Search

Welding processes are widely used technologies in the industrial context for creating permanent connections between mechanical components. This popularity is due to their versatility, which arises from the numerous available process variants and the multiple advantages they offer compared to other joining techniques. In the manufacturing context, where devices often operate in extreme conditions, the quality of welds becomes a critical factor in ensuring the safety and reliability of the manufactured products. Furthermore, a sound joint requires careful compliance with the increasingly stringent design specifications demanded by customers who require industry-standard conformity in order to achieve defect-free, robust, and durable welds. To address these needs and to define the optimal roadmap for the investigated process condition, an experimental investigation was conducted on the submerged arc welding process. The experimental trials involved butt joints of ASTM A516 Gr.70 carbon steel plates with different thicknesses in a flat position, utilizing a U-shaped chamfer and a multi-pass welding technique. For each weldment, the effects of the main process parameters on the qualitative characteristics of the manufactured products were evaluated from a metallurgical perspective. This evaluation included an in-depth metallographic analysis of the heat-affected zone of the carbon steel joint and involved both the measurement of the dimensions of these areas as well as the amount of ferrite and pearlite that resulted as the phases observed in the final microstructure of the steel joint following its solidification. Furthermore, the joint quality was assessed with regard to mechanical strength through hardness measurements. By analysing the experimental data, the paper provides a valuable contribution for increasing the productivity of the investigated welding process, while simultaneously meeting the specified industrial quality requirements for the products made of medium-thickness carbon steels. [ABSTRACT FROM AUTHOR]

In this study, a novel TIP–TIG (TT) automatic welding method was used to weld the girth seams of liquefied natural gas (LNG) tanks composed of 9% nickel steel. The microstructure of the joints was characterized via electron microscopy and x-ray diffraction. The tensile strength and ductility of the joints were evaluated via tensile testing. The low-temperature toughness of the joints was investigated via low-temperature impact testing at - 196 °C. This increased the toughness and strength of the TT-welded joint compared to the corresponding values of joints welded using conventional submerged arc welding (SAW). A comparison with the SAW-welded joints revealed that the TT-welded joint presented high strength and excellent low-temperature toughness, which can be primarily attributed to the low heat input. Compared with SAW, TT welding resulted in a lower joint dilution ratio, smaller heat-affected zone, and lower degree of grain coarsening. In addition to fine austenite, as the joint microstructure and several uniformly distributed carbides in the weld seam. These properties hindered the dislocation slip. However, they promoted precipitation strengthening and grain refinement and provided excellent low-temperature toughness to the TT-welded joints. Notably, TT welding does not require weld-bead cleaning between passes. Additionally, owing to improvements in the degree of automation for TT welding, the welding time can be further matched with that of SAW. TT welding with narrow-gap grooves reduces the required amount of filler metal by more than 50%. Therefore, the TT welding process is significantly advantageous and can replace SAW for girth–seam welding of LNG storage tanks. [ABSTRACT FROM AUTHOR]

In order to alleviate the problem of water resources shortage and unequal distribution in time and space in Guyuan City, this paper firstly analyzes the basic situation of water resources in Guyuan City, and constructs a multi-objective optimal allocation model of water resources with economic benefits, social benefits and ecological benefits as the objectives. Then, NSGA-III algorithm is proposed to solve the optimal allocation scheme of water resources. Based on the original NSGA-III algorithm, multi-point crossover operator and multi-point mutation operator, namely non-dominated sorting genetic algorithm-III with Random multipoint crossover mutation(RNSGA-III), are used. In the selection of the next generation, SAW and MCDM schemes were used to evaluate the chromosomes and set the weights to achieve better and more ideal results. Finally, the proposed scheme is compared with the existing configuration scheme based on NSGA-III and NSGA-II algorithms. Simulation experiments show that the proposed scheme is better than the allocation scheme based on NSGA-III algorithm and NSGA-II algorithm in the comprehensive cost of economic benefits, water shortage and ecological benefits, which can provide a basis for the rational allocation of water resources in Guyuan City, achieve unified management and sustainable utilization of water resources and support the sustainable development of economy and society. [ABSTRACT FROM AUTHOR]

Delta ferrite typically forms during single and multipass welding thermal cycle. It is known that delta ferrite affects corrosion and creep resistances, which are important to the reliability of steam turbine components. This work investigated numerically the effect of thermofluid field on delta ferrite formation during the application of multi-pass submerged arc welding (SAW) in a test coupon fabricated with a high Cr-content (up to 12% wt.) martensitic stainless steel (MSS). Welding parameters and assembly dimensions were similar to those used in the joint between blades and the spacer band for a steam turbine high-pressure module. Also, a finite element model (FEM) was applied to perform the numerical analysis of heat diffusion. The analysis considered the adjusted weld pool morphology and incorporated thermal contact resistances among weld passes with a high tendency to the chemical species concentration. The step thermal cycle induced in each weld pass was employed to estimate the heating and cooling rates at different points of the fusion zone (FZ) and the adjacent region. Enriching of alphagen elements such as Cr and Mo was responsible for eutectic delta ferrite formation in the partial melting zone (PMZ). This fact was corroborated experimentally through microscopy techniques, X-ray diffraction (DRX), and mechanical tests. The comparison between numerical and experimental results indicated that flow velocities and their behavior had the most critical effect on the element accumulation and delta ferrite formation. The mechanical characterization results demonstrated the deleterious ferrite effect on the mechanical properties of critical weld regions in the 12Cr-1Mo MSS. [ABSTRACT FROM AUTHOR]

The active manipulation of particle and cell trajectories in fluids by high-frequency standing surface acoustic waves (sSAW) allows to separate particles and cells systematically depending on their size and acoustic contrast. However, process technologies and biomedical applications usually operate with non-spherical particles, for which the prediction of acoustic forces is highly challenging and remains a subject of ongoing research. In this study, the dynamical behavior of prolate spheroids exposed to a three-dimensional acoustic field with multiple pressure nodes along the channel width is examined. Optical measurements reveal an alignment of the particles orthogonal to the pressure nodes of the sSAW, which has not been reported in literature so far. The dynamical behavior of the particles is analyzed under controlled initial conditions for various motion patterns by imposing a phase shift on the sSAW. To gain detailed understanding of the particle dynamics, a three-dimensional numerical model is developed to predict the acoustic force and torque acting on a prolate spheroid. Considering the acoustically induced streaming around the particle, the numerical results are in excellent agreement with experimental findings. Using the proposed numerical model, a dependence of the acoustic force on the particle shape is found in relation to the acoustic impedance of the channel ceiling. Hence, the numerical model presented herein promises high progress for the design of separation devices utilizing sSAW, exploiting an additional separation criterion based on the particle shape. [ABSTRACT FROM AUTHOR]

