Manufacturing of Continuous Carbon Fiber Composites Using Ultraviolet Laser-Assisted Direct Ink Write 3D Printing

Additive manufacturing (AM), commonly referred to as 3D printing, is a quickly growing field with numerous techniques available to manufacture parts which are stronger, lighter, and more complex than those which could be traditionally manufactured. With the goal of creating stronger parts, a new 3D printing technique was developed which combined properties of several different methods in order to print continuous carbon fiber-reinforced thermosets. This new method is called continuous fiber direct writing (CFDW). The process works by extruding continuous fiber and ultraviolet (UV) curable resin out of a syringe simultaneously and curing the resin immediately upon extrusion via UV lasers aimed at the extrusion point. This was created using the principles behind direct ink writing (DIW), stereolithography (SLA), and fused deposition modeling (FDM). It utilizes DIW technology to extrude liquid resin out of the syringe, SLA technology to cure the resin in situ, and FDM technology to deposit the fiber and resin onto the print path. In order to test this novel method, a custom extrusion system and print head was designed and adapted onto an existing consumer FDM printer. The developed printer is able to successfully print continuous fiber-reinforced samples with control over the fiber direction and fiber volume fraction. Several experiments were conducted in order to characterize the various printing parameters. The largest focus was on the two most important parameters: deposition speed and extrusion pressure. The deposition speed, or feed rate, describes how quickly the print head moves across the build plate, while the extrusion pressure describes how much pressure is applied to extrude the resin out of the syringe. These two parameters together greatly affect the resulting width and shape of a printed line of fiber. In general, increasing the pressure or decreasing the feed rate creates a larger line width. This is very important as it affects the hatch spacing which in turn affects the fiber volume fraction. Additionally, these factors can affect the top surface finish of the resulting part. In addition to these parameter-based studies, bulk rectangular samples and complex samples were printed in order to demonstrate the capabilities of the printer. The CFDW method works well and is fairly consistent with the proper printing parameters. Through future development of this process, composite samples can be made with individual tows of fibers oriented according to the geometry of the part, allowing for reduced weight and increased strength of the additively manufactured components

Madrigal of May

https://digitalcommons.ithaca.edu/sheetmusic/1153/thumbnail.jp

Assessing the viability of mapping bull kelp in Puget Sound using aerial imaging platforms

Bull kelp (Nereocystis luetkeana) is an important primary producer that plays a foundational role in the marine nearshore ecosystems of Puget Sound. Evidence of significant declines in bull kelp forests in this region has motivated efforts to establish region-wide long-term monitoring programs for this critical species. As part of this drive, the Washington State Department of Natural Resources (DNR) has been testing a series of aerial imaging platforms to detect and map the distribution of bull kelp to complement existing monitoring protocols. In 2020, DNR began surveying floating bull kelp canopies in Puget Sound using RGB and multispectral Unmanned Aerial Vehicles (UAVs), as well as low-cost RGB and near-infrared sensors carried by fixed wing aircraft. We have conducted surveys at five diverse kelp forest sites using three different imaging platforms, and additional surveys at many other sites with one or two methods, representing a range of potential trade-offs. Surveys conducted at sites in North Puget Sound were done so in partnership with county Marine Resource Committees through the Northwest Straits Commission, which involved community science efforts from volunteers. Orthomosaics (large format image products) generated from our aerial surveys were georeferenced, analyzed using a supervised object-based random forest classifier, and assessed against technician-verified stratified random accuracy assessment points. From these final classified results, we generated map layers of the floating bull kelp canopy at each site and developed derived metrics to describe each kelp bed including canopy area, overall bed area, and canopy percent cover. Our findings demonstrate the comparative strengths and limitations of each aerial imaging platform with regard to cost, kelp canopy detection capability, resolution, and spatial coverage. These findings enable us to make recommendations for the most appropriate use for each platform with regard to bull kelp canopy mapping in Puget Sound

The 'Ghosts' of Lawn Tennis Past: Exploring the Forgotten Lives of Early Working- Class Coaching-Professionals

This article examines the lives of late-nineteenth and early-twentieth-century lawn tennis coaching-professionals, notably Tom Burke, Harry Cowdrey, Charles Haggett and George Kerr. These men, considered equally if not more gifted than the first-ranked amateur players of the period, have received scant attention or recognition, either as ‘expert’ players or for their role as coaches/ instructors within the ‘amateur’ game. Ostensibly, these working-class boys/ men sought employment in clubs, as ball-boys, groundskeepers, stringers and instructors, but, being immediately classified as ‘professionals’, were subsequently marginalised within clubs and barred from amateur competitions. Few outside of the club environs encountered them, few observed or learned of their skills, and fewer still reported their exploits. While many of the top amateur players of the period recognised the need for coaching-professionals, the British Lawn Tennis Association (LTA) was intransigent. They staunchly refused to sanction professional competitions in Britain, fearing they would provide a pathway away from amateurism, and propel the amateur to seek remuneration from their tennis. Coachingprofessionals had little choice but to remain as ‘servants’ within their clubs, confined by the rigid class system and unyielding amateur ethos. Hitherto largely ignored within lawn tennis historiography, these men are the ‘ghosts’ of lawn tennis past

