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Various types of simple separation on paper have been described as fore-runners of paper chromatography, among them a method of Runge in 1850, and the process called ‘capillary analysis’ (Goppelsroder, 1909). Such methods were really more like adsorption chromatography, and paper chromatography as it is now understood was a development of the partition system introduced by Martin and Synge in 1941 (see Chapter 2). One of the solids which can be used to support the stationary phase is cellulose powder (p. 38). Consden, Gordon and Martin[l] in 1944 separated the amino-acids and peptides in wool protein hydrolysates by a method in which the powder column was replaced by a sheet or strip of paper, freely suspended in a vapour-tight vessel.

Determining the type and amount of organophosphate pesticide residue in food products is a complex problem, and one which concerns both the companies which manufacture the pesticides and the Governmental agencies which enforce their proper use.

Rare earth metals, in the range of 0 to 250 micrograms, have been extracted quantitatively from perchloric, nitric or hydrochloric acid solutions by strong acid ion exchange paper disks in the sodium ion form. After the exchange is completed, the ion exchange paper disk is placed in a rotating sample holder and the amount of rare earth metals exchanged is determined by x-ray emission spectrography. At the 10 microgram level, the accuracy has a mean error of 2% with a precision of 1.5% relative standard deviation. The procedure has been applied to Sc+3, Y+3, Ce+4, Pr+3, Nd+3, Sm+3, Eu+3, Gd+3, Tb+3, Dy+3, Ho+3, Er+3, Tm+3, Yb+3 and Lu+3.

With the advent of various types of chromatography, a wide choice of methods is now available for the resolution and isolation of amino acids in complex mixtures. For quantitative analysis, paper chromatography and ion-exchange chromatography are the methods of choice. One-dimensional rather than two-dimensional paper chromatography is preferred as a routine procedure, samples being pretreated with ion-exchange resins to obtain groups of amino acids. Reliable methods for the isolation of the amino acids in the brain after paper chromatography have been published (Gaitonde, 1961; Gaitonde et al., 1965; Robinson and Williams, 1965).

It is not possible in a short paper to describe the entire fossil fuel technology in any detail. However, for completeness, many of the more commonly used recovery techniques as well as some novel but untested methods are briefly described herein.

Enzymes attached to insoluble supports offer some particularly attractive advantages for many purposes including their use in the food processing industry. These advantages include repeated reuse of the enzyme, ease of removal from the reaction mixture, good or improved enzyme stability and properties which permit use in columns and large continuous reactors. In order to be successful an application must meet these criteria; in addition the costs for the support, the enzyme, the process for attachment, the equipment, and the operating costs must all be low. Previously we have reported on the use of phenol-formaldehyde resins as supports for immobilizing enzymes (1). This paper presents some of the most recent findings with this method of immobilization from pilot scale runs using a β-galactosidase from Aspergillus niger as the model enzyme for the hydrolysis of lactose in milk, whey, and deproteinized whey. Some examples of the variations possible with this method of enzyme immobilization are also discussed.

The heterogeneity of lactate dehydrogenase was first recognized when Neilands (1952) demonstrated activity in each of the two electrophoretically distinct proteins, previously separated by Meister (1950) from the crystalline ox-heart enzyme. Subsequently Vesell and Bearn (1957) found three distinct components when human sera were subjected to starch-block electrophoresis, and Sayre and Hill (1957) obtained similar results with paper electrophoresis and gradient-elution chromatography. About the same time Wieland and Pfleiderer (1957) found that most organs contain up to five protein fractions each exhibiting lactate dehydrogenase activity. Soon afterwards it was appreciated that the isoenzyme composition of the serum was of considerable diagnostic value (Vesell and Beam, 1958a, 1958b; Hess, 1958; Wieme, 1959), and this gave a tremendous impetus to further study of variations in the isoenzyme content of the blood serum.

