نشریه مهندسی بیوسیستم ایران
سال پنجاه و یکم شماره 2 (تابستان 1399)

It is necessary to use methods to monitor the pH of the rumen and maintain it between 5.5 and 7. In this research, a pH Nano-sensor based on EIS technique was developed and assessed in order to be used in wireless monitoring system of rumen pH. Single-Wall Carbone Nanotubes were functionalized with carboxylic groups (COOH), also with Amin groups (NHRNH2). Then interdigitated chrome-gold electrodes were coated by a drop of the solution obtained from dispersing with a known ratio of COOH-SWNT and Amin-SWNT in PECH/THF solution. Finally, the developed electrode was used as working electrode in EIS experiments over the laboratorial and real (rumen liquid) samples in the form of buffer solutions, adjusted at various pH values. Each experiment was done by applying AC voltages of 20 mV with frequencies ranging from 0.1Hz to 1MHz. Results showed that the developed electrode was pH sensitive and for real samples, impedance modulus, |Z|, linearly increased with pH (Freq.=0.4kHz, R2 =0.99).

Analysis of energy consumption provides useful information for planners and policymakers to improve the efficiency of energy consumption. This study was conducted to evaluate and investigating the the energy flow and greenhouse emissions in silage corn production by data envelopment analysis method. The primary data was collected from 50 farms of silage corn production in the Shahrekord County by simple random sampling. The total amount of inputs energy and output energy was 77693 MJ.ha-1 and 502669 MJ.ha-1, respectively, which after improving in inputs consumption was resulted a reduction of 12080 MJ /ha in total inputs energy. Energy ratio (ER) and energy productivity (EP) were determined as 3.1, 2.57 MJ.kg-1 in actual conditions and 3.67 and 2.17 MJ.kg-1 in optimization conditions, respectively. Electricity was identified as major contributor to total energy consumption as 41205 MJ.ha-1 (53.3%) and also after improving in inputs consumption, the summation of water and electricity had the most contribution on the total energy saving with the share of 22%. Also, the total GHG emission in actual and optimum conditions were calculated as 2885.5 and 2554.5 kgCO2eq. per ha, respectively.

The purposes of this study were to determine energy use pattern and study the relationships between energy inputs and yield, costs and revenue for plum production in Khansar Township. In this research, the required information was collected by questionnaire and face-to-face interview with gardeners. The inputs included labor, machinery, diesel fuel, chemical and organic fertilizers, irrigation water and electricity. The Cobb-Douglas model and sensitivity analysis were used to investigate the effect of input energy on performance. In this study the total energy used to produce plum was 56721.19 MJ/ha, and the electricity input with 66.25% was as the most common source of energy in plum production. The share of renewable energy for this product was 3.36%. The results of the Cobb Douglas function showed that the energy inputs of human labor, electricity, chemical fertilizer had a significant effect on performance. The results of sensitivity analysis showed that among the energy inputs, human labor energy had the highest marginal physical productivity (MPP) and the energy of human labor had the highest effect (0.87) compared with other sources in the production of plums. Energy efficiency for plum production was 0.46 and the human labor accounted for the highest production cost with 70.75%. Also, the benefit to cost ratio in the production of plum was calculated as 1.9.

One of the main problems in intercropping is the lack of suitable machinery‏. In this research, a new pneumatic punch planter has been developed and evaluated for intercropping of sugar beet and sunflower. The main components of sunflower pneumatic punch planter were chassis, punching unit, and seed transferring unit.‏ A unit of pneumatic planter fabricated by Trashkadeh Company Karaj (Iran) was removed and a unit of punch planter was incorporated on the toolbar instead and intercropping was performed. The experimental tests were carried out in a 4-ha field and the effect of traveling speeds of 3, 4 and 5 km/h on seed holes, seed depth, the number of germinated seeds and yield was evaluated. A completely randomized design at three speeds and three repetitions using Duncan’s Multiple Range Test was utilized for comparison uses. No variations in hole depth was observed at travel speed of 3 km/h; where the maximum germinated seeds were achieved as well as minimum variation in hole distances. The results showed that the use of pneumatic punch planter caused 9.69 and 12.45 percent increase in sugar beet and sunflower yields, respectively.

In-spite of large amounts production of bread waste annually, this waste is not suitable for food and animal feed applications due to aflatoxin contamination. In this study, bio-ethanol production from bread waste by Saccharomyces cerevisiae was investigated using acidic hydrolysis method. The acidic hydrolysis was performed by an autoclave apparatus. The effect of acidic solution concentration and time on amount of glucose was investigated. The experiments were carried out at loading of 160 g/l. Reduction of aflatoxin was measured for the sample with the greatest yield in acid hydrolysis. The sample obtained from hydrolysis was used for the production of bio-ethanol using Saccharomyces cerevisiae. The results showed that the effect of concentration of acid and time was significant at 1% level on the amount of glucose. Hydrolysis liberated the greatest amount of carbohydrate (80.64 g/l glucose) at the acidic solution concentration of 1% and time of 20 minutes. Also, acidic hydrolysis reduced aflatoxin B1 and B2 by 100% and 20.70%, respectively. The greatest percentage of bio-ethanol production in the fermentation phase of hydrolysis samples was 4.7 (v / v%).

