Aaberg canopy

Grossmann, I. E., Mixed Integer Programming Approach for the Synthesis of Integrated Process Flowsheets, Camp. Chem. Eng., 9 463, 1985.  [c.14]

Davis, M. E., McCammon, J. A. Dielectric boundary smoothing in finite difference solutions of the poisson equation An approach to improve accuracy and convergence. J. Comp. Chem. 12 (1991) 909-912.  [c.195]

Technically Specified Grades. The introduction of the Standard Malaysian Rubber (SMR) scheme in 1965 marked a turning point in the whole approach of production and marketing of natural mbber. The scheme was so successful that it led to the adoption of an international scheme for Technically Specified Rubber (TSR). These schemes led to fewer grades, all with guaranteed specifications relating to quaUty, packed in small, polyethylene-wrapped 33.3-kg bales for easy transport, storage, and factory handling. Faster drying processes for cmmb mbber improved the efficiency of producing factories, and the technical specifications gave consumers a guarantee of quaUty that had not been previously available for the conventional grades.  [c.266]

This approach to Hquid waste treatment requires synergy between different process stages or between various industries (industrial ecology). Suitably matched soHd adsorbents and waste Hquids must be available so that selective wetting and agglomeration take place. Combinations of acceptable feed streams are specific to a given industry or geographic location, but some examples are obvious, such as the emulsions from oil production operations scavenged by thermal coal, eg, in Alberta, Canada oily sludges from coking/steelmaking operations treated by coal or coke in chemical/petrochemical complexes, reject or off-spec solvents and other oily wastes treated by soHd wastes such as mbber cmmb or shredded plastics and purification of oily wastewater by soot peUetization in an oil gasification plant, used commercially by SheU (95).  [c.123]

Field-flow fractionation (FFF) is a set of high resolution liquid chromatography-like elution methods used for sizing and sepai ation of a wide range of particulate, colloidal and macromoleculai materials. Recently the authors have shown that rotating coiled columns (RCC) traditionally applied to separation of different solutes by countercurrent chromatography can be used in FFF methods. A column of a certain configuration rotates ai ound its axis and simultaneously revolves ai ound the central axis of the planetary centrifuge. The asymmetrical centrifugal force field, acting on the RCC, provides different migration speeds of particles in one carrier fluid. As compai ed to the conventional sedimentation FFF (the sepai ation is performed in a one narrow channel) the restriction for particle mass in the sample is avoided in RCC because column volume can be varied through varying the number of turns and layers of the coil. Planetary centrifuge design par ameters have a great influence on the fractionation process this can be used for optimization of separ ation conditions. It has been shown, that fractionation of suspended sample components can be achieved mainly by successive changing fluid pumping rate at a constant value of column rotation speed. The behavior of particles in RCC was studied by the examples of latex, silica gels and natural quartz sand particles of irregular shape. A theoretical model, describing the separ ation process according to design, operation par ameters of RCC, and properties of particles has been proposed. On the basis of experimentally studied dependences of fractionation and retention of different particles and theoretical model, optimal conditions of soil samples separ ation into sill, clay and sand fractions have been selected. RCC can be also applied to the dynamic fractionation of trace elements in each fraction that may help to obtain detailed information about distribution of toxic elements in environmental samples. It may be concluded that the use of RCC for studies on the mobility of heavy metals in soils and sediments provides the basis for a new comprehensive approach to the speciation analysis of environmental samples.  [c.445]

Perhaps the most popular example of 3D QSAR is CoMFA. Developed by Cramer et al. [5], CoMFA elegantly combines the power of molecular graphics and partial least squares (PLS) technique and has found wide applications in medicinal chemistry and toxicity analysis (see Ref. 38 for several excellent reviews). This method is one of the most recent developments in the area of ligand-based receptor modeling. This approach combines traditional QSAR analysis and tliree-dimensional ligand alignment central to AAA into a powerful 3D QSAR tool. CoMFA correlates 3D electrostatic and van der Waals fields around sample ligands typically overlapped in their pharmacophoric conformations with their biological activity. This approach has been successfully applied to many classes of ligands [38].  [c.359]

