Cellulose patches

Many types of matrices have been used in the past to measure the field stability of the test substance. Cotton gloves, cellulose patches, face wipe handkerchiefs and/or gauze face wipe matrices, long underwear (inner dosimeters), pants, shirts, coveralls (outer dosimeters), sorbent tubes, urine, and other matrices are common matrices that have been used for this purpose. 

Phase 1 - During this period the subjects were asked to wear their normal working clothes. Alpha cellulose patches were attached to the interior and exterior on opposing sides of the shirt. Timed urine voids were collected in the field. 

Moreover, the same term was recently used for small cellulose patches formed as parts of open spin-coat films produced from low-concentration trimethylsilylcellulose solutions and by subsequent heterogeneous desilyla-tion of the primary formed silylcellulose layers under cellulose regeneration [5]. 

Among the first dermal dosimeters used in exposure research were 4 x 4-in cellulose or gauze patches which were pinned to the outer and inner surfaces of clothing or vests which farm workers would wear during the application or re-entry phase of the smdy. These patches were easy to manufacture and when pinned to the shirt or pants of the worker made for an easily used dosimeter pad. The major advantage to the use of the patch to estimate worker exposure was this method s ability to differentiate the relative contributions of pesticide residues to different parts of the worker s body. This sampling technique in turn could lead to recommendations (i.e., the use of... 

In the past, 4 x 4 in cotton patches (gauze or cellulose) have been used to estimate face and neck exposure. The patches are designed and manufactured as described above and are pinned or attached with Velcro to the back and front of a hat or protective headgear of the worker. When the exposure period is complete, the patches are removed, and... 

Tests of Penetrability. Treated and untreated cloth as described under Repellency, were used for these tests. In this case however, the test patch was backed by an alpha-cellulose pad 2-hy 6 y 13). The cloth with its alpha-cellulose pad was either... 

In the laboratory the alpha-cellulose pads were received in labelled 60 ml hexane washed jars containing 10 cc of methylene chloride. The outside or exterior patches were identified by the letter 0 after the pad number and the inside or interior pad by an I. These pads were stored at -4° until they were analyzed. 

In order to insure a heavy surface deposit with ample opportunity to penetrate to the alpha-cellulose pad, patches of cloth were fixed at 30 angle backed with the alpha-cellulose pad and then the chemical emulsion applied dropwise with the microsyringe. The droplet was allowed to dry and only then was the pad removed for analyses. This, it was felt might stimulate the exposure that could occur if clothing received a spill and were not removed immediately. Table V summarizes the results obtained. 

Internal medicine, urology, gynecology, otolaryngology, maxillofacial and plastic surgery could be potential users of this designed nanocellulose. For this reason, hollow cellulose tubes with different inside diameter and different wall thickness have been prepared in micro-dimensions. Figure 14 shows a collection of BASYC tubes. Foils, patches, and other shapes are possible, too. 

Stock composition, kinetics of adsorption and hydrodynamic shear dictate the point at which a cationic polymer is added to a papermaking furnish in order to induce flocculation. Flocculation of cellulose fibers in turbulent flow proceeds very rapidly and is completed in less than two seconds.120-123 Flocks form due to charge interactions through a patch-type or a bridging-type mechanism. However, these flocks will be sensitive to shear force and deflocculation and reflocculation might occur. 

Tears are repaired with Japanese tissue, missing areas are filled in with paper similar to the artifact. Repair paper of specific caliper and tone is made in the leaf caster. Adhesives vary methyl cellulose, wheat paste, or a mixture of polyvinyl alcohol with rice paste. The mixture is most useful because it permits use of a warm tacking iron to hasten the drying process. Where missing areas have been patched, the restorer reconstructs only those lines and colors that are already discernable, lest the work be called an attempt at falsification. 

Two types of wood pulp provided the fibrils used for patching. The first was a moderately beaten wood pulp obtained from the Department of Pulp and Paper Science, North Carolina State University. The second was Cellunier P, a cellulose provided by the ITT Rayonier Company. Portions of the pulp and Cellunier P were dyed with 0.5% Cuprophenyl Navy Blue RL (from the Ciba-Geigy Corporation) and 0.5% tetrasodium phosphate for 30 min at 82°C to provide greater visual contrast between the fibers and the substrates. The wood pulp was diluted with distilled water to form 0.5 and 0.1% slurries. The Cellunier P was diluted to a 0.05% slurry. Both were treated in a blender to separate lumps formed during dyeing. 

Duragesic is a transdermal patch that delivers the potent opioid analgesic fentanyl. The life span of the patch is three days and it is manufactured in five sizes 12,25, 50, 75, and 100pg/h. Duragesic is a membraned-moderated patch and consists of four patch layers a backing layer of polyester film, a drug reservoir that contains fentanyl, and U.S. Pharmacopeia (USP) alcohol gelled with hydroxyethyl cellulose,... 

In conducting studies to determine temporal decay rates, sampled areas should be identified so that the same areas are not re-sampled pre-application and post-application. Likewise, if deposition coupons (e.g. a-cellulose filter paper or cotton gauze patches backed with aluminum foil) are placed on the floor during application of the pesticide formulation to estimate initial deposition rates, care should be exercised to avoid sampling in the areas covered by the coupons during subsequent monitoring visits. 

The most susceptible of the plastics used to simulate organics is cellulose nitrate. Signs of instability and imminent degradation are patches of discolouration, surface crazing or blistering, weeping, and fumes. 

Hydroxypropyl cellulose is also used in microencapsulation processes and as a thickening agent. In topical formulations, hydroxypropyl cellulose is used in transdermal patches and ophthalmic preparations. ... 

Hydroxypropyl cellulose is generally regarded as an essentially nontoxic and nonirritant material. However, the use of hydroxypropyl cellulose as a solid ocular insert has been associated with rare reports of discomfort or irritation, including hypersensitivity and edema of the eyelids. Adverse reactions to hydroxypropyl cellulose are rare. However, it has been reported that a single patient developed contact dermatitis due to hydroxypropyl cellulose in a transdermal estradiol patch. ... 

Schwartz BK, Clendenning WE. Allergic contact dermatitis from hydroxypropyl cellulose in a transdermal estradiol patch. Contact Dermatitis 1988 18(2) 106-107. 

Cellulosic fibres are more often damaged by fungi than by bacteria. The microscopic detection of fungi will be described in more detail in Section 8.6.3. Storage of moist fabric overnight in a warm environment can be sufficient to cause fungal attack, leading to variously coloured mildew patches, which are difficult to remove. 

Maneb or mancozeb. Headley (1996) used an inductively coupled plasma-atomic emission spectrometry (ICP-AES) method for occupational exposure estimations that measures mancozeb by determining the elemental manganese portion of the pesticide in a sample. The method was successful in analyzing urine (0.02 mg/L), wash water (0.02 mg/L), tank mixes (0.02 mg/L), cellulose acetate filters (0.5 pg), and fabric from patches and clothing (0.5 pg), with detection limits in parentheses. However, ICP-AES methods cannot differentiate among various forms of manganese, so it is important that background... 

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