Ability to Generalize

They have the ability to generalize from given training data to unseen data.  [c.348]

Leaving the refinery, jet fuel has generally no free water and contains only a small quantity of dissolved water. But humidity from the air and tank breathing result in continuous intrusion of water that must be then removed by decanting and filtration. This is why jet fuel needs to be tested for its ability to separate the contained water.  [c.250]

The most popular of the SCRF methods is the polarized continuum method (PCM) developed by Tomasi and coworkers. This technique uses a numerical integration over the solute charge density. There are several variations, each of which uses a nonspherical cavity. The generally good results and ability to describe the arbitrary solute make this a widely used method. Flowever, it is sensitive to the choice of a basis set. Some software implementations of this method may fail for more complex molecules.  [c.212]

The ability to perform molecular orbital (MO) calculations on metals is extremely useful because molecular mechanics methods are generally unable to treat metals. This is because metals have a wide range of valences, oxidation states, spin multiplicities, and have unusual bonding situations (e.g., dtt-pjt back bonding). In addition, the nondirectional nature of metallic bonding is less amenable to a ball and spring interpretation.  [c.151]

In a flotation column (Fig. 19b), feed slurry is introduced in the top half of the column, and air, sometimes premixed with pulp, is introduced in the bottom half of the column. Numerous variations of feed and air inlet designs have been used. Flotation columns can be up to 18 m high (2,34), having diameters of up to 3.5 m. Columns having much smaller height/diameter ratios have also been developed, eg, the Jameson cell. In this cell, air and feed are mixed at the head of a long vertical pipe and the aerated pulp is introduced near the bottom of a cylindrical vessel with a conical bottom (2). Flotation columns generally have no agitators or moving parts inside. Water sprays are used invariably above the froth phase in order to provide efficient drainage of the mechanically entrained particles. A vast amount of research and development has been conducted on column flotation. Columns have become an integral part of a flotation circuit in most operations. One of the attractive features of a column cell is its ability to make excellent separations even in the very fine (<20 fiva) particle size range.  [c.413]

There are small differences in the properties of asphalts prepared by propane deasphalting and those prepared by vacuum distillation from the same stock (Fig. 4). Propane deasphalting also has the ability to reduce a residuum even further and produce an asphalt product ha-ving a lo-wer -viscosity, higher ductility, and higher temperature susceptibility than other asphalts (23). Ho-wever, such properties might be anticipated to be very much cmde oil dependent. Propane deasphalting is conventionally applied to lo-w asphalt-content cmdes, -which ate generally different in type and source from those processed by distillation of higher yield cmdes.  [c.363]

Manganese steel, containing 12 to 14 percent manganese and 1 to 1.5 percent carbon, is characterized by its exceptional toughness combined with adequate wear resistance, and enhanced by the austenitic microstructure having the ability to work harden. Although the relatively low yield strength can lead to problems of spreading in service, this can be compensated for by the addition of chromium or molybdenum or by the use of a lower manganese grade (6-7 percent) also alloyed with up to 1 percent molybdenum. Applications are generally those involving the highest levels of stress, particularly by high-impact loading, such as jaw-crusher elements, gyratory cone-crusher mantles, and primaiy hammer-mill parts.  [c.1830]

Cathodic protection can be useful, although its ability to protect tube interiors is generally limited to the first 4 to 6 in. of tube length. Such systems, however, must be properly designed and maintained to be effective. Corrosion can be intensified if the polarity of the cathodic protection system is inadvertently reversed.  [c.250]

