Platinum nanoparticles (PtNPs) have long been regarded as the benchmark catalyst for the oxygen reduction reaction (ORR) in the cathode of microbial fuel cells (MFCs). On the other hand, the ...practical applications of these catalysts are limited by the high cost and scarcity of Pt. Therefore, developing an alternative catalyst to PtNPs for efficient ORR activity is essential for meeting the future demands for practical applications in MFCs. In this study, sulfur-doped graphene (S-GN) was synthesized
via
the environmental friendly, economical and facile one pot electrochemical exfoliation of graphene in a unique combination of electrolytes, which both catalyzed the exfoliation reaction and acted a sulfur source. The initial activity of S-GN as an ORR active catalyst was examined by cyclic voltammetry (CV), which showed that the as-synthesized S-GN exhibited better ORR activity than the plain material. Furthermore, the application of S-GN as a cathode material was also studied in MFCs. The results showed that the MFC equipped with the S-GN cathode produced a maximum power density of 51.22 ± 6.01 mW m
−2
, which is 1.92 ± 0.34 times higher than that of Pt/C. The excellent performance of S-GN as a cathode catalyst in MFCs could be due to the doping of graphene with heteroatoms, which increased the surface area and improved the conductivity of graphene through a range of interactions. Based on the above MFC performance, the as-synthesized S-GN catalyst could help reduce the cost and scale up the design of MFCs for practical applications in the near future.
Electrochemically synthesized S-GN was proved to be an efficient alternative cathode catalyst to Pt/C in microbial fuel cell.
Abstract
The Quantum photo-stimulated Peltier effect has been theoretically studied under the influence of confined acoustic phonon in a cylindrical quantum wires with an infinite potential by using ...the quantum kinetic equation method. In this work, we assume that the confined electrons-confined acoustic phonons scattering is essential. Moreover, the presence of a strong electromagnetic wave (EMW) is also taken into account to determine the influence of confined phonons on the aforementioned effects. We have defined the analytical expressions for the kinetic tensors and the Peltier coefficients (PC). In detailed consideration, the quantum number
m
1,
m
2 were changed in order to characterize the influence of confined acoustic phonon (confined AP). As the radius of the wire increases to infinity, we obtained the results that corresponded to the case of bulk phonons (unconfined AP). The theoretical results have been numerically evaluated and discussed for the GaAs/AlGaAs cylindrical quantum wires (CQW). The change of PC in two cases unconfined AP and confined AP have been found according to augment of EMW frequency. The value of resonant peaks has altered under the effect of confined AP. The difference of PC also has been discovered when investigating its dependence on the cyclotron frequency. Furthermore, the PC reduced suddenly when considering the dependence of PC on the radius of wire and PC on the low temperature. All numerical showed that the magnitude of PC diverse significantly in comparison with unconfined AP case and doped two - dimensional semiconductor superlattice. This means that the confinement of the phonon affects the Peltier effect quantitatively and qualitatively. These results are new and provide to completing the theory of the Peltier effect in low-dimensional semiconductor systems.
Equiatomic CrMnFeCoNi high-entropy alloy was joined in solid-state by electrically assisted pressure joining (EAPJ). Cracks and compositional segregation were not found in joining zones (JZ). As the ...applied electric current increased, the microstructure of JZ changed from a deformed and partially recrystallized microstructure to a fully recrystallized one with grain growth. JZ showed sound mechanical properties through the Vickers hardness and uniaxial tension results. EAPJ of high-entropy alloy can overcome the disadvantage of fusion welding.
Display omitted
•3D multifunctional electrode was developed for energy production & storage.•Facile & cost-effective drying technique was developed for carbon foam production.•N-doped carbon foam ...possesses a unique combination of macro, meso, and micropores.•MFC operated with N-doped carbon foams produced very high power density, 36Wm−3.•High charge storage capacity and Li-battery-comparable energy density was obtained.
