Lock pin

Fig ure 5-21. This picture shows the rotor blades from the inlet end. Root design is a four-land fir-tree type. A lock pin on each root platform locates the blade axially in the disc.  [c.306]

Outside of carbon monoxide for which the toxicity is already well-known, five types of organic chemical compounds capable of being emitted by vehicles will be the focus of our particular attention these are benzene, 1-3 butadiene, formaldehyde, acetaldehyde and polynuclear aromatic hydrocarbons, PNA, taken as a whole. Among the latter, two, like benzo [a] pyrene, are viewed as carcinogens. Benzene is considered here not as a motor fuel component emitted by evaporation, but because of its presence in exhaust gas (see Figure 5.25).  [c.260]

Other samples were increasingly more demanding ranging to the very difficult samples containing pin bones (Figure 2). Pin bones are the very small side bones with sizes around 0.3 - 0.5 mm, which need to be detected in order to guarantee the highest grade of raw material, typically used for products such as fish fingers. A lesser grade is designated bone free with pin bone in used for less demanding products, for example pet food, while still lesser grades may be used for grinding up for animal fodder. The price to be paid to the suppliers is directly related to the quality of the raw material.  [c.589]

Lukasiewicz S. (1979) Local loads in plates and shells. PWN-Polish, Warszawa. Noordhoff, Leyden.  [c.382]

Sua Pan, Botswana. A soda ash plant is under construction at Sua Pan ia Botswana (32). The plant will recover ash from an alkaU brine via a process similar to that at Sead.es Lake (29).  [c.526]

In false twist texturing (FTT), shown schematically in Figure 7, a device twists yam upstream of its location as the threadline passes across a heater, and the yam untwists downstream from the device and is wound up. If the yam is not heated downstream from the twist device, it has bulk and high elasticity (stretch). If the yam is heated downstream from the twist device, it has bulk, but much less stretch. FTT machines initially used two steps to sequentially draw and texture. Later machines combined those steps to simultaneously draw and texture (92). Initial machines used pin spindles as the false twist device. Texturing speeds were about 150 m/min and slowly increased to about 300 m/min. As POY quaUty and stmctural stabiUty improved, new  [c.331]

In horizontal rotary tilting pan filters, the wedge-like compartments are arranged as independent pans. Each is coimected to the center valve by a swivel pipe joint that inverts the pan as it passes the discharge point. Air blowback is often used to assist the cake discharge. The units can also be adapted for cloth washing. Typical appHcations include filtration of gypsum from phosphoric acid and many mineral processing uses. Areas from 15 to 250 m are avaUable. The tilting pan is more expensive, requires more door space, and has higher maintenance than the horizontal rotating pan filters. However, its advantages include exceUent cake discharge and control of wash Hquor, and the avaUabUity of larger sizes.  [c.395]

Reprocessing faciUties use equipment capable of shearing entire fuel assembhes. This accounts for a significant portion of the reprocessing cost in terms of size of the equipment needed and the consequent size of the cell required to house it. Shear blade maintenance requirements are also important. There are active programs aimed at reducing these costs. For instance, an operation involving only a single fuel pin would require a significantly smaller shear and cell to house it. Less oxide dust and cladding fines might also be anticipated. However, a fuel disassembly step with its attendant equipment and the space to house it must be added (7).  [c.207]

Class III devices, unless they are substantially equivalent to a device already marketed without a PMA appHcation, require formal PDA approval through the PMA process before initial sale. The PMA process is comparable to the new dmg approval process (18). In both cases, safety and effectiveness data must be reviewed by PDA prior to marketing. An approved PMA appHcation acts like a private Hcense granted to the appHcant to market a particular device. Other firms seeking to market the same type of device for the same use must also have an approved PMA.  [c.85]

To allow manufacturers to develop clinical safety and effectiveness data on devices requiring a PMA submission, PDA has implemented regulations that exempt devices intended solely for investigational use from certain provisions of the Act. This exemption is known as the Investigational Device Exemption (IDE) and allows manufacturers of devices intended solely for human investigational use to ship these products through interstate commerce (19). Like the IND regulations, the IDE regulations shape and control the investigational research. If a device is not considered to present a significant risk, an IDE submission to PDA is not necessary. If a device is considered to present a significant risk, an IDE appHcation must be submitted to PDA for approval. In both cases, patient informed consent and IRB approval and oversight is requited.  [c.85]

