Visible residues

The next step is to chemically extract the lipids from the visible residue, powdered shard, or soil. A number of novel and conventional sample extraction techniques have been compared by Stern et al. (2000). There are two main methods routinely employed, but the exact conditions may vary between different laboratories. 

In the conventional method, the shard powder (or visible residue, or soil) is extracted with three separate aliquots of c. 0.5 ml DCM MeOH (dichlor-omethane methanol 1 1, v/v), with ultrasonication for 5 minutes to break up any particle aggregates and to aid dissolution. The solvent is separated from any insoluble material (including the ceramic) with centrifugation (5 minutes at lOOOrpm) and each of the three solvent aliquots is combined into a new clean vial. The solvent is then removed by placing the sample under a stream of nitrogen on a warm hotplate to aid evaporation, leaving the extracted... 

The above is diluted 5 oz. to 1 gallon of water for use. In wintertime, the recommended dilution is 10 oz. per gallon. Freezing is prevented by the isopropanol. This formulation leaves a small amount of residue on the unwiped portion of the windshield upon drying. There are several ways of preventing these visible residues. 

Archaeological pottery samples AK1 INT RES Pottery fragment with visible residue from Ali Kosh Sherd Dark brown... 

Opening of the chamber door and inspection of the inner areas using a UV lamp. Riboflavin residuals show up under phosphorescent light. The cleaning process can be considered successful if no phosphorescent visible residuals can be detected. 

C. All tools, parts, and equipment will be properly cleaned prior to entering the clean room. Minimum cleaning should be a total wipe-down with isopropyl alcohol, using certified clean-room wipes, to assure that the last wipe does not leave visible residue on the wipe. Parts should be blown off outside the clean room using filtered nitrogen when available. 

Sequential extractions (SSEs) were performed on the surface and subsurface soils, as Summarized in Table 8.2. The first six steps follow the method of Zeien and Briimmer,71 and Briimmer and Herms.72 The residual phase, that is, the phase that remained after step 6, was digested with a two-step microwave procedure. For the first step, 250 mg of sample were added to 4 ml of 65% HN03, 2.5 ml of 32% HC1 and 1 ml of 48% HF, and then heated for 5 min at 150 W and for 15 min at 350 W. For the second step the sample was cooled, and 10 ml of a 6% H3B03 were added and heated for 25 min at 250 W until a pressure of 15 bars was reached. No visible residues were left after this procedure. Extracted Zn was measured by atomic absorption spectrometry (Varian Spectra 220 Fast Sequential). The percentage of total Zn removed in each of the extraction steps is presented in Figure 8.4. The sum of all SSE steps was in good agreement with the total amount determined by XRF (+5%). 

For the Li Ceo syntheses, different stoichiometries of Li and Ceo were dissolved in liquid ammonia. Initially, a Li compound was synthesized by dissolving Li and Ceo in liquid ammonia at -78 °C, and the reaction did not go to completion as evidenced by visible residual Li. An Li Ceo compound with excess Li was then formed. If the reaction was allowed to warm to room temperature before removing the ammonia, the reaction appeared to go to completion. The recovered products were dried in inert atmosphere, stored in a glove box, and transferred to sealed ampoules for structural and H2 capacity determination. 

Neutralization sites were determined by natural escape mutation analysis and peptide mapping [41-44]. The two epitopes identified by this analysis were called A and B. Site A is a spike at the icosahedral 3-fold axes and the B site is on a ridge to the north of the icosahedral 2-fold axes. Interestingly, peptide mapping found additional epitopes at the N terminus. Because the first visible residue is at position 37 and lies inside the virion, it was proposed that these termini might be protruding through the 5-fold axes [40]. 

Emulsifiable concentrates leave little visible residue on plants. However, some plants are sensitive to the solvents and additives and damage (sometimes termed phytotoxicity) may occur. For this reason, an emulsifiable concentrate formulation may not be registered for a particular plant, even though wettable powder and dust formulations of the same active ingredient can be used. 

Typically < 0.1% residue is obtained when a 1 gram sample of diltiazem hydrochloride is ignited in a platinum crucible in the presence of concentrated H2SO4 in a muffle furnace at 800°C until no visible residue remains (21). 

