With the rapid development of agriculture in China today, the demand for agricultural machinery is rapidly increasing. A large amount of exhaust gas emissions poses a severe threat to the environment. To better promote engine fuel and air mixing, enhance engine performance, and achieve low emissions, we conducted a numerical study of the pre-chamber and nozzle design in a gasoline engine for an agricultural tractor by using the G-equation method in Converge CFD software. The relevant optimization of the three model parameters in the G-equation was performed using the improved particle swarm algorithm (PSO). The model parameters after optimization by the PSO algorithm were: a1=0.77, b1=2.0, b3=1.0. It was confirmed that the predicted engine performance was enhanced greatly with the pre-chamber system. More importantly, the results reveal that the volume and area ratios of the pre-chamber played a crucial role in the performance of the pre-chamber. Through a series of parametric studies... [more]

There is global pressure to make advanced biofuels profitable. For cellulosic ethanol, three aspects remain as bottlenecks: collection of feedstocks, pretreatment methods, and enzyme production. In this paper, the first aspect is investigated, by addressing the main challenges for the logistics of agricultural residues. A logistic supply chain of corn stover collection and utilization for cellulosic ethanol production in Mexico is proposed, and a cost structure is designed for its estimation. By applying a value chain methodology, seven links and a set of three minimum selling prices (MSPs) of agricultural residues were determined. Furthermore, the harvest index (HI), crop residue index (CRI), nutrient substitution by extraction of agricultural residues, and harvest costs of corn stover were also calculated for a case study. The main results were a HI of 0.45, a CRI of 1.21, and nutrient substitution potential of 7 kg N, 2.2 kg P2O5, and 12.2 kg K2O per ton of corn stover. The set of t... [more]

With the rapid development of China’s economy, China has become the world’s largest carbon emitter. China not only has an obvious growth rate of industrial carbon emissions but also the intensity of agricultural carbon emissions is hovering at a high level. The development of China’s agricultural economy has largely come at the expense of high emissions. Currently, under the background of global warming and difficulty in controlling greenhouse gas emissions, the development of low-carbon agriculture is an important way to realize the harmonious development of the ecological environment and economic growth and to promote the sustainable development of agriculture. The agricultural production efficiency is the main factor affecting the intensity of agricultural carbon emissions. Based on provincial panel data of China from 2010 to 2019, this paper establishes an indicator system and uses the super-efficiency SBM model to measure agricultural production efficiency. The regional agricultur... [more]

This paper presents results that show the effect of hydrothermal carbonization and subsequent cold plasma jet treatment with helium and argon on the structure and sorption properties of a material—spent brewery grain. Treatment of activated carbon, with a cold atmospheric plasma jet, was used comparatively. The effect of activation on the pore structure of the materials was carried out by the volumetric method at low pressure (N2, 77 K). The specific surface area as well as the total pore volume, average pore size, and pore size distribution were determined using different theoretical models. A high improvement in the sorption capacity parameter was obtained for hydrochars after cold atmospheric plasma jet treatment with an increase of 7.5 times (using He) and 11.6 times (using Ar) compared with hydrochars before cold atmospheric plasma jet treatment. The increase in specific surface area was five-fold (He) and fifteen-fold (Ar). For activated carbon, such a large change was not obtain... [more]

The cultivation of perennial wild plant mixtures (WPMs) is becoming increasingly important in Germany for providing sustainably produced bioenergy. However, perennial energy cropping systems always raise the question of how to reclaim the land for arable crops. This study examined this issue by looking at how a former WPM area was returned to arable cropping for an organic farm. From 2013 to 2018, the WPM area was harvested annually in the autumn. From 2019 to 2020, it was co-managed with the surrounding land as a semi-intensive grassland under a three-cut regime. The area was then ploughed in the spring of 2021 to grow silage maize. Weeds were controlled mechanically once. Nevertheless, the perennial wild plant species grew vigorously, with common tansy (Tanacetum vulgare L.) standing out with a total fresh matter share of 29.0%. This maize−WPM mixture achieved a dry matter yield of 15.5 ± 5.5 Mg ha−1, which was notably but not significantly (p < 0.05) lower than that of silage mai... [more]

