Discharge Outlet Research Articles

Justifying the Operation Parameters of a Robotic Cassette Loading Device of the Carousel Type for a Selection Seeder

Introduction. The development and implementation of automated and robotic machines and devices for performing works on selection and seed production of grain and other crops creates conditions for increasing productivity and reducing labor intensity of work and contributes to increasing the production volume of domestic crop seeds. For sowing crops at the 2nd stage of selection work, there are used cassette seeders, which have special loading devices for feeding cassettes with seeds divided into portions to autonomous seeding units, the number of which corresponds to the number of cells in the cassette. The robotic cassette loading device of selection seeders is designed for successive movement of cassettes with seeds to the seeding units and for feeding cassette blocks to the working area according to a specified program when performing the technological process of sowing on seed plots for breeding grain, leguminous and other crops. In this case, there must be ensured strict coordination of the robotic cassette loading device and seeder seeding units operation and for this it is necessary to justify the engineering parameters of the robotic cassette loading device taking into account its design.Aim of the Study. The study is aimed at analyzing the robotic cassette loading device operation in the interaction system between the seeder working parts during the technological process of sowing crops on selection breeding plots and justifying the parameters of the robotic cassette loading device of the carousel type for loading the selection seeder seeding units.Materials and Methods. To determine the parameters of the robotic cassette loading device, there were used physical and mathematical dependencies describing the operation of the robotic cassette loading device in various modes during selection sowing of grain and other crops at the second stage of work.Results. There were substantiated the parameters of the robotic cassette loading device of the carousel type for two operating modes: feeding cassettes in the working area to the discharge outlets of the work table and feeding a block of cassettes into the working area. There were calculated parameters of the manipulator mechanisms. For the actuator moving the cassettes, the minimum force is 7.2 N, the rod length is 700 mm, the rod speed is 60 mm/s, and for the electric motor rotating the robotic cassette loading device moving platform, the rotation frequency of the output shaft is 10 r/pm, the minimum required power on the output shaft of the moving platform drive is 55.7 W.Discussion and Conclusion. There were determined the engineering parameters of the robotic cassette loading device of the carousel type for loading the seeding units of a selection seeder at the 2nd stage of selection work. The calculation of the cassette feed speed of 0.033 m/s during the main sowing operation was carried out for the initial parameters: the seeder operating speed of 3.0 km/h, the plot length of 1 m and the length of the inter-tier path 0.5 m. For the cassette block feed mode, there was calculated the angular velocity of rotation of the moving platform (1.05 radians per second), at which the cassette block feed will take 1 second.

Impact of offshore energy activities on trace elements content and mobility in marine sediments.

The offshore oilfields in the North Sea area are increasingly employed for projects beyond oil production, like carbon capture and storage (CCS). Still, the fossil fuel production from mature fields is significant. It has raised environmental concerns associated with discharging produced waters (PW) and drilling mud into the sea. These discharges, which may be highly saline and contain production chemicals, vary significantly in metals and particulate content. Due to density and release depth, the plume is assumed to sink towards the seafloor. Also, a single oilfield can input up to 7.5 tons of Ba, 675kg of Fe, and 619kg of P into the water column through PW. Therefore, this study investigates the impact of these discharges on seafloor sediments around two Danish oilfields, assesses the mobility of metals within these sediments, and evaluates the environmental status. PW samples were collected at the discharge outlets from the platforms. Sediment cores were taken near the two oil platforms and from control sites. Using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and an optimized BCR sequential extraction, we analyzed the composition and distribution of 24 elements in sediment samples. The results revealed significant differences in total extracted concentrations between sediments near the platforms and those from distant locations and stratigraphically older samples, with relevant levels of Br, Ba, and Sn near the platforms (averaged 14, 27, and 0.1ppb, respectively). Sediment quality indices showed considerable enrichment and geo-accumulation of toxic metals, particularly at one of the platform sites. However, cumulative indices did not display significant pollution anomalies. Therefore, our findings suggest that oil extraction activities may increase the availability of toxic metals in nearby sediments, potentially impacting marine ecosystems.