Population growth has resulted in an increase in land exploitation on a large scale. Therefore, to increase crop yield and sustainable use of soil, it is necessary to exploit the land according to its potential. Due to land suitability assessment’s multifactor nature, it needs a method for evaluating the factors simultaneously; in this case, multi-criteria decision models can be used. Therefore, this study aimed to compare the efficiency of the parametric method (square root) with multi-criteria decision-making approaches (technique for order of preference by similarity to ideal solution (TOPSIS) and simple additive weighting (SAW)) for evaluating land suitability in some rice cultivated areas in Khuzestan province, southwest Iran. A total of 28 rice farms were selected in the study area, and a pedon was dug, examined, and sampled in each. Several physicochemical land characteristics were used for the evaluation process, such as soil, climate, and topographical factors. According to the results, soil texture is the main limiting factor for rice farming in the study region, and organic carbon, salinity, and alkalinity ranked next. The range of land index for rice cultivation calculated by the square root method was from 19.3 to 70.9, from 49 to 95.3 by TOPSIS, and from 3.57 to 74.7 by SAW. The calculated explanatory coefficients between the actual yield and land indices for rice products estimated by the square root method, the TOPSIS approach, and the SAW method were 0.44, 0.63, and 0.60, respectively. This result confirms the high accuracy of TOPSIS method compared to SAW and square root methods. TOPSIS is therefore the ideal method for prioritizing options based on the simulation of the ideal answer because it is highly technical and robust in its decision-making approach. Furthermore, it uses the standardization method, equations, mathematical matrices, and suitable weights. Overall, it can be recommended as a suitable efficiency approach for land suitability evaluation. [ABSTRACT FROM AUTHOR]

This paper demonstrates a surface acoustic wave (SAW) device based on photopatterned interdigital transducer (IDT) created on a cadmium sulfide layer deposited over a lithium niobate substrate using two methods, viz. chemical bath deposition (CBD) and spin-coating. It allows SAW generation when the photo pattern shines on the photoconductive layer. I–V characteristics are measured for photo pattern-based SAW devices with electrode separation widths of 1 mm, 2 mm, 3 mm, and 5 mm. It is found that a 2 mm sample is best suited for this application in which we need to make photo patterns within this area. For 2 mm CBD sample, I on = 3.36 × 10 - 9 A (obtained by the light exposure) and I dark = 5.4 × 10 - 12 A (obtained in the absence of light) with an I on / I dark ≈ 10 3 is achieved. Similarly, for the spin-coated 2 mm sample, I on = 2.4 × 10 - 10 A and I dark = 2.9 × 10 - 13 A with I on / I dark ≈ 10 3 is obtained. In both methods, x-ray diffraction provides the major reflections at 2 θ = 26 ∘ . Other important analyses such as SEM, PL, and XRD have been done to justify the results. Finally, S 11 parameters with and without photopatterned IDTs have also been measured using a vector network analyzer. [ABSTRACT FROM AUTHOR]

The Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) and Simple Additive Weighting (SAW) are among the most employed approaches for aggregating performances in Multi-Criteria Decision-Making (MCDM). TOPSIS and SAW are two MCDM methods based on the value function approach and are often used in combination with other MCDM methods in order to produce rankings of alternatives. In this paper, first, we analyse some common features of these two MCDM methods with a specific reference to the additive properties of the value function and to the sensitivity of the value function to trade-off weights. Based on such methodological insights, an experimental comparison of the results provided by these two aggregation methods across a computational test is performed. Specifically, similarities in rankings of alternatives produced by TOPSIS and SAW are evaluated under three different Minkowski distances (namely, the Euclidean, Manhattan and Tchebichev ones). Similarities are measured trough a set of statistical indices. Results show that TOPSIS, when used in combination with a Manhattan distance, produces rankings which are extremely similar to the ones resulting from SAW. Similarities are also Experimental results confirm that rankings produced by TOPSIS methods are closer to SAW ones when similar formal properties are satisfied. [ABSTRACT FROM AUTHOR]

Copyright of Rechtsmedizin is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Piezoelectric microelectromechanical system (piezo-MEMS)-based mass sensors including the piezoelectric microcantilevers, surface acoustic waves (SAW), quartz crystal microbalance (QCM), piezoelectric micromachined ultrasonic transducer (PMUT), and film bulk acoustic wave resonators (FBAR) are highlighted as suitable candidates for highly sensitive gas detection application. This paper presents the piezo-MEMS gas sensors' characteristics such as their miniaturized structure, the capability of integration with readout circuit, and fabrication feasibility using multiuser technologies. The development of the piezoelectric MEMS gas sensors is investigated for the application of low-level concentration gas molecules detection. In this work, the various types of gas sensors based on piezoelectricity are investigated extensively including their operating principle, besides their material parameters as well as the critical design parameters, the device structures, and their sensing materials including the polymers, carbon, metal–organic framework, and graphene. [ABSTRACT FROM AUTHOR]

By using laboratory developed agglomerated basic fluxes a study has been carried out to predict the element transfer across the series of bead on plate weld deposits in submerged arc welding process (SAW). With the application of mathematical experiments of mixture design approach different statistical model were developed in terms of flux constituents. Using twenty one basic submerged arc welding fluxes a series of bead on plate weld deposits were made at constant welding parameters. Twenty one submerged arc welding fluxes were prepared as per mixture design approach for CaF2-SiO2-CaO & SiO2-CaF2-Al2O3 flux system. Results indicates that there was predominant effect on weld metal carbon, silicon, manganese, sulphur, phosphorous, molybdenum and chromium contents. The weld bead carbon content for all the fluxes has been increased while it is lower than that of base metal. Individual flux ingredients CaO, SiO2, CaF2 and Al2O3 incresars the delta carbon content and shows synergistic effect on it while binary mixture interations such as CaO.SiO2, CaO.CaF2, CaO.Al2O3, SiO2.CaF2 and CaF2.Al2O3 gives the negative effect on delta carbon content. [ABSTRACT FROM AUTHOR]

Weld mechanical as well as metallurgical properties are widely affected by the flux composition. Selection of flux composition play an important role in determining the good bead quality and mechanical properties of the welded joint. By using laboratory developed agglomerated rutile basic fluxes a study has been carried out to predict the element transfer behaviour in submerged arc welding process (SAW). With the application of mathematical experiments of mixture design approach different statistical model were developed in terms of flux constituents. Using twenty one rutile basic submerged arc welding fluxes a series of bead on plate weld deposits were made at constant welding parameters. Twenty one submerged arc welding fluxes were prepared as per mixture design approach for SiO2-CaO-TiO2 & Al2O3-SiO2-CaO flux system. Regression models were developed in terms of individual, binary and ternary mixture flux constituents for different ∆ quantities. Mathematical regression models have been checked for 95% significance level by using F-test. Results indicates that there was predominant effect on weld metal carbon, silicon, manganese, sulphur, phosphorous, molybdenum and chromium contents. Individual flux ingredients CaO and SiO2, has synergistic effect on ∆C and increases its weld bead carbon content while TiO2 and Al2O3 shows antisynergistic effect on ∆C and decreases the delta carbon content in weld region. [ABSTRACT FROM AUTHOR]

