Microstructural design of cellular materials—II: Microsandwich foams

The linear elastic behaviour of foams is primarily controlled by bending of cell walls. The mechanical performance of foams can be improved by increasing the bending stiffness of the cell walls. Recently, our group has developedmicrosandwich foams in which the cell walls are microsandwich elements. The improved bending stiffness of the walls resulting from the sandwich microstructure increases their performance indices. Here, we describe a finite element analysis of the Young's moduli and Poisson's ratio of microsandwich foams. We then use the analysis to perform a parametric study of the way in which the performance of the microsandwich foams depends on microstructural parameters. Finally we compare the results of the analysis with data for three microsandwich foams. The analysis describes the data well.     

Microstructural design of cellular materials—I: honeycomb beams and plates

Performance indices for materials describe the mechanical efficiency of a component under a given mode of loading: the higher the performance index, the lower the mass of the component for a given mechanical requirement. Material selection charts offer a graphical means of comparing performance indices for a wide range of materials. The performance indices are first described. Micromechanical models for the behaviour of cellular materials are then used to suggest novel microstructural designs for cellular materials with improved performance. Model materials with two of the microstructures, honeycomb beams and plates, have been fabricated and tested. The results of the tests indicate that the new microstructures have higher values of some performance indices than those of the solids from which they are made.     

Effective interface model for design and tailoring of WC–Co microstructures

Interface structures are a key feature in developing modern composite material solutions with ever improved performance. We present a nano-microstructural modelling approach for the tungsten carbide (WC)–Co system which can include the interface structures of WC–Co and various other phases present in the microstructure, utilising a methodology which combines imaging-based and synthetically generated nano-microstructures into an effective interface model for predicting the behaviour and properties of the resulting composite material. The effective model comprises of a local model of the WC/Co interface interacting with a larger-scale model of the WC–Co microstructure. The results provide a linkage between the interface character of cemented carbide microstructures and their properties, for example with respect to compressive strength, fracture toughness and wear resistance. The methodology presents a multiscale formalism for carrying out performance and application-driven evaluation and tailoring of composite interfaces and mesostructures, carried out on the basis of the emerging engineering material properties.     

Simulation and verification of core–shell MC carbide design in Fe–C–Ni–V–Ti steel

Thermodynamic theory was used to calculate the formation temperature and site fraction of MC carbides in Fe–C–Ni–V–Ti system. The calculation results showed the...     

Index of reviews and notes on statistical methods and research design in the Psychological Bulletin, 1967–1978.

Updates the previous index of reviews and notes on statistical methods and research design compiled by T. Andrews (1967). Organization of this index is identical to that of the authors' index of literature reviews (see record 1980-06186-001), and summaries and articles on topics of statistics and research design that are included in the larger index are also included in this index. Author and subject indexes are included. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Optimization of parameters for cerium(Ⅲ) biosorption onto biowaste materials of animal and plant origin using 5-level Box-Behnken design: Equilibrium,kinetic, thermodynamic and regeneration studies

Response surface methodology(RSM) employing 5-level Box-Behnken design was used to optimize the biosorption of cerium(Ⅲ) onto biowaste materials of animal and plant origin viz. prawn carapace(PC) and corn style(CS). Various process parameters viz. pH(A: 3.0–9.0), biomass dosage(B: 0.05–0.35 g/L), initial metal concentration(C: 50–350 mg/L), contact time(D: 2–6 h) and temperature(E: 20–60 °C) were chosen for optimization. A log transformation was suggested by the Box-Cox plot in the present case. A low p-value of 0.0001 validated the significance of the model. Maximum Ce(Ⅲ) uptake of 218.3 mg/g for PC and 180.2 mg/g for CS was noted under optimum conditions. Among the equilibrium isotherms, Freundlich model was found to be the best fitted one suggesting a heterogeneous mode of biosorption on PC whereas Langmuir model showed the best fit suggesting homogeneous mode of cerium biosorption on CS. This was further confirmed by scanning electron microscopy(SEM). Kinetic studies showed better applicability of pseudo-first order model suggesting physisorption as phenomena underlying the process. Film-diffusion was suggested by the non-linearity of the Boyd plot. Thermodynamic studies showed that the process was endothermic and spontaneous. FTIR analysis confirmed a major involvement of the participation of amide, amines, ketones and primary alcohol groups during Ce(Ⅲ) biosorption. EDAX analysis confirmed the major participation of carbon group during Ce(Ⅲ) biosorption. This was the first report on parameter optimization of Ce(Ⅲ) biosorption onto biowaste materials using 5-level Box-Behnken experimental design which might be helpful for the recovery of Ce(Ⅲ) from aqueous environment.     

