Search
Author
- Osman, Ahmed I. (5)
- Daqing, Ma (3)
- Jorgensen, Ed (3)
- Li, Yan (3)
- next >
Subject
- kinh tế (26)
- Economics (12)
- programming (10)
- XRD (10)
- next >
Date issued
- 2020 - 2023 (2117)
- 2010 - 2019 (129)
- 2000 - 2009 (9)
- 1999 - 1999 (1)
Has File(s)
Search Results
Cellulose is a class of biopolymers that prominently contributes to developing lightweight, eco-friendly, and biodegradable plastics. Among them, nanofibrillated cellulose (NFC) is one of the most interesting due to its mechanical behavior. Mixing it with synthetic plastic such as poly(methyl methacrylate) (PMMA) reduces synthetic polymer usage, agro-industrial residue and develops fiber-reinforced composites. NFC was prepared from residual biomass and oxidized with TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl radical). Herein, NFC was incorporated (25, 50 and 75 wt%) in a colloidal emulsion of PMMA, with PMMA particle size control (50 and 175 nm). The investigation of this system on the PMMA/NFC transparency was addressed here. |
Run-time device-level reconfigurability has the potential to boost the performance and functionality of numerous circuits beyond the limits imposed by the integration density. The key ingredient for the implementation of reconfigurable electronics lies in ambipolarity, which is easily accessible in a substantial number of two-dimensional materials, either by contact engineering or architecture device-level design. In this work, we showcase graphene as an optimal solution to implement high-frequency reconfigurable electronics. We propose and analyze a split-gate graphene field-effect transistor, demonstrating its capability to perform as a dynamically tunable frequency multiplier. The study is based on a physically based numerical simulator validated and tested against experiments. |
Vanessa Zamora Mora and Roberto de Mezerville are salaried employees of the Establishment Labs company. Ardeshir Bayat is a co-inventor on a number of patents that were assigned to the Establishment Labs company and he is also a financially compensated member of the scientific advisory board of the same company. |
Water seepage is one of the main factors leading to the damage of grottoes. The sources and pathways of water seepage need to be identified to relieve it. Although the sources and pathways are investigated using geophysical exploration methods commonly, the results are unsatisfactory due to the limitation of resolution. The tracer method has been widely used to examine water seepage in the natural sciences and engineering. However, most tracers have an impact on grottoes, making this method inapplicable. This study was the first to use the carbon quantum dots as a tracer of water seepage in grottoes. The characteristics of the carbon quantum dots, which was synthesized by various biomass precursors through large-scale synthesis in the field, were analyzed to determine the optimal pr... |
The increasing interest in the development of multicaloric materials for solid-state cooling applications is giving rise to the investigation of elastocaloric performance of ferromagnetic Shape Memory Alloys (FeSMA). Moreover, some sintering processes have been proposed to overcome the well-known brittleness of these alloys. In this context, a novel application of the open die pressing (ODP) method for the preparation of NiMnGa polycrystalline samples sets the chance to have interesting mechanical properties, until now never reported in literature. In this work, a tunable optimization of microstructure is presented and the elastocaloric properties are investigated by different mechanical approaches and direct measurement of adiabatic ΔT values. It is observed, for the first time, a ... |
The IIW-Recommendation for fatigue design of welded joints and components presents two different evaluation approaches for multiaxial stress states under constant amplitude: an approach based on the maximum principal stress, which is only applicable under certain conditions, and the Gough-Pollard approach for the remaining cases. In the course of this work, this maximum principal stress-based approach is analyzed. It is examined in which cases the method is applicable, the advantages and disadvantages compared to the approach according to Gough-Pollard are discussed, and an evaluation according to the von Mises equivalent stress is presented as a third alternative. This is followed by a validation based on literature data on laser-welded steel joints using the nominal stress, hot sp... |
To clarify the effect of solution heat-treatment on the oxidation resistance of Ni-base single-crystal superalloy TMS-238, the evaluation of dendrite/inter-dendrite segregation of alloying elements in the as-cast and heat-treated samples, and its effect on cyclic oxidation resistance were investigated. Cyclic oxidation test results at 1100 °C for up to 150 cycles clearly showed that the as-cast samples with element segregations had lower oxidation resistance compared to heat-treated samples with homogeneous structure. Further, for the as-cast sample, rapid growth and spallation of oxide consisting of NiO, Cr2O3, and Al2O3 were observed around the dendrite core for 10 cycles of oxidation. |
In recent years, cardiovascular disease in particular myocardial infarction (MI) has become the predominant cause of human disability and mortality in the clinical setting. The restricted capacity of adult cardiomyocytes to proliferate and restore the function of infarcted sites is a challenging issue after the occurrence of MI. The application of stem cells and byproducts such as exosomes (Exos) has paved the way for the alleviation of cardiac tissue injury along with conventional medications in clinics. However, the short lifespan and activation of alloreactive immune cells in response to Exos and stem cells are the main issues in patients with MI. Therefore, there is an urgent demand to develop therapeutic approaches with minimum invasion for the restoration of cardiac function.<... |
he effect of the thickness of a multilayer TiO2 photoanode on the performance of a dye-sensitized solar cell (DSC) made with a polyethylene oxide-based gel polymer electrolyte containing ternary iodides and performance enhancer 4-tert-butylpyridine is studied. Multilayer photoanodes consisting of up to seven layers of TiO2 nano-particles (13 nm and 21 nm) are prepared by spin coating of successive layers. XRD results confirm the predominant presence of the anatase phase of TiO2 in the multilayer structure after sintering. The SEM images reveal the formation of a single TiO2 film upon sintering due to merging of individually deposited layers. The photocurrent density (JSC) and the efficiency increase with the number of TiO2 layers exhibiting the maximum efficiency and JSC of 5.5% and... |
The global effects of MP (MP) pollution on the environment are concerning, and they are exacerbated by the multiple sources of pollution in aquatic environments such as urban runoff, waste mismanagement, industrial pollution, and so on. South pacific islands host a large diversity of aquatic flora and fauna and given its ecological significance it is necessary to identify the sources of MP pollution in the region. To date, very little attention has been given to identify whether effluents from wastewater treatment plants (WWTP) are acting as a significant source of MP in the South Pacific region and its countries. Therefore, the present study analyzed and compared the treatment methods and fate of MPs in the country’s two main WWTPs: 1) the Kinoya WWTP (simple secondary clarifier an... |
