Inadequate production practices are widely used in aquaculture management, causing excessive water and energy usage, as well as ecological damage. New approaches to sustainable aquaculture attempt to increase production efficiency, while reducing the quantities generated of wastewater and sludge. The sustainable operating techniques are often ineffective, expensive, and difficult to implement. The present article proposes a zero-waste production system, designed for growing fish and vegetables, using a new circular operational concept that creates synergies between fish farming and horticulture. In order to optimize the operational flows with resources, products, and wastes in an integrated zero-waste food production cluster, a business model was designed associating three ecological production practices: a closed fishing pond, a technology for growing vegetables in straw bales, and a composting system. The design had the role to assist the transition toward multiple circular material flows, where the waste can be fully reintegrated into the production processes. A comparative evaluation was conducted in three alternative growing environments, namely, a soilless culture established in straw bales, a culture grown in soil that had received compost fertilizer, and the conventional farming technique. When compared to conventional methods, experiments showed a significant increase in the cluster’s cumulative productivity, resulting in a 12% improvement in energy efficiency, 18% increase in food production, and 25% decrease in operating expenses.
This paper presents theoretical and experimental research studying the influence of process parameters on the quality of biomass pellets. A validated mathematical model was developed, expressing the density of biomass pellets as determined by moisture content, compression pressure, process heat, the initial density of the material, pelleting speed and initial volume of the material. The experiments for determining the influence of these parameters on the compression of biomass into pellets and optimizing the process were conducted on a heated single pellet compression device, using fir sawdust as raw material. To describe and study the process, four input and control parameters were varied—raw material moisture, pelleting speed, maximum force applied and pelleting die temperature. From the experiments, it was noticed that overall, moisture and pressure have the most important effect on the compression process and pelleting speed, and heat applied also affected the process. Pellet density decreased when pelleting speed and material moisture increase and the density increased with a higher compression pressure and higher heat during the process.
Electric boats are evolving, following the trend of imposing electric powered vehicles in all transportation solutions. For a research project, a reed and aquatic weed harvester, the author’s goal is to develop an experimental electrical vehicle aimed at solving several particular problems such as: small speed, big throttle, high maneuverability, big load capacity, small draught and affordable cost. The solution comprises of one electric motor powered by a converter supplied from Li-Ion batteries, which drives a hydraulic pump for simultaneous operation of two lateral-placed paddle wheels and one complex mechanism of cutter and conveyor. The control system of this vehicle consists of one remote controller, with bidirectional radio communication to three on-board controllers used for the management of the electro-hydraulic actuators, the electric motor and the battery storage system. The hardware and the software architectures are presented, underlining the automated operations designed to increase the safety, the maneuverability and the predictability of the vehicle. The advantages of the use of control electronics is the increasing operability of the vehicle by supervising the available stored energy and the predicted consumption of energy, the fast and remote assistance in case of operational failure using online diagnose and the operation optimization by selecting the best load profile for the cutter and for the paddles. The results of this research are the validation of the proposed hardware and software architectures used for the control of an electro-hydraulic vehicle and the feasibility of using radio communication and remote diagnose for vehicle control.
In agrotechnical practice, it was found that between qualitative indices, which express the sowing precision achieved by precision planters determined in the laboratory, and those determined under operating conditions, that there are certain differences, which are sometimes quite significant. The decrease in the value of the quality indices was manifested by the increase of the number of mistakes, either of the number of double planting holes (with at least two seeds), or of the number of missing planting holes. Both cases are unfavorable for the agricultural producer, generating production losses. This paper discusses the influence of the degree of soil grinding on sowing precision in operating conditions, by determining the spectrum of the vibrations induced in the mechanical structure of row units of a precision planter in contact with the soil of three different plots for three working speeds: 4, 6, and 8 km·h−1. Later, the vibrations were simulated under laboratory conditions, on the stand, by means of rubber hemispheres (with diameters between 30 and 100 mm, corresponding to soil fractions resulting from the determination of the degree of soil grinding) mounted on rubber bands, which actuated the seed meters, for testing under an accelerated regime, outside of the optimal agricultural periods (out of season: beginning mid-May until the end of March), in order to obtain the accuracy of the precision planters. It was found that the sowing precision determined in stationary conditions on the stand, and on a plot with an appropriate degree of seedbed preparation, decreased between 2.92% (at 4 km·h−1) and 6.67% (at 8 km·h−1). The main objective of the tests was to reduce labor costs, which was necessary for the staff involved for determining the qualitative indices of work in real field operating conditions, eliminating fuel consumption, while reducing the duration of testing dependent on meteorological factors (season, temperatures, and precipitation, etc.).
Abstract. In many countries, sustainable management, as well as preventing the accumulation and reducing the quantities of waste have become major political priorities, representing an important contribution to the joint efforts to reduce pollution, greenhouse gas emissions and to reduce climate changes at global level. Real actions against global warming represent one of the main priorities of the European energy and environment policies. The European Directives regarding the production of renewable energy, the reduction of GHG emissions and sustainable waste management are based on the commitment of member states to implement adequate measures to fulfil them. The production and use of biogas from anaerobic digestion has the potential to satisfy all the three directives simultaneously. The paper presents an innovative integrated technology for obtaining bioenergy by the means of a mixed system of advanced anaerobic digestion simultaneously in two types of digesters through the process of wet, respectively dry fermentation. The two types of digesters are integrated in a modular system designed and built so that is possible to transport it easily form a micro farm to another. The innovative technology for obtaining biogas through advanced anaerobic digestion will be equipped with a real time command and control system of the methanogenesis process, the necessary energy being ensured by using photovoltaic panels. The results obtained through the innovative technology consisting in a modular system with digesters for wet and dry fermentation of agricultural waste allowed to practically fulfil the concept of farmer energetic independence by using renewable energy sources (biogas, photovoltaic panels, agricultural waste, etc.) and to reduce GHG through the controlled neutralization of important quantities of agricultural waste that otherwise would generate important CO 2 quantities into the atmosphere.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.