Balancing the formation and storage pressure with the storage capacity is one of the most significant steps toward developing H2 storage in hydrates. The large-cage occupancies of hydrogen molecules ...in tetrahydrofuran (THF), acetone, cyclohexanone (CHONE), and methylcyclohexane (MCH) hydrates were investigated by Raman spectroscopy, volumetric gas release measurement, and X-ray diffraction analysis in a pressure region below the equilibrium pressure of pure H2 hydrates at 255 ± 2 K. The results from the measurements show that H2 molecules occupy the large cage of the structure II THF+H2, acetone+H2, and CHONE+H2 hydrates at the suitable pressures and concentrations of promoter guest species, while H2 molecules do not occupy the largest cage of the structure H MCH+H2 hydrates, even around 70 MPa. The present work reveals that the large-cage occupancy of H2 strongly depends on the pressure and the concentration of promoter guest species. The maximum storage amount of H2 in the acetone+H2 hydrate was 3.6 ± 0.1 wt %, similar to that of THF+H2 hydrate, at 74 MPa and 255 ± 2 K. Acetone is superior to THF and CHONE as the promoter based on the relation between pressure and the large-cage occupancy of H2 molecules.
Hydrogen hydrates with tetrahydrofuran (THF) as a promoter molecule are investigated to probe critical unresolved observations regarding cage occupancy and storage capacity. We adopted a new ...preparation method, mixing solid powdered THF with ice and pressurizing with hydrogen at 70 MPa and 255 ± 2 K (these formation conditions are insufficient to form pure hydrogen hydrates). All results from Raman microprobe spectroscopy, powder X-ray diffraction, and gas volumetric analysis show a strong dependence of hydrogen storage capacity on THF composition. Contrary to numerous recent reports that claim it is impossible to store H2 in large cages with promoters, this work shows that, below a THF mole fraction of 0.01, H2 molecules can occupy the large cages of the THF+H2 structure II hydrate. As a result, by manipulating the promoter THF content, the hydrogen storage capacity was increased to ∼3.4 wt % in the THF+H2 hydrate system. This study shows the tuning effect may be used and developed for future science and practical applications.
Assessments of both fitness to stand trial and criminal responsibility are common, complex forensic evaluations with substantial societal implications. Currently in Canada, medical practitioners, in ...particular psychiatrists, conduct the vast majority of assessments of fitness to stand trial and criminal responsibility. Although the Criminal Code of Canada (CCC) allows these evaluations to be completed "by a medical practitioner or any other person who has been designated by the Attorney General," in practice, qualified clinical-forensic psychologists generally have been excluded from performing these types of assessments. This article reviews the historical and contemporary evidence-based and advocacy-driven efforts to change the CCC to allow qualified professionals such as clinical-forensic psychologists to conduct assessments of criminal responsibility and fitness to stand trial. We argue that the training and experience of clinical-forensic psychologists places them in a unique and qualified position to conduct these challenging types of forensic evaluations. We therefore recommend that the Canadian federal government consider changing section 672 of the CCC to allow assessments of fitness to stand trial and criminal responsibility to be conducted by a qualified mental health professional. The change would be consistent with other sections of the CCC and would improve access of accused persons and the courts to qualified assessors. Regardless of discipline, we propose that standardized training and monitoring programs be developed and implemented to promote reliable evaluations and best practices.
Les évaluations de l'aptitude à subir un procès et de la responsabilité pénale sont des évaluations médico-légales courantes et complexes qui ont des conséquences sociétales importantes. À l'heure actuelle, au Canada, les médecins, plus particulièrement les psychiatres, mènent la grande majorité des évaluations de l'aptitude à subir un procès et de la responsabilité pénale. Bien que le Code criminel du Canada (CCC) permette à ces évaluations d'être pratiquées « par un médecin ou toute autre personne ayant été désignée par le procureur général », dans la pratique, des psychologues médico-légaux qualifiés ont été privés du droit d'exercer ces types d'évaluations. Le présent article examine les initiatives de plaidoyer historiques et contemporaines, fondées sur des faits probants, visant à changer le CCC afin de permettre à des professionnels qualifiés tels les psychologues médico-légaux d'exercer des évaluations de l'aptitude à subir un procès et de la responsabilité pénale. Nous prétendons que la formation et l'expérience clinique de psychologues médico-légaux les placent dans une position unique et qualifiée pour effectuer ces types d'évaluations médico-légales. Nous recommandons, par les présentes, que le gouvernement fédéral canadien considère modifier l'article 672 du CCC afin de permettre que les évaluations de l'aptitude à subir un procès et de la responsabilité pénale soient exercées par des professionnels de la santé mentale qualifiés. Ce changement serait cohérent avec les autres articles du CCC et permettrait d'améliorer l'accès aux personnes accusées et des tribunaux aux évaluateurs qualifiés. Quelle que soit la discipline, nous proposons que des formations normalisées et des programmes de surveillance soient mis sur pied et mis en œuvre pour promouvoir les meilleures pratiques et des évaluations fiables.
Public Significance Statement
(a) We are advocating for qualified clinical-forensic psychologists to be designated under the Criminal Code of Canada (CCC) to perform assessments of fitness to stand trial and criminal responsibility. b) Designating qualified clinical-forensic psychologists in Canada to undertake independent assessments of criminal responsibility and fitness to stand trial would serve the public good by improving access to qualified professionals by the courts and accused persons. (c) This article outlines the rationale for change as well as the specific proposed amendments to the wording of the CCC to require that professionals conducting these assessments have specialized qualifications to ensure that courts and accused persons will receive standardized and evidence-based services.