This paper reports the synthesis of N-doped carbon foams (NCFs) using simple, environment-friendly, and self-developed freezing method. A robust structure of NCFs along with high surface area, hierarchical pore structure, and nitrogen/oxygen functionalities allows their application as free-standing electrode. Microbial fuel cell equipped with differently prepared NCFs as free-standing anode and metal-free cathode generates significantly higher power density, 35.74Wm−3 than conventional electrodes. Furthermore, NCF with an optimized resorcinol-formaldehyde content shows significantly high-charge storage capacity, 799Fg−1, at 0.25Ag−1 and also delivers a high energy density, 111Whkg−1, equivalent to that of a Li-ion battery.
Abstract
Based on the quantum kinetic equation method, the quantum Ettingshausen effect has been theoretically studied under the influence of confined acoustic phonon in a cylindrical quantum wire ...(CQW) with infinite potential in the presence of a strong electromagnetic wave. We considered a quantum wire in the presence of a constant electric field, a magnetic field, an electromagnetic wave (EMW) with an assumption that electron – confined acoustic phonon (CAP) scattering is essential. Analytical results obtained show that the EC depends on the amplitude and the frequency of the EMW in a non-linear way. Besides, the impact of phonon confinement on the above effect characterized by
m
-quantum number in the expression of the EC. The theoretical results have been numerically calculated for the GaAS/AlGaAs cylindrical quantum wire model. The obtained results show that the phonon confinement contributes to the EC quantitatively and qualitatively. On the other hand m is set to zero, the result obtained is similar to the case of unconfined phonon. Furthermore, by considering the quantum size effect, the values of the EC increases, the position of the magnetic-phonon resonance peak changes, and the number of peak resonant peak increases while the radius of quantum wire declines. These obtained results are different from bulk semiconductor and unconfined phonon case which donates to the theory of the Ettingshausen effect in low-dimensional semiconductor systems.
Objectives Dioxin levels in the breast milk of mothers residing near hot spots of dioxin contamination areas in South Vietnam remain much higher than in unsprayed areas, suggesting that fetuses and ...breast-fed infants may be exposed to high levels of dioxins. The present study investigated the association of infant neurodevelopment in early infancy and dioxin exposure during the perinatal period. Methods The study involved 216 mother-infant pairs living near the Da Nang airbase, a dioxin contaminated area in Vietnam. Mothers and infants were followed from birth until infants were 4 months old. Dioxin levels in breast milk were measured to estimate the perinatal dioxin exposure, including the infant daily dioxin intake (DDI) via breastfeeding. Infant neurodevelopmental parameters, including cognitive, language and motor domains were assessed at approximately 4 months using the Bayley Scales of Infant and Toddler Development, third edition (Bayley-III). Results The level of 2,3,7,8-tetrachlorodibenzo-p-dioxin and polychlorinated dibenzo-p-dioxins/furans-toxic equivalents in breast milk and the infant DDI showed significant inverse correlations with neurodevelopmental scores. When the subjects were divided into four groups according to dioxin levels in breast milk, the moderate and high DDI groups had significantly lower cognitive, composite motor and fine motor scores, and the high polychlorinated dibenzo-p-dioxins/furans-toxic equivalents group had significantly lower fine motor score than the low exposure group. For all domains, neurodevelopmental scores were decreased with increase in the level of 2,3,7,8-tetrachlorodibenzo-p-dioxin. Conclusion The present study demonstrates a considerable impact of perinatal dioxin exposure on neurodevelopment in 4-month-old infants living in contaminated areas in Vietnam.
Argyrodite-type solid electrolytes of Li6PS5Cl doped with multivalent cations (Mg2+, Ba2+, Zn2+, Al3+, Y3+) were prepared via a mechanochemical synthesis method. The lattice constant (a0), ...interplanar spacing (d220, d311, d222), and micro-strain (ϵ) showed that the doping elements were incorporated into the crystal structure of Li6PS5Cl. The lattice constant and interplanar spacing of the doped samples were smaller than those of Li6PS5Cl. The prepared samples exhibited a positive lattice strain, and the substituted samples exhibited higher strains than Li6PS5Cl. The doped samples exhibited higher ionic conductivity than Li6PS5Cl at 25 °C. Li5.94Al0.02PS5Cl exhibited the highest σDC of approximately 2.36 × 10−3 S cm−1 at 25 °C. The charge carrier movement at the grain boundary changing from long-range diffusion in Li6PS5Cl to short-range diffusion in Li5.94Al0.02PS5Cl enhanced the conductivity.