This paper analyzes the changes in carbon dioxide (CO2) emissions related to energy consumption in the Polish agricultural sector between 2000 and 2019. Based on the Logarithmic Mean Divisia Index (LMDI), the changes in agricultural CO2 emissions are viewed in the context of changes in six factors, i.e., CO2 emission intensity, substitution of fossil fuels, penetration of renewable energies, energy intensity, labor productivity and number of employees. The analysis demonstrated that total energy consumption declined over the study period; this was related to a reduction in the intake of energy derived from solid fossil fuels (−1.05%), crude oil (−1.01%), electricity (−4.89%), and heat (−1.37%), and to an increased consumption of natural gas (5.78%) and biofuels (0.82%). Furthermore, it follows from the analysis that changes in CO2 emissions witnessed in that period were consistent with changes in energy consumption levels; this resulted from a negligible transformation of the energy mi... [more]

Putting glass doors on the display cases of refrigerators is one of the most efficient ways to reduce the energy consumption of supermarkets. However, the glass fogs up when opening the door because of the difference in air temperature inside and outside of the refrigerator, thereby obscuring the view. To defog the glass, anti-sweat heaters (ASHs) are used. In this paper, the power usage of ASHs according to changes in the dew point (DP) inside a supermarket were evaluated for two types of ASH, i.e., the door-frame ASH and the glass ASH. The evaluation was based on measurements of the condensation on the glass doors of vertical display cases, used for the preservation of frozen foodstuffs. A mathematical model of the correlation between the ASH’s power usage and the DP was developed and used for predicting the long-term energy savings. The savings were calculated based on the measured DPs inside the supermarket, which were extrapolated over a longer time period based on their correlati... [more]

Biomass from agriculture is a promising alternative fuel due to its carbon-neutral feature. However, raw biomass does not have properties required for its direct utilization for energy generation. Torrefaction is considered as a pretreatment method to improve the properties of biomass for energy applications. This study was aimed at investigating the effects of torrefaction temperature and residence time on some physical and chemical properties of torrefied corncobs. Therefore, a fixed-bed torrefaction reactor was developed and used in the torrefaction of corncobs. The torrefaction process parameters investigated were the torrefaction temperature (200, 240, and 280 °C) and the residence time (30, 60, and 90 min). The effects of these parameters on the mass loss, grindability, chemical composition, and calorific value of biomass were investigated. It was shown that the mass loss increased with increasing torrefaction temperature and residence time. The grinding throughput of the biomass... [more]

Biogas production is a process with great potential. It uses the biodegradable raw materials of animal, vegetable and municipal waste. The amount of municipal as well as agricultural waste is increasing every year. This waste is an unmanaged and nuisance waste, and using it in biogas plants reduces the amount of waste. Biogas production is part of the EU’s policy to reduce dependence on fossil fuels and use energy from renewable sources (diversification of energy sources). Its importance is certain to increase in the future as energy demand increases. This article deals with the economical use of biodegradable waste for biogas production in Poland and Germany. Both countries have a similar agricultural and municipal waste structure. An agricultural biogas plant is one way of obtaining energy based on renewable energy sources (RES). Energy production from agricultural biogas will allow Poland to meet the 32% obligation imposed by the EU and Germany to continue to be the market leader in... [more]

The yeast Yarrowia lipolytica is an industrially relevant microorganism, which is able to convert low-value wastes into different high-value, bio-based products, such as enzymes, lipids, and other important metabolites. Waste cooking oil (WCO) represents one of the main streams generated in the food supply chain, especially from the domestic sector. The need to avoid its incorrect disposal makes this waste a resource for developing bioprocesses in the perspective of a circular bioeconomy. To this end, the strain Y. lipolytica W29 was used as a platform for the simultaneous production of intracellular lipids and extracellular lipases. Three different minimal media conditions with different pH controls were utilized in a small-scale (50 mL final volume) screening strategy, and the best condition was tested for an up-scaling procedure in higher volumes (800 mL) by selecting the best-performing possibility. The tested media were constituted by YNB media with high nitrogen restriction (1 g... [more]