Optimization of parameters for cerium（III） biosorption onto biowaste materials of animal and plant origin using 5-level Box-Behnken design：Equilibrium,kinetic, thermodynamic and regeneration studies

Response surface methodology （RSM） employing 5-level Box-Behnken design was used to optimize the biosorption of cerium（III） onto biowaste materials of animal and plant origin viz. prawn carapace （PC） and corn style （CS）. Various process parameters viz. pH （A：3.0-9.0）, biomass dosage （B：0.05-0.35 g/L）, initial metal concentration （C：50-350 mg/L）, contact time （D：2-6 h） and temperature （E：20-60 ℃ were chosen for optimization. A log transformation was suggested by the Box-Cox plot in the present case. A low p-value of〈0.0001 validated the significance of the model. Maximum Ce（III） uptake of 218.3 mg/g for PC and 180.2 mg/g for CS was noted under optimum conditions. Among the equilibrium isotherms, Freundlich model was found to be the best fitted one suggesting a heterogeneous mode of biosorption on PC whereas Langmuir model showed the best fit suggesting homogeneous mode of cerium biosorption on CS. This was further confirmed by scanning electron microscopy （SEM）. Kinetic studies showed better applicability of pseudo-first order model suggesting physisorption as phenomena underlying the process. Film-diffusion was suggested by the non-linearity of the Boyd plot. Thermodynamic studies showed that the process was endothermic and spontaneous. FTIR analysis confirmed a major involvement of the participation of amide, amines, ketones and primary alcohol groups during Ce（III） biosorption. EDAX analysis confirmed the major participation of carbon group during Ce（III） biosorption. This was the first report on parameter optimization of Ce（III） biosorption onto biowaste materials using 5-level Box-Behnken experimental design which might be helpful for the recovery of Ce（III） from aqueous environment.     

MMCX—An expert system for metal matrix composite selection and design

Metal Matrix Composites (MMCs) are a relatively new class of engineering materials that offer the designer an opportunity to tailor properties to meet specific requirements. The paper summarizes the development of an expert system which supports engineers in the selection and design of metal matrix composites. The system consists of a dynamic hypertext interface integrated into an expert system developed within the COMDALE/X environment. Mechanical and thermophysical property data for matrix alloys, reinforcement materials, and MMCs are stored in databases accessed by the expert system. Mathematical models which utilize constituent material properties to determine effective composite properties are managed by the system to design metal matrix composites and fill property gaps. Effective elastic modulus, thermal conductivity, coefficient of thermal expansion. Poisson's ratio, shear and bulk moduli mathematical models for particulate, whisker, short fiber and fiber composites are contained in a spread sheet managed by the system. Although the physical and mechanical properties may often limit the constituent selection, it is the chemical reactivity of the ceramic reinforcement with the matrix alloy either during fabrication or service which will generally control the final matrix/reinforcement combination. As a result, constituent material compatibility has been determined and incorporated in the system. A database of appropriate reinforcement coatings for applicable matrix/reinforcement systems is also helpful. The system also includes information on suitable manufacturing techniques. A case study demonstrating the use of the system for selecting an MMC for cryogenic applications is presented.     

Utility of the MMPI–2-RF (Restructured Form) validity scales in detecting malingering in a criminal forensic setting: A known-groups design.