COLOR BLIND TOLERANCE. Control system and other displays should be designed to transmit information to personnel who are color blind. Up to 5% of some male populations are red-green color blind (Freeman, 1996). If the color red is used for stop (or, closed) and green is used for go (or open), an alternate scheme should be used to transmit the same information. One approach for video displays is to design the red symbols with a red outline and black (unfilled) interior and to design the green symbols with a green outline and green (filled) interior (see Figure 6.2). Intensity (brightness) can also be used to convey some status information. Switches and indicator lights should be oriented consistently for example, the start button should have the same position with respect to the off button. There are alternate color schemes that can be seen by most people with red-green color blindness—some examples are white, black, gray, blue, and yellow. Colored lines on a flowsheet can also be coded with dashes, dots, and crosses (this method also retains the information in a photocopy).  [c.107]

The study is performed for a representative section of the hall. A network model was established for COMB, considering doors, openings ar floor level, and rhe large openable ventilation hoods on the roof. Relationships are established for the air-exchange rate as a function of the temperature difference be tween inside and outside for different opening configurations. The effect of a temperature gradient in the hall is evaluated additionally. As a conservative approach, wind effects are neglected.  [c.1099]

The problem with this approach is that the term supporting documentation fails to convey what might be included. In many cases the supporting documentation has been limited to the work instructions but in reality there are many different types of documents that are needed to produce quality products (see Part 2 Chapter 5).  [c.161]

Some petroleum geologists believe that there may be more methane trapped in hydrates than what is associated with natural gas reserves. However, as an energy source, there is considerable uncertainty whether this methane can ever be recovered safely, economically, and with minimal environmental impact. The Russians have experimented with the use of antifreeze to break down hydrates at some onshore locations in Siberia. But perhaps a more promising approach would be to pipe warm surface water to the bottom to melt the hydrates, with a collector positioned to convey the gas to the surface. Another approach might be to free methane by somehow reducing the pressure on the methane hydrates.  [c.795]

Camp P J, Mason C P, Allen M P, Khare A A and Kofke D A 1996 The isotropic-nematic transition in uniaxial hard ellipsoid fluids coexistence data and the approach to the Onsager limit J. Chem. Phys. 105 2837-49  [c.2284]

Anotlier model system consists of polymetliylmetliacrylate (PMMA) latex, stabilized in organic solvents by a comb polymer, consisting of a PMMA backbone witli poly-12-hydroxystearic acid (PHSA) chains attached to it [10]. The PHSA chains fonn a steric stabilization layer at tire surface (see section C2.6.4). Such particles can approach tire hard-sphere model very well [111.  [c.2670]

Amdahl, G. M. Validity of the single processor approach to achieve large scale computing capabilities. In Proc. AFIPS spring computer conf. vol. 30. AFIPS Press, Reston, Virginia, 1967.  [c.481]