Smart Monitoring Method for Land-Based Sources of Marine Outfalls Based on an Improved YOLOv8 Model

Land-based sources of marine outfalls are a major source of marine pollution. The monitoring of land-based sources of marine outfalls is an important means for marine environmental protection and governance. Traditional on-site manual monitoring methods are inefficient, expensive, and constrained by geographic conditions. Satellite remote sensing spectral analysis methods can only identify pollutant plumes and are affected by discharge timing and cloud/fog interference. Therefore, we propose a smart monitoring method for land-based sources of marine outfalls based on an improved YOLOv8 model, using unmanned aerial vehicles (UAVs). This method can accurately identify and classify marine outfalls, offering high practical application value. Inspired by the sparse sampling method in compressed sensing, we incorporated a multi-scale dilated attention mechanism into the model and integrated dynamic snake convolutions into the C2f module. This approach enhanced the model’s detection capability for occluded and complex-feature targets while constraining the increase in computational load. Additionally, we proposed a new loss calculation method by combining Inner-IoU (Intersection over Union) and MPDIoU (IoU with Minimum Points Distance), which further improved the model’s regression speed and its ability to predict multi-scale targets. The final experimental results show that the improved model achieved an mAP50 (mean Average Precision at 50) of 87.0%, representing a 3.4% increase from the original model, effectively enabling the smart monitoring of land-based marine discharge outlets.

Autofluorescence-guided Removal of Bacterial Biofilms from Tissues Using Cold Atmospheric Pressure Plasma (CAP).

Cold atmospheric pressure plasma (CAP) has the potential to completely remove biofilms from surfaces. The goal of this study is to employ the autofluorescence nature of bacterial biofilms to guide the removal of these biofilms using a CAP scalpel. Pseudomonas fluorescens biofilms, which produce a green fluorescence under 405 nm UV light, were grown on 12 chicken samples. The tissue model (chicken tissue) is placed on a motorized X-Y stage with the plasma discharge device directly above the sample. Fluorescent-guided CAP treatment of biofilm regions was carried out using a 1.37 lpm Ar/H2O plasma device with 39.5 × 54 mm2 dimension and a 1 * 0.6 mm2 plasma discharge outlet with discharge speed was 1 mm/s and sample distance of 4 mm. The discharge voltage and current were 3.24 kV and 1.2 mA respectively. Results based on analysis of the fluorescent images show that 97% biofilm removal; CFU analysis confirms that up to 99.98% of the bacteria are now absent from the tissue's surface. This is the first instance of two new applications: using cold atmospheric plasma (CAP) to remove bacterial biofilms from soft tissues and employing CAP in an image-guided procedure.

Identifying the Layout of Retrofitted Rainwater Harvesting Systems with Passive Release for the Dual Purposes of Water Supply and Stormwater Management in Northern Taiwan

