakage samples. The Hall data shows that the enhanced epilayer portraying higher sheet carrier concentration, but comparable carrier mobility in the 2-DEG layer, as compared to the baseline sample. The WinGreen simulation also conformed the enhanced epilayer advantages where wider Schottky barrier is observed and subsequently double carrier concentration is simulated in the channel. Both samples show low AuGe/Au Ohmic contact resistivity of approximately 0.16 Ω.mm. A tremendous advantage on 1 μm Schottky gate leakage is also recorded on enhanced epilayer where the leakage is more than seven times lower than that of the baseline sample. The resulted characteristics are much better than the reported submicron device, thus this device has find an important application in high-gain lossless transmission, especially in underwater optical communication system.
Nondestructive Fruit Ripeness Detection System and its Spectral Analyses
Authors: Hasanuddin N.H. , Wahid M.H.A. , Azidin M.A.M. , Ahmad Hambali N.A.M. , Yusof N.R. , Shahimin M.M.
Published: December 2015

This work focuses on the nondestructive fruit ripeness detection system at difference maturity stages. The study involved a two-step approach which is the absorption and reflection spectral analysis. In this system, light dependent resistor (LDR) is used as the light sensor and displayed on the LCD screen of its resistivity. Portable spectrometer is adopted for measuring the reflection and absorption before processed by simple electronic Arduino-based circuit. The results of the photonic ripeness detection system show that the ripe fruit has higher light reflection rate in comparison to the unripe fruit. If the average value of the resistance is in between 400-600 the fruit is classified as still in immature period. Where as the resistance of 610-800 indicates the fruit is matured. The growth of fruit determines the difference ripeness levels and its resistivity too.
Dynamic System Models Sutami Hydropower Plant Indonesia to Calculate the Economic and Environmental Aspects of Hydropower Plant Operation
Authors: Rohi Daniel , Bisri M. , Seoemarno Seoemarno , Lomi A.
Published: December 2015

The development of the power sector is required to consider not only the environmental factors but also the economic and security factors. Management of electrical energy in Indonesia faced a major problem because of the shortage of energy production demand continues to increase 7.1% annually and the energy production is also very depending on fossil energy sources which dominate 85% of the total power generation. This condition will lead to increasing gas emissions in greenhouse by 78.01 million tons per year. Evaluation of existing plants with a dynamic model of the system will be a consideration for the sustainability of hydropower operation. The simulation results of the Sutami HEPP show more economical and more eco-friendly than fossil energy-based power plant. It is important to build and maintain a HEPP in Indonesia today, due to the potential based on these considerations, the capacity and the reduction of greenhouse gas emissions.
Effect of Heat Treatment on Hardness Behavior of AZ91 and AZ91 Reinforced Carbon Nanotube
Authors: Zaidi Nur Hidayah Ahmad , Jamaludin Shamsul Baharin , Ahmad Khairel Rafezi , Halif Norzilah Abdul , Adnan Sinar Arzuria
Published: December 2015

In the present work the effect of heat treatment on the hardness behavior of AZ91 and AZ91 reinforced carbon nanotube were investigated under FESEM, Xrd and Rockwell hardness tester. Cnt was embedded homogenously into the matrix due to successfully mechanical alloying using planetary milling. Kinetic precipitation of β-phase (Mg17Al12) also reveal in the X-ray diffraction pattern. Meanwhile, the artificial aged nanocomposite found decreased in hardness, compare to monolithic has higher value form early aged until 36 hours aging.
Kinematics Analysis of the Crank Mechanism Conveyor Using MSC Adams
Authors: Hroncová Darina , Šarga Patrik
Published: December 2015

The aim of the thesis is the solution of kinematics analysis model of the conveyor with a crank mechanism. For solution is to use a graphical method for determining the kinematics parameters of the individual members of the mechanism. In part kinematics analysis is also used MSC Adams View program that is designed to address the problems of kinematics and dynamics of systems with more degrees of freedom. This program shows the displacement, velocity and acceleration and angular velocity and angular acceleration of members. Finally, the work presents the results with graphic display of parameters such as displacement, velocity and acceleration. Introductory chapters are devoted to general issues kinematics mechanisms and the following chapters are devoted to a particular model of the conveyor mechanism.
Geometric Indicators of Flexible Slice Lip
Authors: Talaśka Krzysztof , Malujda Ireneusz , Wilczyński Dominik , Górecki Jan , Tarkowski Paweł , Kukla Mateusz
Published: December 2015

