bluuebunny/crossref_metadata_2025 huggingface dataset:
Avaliação da influência do tipo de cimento na expansibilidade das misturas de fosfogesso e cimento
Authors: Kobayashi Andréa Regina Kaneko , Parreira Alexandre Benetti
Published: July 2015

Fosfogesso é um resíduo sólido da produção de ácido fosfórico pelas indústrias de fertilizantes. Geram-se cerca de 180 milhões de toneladas deste resíduo por ano no mundo, causando problemas com a sua armazenagem. Este trabalho apresenta um resumo dos resultados de ensaios laboratoriais para avaliar a influência do tipo de cimento Portland na expansibilidade das misturas de fosfogesso e cimento para uso como material de construção de bases e sub-bases de pavimentos. A expansão foi medida em corpos de prova, compostos com diferentes proporções de fosfogesso e cimento, variando-se o tipo de cimento, a energia de compactação e o período de cura. Para todas as misturas investigadas, considerando-se o período de 84 dias de cura, a maior parte da expansão ocorreu nos primeiros 28 dias. Concluiu-se que a influência do tipo de cimento é significante na expansão destas misturas.
The category of mood in typological aspect
Authors: Alieva E.N.
Published: July 2015

The development of linguistics is a continuous ongoing process. New material is being accumulated, new ideas arise, previous assessments and concepts have been clarified and reevaluated. This makes it necessary to create a synthesis of the work. Their aim might be summarizing research, achievements, consideration of new material and revaluation of previously known one. A considerable improvement over the years of research methodology in linguistics contributes to comparative and universal-typological studies of languages of different building including genetically and typologically distant ones.
About units of household and artistic dialogue
Authors: Sadikova V.A.
Published: July 2015

The article summarizes principles for the distribution of domestic and artistic dialogues, there is a transformation of attitudes in their study. Mikrodejstvie and top are treated as constituents respectively dramatic and everyday communication.
On the frontier of the military glory
Authors: Dergacheva I.V. , Nikanorova O.N. , Silina L.A.
Published: July 2015

The article describes the moto rally along the places of battles of 21st and 18th brigades (16th West Front army), which were participating in Zhizdra offensive operation from 22nd of February to 20th of April 1943. The veterans of e5th Rocket division and representatives of Foreign languages faculty took part in this moto rally.
Polymer‐Coated Tablet Urea Improved Rice Yield and Nitrogen Use Efficiency
Authors: Lyu Xiaoxiao , Yang Yuechao , Li Yuncong , Fan Xiaohui , Wan Yongshan , Geng Yuqing , Zhang Min
Published: July 2015

The high cost of coating materials prevents the wide use of controlled release urea (CRU). A large size polymer‐coated tablet urea (PCTU) can be produced with <30% of coating materials used for traditional size of CRUs. The objective of this experiment was to evaluate the effects of a PCTU produced in our laboratory on root growth, grain yield, and N use efficiency on rice (Oryza sativa L.) grown in a silt loam soil during two growing seasons. The PCTU, regular CRU and urea formaldehyde (UF) were applied into the soil one time before transplanting at the rate of 0.93 g N pot−1, while the conventional urea (U) treatment was applied three times in the tillering (40%), jointing (30%), and heading stages (30%). The results showed that the PCTU treatment produced higher root vigor, peroxidase activity, and yield of rice than the U treatment. There was no significant difference in plant height, SPAD value, growth indexes of plant shoot and root of rice among the PCTU and U treatments in the rice tillering stage, but splitting applications of U at tillering, jointing, and heading stages costs more for labor and machinery than applying once for PCTU. The PCTU treatment increased the yield of grain and total N use efficiency more than the U, CRU, and UF treatments did, but the UF treatment produced the highest yield and N use efficiency of straw.
Nitrous Oxide Emissions from Continuous Winter Wheat in the Southern Great Plains
Authors: Wilson Tracy M. , McGowen Blake , Mullock Jeremiah , Arnall D. B. , Warren Jason G.
Published: July 2015

Fertilizer‐induced N2O‐N emissions (the difference between fertilized and unfertilized soils) are estimated to be 0.01 kg N2O‐N kg−1 of applied N. One approach to limiting N2O‐N production in soils is by improving nitrogen use efficiency (NUE) in dryland agricultural systems. However, baseline data on the rate of emissions is needed to determine the potential impact that these efforts might have on N2O‐N concentrations in the atmosphere. A study was established in a long‐term continuous winter wheat (Triticum aestivum L.) fertility experiment in Stillwater, OK, to determine the effects of N rate on N2O‐N emissions from a dryland winter wheat–summer fallow system in the southern Great Plains of the United States to fill this knowledge gap. Cumulative emissions of N2O‐N varied from year to year and were influenced by environment and N rate. Emissions following N fertilizer application were typically highest following N application, as well as toward the end of the summer fallow period, when summer rainfall and temperatures were conducive for N2O‐N production chambers within plots historically receiving 134 kg N ha−1 annually went unfertilized for the 2012–2013 and 2013–2014 crop years and produced N2O‐N emissions equivalent to the 45 and 90 kg N ha−1 rate treatments. Annual cumulative emissions ranged from 0.009 to 0.024 kg N2O‐N kg−1 N applied with an average of 0.015 kg N2O‐N kg−1 N applied, illustrating the variability in N2O‐N emissions.
Recent multi-year streamflow regimes and water budgets of hillslope catchments in the Canadian High Arctic: evaluation and comparison to other small Arctic watershed studies
Authors: Young Kathy L. , Lafrenière Melissa J. , Lamoureux Scott F. , Abnizova Anna , Miller Elizabeth A.
Published: July 2015

