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3.
Micromachines (Basel) ; 13(9)2022 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-36144041

RESUMO

EHD printing is an advanced deposition technology that is commonly utilized for the direct manufacture of electrical devices. In this study, meander-type resistive electrodes consisting of silver nanoparticles were printed directly on rigid glass and flexible polyethylene terephthalate (PET) substrates. High-resolution patterns of ≈50 µm linewidth were successfully printed on untreated surfaces utilizing a bigger nozzle of 100 µm inner diameter after improving the experimental settings. The manufactured electrodes were evaluated and used as Resistance Temperature Detectors (RTDs) and micro-heaters in a systematic manner. The temperature sensors performed well, with a Temperature Coefficient of Resistivity (TCRs) of 11.5 ×10-3/°C and 13.3 ×10-3/°C, for glass and PET substrates, respectively, throughout a wide temperature range of 100 °C and 90 °C. Furthermore, the RTDs had a quick response and recovery time, as well as minimal hysteresis. The electrodes' measured sensitivities as micro-heaters were 3.3 °C/V for glass and 6.8 °C/V for PET substrates, respectively. The RTDs were utilized for signal conditioning in a Wheatstone bridge circuit with a self-heating temperature of less than 1 °C as a practical demonstration. The micro-heaters have a lot of potential in the field of soft wearable electronics for biomedical applications, while the extremely sensitive RTDs have a lot of potential in industrial situations for temperature monitoring.

4.
Environ Sci Pollut Res Int ; 28(3): 3162-3171, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32902754

RESUMO

The study aims to examine the energy-GDP-exports nexus employing structural break models after testing for co-integration in the form of total/aggregate annual time series data of South Asia region. The novelty of the study rests in dividing the aggregate energy into fossil fuel- and non-fossil fuel-based energy consumptions with structural break at 2008 considering the global financial crisis into the aggregate production function framework with labor, capital stock, and exports, ceteris paribus. The findings corroborate that in all the three models estimated with aggregate energy, fossil fuel-based energy, and non-fossil fuel-based energy consumptions respectively, there is evidence of long-run linkages among the selected variables. The analyses of long run elasticities estimated demonstrate that labor and capital have positive and significant impact on the real economic output before the break date in all the three models. It is however intriguing that aggregate energy use remains positive before and after the break date while fossil fuel-based energy becomes insignificant after 2008. Likely, non-fossil fuel-based energy corroborates insignificant impact on real economic output after 2008. These findings have important bearings for the energy conservation options in the region of South Asia especially for changing/reducing the fossil fuel share with the non-fossil fuels, ceteris paribus.


Assuntos
Desenvolvimento Econômico , Combustíveis Fósseis , Ásia , Dióxido de Carbono/análise , Fontes Geradoras de Energia
5.
Environ Sci Pollut Res Int ; 28(13): 15794-15805, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33241505

RESUMO

The quality of natural honey depends upon many factors with significant contribution of environmental factors. In this study, environmental impact on the quality of honey was assessed by determining concentrations of 11 essential and 17 toxic elements in 24 different honey samples of northern and southern regions of Pakistan and Turkey using inductively coupled plasma mass spectrometry. Statistical analysis showed higher variance in the concentrations of Cu, P, and Mo (essential), and Ga, Rb, Cs, Ba, and Pb (toxic) among all the honey samples (coefficient of variance > 100). Multivariate comparison based on botanical flora, honey bee species, and geographic regions revealed that the honeys of different botanical flora exhibited statistically nonsignificant difference in elemental composition, whereas, species wise, honeys of Apis dorsata contained significantly higher concentration of P than honeys of Apis mellifera and Apis flora (p < 0.01). Geographical regions wise, the honeys showed statistically significant difference in concentrations of six essential elements (K (p < 0.01), Mn (p < 0.001), Fe (p < 0.001), Cu (p < 0.05), P (p < 0.001), and Mo (p < 0.01)), and two toxic elements (V (p < 0.01) and As (p < 0.05)). Principal component analysis (PCA) using the essential elements contents clustered uni-floral honeys together separating out 3 multi-floral honeys including the artificial one, whereas PCA using concentrations of toxic elements showed mixed clustering of all honey samples, representing their independence of floral type. Taken together, our analyses show that the environmental factors of the geographical regions, apart from the honeybee species and the botanical flora, have profound impact on the elemental composition in the natural honeys affecting their quality. Although the concentrations of the toxic elements in the honey samples were not exceeding the permissible limit of FAO/WHO, yet we suggest regular surveillance on toxic elements in the honeys to avoid their harmful effects on human health.


