Degree Of Heat Treatment Research Articles

Curry leaf (Murraya koeneigii) extract as a natural source of antioxidants for enhancing the oxidative and thermal stability of ghee

Ghee is used for making various sweets and dishes in addition to its various culinary purposes. In the course of such preparations, ghee is subjected to different degrees of heat treatment which on combining with air can undergo considerable physico-chemical changes. The high temperature cooking process creates a series of complex chemical reactions in ghee which affects the sensory and the functional properties of foods as well as the ghee used. This leads to adverse health effects on consumers. One of the best ways to protect ghee from autooxidation and thermal oxidation is by the incorporation of antioxidants during their processing. Addition of synthetic antioxidants is restricted in several countries. Scientific investigations have also found that the use of synthetic antioxidants in foods may harm the liver and lead to the development of cancer. The aim of the present study was to check the effect of curry leaves (Murraya koeneigii) extract on the thermal stability of ghee. Based on the peroxide and thiobarbituric acid (TBA) value determinations, it was observed that quality of ghee samples added with 1 % CLE during frying was significantly higher than that of control (ghee without antioxidant) and ghee added with 0.02 % BHA (a synthetic antioxidant). At 15 minutes of frying (180°C), the peroxide value was 3.615±0.24, 1.04±0.10 and1.07±0.02 mM O2/kg fat for the control, BHA added and CLE added ghee respectively and this increased to 8.23±0.23, 6.47±0.21 and 4.0±0.01 mM O2/kg fat after 60 minutes of frying, respectively. Findings suggested that CLE could be used as a source of natural antioxidants for imparting thermal stability to ghee during frying.

DATA MINING AND ITS IMPACT ON MARKETING COMMUNICATION – CASE: HEAT-TREATED BIRCH WOOD

The article presents the results of a marketing survey in the area of customer preferences in the case of different degrees of heat-treated solid wood and birch veneer. Part of the marketing survey was a questionnaire survey, where the respondents, as potential customers, expressed their preferences for individual samples which, at first glance, differed in colour due to the different degrees of heat treatment. The result of the research is a clear preference for the heat-treated samples compared to the reference sample without heat treatment. A more detailed secondary analysis of the data from the questionnaire survey was performed with regard to the gender, age and education of the respondents. Here, too, it is possible to conclude a clear preference for heat-treated samples for these groups of respondents. The article also analyses the possibilities of the marketing strategy with a focus on marketing communication, especially in relation to wood processors and producers.

Performance of Commercial Colorimetric Assays for Quantitation of Total Soluble Protein in Thermally Treated Milk Samples

Commercial colorimetric protein assays have been widely used, but their performance for protein quantitation in thermally processed milk samples has not been investigated. This study evaluated four colorimetric assays for quantitation of soluble protein in nonfat milk samples that were subjected to different degrees of heat treatment. Copper ion-based Pierce™ bicinchoninic acid protein assay (BCA) and Pierce™ modified Lowry protein assay (modified Lowry) consistently registered higher protein levels than those determined by dye binding-based Pierce™ Coomassie Plus (Bradford) assay (Coomassie Plus) or Pierce™ 660-nm protein assay (660-nm). When milk samples were autoclaved or dry-heated at ≥ 121 °C for 10 min, reduction in soluble protein content was reflected in measurements of Coomassie Plus and 660-nm assays but was not indicated by BCA or modified Lowry assays. In samples dry-heated at 176 °C, while no protein was detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), Coomassie Plus or 660-nm, BCA, and modified Lowry indicated protein levels that were 215.7 and 79.4%, respectively, of those of unheated samples. Analysis of lactose samples showed that lactose may contribute to a 13.4 or 1.0% overestimation in BCA or modified Lowry measurement of protein content in unheated dry milk samples. This study demonstrated that quantitation of protein in thermally treated milk samples using copper ion-based BCA and modified Lowry assays could be significantly affected by lactose and, to a greater degree, other reducing substances formed during heating likely via the caramelization and Maillard reaction pathways. In contrast, dye binding-based Coomassie Plus and 660-nm assays were not affected and may be more accurate for measurement of protein content in thermally treated milk samples.

Changes of 5-hydroxymethyl-2-furfural in fresh and processed ginsengs.

