title: Open-source tool for heat exchanger network synthesis

authors: Hall, Keegan

abstract: The synthesis of heat exchanger networks (HEN) is not a trivial task due to the mixed integer and non-linear nature of the optimisation problem, yet it can provide significant cost and energy use savings to an industrial processing site. Many HEN synthesis models are developed using propriety solvers, which make it difficult for industrial companies to realise the potential of optimisation. This paper introduces a new open-source tool for HEN synthesis built in Python using the GEKKO library, which interfaces with the solver APOPT. The tool features three different synthesis methods, two of which utilise a two-step method where step one aims to initialise or narrow the search space prior to global optimisation in the second synthesis step. A unique feature of this work compared to previous HEN synthesis studies is the application of a true driving force constraint, dQ/dA, (instead of the conventional, but at times crude, minimum approach temperature, ∆Tmin) to provide feasible initial variable values to the second step. To demonstrate the current progress in developing the open-source tool, network solutions obtained by the tool were purposefully compared with the best reported solutions for three common case studies in HEN synthesis literature. For a small problem, the tool achieved a solution within 0.02 % of the best literature solution and attained a solution for the two larger problems within 4 % and 21% of the best literature solution. Before the tool can be made publicly available, further work is needed to implement a non-isothermal mixing model across stream splits, which is expected to yield a more optimal HEN.

text: Open-source tool for heat exchanger network synthesis The synthesis of heat exchanger networks (HEN) is not a trivial task due to the mixed integer and non-linear nature of the optimisation problem, yet it can provide significant cost and energy use savings to an industrial processing site. Many HEN synthesis models are developed using propriety solvers, which make it difficult for industrial companies to realise the potential of optimisation. This paper introduces a new open-source tool for HEN synthesis built in Python using the GEKKO library, which interfaces with the solver APOPT. The tool features three different synthesis methods, two of which utilise a two-step method where step one aims to initialise or narrow the search space prior to global optimisation in the second synthesis step. A unique feature of this work compared to previous HEN synthesis studies is the application of a true driving force constraint, dQ/dA, (instead of the conventional, but at times crude, minimum approach temperature, ∆Tmin) to provide feasible initial variable values to the second step. To demonstrate the current progress in developing the open-source tool, network solutions obtained by the tool were purposefully compared with the best reported solutions for three common case studies in HEN synthesis literature. For a small problem, the tool achieved a solution within 0.02 % of the best literature solution and attained a solution for the two larger problems within 4 % and 21% of the best literature solution. Before the tool can be made publicly available, further work is needed to implement a non-isothermal mixing model across stream splits, which is expected to yield a more optimal HEN.

year: 2022-09-05

title: Autistic tendencies at university: An exploration of distress, coping behaviours, and comorbidities

authors: Bruwer, Martina

subjects: Autism

abstract: In recent years, there has been an increase in the number of autistic students attempting tertiary education. However, data show that only about a third of autistic students who enrol in university complete their qualification. The literature suggests that this is usually not due to their intellectual abilities. The current study aims to shed light on factors that might contribute to this low completion rate through gathering data on distress, wellbeing, and coping strategies in autistic students. Due to the heterogeneous nature of autistic traits, and the prevalence of autistic tendencies in the general population, this study employs the use of correlational data to explore possible links.
Eight tertiary institutions across New Zealand were contacted and 430 respondents completed a self-report questionnaire. Students with higher autistic tendencies scored higher on nearly all forms of psychological distress(Anxiety, Depression, and Stress from the DASS-21; Self-Criticism, and Generalisation of Failure from the ATS; Mental Health Component from the SF-8). Higher autistic tendencies were correlated with scoring lower on most aspects of psychological wellbeing (Overall Wellbeing, Environmental Mastery, Personal Growth, Positive Relations with Others, Purpose in Life, and Self- Acceptance, as measured by the Ryff Scales of Psychological Wellbeing). Results showed an association between higher AQ scores (Autism Quotient; measuring autistic tendencies) and engaging in maladaptive coping strategies (Expression of Negative Feelings, Behavioural Disengagement, and Avoidance; as is measured on the Brief COPE). Finally, students with higher autistic tendencies were more likely to report diagnoses of psychiatric disorders in addition to their autism  diagnosis. 
Students who reported a diagnosis of autism (3.7%), were compared to students who reported clinically significant levels of autistic traits but had no formal diagnosis (5.1%; indicated by a score of 32 or above on the AQ measure). No significant differences were found between these two subgroups for any of the psychological wellbeing or distress variables measured, nor physical and mental health components, or coping behaviours. The only significant difference between the two groups was that the diagnosed group had nearly double the rates of diagnosed depression than the clinically significant group. This is argued to be a result of contact with mental health professionals, and does not appear to reflect a difference in the experienced rates of depression between the two groups. 
These findings have strong clinical implications for future interventions at university level and highlight the need for universities to screen for autistic traits in order to adequately support vulnerable students. The best way to implement lasting changes will be to provide tailored programmes or services to address specific areas causing student distress. No significant differences were found between the diagnosed students and the students displaying clinically significant levels of autistic tendencies. Therefore, there is a need to support all students displaying clinically significant autistic traits, and not make services contingent upon a student having an official diagnosis.

