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THEORETICAL AND EXPERIMENTAL STUDY ON ELECTROSTATIC FIBROUS FILTERS
静电-纤维层过滤的理论分析与实验研究

Rong Weidong,Zhang Guoquan,
荣伟东
,张国权

环境科学学报 , 1993,
Abstract: The feasibility of using electrostatic fibrous filters to separate dust from a contaminated gas stream is studied and the model of predicting the collection efficiency considering three deposition mechanisms was proposed and evaluated by experiments.
Successful endoscopic removal of a giant upper esophageal inflammatory fibrous polyp  [cached]
Jie Zhang, Jian-Yu Hao, Simon Wing Heng Li, Shu-Tian Zhang
World Journal of Gastroenterology , 2009,
Abstract: Giant esophageal inflammatory fibrous polyp (especially > 17 cm in size) is seen rarely. Endoscopic removal has been reported rarely because the procedure is technically demanding and the hemostasis is difficult to ascertain. Here, we describe a case of a giant upper esophageal inflammatory fibrous polyp that was resected successfully by endoscopy.
Predicting the efficiency of deposit removal during filter backwash
BM Brouckaert, A Amirtharajah, CJ Brouckaert, JE Amburgey
Water SA , 2006,
Abstract: The long-term performance of granular media filters used in drinking water treatment is ultimately limited by the efficiency of the backwash process. This paper demonstrates that it is possible to develop quantitative predictions of backwash efficiency based on filter operating conditions. An experimental investigation into the effect of backwash rate, type of coagulant, degree of clogging and accumulation of residual deposits (not removed by backwash) on the efficiency of fluidised bed filter backwash in laboratory scale filters is described. A natural raw water was used and small variations in the raw water characteristics (manifested as variations in raw water turbidity, temperature, pH, rate of head loss development and turbidity removal efficiency) within each set of experiments appeared to affect the efficiency of backwash in addition to the parameters varied deliberately. Stepwise linear regression and statistical analysis of model significance were used to determine which of several possible filtration and backwash parameters were the best predictors of backwash performance. Backwash rate, filter run time, rate of head loss development and mass of residual deposits accumulated during previous runs were found to be the best predictors of backwash efficiency for any given filter cycle. Floc deposits appeared to become more difficult to remove the longer they remained in the filter, while rate of head loss development appeared to provide some indication of the strength of cohesive deposits for filter runs of similar length. The efficiency of detachment of freshly deposited floc appeared to increase as the mass of residual deposits and mud balls in the filter increased. The numerical correlations developed in this study are site specific but the methodology can be adapted to any filter operation and backwash regime.
Removal of Trypanosoma cruzi by white cell-reduction filters: an electronmicroscopic study
Fabron Junior, Antonio;Bordin, José Orlando;Moraes-Souza, Hélio;FreyMüller, Edna;Lages-Silva, Eliana;
Revista da Sociedade Brasileira de Medicina Tropical , 1999, DOI: 10.1590/S0037-86821999000300001
Abstract: white cell (wbc)-reduction filters have been shown to be effective in removing infectious agents from infected blood products. in this study, the mechanisms of trypanosoma cruzi (t. cruzi) retention by wbc-reduction filters were assessed. human packed red blood cell (prbc) and platelet concentrate (pc) samples were contaminated with t. cruzi organisms (y strain; 3.4 x 106/ml), and then filtered using wbc-reduction experimental filters that provided about 3 log10 wbc removal. transmission electron microscopy sections showed that t. cruzi parasites were removed from contaminated prbc and pc samples primarily by mechanical mechanism without interacting with filter fibbers or blood cells. in addition, we found that t. cruzi parasites were also removed by a direct fibber adhesion. these data indicate that t. cruzi parasites are removed from infected blood not only by mechanical mechanism but also by biological mechanism probably mediated by parasite surface proteins.
