DESIGN AND DEVELOPMENT OF SPECIAL CUTTING SYSTEM FOR SWEET SORGHUM HARVESTER

Sweet Sorghum is similar to racemose maize with about 3m height and 0.5-3cm thickness of stalk. Sweet Sorghum has sweet flavor stalk, which is used for sugar production. Developed cutting mechanism in this research has a rotary disk with 50 cm diameter and four cutting blades that spin clockwise. The stalks are cut with the impact and inertia forces at the linear velocity of 27 m/s, by cutting blades. This system has a simple bar mechanism guiding the whole-stalk to one side. The cutting quality tests were achieved by two series of blades with 30°and 45° blade angles on the stalk. The results showed that the stalk cutting surface with 30° blade angle was smooth and without fracture on filaments and vasculums, compared to that of 45° blade angle. Blade penetration was accomplished very well with 30° blade angle

STUDY ON MECHANICAL PROPERTIES OF SUNFLOWER SEEDS

ABSTRACT Some physical and mechanical properties of sunflower seeds were studied. The measured parameters were linear dimensions, thousand grain mass, geometric mean diameter, sphericity, surface and projected area, volume, shape parameters (such as flakiness ratio and elongation ratio), true and bulk densities, porosity, angle of repose and static coefficient of friction of the Shamshiri variety in the moisture range from 6.3 to 20% (w.b.) using standard methods. Average rupture force, deformation and absorbed energy at rupture point of the sunflower seeds under compression as well as the extent of physical damage to seeds due to impact were also determined over a range of moisture contents between 1.8% and 20.3% (w.b). The results showed a variation of 14.32 to 31.00 mm for length, 4.73 to 9.82 mm for width and 2.36 to 6.67 mm for thickness of sunflower seeds. The values of the thousand grain mass, seed volume, true density, bulk density and porosity of sunflower seeds were between149. 81-167.77g, 99.05-628.9 mm3, 444.39-521.78 kg/m3, 269.06-275.57 kg/m3 and 39.09-47.18% respectively. The rupture force, deformation, and absorbed energy increased with increase in moisture content from 1.8 to 14.5%, while decreased with further increasing of moisture content from 14.5 to 20.3%. The mean value of percentage of physically damaged seeds increased from 2.75 to 10.81% with increasing the impact velocity from 40.8 to 62.3 m/s. In both impact orientations, the total damaged seeds increased with increase in impact velocity for all moisture contents of seeds

Experimental investigation of conduction and convection heat transfer properties of a novel nanofluid based on carbon quantum dots

So far, many studies have been conducted on heat transfer nanofluids and various nanofluids have been synthesized and evaluated by different nanoparticles. In the present research, the use of biodegradable carbon quantum dots (CQDs) to synthesize heat transfer nanofluids was investigated for the first time. In fact, CQDs are a new generation of carbon nanoparticles and one of the advantages of which is their very small size that facilitates the prepared of nanofluids at very low concentrations with high stability. In the present research, CQDs were synthesized based on microwave method using commercial ammonium hydrogen-citrate as precursor. The nanofluid samples were synthesized based on car radiator coolant and CQDs at the concentrations of 100, 200, 500, and 1000 ppm. Thermal conductivity (k) and convection heat transfer (h) coefficients were investigated as the main features of the fluid's heat transfer characteristics. The obtained results for 200-ppm concentration indicated the improvement of k and h by 5.7% and 16.2%compared to the base fluid, respectively. Besides, the synthesized nanofluids had also significant stability and very low cost which are of great importance for industrial applications. Finally, the heat transfer process in the 200-ppm nanofluid was simulated by Ansys Fluent software

Characteristics of sunflower seed drying and microwave energy consumption

The effect of the microwave-convective drying technique on the moisture ratio, drying rate, drying time, effective moisture diffusivity, microwave specific energy consumption, and energy efficiency of sunflower seedswere investigated.Drying took place in the falling rate period. Increasing the microwave power caused a significant decrease in the drying time. The drying data were fitted to four thin-layer drying models. The performance of these models was compared using the coefficient of determination, reduced chi-square and root mean square error between the observed and predicted moisture ratios. The results showed that the Page model was found to satisfactorily describe themicrowave-convective drying curves of sunflower seeds. The effective moisture diffusivity values were estimated from Fick diffusion model and varied from 1.73 10-7 to 4.76 10-7m2s-1. Increasing the microwave power resulted in a considerable increase in drying efficiency and a significant decrease in microwave specific energy consumption. The highest energy efficiency and the lowestmicrowave specific energy consumption were obtained at the microwave power of 300 W

