THE RELATION OF DEFECTS IN ENAMEL COATINGS TO HYDROGEN IN STEEL*

The effects of hydrogen as functions of time, temperature, and impurities in steel are described and experimentally demonstrated. Experimental evidence is presented to show that the blistering and boiling action over carbide areas in steel are due principally to hydrogen that associates with the carbon. Steel enameling stock contains quantities of hydrogen which may effuse during firing to cause or aggravate such phenomena as “boiling,”“primary boiling,”“rebelling,”“blistering,” and “bubbling.” Low-temperature effusion of hydrogen contributes to other defects, including “fishscaling,”“delayed fishscaling,” and possibly “pop-offs,”“jumping,”“shiners,” and some cases of “chipping” and, perhaps, “bursting” of enamel on cooking utensils. These defects have seldom been identified with hydrogen evolution. An indirect effect of hydrogen on “copperheads” and “black specks” is also identified. An exhaustive review of both English and German literature on enameling defects is included. Many observations recorded in the literature are shown to agree with the hydrogen theory. Certain types of inclusions in steel are shown to react with occluded hydrogen to form compounds that will not dissociate appreciably at some enamel-firing temperatures, and critical quantities of the hydrogen are therefore prevented from reaching the enamel coating during firing to cause blistering and related defects.     

Experimental methodologies to evaluate allelopathic plant interactions

It is difficult to clearly and unambiguously demonstrate an allelopathic mechanism of plant interference. Several types of experimental methodologies such as the additive design, substitutive designs, and several types of plant yield-plant population functions are discussed in terms of their relative merits in terms of providing quantitative and qualitative information in the development of an empirical basis to describe a plant interaction. Additionally, several types of mathematical and graphical representations are presented using data from the velvetleaf (Abutilon theophrasti) and soybean (Glycine max) interaction. The design provides agronomically relevant information about crop yield losses but confounds the separate effects of population density and species proportion in mixtures. The replacement series design separates these two variables by maintaining a constant population of plants while varying the relative proportion of each species in mixtures. The replacement series diagram, relative yield, relative replacement rate, ratio diagram, a scaling test, and the regression of individual yield on the associate yield are discussed in terms of their utility in providing insights into a plant interaction. Individual plant yield-plant population functions such as the “Y-D” and “C-D” effects, the “3/2 power law of self-thinning,” and the “Sakai” test provide a basis to compare plant yield per plant versus plant population responses. Several types of interactions are characterized with this methodology. None of these experimental designs will clearly demonstrate an allelopathic plant interaction alone, but they do provide high-inference experimental methodologies to develop an empirical foundation to describe accurately a plant interaction upon which more specific hypotheses can be developed.     

Classification of properties of elastomers using the “optimum property concept.” I. Introduction

An attempt is made to distinguish properties of elastomers by types. “Basic properties of materials” or “network properties” in elastomers are properties which either increase or decrease from the liquid to the solid state of materials or over the range of the “elastomeric plateau” of elastomers. From these are distinguished properties that exhibit characteristic maxima and are therefore “maximum properties” or bivalued properties. Mechanical failure properties show the characteristics of “maximum properties.” The maxima in “maximum properties” generally do not coincide. This noncoincidence of the maxima with a change in a “basic property of a material” has major theoretical and practical implications, for example, it is the cause of the crossovers in the relative performance rating of materials under different test conditions. The implications of this noncoincidence of the failure property maxima on the relevance of correlations between these properties are discussed. A change in the testing conditions is reflected in a shift of the optimum value in a “basic property of a material” with respect to a specific “maximum property.” Data and certain conclusions in the literature are interpreted on the basis of this concept. Examples of the limitations of the validity of mathematical relationships are presented. Also, a definition of the term “state of cure” is proposed and a suggestion for the rating of severities of test equipment and applications of elastomeric materials recommended. The effect of increased degrees of crosslinking for a series of polymers and crosslinking agents is assessed. It is suggested that the “mechanisms” of failure properties will remain elusive if their rationalization is attempted on the basis of other failure properties, e.g., the mechanism of abrasion on that of tear strength or cut growth. The main purpose of this proposal is to provide support for a drastic reduction in laboratory testing by identifying those properties which can lead to different relative ratings in routine evaluations and actual applications. A more empirical approach to materials evaluations is recommended based on the calibration of laboratory instrumentation with respect to specific applications. A de-emphasis of routine evaluations of materials on the basis of their “maximum properties” seems to be justified.     

