A slope method for the determination of electron energy for quality assurance.

BACKGROUND: Particle accelerators, manufactured for delivering patient radiation treatment, require numerous and frequent quality assurance measures. One of those is the periodic check for electron energy stability. The American Association of Physicists in Medicine has established requirements for this procedure. The current recommendation is to perform a ratio of two ionization points, one at Dmax and another at a point approximately to the 50% depth, compared to a baseline as a relative check. PURPOSE: This ratio method is a sensitive measurement and sometimes produces results that are difficult to interpret or relate to acceptable tolerances. We sought to find a simple method that gives more stable results, which can be interpreted and related to energy changes. METHOD: We propose a method that takes two measurements on the descending portion of the shifted percent depth ionization (PDI) curves to calculate the slope, tangent to the I50 point, the point at which the ionization falls to 50% of its maximum value. We then used the slope measurement, compared to an established baseline, to relate energy. RESULTS: After collecting data over a 3-year period, we saw that standard deviations for the slope method have much less variability than the traditional ratio method. We were also able to correlate the slope results to ionization scans performed in water and found they were in better agreement than the traditional ratio method. CONCLUSION: The slope method does not require precise positioning since the slope remains relatively constant over the descending portion of the curve. Our data show that this results in an easier interpretative test of electron energy stability and delivers reliable feedback for quality assurance.

High-Resolution Ultrasound to Quantify Sub-Surface Wrinkles in a Woven CFRP Laminate.

Carbon fiber reinforced polymer (CFRP) composites are popular materials in the aerospace and automotive industries because of their low weight, high strength, and corrosion resistance. However, wrinkles or geometric distortions in the composite layers significantly reduce their mechanical performance and structural integrity. This paper presents a method for non-destructively extracting the three-dimensional geometry, lamina by lamina, of a laminated composite. A method is introduced for fabricating consistent out-of-plane wrinkled CFRP laminate panels, simulating the in-service wrinkle observed in industries that utilize thick structure composites such as the vertical lift or wind power industries. The individual lamina geometries are extracted from the fabricated coupon with an embedded wrinkle from captured ultrasonic waveforms generated from single-element conventional ultrasonic (UT) scan data. From the extracted waveforms, a method is presented to characterize the wrinkle features within each individual lamina, specifically the spatially varying wrinkle height and intensity for the wrinkle. Parts were fabricated with visibly undetectable wrinkles using a wet layup process and a hot press for curing. Scans were performed in a conventional immersion tank scanning system, and the scan data were analyzed for wrinkle detection and characterization. Extraction of the layers was performed based on tracking the voltage peaks from A-scans in the time domain. Spatial Gaussian averaging was performed to smooth the A-scans, from which the surfaces were extracted for each individual lamina. The extracted winkle surface aligned with the anticipated wrinkle geometry, and a single parameter for quantification of the wrinkle intensity for each lamina is presented.

Automated Foreign Object Detection for Carbon Fiber Laminates Using High-Resolution Ultrasound Testing.

Carbon fiber laminates have become popular in the manufacturing industry for their many desirable properties, like good vibration damping, high strength-to-weight ratio, toughness, high dimensional stability, and low coefficient of thermal expansion. During the manufacturing process, undesirable foreign objects, such as peel-ply strips, gloving material, and Kapton film, can be introduced into the part which can lead to a localized weakness. These manufacturing defects can function as stress concentration points and oftentimes cause a premature catastrophic failure. In this study, a method using high-resolution pulse-echo ultrasound testing is employed for the detection and quantification of the dimensions of foreign object debris (FOD) embedded within carbon fiber laminates. This research presents a method to create high-resolution C-scans using an out of immersion tank portable housing ultrasound scanning system, with similar capabilities to that of a full immersion system. From the full-waveform dataset, we extract the FOD depth and planar dimensions with an automatic edge detection technique. Results from several carbon fiber laminates are investigated with embedded foreign objects that are often considered undetectable. Results are presented for FOD identification for two different shapes: circles with diameters ranging from 7.62 mm to 12.7 mm, and 3-4-5 triangles with hypotenuses ranging from 7.6 mm to 12.7 mm. CT imaging is used to confirm proper FOD placement and that the FOD was not damaged or altered during manufacturing. Of importance for the ultrasound inspection results, in every single case studied, the FOD is detected, the layer depth is properly identified, and the typical error is less than 1.5 mm for the primary dimension.

