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1.
Behav Sci (Basel) ; 13(4)2023 Mar 26.
Artículo en Inglés | MEDLINE | ID: mdl-37102798

RESUMEN

Corporate social responsibility (CSR) provides companies with two benefits: creating social value and strengthening consumer relationships. Companies implement various types of CSR to maximize the positive effects of CSR, participatory CSR being one of these types. However, although the number of companies using participatory CSR in practice is increasing, academic interest in the effectiveness of participatory CSR has been insufficient. In particular, prior studies on the consumer perception of the participation level presented in participatory CSR do not show clear results. This study examines the influence of the participation level based on CSR fit and social support. The results of this study indicate that when there is a high CSR fit, consumers perceive the participation level as a benefit. However, when the CSR fit is low, consumers perceive the participation level as a cost. Additionally, the results show that the interactive effect of the participation level and CSR fit occurs only when there is less social support. When there is strong social support, consumers perceive the participation level as a benefit regardless of the CSR fit. Finally, the academic and practical implications of the results of this study are presented.

2.
Phys Chem Chem Phys ; 23(38): 21972-21980, 2021 Oct 06.
Artículo en Inglés | MEDLINE | ID: mdl-34569569

RESUMEN

In analogy with excited-state proton transfer, proton transfer is significantly facilitated in cationic and anionic molecules of indigo derivatives generated in field-effect transistors. We have prepared extended and truncated indigo derivatives and investigated their ambipolar transistor properties. Since the proton transfer reduces the energy gap from 2.2 to 0.4 eV, the proton transferred states are stabilized in the charge injected cationic and anionic states; the energy increase is as small as 0.5 eV, which is half of that in the neutral state. The intermolecular proton transfer enlarges the equilibrium N-H distance typically by 0.03 Å, and improves the donor and acceptor abilities by 0.2-0.4 eV, though the reorganization energy is practically unchanged. In addition, the transfer integrals along the hydrogen bonds are as large as one third of the columnar transfers, to facilitate the two-dimensional carrier conduction. The influence of proton transfer is most significant in indigo and truncated indigo derivatives, though isoindigo and quinacridone exhibit similar properties. Accordingly, indigo derivatives show much better donor and acceptor abilities than those expected from isolated molecules.

3.
Materials (Basel) ; 14(15)2021 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-34361257

RESUMEN

To solve the problem of black ice, many studies are being carried out. The key in recent days is enhancing the thermal conductivity of concrete. In this study, to improve the thermal conductivity, silicon carbide was used to substitute 50% and 100% of the fine aggregate. In addition, steel fiber is not only for enhancing the mechanical properties but could enhance thermal conductive material. Hence, the arched-type steel fiber was used up to a 1% volume fraction in this study. Furthermore, graphite was used for 5% of the volume fraction for enhancing the thermal conductivity. However, thermal damage would occur due to the difference in thermal conductivity between materials. Therefore, the thermal durability must be verified first. The target application of the concrete in this study was its use as road paving material. To evaluate the thermal durability, freeze-thaw and rapid cyclic thermal attacks were performed. The thermal conductivity of the specimens was increased with the increase in thermal conductive materials. Graphite has already been reported to have a negative effect on mechanical properties, and the results showed that this was the case. However, the steel fiber compensated for the negative effect of graphite, and the silicon carbide provided a filler effect. Graphite also had a negative effect on the freeze-thaw and rapid cyclic thermal attack, but the steel fiber compensated for the reduction in thermal durability. The silicon carbide also helped to improve the thermal durability in the same way as steel fiber. Comprehensively, the steel fiber enhanced all of the properties of the tests. Using 100% silicon carbide was considered the acceptable range, but 50% of silicon carbide was the best. Graphite decreased all the properties except for the thermal conductivity. Therefore, the content of graphite or using other conductive materials used should be carefully considered in further studies.

4.
ACS Appl Mater Interfaces ; 12(21): 24174-24183, 2020 May 27.
Artículo en Inglés | MEDLINE | ID: mdl-32363850

RESUMEN

For basic understanding of transistor properties of doped organic semiconductors, 3,3',5,5'-tetramethylbenzidine charge-transfer complexes are investigated, which change from neutral to ionic by varying the acceptors. When going into the ionic state, the bulk conduction increases more rapidly than the mobility, but sufficiently thin devices exhibit transistor properties. The resulting ambipolar characteristics are analyzed in the linear regions at small drain voltages in analogy with graphene transistors. The model is further extended to include partial overlap of electron and hole transport regions. In the temperature dependence, the activation energy loses gate voltage dependence when the neutral-ionic transition takes place by 0.1-0.2 eV above the equal acceptor and donor levels; the difference comes from the typical trap (polaron) depth or the Madelung energy.

5.
RSC Adv ; 10(49): 29603-29609, 2020 Aug 05.
Artículo en Inglés | MEDLINE | ID: mdl-35521152

RESUMEN

Schiff base complexes derived from salicylaldehyde and ethylene-, propylene-, and trans-1,2-cyclohexane-diamines exhibit p-channel transistor properties. The Cu complexes are open-shell compounds, but the oxidation and the hole transport occur at the highest occupied molecular orbital, where the singly occupied molecular orbital (SOMO) does not participate in conduction. Although Ni complexes tend to show larger mobilities than Cu complexes owing to the molecular planarity, the presence of SOMO is not harmful to the transistor properties.

