In additive manufacturing (AM), it is necessary to know the influence of processing parameters in order to have better control over the microstructure and mechanical performance of the part. Laser powder bed fusion (LPBF) AM is beneficial for many reasons; however, it is limited by the thermal solidification conditions achievable in the available processing parameter ranges for single-beam processing methods. Therefore, this work investigates the effect of multiple, coordinated heat sources, which are used to strategically modify the melting and solidifying in the AM process. To model this, existing thermal models of the LPBF process have been modified to include the effects of multiple, coordinated laser beams. These computational models are used to calculate melt pool dimensions and thermal conditions (thermal gradient and cooling rate). Furthermore, the results of the simulations are used to determine the influence of the distance between the coordinated laser beams in different configurations. The multi-beam scanning strategies modeled in the present study are shown to alter both melt pool shape and size, and the thermal conditions at the onset of solidification. However, these variations are not shown to result in alterations in the grain morphology of Ti-6Al-4V components. This predictive method used in this research provides insight into the effects of using multiple coordinated beams in LPBF, which is a necessary step in increasing the capabilities of the AM process.

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The microstructure of ultra-thin SIMOX depends strongly on implantation dose, energy and annealing conditions. We used TEM combined with AES and RBS to determine the microstructural evolution of SIMOX wafers subjected to various temperatures during annealing. We found that an optimum dose window to produce a continuous buried oxide layer without Si islands is 3.0-3.5×1017 O+/cm2 for 100 keV. The thickness of the silicon overlayer and BOX layer produced in this dose window was about 170 nm and 75 nm respectively. RBS analysis showed that a high quality crystalline Si layer was produced after annealing at 1350 °C for 4 hrs. The defect density was very low (< 300/cm2) for all samples implanted at 100 keV.

In additive manufacturing (AM), it is necessary to know the influence of processing parameters in order to have better control over the microstructure and mechanical performance of the part. Laser powder bed fusion (LPBF) AM is beneficial for many reasons; however, it is limited by the thermal solidification conditions achievable in the available processing parameter ranges for single-beam processing methods. Therefore, this work investigates the effect of multiple, coordinated heat sources, which are used to strategically modify the melting and solidifying in the AM process. To model this, existing thermal models of the LPBF process have been modified to include the effects of multiple, coordinated laser beams. These computational models are used to calculate melt pool dimensions and thermal conditions (thermal gradient and cooling rate). Furthermore, the results of the simulations are used to determine the influence of the distance between the coordinated laser beams in different configurations. The multi-beam scanning strategies modeled in the present study are shown to alter both melt pool shape and size, and the thermal conditions at the onset of solidification. However, these variations are not shown to result in alterations in the grain morphology of Ti-6Al-4V components. This predictive method used in this research provides insight into the effects of using multiple coordinated beams in LPBF, which is a necessary step in increasing the capabilities of the AM process.

BACKGROUND: Sublingual buprenorphine (BUP-SL) and liquid methadone (MET) and are the standard-of-care (SOC), daily maintenance medications for the treatment of opioid use disorder (OUD). A sizable proportion of the OUD treatment population does not adhere to treatment and achieve desired clinical benefit. Two promising therapeutic technologies address this deficit: new medication formulations and psychosocial interventions (PSI). This study will determine: (A) the effectiveness and cost-effectiveness – monthly injectable, extended-release (BUP-XR) a novel formulation in a head-to-head comparison with BUP-SL or MET; and (B) the effectiveness of BUP-XR with PSI versus BUP-SL or MET with PSI. Safety, retention, craving, substance use, quality-adjusted life years, social functioning, and subjective recovery will be also evaluated. METHODS: This is a pragmatic, multi-centre, open-label, four-arm, parallel group, superiority RCT, with a qualitative (mixed-methods) evaluation. The study population is adults. The setting is five specialist National Health Service community treatment programmes in England and Scotland. In all sites, participants will be randomly allocated (1:1) to BUP-XR and BUP-SL or MET. At the London study co-ordinating centre, there will also be allocation of participants to BUP-XR with PSI and BUP-SL or MET with PSI. With 24 weeks of study treatment, the primary outcome is days of abstinence from all non-medical opioids during study weeks 2–24 combined with up to 12 urine drug screen tests for opioids. For 90% power (alpha, 5%; 15% inflation for attrition), 304 participants are needed for the BUP-XR and BUP-SL or MET comparison. Using the same planning parameters, 300 participants are needed for the comparison of BUP-XR and BUP-SL or MET with PSI. Statistical and health economic analysis plans will be published before data-lock on the Open Science Framework. Findings will be reported in accordance with the Consolidated Standards of Reporting Trials and Consolidated Health Economic Evaluation Reporting Standards. DISCUSSION: This pragmatic randomised controlled trial is the first evaluation of injectable BUP-XR versus the SOC medications BUP-SL or MET, and with an adjunctive personalised PSI. If there is evidence for the superiority of BUP-XR over SOC, this will have substantial implications for clinical practice and OUD treatment policy in the UK and elsewhere. TRIAL REGISTRATION: EU Clinical Trials register (number: 2018-004460-63).