Optimization Effect of Ultrasound on Rupture Force and Kernel Extracting Quality of Walnut using Response Surface Method (RSM)

IntroductionOne of the most important and sensitive steps after walnut harvesting is the separation of the kernel from its shell. Walnut rupture force is an appropriate criterion for design with high performance and better quality, which can be used as the basis for designing and adjusting the various parts of machines that are in contact with walnut. The lower rupture force caused the less energy requirement to separate the walnut kernel from the shell. The use of ultrasound in ambient fluids is well known to cause turbulence and biological cell rupture. These effects arise principally from the phenomenon known as cavitation which can scour surfaces and damage cellular material. Therefore the object of this study is to find the effect of ultrasound factors on the amount of walnut rupture force and quality of kernel extraction.Materials and MethodsWalnut paper variety was selected from a Qazvin province orchard for this study. To determine the initial moisture content of the nuts, the samples were dried in an oven at 105°C for 24 h. Initial moisture content was found 5.5 (%w.b). The ultrasounds bath system (D-78224 Singen/htw, Elma, Germany) was used with a nominal frequency of 50 kHz and power of 1000 W. In this research, based on the pretest results and previous studies (Cao et al., 2010; Entezari et al., 2004) walnut samples were treated with three ultrasound time duration (5, 10 and 15 min) and three ultrasound bath temperature (20, 35, and 50ºC). Moisture content of the walnuts after ultrasound treatment was 8.8 (%w.b). After the walnut samples were treated by ultrasonic factors, a material testing machine (H50 K-S, Hounsfield, England) was used to determine the rupture force of the walnuts. The walnut was placed between two plates, and loaded at three loading speeds (0.5, 1.5, and 2.5 mm s-1) and pressed until the walnut ruptured. Rupture force was applied along with X and Y axes. The X-axis was in the longitudinal axis through the hilum to the tip (length) and the Y-axis was in the latitudinal axis (width) at right angles to the X-axis. Kernel extraction quality was classified into grades according to size and number of broken pieces of the kernel. Central composite design (CCD) of resound surface method was used to optimize the effect of ultrasonic factors on walnut kernel extraction.Results and DiscussionThe results indicated that the loading speed, ultrasound time duration, loading direction, and moisture content had a highly significant effect (P<0.01) and ultrasound bath temperature (P<0.05) on the rupture force and kernel extracting quality. Regarding the sum of squares of ANOVA results, the ultrasound time duration factor had the most effect on the rupture force and the loading direction factor had the most effect on kernel extraction quality. By increasing bath temperature and ultrasound time duration, walnut rupture force was decreased. The minimum walnut rupture force was obtained in 25 min ultrasound time duration, 50ºC bath temperature, 1.5 mm s-1 loading speed, and width loading direction for wet walnut. By increasing bath temperature, walnut kernel losses were increased. The best kernel extraction quality was obtained in 2.5 mm s-1 loading speed, 25 min ultrasound duration, 20ºC bath temperature, and longitudinal loading direction. The proposed optimal point was obtained at 64.4 N rupture force, and two half of the kernel at 1.3 mm s-1 loading speed,  25 min ultrasound duration, 50ºC bath temperature, and longitudinal loading direction for wet walnut.ConclusionsThe walnut ultrasound treated samples had minimum rupture force and the best quality kernel extraction. It was observed that by increasing the loading speed and ultrasound time duration, the percentage of whole kernels and the quality degree of broken kernels increased

Effect of Potassium Permanganate Nano-Zeolite and Storage Time on Physicochemical Properties of Kiwifruit (Hayward)

In this research, kiwifruits (Hayward) were selected in two mass ranges (large and small). They were placed in one-liter glass bottles in the vicinity of the polyethylene sachets containing potassium permanganate nano-zeolite (0, 0.2, 0.4 and 0.8 g) and were stored in a germinator (5°C temperature and 30% relative humidity). Then, the physicochemical properties of the fruits (soluble solid content, pH, moisture content and fruit firmness) and potassium permanganate nano-zeolite color (L, Hue angle, Chroma and E) were measured after t 0, 2, 4 and 6 weeks of storage. The factorial treatment structure based on completely randomized block design was used for analyzing the obtained data. The results of analysis showed that potassium permanganate nano-zeolite had a significant effect on the measured physicochemical properties, except for the moisture content (

