A meso-level approach to the 3D numerical analysis of cracking and fracture of concrete materials

A meso‐mechanical model for the numerical analysis of concrete specimens in 3D has been recently proposed. In this approach, concrete is represented as a composite material with the larger aggregates embedded in a mortar‐plus‐aggregates matrix. Both continuum‐type components are considered linear elastic, while the possibilities of failure are provided with the systematic use of zero‐thickness interface elements equipped with a cohesive fracture constitutive law. These elements are inserted along all potential crack planes in the mesh a priori of the analysis. In this paper, the basic features of the model are summarized, and then results of calculations are presented, which include uniaxial tension and compression loading of 14‐aggregate cubical specimen along X, Y and Z axes. The results confirm the consistency of the approach with physical phenomena and well‐known features of concrete behaviour, and show low scatter when different loading directions are considered. Those cases can also be considered as different specimens subjected to the same type of loading.     

Haze Development in Aerobically or Anaerobically Produced Clarified Apple Juices

Haze production in aerobically or anaerobically produced Red Delicious apple juice was assessed following heating, aeration, and protein addition. Stored aerobic juice produced haze in 6 wk, but anaerobic juice was haze-free unless oxygen was introduced. Phenolic material was incorporated into haze in both systems. HPLC (detection at 420 nm) of concentrated juice and addition of 100 mg/L BSA suggested the presence in both juices of ‘reactive’ material which could complex and precipitate during storage. Phenolic compounds, heating, and especially oxidation during processing (and storage) appear to be major determinants of ‘haze potential’ in clarified apple juice.     

An evaluation of imaging spectrometry for estimating forest canopy chemistry

Abstract

High spectral resolution Airborne Imaging Spectrometer (AIS) data were acquired over 20 well-studied Wisconsin forest sites to evaluate the potential of remote sensing for estimating forest canopy chemistry. Intensive nutrient cycling research in these forests demonstrates that canopy lignin content is strongly related to measured annual nitrogen mineralization at the undisturbed sites and may serve as an accurate index for nitrogen cycling rates. Ground measurements were made of foliar biomass and canopy nitrogen and lignin content, the latter within two weeks of the AIS overflight. The spectral data were transformed using derivative techniques modified from laboratory spectroscopy. Stepwise regression assisted in determining combinations of wavelengths most highly correlated with canopy chemistry and biomass. Strong correlations between AIS data and total canopy lignin content in deciduous forests and canopy lignin concentration (total lignin/biomass) in both deciduous and coniferous stands indicate that imaging spectrometry can be used to estimate canopy lignin content and, from that, the spatial distribution of annual nitrogen mineralization rates.     

SOME EFFECTS OF CLINICIAN AND PATIENT PERSONALITY ON DECISION MAKING IN A CLINICAL SETTING.

CONDUCTED A FOLLOW-UP STUDY TO RECENT FINDINGS OF GORDON WHICH SHOWED THAT PSYCHOLOGICAL INTERPRETATIONS BASED ON PARTIAL RORSCHACH PROTOCOLS WERE RELATED TO THE PERSONALITY DIMENSION OF ANALITY IN THE CLINICIANS. 44 PRACTICING CLINICIANS WERE ASKED TO RESPOND TO A 3-PAGE DOCUMENT WHICH THEY WERE TOLD WAS A PARTIAL TRANSCRIPT OF AN INITIAL INTERVIEW WITH A PATIENT. THE RESULTS CONFIRMED THE EARLIER FINDINGS THAT HIGH-ANAL CLINICIANS HAVE LESS CONFIDENCE IN THEIR INTERPRETATIONS, MAKE FEWER SPECIFIC PREDICTIONS, AND IDENTIFY LESS PATHOLOGY IN PATIENTS THAN LOW-ANAL CLINICIANS. ADDITIONAL EVIDENCE IS GIVEN THAT THE PERSONALITY OF THE CLINICIAN INFLUENCES HIS CLINICAL DECISIONS. OTHER HYPOTHESES RELATED TO INTERACTIONS BETWEEN THE PERSONALITY OF THE PATIENT AS PRESENTED IN THE CLINICAL DATA AND THE PERSONALITY OF THE CLINICIAN WERE NOT CONFIRMED. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

RELATIONSHIP BETWEEN SELF-ACCEPTANCE AND ADJUSTMENT, REPRESSION-SENSITIZATION AND SOCIAL COMPETENCE.

SS WERE 40 MALADJUSTED MALE PATIENTS HOSPITALIZED ON A PSYCHIATRIC WARD AND 40 ADJUSTED MALE PATIENTS HOSPITALIZED ON A MEDICAL SURGICAL WARD. THE MEDICAL AND PSYCHIATRIC GROUPS WERE EACH COMPOSED OF EQUAL SUBGROUPS OF LOW- AND HIGH-COMPETENCE REPRESSORS AND SENSITIZERS. ALL SS COMPLETED A SOCIAL DESIRABILITY MINIMIZED Q-SORT FOR "REAL SELF" AND FOR "IDEAL SELF." RESULTS SHOWED THAT SELF-ACCEPTANCE AS EXPRESSED IN A SELF-IDEAL DISCREPANCY SCORE IS SIGNIFICANTLY RELATED TO THE DEFENSIVE-STYLE CONTINUUM OF REPRESSION-SENSITIZATION, WITH REPRESSORS EXPRESSING SIGNIFICANTLY SMALLER SELF-IDEAL DISCREPANCIES THAN SENSITIZERS. NO RELATIONSHIP WAS FOUND BETWEEN SELF-ACCEPTANCE AND THE DIMENSIONS OF ADJUSTMENT OR SOCIAL COMPETENCE. (33 REF.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Influence of sterilization upon a range of properties of experimental bone cements

Bone cement, used to fix prostheses into the bone, must be sterilized prior to implantation. Two sterilization techniques, and radiation, were investigated, examining the influence upon molecular weight, static and dynamic mechanical characteristics and rheological properties. A number of experimental cements were studied prepared from methylmethacrylate (MMA) co-polymers, either single powders or powder blends, mixed with MMA monomer. It was found that with both and radiation, there was a decrease in molecular weight of all powders, including a MMA/styrene co-polymer, in relation to the radiation dose. This fall in molecular weight resulted in a drop in tensile strength, Youngs modulus and strain to failure of all cements tested. However, the deterioration in mechanical strength was highlighted by the dynamic testing. Fatigue lives of cements after testing in tension–tension, at 2 Hz under load control and irradiated with 25 kGy radiation, displayed significant decreases. This result indicated the utmost importance of conducting such tests upon experimental bone cements prior to in vivo use. The rheological time profiles of curing cements were also found to be influenced by 25 kGy radiation, with a reduction of complex viscosity after sterilization.