Slip Melting Point Research Articles

Melting‐point determination of fat products

AbstractA variety of methods exist for the determination of the melting point (mp) of fats. These include the Wiley mp (AOCS Method Cc 2–38), open capillary slip point, softening point and Mettler dropping point. The conditions under which the tests are performed influence the values obtained. Several of these methods were compared using a variety of fats, including margarine and soft margarine oils, lard, butter and hydrogenated Canola oils. The Mettler dropping‐point values were found to coincide with the extrapolated solid fat curves obtained using wide‐line NMR for all fats except butterfat. The reproducibilities of the Mettler dropping point and softening point were excellent; that of the slip point was poor.

Factors affecting slip melting point of palm oil products

AbstractThe effect of different factors affecting the slip melting point of palm oil has been evaluated. The most important factor appears to be the difference in tempering temperatures. The influence of different tempering temperatures on slip point values is, however, dependent on the nature of the sample. For hydrogenated oils and for some high‐melting palm stearins, tempering has no effect. For palm oil and palm olein, higher melting points were obtained when tempering at the higher temperatures in the range of 4–15 C. For some soft stearins, however, lower melting points were obtained at the higher tempering temperatures. These effects are investigated with differential scanning calorimetry and an explanation is offered, based on phase diagrams. A secondary effect on the slip melting point was the height of fat in the capillary tube. Effects of using different methods of determination are also shown. Collaborative trials on a standard testing procedure, AOCS Cc3‐25, revealed the inadequacy for palm oil of the temperature range of 4–10 C specified in the procedure and its fractions. Strict adherence to a fixed tempering temperature produced better precision and reproducibility among laboratories. Tempering at 10±1 C is recommended.

Fractionation of Interesterified Fats for the Preparation of Plastic Fats

AbstractSome specific directed interesterified fat products which had high slip points and had little potentiality for use as edible fats, were crystallized from acetone at different low temperatures. The appropriate fractions obtained from interesterified products of Ricebran containing Mowrah, Palm, Sal and of Sal and Cottonseed mixture (1:1, w/w), appeared to be suitable for utilization as vanaspati and margarine like fat products with high essential fatty acid content and without trans unsaturated fatty acids and also as highly stable deep frying fats and bakery fats.

Studies in the Solvent Interesterification of Acidolysed Cottonseed Oil

AbstractThe directed rearrangement reaction of an acidolysed cottonseed oil (acidolysed with palmitic acid) in solvent has been studied to find out the mode of distribution of the acyl radicals in the triglyceride moiety and also the changes in glyceride pattern and configuration of the oil after such reaction using pancreatic lipase hydrolysis. The glyceride compositions as calculated by the application of 1,3‐random 2‐random distribution hypothesis, of M. H. Coleman and W. C. Fulton of acidolysed cottonseed oil before and after directed interesterification reaction point out remarkable changes in the pattern of glycerides namely a notable increase of trisaturated glycerides with the diminution in the content of triunsaturated glycerides. Solid fat indices as determined by measuring the dilatation of fat, content of trisaturated glycerides and moderate slip points of the order of 37°C denote the suitability of using the modified fat thus produced as a good margarine base fat as the said fat has been shown to have a fairly long and extended plastic range as evidenced by low slopes in dilatometric charts compared to other conventional plastic fats.

A three-dimensional viscoelastic model of a strike slip fault

An analytic approximation to the Green's function for the displacements due to a strike slip point source in an elastic layer over a viscoelastic half-space is developed. This approximate Green's function is useful because it can be analytically integrated over the fault surface. Comparison with a numerical integration of the exact solution integral indicates that the approximation is quite good. The approximate Green's function is integrated analytically to obtain the displacements due to a finite rectangular strike slip fault in an elastic layer over a viscoelastic half-space. Ground displacements and angle changes from a model survey net are computed to illustrate the viscoelastic relaxation which follows a fracture in the elastic region.

Triglyceride composition of Buchanania lanzan seed oil.

AbstractThe fatty acid composition of Buchanania lanzan seed oil, determined by urea complex formation and gas liquid chromatography (g.l.c), was found to be: myristic, 0.6; palmitic, 33.4; stearic, 6.3; oleic, 53.7; and linoleic, 6.0%. Triglyceride compositions of the native seed oil and its randomised product were calculated from the fatty acid compositions of the triglycerides and of the corresponding 2‐monoglycerides produced by pancreatic lipase hydrolysis. The oil is composed of 3.2, 35.8, 45.5 and 15.5% trisaturated, monounsaturated disaturated, diunsaturated monosaturated and triunsaturated glycerides respectively. The special characteristic of the B. lanzan seed oil is its content of 22.7, 31.0 and 11.3% dipalmitoolein, dioleopalmitin and triolein respectively. The percent GS3 content in the oil increased from 3.2 to 7.5 by the process of randomisation. On directed interesterification the oil yielded a product with a slip point of 41.5°C which may be suitable as a coating material for delayed action tablets. The oil also appears to be a promising one as a commercial source of palmitic and oleic acids.