A molecular dynamics simulation consists of numerically solving the equations of motion of a set of particles (atoms), given the forces on the particles. Classical MD simulations that solve Newton s equations of motion generate trajectories belonging to the microcanonical [constant number of particles, volume, and energy (NVE)] statistical mechanical ensemble. It is generally desirable to perfonn simulations in other ensembles such as the isobaric-isothermal ensemble (constant NPT). In addition to being the natural choice for correspondence with typical experimental conditions, the NPT ensemble is useful for validating force fields by checking their ability to reproduce important structural parameters known from experimental measurements, such as the surface area per lipid, the interlamellar spacing, and the membrane thickness, and for predicting these quantities when they are not known (e.g., in membrane-protein systems). Constant pressure and temperature are enforced in simulations by controlling the fluctuations of the particle kinetic energy and system volume, respectively, and there are various ways to do this. The best algorithms, in terms of their ability to rigorously generate the NPT ensemble, are based on the extended system approach [46], in which additional dynamic variables are introduced, for example a time-dependent friction coefficient ( thermostat ) to control the temperature and a piston to control the pressure. The equations of motion and a conserved energy are consistently formulated so that the microcanonical distribution function for the extended phase space gives the isobaric-isothermal distribution function for the particles after integration over the additional dynamic variables [47].  [c.470]

Seleetion of an alloy for high temperature operation depends on its ability to withstand the stresses imposed on it during serviee and on the eorrosion resistanee of the alloy to proteet itself from various atmospheres in serviee. Waspaloy, used for rotating blades and dises in hot gas expanders, has generally been seleeted due to its ability to withstand the neeessary stresses and to provide good oxidation resistanee at elevated temperatures. The blade/dise eomponents for hot gas expanders usually operate in the temperature range of 950-1,200°F. At these temperatures, the ereep rupture properties of Waspaloy are exeellent, whieh makes it a suitable eandidate material. Sinee Waspaloy  [c.236]

Atmospheric haze has been observed in both the western and eastern portions of the United States. Typical visual ranges in the East are <15 miles and in the Southwest >50 miles. The desire to protect visual air quality in the United States is focused on the national parks in the West. The ability to see vistas over 50-100 km in these locations makes them particularly vulnerable to atmospheric haze. This phenomenon is generally associated with diffuse or widespread atmospheric degradation as opposed to individual plumes.  [c.144]

Check valves are required in the piping system at any point where backflow of gas after a shutdown has the ability to restart the compressor, running it backwards or, for that matter, even in the normal direction. Reverse rotation is totally bad, as many components of the various compressor types are not designed for reverse rotation, and there is some possibility, generally remote, that the compressor could reach a destructive over speed. Forward rotation is bad primarily because the intent was to stop the compressor, and it is now operating out of control. This is a problem, particularly if the shutdown was caused by a compressor failure indication, and the need to stop was to prevent further damage. In this mode, it is unlikely that the compressor can attain an overspeed condition. An application with a high potential for backflow is the parallel operation of two or more compressors.  [c.472]

The flow process in an injection mould is complicated by the fact that the mould cavity walls are below the freezing point of the polymer melt. In these circumstances the technologist is generally more concerned with the ability to fill the cavity rather than with the magnitude of the melt viscosity. In one analysis made of the injection moulding situation, Barrie showed that it was possible to calculate a mouldability index (p.) for a melt which was a function of the flow parameters K and the thermal diffusivity and the relevant processing temperatures (melt temperature and mould temperature) but which was independent of the geometry of the cavity and the flow pattern within the cavity.  [c.170]

It was pointed out in Chapters 3 and 4 that rubbers are substantially amorphous polymers with glass transition temperatures below their service temperature. The greatest degree of elasticity is obtained with highly flexible segments, generally low intermolecular forces and little or no crystallinity. In order to reduce creep and high compression set it is usual to lightly cross-link the polymers. For high tensile strength, tear resistance and abrasion resistance the above requirements for high elasticity and resilience may require some modification in particular, some ability to crystallise is often desirable.  [c.784]

Beside their excellent heat resistance, very good electrical insulation characteristics, good hydrolytic stability and generally good physical properties, the polyimides have the added attraction that soluble, fusible intermediates are available, which makes fabrication flexible although in some cases far from simple. This is an important factor because it should be remembered that one of the important characteristics of plastics is their ability to be formed at low temperature. Where ease of shaping is absent it may well be that metals, ceramics or glasses would be preferred to polymers. There is in fact a developing teehnology involving the production of putty-like materials based on some inorganic particle material such as glass beads, silicone nitride and so on, blended with small quantities of some low and often-plasticised polymer. After shaping of the product the plasticised polymer is removed by thermal decomposition and volatilisation and the residue particles subjeeted to high-temperature sintering.  [c.851]