Historically, QSAR has been appHed primarily to dmg molecules however, more recently. Quantitative Stmcture—Property (Toxicology) Relationships (QSP (T) R) have been elaborated by a number of researchers (117). Regardless of the context of appHcation, QSAR has its roots in the use of Linear Free Energy Relationship (LEER) methods of deriving an equation which correlates the observed effect and the stmctural features responsible for the activity. The work of Hansch in relating hydrophobicity to biological activity is exemplary as a pioneering appHcation of LEER in QSAR (118). It is interesting to note, however, that many of the early investigations in QSAR involved analysis of the relationship of hydrophobicity to activity, the nature of which relationship is more often paraboHc rather than linear (119,120). QSARs are usually best derived from a series of compounds (typically differing only at one or two substitution points) for which the activities are weU-deterrnined by a stable biological assay. A QSAR table can be estabHshed wherein the columns are assigned to activities (thejys), and the metrics or properties (the xs which can be either observable properties such as log P, hplc retention times nmr chemical shifts computed values such as shape and size descriptors dipole moments atomic charges or conformational energies. Each row represents an individual compound or conformation. Statistical relationships can then be developed from this table by means of univariate or multivariate techniques such as linear or multiple linear regression (MLR), or partial least squares (PLS). If the statistical significance of the relationship is sufficiently high, then this relationship is robust enough to be used to predict or assess the activity of untested compounds. Usually the known data is divided into two groups, a training set and a test set to estabHsh the statistical model. As a rule of thumb, there should be between 3 and 10 times the number of observations (rows) as x-variables in order to derive a model which would have predictive power and be able to minimize chance correlations. Under these circumstances, there would be some constraints against pursuing QSARs if only a few observations (molecules for which activities or properties are known) are available. Often this is the case, yet investigators have proceeded with the development of the QSAR. A discussion of the use of Partial Least Squares (PLS) as a potential means of resolution for this difficult is treated herein in the context of the CoMFA paradigm. It should also be recognized that many more molecular conformations and property descriptors than ever before can now be computed. For example, in the QSAR and Diversity modules of the Cerius2 software from Molecular Simulations, Inc. (121), there are approximately 160 shape, size, and electrostatics descriptors which can be computed. This relative abundance is in sharp contrast to the small numbers of descriptors available to early investigators, who worked diligently with classical Hammett CJs and log P values to derive LFERs (122—125). A particularly lucid account of the Hansch Approach to appHcation of LFERs in QSAR which is illustrated with numerous examples is given by the Hansch coUaborator and speciaHst in QSAR, T. Fujita (126). An example of the classical linear equation is represented by equation 7  [c.168]

Prostaglandins. Various bioactive Hpids, especially the prostaglandins (qv) (PGs) and leukotrienes (LTs), the principal eicosanoid products of the arachidonic acid cascade, are radioprotective. Indeed, protection of hemopoietic tissue by eicosanoids can approach that achieved using WR-2721 (see Table 1) (214,215). Most attention has focused on the PGs, which are synthesized via the cyclooxygenase pathway and are among the most promising of the newer radioprotective agents for clinical use during cancer treatment (215). The mechanisms by which eicosanoids protect against radiation damage are obscured by their wide range of both pathological and normal physiological effects on tissues and animals. Protection by PGs is seen only when adrninistered prior to irradiation. WR-2721 protects in mg quantities, whereas PGs protect in p.g quantities. Thus the PGs are probably not direct protectors rather, they induce secondary changes within cells that lead to protection (215). Many eicosanoids are vasoactive and some are proinflammatory, although these effects may or may not be observed at radioprotective concentrations. Receptor-mediated mechanisms are clearly important, and many cell types in various tissues express eicosanoid receptors. Eicosanoid receptor expression may be regulated by cellular differentiation, which may in turn influence the location of protection within a tissue. For the E-series PGs, the GC receptor appears to be important (215). Loss of PG-induced protection in cultured cells appears to correlate with the loss of these PG receptors. Membrane effects may be involved in PG-induced protection (215). Whether or not hypoxia plays a significant role in eicosanoid radioprotection is a contentious issue (216,217). PGs may also increase intracellular cycHc adenosine monophosphate (cAMP) levels (218), although elevated cAMP alone does not lead to PG-induced radioprotection of bovine aortic endothehal cells (219). Some eicosanoids may act as free-radical scavengers.  [c.497]

Comparative Molecular Field Analysis Methods. Comparative molecular field analysis (CoMFA) (69,70) has been referred to as 3D-QSAR. CoMFA methodologies ate algorithms that relate the biological activities of a series of molecules to the steric (also known as van der Waals), and electrostatic energy fields calculated from their stmctural data. The CoMFA results are displayed three-dimension ally relative to the stmctures from which the energetics were originally calculated. As with QSAR, CoMFA has led to predictions of a molecule s biological activity after obtaining data from a series of stmcturaHy related compounds (71—73). For the CoMFA approach, a series of compounds that produces a specific biological response is identified, and three-dimensional stmctural models are constmcted. These stmctures are then superimposed upon one another and placed within a fixed lattice. A probe atom, with its own energetic values, is systematicaHy placed at each lattice poiat where it is used to calculate the steric and electrostatic potentials between itself and each of the superimposed stmctures. Again at each lattice poiat, these values ate stored along with each inhibitor s biological  [c.327]