Using the  acoustic response analysis is one of the non-destructive methods to determine the texture quality and firmness of fruits such as apples, pears, peaches and other crops such as watermelon, melon and cantaloupe. In this study, a portable device designed and fabricated which has a pendulum to apply the computer-controlled impact to the sample, to investigate the non-destructive quality of apple fruit based on firmness. When pendulum hits the sample, both the acoustic and vibration sensors simultaneously receive the impact signals and after transferring to the computer, the fast Fourier transform will calculate their dominant frequency. The sample firmness index is calculated from the dominant frequency and weight. The dominant frequencies and firmness indices obtained by this device for apple fruit were correlated more than 92% and 93% with puncture firmness and elasticity module respectively, and were significant at 1% level. Experimental results showed that the vibration signals have better results for estimation of elasticity modulus (more than 96 % accuracy) and acoustic signals to estimate the firmness (accuracy of more than 95 %).

Precision planters provide accurate placement of single seeds at equal and uniform intervals within rows by metering devices. Air drum, inclined plate, belt, horizontal plate and roller meter device used for precision planter which the roller metering device was used mostly. Three levels of number of slots (4, 5 and 6) and three levels of slots mouth (, and ) were considered as the new metering device parameters. So, nine new metering devices were made by PTFE Teflon. The experiments were done by grease belt system with three different forward speeds (2.5, 3.5 and 4.5 km.h-1) and four Rotational speed ratios (0.5, 0.67, 0.75 and 1) in three replications as a completely randomized factorial design. Multiple index, quality of feed index, miss index and precision index were considered for laboratory evaluation of the metering device. Based on the results, the optimum design values for single-seed metering device were 5 slots with 24.5 degrees in the slots mouth in 3.5 km.h-1 forward speed and 0.67 rotational speed ratio (52 rpm rotational speed).

Tractor mounted onion topper is one of the technologies used to remove onion leaves. The position of the blades in this machine plays an important role in the quality of the onion topping. In the case of communication between the physical characteristics of the bulbs and the length of the leaves remaining after the topping, it is possible to provide methods for automatic adjustment of the blades. In this research, a method was proposed to calculate the diameters of the bulbs before topping using image processing. Then the remaining leaf length on onions was estimated in topping process using the Multi-Layer perceptron (MLP) and the bulbs were classified in four groups according to the size of the leaves remaining by using the Learning Vector Quantization (LVQ). The statically parameters such as root mean square error, mean absolute error, specificity, precision, sensitivity and accuracy were used to evaluate the networks. The results showed that the designed neural network predicted leaf cutting height with RMSE and MAE values ​​of 0.025 and 0.01 respectively. Also, the classification of onions was carried out with a total accuracy of 91%. The results of this research can be used to set up automated mechanisms of cutting blades in onion topper.

The sedimentation chambers are used in various agricultural systems. In this study, an innovative design of the chickpea sedimentation chamber including the chamber with the flow path deviation blade are considered and the effect of this blade on the sedimentation efficiency, required flow, distribution of air flow and chamber erosion were investigated experimentally and numerically. The computational fluids dynamics for numerical simulations was used. A laboratory setup equipped with a hot wire anemometer and differential pressure meter was used to obtain the velocity and pressure data and model validation. The results showed that the use of the flow path diversion blade has an 11.4% increase in sedimentation efficiency, reduction of 6.67% of the required airflow and cause the reduction of erosion in chamber.

In this paper, a screw feeder with a helical ribbon mixer was designed and developed and evaluated for feeding Sisybrum seeds into a triboaeroelectrostatic mechanism for separating the impurities of fine grains. In order to check the feeding rates, the effects of rotational speed of screw in 3 levels of (60rpm, 90rpm and 120rpm), channeled plane outlet type in 3 levels of circle perforation with 4mm diameter, circle perforation with 6mm diameter and groove shaped with 5mm width and 280mm length and hopper location in 2 levels of (upside the conveying screw and upside the helical mixer) was investigated. The results was analysed on the basis of factorial experiment with randomized completely design. The results of comparing means based on multi-domain Duncan test showed that the most feeding rate is at the speed of 120rpm, groove shaped outlet and hopper location 2, and the least feeding rate is at the speed of 90rpm and hopper location 1. The most appropriate feeding rate for feeding Sisybrium seed into triboaeroelectrostatic by screw feeder is at the speed of 90rpm, circle perforation outlet with 4mm diameter and hopper location 1. The results by evaluating feeder operation on triboaeroelectrostatic mechanism showed that the feeder caused increasing material weight with the most purity (97%) and increasing separated impurity weight as twice as much of their amount without using feeder, by mixing material and charging them with static electric load.