The study estimated changes of 5‐hydroxymethyl‐2‐furfuraldehyde (5‐HMF) in different ginseng products with different temperatures and time pretreatment. Heat treatment was performed at various temperatures for 1.50, 2.00, 2.50, and 3.00 hr, respectively. Ultrasonic extraction and reflux extraction were used to evaluate the extraction rate and different solvents (such as 80% methanol, dichloromethane, ethyl acetate, and an extraction with both dichloromethane and ethyl acetate solvents) using two extraction methods (liquid–liquid extraction and solid‐phase extraction) to remove matrix interference. An ultraperformance liquid chromatography–mass spectrometer (UPLC‐MS) method was used for quantitative and changing analysis of 5‐HMF in different ginseng samples. The results indicated that the content of 5‐HMF increased dramatically with heating temperature and time, and the 5‐HMF in the ginseng samples ranged from 0.01 to 112.32 g/kg protein. The highest value was observed in the honey‐added ginseng samples with the highest amount of addition and highest temperature treatment, and the lowest value was found in the fresh ginseng samples. These results implied that 5‐HMF may be as an indicator to estimate the honey addition level and heat treatment degree during the processing of ginseng products, and the content of 5‐HMF is a promising parameter to evaluate the quality of products (ginseng). The production and regulation of potentially harmful Maillard reaction products (PHMRPs)‐5‐HMF in ginseng manufacture will provide an important reference for safe ginseng processing.

Endpoint Temperature Influences Sarcoplasmic Proteome Profile of Cooked Beef Longissimus Lumborum

ObjectivesCooking ensures safety and enhances the palatability attributes of meat. Denaturation of myoglobin results in the dull-brown color of cooked meats. The denaturation of sarcoplasmic proteins is influenced by the degree of heat treatment, and their solubility is decreased with an increase in the endpoint cooking temperature. While previous studies examined the relationship between myoglobin denaturation, cooked color, and internal temperature in beef, investigations are yet to be undertaken to characterize the association between endpoint temperature, sarcoplasmic proteome, and color attributes in cooked steaks. Therefore, the objective of the present study was to examine the influence of endpoint cooking temperature (60 and 71°C) on sarcoplasmic proteome and internal color of beef longissimus lumborum (LL) steaks.Materials and MethodsEight (n = 8) beef LL muscles (14 d postmortem; USDA Choice) were obtained from a commercial packing plant. Two 2.5-cm thick steaks were fabricated from the center of the muscles and were cooked to internal endpoint temperature of 60°C (C-60) or 71°C (C-71) in a clam-shell grill. Cooked steaks were immediately cooled in slushed ice, sliced parallel to the grilled surface, and internal redness (a* value) and color stability (R630/580) were evaluated instrumentally. Sarcoplasmic proteome from the interiors of the cooked steaks was analyzed using 2-dimensional electrophoresis, and the gel images were digitally analyzed. The protein spots exhibiting more than 2.5-fold intensity differences (P < 0.05) between C-60 and C-71 were subjected to in-gel tryptic digestion and were identified by tandem mass spectrometry.ResultsThe C-60 steaks demonstrated greater (P < 0.05) a* and R630/580 than their C-71 counterparts. Seven differentially abundant proteins were identified and were over-abundant (P < 0.05) in C-60 compared to C-71. The differentially abundant proteins belong to 6 functional groups, i.e., transport proteins (serum albumin and hemoglobin), energy metabolism (adenylate kinase isoenzyme 1), chaperones (heat shock protein β-1), antioxidant (thioredoxin-dependent peroxide reductase), glycolytic enzymes (fructose-bisphosphate aldolase B), and protease (cytosol aminopeptidase).ConclusionThe findings indicated that the endpoint cooking temperature influences the internal cooked color and the sarcoplasmic proteome profile of beef LL steaks. The overabundant proteins in steaks cooked to 60°C may be utilized as potential biomarkers for undercooked beef, which is a source for foodborne infections.

