Nuisance

Hydrate formation is possible only at temperatures less than 35°C when the pressure is less than 100 bar. Hydrates are a nuisance they are capable of plugging (partially or totally) equipment in transport systems such as pipelines, filters, and valves they can accumulate in heat exchangers and reduce heat transfer as well as increase pressure drop. Finally, if deposited in rotating machinery, they can lead to rotor imbalance generating vibration and causing failure of the machine. 

This, the Darzens reaction, is useful in other circumstances (frames 280-1) but a nuisance here. We must use some means to make the ketone act as the nucleophile in the initial condensation. One effectiye way is to conyert it into an enamine. Draw a mechanism for this reaction. 

After 24 hours, the stirring is stopped. Now it s time to fitter out the Cuprous Chloride, which is one of the two slight nuisances regarding this procedure. Note forget about Palladium Chloride recovery. It s too complex for the simplicity of this procedure and purchased from a photo supplier it shouldn t cost more than 6.50 per gram. We ll call this next process Phase Two. 

Problems associated with excessive levels of nutrients and unwanted nuisance species have already been mentioned. There are cases in which intentional fertilization is used by aquaculturists in order to produce desirable types of natural food for the species under culture. Examples of this approach include inorganic fertilizer appHcations in ponds to promote phytoplankton and zooplankton blooms that provide food for young fish such as channel catfish, the development of algal mats through fertilization of milkfish ponds, and the use of organic fertilizers (from Hvestock and human excrement) in Chinese carp ponds to encourage the growth of phytoplankton, macrophytes, and benthic invertebrates. In the latter instance, various species of carp with different food habits are stocked to ensure that all of the types of natural foods produced as a result of fertilization are consumed. 

Except for siUca and natural abrasives containing free siUca, the abrasive materials used today are classified by NIOSH as nuisance dust materials and have relatively high permissable dust levels (55). The OSHA TWA allowable total dust level for aluminum oxide, siUcon carbide, boron carbide, ceria, and other nuisance dusts is 10 mg/m. SiUca, in contrast, is quite toxic as a respkable dust for cristobaUte [14464-46-1] and tridymite [15468-32-3] the allowable TWA level drops to 0.05 mg/m and the TWA for quartz [14808-60-7] is set at 0.1 mg/m. Any abrasive that contains free siUca in excess of 1% should be treated as a potential health hazard if it is in the form of respkable dust. Dust masks are requked for those exposed to such materials (see Industrial hygene). 

Pentaerythritol and trimethylolpropane are classified as nuisance particulate and dust, respectively. They are both nontoxic to animals by ingestion or inhalation and are essentially nonirritating to the skin or eyes (2,74). 

Mg(OH)2 powder is classified by OSHA as a nuisance dust. ACGIH categorizes the powder form as particulates not otherwise classified. Exposure limits are as follows (108) ACGIH 10 mg/m , OSHA 5 mg/m (respirable), and 15 mg/m (total). Magnesium hydroxide is reported in the EPA TSCA inventory (109). 

Studies carried out on anionic, cationic, and nonionic surfactants bave shown tbat tbe aromatic and bydropbilic portions of molecules are easily oxidi2ed, wbereas tbe long hydrocarbon chains are converted at slower rates. Surfactant activity does, however, disappear upon loss of the aromatic portion, thereby reducing the nuisance of the reactants (32). Total mineraLi2ation to CO2 has been demonstrated for nonionic polyethoxylated 4-nonylphenols having average numbers of 2,5, and 12 ethoxy units (33). 

When considering taxes, all types need to be considered initial fees, capital value, corporate rate, personal income tax, sales tax, property tax, unemployment insurance, workmen s compensation, and nuisance tax. During the constmction phase, several types of taxes may be levied. These include building permits, special fees, assessments, and sewer connection fees. 

PPS dust should be treated as a nuisance particulate. The OSHA permissible exposure limit for respirable dust is 5 mg/m for dust containing no asbestos and less than 1% siUca. The principal decomposition products released during mol ding of PPS and their permissible exposure limits are given in Table 10. Sulfur dioxide and carbonyl sulfide are the most significant off-gases for production of mucous membrane irritation. 

Activated alumina is a relatively innocuous material from a health and safety standpoint. It is nonflammable and nontoxic. Fine dusts can cause eye irritation and there is some record of lung damage because of inhalation of activated alumina dust mixed with siUca [7631-86-9] and iron oxide [1317-61 -9] (30). Normal precautions associated with handling of nuisance dusts should be taken. Activated alumina is normally shipped in moisture-proof containers (bags, dmms, sling bins) because of its strong desiccating action. 

Amorphous sihca is classified by the Occupational Safety and Health Administration as a nuisance dust. The principal reported health reaction is contact dermatitis resulting from the absorption of protective oils from the skin (1). 