Removal of Trypanosoma cruzi by white cell-reduction filters: an electronmicroscopic study
Fabron Junior Antonio,Bordin José Orlando,Moraes-Souza Hélio,FreyMüller Edna
Revista da Sociedade Brasileira de Medicina Tropical , 1999,
Abstract: White cell (WBC)-reduction filters have been shown to be effective in removing infectious agents from infected blood products. In this study, the mechanisms of Trypanosoma cruzi (T. cruzi) retention by WBC-reduction filters were assessed. Human packed red blood cell (PRBC) and platelet concentrate (PC) samples were contaminated with T. cruzi organisms (Y strain; 3.4 x 10(6)/ml), and then filtered using WBC-reduction experimental filters that provided about 3 log10 WBC removal. Transmission electron microscopy sections showed that T. cruzi parasites were removed from contaminated PRBC and PC samples primarily by mechanical mechanism without interacting with filter fibbers or blood cells. In addition, we found that T. cruzi parasites were also removed by a direct fibber adhesion. These data indicate that T. cruzi parasites are removed from infected blood not only by mechanical mechanism but also by biological mechanism probably mediated by parasite surface proteins.
Predicting BCI Subject Performance Using Probabilistic Spatio-Temporal Filters  [PDF]
Heung-Il Suk, Siamac Fazli, Jan Mehnert, Klaus-Robert Müller, Seong-Whan Lee
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0087056
Abstract: Recently, spatio-temporal filtering to enhance decoding for Brain-Computer-Interfacing (BCI) has become increasingly popular. In this work, we discuss a novel, fully Bayesian–and thereby probabilistic–framework, called Bayesian Spatio-Spectral Filter Optimization (BSSFO) and apply it to a large data set of 80 non-invasive EEG-based BCI experiments. Across the full frequency range, the BSSFO framework allows to analyze which spatio-spectral parameters are common and which ones differ across the subject population. As expected, large variability of brain rhythms is observed between subjects. We have clustered subjects according to similarities in their corresponding spectral characteristics from the BSSFO model, which is found to reflect their BCI performances well. In BCI, a considerable percentage of subjects is unable to use a BCI for communication, due to their missing ability to modulate their brain rhythms–a phenomenon sometimes denoted as BCI-illiteracy or inability. Predicting individual subjects’ performance preceding the actual, time-consuming BCI-experiment enhances the usage of BCIs, e.g., by detecting users with BCI inability. This work additionally contributes by using the novel BSSFO method to predict the BCI-performance using only 2 minutes and 3 channels of resting-state EEG data recorded before the actual BCI-experiment. Specifically, by grouping the individual frequency characteristics we have nicely classified them into the subject ‘prototypes’ (like μ - or β -rhythm type subjects) or users without ability to communicate with a BCI, and then by further building a linear regression model based on the grouping we could predict subjects' performance with the maximum correlation coefficient of 0.581 with the performance later seen in the actual BCI session.
Harmful substances and their removal from paper pulp and circular water stream  [PDF]
Jovanovi? Slobodan,Krgovi? Milorad,O?ap Danijela
Hemijska Industrija , 2008, DOI: 10.2298/hemind0804251j
Abstract: This work shows a systematic review of the cause for intensive increase of harmful substances in paper pulp and circular water streams during last twenty years, as well as their negative influence on productivity of paper machines and quality of produced paper or board. A brief description of methods for determining the content of harmful substances in paper pulp and circular water stream, substances used for fixation and deactivation of harmful substances, as well as processes used for removing harmful substances from paper pulp and circular water stream for the purpose of smooth production of paper and board with desired properties are given.