The paper is thematically connected with paper making machines. This type of the machine is equipped with a head which has a flexible slice lip for skimming the pulp applied to produce the paper. The definition of geometric features of the slice lip is a key issue. The slice lip should be made of material which is resistant to external factors, and designers want to obtain a high flexibility of this element. It is possible to get a high flexibility by forming a proper shape of the slice lip. The paper presents the proposal of dimensionless geometric indicators which combine basic geometric parameters of the slice lip. These indicators are the following: indicator of the cross-section, indicator of the length and indicator of the length of the transverse notch. FEM strength analyses were done – the aim of these analyses was the determination of the stress state and maximum deflection of the slice lip. The authors have analysed the slice lip with holes for mounting the actuators and the slice lip and with transverse notches for increasing its flexibility. The results were presented in the form of graphs.
Stepper Motor Control by ATMEL AVR Microcontroller
Authors: Virgala Ivan , Kelemen Michal , Lipták Tomáš , Prada Erik
Published: December 2015

The paper deals with stepper motor control using microcontroller ATmega8-16PU. In the paper are mentioned two ways of control, namely full-step mode and half-step mode control. At first, bipolar stepper motor is introduced. Next, there is created measuring stand consisting of bipolar stepper motor with one step angle 1.8° and encoder with 360 CPR. During the experiment were measured angular velocities by I/O measuring card MF624 cooperating with Matlab/Simulink. The results show differences between used two stepping modes of motor.
The Effect of Magnetic Field on Magnetorheological Composites - Artificial Neural Network Based Modelling and Experiments
Authors: Kukla Mateusz , Tarkowski Paweł , Górecki Jan , Malujda Ireneusz , Talaśka Krzysztof
Published: December 2015

Looking for new applications of the available materials, such as magnetorheological elastomers (MERs) is an important element of machine design process. To this end it is necessary to determine their fundamental mechanical properties, including Young’s modulus and shear modulus. These properties are determined experimentally by testing the material in compression, tension and shear. In the case of the analysed group of materials the above-mentioned constants depend, inter alia, on the parameters of magnetic field acting on them. Therefore, it is necessary to determine the character and the extent of variation of the mechanical properties as a function of the physical constants characterising the active magnetic field, namely magnetic flux and magnetic intensity (field strength).This paper presents the results of static compression tests carried out on magnetorheological elastomers. The parameters measured during the static compression test were force and displacement at a pre-set magnetic flux. The maximum strength of the induced magnetic field was limited by the design parameters of the test set-up. In order to determine the behaviour of the material at greater values of magnetic strength and flux the properties of a real material were modelled with a neural network. The simulation was carried out using a simple, one-layer neural network. The chosen network training approach was error backpropagation. This approach enables approximation and predicting of changes of the properties of the tested material. The output results will enable deriving an analytical model of the tested MREs.
Building Elements of Bond Graphs
Authors: Hroncová Darina , Gmiterko Alexander , Frankovský Peter , Dzurišová Eva
Published: December 2015

The aim of the thesis is to describe of building elements Bond Graph methodology for modeling dynamic systems. Technique of Bond Graph methodology for modeling dynamic systems is demonstrated and its place in the process of modeling of mechanic and electric system and its behavior is discussed. The building elements of bond graphs as source effort and flow, capacitor, resistor, inductor, gyrator and transformer are described.
Specific Car Manufacturer Recalls
Authors: Kováč Jozef , Kádárová Jaroslava , Kalafusová Lenka
Published: December 2015