Influence of Site Conditions and Quality of Birch Wood on Its Properties and Utilization after Heat Treatment. Part I—Elastic and Strength Properties, Relationship to Water and Dimensional Stability

This work deals with the quality of birch (Betula pendula) wood from different sites and the impact of heat treatment on it. Two degrees of heat treatment were used, 170 °C and 190 °C. The resulting property values were compared with reference to untreated wood samples. These values were wood density, compressive strength, modulus of elasticity (MOE), bending strength (MOR), impact bending strength (toughness), hardness, swelling, limit of hygroscopicity, moisture content and color change. It was supposed that an increase in heat-treatment temperature could reduce strength properties and, adversely, lead to better shape and dimensional stability, which was confirmed by experiments. It was also shown that the properties of the wood before treatment affected their condition after heat treatment, and that the characteristic values and variability of birch properties from 4 sites, 8 stems totally, were reflected in the properties of the heat-treated wood. Values of static MOR were the exception, where the quality of the input wood was less significant at a higher temperature, and this was even more significant in impact bending strength, where it manifested at a lower temperature degree. Impact bending strength also proved to be significantly negatively affected by heat treatment, about 48% at 170 °C, and up to 67% at 190 °C. On the contrary, the most positive results were the MOE and hardness increases at 170 °C by about 30% and about 21%, respectively, with a decrease in swelling at 190 °C by about 31%. On the basis of color change and other ascertained properties, there is a possibility that, after suitable heat treatment, birch could replace other woods (e.g., beech) for certain specific purposes, particularly in the furniture industry.

Endpoint Temperature Influences Sarcoplasmic Proteome Profile of Cooked Beef Longissimus Lumborum

ObjectivesCooking ensures safety and enhances the palatability attributes of meat. Denaturation of myoglobin results in the dull-brown color of cooked meats. The denaturation of sarcoplasmic proteins is influenced by the degree of heat treatment, and their solubility is decreased with an increase in the endpoint cooking temperature. While previous studies examined the relationship between myoglobin denaturation, cooked color, and internal temperature in beef, investigations are yet to be undertaken to characterize the association between endpoint temperature, sarcoplasmic proteome, and color attributes in cooked steaks. Therefore, the objective of the present study was to examine the influence of endpoint cooking temperature (60 and 71°C) on sarcoplasmic proteome and internal color of beef longissimus lumborum (LL) steaks.Materials and MethodsEight (n = 8) beef LL muscles (14 d postmortem; USDA Choice) were obtained from a commercial packing plant. Two 2.5-cm thick steaks were fabricated from the center of the muscles and were cooked to internal endpoint temperature of 60°C (C-60) or 71°C (C-71) in a clam-shell grill. Cooked steaks were immediately cooled in slushed ice, sliced parallel to the grilled surface, and internal redness (a* value) and color stability (R630/580) were evaluated instrumentally. Sarcoplasmic proteome from the interiors of the cooked steaks was analyzed using 2-dimensional electrophoresis, and the gel images were digitally analyzed. The protein spots exhibiting more than 2.5-fold intensity differences (P < 0.05) between C-60 and C-71 were subjected to in-gel tryptic digestion and were identified by tandem mass spectrometry.ResultsThe C-60 steaks demonstrated greater (P < 0.05) a* and R630/580 than their C-71 counterparts. Seven differentially abundant proteins were identified and were over-abundant (P < 0.05) in C-60 compared to C-71. The differentially abundant proteins belong to 6 functional groups, i.e., transport proteins (serum albumin and hemoglobin), energy metabolism (adenylate kinase isoenzyme 1), chaperones (heat shock protein β-1), antioxidant (thioredoxin-dependent peroxide reductase), glycolytic enzymes (fructose-bisphosphate aldolase B), and protease (cytosol aminopeptidase).ConclusionThe findings indicated that the endpoint cooking temperature influences the internal cooked color and the sarcoplasmic proteome profile of beef LL steaks. The overabundant proteins in steaks cooked to 60°C may be utilized as potential biomarkers for undercooked beef, which is a source for foodborne infections.

Technology of Creating Decorative Panels Made of Thermomodified Veneer

Development of new technologies for creating artistic products in order to improve their functional, ergonomic and aesthetic properties is an important directions of improving the design of items. The article presents the technology of production of decorative composite panels obtained by gluing coloured veneer sheets made of low-value wood. Staining is proposed to proceed by thermomodification that allows you to obtain natural colours characteristic of valuable tree species, without using chemicals. Research on determination of the basic properties of the plywood produced on the basis of the heat-treated veneer are carried out. Studies have shown that high-temperature processing of veneer when manufacturing plywood provides an increase in the dimensional stability, moisture resistance and durability of the composite, without increasing its toxicity. It is established that in the process of thermomodification wood material changes its colour to darker, the texture is revealed more clearly. Thus, as a result of alternating veneer sheets with different degrees of heat treatment, it is possible to obtain a composite material with high decorative characteristics and interesting transverse texture.