Due to its unique climate and geography, Taiwan experiences abundant rainfall but still faces significant water scarcity. As a result, rainwater harvesting systems (RWHSs) have been recognized as potential water resources within both water legal and green building policies. However, the effects of climate change—manifested in more frequent extreme rainfall events and uneven rainfall distribution—have heightened the risks of both droughts and floods. This underscores the need to retrofit existing RWHSs to function as stormwater management tools and water supply sources. In Taiwan, the use of simple and cost-effective passive release systems is particularly suitable for such retrofits. Four key considerations are central to designing passive release RWHSs: the type of discharge outlet, the size of the outlet, the location of the outlet, and the system’s operational strategy. This study analyzes three commonly used outlet types—namely, the orifice, short stub fitting, and drainage pipe. Their respective discharge flow formulas and design charts have been developed and compared. To determine the appropriate outlet size, design storms with 2-, 5-, and 10-year return periods in the Taipei area were utilized to examine three different representative buildings. Selected combinations of outlet diameters and five different outlet locations were assessed. Additionally, probably hazardous rainfall events between 2014 and 2023 were used to verify the results obtained from the design storm analysis. Based on these analyses, the short stub fitting outlet type with a 15 mm outlet diameter was selected and verified. For determining the suitable discharge outlet location, a three-step process is recommended. First, the average annual water supply reliability for different scenarios and outlet locations in each representative building is calculated. Using this information, the maximum allowable decline in water supply reliability and the corresponding outlet location can be identified for each scenario. Second, break-even points between average annual water supply and regulated stormwater release curves, as well as the corresponding outlet locations, are identified. Finally, incremental analyses of average annual water supply and regulated stormwater release curves are conducted to determine the suitable outlet location for each scenario and representative building. For the representative detached house (DH), scenario 2, which designates 50% of the tank’s volume as detention space (i.e., the discharge outlet located halfway up the tank), and scenario 3, which designates 75% (i.e., the discharge outlet at one-quarter of the tank height), are the most suitable options. For the four-story building (FSB), the outlet located at one-quarter of the tank’s height is suitable for both scenarios 2 and 3. For the eight-story building (ESB), scenario 2, with the outlet at one-quarter of the tank’s height, and scenario 3, with the outlet at the lowest point on the tank’s side, are preferred. The framework developed in this study provides drainage designers with a systematic method for determining the key parameters in passive-release RWHS design at the household scale.

Spatial distribution and risk assessment of heavy metal pollution from enterprises in China

Heavy metal pollution (HMP) directly affects the safety of agricultural products, thereby impacting human health. Industrial emissions, as the main source of soil HMP in China, require in-depth research on their pollution risks. Based on national heavy metal (HM) enterprise data, this paper analyzes the spatial distribution characteristics of key enterprises involved in the HMP across the country. It constructs the risk assessment index system of enterprise HMP based on the “source-pathway-receptor” (SPR) process of the HMP, evaluates and partitions the risk of the HMP from enterprises nationwide. The results show that: (1) Enterprises and pollutant discharge outlets are mainly distributed in the eastern and southeastern coastal regions. Jiangxi, Yunnan, Guangdong, and Hunan Province are the main distribution regions of smelting enterprises, with the most types of HM pollutants. The hazard of pollution sources shows a spatial distribution pattern of higher risk in the southwest and north, and lower risk in the central region. Counties with high-risk pollution sources are mainly distributed in Yunnan, Hunan, Guangdong, Inner Mongolia, and Jiangxi Province. (2) The hazard of pollutant transmission pathways shows a spatial distribution pattern of higher risk in the southeast and lower risk in the central region. About 31.5 % of counties are at extremely high risk, mainly distributed in the southeastern coastal regions of Guangdong, Jiangsu, Zhejiang, Jiangxi, Shandong, and Fujian Province. (3) The vulnerability of the receptors shows significant clustering characteristics in the northeast and central regions. About 3.3 % of counties have a receptor vulnerability level of “extremely high,” mainly distributed in Inner Mongolia, Jilin, Heilongjiang, Liaoning Province in the northeast, as well as Hubei and Jiangsu Province. (4) About 1.55 % of counties nationwide have a comprehensive risk level of the HMP classified as “extremely high,” mainly distributed in Guangdong Province and Inner Mongolia. Additionally, some counties in Yunnan, Hunan, Jiangsu, Jiangxi, and Zhejiang Province have a risk of exceeding pollution standards, requiring further preventive measures to reduce pollution risks in the future. This paper can provide a scientific basis for the prevention and control (P&C) of the HMP in China.

A Method for Real-Time Measurement of the Vertical Vortex at Flood Discharge Outlets Using Ultrasonic Sensors.

