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In this work, the production of ceramic moulds for aluminium casting using a stereolithographic apparatus (SLA) is presented.

Suspensions of silica powders in a photoreactive resin were used in a standard SLA equipment in order to build green parts. SLA, SLA‐250 (3D System, Valencia, CA) was modified in order to fabricate a ceramic green parts.

A characterization of mechanical properties of the material samples was performed. Finally, moulds for aluminium casting were obtained either using the stereolithographic part as a green mould, either by pyrolisis of the organic binder and subsequent sintering at high temperature.

Future investigations will be devoted to optimise the process and the mechanical performances of the sintered parts, improving the rheological properties of suspensions and reducing the building time.

This is a novel work on the production of ceramic moulds for aluminium casting using a SLA.

The purpose of this paper is to expand the theoretical meaning and application of the separate components of the interaction coefficient as obtained from the generalized viscosity model.

Both theoretical and experimental analysis have been utilized to better understand the meaning of the separate components of the interaction coefficient obtained from the generalized viscosity model. Analysis of the experimental data of Schaller and Humphrey has been used to successfully isolate the separate components of the interaction coefficient.

The relative unhindered volume is the volume outside the sphere of influence of a particle that is responsible for the viscosity characteristics of a coating. This is the volume available for particles to move in the suspension and still contribute to the viscosity. The smaller the relative unhindered volume the higher the viscosity. As the interaction coefficient, σ, increases the particles increase their interaction with each other and the relative unhindered volume decreases. Using the data of Schaller and Humphrey, it was found that the interaction coefficient agreed best with the theoretical expectation relative to particle size when the ionic strength was low. At high levels of ionic strength, the solvent‐particle component of the interaction coefficient was dominant and the influence of particle size on the interaction coefficient was minimal.

Only one set of experimental data was successfully utilized for illustrative purposes in this study but the resulting analysis has implicated a broad range of practical applications. In addition, the general theoretical concepts elucidated relative to the interaction coefficient should still be applicable independent of the experimental results.

The analysis presented in this paper provides several practical guidelines to separate and control the charge component of pigments in a suspension from their size component using the interaction coefficient as described in this study. Consequently, the results of this study should provide several new practical approaches to use when attempting to control the viscosity of suspensions for a broad range of practical applications and for a broad range of suspension types including coatings.

This is the first time that the theoretical statistical character of the interaction coefficient as indicated in the generalized viscosity model has been specifically elucidated. In addition, the relatively simple experimental separation of the interaction coefficient into its size and electrical components has been shown to be widely applicable in this paper.

The purpose of this paper is to exploit the effect of equity financing constraints on the firm’s investment in research and development (R&D) by utilizing a quasi-experiment in China.

A difference-in-difference identification strategy is employed to test the treatment effect of the IPO suspension in China. For robustness testing, the authors incorporate cross-sectional variation in external financial dependence to identify the different influences an IPO suspension has on R&D investments for firms across multiple industries through the difference-in-difference-in-difference approach and the authors also adopt a matching approach to check the parallel trend assumption. Moreover, the authors introduce a placebo test to further verify the empirical results.

Through the empirical analysis, the authors find that the firms subjecting to the IPO suspension are more likely to reduce their investments in R&D than those not affected by the IPO suspension. Besides, the negative effect of equity financing constraints on R&D investments is concentrated on external financial dependent industries. The firms in industries with larger external financial dependence tend to decrease more in their R&D expenditures when they experience the equity financing constraints.

This paper provides a new negative evidence on equity financing constraints on R&D investments link so that contributes to the debate about the effect of the financing constraints on R&D investments.

The study provides a meaningful suggestion for governments to diminish the frictions in the financial market and to improve enterprises’ public financing circumstances by finding that equity financing constraints have negative impacts on firms’ R&D investments.

There are some apprehensions around previous empirical studies investigating the impact of financing constraints on R&D investments as the existing literature is unable to provide an unambiguous method to exactly distinguish and measure the degree of financing constraints the firms confronting with. This paper solves this problem by first utilizing an IPO suspension in China as a quasi-experiment to examine the effect of equity financing constraints. Therefore, it gives insight to solve the problem of measuring financing constraints in future researches.

In this paper, improvements in reducing transmitted accelerations in a full vehicle are obtained by optimizing the gain parameters of an active control in a roughness road profile.

For a classically designed linear quadratic regulator (LQR) control, the vibration attenuation performance will depend on weighting matrices Q and R. A methodology is proposed in this work to determine the optimal elements of these matrices by using a genetic algorithm method to get enhanced controller performance. The active control is implemented in an eight degrees of freedom (8-DOF) vehicle suspension model, subjected to a standard ISO road profile. The control performance is compared against a controlled system with few Q and R parameters, an active system without optimized gain matrices, and an optimized passive system.

