Entanglement entropy vs. free energy in IIB supergravity duals for 5d SCFTs

We study entanglement entropy and the free energy in recently constructed holographic duals for 5d SCFTs in type IIB supergravity. The solutions exhibit mild singularities, which could potentially complicate holographic applications. We use the relation of the entanglement entropy for a spherical entangling surface to the free energy of the field theory on the five sphere as a well-motivated benchmark to assess how problematic the singularities are. The holographic supergravity computations give well-defined results for both quantities and they satisfy the expected relations. This supports the interpretation of the solutions as holographic duals for 5d SCFTs and gives first quantitative indications for the nature of the dual SCFTs.Comment: 25 pages, 3 figure

Stability analysis of a pneumatically actuated inverted pendulum

This paper deals with the stabilization of an inverted pendulum on cart; the latter is pneumatically actuated by a double acting cylinder controlled by low cost proportional valves. In particular, a numerical model of whole system is developed in order to find the ability of the pneumatic actuation in stabilizing the pendulum and evaluate its bandwidth. A cascade of two control loops (the inner one for the pendulum angle, the outer one for the cart displacement) are analyzed and proper compensators are defined. The possibility of introducing an additional loop to control the force exerted by the actuator on the cart is evaluated

Unbalance Response Analysis of a Spindle Supported on Gas Bearings: A Comparison between Different Approaches

Gas journal bearings are widely employed in high-speed spindles for the micromachining industry. Compared to their oil and rolling counterparts, gas bearings have a longer life span, lower friction and a lower level of noise. In order to design accurate high-speed spindles supported by externally pressurized gas bearings, it is vital to analyze the characteristics of rotor bearing systems. In this paper, we present an analysis of the unbalance response of a high-speed spindle supported by gas journal bearings. A number of aspects to enhance the accuracy of the system are discussed. We performed the analysis by considering a nonlinear and a linearized numerical model validated through experimental measurements

On the Design of a Diaphragm Valve for Aerostatic Bearings

Because of their almost zero friction, cleanness and long life, aerostatic bearings are commonly used in many applications where high precision of positioning is required, e.g. machine tools, measuring machines, semiconductor manufacturing and power board testing. However, air bearings suffer from low relative stiffness and poor damping. Active and passive compensation are two effective methods to enhance the static and dynamic performance of these kinds of bearings. Despite their higher performance, active compensation solutions are too expensive to be used in industrial applications, as a consequence of the costs related to their controllers, actuators and sensors. This paper presents the design and performance of a passive compensation method that exploits a diaphragm valve. Thanks to its ease of integration, satisfactory performance and relatively low cost, this method could be a valuable solution to increasing the stiffness of aerostatic bearings. This work provides a procedure to design diaphragm valves depending on the type of the integrated pad and the desired nominal air gap height. Results demonstrate that, once correctly designed, the diaphragm valve makes it possible to obtain bearings with quasi-static infinite stiffness at the selected air gap height

An aerostatic pad with an internal pressure control

Because of their almost zero friction and wear, aerostatic pads are widely used in applications where very precise positioning is required. However, this kind of bearing suffers from poor damping and low specific stiffness. This paper presents a new compensation strategy to increase air pad stiffness. This method exploits a custom-built pneumatic valve which can be easily integrated with any commercial pad. The design and the working principle of the proposed system are described and studied with the aid of a lumped parameter model. The effectiveness of the proposed compensation is numerically and experimentally evaluated. The results demonstrate that the solution represents a good and cost-effective method to enhance the static stiffness of aerostatic pads

Air Pad Controlled by Means of a Diaphragm-Valve: Static and Dynamic Behaviour

This paper presents the analysis of the static and dynamic performance of a passively compensated air pad. The proposed method consists in the integration of a custom-built diaphragm valve and a commercial aerostatic pad. A lumped model is used to simulate the static and dynamic performance of the pad. Results demonstrate that the proposed method is very effective when the system works with excitation frequencies below 10 Hz

Comparison of sampling bags for the analysis of volatile organic compounds in breath

Nalophan, Tedlar and Cali-5-Bond polymeric bags were compared to determine the most suitable type for breath sampling and storage when volatile organic compounds are to be determined. Analyses were performed by thermal desorption gas chromatography mass spectrometry. For each bag, the release of contaminants and the chemical stability of a gaseous standard mixture containing eighteen organic compounds, as well as the CO2 partial pressure were assessed. The selected compounds were representative of breath constituents and belonged to different chemical classes (i.e. hydrocarbons, ketones, aldehydes, aromatics, sulfurs and esters). In the case of Nalophan, the influence of the surface-to-volume ratio, related to the bag's filling degree, on the chemical stability was also evaluated. Nalophan bags were found to be the most suitable in terms of contaminants released during storage (only 2-methyl-1,3-dioxalane), good sample stability (up to 24 h for both dry and humid samples), and very limited costs (about 1 for a 20 liter bag). The (film) surface-to-(sample) volume ratio was found to be an important factor affecting the stability of selected compounds, and therefore we recommended to fill the bag completely

Systematic Lab Knowledge Integration for Management of Lipid Excess in High-Risk Patients : Rationale and Design of the SKIM LEAN Project

SKIM LEAN aims at exploiting Electronic Health Records (EHRs) to integrate knowledge derived from routine laboratory tests with background analysis of clinical databases, for the identification and early referral to specialist care, where appropriate, of patients with hypercholesterolemia, who may be inadequately controlled according to their cardiovascular (CV) risk level. SKIM LEAN addresses gaps in care that may occur through the lack of coordination between primary and specialist care, incomplete adherence to clinical guidelines, or poor patient's compliance to the physician's prescriptions because of comorbidities or drug side effects. Key project objectives include: (1) improved health professionals' competence and patient empowerment through a two-tiered educational website for general practitioners (GPs) and patients, and (2) implementation of a hospital-community shared care pathway to increase the proportion of patients at high/very-high CV risk (Familial Hypercholesterolemia, previous CV events) who achieve target LDL cholesterol (LDL-C) levels. Thanks to a close collaboration between clinical and information technology partners, SKIM LEAN will fully exploit the value of big data deriving from EHRs, and filter such knowledge using clinically-derived algorithms to risk-stratify patients. Alerts for GPs will be generated with interpreted test results. GPs will be able to refer patients with uncontrolled LDL-C within the shared pathway to the lipid or secondary prevention outpatient clinics of NIG hospital. Metrics to verify the project achievements include web-site visits, the number of alerts generated, numbers of patients referred by GPs, the proportion of secondary prevention patients who achieve LDL-C 50% decrease from baseline