Number Cross- Confi- Mini- — — Thick- Approx. Thick- Appro.x. all dia. sveighi length type weight d.c. resist- once per citance Direct In In air rating  [c.539]

The use of an acidic solution of p-anisaldehyde in ethanol to detect aldehyde functionalities on polystyrene polymer supports has been reported (beads are treated with a freshly made solution of p-anisaldehyde (2.55 mL), ethanol (88 mL), sulfuric acid (9 mL), acetic acid (1 mL) and heated at 110°C for 4 min). The colour of the beads depends on the percentage of CHO content such that at 0% of CHO groups, the beads are colourless, -50% CHO content, the beads appear red and at 98% CHO the beads appear burgundy [Vdzquez and Albericio Tetrahedron Lett 42 6691 200]]. A different approach utilises 4-amino-3-hydrazino-5-mercapto-1,2,4-triazole (Purpald) as the visualizing agent for CHO groups. Resins containing aldehyde functionalities turn dark brown to purple after a 5 min reaction followed by a 10 minute air oxidation [Coumoyer et al. J Comb Chem 4 120 2002].  [c.76]

Burchell, T.D., Judkins, R.R, Rogers, M.R. and Williams, A.M. A novel approach to the removal of COj. In Proc Tenth Annual Conf. On Fossil Energy Materials, ORNL/FMP-96/1, CONF-9605167, Oak Ridge National Lab, U.S A, 1996, pp. 135 148.  [c.202]

Rebenfeld, L., The research approach to fiber composites. Proc. Annu. Ind. Fabr. Assoc. Int. Conv., 74th, 13-21. Ind. Fabr Assoc. Int., St. Paul, MN, 1986.  [c.1037]

Umeda, T., Itoh, J., and Shiroko, K. (1979). A thermodynamic approach to the synthesis of heat integration systems in chemical processes. Comp. Chem. Eng. 3, 273-282.  [c.247]

A designer, in contrast to an analyst, has one responsibility, and that is to create a structure that meets the design requirements. In doing so, the designer must make certain that all the possible problem areas are either avoided, which is iike waiking around a mountain, or he must go ciimb the mountain and deal with each of those problems directly, i.e., take them into account. In order to use either approach, the designer must know quite a bit about the behavior of composite materials and structures. He must know the significance of each of those problem areas, so that he can recognize whether they are, or are not, important in his design. Unless the designer knows the essential behavioral characteristics of a composite material or structure, he cannot possibly design an adequate composite material or structure, but he can design a dangerous one very easily.  [c.463]

A designer, in contrast to an analyst, has one responsibility, and that is to create a structure that meets the design requirements. In doing so, the designer must make certain that all the possible problem areas are either avoided, which is iike waiking around a mountain, or he must go ciimb the mountain and deal with each of those problems directly, i.e., take them into account. In order to use either approach, the designer must know quite a bit about the behavior of composite materials and structures. He must know the significance of each of those problem areas, so that he can recognize whether they are, or are not, important in his design. Unless the designer knows the essential behavioral characteristics of a composite material or structure, he cannot possibly design an adequate composite material or structure, but he can design a dangerous one very easily.  [c.463]

See pages that mention the term Aaberg canopy : [c.726]    [c.1228]    [c.128]    [c.451]    [c.702]    [c.727]    [c.231]    [c.1747]    [c.2346]    [c.293]    [c.198]    [c.153]   
Industrial ventilation design guidebook (2001) -- [ c.849 , c.865 , c.866 , c.867 , c.868 , c.869 , c.870 , c.871 , c.872 , c.1276 , c.1279 , c.1419 ]