A variety of engineering errors can cause a defect in vehicles. Problems are usually concentrated on models that were produced during a certain time period at one specific plant. Consumers who encounter such problems can report them, fill petitions or put online complaints on specific car manufacturers. Vehicle defects can cause many problems and even endanger human life. That is why, in the interest of safety, any recall affecting the consumer vehicle should be completed without delay. The paper presents recalls of three car manufacturers, namely: Volkswagen group, PSA, and Kia analyzed between years 2005 to 2015. The results are presented in graphs and diagrams. First part of the paper discusses the current terminology and procedures of car recalls. In the second part the three car manufacturers are presented. Recall analysis creates the third part of the paper and the results are presented in form of graphs and diagrams. Also the error rate of each car manufacturer is calculated and presented in the paper.
Concept to Support the Flexibility of Manufacturing System through Reconfigurable Structure Based on Modular Design
Authors: Rudy Vladimír , Lešková Andrea
Published: December 2015

This article deals about the challenges of structural changes in manufacturing conditions. The objective of this paper is to present the modular workstations concept based on miniaturization and re-configurability trends. The article is aimed at problems of designing of production systems with a modular construction structure. The modular structure allows an individual and flexible adaptation to varying requirements but also the realization of low-cost solutions for creation of new or modernized production base. The goal is to present the example of modular workstations solutions that correspond with new designing approach. The specification of basics principles, which should help to designing flexible manufacturing systems, discussed in this paper are: modularity; integrability; convertibility; diagnosability; customization. The theoretical part provides an overview of fundamental design principles in manufacturing structures. In the first part of this article are discussed the specification of basic flexibility types in production system and the main impacts influencing design of manufacturing structures. The closing section of the article provides the specification of example solution of adjustable production platform with modular frame (called desktop factory).
Determination of Boundary Conditions and Optimalisation of the Graphite Electrode Cooling Circuit
Authors: Lázár Marián , Brestovič Tomáš , Čarnogurská Mária , Jasminská Natália
Published: December 2015

The present paper describes the determination of boundary conditions of the 10 kVA plasma reactor graphite electrode cooling. The water cooler installed on the lid of the reactor, connected in open circuit, sustains the permissible service temperatures in the analysed area of the reactor. With the monitoring of the coolant flow and temperatures at the inlet and outlet of the cooler, the heat flux necessary for the design of a closed circulation cooling circuit was determined. Software support of HTC-FC (heat transfer coefficient – natural convection) and simulation software ANSYS CFX were used to solve the design and functionality of the proposed solution. This software is designed for the numerical calculation of differential equations describing fluid flow and heat conduction with the use of the finite volume method. With the application of time-dependent boundary conditions in the simulation tool ANSYS CFX, we acquired information about the temperature distribution of the cooling medium during the operation of the described technology and also about the change in the variation of heat flux between the environment and the proposed container.
Industrial Views to Microbe-Metal Interactions in Sub-Arctic Conditions
Authors: Kinnunen Päivi , Bomberg Malin , Rajala Pauliina , Carpén Leena
Published: December 2015

This paper covers industrial views and challenges related to microbe-metal interactions in the sub-arctic conditions in Finland. The first issue is to operate bioleaching and bio-precipitation processes in cold and rainy environments where microbial activities tend to be low and solutions get diluted. On the other hand, industrial challenges in cold climates are related to the need to hinder the activity of microbe-metal interactions in certain applications, such as closed mines and nuclear waste repositories. Our case examples show the potential of industrial bioprocess utilization in cold climates, but also emphasize their special characteristics and challenges.
Dyp-Type Peroxidase (DypA) from the Bioleaching Acidophilic Bacterium Leptospirillum ferriphilum DSM 14647
Authors: Contreras Mackarena , Mascayano Carolina , Chávez Renato , Ferrer Alonso , Paillavil Barulio , Levicán Gloria J.
Published: December 2015

Leptospirillum
ferriphilum is an acidophilic iron-oxidizing bacterium that is relevant for chemical leaching of sulfide ores. In the extremely acidic conditions found in bioleaching operations, this microorganism deals with an abundant supply of soluble iron and other metals that might induce oxidative damage to biomolecules through the generation of reactive oxygen species (ROS). We evaluated the role of Dyp-type peroxidase in the protection against oxidative stress in L. ferriphilum DSM14647. The genetic region encoding dypA was cloned and sequenced. The predicted DypA enzyme is 295 amino acids long with an estimated molecular mass of 32.9 kDa containing a highly conserved peroxide reduction motif. Genetic complementation of catalases/peroxidases-deficient Escherichia coli cells indicated that expression of dypA from L. ferriphilum restored the resistance to hydrogen proxide to levels exhibited by the wild type strain. Exposure of L. ferriphilum to hydrogen peroxide leads to a significant transcriptional activation of dypA suggesting its involvement in the response to oxidative stress in this bacterium. This is the first Dyp-type peroxidase characterized from an acidophilic microorganism, making it a potential candidate for research in basic and applied biology.
New Insights into Salt-Tolerance in Acidophilic Iron-Oxidising Bacteria
Authors: Johnson D. Barrie , Grail Barry M. , Bonnefoy Violaine
Published: December 2015

