خيارات البحث
النتائج 1 - 10 من 11
Does long-term fungicide exposure affect the reproductive performance of leaf-shredders? A partial life-cycle study using Hyalella azteca
2017
Baudy, Patrick | Zubrod, Jochen P. | Konschak, Marco | Weil, Mirco | Schulz, Ralf | Bundschuh, Mirco
Leaf-shredding amphipods play a critical role in the ecosystem function of leaf litter breakdown, a key process in many low order streams. Fungicides, however, may adversely influence shredders' behavior and the functions they provide, while there is only limited knowledge concerning effects on their reproductive performance. To assess the latter, a semi-static 56-day partial life-cycle bioassay using the model shredder Hyalella azteca (n = 30) was performed applying two environmentally relevant concentrations of a model fungicide mixture (i.e., 5 and 25 μg/L) composed of five fungicides with different modes of toxic action. Variables related to the food processing (leaf consumption and feces production), growth (body length and dry weight), energy reserves (lipid content), and reproduction (amplexus pairs, number and length of offspring) were determined to understand potential implications in the organisms' energy budget. While the fungicides did not affect leaf consumption, both fungicide treatments significantly reduced amphipods' feces production (∼20%) compared to the control. This observation suggests an increased food utilization to counteract the elevated and stress-related energy demand: although growth as well as energy reserves were unaffected, amplexus pairs were less frequently observed in both fungicide treatments (∼50–100%) suggesting a tradeoff regarding energy allocation favoring the maintenance of fundamental functions at the organism level over reproduction. As a result, the time to release of first offspring was delayed in both fungicide treatments (7 and 14 days) and the median number of offspring was significantly lower in the 25-μg/L treatment (100%), whereas offspring length remained unaffected. The results of this study thus indicate that chronic fungicide exposures can negatively impact shredders' reproductive performance. This may translate into lower abundances and thus a reduced contribution to leaf litter breakdown in fungicide-impacted streams with potentially far-reaching consequences for detritus-based food webs.
اظهر المزيد [+] اقل [-]The potential impact of unsaturation degree of the biodiesels obtained from beverage and food processing biomass streams on the performance, combustion and emission characteristics in a single-cylinder CI engine
2019
Chelladorai, Prabhu | Varuvel, Edwin Geo | Martin, Leenus Jesu | Nagalingam, Bedhannan
The purpose of this study is to experimentally investigate the effect of unsaturation of the biodiesels obtained from grapeseed oil, wheat germ oil and coconut oil (reference fuel) for compression ignition (CI) engine application. Fatty acid profile analysis and physio-chemical properties were determined by standard test procedures. Engine testing was carried out in a 5.2-kW single-cylinder CI engine and the combustion, performance and emission characteristics were analysed. The effect of fuel property variation and the combustion reaction kinetics due to unsaturation difference have been discussed. The maximum brake thermal efficiency at full load for diesel was found to be 32.3% followed by 31.3%, 30.2% and 27.4 %, respectively, for coconut biodiesel (CBD), grapeseed biodiesel (GSBD) and wheat germ biodiesel (WGBD). Maximum heat release rate as observed for diesel, CBD, GSBD and WGBD are 63.2 J/°CA 60.7 J/°CA and 59 J/°CA and 43.4 J/°CA respectively. The brake-specific NO emission at full load is higher for CBD followed by GSBD, WGBD and diesel having values of 9.23 g/kWh, 8.91 g/kWh, 8.21 g/kWh and 7.6 g/kWh respectively. Conversely, the smoke emission is lower for CBD compared to the other tested fuels.
اظهر المزيد [+] اقل [-]Detoxification effects of phytonutrients against environmental toxicants and sharing of clinical experience on practical applications
2017
Chung, Raymond Tsz Man
According to the Food and Health Bureau and Trade and Industry Department of the Hong Kong Government, 90 % of the total food supply in Hong Kong was imported from the Mainland China. In addition, the hidden or illegal use of prohibited pesticides, food adulteration (e.g., using industrial salt in food processing, using gutter oil as cooking oil), and pollutions were periodically reported by the media. Excessive exposure to toxic heavy metals or persistent organic pollutants (POPs) from diet or environmental is inevitable amid industrialization and pollution. Understanding of the detoxification ability among nutrients in plant-based food (i.e., phytonutrients in green tea, onion, garlic, coriander, and turmeric) offers therapeutic and preventive effects against the poisoning effects due to these pollutants. Oxidative stress and pro-inflammatory actions are the common mechanisms for heavy metals or POPs toxicities, while phytonutrients counteracts these cellular insults by anti-oxidation, upregulation of anti-inflammatory pathways, and chelation.