This study evaluates whether a recent decline in snowcover extent for circumpolar regions is matched by changes in the seasonal streamflow regime of several small hillslope catchments on Bathurst and Melville Islands. This includes shifts in the timing of initiation, peak discharge and impacts on the spring–summer water budgets. Paired catchments (West and East) at the Cape Bounty Arctic Watershed Observatory (CBAWO) on Melville Island (74.9°N, 109.5°W) have been studied from the pre-snowmelt season to early August since 2003. They are low-rolling tundra catchments between 8.0 and 11.6 km2 in area. Likewise, within the Polar Bear Pass (PBP) watershed, Bathurst Island (75.7°N 98.7°W), two hillslope basins, Windy Creek (4.2 km2) and Landing Strip Creek (0.2 km2) have been investigated since 2007. Detailed snow surveys were conducted each spring and streamflow estimates were made using the mid-section velocity method. Nival regimes continue to dominate in these basins but runoff ratios are variable between catchments, across islands, and from year-to-year. In comparison to earlier streamflow studies across the Queen Elizabeth Islands (QEIs), an earlier response to peak discharge and start of flow for these hillslope streams is confirmed. Water budgets for PBP, CBAWO differ from other small Arctic watersheds.
Cell-Type Specific Penetrating Peptides: Therapeutic Promises and Challenges
Authors: Zahid Maliha , Robbins Paul
Published: July 2015

Cell penetrating peptides (CPP), also known as protein transduction domains (PTD), are small peptides able to carry peptides, proteins, nucleic acid, and nanoparticles, including viral particles, across the cellular membranes into cells, resulting in internalization of the intact cargo. In general, CPPs can be broadly classified into tissue-specific and non-tissue specific peptides, with the latter further sub-divided into three types: (1) cationic peptides of 6–12 amino acids in length comprised predominantly of arginine, lysine and/or ornithine residues; (2) hydrophobic peptides such as leader sequences of secreted growth factors or cytokines; and (3) amphipathic peptides obtained by linking hydrophobic peptides to nuclear localizing signals. Tissue-specific peptides are usually identified by screening of large peptide phage display libraries. These transduction peptides have the potential for a myriad of diagnostic as well as therapeutic applications, ranging from delivery of fluorescent or radioactive compounds for imaging, to delivery of peptides and proteins of therapeutic potential, and improving uptake of DNA, RNA, siRNA and even viral particles. Here we review the potential applications as well as hurdles to the tremendous potential of these CPPs, in particular the cell-type specific peptides.
Identification and Expression Analysis of Glucosinolate Biosynthetic Genes and Estimation of Glucosinolate Contents in Edible Organs of Brassica oleracea Subspecies
Authors: Yi Go-Eun , Robin Arif , Yang Kiwoung , Park Jong-In , Kang Jong-Goo , Yang Tae-Jin , Nou Ill-Sup
Published: July 2015

Glucosinolates are anti-carcinogenic, anti-oxidative biochemical compounds that defend plants from insect and microbial attack. Glucosinolates are abundant in all cruciferous crops, including all vegetable and oilseed Brassica species. Here, we studied the expression of glucosinolate biosynthesis genes and determined glucosinolate contents in the edible organs of a total of 12 genotypes of Brassica oleracea: three genotypes each from cabbage, kale, kohlrabi and cauliflower subspecies. Among the 81 genes analyzed by RT-PCR, 19 are transcription factor-related, two different sets of 25 genes are involved in aliphatic and indolic biosynthesis pathways and the rest are breakdown-related. The expression of glucosinolate-related genes in the stems of kohlrabi was remarkably different compared to leaves of cabbage and kale and florets of cauliflower as only eight genes out of 81 were expressed in the stem tissues of kohlrabi. In the stem tissue of kohlrabi, only one aliphatic transcription factor-related gene, Bol036286 (MYB28) and one indolic transcription factor-related gene, Bol030761 (MYB51), were expressed. The results indicated the expression of all genes is not essential for glucosinolate biosynthesis. Using HPLC analysis, a total of 16 different types of glucosinolates were identified in four subspecies, nine of them were aliphatic, four of them were indolic and one was aromatic. Cauliflower florets measured the highest number of 14 glucosinolates. Among the aliphatic glucosinolates, only gluconapin was found in the florets of cauliflower. Glucoiberverin and glucobrassicanapin contents were the highest in the stems of kohlrabi. The indolic methoxyglucobrassicin and aromatic gluconasturtiin accounted for the highest content in the florets of cauliflower. A further detailed investigation and analyses is required to discern the precise roles of each of the genes for aliphatic and indolic glucosinolate biosynthesis in the edible organs.
A Multispectral Image Creating Method for a New Airborne Four-Camera System with Different Bandpass Filters
Authors: Li Hanlun , Zhang Aiwu , Hu Shaoxing
Published: July 2015

