Enhanced visualisation of complex thermofluid data: Vertical and horizontal combined convection and microscale heat transfer cases

Copyright @ 2000 UITIn general, convective heat transfer is an 'n-dimensional' problem where n is well in excess of 3 for steady flows. Traditionally, the method of dimensional analysis results in a small number of dimensionless groups. In the case of steady forced convection these can reduce to three, namely the Nusselt (Nu), Reynolds (Re) and Prandtl (Pr) numbers, for heat transfer, fluid flow regime and fluid properties respectively. Again, traditionally, data are presented on log-log graphs, say of Nu versus Re, with Pr being a possible third parameter. For natural convection, the Grashof number (Gr) expresses buoyancy effects in place of Re, while for combined (natural and forced) convection Gr becomes additional to, rather than replacing, Re. Using sets of data for: (a) vertical combined convection in nuclear safety, (b) horizontal combined convection review material, and (c) microchannel heat transfer, in the first part of this paper we survey this problem. We reach the following conclusions: that heat transfer data are presented in either 'holistic' or 'reductive' modes, and that other thermodynamic performance data are related to the generic scientific cases of (a) 3-dimensional space and (b) multi-dimensional space. In the second part of the paper we present a first attempt at applying design-type procedures to specifying this problem. Visualisation priorities are suggested from which particular solutions will be developed in future

An Analytical Solution for the Laminar Forced Convection in a Pipe with Temperature-Dependent Heat Generation

n/

On the Solved Turbulent Scales in Turbulent Plume Fires

Plume fires are characterized by a turbulent nature with a large number of different scales. LES is often used to solve the largest structures and to model the smallest ones. Grid size and time steps become decisive to place the limit between resolved and modelled turbulence. Significant information on this limit and its placement can be obtained with spectral analyses of the specific turbulent kinetic energy. While frequency analysis is relatively easy, an analysis in the wavenumber domain is more challenging. The IWC method, typically used in structures and acoustics, is used here for this purpose. IWC method allows to obtain wavenumber spectra with a better resolution than those obtained with a direct approach. Furthermore, in this paper the IWC method is also used in its reverse form to obtain frequency spectra. Although rather dense grids have been chosen, the number of nodes along the plume and their spacing is not such as to guarantee detailed wavenumber spectra with the direct approach and consequently with the reverse IWC. On the contrary, the IWC method provides wavenumber spectra in agreement with those obtained directly, but of much higher quality

Enhancing Brand Image through Events and Cultural Festivals: the Perspective of the Stresa Festival’s Visitors

Cultural events have become a significant component within the strategies of destination branding of a place. Territories are increasingly using events and cultural festivals to enhance their image and boost tourism development. Many destinations worldwide have built events portfolios as a strategic initiative to attract visitors and to develop their own brand. A destination brand represents a dynamic interaction between the destination’s core assets and the way in which potential visitors perceive them. Thus, the visitor perspective is considered as fundamental in triggering processes of destination branding. This paper investigates how the visitors assess the impact of cultural events and festivals in enhancing the image of a tourist destination. The Stresa Festival (Stresa, Lake Maggiore, Italy) has been selected as a case study. Stresa Festival is undoubtedly one of the best-known European classical music festivals that every year offers performances by internationally famous artists to its audiences. Structured questionnaires have been used as the methodology to carry out the research. Online questionnaires have been handed out to residents and non-resident visitors to the Stresa Festival to extract the opinions and experience from the public on the image effects of this festival. Findings reveal that there is a positive relationship between this cultural event and the enhancement of the city image and its territory

Linear Chains of Styrene and Methyl-Styrene Molecules and their Heterojunctions on Silicon: Theory and Experiment

We report on the synthesis, STM imaging and theoretical studies of the structure, electronic structure and transport properties of linear chains of styrene and methyl-styrene molecules and their heterojunctions on hydrogen-terminated dimerized silicon (001) surfaces. The theory presented here accounts for the essential features of the experimental STM data including the nature of the corrugation observed along the molecular chains and the pronounced changes in the contrast between the styrene and methyl-styrene parts of the molecular chains that are observed as the applied bias is varied. The observed evolution with applied bias of the STM profiles near the ends of the molecular chains is also explained. Calculations are also presented of electron transport along styrene linear chains adsorbed on the silicon surface at energies in the vicinity of the molecular HOMO and LUMO levels. For short styrene chains this lateral transport is found to be due primarily to direct electron transmission from molecule to molecule rather than through the silicon substrate, especially in the molecular LUMO band. Differences between the calculated position-dependences of the STM current around a junction of styrene and methyl-styrene molecular chains under positive and negative tip bias are related to the nature of lateral electron transmission along the molecular chains and to the formation in the LUMO band of an electronic state localized around the heterojunction.Comment: 17 pages plus 11 figures. To appear in Physical Review

