19 research outputs found

    Comparison of Two Methods of Purple Top Turnip Drying Based on Energy Consumption and Quality Parameters

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    Drying is one of the oldest methods to preserve agricultural products and hence expanding the food market. By drying, the agricultural products can be stored and transferred to the market throughout the year. One of the most important and nutritious vegetables is turnip which can be used by drying in out of season. In this research, the hot air and vacuum drying methods of turnip were compared. The effect of independent factors including temperature and vacuum, on dependent factors such as the shrinkage, rehydration and rate of electric energy consumption on final products of turnip were investigated. A randomized completely design for hot air dryer and a factorial experiment based on completely randomized design for drying under vacuum condition were used. Results showed that the temperature and vacuum have affected the shrinkage, rehydration and electricity consumption. Shrinkage parameter is more depend on the final humidity of product and the energy consumption of the devices depends on time. The best quality of dried turnip was achieved from hot air drying device with final humidity of 14±1%, shrinkage of 39.98%, rehydration of 4.45 and consumed electricity of 32.36 kWh kg-1 of DM in 60˚C. For the vacuum drying device the best quality of produce achieved with shrinkage of 38.12%, rehydration of 4.87 and consumed electricity of 30.58 kWh kg-1 of DM in vacuum condition of 10 kPa in 60˚C. Comparison of results showed that the vacuum dryer is more appropriate than the hot air dryers for drying turnip with better quality and lower power consumption

    Evaluation of Watermelon Ripeness by Analyzing Sounds Generated from Imposed Impact

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    One of the nondestructive methods for assessing the internal quality of some fruits is the processing and analyzing the sound signals generated by an impact on the fruit. In this regard determining the location and the suitable impact levels for a certain fruit is required. In this study, the selected Crimson sweet variety of watermelon was used for the acoustic tests by imposing the impact force on samples. Acoustic tests were conducted using two independent variables including impact location (two sides of the symmetrical line of watermelon and the opposite of the stem end) and impact levels (12.09, 15.08 and 17.11 kg mm s-1) on the generated sound signals, to evaluate the stiffness of the fruit. The relation between the acoustic signals and the texture of both peel and flesh was examined using puncture test. The results showed that the variation of location and levels of impact on the obtained values of acoustic tests were significan

    Effect of Calcium Chloride Concentration on Some Mechanical Properties of Apple during Storage

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    Today, the use of coatings is common to maintain the quality of fruits in storage period. Previous studies have shown that the calcium compounds can improve and preserve the strength of fruit’s cell wall. In this research, the effect of calcium chloride dehydrate (CaCl2*2H2O) concentration on two varieties of apple (Golden Delicious and Red Delicious), was studied. The apples were immersed in the calcium chloride dihydrate solution and then transferred to a cold storage. The effect of three concentration levels: 0, 3 and 6 percent, and three storage durations: no storage, one month and two months, were investigated on the apples mechanical properties such as failure stress, failure strain, modulus of elasticity and toughness. Statistical factorial experiments in the form of completely randomized design were used to analyze the obtained results. The ANOVA results showed that the effect of calcium chloride concentration was significant on the modulus of elasticity (

    Presentation of a Modified Boustrophedon Decomposition Algorithm for Optimal Configuration of Flat Fields to use in Path Planning Systems of Agricultural Vehicles