This paper describes an airborne high resolution four-camera multispectral system which mainly consists of four identical monochrome cameras equipped with four interchangeable bandpass filters. For this multispectral system, an automatic multispectral data composing method was proposed. The homography registration model was chosen, and the scale-invariant feature transform (SIFT) and random sample consensus (RANSAC) were used to generate matching points. For the difficult registration problem between visible band images and near-infrared band images in cases lacking manmade objects, we presented an effective method based on the structural characteristics of the system. Experiments show that our method can acquire high quality multispectral images and the band-to-band alignment error of the composed multiple spectral images is less than 2.5 pixels.
A Framework for Symmetric Part Detection in Cluttered Scenes
Authors: Lee Tom , Fidler Sanja , Levinshtein Alex , Sminchisescu Cristian , Dickinson Sven
Published: July 2015

The role of symmetry in computer vision has waxed and waned in importance during the evolution of the field from its earliest days. At first figuring prominently in support of bottom-up indexing, it fell out of favour as shape gave way to appearance and recognition gave way to detection. With a strong prior in the form of a target object, the role of the weaker priors offered by perceptual grouping was greatly diminished. However, as the field returns to the problem of recognition from a large database, the bottom-up recovery of the parts that make up the objects in a cluttered scene is critical for their recognition. The medial axis community has long exploited the ubiquitous regularity of symmetry as a basis for the decomposition of a closed contour into medial parts. However, today’s recognition systems are faced with cluttered scenes and the assumption that a closed contour exists, i.e., that figure-ground segmentation has been solved, rendering much of the medial axis community’s work inapplicable. In this article, we review a computational framework, previously reported in [1–3], that bridges the representation power of the medial axis and the need to recover and group an object’s parts in a cluttered scene. Our framework is rooted in the idea that a maximally-inscribed disc, the building block of a medial axis, can be modelled as a compact superpixel in the image. We evaluate the method on images of cluttered scenes.
Focus, Parallelism and Accommodation
Authors: Fox Danny
Published: July 2015

No abstract.
A Before-&-After Picture of When-, Before-, and After-Clauses
Authors: Van Geenhoven Veerle
Published: July 2015

No abstract.
Comparación del comportamiento de sistemas provisionales de protección de borde frente a cargas estáticas y de impacto
Authors: González M. N. , Cobo A. , Castaño A. , Prieto M. I.
Published: July 2015

Los sistemas provisionales de protección de borde (SPPB) están diseñados para detener el impacto de un trabajador que camina, tropieza y golpea contra ellas. Esto supone una acción de naturaleza dinámica. Sin embargo, muchas normas evalúan SPPB utilizando requisitos de tipo estático cuando la superficie de trabajo está poco inclinada (menos de 10°) suponiendo que equivalen al impacto de un trabajador. No obstante, este aspecto no se ha confirmado experimentalmente. En este trabajo SPPB con barandillas de tubos de acero y de tablas de madera se han evaluado usando los requisitos estáticos definidos por la norma EN 13374. Posteriormente, se han sometido a una energía de impacto de 180 J, que simula a un trabajador de 90 kg caminando a una velocidad de 2 m/s. Los resultados demuestran que los requisitos estáticos de la norma EN 13374 son más exigentes que el impacto de 180 J en todos los sistemas estudiados.
Performance Evaluation of Rice Bran and Moringa Blended Biodiesel in CI Engine
Authors: Wakil M.A. , Kalam M.A. , Masjuki H.H. , Sajjad H. , Rashed M.M. , Rashedul H.K.
Published: July 2015

Biofuels are taken to a notable option for research to energy sources because of their beneficial effect to milieu. In this study, two potential sources namely; Moringa and Rice bran oils are investigated critically as potential sources for biodiesel production. The work was classified into some steps. Firstly, biodiesel production from the two feedstock, secondly, measure the important physicochemical properties of biodiesels, and finally engine test is carried out with biodiesel-diesel blends under constant torque with variable speed. The results show that with the increasing speed, BSFC increases for both biodiesel blends and diesel and biodiesel blends shows only about 2% more BSFC than diesel. Exhaust temperature of biodiesel is about 5-8% higher than diesel but this difference is decreasing with increasing speed. It can be concluded that rice bran and moringa oil would be the feasible option for biodiesel as they satisfy ASTM standard limit and their performance is nearly similar to diesel.
On the Question of the Choice of Reducing Agent Tungsten at Electroslag Remelting Flux Containing Scheelite Concentrate to Produce Tungsten Steel
Authors: Kuzmichev Eugenii , Verkhoturov Anatoliy , Shtarev Dmitry
Published: July 2015

Influence of various reducers of tungsten from a scheelite concentrate on a complex alloying of melted low-carbonaceous steel by tungsten through oxides slag system is investigated. By electroslag remelting of low-carbon steel with use of ceramic gumboils on the basis of mineral associations are received high-alloyed by tungsten (to 20 wt.%) became.
Residual Stress Measurement in Inorganic Phosphate Adhesive Joint by Raman Spectroscopy
Authors: Ma Cheng Kun , Zhang Ji Feng , Qi Hui , Zhou Li Min
Published: July 2015

