Similar Output Research Articles

Electric and Magnetic Design of a Deployable WPT System for Industrial and Defense UAV Applications

The following paper presents a highly efficient wireless power transfer (WPT) system for unmanned aerial vehicle (UAV) applications. The proposed system is designed as a deployable landing pad, where UAVs can be efficiently charged at distances up to 20 cm, while the UAV is landing. The operation frequency is 50 kHz. The current work presents two major contributions that help improve this aspect: a novel RX charging pad geometry and an unconventional design of a low-voltage, high-power DC–AC inverter using discrete MOSFET transistors. Both the pad’s geometry and the inverter are designed specifically for UAV applications. The input DC to output AC system efficiency peaks at approximately 95%. The peak efficiency is obtained at power transfers of 625 W. A major difference between the present design and traditionally used state-of-the-art systems is the low DC supply voltage requirement of just 24 V, compared with typical values that range from 50 up to 300 V at similar output power.

Perturbation-specific responses by two neural circuits generating similar activity patterns

A fundamental question in neuroscience is whether neuronal circuits with variable circuit parameters that produce similar outputs respond comparably to equivalent perturbations.1-4 Work on the pyloric rhythm of the crustacean stomatogastric ganglion (STG) showed that highly variable sets of intrinsic and synaptic conductances can generate similar circuit activity patterns.5-9 Importantly, in response to physiologically relevant perturbations, these disparate circuit solutions can respond robustly and reliably,10-12 but when exposed to extreme perturbations the underlying circuit parameter differences produce diverse patterns of disrupted activity.7,12,13 In this example, the pyloric circuit is unchanged; only the conductance values vary. In contrast, the gastric mill rhythm in the STG can be generated by distinct circuits when activated by different modulatory neurons and/or neuropeptides.14-21 Generally, these distinct circuits produce different gastric mill rhythms. However, the rhythms driven by stimulating modulatory commissural neuron 1 (MCN1) and bath-applying CabPK (Cancer borealis pyrokinin) peptide generate comparable output patterns, despite having distinct circuits that use separate cellular and synaptic mechanisms.22-25 Here, we use these two gastric mill circuits to determine whether such circuits respond comparably when challenged with persisting (hormonal: CCAP) or acute (sensory: GPR neuron) metabotropic influences. Surprisingly, the hormone-mediated action separates these two rhythms despite activating the same ionic current in the same circuit neuron during both rhythms, whereas the sensory neuron evokes comparable responses despite acting via different synapses during each rhythm. These results highlight the need forcaution when inferring the circuit response to a perturbation when that circuit is not well defined physiologically.

Long‐term outcomes of 2‐day training on planning and writing research on publication output of medical professionals: 11‐year cohort study

AbstractWe evaluated long‐term publication outcomes of a workshop on planning and writing a research article attended by medical professionals. A prospective cohort study included 243 participants (68 men and 175 women) attending 18‐h workshops on research planning and writing and 243 controls (78 men and 165 women) identified by participants as their professional peers. A total of 17 workshops was organized by the editors of the Croatian Medical Journal, Zagreb, Croatia, from 2003 to 2011. We measured the number of publications, citations and H‐indices in the Web of Science and Scopus databases from the time of each workshop to the end of 2017. While workshop participants and their controls had similar publication output before the workshops, workshop participants published significantly more scientific articles and had higher citation rates and H‐index after the workshops. For the subgroup of authors who were all followed up for 11 years (n = 398), the increase in the number of articles became apparent in the third post‐workshop year, and levelled out after the eighth post‐workshop year. Workshop attendance proved to be a significant predictor of post‐workshop publishing even when controlled for age, gender, and previous publications (OR = 3.547, CI = 2.320–5.423, p < 0.001), indicating that short‐term workshops on planning and writing research may be an important tool to increase long‐term scientific productivity of medical professionals.