Fatty acid composition and characteristics of Pentadesma butyracea fat extracted from ghana seeds

AbstractRecent interest in the development of the tallow tree (Pentadesma butyracea S) as an oil‐tree crop has stimulated agronomic and chemical studies of the tree and the fat obtained from its seeds. Tallow fat extracted from local seeds has been analysed for its chemical and physical constants and fatty acid composition. These characteristics have been compared with those of the better known cocoa butter and shea butter. Dry tallow kernels, shea butter kernels and cocoa beans contained 50, 52.1 and 53.4% fat, respectively. Tallow fat and shea butter are similar in several of their characteristics, particularly slip point, saponification number, solidification point and fatty acid composition; but tallow fat has a much lower unsaponifiable matter content (1.5–1.8%) than shea butter (7.3–9.0%). Both are markedly different from cocoa butter and cocoa butter replacement fats in respect of their melting points and fatty acid composition. Cooling curves of 3:1, 1:1, and 1:3 mixtures of tallow fat and cocoa butter indicate poor compatibility between the two fats.

Crystallographic defects in epitaxial silicon films

A review of the salient theories advanced to account for the formation of crystallographic defects in epitaxially deposited silicon films on silicon substrates is presented. Experimental observations of defect generation processes in epitaxial films due to slip bands and point defect complexes in the substrate are discussed with an analysis of the possible mechanisms involved. The effects of growth stacking faults on p-n junction and bipolar transistor characteristics are also discussed.

A survey of fat characteristics of lamb with particular reference to the soft fat condition in intensively fed lambs

SUMMARYTwo surveys, involving 288 lambs, were carried out on the effects of system of production on the melting (slip) point, iodine value, and fatty acid composition of perinephric and subcutaneous carcass fat. The systems studied were:A, early Spring lambs fattened indoors on concentrates;B, early Spring lambs off grass;C, early Summer lambs off grass;D, Autumn lambs off grass, andE, Winter hoggets.The melting point of both perinephric and subcutaneous fat increased progressively during the season from mean values of 41 and 32°C respectively in group A to mean values of 48 and 42°C respectively in group E. Discolouration of the surface fat was associated with the low melting points of group A.Mean iodine values of both fats decreased progressively from group A to group E and this change was associated with a decrease in levels of oleic and palmitoleic acid and a corresponding increase in the level of stearic acid. In the fat, levels of myristic acid were highest in grass fed lambs while levels of linoleic acid were highest in the concentrate-fed lambs.Within each group, perinephric fat contained more stearic and less oleic, palmitoleic, palmitic and myristic acid than subcutaneous fat.Within animals, the levels between perinephric and subcutaneous fat of melting point, iodine value and most of the individual fatty acids were highly correlated.Within animals also, the melting point of perinephric fat was correlated in decreasing order of significance with stearic acid, oleic acid, iodine value, linoleic acid and palmitoleic acid, while melting point of subcutaneous fat was correlated in decreasing order of significance with stearic acid, oleic acid, palmitoleic acid, iodine value, linoleic acid and total branched-chain fatty acids.

Microscopic Substructure in Face-centered Cubic Metals Fatigued at Elevated Temperatures

The fatigue deformation of 18-8 austenitic steel and aluminum due to high temperature has been investigated mainly from the stand point of cross slip using the replica and transmission electron microscopy technique. The main results obtained are as follows.(1) Remarkable difference is found in the configuration of slip lines in both 18-8 austenitic steel and aluminum when fatigued either at room temperature or at elevated temperatures. In the former of low stacking fault energy, the morphology of surface slip lines formed at room temperature is fine and straight, while at elevated temperatures it is characterized by the thick and wavy appearance. In the latter of high stacking fault energy, on the other hand, the waviness increases with rise in temperature so strikingly that remarkable irregularity on specimen surface occurs. The morphology of deformation structure at high temperatures depends also on the stacking fault energy.The cell structure is more distinct at elevated temperatures than at room temperature.(2) The fatigue crack is initiated at grain boundary in fatigued 18-8 austenitic steel at 500°C, while at 300°C it is initiated at well-developed intrusion and at the region near the grain boundary, where the intensified slip lines including many cross slip lines intersect each other, and finely divided substructures are thus formed.(3) The well-developed substructures are formed near the crack in fatigued 18-8 austenitic steel at elevated temperatures. Therefore the fatigue crack might grow with the same mechanism as that in metals of high stacking fault energy at elevated temperatures. The clear cellular structures on the surface are observed at the crack tip in fatigued aluminum at high temperatures, and fatigue crack grows through the boundaries of these cellular structures of the surface.(4) Many pores were observed on the surface of the specimen of aluminum fatigued at elevated temperatures. It is considered that the pores are formed beneath the surface oxide film by the condensation of vacancies which were abundantly created during fatigue deformation at the elevated temperatures.(5) The characteristic feature in fatigue at elevated temperatures can be explained by considering cross slipping enhanced by high temperature.