A typical sieve is a shallow pan having a wire-mesh bottom or an electroformed grid. Opening dimensions in any mesh or grid are generally uniform within a few percent. Sieves are available having openings from 5 p.m upward in several series of size progression. Woven wire-mesh sieves have approximately square openings electroformed sieves have round, square, or rectangular openings. Wine sieves tend to be sturdier and less expensive, and have a greater proportion of open area. They are much more frequentiy employed than thek electroformed counterparts except in the very fine particle range where only electroformed sieves are available (18).  [c.130]

Dry-sieving is typically performed using a stack of sieves having openings diminishing in size from the top downward. The lowest pan has a soHd bottom to retain the final undersize. Powders are segregated according to size by placing the powder on the uppermost sieve and then shaking the stack manually, using a mechanical vibrator (19,20), or with ak pulses of sonic frequency (21,22) until all particles fall onto sieves through which they are unable to pass or into the bottom pan. The unit, powered by sonic energy shown in Figure 6, confines the sample using very flexible diaphragms, ensuring against loss of fines. In another device, sieves are employed one at a time within a container from which passing particles are captured by a filter. Agitation on the sieve is provided by a rotating ak jet (23). The material retained by the sieve is recorded and recycled to the next coarser sieve until all the powder is exposed to the desked series of sieves or all material passes.  [c.130]

Usc s. The largest use of strontium carbonate is in the manufacture of glass faceplates for color-television tubes. It is present in glass at ca 12—14 wt % on a strontium oxide basis and functions as an x-ray absorber. Strontium carbonate is an effective x-ray barrier because strontium has a large atomic radius, and its presence is required in the relatively high voltage television sets used in the United States and Japan. The lower voltage Western European television faceplates contain the less expensive barium carbonate as an x-ray absorber. Strontium carbonate, when added to special glasses, glass frits, and ceramic glazes, increases the firing range, lowers acid solubiUty, and reduces pin-holing strontium carbonate also has low toxicity. It is used in the production of high purity, low lead electrolytic zinc by a process patented by ASARCO, Inc. (7) and it is used in AustraUa, South Africa, the United States, and Japan. At a use level of 4.4—7.7 kg of strontium carbonate per ton of metal produced, it removes lead from the cathode zinc.  [c.474]

The bulkhead pan roof has open annular compartments at the periphery to prevent the roof from sinking should a leak develop.  [c.314]

Pressure-area isotherms for many polymer films lack the well-defined phase regions shown in Fig. IV-16 such films give the appearance of being rather amorphous and plastic in nature. At low pressures, non-ideal-gas behavior is approached as seen in Fig. XV-1 for polyfmethyl acrylate) (PMA). The limiting slope is given by a viiial equation  [c.537]

The idea that a shared electron pair constitutes a covalent bond ignores any difficulty about the actual position and nature of the electrons in the combining atoms or in the resulting molecule. The idea that electrons are particles revolving in orbits or situated in shells is inadequate when we desire to picture electrons in covalent bonds. It is, however, known that a beam of electrons can undergo diffraction, and that they therefore possess a wave-like nature like light waves. It has also been found that there is a simple relationship between the momentum of an electron (characteristic of its particle-nature) and the wavelength (characteristic of its wave-nature). But if we give a definite wavelength or amplitude to an electron, then its position in space becomes uncertain, i.e. it cannot be pin-pointed. Instead, the wave amplitude (strictly, the square of the amplitude) can be used to represent the probability of finding the electron at a given point in an atom or molecule. This amplitude is usually given the symbol ij/ (psi) and is called a ware function. For hydrogen (or helium), with one (or two) electron in the K shell , ij/ is found to depend only on the distance from the nucleus, diminishing as this distance increases hence our picture of the hydrogen atom is that shown in Figure 2.7.  [c.54]

The second application of the CFTI approach described here involves calculations of the free energy differences between conformers of the linear form of the opioid pentapeptide DPDPE in aqueous solution [9, 10]. DPDPE (Tyr-D-Pen-Gly-Phe-D-Pen, where D-Pen is the D isomer of /3,/3-dimethylcysteine) and other opioids are an interesting class of biologically active peptides which exhibit a strong correlation between conformation and affinity and selectivity for different receptors. The cyclic form of DPDPE contains a disulfide bond constraint, and is a highly specific S opioid [llj. Our simulations provide information on the cost of pre-organizing the linear peptide from its stable solution structure to a cyclic-like precursor for disulfide bond formation. Such  [c.164]