This work presents the experimental results for a surface acoustic wave (SAW) humidity sensor based on fluorinated polyimide (PI) as the sensing layer. The SAW sensor was configured as one port resonator onto an aluminium nitride (AlN)/silicon substrate. The interdigital transducers (IDTs) and reflectors were fully coated with PI film. With the hydrophobic sensing film, the total frequency shift was obtained as 332 kHz in the 10–90% relative humidity (RH) range, and the corresponding sensitivity was calculated as 4.15 kHz/%RH. In contrast to existing SAW humidity sensors, the fluorinated PI-based sensor showed a positive frequency shift in the whole detection range. Based on perturbation theory, the positive shift can be observed due to the stiffening effect during the sorption of vapor molecules occupying polymer-free volume. Furthermore, the sensor was tested in both very low (< 10%RH) and very high (> 90%RH) humidity ranges to verify the reverse trend of increasing frequency. The hydrophobic film was observed to be sensitive in both ranges and the frequency shift was found large in low ranges compared to high ranges, mainly due to the stiffening effect. At high RH levels, two contrary effects were contributing, mass loading, which shifts frequency negatively, and stiffening, which shifts positively. The cancellation between these effects results in low-frequency change at high ranges. Moreover, the sensor exhibits a fast response time, low hysteresis and good repeatability. These findings demonstrate that the SAW sensor with hydrophobic PI sensing film is a good choice for humidity sensing applications. [ABSTRACT FROM AUTHOR]

Electrochemical micromachining (ECMM) is employed to machine Hastelloy C22 a nickel-based alloy, which is applied in chemical, food processing, and pharmaceutical industries. An L18-mixed orthogonal array (OA) experiment plan was considered along with a polytetrafluoroethylene (PTFE)-coated electrode (CE), normal electrode, and mixed electrolyte (equal weight of sodium nitrate (NaNO3) + oxalic salt (C2H2O4)). Criteria importance through inter-criteria correlation and simple additive weighting methods were used to obtain the optimum levels of factors for higher machining rate, lower overcut, and conicity (K). According to the analysis, the optimal parameter combination was PTFE CE with 20 g/L mixed electrolyte, 8 V, 85% duty cycle, and 90-Hz frequency. An analysis of variance (ANOVA) results showed that the electrode type contributes 21.15% and 41.26% for machining rate (MR) and overcut (OC), respectively. The electrolyte concentration is the most significant factor for conicity, which contributes 64.32%. [ABSTRACT FROM AUTHOR]

Global supply chains are increasingly becoming complex by having numerous suppliers around the world. To manage this complexity, organizations must identify the optimum number of suppliers. There have been many examples in the literature that used different approaches to solve this problem. Despite the importance of this issue, less attention has been paid to it and managers of the companies do not know how, and based on which approach and criteria, they should determine the optimal number of suppliers which leads to lower cost and higher reliability of the production line. Therefore, in this study, a hybrid methodology is proposed to expose the process of this problem which helps managers to learn how they can determine the optimal number of suppliers. We address this gap by developing an integrated approach based on multi-criteria decision-making (MCDM) comprising best-worst method (BWM), simple additive weighting (SAW), and technique for order preference by similarity to ideal solution (TOPSIS), and simulation to determine the optimal number of suppliers. This study utilizes a comprehensive approach based on leagile and environmentally sustainable criteria to determine the optimal number of suppliers. To examine the efficiency of the proposed approach, an empirical case study is conducted in an Iranian oil company. The final results represent that the scenario with a 1-1-1 arrangement (one supplier for each type of equipment) is the best possible scenario to determine the optimal number of leagile-sustainable suppliers. To examine the reliability and robustness of the obtained results, a sensitivity analysis based on the three most important criteria is conducted. Finally, discussions on the findings as well as theoretical and managerial implications are presented. [ABSTRACT FROM AUTHOR]

This paper investigates the effect of SiO2 buffer layer on the dispersion characteristics of surface acoustic waves excited in the patterned-ZnO/SiO2/Si a structure on silicon substrate. The performance parameters phase velocity, coupling coefficient (K2) and temperature coefficient of delay (TCD) characteristics of first three surface modes generated in the structure have been studied with respect to thicknesses of ZnO and SiO2 using finite element simulations. Bulk acoustic waves generated in the structure couples acoustically to excite vertically polarized surface modes in the silicon substrate. SiO2 layer is employed between the ZnO pattern and Si, to enhance the performance factors by reducing the acoustic radiation into the bulk. The vertically polarized surface modes have the wave propagation similar to Rayleigh wave are generated in the structure by the acoustic coupling of transverse BAW excited in ZnO pattern exhibit high K2and near zero values of TCD. The zeroth surface mode excited in the structure exhibits nearly zero TCD at hZnO/λ = 0.037, h SiO 2 /λ = 0.025 with phase velocity 4630 m/s, K2 of 2.3%. First higher order surface mode exhibit unique nature of high phase velocity 5078 m/sand high K2 of 5.4% with TCD -15.4 ppm/°C. A surface mode excited by second higher order bulk wave in ZnO pattern exhibit a negligible change in phase velocity for a broad ZnO thickness range of hZnO/λ = 0.12–0.3, with h SiO 2 /λ = 0.2 exhibits a minimal phase velocity of variation of 3.8% and a constant K2 of 1.26% and very low TCD range of −2 to −5 ppm/°C. [ABSTRACT FROM AUTHOR]

As the sawmill industry is moving towards thinner bandsaws for higher yields, it is important to study the cutting force in more detail. The cutting force can be split into two zones. Zone I concerns the force on the major cutting edge as well as the friction force on the major first flank. Zone II considers the forces on the minor cutting edges as well as the friction forces on the minor first flanks. Zone II cutting can significantly affect the cutting force and has not been studied in great detail. Frozen, non-frozen and dry heartwood of Norway spruce and Scots pine were cut using different tooth geometries and the cutting force was measured. The major cutting edge, clearance, band thickness, minor cutting edge angle and minor cutting edge clearance angle were investigated. The y-intercept of the cutting force–width graph was used as the Zone II force (at this point the Zone I forces are assumed to be zero). The Zone II force contribution to the cutting force was studied. The results show that frozen wood has less elastic spring-back and therefore less Zone II cutting. Dried wood showed a significantly higher degree of Zone II cutting (55−75% contribution to the cutting force). Changing the major cutting edge from 2.87 mm to 1.6 mm resulted in 10–15% higher Zone II force contributions. [ABSTRACT FROM AUTHOR]

Purpose: To compare the intraoperative utility of bur and saw and to examine the pattern of lingual split during bilateral sagittal split osteotomy of mandible. Material and methods: This study prospectively compares the intraoperative utility of bur and saw in bilateral sagittal split osteotomy as split-mouth model. Study includes 16 patients (representing 32 sagittal split osteotomies) divided into two groups. The procedure to be performed was explained to the patient, followed by written informed consent. The institutional ethical committee approved the clinical study and all subjects gave informed consent. Results: We found that the ease of handling of the bur was good compared to saw. The duration required for completion of osteotomy using bur was less compared to saw. Conclusions: The use of surgical drills and burs is still the gold standard in most developing nations and countries in transition like India. Depending upon the expertise of the surgeon, availability of precise dissecting instruments, one can go with either of the instrument for BSSO. [ABSTRACT FROM AUTHOR]