As with any new technology, the ability to successfully employ such agents is dependent on a thorough understanding of their appropriate use as well as experience with the materials. In fact, a significant learning curve exists with these agents. The surgical specialty is predicated on an apprenticeship process which facilitates the development of increasing levels of skill and knowledge over a period of years characterized by increasing graded responsibilities. This practical experience has evolved and developed to train the best qualified individuals as surgeons. During this process the physician learns clinical judgement as well as how to cut, sew, and perform a wide variety of different operations. Up to the present time, however, the use of tissue adhesives and hemostats has not been an element of this practical educational process. In fact, during residency training, young surgeons have had some experience with a variety of different hemostatic agents other than the newly evolving agents. It is not generally accepted that skill in the use of these hemostatic agents is required. Rather it is assumed to be a simple intervention that can be easily done to stop bleeding. Thus many surgeons are under the misunderstanding that these newer agents do not require significant learning and experience for successful use. This could not be further from the truth, as the new agents do require skill in application for efficacious results. Improved technical understanding of the use of these materials significantly enhances their efficacy.  [c.1108]

Carbon not only eombines covalently with other non-metals, but also with itself. Oxygen also reaets with itself to form O2, hydrogen reaets with itself to form Hj, nitrogen reacts with itself to form Nj, fluorine reacts with itself to form Fj, and ehlorine reaets with itself to form Cl 2. Forming diatomie moleeules, however, is the extent of the self-reaetion of the elemental gases, while earbon has the ability to combine with itself almost indefinitely. Although the elemental gases form molecules when they combine with themselves, the carbon-to-carbon combination must include another element or elements, generally hydrogen. This combination of carbon with itself (plus hydrogen) forms a larger molecule with every carbon atom that is added to the ehain. When the chain is strictly carbon-to-carbon with no branching, the resulting hydrocarbon is referred to as a straight-chain hydrocarbon. Where there are earbon atoms joined to earbon atoms to form side branches off the straight chain, the resulting eompound is known as a branched hydrocarbon, or an isomer.  [c.181]

Over the years, many improvements have been made to the catalytic cracking process. Basically, the total development of process and mechanical improvements in catalytic cracking since its inception can be divided into two time periods pre-zeolitic catalyst introduction and post-zeolitic catalyst introduction. In the period from the early 40 s to the early 60 s, there were some improvements made in catalyst quality, but in general these catalyst changes did not dictate mechanical and operational changes in the basic units. Rather, significant improvements were made in unit service factor and flexibility. One of the most important advances came from the ability to crack heavy feeds. Original moving bed units cracked only light feeds that were completely vaporized. The new fluid units could handle both vapor and liquid feeds of high boiling points. Final cut points are now generally held to about 1050°F to avoid metals contamination of the catalyst. Many engineering improvements were made, reducing investments, improving run lengths and service factors, and lowering operating costs. The use of CO boilers to recover heat from the CO content and sensible heat in regenerator flue gases was another important step in  [c.24]

From a practical standpoint, a net designer is just as interested in a net s generalization ability as he is about a net s innate pattern capacity. Generalization is the ability to recognize correct relationships in sets of facts that were not part of the originEil training set. Intuitively, we can expect there to be some kind of trade-off. On the one hand, we obviously do not want a net to be able to store given associations perfectly but completely unable to find similar patterns in new data. A look up table approach would probably make a better choice in this case. On the other hand, we should not expect a net to develop an ability to generalize unless it has seen a sufficient number of patterns that it can learn to generalize from. In this case, we may be have to be satisfied with a less than saturated capacity. Indeed, one can show that for good generalization, the training set should be severEil times larger than the net s expected capacity [baum89].  [c.551]

One common reason for imposing constraints results from areas of integrity A process is often normally designed to have logically identifiable sections or areas. An example might be reaction area and separation area of the process. These areas are kept separate for reasons such as start-up, shutdown, operational fiexibility, safety, etc. The areas are often made operationally independent through the use of intermediate storage of process materials between the areas. Such independent areas are generally described as areas of integrity and impose constraints on the ability to transfer heat. Clearly, to maintain operational indepedence, two areas cannot be dependent on each other for heating and cooling by recovery.  [c.181]

