Saddle block

Three different specimens are considered here. Penetration depths range from 0.7 mm for aluminium to 0.15 mm for the steel block. For the experimental test frequencies used the electromagnetic skin depth is much smaller than the depth of the cracks for all the measurement considered.  [c.143]

The dual array was characterized through the Plexiglas wedge used for sensitivity measurements (see figure 3a). When no time delay is applied to the element, the acoustic beam is perpendicular the output and define the reference direction. The effect of steering at certain angle was evaluated separately and consistent with modelling. Note that the cross-section of the beam must be achieved in the far-field to yield accurate angle measurements. The focused beam characteristics were checked with steel block at 45°, in water using an hydrophone as shown in figure 3b.  [c.823]

When the surfaces of two solid bodies are in contact a certain amount of force must be applied to one of them if relative motion is to occur. Taking a simple example, if a dry steel block is resting on a dry steel surface, relative sliding motion will not start until a force approximately equal to one fifth the weight of the steel block is applied. In general, the static friction between any two surfaces of similar materials is of this magnitude, and is expressed as a coefficient of friction of 0.2. As soon as the initial resistance is overcome, a very much smaller force will keep the slider moving at uniform velocity. This second frictional condition is called dynamic friction. In every bearing or sliding surface, in every type of machine, these two coefficients are of vital importance. Static friction sets the force required to start the machine and dynamic friction absorbs power that must be paid for in terms of fuel consumed. Also, friction resistance of non-lubricated surfaces causes heating, rapid wear and even, under severe conditions, actual welding together of the two surfaces.  [c.844]

The blowout preventers are a series of powerful sealing elements designed to close off the annular space between the pipe and the hole through which the mud normally returns to the surface. By closing off this route, the well can be shut in and the mud and/or formation fluids are forced to flow through a controllable choke, or adjustable valve. This choke allows the drilling crew to control the pressure that reaches the surface and to follow the necessary steps for killing the well, i.e. restoring a balanced system. Fig. 3.12 shows a schematic of a typical set of blowout preventers. The annular preventer has a rubber sealing element that is hydraulically inflated to fit tightly around any size of pipe in the hole. Ram type preventers either grip the pipe with rubber lined steel pipe rams, block the hole with blind rams when no pipe is in place, or cut the pipe with powerful hydraulic shear rams to seal off the hole.  [c.40]

The technique presented above has been extensively evaluated experimentally using ultrasonic data acquired from a test block made of cast stainless steel with cotirse material structure. Here we briefly present selected results obtained using two pressure wave transducers, with refraction angles of 45° and 0°. The -lOdB frequency ranges of the transducers were 1.4-2.8 MHz and 0.7-1.4 MHz, respectively. The ultrasonic response signals were sampled at a rate of 40 MHz, with a resolution of 8 bits, prior to computer processing.  [c.92]

In the first case, the ultrasonic signal is disturbed by a low frequency component due to thermal phenomenon which prevents from the visualization of elastic waves (Fig. 5.a). Nevertheless, this configuration is interesting because of its analogy with the emission-reception configuration of focused transducers. Thus, to reduce the thermal phenomenon, we introduce an analogical high-pass filter (Fig. 5.b). Some oscillations still appear at the beginning of the signal (ultrasonic signal ten times shorter than in figure 5.a), able to disturb the detection of a lack of weld penetration according to the sample thickness and the material propagation velocities. A solution to completely eliminate the thermal component is to separate the pump and the probe beams. In this case, the Rayleigh wave added to the bulk waves is also generated and detected. The arrival time of this surface wave depends on the distance separating the two laser beams and on the material velocities. By considering the specific directivity patterns of the ultrasonic waves, the shifting distance has also to be adjusted to promote either the longitudinal or the shear wave generation. The interaction between the generation laser beam and the cylindrical surface involves that the spatial distribution of the source is ehosen circular more than linear for a better ineident energy distribution. So, the directivity pattern of the shear wave and the energy reflection coefficients in the far field allow to determine the optimal incident angle to obtain a total reflection of the shear wave. For gold-nickel alloy, this angle is around 24° (vl=3575 m/s et v-r=1430 m/s), while for tantalum, it is around 29° (vl=4170 m/s et Vx=2050 m/s). Thus, the distance separating the generation and the detection is equal to 2.2 mm for both.  [c.696]

