Tubular Expansion in Irregularly Shaped Boreholes—Computer Simulation and Field Measurement

Abstract

Abstract Recently, field engineers have tried to use a new technique using expandable tubular with elastomers to seal the annulus. Ultrasonic down-hole measurements carried out for evaluation of zonal isolation revealed that the tubular expanded to an oval x-section instead of the desired circular x-section at certain locations. This is a phenomenon previously unknown. It is believed to occur due to expansion in irregularly shaped boreholes. The ovalization of expanded tubular was studied to avoid such problems in future. The finite element method was used to predict tubular ovality and compare it to measured values. Results were then used to develop ready-to-use design curves in making decisions for running a completion tool in expanded tubular.     

Impact of heat processing on the detection of the major shellfish allergen tropomyosin in crustaceans and molluscs using specific monoclonal antibodies

The major heat-stable shellfish allergen, tropomyosin, demonstrates immunological cross-reactivity, making specific differentiation of crustaceans and molluscs for food labelling very difficult. The aim of this study was to evaluate the application of allergen-specific monoclonal antibodies in differential detection of shellfish-derived tropomyosin in 11 crustacean and 7 mollusc species, and to study the impact of heating on its detection. Cross-reactive tropomyosin was detected in all crustacean species, with partial detection in molluscs: mussels, scallops and snails but none in oyster, octopus and squid. Furthermore, we have demonstrated that heating of shellfish has a profound effect on tropomyosin detection. This was evident by the enhanced recognition of multiple tropomyosin variants in the analysed shellfish species. Specific monoclonal antibodies, targetting the N-terminal region of tropomyosin, must therefore be developed to differentiate tropomyosins in crustaceans and molluscs. This can help in correct food labelling practices and thus protection of consumers.     

Assessment of the Anti-Microbial Activity of Dried Garlic Powders Produced by Different Methods of Drying

The anti-microbial activity of a range of garlic products including dried garlic powder produced by different methods, commercial garlic products, and garlic oil was determined against a range of selected bacteria. The bacteria included food borne pathogens, spoilage agents, and health-beneficial agents, namely Staphylococcus aureus, Escherichia coli, Salmonella typhimurium, Bacillus cereus, and a mixed lactic culture consisting of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus. The dried powders were produced using air-drying at both 60 and 80°C, vacuum-drying at 50 and 60°C, and freeze-drying at ?20°C. In addition, five commercial products were tested, two of which are used as spices, and three as food supplements. Before testing, the moisture content of the dried garlic powders was raised to that of fresh garlic before drying. Garlic oil was used without any addition of water. In general, the results showed that the lactic culture was the most sensitive to the growth inhibitory active compound of garlic used in this study, followed by Staphylococcus aureus. In contrast Salmonella typhimurium and Bacillus cereus demonstrated the greatest resistance to garlic. Generally, fresh garlic produced the greatest inhibition followed by freeze-dried powder. The anti-microbial activity decreased with decreasing dried garlic powder concentration. The results showed that both drying temperature and time have major effects on retaining the active components responsible for the inhibition of microbial growth. The anti-microbial substances in the moist fresh garlic were also affected by moist-heating temperatures and time. Higher heating temperatures caused faster loss of anti-microbial activity. The decrease in growth-inhibition zones for moist-heated fresh garlic followed zero-order kinetics.     

Alternative Treatments for Weight Loss: Safety/Risks and Effectiveness of Anti-Obesity Medicinal Plants

Obesity is emerging globally as a leading, underlying contributor to a variety of different diseases, some of which are fatal. This study aims to provide a brief review of the botanical sources which are available to serve as an alternative to modern, synthetic anti-obesity drugs, and to provide a brief discussion of their mechanism of action, and their safe and effective usage. Information was gathered from books, journals, and a variety of electronic sources published in the period of 1991 to 2014. Medicinal plants can reduce weight through five basic mechanisms: controlling appetite, stimulating thermogenesis and lipid metabolism, inhibiting pancreatic lipase activity, preventing adipogenesis, and promoting lipolysis. Based on a review of the available literature, the consumption of recommended medicinal plants in a single form, and at an optimum dosage, could be a safe and effective complementary treatment for obesity.     

Development of a Versatile Database for Transport Properties of Foods

The requirement of reliable data on transport properties of foods has emerged in the last decade due to their importance in the design and simulation of food processing operations. An international effort to obtain and analyze the published data has been made recently, due to the lack of reliable theoretical predictive models. In this framework, a user-friendly database system for the storage and maintenance of the transport properties of foodstuffs is proposed and developed in a Microsoft Access environment. The system allows the end-user to input and retrieve data, as well as to view diagrams with single or comparative data and predict values via a fully featured user-friendly interface. Currently the database has registered over 250 articles, which correspond to approximately 1200 records for the thermal conductivity and 1780 records for moisture diffusivity. Due to its flexibility, the system can be used as an universal template for developing similar database systems.     