Pharmacokinetics and diuretic effect of furosemide after single intravenous, oral tablet, and newly developed oral disintegrating film administration in healthy beagle dogs

BackgroundFurosemide, a diuretic that acts on the loop of Henle, is commonly used to treat congestive heart failure in veterinary medicine. Some owners have difficulty in administering oral tablet medication to animal patients, which leads to noncompliance, especially during long-term administration. Oral disintegrating film (ODF) has the advantages of easy administration via a non-invasive route, rapid dissolution, and low suffocating risk. The objective of this study was to research the pharmacokinetic (PK) profiles and diuretic effect of furosemide after intravenous (IV), orally uncoated tablet (OUT), and newly developed ODF administration in healthy beagle dogs. In this study, a furosemide-loaded ODF (FS-ODF) formulation was developed and five beagle dogs were administered a single dose (2 mg/kg) of furosemide via each route using a cross-over design.ResultsThe most suitable film-forming agent was sodium alginate; thus, this was used to develop an ODF for easy drug administration. No significant differences were detected in the PK profiles between OUT and FS-ODF. In the blood profiles, the concentration of total protein was significantly increased compared to the baseline (0 h), whereas no significant difference was detected in the concentration of creatinine and hematocrit compared to the baseline. FS-ODF resulted in a similar hourly urinary output to OUT during the initial 2 h after administration. The urine specific gravity was significantly decreased compared to the baseline in each group. The peak times of urine electrolyte (sodium and chloride) excretion per hour were 1 h (IV), 2 h (OUT), and 2 h (FS-ODF).ConclusionsThese results suggest that the PK/PD of furosemide after administration of newly developed FS-ODF are similar to those of OUT in healthy dogs. Therefore, the ODF formulation has the benefits of ease and convenience, which would be helpful to owners of companion animals, such as small dogs (< 10 kg), for the management of congestive heart failure.

Aging Sambar (Rusa unicolor) Using Cementum Annuli and Eruption and Wear: Implications for Predicting Populations

ABSTRACTSambar (Rusa unicolor), one of 6 deer species introduced to Australia, are poorly studied and declared vulnerable in their native range of India and southern Asia. In southeastern Australia sambar are increasing in abundance and distribution despite commercial venison harvest and unlimited public hunting. The ability to accurately age individuals is important for management of cervid populations because many life history events are age dependent. The techniques most widely used to estimate the age of cervids involve tooth eruption and molar wear (EW), and interpretation of cementum annuli (CA) in incisors. Aging techniques based on teeth are influenced by diet, body condition and metabolic stressors such as disease and reproduction. We compared age estimation derived by both EW and CA techniques and applied age estimates from both methods to lifetables and the Euler‐Lotka equation to predict population growth. Sambar have CA that are discernible and correspond to midwinter despite calving throughout the year in a temperate environment. Age estimation by eruption times of molar teeth appears reliable in sambar but estimation based on wear patterns of molar teeth is less accurate than CA. Assuming CA is accurate, aging by EW was less than 30% for sambar 3 years and older. For management purposes, however, estimation of rates of population growth using either the Euler‐Lotka equation or a lifetable provided similar outputs using ages estimated by either CA or EW. © 2021 The Wildlife Society.

Performance evaluation of GaN and Si based driver circuits for a SiC MOSFET power switch

&lt;p&gt;Silicon Carbide (SiC), new power switches (PSW) require new driver circuits which can take advantage of their new capabilities. In this paper a novel Gallium Nitride (GaN) based gate driver is proposed as a solution to control SiC power switches. The proposed driver is implemented and is performance compared with its silicon (Si) counterparts on a hard switching environment. A thorough evaluation of the energy involved in the switching process is presented showing that the GaN based circuit exhibits similar output losses but reduces the control power needed to operate at a specified frequency.&lt;/p&gt;

Comparative study of efficiency and characteristics of FMT and DRT installed in human cadavers for round-window stimulation