6.
Small ; 16(15): e1901901, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-31338976

RESUMEN

TaS2 nanolayers with reduced dimensionality show interesting physics, such as a gate-tunable phase transition and enhanced superconductivity, among others. Here, a solution-based strategy to fabricate a large-area foil of hybrid TaS2 /organic superlattice, where [TaS2 ] monolayers and organic molecules alternatively stack in atomic scale, is proposed. The [TaS2 ] layers are spatially isolated with remarkably weakened interlayer bonding, resulting in lattice vibration close to that of TaS2 monolayers. The foil also shows excellent mechanical flexibility together with a large electrical conductivity of 1.2 × 103 S cm-1 and an electromagnetic interference of 31 dB, among the highest values for solution-processed thin films of graphene and inorganic graphene analogs. The solution-based strategy reported herein can add a new dimension to manipulate the structure and properties of 2D materials and provide new opportunities for flexible nanoelectronic devices.

7.
ACS Appl Mater Interfaces ; 10(12): 10262-10269, 2018 Mar 28.
Artículo en Inglés | MEDLINE | ID: mdl-29508608

RESUMEN

Dithieno[2,3- d;2'3'- d']benzo[1,2- b;4,5- b']dithiophene forms mixed-stack charge-transfer complexes with fluorinated tetracyanoquinodimethanes (F nTCNQs, n = 0, 2, and 4) and dimethyldicyanoquinonediimine (DMDCNQI). The single-crystal transistors of the F nTCNQ complexes exhibit electron transport, whereas the DMDCNQI complex shows hole transport as well. The dominance of electron transport is explained by the superexchange mechanism, where transfers corresponding to the acceptor-to-acceptor hopping ( teeff) are more than 10 times larger than the donor-to-donor hopping ( theff). This is because the donor orbital next to the highest occupied molecular orbital makes a large contribution to the electron transport owing to the symmetry matching. Like this, inherently asymmetrical electron and hole transport in alternating stacks is understood by analyzing bridge orbitals other than the transport orbitals.

8.
Carcinogenesis ; 27(7): 1398-403, 2006 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-16401636

RESUMEN

The goal of this study was to determine whether short-term fasting changes in urinary biomarkers related to oxidative stress: malondialdehyde (MDA), 8-isoprostaglandin F2alpha (8-isoPGF), 8-hydroxydeoxy-guanosine (8-OHdG) and 1,N6-ethenodeoxyadenosine (epsilondA) among female volunteers participating in the short-term fasting program in South Korea. The study subjects were 52 healthy women (mean age 28, range 15-48 years old) who provided urine samples both before and after the fasting program (average 7.2, range: 3-11 days). Urinary MDA was measured by HPLC-UV and epsilondA levels were measured by immuno-affinity purification followed by HPLC-fluorescence detection. Urinary 8-OHdG and 8-isoPGF concentrations were determined by ELISA. Plasma leptin levels were also measured by radioimmunoassay. Information on demographic characteristics, personal habits (smoking and alcohol consumption) and previous medical history were collected by a self-administered questionnaire. Percent loss of body weight (average 6.3%, 4.28 +/- 0.25 kg) was significantly correlated with fasting duration (r = 0.70, n = 52, P < 0.01). The plasma leptin levels after fasting (5.89 +/- 1.10 ng/ml) were significantly lower than before fasting (6.91 +/- 1.13 ng/ml) (n = 27, P = 0.05). Urinary MDA levels after fasting (0.18 +/- 1.10 mg/g creatinine) were significantly lower than before fasting (0.37 +/- 1.11) (n = 51, P < 0.01). Urinary 8-isoPGF also were significantly reduced after fasting (n = 47, P < 0.01). However, there was no significant difference in 8-OHdG or epsilondA. There was a statistically significant correlation between % change of urinary MDA level with % change of 8-isoPGF level (partial correlation coefficient r = 0.57, n = 46, P = 0.01). The correlations between % change of 8-OHdG and plasma leptin was also significant (partial correlation coefficient r = 0.51, n = 27, P = 0.02). Our results demonstrate that the short-term fasting reduces lipid peroxidation products but does not affect oxidative stress-induced DNA damage.


Asunto(s)
Daño del ADN/fisiología , Ayuno/orina , Peroxidación de Lípido/fisiología , Estrés Oxidativo/fisiología , 8-Hidroxi-2'-Desoxicoguanosina , Adolescente , Adulto , Cromatografía Líquida de Alta Presión , Desoxiadenosinas/orina , Desoxiguanosina/análogos & derivados , Desoxiguanosina/orina , Ensayo de Inmunoadsorción Enzimática , Femenino , Humanos , Leptina/sangre , Malondialdehído/orina , Persona de Mediana Edad , Prostaglandinas A/orina , Factores de Tiempo
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