This paper deals with the determination of residual stress in SiC adherend bonded with inorganic phosphate adhesive using Raman and fluorescence spectroscopy in a micro-Raman system. To determine the stress mode in the specimen, we descript the corresponding relation between the Raman effect and residual stress. The laser with wavelength at 532nm and 785nm was respectively applied to test hundreds of test points on the SiC adherend and selected 785nm wavelength laser as the illuminant. Meanwhile, Raman imaging was used to analyze the surface of SiC and inorganic phosphate adhesive. Meanwhile, we determined the unreliability of estimating by Si peak. Taking E2-TO peak as reference, residual stress of six selected points was obtained. Then, we summarized the mechanism of compressive stress, and analyzed the stress change regulation.
Experimental Study on the Mechanical Properties of Shape Memory Alloy
Authors: Xu Cheng , Zhu Qi Rong
Published: July 2015

In this paper, the technology, equipment and method used to m easure the mechanical properties of micro-scale new-style intelligent shape memory alloy material were studied. First, two groups of small-scale shape memory alloy samples were made and the suitable micro load device was designed according to samples’ size and force range. Then the strain of the samples were observed with the video microscopy and calculated. Comparing with the corresponding force, the stress-strain curves of the two groups of samples were obtained respectively. After fitting these two curves, the stress-strain curve of the sample material was obtained. Finally, the basic mechanical properties of this shape memory alloy materials were discussed.
The Surface Quality Detection and Electrical Discharge Mirror Machining with Non-Mixed-Powder
Authors: Lin Yuan , Jiang Hao , Lv Huan Ran , Sui Xiu Wu
Published: July 2015

By using analytical and finite element analysis method, this paper analyzes the various factors on the impact of EDM surface roughness, puts forward a new mirror machining method of changing the order of the processing conditions and increasing the momentum of the swinging electrode in the process of EDM. Puts a measuring method for the surface quality with white light interferometer characterized by non-contact, high precision and vertical resolution in nanometer. Experiments show that in the non-mixed powder fluid, without replacing the electrodes and the processed work-piece is 45 # steel, the surface roughness of work-piece is 0.02 micro-meter, which meets the requirements for precision of the electrical discharge mirror machining.
Damage State Identification and Seismic Fragility Evaluation of the Underground Tunnels
Authors: Le Thai Son , Huh Jung Won , Ahn Jin Hee , Haldar Achintya
Published: July 2015

An efficient seismic fragility assessment method is proposed for underground tunnel structures in this paper. The ground response acceleration method for buried structure (GRAMBS), an efficient quasi-static method considering soil-structure interaction (SSI) effect, is used in the proposed approach to estimate the dynamic response behavior of the underground tunnels. In addition, the pushover analyses are conducted to identify the damage states of tunnels and Latin Hypercube sampling technique is used to consider uncertainties in the design variables. A large set of artificially generated ground motions satisfying a design spectrum for specific earthquake intensity are generated and fragility curves are developed. The seismic fragility curves are represented by two-parameter lognormal distribution function and its two parameters, namely the median and log-standard deviation, are estimated using the maximum likelihood estimates method.
Dynamics Modeling and Analysis of Multi-Point Ejection Mode of Space Nets System
Authors: Gao Qing Yu , Tang Qian Gang , Zhang Qing Bin , Feng Zhi Wei
Published: July 2015

Space nets is one of most promising conceptions that designed for the space debris removal. A critical issue in the design and analysis of space net system is the deployment modeling technology. The dynamic behavior of space net system in different ejection modes is investigated based on finite segment approach. The simulation results show that the model and the evaluation index developed in this paper provide a valid method to evaluate the deployment property of different ejection modes.
Study on Iterative Learning Control of Mobile Robot
Authors: Qu Li Ping , Qu Yong Yin , Zhou Hao Han
Published: July 2015

In order to solve the mobile robot trajectory tracking problem better, an iterative learning control (ILC) was applied. And the efficiency of mobile robot trajectory tracking was improved. From the simulation result, ILC with forgetting factor has very good performance for solving mobile robot trajectory tracking problem, and the smooth of trajectory tracking process also improved well.
New Results on PID Stabilization of Integral Process with Time Delay
Authors: Dong Yu
Published: July 2015

This paper considers the problem of stabilizing an integral process with time delay by a PID controller. As the proportional gain reaches the extreme value, the closed-loop system contains a double pole on the non-negative imaginary axis. Using this property, the admissible range of the proportional gain is derived, also the corresponding integral gain and derivative gain are obtained. For a fixed value of the proportional gain, the stability region in the plane of the integral and derivative gains is determined analytically. Moreover, the admissible ranges of the integral and derivative gains are computed and found to be non-convex. A numerical example illustrates the method presented.
Induced Lightning Stroke Identification on Protection Relays
Authors: Morales John , Carpio Marco
Published: July 2015