Generally, a contact line traversing a heterogeneous surface will become pinned to the patches, producing a lower contact angle (for a review of the theories of pinning, see Ref. 55). There are energy barriers to surpass as the contact line moves across these pinning points. The ability to cross these energy barriers and hence the magnitude of the contact angle hysteresis is very sensitive to ambient vibrations [56, 57], hence the variability in the literature. As a test of the forces pinning the contact line to heterogeneities, Nadkami and Garoff [58] measured the distortion of a contact line traversing a single 20-100-/im defect produced by melting a polymethylmethacrylate (6 = 90°) particle on a polystyrene (9 = 83°) surface. The contact line on a vertical Wilhelmy plate follows  [c.357]

In typical experiments, the laser fluence, or the energy per unit area, is limited to the sample s damage tlueshold. This generally lies in the range J and constrains our ability to increase signal strength by increasing the pump energy. Frequently, the use of femtosecond pulses is advantageous, as one may obtain a higher intensity (and, hence, higher nonlinear conversion efSciency) at lower fluence. In addition, such sources generally penult one to employ lower average intensity, which reduces average heating of the sample and other undesired effects [59]. Independently of these considerations, femtosecond lasers are, of course, also attractive for the possibilities that they offer for measurements of ultrafast dynamics.  [c.1281]

The machine learning process usually begins with the selection of a data set, which is then divided into two subsets a training set which is used to train the system and a test set which provides a means to evaluate the results. Machine learning is done by training. The machine learning system uses a training set and tries to learn from these examples. Afterwards the quality of learning is estimated by appraising the ability of the system to predict the outputs from a test set. The cap-abihty to predict an output is called generali2ation. If the system just memorized the input data and did not successfully learn from them, it will not be able to generalize.  [c.441]

One of the most important characteristics of micelles is their ability to take up all kinds of substances. Binding of these compounds to micelles is generally driven by hydrophobic and electrostatic interactions. The dynamics of solubilisation into micelles are similar to those observed for entrance and exit of individual surfactant molecules. Their uptake into micelles is close to diffusion controlled, whereas the residence time depends on the sttucture of the molecule and the solubilisate, and is usually in the order of 10 to 10" seconds . Hence, these processes are fast on the NMR time scale.  [c.127]

Low allow steels are readily welded but less easily so than plain carbon steels. Alloying additions increase the hardenability of steel, defined as the ability to form the hard, britde, nonequilibtium-phase martensite upon fast cooling. Hydrogen, which can come from moisture in the welding consumables or grease on the base metal, can cause cracking in steel when martensite is present. As such, low alloy steels ate generally preheated to allow hydrogen diffusion out of the weld and to slow down the weld-metal cooling rate to avoid the formation of martensite. In some cases, it may be necessary to subject the welded joint to heat treatment after welding to reUeve residual stress and to temper any martensite that may have formed. AH of the welding processes previously mentioned may be used for low alloy steels. The filler metal is usually also low alloy steel.  [c.347]

Various additives can impart desired handling and performance properties. Sodium bicarbonate used with sodium silicate grouts produces low strength semipermanent grouts to stabilize formations during constmction projects. Portland cement is used as a reactant with sodium silicate grouts to obtain short gel times, useful to stop flowing water and seal grouting cavities. Silicate-based grouts containing added Portland cement cannot be injected into medium sands or finer soils. Addition of particulates to grouts generally reduces their ability to penetrate finely divided formations. Several patents describe the use of organic grouting systems in combination with silicate-based grouts.  [c.227]

Most equipment for this service is some adaptation of a materialhandling device whether or not the transport ability is desired. The old vertical tube and the vertical shell (fluidizer) are exceptions. Mate-rial-handling problems, plant transport needs, power, and maintenance are prime considerations in equipment selection and frequently overshadow heat-transfer and capital-cost considerations. Material handling is generally the most important aspect. Material-handling characteristics of the divided solids may vary during heat processing. The body changes are usually important in drying, occasionally significant for heating, and only on occasion important for cooling. The ability to minimize effects of changes is a major consideration in equipment selection. Dehydration operations are better performed on contactive apparatus (see Sec. 12) that provides air to cany off released water vapor before a semiliquid form develops.  [c.1092]