Determining the degree of heat treatment of wood by light polarization technique

Thermal modification of wood enables the use of non-durable wood species in exterior applications, but quality control methods are required to monitor the product variability. This study tests the potential of a light polarization technique where visible light (400–500 nm) is directed through a linear polarizer to the surface of thermally modified wood to measure the reflectance. Besides an effect of the grain direction, the reflectance decreased with increasing temperature during the thermal modification process. The technique could be used for quality control, but further studies are required to understand its modes of action.

Classification of the hot air heat treatment degree of larch wood using a multivariate analysis of near-infrared spectroscopy

In this study, hot air heat treatments of larch (Larix kaempferi) wood specimens were conducted at various temperatures (160–220 °C) and times (1–12 h) to classify the degree of hot air heat treatment using near-infrared (NIR) spectroscopy. NIR reflectance spectra were acquired from specimen cross-sections and were then preprocessed using the standard normal variate. Hierarchical clustering analysis (HCA) using the complete linkage and squared Euclidean distance was conducted to classify the three degrees of heat treatment. A principal component score plot of the NIR spectra was well grouped by the HCA grouping result, and the first component reflected the cluster analysis grouping well. A partial least squares discriminant analysis was performed to develop the discriminant regression model of the three heat treatment degrees. The R2 and root mean square error of validation were 0.959 and 0.191, respectively. NIR is considered to be a good candidate to routinely measure the degree of hot air treatment for larch wood.

Effect of light-curing, pressure, oxygen inhibition, and heat on shear bond strength between bis-acryl provisional restoration and bis-acryl repair materials.

PURPOSEThis study aimed to discover a way to increase the bond strength between bis-acryl resins, using a comparison of the shear bond strengths attained from bis-acryl resins treated with light curing, pressure, oxygen inhibition, and heat.MATERIALS AND METHODSSelf-cured bis-acryl resin was used as both a base material and as a repair material. Seventy specimens were distributed into seven groups according to treatment methods: pressure - stored in a pressure cooker at 0.2 Mpa; oxygen inhibition- applied an oxygen inhibitor around the repaired material,; heat treatment - performed heat treatment in a dry oven at 60℃, 100℃, or 140℃. The shear bond strength was measured with a universal testing machine, and the shear bond strength (MPa) was calculated from the peak load of failure. A comparison of the bond strength between the repaired specimens was conducted using one-way ANOVA and Tukey multiple comparison tests (α=.05).RESULTSThere were no statistically significant differences in the shear bond strength between the control group and the light curing, pressure, and oxygen inhibition groups. However, the heat treatment groups showed statistically higher bond strengths than the groups treated without heat, and the groups treated at a higher temperature resulted in higher bond strengths. Statistically significant differences were seen between groups after different degrees of heat treatment, except in groups heated at 100℃ and 140℃.CONCLUSIONStrong bonding can be achieved between a bis-acryl base and bis-acryl repair material after heat treatment.

Diffraction, attenuation, and source corrections for nonlinear Rayleigh wave ultrasonic measurements

This research considers the effects of diffraction, attenuation, and the nonlinearity of generating sources on measurements of nonlinear ultrasonic Rayleigh wave propagation. A new theoretical framework for correcting measurements made with air-coupled and contact piezoelectric receivers for the aforementioned effects is provided based on analytical models and experimental considerations. A method for extracting the nonlinearity parameter β11 is proposed based on a nonlinear least squares curve-fitting algorithm that is tailored for Rayleigh wave measurements. Quantitative experiments are conducted to confirm the predictions for the nonlinearity of the piezoelectric source and to demonstrate the effectiveness of the curve-fitting procedure. These experiments are conducted on aluminum 2024 and 7075 specimens and a β117075/β112024 measure of 1.363 agrees well with previous literature and earlier work. The proposed work is also applied to a set of 2205 duplex stainless steel specimens that underwent various degrees of heat-treatment over 24h, and the results improve upon conclusions drawn from previous analysis.