It is well known that lightning strokes produce mal-operation of transmission line protection relays. Where, protection devices cannot identify correctly between lightning stroke that generates or not permanent faults. Thus, when a flash produces a permanent fault, the protection relay sends a trip order, and the Transmission Line (TL) is disconnected correctly. However, when a lightning stroke does not produce a permanent fault, the protection devices also send the trip order, and the TL is disconnected unnecessary. In this context, these phenomena can produce unnecessary electric power outages, producing damage for the society and economic. Therefore, it is necessary to correctly identify between these lightning stroke signals. Besides that, direct lightning strokes, which hit directly on TLs or transmission towers, have usually been analyzed. However, induced lightning strokes, which hit on ground, have not been considered in previous analyzed. In this paper, in order to identify these induced lightning strokes, an algorithm based on a deterministic focus is proposed.
Overvoltage Analysis Considering Transmission Tower Models Based on Impedances and Inductances
Authors: Morales John , Montesdeoca Julio , Guidi Guillermo
Published: July 2015

It is clear that lightning strokes produce overvoltages on Transmission Lines (TLs), which can be higher that the Basic Insulator Level (BIL), generating a fault or short circuit. Thus, in order to adequately analyze when a lightning hits on a TL, it is necessary to simulate different elements corresponding to Electric Power Systems (EPSs) as real as possible. In this context, transmission towers are considered crucial parameters in lightning studies, which must be correctly selected and simulated in order to consider reflected voltage waveforms from cross arms.
Based on the above said, this paper presents a comparative study corresponding to the transmission tower simulation using two models. The first uses inductances, and the second uses distributed parameters impedances characterized by their impedance and travel time.
This paper presents voltage variations that exist in each phase, using different lightning features. Alternative Transients Program (ATP) is used to simulate the TL model considering different lightning currents and the two tower models. Results show that the impedance model analyze reflected waveforms, while that the inductance model does not analyze this issue.
Algorithms for Maximum Leaf Spanning Tress of Edge-Growing Network Models in Information System
Authors: Wang Xiao Min , Zhao Xi Yang , Yao Bing , Yao Ming , Chen Xiang En
Published: July 2015

For system modeling, simulation techniques and sensors networks the edge-growing network models with any connected initial network model are introduced in this paper. We design some algorithms for finding Maximum Leaf Spanning Trees (MLS-trees) of the models. Our algorithms can find the MLS-trees having scale-free behavior and short diameters. These algorithms are designed by techniques including big-degree-first level-searching and first-first level-searching in order to scan the desired spanning trees.
Study on Energy Saving of the Air-Conditioning Exhaust Heat Recovery System in Office Buildings
Authors: Zou Yan
Published: July 2015

The study analyzed the thermal performance of a sensible heat recovery system in an office building in Beijing area. Based on proposing the basic evaluation index of the thermal performance, the study analyzed the effect of outdoor temperature and wind speed on the heat recovery efficiency and the reduction of fresh air load. The analysis results show that, the operation effect of the sensible heat recovery device in winter is better. In winter, the sensible heat efficiency η is higher than 60%, the system has higher EER, and the fresh air load can be reduced more than 50%. While the sensible heat efficiency η is lower than 60% in most time in summer. And in a hot, humid climate, the recovery effect of sensible heat recovery device is significantly reduced.
An Optimal Algorithm for Scheduling with Variable Job Processing Times and Rejection
Authors: Wang Ji Bo , Hsu Chou Jung
Published: July 2015

This paper studies a single machine scheduling problem with rejection. Each job has a variable processing time and a rejection penalty. The objective function is to minimize the sum of the makespan of the accepted jobs and the total rejection penalty of the rejected jobs. We show that the problem can be solved in polynomial time.
Application of Ontology in Event-Driven Job-Shop Scheduling Problems
Authors: Xu Xiang Min , Yao Xi Fan
Published: July 2015

Aiming at the flexible flow-shop scheduling problem of cloud manufacturing, this paper introduces event driven concept and apply ontologies to Job-Shop scheduling problem FT46. The inference of ontology models allows the system to gain the dynamic information of workshop, and then rule engine is used to match event patterns to optimize the job shop scheduling problem.
The Study of AERMOD and ISCST3 for Area Source Simulation in Taiwan
Authors: Tseng Wei Jen , Tseng Chao Heng , Liu Han Chi
Published: July 2015

This research compared the performance of ISCST3 model with the AERMOD simulated for six selected environmental impact assessment (EIA) cases which belongs four kinds of area in Taiwan (hotel, industrial area, road, reservoir). The influence of different terrain (complex or flat) and land use (countryside or urban) was then determined for the two air dispersion models.The results of the cross analysis indicated that there is no significant difference between of the complex terrain and flat terrain on the incremental concentration ratio. However, the biggest difference of incremental concentration of particulate matter (PM) is in the simulation for case in urban (ISCST3 is 1.96 times higher than AERMOD), and the gas pollutants in ISCST3 of incremental concentration simulation results ratio reach to 65.38% more than others. The highest incremental concentration of ISCST3 is 2.67 times to AERMOD. The concentration in AERMOD higher than that in ISTSC3 was 20% in the total 40 simulation values, due to the difference between their vertical diffusion simulations. The ratio of maximum incremental concentration in AERMOD was higher than ISCST3 by 42.5%. By the cross match of these incremental concentration, the ratio that maximum incremental concentration in AERMOD being less than ISCST3 was 22.5% after diffusion, which shows that the sinking rate in AERMOD is faster than ISCST3.The simulation of AERMOD considers more in complex terrain and surface characteristics. It uses the stratified flow over complex terrain and considers the effect in characteristics of the Earth’s surface. Thus, the theoretical basis of AERMOD is solider than ISCST3, and its simulation has more reliability.
The Study of PTFE Wicks Application to Loop Heat Pipes with Flat Evaporator
Authors: Wu Shen Chun , Yan Shih Syuan , Chung Chen Yu , Su Shen Jwu
Published: July 2015