In our rheumatism research unit we are interested in the excretion of unconjugated corticosteroid metabolites because they may provide some evidence of the extra-hepatic metabolism of corticosteroids. A method was developed for estimating Cortisol metabolites in urine (1) which involved a preliminary separation of the extract by paper chromatography (Bush B5 system) and, after bismuthate oxidation, determination by GLC on a neopentyl glycol adipate column. This communication describes an improvement on the method and involves the following procedure.

In the manufacturing of TNT, there are three waste water streams that must be processed in order to comply with federal and local government regulations. These are: (1) “red” water which is produced by the sellite (sodium sulfite) treatment; (2) “pink” water which is produced when the partially purified TNT is washed following the sellite treatment; and (3) wash waters from the TNT finishing process. While all these polluted streams are being investigated at the U. S. Army Natick Laboratories, this paper will cover results obtained with wash waters from TNT finishing processes.

Strips of Kodirex-X ray film, immersed for a few minutes into the chosen buffer, then quickly blotted between two sheets of filter paper, have been used as a supporting medium for the electrophoretic separation of various radioactive ions. After the electrophoretic run, the film strip was dried and stored in the dark until developed. Autoradiographic electrophoresis has been carried out with sulfate, taurine, taurocholate-35S, tritium-labeled succinic acid, histidine, glutamic acid-14C, tritium-labeled valine, and methionine. The separation of glutamic acid, histidine -14C, and tritium -labeled valine has been achieved at pH 7.25 and 5.25 (20 to 30 volts per centimeter for 60 min) (Fig. 1). The use of glucose-14C has shown that the nonelectrophoretic migration due to electro-osmosis and evaporation is negligible at the two above pH values (Fig. 2). The separations are sharp, the diffusion is weak, and unless the specific activities are very high, radioactive ions have no time to leave any track as they move in the photographic gelatin.

Laboratory, pilot and large field demonstration units were used concurrently to develop engineering design factors for concentration treatment of four different pulp and paper industry waste streams by reverse osmosis. Eleven, half-inch diameter tubular modules with cellulose acetate membranes were operated in parallel under closely controlled conditions of flow rate (to 5 1/2 gallons/minute per module); velocity (to 9 feet/second); concentration (tap water controls to 10% waste liquor solids); pH (2.5–7.5); temperature (20°C to 40°C); viscosity (0.8–2.0 cp); and time of continuous operation (to ten days/run). Detailed data obtained include turbulence (N Re ); viscosity; osmotic pressure; pressure drop; permeation resistance; and effect of reverse osmosis in terms of rejections of dissolved solids, BOD, COD, and Color (OD) for the individual wastes processed. Design factors developed from these data include pumping energy per unit volume; hydrolysis rates on cellulose acetate; concentration polarization; fouling rates by microbiological growth and other surface accumulations; and membrane compaction rates. Auxiliary information is being developed from these studies to provide a firm base upon which methods of pretreatment and of operation can be developed to maintain sustained operation with minimum membrane fouling and also methods and routines for systematic cleanups where required.

Chlorination of benzene was one of the first manufacturing processes for an organic chemical to be carried out industrially. Production was started in England in 1909 by the United Alkali Company (now part of Imperial Chemical Industries Limited) [1] and in the United States in 1915 by the Dow Chemical Company [2]. Up to that time the ‘heavy’ chemical industry had been mainly concerned with production of inorganic chemicals, particularly acids and alkalies. Widespread introduction of manufacture of sodium hydroxide by electrolysis of brine led to production of large amounts of chlorine for which, at that time, there were no commercial outlets, particularly as manufacture of bleaching powder was becoming obsolescent. Petrochemicals were still a thing of the future and the only organic raw materials which were available in large amounts were those derived from coal-tar, such as benzene. It was thus logical to look to chlorination of these products as a possible profitable use of the excess of chlorine to which industry was irrevocably tied as a result of the natural association of one atom of sodium with one atom of chlorine.

Lake and stream pollution remains a major national concern. New regulations, either now in effect or to be imposed in the next few years, will limit severely the amount of solids that industry and municipalities can discharge into natural waters. Among the industries affected are those either manufacturing starch or using it in processes where some starch may get into waste streams. Because dilute starch solutions suspend other solid materials, they constitute a problem in waste treatment.