Detection of Pistachio Aflatoxin Using Raman Spectroscopy and Artificial Neural Networks

Pistachio contamination to aflatoxin has been known as a serious problem for pistachio exportation. With regards to the increasing demand for Raman spectroscopy to detect and classify different materials and also the current experimental and technical problems for measuring toxin (such as being expensive and time-consuming), the main objective of this study was to detect aflatoxin contamination in pistachio by using Raman spectroscopy technique and artificial neural networks. Three sets of samples were prepared: non-contaminated (healthy) and contaminated samples with 20 and 100 ppb of the total aflatoxins (B1+B2+G1+G2). After spectral acquisition, considering to the results, spectral data were normalized and then principal components (PCs) were extracted to reduce the data dimensions. For classification of the samples spectra, an artificial neural network was used with a feed forward back propagation algorithm for 4 inputs and 3 neurons in hidden layer. Mean overall accuracy was achieved to be 98 percent; therefore, non-liner Raman spectra data modeling by ANN for samples classification was successful

Paddy/Rice Singulation for Determination of Husking Efficiency and Damage Using Machine Vision

In this study a system of machine vision and singulation was developed to separate paddy from rice and determine paddy husking and rice breakage percentages. The machine vision system consists of three main components including an imaging chamber, a digital camera, a computer equipped with image processing software. The singulation device consists of a kernel holding surface, a motor with vacuum fan, and a dimmer. For separation of paddy from rice (in the image), it was necessary to set a threshold. Therefore, some images of paddy and rice were sampled and the RGB values of the images were extracted using MATLAB software. Then mean and standard deviation of the data were determined. An Image processing algorithm was developed using MATLAB to determine paddy/rice separation and rice breakage and paddy husking percentages, using blue to red ratio. Tests showed that, a threshold of 0.75 is suitable for separating paddy from rice kernels. Results from the evaluation of the image processing algorithm showed that the accuracies obtained with the algorithm were 98.36% and 91.81% for paddy husking and rice breakage percentage, respectively. Analysis also showed that a suction of 45 mmHg to 50 mmHg yielding 81.3% separation efficiency is appropriate for operation of the kernel singulation system

Design of ultrasonic probe and evaluation of ultrasonic waves on E.coli in Sour Cherry Juice

