Theoretical study of the effect of fibre orientations and porosity on heat conductivity of reinforced polymer composites

In recent years, there has been an increasing demand for engineering materials which not only possess good mechanical and thermal properties but are also cheap and environmentally friendly. Composites are unique engineering materials which can be tailor made from a large variety of materials to suit specific applications. Composites primarily consist of a polymer resin matrix in which other material is incorporated in discrete units for reinforcing. The reinforcing materials can be in the form of fibres or flakes orientated in various ways to impart maximum performance. Natural fibres such as sisal, kenaf, bagasse, hemp etc. have been studied as reinforcing material for conventional polymer resins. Such composites are often termed green composites and they have unique mechanical properties when compared to conventional composites. They are also available at a cheap price and weigh a lot less. In addition, they can also offer unique thermal and acoustic insulation properties. Due to these attractive features they are used in the automotive, aerospace, textile and construction industries. A particularly important feature which determines the properties of natural fibre composites and their porosity. From an industrial and academic point of view, there is a need to study the heat conductivity of newly developed composites. This is influenced by the porosity of the composite. This project, investigated the effect of porosity and their orientation on the heat conductivity of polymer composites. Experimental and theoretical studies were conducted on mainly sisal-glass fibre polymer composites. Different volume of fibre fractions were tested in this study. It was expected that the presence of the fibres would dramatically improve the heat conductivity properties of the materials because the sisal fibres have internal porosity. The results of this work are expect to contribute to academic and industrial knowledge about the thermal performance of fibre composites. The data will be published in a professional journal. This knowledge will contribute to the manufacturing of newly developed materials for industrial applications

The Protective Properties of the Strawberry (Fragaria ananassa) against Carbon Tetrachloride-Induced Hepatotoxicity in Rats Mediated by Anti-Apoptotic and Upregulation of Antioxidant Genes Expression Effects

The strawberry (Fragaria ananassa) has been extensively used to treat a wide range of ailments in many cultures. The present study was aimed at evaluating the hepatoprotective effect of strawberry juice on experimentally induced liver injury in rats. To this end, rats were introperitoneally injected with carbon tetrachloride (CCl4) with or without strawberry juice supplementation for 12 weeks and the hepatoprotective effect of strawberry was assessed by measuring serum liver enzyme markers, hepatic tissue redox status and apoptotic markers with various techniques including biochemistry, ELISA, quantitative PCR assays and histochemistry. The hepatoprotective effect of the strawberry was evident by preventing CCl4-induced increase in liver enzymes levels. Determination of oxidative balance showed that strawberry treatment significantly blunted CCl4-induced increase in oxidative stress markers and decrease in enzymatic and non-enzymatic molecules in hepatic tissue. Furthermore, strawberry supplementation enhanced the anti-apoptotic protein, Bcl-2, and restrained the pro-apoptotic proteins Bax and caspase-3 with a marked reduction in collagen areas in hepatic tissue. These findings demonstrated that strawberry (Fragaria ananassa) juice possessed antioxidant, anti-apoptotic and anti-fibrotic properties, probably mediated by the presence of polyphenols and flavonoids compounds

NeuroPlace: categorizing urban places according to mental states

Urban spaces have a great impact on how people’s emotion and behaviour. There are number of factors that impact our brain responses to a space. This paper presents a novel urban place recommendation approach, that is based on modelling in-situ EEG data. The research investigations leverages on newly affordable Electroencephalogram (EEG) headsets, which has the capability to sense mental states such as meditation and attention levels. These emerging devices have been utilized in understanding how human brains are affected by the surrounding built environments and natural spaces. In this paper, mobile EEG headsets have been used to detect mental states at different types of urban places. By analysing and modelling brain activity data, we were able to classify three different places according to the mental state signature of the users, and create an association map to guide and recommend people to therapeutic places that lessen brain fatigue and increase mental rejuvenation. Our mental states classifier has achieved accuracy of (%90.8). NeuroPlace breaks new ground not only as a mobile ubiquitous brain monitoring system for urban computing, but also as a system that can advise urban planners on the impact of specific urban planning policies and structures. We present and discuss the challenges in making our initial prototype more practical, robust, and reliable as part of our on-going research. In addition, we present some enabling applications using the proposed architecture

An acute bout of swimming increases post-exercise energy intake in young healthy men and women