Equilibria in the alcoholysis reactions of terephthalic esters and chemical valorization of polyethyleneterephthalate waste. I. Equilibrium constants determination

The depolymerization of polyethyleneterephthalate (PET) by alcoholysis is an easy operation and gives interesting prospects for the valorization of wastes. The reactive species being composed of esters and alcohols, all possible alcoholysis reactions happen, whether wanted or not. Finally, a complex blend of many molecules follows. Practically, two great types of reactions occur: a reaction called “interchange,” and a reaction called “polycondensation.” We have determined the values of global equilibrium constants of those two types of reaction. The values of polycondensation equilibrium constants are close to those estimated from the “equireactivity” principle. We did not observe any particular behavior of monomer species. When reactants are the di‐ or mono‐propylene glycols, the molar proportion of these glycolic radicals is higher in the free glycols than in the polyester chains. Both proportions are similar, when diethylene glycol or 2‐ethylhexanol are used. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 72: 329–340, 1999     

A classification of fischer–tropsch synthesis product distributions

Two types of product distributions in Fischer–Tropsch synthesis have been observed; the “classical” distribution where successive carbon numbers contain homologous groups of compounds and the “non-classical” where the product spectrum deviates from the above picture. It is proposed that the non-classical distributions arise on bifunctional catalysts on which primary synthesis products are rapidly converted to isomeric secondary products.     

Modeling and analysis of the compatibility of poly(ethylene oxide)/poly(methyl methacrylate) blends with surface and shear inducing effects

The compatibility of poly(ethylene oxide) (PEO) and poly(methyl methacrylate) (PMMA) blends was studied over a wide range of compositions at 400 K by mesoscopic modeling. Sixteen patterned surfaces of four types were designed and designated as “ci,” “co,” “gra,” and “rg” to study their influence on changing the microscopic phase morphology. The topography of the “ci” series surfaces was shaped by semicircular balls. Different radii were applied to simulate different degrees of surface roughness. The “co” series were composed of cubic columns as the mask, and the cubic columns were separated by equal spaces. Various sizes and heights of columns were used to simulate different degrees of surface roughness. The “gra” series were composed of surfaces with different areas of section and the same height to simulate different degrees of surface roughness. The “rg” series were composed of concentric cuboids with continuous increasing heights and sizes. The “co” series surfaces were the most efficient distribution in changing the microscopic phase morphology, the “gra” and “rg” series surfaces were both the secondary, and the “ci” series surfaces placed the last. The results show that the effect of inducing surfaces depended on both the pattern of surfaces and the compositions of the blends. The shear effect was effective in changing the phase morphology, but its influencing effect depended on not only the shear rate, but also the compositions of the blends, especially when the blends were rich in PEO. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Three are Not Enough: An INDSCAL Analysis Suggesting that Color Space Has Seven (£1) Dimensions

