Search results for "Micro"
showing 10 items of 23412 documents
Development and characterisation of polymer composite materials with bio-inspired functions
2018
Promocijas darbs ir izstrādāts disertācijas veidā fizikas nozarē materiālu fizikas apakšnozarē. Pētījums tika veikts LU Materiālu mehānikas institūtā. Darbs saistīts ar aktuālu un jaunu pētījumu virzienu: bioinspirēto funkciju tālāku attīstīšanu slodzi nesošos kompozītos. Tās ir mehānisku triecienu vizuālās indikācijas un polimēru matricas vaskulārās pašdziedināšanas funkcijas. Šīs funkcijas tika nodrošinātas, izveidojot viedus slāņus un iebūvējot tos kompozītā. Pētījumā tika noskaidrotas piemērotās pārbaužu secības, attīstītas kvantitatīvas metodes un mehānisks modelis, lai novērtētu jauno funkciju efektivitāti kompozītos. Ir pierādīta funkciju augstā efektivitāte un spēja uzlabot slodzi n…
An Upper Mississippian echinoderm microfauna from the Genicera Formation of northern León (Carboniferous, Cantabrian Mountains, N Spain)
2020
For the first time an echinoderm microfauna is recorded from the cephalopod limestone facies (‘griotte facies’) of the lower Carboniferous (Mississippian) Genicera Fm. (Alba Fm.). The formation is widespread in the Cantabrian Mountains in NW Spain, but the ossicles are from some sections in the surroundings of the Bernesga valley in northern León. They have been derived from insoluble acetic acid residues from samples of the upper and especially of the uppermost part of the formation (Canalón Mb. and Millaró Beds). The microfauna include taxonomically treated wheel-shaped ossicles, sieve-plates and rods of holothurians, goniodonts of ophiocistioids, and ophiuroid and stenuroid skeletal elem…
Endophytic Fungi in Asymptomatic Vitis vinifera L. and their Effects on Plasmopara viticola
2016
During a multi-year study on the life cycle of Plasmopara viticola to assess the typical epidemiology of downy mildew on grapevine (Vitis vinifera) in west Sicily (Italy), several leaves on which the downy mildew had collapsed were found and observed in a vineyard located in Marsala, in Trapani Province. An antagonistic fungus was isolated from these leaves and named A20; through its morphology, it was identified as a hyphomycete belonging to the genus Acremonium. The antagonism of A20 against the asexual and sexual spores of P. viticola, as well as endophytic nature of the genus Acremonium in V. vinifera were confirmed by further studies which have been carried out over the past decade. In…
Characterization of the "viable but nonculturable" (VBNC) state in the wine spoilage yeast Brettanomyces.
2012
Although the viable but not culturable (VBNC) state has been studied in detail in bacteria, it has been suggested that maintenance of viability with loss of culturability also exists in eukaryotic cells, such as in the wine spoilage yeast Brettanomyces. To provide conclusive evidence for the existence of a VBNC state in this yeast, we investigated its capacity to become viable and nonculturable after sulfite stress, and its ability to recover culturability after stressor removal. Sulfite addition induced loss of culturability but maintenance of viability. Increasing the medium pH to decrease the concentration of toxic SO(2) allowed yeast cells to become culturable again, thus demonstrating …
Electrical conductivity of glass fiber-reinforced plastic with nanomodified matrix for damage diagnostic
2021
The electrical conductivity of glass fiber-reinforced plastic (GFRP) with epoxy matrix modified by multiwall carbon nanotubes (MWCNT) was studied. The electrical conductivity of nanomodified lamina and multi-layered GFRP was investigated on several levels using a structural approach. Components of the electrical conductivity tensor for unidirectional-reinforced monolayer were calculated similarly as in micromechanics using the conductivity of the nanomodified matrix. The electrical conductivity of multilayer composite was calculated using laminate theory and compared with values measured experimentally for various fiber orientation angles. Calculated and experimental data were in good agree…
Micro-determination of dithiocarbamates in pesticide formulations using voltammetry
2013
Abstract The purpose of this work was to develop a reliable method for the micro-determination of dithiocarbamates (mancozeb, maneb, propineb, nabam, Na(CH3)2DTC, zineb, ziram, ferbam and thiram) in pesticide formulations for agriculture using adsorptive stripping voltammetry (AdSV). The accuracy of analytical method was valued by analyzing simulate formulation samples prepared by us with known amounts of active ingredients. In addition, the applicability of the AdSV procedure for the analysis of DTCs and EBDTCs in micro-samples was evaluated by estimating its recoveries from spiked commercial formulate samples. The accuracy, valuated as recovery percentage ranged between 85% and 97%. The p…
Complex plant quality—microbiota–population interactions modulate the response of a specialist herbivore to the defence of its host plant
2022
Many specialist herbivores have evolved strategies to cope with plant defences, with gut microbiota potentially participating to such adaptations. In this study, we assessed whether the history of plant use (population origin) and microbiota may interact with plant defence adaptation. We tested whether microbiota enhance the performance of Melitaea cinxia larvae on their host plant, Plantago lanceolata and increase their ability to cope the defensive compounds, iridoid glycosides (IGs). The gut microbiota were significantly affected by both larval population origin and host plant IG level. Contrary to our prediction, impoverishing the microbiota with antibiotic treatment did not reduce larv…
Doslidžennâ bìologìčnoï aktivnostìvtorinnogo ekstraktu zì šrotu travimaterinki zvičajnoï (Origanum vulgare)
2015
Studied the antimicrobial activity of secondary extract from oregano herbs waste (Origanum vulgare)against 7 standard test strains of microrganisms. Minimum bactericidal concentration of the extract to Staphylococcus aureus ATCC 6538 P-is 3.125-6.25 mg/ml and 6.25-12.5 mg/ml to gram-negative bacteria and Candida albicans ATCC 10231.Total antioxidant activity determined by DPPH, secondary extract at a concentration of 400 ug/ml was 92 %. The tested extract had photoprotective activity. Obtained results confirm the perspective of using waste of oregano herbs for making extracts and creation on their basis of pharmaceuticals, veterinary drugs and cosmetics.
Particle balance and return loops for microplastics in a tertiary-level wastewater treatment plant.
2021
Highlights: Dewatering by centrifugation was a step that removed a high number of MPs from the sludge. Sludge retained especially the fibrous microplactics. Reject water transported microplastics inside a wastewater treatment plant. Disc filter-based tertiary treatment ensured removal of 99% of microplastics in wastewater. Microplastics (MPs) from households, stormwater, and various industries are transported to wastewater treatment plants (WWTPs), where a high proportion of them are captured before discharging their residuals to watersheds. Although recent studies have indicated that the removed MPs are mainly retained in wastewater sludge, sludge treatment processes have gained less atten…
The role of microbial ecology during biogas production from renewable energy sources. Characterizing microbial community structures in bioenergy prod…
2019
La Microbiología tiene un rol fundamental en la integración de procesos para la recuperación de nutrientes, energía y agua durante el tratamiento biológico del agua residual. La identificación de los grupos microbiológicos clave, así como de sus dinámicas, ecología y estructuras microbianas, mejorará el entendimiento de los procesos que integran las futuras plantas de recuperación de recursos, conocidas por sus siglas en inglés como Water Resource Recovery Facilities (WRRF). Este conocimiento podría ser de gran utilidad durante la optimización de sistemas anaerobios que recuperan energía a partir de fuentes de biomasa renovables. Hasta la fecha, diferentes estudios han demostrado que la com…