The high safety factor expected from transport vehicles results in high costs. Moreover, the environmental and financial concerns in transport vehicle technology make the minimization of production factors obligatory. This causes a decision problem between high safety and production at low cost. In this study, modeling and analysis with multi-criteria decision-making methods for freight wagon bogie operating with high safety and minimum cost were aimed. The decision problem was created considering the factors of safety, manufacturability and cost for three different materials, and the most appropriate material combination was determined for the bogie construction. In data production for the decision factors, the application of computer-aided engineering and chemical content of the materials were taken into consideration. The real tonnage prices of the related material were used for the cost criterion. TOPSIS, VIKOR and SAW, which are among the multi-criteria decision-making methods, were used for the solution of the decision problem. Fishbone, Cronbach's alpha and regression methods were used for quality and reliability analysis. It was found that the solutions obtained from the chosen models validate each other. Together with the concept of economy and computer-aided engineering applications, its successful applicability to decision problems developed for freight wagons and providing a solution to them is the originality of this paper. According to the methods, the ideal solution was found as the material S355 for the pivot, S235 for the carrier and the bolster. According to reliability analysis, the data produced were found statistically sufficient and significant (Adj. R-Sq's obtained above 95%). [ABSTRACT FROM AUTHOR]

This research aims at optimum utilization of waste recycled submerged arc welding slag along with virgin flux in place of pure virgin flux without compromising the quality of welding and effective waste reduction. The related quality aspects, determination of quantum of recycled slag to be used are evaluated through suitable experimentation. The application, process parameters, welding parameters, parent material and filler wires are also changing in line with the job order. In such a dynamic environment weld economy has to be inbuilt through proper mechanism. A suitable mechanism involving optimum usage of spent slag with virgin flux will be ideal in such a dynamic environment An attempt has been made to introduce the waste recycled slag along with virgin flux during Submerged Arc Welding (SAW) of low carbon steel with suitable wire and optimum welding parameters. Varying weight percentage (20, 30,40 & 50 wt.%) of waste slags were mixed and submerged arc welding was carried out; Mechanical testing, Radiography, Ultrasonic tests were employed to ascertain the quality and arrived the optimum mixture of slag and virgin flux. Results revealed that usage of waste slag between 20 and 30 wt.% showcased optimum tensile strength, impact strength, hardness and reduction of cost. However any deviation from the optimum level of recycled slag with virgin flux will deviate from optimum level of quality or profit. [ABSTRACT FROM AUTHOR]

Big data is prominent for the systematic extraction and analysis of a huge or complex dataset. It is also helpful in the management of data as compared to the traditional data-processing mechanisms. In this paper, an efficient ant colony optimization (ACO) and particle swarm optimization (PSO)-based framework have been proposed for data classification and preprocessing in the big data environment. It shows that the content part can be collaborated and fetched for analysis from the volume and velocity integration. Then weight marking has been done through the volume and the data variety. In the end, the ranking has been done through the velocity and variety aspects of big data. Data preprocessing has been performed from weights assigned on the basis of size, content, and keywords. ACO and PSO are then applied considering different computation aspects like uniform distribution, random initialization, epochs, iterations, and time constraint in case of both minimization and maximization. The weight assignments have been done automatically and through an unbiased random mechanism. It has been done on a scale of 0–1 for all the separated data. Then simple adaptive weight (SAW) method has been applied for prioritization and ranking. The overall average classification accuracy obtained in the case of PSO-SAW is 98%, and in the case of ACO-SAW, it is 95%. PSO-SAW approach outperforms in all cases, in comparison to ACO-SAW. [ABSTRACT FROM AUTHOR]

Drought is one of the natural hazards affecting all activities of living things. High and low droughts occur in different parts of the country, and their effects are more noticeable in arid and semiarid regions. One of these areas is the south-west of Iran. The purpose of this study is drought modelling and analysis in the south-west of Iran. To do this, climatic parameters were first used, including precipitation, temperature, sunshine, relative humidity and wind speed in the period of 32 years (1987–2018) at 15 stations in the south-west of Iran. For modelling the TIBI fuzzy index, at first, four indices (SET, SPI, SEB and MCZI) were fuzzy in MATLAB software, and then the indices were compared and finally SAW multivariate decision-making model was used to prioritize areas affected by drought. The results of this study showed that the highest frequency of drought at 6- and 12-month scale occurred in Islamabad Gharb station and the lowest frequency was in Hamedan airport station. The T.I.B.I index accurately reflects the four indicators: SET, SPI, SEB and MCZI. Based on the modelling, T.I.B.I fuzzy index showed relative superiority to the SPEI fuzzy index. Finally, according to the SAW multivariate decision-making method, the Islamabad Gharb station with a score of 1 was more prone to drought occurrence. [ABSTRACT FROM AUTHOR]

Flood is one of the natural disasters that generates a lot of damages every year in different points of the world. Also, soil erosion is among the processes that threats the soil and water resources of the country. The performance of a small watershed is not same as the hydrologic response of a large watershed. Determining the amount of participation and prioritizing the sub-basins in terms of flood generation in the outlet of the basin can be a large help in correct locating the flood control and soil and water conservation projects and leads to decreasing the negative impacts of the flood control operations at unnecessary regions or at the regions with lower priority and also it prevents personal tastes. Therefore, determining the flood generator regions and prioritizing the sub-basins in terms of flooding and sedimentation potential is essential for better management of the watersheds. For this purpose, the aim of this research is to determine the amount of participation of the eastern sub-basins of the Gorganrud River Basin of Golestan province, Iran in flooding and sedimentation and their prioritization in terms of flooding and sedimentation potential using the multi-criteria decision-making methods. In this present study, we used area estimation indices, gravel coefficient, drainage density, basin average slope, basin average height, curve number, cover percentage, sediment yield, sediment delivery ratio, runoff height and concentration time. Indicators are considered to be important indicators affecting water permeability, runoff production and, consequently, the potential for flooding and sedimentation. Following the formation of decision matrix with 13 options (sub-basins) and 11 criteria (evaluation index), Technique For order Preference by Similarity to ideal Solution (TOPSIS), Simple Additive Weighting (SAW), Elimination Et Choice Translation Reality (ELECTRE) and Vise Kriterijumska Optimizacija Kompromisno Resenje (VIKOR) techniques were used to prioritize sub-basins. Borda and Copland methods were used to combine the rank of proposed techniques. Also, in order to validate the models, we estimated the percentage change and the intensity of the changes. The results showed that the highest runoff height index (0.179) and the average height index of the basin had the lowest weight (0.031), according to experts. Considering the results of the combined ranking of the proposed techniques, sub-basins 12, 1 and 2 are in first to third priority, respectively, and have a more critical situation than the rest of the sub-basins. Field studies clearly show the results of the research, because sub-basins 12 and 1 exhibit the highest erosion, poor soil and gradient. Also, zones with flood and sedimentation potential in the area showed that 49/31% of the area in high and very high risk. This study proves that multi-criteria decision-making methods and RS and GIS techniques are very suitable, precise, economically and temporally advantageous, and helpful tools to evaluate and prioritize the sub-basins in the soil erosion and soil and water conservation topics. Therefore, considering the multiple objective functions and the costly watershed management operations, it can be said that multi-criteria decision-making methods can be used for better management of watersheds in terms of biological and structural flood control operations. So, prioritization can be done based on a mathematical logic. The proposed method in this research is very suitable for watersheds without sufficient data. Hence, such researches which are low cost as well as quick can be used and watersheds can be prioritized for management and conservative acts. [ABSTRACT FROM AUTHOR]

