The effect on the performance of listed family and non-family firms

Purpose: The purpose of this paper is to examine whether the ownership of public firms is related to accounting and market performance, comparing family and non-family listed firms. Design/methodology/approach: We use regression analysis, considering a sample of Portuguese family and non-family firms for the period between 1999 and 2010. Findings: Overall, the results show that family firms are older, are more indebted and have higher debt costs than non-family firms. However, they present lower levels of risk. The evidence suggests that family firms outperform non-family firms when we consider a market performance measure. The market performance of family-controlled firms is more sensitive to the crisis periods and age, compared to their counterparts. The empirical findings suggest that under economic adversity, the performance is especially compromised by the firms’ age. Research limitations/implications: A limitation of this study is the small size of the sample, which derives from the small size of the Portuguese stock market, the Euronext Lisbon. Originality/value: This paper offers some insights on the ownership of public firms and firm performance by investigating a small European economy. The study also contributes to the stream of firm performance, considering new independent variables as determinants of firm performance, such as operational risk. Finally, the study examines the interaction between ownership and performance under both steady and adverse economic conditions, giving the opportunity to analyze whether firm performance differs according to market conditions.

Discrete-event Simulation and Optimization to Improve the Performance of a Healthcare System

Thesis (Ph.D.)--University of Washington, 2016-08

Role of substrate quality on the performance of semipolar (11 2 - 2) InGaN light-emitting diodes

We compare the optical properties and device performance of unpackaged InGaN/GaN multiple-quantum-well light-emitting diodes (LEDs) emitting at ∼430 nm grown simultaneously on a high-cost small-size bulk semipolar (11 2 - 2) GaN substrate (Bulk-GaN) and a low-cost large-size (11 2 - 2) GaN template created on patterned (10 1 - 2) r-plane sapphire substrate (PSS-GaN). The Bulk-GaN substrate has the threading dislocation density (TDD) of ∼ and basal-plane stacking fault (BSF) density of 0 cm-1, while the PSS-GaN substrate has the TDD of ∼2 × 108cm-2 and BSF density of ∼1 × 103cm-1. Despite an enhanced light extraction efficiency, the LED grown on PSS-GaN has two-times lower internal quantum efficiency than the LED grown on Bulk-GaN as determined by photoluminescence measurements. The LED grown on PSS-GaN substrate also has about two-times lower output power compared to the LED grown on Bulk-GaN substrate. This lower output power was attributed to the higher TDD and BSF density.

Adaptation to hot environmental conditions : An exploration of the performance basis, procedures and future directions to optimise opportunities for elite athletes

Predicting the performance of passenger ships using computer simulation

When designing a new passenger ship or naval vessel or modifying an existing design, how do we ensure that the proposed design is safe from an evacuation point of view? In the wake of major maritime disasters such as the Herald of Free Enterprise and the Estonia and in light of the growth in the numbers of high density, high-speed ferries and large capacity cruise ships, issues concerned with the evacuation of passengers and crew at sea are receiving renewed interest. In the maritime industry, ship evacuation models are now recognised by IMO through the publication of the Interim Guidelines for Evacuation Analysis of New and Existing Passenger Ships including Ro-Ro. This approach offers the promise to quickly and efficiently bring evacuation considerations into the design phase, while the ship is "on the drawing board" as well as reviewing and optimising the evacuation provision of the existing fleet. Other applications of this technology include the optimisation of operating procedures for civil and naval vessels such as determining the optimal location of a feature such as a casino, organising major passenger movement events such as boarding/disembarkation or restaurant/theatre changes, determining lean manning requirements, location and number of damage control parties, etc. This paper describes the development of the maritimeEXODUS evacuation model which is fully compliant with IMO requirements and briefly presents an example application to a large passenger ferry.

Role of nitrogen doping on the performance of carbon nanotube catalysts: a catalytic wet peroxide oxidation application

Four magnetic carbon nanotube samples (CNTs: undoped, completely N-doped and two selectively N-doped) have been synthesized by chemical vapor deposition. The materials were tested in the catalytic wet peroxide oxidation (CWPO) of highly concentrated 4 nitrophenol solutions (4-NP, 5 g L-1). Relatively mild operating conditions were considered (atmospheric pressure, T = 50 ºC, pH = 3), using a catalyst load of 2.5 g L-1 and the stoichiometric amount of H2O2 needed for the complete mineralization of 4-NP. N doping was identified to influence considerably the CWPO performance of the materials. In particular, undoped CNTs, with a moderate hydrophobicity, favor the controllable and efficient decomposition of H2O2 into highly reactive hydroxyl radicals (HO•), thus showing high catalytic activity for 4-NP degradation. On the other hand, the completely N-doped catalyst, fully hydrophilic, favors a quick decomposition of H2O2 into non-reactive O2 and H2O species. The selectively N-doped amphiphilic catalysts, i.e. hybrid structures containing undoped sections followed by N-doped ones, provided intermediate results, namely: a higher N content favored H2O2 decomposition towards non-reactive H2O and O2 species, whilst a lower N content resulted in the formation of HO•, increasing 4-NP mineralization. Catalyst stability and reusability were also investigated by consecutive CWPO runs.

Boosting the performance of metaheuristics for the MinLA problem using a more discriminating evaluation function

International audience

Unraveling the performance of dispersion-corrected functionals for the accurate description of weakly bound natural polyphenols

Long-range non-covalent interactions play a key role in the chemistry of natural polyphenols. We have previously proposed a description of supramolecular polyphenol complexes by the B3P86 density functional coupled with some corrections for dispersion. We couple here the B3P86 functional with the D3 correction for dispersion, assessing systematically the accuracy of the new B3P86-D3 model using for that the well-known S66, HB23, NCCE31, and S12L datasets for non-covalent interactions. Furthermore, the association energies of these complexes were carefully compared to those obtained by other dispersion-corrected functionals, such as B(3)LYP-D3, BP86-D3 or B3P86-NL. Finally, this set of models were also applied to a database composed of seven non-covalent polyphenol complexes of the most interest.

