Search results for "mixture"

Nano-demixing as a novel strategy for magnetic field responsive systems: the case of dibutyl phosphate/bis(2-ethylhexyl)amine systems

2016

Pure surfactant liquids and their binary mixtures, owing to the amphiphilic nature of the molecules involved, can exhibit nano-segregation and peculiar transport properties. The possibility of opportunely choosing the amphiphiles should lead to the formation of anisotropic aggregates that can be oriented by an external factor like a magnetic field. In this case some properties, like optical birefringence, can be induced by the use of a magnetic field. Dynamic features of dibutyl phosphate (DBP)/bis(2-ethylhexyl)amine (BEEA) mixtures have been investigated by FT-IR, NMR, rheometry, Brillouin scattering, and magnetically-induced birefringence measurements as a function of the BEEA mole fracti…

Study of elution behaviour with gradient voltage in CEC using methacrylate monolithic columns.

2010

A theoretical study on the retention behaviour and chromatographic performance of neutral solutes using a lauryl methacrylate-based monolithic column under voltage gradient mode in CEC was carried out. Through a flexible mathematical function based on a modified Gaussian model, the peak shape of compounds was firstly fitted under constant and gradient voltage. Using the peak shape parameters and retention time, the estimation of global chromatographic performance, efficiency and peak capacity under several voltage conditions was performed. The influence of voltage gradient on the separation efficiency is discussed and simple equations are presented to calculate retention and peak widths und…

Segmenting customers according to online word-of-mouth about hotels

2021

There is a renewed interest in the study of online word-of-mouth behavior due to the increasing use of the Internet and the development of social networks. This paper focuses on the receiver perspective to analyze the unequal influence of the antecedents of online consumer searches. The main purpose is to detect the heterogeneity of the effect of different motivations (convenience, risks reduction and social reassurance) and the volume of comments on the willingness to check online reviews. Based on 393 guests of hotels, a mixture regression model indicates the existence of three internally consistent segments, which reveal the varying influence on consumer intentions to look at online comm…

Plant growth improvement mediated by nitrate capture in co-composted biochar

2015

AbstractSoil amendment with pyrogenic carbon (biochar) is discussed as strategy to improve soil fertility to enable economic plus environmental benefits. In temperate soils, however, the use of pure biochar mostly has moderately-negative to -positive yield effects. Here we demonstrate that co-composting considerably promoted biochars’ positive effects, largely by nitrate (nutrient) capture and delivery. In a full-factorial growth study with Chenopodium quinoa, biomass yield increased up to 305% in a sandy-poor soil amended with 2% (w/w) co-composted biochar (BCcomp). Conversely, addition of 2% (w/w) untreated biochar (BCpure) decreased the biomass to 60% of the control. Growth-promoting (BC…

Effect of Lignin-Containing Media on Growth of Medicinal Mushroom Lentinula Edodes

2017

Abstract The effect of lignocellulose and lignin on growth of mycelium of mushroom Lentinula edodes and laccase activity in cultivation medium was studied. It was shown that cultivation of L. edodes mycelium in liquid nutrient medium with addition of 0.25-0.5% of kraft lignin increased mycelium biomass yield approximately two times compared with reference conditions without addition of lignin. Similar results were obtained in experiments in which 0.5% lignocellulose that remained after obtaining furfural, and 0.5% lignin that remained after obtaining furfural and glucose from wheat straw, were added to the nutrient medium. This effect was greater in the conditions of cultivation with good a…

Copulation and sperm induction by normal and palpless male linyphiid spiders.

1967

The performance by palpless male linyphiid spiders of behaviors associated with copulation and sperm induction indicates that occurrence of these sexual activities does not depend on peripheral input from the palps.

2015

We present a method to discover discriminative brain metabolism patterns in [18F] fluorodeoxyglucose positron emission tomography (PET) scans, facilitating the clinical diagnosis of Alzheimer's disease. In the work, the term "pattern" stands for a certain brain region that characterizes a target group of patients and can be used for a classification as well as interpretation purposes. Thus, it can be understood as a so-called "region of interest (ROI)". In the literature, an ROI is often found by a given brain atlas that defines a number of brain regions, which corresponds to an anatomical approach. The present work introduces a semi-data-driven approach that is based on learning the charac…

Preliminary Studies on Microbial Biomass and the Microarthropod Community as Soil Health and Quality Indicators in Urban Grasslands, Rīga as an Examp…

2015

Antropogēnais piesārņojums tiek uzskatīts par vienu no galvenajiem faktoriem, kas ietekmē augsni pilsētās. 2014. gadā uzsākts pētījums par augsnes kvalitāti urbānajos zālājos Rīgā. Pētījuma mērķis bija noteikt augsnes mikrobiālo biomasu un augsnes sīkposmkāju kopienu dažādu zālāju augsnēs Rīgā un izvērtēt iespējas tos izmantot kā pilsētvides augsnes veselības un kvalitātes rādītājus. Rīgā atšķirīgos pilsētas rajonos tika izvēlēti seši dažāda lieluma parauglaukumi ar atšķirīgām vietas apbūves īpatnībām, ielu un dzelzceļu tīkla blīvumu un transporta noslogojumu, vidi piesārņojošo objektu iespējamo ietekmi, kā arī citām, urbānu vidi raksturojošām īpatnībām. Substrāta izraisītas elpošanas metod…

Embedding Quantum into Classical: Contextualization vs Conditionalization

2014

We compare two approaches to embedding joint distributions of random variables recorded under different conditions (such as spins of entangled particles for different settings) into the framework of classical, Kolmogorovian probability theory. In the contextualization approach each random variable is "automatically" labeled by all conditions under which it is recorded, and the random variables across a set of mutually exclusive conditions are probabilistically coupled (imposed a joint distribution upon). Analysis of all possible probabilistic couplings for a given set of random variables allows one to characterize various relations between their separate distributions (such as Bell-type ine…

LisRK is required for optimal fitness ofListeria monocytogenesin soil

2020

ABSTRACTListeria monocytogenes is a food-borne pathogen responsible for the disease listeriosis. It is ubiquitously found in the environment and soil is one of its natural habitats. Listeria monocytogenes is highly capable of coping with various stressful conditions. We hypothesized that stress-responsive two-component systems such as LisRK might contribute to the adaptation of L. monocytogenes to the soil environment. Indeed, investigations of the population dynamics of wild-type and mutant strains suggest an important role of LisRK for optimal fitness of L. monocytogenes in sterile soil. Results from non-sterile soil showed that the parental strain was capable of surviving longer than mut…