774 research outputs found
THE RELATIONSHIP BETWEEN CHANGE AND ORGANIZATIONAL DEVELOPMENT
Through a correct management of an organization, it can lead to its development and improvement of the organizational structure, resulting in an increase in the effectiveness of carrying out specific activities. Change management is seen as a challenge for any organization whether they are aware of it or not. An organization is exposed to failure if it lets change control it. Improving the performance of an organization is based on identifying and understanding the functioning of governance structures and mechanisms. A successful organization achieves the best results in unpredictable moments, this cannot be achieved if it does not adapt to changes, does not take risks or if it is not flexible at key moments. The process of adapting an organization in the context of change can induce a process of evolution or involution. Change management can facilitate the elimination of risk situations and the maintenance of the organizational environment in a situation of balance, thus contributing to ensuring a continuous development
3D TCAD modeling of NO2CNT FET sensors
A new approach for TCAD modeling of CNT FET gas sensors is presented, whose key feature is the use of an effective Gaussian DOS to mimic the 1D CNT DOS. The TCAD procedure has been applied to the simulation of a suspended CNT FET for NO2sensing. Our results indicate that the model is able to provide I-V characteristics in excellent agreement with the experimental data, both before and after gas exposure
Towards Internet of Things for event-driven low-power gas sensing using carbon nanotubes
One of most important applications of sensing devices under the Internet of Things paradigm is air quality monitoring, which is particularly useful in urban and industrial environments where air pollution is an increasing public health problem. As these sensing systems are usually battery-powered and gas sensors are power-hungry, energy-efficient design and power management are required to extend the device's lifetime. In this paper, we present a two-stage concept where a novel low-power carbon nanotube is used as a gas detector for an energy-consuming metal-oxide (MOX) semiconductor gas sensor. We propose a design of a heterogeneous sensor node where we exploit the low-power nanotube gas sensor and the more accurate MOX sensor. This work performs energy consumption simulations for three event-driven scenarios to evaluate the power consumption reduction, as well as the limitations of carbon nanotubes. Our results show the benefits of the proposed approach over the scenarios with adaptive duty-cycling with only MOX gas sensors, proved with 20%-35% node lifetime prolongation. The delay introduced due to the nanotube recovery time can be overcome by radio duty-cycled activity for detecting alarm messages from the neighbour nodes
Radio Frequency Magnetron Sputter Deposition as a Tool for Surface Modification of Medical Implants
The resent advances in radio frequency (RF)âmagnetron sputtering of hydroxyapatite films are reviewed and challenges posed. The principles underlying RFâmagnetron sputtering used to prepare calcium phosphateâbased, mainly hydroxyapatite coatings, are discussed in this chapter. The fundamental characteristic of the RFâmagnetron sputtering is an energy input into the growing film. In order to tailor the film properties, one has to adjust the energy input into the substrate depending on the desired film properties. The effect of different deposition control parameters, such as deposition time, substrate temperature, and substrate biasing on the hydroxyapatite (HA) film properties is discussed
Testing campaign for ECRIDA: the UV resin 3D printer flying on REXUS
ECRIDA is a student project participating in the REXUS/BEXUS campaign that develops a UV resin 3D printer device capable of working in the low-gravity environment offered by the REXUS rocket flight. Our main objective is to describe the impact of low gravity on the UV resin 3D printing process by comparing samples printed on Earth with samples printed in space. Due to the requirements of the host vehicle and driven by the novel design of our device, a thorough testing campaign must be planned and completed to qualify the device for flight and maximise the success of the scientific objectives. This paper describes the requirements that the device must fulfil and goes into the design of our test plan describing the procedures and the results. Vacuum, vibration, pressure, and functional tests were performed and described together with our learned lessons and conclusions in our will to help student teams with their testing activitie
Pectin coatings on titanium alloy scaffolds produced by additive manufacturing:Promotion of human bone marrow stromal cell proliferation
Ti6Al4V is a popular biomaterial for load-bearing implants for bone contact, which can be fabricated by additive manufacturing technologies. Their long-term success depends on their stable anchoring in surrounding bone, which in turn depends on formation of new bone tissue on the implant surface, for which adhesion and proliferation of bone-forming cells is a pre-requisite. Hence, surface coatings which promote cell adhesion and proliferation are desirable. Here, Ti6Al4V discs prepared by additive manufacturing (EBM) were coated with layers of pectins, calcium-binding polysaccharides derived from citrus (C) and apple (A), which also contained alkaline phosphatase (ALP), the enzyme responsible for mineralization of bone tissue. Adhesion and proliferation of human bone marrow stromal cells (hBMSC) were assessed. Proliferation after 7âŻdays was increased by A-ALP coatings and, in particular, by C-ALP coatings. Cell morphology was similar on coated and uncoated samples. In conclusion, ALP-loaded pectin coatings promote hBMSC adhesion and proliferation
Mechanical design of the optical modules intended for IceCube-Gen2
IceCube-Gen2 is an expansion of the IceCube neutrino observatory at the South Pole that aims to increase the sensitivity to high-energy neutrinos by an order of magnitude. To this end, about 10,000 new optical modules will be installed, instrumenting a fiducial volume of about 8 km3. Two newly developed optical module types increase IceCubeâs current sensitivity per module by a factor of three by integrating 16 and 18 newly developed four-inch PMTs in specially designed 12.5-inch diameter pressure vessels. Both designs use conical silicone gel pads to optically couple the PMTs to the pressure vessel to increase photon collection efficiency. The outside portion of gel pads are pre-cast onto each PMT prior to integration, while the interiors are filled and cast after the PMT assemblies are installed in the pressure vessel via a pushing mechanism. This paper presents both the mechanical design, as well as the performance of prototype modules at high pressure (70 MPa) and low temperature (â40âC), characteristic of the environment inside the South Pole ice
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