The purification of proteins to oe used for therapeutic purposes presents more than just the technical problems associated with the separation process. Owing to the complex nature and intricate three-dimension structure, the routine determination of protein struc ture as a quahty-control tool, particiilarly in its final medium for use, is not well established. In addition, the complex nature of the human immune system allows for even minor quantities of impurities and contaminants to be biologically ac tive. Thus, regulation of biologies produc tion has resulted in the concept of the process defining the produc t since even small and inadvertent changes in the process may affect the safety and efficacy of the product. Indeed, it is generally acknowledged that even trace amounts of contaminants introduced from other processes, or contaminants resulting from improper equipment cleaning can compromise the product. From a regiilatoiy perspec tive, then, operations should be chosen for more than just efficiency. The consistency of the unit operation, particularly in the face of potentially variable feed from the culture/fermentation process, is the cornerstone of the process definition. Operations that lack robustness or are subject to significant variation sTould not be considered. Another aspect of process definition is the ability to quantify the operation s performance. Finally, the ease with which the equipment can be cleaned in a verifiable manner should play a role in unit-operation selection.  [c.2057]

The steroid hormones are metabolically derived from cholesterol, and are biologically stable, lipophilic chemicals which are active at low concentrations. Many steroid hormones exist, and are generally named after their principal organ of origin or their main biological function. Because of the complexity and evolutionary history of the endocrine system, these hormones may serve several functions within different tissues of an organism. For example, the sex hormones are primarily produced by the gonads, and comprise the androgens (male hormones) and oestrogens (female hormones). These chemicals have vital roles in the control of reproductive functions such as sperm or ova development, and the development and maintenance of secondary sexual characteristics. During development, the balance of these hormones also plays a key role in the formation and functioning of sexually dimorphic parts of the brain (with consequent implications for sexual behaviour) and in the development of a sexually dimorphic immune system. The glucocorticoid hormones, such as cortisol, are produced by the adrenal glands. In addition to their principal effects on metabolism, they influence the immune and reproductive systems." Less well known is thymulin, a polypeptide hormone found mainly in the cortex and medulla of the thymus and thought to be involved in the education and maturation of the immune system s T-cells. Interference with the production of this hormone seriously compromises the thymus s ability to produce mature T-cells. Trace amounts of thymulin have also been detected in the gonads, and this hormone appears to play a role in gonadogenesis and the embryonic development of oocytes. There are thought to be feedback mechanisms linking thymulin to testosterone, oestrogen, cortisol and thyroid hormone metabolism.  [c.63]

Although it is generally mre that the catalyst is not affected physically by the catalysed reaction, in many instances it is probable tlrat the catalyst supplies electrons during the course of the reaction to the reacting molecules thus enhancing the bond exchanges. In tire case of hydrocarbon adsorbates there is evidence tlrat dehydrogenation occurs as a result of dre interaction between the catalyst and the adsorbate, and oxidation of non-stoichiometric oxide catalysts occurs in some reactions involving oxygen and oxygen-containing gases. The ability to supply elecuons is why metals form a large part of catalytic materials, and a number of oxide catalyst are more active when tire positive hole concentration is high, leading to semi-conductivity. In some catalysts, nickel for example, iron-metallic elements such as hydrogen, oxygen and carbon are soluble to a limited extent, and this solution provides a means to U airsport the interstitial atoms from one site, drrough the catalyst, to anotlrer site.  [c.119]