Parameters for Bed Slip Point in Two-Phase Flow

Earlier work showed that the limit of deposition is given by the slip point, when the bed begins to slide. It had been found that the pressure gradient at slip point depends on the angle subtended by the bed and other factors. In this paper, suitable parameters representative of the pressure gradient, discharge and concentration of solids at the slip point are expressed in terms of this angle. For specific cases, with given pipe size and particle properties, the angle of deposition can be eliminated by plotting gradient parameter versus discharge parameter. This gives a graph similar to those generally used for plotting experimental results for two-phase pipeline flow, on which the locus of the slip point defines regions with and without deposition. It is found that the discharge at the slip point defines regions with and without deposition. It is found that the discharge at the slip point rises to a maximum and then decreases with increasing gradient. In combination with efficiency considerations, this indicates that it is desirable to operate pipelines with high solids' concentration.

Erratum for “Slip Point of Beds in Solid-Liquid Pipeline Flow”

Erratum for “Slip Point of Beds in Solid-Liquid Pipeline Flow”

A chemical study of soft fat in cross-bred pigs

SUMMARYIodine values, melting (slip) points and fatty acid analyses for back (‘bung’) and perinephric (kidney) fats from 114 pure and cross-bred pigs are reported.In most cases the effects of breed were small, but half-Hampshire crosses showed a high proportion of pigs producing abnormally soft and highly unsaturated fats, though others were normal.Although a general correlation existed between iodine value and melting-point the relationship broke down in some cases, and the ratio of monoene to saturated fatty acids of carbon chain length 16 and 18 is suggested as a better chemical index of softness due to causes other than dietary lipid.

Slip Point of Beds in Solid-Liquid Pipeline Flow

In view of the relatively low mean velocities which give optimum efficiency for pipelines transporting granular solids, it is important to study the conditions for which stationary deposits occur in pipes. The limit of deposition is the slip point, at which the force driving the bed exceeds the coefficient of friction times the total normal force exerted by the bed grains against the pipe wall. Although the state of intergranular stress in the deposit is generally indeterminate, it is shown that near the slip point it is a reasonable assumption that the granular pressure at the periphery of the bed follows a hydrostatic distribution. Experimental verification of this assumption was obtained from two types of tests, one involving flow conditions in a recirculating system and the other the slipping of deposits in a tilting pipe. The relationship derived for the hydrostatic distribution of granular pressure shows that the pressure gradient at the slip point is directly proportional to the underwater weight per unit volume of bed, and increases with the angle subtended by the deposit.

スピニング加工法の研究(第3報)

At the latter stroke of conventional simple spinning, the wall of the cup which is thickened with drawing process will be ironed by the roller. Then the three components of force increase again. This paper deals with an analysis of this process in detail: This process will be explained by the superposition of ironing deformation upon the previous drawing process, and ironing deformation is assumed to be the tube spinning of an ideal uniform pipe. As the results of the numerical calculation, there is no slip point under the roller and it is suggested that no slip point consists with a neutral line which is arised by the difference of velocity of the roller and the blank. From the comparison of the experimental and theoretical results, the boundary condition considereds that σz at θ=θA or θ=θB is compressive is selected. From the 2 nd report and this 3 rd rep prt, the foundamental mechanism of conventional simple spinning is clarified.

A SLIP PAINTING PROCESS SUITED TO THE CRAFTSMAN WHOSE EQUIPMENT IS LIMITED1

The raw materials of the common stoneware business are used. The temperature needed is that of the maturing point of Albany slip, or cones 6 to 9. The kiln should be one designed to stand up under rather high temperatures. The ware is essentially once fired common stoneware decorated with a slip painting process.