ADSORPTION OF HEAVY METAL CATIONS ON KLASON LIGNIN FROM PAULOWNIA ELONGATA AND KRAFT LIGNIN

Lignin produced from two processes, 1. An acid hydrolysis process: sequential acid hydrolysis of Paulownia elongata wood powder (Klason lignin); 2. Kraft pulping process: black liquor (Kraft lignin), were studied for their heavy metal adsorption affinities. Both lignin samples were effective in removing Pb(II), providing the industrial application potential of lignin in treating lead contaminated wastewater. Hot water treatment of woody biomass is a typical biorefinery process that can result in lignin extraction for potential applications. Hot-water treatment was thus evaluated for its impact on the heavy metal adsorption affinities of Klason lignin. It was found hot water treatment can either enhance or weaken the lignin adsorption capacity depending on the severity of the treatment. Samples with long duration of treatment encountered a substantial loss in the adsorption ability. Depolymerization and condensation lignin reaction schemes under acidic and high temperature environment were summarized and applied to explain the affinity changes. The adsorption mechanism was further studied with Kraft lignin. The Pb(II) adsorption affinity of Kraft lignin was found to follow an “S” dependency on the environmental pH, indicating the existence of more than one ion-exchanging functional groups involved in the adsorption process. NMR characterization of Kraft lignin discovered phenolic hydroxyl groups and carboxyl groups as ion-exchanging functional groups. Other chemical structures in Kraft lignin such as aldehyde groups, ketone groups, ether bond, and aromatic rings are also considered as adsorption functional group because of their potential to complex with heavy metal cations. In order to explain the process from a mechanistic point of view, an novel adsorption theory named “1-n cooperative adsorption theory” was proposed which considered the existence of multiple active sites and the interaction of one adsorbate to multiple sites. The derived model evaluated the effect of temperature and pH on the adsorption affinity, which achieved a significant improvement compared to the Langmuir model. The simulation results show the binding affinity towards Pb(II) is significantly higher than Cd(II) and Ni(II). The new theory also has wide application range to other multivalent interactions including adsorption, flocculation, chelation, and filtration

The Research on the Impact of Service Failure Severity on Customer Service Failure Attribution in the Network Shopping

In recent years, the rapid development of electronic commerce in China has made online shopping one of the most important shopping ways. However, there are more and more service failures on online shopping, and complaints about them are increasing, which will hinder the development of e-commerce in China. After service failure occurring, customers are going to decide the parties who are responsible for the failure typically based on specific failure situation and personal experience, namely service failure attribution. A lot of research has discussed the effect of service failure attribution on service recovery, customer satisfaction, trust and loyalty, as well as consumer intent of sequent behavior. And yet, the research on service failure attribution process is relatively less. Based on the literatures, this paper examines the effect of failure severity on service failure attribution of locus, controllability, and the moderating role of customer relationship and social responsibility image. The results of this study suggest that: Severity of failure has a significantly positive effect on service failure attribution of locus, controllability; Customer relationship significantly moderates the influences of failure severity on service attribution of locus, controllability; Social responsibility image significantly moderates the influences of failure severity on service attribution of locus, controllability

Startup innovation capability from a dynamic capability-based view: A literature review and conceptual framework

While there is a rich body of literature on innovation, the concept of innovation capability (IC) is barely identifiable as a distinct construct. Startup IC is tacitly covered in innovation management, entrepreneurship, or small business literature. We suggest a dynamic capability (DC) approach to study innovation as a distinctive capability of startup firms. A semi-structured literature review of 125 articles combining various theoretical backgrounds is discussed, including the IC conceptualizations and operationalization that we extracted and clustered into a comprehensive yet synthetic framework. This paper suggests an IC construct as a higher order DC composed of three DCs—sensing, seizing, and transforming—and three layers of foundations—core IC, supporting IC, and startup entrepreneurial capabilities. This work adds to the emerging capability-based view of the innovation stream by addressing the specific case of startups. It recognizes their entrepreneurial nature and the important role of the entrepreneur’s capabilities and behaviors. It also contributes to the entrepreneurship theory by identifying the capabilities contributing to opportunity sensing and seizing and the capabilities required for transforming and shaping new opportunities. For practitioners, the IC framework offers a practical tool to assess startup ICs and identify strengths, weaknesses, and external complementarities

The Gender Differences in the Effect of Two-sidedness E-WOM Presentation Order on Product Attitude

In the Internet environment, electronic word-of mouth plays an important role in affecting consumers’ attitude toward product and service. However, there exists a widespread situation that consumers may receive two-sidedness e-WOM (An e-WOM has both positive and negative message about the same object), and past research has shown that gender differences and situational involvement affect consumers’ perception of e-WOM. This article demonstrates how presentation order of two-sidedness electronic word-of-mouth and gender influence in consumers’ perception and attitude toward product under different situations. Our study found that two-sidedness e-WOM presentation order and gender influenced product attitude: under low-involvement situation, males (females) exhibited primacy (recency)effects when receiving a two-sidedness e-WOM which containing both positive and negative messages about product. Under high-involvement situation, all respondents appeared to process two-sidedness e-WOM systematically and consider more relevant information in their evaluations. The result revealed that females continued to exhibit recency effects, but the primacy effects with males disappeared, they will exhibit obvious recency effects

A planar microphone array for spatial coherence-based source separation

We proposed a spatial coherence-based PSD estimation and source separation technique in [1] using a 32-channel spherical microphone array. While the proposed spherical microphone-based method exhibited a satisfactory performance in separating multiple sound sources in a reverberant environment, the use of a large number of microphones remains an issue for some practical considerations. In this paper, we investigate an alternative array structure to achieve spatial coherence-based source separation using a planar microphone array. This method is particularly useful in separating a limited number of sound sources in a mixed acoustic scene. The simplified array structure we used here can easily be integrated with many commercial acoustical instruments such as smart home devices to achieve better speech enhancements.This work is supported by Australian Research Council (ARC) Discovery Projects funding scheme (project no. DP140103412

3D sound field analysis using circular higher-order microphone array

This paper proposes the theory and design of circular higher-order microphone arrays for 3D sound field analysis using spherical harmonics. Through employing the spherical harmonic translation theorem, the local spatial sound fields recorded by each higher-order microphone placed in the circular arrays are combined to form the sound field information of a large global spherical region. The proposed design reduces the number of the required sampling points and the geometrical complexity of microphone arrays. We develop a two-step method to calculate sound field coefficients using the proposed array structure, i) analytically combine local sound field coefficients on each circular array and ii) solve for global sound field coefficients using data from the first step. Simulation and experimental results show that the proposed array is capable of acquiring the full 3D sound field information over a relatively large spherical region with decent accuracy and computational simplicity.This work was supported under the Australian Research Councils Discovery Projects funding scheme (project no. DP140103412)