Nondestructive Inspection and Quantification of Select Interface Defects in Honeycomb Sandwich Panels.

Honeycomb sandwich panels are utilized in many industrial applications due to their high bending resistance relative to their weight. Defects between the core and the facesheet compromise their integrity and efficiency due to the inability to transfer loads. The material system studied in the present paper is a unidirectional carbon fiber composite facesheet with a honeycomb core with a variety of defects at the interface between the two material systems. Current nondestructive techniques focus on defect detectability, whereas the presented method uses high-frequency ultrasound testing (UT) to detect and quantify the defect geometry and defect type. Testing is performed using two approaches, a laboratory scale immersion tank and a novel portable UT system, both of which utilize only single-side access to the part. Coupons are presented with defects spanning from 5 to 40 mm in diameter, whereas defects in the range of 15-25 mm and smaller are considered below the detectability limits of existing inspection methods. Defect types studied include missing adhesive, unintentional foreign objects that occur during the manufacturing process, damaged core, and removed core sections. An algorithm is presented to quantify the defect perimeter. The provided results demonstrate successful defect detection, with an average defect diameter error of 0.6 mm across all coupons studied in the immersion system and 1.1 mm for the portable system. The best accuracy comes from the missing adhesive coupons, with an average error of 0.3 mm. Conversely, the worst results come from the missing or damaged honeycomb coupons, with an error average of 0.7 mm, well below the standard detectability levels of 15-25 mm.

Nondestructive quantification of internal raster path for additively manufactured components via ultrasonic testing.

This work investigates the viability of discerning the raster pattern of additively manufactured components using high frequency ultrasonic nondestructive testing. Test coupons were fabricated from poly cyclohexylenedimethylene terephthalate glycol using the fused filament fabrication process, in which layers were deposited at various predetermined raster angles. Each printed part was scanned using spherically focused, high-resolution, ultrasonic transducers of various peak frequencies between 7.5 and 15 MHz. From the captured waveform data, images are extracted to observe the raster pattern in a layer-by-layer manner, with the results from the 10 MHz element yielding the best performance. An in-house MATLAB script was developed to analyze the transducer signal to investigate C-scan images at various depths throughout the component. From the resulting C-scan images, one can consistently identify the proper raster orientation within 2°-4° in each of the first 10 deposited layers, with the accuracy decreasing as a function of depth into the component. Due to signal attenuation, there is insufficient data at depths beyond the 11th and 12th layer, to properly analyze the present data sets accurately. Validation was performed using X-ray computed tomography scans to demonstrate the accuracy of the ultrasonic inspection method.

Perspectives on Self-Harm and Suicidal Ideation in Nigeria: A Mixed-Methods Study of Patients, Family Caregivers, Clinicians, and the Public.

BACKGROUND: Suicide and self-harm are global disease burden that contributes significantly to years of lost life and mortality. Despite the increasing rates of suicide and self-harm in Nigeria, this topic is understudied. METHODS: A mixed-methods design was adopted. Study 1 interviewed n = 18 participants (n = 11 clinicians; n = 5 patients with a history of self-harm and suicide ideation; and n = 2 caregivers). All interviews were audio-recorded, transcribed verbatim, and analyzed using IPA. Study 2 surveyed n = 562 non-clinical sample about their tolerance toward self-harm and the data was analyzed using One-way ANOVA in SPSS. RESULTS: Study 1 qualitative findings showed substance use, perceived rejection and social isolation were considered predisposing factors for suicide and self-harm. Cultural and religious beliefs shaped help-seeking behaviours. Although Study 2 found no significant differences in demographic characteristics concerning public tolerance toward persons with a history of self-harm, 64% believed that individuals who died by suicide would face punishment after death; 51% believed that victims of attempted suicide are a source of shame to their families; and 33.8% agreed that dying by suicide is the correct behaviour. CONCLUSIONS: Patients with a history of self-harm and suicidal ideation consider family members and close friends as valuable sources of support. Due to the potential clinical implication of cultural and religious beliefs, as shown in the present study's findings, the authors recommend a co-development of culturally appropriate psychological intervention for persons with a history of self-harm and suicidal ideation to be tested in randomized control trials.

Management of Lymph Node-positive Penile Cancer: A Systematic Review.

