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HighlightsDesiccant-based convective drying systems can remove moisture from agricultural commodities.More than 85% of FlexiDry system’s energy consumption was used for desiccant regeneration.Desiccant regeneration provides an opportunity to switch from natural gas or propane combustion to electricity.Greenhouse gas emissions can be reduced in desiccant drying systems by the increased use of renewable electricity.Abstract. FlexiDry® is a commercially available desiccant-based drying system designed to reduce seed moisture content and promote seed preservation. The purpose of this study was to evaluate FlexiDry in drying 130 kg of whole yellow corn kernels (Zea mays) for large-scale human and animal consumption. FlexiDry was tested in two treatments, using heated (HA) and unheated (UA) air, and compared to conventional heated-air (CHA) drying. The desiccant (Drying Beads) was regenerated (moisture removed) at 250°C using a furnace within the FlexiDry system. All treatments properly dried the corn below the target value of 15% dry basis moisture content (MD). The CHA and HA treatments yielded an average moisture extraction rate (MER) of 1.42 kg h-1, compared to 0.58 kg h-1 for the UA treatment. In terms of energy consumption, the specific moisture extraction rate (SMER) was 0.20, 0.44, and 1.11 kg kWh-1 for the UA, HA, and CHA treatments, respectively. The coefficient of performance (COP), i.e., the ratio between the theoretical heat delivered and the total energy consumed, was 0.14, 0.30, and 0.75 for the UA, HA, and CHA treatments, respectively. The FlexiDry treatments (HA and UA) consumed more energy than the CHA treatment, with more than 85% of the energy consumption used to regenerate the Drying Beads. The system yielded a global warming potential (GWP) of 0.931 and 0.425 kg CO2-eq kg-1 of water removed for the UA and HA treatments, respectively. These values are higher than the GWP of the U.S. corn industry drying standard, which is reported as 0.383 kg CO2-eq kg-1 water. Thus, if the regeneration process can be optimized, there is potential for reductions in energy intensity and GWP with large-scale, desiccant-based drying of agricultural commodities. Keywords: ,Dehydration, Energy, Food safety, Moisture, Regeneration.

The modern development in unmanned aerial vehicles (UAV) providing aerial imagery attracts researchers to improve the object detection algorithms to be used in various applications. Lightweight object detection models are required for low computational resource devices. This study developed a lightweight object detection model by improving the architecture of YOLOv4 Tiny to detect vehicles from the VEDAI dataset. In the developed model, one additional scale feature map is added to the architecture. Besides that, the sizes of output images for the second and third prediction boxes are upscaled with the aim of detecting the small pixels of vehicles in the aerial imagery with better accuracy. The experimental results showed an improvement in the detection accuracy and precision when compared with several state-of-the-art methods to detect small objects such as vehicles in aerial imagery.

In this paper, the effect of two options (first option: fluidized bed drying (120–160 °C) + sun drying; second option: fluidized bed drying (120–160 °C) + again fluidized bed drying (65 ± 2 °C)) of two-stage drying on kinetics, energy consumption, quality of dried maize as color, nutritional properties, and hardness was evaluated to assess the drying performance. First stage drying for both options was executed by FBD at 7.0 cm bed thickness within the temperature range of 120–160 °C for 1.5–4 min. Then, the samples were tempered for 45 min in a closed container after completion of first stage drying. Second stage drying was then done by sun drying method (temperature: 33–36°C, RH: 52–65%, air velocity 0.4–0.6 m/s) for first option while for second option, it was accomplished again by FBD (65 ± 2°C). Drying time was shorter in the case of second option (2.23 h) than first option (4.98 h). Effective moisture diffusivity was found higher in both options of two-stage drying (10.5 × 10−09 m2/s to 63 × 10−09 m2/s) than control drying. Specific energy consumption was lower in first option compared to second option. Color of dried maize in two-stage options deteriorated markedly. However, nutritional qualities of dried grain for two-stage drying technique were similar to control sample. Hardness of the two-stage dried maize was lesser than control product. The two-stage drying options of maize drying instead of conventional sun drying method can be considered an alternative drying technique for the commercial maize drying industries.