In vitro cytoprotective effect of infant milk formula fortified with human rotavirus-specific hyperimmune yolk immunoglobulins (IgY)

Infant formula supplemented with hyperimmune immunoglobulin Y (IgY) against human rotavirus (HRV) was evaluated in vitro against HRV reassortant clinical strains ATCC VR 2273 and ATCC VR 2274. Specific antihuman rotavirus antibody powder (Rotamix IgY) was prepared. The effectiveness of Rotamix IgY alone and as a pre-mixed solution with infant formula was evaluated for neutralizing rotavirus infectivity in MA104 cells. The test infant formula cross-reacted strongly against different human rotavirus strains with titers of 80-320 using a 50% fluorescent focus (FF) inhibition test. Both rotamix IgY alone and in a pre-mixed solution with infant formula showed multi-serotypic cross neutralization activities against the major rotavirus global serotypes G1, G2, G3, and G4 alone and with other human and animal-strains in vitro. Cell-rotavirus adhesion and cell damage arising from rotavirus infection were significantly inhibited in a dose dependent manner, compared to control IgY supplemented infant formula.     

Effects of Moisture and pH on Supercritical Fluid Extraction of Cocoa Butter

The effects of moisture content and alkali treatment on cocoa butter extraction using supercritical fluid were studied. Ground cocoa nibs were examined at moisture contents of 1.95 %, 3.91 %, 5.87 %, 9.79 % and 17.64 % and the pH of the cocoa liquor was maintained at 5.0–5.9, 6.8–7.2 and 7.5–7.9. Cocoa butter was successfully extracted, using supercritical carbon dioxide (SC-CO₂) for the moisture content study and SC-CO₂ with 25 % ethanol as a cosolvent for the pH-level alkali treatment study, at 35 MPa, 60 °C and 2 ml/min. The results showed that increases in moisture content and pH level significantly (p?<?0.05) increase the yield efficiency. A moisture content of 9.79 % and pH-alkali treatment at 7.5–7.9 produced the highest yield (60.36 % and 73.70 % at 20 and 18 h extraction time, respectively). Triglycerides (TG) and fatty acids (FAs) were similar to those found in cocoa butter obtained using the Soxhlet method. Saturated and short-chain TG and FA constituents were more soluble than unsaturated and long-chain constituents.     

Development of multilayer polyelectrolyte thin‐film membranes fabricated by spin assisted layer‐by‐layer assembly

Polyelectrolyte multilayer (PEM) thin films consisting of alternate layers of two PEM systems, that is poly(diallyl dimethyl ammonium chloride)/poly(vinyl sulfate) (PDAC/PVS) and poly(allyl amine hydrochloride) (PAH)/ are successfully deposited on polysulfone (PSF) support using spin‐assisted layer‐by‐layer assembly. The films are characterized using atomic force microscope, Fourier transform Infrared, and contact angle measurement. The salt (NaCl) rejection and water flux of the [PDAC/PVS] and [PAH/PVS] membranes are also evaluated using a crossflow permeation test cell. The permeation test shows that 120 bilayers of [PAH/PVS] on PSF substrate provide salt rejection of 53% and water flux of 37 L/m² h, whereas that of PDAC/PVS on PSF substrate provide salt rejection of 21% and water flux of 90 L/m² h for a 2000‐ppm NaCl solution feed at a pressure of 40 bar and temperature of 25°C. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Preparation and properties of polydimethylsiloxane (PDMS)/polytetramethyleneadipate glycol (PTAd)-based waterborne polyurethane adhesives: Effect of PDMS molecular weight and content

Waterborne polyurethane (WBPU) dispersions were prepared by pre-polymer process using siloxane polyol, namely polydimethylsiloxane (PDMS), and polyester polyol, namely poly(tetramethyleneadipate glycol) (PTAd), as a soft segment. Three different molecular weights (M_n = 550, 6000, 110,000) of PDMS and one fixed molecular weight of PTAd (M_n = 2000) was used during preparation of WBPU dispersions. This research aims to explore the potential use of PDMS in complementing WBPU by boosting flexibility, water resistance, and adhesive strength. The water swelling (%), tensile strength, and adhesive strength of WBPUs were investigated with respect to PDMS molecular weight and PDMS content (PDMS mol %). The water swelling (%) and tensile strength decreased with increasing PDMS molecular weight at a fixed PDMS content (mol %) in mixed polyol of WBPU films. By contrast, the peel adhesive strength peaked at 6.64 mol % and 4.43 mol % with molecular weight of PDMS at 550 and 6000, respectively, while it only decreased when the molecular weight of PDMS stood at 110,000. The adhesive strength was almost unaffected with optimum content (6.64 mol %) of lower PDMS molecular weight (M_n = 550) in mixed polyol-based WBPU after immersing the adhesive bonded nylon fabrics in water for 48 h among all of the samples. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Effect of epoxy resin on the intrinsic properties of masonry mortars

The paper presents an assessment on the properties of three different types of masonry mortars, namely Portland cement mortar (CM), polymer cement mortar (PCM) and polymer mortar (PM) of various compositions. The effect of binder content (cement and/or epoxy) on CM, PCM or PM has been explored in the study. An assessment was carried out on the basis of mechanical (compressive, tensile and flexural strength), physical (water uptake, chloride ion permeability), morphological (porosity) and thermal (coefficient of thermal expansion) properties of the mortars. A comparative cost analysis of the mortars is also discussed in this article. The results show that the mechanical strength of both PCM and PM improves markedly with the addition of epoxy resin, and the higher rate of incremental strength is found for PM. Consequently, the chloride ion penetration, water uptake, porosity and thermal expansion of the mortars decrease significantly with the resin content, but the rate of drop in chloride ion penetration, water uptake, porosity and thermal expansion is much higher for PM. The test results indicate that the variation of binder content (epoxy/cement) is found to be the key factor determining the mortar properties and cost.