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    Introduction The demand of pre-determined optimal coverage paths in agricultural environments have been increased due to the growing application of field robots and autonomous field machines. Also coverage path planning problem (CPP) has been extensively studied in robotics and many algorithms have been provided in many topics, but differences and limitations in agriculture lead to several different heuristic and modified adaptive methods from robotics. In this paper, a modified and enhanced version of currently used decomposition algorithm in robotics (boustrophedon cellular decomposition) has been presented as a main part of path planning systems of agricultural vehicles. Developed algorithm is based on the parallelization of the edges of the polygon representing the environment to satisfy the requirements of the problem as far as possible. This idea is based on "minimum facing to the cost making condition" in turn, it is derived from encounter concept as a basis of cost making factors. Materials and Methods Generally, a line termed as a slice in boustrophedon cellular decomposition (BCD), sweeps an area in a pre-determined direction and decomposes the area only at critical points (where two segments can be extended to top and bottom of the point). Furthermore, sweep line direction does not change until the decomposition finish. To implement the BCD for parallelization method, two modifications were applied in order to provide a modified version of the boustrophedon cellular decomposition (M-BCD). In the first modification, the longest edge (base edge) is targeted, and sweep line direction is set in line with the base edge direction (sweep direction is set perpendicular to the sweep line direction). Then Sweep line moves through the environment and stops at the first (nearest) critical point. Next sweep direction will be the same as previous, If the length of those polygon's newly added edges, during the decomposition, are less than or equal to the base edge, otherwise a search is needed to choose a new base edge. This process is repeated until a complete coverage. The second modification is cutting the polygon in the location of the base edge to generate several ideal polygons beside the base edges. The algorithm was applied to a dataset (including 18 cases, ranging from simple-shaped to complex-shaped polygons) gathered from other studies and was compared with a split-merge algorithm which has been used in some other studies. The M-BCD algorithm was coded in C++ language using Microsoft Visual Studio 2013 software. Algorithm was run on a laptop with 2.5 GHz Intel(R) core™ i5-4200M CPU, processor with 4 GB of RAM. Also Split-merge algorithm provided by Driscoll (2011) was coded. Two algorithms were applied to the dataset. Cost of coverage plan was calculated using cost function of U-shaped turns in study Jin and Tang (2010). In this paper machine-specific parameters were working width 10 m and minimum turning radius 5 m. Results and Discussion Based on the results, the proposed algorithm has low computational time (below 100 ms in dataset and runs many times (on average 75 times) faster than split-merge algorithm. Algorithm resulted in a calculated savings up to 12% and on average 2% than the split-merge algorithm. Another consequence from parallelization method was effectiveness of multi-optimal direction coverage pattern than a single-optimal direction coverage; a calculated savings up to 14% and 2% on average than a single optimal direction achieved. Algorithm was evaluated on several test cases in detail. Based on the results, it is possible to loose optimal solutions especially in the case of simple shaped environments (in terms of number of convex points and internal obstacles), for example case 10 in dataset, is a case with a number of orthogonal edges. Reviewing the algorithm and Figure 4 demonstrate that sweep line moves down from the first longest edge in top of the polygon, and it doesn't stop during the process until the whole area is covered with a single coverage path direction (parallel to the longest edge). As it can be seen, no decomposition is proposed, because sweep line has faced no critical points. Based on the results in Table 2, there is 8% (equal to 88m) more cost (in term of the non-effective distance) in this case than an optimal direction and the split-merge algorithm. There are similar cases in the dataset: number 9, 12 and 13. This condition rarely occurs in complex environments, but in general it can be prevented by using an evaluation step at the end of the decomposition process. Ideally, the cost of coverage plan must be significantly less than related costs of a single optimal direction. Unlike the simple cases, algorithm returns near the optimal solution, especially in the case of complex environments. A good example of this ability of the algorithm can be seen in Figure 6. This field is case 17 in the dataset. It has many edges (almost 90 edges) and several non-convex points and an internal irregular shaped obstacle. M-BCD algorithm in a very short time (87 ms) generated several near to ideal shaped sub-regions around the field. Algorithm resulted in a calculated saving of 5% than an optimal direction with minimum non-effective distance. We can see the solution of split-merge algorithm by Oksanen and Visala (2009) in Figure 6, it can be clearly seen that coverage pattern by M-BCD is very close to the high time-consuming and optimal split-merge algorithm by Oksanen and Visala (2009). It verifies that M-BCD is efficient and optimal. There are similar test cases as hard cases in which considerable savings has been achieved (cases 6, 8 and 14). Conclusions In this paper a modified decomposition algorithm as a main part of path planning systems in agricultural environments was presented. Proposed algorithm uses method of parallelization of the edges of polygon. This method is based on encounter concept and "minimum facing to cost making condition". Although the general problem had been proved to be NP-hard problem, the method has limited the search space correctly and effectively which resulted close to the optimal solutions quickly. Another advantage of the method is suitability of the solutions for any kind of machine and any polygonal flat field (and those which can be considered as flat fields)

    Analysis of different inputs share and determination of energy Indices in broilers production in Mashhad city

