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Detecting precursory signals is critical to increasing the resilience of megaprojects to crises. This study aims to investigate key crisis precursors to better apprehend traces of megaproject crises and proactively respond to approaching crises, thereby increasing project resilience.

Drawing on the theory of weak signals, 25 potential precursors of megaproject crises are extracted. Using exploratory structural equation modeling (ESEM), four models were tested to identify key crisis precursors based on a questionnaire survey of 168 megaproject participants in China. Analysis of variance (ANOVA) was employed to examine the differences in participants’ perceptions of key crisis precursors.

Four key crisis precursors were identified: Imbalance of Benefits and Costs, Irresponsible and Unqualified Key Participants, Regulatory Mechanisms Lacking Transparency and Flexibility, and Information Uncertainty and Asymmetry. Compared with senior executives, team members think that key crisis precursors related to regulatory mechanisms and key participants are more likely to trigger crises, which affects responsive actions toward detected crisis precursors. The findings help identify problems at an early stage and enable timely intervention to mitigate crises.

Detection of key crisis precursors allows for proactive and targeted actions to mitigate crises. Megaproject development is affected by institutional mechanisms. The influence of institutions on the effectiveness of crisis management needs further investigation.

Limited attention has been paid to recognizing precursors of megaproject crises. This study identifies four key crisis precursors by uncovering the interrelationships among potential precursors, which enables rapid adaptation to future crises.

The purpose of this paper is to prepare polypyrrolone nanofibres and investigate the effects of concentration of polypyrrolone precursor and voltage on polypyrrolone precursor nanofibres by electrospinning, in order to achieve ideal nanofibres.

Polypyrrolone nanofibres were prepared by polypyrrolone precursor electrospinning. Various fibres were made with different concentrations of polypyrrolone precursor and different voltages. Morphology of fibres was characterised by scanning electron microscopy to study the effect of different preparation conditions on morphology of fibres.

A method of preparation of polypyrrolone nanofibres with the polypyrrolone precursor by electrospinning was introduced which had not been reported. The effects of concentration of polypyrrolone precursor and voltage on the morphology of the nanofibres were studied. It was found that the concentration of polypyrrolone precursor was the major factor and the voltage also affected the distribution and dimension of polypyrrolone fibres to an extent.

Polypyrrolone nanofibres provided potential applications in solar cells and field‐effect transistors.

To the best of the authors' knowledge, there is no literature on the preparation of polypyrrolone nanofibres by electrospinning. Herein the preparation of polypyrrolone nanofibres by electrospinning is first reported. The polypyrrolone nanofibres might be used in solar cell, non‐linear optics, conducting and semi‐conducting materials.

According to UNDCP's World Drug Report published in 1997, the illicit drug industry's annual turnover is estimated to be US$400bn, roughly equivalent to 8 per cent of total international trade. The profit in the drugs business depends heavily on the availability of precursors. Only opium and cannabis — which are not as costly as heroin and some other drugs — are consumed in a relatively raw form without being chemically processed. Other drugs of abuse require precursor chemicals in their manufacture. In the case of opium, for example, a farmer will be offered only US$80 for 1 kg of opium. With the availability of chemicals, this opium will be converted, in stages, into heroin. The street value of 1 kg of heroin in the United States, for instance, is US$290,000. This staggering profit is only possible if the illicit drug industry can access the chemicals they need for the conversion.

The purpose of this paper is to study the effect of silver (Ag) precursor on friction and wear.

Thermogravimetric analysis of the oil with Ag precursor and X-ray diffraction of the decomposition product of the Ag complex were performed. The tribological behavior was evaluated on a UMT-3M Tribometer (CETR) using pure military-grade oil lubricant and the prepared lubricant at room temperature and at 300°C. Energy-dispersive spectroscopy of the chemical composition on the wear scar was performed.

When there is 1 weight per cent Ag precursor in the lubricant, the coefficient friction reduces by about 8 per cent at room temperature and by about 14 per cent at 300°C, and the wear probability also decreases, from moderate wear to mild wear at 300°C. There were more productions which could form metal Ag boundary films possessing low shearing stress and excellent lubricity at 300°C.

Ag precursors used as additives in a military-grade oil lubricant and excellent lubricity found at high temperature.

This paper aims to evaluate the effect of precursors on the anticorrosion property of silica encapsulated waterborne aluminium pigments (WBAPs).