Drying is an important issue for all paddy-producing countries in the world. Paddy drying facts and figures in industrial LSU (Louisiana State University) dryer for the major rice processing areas ...

Groundwater is a crucial natural resource that varies in quality and quantity across Bangladesh. Increased population and urbanization place enormous demands on groundwater supplies, reducing both their quality and quantity. This research aimed to delineate the groundwater potential zone in the Gazipur district, Bangladesh, by integrating eleven thematic layers. Data and information were gathered from Landsat 8, the digital elevation model, the google earth engine, and several ancillary sources. A multi-criterion decision-making (MCDM) based analytical hierarchy process (AHP) was used in a GIS platform to estimate the groundwater potential index. The potential index values were finally classified into five sub-groups: very low, low, moderate, high, and very high to generate a groundwater water potential zone (GWPZ) map. The results show that groundwater potential in about 0.002% (0.026 km2) of the area is very low, 3.83% (63.18 km2) of the area is low, 56.2% (927.05 km2) of the area is medium, 39.25% (647.46 km2) of the area is high, and the rest 0.72% (11.82 km2) of the area is very high. The validation of GWPZ maps based on the groundwater level data at 20 observation wells showed an overall accuracy of 80%. In addition, the ROC curve showed 84% accuracy of GWPZ maps when validated with water inventory points across the study region. Overall, this study presents an easy and practical approach for identifying groundwater potential zones, which may help improve planning and sustainable groundwater resource management.

Evolution of energetic and exergetic performance is an important concern for selecting suitable dryer for any drying process. This paper attempts to observe performance evaluation in terms of energ...

In this paper, the tunability of the fluorescence capacity of ZnS quantum dot (QD) after the effective doping of transition metal iron (Fe) have been studied. The structural, electronic, and optical properties have been optimized for pure and Fe doped ZnS QDs by using local density approximation in density functional theory framework. The optimized lattice volumes show a reasonable agreement with previously obtained experimental and theoretical data for both the doped and un-doped system. As Fe is doped to ZnS, the crystal system transforms from cubic to tetragonal structure with an increased lattice volume compared to the pure system and exhibits a narrow band gap with a negative value. Moreover, the absorption peak is broadened in the ultraviolet to the blue (visible) region and it shows a low intense peak in the infrared region. These results indicate the increase of fluorescence capacity that may be expected to apply for rapid detection of virus-like as SARS CoV-2. © 2021 Wiley Periodicals LLC.

In this paper, the effect of high concentrated Iron (Fe) doping on the structural, electronic and optical properties of Barium Titanate (BaTiO3) based on density functional theory (DFT) are reported. The calculated lattice parameters show that the phase of BaTiO3 transformed into tetragonal from cubic phase after Fe doping. The electronic structure shows that Fe creates some defect states in the energy band which create weak coordinate covalent bond because of metal-metal interaction. The complex dielectric function, absorption, reflectivity, refractive index, optical conductivity and energy-loss spectrum for BaTiO3 and Fe doped BaTiO3 are calculated, and the results show a dramatic behavior near Fermi level after Fe doping.

Compact load cells have been developed using multiwall carbon nanotube/cotton (MWCNT/cotton) composites, whose performance has been optimized by varying the concentration of MWCNTs and the thickness of the composite. The sensitivity of the load cell, which is defined as the ratio of the change in the relative electric resistance to the change in applied pressure, is measured to be in the range of 180-0.20 kPa-1 for applied pressures of 8.84 Pa-884 kPa (F=1.0 mN-100 N). The load cells show a rapid response in situations with a frequently changing force, with response times τ1/2 of 4.5 and 5.0 ms for the application and release of load, respectively. The load cell demonstrates high reproducibility in tests involving more than 11,200 compression/relaxation cycles. It also has high reproducibility in different harsh environments and has a good electric-conductance recovery property. The load cell is successfully used to monitor the time-varying center of gravity of a human foot, which can be applied to the diagnosis of sick and healthy people. The MWCNT/cotton load cells can be used as wearable and flexible devices for monitoring human health.