The scan area" field which is white at the start of scanning is painted black during the test so that the inspector will immediately see which areas still remain to be tested. The zone has not been 100% scanned until the entire field is black. If the probe movement is too fast, or if there is no coupling, or if the probe is rotated at too large an angle, there is no change in the color this means that the corresponding zone has not been properly scanned.  [c.780]

DGS and Reference Block Methods - Are They Still Competitors  [c.812]

An interesting question that arises is what happens when a thick adsorbed film (such as reported at for various liquids on glass [144] and for water on pyrolytic carbon [135]) is layered over with bulk liquid. That is, if the solid is immersed in the liquid adsorbate, is the same distinct and relatively thick interfacial film still present, forming some kind of discontinuity or interface with bulk liquid, or is there now a smooth gradation in properties from the surface to the bulk region This type of question seems not to have been studied, although the answer should be of importance in fluid flow problems and in formulating better models for adsorption phenomena from solution (see Section XI-1).  [c.378]

For model A, the interfaces decouple from the bulk dynamics and their motion is driven entirely by the local curvature, and the surface tension plays only a background, but still an important, role. From this model A  [c.745]

The momentum-selected ion beam passes through the field-free region (FFR) of the instrument on its way to the electrostatic sector. The FFR is the main experimental region of the magnetic sector mass spectrometer. Significant features of tire FFR can be collision cells and ion beam deflection electrodes. One particular arrangement is shown in figure Bl.7.4. A collision cell consists of a 2-3 cm long block of steel with a groove to pass the ion beam. A collision (target) gas can be introduced into the groove, prompting projectile-target gas collisions. The beam deflecting electrode assembly allows the ion beam to be deflected out of the beam path by the application of a potential difference across the assembly (see section (Bl.7.3.2)).  [c.1334]

Another recent development in the use of Raman spectroscopy for the characterization of surfaces has been the employment of UV light for the initial excitation of the sample [54]. The advantage of UV over conventional Raman spectroscopy is twofold (1) since the nomial Raman scattering cross sections are proportional to the fourth power of the scattered light frequency, the use of higher-energy photons significantly increases the signal intensity and (2) by using UV light the spectral range is moved away from that where fluorescence de-excitation is observed. This allows for the Raman characterization of virtually any high-surface-area sample, including opaque solids such as black carbon. Unfortunately, UV-Raman spectroscopy is still not conunercially available.  [c.1788]

It may seem curious that Knudsen diffusion coefficients still appear in equations (5.18) and (5.19), which supposedly give the flux relations at the limit of bulk diffusion control. However, inspection reveals that only ratios of these coefficients are effectively present, and from equation (2,11) it follows that  [c.41]

Then add too ml. of water, shake well to extract excess of acid, and allow the black oily drops to settle. Then decant the clear reddish-brown aqueous solution from the heavy black residual oil this can readily be done if the nitration mixture has been set aside overnight, as the oily drops then rapidly sink and collect at the bottom of the aqueous layer, but if the mixture has been allowed to stand for only 2 hours, care must be taken that any oily drops still floating on the surface of the solution are not poured away with the aqueous solution. Now add 200 ml. of water, repeat the shaking, when the heavy oil will become semi-solid and the aqueous layer can readily be poured off. Add 300 ml. of water to the residue in the flask, fit the latter with the steam-distillation inlet and outlet tubes, and assemble the complete apparatus for steam-distillation (Fig. 15, p. 33), using a single-surface glass-jacketed condenser of wide bore. Steam-distil the mixture until about 250 ml. of distillate have been collected, the receiver being meanwhile cooled in ice-water. The o-nitrophenol readily passes over in the steam and crystallises in the cold distillate. If the nitrophenol crystallises in the condenser, run out the condenser-water for a few moments the nitrophenol will then soon melt and pass on into the distillate. When the distillation is complete i.e,y when a few ml. of the distillate collected in a test-tube give no cry stalline deposit on thorough cooling), cool the distillate in ice-water for a further few minutes to ensure complete solidification of the >-nitrophenol, and then filter the  [c.171]