The chief aim of the usual methods for eliminating styphnic acid from plant effluents resulting from the manufacture of lead styphnate is to avoid explosive hazards. They are based on the destruction of styphnic acid, either by oxidation or by reduction. Their main disadvantage is the formation of toxic reaction products and the toxic reagents added in some cases.

Poly(tetrafluoroethylene) (PTFE) is unique among polymers in its ecological position. Although there has been considerable discussion on recycling waste polymers such as poly(ethylene) (PE), poly(styrene) (PS), and poly(vinyl chloride) (PVC), only poly(tetrafluoroethylene) has been recycled in quantities significant compared to production. Over fifty times more PE is consumed in the form of trash bags for waste disposal than PTFE manufactured. Further, the growth rate of PE, PVC, and PS is continuing at 5–10%o per year while PTFE growth has plateaued. On a tonnage basis, then, the recycling of PTFE appears anomalous. The discrepancy disappears when the economic reward of reprocessing a $2.75/1b material is contrasted with that of a $0.14/1b material. The high scrap value of PTFE provides an incentive for both fabricators and end-users to accumulate waste in reasonably concentrated bulk. Further, freight cost to reprocessing installations is not a significant portion of the polymer cost. Due to the economic incentive a wide variety of methods for up-grading waste PTFE to reprocessable grades have been evaluated. The techniques employed may be transferable to other polymers of greater ecological impact.

Ethylene oxide (ETO), an alkylene oxide, has been used for many years to kill microorganisms and insects (1,2). The principle use in the past has been the fumigation of foodstuffs and spices; ethylene oxide is still used extensively in agricultural industries for this purpose (3). During the last 20 years the effect of time, temperature, relative humidity, and concentration of ETO on sterility has been repeatedly discussed (4,5,6,7,8).

Within the last 3 yr. there has been a very rapid increase in the usage of urea as a high grade fertilizer, animal feed supplement, and raw material for certain resins. The low-cost production of urea in large quantities has been widely studied by chemical engineers, and a number of processes have been developed, both in this country and abroad, which reflect considerable sophistication in engineering technology and in the use of specialized alloys to meet the corrosion problems encountered in the reactions required to produce urea.

It has been known for some time that certain Ascomycetes and Fungi Imperfecti are capable of attacking cellulose and nonlignified materials. For instance: 1. A great many can attack cellulose plant fibers such as cotton, causing serious destruction of fabrics. 2. Others may grow through wood, living on stored food materials, such as starches and sugars in the ray cells, and thereby stain and discolor the wood. 3. Others not only utilize the food material within the ray cells but also the pectin and hemicelluloses of the walls. When the cells are dissolved, porosity is increased, and the wood becomes more absorptive of water and preservatives. It is of interest to note here that certain bacteria also are capable of dissolving the ray cells in logs stored in ponds for the purpose of preventing stains and decay (Ellwood and Ecklund, 1959). Increased absorptiveness may cause considerable drying and paint-maintenance problems. Increased porosity in wood can, on the other hand, be of value to the wood preserver. In experiments directed toward improving the penetration of preservatives, chemicals, such as sodium fluoride, have been sprayed on logs to stimulate the growth of molds, particularly Tricho-derma (Lindgren, 1952). 4. A few bark-inhabiting Ascomycetes are known to decay small branches and twigs. Their attack on the lignified walls of tracheids, vessels,and fibers, however, has been regarded as unimportant.

Oxidation ponds are one of the common methods for stabilizing domestic and industrial wastes, and are used widely in many countries. They have become one of the most accepted solutions for treatment of wastes in Israel and a large-scale project, the “Recovery of the Dan Region Wastewater”, is in operation in this country.

This section contains the title and contents of 98 of the more relevant textbooks published in the field of industrial microbiology. All but 12 of the books have been published since 1960.