Occupational Safety and Health. OSHA has set no specific limits for sodium and potassium sibcates (88). A pmdent industrial exposure standard could range from the permissible exposure limit (PEL) for inert or nuisance particulates to the PEL for sodium hydroxide, depending on the rate of dissolution and the concentration of airborne material. Material safety data sheets issued by siUcate producers should be consulted for specific handling precautions, recommended personal protective equipment, and other important safety information. 

Talc is considered a nuisance dust and subject to regulation in the workplace by both the Occupational Health and Safety Administration and the Mine Safety and Health Administration. Eight-hour exposure limits for talc dust are two milligrams of talc per cubic meter. 

OSHA and ACGIH have not estabhshed specific airborne exposure limits for PVB and PVF resias however, some products may contain sufficient fines to be considered nuisance dust and present dust explosion potential if sufficient quantities are dispersed ia air. Unformulated PVB and PVF resias have flash poiats above 370°C. The lower explosive limit (lei) for PVB dust ia air is about 20 g/m. ... 

Short-term inhalation of PVA dust has no known health significance, but can cause discomfort and should be avoided in accordance with industry standards for exposure to nuisance dust. The dust is mildly irritating to the eyes. There are no known dermal effects arising from short-term exposure to either soHd PVA or its aqueous solutions. 

A portion of the effluent is recirculated, ia order to smooth out flow, keep the food concentration constant, lower film thickness and control psychoda flies, and reseed the appHed sewage with acclimatized organisms. The psychoda, or filter fly is a very small iasect that breeds ia thick trickling-filter slimes. It does not bite, but can be a nuisance. Its radius of flight is small, but it can be carried great distances by the wiad. The fly can be controlled ia the development phase by occasional flooding of the filter or chlorination of the appHed sewage. 

Intensive or extensive culture of aquatic animals requires chemicals that control disease, enhance the growth of cultured species, reduce handling trauma to organisms, improve water quality, disinfect water, and control aquatic vegetation, predaceous insects, or other nuisance organisms. The aquacultural chemical need for various species have been described for rainbow trout, Oncorhjnchus mjkiss (1) Adantic and Pacific salmon, Salmo and Oncorhjnchus sp. (2) channel catfish, Ictaluruspunctatus (3) striped bass, Morone saxatilis (4) milkfish, Chanos chanos (5) moUusks (6) penaeid (Penaeus sp.) shrimp (7) and a variety of other marine species (8). 

Piscicides. The two piscicides, antimycin and rotenone, are both used in ponds to control nuisance fish. Antimycin is used selectively to remove scaled fishes from catfish ponds, and rotenone is used as a general fish toxicant (9,10). Recent observations by catfish farmers indicate that antimycin at low concentrations also acts as a therapeutant against external parasites. 

Table 8. Exposure Limits for Asbestos Fibers, Synthetic Mineral Fibers (SMF) and Nuisance Dust in the Workplace ...

Country Asbestos exposure limits Fiber type Exposure limits for SMF and nuisance dust... 

Activated carbon generally presents no particular health hazard as defined by NIOSH (62). However, it is a nuisance and mild irritant with respect to inhalation, skin contact, eye exposure, and ingestion. On the other hand, special consideration must be given to the handling of spent carbon that may contain a concentration of toxic compounds. 

Traditionally, one of the biggest problems with colorants is their dustiness. Besides a contamination problem, inhalation can either be a nuisance or ha2ardous, depending on the colorant involved. Several producers offer low dusting products or encapsulated products to improve this situation. 

FPDs). They often have less aesthetically pleasing restoration than FPDs coupled with the nuisance of removing them at night and a psychologically less satisfying lack-of-permanency. 

From an electroanalytical point of view, the double-layer capacitance is a nuisance resulting in the charging current, which has no analytical value. 

The accident at the Three Mile Island nuclear plant clearly demonstrated that an alarm system can be counterprociuc tive. An excessive number of alarms can distract the operator s attention from the real problem that needs to be addressed. Alarms that merely tell the operator something that is already known do the same. In fac t, a very good definition of a nuisance alarm is one that informs the operator of a situation of which the operator is already aware. The only problem with applying this definition is determining what the operator already knows. 

While generally fog formation is a nuisance, it can occasionally be useful because of the high surface area generated by the fine drops. An example is insecticide application. 

Flares are mostly used for the disposal of hydrocarbons. Waste gases composed of natural gas, propane, ethylene, propylene, butadiene, and butane probably constitute over 95 percent of the material flared. Flares have been used successfully to control malodorous gases such as mercaptans and amines, but care must be taken when flaring these gases. Unless the flare is very efficient and gives good combustion, obnoxious fumes can escape unburned and cause a nuisance. 

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