Understanding and predicting sealing characteristics and containment efficiency as a function of burial depth across sedimentary basins is a prerequisite for safe and secure subsurface storage. Instead of estimators and empirical relationships, this study aimed to delineate data-driven variability domains for non-cemented fine-grained clastic caprocks. Constant rate-of-strain uniaxial compression experiments were performed to measure changes in properties of brine-saturated quartz−clay mixtures. The binary mixtures were prepared by mixing quartz with strongly swelling (smectite) and non-swelling (kaolinite) clays representing end-member clay mineral characteristics. The primary objective was to evaluate the evolution of mudstone properties in the first 2.5 km of burial depth before chemical compaction and cementation. By conducting systematic laboratory tests, variability domains, normal compaction trends, and the boundaries in which characteristics of fine-grained argillaceous caprock... [more]

Combining iron and copper ores can generate an oxygen carrier that has a synergic effect of high temperature resistance and high reactivity. In this work, typical cements available in the market were studied as binders to bind magnetite and chalcopyrite to develop a suitable oxygen carrier for chemical-looping combustion (CLC). A first selection step suggested that an aluminate cement, namely CA70, could favor the generation of oxygen carrier particles having good crushing strength, good particle yield, and high reactivity. The CA70-bonded oxygen carrier was then subjected to cyclic tests with CH4, CO, and H2 in reduction and in air oxidation at temperatures of 850, 900, and 950 °C with gas concentrations of 5, 10, 15, and 20% in a batch-fluidized bed reactor. The increase in temperature promoted the fuel conversion. At 950 °C, the conversions of CH4 and CO reached up to 80.4% and 99.2%, respectively. During more than 30 cycles, the oxygen carrier kept a similar reactivity to the fresh... [more]

Considering the cost-effectiveness of bioethanol production at high temperatures, there is an enduring need to find new thermotolerant ethanologenic yeasts. In this study, a total of eighteen thermotolerant yeasts were isolated from various natural fermented products in Morocco. Ethanol production using 50 g/L glucose or 50 g/L xylose as the sole carbon source revealed potential yeasts with high productivities and volumetric ethanol productivities at high temperatures. Based on molecular identification, the selected thermotolerant fermentative isolates were affiliated with Pichia kudriavzevii, Kluyveromyces marxianus, and Kluyveromyces sp. During the simultaneous saccharification and fermentation of lignocellulosic biomass at a high temperature (42 °C), the designated yeast P. kudriavzevii YSR7 produced an ethanol concentration of 22.36 g/L, 18.2 g/L and 6.34 g/L from 100 g/L barley straw (BS), chickpea straw (CS), and olive tree pruning (OTP), respectively. It also exhibited multi-str... [more]

With increasing climate variability, a sustainable crop production approach remains an indispensable concern across the globe. In this study, P retention/availability of MgCl2.6H2O/KOH modified Douglas fir biochar was assessed. The MgCl2·6H2O/KOH treated Douglas fir biochar was prepared by sequentially treating Douglas fir biochar with magnesium chloride and potassium hydroxide solutions. The biochar’s surface area, pore volume, morphology, and elemental compositions were determined using BET, SEM, SEM/EDS, and powder X-ray analyzes. Both surface area and pore volume were reduced by more than 97% following modification. Similarly, the morphology and elemental compositions changed after modification. The maximum P adsorbed corresponding to Langmuir−Freundlich model was 41.18 mg g−1. P sorption on biochar soil mixture was pH dependent. More studies are required to establish the field applicability of P-laden MgCl2 ·6H2O/KOH-modified Douglas fir biochar as a soil additive.

In-situ biomethanation combines conventional biogas production from the anaerobic digestion (AD) of organic matter with the addition of hydrogen to produce a higher quality biomethane gas. However, challenges surrounding its performance and control could hinder its uptake. To investigate this, an automated rig was designed and operated to study in-situ biomethanation with sewage sludge (SS) and food waste (FW) feedstocks. The effects that were experimentally investigated included the biogas recirculation rate, stirring intensity, and organic loading rate (OLR). All the results highlighted the rate-limiting effect of H2 gas−liquid mass transfer (measured kLa in the range of 43−82 day−1), which was implied by a lack of evidence of hydrogen-induced biological inhibition and a high average equilibrium hydrogen content in the biogas (a volume of 7−37%). At an OLR of 2 g VS L−1day−1, increasing biogas recirculation and mechanical stirring rates improved the methane evolution rate up to 0.17... [more]