The development of reverse osmosis as a process for desalting brackish and seawater originated with the research of Reid and Breton at the University of Florida in 1954–1956. These investigators showed that cellulose acetate film is capable of separating salt from water by reverse osmosis, although at a very slow rate. Soon after this, Loeb and Sourirajan at the University of California developed a unique process for making an asymmetric or “skinned” cellulose acetate membrane. The water flux and salt rejection of this membrane were sufficiently high to make the reverse osmosis process an attractive candidate for desalination. Just ten years later, small capacity commercial reverse osmosis units were available to the public.

The trend toward tougher anti-pollution standards has had a tremendous impact on the coatings industry. In the recent past, research and development efforts have been directed toward new coatings or coating methods which can fill existing customer needs while eliminating the associated pollution problems. Much of that effort has been or is going into water based coatings. The principal advantages and disadvantages of water based coatings over conventional organic systems are tabulated below. In the past, the higher heat input and longer flash-off time generally required for water based coatings may have hindered the growth of these systems. In addition, water based systems were found to be slower curing. To overcome these drawbacks, new developments in polymer systems and cross-linking agents were needed. In the late 1960’s water soluble, fast-curing, partially methylated melamine resins were introduced and found immediate acceptance in water- and solvent-based systems. With the subsequent development of methylated urea formaldehyde cross-linking agents, however, even faster curing speeds are now obtainable.

Several years ago it became apparent that uridine nucleotides containing various carbohydrate moieties were the probable precursors of polysaccharides. This observation followed largely from the initial work of Leloir and his collaborators [1] and of Park [2]. Work by Cifonelli and Dorfman [3] showed that Group A streptococci contain UDP-glucuronic acid (UDPGA), UDP-N-acetylglucosamine (UDPAG), and UDP-N-acetylmuramic acid. The first two, UDPGA and UDPAG, contain the constituent monosaccharides of hyaluronic acid (HA), an acid mucopolysaccharide that occurs in connective tissues and in the capsule of certain Group A streptococci. Although reasonable quantities of the nucleotide precursors of HA were available, labeling with C14 would have been both difficult and time consuming.

The industrial microcapsules first disclosed in the patent literature in 1957 are prepared as microscopic containers of oily material (1). These microcapsules containing oil are coated on paper. Mechanical pressure rupture these microcapsules, releasing their oily content to form prints—the basis of the well-known NCR carbonless paper. Since then, most of the industrial and pharmaceutical microencapsulation technology are similarly prepared to contain medication, fuel, perfumes, adhesives, and others. In all cases, the enclosing wall of these microcapsules are made as impermeable to external and internal molecules as possible, and the enclosed material can act only when the microcapsule wall is disrupted releasing the enclosed material. The enclosing walls are, therefore, rather thick (greater than 1 micron).

Using a novel DTA technique, it has been reported that polyethylene (PE) single crystals exhibit narrow multiple-peaked thermograms1. The half-width of the individual peaks is usually less than 1.5°C. These peaks widths are comChapauble to those obtained using pure non-polymeric organics. Previous work suggested that discrete transformation temperatures exist for the {100} and {110} fold sectors2. The work that led to this suggestion was performed on lamellae produced by isothermal crystallization from a dilute (.1%) solution of PE in xylene. The solution was heated to the boiling point of xylene prior to being quenched to a particular crystallization temperature. Several questions evolved from this latter paper. The first of these concerns the homogeneity of lamellae produced in this way. Since not all lamellae began to crystallize at the same time, a distribution of sizes appears. Crystals often possessed overgrowths and/or defects. One might also question both the heating rate effects reported and the justification for resolving multiple-peaked thermograms into discrete components. It is the object of this paper to attempt to answer these questions.