Internet of Things (IoT) is supposed to be the future form of communication where objects can communicate with each other via the Internet. Due to heterogeneous network technologies and infrastructures, the overall IoT system is getting more complex than the traditional system. This research discusses about integrating SDN in IoT system for better network functionalities in terms of optimization, controlling, dynamic resource management, etc., whereas fog computing provides quick time response for real-time applications with security where computation is done at the edge of the network. Also, adding edge encryption provides better security, privacy, and sharing of sensitive data where data is encrypted before sending to the cloud. Thus, a four-layered IoT architecture is proposed and explained here with two use cases where each layer is capable to respond to specific security requirements as well as open for adding new security frameworks.

The cut quality of sugarcane stems during harvesting is of considerable importance, as any damage inflicted on the stems and root systems affects ratooning and reduces yield. In current conventional cutting systems for sugarcane, relatively little attention has been paid to optimizing the cutting dynamics by investigating various blade designs and configurations. One limitation of impact cutting methods is the relatively rapid blunting of the blade edges through wear, leading to stem damage. This study aimed at investigating the effects on sugarcane cut quality of four base cutter blade designs: a conventional straight blade, a 30° angled blade, a serrated blade, and a straight blade with laser cladding on its underside. Blades of each type were installed at a 45° angle on a base cutter fitted to a John Deere 3520 sugarcane harvester. Stem damage, root system damage, and stubble height were considered as cut quality indicators, and blade wear was evaluated as the percentage of metal mass loss after completing each harvesting operation. In this study, the extent of stem and root system damage was classified into nine categories: (1) undamaged stem, not uprooted, (2) undamaged stem, partially uprooted, (3) undamaged stem, uprooted, (4) partially damaged stem, not uprooted, (5) partially damaged stem, partially uprooted, (6) partially damaged stem, uprooted, (7) severely damaged stem, not uprooted, (8) severely damaged stem, partially uprooted, and (9) severely damaged stem, uprooted. The highest percentage of stems damaged during harvesting (approx. 38%) and the highest percentage of root systems damaged (approx. 36%) occurred with the angled blade. The percentages of undamaged stems for the straight, angled, serrated, and laser clad blades were 76.9%, 62.1%, 83.1%, and 72.3%, respectively; partially damaged stems were 11.25%, 21.97%, 11.29%, and 17.73%, respectively; and severely damaged stems were 11.9%, 15.9%, 5.65%, and 9.9%, respectively. Except for the angled blade, all the blades cut almost 80% of stems without affecting the root system, and only 5% of stems were uprooted. Indices for stem damage and uprooting damage were calculated to evaluate the cut quality on a scale from -1.00 (least damage) to +1.00 (greatest damage). For both indices, the serrated blade had values closest to the target value of -1.00, implying the least damage to stems and root systems. Greater stubble heights (110 mm) were observed for the angled blade, with 76% of cut stems above the target 75 mm threshold, which was selected based on the farmer’s suggestion. Comparatively less stubble height was obtained with the serrated and laser clad blades, and roughly 60% of stems were cut in the ideal range (

Synthesis of plasma polymerized cyclohexane (PPCHex) thin films on to glass substrates has been done using a capacitively coupled parallel plate low-pressure glow discharge technique from cyclohexane at room temperature. From scanning electron microscopy, smooth and homogeneous surface of PPCHex thin films is observed and atomic force microscopic micrographs show the roughness of 0.815 to 0.364 nm which also confirm the smooth, homogenous, pinhole free and uniform surface of the PPCHex thin films. The presence of 73.1 and 74.7 percentage of carbon in PPCHex thin films of thicknesses 220 and 350 nm with a small percentage of oxygen is confirmed by the energy dispersive x-ray analysis. The PPCHex thin film is thermally stable up to about 510 K. The structure of PPCHex thin films is observed to vary with film’s thickness by forming new chemical bonds such as O-H stretching, C=C stretching, C≡C stretching, C-O stretching compared to that of the monomer. Allowed direct band gaps of PPCHex thin films are found between 2.97 and 3.61 eV for different thicknesses and allowed indirect band gaps are found to be 1.83 to 2.31 eV. Therefore, the PPCHex could be used in different type of optoelectronic devices.

