Polymorphism and polymerisation of acrylic and methacrylic acid at high pressure

The polymorphism and polymerisation of two related acids have been investigated under high pressure conditions. Acrylic acid crystallises as a new polymorph at 0.65 GPa whilst methacrylic acid crystallises in a new polymorph at a higher pressure of 1.5 GPa. Both these new polymorphs exhibit similar hydrogen bonding motifs to the low temperature phases, however, the molecular packing differs significantly

Portfolio management with cryptocurrencies: the role of estimation risk

This paper contributes to the literature on cryptocurrencies, portfolio management and estimation risk by comparing the performance of naïve diversification, Markowitz diversification and the advanced Black–Litterman model with VBCs that controls for estimation errors in a portfolio of cryptocurrencies. We show that the advanced Black–Litterman model with VBCs yields superior out-of-sample risk-adjusted returns as well as lower risks. Our results are robust to the inclusion of transaction costs and short-selling, indicating that sophisticated portfolio techniques that control for estimation errors are preferred when managing cryptocurrency portfolios

Impact of contractor internal tendering procedure governance on tender win-rates: How procedures can be improved

Construction contractors normally, though not always, pursue tenders with the expectation of winning and subsequently making a project profit. Corporate governance (CG) constraints, risk appetite, and selected tender strategy impact contractors' tendered prices and any associated qualifications. Therefore, failure to win may not constitute 'failure' in senior executive's eyes. Increasing CG within some jurisdictions has led to more complicated contractor internal tendering procedures (ITP) with layers of management reviews and risk committee sign-offs. The question arises as to whether these changes make any difference to tender win rates and subsequent project outcomes. A series of qualitative semi-structured interviews were undertaken with 25 high-profile Australasian based construction contractors (11, either directly or via parent companies, operate internationally-Europe, Africa, Asia and North America), providing a mix of publicly listed and privately owned companies, as part of a wider research program investigating the efficiency and effectiveness of contractors' ITP. Moving beyond previous research limitations of smaller contractors (often sub-AU$100m turnover) this qualitative research looks at much larger contractors. Content analyses of the interview transcripts found that, while contractors talked equally about 'win' and 'lose', most did not see losing a tender as 'failure'. Only a quarter felt their changed ITP made a difference to their tender win-rate. Somewhat unexpectedly interview findings suggest that approximately three-quarters of contractors have ITP that do not formally require lessons learned (LL) from previous tenders nor projects to be inputs in subsequent tender pursuits. Larger contractors (over AU$500m turnover) were twice as likely to discuss LL, indicating different governance approaches to tender outcome expectations. Informal LL approaches were applied to clients' reputations (particularly payment) in bid/no-bid decisions. Interviewee suggestions of processes by which contractors can improve resultantly their LL procedures, as part of their CG, are also presented

The performance of technical trading rules in Socially Responsible Investments

This study is the first to examine the performance of technical trading in tradeable Socially Responsible Investment (SRI) indices. We employ a number of popular trend-following and mean-reverting technical trading rules and find that trend-following technical trading rules offer very little predictive power or significant returns to investors. However the mean-reverting technical trading rules do offer significant returns, even after controlling for data-snooping, risk, transaction costs and out-of-sample testing. Therefore our results add to the literature by showing that mean-reverting technical trading rules offer substantial predictive power in SRI indices, but traditional trend-following rules offer very little predictive power

Rethinking the tendering frameworks of construction contractors in the context of a soft systems methodology approach

