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Article
Publication date: 24 October 2022

Babak Lotfi and Bengt Ake Sunden

This study aims to computational numerical simulations to clarify and explore the influences of periodic cellular lattice (PCL) morphological parameters – such as lattice…

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Abstract

Purpose

This study aims to computational numerical simulations to clarify and explore the influences of periodic cellular lattice (PCL) morphological parameters – such as lattice structure topology (simple cubic, body-centered cubic, z-reinforced body-centered cubic [BCCZ], face-centered cubic and z-reinforced face-centered cubic [FCCZ] lattice structures) and porosity value ( ) – on the thermal-hydraulic characteristics of the novel trussed fin-and-elliptical tube heat exchanger (FETHX), which has led to a deeper understanding of the superior heat transfer enhancement ability of the PCL structure.

Design/methodology/approach

A three-dimensional computational fluid dynamics (CFD) model is proposed in this paper to provide better understanding of the fluid flow and heat transfer behavior of the PCL structures in the trussed FETHXs associated with different structure topologies and high-porosities. The flow governing equations of the trussed FETHX are solved by the CFD software ANSYS CFX® and use the Menter SST turbulence model to accurately predict flow characteristics in the fluid flow region.

Findings

The thermal-hydraulic performance benchmarks analysis – such as field synergy performance and performance evaluation criteria – conducted during this research successfully identified demonstrates that if the high porosity of all PCL structures decrease to 92%, the best thermal-hydraulic performance is provided. Overall, according to the obtained outcomes, the trussed FETHX with the advantages of using BCCZ lattice structure at 92% porosity presents good thermal-hydraulic performance enhancement among all the investigated PCL structures.

Originality/value

To the best of the authors’ knowledge, this paper is one of the first in the literature that provides thorough thermal-hydraulic characteristics of a novel trussed FETHX with high-porosity PCL structures.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 33 no. 3
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 3 May 2016

Stephane M. Shepherd and Susanne Strand

The psychopathy checklist: youth version (PCL: YV) checklist is an assessment of youth psychopathic traits and is regularly validated by way of its associations with re-offending…

Abstract

Purpose

The psychopathy checklist: youth version (PCL: YV) checklist is an assessment of youth psychopathic traits and is regularly validated by way of its associations with re-offending and violence. Yet existing research has been conducted with predominantly white Caucasian cohorts and extant evidence suggests that associations with recidivism are stronger in samples with greater proportions of white offenders. The paper aims to discuss these issues.

Design/methodology/approach

This study investigated the cross-cultural validity of the PCL: YV for an ethnically diverse Australian sample of 175 young male offenders in custody. Participants were assessed in custody with the PCL: YV and offending data were collected post-release for up to 18 months.

Findings

PCL: YV total and domain scores were comparable across ethnicity; however the instrument demonstrated stronger relationships with recidivism for Australian participants with an English speaking background compared to Indigenous and culturally and linguistically diverse participants.

Practical implications

The authors advocate the cautionary employment of the PCL: YV as a violence risk prediction instrument with minority young offenders regionally, pending further evidence.

Originality/value

This study addresses the capacity of the PCL: YV to predict violence across different ethnic groups. Cross-cultural youth psychopathy research is currently inadequate and existing studies suggest that the PCL: YV is a weaker predictor of violence in culturally diverse samples. This investigation provides much needed information on the capacity of the PCL: YV to extend to different ethnic groups who are represented Australia’s youth prison population. This is the first study of its kind regionally, and more importantly is the first PCL: YV study with an Indigenous Australian comparison group. This is particularly important given that Indigenous Australians are heavily overrepresented in Australia’s criminal justice system and require appropriate risk assessment measures to ensure they are not misclassified. Research such as this is now of particular interest given the recent judicial decision made in Ewert vs Canada.