This study investigates the application of PTFE wicks to flat-plate loop heat pipes (FLHPs). PTFE’s low heat transfer coefficient effectively prevents heat-leakage, which is a problem with using metal wicks, lowering the operating temperature and pressure. This paper uses PTFE particles to form wicks, and the effect of PTFE on flat-plate LHP performance is investigated. Experimental results shows that the highest heat load reached was 100W, with lowest thermal resistance of 0.61°C/W, and heat flux of about 10W/cm2, For the wick properties, the wick had an effective pore radius of the wick was around 9.2μm, porosity of 47%, and permeability of 1.0 x 10-12m2. Compared to the highest heat flux reported in literature thus far for PTFE flat-plate LHPs, the heat flux in this study was enhanced by around 50%.
The Rapid Engineering Aero-Heating Calculation Method for Hypersonic Vehicles
Authors: Huo Lin , Yang Tao
Published: July 2015

The rapid engineering aero-heating calculation method for hypersonic vehicles is established for the question of computational efficiency during conceptual design stage. First the pressure distribution along vehicle’s surface is calculated by modified Newtonian theory. Secondly, the streamline along the surface is calculated with Newtonian steepest decent concept. Then by using reference enthalpy method, the heat flux on the surface is given. Finally, the heat flux on the surfaces of blunted cone, lifting body and wave-rider vehicle is calculated The analysis result shows the method used in this paper is fit for hypersonic vehicles, and can satisfies the aero-heating calculation during conceptual design stage in both efficiency and accuracy.
Effects of Mission Requirements on Primary Parameters of Wing-Sail Solar-Powered Aircraft
Authors: Xuan Jian Lin , Song Bi Feng
Published: July 2015

Solar-powered aircraft of wing-sail configuration employ sail tails mounted with photovoltaic (PV) modules, which could maximize solar energy absorption by rotation around individual roll axes or by yawing control of the aircraft. The guidelines of determining primary parameters for the wing-sail configuration differ significantly from solar-powered aircraft of conventional configuration. Effects of top-architecture mission requirements under the constraints of energy balance and mass balance are explored to investigate flight principles of the wing-sail configuration. The results show that the wing-sail has more potential for year-round operation at wide latitudes, equilibrium ceiling capacity of the wing-sail still differs significantly in a whole year: higher near summer and lower near winter and larger payload mass leads to higher payload-carrying capacity.
Vibration Characteristics Analysis of an Elastic Cavity
Authors: Kang Man , Lu Jing
Published: July 2015

A semi-analytical method was proposed to analyze the vibration characteristics of an elastic cavity. Combining the precise integration method and bent theory of the beam, the transfer relationship of the ends of the beam was derived. Based on the displacement continuity conditions and equilibrium equations of the junction, the conversion relation of the beams was also established. Then, the dynamics control equations of an elastic cavity were assembled by the above relationship and boundary conditions. The comparison with the FEM had verified the accuracy of the present method. This method avoids the shortage that the calculation accuracy over-depends on the element types and the mesh dividing methods, which is existed in the finite element method. In addition to this, the process of this method is efficient, so it is a useful method to the structural design and optimization of the cavity.
Design of the Main Working Tools for Non-Ferrous Alloys Processing Using Multi-Pass ECAP Technique
Authors: Şerban Nicolae , Răducanu Doina , Cojocaru Vasile Danut , Ghiban Alexandru
Published: July 2015

Equal-Channel Angular Pressing (ECAP) is a very interesting method for modifying microstructure in producing ultra-fine grained materials (UFG) and nanomaterials (NM). In the ECAP processing a sample is pressed through a die in which two channels of equal cross-section intersect at an angle of ϕ and an additional angle of ψ define the arc of curvature at the outer point of intersection of the two channels. ECAP is unique because significant cold work can be accomplished without reduction in the cross sectional area of the deformed workpiece. The key feature of ECAP processing is almost as a general rule the die design and manufacture as there is limited knowledge about ECAP and especially about ECAP die design, present paper offering an optimum solution to this problem, applied to multi-pass ECAP processing of an aluminum alloy. In this study a number of three ECAP dies with vertical configuration were considered, thereby combining the ease of execution with a relatively high maneuverability and posing minimum difficulties when extracting samples from the output channel. An optimum solution is also given by the present paper for designing and manufacturing the punches used for pressing the aluminum alloy through the three ECAP dies, minimizing this way the force required for plastic deformation and the power consumption and improving the ECAP process efficiency and stability.
Structural Features of Ti-25Ta-25Nb Alloy Thermo-Mechanically Processed
Authors: Angelescu Roxana Maria , Călin Vulcan Andreea Daniela , Angelescu Mariana Lucia , Căprarescu Andreea , Raducanu Doina
Published: July 2015