CONTEXT: Lymph node (LN) involvement in penile cancer is associated with poor survival. Early diagnosis and management significantly impact survival, with multimodal treatment approaches often considered in advanced disease. OBJECTIVE: To assess the clinical effectiveness of treatment options available for the management of inguinal and pelvic lymphadenopathy in men with penile cancer. EVIDENCE ACQUISITION: EMBASE, MEDLINE, the Cochrane Database of Systematic Reviews, and other databases were searched from 1990 to July 2022. Randomised controlled trials (RCTs), nonrandomised comparative studies (NRCSs), and case series (CSs) were included. EVIDENCE SYNTHESIS: We identified 107 studies, involving 9582 patients from two RCTs, 28 NRCSs, and 77 CSs. The quality of evidence is considered poor. Surgery is the mainstay of LN disease management, with early inguinal LN dissection (ILND) associated with better outcomes. Videoendoscopic ILND may offer comparable survival outcomes to open ILND with lower wound-related morbidity. Ipsilateral pelvic LN dissection (PLND) in N2-3 cases improves overall survival in comparison to no pelvic surgery. Neoadjuvant chemotherapy in N2-3 disease showed a pathological complete response rate of 13% and an objective response rate of 51%. Adjuvant radiotherapy may benefit pN2-3 but not pN1 disease. Adjuvant chemoradiotherapy may provide a small survival benefit in N3 disease. Adjuvant radiotherapy and chemotherapy improve outcomes after PLND for pelvic LN metastases. CONCLUSIONS: Early LND improves survival in nodal disease in penile cancer. Multimodal treatments may provide additional benefit in pN2-3 cases; however, data are limited. Therefore, individualised management of patients with nodal disease should be discussed in a multidisciplinary team setting. PATIENT SUMMARY: Spread of penile cancer to the lymph nodes is best managed with surgery, which improves survival and has curative potential. Supplementary treatment, including the use of chemotherapy and/or radiotherapy, may further improve survival in advanced disease. Patients with penile cancer with lymph node involvement should be treated by a multidisciplinary team.

Tensile and Compression Strength Prediction and Validation in 3D-Printed Short-Fiber-Reinforced Polymers.

In the current study, a methodology is validated for predicting the internal spatially varying strength properties in a single 3D-printed bead composed of 13%, by weight, carbon-fiber-filled acrylonitrile butadiene styrene. The presented method allows for the characterization of the spatially varying microstructural behavior yielding a local anisotropic stiffness and strength that can be integrated in a finite element framework for a bulk estimate of the effective stiffness and strength. The modeling framework is presented with a focus on composite structures made from large area additive manufacturing (LAAM). LAAM is an extrusion-based process yielding components on the order of meters, with a typical raster size of 10 mm. The presented modeling methods are applicable to other short-fiber-reinforced polymer processing methods as well. The results provided indicate the modeling framework yields results for the effective strength and stiffness that align with experimental characterization to within ∼1% and ∼10% for the longitudinal compressive and tensile strength, respectively, and to within ∼3% and ∼50% for the longitudinal compressive and tensile stiffness, respectively.

Fiber Orientation Quantification for Large Area Additively Manufactured Parts Using SEM Imaging.

Polymer-based additively manufactured parts are increasing in popularity for industrial applications due to their ease of manufacturing and design form freedom, but their structural and thermal performances are often limited to those of the base polymer system. These limitations can be mitigated by the addition of carbon fiber reinforcements to the polymer matrix, which enhances both the structural performance and the dimensional stability during cooling. The local fiber orientation within the processed beads directly impacts the mechanical and thermal performances, and correlating the orientation to processing parameter variations would lead to better part quality. This study presents a novel approach for analyzing the spatially varying fiber orientation through the use of scanning electron microscopy (SEM). This paper presents the sample preparation procedure including SEM image acquisition and analysis methods to quantify the internal fiber orientation of additively manufactured carbon fiber-reinforced composites. Large area additively manufactured beads with 13% by weight large aspect ratio carbon fiber-reinforced acrylonitrile butadiene styrene (ABS) pellets are the feedstock used in this study. Fiber orientation is quantified using the method of ellipses (MoE), and the spatial change in fiber orientation across the deposited bead cross-section is studied as a function of process parameters including extrusion speed, raster height, and extrusion temperature zones. The results in the present paper show the results from the novel use of SEM to obtain the local fiber orientation, and results show the variation in alignment within the individual processed bead as well as an overall aligned orientation state along the direction of deposition.

