Simulation of brittle damage for fracture process of endodontically treated tooth

The mechanics of brittle damage in porcelain of an endodontically treated maxilla incisor tooth was simulated using finite element method (FEM). For this purpose a very complex composite structure of endodontically treated tooth is simulated under transverse loading. Three dimensional (3D) model of human maxilla incisor tooth root was developed based on Computed Tomography (CT) scan images. Crown, core cement, resin core, dental post, post cement and dentin were created using SolidWorks software, and then the model was imported into ABAQUS-6.9EF software for nonlinear behavior analysis. This study utilizes finite element method to simulate onset and propagation of crack in ceramic layer (porcelain) by the cause of both tension and compression loading related to complexity of the geometry of tooth implant. The simulation has been done using brittle damaged model available in ABAQUS/Explicit in quasi-static load condition. The load-displacement response of whole structure is measured from the top of porcelain by controlling displacement on a rigid rod. Crack initiated at the top of porcelain bellow the location of the rod caused by tension damage at equivalent load of 590 N. Damage in porcelain accounts for up to 63% reduction of whole structure stiffness from the undamaged state. The failure process in porcelain layer can be described by an exponential rate of fracture energy dissipation. This study demonstrated that the proposed finite element model and analysis procedure can be use to predict the nonlinear behavior of tooth implant

Potential for cogeneration of heat and electricity in California industry, phase 2

The nontechnical issues of industrial cogeneration for 12 California firms were analyzed under three categories of institutional settings: (1) industrial ownership without firm sales of power; (2) industrial ownership with firm sales of power; and (3) utility or third party ownership. Institutional issues were analyzed from the independent viewpoints of the primary parties of interest: the industrial firms, the electric utilities and the California Public utilities Commission. Air quality regulations and the agencies responsible for their promulgation were examined, and a life cycle costing model was used to evaluate the economic merits of representative conceptual cogeneration systems at these sites. Specific recommendations were made for mitigating measures and regulatory action relevant to industrial cogeneration in California

Damage Prediction in Woven and Non-woven Fabric Composites

This chapter presents a step-by-step review on different damage prediction approaches for woven and non-woven fabric composites. First, the characteristics of woven and non-woven fabrics are distinguished one from another, suggesting more complex analyses required for non-woven fabrics. Then, the subsequent sub-sections are geared toward a comparison of different approaches utilized in predicting the mechanical behavior and damage mechanisms of these composites at various material scales including micro, meso, and macro. The merits and demerits of each approach with regard to practicality, accuracy, effectiveness, and characterization expense are discussed. Moreover, using recent experimental evidences, the chapter aims to highlight a number of inherent complexities in the interlaced architecture of woven composites, which may not be precisely taken into account by the damage models originally developed for non-woven and unidirectional composites. Finally, two illustrative examples on the effect of the aforementioned complexities on the mechanical behavior of woven composites are presented in more detail, through some recent works of the authors

Music and anxiety in hospitalized children

Purpose: Music is a method of stress reduction and could be used as a non-invasive therapeutic tool to relieve the pain and anxiety of patient. This study is designed to evaluate the role of music therapy on the level of anxiety in children aged 912 yearsold, in an academic hospital in Gorgan, northeast of Iran. Methods: Sixty hospitalized children were categorized into the intervention (case=30) and the control groups (N=30) by using a simple randomized method. The data gathering instruments were questionnaires which included demographic information and a trait anxiety inventory for children, the Spielberger test (STAIC). For the intervention group, for 2 days, 20 minutes (3 am-6 pm), the soothing rhythmic music of Johann Sebastian Bach was released through a tape recorder which was equipped with a headphone and then, the Spielberger questionnaires were refilled by each patient. The control group did not receive any intervention. Results: The results showed that the anxiety scores between the control and the intervention groups had no significant difference before the application of the music. The mean anxiety after the application of music in the control group was 49.4±7.2 and in the intervention group, it was 30.7±7.5. The results showed a significant difference between the mean anxiety in the control and the intervention groups (p<0.05). Conclusions: Our results showed that in hospitalized children, music therapy reduced the anxiety level

Sunflower, Soybean And Meat Meals In Laying Diets

A previous study (POULTRY 81-6) had shown that hens on diets utilizing sunflower meal as the major protein source supported fair egg production, whereas meat and bone meal as the major protein source supported substandard performance. Hen-day egg production was 15% poorer and feed intake was off by 22 grams per day averaged for all groups on the meat and bone meal diets

Antimicrobial peptides of the vaginal innate immunity and their role in the fight against sexually transmitted diseases

Some antimicrobial peptides (AMPs) are produced in the vaginal innate immune system and play an important role in protecting this organ against pathogenic agents. Moreover, sexually transmitted diseases have become a major problem in human societies and are rapidly spreading. The emergence of antibiotic-resistant microbes (superbugs) can pose a major threat to human societies and cause rapid spread of these diseases. Finding new antimicrobial compounds to fight superbugs is therefore essential. It has been shown that AMPs have good potential to become new antibiotics. The most important AMPs in the vaginal innate immune system are defensins, secretory leucocyte protease inhibitors, calprotectin, lysozyme, lactoferrin and elafin, which play an important role in host defence against sexually transmitted infections, modulation of immune responses and anticancer activities. Some AMPs, such as LL-37, magainin 2 and nisin, show both spermicidal and antimicrobial effects in the vagina. In this summary, we will discuss vaginal AMPs and continue to address some of the challenges of using peptides to control pathogens that are effective in sexually transmitted diseases. © 2019 The Author(s