970 resultados para EQUIPMENT CONTAMINATION


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Absence of regular cleaning has been found to result in heavy bacterial loads on the surfaces of utensils and other equipment used in prawn processing factories and peeling centers. Instance of high faecal contamination is also sometimes met with. Detailed investigations have shown that a cleaning schedule comprising of treatment of these surface with a detergent followed by application of an effective disinfectant like sodium hypochlorite would prevent such bacterial build up.

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This paper develops a modelling technique for equipment load panels which directly produces (adequate) models of the underlying dynamics on which to base robust controller design/evaluations. This technique is based on the use of the Lagrange's equations of motion and the resulting models are verified against those produced by a finite Element Method Model.

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A number of wide-ranging monitoring studies have been performed in order to estimate the degree of mercury (Hg) contamination in freshwater ecosystems. Knowledge regarding contamination of different levels of the food chain is necessary for estimation of total pollutant input fluxes and subsequent partitioning among different phases in the aquatic system. The growing international concern about this environmental data is closely related to the strongly developing ecological risk assessment activities. In addition,freshwater monitoring outputs hold a key position in the estimation of the Hg dose consumed by the human population as it is highly dependent on fish consumption. So monitoring of Hg in the tissue of edible fish is extremely important because of contaminated fish has caused serious neurological damage to new born babies and adults. Mercury tends to accumulate in fish tissue, particularly, in the form of methyl mercury, which is about 10 times more toxic than inorganic mercury. The Anzali lagoon is one of the biggest wetland of Guilan province, which joins to the Caspian sea. Many Chemical and industrial factories plus agricultural runoffs and urban and rural sewages are major polluting sources of the Anzali wetland. Since many of those polluting sources drain their wastes directly or indirectly into the Anzali wetland and their sewages may be polluted with Hg, this study was conducted to find out the bioaccumulation of Hg bioaccumulation in pike (Esox lucius) food chain from Anzali lagoon, Iran. Sampling were carried out from July 2004 to July 2005, in addition 318 speciments of 9 fish species were collected. T-Hg was measured by LECO AMA 254 Advanced Mercury Analyzer (USA) according to ASTM standard No D-6722. Each sample was analyzed 3 times. Accuracy of T-Hg analysis was checked by running three samples of Standard Reference Materials; SRM 1633b, SRM 2711 & Sra 2709. Detection limit was 0.001 mg/kg in dry weight. The Accuracy degree of analyzor equipment with RSD<%0.05 (N=7) was between %95.5 and %105. In overal eigth fish species were distingushed in the gut content of 87 speciments of pike with age 1-5 year and maximum length 550mm. The max. and min. concentration of T-Hg in dorsal muscle of pjke was 0.2ppm in one year and 1.2ppm in five year class. The mean of T-Hg significantly increased with age and length increased (P<0.05).Mercury accumulation pattern in pike was as well as muscle > liver > spleen (P<0.05). THg content in female was higher than male(P<0.05). In contrast the mean of THg concentration in dorsal muscle of eigth fish species as prey was 0.282, 0.261, 0.328, 0.254, 0.256, 0.286, 0.322 and 0.241 ppm for Carassius auratus gibelio, Hemiculter leucisculus, Blicca bjoerkna transcaucasica, Chalcalburnus mossulensis, Rhodeus sericeus amarus, Gambusia holbrooki, Alburnus charusini hohenackeri & Scardinius Erythrophthalmus respectively.Liner regresion indicated that high degree of relationship between age of pike and Uptak/Intake ratio (R2=%99.12) and indicated that the mercury bioaccumulation in the pike dorsal muscle increased with age increased. BFA was >1 and and indicating the mercury biomagnification in the pike food chain. Trophy level of pike in the Anzali lagoon was estimated as well as 3.5 and 4 . It is generally agreed that Hg concentration in carnivorous fish are higher than in noncarnivorous species.

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In this study microbiological , chemical quality and fatty acid composition of grass carp (Ctenopharyngodon idella) fillets treated by dipping in sodium acetate (%1 and %3), nisin (% 0.1 and % 0.2) and combination of sodium acetate and nisin was evaluated during 16 days of refrigerated of 4°C Antilisterial effect of nisin was enhanced with the increased concentration of sodium acetate. At day 12 post storage, Listeria monocytogenese count was higher in the control group than the recommended value, however in sodium acetate and nisin treated samples, the count was lower (5.17-5.91 log cfu/g). With increasing the concentrations of sodium acetate, mesophilic counts were lower. Regarding nisin, better results was obtained by applying %0.1 nisin. Greater inhibition of mesophile bacteria was observed when combination treatment was used. The number of lactobacillus was lower when higher concentrations of sodium acetate and nisin were used. Total Volatile Nitrogen values at the end of the experiment were lower in the samples treated with both nisin and sodium acetate and the better results were obtained in combination treatments. Peroxide (PV) at the end of the experiment was 1.9 meq/kg in control, and the lowest values were observed for the treatments 3(%0 sodium acetate +% 0.2 nisin) and 9(%3 sodium acetate +% 0.2 nisin) between 1.08 and 1.62 meq/kg without significant difference. Thiobarbituric acid (TBA) levels at the end of experiment have been shown to be 0.46 mg malonaldehyde per kg in the control. On the other hand treatments 9 had the TBA values of 0.19 mg malonaldehyde per kg which was significantly lower than that of control. Polyunsaturated fatty acids increased by increasing the sodium acetate doses and instead saturated fatty acids and n-6/n-3 ratio decreased. The ratio of UFA/SFA and also C22:6/C16:0 increased when a higher concentration of sodium acetate has been used. The best result obtained by using 3% of sodium acetate but no such relation with nisin was observed.