In a previous paper (1) we had already reported results on the erasure by an ac field (1 KHz) of the texture stored in nematic-cholesteric mixtures by application of a dc field. The decay of the scattered light intensity after the dc field removal can be characterized by an erasure time τE defined as the time during which this intensity falls from 90 to 10 per cent of its initial value. This time can easily be determined and the variations of τE with various parameters have been examined for mixtures of negative dielectric anisotropy consisting of a commercial product (LCI), nematic in the range 5–70°C and of cholesteryl nonanoate (CN). The experimental results showed that the time τE decreases when the temperature increases (following a law similar to that of the pure nematic substance)and also when the erasing ac voltage rises, the greater the concentration the faster the decrease. In this paper we have studied in more detail for the same mixtures, the variations of the erasure time τE (for 1 KHz) with the dc voltage producing the storage effect.

Backscattering techniques allow determination of elemental composition as a function of depth with typical values of depth resolution of 100 to 300A. The technique is ideally suited to measurements in thin film systems of thicknesses of several thousand Angstroms and has provided a basis for examination of thin film interactions. This presentation is intended as an introduction to the papers presented in this session of the conference. These papers represent examples of the type of studies carried out in this field: interdiffusion and mixing between thin metal films, and reaction kinetics and silicide formation in systems composed of metal films deposited on Si or SiO2. These studies involve solid-solid diffusion and reactions since the process temperatures are below the eutectic. Although backscattering techniques provide depth-microscopy, supplemental measurements are often required to establish lateral uniformity and the relative importance of grain boundary and bulk diffusion.

In a previous publication on the thermal decomposition of hydrated and deuterated Rochelle Salts (1), a mechanism was proposed to explain the observed thermal data that involved assumptions of the thermal decomposition of both sodium and potassium tartrates. This study showed that endothermic transitions were obtained in the temperature ranges of 108–125°C, and 158-l80°C, which were attributed to the dehydrations of sodium and potassium tartrates, respectively. Also, the weight losses obtained at 250°C were attributed to the decomposition of the tartrates to the oxalates with the deposition of carbon. A search of the available literature showed that Mattu and Pirisi (2) published the only previous paper on the alkali tartrates. They presented DTA thermograms of sodium and potassium tartrates, but the data was not sufficient to permit the analysis of the thermal decomposition of these compounds. It is, therefore, the purpose of this paper to study the thermal decompositions of sodium and potassium tartrates by modern thermoanalytical techniques (DTA and TGA), and to relate these studies to the previous investigation of the Rochelle Salts.

Although pulsed lasers have been commercially available for only one decade, they have been utilized in chemical analysis as highly monochromatic light sources, as intense, short duration sources for photolysis, and during the last few years, as thermal sources for degradation processes. Pulsed laser energy offers unique properties for the initiation of thermal degradation. Especially sensible is the combination of laser induced thermal degradation with gas chromatography. This paper reviews some applications and experimental possibilities of this new pyrolysis method. It should be noted that only a few papers have appeared on this topic and certainly much still needs to be done to fully characterize the potentialities of this technique.

One of our major interests has been the glycolytic control mechanisms in the red cell which determine DPG levels normally and during hypoxic stress. We have increasingly utilized the method of assaying the measurable intermediates throughout the glycolytic pathway, along the lines suggested by Yoshikawa and Minakami (1968), in order to determine the key enzymatic step or steps which bring about changes in DPG. Through these studies we have begun to discern a rather consistent pattern, suggesting that the activity of hexokinase, already known to be one of the key regulators of erythrocyte glycolysis (Rapoport, 1968; Yoshikawa and Minakami, 1968), may be a very important factor in regulating DPG levels, in a number of circumstances. This pattern is illustrated in papers on anemia (Oelshlegel, et al. 1972) and altitude adaptation (Moore, et al. 1972) in this volume, but we would also like to illustrate it in the first part of this paper in differences between normal men and women.

In the last few years several papers have appeared on the effects of ultrasonics on crystallizing substances [1, 2], These papers dealt with polycrystalline materials formed from melts, and did not touch on monocrystals. We give here some data on the effects of ultrasonics on monocrystals of potash alum.

