Asymptotic Distortion Performance of Source-Channel Diversity over Multihop and Relay Channels

A key challenge in the design of real-time wireless multimedia systems is the presence of fading coupled with strict delay constraints. A very effective answer to this problem is the use of diversity achieving techniques to overcome the fading nature of the wireless channels caused by the mobility of the nodes. The mobility of the nodes gives rise to the need of cooperation among the nodes to enhance the system performance. This paper focuses on comparing systems that exhibit diversity of three forms: source coding diversity, channel coding diversity, and user cooperation diversity implemented through multihop or relay channels with amplify-and-forward or decode-and-forward protocols. Commonly used in multimedia communications, performance is measured in terms of the distortion exponent, which measures the rate of decay of the end-to-end distortion at asymptotically high signal-to-noise ratio (SNR). For the case of repetition coding at the relay nodes, we prove that having more relays is not always beneficial. For the general case of having a large number of relays that can help the source using repetition coding, the optimum number of relay nodes that maximizes the distortion exponent is determined in this paper. This optimum number of relay nodes will depend on the system bandwidth as well as the channel quality. The derived result shows a trade-off between the quality (resolution) of the source encoder and the amount of cooperation (number of relay nodes). Also, the performances of the channel coding diversity-based scheme and the source coding diversity-based scheme are compared. The results show that for both relay and multihop channels, channel coding diversity provides the best performance, followed by the source coding diversity.     

Temperature Control of a Thermal Plasma Torch with Inductive Coupling Using the Arduino Board

Plasma torch is a device that transforms electrical energy into heat carried by a gas and its safe operation is necessary to control her temperature. This paper presents the use of the Arduino board in temperature control of a plasma torch through fuzzy control. The plasma torch of this project was built so that a flow of water can circulate through your body, allowing its cooling. The cooling system mounted consists of one radiator, one expansion vase, one water pump and one temperature sensor. The heated water coming the plasma torch is passed by the temperature sensor. This is converted in a voltage and read by an analog input port of the Arduino. This processes the information received and makes the decision to turn on/off the radiator fan and/or powered the frequency inverter water pump to control the temperature. The graph of the fuzzy control showed an oscillation between 104 °F to 122 °F around the chosen reference 113 °F. The results show that it is possible to control the temperature of a plasma torch using the Arduino board and fuzzy logic.     

Influence of oxygen on the sputtering of aluminum oxide for the surface passivation of crystalline silicon

While sputtering has been shown to be capable of depositing aluminum oxide suitable for surface passivation, the mechanisms for this are yet to be firmly established and its potential realized. In this paper, we investigate the relationships between the oxygen in the sputtering process to the resulting composition of the deposited film and the surface passivation obtained. We find that surface passivation is not strongly dependent on the bulk composition of the film. Instead the results indicate that the interfacial silicon oxide layer that forms after annealing between the aluminum oxide film and the silicon is a much more important factor; it is this combined structure of aluminum oxide, silicon oxide and silicon that is crucial for obtaining negative charges and excellent surface passivation.     

Volatile aldehyde emissions from heated cooking oils

Low molecular weight aldehydes (LMWAs) formed during the heating of frying media (triglycerides) were adsorbed onto tenax and analyzed by GC‐MS after thermal desorption. Six alkanals (C₅ to C₁₀), seven 2‐alkenals (C₅ to C₁₁) and 3 alkadienals (C₇, C₉ and C₁₀) were found in the fumes of canola oil (control), extra virgin olive oil, and refined olive oil, heated at 180 and 240 °C. The emission rates of these aldehydes depended on the heating temperature. Frying in any type of olive oil, independently of its commercial category, will effectively decrease the emission of volatile aldehydes at temperatures below the smoking point. Thus, using the cheaper olive oil for deep‐frying purposes will not affect aldehyde emissions. This is important since olive oil is usually used for deep‐frying operations while extra virgin olive oil is used as salad dressing in Spain. The mixture of refined olive oil with some virgin olive oil is the most acceptable type of olive oil in non‐Mediterranean countries due to its milder flavor. However, if higher temperatures are needed the use of canola oil is more advisable due to its higher smoke point. Copyright © 2004 Society of Chemical Industry     

Biosecurity Measures to Control Salmonella and Other Infectious Agents in Pig Farms: A Review

Salmonellosis is the 2nd most common cause of human bacterial food poisoning and can be acquired from meat or eggs, either via direct consumption or cross‐contamination in the kitchen. The European Commission has set the criteria to control Salmonella infections within the poultry sector and it is proposed that the swine sector should follow. Pork is considered, after eggs, the major source of infection in humans in the EU, with Salmonella typhimurium, including monophasic strains, being frequently implicated. Good control measures at the farm level are likely to correspond with lower prevalence of Salmonella infection and, subsequently, a reduction of cross‐contamination of carcasses processed at the slaughterhouse and a reduction in human salmonellosis. This review focuses on biosecurity measures in pig farms that can help to control important pig diseases at the same time as reducing the within‐herd prevalence of Salmonella. This information is likely to provide an economic incentive for farmers to apply improved general standards of farm biosecurity and hygiene management that would have a positive impact in food safety.     

Intermolecular interaction of thermoresponsive poly-2-isopropyl-2-oxazoline in solutions and interpolymer complex with fiber-forming polyethylene oxide

The cross-linked poly-2-isopropyl-2-oxazolines (PiPrOx) differing in cross-linker content have been synthesized and characterized by light scattering, chromatography, and rheometry. The dramatic influence of the cross-linker content on solubility and uni- or bimodality was observed. For the first time, the interpolymer complex of cross-linked PiPrOx with polyethylene oxide is manufactured in fibrous form by the electrospinning method. The role of intermolecular hydrogen bonds in the structure and properties of electrospun fibers (EF) was studied by infrared spectroscopy, differential scanning calorimetry, and scanning electron microscopy. It was established that these interactions allow to obtain a uniform fibrous membrane. At the same time, hydrogen bonding is responsible for the self-organization of PiPrOx in water.     

Effect of high-pressure homogenisation on metabolic potential of Lacticaseibacillus paracasei 90: in vitro and in situ studies in fermented milk and semihard cheese

The influence of high-pressure homogenisation (HPH) at 100 MPa on Lacticaseibacillus paracasei 90 (L90) was studied in vitro and in situ (fermented milk and cheese). Lysis and injury signs were observed in cells treated with HPH, which were linked to the release of intracellular enzymes and changes in the metabolic activity of L90. HPH treatment led to a higher lactic acid content and lower pH and pyruvic acid levels in fermented milk. The microbiological and peptide profiles of cheeses were modified by using cells or cell-free extracts of L90. Finally, this study suggests that L90 could release bioactive peptides.     

Effect of Volumetric Energy Density on Microstructure and Properties of Grade 300 Maraging Steel Fabricated by Laser Powder Bed Fusion

Metallurgical and Materials Transactions A - This study investigated the effect of laser powder bed fusion process parameters on the microstructure and properties of maraging steel. The results...