970 research outputs found
The Mediation Effect of Trusting Beliefs on the Relationship Between Expectation-Confirmation and Satisfaction with the Usage of Online Product Recommendation
Online Product Recommendations (OPRs) are increasingly available to onlinecustomers as a value-added self-service in evaluating and choosing a product.Research has highlighted several advantages that customers can gain from usingOPRs. However, the realization of these advantages depends on whether and towhat extent customers embrace and fully utilise them. The relatively low OPR USAgerate indicates that customers have not yet developed trust in OPRs’ performance.Past studies also have established that satisfaction is a valid measure of systemperformance and a consistent significant determinant of users’ continuous systemusage. Therefore, this study aimed to examine the mediation effect of trustingbeliefs on the relationship between expectation-confirmation and satisfaction. Theproposed research model is tested using data collected via an online survey from626 existing users of OPRs. The empirical results revealed that social-psychologicalbeliefs (perceived confirmation and trust) are significant contributors to customersatisfaction with OPRs. Additionally, trusting beliefs partially mediate the impactof perceived confirmation on customer satisfaction. Moreover, this study validatesthe extensions of the interpersonal trust construct to trust in OPRs and examinesthe nomological validity of trust in terms of competence, benevolence, andintegrity. The findings provide a number of theoretical and practical implications. 
Isolated Magnetic Dipole MIMO Antenna with Linear Port Configuration for Wireless Applications
This paper is presenting preliminary research to design Isolated Magnetic Dipole MIMO Antenna for wireless application. Isolated Magnetic Dipole (IMD) structure is one of the unique geometries that offers compact and low damaging electrical current at the ground surface. However, less attention in discussing design the MIMO antenna using IMD structure. The two elements MIMO antenna using IMD with linear port configuration has constructed at 2.4 GHz. Then simulated and analyzed to validate the feasibility of the IMD-MIMO antenna. The simulation and analysis cover S-Parameters, radiation, Gain, Correlation coefficient, and diversity gain. In addition, simple Semi-circle structure etched on the ground layer to improve the isolation of MIMO antenna. From the simulation results, the IMD-MIMO antenna has better results and highly recommended for designing compact MIMO antenna
QUALITATIVE PHYTOCHEMICAL COMPARISON BETWEEN FLAVONOIDS AND PHENOLIC ACIDS CONTENTS OF LEAVES AND FRUITS OF MELIA AZEDARACH (FAMILY: MELIACEAE) CULTIVATED IN IRAQ BY HPLC AND HPTLC
Objective: The aim of our study was to compare between flavonoids and phenolic acids contents of leaves and fruits of Melia azedarach since no phytochemical investigation had done previously in Iraq.Methods: The leaves and fruits of Melia azedarach were extracted by soxhlet using 80% ethanol then the dried extract was suspended in water and fractionated using petroleum ether, chloroform, ethyl acetate, and n-butanol. The n-butanol fraction was hydrolyzed by acid and partitioned with ethyl acetate. The different fractions containing flavonoids and phenolic acids were analyzed by HPLC and HPTLC.Results: The HPLC results revealed the presence catechin-7-O-glycoside in fruit only, while kaempferol-7-O-glycoside is found in the leaves only. Catechin and its glycosides are more abundant in the fruits than in the leaves. The HPTLC results revealed that kaempferol and quercetin are present in all fractions of leaves and fruits as aglycones and as glycosides. Free chlorogenic was found in both leaves and fruits.Conclusion: No major differences were found between the flavonoids and phenolic acids contents of the leaves and fruits of Melia azedarach
Wavelength dependent light tunable resistive switching graphene oxide nonvolatile memory devices
This paper reports on the first optically tunable graphene oxide memristor device. Modulation of resistive switching memory by light opens the route to new optoelectronic devices that can be switched optically and read electronically. Applications include integrated circuits with memory elements switchable by light and optically reconfigurable and tunable synaptic circuits for neuromorphic computing and brain-inspired, artificial intelligence systems. In this report, planar and vertical structured optical resistive switching memristors based on graphene oxide are reported. The device is switchable by either optical or electronic means, or by a combination of both. In addition the devices exhibit a unique wavelength dependence that produces reversible and irreversible properties depending on whether the irradiation is long or short wavelength light, respectively. For long wavelength light, the reversible photoconductance effect permits short-term dynamic modulation of the resistive switching properties of the light, which has application as short-term memory in neuromorphic computing. In contrast, short wavelength light induces both the reversible photoconductance effect and an irreversible change in the memristance due to reduction of the graphene oxide. This has important application in the fabrication of cloned neural networks with factory defined weights, enabling the fast replication of artificial intelligent chips with pre-trained information