Is there a choice to make? A pilot study investigating attitudes towards treatment in an Early Intervention for Psychosis Service

Purpose The purpose of this paper is to investigate health care professionals’ (HCPs) and service-users’ (SUs) attitudes towards different treatment options in an Early Intervention for Psychosis (EIP) service as well as the topical issue of offering choice over treatment. Design/methodology/approach Seven SUs accessing an EIP service and nine HCPs completed qualitative surveys about treatment for psychosis. Data were analysed thematically. Findings Both HCPs and SUs appeared to have a generally positive attitude to the range of interventions offered by the EIP service and SUs talked about the importance of all treatment options being explored. There was variation in attitudes towards SUs having choice over their treatment and a number of factors were identified as crucial in influencing attitudes including mental capacity, risk and level of engagement. Research limitations/implications Small sample size, recruitment from only one EIP service and using a survey design limit generalisability and depth of analysis. Practical implications HCPs working in EIP services should explore different treatment options fully with SUs but be aware that they may feel unable to make the decision themselves. Such discussions should be revisited throughout an individual’s care as their ability and desire to make informed choices may change over time. Continuing Professional Development and clinical supervision should be used to help HCPs reflect on the choice agenda and the implications of this for clinical practice. Originality/value Few studies have examined attitudes towards treatments for psychosis. This is an evolving and important clinical area that remains under researched. Recommendations for service-development, future research and clinical practice are made. </jats:sec

Alliance, technique, both, or more? Clinicians' views on what works in cognitive-behavioral therapy for eating disorders

Objective This study examined clinicians' views of the roles of two elements of cognitive behavioral therapy (CBT) in explaining treatment outcomes—CBT techniques and the therapeutic alliance. Method Ninety‐eight clinicians who reported delivering CBT for eating disorders completed measures addressing their beliefs about what is effective in CBT, their use of specific techniques, and their own anxiety levels. Results Clinicians substantially overestimated the role of both therapeutic techniques and the alliance in explaining treatment outcomes in CBT. Weak but significant correlations were found between therapist anxiety levels and their beliefs about the value of therapeutic techniques or the alliance. However, these associations were in different directions, with higher levels of clinician anxiety associated with more belief in the effects of the alliance but with less belief in the role of CBT techniques. Belief in the role of the therapeutic alliance was associated with a lower likelihood of encouraging the patient to change their eating pattern, while belief in the role of techniques was linked to greater use of case formulation, cognitive restructuring, behavioral experiments and body image work. Discussion Clinicians overestimate the value of both the alliance and therapy techniques in explaining treatment outcomes in CBT for eating disorders. Their beliefs about the strength of these factors are related to their own anxiety, and to their choice of techniques. Clinicians and supervisors should attend to the evidence regarding the impact of a range of elements of therapy, and work with all of those factors to enhance outcomes

A sense of embodiment is reflected in people's signature size

BACKGROUND: The size of a person's signature may reveal implicit information about how the self is perceived although this has not been closely examined. METHODS/RESULTS: We conducted three experiments to test whether increases in signature size can be induced. Specifically, the aim of these experiments was to test whether changes in signature size reflect a person's current implicit sense of embodiment. Experiment 1 showed that an implicit affect task (positive subliminal evaluative conditioning) led to increases in signature size relative to an affectively neutral task, showing that implicit affective cues alter signature size. Experiments 2 and 3 demonstrated increases in signature size following experiential self-focus on sensory and affective stimuli relative to both conceptual self-focus and external (non-self-focus) in both healthy participants and patients with anorexia nervosa, a disorder associated with self-evaluation and a sense of disembodiment. In all three experiments, increases in signature size were unrelated to changes in self-reported mood and larger than manipulation unrelated variations. CONCLUSIONS: Together, these findings suggest that a person's sense of embodiment is reflected in their signature size

A computational study of the influence of methyl substituents on competitive ring closure to α- and β-lactones

Ring-closure of substituted 2-chlorosuccinates to α- or β-lactones has been studied by means of MP2/6-311+G(d,p)//MP2/6-31+G(d) calculations in water treated as a polarised continuum (PCM) and in vacuum. Optimised geometries have been obtained for 2-chlorosuccinate and its 2-methyl, 3,3-dimethyl, and 2,3,3-trimethyl derivatives, along with the transition structures and products for intramolecular nucleophilic displacement leading to the 3- or 4-membered rings. Relative enthalpies and Gibbs free energies of activation and reaction are presented, along with key geometrical parameters, and changes in electrostatic-potential-derived atomic charges. The difference in free-energy barriers for α- and β-lactone formation from the 2-methyl substrate at 298 K is less than 1 kJ mol−1. Primary 14C kinetic isotope effects calculated for substitution at C2 are significantly smaller for α-lactone formation than for β, suggesting a possible way to distinguish between the competing pathways of reaction. The B3LYP method without dispersion corrections predicts the wrong relative stability order for methyl-substituted succinate dianions in PCM water