188 research outputs found
The relationship between household life cycle and brand loyalty
types: ArticleThis research investigates changes in brand loyalty as households pass from one stage of the household life cycle to another. Analysing 45 brands in three consumer product categories in the UK, we find that the changes follow a U shape pattern. Brand loyalty declines as households shift from the young single stage to the young couple and the young family stage, remains relatively lower through the older family stage, and then increases at the post family and older single stages
"Глюкомет" в комплексном лечении пациенток с синдромом поликистозных яичников
ГЛЮКОМЕТМЕТФОРМИНПОЛИКИСТОЗНОГО ЯИЧНИКА СИНДРОМ /ЛЕК ТЕ
KxNiy[Fe(CN)6].xH2O Prussian blue analogue: A study of size effect on the structural, optical and magnetic propertiecs
Recently, striking effects of light irradiation on the magnetic state were reported for Prussian blue (PB) analogues AxCoy[Fe(CN)6] (A = Na, K, Rb, Cs). The physical and optical properties of these compounds are dependent on the size of the particles of the measured samples. However, there have been few reports on the formation of nano-sized particles of the material and the effect of size of the particles on the properties of the compounds. In this report, we present a novel synthesis method of the KxNiy[Fe(CN)6] PB nano-particles and investigate the effect of particlesize on the properties of the Prussian blue analog KxNiy[Fe(CN)6] by analysising the results of the X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-vis absorption and magnetization measurements of the compounds.
Keywords: Prussian Blue, nanoparticle, size effect, magnetic propert
Top-management compensation and environmental innovation strategy
The increasing awareness of global climate change puts more pressure on firms to reduce their environmental externalities. Managers long ignored this responsibility as it may erode business profits, going against their traditional goals. In this study, we examine the effect of extrinsic incentives (i.e., reward-driven motivation) for top management on corporate environmental innovation strategy (i.e., eco-innovation), using a large dataset of S&P1500 non-financial firms for 2000-2020. The results indicate that firms with greater levels of top-management compensation exhibit higher scores of eco-innovation engagement. The effect holds after we address the endogeneity problem through the quasi-natural experiment using the difference-indifferences analysis on the event of the Paris Agreement 2015. Our further investigations reveal that such a positive impact of managerial incentives on eco-innovation is less intensified in the more polluting industries but more pronounced in more innovative ones
Modelling and validation of synthesis of poly lactic acid using an alternative energy source through a continuous reactive extrusion process
PLA is one of the most promising bio-compostable and bio-degradable thermoplastic polymers made from renewable sources. PLA is generally produced by ring opening polymerization (ROP) of lactide using the metallic/bimetallic catalyst (Sn, Zn, and Al) or other organic catalysts in a suitable solvent. In this work, reactive extrusion experiments using stannous octoate Sn(Oct)2 and tri-phenyl phosphine (PPh)3 were considered to perform ROP of lactide. Ultrasound energy source was used for activating and/or boosting the polymerization as an alternative energy (AE) source. Ludovic® software, designed for simulation of the extrusion process, had to be modified in order to simulate the reactive extrusion of lactide and for the application of an AE source in an extruder. A mathematical model for the ROP of lactide reaction was developed to estimate the kinetics of the polymerization process. The isothermal curves generated through this model were then used by Ludovic software to simulate the “reactive” extrusion process of ROP of lactide. Results from the experiments and simulations were compared to validate the simulation methodology. It was observed that the application of an AE source boosts the polymerization of lactide monomers. However, it was also observed that the predicted residence time was shorter than the experimental one. There is potentially a case for reducing the residence time distribution (RTD) in Ludovic® due to the ‘liquid’ monomer flow in the extruder. Although this change in parameters resulted in validation of the simulation, it was concluded that further research is needed to validate this assumption
EVALUATION OF ACUTE AND SUB-ACUTE ORAL TOXICITY OF CLINACANTHUS NUTANS LEAVES EXTRACT IN MICE
Objective: This study aimed to evaluate acute and sub-acute oral toxicity of ethanol extract of Clinacanthus nutans leaves in Swiss mice.
Methods: Acute oral toxicity study was performed as per OECD-423 guidelines. Sub-acute oral toxicity study was performed as per OECD-407 guidelines. The extract was dissolved in 10% dimethyl sulfoxide and administered orally, while the control group received only the vehicle.
Results: The acute oral toxicity test on mice showed that this extract was well tolerated up to LD50 5000 mg/kg body weight/day oral dosage level and non-toxic to mice under the present experimental conditions. The sub-acute toxicity study was carried out on mice with the oral dosage of the extract from 100 mg/kg–500 mg/kg body weight/day and 5000 mg/kg body weight/day for 28 d. The results showed that this extract did not induce death or adverse effects in activity, feed consumption or body weight gain. There were not significant changes in heamotological and biochemical parameters between control and experiment groups.