Details

Journal of Criminal Psychology, vol. 6 no. 2
Type: Research Article
ISSN: 2009-3829

Keywords

Article
Publication date: 14 May 2018

Hanxiao Wang, Marco Domingos and Fabio Scenini

The purpose of this paper is to study the effect of nano hydroxyapatite (HA) and graphene oxide (GO) particles on thermal and mechanical performances of 3D printed…

Abstract

Purpose

The purpose of this paper is to study the effect of nano hydroxyapatite (HA) and graphene oxide (GO) particles on thermal and mechanical performances of 3D printed poly(ε-caprolactone) (PCL) filaments used in bone tissue engineering (BTE).

Design/methodology/approach

Raw materials were prepared by melt blending, followed by 3D printing via 3D Discovery (regenHU Ltd., CH) with all fabricating parameters kept constant. Filaments, including pure PCL, PCL/HA and PCL/GO, were tested under the same conditions. Several techniques were used to mechanically, thermally and microstructurally evaluate properties of these filaments, including differential scanning calorimetry, tensile test, nano indentation and scanning electron microscope.

Findings

Results show that both HA and GO nano particles are capable of improving mechanical performance of PCL. Enhanced mechanical properties of PCL/HA result from reinforcing effect of HA, while a different mechanism is observed in PCL/GO, where degree of crystallinity plays an important role. In addition, GO is more efficient at enhancing mechanical performance of PCL compared with HA.

Originality/value

For the first time, a systematic study about effects of nano HA and GO particles on bioactive scaffolds produced by additive manufacturing for BTE applications is conducted in this work. Mechanical and thermal behaviors of each sample, pure PCL, PCL/HA and PCL/GO, are reported, correlated and compared with literature.

Details

Rapid Prototyping Journal, vol. 24 no. 4
Type: Research Article
ISSN: 1355-2546

Keywords

Article
Publication date: 17 October 2017

Yang Wu, Jerry Fuh, Yoke San Wong and Jie Sun

Fabricating functionally graded scaffolds to mimic the complex spatial distributions of the composition, micro-structure and functionality of native tissues will be one of the key…

Abstract

Purpose

Fabricating functionally graded scaffolds to mimic the complex spatial distributions of the composition, micro-structure and functionality of native tissues will be one of the key objectives for future tissue engineering research. This study aims to create a scaffold to mimic functionally-graded tissue using a hybrid process, which incorporated electrospun polycaprolactone (PCL) and electrosprayed hydroxyapatite (HA) in a simple pathway.

Design/methodology/approach

The PCL and HA were dispensed simultaneously from different positions to form a layer on a rotational mandrel, and a gradient construct was achieved by adjusting dispensing rates of both materials.

Findings

The morphology of scaffolds changed gradually from one layer to another layer with the change of the dispensing conditions of the two materials. The elemental distribution analysis revealed that C/Ca ratio linearly increased with certain dispensing rate ratio of PCL:HA. In addition, the thickness, mechanical properties (i.e. ultimate tensile stress and Young’s modulus), surface roughness and water contact angle of each layer changed accordingly with the variation of dispensing rate of PCL and HA, and the diameter distributions of PCL fibres and HA particles did not vary significantly.

Originality/value

This study showed the hybrid process has the potential to be used in fabrication of scaffold with functionally graded structure for tissue engineering applications, especially for mimicking the nature of the native 3D tendon–bone interface.

Details

Rapid Prototyping Journal, vol. 23 no. 6
Type: Research Article
ISSN: 1355-2546

Keywords

Article
Publication date: 1 December 2006

Brian Thomas‐Peter and Jason Jones

The PCL‐R has been heralded as the ‘unparalleled’ (Salekin et al, 1996) risk assessment tool for assessing risk of violent and non‐violent recidivism. In the UK, the PCL‐R looks…

Abstract

The PCL‐R has been heralded as the ‘unparalleled’ (Salekin et al, 1996) risk assessment tool for assessing risk of violent and non‐violent recidivism. In the UK, the PCL‐R looks likely to become an industry standard assessment in psychological evaluation of individuals thought to have a dangerous and severe personality disorder. However, current knowledge about the PCL‐R is unsatisfactory, and a number of issues need to be addressed before clinicians can be confident in the use of this measure. This paper highlights these issues from the perspective of the practising clinician. Questions are raised about the theoretical, methodological and treatment implications of the use of the PCL‐R. Future research needs are established in this context of caution over the use of the measure in routine clinical and academic assessment.