In this study, ultrasonic sensors were used to measure the vertical vortex at flood discharge outlets in real time, and numerical simulations and model experiments were conducted. When a sound signal passes through a vortex, its propagation characteristics will change, which helps to determine the existence of the vortex. Moreover, its characteristic parameters can be obtained through inversion. In this paper, first, the theories of acoustic measurement methods were introduced and their feasibility was verified through a comparison between Particle Image Velocimetry (PIV) measurement and numerical simulation results. Then, the Computational Fluid Dynamics (CFD) method was used to simulate the vertical vortex at the flood discharge outlets of hydraulic structures and the simulation data were restored to the actual size at scale. Finally, acoustic numerical simulations of actual vortex data were conducted, and ultrasonic sensors were used to measure the velocity of a simplified vertical vortex model under laboratory conditions. The research results indicate that the acoustic measurement method proposed in this article is effective in the measurement of the characteristic parameters of vertical vortex with a core radius of 0.03~0.05 m and a maximum tangential velocity of 0.5 m/s, the measurement error of the maximum tangential velocity is within 10%.

Process exploration for scale melting and solidifying of municipal solid waste incineration (MSWI) fly ash by horizontal cyclone melting furnace

This study used the horizontal tubular heating furnace to explore the melting potential of circulating fluidized bed (CFB) incinerator fly ash and mechanical grate furnace (MGF) incinerator fly ash. The horizontal cyclone melting furnace was then built to explore further the feasibility of scale melting of MSWI fly ash. The melting characteristic temperature, amorphous content, and heavy metal leaching concentration characterized the melting potential and solidification effect of MSWI fly ash. The experimental results show that the amorphous content of CFB fly ash after melting is up to 92.37%, and the volatilization rate of heavy metals Zn, Pb, and Ni does not exceed 30%. MGF fly ash exhibits the “sintering into shells” phenomenon during heating, and the leaching concentrations of heavy metals Pb in the sintered products still exceed the standard limits. In addition, the volatilization rates of heavy metals Cu, Zn, Cd, Pb, Cr, and Ni in Slag II are above 50%, and the volatilization rate of Cr reaches 85%. So, slag’s amorphous content also affects heavy metals’ volatilization rate. The MSWI fly ash melting characteristic temperature decreases with the decrease of alkalinity value. When the alkalinity value drops to 0.6, the melting characteristic temperature reaches its lowest value. Mixing 80% CFB fly ash or 50% MGF bottom ash into MGF fly ash can significantly enhance the melting potential to reduce hazardous waste. When using the horizontal cyclone melting furnace to process MSWI fly ash on a large scale, MSWI fly ash achieves an excellent melting effect with an amorphous content of over 93% at the positions of the furnace middle section, inner tail cone, slag discharge outlet, and flue gas outlet. The fly ash particles are in motion in the melting furnace, so the particle size distribution affects the melting effect of MSWI fly ash.

Study on the Fluctuating Load Characteristics of the Submerged Radial Gate in the High-Head Flood Discharge Outlet

The fluctuating pressure acting on the radial gate in the high-head flood discharge outlet is the main excitation source of flow-induced vibration. Therefore, this paper delves into the distribution characteristics of fluctuating pressure on the panel of the high-head submerged radial gate based on hydraulic model tests. Hydraulic tests were first conducted to obtain the distribution patterns of time-averaged pressure and the root mean square (RMS) of fluctuating pressure on the radial gate panel. Secondly, the improved complete ensemble empirical mode decomposition with adaptive noise (ICEEMDAN) and HHT method was employed to identify the causes of the fluctuating pressure on the gate panel. Finally, the ICEEMDAN-SSA (the sparrow search algorithm)–LSTM (long short-term memory) method was utilized to achieve accurate prediction of the fluctuating pressure on the gate panel. The results show that the time-averaged pressure in the middle of the gate panel is higher than that at the top and near the bottom edge, which differs significantly from the static pressure distribution. The RMS of the fluctuating pressure near the bottom edge is higher than that in the middle and at the top. The fluctuating pressure acting on the gate panel in the time domain can be regarded as a stationary process. The fluctuating pressure on the gate panel is caused by the combined diffusion and random mixing of multi-scale vortices in the turbulent eddy structure. The ICEEMDAN-SSA-LSTM combined method significantly improves the prediction accuracy of fluctuating pressure on the gate panel compared to the LSTM and ICEEMDAN-LSTM methods.