Acoustic hearing aids generate amplified sound in the ear canal, and they are the standard of care for patients with mild to moderate sensorineural hearing loss. However, because of their limited frequency bandwidth, gain, and feedback, there is substantial room for improvement. Active middle ear implants, which directly vibrate the middle ear and cochlea, are an alternative approach to conventional acoustic hearing aids. They provide an opportunity to improve sound quality and speech understanding with amplification rehabilitation. For floating-mass type and direct-rod type (DRT) middle ear transducers, a differential floating-mass transducer (DFMT) and a tri-coil bellows transducer (TCBT), respectively, were fabricated to measure the output characteristics in four human temporal bones. Both were fabricated to have similar output forces per unit input and were placed in four human temporal bones to measure their output performances. The TCBT resulted in higher output than did the DFMT throughout the audible frequency range, and the output was more prominent at lower frequency ranges. In this study, we showed that DRT was a more effective method for round window stimulation. Because of its frequency characteristics and vibration efficiency, this implantation method can be utilized as a driving solution for middle ear implants.

Metabolic changes in leaves of N. tabacum and N. benthamiana during plant development

Dwindling fossil fuel reserves and poor environmental credentials of chemical synthesis means, new renewable sources for the production and manufacture of valuable chemicals and pharmaceuticals are required. Presently, tobacco is an underutilised non-food crop with the potential to act as a biofactory. In this study, metabolite profiling across vegetative development has been carried out to provide a quantitative baseline of metabolites, their formation and interaction. Two tobacco platforms have been used, Nicotiana benthamiana and Nicotiana tabacum. Our data generated has provided the quantitative and qualitative baseline levels for exploitable pathways and metabolites, across two complementary Nicotiana species. N. benthamiana is the chassis of choice for transient expression. The metabolite data obtained for N. benthamiana highlighted that before flower emergence, the increased central carbon metabolism and high amino acid levels are available for the biosynthesis of endogenous or heterologous metabolites. In the future, engineering pathways or biocatalysts into N. benthamiana could add value to the process presently used to produce low volume, high cost pharmaceuticals. Similar outputs were obtained for N. tabacum, which has the advantage of providing a large biomass and hence, high product yield. These data provide an insight into the metabolite pools available in tobacco for future exploitation by emerging New Plant Breeding Techniques.

Analysis of Imaging Internal Defects in Living Trees on Irregular Contours of Tree Trunks Using Ground-Penetrating Radar

The outer contours of living trees are often considered as a standard circle during non-destructive testing (NDT) of internal defects using ground-penetrating radar (GPR). However, the detection of classical cross-sections (circular) lacks consideration of irregular contours, making it difficult to accurately locate the radar image of the target. In this paper, we propose a method based on the image affine transformation and the Riemann mapping principle to analyze the effect of irregular detection routes on the geometric characteristics of target reflection hyperbola. First, for the similar output phenomenon in the “hyperbola fitting”, geometric analysis and numerical simulation were performed. Then, the conversion of irregular trunk radar images and physical domain radar images was implemented using the method of image affine transformation and the Riemann mapping principle. Finally, the influence of irregular detection routes on the geometry of the target reflection curve was investigated in detail through numerical simulations and actual experiments. The numerical simulation and measurement results demonstrated that the method in this study could better reflect the imaging characteristics of the target reflection hyperbola under the irregular detection pattern. This method provides assistance to further study the defects of irregular living trees and prevents the misjudgment of targets as a result of hyperbolic distortion, resulting in a greater prospect of application.

Selection of Sampling Keys for Cryptographic Tests

Abstract The keys of modern cryptographic algorithms have an enormous size, so the testing of the algorithm performance for all key combinations, will take practically an infinite time. To avoid this, the sampling method is used, where a much smaller number of keys is tested and then the estimation of the algorithm performance for all the keys is calculated with a predetermined sampling error. For each sampling key, an output sample of the algorithm must be generated and tested. Therefore, in order to have sampling results as close as possible to the real performance of the algorithm, the key question is whether the selection of the keys should be random or it must follow some rules. If the selection of the keys is completely random, there is a high probability that the tests will not find some "weak" or "equivalent" keys, which give non-random or similar outputs and therefore reduce the total number of active keys. But if the sampling keys are selected with some specific criteria, there is a much greater probability of detecting any weak or equivalent key. In this study an optimal key selection methodology is proposed, which combines the random and the non-random key selection. Keywords: Cryptography, Data encryption, Communication security, Computer security, Data security, Information security.