The Ti-25Ta-25Nb alloy was produced in a levitation induction melting furnace, under argon protective atmosphere. The obtained ingots were two times remelted, in order to obtain a high degree of chemical homogeneity. The alloy was then thermo-mechanically processed by a first cold-rolling and a recrystallization treatment in a heat treatment oven, followed by a second cold-rolling, to achieve final strips of 141 μm thickness. Using a PanalyticalX’Pert PRO MRD diffractometer, the as-cast specimens and the final cold processed specimens were XRD characterized, so that the phase structure and phase characteristics could be determined. The position of each diffraction peak, the intensity and the peak broadening parameters were determined using the PEAKFIT v4.11 software package. Finally the structural features of Ti-25Ta-25Nb alloy in the as-cast state and thermo-mechanically processed state were shown and discussed.
Research on Laser Micro Welding of an Aluminum Alloy Pressure Sensor
Authors: Ciobanu Robert , Donţu Octavian , Besnea Daniel , Constantin Victor , Cioboata Doina
Published: July 2015

This paper presents in detail the laser welding of a new mechatronic component belonging to the pressure sensors made ​​by aluminum alloy AW2007. Due to very high reflectivity of aluminum alloys, fast oxidation, the absorption of gases from the surrounding medium, special difficulties arise at laser beam welding and most situations require appropriate surface pretreatment. Given these issues, the paper present an experimental study on the influence of welding parameters on the seam quality for the aluminum alloy AW2007. In addition of the study regarding the influence of welding parameters, such as, laser power, welding speed, we conducted an analysis on the influence of the initial temperature of the material on the quality of the weld. Besides these aspects the paper presents a constructive solution for a device used to optimize the laser welding process of the sensor.
Thermophysical Properties in Assembling Process at Macro and Micro Level
Authors: Branzei Mihai , Plotog Ioan
Published: July 2015

The electronic modules are complex ensemble of electronic components having terminals (PIN) connected by solder joints on dedicated metallic surfaces (PAD) parts of conductive interconnection structure realized on rigid or flexible dielectric substrate having different core materials. The reliability of the electronic modules could be considered as expression of solder joints functionality (SJF) relating to working conditions and unique defined by their electrical, mechanical and thermal properties. These properties are in close connection with the solder joints microstructures, result of the soldering Process temperature gradient action over the trinomial solder alloy Paste, Pin and Pad. Consequently the solder joints quality can be correctly evaluated taking into consideration not only the severally intrinsic parameters of the trinomial elements Pin-Pad-Paste characterized by specific thermophysical properties (ThP), but also interrelate the complex reaction at the interface between them and interdependence with the soldering Process parameters.In the paper, will be analyzed the influencing factors of manufacturing processes, the most important assembling defects at macro and micro level, their causes relating to specific ThP and processes at interfaces Pin-solder joints-Pad, it will be identify the Key Process Input Variables (KPIV) and propose a structural model for assembling processes, 4P Soldering Model, as an useful tool in engineering of electronic product in order to assure the assumed goal for assembling stage.
Hardfacing Corrosion and Wear Resistant Alloys
Authors: Vasilescu Marius , Dobrescu Mircea
Published: July 2015

Hardfacing can be broadly defined as the application of a wear-resistant material, in depth, to the vulnerable (or worn) surfaces of a component by a weld overlay or thermal spray process.In the paper are presented the main hard facing iron-base and nonferrous alloys together with their properties and applications, together with a comparison of its performances.In addition, hardfacing alloys are applied to critical wear areas of original equipment or during reclamation of parts. These alloys, which are referred to as buildup alloys, are not designed to resist wear but to return a worn part beck to, or near, its original dimensions and/or to provide adequate support for subsequent layers of more wear-resistant hardfacing alloys.
Development of a Metal Coated Conformal Periodic Geometry for Electromagnetic Application
Authors: Peter Ildiko , Matekovits Ladislau , Rosso Mario
Published: July 2015

Conformal metasurfaces are even more diffused in different fields from optics to electromagnetics. Advanced applications, as making object invisible to incident fields also known as cloaking, require high precision realizations, since the resonant answer of the system is very sensitive to geometry details. Practical realizations are provocative, since material characteristics and mechanical restrictions should also be considered. Multi- and inter-disciplinary interactions are mandatory to overcome such technological challenges. Due to its excellent esthetic characteristics, good physical and mechanical properties, Aluminium is widely used for deposition on different substrates: physical and chemical vapor depositions are very suitable for micro-metallization process and for the realization of multilayered structures. This paper presents some results about the behavior of a cylindrical-shape system realized by Al films deposition on flexible, polymeric organosilicon substrate.
In Vitro Assessment of a New Proposed Biomaterial and Dental Implant Abutments Understatic Load
Authors: Weschler Mishel , Antoniac Aurora , Cojocaru Danut , Antoniac Iulian Vasile
Published: July 2015