Forty-five subjects, including color normals, protanomalous, deuteranomalous, protanopes, and deuteranopes, judged dissimilarities of 26 Munsell color chips chosen to span the full color space (i.e., all three parameters—hue, saturation, and lightness—were varied). Each of the 325 pairs of colors was mounted on a standard grey background board. They were presented to subjects in different random orders and were viewed under a Macbeth daylight lamp. For each pair the subject circled a number varying from 0 (for “identical”) to 9 (for “maximally dissimilar”). Fifty data matrices obtained from 45 subjects (5 were from the same subject on different dates and 2 were from another subject) were analyzed by the INDSCAL method. The three-dimensional solution yielded the “standard” three dimensions (lightness, red-green, and yellow-blue) with the classical “color circle” emerging, in a slightly distorted form, in the plane of the second and third dimensions. Seven dimensions seemed necessary to account fully for these data, however. In seven dimensions each of the “standard” dimensions is paired with a “folded” version. Accompanying lightness is a “folded” lightness dimensions, which we have called “lightness contrast.” The light and dark colors are at one end, contrasted with medium colors at the other. Similarly, “folded” red-green roughly contrasts red and green with blue, yellow, and the greys, while “folded” yellow-blue contrasts blue and yellow with red, green, and the greys. The seventh dimension, which may be artifactual, was called “split yellow.” It contrasts very brilliant (high Munsell value and chroma) yellow and orange colors with all the other colors. It is speculated that some of these extra dimensions may relate to anomalous receptor processes characteristic of deviant subjects. The INDSCAL subject space enables discrimination among all five subject types. Specifically, one of the “natural planes” (the red-green versus “folded” yellow-blue plane) of the seven-dimensional solution can be divided into contiguous and fairly compact regions, with each subject type occupying a unique region.     

Diterpene in Kaffeeölen zur Beurteilung von Rohkaffee nach Art und Bearbeitung

Diterpenes in Coffee Oils for the Evaluation of Raw Coffee According to Type and Processing Commercial varieties of coffee are classified into the types “Arabica” and “Robusta”. Differences between these two types are shown and the possibilities for their detection on the basis of diterpenes (cahweol) are explained. Arabica types contain cahweol in varying amounts, which can be quantitatively expressed by a colour reaction. Examples are given to show that the processing of raw coffee (steaming, decoffeination, C-5-HT-reduction) leads to varying degrees of reduction of cahweol colour absorption. Thus it is possible to recognize processed raw coffee on the basis of cahweol colour reaction and to express the effects of processing. Cahweol colour reaction is a suitable indicator for processed raw coffee, especially for steamed raw coffee.     

Analysis of coating on glass fiber reinforcements

Several commercially available glass fiber reinforcements were analyzed to determine the amounts (“loadings”) and types of coatings applied by their manufactures. Loadings were determined by solvent extraction and pyrolysis and ranged from 0.54 to 4.22 weight percent with the heaviest amounts on random mats and the least amounts on rovings intended for filament winding and weaving. The major components of the solvent-extracted coatings were identified by infrared (IR) and proton nuclear magnetic resonance (NMR) spectroscopies. All of the coatings analyzed could be sorted into three classes of coatings which matched the matrix types recommended by the glass manufacturers. In each case, the coating consisted primarily of a mixture of two separate materials, designated as the “unreacted resin” and the “lubricant”.     

Fluorescence polarization study of the curing process of epoxide with aminimide

The curing process of epoxide (Epikote 828, EK) with aminimide (trimethylamine valerimide, TMAV) was studied by a fluorescence polarization method. Two types of probe molecules were used: One was perylene (PE), which was just physically incorporated into the curing mixture and termed as the “extrinsic” probe, and the other was fluorescent product(s) formed during curing of EK with TMAV, which was termed as the “intrinsic” probe. Extraction experiments revealed that the “intrinsic” probe was covalently incorporated into the crosslinked matrix. No emission was observed for the “intrinsic” probe before heating, but its intensity increased with curing at 150°C. Fluorescence anisotropy (r) of both EK/TMAV/PE and EK/TMAV systems increased monotonically with curing time at the initial stage and then remained nearly constant. This means that at the early stage of curing the network becomes rigid enough to restrict rotational diffusion of the probe molecules. Calculated r values for the “extrinsic” probe alone were lower than observed r values of the “intrinsic” probe, which was well explained in terms of the mode of incorporation of the two types of the probe molecules into the matrix.     