Mitigation of acrylamide and hydroxymethyl furfural in instant coffee by yeast fermentation

Acrylamide being known as carcinogenic and hydroxymethyl furfural (HMF) being known as cytotoxic compounds are heat induced process contaminants found in instant coffee. Today's instant coffee production method involves roasting of coffee beans, grinding, flavor and aroma separation, extraction, concentration, and drying steps. During roasting, acrylamide and HMF are formed in varying amounts depending upon the degree of heat treatment as a result of the Maillard reaction. This study was conducted in order to reduce the concentrations of acrylamide and HMF in instant coffee. Instant coffee (20%, w/v) was mixed with sucrose (0–10, w/v) and baker's yeast (Saccharomyces cerevisiae, 1–2%, w/v) in a tightly closed glass vessel. The mixture was fermented at 30°C for 48h. The kinetics of acrylamide and HMF degradation was investigated. HMF and acrylamide contents were reduced exponentially at varying rates, depending upon fermentation medium and time. After 24h, HMF concentration was decreased by 61.2%, 75.7%, 93.6% and 99.2% in the fermentation media containing none, 1%, 5%, and 10% of sucrose, respectively. After 48h, acrylamide concentration was decreased by about 70%. These results revealed that yeast fermentation is promising for the mitigation of HMF and acrylamide in instant coffee.

Effect of particle size and heat treatment of soybean meal on standardized ileal digestibility of amino acids in growing pigs1

A study with growing barrows was conducted to evaluate of variations in particle size and degree of heat treatment during processing on standardized ileal digestibility (SID) of AA in soybean (Glycine max) meal (SBM). A commercial SBM batch was visually identified as being overtoasted due to its brownish color and was separated into small and large particles using a 1-mm sieve. In addition, 3 SBM were produced from 1 batch of soybean and exposed to different processing conditions (temperature and direct steam contact) referred to as mild (105°C; 34 min), medium (115°C; 45 min), and strong (139°C; 7 min). In total, 5 SBM-corn (Zea mays) starch-based diets were formulated to contain SBM as the sole protein source. This experiment was conducted according to a 6 × 6 Latin square design using 6 barrows (23 kg initial BW) fitted with a T-cannula at the distal ileum. With increasing particle size, SID of His and some dispensable AA increased (P < 0.05). Lower SID values in small compared to large SBM particles indicate more pronounced heat damage possibly due to increased surface area. The SID of CP and AA was lowest in the mild, intermediate in the strong, and highest in the medium toasted SBM (P < 0.001). These differences in SID are reflected in varying contents of trypsin inhibitors, Lys, reactive Lys, and NDF. In conclusion, both differences in particles size and variations in thermal processing conditions of SBM may affect SID of CP and AA.

Modelling of metal forging using SPH

In solid metal forming processes, such as forging, large distortions in the material present challenging problems for numerical simulation using grid based methods. Computations invariably fail after some level of mesh distortion is reached unless suitable re-meshing is implemented to cope with the mesh distortion arising from the material deformation. The issue of mesh distortion and the subsequent re-meshing are topics of much research for grid based methods. These problems can be overcome by using a mesh-less numerical framework. In this paper, the application of a mesh-less method called Smoothed Particle Hydrodynamics (SPH) for modelling three-dimensional complex forging processes is demonstrated. It is shown that SPH is a useful simulation method for obtaining insights into the material deformation and flow pattern during forging of realistic industrial components. The effect of process parameters and material properties on the quality of the forged component is evaluated via SPH simulations. This includes the determination of forging force required for adequate die filling which is an important criterion for die designs. Material hardening, controlled by the degree of heat treatment, is found to have a profound effect on the material deformation pattern and the final product. Forging defects such as incomplete die filling, asymmetry in forged components, flashing and lap formation are shown to be predicted by SPH. SPH can thus potentially be used both for assessment of the quality of forged products and evaluation of prototype forging system designs.