The growing number of services that can meet the users' functional requirements, inspired many researchers to provide some approaches to rank and select the best possible services regarding their quality of service (QoS) and users' preferences. Considering various criteria which should be considered in the service selection process, multi-criteria decision making (MCDM) techniques have been vastly applied to help a decision-maker in determining the weight of each QoS factor and ranking the services provided by different service providers. This paper provides an extensive investigation of the state of the art MCDM-based service selection schemes proposed in the literature. It provides the required background knowledge and puts forward a taxonomy of the investigated service selection schemes regarding their applied MCDM methods. Also, it describes how the MCDM methods are adapted by the studied schemes, which datasets and QoS criteria are employed by each system, and which factors and environments are utilized to evaluate the service selection schemes. Finally, the concluding remarks are provided, and directions for future studies are highlighted. [ABSTRACT FROM AUTHOR]

In this study, heat affected zone (HAZ) specimens were fabricated by applying flux-cored arc welding (FCAW) and submerged arc welding (SAW) processes to steel plate with a thickness of 100 mm and yield strength of 460 MPa for use in offshore platforms. The correlation between microstructure and Charpy absorbed energy was investigated, and fracture mechanisms were analyzed. As distance from the fusion line increases, heat input and cooling rate decrease, making it difficult to form low-temperature transformation microstructures in HAZ specimens and increasing the grain size of quasi-polygonal ferrite. The FCAW process is advantageous for low-temperature transformation microstructures because it has a lower heat input and a faster cooling rate than the SAW process. Plastic deformation and ductile fracture occurred at low temperatures in fine acicular ferrite and quasi-polygonal ferrite regions of HAZ specimens, but brittle fractures occurred in bainitic ferrite, granular bainite, and coarse quasi-polygonal ferrite regions. The unit crack path in the brittle fracture region was similar to the grain size. In other words, as the volume fraction of fine acicular ferrite and quasi-polygonal ferrite increased in HAZ specimens, Charpy absorbed energy at low temperature increased. 100 mm thick steel plate with yield strength of 460 MPa for offshore platforms is fabricated by TMCP. The SAW and FCAW HAZ specimens are consisted of AF, QPF, and small amounts of GB, BF, and secondary phases. Secondary phases are evenly distributed of the HAZ specimens. So the average Charpy absorbed energy at − 20 °C of the SAW and FCAWHAZ are very high at 100 and 230 J, respectively. Plastic deformation occurred around the AF grain, leading to ductile fracture, while brittle fracture occurred without plastic deformation around the BF and GB grains, resulting in long unit crack paths. [ABSTRACT FROM AUTHOR]

In this study, double-sided submerged-arc-welded CSEF steel joints were considered for microstructural and mechanical (hardness, ductility and strength) characterisations for four different cases of preheating and PWHT processes. The XRD and EDS analyses were also performed to investigate the phase transformation and chemical composition. Preheating was observed to be an improving factor for ductility and hardness of the welds. Similarly, PWHT enhanced the uniformity in the hardness distribution owing to reduced austenitic grain size in the HAZ as well as equiaxed fine-grained ferrite matrix in the FZ. It was observed that preheating and combined preheating and PWHT increased the ductility of the weld by 16.9% and 56.3%, respectively, from the as-welded case. Furthermore, it was also observed that preheating individually and preheating combined with PWHT reduced the maximum hardness values by 8.2% and 60.2%, respectively. [ABSTRACT FROM AUTHOR]

Prioritization of watersheds for conservation measures is essential for a variety of functions, such as flood control projects in which the determination of top priority areas is an important management decision. The purpose of this study is to examine watershed morphological characteristics and identify critical sub-watersheds, which are prone to be damaged, using Remote Sensing/Geographical Information Systems (GIS) and SAW/TOPSIS (Simple Additive Weighting/ Technique for Order of Preference by Similarity to Ideal Solution). Fourteen morphometric parameters were chosen to organize sub-watersheds using SAW/TOPSIS, which examines sub-watersheds (as susceptible zones) from the perspective of classification in four priority levels (namely, low, moderate, high and very high levels). The SAW/TOPSIS approach is a useful strategy to find out potential zones provided that the ultimate goal is to achieve successful management strategies, particularly in particular zones where information accessibility is limited and soil assorted variety is high. Without facing with high cost and exercises in futility, sub-watersheds could be organized through morphometric parameters in executing conservational measures to save soil and the earth at the same time. In short, our results showed that morphometric parameters are highly efficient in identifying erosion-prone areas. [ABSTRACT FROM AUTHOR]

The surface acoustic wave (SAW) sensor has been widely used to measure torque, and the temperature effect on torque sensitivity has been taken into account. However, few studies have been devoted to the influence of electrode on the torque sensitivity. In order to design a SAW torque sensor with high performance, it is necessary to analyze the effect of electrode. We adopt the Mindlin's thin plate equations as a boundary condition due to the electrode, propose a method to evaluate the effect of electrode and make a comparison between our calculation and experimental results. Then, we obtain the frequency shifts with different electrode materials when the applied torque is zero. Finally, we evaluate the torque sensitivity with the effect of electrode and obtain the result with the errors about 1.7 and 7.6% compared with experimental data. The errors have been improved greatly with respect to the calculation ignoring electrode effect, about 30%. However, the analysis is valid only under the condition that the thickness of electrode is relatively small, which is satisfied in the general conditions. [ABSTRACT FROM AUTHOR]

Landfill is the most common method used to eliminate municipal solid waste in developing countries. As in all developing residential units, Sivas city is also encountering a major solid waste problem menacing both public health and environment. This study analyzes the 7 criteria (geological structure, land ability class, transportation, groundwater, surface water, residential areas, and existing land use) utilized for solid waste landfill area preference reasons by employing some Geographical Information System (GIS) based, multi-criteria decision-making methods such as Analytical Hierarchy Process (AHP) and Simple Additive Weighting (SAW). Evaluation of alternative areas defined by AHP and SAW methods is conducted with the help of Combinative Distance-Based Assessment (CODAS). The study area was classified as "most suitable", "suitable", "averagely suitable", "too little suitable" and "not suitable" in terms of their sanitary landfill properties. According to AHP and SAW analyses results, it was determined that a large part of the study area (respectively, 46.82% and 27.81%) is within the category of "averagely suitable". After the application based on GIS oriented multi-criteria decision-making analysis, 4 alternative places as solid waste disposal areas were recommended by taking environmental and physical factors into consideration. AHP–CODAS and SAW–CODAS methods were mutually utilized to rank these 4 areas according to their suitability. As a result, "Area1" in integrated weights (AHP and SAW)–CODAS was selected as the most appropriate place for sanitary permanent landfill. [ABSTRACT FROM AUTHOR]

In certain platforms, such as Google Docs, documents are adapted for specific mobile device types, and the installation of their applications is required. Although the documents can be accessed via Web browsers, their correctness is not guaranteed. In content selection, the document is adapted into various versions, from which the optimal one, based on a quality of experience (QoE) criterion, is delivered. Existing works evaluate the QoE of each content version using the user’s preferences and context parameters, such as device resolution and network bitrate. They ask the user to weight the context parameters, and then combine them using the simple-additive-weighting (SAW) method. However, not all users are familiar with the context parameters, and cannot understand their relationship with the requested content. Besides, not all parameters are compensatory to be summed up. In this paper, we propose a TOPSIS-based QoE model to address the two aforementioned drawbacks. We use the context parameters to define high-level functions understandable by all users, and combine them using the TOPSIS method. Experimental results show the convenience of our QoE model and its reliability over the SAW-based method, as well as the weighting-product (WP) method, which is used as an alternative to the SAW one. [ABSTRACT FROM AUTHOR]