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The article presents new food processing equipment for coating and frying. These are predusters, liquid enrobers and applicators for large-particle crumbs.

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Vision-based object detection has been introduced in construction for recognizing and locating construction entities in on-site camera views. It can provide spatial locations of a large number of entities, which is beneficial in large-scale, congested construction sites. However, even a few false detections prevent its practical applications. In resolving this issue, this paper presents a novel hybrid method for locating construction equipment that fuses the function of detection and tracking algorithms. This method detects construction equipment in the video view by taking advantage of entities' motion, shape, and color distribution. Background subtraction, Haar-like features, and eigen-images are used for motion, shape, and color information, respectively. A tracking algorithm steps in the process to make up for the false detections. False detections are identified by catching drastic changes in object size and appearance. The identified false detections are replaced with tracking results. Preliminary experiments show that the combination with tracking has the potential to enhance the detection performance.

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To investigate the occupational exposure levels to polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polybrominated diphenyl ethers (PBDEs), and polychlorinated biphenyls (PCBs), indoor dust (n = 3) in workshops and hair samples from male workers (n = 64) were collected at two electrical and electronic equipment waste (E-waste) dismantling factories located in the LQ area in east China in July 11-13, 2006. Pre- and postworkshift urines (64 of each) were also collected from the workers to study oxidative damage to DNA using 8-hydroxy-2'-deoxyguanosine (8-OHdG) as a biomarker. The concentrations of PCDD/Fs, PCDD/F-WHO-TEQs, PBDEs, PCBs and PCB-WHO-TEQs were (50.0 +/- 8.1) x 10(3), 724.1 +/- 249.6, (27.5 +/- 5.8) x 10(6), (1.6 +/- 0.4) x 10(9), (26.2 +/- 3.0) x 10(3) pg/g dry weight (dw) in dust, and (2.6 +/- 0.6) x 10(3), 42.4 +/- 9.3, (870.8 +/- 205.4) x 10(3), (1.6 +/- 0.2) x 10(6), 41.5 +/- 5.5 pg/g dw in hair, respectively. The homologue and congener profiles in the samples demonstrated that high concentrations of PCDD/Fs, PBDEs, and PCBs were originated from open burning of E-waste. The 8-OHdG levels were detected at 6.40 +/- 1.64 mu mol/mol creatinine in preworkshift urines. However, the levels significantly increased to 24.55 +/- 5.96 mu mol/mol creatinine in postworkshift urines (p < 0.05). Then, it is concluded that there is a high cancer risk originated from oxidative stress indicated by the elevated 8-OHdG levels in the E-waste dismantling workers exposed to high concentrations of PCDD/Fs, PBDEs, and PCBs.

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The contamination and distribution of polychlorinated dibeinizo-p-dioxins and dibenzofurans (PCDD/Fs) from two agricultural fields of a heavily polluted lake area in China (Ya-Er Lake) are presented. The vertical distribution pattern of total PCDD/Fs in soil cores reveals that the maximum concentration was in the layer of 20-30 cm. The concentrations in the top layer of soil at the two sites were similar (17.48 ng/kg at Site 1 and 18.10 ng/kg at Site 2), but the maximum concentration of Site 1 (120.8 ng/kg) was two times higher than that of Site 2 (64.39 ng/kg). The maximum concentration of PCDD/Fs in mud cores in rice fields (0-50 cm) at Sites 1 and 2 was in the layer of 0-10 cm. The maximum PCDD/F concentration in the top layer in mud at Site 1 (203.1 ng/kg) was higher than that at Site 2: (143.3 ng/kg). Significant correlations were found between the mind PCDD/Fs and the organic carbon content (R = 0.9743, P< 0,05 at Site 1; R = 0.9821, P< 0.05 at Site 2), the two variables being highly correlated (R = 0.9049, P< 0.05, at Site 1; R = 0.9916, P< 0.05 at Site 2). All correlation coefficients were significant at the 95% level. Concentrations were highly correlated with organic carbon, indicating that sorption to organic carbon was the dominant mechanism. Using principal component analysis, the homologue profiles of soil, mud, and plants (rice and radish) were compared. The PCDD/F patterns in plants were found not to be correlated to those in soil and mud. This suggests that atmospheric deposition may be the main source of PCDD/Fs in rice grain. However, mixed exposure involving uptake mechanisms and atmospheric deposition is considered main the source of PCDD/F pollution in radishes. (C) 2002 Elsevier Science (USA).

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This paper discovers some shortcomings in the algorithm for the incorporation of Si into GaAs in the GaAs VPE process. These faults arise from neglecting a link, the compatibility relationship, in chemical thermodynamics. The meaning of said relationship is as follows: In an equilibrium complex system, each species can only contribute one and the same quantity (its equilibrium quantity) to the different equilibria of the various reactions involving it; yet even under this restriction, every equilibrium constant is satisfied, and all the reaction equilibria coexist compatibly in the system. Only by adding the relationship can the equilibrium theory for the complex system be complete. This paper also tells its position in chemical thermodynamics. Such a compatibility concept directly leads to an equivalence principle: In a complex system, a certain species can usually be simultaneously formed by many chemical reactions; when the system has reached equilibrium under fixed environmental conditions, the equilibrium quantity of said species calculated according to each chemical equation of these reactions will be equal and the various reaction approaches will be equivalent, provided that for all the reactants and all the other products of these reactions their equilibrium quantities in the system are respectively taken as corresponding knowns for the calculations, which is extremely useful for seeking a functional relation among the species' equilibrium quantities in a system (Si contamination is one of the examples). Under the guidance of those arguments, the various schools' algorithms for the Si contamination can be uniformized and simplified, and the contamination quantity relation between Si and O, two very important impurities, is found.