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Plastic Sheets (plastic + sheet)
Selected AbstractsCOMPARISON OF SIX NON-INVASIVE SUPPLEMENTAL OXYGEN TECHNIQUES IN DOGS AND CATSJOURNAL OF VETERINARY EMERGENCY AND CRITICAL CARE, Issue S1 2004MH Engelhardt Objective: To determine the amount of time required to reach the highest concentrations of oxygen at the patient's face and to determine what these highest concentrations of oxygen were with various non-invasive methods of providing supplemental oxygen using a commercial oxygen content analyzer. Procedure: Three healthy cats and 3 healthy dogs were each individually given supplemental oxygen by 6 different means, each done at 2 rates (5 L and 15 L per minute). The methods tested were: 1) Plastic sheet over conventional cage door (PSCD); 2) Blow-by where the tubing delivering the oxygen was held 8 cm from the face (BB); 3) Large plastic bag covering the patient (BAG); 4) Anesthesia induction chamber (AIC); 5) Synder oxygen cage (SOC); and 6) Crowe Oxygen E-Collar (COC). Prior to the testing, the commercial oxygen content analyzer (Mini-Ox) was calibrated. Results: Significant repeatable differences were consistently observed between the 6 methods of oxygen delivery. Results of both 5 L and 15 L/min oxygen flow rates consistently indicated that the highest oxygen concentrations were achieved with the anesthesia induction chamber and large plastic bag with oxygen concentrations reaching approximately 95% and 90%, respectively between 5 to 15 min. The BAG method had the advantage of allowing additional room for patient manipulation and the ability to place intravenous catheters while continuing to give supplemental oxygen. The plastic sheet covering a conventional cage door provided oxygen concentrations of 50% and 60% at 15 and 45 min, respectively. The Crowe Oxygen E-Collar achieved oxygen concentrations of 70% in 1.5 min. Blow-by was found to be the simplest method. It increased FiO2 to 40% within 2 min. The Synder oxygen cage was able to achieve 45% oxygen concentration within 30 min with an oxygen flow rate of 15 L/min. It was able to achieve 60% at 45 min (similar to the plastic bag on the cage). Conclusion: The order of effectiveness of providing non-invasive oxygen supplementation, from the highest to the lowest concentrations, was AIC, BAG, COC, PSCD, SOC, and BB. The fastest to the slowest increases in oxygen concentrations followed the same order at both 5 L and 15 L/min oxygen flow rate and they were BB, COC, AIC, BAG, PSCD, and SOC. SOC was the most inefficient means of providing oxygen while AIC, BAG and COC were the most efficient. [source] The Thanksgiving Turkey Tap: A New and Simple Model for Teaching Ultrasound-guided ThoracentesisACADEMIC EMERGENCY MEDICINE, Issue 2009Derek Richardson Thoracentesis is a critical procedure that every emergency physician must be able to perform comfortably. By introducing ultrasound technology to the procedure, we have the potential to redefine the standard of care for emergency department thoracentesis by effectively decreasing complication rates of this procedure. Ultrasound-guided thoracentesis has been shown to lead to fewer incidents of pneumothorax than the traditional technique; however, due to the complicated anatomy of the chest wall, this skill is difficult to teach without using living patient models. The NewYork-Presbyterian Emergency Medicine Residency Program has developed an effective model for teaching and practicing ultrasound-guided thoracentesis. The Presbyterian model uses a whole turkey with the cavity lined with a water-retaining plastic sheet, containing water and an air-filled balloon. Ultrasound can then be used to visualize the ribs, the underlying fluid, and the balloon representing lung space. By using a standard thoracentesis kit with our model, the complete procedure can be performed and techniques of positioning, entry point, and fluid collection can be demonstrated and practiced. This was performed for 50 medical students, residents, and attending physicians in late November 2008 for under $100. This simple model may be used to introduce new practitioners to thoracentesis, or to update experienced physicians on new techniques to decrease complication rates during procedures with an effective and inexpensive model. [source] Case study: A novel surface scanning systemJOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 7 2005K. W. Tam This paper presents the design and development of a novel surface scanning system that employs an array of 144 equal spaced probing pins for capturing the surface coordinates of an object simultaneously. Operation of the system is computer driven. The captured surface data is saved in a point-cloud data file, which can be postprocessed by a CAD system to construct a surface model of the scanned object. The created CAD model can be used to facilitate the design and making of thermoforming moulds. The thermoforming moulds are to be used for forming plastic sheets for packaging consumer products for retail selling. A prototype of the system has been built. Test results demonstrate that the developed system can satisfy the technical and economical requirements of the packaging industry. © 2005 Wiley Periodicals, Inc. [source] Dynamic optimization of the methylmethacrylate cell-cast process for plastic sheet productionAICHE JOURNAL, Issue 6 2009Martķn Rivera-Toledo Abstract Traditionally, the methylmethacrylate (MMA) polymerization reaction process for plastic sheet production has been carried out using warming baths. However, it has been observed that the manufactured polymer tends to feature poor homogeneity characteristics measured in terms of properties like molecular weight distribution. Nonhomogeneous polymer properties should be avoided because they give rise to a product with undesired wide quality characteristics. To improve homogeneity properties force-circulated warm air reactors have been proposed, such reactors are normally operated under isothermal air temperature conditions. However, we demonstrate that dynamic optimal warming temperature profiles lead to a polymer sheet with better homogeneity characteristics, especially when compared against simple isothermal operating policies. In this work, the dynamic optimization of a heating and polymerization reaction process for plastic sheet production in a force-circulated warm air reactor is addressed. The optimization formulation is based