There are different herbal teas in the world, however always new and functional herbal teas are presented to consumer preference. The seeds of Rumex crispus L., also known as ‘kalmuk’ or ‘kalmek’ are infused by boiling water and filtrated and mixed boiled milk. Generally it is consumed in autumn and winter season. The consumption of this herbal tea could offer some beneficial influence as it contains antioxidant substances and phenolics which is associated with the health effects. In the present study, milk was incorporated with the Rumex crispus L. extract at different concentrations and some physicochemical, bioactive and sensory properties of samples were investigated by using multi-criteria decision making techniques. The technique for order preference by similarity to ideal solution (TOPSIS) approach and simple additive weighting (SAW) approach were used for the determination of the optimum sensory and bioactive characteristics of the products. The total phenolic content of the extract of R. crispus L. seeds was found as 31.82 ± 1.6 mg GAE/g. The highest IC50 value was observed in sample containing 70% milk and the lowest was observed in extract of R. crispus L. According to the results of SAW and TOPSIS methods, the samples coded as S5 and S6 were the best samples based on the sensory and bioactive properties. [ABSTRACT FROM AUTHOR]

This paper presents an original passive wireless rotation speed measurement method based on surface acoustic wave (SAW) technology. A theoretical analysis was conducted on the principle of SAW rotation speed measurement and a numerical analysis on the SAW response energy pulses with different rotation angles and resonance frequencies was performed. Numerical calculation results showed that when the distance and the effective length of the antenna connected to SAWR vary with the rotation angle, the energy of acquired SAW response varies periodically. The rotation speed was estimated by searching the crossing points of the SAW response energy pulses and its mean value line. The SAW rotation speed measurement system was set up and the high performance SAW resonators were fabricated on a quartz substrate. The proposed measurement system was tested with a maximum error of 0.6 rpm, indicating that the system is capable of measuring rotation speeds from 10 to 100 rpm. Experimental results verified the validity and feasibility of presented rotation speed measurement method. [ABSTRACT FROM AUTHOR]

Seamless handover between different radio access technologies is a great challenge since it needs to guarantee the link continuity and satisfy the subscriber's quality-of-services (QoS) requirements. The performances of roaming across different technologies depend on the number of implemented handover criteria, which can be large. In this case, multiple attribute decision making (MADM) methods such as simple additive weighting, technique for order preference by similarity to ideal solution and the compromise ranking method called (VIKOR: VlseKriterijumska Optimizacija I Kompromisno Resenje) have been proposed to solve this kind of multi-criteria problems. However, the major shortcomings of these techniques are the high decision delay and the complexity. In this paper, we propose a novel handover (HO) scheme called Fuzzy-MADM. It is based on the combination of one classical MADM method with a fuzzy logic inference system in order to reduce decisional time. The optimal network is selected, based on multiple criteria such as network QoS indicators, speed of mobile station, battery level and signal strength. The efficiency of our approach is evaluated through appropriate simulations. The results related to HO delays, throughput, complexity and number of executed handovers show the performances of our proposal when compared to classical MADM and load balancing methods. [ABSTRACT FROM AUTHOR]

Selecting a landfill site is a difficult task because the process depends on many factors and restrictions. Landfill is an optimal solution for the disposal of solid waste in Al-Musayiab Qadhaa, which is located in the northern part of Babylon Governorate. At the moment, there is no landfill site in that area that follows the scientific selection site criteria. For this reason, in this research, fifteen variables were considered (groundwater depth, rivers, soil types; agriculture lands use, land use, elevation, slope, gas pipelines, oil pipelines, power lines, roads, railways, urban centers, villages and archeological sites) using geographic information system (GIS) to find out the best suitable landfill site. In addition, two methods of multi-criteria decision-making were used to derive weights for criterion's maps on GIS to obtain potential landfill sites. The first method is analytical hierarchy process (AHP) which was used to identify the weight for each criterion from the matrix of pairwise comparisons. The second method was the simple additive weighting (SAW) which is a simple method to solve the problem of the selection landfill sites. After comparison of the results obtained based on combining two final maps resulted from methods of AHP and SAW using GIS environment to determine the pixels percentage of matching and non-matching for two maps, two suitable candidate landfill sites were identified that satisfy the requirements with an area of 7.965-5.952 km. Area of these sites can accommodate the solid waste generated from the Qadhaa up to 2030. [ABSTRACT FROM AUTHOR]

In this work, we discuss and demonstrate the principle features of surface acoustic wave (SAW) aerosol generation, based on the properties of the fluid supply, the acoustic wave field and the acoustowetting phenomena. Furthermore, we demonstrate a compact SAW-based aerosol generator amenable to mass production fabricated using simple techniques including photolithography, computerized numerical control (CNC) milling and printed circuit board (PCB) manufacturing. Using this device, we present comprehensive experimental results exploring the complexity of the acoustic atomization process and the influence of fluid supply position and geometry, SAW power and fluid flow rate on the device functionality. These factors in turn influence the droplet size distribution, measured here, that is important for applications including liquid chromatography, pulmonary therapies, thin film deposition and olfactory displays. [ABSTRACT FROM AUTHOR]

Heat supply is the most energy-consuming sector of the economy. Approximately 30% of all used primary fuel-and-energy resources is spent on municipal heat-supply needs. One of the key indicators of activity of heat-supply organizations is the reliability of an energy facility. The reliability index of a heat supply organization is of interest to potential investors for assessing risks when investing in projects. The reliability indices established by the federal legislation are actually reduced to a single numerical factor, which depends on the number of heat-supply outages in connection with disturbances in operation of heat networks and the volume of their resource recovery in the calculation year. This factor is rather subjective and may change in a wide range during several years. A technique is proposed for evaluating the reliability of heat-supply organizations with the use of the simple additive weighting (SAW) method. The technique for integrated-index determination satisfies the following conditions: the reliability level of the evaluated heat-supply system is represented maximum fully and objectively; the information used for the reliability-index evaluation is easily available (is located on the Internet in accordance with demands of data-disclosure standards). For reliability estimation of heat-supply organizations, the following indicators were selected: the wear of equipment of thermal energy sources, the wear of heat networks, the number of outages of supply of thermal energy (heat carrier due to technological disturbances on heat networks per 1 km of heat networks), the number of outages of supply of thermal energy (heat carrier due to technologic disturbances on thermal energy sources per 1 Gcal/h of installed power), the share of expenditures in the cost of thermal energy aimed at recovery of the resource (renewal of fixed assets), coefficient of renewal of fixed assets, and a coefficient of fixed asset retirement. A versatile program is developed and the analysis of heat-supply organizations is performed by the example of the Republic of Tatarstan. The assessment system is based on construction of comparative ratings of heat-supply organizations. A rating is the assessment of reliability of the organization, is characterized by a numerical value, and makes it possible to compare organizations engaged in the same kind of activity between each other. [ABSTRACT FROM AUTHOR]