Accumulation and partitioning of total phenols in two varieties of Labisia pumila Benth. under manipulation of greenhouse irradiance
Two varieties of Labisia pumila (var. pumila and alata) were exposed to four levels of greenhouse irradiance (100, 70, 50, 30% of the incoming radiation (IR); equivalent to respective 670, 630, 470, 240 μmol m-2 s -1) in a 2-factorial Randomized Complete Block Design trial with the aim to determine the existence of varietal preferences in total phenols (TP) accumulation and their distribution to different organs (leaf, stem, root) due to manipulation in irradiance levels. TP were determined according to Folin-Ciocalteu method and results expressed in mg Gallic acid g-1 dry weight (DW). Total phenolic content in red var. alata consistently recorded lower values (p≤0.0001) than green var. pumila when exposed to high irradiance (100-70% IR) by 4.5-6.6%. Reducing irradiance to 50% IR; however, increased TP in red higher than green var. by 39.2% (10.96 vs. 7.87 mg GAE g-1 DW) due to marked increase (p≤0.0001) in phenols partitioning to the leaf of red var. compared to green var. (4.6 vs. 3.0 mg g"). Partitioning of phenols to the leaf in red var. alata, although kept increasing (6.5% over green var.), did not continue to enhance plant TP with further decrease in irradiance to 30% IR. Instead TP partitioning to the stem and root in green var. pumila exceeded substantially over red var. alata by 11.8-18.4%, respectively, implying there are varietal preferences between var. pumila and alata in terms of TP accumulation and partitioning related to varying levels of irradiance. Although both varieties are shade loving, var. alata was more sensitive to high irradiance than var. pumila in accumulation of TP in the plants and that manipulation of irradiance in controlled environment agriculture was able to enhance partitioning of phenols to different parts or organs of Labisia pumila for potential niche production of plant parts
Incorporating capacitative constraint to the preference-based conference scheduling via domain transformation approach
No AbstractKeywords: conference scheduling; domain transformation approach; capacity optimizatio
Short communication: Survey of Methyl Tertiary Butyl Ether (MTBE) toxicity using bioassay on Daphnia magna
In this study, the toxicity of MTBE on the crustacean Daphnia magna (Cladocera) has been studied. At the beginning, for finding the range of sensitivity of D. magna to MTBE, a test had been conducted at 24h. The initial and final tests with synthetic MTBE has been done with containing solutions of water accommodated fractions (WAFs) in periods of 24 and 48h and then static bioassay was calculated in two phases of tests and the data were obtained and analyzed by SPSS 13 by using probit analysis. In 24h, lc10, lc50 and lc90 for MTBE on D. magna were 345, 646 and 941mg/l and for 48h, they were 361, 476 and 893mg/l, respectively. Also, the maximum allowable concentration (MAC) of MTBE (WAFs) on D. magna was determined in 24 and 48h, 64.6 and 47.6mg/l, respectively. Results indicated that D. magna could be used for toxicity tracing MTBE in surface and ground water, because these crustaceans have perfect resistance against pollution of MTBE. It is also concluded that after 24 and 48h exposure time, there was no significant difference observed in the activity and mortality of D. magna
Modelling of precast concrete composite slab using finite and interface elements
This study presents an efficient finite element analysis technique which shows great versatility in modelling of precast composite flooring system subjected to static loadings. The method incorporates sliding and opening in the analysis of composite structures using the interface element which was specifically designed to simulate the actual behaviour at the interfaces between contacting materials. A three-dimensional finite element model of the precast composite slab which exhibits discontinuous behaviour was performed to demonstrate the potential and applicability of the proposed method of analysis. The results of the analysis demonstrate that the overall response of a discontinuous system to external loading is significantly affected by the bonding condition at the interfaces between the contacting materials
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