Dioxin concentrations remain elevated in both the environment and in humans residing near former US Air Force bases in South Vietnam. This may potentially have adverse health effects, particularly on ...infant neurodevelopment. We followed 214 infants whose mothers resided in a dioxin-contaminated area in Da Nang, Vietnam, from birth until 1 year of age. Perinatal exposure to dioxins was estimated from toxic equivalent (TEQ) levels of polychlorinated dibenzodioxins and polychlorinated dibenzofurans (PCDDs/Fs-TEQ), and 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TetraCDD) concentrations in breast milk. In infants, daily dioxin intake (DDI) was used as an index of postnatal exposure through breastfeeding. Neurodevelopment of toddlers was assessed using the Bayley Scales of Infant and Toddler Development, Third Edition (Bayley-III). No significant differences in neurodevelopmental scores were exhibited for cognitive, language or motor functions between four exposure groups of PCDDs/Fs-TEQ or 2,3,7,8-TetraCDD. However, social-emotional scores were decreased in the high PCDDs/Fs-TEQ group and the high 2,3,7,8-TetraCDD group compared with those with mild exposure, after adjusting for confounding factors. Cognitive scores in the mild, moderate, and high DDI groups were significantly higher than those in low DDI group, but there were no differences in cognitive scores among the three higher DDI groups. These results suggest that perinatal exposure to dioxins may affect social-emotional development of 1-year-old toddlers, without diminishing global neurodevelopmental function.
Germinated soybean (GSB) has a high interest in the food industry due to its potential health benefits. However, the understanding of physicochemical properties as well as sensory properties of ...plant‐based milk made of GSB is very limited. This study, therefore, formulated GSB milk and identified its nutritional value, rheological property, and perception of consumers. The obtained result revealed that GSB milk had a high gamma‐aminobutyric acid (GABA) content (127–135 mg/L) while its other properties including pH, crude protein content, and total soluble solid were equivalent to those of conventional soymilk. Due to the denaturation of protein in germination, GSB milk had a bigger droplet size in comparison with conventional soymilk, resulting in a lower viscosity. For consumer perception, sensory properties of GSB milk were evaluated as better than those of conventional soymilk.
Practical applications
Nutritional profiles of soymilk prepared from Germinated soybean (GSB) can be comparative with those of conventional soymilk. The increase of gamma‐aminobutyric acid content and the changes in sensory properties of GSB milk bring the opportunity to develop new products prepared from this soymilk.
In the digital age and technological advancements, short video platforms have become essential tools for online sales and marketing. In addition, shopping through short video marketing has gained ...significant attention, especially among Generation Z, as it brings unique and novel shopping experiences. The primary goal of this study is to explore the factors of short video marketing that influence the purchase intentions of Generation Z consumers in Vietnam. To conduct this study, a quantitative approach was employed, utilizing a 5-point Likert scale questionnaire administered online through a non-probability sampling method. The sample comprised 350 respondents aged between 16 and 26 from Vietnam, representing Generation Z, who made purchases through short video marketing. The relationships among various variables were analyzed using Structural Equation Modeling (SEM). The study’s results demonstrated a positive, significant, and direct relationship between all factors of short video marketing, including interesting content, perceived usefulness, scenario-based experience, user interaction, perceived enjoyment, and involvement of celebrities and consumer brand attitude. Among these factors, perceived usefulness is the most influential factor on customer brand attitude. In addition, the study revealed that consumer brand attitude, acting as a mediating variable, had a positive and significant impact on consumers’ purchase intentions. Based on the findings, the study suggested strategies for businesses to enhance the quality and content on short video platforms, thereby improving the effectiveness of their marketing strategies.
AcknowledgmentThe authors express a sincere gratitude to all the participants who generously took part in this research study.
PDF