Assessment of environmental impacts from authorized discharges of tritiated water from the Fukushima site to coastal and offshore regions

In August 2023, the long-planned discharging of radioactive wastewater from the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) started after the confirmation of its feasibility and safety. As this water contains elevated amounts of tritium even after being diluted, a lot of resources have been invested in the monitoring of the Fukushima coastal region where the discharge outlet is located. We compare the first 3H surface activity concentrations from these measurements (up to the end of November 2023) with the available background values to evaluate a possible impact of the long-term discharging on humans and environmental levels of the radionuclide of interest in the same or nearby area. From our results, we can conclude that the joint effect of horizontal and vertical mixing has been significant enough to reduce tritium concentrations at the monitored locations in the region close to the FDNPP port two days after the end of the respective phase of the discharging beyond the detection limit of the applied analytical methods (∼0.3 Bq L−1) which is by five orders of magnitude lower than safety limit for drinking water set by the World Health Organization (WHO). Moreover, the distant correlation analysis showed that tritium concentrations at stations located further than 1.4 km were very close to pre-discharge levels (∼0.4 Bq L−1). We also estimated that the 3H activity concentration in the offshore Fukushima region would be elevated by 0.01 Bq L−1 at maximum over a year of continuous discharging, which is in concordance with the already published modeling papers and much less than the impact of the FDNPP accident in 2011.

Computational Fluid Dynamics Modelling of the Temperature Distribution in Power Plant's Cooling Canal

Seawater used as a heat exchanger in the coal-fired power plant condenser system has a higher water temperature than the natural temperature of seawater. There was an increase in the temperature of the waters around the coal-fired power plant due to the discharge of boiling water reaching 6.50C. According to the regulations in force in Indonesia, the hot water temperature at the water discharge outlet should not be more than 20C of the natural temperature of seawater. The purpose of this study is to predict the pattern of temperature decrease in the temperature of the boiling water along the cooling line. The method used to predict temperature drop patterns along the cooling line uses a 3-dimensional CFD (Computational Fluid Dynamics) modelling approach with the Ansys Fluent 2023 RI application. The K-Epsilon turbulence model was chosen to describe the effect of flow turbulence on temperature changes. The modelling results were validated by comparing the actual measurements of the water temperature field data representing along the cooling line. The results showed that the performance of reducing the temperature of the water increased when passing through the cascade aeration downstream of the channel. The flow of water along the channel tends to be on the lower side, and downstream, the flow is on the left–middle side. The error calculation using MAPE resulted in 9.49%.

Monitoring Dissolved Oxygen Concentrations in the Coastal Waters of Zhejiang Using Landsat-8/9 Imagery

The Zhejiang coastal waters (ZCW), which exhibit various turbidity levels, including low, medium, and high turbidity levels, are vital for regional ecological balance and sustainable marine resource utilization. Dissolved oxygen (DO) significantly affects marine organism survival and ecosystem health, yet there is limited research on remote sensing monitoring of DO in the ZCW, and the underlying mechanisms are unclear. This study addresses this gap by utilizing high-resolution Landsat 8/9 imagery and sea surface temperature (SST) data to develop a multiple linear regression (MLR) model for DO estimation. Compared to previous studies that utilize remote sensing band reflectance data as inputs, the results show that the red and blue bands are more suitable for establishing DO inversion models for such water bodies. The model was applied to analyze variations in the DO concentrations in the ZCW from 2013 to 2023, with a focus on Hangzhou Bay (HZB), Xiangshan Bay (XSB), Sanmen Bay (SMB), and Yueqing Bay (YQB). The temporal and spatial distributions of DO concentrations and their relationships with environmental factors, such as chlorophyll-a (Chl-a) concentrations, total suspended matter (TSM) concentrations, and thermal effluents, are analyzed. The results reveal significant seasonal fluctuations in DO concentrations, which peak in winter (e.g., 9.02 mg/L in HZB) and decrease in summer (e.g., 6.83 mg/L in HZB). Changes in the aquatic environment, particularly in the thermal effluents from the Sanmen Nuclear Power Plant (SNPP), significantly decrease coastal dissolved oxygen (DO) concentrations near drainage outlets. Chl-a and TSM directly or indirectly affect DO concentrations, with notable correlations observed in XSB. This study offers a novel approach for monitoring and managing water quality in the ZCW, facilitating the early detection of potential hypoxia issues in critical zones, such as nuclear power plant heat discharge outlets.