Assuntos
Mel , Animais , Abelhas , Meio Ambiente , Mel/análise , Espectrometria de Massas , Paquistão , Turquia
6.
Environ Sci Pollut Res Int ; 27(22): 27807-27818, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32399878

RESUMO

This study has employed aggregate energy augmented production framework utilizing the gross domestic product (GDP), labor input, capital stock, energy, and export over the years from 1980 to 2014 on annual time series of the variables for Pakistan and South Asia panel. There is statistically insignificant association amid the variables for Pakistan while there is indication of long-run association amid the variables for panel of South Asia. The findings imply that energy conservation is efficient without hindering the economic growth and export expansion in Pakistan, albeit such kind of policy option is not much promising for the panel of four other South Asian countries. Furthermore, energy demand models must consider the role of exports expansion and its due impacts on the energy conservation of fossil fuels-based energy source and thereby on the trajectory of sustainable economic growth in the region.


Assuntos
Dióxido de Carbono/análise , Desenvolvimento Econômico , Produto Interno Bruto , Índia , Paquistão
7.
Insects ; 11(3)2020 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-32168886

RESUMO

Dengue fever is one of the most rapidly spreading arthropod-borne diseases. Diurnal vectorial properties of Aedes albopictus contribute to the dispersion of the dengue viruses. Frequent and injudicious use of synthetic insecticides led to the evolution of resistant phenotypes in Ae. albopictus which necessitates the search for an alternative of current control strategies. Developing a long-lasting and environmentally safe tactic based on knowledge of ecology and population dynamics of Ae. albopictus is critical. Therefore, with a view towards biological control and ecology, the effect of entomopathogenic fungi (EPF) Beauveria bassiana on filial and first filial generations of Ae. albopictus were studied. Investigations showed 87.5% adulticidal activity leading to altered fecundity and adult longevity in a filial generation. The lethal (LC50) and sublethal (LC20) concentrations of B. bassiana were applied to filial generation (F0) to study demographic parameters in the first filial generation (F1). Results showed reduced net reproductive rates (Ro) intrinsic rate of increase (r), and mean generation time (T) compared to uninfected controls. Prolonged larval and pupal duration were observed followed by reduced longevity of male and female adults. Fecundity in the first filial generation was significantly changed with the lethal and sublethal concentrations of B. bassiana. Thus, it is concluded that B. bassiana has the potential to play a vital role in integrated mosquito management strategies.

8.
Biol Trace Elem Res ; 182(1): 57-69, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28631137

RESUMO

This study assessed the protective effects of Cinnamomum cassia (cinnamon) bark extract in rats exposed to titanium dioxide nanoparticles or titanium dioxide bulk salt. For in vivo evaluation of the ameliorative role of the cinnamon extract, the experimental groups were orally administered with the cinnamon extract at different dose levels (50 or 100 or 150 mg/kg bodyweight) along with the subcutaneous injections of 150 mg/kg bodyweight titanium dioxide nanoparticles or titanium dioxide bulk salt. The extract showed significant ameliorative role on the antioxidant system in response to elevated levels of titanium dioxide nanoparticles or titanium dioxide bulk salt-induced oxidative stress. It aided in the recovery of the antioxidant system as well as protective role in histological damages and some haematological parameters in the rat liver treated with titanium dioxide nanoparticles or titanium dioxide bulk salt.


Assuntos
Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Cinnamomum aromaticum/química , Fígado/efeitos dos fármacos , Nanopartículas Metálicas/toxicidade , Extratos Vegetais/farmacologia , Titânio/toxicidade , Animais , Antioxidantes/farmacologia , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Dano ao DNA , Relação Dose-Resposta a Droga , Fígado/metabolismo , Fígado/patologia , Masculino , Fitoterapia/métodos , Casca de Planta/química , Extratos Vegetais/administração & dosagem , Substâncias Protetoras/farmacologia , Ratos Sprague-Dawley
9.
Biol Trace Elem Res ; 182(1): 130-139, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28634814