The current study examined the utility of the recently released Minnesota Multiphasic Personality Inventory–2 Restructured Form (MMPI–2-RF; Ben-Porath & Tellegen, 2008) validity scales to detect feigned psychopathology in a criminal forensic setting. We used a known-groups design with the Structured Interview of Reported Symptoms (SIRS; Rogers, Bagby, & Dickens, 1992) as the external criterion to determine groups of probable malingering versus nonmalingering. A final sample of 125 criminal defendants, who were administered both the SIRS and the MMPI–2-RF during their evaluations, was examined. The results indicated that the two MMPI–2-RF validity scales specifically designed to detect overreported psychopathology, F-r and FP-r, best differentiated between the malingering and nonmalingering groups. These scales added incremental predictive utility to one another in this differentiation. Classification accuracy statistics substantiated the recommended cut scores in the MMPI–2-RF manual (Ben-Porath & Tellegen, 2008) in this forensic setting. Implications for these results in terms of forensic assessment and detection of malingering are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Determination of Standard Molar Enthalpies of Formation of Complexes of Rare Earth Bromides with Glycine

ＤｅｔｅｒｍｉｎａｔｉｏｎｏｆＳｔａｎｄａｒｄＭｏｌａｒＥｎｔｈａｌｐｉｅｓｏｆＦｏｒｍａｔｉｏｎｏｆＣｏｍｐｌｅｘｅｓｏｆＲａｒｅＥａｒｔｈＢｒｏｍｉｄｅｓｗｉｔｈＧｌｙｃｉｎｅＳｕｎＴｏｎｇｓｈａｎ（孙同山），ＷａｎｇＦｅｎｇｌｉａｎ（王凤廉），...     

Determination of Crystal Structure of Britholite-Y

ＤｅｔｅｒｍｉｎａｔｉｏｎｏｆＣｒｙｓｔａｌＳｔｒｕｃｔｕｒｅｏｆＢｒｉｔｈｏｌｉｔｅ－ＹＺｈａｎｇＪｉａｎ－Ｈｏｎｇ；（张建洪）；ＦａｎｇＺｅ；（方泽）；ＬｉａｏＬｉ－Ｂｉｎｇ；（廖立兵）（ＣｈｉｎａＵｎｉｖｅｒｓｉｔｙｏｆＧｅｏｓｃｉｅｎｃｅｓ，...     

Standard Enthalpies of Formation of Solid Complexes of Lanthanide Nitrates with Alanine

Ｇｒｅａｔｉｎｔｅｒｅｓｔｈａｓｂｅｅｎａｒｏｕｓｅｄｉｎｔｈｅｓｔｕｄｙｏｆｃｏｍｐｌｅｘｅｓｏｆｒａｒｅｅａｒｔｈｓａｌｔｓｗｉｔｈａｍｉｎｏａｃｉｄｓｂｅｃａｕｓｅｒａｒｅｅａｒｔｈｉｏｎｓｐｏｓｓｅｓｓｓｏｍｅｓｐｅｃｉａｌｆｕｎｃｔｉｏｎｓｉｎｂｉｏｃｈｅｍｉｓｔｒｙ .Ｔｈｅｙｃａｎｂｅｕｓｅｄａｓａｐｒｏｂｅｔｏｌａｂｅｌｔｈｅｃａｌｃｉｕｍｉｏｎ .Ｍｏｒｅｏｖｅｒ,ａｍｉｎｏａｃｉｄｓａｒｅｔｈｅｓｔｒｕｃｔｕｒｅｕｎｉｔｏｆｐｒｏｔｅｉｎｓ .Ｇａｏａｎｄｃｏｗｏｒｋｅｒｓｒｅｃｅ…     

of tend

on transplant are as follows: autologous tendon, allogeneic tendon, artificial tendon and tissue engineered tendon. Recently, studies on allogeneic tendon are more and more favorable. In late 1980s, establishment and development of tissue engineering bring a new way for repairing de     

Effect of Morphology of Instantaneous Inoculant on Inoculated Result of Melted Iron