Correlations of power output fluctuations in an offshore wind farm using high-resolution SCADA data

Abstract. Space–time correlations of power output fluctuations of wind turbine pairs provide information on the flow conditions within a wind farm and the interactions of wind turbines. Such information can play an essential role in controlling wind turbines and short-term load or power forecasting. However, the challenges of analysing correlations of power output fluctuations in a wind farm are the highly varying flow conditions. Here, we present an approach to investigate space–time correlations of power output fluctuations of streamwise-aligned wind turbine pairs based on high-resolution supervisory control and data acquisition (SCADA) data. The proposed approach overcomes the challenge of spatially variable and temporally variable flow conditions within the wind farm. We analyse the influences of the different statistics of the power output of wind turbines on the correlations of power output fluctuations based on 8 months of measurements from an offshore wind farm with 80 wind turbines. First, we assess the effect of the wind direction on the correlations of power output fluctuations of wind turbine pairs. We show that the correlations are highest for the streamwise-aligned wind turbine pairs and decrease when the mean wind direction changes its angle to be more perpendicular to the pair. Further, we show that the correlations for streamwise-aligned wind turbine pairs depend on the location of the wind turbines within the wind farm and on their inflow conditions (free stream or wake). Our primary result is that the standard deviations of the power output fluctuations and the normalised power difference of the wind turbines in a pair can characterise the correlations of power output fluctuations of streamwise-aligned wind turbine pairs. Further, we show that clustering can be used to identify different correlation curves. For this, we employ the data-driven k-means clustering algorithm to cluster the standard deviations of the power output fluctuations of the wind turbines and the normalised power difference of the wind turbines in a pair. Thereby, wind turbine pairs with similar power output fluctuation correlations are clustered independently from their location. With this, we account for the highly variable flow conditions inside a wind farm, which unpredictably influence the correlations.

Design and Evaluation of Fuzzy Adaptive Particle Swarm Optimization Based Maximum Power Point Tracking on Photovoltaic System Under Partial Shading Conditions

Artificial intelligence methods such as fuzzy logic and particle swarm optimization (PSO) have been applied to maximum power point tracking (MPPT) for solar panels. The P-V curve of a solar panel exhibits multiple peaks under partial shading condition (PSC) when all modules of a solar panel do not receive the same solar irradiation. Although conventional PSO has been shown to perform well under uniform insolation, it is often unable to find the global maximum power point under PSC. Fuzzy adaptive PSO controllers have been proposed for MPPT. However, the controller became computation-intensive in order to adjust the PSO parameters for each particle. In this paper, fuzzy adaptive PSO-based and conventional PSO-based MPPT are compared and evaluated in the aspect of design and performance. A simple fuzzy adaptive PSO controller for MPPT was designed to reach the global optimal point under PSC and uniform irradiation. The controller combines the advantages of both PSO and fuzzy control. The fuzzy controller dynamically adjusts the PSO parameter to improve the convergence speed and global search capability. Since tuning of the PSO parameter is designed to be common for all particles, it reduced the computation complexity. The fuzzy controller’s rule base is designed to obtain a fast transient response and stable steady state response. Design of the fuzzy adaptive PSO-based MPPT is verified with simulation results using a boost converter. The results are evaluated in comparison to the results using a conventional PSO controller under PSC. Simulation shows the fuzzy adaptive PSO-based MPPT is able to improve the global search process and increase the convergency speed. The comparison indicates the settling time using the fuzzy adaptive PSO-based MPPT is 14% faster under PSC on average and 30% faster under uniform irradiation than the settling time using the conventional PSO. Both the fuzzy adaptive and conventional PSO controllers have similar output power tracking accuracy.

