Conventional Washing Procedure Research Articles

Impact of conventional and advanced cleaning techniques on the durability of firefighter turnout ensembles

The concern for firefighters’ occupational exposure to harmful contaminants is growing due to the increase in health issues in the firefighting community. At such times, effective decontamination of personnel and equipment is an essential component of a hazard mitigation strategy. The current decontamination practices used for firefighter protective clothing have been shown to not be very effective. Hence, the scientific community is looking for several alternatives to conventional washing procedures. Liquid carbon dioxide (CO2) has been used in laundering and has distinct advantages over conventional dry-cleaning solvents such as perchloroethylene. The following study is aimed to assess how different washing procedures affect the durability of the turnout material. The study includes using three washing procedures on different samples: 1) conventional washing procedure, 2) liquid CO2 washing procedure, and 3) a high-temperature washing procedure. Samples for durability testing were constructed from a common aramid fabric used in firefighter turnout ensembles. These swatches were subjected to different washing techniques. The durability assessment was performed for physical testing of the samples, visual inspection, water repellency, and quantifying color changes using spectrophotometric analysis. The conventional wash and high-temperature washing affected the durability of the outer shell material in a significant manner. The liquid CO2 process did not affect the samples’ water repellency or physical strength. In contrast, conventional and high-temperature washing significantly affected the durability of the outer shell material. However, all samples met the criteria for tearing strength outlined in the NFPA 1971 standard subsection 7.1.11.

From whey robocasting to custom 3D porous carbons

We describe how robocasting and carbonisation of partially dehydrated whey, a surplus of the dairy industry, produced 3D porous carbons with custom morphologies. A relatively simple printing device was first used to manufacture 3D structures of whey pastes. The whey pastes behaved as a thermoset polymer when heated hence keeping the original shape of the printed pieces upon carbonisation, albeit an isotropic size reduction (23%) due to thermal shrinkage. The rheological properties of the whey pastes were similar to those of other inks commonly used in direct ink writing, with a shear thinning behaviour and static and dynamic yield stresses that predicted their printability in most robocasting devices. Once the 3D whey structures were printed, a heat-curing process was required to avoid the uncontrolled emission of volatiles that would otherwise distort them. When doing so, 3D lattices of carbon filaments with ca. 500 µm in diameter and ca. 425 µm mesh size were manufactured. The ash content of the carbonised structures, which is related to the salt content of the original whey, was reduced by conventional washing procedures, bringing about 3D hierarchical porous carbons (70% porosity) with modest specific surface areas (500 m 2 /g) and relatively high compressive strengths (5 MPa). • Whey/water pastes can be printed using 3D extrusion printers. • Carbonisation of printed pieces preserves their shape (albeit thermal shrinkage). • 3D carbon pieces combine good mechanical properties and high porosities.

Application of Soxhlet Extractor for Ultra-clean Graphene Transfer.

Surface contamination experienced during polymer-assisted transfer is detrimental for optical and electrical properties of 2D materials. This contamination is usually due to incomplete polymer removal and also due to impurities present in organic solvents. Here, we report a simple, economical, and highly efficient approach for obtaining pristine graphene on a suitable substrate (e.g., SiO2/Si) by utilizing Soxhlet extraction apparatus for delicate removal of the polymer with a freshly distilled ultrapure solvent (acetone) in a continuous fashion. Excellent structural and morphological qualities of the material thus produced were confirmed using optical microscopy, atomic force microscopy, scanning electron microscopy, and Raman spectroscopy. Compared to the conventional protocol, graphene produced by the current approach has a lower residual polymer content, leading to a root mean square roughness of only 1.26 nm. The amount of strain and doping was found to be similar, but the D-band, which is indicative of the defects, was less pronounced in the samples prepared by Soxhlet-assisted transfer. The new procedure is virtually effortless from the experimental point of view, utilizes much less solvent compared to the conventional washing procedure, and allows for easy scale-up. Extension of this process to other 2D materials would not only provide samples with superior intrinsic properties but also enhance their suitability for advanced technological applications.

Assessment of bioremediation potential of Microcystis aeruginosa for removal of cadmium and lead ions from aqueous matrices

Capability of cyanobacterium Microcystis aeruginosa, isolated from effluent of a wastewater stabilization pond, for removal of cadmium and lead ions was investigated. Variation of removal efficiency as a function of metal concentration, pH, temperature and biomass dosage was studied. Also, use of closed reflux digestion technique as an innovative option for decomposition of cyanobacterial pellet was studied. A multi-phase washing method was developed in order to attain more elevated desorption efficiency. Maximum removal efficiency occurred in pH 7, temperature 28°C and biomass dosage 0.2g for Cd2+ and corresponding values of 6, 25°C and 0.1g for Pb2+. In all tested concentrations of lead and cadmium, extracellular absorption overweighed intracellular uptake with highest ratio of former to later of 172 for Cd2+and 143 for Pb2+. EC50 values attained for Cd2+and pb2+were respectively 20mg/l and 15mg/l. Closed-reflux digestion method was found as a good option for cyanobacterial pellet digestion. Three-stage consecutive washing procedure devised in our study gave desorption efficiencies of 92 and 86 percent for Cd2+ and Pb2+ respectively as compared with values of 52 and 44 percent for Cd2+ and pb2+ obtained by conventional washing procedure. This investigation verifies possibility of employing Microcystis aeruginosa for removal of Cd2+ and Pb2+ from aqueous and wastewater solutions.