In the present series of papers we have investigated the effects of morphological changes (produced by treating the film with different swelling agents and also by heat treatments) on the mechanical properties of nylon 6 film. Parts I, II and III (1,2,3) have discussed the types of morphological change produced, dynamic mechanical properties, and stress-strain properties, respectively. In the present paper we have examined in more detail the effects produced on the stress-strain behavior, by use of stress-strain cycling. In particular, we have examined the nature of the recoverable and total work of extension at different points of the stress-strain curve (both before and after the yield point ) and at different temperatures (both below and above what is generally regarded as the glass transition temperature of the polymer).

A fairly extensive review of the literature on the nature of liquid-liquid phase separation in silicate melts and glasses has already been given in the preceding paper by Galakhov and Varshal. The views of various writers on the nature of phase separation are in the main either purely qualitative or involve attempts to find formal relationships between ionic radii, cationic field strengths, hypothetical local structures, and experimental characteristics of phase separation. All this can be regarded merely as preliminary steps toward derivation of a theory of phase separation, which must be a statistical physical theory based on more or less detailed analysis of interatomic interactions. An advance in this direction is, for example, the work of Kozheurov [1], who made an attempt to write an expression for the free energy of a silicate melt undergoing phase separation. Owing to the complexity of his polymeric model, he did not fully succeed in substantiating theoretically the addition of free energy postulated by him, so that the final formulas are of semiempirical character. In the present paper we derive a model, based on simplified concepts of structure and atomic-ionic interactions, making it possible to make approximate calculations of the free energy of a silicate melt or glass as a function of its composition and temperature. In our opinion, this model combines to a certain degree the views put forward earlier by Warren and Pincus [2], Dietzel [3], and Markhasev and Sedletskii [4] on the nature of phase separation.

The normal procedure for a quantitative measurement of two phases with an X-ray diffractometer is to scan or count the intensities of two diffraction peaks and then to calculate the ratio of the two phases using an appropriate equation. This paper will describe an improved method of quantitatively measuring two phases in a sample. The diffractometer, which was constructed by Philips Electronics Instruments, consists of two fixed scintillation counters mounted at the Seeman-Bohlin focusing positions for the two desired diffraction lines. Each counter is preceded by a lithium fluoride curved crystal monochromator. The output from each counter feeds to a separate scaler which can be arranged to gate both scalers at a preselected number of counts. At this point a tape printer prints out the counts for both scalers. These counts are then related to the proportions of each phase present by an appropriate equation. Most of the electronics are solid-state designs. This paper will describe the instrumentation and show how it can be used to measure rapidly and precisely the ratio of anatase to rutile in a titanium dioxide system. The savings in time over the conventional method can be as much as 100 to 1.

The characteristic property of viscoelastic solids which distinguishes them from perfectly elastic solids is the fact that, if they are subjected to a deformation which varies with time, the stress measured at time t, say, depends not only on the instantaneous value of the deformation gradients, but also on the whole previous history of the deformation gradients. In a series of papers, Green and Rivlin1,2 and Green, Rivlin, and Spencer3 have developed constitutive equations for such materials, in which the stress is expressed in terms of the deformation in the form of series of multiple integrals. It is the object of this paper to recapitulate this development, with particular emphasis on the physical assumptions regarding the material which are implied by the mathematical assumptions made in the theory. Such a development is perhaps timely in view of the extensive attempts in recent years to represent the behavior of actual materials in the form given by the theory.

The main purposes of this paper are to provide background information for the theoretical papers that follow by Schick, Novaco and Woo and to review some recent developments in areas that these papers will not cover.

This paper deals with super or collective paramagnetism and the possible applications of Mossbauer spectroscop to collectively paramagnetic systems such as oxides, catalysts with metal dispersions on the surface of diamagnetic supports, and dispersion within a silicate matrix. The last named area represents a superparamagentic system, developed and studied in our laboratory, Papers dealing with the Mossbauer spectra of superparamagnetic systems are reviewed and the possibilities of relationships between the relative line intensities of quadrupole-split Mossbauer spectra and the cluster sizes of superparamagnetic systems are considered.