Weigh out 8 g. of phenol into a dry 750 ml. flat-bottomed flask, add 10 ml. (18-5 g.) of concentrated sulphuric acid, and shake the mixture, which becomes warm. Now heat the flask on a briskly boiling water-bath for 30 minutes to complete the formation of the phenol-sulphonic acid, and then chill the flask thoroughly in an ice-water mixture. Place the flask on a wooden block (or on some similar non-conducting surface) in an efficient fume-cupboard, and without delay, /.e., whilst the phenol-sulphonic acid is still a cold viscous syrup, add 30 ml. of concentrated nitric acid and at once thoroughly mix the liquids by shaking for a few seconds. Then allow the mixture to stand undisturbed. Usually within one minute a vigorous (but harmless) reaction occurs, and red fumes pour out of the flask. When the action subsides, heat the flask on a boiling water-bath for hours, with occasional shaking. During this period the heavy oil, which is present at the beginning, ultimately forms a mass of crystals. When the heating is complete, add 100 ml. of cold water, mix well and then chill thoroughly in ice-water. Filter the yellow crystals at the pump, wash thoroughly with water to eliminate all inorganic acid and drain. Recrystallise from a mixture of i volume of ethanol and 2 volumes of water, about 90 ml. of the mixed solvent being required. Picric acid is obtained in pale yellow leaflets, m.p. 122 . Dry by pressing between sheets of drying-paper, or in a desiccator. Yield of recrystallised material.  [c.173]

Push one end of a length of 20 cm. of stout copper wire into a cork (this wUl serve as a holder) at the other end make two or three turns about a thin glass rod. Heat the coil in the outer mantle of a Bunsen dame until it ceases to impart any colour to the dame. Allow the wire to cool somewhat and, while still warm, dip the coil into a small portion of the substance to be tested and heat again in the non-luminous dame. If the compound contains a halogen element, a green or bluish-green dame will be observed (usually after the initial smoky dame has disappeared). Before using the wire for another compound, heat it until the material from the previous test has been destroyed and the dame is not coloured.  [c.290]

Using the optimised parameters, rf signals from fatigue cracks with depths ranging from 7 mm to 28 mm in 56 mm thick carbon steel specimen and machined notches with depths ranging from 8 mm to 16 mm (width 1mm) in 150 mm thick carbon steel block were recorded. It is very essential in TOED method to measure the time-of-flight precisely. The beam entry point was determined by the back wall echo arrival time. Further, by applying easily implementable analytic signal and cross-correlation methods the peak amplitude of the rf signal was detected and the time-of-flight was calculated precisely [II]. Figure 6 shows the experimentally obtained depths of various surface breaking defects in carbon steel specimens and their actual depths. Despite scatter, a clear linear relationship was observed with a correlation coefficient of 0.997, thus establishing the possibility of using diffracted SH waves for quantitative defect sizing.  [c.725]

Fig. 4a shows a characteristic narrow banded signal (860 kHz center frequency) from a flat steel surface (reference signal). A steel block was milled in a way that the distance of the upper and graved surface varied from 0 to about 1300 microns (Fig. 5). Moving the probe along the edge (see Fig. 5) about 30 signals have been acquired equidistantly (all 4 mm). Fig. 4b and 4c show two characteristic signals (position 6 and 12). The 30 measured signals have been preprocessed and deconvolved. Fig. 6 shows the evident correlation between measured TOF difference and signal position (depth of milled grave). Fig. 4a shows a characteristic narrow banded signal (860 kHz center frequency) from a flat steel surface (reference signal). A steel block was milled in a way that the distance of the upper and graved surface varied from 0 to about 1300 microns (Fig. 5). Moving the probe along the edge (see Fig. 5) about 30 signals have been acquired equidistantly (all 4 mm). Fig. 4b and 4c show two characteristic signals (position 6 and 12). The 30 measured signals have been preprocessed and deconvolved. Fig. 6 shows the evident correlation between measured TOF difference and signal position (depth of milled grave).
O. L. Laskin, C. M. Stahl-Bayliss, C. M. Kalman, and L. R. Rosecan, / Infect. Dis. 155, 323 (1987).  [c.316]

Calcium carbide for acetylene is mainly packed in returnable steel bulk containers ranging in capacity from 2.5—4.5 t, suitable for lift tmcks and unloa ding conveyors. The granular carbide is lightly oiled with a lubricating oil (see LUBRICATION AND LUBRICANTS), which decreases the rate of reaction when exposed to moist air and also reduces dust formation during handling.  [c.461]

Chromium dioxide. Cr02 (HjO plus O2 on Cr03 at high temperature). Black solid with the rutile structure forming chromates(IV) in solid stale reactions. Used in magnetic lap>es.  [c.99]

