Atoms confined by very thin layers

The Hamiltonian of an atom with $N$ electrons and a fixed nucleus of infinite mass between two parallel planes is considered in the limit when the distance $a$ between the planes tends to zero. We show that this Hamiltonian converges in the norm resolvent sense to a Schr\"{o}dinger operator acting effectively in $L^{2}(\mathbb{R}^{2N})$ whose potential part depends on $a$. Moreover, we prove that after an appropriate regularization this Schr\"{o}dinger operator tends, again in the norm resolvent sense, to the Hamiltonian of a two-dimensional atom (with the three-dimensional Coulomb potential-one over distance), as $a\to 0$. This makes possible to locate the discrete spectrum of the full Hamiltonian once we know the spectrum of the latter one. Our results also provide a mathematical justification for the interest in the two-dimensional atoms with the three-dimensional Coulomb potential

The magnetic Laplacian in shrinking tubular neighbourhoods of hypersurfaces

16 pagesInternational audienceThe Dirichlet Laplacian between two parallel hypersurfaces in Euclidean spaces of any dimension in the presence of a magnetic field is considered in the limit when the distance between the hypersurfaces tends to zero. We show that the Laplacian converges in a norm-resolvent sense to a Schrödinger operator on the limiting hypersurface whose electromagnetic potential is expressed in terms of principal curvatures and the projection of the ambient vector potential to the hypersurface. As an application, we obtain an effective approximation of bound-state energies and eigenfunctions in thin quantum layers

Internal audit activities as a support to governance processes

Lately, the role of internal audit is viewed with great importance in the context of the supervisory mechanisms of corporate governance, which is a direct result of requests for more effective corporate governance and the need for control. Corporate governance foundation may be considered through the four cornerstones: Audit Committee, Executive Management, Internal Auditors and External Auditors. Internal audit contributes to corporate governance effectiveness through relations and communication with other cornerstones. It is believed that by providing assurance on the effectiveness of risk management, control and governance processes, internal audit is becoming a "key cornerstone" underlying the effective management. This paper analyzes how internal audit contributes to strengthening the governance processes through its relation with the primary beneficiaries, managers and the Audit Committee. The Audit Committee, focused on oversight of financial reporting, controls and risk management, relies on internal audit to assist in carrying out its responsibilities. Also, internal audit provides advice to managers at all levels and information related to the effectiveness of the internal control and risk management processes as well as other important services. It may be concluded that internal audit activities, through its impact on other participants in governance, affect the quality of corporate governance. Internal audit is an important factor in achieving effective governance and is considered as an "integral part of corporate governance mosaic".peer-reviewe

Effects of psychological interventions and patients' affect on short-term quality of life in patients undergoing colorectal surgery

Psychological interventions can improve Quality of Life (QoL). Object of interest was if different psychological interventions influence short-term QoL after colonic resection for carcinoma. Furthermore, we wanted to see if there is a correlation between patients` preoperative affect and postoperative QoL. Sixty patients that underwent colorectal surgery were divided into three groups. Group one (n = 20) received Guided Imagery and group 2 (n = 22) Progressive Muscle Relaxation. The third group (Control, n = 18) had no intervention. Quality of Life (QoL) was measured using the EORTC QLQ-C30 and the Gastrointestinal Quality of life Index (GIQLI). Patients' affect was measured by the PANAS questionnaire. The higher the preoperative Negative Affect was, the lower were the scores for QoL on the 30th postoperative day. Patients' QoL was highest preoperatively and lowest on the third postoperative day. On the 30th postoperative day scores for QoL were almost as high as preoperative without difference between the three groups. Neither Guided Imagery nor Progressive Relaxation was influencing short-term QoL measured by the EORTC QLQ-C30 and the GIQLI questionnaire after colorectal surgery for cancer. Screening patients' with the PANAS questionnaire might help to identify individuals that are more likely to have a worse QoL postoperatively