Colonies of iron-oxidising acidophilic bacteria were isolated on solid media containing up to 500 mM NaCl from non-saline samples from the Rio Tinto (Spain). One of these isolates was identified as an "Acidithiobacillusferriphilus" strain. Laboratory cultures of the type strain ofAcidithiobacillusferriduransgrown on hydrogen for one year were also found to adapt to the presence of 500 mM salt. This culture also grew on sulfur, but not on ferrous iron, in media containing 500 mM NaCl. It regained its ability to oxidise iron only after protracted incubation in salt-free media. Molecular analysis found an insertion of about 1.5 kb in the regulatory region of therusoperon of the strain that was unable to oxidize iron. This insertion was lost in the strain that had subsequently regained this ability. Our results suggest that chloride tolerance and dissimilatory oxidation of iron by these bacteria do appear to be mutually exclusive.
FTIR Analysis on Organic Sulfur Distribution: Aliphatic Mercaptans in Lignite, Prior and after Multistage Artificial Biotreatment Process
Authors: Handayani Ismi , Paisal Yustin , Chaerun Siti Khodijah , Soepriyanto Syoni
Published: December 2015

Aliphatic mercaptans (R-SH) are organic sulfur containing functional groups in coal maceral that makes up lignite. Prior and after specific bioprocess on the lignite, namely multistage artificial biotreatment (A-Bmt), organic sulfur rich lignite sample was treated and analyzed by spectroscopic methods. To determine the qualitative change in aliphatic mercaptans on lignite maceral surface, Fourier transform infrared (FTIR) method at transmittance spectrum of 400-4000 cm-1 was used on lignite sample in the form of pellet with a KBr mixture. The results of FTIR analysis indicate significant spectrum gradations between natural samples, samples from biooxidation, and samples from column bioflotation. This can be seen in the spectrum distribution pattern of transmittance at 620-690 cm-1 and 1530-1580 cm-1, which gradually and significantly change. The results of biotreatment with the addition of bioreagent Pseudoclavibacter sp. strain SKC/XLW-1 both at biooxidation and column bioflotation stage on A-Bmt method showed that there was a significant difference on spectrum pattern compared to the results with no biotreatment. The spectrum distribution pattern resulted from FTIR analysis also showed a strong correlation with the distribution pattern of decreased levels of organic sulfur and trace elements.
Culture/Co-Culture Dependent and Independent Identification of Bacterial Communities along a Chronosequence of Spontaneous Reclamation on Gold Mine Spoils in Peru
Authors: Cornejo Melitza , Pretell Krizia , Arévalo Akemy , Sernaqué Yacory , Mialhe Eric
Published: December 2015

Cyanide leaching is currently the dominant process used by the mineral industry to extract gold and silver minerals. Cyanide is a nitrogen compound toxic for most living organisms. Many microorganisms are able to tolerate and degrade cyanide and its derivatives. In this study, were considered bacteria from soil and water samples corresponding to a chronological sequence (up to 5 years) of spontaneous cyanide bioremediation in a gold mining area (La Libertad Region, Peru). Culture dependent molecular identifications, based on 16S rDNA amplification and sequencing, were performed for bacteria isolated on agar media. Co-culture dependent molecular identifications were performed through 16S rDNA targeted metagenomics based on Next generation Sequencing with DNA directly extracted from the co-cultures in order to determine bacteria species unable to grow individually on agar media. Culture independent identifications were similarly performed through 16S rDNA targeted metagenomics from DNA directly extracted from water or soil samples in order to establish their respective global microbiota. Concerning cyanide contaminated soils, more than one hundred operational taxonomic units (OTU) were identified by metagenomics with only 30% species co-cultivable in broth medium and 82 isolated strains, in particularPseudomonasspp. The global microbiota in non-contaminated soils was markedly different. Concerning cyanide contaminated waters, about one hundred operational taxonomic units (OTU) were identified by metagenomics with only 30% species co-cultivable in broth medium. The most frequently identified species belong toAlcaligenes, Alkalibacterium, Bacillus, PaenibacillusandSerratia. Bacteria isolated and co-cultivated from contaminated waters and soils are currently analyzed as candidates for cyanide bioremediation.
Potentials of some Waste Biomaterials as Sorbents for Gold- and Silver-Cyanide Removal from Aqueous Matrices
Authors: Patil Yogesh , Gaddi Shivanand , Hunashal Rajiv
Published: December 2015