Towards bedside washing of stored red blood cells: a prototype of a simple apparatus based on microscale sedimentation in normal gravity.

Infusion of by-products of red blood cell (RBC) storage-induced degradation as well as of the residual plasma proteins and the anticoagulant-preservative solution contained in units of stored blood serve no therapeutic purpose and may be harmful to some patients. Here, we describe a prototype of a gravity-driven system for bedside washing of stored RBCs. Stored RBCs were diluted to 10% haematocrit (Hct) with normal saline, matching the conventional washing procedure. The dilute RBC suspensions were passed through a column of coiled tubing to allow RBC sedimentation in normal gravity, thus separating them from the washing solution. Washed RBCs were collected using bifurcations located along the tubing. Washing efficiency was quantified by measuring Hct, morphology, deformability, free haemoglobin and total-free protein. The gravity-driven washing system operating at 0·5ml/min produced washed RBCs with final Hct of 36·7±3·4% (32·3-41·2%, n=10) and waste Hct of 3·4±0·7% (2·4-4·3%, n=10), while removing 80% of free haemoglobin and 90% of total-free protein. Washing improved the ability of stored RBCs to perfuse an artificial microvascular network by 20%. The efficiency of washing performed using the gravity-driven system was not significantly different than that of conventional centrifugation. This proof-of-concept study demonstrates the feasibility of washing stored RBCs using a simple, disposable system with efficiency comparable to that of conventional centrifugation, and thus represents a significant first step towards enabling low-cost washing of stored blood at bedside.

The Detection of Cortisol in Human Sweat

Hair cortisol analysis has been shown to be an effective measure of chronic stress. Cortisol is assumed to incorporate into hair via serum, sebum, and sweat sources; however, the extent to which sweat contributes to hair cortisol content is unknown. Sweat and saliva samples were collected from 17 subjects after a period of intensive exercise and analyzed by salivary enzyme-linked immunosorbent assay (ELISA). Subsequently, an in vitro test on exposure of hair to hydrocortisone was conducted. Residual hair samples were immersed in a 50-ng/mL hydrocortisone solution for periods lasting 15 minutes to 24 hours, followed by a wash or no-wash condition. Hair cortisol content was determined using our modified protocol for a salivary ELISA. Postexercise control sweat cortisol concentrations ranged from 8.16 to 141.7 ng/mL and correlated significantly with the log-transformed time of day. Sweat cortisol levels significantly correlated with salivary cortisol concentrations. In vitro hair exposure to a 50-ng/mL hydrocortisone solution (mimicking sweat) for 60 minutes or more resulted in significantly increased hair cortisol concentrations. Washing with isopropanol did not affect immersion-increased hair cortisol concentrations. Human sweat contains cortisol in concentrations comparable with salivary cortisol levels. This study suggests that perfuse sweating after intense exercise may increase cortisol concentrations detected in hair. This increase likely cannot be effectively decreased with conventional washing procedures and should be considered carefully in studies using hair cortisol as a biomarker of chronic stress.

Cell processing for haplo-identical hematopoietic stem cell transplantation: automated washing and immunomagnetic-positive selection

Immunomagnetic cell selection (ICS) of CD34(+) cells is being used increasingly in allogeneic transplantation in order to reduce T-cell quantity. The aim of this study was to evaluate an automated washing protocol before immunomagnetic selection. The automated method was compared with a conventional washing procedure. In the study group the cell processing using the automated procedure, both before and after antibody incubation, was performed with a Sepax S-100 device. The efficacy of the automated procedure was compared with the control group, where washing were performed using a standard method. The results obtained after pre-incubation washing performed using the automated system showed a total nucleated cell (NC) and CD34(+) cell recovery of 84.87% (71.80-105, SD 8.62; range, standard deviation) and 83.45% (47-109, SD 16.12), respectively. The NC and CD34(+) cell recovery after the pre-incubation washing cycle was performed using the standard method was 75.54% (38.36-97.76, SD 22.5) and 61.51% (30.87-81.79, SD 19.3), respectively. The CD34(+) cell recovery after ICS was 51.27% (13.77-98.82, SD 24.97) and 48.89% (15.57-88.24, SD 25.91) for group 1 and group 2, respectively. The average purity in group 1 was 86.46% (67.4-96.10, SD 13.07) and in group 2 84.97% (58.1-97.8, SD 15.58). The efficacy of the ICS led to an optimal purity without affecting cell recovery, which was higher in group 1. Overall, our data suggest that the automated method is suitable for washing hematopoietic progenitor cell apheresis (HPC-A) concentrates before immunomagnetic cell selection in daily clinical routines.