The control with 12 optimized parameters for Q and R provided the best vibration attenuation, reducing significantly the Root Mean Square (RMS) accelerations at the driver’s seat and car body.

The research has positive implications in a wide class of active control systems, especially those based on a LQR, which was verified by the multibody dynamic systems tested in the paper.

Better active control gains can be devised to improve performance in vibration attenuation.

The main contribution proposed in this work is the improvement of the Q and R parameters simultaneously, in a full 8-DOF vehicle model, which minimizes the driver’s seat acceleration and, at the same time, guarantees vehicle safety.

Many European countries suspended mandatory conscription after the Cold War, and especially between 2000 and 2010. However, with the changing security situation in Europe, more and more countries are considering the re-introduction of the draft. That is why, it is important to evaluate the impact of conscription on draftees, including its effect on fertility outcomes. Additionally, fertility is of particular interest because birth rates have been below replacement levels in most European countries at least in the last two decades. This, combined with the increase in life expectancy, has contributed to aging population and raises concerns about the future economic prospects and sustainability of the continent. Military service could be related to fertility in several ways. Compulsory service for men would affect the marriage market and subsequently child-bearing outcomes. For example, men who serve in the military would have to delay higher education at least by a year, given that they plan to continue their education after high school. One possibility is that this leads to older men meeting younger women if partners meet at college. Alternatively, in case the partners know each other prior to the draft, service could delay marriage by up to a year due to the conscription, postponing planning and having children, and potentially having fewer children as women might be less able or less willing to have a child after a certain age. Finally, some men who plan and would otherwise continue their education might choose to not do so or to further postpone it once they disattach from studying during their service. For some men, this might influence their marital and subsequent fertility outcomes. In either of these scenarios, a draft or its suspension is likely to be connected to fertility.

This study examines the effect of the suspension of the draft in Spain in December 2001 on three fertility outcomes of men that would have been drafted in the absence of the suspension. The author performs the analysis in a difference-in-differences framework. Potential concerns and policy implications are also discussed.

The findings suggest that after the suspension of the draft, individuals started to have their first child earlier given that they decide to have children. Consistent with the overall time trend, they became less likely to have a child and started to have fewer children. However, the age at birth of the first child decreased while the number of children and the likelihood of having a child increased for men relative to women, after compared to before the suspension of the mandatory draft.

The author extends prior literature by investigating the effect of the abolition of compulsory military service in Spain in December 2001 on fertility. This is novel is several ways. First, to the best of the author’s knowledge, previous literature has examined the effect of this Spanish reform only on labor market outcomes prior to men's conscription. Second, even for other countries that terminated the compulsory draft, fertility has been under-studied, providing an opportunity for further exploration. Third, this analysis is based on rich Census data, representative of the population in Spain. Finally, given the inconclusive findings of previous studies for other countries and the proposed re-introduction of the draft in some parts of Europe, additional evidence of the effect of the conscription has important policy implications necessary for the evaluation of future military service policy decisions.

The National Pension Service (NPS) of Korea suddenly announced that they would suspend their stock lending business from October 22, 2018. Using this ideal setting, the authors investigate the effects of this suspension on market quality and short-selling activities. The authors find that stock return does not increase after the suspension of stock lending for both the KOSPI and KOSDAQ markets. However, the returns of stocks with NPS ownership decline less than those without NPS ownership. The authors also find that the institutional and foreign investors' short sales did not increase in both markets after the lending business suspension by the NPS. In addition, the effect of suspension of stock lending on market quality is mixed, so the authors cannot conclude that market quality has improved. Overall, the authors’ results indicate that the stock market, especially for short-sales activity, has not been affected by the suspension of the stock lending service by the NPS.

The main purpose of this research study is to investigate the impact of quarterly earnings announcements on stock price movement of the firms constituting the SENSEX under two different market conditions – booming followed by recessionary. Analysis of price effect of quarterly earnings announcements during the five-year period prior to trading suspension, which is also characterized by a booming market condition have been made. Similar analysis during the five-year period following the trading suspension and marked by recessionary market condition has also been carried out side by side.

Event study methodology using daily returns and market model has been used for the purpose of analyzing the quarterly earnings announcement effects on the security prices of the firms. A sign test has also been used along with the event study.

The study reveals that quarterly earnings announcement does not have statistically significant effect on stock returns during the booming as well as the recessionary market conditions. The impact of quarterly earnings announcements on stock price movement of firms constituting the SENSEX has been similar for both periods undertaken in the study.

The study has been undertaken using the firms listed in BSE SENSEX. The effect of the quarterly earnings announcement with reference to firms listed in other indices, if covered, may provide different sets of results.

The paper identifies the informational value of quarterly earnings announcement of BSE-SENSEX.