Single bouts of land-based exercise (for example, walking, running, cycling) do not typically alter post-exercise energy intake on the day of exercise. However, anecdotal and preliminary empirical evidence suggests that swimming may increase appetite and energy intake. This study compared the acute effects of swimming on appetite, energy intake, and food preference and reward, versus exertion-matched cycling and a resting control. Thirty-two men (n=17; mean ± SD age 24 ± 2 years, body mass index [BMI] 25.0 ± 2.6 kg/m2) and women (n=15; age 22 ± 3 years, BMI 22.8 ± 2.3 kg/m2) completed three experimental trials (swimming, cycling, control) in a randomised, crossover design. The exercise trials involved 60-min of ‘hard’ exercise (self-selected rating of perceived exertion: 15) performed 90-min after a standardised breakfast. Food preference and reward were assessed via the Leeds Food Preference Questionnaire 15-min after exercise, whilst ad libitum energy intake was determined 30-min after exercise. The control trial involved identical procedures except no exercise was performed. Compared with control (3259 ± 1265 kJ), swimming increased ad libitum energy intake (3857 ± 1611 kJ; ES=0.47, 95% CI of the mean difference between trials 185, 1010 kJ, P=0.005); the magnitude of increase was smaller after cycling (3652 ± 1619 kJ; ES=0.31, 95% CI -21, 805 kJ, P=0.062). Ad libitum energy intake was similar between swimming and cycling (ES=0.16, 95% CI -207, 618 kJ, P=0.324). This effect was consistent across sexes and unrelated to food preference and reward which were similar after swimming and cycling compared with control. This study has identified an orexigenic effect of swimming. Further research is needed to identify the responsible mechanism(s), including the relevance of water immersion and water temperature per se

Synthesis, characterization and antibacterial activity studies of new 2‑pyrral‑L‑amino acid Schif base palladium (II) complexes.

Three new 2-pyrral amino acid Schif base palladium (II) complexes were synthesized, characterized and their activity against six bacterial species was investigated. The ligands: Potassium 2-pyrrolidine-L-methioninate (L1), Potassium 2-pyrrolidine-L-histidinate (L2) and Potassium 2-pyrrolidine-L-tryptophanate (L3) were synthesized and reacted with dichloro(1,5- cyclooctadiene)palladium(II) to form new palladium (II) complexes C1, C2 and C3, respectively. 1 NMR, FTIR, UV–Vis,elemental analysis and conductivity measurements were used to characterize the products. The antibacterial activities of the compounds were evaluated against Gram-positive Staphylococcus aureus (S. aureus, ATCC 25923), methicillin-resistant Staphylococcus aureus (MRSA, ATCC 33591), Staphylococcus epidermidis (S. epidermidis, ATCC 12228) and Streptococcus pyogenes (S. pyogenes, ATCC 19615) and, gram-negative Pseudomonas aeruginosa (P. aeruginosa, ATCC 27853) and Klebsiella pneumoniae (K. pneumoniae, ATCC 13883) using the agar well difusion assay and microtitre plate serial dilution method. The palladium complexes were active against the selected bacteria with the imidazole ring containing complex C2 and indole heterocyclic ring containing complex C3 showing the highest activity

Investigation of ultrasonic atomization to enhance performance of a micro jet engine using biofuel

A jet engine is commonly used in aeronautical applications such as civilian airplanes, armed fighters, and helicopters, as it is one of the types of the gas turbine engine. Air enters through the compressor and injected into the combustion chamber to be mixed with fuel under pressure for combustion. This releases the energy of the heat to expand the volume of hot fluids and impact to the turbine wheel and generate the power of the hot gases. Such engines require tremendous amount of biodiesle. The ultrasonic atomization has been applied in different areas and shows positive potential performance. However, this promising atomizer technology has not yet applied in the micro jet engine to use biodiesel blends fuels. This gap in previous studies gave the motivation to investigates the potential of using ultrasonic atomization technology to assist the combustion process as a contribution for promising an alternative to the normal fuel atomization system. Firstly the new combustion equation is developed and validated, followed by determination of optimum conditions for combustion performance including optimum size of ultrasonic droplets. An experimental rig was set up to determine the performance of jet engine using ultrasonic droplets. The four- component set of ultrasonic atomizer devices delivers the fuel through the jet engine intake area, each device can deliver a 5 liter/ hour. The air mass flow was measured using a hot wire anemometer with speed limit 30 m/s fixed in front of the intake area. A load cell was installed to measure the actual thrust from the engine in units kgf. A gas analyzer was used to measure oxygen percentage, carbon monoxide, carbon dioxide and unburned hydrocarbons (uHC), nitrogen monoxide and nitrogen dioxide of the exhaust gas. The performance of the engine was tested under three levels of load (high, medium, low) starting from 10-psi at steady state to the minimum value. A significant result has been tested for a low value of nitrogen monoxide at the three levels of load, a specific result has been tested for efficiency value of 2% at the three levels of load, carbon dioxide is decreasing at the low level of load. The use of the ultrasonic atomization device to assist in the combustion process was useful in achieving engine efficiency of 1% of the micro jet performance and the reduce the emission of carbon dioxide exhaust gas to almost 25%