In 192 2 ,AmericanMeehanappliedthefirstpatentforinoculatedcastiron .Nowtherearemorethan 10 0 0kindsofinoculantsintheworld .Thein oculationmeansthatsomematerialisputintomeltedirontocausesome physicalandchemicalchangeswhicharedifferentfromthosecausedbythealloyingelementinthecastiron .Intheearlydays ,themaincontentofinoculantwassilicon ,andsoonafterwardscalcium ,aluminium ,barium ,strontiumandmanga nese ,etcwereincluded .In 196 1,ceriumwasintro ducedintoinoculant .Nowtheinoculantsarewidelyappli…     

Analysis of the Specific Features of Wear of the Working Rolls of the Finishing Group of Stands Under Conditions of the 1950 Mill at the Casting-Rolling Complex of the “VMZ” JSC

Metallurgist - We present the analysis of the mechanism of in-service wear of the working rolls of wide-band rolling mills on an example of a 1950 mill from the casting-rolling complex of the...     

Investigation of Crystallization Incorporation of Er-implanted Silicon

ＩｎｖｅｓｔｉｇａｔｉｏｎｏｆＣｒｙｓｔａｌｌｉｚａｔｉｏｎＩｎｃｏｒｐｏｒａｔｉｏｎｏｆＥｒ－ｉｍｐｌａｎｔｅｄＳｉｌｉｃｏｎＷａｎＹａ（万亚）；ＬｉＤａｉｑｉｎｇ（李岱青）（ＤｅｐａｒｔｍｅｎｔｏｆＣｈｅｍｉｓｔｒｙ，ＹａｎｔａｉＴｅａｃｈｅｒｓ...     

Influence of Light Rare Earth on Toughness of Welded Seam of LAHS Steel

The influence mechanism of light rare earth elements, which are transited to the welding seam of low-alloy high strength (LAHS) steel through the covering of the electrode, on the toughness of the welding seam was studied. The experimental results show that proper amount of rare earth elements can desulfurate, dehydrogenate, reduce inclusions and purify the structure of the welding seam. Rare earth element additions have .the effect on welding seam and, at the same time, the transformation of side-batten ferrite is resisted while the pin-ferrite structure is promoted. The improvement of the toughness of the welding seam is due to the purifying action of rare earth elements as well as their refining effect on the structure. However, the toughness of the welding seam can decrease when the amount of light rare earth elements are added excessively because the crystal grains become coarser, porosities appear and the inclusions increase as well. The experimental results show that the suitable amount of light rare earth element additions is about 2%.     

The Characteristics of Adsorption and Desorption of Rare Earth Elements by the Main Types of Soils of China

The adsorption-desorption behavior of the mixed rare earth elements(RE)on the main types ofsoils of China,kaolinite and synthetic oxides was studied.The isothermal adsorption of RE was fitted toLangmuir.Freundlich and Temkin equations.The main factors determining the RE adsorption capacity ofthe soils are the type of clay mineral and the content of amorphous iron oxide in the soils.The above two fac-tors and the pH of soil determine the RE adsorption ability of the soils.The soil and synthetic iron,manga-nese oxides strongly adsorb RE specifically.     

Effect of Cerium on the Viscosity of Liquid Fe-C Alloy of Eutectic Content

The viscosities of liquid Fe-4.30C and Fe-4.30C-Ce alloys were measured by oscillating crucible viscometer. The results show that viscosity of Fe-4.30C alloy changes from 5.50 to 8.30 MPa~s when the liquid is cooled from 1425℃ to the melting point. The abnormity of viscosity of Fe-4.30C alloy near the melting point is reasonable due to the formation of graphite. The addition of cerium especially with content higher than 0.21% causes an evidently decrease in viscosity for eutectic alloy resulting from increase of free volume and size decrease of atom cluster in the liquids. It can be concended that the existence of C-Ce compound contributes to the discontinuous of viscosity at 1340 ～ 1370 ℃ for the Fe-4.30C-Ce alloy by experinments with differential scanning calorimeter.     

Prediction of Heat of Fusion of Rare Earth Compounds from Binary Phase Diagrams

Based on the thermodynamical principle the new formula for calculation of heat of fusion and its error havebeen derived from binary phase diagrams which could be classified to eutectic,solid solution,degenerate eutecticand involving a compound phase diagram and so on.Using these formulae heats of fusion of some rare earth ox-ides have been predicted.