Experimental study on performance and compressor characteristics of transcritical CO2 heat pump system

The accelerated advancement of the economy has led to a heightened focus on the issue of energy conservation and reduced consumption within heat pump systems. An experimental investigation was conducted to analyze the impact of discharge pressure and outlet water temperature on the performance of the transcritical CO2 single-stage heat pump system and vapor injection heat pump system. The experimental results show that the heating capacity first increases and then tends to be constant or even slightly decreases with the increase of discharge pressure in single-stage heat pump system. When subjected to the same operating conditions, the coefficient of performance of vapor injection heat pump system exceeds that of single-stage heat pump system. Compared with single-stage heat pump system, the performance coefficient of vapor injection heat pump system has increased by an average of 6.21% and the heating capacity has increased by an average of 9.54%. Additionally, the volumetric efficiency of the compressor substantially decreases when producing high-temperature hot water. Semi-empirical models for evaluating the compressor performance in both single-stage heat pump system and vapor injection pump system are established through the parameterization of the volumetric efficiency with respect to the pressure ratio and compressor speed. These models effectively forecast compressor performance.

Adaptive control method and experimental study of cone crusher based on aggregate online detection

The size of the discharge outlet of a cone crusher directly impacts the size of the aggregate produced. However, the discharge outlet is still adjusted manually, which has a significant error and affects production efficiency. For this reason, this study proposed an adaptive control method for cone crushers based on aggregate online detection. Firstly, the aggregate image was segmented using an instance segmentation model and the anchor and structure of the model were optimised. Then, this study proposed an evaluation method for quickly and accurately assessing the overall segmentation effect of network models. By comparing the results with those before optimisation, the accuracy of the optimised network model was improved from 0.923 to 0.940. Finally, an adaptive control experiment was conducted based on the online aggregate detection results. The experimental results showed that the discharge particle size distribution of the cone crusher becomes more stable after intelligent control is added, with the variance of the proportion of cumulative gradation at 15 mm decreased from 34.3 to 14.4. These results indicated that the developed adaptive control system effectively controls the fine processing of coarse aggregates and significantly improves the quality of aggregate crushing and processing.

Pebble flow in the HTR-PM reactor core by GPU-DEM simulation: Effect of friction

The high-temperature gas-cooled reactor (HTGR) with spherical fuel elements contains complex pebble flow. The flow behavior of pebbles is influenced by various factors, such as pebble density, friction coefficient, wall structure, and discharge port size. Using a GPU-DEM numerical model, the effects of the friction coefficient on the cyclic loading and unloading of pebbles in the full-scale HTR-PM are studied. Numerical simulations with up to 420,000 spherical pebbles are conducted. Four sets of friction coefficient values are determined for comparative analysis based on experimental measurements. Discharging speed, residence time, stress, porosity, and velocity distribution are quantitatively analyzed. In addition, a comparison with the CT-PFD experiment is carried out to validate the numerical model. The results show that near-wall retention phenomena are observed in the reactor core only when using large friction coefficients. However, using friction coefficient values closer to the measured experimental values, the pebble bed in HTR-PM exhibited good flow characteristics. Furthermore, the friction coefficient also influences the porosity and velocity distribution of the pebble bed, with lower friction coefficients resulting in lower overall stress in the bed. The discharge outlet's influence varies with different friction coefficient values. In summary, this study demonstrates that the value of the friction coefficient has a complex influence on the pebble flow in HTR-PM, which provides important insights for future numerical and experimental studies in this field.