Evaluation of Functional Properties of Four Soy Flours Produced in Iran

Soy flour is the least processed form of soy protein products which has become increasingly popular in food technology for its nutritional benefits, low cost and good functional properties. The aim of this study was to investigate functional properties of soy flours produced by four different industrial processes: defatted, defatted and toasted, low fat, and full fat soy flours. Because of different production procedure and degrees of heat treatment, soy flours had significant differences in protein dispersibilities (which determine the amount of residual trypsin inhibitors and use of the final products) and fat contents which affected on other functionalities. Soy flours with lower protein dispersibility indices (PDI) had lower foaming properties (capacity and stability), emulsification (activity and stability), water holding and fat binding capacities, and solid dispersibility indices. Comparison of low fat and full fat soy flour showed that fat content result in reduced functionalities such as water holding and fat binding capacities, emulsification stability, and solid dispersibility. Negative effects of fat content increase on functional properties are equal or more than PDI. Keywords: Defatted soy flour, Defatted and toasted soy flour, Full fat soy flour, Low fat soy flour, Functional properties, Soy

Bonding of Heat-Treated Spruce with Phenol-Formaldehyde Adhesive

The modified chemical, physical and structural properties of wood after heat treatment can affect the bonding process with adhesives. The objective of this research was to determine to what extent the degree of heat treatment influenced the bonding of treated wood with phenol-formaldehyde (PF) adhesive. Spruce (Picea abies Karst) lamellas were heat treated at 180°C and 220°C and then bonded. The shear strength and wood failure of the differently pretreated specimens were determined. Wettability and penetration of the adhesive were also investigated. The results showed that the shear strength of the PF adhesive bond was influenced by the heat treatment of the spruce wood, and depended on the type of pretreatment of the wood specimen prior to testing. The observed reduction in the shear strength of the PF adhesive bond was ascribed to a decrease in the wood strength itself, caused by the heat treatment, and also to other effects induced by exposure of the wood to elevated temperatures. The changes in wettability and adhesive penetration did not significantly influence the bonding process of the heat-treated wood with the PF adhesive.

Improved dissolution and chemical separation methods for Lu‐Hf garnet chronometry

Garnet‐based Lu‐Hf geochronology using conventional (HF‐HNO3) dissolution methods may be compromised by full or partial digestion of Hf‐rich zircon inclusions. This study integrates two complimentary methods to substantially reduce zircon digestion while assuring complete digestion of garnet and sample‐spike equilibration. Handpicked garnet fractions are heat treated to &gt;1000°C in an evacuated silica glass ampoule to anneal zircon inclusions and then dissolved with 12 M HCl at 210°C and cold 28 M HF. Analyses of heat‐treated garnet (and their high‐temperature breakdown products orthopyroxene‐spinel‐quartz) from Gore Mountain, New York, demonstrate the method is capable of complete dissolution of garnet and routinely achieving sample‐spike equilibration. Independent analyses of annealed and unannealed zircons dissolved by HCl – cold HF demonstrate the benefit of heat treatment prior to dissolution. Analyses of zircon‐rich garnets from peletic paragneisses of Labrador, Canada, show the potential of this method by returning Lu‐Hf ratios commensurate with the degree of heat treatment. Finally, a complementary chemical separation method for Lu and Hf is presented that supports analysis of garnet by MC‐ICP‐MS.

Effects of borate impregnation on the response of wood strength to heat treatment

Based on the strong correlation between acidity and thermal degradation in wood reported in previous studies, the effect of borate impregnation as an alkali-buffering medium was investigated on the strength properties of thermally modified wood. Wood samples were impregnated with 0.1 M Sodium borate solution (pH=9) before they were subjected to heat treatment at temperatures of 180°C and 200°C for durations of 2 and 4 h. The borate impregnation results in some reductions in the severity of strength loss during heat treatment and this is invariably due to buffering effect of the alkali on the acidity of wood, which could have mitigated the degree of degradation. The positive effects of borate impregnation as a pretreatment on the strength properties of heat-treated wood depend on the degree of heat treatment. Hence, the use of borate impregnation as a pretreatment method for heat treatment is recommended only where a relatively mild heat treatment is involved.

An Assessment of the Mechanical Strengths of Aluminide-based Thin Coatings

ABSTRACTTitanium aluminide and nickel aluminide-based thin coatings were synthesized by magnetron sputtering from intermetallic TiAl and Ni3Al alloy targets on nickel substrates. Both types of aluminide coatings exhibited high surface hardness values that varied with the degree of heat treatment. The hardness of the coatings was investigated using micro- and nano- indentation techniques. In order to estimate the intrinsic strength of the films, the indentation size effects of the apparent hardness were analyzed by the Jönsson-Hogmark model and a model recently proposed by the authors. The analysis indicated that the strengths of the aluminide coatings may considerably exceed their strengths in bulk.