Structural, electronic, optical, and thermal properties of undoped and metal, M (Ni, Cu, and Zn), doped cadmium iodide (CdI2) were studied using a generalized gradient approximation of density functional theory. Lattice constants found from the theoretical studies of the structure of the undoped and doped CdI2 are in good agreement with those found in the available experimental and theoretical investigations. A strong mixing of I 5p and M 3d states is found after the doping of 3d M in CdI2, which alters the bandgap from positive to negative. Among all M (Ni, Cu, and Zn), Ni doped CdI2 with a narrow negative bandgap evolve the quantum dot level. Due to interactions between the Cd 4d and M 3d states, the measured optical and thermal properties of the doped system assessed with pure CdI2 indicate unusual behaviors, which suggest that the material can be used in different nano-electronic and electrochemical applications and in biological levels such as detection of COVID-19 pathogens.

Highly sensitive pressure sensors have been developed from multiwall carbon nanotube (MWCNT) coated cotton fibers to utilize them in monitoring of human activities. The sensing mechanism is discussed through experimental and theoretical explanations. The principle of the sensing mechanism is related with the number of contacts among the MWCNT coated fibers and contact area among the fibers when a force is applied. Using the three sensors a foot pressure sensor system has been developed, which can detect the exerted force of human foot during standing, walking, running, jumping, and other activities. The locus of the center of gravity is also measured by these sensors during these human activities. The exerted force increases instantaneously when a person jumps from an upper step of a ladder onto a floor, which is clearly recorded. The foot pressure sensors can be used to monitor the real-time sporting performances. To prevent the ankle and knee injury of sportsmen and to monitor the activities of the patients, and old persons, the foot pressure sensors can be utilized.

High-performance plasma polymerized organic thin films have been synthesized by employing a capacitively coupled glow discharge technique and cyclohexane is used as a precursor material. The surface of the plasma polymerized cyclohexane (PPCHex) thin films observed to be smooth, pinhole free and uniform. It is observed from thermal analysis that the rate of loss of mass is very low in air atmosphere below 510 K and the films are thermally stable. Above 510 K weight loss takes place in different stages in air. The current density of the PPCHex thin films is increased when the thicknesses is decreased and that is increased with increasing temperatures. The conduction mechanism of carrier transport operative in these PPCHex thin film is dominated by Schottky type conduction mechanism. The activation energy of the PPCHex thin films for applied voltage 10 V is found 0.14 ± 0.05 eV near room temperature region and that in the higher temperature region is 0.57 ± 0.04 eV. The activation energy in the Schottky region for the applied voltage 50 V is about 0.16 ± 0.06 eV near the room temperature region and that is 0.83 ± 0.05 eV at the higher temperature region.

Density functional theory based First-principles calculations have been performed to investigate the structural, optical and electronic properties of CuO and Zn doped CuO and compared with experimental results. Calculations are demonstrated by Cambridge Serial Total Energy Package. Calculated values of lattice parameters matched 80% with experimental data of CuO and for Zn doped CuO, there was a 55% match. Figures of electronic band structure, TDOS and PDOS have been computed from the electronic structure of CuO and Zn doped CuO. Significant transition occurs in band gap after Zn doping. Optical properties showed that CuO and Zn doped CuO were transparent, having a small energy gap and maximum reflectivity at infrared region. The real part of refractive index was higher at lower energy region and imaginary part of refractive index was zero at 28 eV photon energy. The calculated value of band gap was in good agreement with the experimental value.

Densities, p, and viscosities, ?, of four binary systems: N,N-dimethyl formamide (DMF) + 1-propanol, DMF + 2-propanol, DMF + butanol and DMF + 1-pentanol have been measured at five different temperatures ranging form 303.15K to 323.15K at an interval of 5K. Excess molar volumes were found to be negative over the entire concentration ranges. The negative excess molar volume decreases with the increase of chain length of alcohol, the magnitude follows the order DMF+ 1-propanol >, + 2-propanol >, +butanol >, + 1-pentanol. The change of viscosity has been found to be sensitive to the chain length of alcohols. Excess viscosities and Grunberg- Nissan interaction parameters have been found to be positive for DMF + 1-propanol and DMF + 2-propanol systems, and negative for other two systems DMF + butanol and DMF + 1-pentanol. The thermodynamic energy of activation; such as, positive ?G#E each also compatible with the observation.