Plating, printed circuit board, jewellery units, photofinishing and mining industries emanate large-volume low-tenor effluents containing metal-cyanide (MxCN) like gold-and silver-cyanide. Since metal moiety of MxCN being precious, non-renewable and finite resource; their complete removal from effluents is the key. Biosorption has immense potential of becoming efficient and economical alternative to recover the wasted metal resource over conventional methods. Twenty-eight low-cost biomaterials obtained from diverse sources were screened for gold-and silver-cyanide uptake. Study revealed that maximum uptake of both MxCN took place at acidic pH. Based on maximum uptake, Rice Husk (RH) andEicchorniaroot (ER) biomass were selected for gold-and silver-cyanide sorption, respectively, for further studies. Optimal conditions for sorption were: pH (4.0-7.0), biosorbent quantity (1-3%), rate of uptake (40 min) and initial MxCN concentration (5-500 μmol). Biosorption data obtained conformed to Freundlich and Langmuir adsorption models (R2>0.98). NaOH acted as an efficient desorbing agent (>95%).
Modeling and Simulation of Nanoscale Lateral Gaussian Doped Channel Asymmetric Double Gate MOSFET
Authors: Kumari Vandana , Saxena Manoj , Gupta Mridula
Published: December 2015

This work presents the drain current model using Evanescent Mode Analysis (EMA) for nanoscale Double Gate MOSFET having Gaussian doping profile along the horizontal direction in the channel i.e. from source to drain region. Due to heavily doped channel, band gap narrowing effect is incorporated in the analytical modeling scheme. The various parameters evaluated in this work using analytical modeling scheme are surface potential, electric field, threshold voltage, sub-threshold slope and drain current. The impact of peak Gaussian doping profile on the drain current and trans-conductance has been demonstrated which are important for assessing the analog performance of the device. The results are also compared with the uniformly doped DG MOSFET. The asymmetric behaviour of Gaussian doped DG MOSFET has also been investigated. In addition to this, digital performance of Gaussian doped DG MOSFET has also been assessed using exhaustive device simulation.
Assessment of the invasive status of newly recorded cactus species in the central Tugela River basin
Authors: Cheek Michael D. , Crouch Neil R.
Published: December 2015

Background: Current distribution information on cacti in the Tugela River basin in KwaZulu-Natal, South Africa, is scant. Accordingly, surveys in this region substantially improve our understanding of regional invasions by this succulent group. The identification of new or extended invasions requires (re)assessments of their invasion status and consideration of possible management interventions.Objectives: To identify and collect cacti either not previously recorded or poorly known in the central Tugela River basin, and to assess their invasion status.Method: A 40 km section of tertiary road was travelled through the topocadastral square 2830 CC, from the R74 main road northward across the Bloukrans River towards the Tugela River. Herbarium specimens were collected to vouch for new instances of naturalisation of cacti, the colony sizes of which were estimated and invasion stages determined. An applicable weed risk assessment model was used to determine the threat status of one cactus species not previously evaluated for South Africa. Based on the South African Plant Invaders Atlas database records and field observations, management recommendations were suggested for six cacti species.Results: The first naturalised population of Opuntia microdasys in KwaZulu-Natal was detected, as was the first confirmed South African record of Echinopsis oxygona. Four populations of Peniocereus serpentinus were also found, ranging in size from several square metres to 0.4 ha. Echinopsis oxygona generated a score that falls into the reject category of the risk assessment model used.Conclusion: It is recommended that E. oxygona be added to the Species Under Surveillance for Possible Eradication or Containment Targeting list to investigate whether this species requires formal legal listing and the development of a specific eradication plan. Immediate action from local authorities is recommended for the manual removal of P. serpentinus and O. microdasys populations.
Reflections on clinical practice whilst developing a portfolio of evidence: Perceptions of undergraduate nursing students in the Western Cape, South Africa
Authors: Ticha Victoire , Fakude Lorraine P.
Published: December 2015