The silica encapsulated WBAPs were prepared using different siloxanes as precursors. The anchorage and compactness of silica films on aluminium flakes were characterized by optical microscopy, scanning electron microscopy and N2 adsorption-desorption. The anticorrosion property and glossiness of WBAPs were evaluated.

The effect of precursors on anticorrosion property of silica encapsulated WBAPs is reflected from the anchorage and the compactness of silica on aluminium flakes surface. Furthermore, the structure of γ-aminopropyl triethoxysilane benefits the anchorage and the compatibility between pigment and acrylic resin. Neither high nor low ratio of tetraethoxysilane/γ-aminopropyl triethoxysilane is favourable to the anchorage and formation of dense silica film on the aluminium flakes surface. To obtain perfect WBAP, the precursors of silica must be carefully selected.

Only four kinds of precursors were used in this work; other precursors could also be studied.

The investigation results provide theoretical basis to obtain excellent WBAPs.

The method to investigate anticorrosion property of WBAPs that is based on the effect of precursors on the performance of silica was novel.

This study aims to investigate the morphology and physicochemical properties of BiOBr/Polyvinylidene fluoride (PVDF) composite membranes and the differences in the properties of BiOBr/PVDF composite membranes made by adding different precursor ratios during the casting process.

In this paper, sodium bromide and Bi(NO3)3 were used as precursors for the preparation of BiOBr photocatalysts, and PVDF membranes were modified by using the phase conversion method in conjunction with the in situ deposition method to produce BiOBr/PVDF hydrophilic composite membranes with both membrane separation and photocatalytic capabilities.

The characterization results confirmed that the composites were successfully and homogeneously co-mingled in the PVDF membranes. The related performance of the composite membrane was tested, and it was found that the composite membrane with the optimal precursor incorporation ratio had good photocatalytic efficiency and antipollution ability; the removal efficiencies of methyl orange, rhodamine B and methylene blue were 80.43%, 85.02% and 86.94%, respectively, in 2.5 h. The photocatalytic efficiency of composite membranes with different precursor ratios increased and then decreased with the increase of the precursor addition ratio.

The composite membrane is prepared by phase conversion method with in situ deposition method, and the BiOBr material has unique advantages for the degradation of organic dyes. The comprehensive experimental data can be known that the composite membrane prepared in this paper has high degradation efficiency and good durability for organic dyes.

In this chapter, we examine several attributes of lone wolf terrorists and how their activities are temporally and geospatially patterned. In particular, we demonstrate how precursor behaviors and attack characteristics of lone wolves are similar and different compared to those of group-based terrorists.

Based on data drawn from the American Terrorism Study (ATS), we examine 268 federal terrorism “indictees” linked to 264 incidents. Three types of loners are identified based on group affiliations and levels of assistance in preparing for and executing terrorist attacks. A series of analyses comparatively examine loners who had no assistance and those actors that did.

The results of this study suggest that lone wolf terrorists are more educated and socially isolated than group-based actors. Lone wolves also engage in less precursor activities than group actors, but are willing to travel greater distances to prepare for and execute attacks. Explanations for why lone wolves are able to “survive” longer than terrorist groups by avoiding arrest may in part stem from their ability to temporally and geospatially position their planning and preparatory activities.

Studies on lone wolf terrorism remain few and many are plagued by methodological and conceptual limitations. The current study adds to this growing literature by relying on lone wolf terrorism data recently made available by the American Terrorism Study (ATS). Our findings are valuable for members of the law enforcement and intelligence communities responsible for the early detection and prevention of lone wolf terrorism in the United States.

Although much research focuses on the compulsive buying behavior theory, little attention has been paid to evaluation and diagnosis of compulsive buying in Eastern Europe. This is surprising, given an increasing prevalence of consumerism in many transitioning economies. Young consumers are particularly vulnerable to this phenomenon. The purpose of this study is to adapt the Richmond Compulsive Buying Scale to the Eastern European, specifically Polish cultural and language environment, and to validate it within a group of young Polish consumers, as well to assess the compulsive buying prevalence and the relationship between the compulsive buying and its precursors.