Mango (Mangifera indica) is an important, and popular fruit in Bangladesh. However, the post-harvest processing of it is still mostly performed manually, a situation far from satisfactory, in terms of accuracy and throughput. To automate the grading of mangos (geometry and shape), we developed an image acquisition and processing system to extract projected area, perimeter, and roundness features. In this system, images were acquired using a XGA format color camera of 8-bit gray levels using fluorescent lighting. An image processing algorithm based on region based global thresholding color binarization, combined with median filter and morphological analysis was developed to classify mangos into one of three mass grades such as large, medium, and small. This system achieved an accuracy of 97% for projected area and Feret diameter, 79% for perimeter, and 36% for roundness. To achieve a finer grading, two different grading features could be used in sequence. The image grading system is simple and efficient and can be considered a suitable first stage to mechanizing the commercial grading of mangos in Bangladesh. Moreover, the method has the potential to be applied to other crops with suitable adjustments.

The present study was undertaken in different areas of Tangail district to investigate the presence of haemosporidian parasites in domestic poultry (Chicken, duck and pigeon). A total of 72 samples were examined from December, 2013 to May, 2014. Microscopical examinations of peripheral blood were performed. Among the examined samples, 33(45.8%) poultry were found to be infected with different blood protozoa. Two species of blood protozoa were identified such as Leucocytozoon spp. in chickens (34.6%) and ducks (58.3%); Haemoproteus spp. (22.7%) and Leucocytozoon spp. (22.7%) in pigeons. Female (46.5%) were 1.10 times more susceptible than male (44.8%) which was statistically significant (P

This study was conducted to identify the technical and economical performance of the existing models of maize sheller in the country and suggest the best maize sheller models for the farmers during 3 September 2006 to 30 March 2007 in the area of Bogra, Rangpur, Dinajpur, Rajshahi and Jessore. Detail field tests were conducted on seven selected maize sheller models of three categories to assess the comparative performance. Three basic designs of maize sheller models were identified through field survey and secondary information. The models were Spike-pinion (SP) type, Spiral rasp-bar cylinder (SBC) type and Parallel rasp-bar cylinder (PBC) type. The technical performances of the selected maize sheller models were evaluated on the basis of throughput capacity, shelling capacity, cylinder loss, separating loss, broken kernel and shelling efficiency. The shelling capacity and efficiency of Binimoy and Sarker spike-pinion (SP) type models were found about 0.45 ton/hr and 93%, respectively. Similarly, the shelling capacities and efficiencies of Farida, Rahman and Uttaran spiral rasp-bar cylinder (SBC) models were ranged between 2.8 to 4.0 ton/hr and 93 to 97%, respectively. Farida parallel rasp-bar (PBC) type maize sheller had shown incredible shelling efficiency of about 99% with almost negligible cylinder (0.25%) and separating (0.25%) losses along with lowest broken kernel (2.5%) percentage. However, the shelling capacity was found comparatively low about 1.9 ton/hr. The shelling costs, benefit-cost ratios and net margins of spiral rasp-bar cylinder models vary between Tk. 91-97/ton, 1.28-1.37 and Tk78-134/hr, respectively. Among the models Farida (SBC) appeared as the most economic one having lowest shelling cost of Tk. 91/ton with the highest benefit-cost ratio of 1.37 and net margin of Tk. 134/hr (determined at a custom-hire rate of Tk. 7 per 40 kg of shelled kernel). Comparative economic uses of the selected maize shellers suggest that the use of hand sheller is beneficial up to an annual use of 13 ton. Whereas, Binimoy (SP) and Sarker (SP) models are economic for annual use between 13 and 30 ton, and Farida (SBC), Rahman (SBC) and Uttaran (SBC) models are economic for shelling over 30 ton per annum. Economic analysis suggest that hand sheller could be beneficial for very small farm holdings, Binimoy (SP) and Sarker (SP) models for small farm holdings and Farida (SBC), Rahman (SBC) and Uttaran (SBC) models for medium to large farm holdings and custom-hire service.DOI: http://dx.doi.org/10.3329/pa.v20i1-2.16873 Progress. Agric. 20(1 & 2): 207 – 220, 2009