For the linear form of DPDPE (Tyr-D-Pen-Gly-Phe-D-Pen, where D-Pen is the D isomer of /3,/ -dimethylcysteine) free energy differences were calculated between four structures, denoted as Cyc, Ext, /3c and 0e [9, 10]. The Cyc or cyclic-like conformer corresponds to an experimental structure of the cyclic form with the disulfide bond removed, Ext - to an extended structure. The two type IV (3 turns, /3c and (3e, have been identified as the stable, representative structure of linear DPDPE in solution based on previous unconstrained simulations [14]. Three conformational free energy simulations were performed Cyc —t /3c, Ext —> /3b, and pc —> Pe- Each simulation involved generation of a series of intermediate states lying along a straight line connecting the initial and final state in dihedral angle space (29 for Cyc —> Pc, 13 for Ext —> Pe, and 15 for Pc -+ Pe)- At each state 20 ps equilibration  [c.169]

Our interest has been to parallelize PME some of our efforts are described in [4]. The three dimensional FFT needed by PME is notoriously difficult to parallelize, while the real-space contribution is quite easy to parallelize, so we first bias the work as much as possible to favor the real-space term. We can do this by adjusting the free parameter in the method which controls the Gaussian width of the fictitious charge and counter-charge distributions added to the system. A larger value of this width allows a coarser grid in Fourier space (and thus less work to evaluate the FFT) but a larger real-space cut-off radius for the complementary error function (and thus more work in the real-space sum). The ability to trade off work between the real and reciprocal space sums is further limited by the requirement that the real-space cut-off radius cannot exceed half the side length of the original simulation cell.  [c.465]

To this pom t, th e basic approxmi alien is th at th e total wave I lnic-tion IS a single Slater determinant and the resultant expression of the molecular orbitals is a linear combination of atomic orbital basis functions (MO-LCAO). In other words, an ah miiio calculation can be initiated once a basis for the LCAO is chosen. Mathematically, any set of functions can be a basis for an ah mitio calculation. However, there are two main things to be considered m the choice of the basis. First one desires to use the most efficient and accurate functions possible, so that the expansion (equation (49) on page 222). will require the few esl possible term s for an accurate representation of a molecular orbital. The second one is the speed of tW O-electron integral calculation.  [c.252]

In the cross-flow mode, fluid is passed across the membrane surface while a portion of the flow is diverted through the filter (permeate). A portion of flow is returned to the central reservoir as retentate. In this process the volume of fluid in the retentate continually decreases as more of the initial volume is collected as permeate. Viral particles are concentrated in the retentate. The advantage of this process is that the cross-flow across the membrane helps extend filter life by reducing gel layer formation. Typically the filtration systems utilizing cross-flow are either in the tangential-type system where fluid passes between two flat sheets of membrane material (Fig. 3) or consist of hoUow-fiber filters where the fluid passes through the middle of hoUow tubes (Fig. 4) (see Hollow-fibermembranes). For tangential flow, the membrane pore sizes range from 70—180 KD (27—29), as well as 100 and 300 KD polyethersulfone membranes. HoUow-fiber ultrafilters between 100 and 6 KF) have been used for vims removal (30—33). These have been constmcted from regenerated cellulose fiber, poly acetalnittile (PAN), and polysulfone (PS). Both types of filters (tangential flow and hoUow fiber) are typicaUy designed for reuse after cleaning and sanitization and thus can be cost effective in terms of the filter cost. On the other hand, these systems may have higher holdup volumes and thus greater loss of production than single-pass systems. The cross-flow system may also be more complex and cosdy to instaU. AdditionaUy, it is necessary to vaUdate the filtration process. In the case of reuse of the filter system the cleaning and sanitization procedures also require vaUdation.  [c.143]