Predicting Hourly Stream Temperatures Using the Equilibrium Temperature Model  [PDF]
Cindie Hébert, Daniel Caissie, Mysore G. Satish, Nassir El-Jabi
Journal of Water Resource and Protection (JWARP) , 2015, DOI: 10.4236/jwarp.2015.74026
Abstract: Water temperature is a key physical habitat determinant in lotic ecosystems as it influences many physical, chemical and biological properties of rivers. Hence, a good understanding of the thermal regime of rivers is essential for effective management of water and fisheries resources. This study deals with the modeling of hourly stream water temperature using the equilibrium temperature model. This water temperature model was applied on two thermally different watercourses, namely, the Little Southwest Miramichi River (LSWM) and Catamaran Brook (CatBk; New Brunswick). The equilibrium temperature model is a simplified version of a deterministic model. As such, in the equilibrium temperature model the total heat flux at the surface is assumed proportional to the difference between the water temperature and an equilibrium temperature. In the present study, the equilibrium temperature was assumed to vary linearly with hourly air temperature. This study showed that there was a good relationship between the equilibrium and air temperature at the hourly time scale. The root-mean-square error (RMSE) obtained with the hourly equilibrium temperature model was similar to results reported in previous studies with values of 1.05°C (CatBk) and 1.36°C (LSWM). The model’s performance was best in late summer and autumn when water levels were low. In contrast, the presence of snowmelt in the spring resulted in poorer performances. This study also showed good results in estimating the daily mean (Tmean) and maximum (Tmax) water temperatures from the predicted hourly water temperatures, which were often required in fishery management.
BIOLOGICAL AERATED FILTERS (BAFs) FOR CARBON AND NITROGEN REMOVAL: A REVIEW  [PDF]
BIPLOB KUMAR PRAMANIK,SUJA FATIHAH,ZAIN SHAHROM,ELSHAFIE AHMED
Journal of Engineering Science and Technology , 2012,
Abstract: Biological aerated filters (BAFs) are an emerging wastewater treatment technology designed for a wide range of municipal and industrial applications. This review paper presents and discusses of the influence C/N ratio, nitrification and denitrification principle, effect of pH, DO and alkalinity on the nitrification and denitrification systems, organic and hydraulic loading of BAF reactor, etc. Results from upflow and downflow biofilter pilot at different condition, with nitrification and denitrification are reviewed. Under the optimal conditions, significant amount of COD, ammonia-nitrogen and total nitrogen were removed. Removal rates based on reactor volume for different carbon-aceous COD and ammonia loading rate are reported. The BAF system for the nitrification and denitrification processes for carbon and nitrogen removal from the wastewater need to be evaluated and applied properly to protect of our environment and resources.
Carbon Nanotube Filters for Removal of Air Pollutants from Mobile Sources  [PDF]
L. Romero-Guzmán, L. R. Reyes-Gutiérrez, E. T. Romero-Guzmán, E. Savedra-Labastida
Journal of Minerals and Materials Characterization and Engineering (JMMCE) , 2018, DOI: 10.4236/jmmce.2018.61009
Abstract: The aim of this work was the assessment of the removal of air pollutants from mobile sources by commercial carbon nanotubes (CNTs). For this, the nanomaterial was characterized by different techniques: SEM, EDS, TEM, XRD, BET, and Raman. Subsequently, the CNTs were packed in a stainless steel filters which was designed from different prototypes that were developed during the investigation. Tests were performed in the TO-913 Verificenter Macrover Auto SAQ. Inc. de CV. The results revealed that particle type sand CNTs loading had greater effects on the efficiencies than the membrane type sand pore sizes tested. When collecting NOx, the efficiencies were observed relatively lower, below 20% for loadings of 0.3 - 1.5 mg/cm2. The studied CNTs were multi-walled: two layers, show a nonlinear growth and morphology varied since they are of different diameters and longitudes, it was observed that half of the nanotubes were coated with amorphous carbon. The composition is mainly carbon and oxygen, iron is also present. The adsorption capacity of CNTs was significantly influenced by the different aspects, like model, brand, fuel, year and the conditions of each car. The removal efficiencies of CNTs filters were shown to range from 10% to 95% in average for the CNTs loadings of 0.2 - 1.6 mg/cm2. When collecting CO, CO2, NOx, HC, the efficiencies were shown to range from 5% to 60% given similar CNTs loadings used.
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