RESUMO

Silver nanoparticles (Ag-NPs) have wide applications in the medical field; however, the toxicological effects are still poorly studied. The study was aimed to determine the effects of 15.78 nm spherical and amine-coated Ag-NPs on hematology and histology of gills and liver tissues in 28 days treated Labeo rohita (L. rohita). It was found that Ag-NPs induced alterations in the hematological parameters in a dose dependent manner. The Ag-NPs also induced histological alterations in a dose-dependent manner. In gill tissues, it induced fusion of secondary lamellae, separation of gill epithelium, fusion and necrosis of lamellar cells, hyperplasia, deformed cartilaginous skeleton, separation and lifting of epithelium, and curling of lamellae in a dose dependent manner. In the liver, Ag-NPs produced abnormalities in hepatic tissues by reducing the size of hepatocytes and nuclei, and stimulated the production of necrotic and apoptotic bodies. It was concluded that Ag-NPs are toxic to aquatic organisms and induce hematotoxicity and histopathological conditions in exposed fish.


Assuntos
Aminas/química , Brânquias/patologia , Fígado/patologia , Nanopartículas Metálicas/química , Prata/química , Animais , Apoptose/efeitos dos fármacos , Cyprinidae , Brânquias/efeitos dos fármacos , Hepatócitos/efeitos dos fármacos , Hepatócitos/patologia , Fígado/efeitos dos fármacos , Nanopartículas Metálicas/toxicidade , Necrose/etiologia , Poluentes Químicos da Água/toxicidade
10.
Biol Trace Elem Res ; 176(2): 416-428, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27587025

RESUMO

The physicochemical and biological properties of metals change as the particles are reduced to nanoscale. This ability increases the application of nanoparticles in commercial and medical industry. Keeping in view this importance, Silver nanoparticles (Ag-NPs) were synthesized by reduction methods using formaldehyde as reducing agent in the chemical route and lemon extracts in the biological route. The scanning electron microscope (SEM) images of nanoparticles suggested that the particles were either agglomerated or spherical in shape with mean diameter of 16.59 nm in the chemical route and 42.93 nm in the biological route. The particles were between 5 and 80 nm with maximum frequency between 5 and 20 nm in the chemical route and between 5 and 100 nm with maximum frequency between 15 and 50 nm in the biological method. In the second phase of the study, the effect of Ag-NPs on the oxidative stress was studied. For this purpose, Labeo rohita (20 ± 2.5 g in weight and 12 ± 1.4 cm in length) were involved. Six treatments were applied in three replicates having five fishes in each replicate. The first treatment was used as control group, and the other five treatments were exposed to either 10 or 20 or 30 or 45 or 55 mg L-1 of Ag-NPs for 28 days. The treatment of Ag-NPs caused oxidative stress in the liver and gill tissues, which induced alterations in the activities of antioxidant enzymes. The level of catalase (CAT) was decreased in response to Ag-NPs concentration in dose-dependent manner. Ag-NPs treatment stimulated the liver and gill tissues to significantly increase the level of superoxide dismutase (SOD), which might be due to synthesis of SOD and addition in the pre-existing SOD level. The level decreases again due to depletion of SOD level. There was a sharp decline in the activities of glutathione S-transferase (GST) in both gills and liver tissues even at lower concentration, and this decrease in the GST activity was significantly different at each treatment after 28 days of treatment except 20 mg L-1. The malondialdehyde (MDA) levels of gills and liver tissues were increased with the increase in the concentration. The elevated levels of glutathione (GSH) showed that the liver started defensive mechanism against the oxyradicals. This study finds out the cheap eco-friendly and economical method of Ag-NP synthesis. It is further revealed that Ag-NPs caused oxidative stress in the aquatic animals if exposure occurs at high concentrations.


Assuntos
Cyprinidae/metabolismo , Nanopartículas Metálicas/economia , Nanopartículas Metálicas/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Prata/economia , Prata/toxicidade , Animais , Relação Dose-Resposta a Droga , Formaldeído/química , Brânquias/química , Brânquias/efeitos dos fármacos , Glutationa/análise , Fígado/química , Fígado/efeitos dos fármacos , Malondialdeído/análise , Nanopartículas Metálicas/química , Tamanho da Partícula , Prata/química , Propriedades de Superfície
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