HPAM, like POE, exhibits an aging process ia which the solution viscosity continues to change. This is most likely due to incomplete hydration of the dispersed polymer particle. Because the synthesis of HPAM can be conducted ia water, the problem of dissolution ia many appHcations is addressed by polymerizing the monomer ia water-ia-oil emulsions aerosol OT, a branched anionic surfactant, is the primary stabilizer. The thermal stabiUty of acrylamide solutions are generally higher than most other water-soluble polymers however, the high molecular weight species, like their POE equivalents, have very high extensional viscosities (see Fig. 7), favorable for good drag reduction behavior. This also, however, reflects on their rapid degradation under mechanical deformation. The other negative aspect of PAM or HPAM aqueous solutions is hydrolysis of the amide group. This is most apparent ia caustic flooding ia secondary petroleum recovery appHcations. Studies have shown that the hydrolysis to carboxylate groups is limited by the electrostatic repulsion of charged carboxylate groups, below 50 mole carboxylate units there is Htfle hydrolysis (33) of the remaining amide units.  [c.317]

Formaldehyde homopolymer is composed exclusively of repeating oxymethylene units and is described by the term poly oxymethylene (POM) [9002-81-7]. Commercially significant copolymers, for example [95327-43-8] have a minor fraction (typically less than 5 mol %) of alkyUdene or other units, derived from cycHc ethers or cycHc formals, distributed along the polymer chain. The occasional break in the oxymethylene sequences has significant ramifications for polymer stabilization.  [c.56]

Sodium carbonate beating deposits and brines exist around the world. Locations are known ia the United States, China, Turkey, BoHvia, Brazil, Venezuela, Mexico, India, Pakistan, USSR, Kenya, AustraHa, and Botswana (14—20). The overwhelming majority of natural ash production comes from the Green River Basia ia southwestern Wyoming. Significant amounts are also produced at Seades Lake ia California lesser amounts at Lake Magadi ia Kenya. Minor quantities are reportedly produced ia Pakistan, the USSR, and China and small amounts of impure trona come from Owens Lake, California. A plant is currentiy under constmction to recover soda ash from brine at Sua Pan, Botswana. Each deposit has its own distinctive characteristics and each requires different processiag techniques.  [c.524]

At high frequencies ferrites exhibit energy losses resulting from various physical mechanisms at different frequencies and appearing as heat dissipation. Hysteresis losses arise from irreversible domain wall jumps. During each cycle of the JT- and E-ftelds one hysteresis loop is completed and the loss per cycle is proportional to the area of the loop. A way to reduce hysteresis losses, ie, prevent domain wall jumps, is to reduce the number of inhomogeneities able to pin domain walls, eg, pores and impurities, and to reduce magnetocrystalline and stress anisotropy (51,52). Another method is to dehberately pin the walls, for instance by addition of Co and Ti ions or by using ceramic microstmctures having small grains (53,54). A second important loss contribution comes from eddy currents, induced by alternating magnetic fluxes. This contribution can be limited by providing a high electrical resistivity (55,56). At high frequencies this is not easy at all, because insulating grain boundaries tend to become short circuited as a result of the permittivity of the ferrite (28). A third main loss contribution is from magnetic resonances. Above about 1 MHz this is usually the dominant contribution. When the driving frequency is in resonance with the natural frequency at which the magnetization rotates, there is a large peak in power absorption. This effect can be seen when the magnetic permeabiUty is considered as the complex parameter ji = ji jji. The ratio ]l is usually expressed as tan 5, where 5 is the so-called loss angle, the phase-lag of the magnetic induction with respect to the appHed magnetic field. For inductors in electrical circuits, 5 expresses the phase difference between voltage and current. Figure 5 shows ]l and ]l" as functions of frequency for some commercial ferrites. These ferrites show large differences concerning the frequencies where ]l" starts to come up and accordingly, in the resonance frequencies, where tan6 = 1. But also the low frequency permeabiUties differ. The resonance frequency is inversely proportional to the low frequency permeabiUty (58). Applying this, shifting resonance to high frequencies can be realized by small grain sizes. The ferrites of Figure 5 are optimized for a range of frequencies and induction levels (57).  [c.190]