After the drilling has progressed for some time, a new piece of drill pipe will have to be added to the drill string (see below). Alternatively, the bit may need to be replaced or the drill string has to be removed for logging. In order to pull out of hole , hoisting equipment is required. On a rotary rig this consists of the hook which is connected to the travelling block. The latter is moved up and down via a steel cable block Und ) which is spooled through the crown blockon to a drum draw workd ). The draw works, fitted with a large brake, move the whole drill string up and down as needed. The derrick or mast provides the overall structural support to the operations described.  [c.38]

TRIFOU can model any isotropic material encountered in eddy current inspections such as ferromagnetic steel and aluminium. TRIFOU can model any type of probe with one or several coils, including those containing ferrite cores and shields. For the thin-skin regime modelling, basic rules are needed for accurate results. The ratio between the mapped mesh step and the penetration depth in the test block has to be small enough to ensure good precision in the results. But too many elements increase the calculation time and the memory space needed, so that a compromise has to be made. For the following calculations the ratio between mesh step and penetration depth is greater than 3. This hypothesis is to be validated.  [c.141]

When a block is inside, the entrance panel is closed and the inspection is ready to start. The inside of the stainless steel X-ray tubehead housing is clad in lead with an on/ofT shutter in front of a thin plastic X-ray window. The thin window is to ensure the IP 65 classification. The window is of plastic that is not affected by the cleaning agents. The on/off shutter is interlocked with the entrance and exit panels so X-rays can be kept on at all times without risk of radiation leakage or exposure of the frozen fish blocks prior to the actual inspection.  [c.591]

The use of air-bome ultrasound for the excitation and reception of surface or bulk waves introduces a number of problems. The acoustic impedance mismatch which exists at the transducer/air and the air/sample interfaces is the dominant factor to be overcome in this system. Typical values for these three media are about 35 MRayls for a piezo-ceramic (PZT) element and 45 MRayls for steel, compared with just 0.0004 MRayls for air. The transmission coefficient T for energy from a medium 1 into a medium 2 is given by  [c.840]

Returning to multilayer adsorption, the potential model appears to be fundamentally correct. It accounts for the empirical fact that systems at the same value of / rin P/F ) are in essentially corresponding states, and that the multilayer approaches bulk liquid in properties as P approaches F. However, the specific treatments must be regarded as still somewhat primitive. The various proposed functions for U r) can only be rather approximate. Even the general-appearing Eq. XVn-79 cannot be correct, since it does not allow for structural perturbations that make the film different from bulk liquid. Such perturbations should in general be present and must be present in the case of liquids that do not spread on the adsorbent (Section X-7). The last term of Eq. XVII-80, while reasonable, represents at best a semiempirical attempt to take structural perturbation into account.  [c.654]

Wlien F F all off-diagonal matrix elements between fiinctions of symmetry and F will vanish if (equation A1.4.87) is satisfied, and there will also be a block diagonalization of H (it will be necessary to rearrange the rows or colimnis of H, i.e., to rearrange the order of die iF , fiinctions, to obtain H in block diagonal fomi). However, now nonvanishing matrix elements occur in//that connect iF, functions of different synnnetry in G and as a result the eigenfiiiictioiis of //may not contain only fiinctions of one synnnetry type of G when F F the group G is not a synnnetry group of //and its eigenfLuictions Vj camiot be classified in G. However, the classification of the basis fiinctions i ) in G will still allow a simplification of the Hamiltonian matrix.  [c.161]

The three-dimensional synnnetry that is present in the bulk of a crystalline solid is abruptly lost at the surface. In order to minimize the surface energy, the themiodynamically stable surface atomic structures of many materials differ considerably from the structure of the bulk. These materials are still crystalline at the surface, in that one can define a two-dimensional surface unit cell parallel to the surface, but the atomic positions in the unit cell differ from those of the bulk structure. Such a change in the local structure at the surface is called a reconstruction.  [c.289]

The surface unit cell of a reconstructed surface is usually, but not necessarily, larger than the corresponding bulk-tenuiuated two-dimensional unit cell would be. The LEED pattern is therefore usually the first indication that a recoustnictiou exists. However, certain surfaces, such as GaAs(l 10), have a recoustnictiou with a surface unit cell that is still (1 x i). At the GaAs(l 10) surface, Ga atoms are moved inward perpendicular to the surface, while As atoms are moved outward.  [c.291]

