Application of a non-parametric method to analyze energy consumption for orange production

Due to good climate condition and large cultivation area in Mazandaran province of Iran, orchard commodities products, especially orange production is widely improved in this region.  In this study, Data Envelopment Analysis (DEA) technique was used to analyze the efficiency of farmers, discriminate efficient orchards from inefficient ones and to identify wasteful uses of energy for orange producers in Sari region.  Data were collected using face-to-face surveys from 86 orange orchardists and included the human power, machinery, diesel fuel, chemicals, fertilizer, farmyard manure, water for irrigation and electricity input sources used per hectare of orange production.  The data was organized and analyzed by DEA Techniques.  The results revealed that the total input and output energy were 54.2 and 59.2 GJ/ha, respectively.  Diesel fuel, fertilizer and water for irrigation energies had the highest energy values per hectare respectively.  Pure technical and scale efficiencies were calculated using CCR (Charnes–Cooper–Rhodes) and BCC (Banker-Charnes-Cooper) models.  The technical, pure technical and scale efficiencies were calculated as 0.92, 0.96 and 0.97, respectively.  The highest contribution to the total saving energy was provided by diesel fuel followed by fertilizer and water for irrigation energy input.   Keywords: technical efficiency, energy saving, data envelopment Analysis, orange production, Sar

Reliability analysis of agricultural machinery: A case study of sugarcane chopper harvester

the performance of agricultural machines depends on the reliability of the machinery used, the operating environment, the maintenance efficiency, the operating process, the technical expertise of the farmers and etc. As the size and complexity of farm equipment continue to increase, the implications of equipment failure become over more critical. Therefore, reliability analysis is required to identify the bottlenecks in the system and to find the components or subsystems with low reliability for a given designed performance. It is important to select a suitable method for data collection as well as for reliability analysis. This paper presents a case study describing reliability and availability analysis of the sugarcane 7000 series chopper harvester at Hakim Farabi agro- industry in Iran. In this study, the harvester is divided into nine subsystems. The parameters of some probability distributions, such as weibull, exponential and lognormal distributions have been estimated by using ReliaSoft Weibull++6 software. The results of the analysis show that feed rollers and hydraulic subsystems are critical from a reliability point of view, and the wheels subsystem and hydraulic subsystem are critical from an availability point of view. The study also shows that the reliability analysis is very useful for deciding maintenance intervals

Failure rate analysis of four agricultural tractor models in southern Iran

Tractors play an important role in agricultural mechanization.  A repairable mechanical system (as agricultural tractor) is prone to deterioration or repeated failures.  In this study, the owners of three hundred tractors, which include Massey Ferguson (MF285 model and MF399 model), John Deere (JD3140 model) and Universal (U650 model), were interviewed, from five regions of Khouzestan Province.  A regression model was used to predict the tractors failure rate.  The machine failure pattern was carefully studied and key factors affecting the failure rate were identified in these regions.  The data obtained from farm records valid by using questionnaire was separated into two groups according to how those tractors were stored.  Results showed that the majority of recorded failures were observed in the electrical system for all tractors.  According to the results of the research, different storage policies significantly affected the failure rate for MF285, MF399 and JD3140 tractors (63%, 55.5% and 61.6% respectively), whereas inside storage of U650 tractors slightly decreased the failure rate (7.4%).  Also, closed storage condition was found to reduce annual repair and maintenance costs by 33.6%, 33.6%, 29.6% and 2.56% in comparison with open air storage condition for the study tractors respectively.  The observational estimate showed that all tractors were in the wear out period under outside storage conditions, against inside storage had a considerable effect on the failure rate of MF285, MF399 tractors and they were commonly in a randomized breakdown period within their useful life, JD3140 tractors were in the beginning of wear out period, but U650 tractors were in the wear out period for both storage conditions.  Therefore, it can be said that by storing the tractors out of the weather conditions slowly exposed by failure and breakdowns, especially in warm climate and presented of dust haze phenomenon.   Keywords: failure rate, tractor, storage condition, Khouzesta

Monitoring and Estimating Sugarcane Losses during Harvesting Using Sound Analysis

Mechanical harvesting of sugarcane is done in two ways: green and burnt, and usually burnt harvest has between 25-50% less losses. When harvesting sugarcane, the sound of sugarcane pieces hitting the wall of the primary extractor hood can clearly be heard. Accordingly, it was decided to use the audio system to determine the relationship between these sounds and the losses of the primary extractor. To record sounds in the basic extractor, two models of full-directional and one-way capacitive microphone (cardioid) and Cool Record Edit Deluxe and Audacity software were used. To detect the wavelength of the sounds caused by the collision of different parts of sugarcane with the hood cap and extractor blades by throwing a large volume of straw along with 25 cm pieces of sugarcane billets, a sound record was set. A camera was also installed there to record the video of what was happening under the extractor compartment. The results showed that the one-way capacitive microphone installed in the upper part of the primary extractor housing received clearer sounds. Analyzing the recorded sounds and comparing them with the images obtained from the camera under the primary extractor revealed that the audio loss detection system detects the losses in the primary extractor with an accuracy of about 75 to 80%. The loss rate at 1200 rpm was about 1.5 times higher than the loss rate at 1100 rpm