The first to produce nongranular MAP commercially was Scottish Agricultural Industries, Ltd. under the trade name Phos SAL In the SAI process, gaseous ammonia and wet-process acid are allowed to react in a tank to produce a slurry having an N P mole ratio 1.3 1. Acid is added to the slurry in a pin mixer to adjust the mole ratio to 1.0 and to disengage water vapor (63). The powder product contains 6% moisture which is a claimed advantage over smaller amounts because of less dustiness and higher ammonia reactivity. A gel impurity phase covers the surface of the crystals and is claimed to have beneficial effect on the granulation quaHty of the material. In a process developed by Fisons Ltd., ammonia vapor and 48—52% P2O5 wet-process acid are mixed in a reactor at 308 kPa (30 psig) in an N P mole ratio of 1. The hot reaction product containing 9—10% water is sprayed through a nozzle into a tower where water flashes off and powder MAP coUects. The product contains about 6% moisture. A number of such plants have been built. The characteristic feature of another process developed by Swift, Inc., is a two-fluid nozzle that gives instantaneous mixing of Hquid ammonia and 49—51% P20 wet-process acid. A reactor pipe discharges the slurry at about 127°C into the top of a tower, in which water is flashed and powder MAP coUects. A typical product grade is 10.5-53.0-0 and moisture content is 4%. The heart of another powder MAP process, developed by Gardinier, is a novel pipe reactor. Wet-process acid and ammonia are iatroduced tangentially into the reactor through diametrically opposed inlet lines. The reactants flow in a spiral  [c.230]

Industrial use of acryUc fiber broadwoven goods has increased in recent years. The advantages are uv stabiUty and its wide range of options for dyeing. The primary products are marine fabrics, awnings, and outdoor furniture. High performance fibers such as Kevlar, Spectra, and Vectran may eventually see competition from acryUc fiber. Gel spinning of ultrahigh molecular weight PAN is capable of producing fibers of comparable strength and modulus. The technology has been proven in the laboratory, but no commercial products have appeared thus far. AcryUcs have also captured a share of the market for woven fabrics used in casual furniture. SunbreUa is one such product. The market for outdoor fabrics, such as awnings and marine fabrics, has been a boon to acryUc fiber producers. Brightly colored acryUcs and innovative products, such as backht awnings, have created a new surge of business. The marine fabrics market has been hurt by the effects of recession, but acryUcs have been hurt the least. As in other markets, the colorful styles of acryUcs have been a key to success. AcryUc fiber is also enjoying a comeback in the carpet market. Monsanto s Acrilan Plus and Traffic Control are examples of current carpet products. Acrilan Plus offers the wool-like hand, rich color, and styling variety possible with acryUcs. Traffic Control, while primarily a nylon product, employs a high shrink acryUc blend to enhance appearance retention in high traffic areas. The worldwide picture for acryUcs is summarized in Tables 5-7 (106).  [c.286]

Placer mining is the oldest form of gold mining. Auriferous sand or gravel is swided with water in a pan and gold, which setdes out owing to its high density, is collected. On a large scale, a mixture of sand, gravel, and water is passed through a sluice box fitted with transverse riffles behind which the gold accumulates. The technique is still in use in places where appropriate alluvial or marine deposits exist, such as Alaska, but requires large quantities of water (7). Air classification also is possible but less efficient (8) (see Separation, size). At present, most gold is obtained either by deep mining, most notably in South Africa, or by open pit mining such as in the United States.  [c.378]

Process. Any standard precursor material can be used, but the preferred material is wet spun Courtaulds special acrylic fiber (SAF), oxidized by RK Carbon Fibers Co. to form 6K Panox B oxidized polyacrylonitrile (PAN) fiber (OPF). This OPF is treated ia a nitrogen atmosphere at 450—750°C, preferably 525—595°C, to give fibers having between 69—70% C, 19% N density less than 2.5 g/mL and a specific resistivity under 10 ° ohm-cm. If crimp is desired, the fibers are first knit iato a sock before heat treating and then de-knit. Controlled carbonization of precursor filaments results ia a linear Dow fiber (LDF), whereas controlled carbonization of knit precursor fibers results ia a curly carbonaceous fiber (EDF). At higher carbonizing temperatures of 1000—1400°C the fibers become electrically conductive (22).  [c.69]