text: Autistic tendencies at university: An exploration of distress, coping behaviours, and comorbidities In recent years, there has been an increase in the number of autistic students attempting tertiary education. However, data show that only about a third of autistic students who enrol in university complete their qualification. The literature suggests that this is usually not due to their intellectual abilities. The current study aims to shed light on factors that might contribute to this low completion rate through gathering data on distress, wellbeing, and coping strategies in autistic students. Due to the heterogeneous nature of autistic traits, and the prevalence of autistic tendencies in the general population, this study employs the use of correlational data to explore possible links.
Eight tertiary institutions across New Zealand were contacted and 430 respondents completed a self-report questionnaire. Students with higher autistic tendencies scored higher on nearly all forms of psychological distress(Anxiety, Depression, and Stress from the DASS-21; Self-Criticism, and Generalisation of Failure from the ATS; Mental Health Component from the SF-8). Higher autistic tendencies were correlated with scoring lower on most aspects of psychological wellbeing (Overall Wellbeing, Environmental Mastery, Personal Growth, Positive Relations with Others, Purpose in Life, and Self- Acceptance, as measured by the Ryff Scales of Psychological Wellbeing). Results showed an association between higher AQ scores (Autism Quotient; measuring autistic tendencies) and engaging in maladaptive coping strategies (Expression of Negative Feelings, Behavioural Disengagement, and Avoidance; as is measured on the Brief COPE). Finally, students with higher autistic tendencies were more likely to report diagnoses of psychiatric disorders in addition to their autism  diagnosis. 
Students who reported a diagnosis of autism (3.7%), were compared to students who reported clinically significant levels of autistic traits but had no formal diagnosis (5.1%; indicated by a score of 32 or above on the AQ measure). No significant differences were found between these two subgroups for any of the psychological wellbeing or distress variables measured, nor physical and mental health components, or coping behaviours. The only significant difference between the two groups was that the diagnosed group had nearly double the rates of diagnosed depression than the clinically significant group. This is argued to be a result of contact with mental health professionals, and does not appear to reflect a difference in the experienced rates of depression between the two groups. 
These findings have strong clinical implications for future interventions at university level and highlight the need for universities to screen for autistic traits in order to adequately support vulnerable students. The best way to implement lasting changes will be to provide tailored programmes or services to address specific areas causing student distress. No significant differences were found between the diagnosed students and the students displaying clinically significant levels of autistic tendencies. Therefore, there is a need to support all students displaying clinically significant autistic traits, and not make services contingent upon a student having an official diagnosis.

year: 2019

title: Barriers and facilitators of access to psychological services for indigenous populations: A scoping review and thematic analysis

authors: Plessas, Anna

abstract: Background:
The extent to which behavior-analytic interventions are offered to Indigenous populations across CANZUS in accessible and culturally appropriate ways is unknown. We conducted a scoping review with a thematic analysis of the extant literature to find: (1) what are the barriers and facilitators for providing effective and equitable delivery of psychological services (with a behavioral component) to Indigenous populations; and (2) what tools and practices exist for an effective and equitable service delivery.
Methods:
We systematically reviewed Medline, CINAHL, PubMed, PsycInfo, Web of science, Ovid and INNZ databases between 1990 and 2020. For the scoping review, we adhered to the JBI methodological approach (2015) and the PRISMA strategy for the identification, selection, and appraisal of the reviewed articles. A total of 1265 unique articles met the criteria for the screening by title; 238 by abstract; 57 were included for full text assessment; and 37 were included in the final analysis.
Results:
Three themes were revealed to account for the barriers and facilitators of culturally friendly practices: (1) connecting practices are about interactions shaping the relationship between service provider and service client; (2) innovative practices test new approaches and innovations that could facilitate access to psychological services and overcome barriers, and (3) reflective practices are about critically examining the processes and actions undertaken toward effective cultural adaptation of services.
Conclusions:
Our analysis suggests that the level of success in bringing together services and the recipients of treatment (connection), showing flexibility and persistence in finding solutions (innovation) and examining the role of our behaviors in reaching our goals (reflection) is determined by the providers' action in the aforementioned three dimensions of practice.

text: Barriers and facilitators of access to psychological services for indigenous populations: A scoping review and thematic analysis Background:
The extent to which behavior-analytic interventions are offered to Indigenous populations across CANZUS in accessible and culturally appropriate ways is unknown. We conducted a scoping review with a thematic analysis of the extant literature to find: (1) what are the barriers and facilitators for providing effective and equitable delivery of psychological services (with a behavioral component) to Indigenous populations; and (2) what tools and practices exist for an effective and equitable service delivery.
Methods:
We systematically reviewed Medline, CINAHL, PubMed, PsycInfo, Web of science, Ovid and INNZ databases between 1990 and 2020. For the scoping review, we adhered to the JBI methodological approach (2015) and the PRISMA strategy for the identification, selection, and appraisal of the reviewed articles. A total of 1265 unique articles met the criteria for the screening by title; 238 by abstract; 57 were included for full text assessment; and 37 were included in the final analysis.
Results:
Three themes were revealed to account for the barriers and facilitators of culturally friendly practices: (1) connecting practices are about interactions shaping the relationship between service provider and service client; (2) innovative practices test new approaches and innovations that could facilitate access to psychological services and overcome barriers, and (3) reflective practices are about critically examining the processes and actions undertaken toward effective cultural adaptation of services.
Conclusions:
Our analysis suggests that the level of success in bringing together services and the recipients of treatment (connection), showing flexibility and persistence in finding solutions (innovation) and examining the role of our behaviors in reaching our goals (reflection) is determined by the providers' action in the aforementioned three dimensions of practice.

year: 2021