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Biodiesel from waste cooking oil (WCO) requires antioxidants to meet oxidation stability specifications set forth in ASTM D6751 or EN 14214. In contrast, unrefined cottonseed oil (CSO), containing tocopherols and gossypol, produces biodiesel of higher oxidation stability. However, only a portion of these CSO endogenous antioxidants are suspected to be retained in biodiesel. Because the economics of biodiesel manufacturing rely upon inexpensive sources of triglycerides, emphasis was placed on developing improved alternative processing methods where WCO was the main source of methyl esters (WCOME) and CSO was used as a supplemental source of triglycerides and antioxidants in a 4:1 ratio. This study compared four processing methods for their ability to produce biodiesel of increased oxidative stability prepared from a 4:1 ratio of WCO:CSO. Two novel processing methods developed for this study utilise solvent properties of fatty acid methyl esters and glycerol to avoid additional chemical inventory fo...

The Propensities Model is now the dominant applied conceptualization of dynamic risk factors for sexual offending. In this paper five important limitations of this model are identified: it asserts ...

Comprehensive risk assessment can benefit from combining static and dynamic scales. The purpose of this study was to validate the Risk Matrix 2000, examine incremental validity of the STABLE-2007 and develop structured rules for combining the two scales. In a routine sample of Canadian sex offenders (n = 710), the Risk Matrix 2000/Sex, /Violence and /Combined scales significantly predicted the six recidivism outcomes: sexual, any sexual (including sexually motivated breaches), non-sexual violent, violent, any crime (excluding breaches) and any recidivism (including breaches). Area under the receiver operating characteristic curve (AUC) values were moderate to large. The STABLE-2007 generally added incremental predictive validity to the Risk Matrix 2000. Structured rules and recidivism estimates are provided for combining the two scales. The current study illustrates that predictive accuracy can be improved by combining static and dynamic risk scales in a structured manner.

The aim of the present study was to investigate the inter-correlation between three different instruments for the assessment of psychopathic personality disorder. Eighty male inmates at Bergen prison (Norway) participated in the study. All the participants were assessed for psychopathy using the Psychopathy Checklist Revised (PCL-R; Hare, 1991), the Comprehensive Assessment of Psychopathic Personality – Institutional Rating Scale (CAPP-IRS; Cooke, Hart, & Logan, 2004), and the questionnaire Self-Report of Psychopathy Scale–III (SRP-III; Paulhus, Neumann, & Hare, in press). The correlational analysis revealed significant correlations between all the instruments, but substantial diverges were also found. CAPP-IRS and PCL-R showed high inter-correlations and, hence, seem to tap into the same underlying construct. The CAPP-IRS seems, however to have a higher affect focus in all its domains. Our finding of lower correlation between the SRP-III and the other two clinical tools may suggest a limitation in the in...

The aim of this article was to advance risk communication by examining percentile ranks as a non-arbitrary metric for quantifying risk. Although percentile ranks have a simple meaning, their calculation is complicated by ties (i.e., more than one offender having the same score). The strengths and weaknesses of percentile ranks are discussed, as are the options for calculating and presenting them in applied risk communication. As a demonstration, percentile ranks for Canadian sexual offenders were computed for the most popular sexual offender risk assessment tools (Static-99, Static-99R, Static-2002 and Static-2002R). The distribution of Static-99 scores was highly stable in international comparisons of sexual offenders from Canada (1990 to 2005; n = 2,011), Sweden (1993 to 1997; n = 1,278) and California (2008 to 2010; n = 37,600). The major limitation of percentile ranks is that they measure the “unusualness” of scores in a particular reference group, and may not correspond to other indicators of relativ...

The present study examined the relationship between reliably identified therapist characteristics and treatment-induced changes in sexual offender treatment programmes in English prisons. The results indicated that 10 therapist features predicted beneficial changes in coping skills, perspective-taking, and relationship difficulties. A confrontational style, on the other hand, was negatively related to increased competence in coping. The results are discussed in terms of their research and clinical implications.

This paper reviews the literature pertaining to risk factors for further offending in convicted sex offenders. Various studies have shown that data on past convictions in sex offenders have predict...