For centrosynnnetric media the spatially local contribution to the second-order nonlinear response vanishes, as we have previously argued, providing the interface specificity of the method. This spatially local contribution, which arises in the quantum mechanical picture from the electric-dipole tenns, represents the dommant response of the medium. Flowever, if we consider the problem of probing interfaces closely, we recognize that we are comparing the nonlinear signal originating from an interfacial region of monolayer thickness with that of the bulk media. In the bulk media, the signal can build up over a thickness on the scale of the optical wavelength, as dictated by absorption and phase-matching considerations. Thus, a bulk nonlmear polarization that is much weaker than that of the dipole-allowed contribution present at the interface may still prove to be significant because of the larger volume contributing to the emission. Let us examine this point in a somewhat more quantitative fashion.  [c.1279]

Similarly to polymer mixtures, block copolymers can fonn an homogeneous phase but also separate into phases of different compositions. However, tire presence of covalent bonds between tire different blocks has important consequences on tire stmctural arrangement after phase separation. Each of tire different types of monomer segregate and almost pure domains are fonned, but tire domains have mesoscopic dimensions corresponding to tire sizes of tire blocks. Furtliennore, since tire block lengtlis usually have unifonn sizes, tire arrangement of tire different domains are ordered. In tire case of di-block copolymers the type of order depends on tire ratio of tire degree of polymerizations of block A and block B (figure C2.1.11). Tri- and multi-block binary systems exlribit qualitatively tire same phase behaviour as di-block polymers. Changes occur for ternary systems. Their stmctures still exlribit periodic order, but tire lattices are more complex [301.  [c.2526]

Although chemical data analysis has become highly automated through the development of computer-aided methods and applications, an effective extraction of new knowledge and information still requires intervention and interaction through the scientist. Especially in the case of complex problems, a successfiil solution is only warranted if human intuition, flexibility, creativity, and expert knowledge are included in the decision process. However, classical, computer-aided data mining methods are usually so-called "black box systems that only allow a very limited or no interposition through the scientist. Furthermore, these approaches often require expert knowledge.  [c.475]

You can study the lowest excited singlet stale of a system with a closed-shell ground stale. ITi c. difference in energy belwceu this stale and the singlet ground state is related to the lowest electron ic absorption frequency. Here, th e calcu lation is carried out for the half-eleclron triplet stale. The final energy is computed using the appropriate singlet wave function (which involves Uvo detenu i-Tian Is) for th is sin gly excited state.  [c.47]

The digestion mixture is allowed to cool in the Kjeldhal flask and then diluted with 10 ml. of distilled water. It is then carefully poured into the funnel G (Fig. 88), the last drop on the lip of the flask being washed off with a few drops of distilled water from a wash-bottle. The tap T3 is then carefully opened and the acid solution allowed to run down into the bulb F. A small quantity of the solution is prevented from flowing through T3 by closing the tap this is to prevent the possibility of any of the ammonia, liberated when the acid ammonium sulphate solution is run into an excess of alkali, from escaping through T3 and thus introducing a large error into the determination. The flask L is now carefully washed out with 5 ml. of distilled water from a wash-bottle and the washings transferred to the funnel G. The washings are run into the bulb F by opening the tap T3, but again a small liquid seal is left in G by closing T3 before all the liquid has passed through. This washing is repeated twice more each time a small liquid seal being left in the funnel G. Finally, the walls of the funnel are washed with 5 ml. of distilled water and the wash allowed to flow through T3 into the bulb F a small liquid seal is still left at T3 above the closed tap. The liquid in the bulb will now be black owing to the precipitation of mercury sulphide by the interaction of the sodium sulphide solution and the mercuric sulphate of the catalyst mixture— this prevents the possible formation of any mercury-ammonia complexes that might prevent the quantitative distillation of the latter.  [c.495]

Place 10 g. of phenol in a dry 750 ml. or 1 htre flat-bottomed flask and add 23 g. (12-5 ml.) of concentrated sulphuric acid, shake the mixture (which becomes warm) and heat it on a boihng water bath for 30 minutes to complete the formation of the o-and p-phenolsulphonic acids, and then cool the flask thoroughly in an ice-water mixture. Place the flask on a nonconducting surface [e.g., a wooden block or an asbestos board) in a fume cupboard, and, whilst the phenolsulphonic acids are still a viscous syrup, add 38 ml. of concentrated nitric acid and immediately mix the hquids by shaking for a few seconds. Allow the mixture to stand generally within 1 minute a vigorous but harmless reaction takes place and copious red fumes are evolved. When the reaction subsides, heat the flask in a boiling water bath for 1 5-2 hours with occasional shaking the heavy oil, initially present, will ultimately form a mass of crystals. Add 100 ml. of cold water, chill thoroughly in ice water, filter the crystals at the pump, wash well with water to remove all the nitric acid, and drain. RecrystaUise from dilute alcohol (1 volume of alcohol 2 volumes of water) about 110 ml. are required. Filter off the recrystallised material and dry between filter paper. The j ield of picric acid (yellow crystals), m.p. 122°, is 16 g.  [c.678]

