A comprehensive evaluation of physical and environmental performances for wet-white leather manufacture

This paper presents the comprehensive evaluation results of physical and environmental performances for a novel wet-white (chrome-free) leather manufacturing. The tanning process is optimized as 15 wt% tannic acid (TA) combination with 4 wt% Laponite nanoclay, giving the leather with shrinkage temperature (Ts) above 86 °C. Inductively coupled plasma-atomic emission spectrometry (ICP-AES) measurements indicate that Laponite can be evenly and tightly bound within the leather matrix, which is further confirmed by scanning electron microscopy and energy dispersive X-ray (SEM-EDX) spectroscopy analysis. The resultant wet-white leathers have reasonable good physical properties that can meet the standard requirements for furniture leather without containing hazardous Cr(VI) and formaldehyde. Further life cycle assessment (LCA) studies shows that tanning process is the main contributor to environmental impact categories in the wet-white tanning process, and tannic acid is the most significant substance factor. Compared to conventional chrome tanning, the wet-white tanning process exhibits much lower abiotic depletion potential (ADP), and reduced global warming potential (GWP) and human toxicity potential (HTP) impacts due to the nature of vegetable tanning; whereas, GWP excluding biogenic carbon and energy consumption are higher owing to prolonged run time.Peer ReviewedPostprint (published version

Note on a non-critical holographic model with a magnetic field

We consider a noncritical holographic model constructed from an intersecting brane configuration D4/$\bar{\rm{D4}}$-D4 with an external magnetic field. We investigate the influences of this magnetic field on strongly coupled dynamics by the gauge/gravity correspondence.Comment: 18 pages, references added and typos revise

Enhancing Learning Engagement and Academic Performance: A Systematic Review among Private College and University Students in Xi'an, China

This systematic review aims to explore the factors influencing learning engagement and its impact on learning performance among private college and university students in Xi'an, China. Learning engagement is a crucial element in students' educational experiences, and understanding the factors that contribute to it can significantly enhance learning outcomes. By systematically reviewing and synthesizing existing literature, this study identifies the key factors influencing learning engagement and investigates the relationship between learning engagement and learning performance. The findings of this review can inform educational institutions and policymakers in designing effective strategies to enhance student engagement and improve academic performance

Precoding Method Interference Management for Quasi-EVD Channel

The Cholesky decomposition-block diagonalization (CD-BD) interference alignment (IA) for a multiuser multiple input multiple output (MU-MIMO) relay system is proposed, which designs precoders for the multiple access channel (MAC) by employing the singular value decomposition (SVD) as well as the mean square error (MSE) detector for the broadcast Hermitian channel (BHC) taken advantage of in our design. Also, in our proposed CD-BD IA algorithm, the relaying function is made use to restructure the quasieigenvalue decomposition (quasi-EVD) equivalent channel. This approach used for the design of BD precoding matrix can significantly reduce the computational complexity and proposed algorithm can address several optimization criteria, which is achieved by designing the precoding matrices in two steps. In the first step, we use Cholesky decomposition to maximize the sum-of-rate (SR) with the minimum mean square error (MMSE) detection. In the next step, we optimize the system BER performance with the overlap of the row spaces spanned by the effective channel matrices of different users. By iterating the closed form of the solution, we are able not only to maximize the achievable sum-of-rate (ASR), but also to minimize the BER performance at a high signal-to-noise ratio (SNR) region

Upward earnings mobility on the decline in Hong Kong? A study based on census data

This paper offers a new intuitive approach using census data to cast light on earnings mobility. We find that in Hong Kong upward mobility opportunities indeed fell for those born in the mid 70s and later, but that there has been a remarkable improvement for degree holders in recent years. Contrary to common belief, even though starting salaries had fallen, degree holders more or less maintained their relative advantage by age 31-35. Moreover, among degree holders, beginning in 2011 upward mobility showed an improvement for all cohorts at the higher income end though less so at the lower end. The mobility ratios of degree holders born after 1980 are higher than almost all of the earlier cohorts. The evidence suggests that this improvement is likely to be related to the retirement of the babyboomers, and is expected to continue for some time

Delayed compensation and the hiring of older workers : evidence from Hong Kong

An original survey of Hong Kong establishments identifies hiring and employment patterns by age of worker. As in the U.S., there exist many firms which employ older workers but do not hire older workers. This similarity is important as Hong Kong neither prohibits age discrimination nor requires uniform fringe benefit provision. Thus, these laws thought to account for the U. S. pattern may not be a sufficient explanation. Instead, our finding that those Hong Kong firms delaying compensation disproportionately hire younger workers suggests that existing hiring patterns may largely be a response to inherent monitoring difficulties