In order to reduce the mechanical damage during the kiwifruit picking process, the fruit rate of the picked fruit should be improved. The mechanical properties of the epidermis and interior of the fruit during the harvesting process were studied, so as to analyze the damage principle of the fruit. Firstly, a three-dimensional model of kiwifruit was constructed by point cloud scanning, and the flesh and placenta were filled in order to become a complete kiwifruit model. The elastic modulus, failure stress, and density of the kiwifruit skin, flesh, and placenta were obtained experimentally, and the material properties of the kiwifruit model were endowed with properties. Secondly, the finite element method was used to analyze the epidermis and internal stress of the kiwifruit by simulating the two processes of grabbing kiwifruit and picking to fruit boxes. The results show that the relative error of the simulation and test of the simulated grasping of kiwifruit was 6.42%, and the simulati... [more]

Food packaging systems are continually impacted by the growing demand for minimally processed foods, changing eating habits, and food safety risks. Minimally processed foods are prone to the growth of harmful microbes, compromising quality and safety. As a result, the need for improved food shelf life and protection against foodborne diseases alongside consumer preference for minimally processed foods with no or lesser synthetic additives foster the development of innovative technologies such as antimicrobial packaging. It is a form of active packaging that can release antimicrobial substances to suppress the activities of specific microorganisms, thereby improving food quality and safety during long-term storage. However, antimicrobial packaging continues to be a very challenging technology. This study highlights antimicrobial packaging concepts, providing different antimicrobial substances used in food packaging. We review various types of antimicrobial systems. Emphasis is given to... [more]

Excessive fertilizer application in the cropping industry leads to excessive nitrogen and phosphorus in surrounding water bodies, which causes farmers to increase economic cost and damage the environment. To address the problem, we built a crop-soil runoff soil column test system, setting eight fertilizer application levels for eggplants. Then, crop yield, soil fertility and pollutant concentrations in the receiving water bodies were measured. The process of fertilizer application on the water quality of surrounding receiving water bodies and the rationality of fertilizer application were analyzed. The results showed that crop yield, soil fertility, and pollutant concentrations in the receiving water increased with the increase in fertilizer application. The crop yield stabilized when the fertilizer application amount was higher than 0.12 kg/m2; the concentrations of total nitrogen (TN) and total phosphorus (TP) in the water increased significantly with the increase in fertilizer appli... [more]

In this study, the effects of oven dehydration on chemical and bioactive properties, fatty acids, polyphenolic compounds and minerals of sandal strawberry tree fruit were investigated. While total carotenoid contents of the sandal strawberry tree fruit are determined between 4.20 (120 °C) and 5.43 µg/g (70 °C), tannin amounts of the sandal strawberry tree fruit were recorded between 5.13 (control) and 6.37% (70 and 120 °C). While total phenolic contents of dehydrated sandal strawberry tree fruit were found between 444.16 (120 °C) and 665.13 mgGAE/100 g (control), total flavonoid amounts of dehydrated sandal strawberry tree fruit were recorded between 592.91 (control) and 788.71 mg/100 g (120 °C). Antioxidant activity values of fruit ranged from 4.10 (120 °C) to 7.30 mmol TE/kg (control). Both total phenolic amounts and antioxidant activity values of untreated (control) sandal strawberry tree fruit were found to be higher than dehydrated ones, and a linear relationship was determined be... [more]

Yogurt is known as a healthy food, but some synthetic additives that are commonly added to it can be one of the factors that restricts yogurt’s consumption. The aims of this study were to prepare and evaluate yogurts with the addition of spray-dried, anthocyanin-rich colorant extracted from jabuticaba (Myrciaria cauliflora Mart.) skin. The concentrated extract was spray-dried using maltodextrin (20 g/100 g w/w) as a carrier and added to yogurts in the concentrations of 0.5, 1.0, 1.5, and 2.0 g/100 g w/w. The yogurts were stored for up to 28 days under refrigeration and periodically evaluated. Except for the yogurts to which 1.5 g of extract was added, all samples had a slight pH reduction in the first 7 days of storage. Throughout the yogurts’ storage period, the anthocyanin and a* values were slightly reduced (p < 0.05), indicating some anthocyanin instability. The rheological behavior was typical for yogurts, but the casein gel network was probably disrupted by the jabuticaba extr... [more]