Assessing the relationship between the rumen microbiota and feed efficiency in Nellore steers

BackgroundRuminants rely upon a complex community of microbes in their rumen to convert host-indigestible feed into nutrients. However, little is known about the association between the rumen microbiota and feed efficiency traits in Nellore (Bos indicus) cattle, a breed of major economic importance to the global beef market. Here, we compare the composition of the bacterial, archaeal and fungal communities in the rumen of Nellore steers with high and low feed efficiency (FE) phenotypes, as measured by residual feed intake (RFI).ResultsThe Firmicutes to Bacteroidetes ratio was significantly higher (P < 0.05) in positive-RFI steers (p-RFI, low feed efficiency) than in negative-RFI (n-RFI, high feed efficiency) steers. The differences in bacterial composition from steers with high and low FE were mainly associated with members of the families Lachnospiraceae, Ruminococcaceae and Christensenellaceae, as well as the genus Prevotella. Archaeal community richness was lower (P < 0.05) in p-RFI than in n-RFI steers and the genus Methanobrevibacter was either increased or exclusive of p-RFI steers. The fungal genus Buwchfawromyces was more abundant in the rumen solid fraction of n-RFI steers (P < 0.05) and a highly abundant OTU belonging to the genus Piromyces was also increased in the rumen microbiota of high-efficiency steers. However, analysis of rumen fermentation variables and functional predictions indicated similar metabolic outputs for the microbiota of distinct FE groups.ConclusionsOur results demonstrate that differences in the ruminal microbiota of high and low FE Nellore steers comprise specific taxa from the bacterial, archaeal and fungal communities. Biomarker OTUs belonging to the genus Piromyces were identified in animals showing high feed efficiency, whereas among archaea, Methanobrevibacter was associated with steers classified as p-RFI. The identification of specific RFI-associated microorganisms in Nellore steers could guide further studies targeting the isolation and functional characterization of rumen microbes potentially important for the energy-harvesting efficiency of ruminants.

Modeling of Reversible Solid Oxide Cell Stacks with an Open-Source Library

This study describes a homogenized model of reversible solid oxide cell (rSOC) stacks. The model enables steady-state simulations of rSOC stacks in both fuel cell and electrolyzer modes to be conducted. It accounts for multi-component species diffusion, and heat and mass transfer, including thermal radiation and electrochemical reactions. An open-source library, OpenFOAM, provides a platform for the model’s implementation. Numerical simulations were performed using an in-house-designed rSOC stack. A previously-developed, one-dimensional Simulink model was also applied to the stack. Both models predict similar output voltages, within 2% difference, under the same operating conditions. Temperature variations were also compared; the stack model’s results were closer to experimental measurements than the Simulink model. The new model was able to perform faster simulations (less than 2 hours) for the prescribed stacks.

Design and analysis of hybrid stepping motors with integrated planetary gear trains.

This work presents a novel integrated device that combines a hybrid stepping motor (HSM) and a planetary gear train (PGT) reducer as a compact structural assembly. In this study, a systematic design process was developed to efficiently implement the integrated device. By applying the gear profile on the rotor and the stator, a 9:1 two stages PGT reducer is integrated with a standard 42 type 2-pole stepping motor. The quadratic interpolation method was applied to derive the optimal design of the geometric configurations of the HSM. The electromagnetic characteristics and output performance of the integrated device, including flux linkage, back-emf constant, holding torque, and output torque, were analysed. Finally, the output performance between an existing design and the novel integrated design were compared. The two designs had similar output and holding torque, but the torque ripple was approximately 44.7% lower in the integrated device from 30% to 16.6%. In addition, the axial space arrangement was reduced by 5.2% from 67.7mm to 64.1 5mm, and the torque density was improved by 4.4%.