Conclusion: Thus, Clinacanthus nutans leaf has a very low toxicity value
Broadening the absorption bandwidth of metamaterial absorber by coupling three dipole resonances
THE AMOUNT AND SPECIATION OF TRACE ELEMENTS TRANSPORTED FROM RICE FIELD TO CANAL DURING A FLOODING EVENT
Trace element pollution of soils, sediments and surface water can pose a risk for the local population and the environment of Vietnam. Rice fields can be affected by storm events, which cause the release of trace elements into surface water and transport them into drinking wells. The aim of this study was to investigate if dissolved and suspended As, Pb and Zn concentrations in surface water of a paddy rice fields and an irrigation canals increased during a flooding event and exceed the Vietnamese Surface Water Quality Standards and WHO Guidelines for Drinking-water Quality. The study site is a rice field area in the Thanh Hoa province in Central Vietnam, which experiences an average of 2.4 storms every year causing overflow of streams and low-order canals. Concentrations of As increased during the flooding event with dissolved As being the prevailing fraction, which followed a late flush behavior. Lead showed no significant difference in concentration over time. Zn concentrations only increased significantly in the canal upstream the field in the morning of the first day. Suspended Zn dominated at that time, following the first flush behavior of TSS concentrations. Concentrations of As, Pb and Zn did not exceed the Vietnamese Surface Water Quality Standards or WHO Guidelines for Drinking-water Quality at any time and they are therefore of no concern for the health of the local populatio
Crystallography: Deep understanding the mechanism of -form nucleation in cooling crystallization of L-glutamic acid
The mechanism of heterogeneous β-form nucleation was investigated during the phase transformation of L-glutamic acid in the stirring cooling crystallization. In the present study, a new mechanism of heterogeneous β-form nucleation was explored, where the β-form nuclei was favorably crystallized on the (001) and (011) surfaces rather than the (111) surface of α-form crystal during the phase transformation. This result was confirmed via the molecular simulation, in which the functional groups of molecule on various surfaces of α-form crystal were different, so the degree of lattice matching (E) between the α-form substrate surfaces and β-form molecule aggregate was distinguished and ordered as (001) (011) (111), meaning that the nucleation of heterogeneous β-form was more facilitated on the (001) and (011) surfaces compared to that on the (111) surface of α-form crystal. Keywords. Crystallization, crystallography, polymorphism, nucleation, crystal growth
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Laboratory and Clinical Predictors of Disease Progression following Initiation of Combination Therapy in HIV-Infected Adults in Thailand
Background: Data on determinants of long-term disease progression in HIV-infected patients on antiretroviral therapy (ART) are limited in low and middle-income settings. Methods: Effects of current CD4 count, viral load and haemoglobin and diagnosis of AIDS-defining events (ADEs) after start of combination ART (cART) on death and new ADEs were assessed using Poisson regression, in patient aged ≥18 years within a multi-centre cohort in Thailand. Results: Among 1,572 patients, median follow-up from cART initiation was 4.4 (IQR 3.6–6.3) years. The analysis of death was based on 60 events during 6,573 person-years; 30/50 (60%) deaths with underlying cause ascertained were attributable to infections. Analysis of new ADE included 192 events during 5,865 person-years; TB and Pneumocystis jiroveci pneumonia were the most commonly presented first new ADE (35% and 20% of cases, respectively). In multivariable analyses, low current CD4 count after starting cART was the strongest predictor of death and of new ADE. Even at CD4 above 200 cells/mm3, survival improved steadily with CD4, with mortality rare at ≥500 cells/mm3 (rate 1.1 per 1,000 person-years). Haemoglobin had a strong independent effect, while viral load was weakly predictive with poorer prognosis only observed at ≥100,000 copies/ml. Mortality risk increased following diagnosis of ADEs during cART. The decline in mortality rate with duration on cART (from 21.3 per 1,000 person-years within first 6 months to 4.7 per 1,000 person-years at ≥36 months) was accounted for by current CD4 count. Conclusions: Patients with low CD4 count or haemoglobin require more intensive diagnostic and treatment of underlying causes. Maintaining CD4≥500 cells/mm3 minimizes mortality. However, patient monitoring could potentially be relaxed at high CD4 count if resources are limited. Optimal ART monitoring strategies in low-income settings remain a research priority. Better understanding of the aetiology of anaemia in patients on ART could guide prevention and treatment
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