Details

The British Journal of Forensic Practice, vol. 8 no. 4
Type: Research Article
ISSN: 1463-6646

Article
Publication date: 11 March 2014

T. Patrício, M. Domingos, A. Gloria, U. D'Amora, J.F. Coelho and P.J. Bártolo

The main purpose of this research work is to study the effect of poly lactic acid (PLA) addition into poly (e-caprolactone) (PCL) matrices, as well the influence of the mixing…

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Abstract

Purpose

The main purpose of this research work is to study the effect of poly lactic acid (PLA) addition into poly (e-caprolactone) (PCL) matrices, as well the influence of the mixing process on the morphological, thermal, chemical, mechanical and biological performance of the 3D constructs produced with a novel biomanufacturing device (BioCell Printing).

Design/methodology/approach

Two mixing processes are used to prepare PCL/PLA blends, namely melt blending and solvent casting. PCL and PCL/PLA scaffolds are produced via BioCell Printing using a 300-μm nozzle, 0/90° lay down pattern and 350-μm pore size. Several techniques such as scanning electron microscopy (SEM), simultaneous thermal analyzer (STA), nuclear magnetic resonance (NMR), static compression analysis and Alamar BlueTM are used to evaluate scaffold's morphological, thermal, chemical, mechanical and biological properties.

Findings

Results show that the addition of PLA to PCL scaffolds strongly improves the biomechanical performance of the constructs. Additionally, polymer blends obtained by solvent casting present better mechanical and biological properties, compared to blends prepared by melt blending.

Originality/value

This paper undertakes a detailed study on the effect of the mixing process on the biomechanical properties of PCL/PLA scaffolds. Results will enable to prepare customized PCL/PLA scaffolds for tissue engineering applications with improved biological and mechanical properties, compared to PCL scaffolds alone. Additionally, the accuracy and reproducibility of by the BioCell Printing enables to modulate the micro/macro architecture of the scaffolds enhancing tissue regeneration.

Details

Rapid Prototyping Journal, vol. 20 no. 2
Type: Research Article
ISSN: 1355-2546

Keywords

Article
Publication date: 2 January 2018

Yubing Dong, Chen Qian, Jian Lu and Yaqin Fu

Epoxy (EP) and polye-caprolactone (PCL) are typical dual-shape memory polymer (DSMP). To get excellent triple-shape memory effect (TSME) polymer composites which are made from EP…

Abstract

Purpose

Epoxy (EP) and polye-caprolactone (PCL) are typical dual-shape memory polymer (DSMP). To get excellent triple-shape memory effect (TSME) polymer composites which are made from EP and PCL. Miscible PCL/EP blend composites have been investigated and compared to the TSMEs with electrospun PCL microfiber membranes/EP composites. Clay montmorillonite (MMT)-modified electrospun PCL microfiber membranes were prepared to improve the shape memory fixities of electrospun PCL microfiber membranes/EP composites.

Design/methodology/approach

The morphologies of electrospun PCL microfiber membranes and the cross section of PCL/EP composites were studied using a field emission scanning electron microscope (FE-SEM), and the existence of MMT was confirmed by a transmission electron microscope. Thermal mechanical properties were observed by a differential scanning calorimeter (DSC) and a dynamic thermomechanical analysis machine, and the TSMEs were also determined through dynamic mechanical analysis.

Findings

Results indicate that the TSMEs of electrospun PCL microfiber membranes/EP composites were excellent, whereas the TSMEs of PCL/EP blend composites were poor. The TSMEs of PCL electrospun microfiber membranes/EP composites significantly improved with the addition of the PCL electrospun microfiber modified with moderate MMT.

Research limitations/implications

Adding a moderate content of MMT into the electrospun PCL fibers, could improve the TSME of the PCL fiber membranes/EP composites. This study was to create a simple and effective method that can be applied to improve the performance of other SMP.

Originality/value

A novel triple-shape memory composite were made from dual-shape memory EP and electrospun PCL fiber membranes.