A reduced‐dimension dynamic model of a proton‐exchange membrane fuel cell

The existing models of proton-exchange membrane fuel cells, such as computational fluid dynamics and lumped-parameter models, cannot provide a comprehensive description of mass-transport mechanisms without incurring a high computational load. This paper proposes a reduced-dimension dynamic model of fuel cells that considers main mass-transport mechanisms, including two-phase flow in the gas diffusion layer. Under the quasi-steady-state assumption, the distributions of liquid water and gas species in the through-plane direction are calculated through analytical expressions. Thus, the reduced-dimension fuel-cell model can obtain a similar output to a one-dimensional model without needing to solve partial differential equations. The reduced-dimension model was validated on steady state and transient experimental data. The computational load of the reduced-dimension model was only 1/60 that of a one-dimensional model. To simulate the transient behavior of the fuel-cell system, the reduced-dimension fuel-cell model was integrated with a comprehensive balance-of-plant model. The system model could execute long-time-scale transient simulations and evaluate the internal states of the fuel cell while minimizing the computing resources. Finally, the contradiction between the power response rate and oxygen starvation under the load-delay strategy was analyzed with the system model, and the delay duration was optimized. Results verify the potential of the reduced-dimension model in control-oriented applications. Novelty statement The existing models of proton-exchange membrane fuel cells, such as computational fluid dynamics and lumped-parameter models, cannot provide a comprehensive description of mass-transport mechanisms without incurring a high computational load. This work proposes a reduced-dimension dynamic model of fuel cells that considers main mass-transport mechanisms, including two-phase flow in the gas diffusion layer. Under the quasi-steady-state assumption, the distributions of liquid water and gas species in the through-plane direction are calculated through analytical expressions. Thus, the reduced-dimension fuel-cell model can obtain a similar output to a one-dimensional model without needing to solve partial differential equations. The computational load of the reduced-dimension model was only 1/60 that of a one-dimensional model.

Revisiting the drivers of acoustic similarities in tropical anuran assemblages.

Acoustic signaling is key in mediating mate choice, which directly impacts individual fitness. Because background noise and habitat structure can impair signal transmission, the acoustic space of mixed-species assemblages has long been hypothesized to reflect selective pressures against signal interference and degradation. However, other potential drivers that received far less attention can drive similar outputs on the acoustic space. Phylogenetic niche conservatism and allometric constraints may also modulate species acoustic features, and the acoustic space of communities could be a side-effect of ecological assembly processes involving other traits (e.g., environmental filtering). Additionally, the acoustic space can also reflect the sorting of species relying on public information through extended communication networks. Using an integrative approach, we revisit the potential drivers of the acoustic space by addressing the distribution of acoustic traits, body size, and phylogenetic relatedness in tropical anuran assemblages across gradients of environmental heterogeneity in the Pantanal wetlands. We found the overall acoustic space to be aggregated compared with null expectations, even when accounting for confounding effects of body size. Across assemblages, acoustic and phylogenetic differences were positively related, while acoustic and body size similarities were negatively related, although to a minor extent. We suggest that acoustic partitioning, acoustic adaptation, and allometric constraints play a minor role in shaping the acoustic output of tropical anuran assemblages and that phylogenetic niche conservatism and public information use would influence between-assemblage variation. Our findings highlight an overlooked multivariate nature of the acoustic dimension and underscore the importance of including the ecological context of communities to understand drivers of the acoustic space.

Economic and environmental effects of revised metabolizable protein and amino acid recommendations on Canadian dairy farms

The objective of this research was to evaluate the potential economic and environmental effects of the formulation model used to balance dairy rations for metabolizable protein (MP) or 3 essential AA (EAA: His, Lys, and Met) in 3 regions of Canada with different farming systems. The Maritimes, Central Canada, and the Prairies reference dairy farms averaged 63, 71, 144 mature cows per herd and 135, 95, 255 ha of land, respectively. Using N-CyCLES, a whole-farm linear program model, dairy rations were balanced for (1) MP, based on National Research Council (NRC) requirements (MP_2001); (2) MP plus Lys and Met, based on NRC (AA_2001); (3) MP (MP_Rev); or (4) for His, Lys, and Met (AA_Rev), both based on a revised factorial approach revisiting both supply and requirements of MP and EAA. Energy was balanced to meet requirements based on NRC (2001). Assuming the requirements were met within each approach, it was considered that milk yield and composition were not affected by the type of formulation. Given the assumptions of the study, when compared with MP_2001 formulation, balancing dairy rations using the AA_Rev approach reduced calculated farm N balance by 3.8%, on average from 12.71 to 12.24 g/kg of fat- and protein-corrected milk; it also enhanced farm net income by 4.5%, from 19.00 to 19.70 $CAN/100 kg of fat- and protein-corrected milk, by reducing inclusion of protein concentrate in dairy rations. Calculated animal N efficiency was on average 4.3% higher with AA_Rev than with MP_2001 for mid-lactation cows. This gain in N efficiency would result in a reduction in N2O emission by manure, contributing to a partial decrease of total greenhouse gas emission by 1.7%, through a reduction of N excreted in manure. With the AA_2001 formulation, farm N balance was 1% higher than with MP_2001 formulation while reducing farm net income by 6.4%, due to the need to purchase rumen-protected AA, with no effect on total greenhouse gas emission. Both MP formulations lead to fairly similar outputs. The AA_Rev formulation also indicated that His might be a co-limiting AA with Met in dairy rations balanced with ingredients usually included in Canadian dairy rations. Given the assumptions of the study, balancing dairy rations for 3 EAA (His, Lys, and Met) rather than MP, has some potential positive effects on Canadian dairy farms by increasing net incomes through a reduction of crude protein supply, leading to a decreased environmental effect.