In regard to the Tybrind Vig pottery analysis, different studies appear to produce contradictory results. The radiocarbon investigations pointed to a terrestrial source for the carbon in the pottery the organic chemistry indicates a marine and freshwater origin for the carbon. The physical evidence in the visible residues on the pottery itself contains both fish bone and terrestrial plant remains suggesting that foods from both land and water were cooked in the pots. It is also very important to remember that these ceramic vessels have a life of months or years and likely have many different things cooked or stored in them during that period. 

U.S. 5213793 (1993) Moses et al. (Gillette) <1% solid 0.01-0.5% cationic conditioning agent 5-10% volatile oil <3% hydrophobic emulsifying agent Rinse-on or leave-in no visible residual by a leave-in application... 

Tests.— A fluid ounce evaporated in a clean glass capsule should leave scarcely any visible residue, indicating the. absence of solid non-volatile impurities. Should not be affected by sulphuretted hydrogen, ammonium oxalate, silver nitrate, barium chloride, or lime water, proving the absence of lead and other metals precipitable by sulphuretted hydogen, calcium salts, chlorides, sulphates, carbonates, and carbonic acid respectively. 

In the file zr5-04.res, a second position of fhe first MeC5H4 ligand, the one not affected by the fourfold axis, becomes visible residual electron density maxima Q(8), Q(5), Q(6), Q(3), Q(2), and Q(7) correspond to atoms C(IOA) to C(15A). Using our refinement skills from Chapter 5, we can formulate this disorder, as it has been done in the file zr5-05.ins. 

Clear antiperspirants have become popular because they leave no visible residue.They are not always formulated through a microemulsion route. Clear sticks can be based on dibenzylidene sorbitol acetal (DBSA) gelling agent and zirconium or glycine-complexed aluminum chlorhydrate antiperspirant actives that are soluble in propylene glycol without water. An alternative route is to closely match the refractive indices of the oil and water phases so a clear product (not a microemulsion) results for an antiperspirant gel [20,23]. Clear deodorant sticks with the active ingredient triclosan can be solidified with sodium stearate, which is incompatible with antiperspirant active ingredients (aluminium chlorhydrates). 

Each core was inspected after the completion of displacement experiments. Unexpectedly, a visible residual oil saturation (ROS) ring (adjacent to the zone which was totally cleaned out of oil near the injection sand face) was observed in both radial and linear cores which underwent the PAAF process. On the contrary, such an effect did not occur in the cores flooded with either alkaline or polymer solution alone. Figures 5.a and 5.b illustrate this newly recognized effect in radial and linear cores, respectively. 

Pipe fragments may be extracted by sonication with acetone prior to TEA analysis. The concentrated acetone extract may be subjected to TLC as described above. Pipe samples without visible residue may be extracted with methylene chloride and examined by GC-TEA for the detection of NG. These pipe fragments may be re-extracted with acetone and the extract examined by TLC to detect the presence of both NG and NC. This provides good confirmation of smokeless powder as the explosive in the absence of even partial powder grains. Although examination of residues of low explosives by IR spectroscopy has been reported, the results are equivocal and difficult to interpret. 

Removal of all visible rust, mill scale, paint, and foreign matter by blast cleaning, by wheel or nozzle, dry or wet, using sand, grit, or shot for very corrosive atmospheres where high cost of cleaning is warranted Blast cleaning until at least two-thirds of the surface area is free of all visible residues (for severe exposure)... 

No visible residue fromcleanable or any activated fluxes is allowed. Production operations may not be required to remove cleanable residues if qualification testing is performed that demonstrates no need for cleaning the assembly. No-clean or low-residue flux chemistries may be allowed during the soldering process. However, it is critical that the cleanliness of the elements such as the bare boards and components be specified, controlled, and closely monitored otherwise, the contaminant build-up can far exceed allowable limits for the end item s functional performance. 

Along with the beam hazard, care should also be taken in performing maintenance on laser marking systems because of the potential for chemical contamination from antimony trioxide (a fire retardant added to the epoxy plastic packages) and beryllium (ceramic packages containing this compound will be labeled). The potential for contamination with visible residues from either of theses two toxic metals is likely. 

Biodegradation presents an ideal vision of matter, lapsing back into nature without leaving a visible residue. To be biodegradable is to be eco-friendly, to embody the promise to disappear into the earth without a trace. Biodegradability - even if this process involves fragmenting into toxic particles - may be seen to be preferable to being confronted with the visual... 

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