Leather damaged

Materials that have been buried underwater cause a special problem. Waterlogged woods and leathers (139), although quite stable under such burial conditions, are ia danger of irreversible damage through drying out upon recovery. Indeed, after excavations from bogs or upon recovery from underwater sites, these items need to be stored underwater until laboratory treatment. 

Sodium bifluoride, by itself or ia conjunction with other materials, is a good laundry sour because, ia the concentrations used, it does not create a pH below 4.0 and thus causes no damage to textile fibers, although it removes iron stains. Leather (qv) bleaching and cleaning of stone and brick building faces are other uses for this material (3). 

Sulfur dioxide emissions may affect building stone and ferrous and nonferrous metals. Sulfurous acid, formed from the reaction of sulfur dioxide with moisture, accelerates the corrosion of iron, steel, and zinc. Sulfur oxides react with copper to produce the green patina of copper sulfate on the surface of the copper. Acids in the form of gases, aerosols, or precipitation may chemically erode building materials such as marble, limestone, and dolomite. Of particular concern is the chemical erosion of historical monuments and works of art. Sulfurous and sulfuric acids formed from sulfur dioxide and sulfur trioxide when they react with moisture may also damage paper and leather. 

When dried in an oven, hydrated silica loses its water and becomes a desiccant (a substance that attracts water from the air). You find little packets of silica gel crystals in containers whose contents would be damaged by condensing moisture, such as vitamin bottles, consumer electronics, pepperoni, or leather products. 

L.L. Varonina, O.N. Nazarova, U.P. Petushkova, N.L. Rebrikova, Damage of Parchment and Leather Caused by Microbes, ICOM Committee for Conservation, 6th Triennial Meeting, Ottawa, 21 25 September (1981). 

Biomarkers that demonstrate chromium exposure under field conditions is under active investigation. Laboratory studies with Prussian carp (Carassius auratus gibelio) exposed for 3 to 9 days to 25 to 100 pg Cr /L or 50 to 200 pg Cr+3/L show a dose-dependent increase in the frequency of micronuclei in erythrocytes, and this increase is considered indicative of increasing DNA damage (Al-Sabti et al. 1994). Similar increases in micronuclei were observed in Prussian carp from the River Ljubjanica near chromium-containing outfalls from leather waste products in the Republic of Slovenia (Al-Sabti et al. 1994). 

You deliberately delay your answer as you give Sally a chance to admire your car seats made of Cordovan chamois leather—a luxurious, soft, porous leather that could be repeatedly wetted and dried without damage. Although your sporty, red Porsche Carrera XI is out of character with the spartan life of an FBI agent, you appreciate the car s sleek lines and blazing acceleration. 

Dimethylformamide-induced liver damage among synthetic leather workers. Arch, environ. 

Materials and Structures. Building materials have become soiled and blackened by smoke, and damage by chemical attack from acid gases in the air has led to the deterioration of many marble statues in western Europe. Metals are also affected by air pollution for example, S02 causes many metals to corrode at a faster rate. Ozone is known to oxidize rubber products, and one of the effects of Los Angeles smog is cracking of rubber tires. Fabrics, leather, and paper are also affected by S02 and sulfuric acid, causing them to crack, become brittle, and tear more easily. 

Although the deacidifying agent does not harm leather, leather bound books are not recommend for the treatment. It is anticipated that during pre-drying process, leather can be irreversibly damaged. 

An important advantage of the plastic is that in thermal processing the finish on the surface of the tool—whether it be matt, leather grain, jazzy pattern, or what you will—can be transferred directly to the workpieces. One proviso when a design is applied in this way is that the tool should not wear quickly (which will result in loss of definition of the decoration) or, worse, that it be scratched or damaged so that the unwanted mark is carried over to the products. 

Wear a plastic high-impact face shield and heavy leather welder s gloves while loading the primers. If an accidental detonation does occur, it will be semiccntained in the soft brass case, and it should be very small as a result of using only small amounts of primer compound. Damage, as a result, should be held to a minimum. 

When books are removed from the shelves, one should not pull on the headcaps. The best method is to push the books on either side forward so that the sides of the required volume can be gripped. Damage to the top of the spine of fine leather-bound books can cost 30 or more and much inconvenience to rectify, and carelessness of this kind can spoil the quality of a collection in a very short time. 

It is not an uncommon practice for disintegrating books to be held together with rubber bands. As their removal often causes much damage to powdering leather spines, it is clearly a costly and unwise practice. 

If a book is to be rebound or repaired, a sound block is not touched, that is, no resewing is done. Exceptions to this rule would be books that must be taken apart for chemical treatment, or books that must be repaired in a leaf caster because of extensive damage, for example, by insects. In such cases, if a leather binding of rare or historical value is salvageable, it is removed carefully for later use. Samples of the book s components are saved notations are made of details that will permit duplication of the original craftwork. Additional photographs are taken if necessary. 

Leather Air pollutants, SO2, and acid gases cause disintegration, and siuface damage... 

Leather rot a brown discoloration is found on unripe fruits the fruits have a leathery consistency. The symptoms of damage (watery white, brown infected areas, flesh bitter) are rarer in ripe fruits. 

It is a white solid used in removal of certain kinds of stains, in removing calcium ions from solutions, and in tanning leather. It occurs naturally and is toxic. The potassium and calcium salts of oxalic acid are found naturally in cabbage, spinach, and rhubarb leaves, and are also found in the bark of some species of eucalyptus trees. The metabolism of sugar by many species of mold results in the production of oxalic acid. Ingestion of large amounts can cause kidney damage, convulsions, and death. 

Less recognized but also important is SO- damage to paper and leather. Paper products produced from about 1/50 on are embrittled by sulfur compounds converted to sulfuric acid which causes hydrolysis. Thus old books which are not stored in sealed cases undergo a gradual deterioration. Leather bindings are similarly affected. 

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