A Cognitive Load Theory Approach to Understanding Expert Scaffolding of Visual Problem-Solving Tasks: A Scoping Review

Visual problem-solving is an essential skill for professionals in various visual domains. Novices in these domains acquire such skills through interactions with experts (e.g., apprenticeships). Experts guide novice visual problem-solving with scaffolding behaviours. However, there is little consensus about the description and classification of scaffolding behaviours in practice, and to our knowledge, no framework connects scaffolding to underlying cognitive mechanisms. Understanding effective scaffolding is particularly relevant to domain-specific expert-novice research regarding visual problem-solving, where in-person scaffolding by an expert is a primary teaching method. Scaffolding regulates the flow of information within the learner’s working memory, thereby reducing cognitive load. By examining scaffolding research from the perspective of cognitive load theory, we aspire to classify scaffolding behaviours as cognitive behaviours of cueing (which involves attention allocation) and chunking (the practice of grouping information, often in conjunction with prior knowledge), into a cohesive and unified framework. In this scoping review, 6533 articles were considered, from which 18 were included. From these 18 articles, 164 excerpts describing expert-novice interaction were examined and categorised based on cognitive strategy (cueing or chunking) and method of expression (verbal or nonverbal). An inductive category (active or passive) was also identified and coded. Most scaffolding behaviours were categorised as active verbal cueing and active verbal chunking. Qualitative patterns in excerpts were collated into 12 findings. Our framework may help to integrate existing and new scaffolding research, form the basis for future expert-novice interaction research, and provide insights into the fine-grained processes that comprise scaffolded visual problem-solving

Effect of blade vibration on mulch tillage performance under silt clay loam soil

Introduction: Mulch tillage system is an intermediate system which covers some of disadvantages of no tillage and conventional tillage systems. In farms in which tillage is done with a chisel plow, runoff and soil erosion have a less important relation to moldboard and disk plow and naturally absorption of rainfall will be developed. Thus, the mulch tillage system is an appropriate alternative to conventional tillage and no tillage (Backingham and Pauli, 1993). The unwanted vibration in machinery and industry mainly processes most harmful factors, for example: bearing wear, cracking and loosening joints. And noise is produced in electrical systems by creating a short circuit (Wok, 2011). Self-induced and induced vibration are used in tillage systems. Induced vibration is created by energy consumption and self-induced vibration is created by collision among the blades and soil at the shank (Soeharsono and Setiawan, 2010). A study by Mohammadi-gol et al. (2005) was conducted. It was found that on the disk plow, plant residues maintained on the soil are more than that of moldboard plow. 99% frequency and amplitude, speed and rack angle of blade directly affect soil inversion and indirectly affect preservation of crop residue on the soil. The effect of vibration frequency and rack angle of blade to reduce the tensile strength is also clear. Moreover, in contrast to previous studies when speed progressing is less than (λ), not only the relative speed (λ), but also frequency can reduce the tensile strength (Beiranvand and Shahgoli, 2010; Awad-Allah et al., 2009). Therefore, aim of this study was to determine the effect of vibration and the speed of tillage on soil parameters and drawbar power in using electric power. Materials and Methods: To perform this test, three different modes of vibration (fixed, variable and induced vibration) and two levels of speed in real terms at a depth of 20 cm were used for farming. The test was performed with a split plot and randomized complete block design and three replications, and the fixed factors were: the depth of tillage: 20 cm, soil moisture: 16 to 17 percent and rack angle: 15 degrees; and the variable factors were the rate of progress in both 4.5 and 7.5 kilometers per hour and six levels of frequency, 1 fixed (zero) 2 variables (self-induced), 3 (positive19) and 4 (negative19), 5 (positive37) and 6 (negative37) Hz were performed. An electric generator was used to create vibration power. The equation (1) was used to calculate the vibration power: (1) Where P: Electric power (W), V: voltage (V), I: current (amps) and Ǿ: phase angle (degrees) between the voltage and current. After the calculation, the required power of 19 Hz was calculated to be 0.6, and the required power of 37Hz, was calculated to be 0.75 kilowatts, respectively. The sample of mean weighted diameter, after tillage in each plot, was about 10 kg soil (0 to 20 cm depth) with 3 replicates and through the equation (2), mean weight diameter was calculated as follows: (2) Where MWD: Mean weight diameter (cm), Xi: Two Elk consecutive mean diameters (cm) and Wi: weight ratio of the soil remaining on the sieve to the total weight of the sample. In order to calculate the specific energy tension due to the width of tillage (28 Cm), equation (3) was used. (3) Where E: tensile special energy in kilojoules per square meter, P1: drawbar pulling power required in kW, P2: the vibration according to equation (1) based on kilowatt, T: tillage time in one square meter per second. Results and discussion: According to analysis of variance (Table 2) interaction effects of frequency and speed to keep the residue are significant at 1%, and this situation was shown well in Fig.2 Therefore, in practice, with increasing frequency in both induction and self-induction vibration, the tillage blades created a groove at the soil surface with less turmoil, and this would maintain the maximum residue on the surface of the soil. As is clear from Fig.3, treatment of the frequency of 37+ (code 5) in both the first and second average forward speed is highest in remaining residue with 85% and 74%, respectively (Liu and Chen, 2010) and (Awad-Allah et al., 2009). By applying induced vibrations, a significant reduction in tensile strength occurs, because it reduces the time to deal with the blade of soil tillage and soil fractures with blows of the blade. It is clear that vibration reduces slip and real wheel speed is progressing, and following it, the increase in tensile strength occurs and it should not be considered due to the in efficiency of vibration tillage, since vibration may increase the depth of tillage, with the same vertical force component (Sahaya et al., 2009). Specific energy (plus drawbar and vibration) are shown in Figure.5 and the lowest energy consumption in both the first and the second speeds was on treatment of frequency +19, being 18.9 kJ m and 23.2 kJ m to first and second speeds, respectively. Conclusions: In general, both factors (vibration and speed) affected tillage parameters and energy consumption and induced vibration caused by the system of unequal mass and electrical power properties was very easy to change phase vibration and transfer of power. This study was designed because of the significant effects on the important parameters of quality by vibration frequency of tillage and different frequencies to control the way in which tillage parameters are controlled. We can take it as a precision tillage that introduced variable control rate of percent residue on the soil, clod mean weight diameter that is suitable for the cultivation combined with reduced energy consumption