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    Introduction The high energy consumption is one of the serious problems in poultry industry. The poultry industry consume about five percent of total energy sources in different countries, with consideration of losses, it increases up to 16-20%. In the year 2003 also, the Iranian chicken meat consumption per capita was 13.3 kg, while in the year 2013 it increased to 25.9 kg (FAO, 2014). It shows that in the diet of Iranian people, the chicken meat has become a strategic food. Poultry industry is one of the biggest and most developed industries in Iran. In the past two decays, mainly due to population growth and increase demand of white meats, it is necessary to change and improve energy efficiency in this industry. Technical efficiency of broiler farms in the central region of Saudi Arabia was analyzed through stochastic frontier approach (Alrwis and Francis, 2003). They reported that many farms under study work lower than their total capacity. In the research, the output was chicken meat weight in the term of the kilogram per one period and the inputs were the number of chicks, feed, the total of all variable expenses and fixed input except chicks and feed and the total cost of fixed inputs including building, equipment and machinery used for the broiler houses. They found that the small and large size broiler farms in the Central Region of Saudi Arabia were produced chicken with mean technical efficiency 83 and 88%, respectively (Alrwis and Francis, 2003). Efficiency measurement of broiler production units in Hamadan province was investigated by Fotros and Solgi (2003). They reported that the minimum, maximum and mean technical efficiency under variable return to scale were 12.7, 100 and 64.4%, respectively. Their results showed that technical efficiency at 16.5 (14 units) and 42.35% (24 units) of farms were more than 90 and 70%, respectively (Fotros and Salgi, 2003). Khorasan Razavi province after Esfahan and Mazandaran provinces is the third largest producer of broilers in Iran. This research was performed because it is necessary to have energy consumption status; also there is a few data about broiler’s energy consumption in Mashhad. In this research, the data of Mashhad’s broilers was analyzed by Data Envelopment Analysis Method. The other objectives of this study were to separate efficient and inefficient units to use energy resource efficiently and determine total energy saving. Materials and Methods This study was performed in 2013 in Mashhad, Iran. The data were collected through interviews and questionnaires from 36 poultry farmers for a growing period of April to May. Input energies were the feed, fuel (gas and gas oil), electricity, labor, equipment and chicken, and the output energies were the chicken meat and the manure. The energy consumption for each element was calculated by multiplied amount of inputs/outputs to energy equivalents. Results and Discussion The total of input and output energies were obtained 125.2, 24.9 GJ/1000Birds, respectively. Energy indices such as energy ratio, energy efficiency and specific energy were determined to be 0.2, 0.019 kg/MJ and 52.55 MJ/kg, respectively. The highest share of energy consumption were 50.84 and 42.43%, for fuel (natural gas and diesel fuel) and feed respectively, the lowest share among the input energies were 0.39 and 0.06%, for chicken and labor respectively. Comparison of energy in three levels of farm sizes (≤15000, 15000-30000 and ≥30000 chicks) showed the energy ratio for large farms were higher than the other levels. Data Envelopment Analysis (DEA) was used to evaluate the poultry efficiency. The results showed that 13 poultry units had average technical efficiency (0.93) in the definition of Constant Returns to Scale (CRS), and 21 poultry units had pure technical efficiency (0.99) in the definition of Variable Returns to Scale (VRS). Conclusions The Fuel (natural gas and diesel fuel) consumption energy had the highest shares of energy consumption; it is because of the low efficient heating equipment in poultry houses and low fuel prices in Iran. Energy efficiency of broiler farms in Mashhad was obtained 0.2 that show low energy efficiency. Improvements in energy efficiency could be achieved by increasing yield or reducing inputs energies

    Predicting working days for secondary tillage and planting operation in fall

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    Introduction The working day is an important component in selection and analysis of farm machinery systems. The number of working days is affected by various factors such as climate, soil characteristics and type of operation. Daily soil moisture models based on weather long-term data and soil characteristics were almost used for calculating probability of working days. The goal of this study was to develop a simulation model to predict the number of working days for secondary tillage and planting operation in fall at 50, 80 and 90% probability levels. Materials and Methods A Simulation model was developed using 21 years weather data and soil characteristics for calculate daily soil moisture content in Research Station of Ferdowsi University of Mashhad. So soil moisture was calculated using daily soil water equation for top 25 centimeter of soil depth. Moisture equal or lower than 85% of soil field capacity and precipitation lower than 4 millimeter (local data) were considered as soil workability criteria. Then the working days were determined for secondary tillage and planting operation at 50, 80 and 90% probability levels in falls. The number of days at 50% probability was the mean over 21 years and the number of days at 80% and 90% were determined for each two weeks period as the average number of working days minus the product of t value and standard deviation of those numbers. Model Evaluation Evaluation of model included a comparison of predicted and the observed the number of working days in Research Station of Ferdowsi University of Mashhad during 2002-2010 and sensitivity analysis was implemented to test the effect of changes in soil workability criterion (80, 90, 95 and 100% of soil field capacity), drainage coefficient (25 % decrease and increase) and soil field capacity (40% increase) on simulation results. Results and Discussion Comparison of predicted and observed days showed that correlation coefficient was 0.998 and the difference between the simulated data and observed data was not significant at the 5% level. Results from sensitivity analysis in Table 3 showed that when soil workability, drainage coefficient and field capacity increased, the number of working days increased, but model sensitivity was very low to drainage coefficient and soil field capacity. In general, the most important factor is precipitation in this weather conditions. The number of working days for secondary tillage and planting operation for each period in fall are shown in Table 4. Conclusions A simulation model was developed for predicting the number of working days for secondary tillage and planting operation in fall. This model was based on weather long-term data and soil characteristics for the Research Station of Ferdowsi University of Mashhad. The most important factor was precipitation and the model had low sensitivity to drainage coefficient and soil field capacity. The number of working days in 50%, 80% and 90% probability levels for period of ten days was on average 9.94, 9.21, 8.57 days for 23th September to 22th October and 9.77, 8.02, 6.41 days for 23th October to 21th November and 9.68, 7.48 and 5.24 for 22th November to 21th December, respectively