Occurrence of pyrophoric iron immune to chemical washing in vacuum distillation columns

Pyrophoric iron deposits on vacuum distillation column internals can become immune to water and chemical washing, by coating with asphaltenes entrained in the flash zone vapors. This hypothesis was confirmed by obtaining and inspecting samples of a vacuum distillation column mist eliminator on which pyrophoric iron ignitions were observed that were not affected by the conventional washing procedures. Three conditions are highlighted whose fulfillment significantly increases the probability of persistent pyrophoric iron occurrence on vacuum distillation column internals. A handling strategy is outlined which was based on the experience gained from the described incident.

New On Line Washing Technique for Prevention of Performance Deterioration due to Fouling on Steam Turbine Blades (2nd Report, Basic Experiment and Analysis for Actual Operation of Washing System)

Mechanical-drive steam turbines have the heavy deposition of fouling materials on blade and nozzle path surfaces due to contamination. As a result, turbine performance tends to be deteriorated gradually. The first paper introduced this fouling phenomena and actual conventional washing procedure in order to prevent the fouling problem and its practical disadvantage. In this second report, regarding new washing method to resolve above disadvantage, the results of detail analysis for erosion damage, thermal stress evaluation of internal parts due to injected water and heat balance of steam/water mixture are introduced in comparing online washing test results.

New On Line Washing Technique for Prevention of Performance Deterioration due to Fouling on Steam Turbine Blades (1st Report, Fouling Phenomena, Conventional Washing Technique and Disadvantages)

Mechanical-drive steam turbines have the heavy deposition of fouling materials on blade and nozzle path surfaces due to contaminated materials such as silica and sodium in steam. As a result, turbine performance tends to be deteriorated gradually. This first paper introduces this fouling phenomena and actual conventional washing procedure in order to prevent the fouling problem and its practical disadvantage by showing thermodynamics analysis. In the second report, the new online washing technology by water injection nozzles is introduced and the most important design factors of this washing system are discussed by showing the results of detail analysis and online washing test results.

Removal of Escherichia coli O157:H7 from Surface Tissues of Beef Carcasses Inoculated with Wet and Dry Manure

Beef tissues were contaminated with wet and dry manure. The manure was previously inoculated with Escherichia coli O157:H7 GFP, genetically modified with a plasmid encoding a protein that fluoresces green when exposed to long-wave ultraviolet light. After incubation at 37°C for 5 days, the wet manure was spread on the surface of beef tissues at an average E. coli O157:H7 GFP level of 6.62 log CFU/cm2. Dry manure was obtained by subjecting wet manure to natural drying (simulating dry manure adhering to the hides of cattle) and was also applied to the surfaces of beef tissues. The degree of removal of E. coli O157:H7 GFP by washing was compared to the removal of cells of the same strain that had been inoculated as a suspension. The E. coli O157:H7 mixed into feces of cattle adhered more strongly to meat surfaces than that applied as a suspension, complicating the removal by conventional washing procedures. The fate of the bacterium mixed into wet or dry manure was evaluated. An initial decrease of the inoculated population was observed; this was probably an effect of the changed environment represented by the manure. After adaptation, the inoculated bacteria grew in the wet manure; a maximum population was reached in 5 days at 37°C; levels declined with drying. The use of the GFP marker was of great value, since it allowed enumeration of E. coli O157:H7 in the presence of the natural flora of manure.

The Hydrolysis of Gelatin by Proteolytic Enzymes and their Use in Photographic Emulsion Preparation

An outline of the hydrolysis of gelat in by enzymes is given and the use of proteolytic enzymes in photographic emulsion preparation is reviewed. The rate of hydrolysis of gelatin by a commercially available enzyme has been investigated, together with means of inhibiting its action.Photographic results from an emulsion prepared using a conventional washing procedure are compared with an emulsion in which the washing stage was carried out by an enzymatic technique, and the advantages and limitations of the laller method are considered.

Calf serum content of various viral vaccines and possibilities for its reduction

A total of 26 inactivated or live virus vaccines obtained from different sources and prepared on different cell cultures were examined, by a semiquantitative procedure of immunoprecipitation, for their concentrations of calf serum albumin and calf serum globulin. The highest serum protein concentrations (≈ 2 to > 10 μg/ml) were found in single (first) harvest vaccines from large enveloped viruses. The serum content of single harvest vaccines from small, naked viruses was intermediate (< 1–2 μg/ml) and lowest for multiple harvest or single second harvest vaccines (usually < 1 μg/ml). Using a similar evaluation system the effectiveness of different washing and refeeding procedures for the removal of serum proteins from cultures of permanent monkey cells was studied. The conventional washing procedures proved rather ineffective even if the washing fluid was kept on the cells for a prolonged period. Serum proteins could be almost completely removed only by refeeding the cell cultures once for 24 h with serum-free medium. It was concluded from these results that serum proteins (especially the globulin fraction) are adsorbed onto the cells and possibly also onto the surface of larger, enveloped viruses and are not completely removed by the conventional washing procedures. The importance of the contamination of vaccines with residual calf serum for evoking allergic reactions and the possibility of eliminating such serum from vaccines are discussed briefly.