Introduction: The common method used for juice pasteurization is the thermal method since thermal methods contribute highly to inactivating microbes. However, applying high temperatures would lead to inefficient effects on nutrition and food value. Such effects may include vitamin loss, nutritional flavor loss, non-enzyme browning, and protein reshaping (Kuldiloke, 2002). In order to decrease the adverse effects of the thermal pasteurization method, other methods capable of inactivation of microorganisms can be applied. In doing so, non-thermal methods including pasteurization using high hydrostatic pressure processing (HPP), electrical fields, and ultrasound waves are of interest (Chen and Tseng, 1996). The reason for diminishing microbial count in the presence of ultrasonic waves could be due to the burst of very tiny bubbles developed by ultrasounds which expand quickly and burst in a short time. Due to this burst, special temperature and pressure conditions are developed which could initiate or intensify several physical and/or chemical reactions. The aim of this study is to evaluate the non-thermal ultrasonic method and its effective factors on the E.coli bacteria of sour cherry. Materials and methods: In order to supply uniform ultrasonic waves, a 1000 W electric generator (Model MPI, Switzerland) working at 20±1 kHz frequency was used. The aim of this study is to evaluate the non-thermal ultrasonic method and its effective factors on the E.coli bacteria of sour cherry. For this purpose, a certain amount of sour cherry fruit was purchased from local markets. First, the fruits were washed, cleaned and cored. The prepared fruits were then dewatered using an electric juicer. In order to separate pulp suspensions and tissue components, the extracted juice was poured into a centrifuge with the speed of 6000 rpm for 20 min. For complete separation of the remaining suspended particles, the transparent portion of the extract was passed through a Whatman filter paper using a vacuum pump (Mehmandoost et al., 2011). Afterwards, the samples were poured into a reactor with diameter and height of 80 and 50 mm, respectively. It is necessary to mention that the dimensions of the reactor were optimized during pretests. Probe design: One of the most common types of horns used for ultrasonic machining technologies is step type horn (Naď, 2010). For obtaining the governing equations on deformation along the step type horn in steady state conditions, Eq. (1) was used. In the solution of the mentioned differential equation, the answers are divided into two subsets and each of the answers is obtained considering the boundary conditions (Hosseinzadeh et al., 2013): (1) c^2.[(∂S/∂x)/(S(x)).(∂u(x,t))/∂x+(∂^2 u(x,t))/〖∂x〗^2 ]=(∂^2 u(x,t))/〖∂t〗^2 From Eq. (1), it can be concluded that: (2) u(x,t)=(A cos⁡〖ωx/c〗+B sin⁡〖ωx/c)(C cos⁡〖ωt+D sin⁡ωt 〗 〗) The boundary conditions for Eq. (2) are written as follows: (3) {■(a) (∂u(x))/∂x=0,x=0@b) (∂u(x))/∂x=0,x=l@c) u(0)=u_in )} One of the most important parts in probe design is preventing stress concentration in locations in which the area changes. To avoid this problem, the displacement in this section must be equal to zero (Hosseinzadeh et al., 2013). For obtaining the probe length, the displacement equation and the l1 parameter are used: σ=-E.u_in.ω/c.sin⁡〖(ω.x)/c〗 (4) In order to determine the maximum axial stress in step type probe, Eq. (3) and (4) are derived and set equal to zero. Therefore, the maximum stress will be equal to: σ_max=π.E.u_in/l (5) Optimization and Modeling using Response Surface Method: Response surface methodology (RSM) has an important application in the design, development and formulation of new products, as well as in the improvement of existing product designs. It defines the effect of the independent variables, alone or in combination, on processes. In addition, to analyzing the effects of the independent variables, this experimental methodology generates a mathematical model which describes the chemical or biochemical processes (Anjum et al., 1997, Halim et al., 2009). In order to obtain the optimum value, Eq. (1) will be used: (6) Y_i=β_0+∑▒〖β_i X_i+∑▒〖β_ij X_i X_j+〗〗 ∑▒〖β_ij X_i^2 〗+ε where, β0, βj, βij, βjj are regression coefficients for intercept, linear, interaction and quadratic coefficients, respectively, while Xi and Xj are coded independent variables and ε is the error. For this purpose, four factors of ultrasonic power (200 to 600 W), wave exposure time (5 to 15 min), probe diameter (20 to 40 mm), and probe penetration depth in sour cherry juice container (0 to 40 mm) were selected. First, the probes with the desired diameters were designed using the related formulas by using CAD-CAM. Results and Discussion: Surface Method (RSM) indicated that the quadratic model with 0.96 coefficient of friction, standard error of 1545.3, and coefficient of variation of 14% is the best model for estimating the number of E.coli bacteria among the different studied treatments. The results showed that with increasing probe diameter and probe depth, the destructive effects of ultrasonic wave increase. It was also revealed that as the probe diameter and penetration depth increase, the destructive effect of ultrasonic wave is initially increased and then follows by a decreasing trend. With the increasing power of ultrasonic, ultrasonic intensity increases and leads to reducing number of E.coli in sour cherry juice. The increase in time of treatment with ultrasonic causes a decrease in the number of E.coli in sour cherry juice. This is due to the fact that the increase of ultrasonic exposure time leads to the increase of sonic stream in reactor and results in higher contributions of ultrasonic waves to E.coli. Finally, the examined variables were optimized by RSM and the values of ultrasonic power, waves exposing time, probe diameter, and probe penetration depth were obtained as 600 W, 15 min, 35.31 mm, 20.83 mm, respectively. Considering the mentioned values, the amount of E.coli bacteria reduction was estimated to be 1.97 logarithmic period. Conclusions: 1. Increasing probe diameter and probe depth increasesthe destructive effect of ultrasonic wave. 2. The examined variables were optimized by RSM and the values of ultrasonic power, waves exposure time, probe diameter, and probe penetration depth were obtained as 600W, 15 min, 35.31 mm, 20.83 mm, respectively. Considering the optimum values, the amount of E.coli bacteria reduction was estimated to be 1.97 logarithmic period. 3. With the increasing power of ultrasonic waves, ultrasonic intensity increases and leads to a reduction of the number of E.coli in sour cherry juice. 4. The increase in time of treatment with ultrasonic causesa decrease in the number of E.coli in sour cherry juice