The paper considers the technological development of rapid bus routes in the network of Vilnius public transport. All rapid bus routes of the scheme for Vilnius public transport are presented and analysed with reference to the selected system of criteria. This article describes the situation of the public transport system in Vilnius and shows the influence of rapid bus routes. The paper also analyses parameters for the lines used for the multiple attribute ranking of rapid bus routes in Vilnius city. Multi-criteria methods have been chosen to rank six rapid bus routes and to estimate the best and most effective alternative based on the preferred technological and financial data. The experts of different decision-making groups have analyzed the importance of parameters selected for assessing alternatives to ranking rapid bus routes. The experts on the transport system have been invited to determine the relative weights of the defined criteria. Three techniques, including analytical hierarchical process, simple additive weighting and TOPSIS methods have been used and compared to determine the most efficient rapid bus route based on economic and technological parameters. To rank alternatives and to make a comparison of the obtained calculation results, three multi-criteria methods have been applied in this research. [ABSTRACT FROM AUTHOR]

Surface acoustic wave (SAW) devices have been utilized for the sensing of chemical and biological phenomena in microscale for the past few decades. In this study, SAW device was fabricated by electrospinning poly(vinylidenefluoride-co-trifluoroethylene) (P(VDF−TrFE)) incorporated with zinc oxide (ZnO) nanoparticles over the delay line area of the SAW device. The morphology, composition, and crystallinity of P(VDF−TrFE)/ZnO nanocomposites were investigated. After measurement of SAW frequency response, it was found that the insertion loss of the SAW devices incorporated with ZnO nanoparticles was much less than that of the neat polymer-deposited device. The fabricated device was expected to be used in acoustic biosensors to detect and quantify the cell proliferation in cell culture systems. [ABSTRACT FROM AUTHOR]

The multi-criteria decision-making techniques are applied in many areas such as integrated manufacturing systems, evaluation of technology investment, water and agriculture management and energy planning. However, there are very few studies in the field of food. In this work, the selection of optimum fat content in the model beverage of instant hot chocolate beverage was evaluated based on sensory analyses by performing multi-criteria decision techniques (analytic hierarchy process, simple additive weighting, technique for order preference by similarity to ideal solution and elimination et choixtraduisant la realite-elimination and choice translating reality). The wettability, solubility, bulk density, soluble solids, pH, color values, and rheological and sensory properties of the nine samples were evaluated. According to the results of multi-criteria decision techniques, sample S2 which had a relatively high amount of fat content was the most preferred beverage among the samples. Study showed that the use of different fat contents of milk and cocoa powder positively affected the rheological parameters and preferences of consumers. The findings may be considered to improve dairy and cocoa-based products formulation by the food industry. [ABSTRACT FROM AUTHOR]

An automated submerged arc welding (SAW) platform for welding of complex seams of large-size and thick-wall workpieces is introduced in this paper. The orthogonal intersection of a cylinder and a brunch pipe is taken as an example. The mathematical models of the weld trajectory in a dynamic coordinate system and in an absolute coordinate system are built respectively. A collaborative control algorithm and control strategy for the pose of the workpieces and the position of the welding torch is proposed based on coordinate transformation and discrete approximation theory. Closed form expressions of the control laws for the workpieces and the welding torch are worked out under the constraints of SAW process. The control effect of the algorithm is simulated and the approximation error is analyzed in MATLAB. Simulation results show that the approximation error of the proposed discrete control method and the tracing accuracy of the welding torch are satisfactory. The proposed welding platform provides a practical method for automated SAW process in intersection seam welding for large-size and thick-wall workpieces, in which stabilized welding quality, high efficiency, high productivity, and good production environment are promising. In the end, the application of cloud technology in the automated welding platform is also discussed, which can further improve the applicability and flexibility of the platform. [ABSTRACT FROM AUTHOR]

The paper presents 3D finite element simulation of a Love wave resonator using coupled resonance with ZnO nanorods for biosensing application. The variation in mode shape, phase velocity, and coupling coefficient with rotation angle for a Y-cut LiTaO crystal is reported. At rotation angle of 36° the leaky SAW is transformed into a perfect shear horizontal surface wave with high coupling coefficient. Mass sensitivity and electromechanical coupling coefficient of Love wave resonator are calculated for different guiding layer materials (ZnO, SiO and PMMA) of varying thickness. The mass sensitivity provided by PMMA is about 15 times that of SiO layer but coupling coefficient falls rapidly as its thickness increases, offering a narrow range of thickness of the guiding layer. Simulations are performed for ZnO nanorods of varying height (300-1800 nm) present over 315.605 MHz Love wave resonator having 4.7 μm thick SiO waveguide layer. The addition of double stranded DNA is simulated by applying its equivalent surface mass density on the sensor surface. Coupled resonance occurs when the resonance frequency of ZnO nanorods is close to the device operating frequency and causes frequency shift of about 10.5 MHz which is about 20 times greater than the value obtained in the absence of coupled resonance. Love wave device with resonant nanostructures operating in coupled resonance is a promising candidate for designing highly sensitive biosensor. [ABSTRACT FROM AUTHOR]

We introduce a microfluidic band-pass filter for particles that is fully integrated in a polydimethylsiloxane-based microchannel device. This acoustic filter allows a continuous and label-free separation of particles. To demonstrate the functionality, mixtures of particles with different sizes are exposed to propagating surface acoustic waves generated by two laterally displaced interdigitated transducers, one on each side of the microchannel. Dependent on the frequency used, a specific size or even a size range of particles can be extracted. We sort particles of sizes of ~1-10 µm and estimate the size resolution to be smaller than ∆ r < 0.88 µm. We examine the performance of the device and achieve a throughput of ~10 particles/s with an efficiency as high as 99 %. [ABSTRACT FROM AUTHOR]

To date, most surface acoustic wave (SAW) devices have been made from bulk piezoelectric materials, such as quartz, lithium niobate or lithium tantalite. These bulk materials are brittle, less easily integrated with electronics for control and signal processing, and difficult to realize multiple wave modes or apply complex electrode designs. Using thin film SAWs makes it convenient to integrate microelectronics and multiple sensing or microfluidics techniques into a lab-on-a-chip with low cost and multi-functions on various substrates (silicon, glass or polymer). In the work, aluminum nitride (AlN)-based SAW devices were fabricated and characterized for discrete microfluidic (or droplet based) applications. AlN films with a highly c-axis texture were deposited on silicon substrates using a magnetron sputtering system. The fabricated AlN/Si SAW devices had a Rayleigh wave mode at a frequency of 80.3 MHz (with an electromechanical coupling coefficient k of 0.24 % and phase velocity v of 5,139 m/s) and a higher-frequency-guided wave mode at 157.3 MHz (with a k value of 0.22 % and v of 10,067 m/s). Both modes present a large out of band rejection of ~15 dB and were successfully applied for microfluidic manipulation of liquid droplets, including internal streaming, pumping and jetting/nebulization, and their performance differences for microfluidic functions were discussed. A detailed investigation of the influences of droplet size (ranging from 3 to 15 μL) and RF input power (0.25-68 W) on microdroplet behavior has been conducted. Results showed that pumping and jetting velocities were increased with an increase of RF power or a decrease in droplet size. [ABSTRACT FROM AUTHOR]