on the dynamic representation of the two-directional heating and reaction process taking place within the system, and includes kinetic equations for the bulk free radical polymerization reactions of MMA. The mathematical model is cast as a time dependent partial differential equation (PDE) system, the optimal heating profile calculation turns out to be a dynamic optimization problem embedded in a distributed parameter system. A simultaneous optimization approach is selected to solve the dynamic optimization problem. Trough full discretization of all decision variables, a nonlinear programming (NLP) model is obtained and solved by using the IPOPT optimization solver. The results are presented about the dynamic optimization for two plastic sheets of different thickness and compared them against simple operating policies. © 2009 American Institute of Chemical Engineers AIChE J, 2009 [source] Role of rainfall in the development of coffee berry disease in Coffea arabica caused by Colletotrichum kahawae, in CameroonPLANT PATHOLOGY, Issue 2 2010J. A. Mouen Bedimo The development of coffee berry disease (CBD) epidemics (caused by Colletotrichum kahawae) in Cameroon was monitored over two successive years (2004 and 2005) on coffee trees protected from rainfall by transparent plastic sheets and on unprotected control trees. This work was done to assess how rain affected disease development when it did not fall directly onto the coffee trees and to determine the influence of primary inoculum on the severity of CBD. Weekly observations over the 2 years showed that there were 1·1% diseased berries on coffee trees completely protected from rainfall, compared with 45% diseased berries on unprotected coffee trees. Disease severity on unprotected trees during the 2 years of the experiment was estimated at 53% diseased berries, compared with 27% on trees only protected in the first year. These results confirmed rainfall as one of the key physical factors in the development of Arabica CBD. They also provided evidence of a subsequent effect of protecting coffee trees from rainfall in 2004 on the severity of CBD in 2005. This suggested some practices that might lead to very effective cultural control of CBD in regions where severe epidemics of the disease occur. [source] TCOs for nip thin film silicon solar cellsPROGRESS IN PHOTOVOLTAICS: RESEARCH & APPLICATIONS, Issue 3 2009T. Söderström Abstract Substrate configuration allows for the deposition of thin film silicon (Si) solar cells on non-transparent substrates such as plastic sheets or metallic foils. In this work, we develop processes compatible with low Tg plastics. The amorphous Si (a-Si:H) and microcrystalline Si (µc-Si:H) films are deposited by plasma enhanced chemical vapour deposition, at very high excitation frequencies (VHF-PECVD). We investigate the optical behaviour of single and triple junction devices prepared with different back and front contacts. The back contact consists either of a 2D periodic grid with moderate slope, or of low pressure CVD (LP-CVD) ZnO with random pyramids of various sizes. The front contacts are either a 70,nm thick, nominally flat ITO or a rough 2,µm thick LP-CVD ZnO. We observe that, for a-Si:H, the cell performance depends critically on the combination of thin flat or thick rough front TCOs and the back contact. Indeed, for a-Si:H, a thick LP-CVD ZnO front contact provides more light trapping on the 2D periodic substrate. Then, we investigate the influence of the thick and thin TCOs in conjunction with thick absorbers (µc-Si:H). Because of the different nature of the optical systems (thick against thin absorber layer), the antireflection effect of ITO becomes more effective and the structure with the flat TCO provides as much light trapping as the rough LP-CVD ZnO. Finally, the conformality of the layers is investigated and guidelines are given to understand the effectiveness of the light trapping in devices deposited on periodic gratings. Copyright © 2008 John Wiley & Sons, Ltd. [source] Browning reactions during storage of low-moisture Australian sultanas: Further evidence for arginine-mediated Maillard reactions during storage, and some effects of vine-shading and harvest dateAUSTRALIAN JOURNAL OF GRAPE AND WINE RESEARCH, Issue 3 2004DAMIAN FRANK Abstract Sultana grapevines (Vitis Vinifera L. cv. Sultana syn. Thompson Seedless) were subjected to four shading regimes: 50% shading (1), 25% shading (2), fully exposed-top of canopy (3) and beneath canopy (4) and harvested early (21 February) and late (13 March) in the 1996/1997 sultana season. Grapes from each of the eight field-treatment combinations represented a range of maturities (14.4 to 23.50oBrix). Grape samples from each of the treatments were dipped and dried to 18% moisture, with half of each of the sultana samples further reduced in moisture by sunfinishing on plastic sheets in direct sun. These field treatments resulted in sixteen unique dried sultana bulk samples with a range of initial chemico-physical properties; aw (0.481,0.691), skin-polyphenoloxidase (PPO) activity (4.40,9.05 ,mol O2/g.minute) free arginine in skin tissues (1.0,5.10 mg/g) and protein (16.40,27.18 mg/g). Sultanas were stored at 10oC and 30oC in either the presence or absence of oxygen for 10 months, and changes in CIE L*a*b* tristimulus values, hue-angle (hab*) and chroma (Cab*) were monitored. Significant changes in sultana colour occurred in samples stored at 30oC, especially in higher aw non-sunfinished sultanas. Although browning was more intense in the presence of oxygen, significant browning also occurred in the absence of oxygen. Lower concentrations of 5-hydroxy methylfurfural, a key marker of Maillard browning in samples stored at 30oC in the presence of oxygen, indicated that the non-enzymatic reactions were sensitive to oxygen. Changes in the concentration of trans -caftaric acid, the main substrate of grape PPO, were also measured during sultana drying. Storage browning (changes in L*, b*, hab*, Cab*)in dried sultanas could be predicted by regression models using pre-storage aw, free-skin arginine or Kjeldahl protein after 10 months' storage between 10oC and 30oC. Non-enzymatic and Maillard-type reactions (sensitive to both oxygen and aw), made an important contribution to sultana storage browning. We provide only weak evidence that either shaded (immature) or green fruit was more susceptible to storage browning. [source] | ||||||||||||||||