Search results for "heating"
showing 10 items of 248 documents
Innovative technologies for food preservation
2018
Abstract Several techniques have been developed during the 20th century in order to preserve foods. These innovative technologies vary considerably and embrace physical technologies (e.g., high hydrostatic pressure and high-pressure homogenization), electromagnetic technologies (e.g., pulsed electric fields, ohmic heating, microwaves, radio-frequency, and UV-light), acoustic technologies (e.g., ultrasound and shockwaves), and others such as membrane filtration and dense phase CO 2 . In this chapter, the theoretical background and definition of the technologies are explained together with a description of the equipment, main technological/processing parameters, and some advantages and limita…
Heating glaciers from below
2013
Climate change is affecting the cryosphere from above. Geothermal heat flux from below is also contributing to conditions at the base of Greenland's ice sheet, which sits atop a lithosphere of variable thickness.
Acceptability of the e-authentication in higher education studies: views of students with special educational needs and disabilities
2021
AbstractTrust-based e-assessment systems are increasingly important in the digital age for both academic institutions and students, including students with special educational needs and disabilities (SEND). Recent literature indicates a growing number of studies about e-authentication and authorship verification for quality assurance with more flexible modes of assessment. Yet understanding the acceptability of e-authentication systems among SEND students is underexplored. This study examines SEND students’ views about the use of e-authentication systems, including perceived advantages and disadvantages of new technology-enhanced assessment. This study aims to shed light on this area by exa…
A correlation linking the predicted mean vote and the mean thermal vote based on an investigation on the human thermal comfort in short-haul domestic…
2015
Abstract The results of an experimental investigation on the human thermal comfort inside the cabin of some Airbus A319 aircrafts during 14 short-haul domestic flights, linking various Italian cities, are presented and used to define a correlation among the predicted mean vote (PMV), a procedure which is commonly used to assess the thermal comfort in inhabited environments, and the equivalent temperature and mean thermal vote (MTV), which are the parameters suggested by the European Standard EN ISO 14505-2 for the evaluation of the thermal environment in vehicles. The measurements of the radiant temperature, air temperature and relative humidity during flights were performed. The air temper…
When Competition Is Pushed Too Hard. An Agent-Based Model Of Strategic Behaviour Of Referees In Peer Review
2013
This paper examines the impact of strategic behaviour of referees on the quality and efficiency of peer review. We modelled peer review as a process based on knowledge asymmetry and subject to evaluation bias. We built two simulation scenarios to investigate largescale implications of referee behaviour and judgment bias. The first one was inspired by “the luck of the reviewer draw” idea. In this case, we assumed that referees randomly fell into Type I and Type II errors, i.e., recommending submissions of low quality to be published or recommending against the publishing of submissions which should have been published. In the second scenario, we assumed that certain referees tried intentiona…
Influence of greenhouse volume/area ratio on soil solarization efficiency
2008
Soil temperature under plastic cover is function of incoming radiation and thermal characteristics of the mulching material and the soil, but it could be also affected by greenhouse characteristics (structure, cover, Volume/Area ratio). The aim of this research was to evaluate the effects of different greenhouse unitary volumes and different plastic mulching on soil temperature and soil solarization efficiency. The experiment was carried out in nonheated greenhouses covered with low density transparent polyethilene (PE), located at the experimental field of AAT Department of Palermo University, Italy (138° 7' N, 13° 22' E). Four Volume/Area (V/A) ratios were tested: 1.5 - 2.0 - 2.5 - 3.0. I…
Ohmic treatment of fresh foods: Effect on textural properties
2013
The aim of this work was to verify the effects of ohmic heating (OH) treatment on texture of fresh solid food (without pre-treatment in brine solutions), subjected to constant electrical field gradient (1100 V/m; 2200 V/m; 3300 V/m). Samples of fresh potatoes, carrots and apples cut into cylinders (d = 30 mm, h = 9.0 mm) underwent OH for 60, 120, 180 and 240 seconds. Texture measurements were performed in a universal testing machine Instron 4301, with a 100 N load cell, using a single-cycle compression test. The raw untreated sample was used as control. Stress–deformation behavior of food samples processed by OH differs appreciably from raw untreated samples for all cooking times. Firmness …
Impact of Different Building Materials on Summer Comfort in Low-Energy Buildings
2015
Abstract The aim of the current paper is to analyse thermal comfort and overheating risks in the low-energy buildings in a summer season under Latvian climate conditions both experimentally and numerically. An interior temperature and relative humidity are analysed under free-floating conditions. Two cases are analysed: in one case, the solar influence through the window is taken into account; in the other this influence is omitted. Three different building solutions are observed: two building structures which mainly consist of the mineral wool and wooden materials and one structure from aerated clay bricks and mineral wool. The experiments have been implemented in test stands in Riga, Latv…
Monitoring results and analysis of thermal comfort conditions in experimental buildings for different heating systems and ventilation regimes during …
2017
This paper focuses on the long-term monitoring of thermal comfort and discomfort parameters in five small test buildings equipped with different heating and cooling systems. Calculations of predicted percentage of dissatisfied people (PPD) index and discomfort factors are provided for the room in winter season running three different heating systems – electric heater, air-air heat pump and air-water heat pump, as well as for the summer cooling with split type air conditioning systems. It is shown that the type of heating/cooling system and its working regime has an important impact on thermal comfort conditions in observed room. Recommendations for the optimal operating regimes and choice o…
Mathematical Model of Solid Food Pasteurization by Ohmic Heating: Influence of Process Parameters
2013
Pasteurization of a solid food undergoing ohmic heating has been analysed by means of a mathematical model, involving the simultaneous solution of Laplace’s equation, which describes the distribution of electrical potential within a food, the heat transfer equation, using a source term involving the displacement of electrical potential, the kinetics of inactivation of microorganisms likely to be contaminating the product. In the model, thermophysical and electrical properties as function of temperature are used. Previous works have shown the occurrence of heat loss from food products to the external environment during ohmic heating. The current model predicts that, when temperature gradient…