Corresponding Author The Evaluation of wheat losses harvesting in two conventional combine (John Deere 1165, 955) in Iran

ABSTRACT Wheat is one of the most important food staff in consumption pattern of each country. More than 50 percent of energy is provided by bread in the developing countries. The aim of this study was measuring wheat losses during pre-harvest and harvest stages in Chaharmahal and Bakhtiari province of Iran in year 2013. Wheat losses at harvest stages were measured to wheat varieties in 2 levels of Omid and Alvand were chosen and Combine types in 2 levels: JD 955 and JD 1165 while were chosen. The data analyzed using and means were compared using SAS Software's and Duncan's Multiple Range Tests were. The results showed that higher amount of losses were in the Omid variety and JD 955 with totally 6.83 % (307.4 kg ha-1) that 10.5 % of them attributed on the cleaning, 34 % on Header, 16.5 % on Drum, 21 % on impurity and 18% broken grain losses. The lowest losses related to JD 1165 and Alvand variety with 3.97 % (178.66 kg ha-1) that 10 % of them attributed on the cleaning, 38 % on Header, 13 % on Drum , 22 % on impurity and 17% broken grain losses. Also, average pre-harvest losses amount was in all fields the study 24.5 kg ha-1 that 9.8 % of total losses represent the measured total losses Alvand 20.5 kg ha-1 and the variety of Omid 28.5 kg ha-1 respectively

AC-Side Impedance-Based Stability Assessment in Grid-Forming Modular Multilevel Converters

Grid-forming converters can emulate the behavior of a synchronous generator through frequency droop control. The stability of grid-forming modular multilevel converters can be studied via the impedance-based stability criterion. This paper presents an ac-side impedance model of a grid-forming modular multilevel converter which includes a complete grid-forming control structure. The impact of different control schemes and parameters on the closed-loop output impedance of the converter is thoroughly analyzed and the learnings have been used in mitigating undesired control interactions with the grid. The results are verified through simulations in time- and frequency-domains along with experiments on a down-scaled laboratory prototype

Podcasting in a virtual English for academic purposes course: learner motivation

© 2014 Informa UK Limited, trading as Taylor & Francis Group. In this study we explored the effect of podcasting on the motivation of the students in an online English for Academic Purposes (EAP) course at the university level (N = 179). By using a mixed-method approach, we analyzed the data collected on the learners' impressions about using podcasts as a learning tool. The particular aim of this study was to help learners do research in English in their specific academic field. In their EAP course the learners are expected to study various types of English texts, listen to media and give lectures on their academic findings. The findings of this study revealed that males found podcasting significantly more relevant and attractive than females. Females, on the other hand, were significantly more satisfied with using podcasts in their EAP class. Further, results showed that learners who had no prior experience of podcasts for academic purposes outperformed the learners with medium experience. For further qualitative investigation, several sources were used for data collection including interviews with the learners, the course forums, emails, the class groupblog, podcasts and open-ended questions. Overall podcasting proved highly effective in motivating the students to learn in the online environment.peerreview_statement: The publishing and review policy for this title is described in its Aims & Scope. aims_and_scope_url: http://www.tandfonline.com/action/journalInformation?show=aimsScope&journalCode=nile20status: publishe