The average transmitted wave in random particulate materials

Microwave remote sensing is significantly altered when passing through clouds or dense ice. This phenomenon isn't unique to microwaves; for instance, ultrasound is also disrupted when traversing through heterogeneous tissues. Understanding the average transmission in particle-filled environments is central to improve data extraction or even to create materials that can selectively block or absorb certain wave frequencies. Most methods that calculate the average transmitted field assume that it satisfies a wave equation with a complex effective wavenumber. However, recent theoretical work has predicted more than one effective wave propagating even in a material which is statistical isotropic and for scalar waves. In this work we provide the first clear evidence of these predicted multiple effective waves by using high fidelity Monte-Carlo simulations that do not make any statistical assumptions. To achieve this, we also had to fill in a missing link in the theory for particulate materials: we prove that the incident wave does not propagate within the material, which is usually taken as an assumption called the Ewald-Oseen extinction theorem. By proving this we conclude that the extinction length - the distance it takes for the incident wave to be extinct - is equal to the correlation length between the particles

Pre-packaged food products business to consumer (B2C) distance selling and information obligations in Italian mass market retailers

The supply and sale of food online are on the rise. The value of e-commerce in Europe has been estimated in 602 billion euros in 2017, 324 million people in the old continent purchase online. In the European area, the Netherlands and Italy are the countries where the e-commerce market grew faster in the last five years. Nevertheless, in Italy the spread of online shopping has reached the 89.9% of the population between 11 and 74 years old. The access to the Internet, as declared by 43 million Italians, it is carried out from fixed or mobile locations. In terms of revenues the food sector recorded a +24% among the different sectors facing one of the higher grows in terms of percentages. The regulatory framework that disciplines the food products distance selling can be traced back to two fundamental pillars: the European legislation on e-commerce on the one side and the food information to consumers on the other side. Under article 14 of the Regulation (EU) No. 1169/2011, the European legislator states that the mandatory information, as indicated in article 9, shall be available to the consumer before the purchase is concluded and when the product is delivered. The study aims at verifying: the level of compliance by Italians MMR with the information regulation about food products distance selling in relation to (a) the fulfillment of the obligation concerning mandatory provisions and (b) the fulfillment of the obligations concerning availability and readability of the information provided. The research has been conducted analyzing the websites of the ten largest Italian MMR and in particular: if the mandatory information were provided, the availability of the information according to the Regulation (EU) 1169/2011; the number of clicks needed to identify the food product in the website and the number of clicks Non required to obtain all the information. The observation testified a substantial compliance with the information obligations according to the European regulation. Differently, when considering the availability and readability of the information, from the analysis emerged that consumers have to follow a path that is not immediate and intuitive. Conclusions are provided in relation to the presented research

Knee stability, athletic performance and sport-specific tasks in non-professional soccer players after ACL reconstruction: comparing trans-tibial and antero-medial portal techniques.

Background: a wrong position of bone tunnels, in particular on the femur, is one of the most frequent causes of a failed anterior cruciate ligament (ACL) reconstruct ion. Several studies demonstrated that drilling the femoral tunnel through the antero-medial portal (AMP) allows a more anatomical placement on the lateral femoral condyle and higher knee stability, compared to trans-tibial (TT) technique. The aim of this study was to retrospectively evaluate two groups of soccer players operated on for ACL reconstruction according to either one of these two techniques. Methods: two groups of non-professional soccer players operated on for a single bundle ACL reconstruction with hamstrings autograft using either a TT (20 patients) or an AMP (23 patients) technique were retrospectively evaluated with KT- 1000 arthrometer, manual pivot shift test, isokinetic test, the incremental treadmill-running test, athletic and sport specific tasks, and knee scores (IKDC, Lysholm and KOOS). Results: the AMP group showed better results at pivot shift test and KOOS, but lower flexion angles at single leg squat test. There were no differences in all the other considered outcomes. Conclusions: the better rotational stability of the knee achieved in AMP group did not lead to significantly better clinical and functional results in our patients. Level of evidence III. Treatment study: Case-control study

Viability of a Five-Strain Mixture of Listeria monocytogenes in Vacuum-Sealed Packages of Frankfurters, Commercially Prepared with and without 2.0 or 3.0% Added Potassium Lactate, during Extended Storage at 4 and 10° C†‡

The viability of Listeria monocytogenes was monitored on frankfurters containing added potassium lactate that were obtained directly from a commercial manufacturer. Eight links (ca. 56 g each) were transferred aseptically from the original vacuum-sealed bulk packages into nylon-polyethylene bags. Each bag then received a 4-ml portion of a five-strain mixture of the pathogen. Frankfurters containing 2.0 or 3.0% potassium lactate were evaluated using 20 CFU per package, and frankfurters containing 3.0% potassium lactate were evaluated using 500 CFU per package. The packages were vacuum-sealed and stored at 4 or 10°C for up to 90 or 60 days, respectively. During storage at 4°C, pathogen numbers remained at about 1.6 log10 CFU per package over 90 days in packages containing frankfurters with 2.0% potassium lactate that were inoculated with about 20 CFU. In packages containing frankfurters with 3.0% potassium lactate that were inoculated with about 20 CFU and stored at 4°C, pathogen numbers remained at about 1..