A Comparative Study of Primary School Visual Arts Curriculum in Australia, Canada, Iran and Ireland

The purpose of this study was a comparative investigation of visual arts education curricula in Australia, Canada, Iran and Ireland. The research method is qualitative comparative; the unit of observation and analysis is at macro level. The study population includes all countries of the world and country selection strategies are systems, similar outputs (Australia, Canada, Ireland) and systems, different outputs (Iran) using purposeful sampling method. The findings were presented based on Bereday’s approach. Findings showed that teaching visual arts in Iran is less important than other school subjects compared to other countries. Also, there are limitation of time for teaching and lack of special space for visual arts curriculum. With respect to the goal component, the findings show that selected countries have jointly addressed issues of aesthetics, familiarity with history and culture, understanding of creativity and nature. Relating to the content component, all countries have pointed out importance of creativity and aesthetics. Also, Australia and Canada, compared to Iran and Ireland, have been more successful in recognizing and using Indigenous art in visual arts education. As for teaching strategies component, all selected countries refer to role of teacher facilitation in art education. Canada differs from Australia, Iran and Ireland in use of art professionals alongside teachers. In terms of educational materials and resources, all four countries have designated educational resources based on national curriculum and teacher guide. Regarding teaching and learning activities, Canada and Australia have a special focus on teaching visual arts based on art of indigenous peoples and are more flexible in implementing art program compared to Iran and Ireland. In terms of educational space, Iran is at a lower level compared to other three countries, while Ireland is a leader. From time aspect, Iran has allocated fewer hours to art curriculum compared to other countries. Referring assessment component, the findings show that use of formative-descriptive and portfolio methods are common in all selected countries, although in Iran there is no formal plan for assessment. According to findings and in order to develop the position of visual arts curriculum in formal education of Iran, it is recommended that art education and its components be seriously and properly considered by educational policy makers.

How Comparable are Microbial Electrochemical Systems around the Globe? An Electrochemical and Microbiological Cross-Laboratory Study.

A cross‐laboratory study on microbial fuel cells (MFC) which involved different institutions around the world is presented. The study aims to assess the development of autochthone microbial pools enriched from domestic wastewater, cultivated in identical single‐chamber MFCs, operated in the same way, thereby approaching the idea of developing common standards for MFCs. The MFCs are inoculated with domestic wastewater in different geographic locations. The acclimation stage and, consequently, the startup time are longer or shorter depending on the inoculum, but all MFCs reach similar maximum power outputs (55±22 μW cm−2) and COD removal efficiencies (87±9 %), despite the diversity of the bacterial communities. It is inferred that the MFC performance starts when the syntrophic interaction of fermentative and electrogenic bacteria stabilizes under anaerobic conditions at the anode. The generated power is mostly limited by electrolytic conductivity, electrode overpotentials, and an unbalanced external resistance. The enriched microbial consortia, although composed of different bacterial groups, share similar functions both on the anode and the cathode of the different MFCs, resulting in similar electrochemical output.