Influence of levels and forms of selenium associated with levels of vitamins C and E on the performance, yield and composition of tilapia fillet

Objetivou-se avaliar a influência da vitamina C (VC), vitamina E (VE) e de duas formas de selênio sobre o desempenho, rendimento e qualidade do filé de tilápia Nilótica. O experimento foi realizado num delineamento inteiramente casualizado composto por seis tratamentos, os quais foram constituídos pela adição de 100, 200 e 400 mg kg-1 das vitaminas C e E, associados com 0,1, 0,2 e 0,4 mg kg-1 de duas formas de selênio. Cada tratamento foi constituído por cinco repetições de 30 peixes cada. A dieta com 200 mg kg-1 de VC e VE + 0,2 mg kg-1 de selênio orgânico proporcionou ganho de peso, comprimento corporal e fator de conversão alimentar semelhantes aos tratamentos com 400 mg kg-1 de VC e VE + 0,4 mg kg-1 de selênio orgânico ou inorgânico. A adição de selênio orgânico à dieta melhorou o ganho de peso e o fator de conversão alimentar em comparação com o selênio inorgânico. A dieta com 0,2 mg kg-1 de selênio orgânico apresentou nível de glutationa peroxidase igual ao da dieta com 0,4 mg kg-1 de selênio inorgânico. Os rendimentos de carcaça e filé não foram influenciados pelos tratamentos, entretanto houve efeito dos tratamentos na composição química do filé.

Development of a 1-D Catalyzed Diesel Particulate Filter Model for Simulation of the Performance and the Oxidation of Particulate Matter and Nitrogen Oxides Using Passive Oxidation and Active Regeneration Engine Experimental Data

Back-pressure on a diesel engine equipped with an aftertreatment system is a function of the pressure drop across the individual components of the aftertreatment system, typically, a diesel oxidation catalyst (DOC), catalyzed particulate filter (CPF) and selective catalytic reduction (SCR) catalyst. Pressure drop across the CPF is a function of the mass flow rate and the temperature of the exhaust flowing through it as well as the mass of particulate matter (PM) retained in the substrate wall and the cake layer that forms on the substrate wall. Therefore, in order to control the back-pressure on the engine at low levels and to minimize the fuel consumption, it is important to control the PM mass retained in the CPF. Chemical reactions involving the oxidation of PM under passive oxidation and active regeneration conditions can be utilized with computer numerical models in the engine control unit (ECU) to control the pressure drop across the CPF. Hence, understanding and predicting the filtration and oxidation of PM in the CPF and the effect of these processes on the pressure drop across the CPF are necessary for developing control strategies for the aftertreatment system to reduce back-pressure on the engine and in turn fuel consumption particularly from active regeneration. Numerical modeling of CPF's has been proven to reduce development time and the cost of aftertreatment systems used in production as well as to facilitate understanding of the internal processes occurring during different operating conditions that the particulate filter is subjected to. A numerical model of the CPF was developed in this research work which was calibrated to data from passive oxidation and active regeneration experiments in order to determine the kinetic parameters for oxidation of PM and nitrogen oxides along with the model filtration parameters. The research results include the comparison between the model and the experimental data for pressure drop, PM mass retained, filtration efficiencies, CPF outlet gas temperatures and species (NO2) concentrations out of the CPF. Comparisons of PM oxidation reaction rates obtained from the model calibration to the data from the experiments for ULSD, 10 and 20% biodiesel-blended fuels are presented.

THE PERFORMANCE AND MODIFICATION OF RECYCLED ELECTRONIC WASTE PLASTICS FOR THE IMPROVEMENT OF ASPHALT PAVEMENT MATERIALS

Bulk electric waste plastics were recycled and reduced in size into plastic chips before pulverization or cryogenic grinding into powders. Two major types of electronic waste plastics were used in this investigation: acrylonitrile butadiene styrene (ABS) and high impact polystyrene (HIPS). This research investigation utilized two approaches for incorporating electronic waste plastics into asphalt pavement materials. The first approach was blending and integrating recycled and processed electronic waste powders directly into asphalt mixtures and binders; and the second approach was to chemically treat recycled and processed electronic waste powders with hydro-peroxide before blending into asphalt mixtures and binders. The chemical treatment of electronic waste (e-waste) powders was intended to strengthen molecular bonding between e-waste plastics and asphalt binders for improved low and high temperature performance. Superpave asphalt binder and mixture testing techniques were conducted to determine the rheological and mechanical performance of the e-waste modified asphalt binders and mixtures. This investigation included a limited emissions-performance assessment to compare electronic waste modified asphalt pavement mixture emissions using SimaPro and performance using MEPDG software. Carbon dioxide emissions for e-waste modified pavement mixtures were compared with conventional asphalt pavement mixtures using SimaPro. MEPDG analysis was used to determine rutting potential between the various e-waste modified pavement mixtures and the control asphalt mixture. The results from this investigation showed the following: treating the electronic waste plastics delayed the onset of tertiary flow for electronic waste mixtures, electronic waste mixtures showed some improvement in dynamic modulus results at low temperatures versus the control mixture, and tensile strength ratio values for treated e-waste asphalt mixtures were improved versus the control mixture.