Bipolar disorders in Nigeria: a mixed-methods study of patients, family caregivers, clinicians, and the community members' perspectives.

BACKGROUND: Bipolar Disorders (BDs) are chronic mental health disorders that often result in functional impairment and contribute significantly to the disability-adjusted life years (DALY). BDs are historically under-researched compared to other mental health disorders, especially in Sub-Saharan Africa and Nigeria. DESIGN: We adopted a mixed-methods design. Study 1 examined the public knowledge of BDs in relation to sociodemographic outcomes using quantitative data whilst Study 2 qualitatively assessed the lived experiences of patients with BDs, clinicians, and family caregivers. METHODS: In Study 1, a non-clinical sample of n = 575 participants responded to a compact questionnaire that examined their knowledge of BDs and how they relate to certain sociodemographic variables. One-way ANOVA was used to analyse quantitative data. Study 2 interviewed N = 15 participants (n = 5 patients with BDs; n = 7 clinicians; n = 3 family caregivers). These semi-structured interviews were audio-recorded, transcribed, and thematically analysed. RESULTS: In Study 1, findings showed no statistically significant differences, suggesting low awareness of BDs, especially among vulnerable populations such as young people and older adults. However, there was a trajectory in increased knowledge of BDs among participants between the ages of 25-44 years and part-time workers compared to other ages and employment statuses. In Study 2, qualitative findings showed that BDs are perceived to be genetically and psycho-socially induced by specific lived experiences of patients and their family caregivers. Although psychotropic medications and psychotherapy are available treatment options in Nigeria, cultural and religious beliefs were significant barriers to treatment uptake. CONCLUSIONS: This study provides insight into knowledge and beliefs about BDs, including the lived experiences of patients with BDs, their caregivers and clinicians in Nigeria. It highlights the need for further studies assessing Nigeria's feasibility and acceptability of culturally adapted psychosocial interventions for patients with BDs.

European Association of Urology-American Society of Clinical Oncology Collaborative Guideline on Penile Cancer: 2023 Update.

CONTEXT: Penile cancer is a rare disease but has a significant impact on quality of life. Its incidence is increasing, so it is important to include new and relevant evidence in clinical practice guidelines. OBJECTIVE: To provide a collaborative guideline that offers worldwide physician and patient guidance for the management of penile cancer. EVIDENCE ACQUISITION: Comprehensive literature searches were performed for each section topic. In addition, three systematic reviews were conducted. Levels of evidence were assessed, and a strength rating for each recommendation was assigned according to the GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) methodology. EVIDENCE SYNTHESIS: Penile cancer is a rare disease but its global incidence is increasing. Human papillomavirus (HPV) is the main risk factor for penile cancer and pathology should include an assessment of HPV status. The main aim of primary tumour treatment is complete tumour eradication, which has to be balanced against optimal organ preservation without compromising oncological control. Early detection and treatment of lymph node (LN) metastasis is the main determinant of survival. Surgical LN staging with sentinel node biopsy is recommended for patients with a high-risk (≥pT1b) tumour with cN0 status. While (inguinal) LN dissection remains the standard for node-positive disease, multimodal treatment is needed in patients with advanced disease. Owing to a lack of controlled trials and large series, the levels of evidence and grades of recommendation are low in comparison to those for more common diseases. CONCLUSIONS: This collaborative penile cancer guideline provides updated information on the diagnosis and treatment of penile cancer for use in clinical practice. Organ-preserving surgery should be offered for treatment of the primary tumour when feasible. Adequate and timely LN management remains a challenge, especially in advanced disease stages. Referral to centres of expertise is recommended. PATIENT SUMMARY: Penile cancer is a rare disease that significantly impacts quality of life. While the disease can be cured in most cases without lymph node involvement, management of advanced disease remains challenging. Many unmet needs and unanswered questions remain, underlining the importance of research collaborations and centralisation of penile cancer services.

Systematic Review and Meta-analysis of Minimally Invasive Procedures for Surgical Inguinal Nodal Staging in Penile Carcinoma.