    A study on demographic characteristics of drug resistant Mycobacterium tuberculosis isolates in Belarus

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    Objective: A descriptive study of drug-resistance patterns by age group and among culture-positive pulmonary tuberculosis (TB) patients referred to the Research Institute for Pulmonology and Phthisiology of Belarus between January 2007 and January 2008. Methods: Drug susceptibility tests were performed for first- and second-line anti-tuberculosis drugs. Patients were clustered into five resistance categories: mono-resistant (Mono); multi-drug resistant (MDR); all first-line drug resistance (MDR+ES); and extensively drug resistant (XDR). The patients were divided into primary and secondary and into six groups based on age in years (65). Results: An analysis was undertaken of information gathered from 934TB patients, of whom 660 were men (70.67±1.5%) and 274 were women (29.33±1.5%) (p 0.05); 756 of the patients were of working age, and 170 were of non-working age, of whom 570 men of working age (18–60 years) and 188 women of working age (18–55 years) participated. Males were significantly more likely to have MDR-TB than females. All cases with XDR-TB were older than 14 years old. Conclusion: As Belarus is a high-burden MDR-TB country and treatment of drug-resistant TB is long and complicated, the findings of this study provided useful information to deliver effective community-based disease control measures and a proposed plane for the effective management of drug-resistant TB at the national level

    Designing and evaluation of rapid molecular assays for first and second-line anti-tuberculosis drugs

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    Introduction: The four basic or “first-line” TB drugs are Isoniazid, Rifampicin, Pyrazinamide and Ethambutol. For the treatment of drug-resistant TB, the current TB drugs are grouped according to their effectiveness and experience of use, such as Streptomycin, pyrazinamide, rifabutin, kanamycin, amikacin, ofloxacin, etc. The drug susceptibility test (DST) is a time-consuming and costly method. Rapid molecular tests may be used by detection of related mutations. The aim of this study is to design and evaluate the quickest methods of detection. Materials and Methods: 120 resistant and susceptible clinical isolates of Mycobacterium tuberculosis (MTB) were evaluated for probable mutations in resistance-related genes. Molecular methods of polymerase chain reaction (PCR)-RFLP, AS-PCR and MAS-PCR as nested or semi-nested forms were used for mutation detection in katG, rpoB, pncA, rpsL, gyrA,inh, rrs, inhA and embA. Evaluation of ethA and pncA genes in the isolates was accomplished by sequencing. Furthermore, the sequencing method was used for all the genes as the golden standard. Results: 88% prevalence of the katG315 mutation was detected in INH-resistant isolates by AS-PCR and 95.6% by PCR-RFLP. In 93% of rifampin-resistant isolates point mutation at codons 516, 526 or 531 were detected by MAS-PCR method and 75% by AS-PCR method. In rapid detection of resistance to injectable drugs, the sensitivity and specificity of PCR-RFLP method for mutation detection in rrs gene by BSTFNI enzyme were 95/65% and 70/83%, by AJIi enzyme were 60% and 90/62% and by MAS-PCR method were 50% and 70/58%, respectively. Ofloxacin resistance was detected in 84.6% of resistant isolates by 4 endonuclease enzymes in PCR-RFLP method and sensitivity and specificity of a MAS-PCR method were 86/11% and 100%, respectively. Sensitivity and specificity of a MAS-PCR method for pncA were 66% and 90% and for PCR-RFLP method for rpsL were 90% and 95%, 36.5% (CI:0.09–0.45) and 100% only for one resistance-related codon for emb gene, respectively. Ethionamide and Pyrazinamide resistance in resistant isolates was proved by 100% sensitivity by the sequence method. Conclusion: Molecular methods of PCR-RFLP, MAS-PCR and sequencing were successfully used for rapid detection of first- and second-line antimycobacterial drugs
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