Design, fabrication and evaluation of small-scale disc and drum pulpers for Arabica (Coffea arabica L.) and Robusta (Coffea canephora L.) coffee

This study describes small-scale drum and disc pulpers developed to depulp Arabica and Robusta cherries in line with Benin and Rwandan farmers' needs. The purpose of the machines is to improve the uncontrolled conventional depulping means, which have led to a decline in parchments quality and can discourage coffee farmers. The development of the machines started with the identification of coffee depulping requirements, followed by analytical sizing of the major components, modeling, fabrication and finally testing. The fabricated machines using local material consist mainly of a hopper, depulping unit, discharge outlet, transmission system and a diesel engine, all supported by a rigid frame. The performance parameters of the machines evaluated with three replications of 3 kg for each variety and depulping clearance of 16 and 12 mm for Arabica and Robusta, respectively at 1200 rpm were analysed in GraphPad Prism V10.0.3. The t-test results of the drum pulper showed a mean pulping efficiency of 98.37 ± 0.73 and 85.00 ± 3.81 %, a capacity of 872.3 ± 91.05 and 924.1 ± 108.3 kg/h, a breakage rate of 0.91 ± 0.27 and 0.00 ± 0.00 %, a pulping index of 0.95 ± 0.01 and 0.70 ± 0.07 and a fuel consumption rate of 1.22 ± 0.54 and 0.86 ± 0.072 l/h for Arabica and Robusta, respectively. Whereas, the disc pulper showed a mean pulping efficiency of 75.56 and 87.5 ± 5.63 %, a capacity of 684.4 ± 215.9 and 756.80 ± 91.54 kg/h, a breakage rate of 0.15 ± 0.26 and 0.00 ± 0.00 %, a pulping index of 0.50 ± 0.14 and 0.79 ± 0.89 and a fuel consumption rate of 0.71 ± 0.30 and 0.73 ± 0.16 l/h for Arabica and Robusta, respectively. The drum pulper outperformed the disc pulper considering efficiency, the pulping index, and the mass of unpulped cherries. The performances revealed that smallholders could prefer both machines based on their settings for each coffee variety.

Numerical simulation investigating the impact of regulated underflow rate on the performance of a cyclone with split flow

A novel cyclone design called enhanced cyclone with split flow (ECSF) incorporates bypass flow and underflow to eliminate or suppress localized secondary flow observed in conventional cyclones. The present study aims to investigate the mechanism of ECSF in suppressing localized secondary flow and explore methods for regulating the bottom flow rate. The turbulent characteristics within the ECSF are obtained using Reynolds stress model, while the trajectory of particles is predicted using discrete phase model to derive the separation performance. The accuracy of the simulation model has been validated through experimental verification. The results demonstrated that the full separation efficiency of ECSF for PM10 and PM2.5 remained above 90 % and 70 %, respectively. Moreover, it exhibited an increasing trend with the rise in the full split ratio, eventually stabilizing at approximately 95 % and 77 %, correspondingly, when the full split ratio reached 20 %. The bypass flow and underflow effectively eliminated or suppressed the upper ash ring and processing vortex core (PVC) phenomenon, respectively. However, the exacerbation of the short-circuit flow phenomenon hindered further improvement in separation efficiency beyond a full diversion ratio of 20 %. When the full split ratio is relatively small, particles may accumulate in the discharge pipe, which can be resolved by introducing auxiliary airflow; however, it is crucial to ensure that the flow rate of auxiliary flow does not exceed 14.29 % of that of feed flow to avoid compromising the separation efficiency. Furthermore, the split flow induces an additional reversed vortex within the ECSF, which extends from the overflow pipe to conical section. Its structural characteristics are influenced by both back pressure of discharge outlet and diameter of underflow pipe. To ensure optimal performance of the ECSF, it is recommended that the underflow pipe diameter should not be smaller than that of the outlet in conical section.