生物可降解山麻杆韧皮纤维增强PBS复合材料的性能研究

以山麻杆韧皮纤维为增强体,其与PBS颗粒按质量比20∶80模压成型制备了4种板材,探讨了表面处理对纤维微观结构与物理性能的影响,分析比较了板材力学性能及生物降解性。结果表明, 采用物理化学相结合方法预处理后,表面依然存留一定量的果胶等物质;预处理纤维进一步碱处理后表面出现“S”形凹槽,预处理纤维进一步偶联剂处理后表面凹槽连续性好、深度深;碱处理、偶联剂处理后纤维拉伸强度分别提高5.08 %和降低3.58 %;相比纯PBS,偶联剂处理后纤维复合材料拉伸强度与弯曲强度各提高48.32 %和25.97 %,拉伸模量与弯曲模量各提高146.45 %和128.30 %;3种纤维复合材料生物可降解性变化趋势一致,但偶联剂处理后的材料失重率变化幅度最小。     

Purification of Polluted Source Water with Ozonoation and Biological Activated Carbon

In order to determine effective processes for purifying polluted source waters 1n Harbin City, various processes consisting of ozonation, sand filtration, and/or GAC filtration and adsorption, i.e., ozonation ( “O₃” Process), ozonatlon/sand filtration ( “O₃ + SF” Process), ozonation/biological activated carbon ( “O₃ + BAC” Process), ozonation/sand filtration/biological activated carbon ( “O₃ + SF + BAC” Process), and granular activated carbon (“GAC” Process) were tested In an 8 m³/d capacity pilot plant. In addition, a small plant of 500 L/d capacity was used to conduct comparative studies between the two processes “GAC” and “O₃ + BAC”, as well as two types of carbon.     

Analysis of Moisture Content and Density of Pears During Drying

Abstract

Solar dried pears of the “S. Bartolomeu” variety are a very much appreciated and preferred dried food product in Portugal. Nevertheless, the traditional solar drying is carried out at open air during the months of 07 and 08, and this nowadays is a disadvantage for larger productions. This work is to evaluate the possibility of producing dried pears from this and other varieties, maintaining the characteristics of the traditional dried pears. In this study four different types of pears were studied, including “S. Bartolomeu” as a basis for comparison and the drying method employed was the traditional one. From the results it was concluded that, although the behaviour of the four varieties do not vary significantly, one particular variety (“D. Joaquina”) is a good alternative to the “S. Bartolomeu” pear.     

Der Begriff der hochwertigen Dichtung für lösbare Rohrleitungsverbindungen

Concept of High-Quality Seals in Disconnectable Pipeline Connections. The “Technical Instruction Air” of the Federal Republic of Germany stipulates the use of highquality gaskets in flange connections employed in handling of certain hazardous materials, but it gives no detailed informations concerning the high-quality criterion. This article gives reasons why the highquality criterion should be extended on all elements of disconnectable pipeline connections of various types which are to be evaluated as systems. It further discusses the basic aspect of quality management as well as the terms ?secluded emission”? and “diffuse emission”, which should be avoided or minimized respectively. The following criteria of high-quality pipeline connections are discussed: Design reserves, corrosion resistance, position fixing, safety against fracture without deformation, tightnessperiod and process hygiene.     

Fabrication of Function‐Graded Proton Exchange Membranes for Direct Methanol Fuel Cells Using Electron Beam‐Grafting

Function‐graded proton exchange membranes (G‐PEMs) based on poly(tetrafluoroethylene‐co‐hexafluoropropylene) were fabricated for direct methanol fuel cells (DMFCs) via electron beam‐grafting using the heterogeneous energy deposition technique. The G‐PEMs had a water uptake gradient in the proton transfer direction, originating from the sulfonic acid group gradient. The distribution of sulfonic acid groups in the various G‐PEMs was evaluated using X‐ray photoelectron spectroscopy. Four types of PEMs (flat‐type, strong‐gradient, meso‐gradient, and weak‐gradient types) were fabricated. By varying the direction of the G‐PEMs, the methanol permeation test and DMFC operation were performed with two orientations of the sulfonic acid group gradient, decreasing from the methanol injection (anode) side (decrease‐type) or the other (cathode) side (increase‐type). The methanol permeability of the strong‐gradient, meso‐gradient, and weak‐gradient G‐PEMs was lower than that of Nafion®117 and the flat‐type PEM. The “increase‐type” orientation of the strong‐gradient G‐PEM resulted in the lowest methanol permeability. The DMFC performance of the G‐PEMs was influenced by the thickness direction, such as “decrease‐type” and “increase‐type.” The performance of the “decrease‐type” assembly was higher than that of the “increase‐type.” The “decrease‐type” assembly with P‐200 k (weak‐gradient G‐PEM) exhibited the highest performance of the fabricated PEMs, comparable to that of Nafion®117.     