Background: In order to develop clinical judgement, nurses should be encouraged to become analytical and critical thinkers. Development of a portfolio of evidence (PoE) of reflection on clinical experiences is one of the strategies that can be used to enhance analytical and critical thinking amongst nursing students. Students’ perceptions of the process are important in order to encourage their reflective practice. PoE compilation at a school of nursing at a university in the Western Cape includes evidence of students’ clinical learning which they present in a portfolio. The students are expected to reflect on their clinical learning experiences and include these reflections in their portfolios.Objective: To describe the perceptions of fourth-year nursing students regarding reflective practice whilst compiling their PoEs.Method: A qualitative design was used to explore the perceptions of registered fourth-year nursing students with regard to their reflective practice whilst compiling their PoEs. Purposive sampling was used for selection of participants. Three focus group discussions were held, each consisting of six to eight participants. Data saturation was reached during the third meeting. Tesch’s method of data analysis was used.Results: Findings revealed that reflection enabled the learners to gain experience and identify challenges related to the expected events and tasks carried out at the hospitals and in the classroom whilst developing their PoE.Conclusion: The compilation of a PoE was a good teaching and learning strategy, and the skills, experience and knowledge that the participants in this study acquired boosted their self-esteem, confidence and critical thinking. Reflection also assisted in self-directed learning.
Топологическая рекурсия для гауссовых средних и когомологические теории поля
Authors: Andersen Jorgen Ellegaard , Chekhov Leonid Olegovich , Norbury Paul , Penner Robert C
Published: December 2015

Приводятся явные соотношения между разложенными по родам $s$-петлевыми средними гауссовой матричной модели и членами разложения по родам матричной модели Концевича-Пеннера, которая задает производящую функцию для объемов дискретизованных (открытых) пространств модулей $M_{g,s}^\mathrm{disc}$ (дискретных объемов). С помощью этих соотношений гауссовы средние во всех порядках разложения по родам представляются в виде многочленов от специальных переменных времен с коэффициентами, оказывающимися инвариантными интегралами потомков для подлежащей когомологической теории поля. Топологическая рекурсия для гауссовой модели переводится в рекуррентные соотношения на коэффициенты этих многочленов, что позволяет доказать их целочисленность и положительность. Найдены коэффициенты в первом поправочном порядке для ${\mathcal M}_{g,1}$ при всех значениях $g$ тремя способами: с применением улучшенных рекуррентных соотношений Харера-Цагира, с применением разложения гивенталевского типа для матричной модели Концевича-Пеннера и с помощью явного подсчета диаграмм.
Impact of major volcanic eruptions on stratospheric water vapour
Authors: Löffler M. , Brinkop S. , Jöckel P.
Published: December 2015

Abstract. Volcanic eruptions can have significant impact on the earth's weather and climate system. Besides the subsequent tropospheric changes also the stratosphere is influenced by large eruptions. Here changes in stratospheric water vapour after the two major volcanic eruptions of El Chichón in Mexico in 1982 and Mount Pinatubo on the Philippines in 1991 are investigated with chemistry-climate model simulations. This study is based on two simulations with specified dynamics of the EMAC model, performed within the Earth System Chemistry integrated Modelling (ESCiMo) project, of which only one includes the volcanic forcing through prescribed aerosol optical properties. The results show a significant increase in stratospheric water vapour after the eruptions, resulting from increased heating rates and the subsequent changes in stratospheric and tropopause temperatures in the tropics. The tropical vertical advection and the South Asian summer monsoon are identified as important sources for the additional water vapour in the stratosphere. Additionally, volcanic influences on the tropospheric water vapour and ENSO are evident.