Advancing the Engineering Approach to Improving the Quality Cracking Efficiency of Palm Nut Crackiing Machine

A Palm Nut cracking machine with an improved beater configuration was developed to effectively crack Palm Nuts of various species and sizes. This research aim at improving the quality of the Palm kernel recovered at relatively low cost during Palm kernel oil production. Durable materials were acquired locally to fabricate the machine for ease of usage and maintenance, also to make it affordable for small and large scale processors. Basic features of the machine are; hopper, electric motor (prime mower), cracking chamber, cracking beater and discharge outlet. The design of the cracking drum and beater configuration was based on the impact force required to crack the Palm Nut which is a function of Palm Nut shear strength. A 5 hp electric motor was selected based on the power required to effectively operate the machine. The machine was tested with “Tenera” varieties, three nut sizes (14.5, 22.15 and 29.43mm) and five speeds (970, 1200, 1450, 1750 and 2430rpm). Result shows that the change in machine speed significantly (P<0.05) affects all the machine performance irrespective of the Palm Nut size and variety, which agrees with the report of several other researchers. The obtained optimum machine performance values are 14,874 nuts/h, 89.5%, 98% for the machine capacity, quality performance efficiency and cracking efficiency for Tenera variety. The best crop and machine parameter for the optimum performance of the Palm Nutcracker are 29.43 mm and 970 rpm, nut size and machine speed. It was concluded that the overall performance of this developed Palm Nut cracking beater was effective because it fell within the range of 80 to 98% efficiency.

Intelligent Recognition of Coastal Outfall Drainage Based on Sentinel-2/MSI Imagery

In this study, we developed an innovative and self-supervised pretraining approach using Sentinel-2/MSI satellite imagery specifically designed for the intelligent identification of drainage at sea discharge outlets. By integrating the geographical information from remote sensing images into our proposed methodology, we surpassed the classification accuracy of conventional models, such as MoCo (momentum contrast) and BYOL (bootstrap your own latent). Using Sentinel-2/MSI remote sensing imagery, we developed our model through an unsupervised dataset comprising 25,600 images. The model was further refined using a supervised dataset composed of 1100 images. After supervised fine-tuning, the resulting framework yielded an adept model that was capable of classifying outfall drainage with an accuracy rate of 90.54%, facilitating extensive outfall monitoring. A series of ablation experiments affirmed the effectiveness of our enhancement of the training framework, showing a 10.81% improvement in accuracy compared to traditional models. Furthermore, the authenticity of the learned features was further validated using visualization techniques. This study contributes an efficient approach to large-scale monitoring of coastal outfalls, with implications for augmenting environmental protection measures and reducing manual inspection efforts.

Interpretation of Water Quality Using Principal Component Analysis – A Case Study from A Tropical Ramsar Wetland Site Adjacent to the Seafood Processing Facilities

Cluster analysis and PCA were applied for the evaluation of water quality data of vembanad wetland adjacent to the seafood processing facilities. The water samples were collected from ten different stations for a period of two years (2010-2012) on a monthly basis. The stations, S1 -S9 were closely associated with the seafood processing discharge outlets and the S10, was kept as a reference site, which is free from the seafood processing discharge. The physico-chemical parameters (atmospheric and water temperature, TDS, pH, EC, salinity, DO, BOD, alkalinity, COD, hardness and nutrients such as nitrate, phosphate, ammonia and silica) were studied. Hierarchical cluster analysis was performed and dendrogram was generated, which grouped all 10 sampling sites into three statistically significant clusters. Thus, the water quality around the site may be categorized as relatively less polluted, moderately polluted and highly polluted. PCA could extract 6 principal components and they account for 65.79% of the total variance of the original data. The parameters that contributed to the first component include alkalinity, free CO2 , BOD, COD and nutrients. The organic pollution and dumping of waste from the seafood industry altered the water quality significantly. This study illustrates the benefit of multivariate statistical techniques for analyzing and interpretation of complex data sets, and to plan for future studies.