Isolation and Characterization of Chicken Yolk Vitelline Membrane Lipids Using Eggs Enriched With Conjugated Linoleic Acid

The vitelline membrane (VM) encloses the chicken egg yolk, separating it from albumen. The VM weakens during storage, and dietary lipid modification significantly affects its strength. However, no studies have characterize the fatty acyl residue (FA) composition of the VM, and reports of VM isolation and quantified lipid content are inconsistent. Therefore, the objectives of this study were: (1) to develop a washing and isolation method that removes residual yolk from VM without damage; (2) to determine the FA and lipid composition of CLA‐rich egg yolk VM, relative to controls; (3) to determine the effect of 20 days of refrigeration on VM FA and lipid composition. To determine VM FA and lipid composition, 36 hens received either a corn‐soybean meal‐based control diet (“Control”), or the Control supplemented with either 10 % soy oil (“Soy control”), or 10 % CLA‐rich soy oil (“CLA”) for 30 days. VM were analyzed the day of collection (“fresh”), or after 20 days of refrigeration (“refrigerated”). There were no differences in FA compositions of fresh and refrigerated membranes within a treatment. CLA‐rich yolk VM contains CLA, greater SFA, and significantly greater DHA relative to controls. Direct MALDI‐TOF–MS identified 15 phosphatidylcholines, three phosphatidylethanolamines, one sphingomyelin, and 15 triacylglycerols in VM. Lipid species that showed significant differences among egg types included nine phosphatidylcholines and six triacylglycerols. MALDI analysis indicated significant differences in nine lipid classes on the VM inner layer. After refrigeration, five lipid classes on the inner layer and seven lipid classes on the outer layer had statistically significant differences among VM types.     

A Brief History of Chemical Reactor and Reaction Technology

The term “chemical reactor” appears for the first time in open literature at the end of First World War, while in Germany the term “reaction technology” was coined in the 1950s, although chemical reactions and processes have been known for thousands of years. In the early days, reactors were furnaces and pots, which specialized further over the centuries. With the Industrial Revolution many reactor types were already known, and industrialization brought an enormous innovation thrust in the field of products as well as technologies. The diversity of reactors today is almost uncomprehensive and so efforts to standardize apparatus are understandable.     

Molecular Fingerprint Recombination: Generating Hybrid Fingerprints for Similarity Searching from Different Fingerprint Types

Molecular fingerprints have a long history in computational medicinal chemistry and continue to be popular tools for similarity searching. Over the years, a variety of fingerprint types have been introduced. We report an approach to identify preferred bit subsets in fingerprints of different design and “recombine” these bit segments into “hybrid fingerprints”. These compound class‐directed fingerprint representations are found to increase the similarity search performance of their parental fingerprints, which can be rationalized by the often complementary nature of distinct fingerprint features.     

The function of lubricants in processing of rigid poly(vinyl chloride)

In this review of lubricants and how they function the lubrication mechanism is broken down into three stages: the heat absorption (onset of gelation), gelation (fusion process), and melt flow (postfusion) stages. The terms “internal” and “external” are used to describe the functionality of the lubricant at each stage. It is pointed out that these terms should not be used to label lubricants themselves, because most lubricants perform differently at each stage of processing. How the chemical and physical properties of various types of lubricants perform in each of the fusion stages is also discussed.