In the preceding sections discussion has centred on the problem of obtaining a reliable, well-resolved spectrum. Before interpretation of the spectrum is attempted the frequency (wavelength) accuracy must be known, either by pre-calibration of the instrument using ammonia gas, water vapour, indene or polystyrene as references, or by calibration of individual spectra, usually by means of a polystyrene film. The latter procedure requires only a minute or so on most instruments and should be a standard operation with low-cost instruments, or whenever single chart papers are used, since the positioning of the paper on the recording drum constitutes a source of error. Polystyrene calibration (e.g. Figures 13–16) covers effectively the range 4,000–650 cm-1 (2·5–15·4 μ). Positions of the principal bands, in cm-1 and μ units, are presented in Table 7; and the complete spectrum is included here (Figure 20).

In 1961 Gutman and Yu proposed a three component system for the regulation of the renal excretion of uric acid in man. The first component of this system is filtration of plasma urate at the glomerulus. While this process is certain to be operative in the human kidney, its quantitative role in the renal excretion of uric acid in man depends upon the extent of urate binding to plasma proteins in vivo. This is a subject that is being discussed in another section of this symposium and will not be considered further in this paper. The second and third component of this system relate to uric acid reabsorption and secretion by the human nephron. Ample data is available to document that both of these processes are operable in the human kidney (Gutman and Yu, 1957; Gutman, et al., 1959), but the relative contribution of each to the final excretion of uric acid has been difficult to determine with conventional clearance techniques. However, a potential solution to this problem of bidirectional uric acid transport appeared in 1967 when Steele and Rieselbach introduced the “pyrazinamide suppression test”.

Our investigations with immobilized enzymes have been guided by how they may assist in finding out more about enzymic phenomena and how they could ultimately be utilized in processes and analyses, particularly those related to agriculture and food. In the latter area economic as well as scientific factors play a very important role. A complete evaluation of all of these factors is beyond the scope of this paper. However, we have considered many of these factors in both the choice of the systems for immobilization and the applications we have elected to study. The criteria we used in selecting methods for enzyme immobilization included: successful achievement of stable enzyme immobilization; an acceptable degree of retention of enzyme activity; good pH and temperature characteristics; simplicity of the method; use of impure or inexpensive enzyme preparations; a potential for large volume application; and low cost.

For many materials immersed in either liquid 3He or liquid 4He the low-temperature thermal boundary resistance is found to vary approximately as 1/T 3. This behavior is often discussed in terms of the acoustic mismatch theory1 in which phonons are assumed responsible for transferring thermal energy between the solid and the liquid helium. At least one system has been found for which the phonon resistance is not the limiting low-temperature resistance. That system is cerium magnesium nitrate (CMN) immersed in liquid 3He, for which the very low-temperature thermal boundary resistance is found experimentally to vary linearly with the temperature2 and to decrease in the presence of a small magnetic field.3 This resistance has been discussed4,5 in terms of thermal energy exchange via a surface magnetic coupling between the cerium spins of the CMN and the 3He nuclear spins. In this paper we present data which suggest that the thermal boundary resistance between Pt and liquid 3He is qualitatively different from the phonon and magnetic boundary resistances mentioned above.

In many of his papers and treatises, Oparin advanced the hypothesis that the formation of biomacromolecules from biomonomers might have taken place inside coacervates (1), droplets consisting of polymers separating out from a solution in which a monomer polymerizes in the presence of another polymer. When the new polymer reaches a certain size, phase separation, accompanied by a sharp shift towards synthesis (2), takes place. Evreinova et al. have shown that monomers of the surrounding medium can concentrate inside such coacervates up to a hundred-fold, depending on the type of the polymer forming the coacervate and on the nature of the monomers in the solution (3). These experiments led Oparin to the idea that coacervates were the means of concentration of monomers from dilute solutions and that polymerization takes place inside them.