Printing toners are polymer composites accountable for transmission of digital images onto target substrates. Bearing in mind the ever increasing demand for high quality digital printing, modification and/or integration of existing techniques for manufacturing toners with favourable morphological and colour characteristics appears of vital importance. The present study aims to uncover the significance of in-situ polymerisation method, i.e. suspension, emulsion and mini-emulsion to control the microstructure of toner particles (particle size, particle size distribution and sphereness) while keeping the energy required for polymerisation along with reaction conversion at a reasonable level.

Assessment of particle size, particle size distribution and reaction conversion visualised the potential of suspension, emulsion and mini-emulsion polymerisation techniques to control microstructure, and colour characteristics of synthesized toners as well.

The results provided support for the fact that either the emulsion or mini-emulsion polymerisation routes will result in toners having an acceptable particle size and particle size distribution in the presence of a redox precursor. The higher monomer conversion at low temperature, as compared to the suspension polymerisation, was noticeable.

Analysing the glass transition temperature and colour characteristics of the resulting toners elucidated the superiority of mini-emulsion with respect to the other two cases which ranks this method on account of application.

For the first time, mini-emulsion route was put into practice and toners with acceptable colour and microstructure features were synthesised. In spite of lower polymerisation temperature and higher conversion of mini-emulsion compared to suspension and emulsion polymerisation techniques, further investigations are required to fine-tuning the properties of toners produced through this method.

The purpose of this paper was to show that the generalised viscosity model can correctly characterise suspension data over both a wide range of concentration as well as a wide range of temperature. A second objective of this study was to show theoretically and experimentally how the interaction coefficient from the generalised viscosity model also appears to have some thermodynamic properties.

In this study, many well‐known suspension equations were shown mathematically to be subsets of the generalised viscosity equation. The generalised viscosity equation was also found to be able to be reduced mathematically to two well‐known dilute solution equations (Huggins and Kramer's equations) as well. The relationship between Huggins and Kramer's constants and the interaction coefficient from the generalised viscosity equation yielded the potential to evaluate the solubility characteristics of the interaction coefficient. The value of the interaction coefficient was then found to be able to be evaluated as a function of temperature to enhance an understanding of the thermodynamic characteristics of the interaction coefficient using the data of Bueche.

In this study, a polymer plasticiser system involving polymethyl methacrylate in the plasticiser diethyl phthalate yielded an interaction coefficient, σ, primarily in the expected plasticiser range from 0< σ<1. It was also found that the generalised viscosity equation fit Bueche's polymer plasticiser data remarkably well over the whole concentration range for temperatures ranging from 30°C to 140°C. This study also appeared to show that the interaction coefficient from the generalised viscosity model can apparently characterise thermal transitions as well as thermodynamic solubility for a polymer solute (i.e. polymethyl methacrylate) when viscosity is evaluated over a wide temperature range. This result was particularly significant since Bueche's data covered 25 decades of viscosity on a log scale.

This is the first paper to successfully explore the thermodynamic characteristics of the interaction coefficient of the generalised viscosity equation. This opens up new avenues for evaluating the solubility and thermodynamic characteristics of various additives in solutions and polymeric formulations.

One of the problems encountered by developers of inertial systems, such as gyroscopes and accelerometers, is the critical dependence of the eigenfrequencies of elastic suspensions (ES) on temperature when using substrates for sensors made of dielectric materials, such as borosilicate glass. The internal stresses arising in the ES caused by the difference in the temperature coefficients of linear expansion (TCLE) lead to deformation of the sensor and complication of the electronic part of the sensor. The purpose of this paper is to approach for in-plane and out-of-plane ES are considered that allow for minimization of the influence of internal stresses on eigenfrequencies.

Analytical, finite element and experimental results are considered. The temperature coefficient of thermal expansion, the Young’s modulus and the Poisson ratio are given as a function of temperature. The shape of the spring elements (SEs) and the construction of the elastic suspension are the main topics of focus in this study. The authors’ out-of-plane ES based on a meander-like spring element implemented via finite element modeling show good agreement with the experimental results.

Meander-like SEs have been developed that have lower temperature errors in comparison with traditional types of SEs. The main contribution to the change in the eigenfrequency from temperature is made by internal stresses that arose from the deformation of the bonded materials with different TCLE. The change of eigenfrequency from the temperatures that were calculated by finite element method did not exceed 0.15%, however, in practice, the scatter of the obtained characteristics for different samples showed a change of up to 0.3%.

This study shows a way to design and optimize the structure and theoretical background for the development of the microelectromechanical systems (MEMS) inertial module combining the functions of gyroscope and accelerometer. The obtained results will improve and expand the manufacturing technology of MEMS gyroscopes and accelerometers.