اظهر المزيد [+] اقل [-]Extraction of sage and coriander seed using near-critical carbon dioxide
1997
Catchpole, O.J. | Grey, J.B. | Smallfield, B.M.
Extraction of dried sage and coriander seed was carried out using near critical carbon dioxide to obtain oleoresin, non-volatile oil and essential oil extracts. Extractions were carried out in both a 4 litre and 75 litre extraction plant, to determine the effects of the particle size, carbon dioxide flow rate, bulk density and extraction temperature and pressure on the yield and extraction time. The rate of extraction of oleoresin from sage depended only on the particle diameter, and was limited by intra-particle diffusion. The rate of extraction of non-volatile oil from coriander seed was limited both by its solubility in carbon dioxide, and intra-particle diffusion. The results were satisfactorily correlated with a mathematical model. Scale-up calculations were performed to enable the economics of the extraction process to be evaluated.
اظهر المزيد [+] اقل [-]Supercritical fluid extraction with reflux for citrus oil processing
1997
Sato, M. | Goto, M. | Kodama, A. | Hirose, T.
Terpenes in citrus oil must be removed to stabilize the products and to dissolve it in aqueous solution. Supercritical fluid extraction has been investigated for the terpeneless citrus oil processing as a lower temperature process. In order to achieve higher yield and higher separation selectivity, a continuous countercurrent extraction with reflux was studied at a temperature of 333 K and a pressure of 8.8 MPa. Cold-pressed orange oil from Brazil and a model mixture of 80% limonene and 20% linalool, where limonene and linalool are principal constituent of terpenes and oxygenated compounds in orange oil, were used as feed and carbon dioxide was used as solvent. Operation at total reflux was carried out to calculate the minimum number of plates required to achieve a separation between limonene and linalool. Effects of the solvent-to-feed ratio, reflux ratio, and feed inlet position on the yield and selectivity were investigated for continuous operation. The selectivity increased with the increase in the solvent-to-feed ratio. Terpeneless citrus oil was obtained on the operation at the higher solvent-to-feed ratio and longer stripping section.
اظهر المزيد [+] اقل [-]The effect of fly ash on sunflower growth and human health
2018
Oncioiu, Ionica | Grecu, Eugenia | Mâşu, Smaranda | Morariu, Florica | Popa, Maria
One of the challenges brought by the circular economy requires a reconsideration of waste, which may under certain circumstances turn into genuine resources. By extension, soil pollution with heavy metal is a major concern since it directly affects the health of the population. The goal of the present research work is to analyze the impact of the use of waste from other technological processes in agriculture: fly ash (resulting ash from thermal power plants), zeolite bush (resulting from the processing of rock from zeolite quarries), and manure (garbage from zoo technical farms). In this respect, complex treatments based on inorganic substances (fly ash and volcanic indigenous tuff with 70% clinoptilolite) were applied to less-favored agricultural soils in the absence and in the presence of an organic fertilizer (manure), respectively. After cultivating sunflower (Helianthus annuus L.), a semi-early hybrid grown in the type of soil on which fly ash has been applied, there have been obtained seed crops 15.8% higher than the seed crops grown in the soil on which no fertilizer has been applied. The results obtained when combining fly ash and manure tend to amount to those obtained when combining manure with indigenous volcanic tuff with 70% clinoptilolite. The quality of the seed crops, obtained in the case of the three types of soil on which amendments were added in the absence/presence of the fertilizer, corresponds to the requirements of the national rules and allows their food processing.