Equip a 500 ml. three-necked flask with a furmel for introducing a Bohd, a wide air condenser and a stainless steel stirrer with crescent blade, 1 cm. long and 8 cm. wide, so shaped that it conforms to the bottom of the flask. Immerse the flask in a metal bath at 350°. Add the powder through the funnel, with rapid stirring, during a period of 15 minutes. Heat with stirring at a hath temperature of 350° for 20 minutes after all the solid has been added. Leach the product by stirring for 30minutes with 300 ml. of 10 per cent, acetic acid at room temperature. Allow to settle, decant the solution, and wash the residue with six 50-60 ml. portions of water. Filter with suction on a Buchner funnel, dry at 12. )° for 12 hours, and grind finely in a mortar. The yield of catalyst (a brownish-black powder) is 85 g. No special precautions are necessary in handling or storing the catalyst since it is unaffected by exposure to air or moisture.  [c.873]

Aluminium tert.-butoxide. In a 500 ml. louiid-bottomed ilask fitted with a reflux condenser protected by a calcium chloride or cotton wool tube, place 16 g. of aluminium turnings, 50 g. (63 5 ml.) of anhydrous fert.-butyl alcohol and 2 g. of aluminium isopropoxide (Section VI,12 to remove traces of water). Heat the mixture to boiling on a steam bath, add about 0 -1 g. of mercuric chloride and shake vigorously the object of the shaking is to distribute the mercuric chloride and thus assist an even amalgamation of the aluminium. Continue the heating on the steam bath the colour of the reaction mixture gradually changes from clear to milky to black and hydrogen is evolved. Remove the flask from the steam bath when the mixture is black, allow the reaction to proceed for an hour, and then add 61 g. (77 ml.) of anhydrous butyl alcohol and 50 ml. of anhydrous benzene. Heat gently to restart the reaction it will continue vigorously without further heating for about 2 hours when the reaction subsides, reflux the mixture for 12 hours. Remove the benzene and unreacted [c.887]

To a mixture of pure phenol and 25 g. of phthalic anhydride contained in a 250 ml. round-bottomed flask, add 20 g. (11 ml.) of concentrated sulphuric acid. Heat the flask in an oil bath at 115-120° for 9 hours. Then pour the reaction mixture whilst still hot into 1 litre of hot water contained in a 2 htre beaker, and boil until the odour of phenol has disappeared add water to replace that lost by evaporation. When cold. Alter the yellow, granular precipitate at the pump and wash it with water. Dissolve the solid in dilute sodium hydroxide solution, filter from the undissolved residue (the by-products of the reaction). Acidify the filtrate with dilute acetic acid and a few drops of dilute hydrochloric acid, and allow to stand overnight. The crude phenolphthalein separates as a pale yellow, sandy powder filter and dry. Purify the crude product by dissolving it in six times its we ht of absolute alcohol, add decolourising carbon and reflux on a water bath for 1 hour. Filter the hot solution through a preheated Buchner funnel, wash the residue with 2 parts by weight of boihng absolute alcohol and concentrate the combined filtrate and washings to two-thirds of its bulk on a water bath. Dilute the cooled solution with eight times the weight of cold water (it will become turbid), stir the mixture well aud, after standing for a few seconds, filter through a wet filter to remove the resinous oil which separates. Heat the filtrate on a water bath to evaporate most of the alcohol the turbidity disappears and the phenolphthalein separates out in the form of a white powder. Filter this oflF and dry. The yield of pure phenolphthalein, m.p. 256-258°, is 18 g.  [c.985]

See pages that mention the term Saddle block : [c.342]    [c.423]    [c.9]    [c.80]    [c.386]    [c.289]    [c.1265]    [c.2397]    [c.2399]    [c.2490]    [c.162]    [c.469]    [c.23]   
The organic chemistry of drug synthesis Vol.1 (1977) -- [ c.7 ]