Disasters Information-Seeking Behavior via Social Networking Sites

Disasters bring uncertainties and substantial health, economic, social, and psychological challenges. Effective management of disasters requires a thorough understanding of their causes, nature, and consequences. Affected individuals may, therefore, seek instant, trustworthy information from different sources, including social networking sites (SNSs). This study investigates what leads individuals to seek disaster information on SNSs. The investigated potential drivers are source credibility (SC), argument quality (AQ), self-efficacy (SEF), perceived usefulness of information (OUI), and behavioral intention (INT). The results confirm the newly emerged source & argument quality (SAQ) construct, SEF, and PUI are significant antecedents of INT, which in turn influences disaster information-seeking behavior (ISB) via SNSs

Numerical study of the combustion of conventional and BioFuels using reduced and advanced reaction mechanisms

Combustion process of conventional liquid fuels and BioFuels depend on many factors including thermo - physicochemical properties associated with such fuels, their chemical structure and the combustion infrastructure used. This manuscript summarises the computational results of a steady cfd simulation for reactive flows performed to validate advanced reaction mechanisms for both conventional and BioFuels. The computational results have shown good agreement with the available experimental data with the differences thoroughly discussed and explained. An important observations and findings reported in this work was that when comprehensive reaction models were used, the injected fuels burned at a slower rate compared to the situation when reduced models were employed. While such comprehensive models predicted better flame structure and far better biproducts compared to the existing experimental results, it has also led to over-predicting the temperature field. The computational results have also shown that BioDiesel produces a marginally higher rate of CO2 compared to Diesel. Such results are thought to be due to the Oxygenated nature of the fuel and how such feature influences the development of a comprehensive reaction mechanism for such fuels

Ocklusionshantering i kontexten augmenterad verklighet

Handling occlusion between real and virtual objects is a challenging problem in Augmented Reality (AR) applications. Incorrect and inaccurate occlusion handling may cause confusion in users’ perception which leads to non-realistic and non-immersive AR experiences. Even though there are important research examples and implementations on this topic, they typically suffer from important limitations. The method presented in this thesis takes both raw depth and color information from an RGB-D sensor in order to solve occlusion in unknown AR contexts. The novelty of this method is the automatic trimap generation which is based on the color distribution information of the real scene. Moreover, the proposed method can operate using the information from only the latest frame, or efficiently use the information from multiple frames. In the second case, the knowledge of the previous frame output is used to improve the trimap generation of the latest frame. Experimental evaluations of several scenes demonstrate that this approach largely improves automatic trimap generation using both the RGB and depth information. Furthermore, the final proposed method is compared with some recent state of the art approaches in terms of quality and accuracy, showing that it overcomes some of the known limitations.Hantering av ocklusion mellan verkliga och virtuella objekt är ett utmanande problem i applikationer med augmenterad verklighet (AR). Felaktig ocklusionshantering kan orsaka förvirring i användarnas uppfattning vilket leder till icke-realistiska AR-upplevelser. Trots att det finns forskningsexempel och implementeringar av framgång inom detta område så har de ofta betydliga begränsningar. Metoden som presenteras i detta arbete tar både rå djup- och färginformation från en RGB-D-sensor för att lösa ocklusion i okända AR-sammanhang. Innovationen med denna metod är den automatiska trimapgenerationen som bygger på informationen i färgdistributionen i den verkliga scenen. Dessutom kan den föreslagna metoden fungera med hjälp av informationen från endast den senaste bilden, eller effektivt använda informationen från flera bilder. I det andra fallet används information från den tidigare bildutmatningen för att förbättra trimapgenerationen av den senaste bilden. Experimentella utvärderingar av flera scener visar att denna metod i stor utsträckning förbättrar automatisk trimapgenerering med både RGB och djupinformation. Vidare jämförs den föreslagna metoden med några av de andra främsta tillvägagångssätt med avsende på kvalitet och noggrannhet, vilket visar att den övervinner några av de kända begränsningarna