PMMA/SWCNT Composites with Very Low Electrical Percolation Threshold by Direct Incorporation and Masterbatch Dilution and Characterization of Electrical and Thermoelectrical Properties.

In the present study, Poly(methyl methacrylate) (PMMA)/single-walled carbon nanotubes (SWCNT) composites were prepared by melt mixing to achieve suitable SWCNT dispersion and distribution and low electrical resistivity, whereby the SWCNT direct incorporation method was compared with masterbatch dilution. An electrical percolation threshold of 0.05-0.075 wt% was found, the lowest threshold value for melt-mixed PMMA/SWCNT composites reported so far. The influence of rotation speed and method of SWCNT incorporation into the PMMA matrix on the electrical properties and the SWCNT macro dispersion was investigated. It was found that increasing rotation speed improved macro dispersion and electrical conductivity. The results showed that electrically conductive composites with a low percolation threshold could be prepared by direct incorporation using high rotation speed. The masterbatch approach leads to higher resistivity values compared to the direct incorporation of SWCNTs. In addition, the thermal behavior and thermoelectric properties of PMMA/SWCNT composites were studied. The Seebeck coefficients vary from 35.8 µV/K to 53.4 µV/K for composites up to 5 wt% SWCNT.

Relationship between functional constipation and anal-retentive behavior features.

OBJECTIVES: Constipation is the most commonly seen defecation problem related to several environmental factors. Defecation is learned in the childhood anal period in which anal characteristic features appear. Problems in the childhood anal period may affect not only characters but also defecation function. This study aimed to evaluate the relationship between constipation and anal characteristic features of participants with functional constipation. MATERIAL AND METHODS: Patients with functional constipation were included into the study according to the ROME III criteria. Patients with irritable bowel disease, slow transit constipation, outlet obstruction constipation, malignancy, and psychiatric diseases were excluded from the study. Patients filled out Personality Belief Questionnaire, Hospital Anxiety and Depression Scale, and Obsessive Belief Questionnaire. The results were compared with healthy individuals. RESULTS: A total of 47 patients with functional constipation were included in the study. Avoidant, obsessive-compulsive, antisocial, narcissistic, and paranoid personality traits were found to be higher in patients with constipation than in the control group. Perfectionism/certainty, importance and control, and hospital anxiety scores were found to be higher in patients with constipation than in the control group. CONCLUSION: Constipation may be related to several factors, such as socioeconomic environment, emotional stress, age, and diet, among others. Here, it was found that anal-retentive behavior features are prominent in functional constipation. Biofeedback, which can be regarded as psychotherapy of defecation control, can be used for treatment.

Relationship of functional constipation and anal-retentive behavior features.

OBJECTIVES: Constipation is the most commonly seen defecation problem and related with several environmental factors. Learning defecation is learned in the childhood anal period in which anal characteristic features appear. Problems in the anal period of childhood may affect not only the characters but also the defecation function. We aimed to evaluate the relationship between constipation and anal characteristic features of participants with functional constipation. MATERIAL AND METHODS: Patients with functional constipation were included in the study according to the ROME III criteria. Patients with irritable bowel disease, slow transit constipation, outlet obstruction constipation, malignancy, and psychiatric diseases were excluded from the study. Patients filled out the Personality Belief Questionnaire, Hospital Anxiety and Depression Scale, and Obsessive Belief Questionnaire. The results were compared with healthy individuals. RESULTS: A total of 47 patients with functional constipation were included in the study. The avoidant, obsessive-compulsive, antisocial, narcissistic, and paranoid personality beliefs were found to be higher in patients with constipation than in the control group. Perfectionism/certainty, importance and control, and hospital anxiety scores were found to be higher in patients with constipation than in the control group. CONCLUSION: Constipation may be related to several factors, such as socioeconomic environment, emotional stress, age, and diet, among others. Here we found that anal-retentive behavior features are prominent in functional constipation. Biofeedback, which can be regarded as psychotherapy of defecation control, can be used for treatment.