The purpose of our study was to compare the mechanical properties of the different abutment under the static loading, aspect treated by many researchers [1-4], especially following the improvements given by the new proposed three-piece abutment, described below. We evaluated the effect of compression loading on the screw joint stability of the two-piece abutment and a new proposed three-piece abutment connected to an internal hexagon implant in vitro.The dental implant used was type AlphaBio SPI with an internal hexagon shape with following dimensions: length 13mm and diameter 3.75mm. The two types of abutment were used: the common type consisting of two piece straight titanium abutment and the second type consisting of three piece abutment (two titanium pieces and the third piece made of UHMWPE). For two-piece titanium implant/abutment systems with a screw-retained connection, the respective prefabricated straight abutments were tightened with a torque gauge using titanium abutment screws (type M-TLA) according to the manufacturer’s instructions. In the second case, the first titanium piece was a connector base between the implant and the UHMWPE abutment body which is assembled all together with the implant abutment fixation screw. The experimental systems were positioned in bovine cortical bone with a central hole (3.75 mm in diameter), and mechanical characteristics were evaluated using mechanical tensile tests. The mechanical tensile tests were carried out using INSTRON 3382 tensile test equipment. All tensile tests were performed at a constant strain rate of 1mm/min until a maximum elongation of 4mm. Stress-strain tensile curves were obtained for each experimental system.There were significant differences in the case of using the system with three piece abutment and we could conclude that this type of abutment assure a lower pressing on the entire system due to the shock absorbent properties of the piece made by UHMWPE.
Microstructural Refinement in a Commercial Aluminum Alloy Processed by ECAP Using a Die Channel Angle of 110 Degrees
Authors: Şerban Nicolae , Răducanu Doina , Ghiban Nicolae , Cojocaru Vasile Dănuţ
Published: July 2015

The properties of ultra-fine grained materials are superior to those of corresponding conventional coarse grained materials, being significantly improved as a result of grain refinement. Equal channel angular pressing (ECAP) is an efficient method for modifying the microstructure by refining grain size via severe plastic deformation (SPD) in producing ultra-fine grained materials (UFG) and nanomaterials (NM). The grain sizes produced by ECAP processing are typically in the submicrometer range and this leads to high strength at ambient temperatures. ECAP is performed by pressing test samples through a die containing two channels, equal in cross-section and intersecting at a certain angle. The billet experiences simple shear deformation at the intersection, without any precipitous change in the cross-section area because the die prevents lateral expansion and therefore the billet can be pressed more than once and it can be rotated around its pressing axis during subsequent passes. After ECAP significant grain refinement occurs together with dislocation strengthening, resulting in a considerable enhancement in the strength of the alloys. A commercial AlMgSi alloy (AA6063) was investigated in this study. The specimens were processed for a number of passes up to nine, using a die channel angle of 110°, applying the ECAP route BC. After ECAP, samples were cut from each specimen and prepared for metallographic analysis. The microstructure of the ECAP-ed and as-received material was investigated using optical (OLYMPUS – BX60M) and SEM microscopy (TESCAN VEGA II – XMU). It was determined that for the as-received material the microstructure shows a rough appearance, with large grains of dendritic or seaweed aspect and with a secondary phase at grain boundaries (continuous casting structure). For the ECAP processed samples, the microstructure shows a finished aspect, with refined, elongated grains, also with crumbled and uniformly distributed second phase particles after a typical ECAP texture.
Microstructural Investigation of Aluminum Alloys Type "2024" for the Aviation Industry
Authors: Anghelina Florina Violeta , Bratu Vasile , Stoian Elena Valentina , Popescu Ileana Nicoleta
Published: July 2015

This paper presents experimental results revealed on the samples type 2024 aluminum alloy used in aeronautics. The results of microstructural and compositional investigations presented in this paper were performed on samples taken from 2024 Al alloy samples produced by ALRO Slatina. The main objective of the investigation is the conformity assessment of alloys in terms of chemical composition with the specifications type of aviation [SAE AMS 47N, EN 515, etc]. It also aims microstructural conformity assessment in terms of the grain and the hardening effects by natural or artificial aging applied by the manufacturer. Adequate characterization of 2024 aluminum alloys type was achieved by combined investigations: (i) Wet Chemical Analysis, (ii) Spectrochemical Analysis and (iii) Electron Microscopy. The main conclusion that emerges from the investigations carried out on aluminum samples revealed that: (a) alloys fits in terms of composition with the standard specification for 2024, in all cases; (b) microstructure vary in fineness of grain, but meets the requirements of aviation rules; the investigated microstructures have been appreciated as adequate of aluminum alloys type "2024".
Synthetic of Pure Alumina from Aluminum Scrap
Authors: Najib Khan Abdul Shafiq Khan A. , Othman Nur Ezzah Faezah , Purwanto Hadi , Abdul Halim Hafasihah , Shamsul Baharin Ahmad Firdaus
Published: July 2015

Abundance in aluminum scrap metals can cause problem such as limited space allocation and pollution. The solution to solve these problems were by recycling the aluminum scrap metal as secondary production of aluminum. Among the recycling process alternative is smelting, However, the process consumes high energy with low productivity. This study focuses on alumina production from aluminum scrap waste. Dissolution process of Al scrap with 0.5M sodium hydroxide (NaOH) yields Al (OH)3and hydrogen gas. Results show that the temperature gradually decreased from 40°C to 35.7°C as the reaction took place. The pH of the solution during dissolution process increased from 12.08 to 12.38. The XRD results show that after calcination of Al (OH)3powders at 1500°C, α-Al2O3peaks could be observed. SEM morphology shows that the calcination process changes the Al (OH)3powders from hexagonal shape to form α-Al2O3with rounded shape.