Limited research has been conducted on the internal tendering procedures (ITP) of construction contractors because of the commercially sensitive and confidential nature of the subject matter. This limitation explains the reluctance of contractors to undergo interviews. Existing research (outside bid/no-bid and margin decision factor identification and subsequent decision modeling development) only begins to provide insights into key tendering stages, particularly around risk assessments and corporate review processes. Early research suggested one to three review stages. However, when considering the whole work procurement process from prospect identification to contract execution, five to seven series of reviews can be arguably applied by some contractors, wherein some reviews stepped through several layers of internal senior management. Tendering processes were presented as flowchart models that traditionally follow “hard” system (rectangular shapes and straight line arrows) steps, which suggest that a precise process also leads to precise results. However, given that contractors do not win every tender they submit, the process is less precise than that suggested in rigidly structured flowcharts. Twenty-five detailed semi-structured interviews were held with purposely selected high-profile publicly and privately owned construction companies in Australia with significantly varied turnovers. Analyses show that contractors are concerned about the negative effects of increasing corporate governance demands, with many stating that people involved are the most critical element to tendering success. A new way of presenting the ITP of contractors is assessed using a soft systems methodology (SSM) approach. SSM offers an alternative way of considering human interaction challenges within the ITP of contractors, which needs to be tested with the industry. The format graphics of SSM guidelines are presented as a way of offering contractors a different approach, which may assist individuals who are looking to re-structure their tendering activities in a more humanistic and less rigid procedural approach

Do momentum and reversal strategies work in commodity futures? A comprehensive study

Purpose Motivated by the debate on the patterns and sources of commodity futures returns, this paper investigates the performance of three investment trading strategies, namely, the momentum strategy of Jegadeesh and Titman (1993), the 52-week high momentum strategy of George and Hwang (2004) and the pairs trading strategy of Gatev et al. (2006) in the commodity futures market. Design/methodology/approach The three strategies are those given by Jegadeesh and Titman (1993), George and Hwang (2004) and Gatev et al. (2006), respectively. Findings The authors find that there is no significant reversal profit across 189 formation-holding windows for all the three strategies. However, there are statistical and economically significant momentum profits, and the profitability increases with the rising of formation-holding periods. Momentum returns are quite sensitive to market conditions but the crash of momentum returns is partly predictable. Return seasonality, risk and herding also provide partial explanation of the momentum profits. Originality/value The authors are the first to compare the performances of the pairs trading strategy of Gatev et al. (2006), the conventional momentum of Jegadeesh and Titman (1993), and the 52-week high momentum of George and Hwang (2004) under 189 formation-holding windows. Also, the authors are the first to investigate the association between herding behaviour and momentum returns in the commodity futures market

The emotive qualities of patterns : insights for design

The role of pattern use in the visual arts has not been fully analysed in terms of its emotive and semantic values. Patterns have played a dominant role in art, architecture and design for thousands of years but their nuanced relationship with human observers has not been systematically analysed – the emotive and semantic qualities of their forms are yet to become fully clear. This paper presents work in experimental aesthetics, analysing the emotive and semantic qualities of commonly used patters. Focus groups were used as a means of analysing a set of sixteen distinct patterns where each group considered each pattern and assigned each one emotive and semantic values. The patterns were sourced from a wide variety of cultures and varied hugely in terms of their underlying geometry; angular forms, curved forms and symbolic content. Our results reveal that many patterns have complex emotive connotations and can sometimes convey strong value judgements that we suggest are derived from the qualities of their form and foundational structure. The possible reasons for these phenomena and the implications for design practice and design research and subsequently discussed

Does Twitter predict Bitcoin?

This paper adds to the growing literature of Bitcoin by examining the link between investor attention and Bitcoin returns, trading volume and realized volatility. Unlike previous studies, we employ the number of tweets from Twitter as a measure of attention rather than Google trends as we argue this is a better measure of attention from more informed investors. We find that the number of tweets is a significant driver of next day trading volume and realized volatility which is supported by linear and nonlinear Granger causality tests

Bitcoin Under the Microscope

This paper explores and describes historical on-chain transaction data recorded on the Bitcoin blockchain, constructs a panel of all individual Bitcoin users, and computes their balances in the cross-section and over time. We run clustering algorithms to combine addresses that belong to the same user into wallets and we find that using wallets over addresses as the unit of analysis allows for more economically meaningful interpretations of user behavior. We identify and divide wallets into user categories - miners, exchanges, services, retail wallets and receiving-only addresses - and observe varying activity levels and balances in the cross-section and over time, corresponding to their intended role in the Bitcoin network. Our findings also suggest heterogeneity in financial performance across user categories with miners exhibiting higher realized returns relative to exchanges and retail users