Details

Pigment & Resin Technology, vol. 47 no. 1
Type: Research Article
ISSN: 0369-9420

Keywords

Article
Publication date: 28 September 2017

Holly Ellingwood, Karla Emeno, Craig Bennell, Adelle Forth, David Kosson and Robert D. Hare

The purpose of this paper is to examine the structure of juvenile psychopathy, as measured by the Psychopathy Checklist: Youth Version (PCL: YV).

Abstract

Purpose

The purpose of this paper is to examine the structure of juvenile psychopathy, as measured by the Psychopathy Checklist: Youth Version (PCL: YV).

Design/methodology/approach

Using a sample of 2,042 male youths from the USA, Canada, and the UK, the study was a conceptual replication of Bishopp and Hare’s (2008) multidimensional scaling (MDS) analysis of adult male offenders assessed with the Psychopathy Checklist-Revised.

Findings

The scaling analyses generally replicated those obtained by Bishopp and Hare, providing support for a multidimensional, four-factor model of juvenile psychopathy similar to that obtained with adults. However, a small number of items fell outside their predicted regions. Slight differences in the structure of juvenile psychopathy were found for incarcerated and supervised samples of youth, with the four-factor model breaking down slightly for the supervised sample. Item misplacements may indicate that certain items on the PCL: YV are being misinterpreted, reflect different dimensions for different samples, or cannot be reliably measured. Future research should examine these possibilities, with special attention being paid to supervised samples.

Originality/value

To the authors’ knowledge, this is one of the first known attempts to use MDS analysis to examine the psychopathy structures that emerge for male juvenile offenders. The greater nuances afforded by using MDS offer a more comprehensive understanding of psychopathy between incarcerated and supervised youth using the PCL: YV.

Details

Journal of Criminal Psychology, vol. 7 no. 4
Type: Research Article
ISSN: 2009-3829

Keywords

Article
Publication date: 20 September 2013

Katie Dhingra and Daniel Boduszek

This paper aims to provide a critical review of the psychopathy literature, with a particular focus on recent research examining the relationship between psychopathy and various…

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Abstract

Purpose

This paper aims to provide a critical review of the psychopathy literature, with a particular focus on recent research examining the relationship between psychopathy and various forms of criminal behaviour.

Design/methodology/approach

The authors provide an overview of the studies conducted to date. To identify relevant published studies for this review, literature searches were completed using Web of Science, Scopus, PsychINFO, and PubMed.

Findings

Substantial empirical research exists to suggest that psychopathy is a robust predictor of criminal behaviour and recidivism. Furthermore, considerable support for the assertion that the violence perpetrated by psychopathic offenders is more instrumental than the violence committed by other offenders was found. In addition, some research suggests that the greater use of instrumental violence among psychopathic offenders may be due to the interpersonal/affective traits of psychopathy, and not the impulsive/antisocial traits.

Originality/value

The current paper is the first to provide an in‐depth review of the literature examining the association between psychopathy and criminal offending with a particular focus on violent and homicidal behaviour.

Details

Journal of Criminal Psychology, vol. 3 no. 2
Type: Research Article
ISSN: 2009-3829

Keywords

Article
Publication date: 28 April 2010

Mark Olver and Keira Stockdale

Empirical research concerning the reliability and predictive validity of the juvenile psychopathy construct, as assessed by the Psychopathy Checklist: Youth Version (PCL: YV;…

Abstract

Empirical research concerning the reliability and predictive validity of the juvenile psychopathy construct, as assessed by the Psychopathy Checklist: Youth Version (PCL: YV; Forth et al, 2003) is reviewed. The results of an updated meta‐analysis (k = 38) investigating the interrater reliability of the PCL: YV are presented, along with an examination of meta‐analytic findings on the predictive accuracy of the tool. Considerations with respect to gender, ethnicity and development are explored. Some discussion points are offered regarding potential clinical applications of the construct of juvenile psychopathy and the PCL: YV with violent and other criminally adjudicated youths.

Details

The British Journal of Forensic Practice, vol. 12 no. 2
Type: Research Article
ISSN: 1463-6646

Keywords

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