We have designed an atomic beam experiment to be performed at low temperature in order to study the scattering of helium atoms at the liquid surface. This work has been partly stimulated by the theoretical papers of Anderson1 and Hyman et al.2 as well as by the experimental work of Johnston and King3. Anderson pointed out that the spectrum of atoms evaporating from the liquid should show a sharp increase in intensity at an energy corresponding to the difference between the atomic binding energy L and the roton minimum Δ. This prediction is made by assuming that inelastic processes at the surface play a minor role in evaporation.

Brandenberger attached lipase to the isocyanato derivative of poly-p-aminostyrene in 1956 (1). This was the first time that lipase was immobilized to an insoluble carrier through covalent bond formation. Kitajima also entrapped the lipase in microcapsule (2). The present paper describes the preparation and some properties of lipase bound to polysaccharides following cyanogen bromide activation.

Earlier measurements of the diffusion constant of the impurity molecule tetramethylsilane (TMS) when dissolved in a smectic A and smectic B liquid crystal have shown this quantity to be strongly anisotropic.1 That is, the diffusion constant in a direction perpendicular to the long molecular axis, D⊥, (diffusion within the smectic layers) is a much larger quantity than that in a direction parallel to the long molecular axis, D||, with a typical value for the ratio D||/D⊥ ~ 0.1. In the earlier work it was not possible, however, to obtain a measure of this ratio in the nematic phase. In this paper we report such a measurement as well as a measurement of the anisotropy in the smectic C phase. Much to our surprise, the ratio D||/D⊥ in the nematic phase varies strongly with temperature, exhibiting strong pretransition effects over most of the nematic temperature range.

Many nematic liquid crystals, when cooled to temperatures below the normal melting point, form a phase which is not the equilibrium crystalline solid. This behaviour has been shown in MBBA, (1) which will be the subject of the present paper.

Studies on bacterial transformation have contributed to the understanding of the physical state of transforming DNA in recipient cells. In the early stage of transformation a double-stranded DNA with low transforming activity was found in periplasm of Bacillus subtilis (Dubnau and Davidoff-Abelson, 1971). Single-stranded intermediates were found in Pneumococcus (Lacks, 1962) and in B. subtilis (Piechowska and Fox, 1971; Davidoff-Abelson and Dubnau, 1973a) which were later found as heteroduplex donor-recipient complexes in Pneumococcus, Haemophilus, and B. subtilis (Lacks, 1962; Fox and Allen, 1964; Notani and Goodgal, 1966; Davidoff-Abelson and Dubnau, 1973b). However, the molecular mechanisms of transformation, which may involve enzyme(s), cellular structure(s), and other factors, still remain obscure. In this paper we report on transformation studies in toluene-treated B. subtilis, in which DNA, protein, and RNA synthesis in the presence of proper substrates and ATP has been shown to occur.

At present there is no useful theory in the field of liquid crystals which allows the prediction of whether a given molecule will show, for example, a smectic or nematic mesophase and what the thermal range of the mesophase will be. All nematogenic compounds to date which are useful in electronic display devices contain para-alkoxy/alkyl-substituted benzene rings held together by a central group containing Π-electron density. For the past few years we have been carrying out heuristic investigations on the. effect of different central groups on liquid crystalline behavior. In this paper we report some recent results.

Much evidence has accumulated which indicates that phospholipid bilayers form an especially important part of the structure of biological membranes, as was first suggested by Danielli and Davson1 in 1935. For example, recent x-ray2 and calorimetric3,4 observations on the membranes of Mycoplasma laidlawii give strong support to the existence of the lipid bilayer structure in this micro-organism. Because of their probable significance in connection with the structure and function of biological membranes, phospholipids have in recent years been the subject of many studies by a wide variety of experimental techniques. This paper summarizes investigations of the thermal behavior of phospholipids utilizing high-sensitivity differential scanning calorimetry as the primary observational technique. This technique provides certain insights into the nature of the phase transitions of phospholipid bilayers which cannot be contained by any other method. Furthermore, it permits observations on much more dilute suspensions of phospholipids that can be handled by other techniques.