Extensive industrial use of thick high-strength steel plates in Arctic shipbuilding calls for submerged arc welding (SAW) processes with higher deposition rates. One of the most effective ways of increasing the deposition rate is to increase the number of welding wires. Although SAW processes with up to six wires exist, their use is not widespread and two- or three-wire modifications, which are the focus of this paper, are the most common approaches. This paper presents a case study of the development of a welding procedure for welding of high-strength steel shipbuilding plates using a three-wire SAW process. Welding parameters and conditions were evaluated with the aim of achieving a high-quality weld. Optimal parameters for 12-mm plate thickness were found to be: Св-08ГСМТ wire (similar to Mn4Ni1Mo) of 3.2 mm in diameter, single-pass welding, welding flux 48AF-56, I = 840 A, U = 37 V, Q = 5.4 kJ/mm. Optimal parameters were also found for 16-mm plate for two pass welding. Testing of the weld joint included a static tensile strength test, an impact energy test at different temperatures, a bending test, a low-cycle fatigue strength test, microstructure examination and a hardness test. The tests showed satisfactory results that indicate that the developed welding technique is applicable for Arctic shipbuilding applications. The paper provides improved understanding of the welding technique selection process for Arctic shipbuilding as well as providing industrially valuable information about the developed welding technique. [ABSTRACT FROM AUTHOR]

We developed a surface acoustic wave (SAW) atomizer, which can produce a narrow mist spray of submillimeter width. The atomized mist spray converges spontaneously and thus requires no additional spray converging system. Key features in achieving the self-converging atomization are two-port interdigital transducers (IDTs) with a groove in between. The SAW is driven by applying an electric field on IDTs patterned on a piezoelectric substrate. The two-port IDTs drive SAWs in opposite directions toward the groove, which then separates the SAW-driven streaming on each side of the groove. Two types of self-converging atomizer were experimentally demonstrated, a line and a point atomizer. While the former uses parallel IDTs to atomize water from the groove into a thin-planar-shaped spray, the latter uses arc-shaped SAW lenses to focus the SAW into a certain point in the groove to atomize water into a narrow point spray. In addition, by adding a water reservoir, continuous operation of up to 30 s was achieved with the submillimeter narrow point atomizer. [ABSTRACT FROM AUTHOR]

A strong hydrogen-bond acidic (HBA) polymer linear fluoroalcoholic polysiloxane (PLF), synthesized by one-step hydrosilylation, was introduced for 2,4-dinitrotoluene (2,4-DNT) detection using surface acoustic wave (SAW) devices. FT-IR spectra and H NMR spectra characterizations confirmed its molecular structure. Then, PLF was dissolved in chloroform, and spray coated onto a 434 MHz SAW device. And subsequently, the sensitivity and selectivity of the fabricated sensor were studied based on a SAW test platform. To 2,4-DNT of 1 ppm and 100 ppb (for DNT, 1 ppm = 8.1 mg/m; 1 ppb = 8.1 μg/m), the responses of the sensor rose 7.7 and 1.5 kHz, respectively. Furthermore, compared with some common interference vapors at 10 mg/m, the response of the sensor to 2,4-DNT at 1 ppm was 5 times stronger. The sensitive property was attributed to the hydrogen bond interaction between the hexafluoroisopropanol (HFIP) group in PLF and the basic lone electron pairs of nitro-groups in 2,4-DNT. Comparison between the PLF sensor and hydroxyl group functionalized polymer (carbowax and MOBCD)-coated sensors was investigated, and the results showed that the PLF sensor exhibited better sensitivity. In a word, the PLF sensor exhibited fast response, negligible baseline drifts and excellent reversibility, indicating good candidates of HFIP group functionalized HBA polymers for practical nitroaromatic explosives detection. [ABSTRACT FROM AUTHOR]

Currently, laser radiation is used routinely in medical applications. For infrared lasers, bone ablation and the healing process have been reported, but no laser systems are established and applied in clinical bone surgery. Furthermore, industrial laser applications utilize computer and robot assistance; medical laser radiations are still mostly conducted manually nowadays. The purpose of this study was to compare the histological appearance of bone ablation and healing response in rabbit radial bone osteotomy created by surgical saw and ytterbium-doped fiber laser controlled by a computer with use of nitrogen surface cooling spray. An Ytterbium (Yb)-doped fiber laser at a wavelength of 1,070 nm was guided by a computer-aided robotic system, with a spot size of 100 μm at a distance of approximately 80 mm from the surface. The output power of the laser was 60 W at the scanning speed of 20 mm/s scan using continuous wave system with nitrogen spray level 0.5 MPa (energy density, 3.8 × 10 W/cm). Rabbits radial bone osteotomy was performed by an Yb-doped fiber laser and a surgical saw. Additionally, histological analyses of the osteotomy site were performed on day 0 and day 21. Yb-doped fiber laser osteotomy revealed a remarkable cutting efficiency. There were little signs of tissue damage to the muscle. Lased specimens have shown no delayed healing compared with the saw osteotomies. Computer-assisted robotic osteotomy with Yb-doped fiber laser was able to perform. In rabbit model, laser-induced osteotomy defects, compared to those by surgical saw, exhibited no delayed healing response. [ABSTRACT FROM AUTHOR]

The selection of optimum aroma among vanilla, strawberry and cacao for prebiotic pudding was aimed based on sensory analyses by performing multi-criteria decision techniques [analytic hierarchy process (AHP), simple additive weighting (SAW), technique for order preference by similarity to ideal solution (TOPSIS) and elimination et choix traduisant la realite-elimination and choice translating reality (ELECTRE)]. In the first part of the study, the physicochemical (pH, viscosity, dry matter and ash content) and functional properties (bulk density, water-holding capacity and oil-holding capacity) of the dietary fibres (lemon, inulin, apple and wheat) were determined. According to our results, there are significant differences between the fibres ( P < 0.05). In the second part of the study, the INU/OLI dietary fibre was added to the different flavoured pudding samples (cacao, strawberry and vanilla). Some of their physicochemical (bulk density, dry matter and viscosity) and sensorial properties (appearance, consistency of appearance, consistency in the mouth, taste and smell, adhesiveness and general acceptability) were identified. In the last part of the study, multi-criteria decision techniques (AHP, SAW, ELECTRE and TOPSIS) were applied to obtain the ranking of the pudding samples based on the sensorial scores. According to the results of this study, strawberry-flavoured pudding (not including fibre) was mostly preferred. By considering the ranking of the puddings, it was seen that strawberry flavour was the most appropriate for prebiotic pudding. As a result of this study, it was found that multi-criteria decision techniques may be performed to sensorial scores in the food industry to reduce many results to one result thus facilitating the comparison of samples and the explication of results obtained from sensory analysis. [ABSTRACT FROM AUTHOR]

In this paper, the development of a fully implantable wireless sensor able to provide continuous real-time accurate pressure measurements is presented. Surface Acoustic Wave (SAW) technology was used to deposit resonators on crystalline quartz wafers; the wafers were then assembled to produce a pressure sensitive device. Excitation and reading via a miniature antenna attached to the pressure sensor enables continuous external interrogation. The main advantages of such a configuration are the long term stability of quartz and the low power necessary for the interrogation, which allows 24/7 interrogation by means of a hand-held, battery powered device. Such data are of vital importance to clinicians monitoring and treating the effects of hypertension and heart failure. A prototype was designed and tested using both a bio-phantom test rig and an animal model. The pressure traces for both compare very well with a commercially available catheter tip pressure transducer. The work presented in this paper is the first known wireless pressure data from the left ventricle of the heart of a living swine. [ABSTRACT FROM AUTHOR]