Department of Farm Power and Machinery, Bangladesh Agricultural University, Mymensingh-2202, Bangladesh(Received: 20 March 2012. Accepted: 10 October 2012)In order to develop fully-automatic grafting robot for tomato seedlings, the machine vision system forsorting grafting seedling and inspecting grafted seedling was studied. In this paper, the devices anddifferent lighting (Front lighting, Backlight, and both Front lighting and Backlight) of machine visionsystem were optimized and selected. The result shows that Blue Backlight without filter device isbest for both sorting and inspecting seedlings. Then the images of sorting and inspecting seedlingswere acquired using the selected machine vision system and processed by the program. Experimentresults show the success rate on processing the images of sorting seedlings can reach 96% andeven the gap of 0.2 mm between scion and rootstock can be found easily when inspecting graftedseedling.

Fluorescence imaging has been used to detect peel defects in many citrus varieties, but not in lemon and yuzu. In this study, we extract and identify fluorescent components from the peel of lemon and yuzu. The characteristics of excitation and fluorescence of these extracted components were determined, and their identity clarified using NMR spectroscopy. Extracted fluorescent components for both lemon and yuzu have a coumarin structure. Two coumarins (5-7-dimethoxycoumarin,5-geranyloxy-7-methoxycoumarin) were identified in lemon and one (5-geranyloxycoumarin) in yuzu. Their excitation and fluorescence wavelength were observed at 320–330 nm and 380–400 nm, respectively. Moreover, when a fluorescence imaging system was set-up with UV-A illumination, it was shown that this systemcan detect peel defects in lemon, and to a lesser extent in yuzu.

Unshu citrus were sorted by fluorescence imaging in a commercial packinghouse and undamaged-appearing unshu that had been rejected by the packinghouse due to fluorescence appearing on their peel were studied. We examined the various visible patterns, based upon fluorescence and microscopic images, to provide a categorization of physical reasons for the observed fluorescence. The categorization classes were: 1) slight physical damage: thin scar, hole and flow, shrunken at calyx; 2) rubbing against decayed fruits; 3) green spots; and 4) rind puffing. The percentage of observation for each of the four classes was 22 %, 15 %, 42 % and 21 %, respectively. Storage of the classes indicated that, except for the green spot class, the injured area expanded quickly and caused the fruits to rot within a week.

Machine vision based automatic crop or weed detection in commercial fields is still an open problem, because of wide variety of plant species and the unstructured lighting condition. The task becomes even more challenging when weeds are prominent and overlap with crops. This paper presents an image processing method for fast discrimination of crops and weeds in fields with high weed infestation levels. Mahalanobis distance was used to classify crop and weed pixels in field images based on their differences in hue and saturation. A Naive Bayes classifier was built to compare with the Mahalanobis distance based classifier. 80 images (100 by 100 pixels) of celery cabbage, broccoli and weeds were used to train and evaluate the method. Evaluation result showed that this method correctly discriminated 68.0% of crop pixels and 83.2% weed pixels in celery cabbage and weed images, and 97.0% of crop pixels and 99.7% of weed pixels in broccoli and weed images. The average time requirement for processing each 100-by-100-pixel image was 9.7 ms. Compared with the Naive Bayes classifier, the Mahalanobis distance based classifier was more suitable to address the problem of this study. In addition, this method was built into a crop detection method designed in our previous work. A series of 15 field images of broccoli with high weed pressure were used to test the combined method. The results indicated that the combined method correctly detected 93.6% of the cops, a significant improvement over the previous method.

A study was conducted to investigate the best wavelengths for fluorescence excitation and the resulting fluorescence wavelengths in the range of 300-700 nm with citrus peels taken from 15 varieties, which are concerned with detection of surface defects of citrus fruits. Characteristics of UV absorbance, excitation and fluorescence spectra were observed by variety, and principle components analysis (PCA) and discriminate analysis (DA) were used to categorize the citrus varieties by fluorescence intensity levels in order to give some tips for optimizing the fluorescence imaging based machine vision system. The observed proper excitation wavelength for best fluorescence emmision and resulting peak fluorescence wavelength varied variety to variety and ranged from 350 to 380 nm and 490 to 540 nm respectively. The selected varieties of citrus were categorized successfully into four groups of known fluorescence level, namely strong, medium, weak and no fluorescence groups.