The largest share of greenhouse gases in the world is related to the use of fossil fuels in power plants for electricity generate. Production and emissions of greenhouse gas are more important for the drying process that has high specific energy consumption (SEC). In this study, modeling and optimization of SEC and greenhouse gas emissions including CO2 and NOx during the process of blackberry drying under infrared-hot air combined dryer (at three inlet air temperature levels 50, 60 and 70 ° C) with different pretreatments including of microwave (90, 180 and 360 w), blanching (70, 80 and 90 ° C) and ultrasond (15, 30 and 45 min) were evaluated by response surface methodology. The drying energy was provided by various steam turbines, gas turbines and combined plants using natural gas, heavy oil and gas oil as fuel. The results showed that by increasing the microwave power and ultrosond time decreased quadraticly the amount of SEC (from 185.55 to 55.53 kWh/kg). However, this value decreased linearly (from 208.08 to 88.56 kWh/kg) with increasing blanching temperature. Emissions amount for all greenhouse gas decreased quadraticly (from 194460.67 to 24987.97g for CO2 and from 1074.36 to 106.06 g for NOx) with increasing microwave power, ultrosound time and hot air tepmerature for all turbines with different fuels. However, this amount decreased linearly with increasing blanching temperature (from 218063.85 to 39985.54g for CO2 and from 1204.76 to 169.72 g for NOx). Based on modeling using RSM, optimum conditions for the minimum SEC were determined to be microwave power of 349.7 W and inlet air temperature of 69.8 oC for microwave pretreatment, ultrasound time of 45 min and inlet air temperature of 70 oC for ultrasound pretreatment, blanching temperature of 90 oC and inlet air temperature of 70 oC for blanching pretreatment with disierability mean of 99.8%.

In this study, the amount of produced thermal energy, exergetic and energetic efficiency of a collector at three conditions with porous plate (PS), with recycling system (PRS) and with reflectors (PRE) in a solar dryer was investigated. For all the experiments the fluid flow rate was 0.018 kg/s. Tomato slices with 7 mm thickness were considered for drying process evaluation. All the experiments were carried out during three consecutive days of June of 2018 from 8:00 to 18:00. The value of total energy enters to the dryer for PS, PRS and PRE changed to 21.94, 24.93 and 28.77 MJ, respectively. Moreover, the energy efficiency obtained 21.03-52.30% for PS, 23.12-58.23% for PRS and 30.01-69.75% for PRE. The maximum exergy efficiency for mentioned conditions was calculated about 19.40%, 21.20% and 23.12%, respectively. The specific energy used for drying of the slices for PS, PRS and PRE was obtained 9.68, 9.28 and 8.82 MJ/kg, respectively and this shows that using the reflectors is proper method to increase thermal efficiency of the flat plate collectors.

Fuel supply for cooking among Iranian nomads have always been problematic job. The use of wood as a source of energy is very common in nomads. Traditional method of firing releases a huge amount of smoke, which may lead to respiratory problems in women. Moreover, collection of wood corresponds to destroy of natural resources. The aim of this study is to assess the feasibility of using ship dung (as the most available biomass in nomadic life), as a cleaner cooking fuel in an improved biogas stove. In this research a micro gasifier biomass cook stove as an improved biomass cook stove was evaluated based on Emission & Performance Test Protocol. Sheep dung pellets of 38 mm length and 13.6 mm diameter was used as biofuel. In addition to measurement of descriptive characteristics, the heating value of fuel was estimated based on elemental analyzing results and the models presented in previous researches. Emission of Carbon monoxide was monitored throughout the test. No smoke was observed during the stove operation. The thermal power of the stove was measured to be 3.4 kW. With the efficiency of 28 percent, 3 L of water got to boiling point in 16 min consuming 440 g of pellet. The average amount of emitted CO was recorded to be acceptable range. The results of micro gasifier biomass cook stove evaluation with sheep dung pellet as fuel showed that, this devise has a good technical and emission performance with this fuel and it can be used for nomad’s household. Further on field research is needed to adjust the stove size and design to the common life style of nomads.

Since white berry has much medical and edible benefit, it is known as a popular fruit. This research is carried out in order to classify ripe and unripe berries from each other using active thermography method. In this research 70 berries have been used as experimental samples randomly selected from a tree. They were sorted to “ripe” and “unripe” class by 5 expert people with attention to the color and texture of fruits. The temperature changes of samples by heat shock induction were recorded with a thermal camera and coefficients of first order, second order and logarithmic equations fitted to temperature-time graphs were employed for classification in MATLAB software. Using Principal Component Analysis (PCA) method, in MATLAB software, causes to use only first order equation coefficients, with an accuracy of 90 percent. Using the results of this research, the speed and accuracy of classification can be effectively increased in berry classification lines.