The Richmond Compulsive Buying Scale was selected for adaptation to the Polish context as it represents one of the best methodological and substantive compulsive buying measures in literature. The research is composed of two studies. Study 1 uses an in-person survey of young consumers (N = 504). A wide range of statistical procedures and latent variable modeling was used in the analysis. Study 2 (N = 756) uses an online survey to evaluate the correlation and relationship between the compulsive buying measure and its precursors, including consumers’ traits and states, by implementing a multiple indicators and multiple causes model.

The results of the two studies confirm that the adapted scale represents a valid and reliable measure of compulsive buying tendency in Poland, with the identified incidence rate of compulsive buying among Polish young consumers ranging from 11% in Study 1 to 11.6% in Study 2. In comparison with the results of other studies using the same measure, the current research findings reveal a similarity with the compulsive buying prevalence in China (10.4%; He et al., 2018), Brazil (9.8%; Leite et al., 2013) and slightly exceed the level found in western societies (e.g. 8.9% in the USA; Ridgway et al., 2008). The results of Study 2 indicate that compulsive buying in Poland is induced by low self-esteem and high levels of materialism, depression, anxiety, stress and negative feelings.

The present research offers a methodological and substantive contribution by adapting and testing the original version of the Richmond Compulsive Buying Scale within an Eastern European transitional market; specifically Poland. In addition, the study offers an empirical contribution to the international research on compulsive behavior, including its precursors, as seen in young consumers.

This research offers important public policy implications and highlights ethical implications for business organizations. In particular, the findings of this study offer suggestions for enhancing policies and processes of programing appropriate social and educational campaigns that can save young consumers from the negative consequences of compulsive buying.

The transitional status of the Polish economy and other Eastern European countries has given rise to compulsive buying behavior, especially among young consumers. This emerging consumer behavior trend in Eastern Europe is still underexplored and underreported; hence, there exists a strong need for exploring and measuring such behavior across different Eastern European markets.

Urban tropospheric ozone (O₃) concentrations can reach 40 folds its background level due to traffic‐induced emissions and extensive industrial activities. As such, O₃ has become a pervasive air pollution problem in urban areas despite major efforts to control its precursors. In this paper, O₃ formation mechanisms are briefly described, countrywide emissions with emphasis on O₃ precursors are summarized, and field measurements of O₃ background levels and its precursors in an urban area are presented. Simulation results using a photochemical air quality model including a sensitivity analysis with respect to design ratios and mixing heights are then presented. Mitigation alternatives and policies to control O₃ formation are examined in the context of country‐specific characteristics.

Various approaches have been made to alter the vibration sensing properties of zinc oxide (ZnO) films to achieve high sensitivity. This paper aims to report the experimental study of the fabrication of precursor molar ratio concentration varied ZnO nanostructures grown on rigid substrates using the refresh hydrothermal method. The effect of these fabricated ZnO nanostructures-based vibration sensors was experimentally investigated using a vibration sensing setup.

ZnO nanostructures have been grown using low temperature assisted refresh hydrothermal method with different precursor molar concentrations 0.025 M (R1), 0.075 M (R2) and 0.125 M (R3). Poly 3,4-ethylenedioxythiophene polystyrene sulfonate, a p-type material is spun coated on the grown ZnO nanostructures. Structural analysis reveals the increased intensity of the (002) plane and better c-axis orientation of the R2 and R3 sample comparatively. Morphological examination shows the changes in the grown nanostructures upon increasing the precursor molar concentration. The optical band gap value decreases from 3.11 eV to 3.08 eV as the precursor molar concentration is increased. Photoconductivity study confirms the formation of a p-n junction with less turn-on voltage for all the fabricated devices. A less internal resistance of 0.37 kΩ was obtained from Nyquist analysis for R2 compared with the other two fabricated samples. Vibration testing experimentation showed an improved output voltage of the R2 sample (2.61 V at 9 Hz resonant frequency and 2.90 V for 1 g acceleration) comparatively. This also gave an increased sensitivity of 4.68 V/g confirming its better performance when compared to the other fabricated two samples.

Photoconductivity study confirms the formation of a p-n junction with less turn-on voltage for all the fabricated devices. A less internal resistance of 0.37 kΩ was calculated from the Nyquist plot. Vibration testing experimentation proves an increased sensitivity of 4.68 V/g confirming its better performance when compared to the other fabricated two samples.

Vibration testing experimentation proves an increased sensitivity of 4.68 V/g for R2 confirming its better performance when compared to the other fabricated two samples.