Selective detection of gaseous ammonia with specifically functionalized silicon photonic microring resonator: towards low cost and portable breath monitoring

We demonstrate a selective ammonia sensor based on a silicon photonic microring resonator functionalized with nanoporous silicate films. The potential of this sensor as a low cost, portable and real-time medical breath monitoring device is discussed

Corporate governance and board effectiveness : beyond formalism

Mainstream research on boards of directors has been focusing on a direct relationship between board characteristics and firm performance, but up till now the results are inconclusive. Different reasons are put forward to explain this inconsistency, but it can be argued that ‘traditional' board research has been neglecting potential intervening variables. In this paper we present a process-oriented model for board effectiveness by relying on the corporate governance literature and the literature on group effectiveness. We follow the input-process-output approach to extract the significant variables from literature and integrate them into a research framework for studying board effectiveness. In particular, we identify three intervening variables (cohesiveness, debate and conflict norms) which we believe mediate the effects of board characteristics on board performance. The rationale for including these ‘process' variables is the belief that the interactions and relationships among board members determine to a large extent the collective outcomes of the board of directors. In this respect, the model goes beyond the traditional structural attributes of boards of directors to include behavioural or attitudinal measures of board effectiveness. It also highlights the need for a multi-disciplinary approach in empirical research on boards of directors

Identifying key determinants of effective boards of directors

Mainstream research on boards of directors has been focusing on a direct relationship between board characteristics and firm performance, but up till now the results are inconclusive. Although these studies revealed interesting and useful insights, little is known about the factors that shape board effectiveness. This paper aims to reduce this gap by exploring the variety of indicators that contribute to the effectiveness of boards. The paper derives from an interview-based investigation among 104 directors of Belgian listed companies. The findings are further elaborated with quantitative data from two written questionnaires, involving directors of non-listed companies and experts in the field of corporate governance. The results point to three major issues. First, there appears to be a gap between a limited number of structural board measures consistently found in literature and the systematic occurrence of a set of behavioural criteria of board effectiveness in the perceptions of (Belgian) directors. Second, the findings suggest that the value of independence may be overemphasized at the cost of the broader issue of diversity. Third, it appears that mainstream board research ignores to a large extent two additional conditions (the information flow and the leadership style of the chairman) under which a board of directors can make an effective contribution to the strategic direction and control of a company. Our findings suggest that the ambiguity found in current research evidence can to some extent be attributed to the ignorance of a wide range of interconnected structural (such as diversity and competence) and behavioural factors (such as trust, attitude, norms and conduct) which actually shape the effectiveness of boards in performing their roles

Modification of ultra low-k dielectric films by O₂ and CO₂ plasmas

Low-k materials developed for ULSI interconnects should have sufficient resistance to processing plasma. CO2 plasma is being considered as a promising candidate for low damage photoresist ash and as a surface activation chemistry for self-assembled monolayers and atomic layer deposition on low-k materials. This article explores the interaction of two organosilicate (OSG) based low-k materials with different k-values (OSG2.4 and OSG2.2) with CO2 plasma in both CCP and ICP-remote plasma chambers. Time dependent exposure of the materials to CO2 plasma revealed quick and effective sealing of OSG2.4 surface whereas it takes longer time for OSG2.2. The sealing reduces further plasma damage and leads to accumulation of CO2 in the pores of both materials. The same behavior occurs in ICP-remote plasma but without a complete sealing of the surface. This suggests the important role of ion bombardment. Damage to low-k by conventional O-2 plasma was studied alongside and it was found that for t 60 s. Furthermore, lesser time exposure to CO2 plasma was investigated with respect to source power at constant pressure and it was discovered that damage although small, increases with varying source power

Une méthode d'identification de la rhéologie du métal et du lubrifiant lors du tréfilage

National audienceNous montrons comment l'analyse thermomécanique élémentaire d'une passe de tréfilage et la mesure de la force et d'une température de filière pour divers lubrifiants permettent d'identifier le travail de déformation plastique lié à la réduction du fil, ainsi que les cissions de frottement relatives aux lubrifiants utilisés. Nous présentons le protocole expérimental et discutons la relation entre la formulation des lubrifiants et le frottement estimé