اظهر المزيد [+] اقل [-]Occurrence and transformations of carbon, nitrogen, and phosphorus related to particle size fraction of sweet potato starch wastewater during hydrolytic acidification processes
2017
Zhu, Haixiao | Qin, Long | Hu, Yue | Wei, Dongyang | Hai, Zibin | Li, Aimin | Xie, Xianchuan | Han, Chao
Sweet potato starch wastewater (SPSW) is an industrial food-processing waste product, which is a significant pollution source due to its high chemical oxygen demand (COD), nitrogen, and phosphorus loads. The influence of hydrolytic acidification (HA) process on C, N, and P as well as other main parameters were evaluated. It is essential to treat these wastewaters with effective methods such as HA, a general pretreatment application. In this study, we investigate the scientific link between the changes of different fractions of C, N, and P with particle size distribution in response to the newly introduced HA process. Results showed that the levels of COD, TN, and TP remained ultimately stable; pH and suspended solids (SSs) decreased obviously. HA process exhibits excellent capability of reducing the larger particulars (with diameter of >5 μm) into smaller ones (with diameter of <0.1 μm). The most significant initial concentration contribution to COD, TN, and TP pollution came from particles and matter with a diameter of >5 μm, at 41.8, 57.3, and 43.5%, respectively. While the most significant contribution to COD, TN, and TP was resulting from micro-molecular size particles (<0.1 μm) after 48 h. The smallest particles (<0.1 μm) were the most dominant contribution to all pollutants measured, with COD, TN, and TP contributions of 63.2, 50.4, and 59.3%, respectively. While the contribution of larger particles (particle size >5 μm) reduced to 10.2, 15.3, and 7.1%, respectively.
اظهر المزيد [+] اقل [-]Thermodynamic analysis of fatty acid harvesting by novel carbon-based adsorbent
2016
Do, Quoc Cuong | Kang, Seoktae
In this study, separation and concentration of fatty acids (FA) from the synthetic food processing wastewater containing low concentration of FA (250 mg/L) were investigated using expanded graphite (EG) as a novel adsorbent at different temperatures (298~318 K). The adsorption results were further analyzed to verify adsorption mechanisms and thermodynamics of FA onto EG. Results show that the adsorption of FA onto EG was explained well by the Langmuir model with the maximum adsorption capacity up to 8.01 g FA/g EG at 298 K, and considerably affected by temperature. The adsorption kinetics fitted with pseudo-second-order kinetic model and the adsorption mechanism analysis showed that the intraparticle diffusion was not the rate-limiting step, but the coalescence of FA droplets played the significant role for novel adsorption of FA onto EG. The calculated activation energy and thermodynamic parameters such as Gibbs free energy change (ΔG⁰), enthalpy change (ΔH⁰), and entropy change (ΔS⁰) indicated that the adsorption of FA onto EG was very feasible, was highly spontaneous, occurred physically, was exothermic in nature, and was stable in aquatic environmental changes. Overall, FA can be effectively harvested and concentrated from the food processing wastewater by EG even at low concentration.
اظهر المزيد [+] اقل [-]Residue dissipation, evaluation of processing factor and safety assessment of hexythiazox and bifenazate residues during drying of grape to raisin
2020
Thekkumpurath, Ahammed Shabeer | Girame, Rushali | Hingmire, Sandip | Jadhav, Manjusha | Jain, Prachi
An analytical method for the simultaneous analysis of hexythiazox and bifenazate residues in grape and raisin was validated by liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. The extraction method involved liquid-liquid extraction with ethyl acetate and dSPE cleanup with primary secondary amine (PSA). The drying of grape to raisin may increase or decrease residues of pesticides. During the raisin making process, the dissipation of residue was evaluated and the processing factor (PF) was established for drying. Dissipation data were best fitted to 1ˢᵗ + 1ˢᵗ-order kinetics with a half-life ranging between 6–10 days for hexythiazox and 5–6 days for bifenazate. The PF value for overall raisin making was found to be 0.20–0.36 for hexythiazox and 0.14–0.15 for bifenazate indicating degradation of the residues. However, the PF value varies between 1.13–1.64 for hexythiazox and 0.94–1.12 for bifenazate during the drying process indicating concentration of the residues in drying. The dietary exposure on each sampling day was less than the respective maximum permissible intake (MPI). The residues in market samples of raisins were devoid of any risk of acute toxicity related to dietary exposure. The PF value generated will be useful for the field level management of residues in grape intended for raisin preparation.
اظهر المزيد [+] اقل [-]Phase equilibria of vegetable oils with near-critical fluids
1997
Fuente B, J.C de la | Fornari, T. | Brignole, E.A. | Bottini, S.B.
The application of the SRK equation of state for the prediction of the phase behaviour of mixtures of vegetable oils with near critical solvents is studied. The use of binary interaction parameters in the combinatorial rules for both the co-volume and the energy parameter is discussed. Two different sets of binary interaction parameters are needed in order to correlate the vapor-liquid and liquid-liquid equilibria. This indicates a serious limitation of van der Waals type of equations of state for modeling the phase equilibria of this type of systems.
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