KedPigments. There ate mote ted pigments used than any other organic type and they range in shade from yeUowish ted to deep maroon and from dirty teds to very clean, brilliant teds. A few of the mote common types ate as foUows. (/) The para teds and toluidines ate fairly fast to light and semitransparent. They ate used in poster and label inks. (2) The Hthol teds ate avaUable in a wide range of shades with moderate permanency to light. (3) Lithol Rubine teds ate widely used as magentas in aU types of four-color process printing. (4) Rhodamine teds ate brilliant and have good Hghtfastness, when laked with phosphotungstic (PTA) and/or phosphomolybdic (PMA) acids. They ate extremely cosdy, and for this reason, ate not widely used as process magentas. (5) Red Lake C is used for making the clean, brilliant orange or warm ted shades. (6) Watchung teds or Permanent Red 2B pigments ate  [c.248]

Basic dyes are characteri2ed by bright shades and high strength but poor lightfastness. However, when laked by precipitation with soluble salts of organic acids such as tannic acid, or inorganic heteropoly acids like phosphotungstic (PTA M = W) and phosphomolybdic (PMA M = Mo), and the combined phosphotungstomolybdic acid (PTMA), the resulting pigments retain the dyes tinctorial attributes, but become insoluble and show improved lightfastness. Ideally three acidic hydrogens can be replaced by three dye molecules to form pigments which are characteri2ed by uncommonly clean and brilliant red and violet shades. They are, however, not stable to polar solvents or alkaU and fail to satisfy stringent fastness requirements, particularly in packaging and special inks. Representative basic dyes which are converted to pigments by complex formation are Hsted in Table 5.  [c.30]

Several state highway departments have undertaken toad constmction-related fill projects using tire chips, including Oregon, Colorado, North Carolina, Virginia, Maine, Minnesota, and Wisconsin. Minnesota has achieved considerable private use of tire chips as fill material, as has Vermont. Several states have approved the use of tire chips in private septic systems as backfill for leach fields, including Iowa, Georgia, and South Carolina. Whole used tires are used for a thick flow 2one for leachate and as a protective barrier at the Pen Argyl landfill in Peimsylvania (51).  [c.20]

Three specialty types of salt are produced by variations of the evaporating process. Alberger salt is produced with a modified grainer method and results in a combination of flakes and cubic crystals of salt. It is less dense than granulated—evaporated salt and, like grainer salt, is typically used where coarser salt is required, as in koshering. Dendritic salt is made by adding yellow pmssiate of soda (YPS) (sodium ferrocyanide) to the brine the YPS modifies the crystal stmcture of sodium chloride to form a branch-like, low density dendritic salt crystal. The recrystallizer process (Fig. 5) is a means of producing purified salt. Brine made by dissolving rock salt or solar salt is purified and fed to vacuum pan evaporators. The result is granulated—evaporated salt of excellent purity. Granulated—evaporated salt has many uses where purity and consistency of grain size and shape are important.  [c.181]

Crystallization batches range from 30,000 to 60,000 Hters for each pan. Continuous centrifugals are typically used for second, third, and affination steps continuous vacuum pans are less common but are used in the U.S. for intermediate strikes. Most horizontal batch crystallizers have been replaced by continuous units, and all are designed for controlled cooling of the massecuite to maintain supersaturation.  [c.28]

Balancing these crystallization steps to maximize the yield and maintain high product quaUty is a significant operational challenge, especially when confronted with changing thick juice quaUty, ie, color, purity, and pH stabiUty (Table 1). These values reveal the critical dependence of performance on the quahty of the thick juice and, by inference, on the nature of the beets. Calculations have assumed the same yield for each of the boilings. The higher nonsucrose loading has reduced the final yield by 5% for the low purity thick juice. For the same 100 kg of sugar entering crystallization, each stage of the low purity scenario has to handle 40—50% more material because of increased concentrations of returned sugar from the second and third stages. Because the process is controlled by kinetics, either pan yields must be sacrificed or overall throughput must be reduced either choice has cosdy results. Low purity juices tend to be less stable with respect to color, pH, and calcium precipitation, and the choice is always between bad and worse.  [c.28]

Interna.1 Floa.ting Roofs. Pan roofs are simple sheet steel disks where the edge is turned up for buoyancy. These roofs are prone to capsiting and sinking owing to the fact that a small leak can cause them to sink (see Fig. 6).  [c.314]

See pages that mention the term Lock pin : [c.1095]    [c.483]    [c.339]    [c.310]    [c.24]    [c.180]    [c.293]    [c.542]    [c.109]    [c.284]    [c.56]    [c.372]    [c.448]    [c.464]   
Turboexpanders and Process Applications (0) -- [ c.306 ]