The by-products of the winemaking process can represent chances for the development of new products. This study focused on the “zero waste” strategy development for by-products generated within winemaking from white and red grape varieties cultivated in the north of Portugal. The phytochemical properties of by-products were identified and characterized. Ohmic heating (OH) as a green extraction method was also applied to grape pomace due to their unknown effects on centesimal and phytochemical compositions. Both protein and carbohydrates were shown to be higher in grape bagasse than in stems. Additionally, red bagasse is richer in bioactive compounds (BC) than white bagasse. The sugar content was 21.91 and 11.01 g/100 g of DW in red and white grape bagasse, respectively. The amount of protein was 12.46 g/100 g of DW for red grape bagasse and 13.18 g/100 g of DW for white. Regarding the extraction methods, two fractions were obtained, a liquid fraction and solid (the remainder after the... [more]

As an important production factor of grain production, agricultural machinery can effectively provide a theoretical basis for agricultural modernization development strategies by exploring its impact on grain production capacity and efficiency. This research starts from the two aspects of grain production capacity and grain production efficiency, takes rice, wheat, and corn as the research objects, and uses the C−D production function and Tobit model as the basis, respectively, to establish two impact models of production capacity and production efficiency. At the same time, according to the different emphases of the two models, this research designs different variable systems and finally uses the data from 2017 to 2021 for empirical analysis. The research results show that the influence coefficients of machinery service income and machinery power resource input on the total grain production capacity are 0.0976 and 0.0437, respectively, with a significant positive impact. At the same t... [more]

Madeira wine is produced via spontaneous alcoholic fermentation arrested by ethanol addition. The increasing demand of the wine market has led to the need to standardize the winemaking process. This study focuses on identifying the microbiota of indigenous yeasts present during Madeira wine fermentation and then evaluates the impact of selected indigenous non-Saccharomyces as pure starter culture (Hanseniaspora uvarum, Starmerella bacillaris, Pichia terricola, Pichia fermentans, and Pichia kluyveri) in the chemical and phenolic characterization of Madeira wine production. Results showed that the polyphenol content of the wines was influenced by yeast species, with higher levels found in wines produced by Pichia spp. (ranging from 356.85 to 367.68 mg GAE/L in total polyphenols and 50.52 to 51.50 mg/L in total individual polyphenols through HPLC methods). Antioxidant potential was higher in wines produced with Hanseniaspora uvarum (133.60 mg Trolox/L) and Starmerella bacillaris (137.61 m... [more]

The present paper evaluated the influence of heat treatment (HT) and high-intensity ultrasound (HIUS) on the chemical profile of the Amazon fig (Ficus subapiculata, Moraceae) juices. Antioxidant activity, quantification of carotenoids, total phenolic compounds (TPC), pH, titratable acidity, soluble solids, color and chemical profile (NMR) were evaluated. Treatments did not change the pH (3.4−3.5), titratable acidity (0.044−0.048%) and soluble solids (2.3−2.4 °Brix). The highest antioxidant activity (DPPH, ABTS) and TPC were presented by the HT-treated juice, which was equivalent to 1235 ± 11 µM TE, 1440 ± 13 µM TE and 312 ± 5 mg GAE mL−1, respectively. The treatments influenced the color luminosity according to the L* and a* parameters, while the b* parameter showed no significant change. The L* parameter was elevated in all treated samples compared to the control sample. Analyzing the parameter a* f, it was verified that the sample with thermal treatment (HT) was different from the co... [more]

Runoff from agricultural irrigation is contaminated and loaded with pesticides. Frequent toxic levels of pesticide detection in the ecosystem motivate scientists and engineers to diminish agro-chemicals flowing into the environment. Constructed wetland, CWs, treatments are a sustainable methodology of special interest since it possess a symbiosis value. Flytek (FT) pesticide use has increased at an unprecedented rate for crop production as well as an increase in runoff loaded with Flytek. This study introduces the use of constructed wetlands based on an alum- sludge substrate for the purpose of Flytek (FT) removal performance. The system is based on an adsorption column and a sludge cake coupled with gravel acting as a carrier in order to be an adsorption bed and filtration system for Flytek removal. The structure, morphology and characteristics of the adsorption bed material “alum sludge” were characterized using X-ray diffraction spectroscopy and Scanning Electron Microscope (SEM). A... [more]