The force fields used in atomistic membrane simulations have the same form as the analytical, empirical molecular mechanics potentials used in classical simulations of proteins and nucleic acids (see Chapter 2). These potential functions contain hannonic terms for deforming bonds and bond angles, periodic and harmonic potentials for torsions, and van der Waals and Coulomb nonbonded interactions. The atomic charges are often obtained from quanmm chemical calculations on lipid fragments. Most of the other potential parameters are taken from existing force fields for proteins and nucleic acids, which are generally built up from parametrizations of model compounds. Details on biomolecular force field parametrization are given in Refs. 40 and 41, and in Chapter 2. The quality of lipid force fields may be evaluated with simulations of crystals of lipid fragments [40,42,43] and by checking their ability to reproduce well-established experimental results in simulations of hydrated lipid bilayers (see Section III.A). The level of accuracy that we have been able to achieve is typified by the densities of phospholipid and cholesterol crystals from constant-pressure MD simulations with fully flexible unit cells, plotted in Figure 3 versus the experimental values.  [c.468]

All viruses depend for their existence on their ability to infect cells, causing them to make more virus particles. The infected cells generally die in the process. Even though the infection cycles of different types of viruses vary in detail, they all follow the same basic pattern. First, the viruses deliver their nucleic acid genome into the host cell, often in association with viral proteins the mechanism of delivery varies depending on the virus, but the end result is the same. Second, the host cell s biosynthetic machinery is subverted for the replication, transcription, and translation of the viral genes at the expense of cellular gene expression. Finally, progeny virus particles assemble in the infected cell and by one route or another leave it to infect a fresh host cell. Individual viruses can only infect a restricted range of hosts, and the host organisms usually have defense mechanisms, ranging from restriction enzymes in bacteria to the immune system of vertebrates. The combination of restricted host ranges and host defense mechanisms keeps in check the extent of viral infections.  [c.325]

As with any analytical method, the ability to extract semiquantitative or quantitative information is the ultimate challenge. Generally, static SIMS is not used in this mode, but one application where static SIMS has been used successfully to provide quantitative data is in the accurate determination of the coverage of fluropolymer lubricants. These compounds provide the lubrication for Winchester-type hard disks and are direaly related to ultimate performance. If the lubricant is either too thick or too thin, catastrophic head crashes can occur.  [c.555]

Filters are an additional water treatment option, opten used with chemical treatment. A 100 ton cooling tower processes about 40 tons of air in an eight hour period retaining all the air borne debris in the tower water. Ideally, this debris would stay in suspension and be removed by the bleed but a good portion typically manages to settle in the tower basin and on heat exchange surfaces. Such debris tends to reduce the effectiveness of water treatment chemicals. Full flow filtration is generally limited to devices that operate with low pressure drop and those that have an ability to purge debris while in operation. Strainers that swing into the flow stream while others backwash and centrifugal separators can be used full flow. Another option is a centrifugal separator, which directs the water flow tangentially into a cylinder causing the water to rotate.  [c.88]

Activated Carbon versus Molecular Sieves The process of activation using activated carbon can be described as slow dehydration and carbonization, usually effected by heating the raw material in the absence of air. Experimental work has shown that activation of carbon can only occur on chars that have been made at temperatures below 600 to 700 °C. The activation process selectively enlarges the pores of the carbon to provide high adsorptive capacity. The surface of activated carbon presents a largely homogeneous distribution of electrical charge. For this reason, activated carbon does not show any preferential adsorption of polar molecules such as water, but rather will desorb polar materials in favor of nonpolar or materials of higher molecular weight. Thus, a nonpolar solvent would be preferentially adsorbed in a water- solvent mixture. Because there are many types and grades of activated carbon available commercially, it has become necessary to establish specifications to obtain the proper carbon. The activity and retentivity of the carbon are generally based on their ability to adsorb a standard CCI4 solvent. A typical set of carbon specifications is shown in Table 2. Zeolites are crystalline aluminosilicate minerals. A zeolite is an alummosilicate with a framework structure endorsing cavities occupied by large ions and water molecules, both of which have considerable freedom of movement, permitting ion exchange and reversible dehydration.  [c.295]

See pages that mention the term Ability to Generalize : [c.1]    [c.551]    [c.552]    [c.253]    [c.2482]    [c.2501]    [c.2698]    [c.332]    [c.519]    [c.91]    [c.453]    [c.304]    [c.142]    [c.576]    [c.40]   
See chapters in:

Cellular automata  -> Ability to Generalize