CONTEXT: There are several procedures for surgical nodal staging in clinically node-negative (cN0) penile carcinoma. OBJECTIVE: To evaluate the diagnostic accuracy, perioperative outcomes, and complications of minimally invasive surgical procedures for nodal staging in penile carcinoma. EVIDENCE ACQUISITION: A systematic review of the Medline, Embase, and Cochrane controlled trials databases and ClinicalTrials.gov was conducted. Published and ongoing studies reporting on the management of cN0 penile cancer were included without any design restriction. Outcomes included the false negative (FN) rate, the number of nodes removed, surgical time, and postoperative complications. EVIDENCE SYNTHESIS: Forty-one studies were eligible for inclusion. Four studies comparing robot-assisted (RA-VEIL) and video-endoscopic inguinal lymphadenectomy (VEIL) to open inguinal lymph node dissection (ILND) were suitable for meta-analysis. A descriptive synthesis was performed for single-arm studies on modified open ILND, dynamic sentinel node biopsy (DSNB) with and without preoperative inguinal ultrasound (US), and fine-needle aspiration cytology (FNAC). DSNB with US + FNAC had lower FN rates (3.5-22% vs 0-42.9%) and complication rates (Clavien Dindo grade I-II: 1.1-20% vs 2.9-11.9%; grade III-V: 0-6.8% vs 0-9.4%) in comparison to DSNB alone. Favourable results were observed for VEIL/RA-VEIL over open ILND in terms of major complications (2-10.6% vs 6.9-40.6%; odds ratio [OR] 0.18; p < 0.01). Overall, VEIL/RA-VEIL had lower wound-related complication rates (OR 0.14; p < 0.01), including wound infections (OR 0.229; p < 0.01) and skin necrosis (OR 0.16; p < 0.01). The incidence of lymphatic complications varied between 20.6% and 49%. CONCLUSIONS: Of all the surgical staging options, DSNB with inguinal US + FNAC had the lowest complication rates and high diagnostic accuracy, especially when performed in high-volume centres. If DSNB is not available, favourable results were also found for VEIL/RA-VEIL over open ILND. Lymphatic-related complications were comparable across open and video-endoscopic ILND. PATIENT SUMMARY: We reviewed studies on different surgical approaches for assessing lymph node involvement in cases with penile cancer. The results show that a technique called dynamic sentinel node biopsy with ultrasound guidance and fine-needle sampling has high diagnostic accuracy and low complication rates. For lymph node dissection in penile cancer cases, a minimally invasive approach may offer favourable postoperative outcomes.

The relative abundance of mountain pine beetle fungal associates through the beetle life cycle in pine trees.

The mountain pine beetle (MPB) is a native bark beetle of western North America that attacks pine tree species, particularly lodgepole pine. It is closely associated with the ophiostomatoid ascomycetes Grosmannia clavigera, Leptographium longiclavatum, Ophiostoma montium, and Ceratocystiopsis sp.1, with which it is symbiotically associated. To develop a better understanding of interactions between beetles, fungi, and host trees, we used target-specific DNA primers with qPCR to assess the changes in fungal associate abundance over the stages of the MPB life cycle that occur in galleries under the bark of pine trees. Multivariate analysis of covariance identified statistically significant changes in the relative abundance of the fungi over the life cycle of the MPB. Univariate analysis of covariance identified a statistically significant increase in the abundance of Ceratocystiopsis sp.1 through the beetle life cycle, and pair-wise analysis showed that this increase occurs after the larval stage. In contrast, the abundance of O. montium and Leptographium species (G. clavigera, L. longiclavatum) did not change significantly through the MPB life cycle. From these results, the only fungus showing a significant increase in relative abundance has not been formally described and has been largely ignored by other MPB studies. Although our results were from only one site, in previous studies we have shown that the fungi described were all present in at least ten sites in British Columbia. We suggest that the role of Ceratocystiopsis sp.1 in the MPB system should be explored, particularly its potential as a source of nutrients for teneral adults.

Effect of a virtual simulated participant experience on antibiotic stewardship knowledge among pre-licensure baccalaureate nursing students: A pilot study.

BACKGROUND: Antibiotic resistant infections are a growing global public health threat poised to render antibiotics ineffective in treating even the most common infectious diseases. It is essential that future nurses have the knowledge and skills to keep patients safe from antibiotic harm in all health care settings, however, studies indicate that there is limited education provided in nursing schools regarding antibiotic use, antibiotic resistance, and antibiotic stewardship nursing practices. OBJECTIVE: Evaluate the effect of a virtual, scenario-based simulation experience using simulated participants on pre-licensure baccalaureate nursing students' antibiotic, antibiotic resistance, and antibiotic stewardship nursing practice knowledge. METHODS: A quasi-experiential repeated measure pre-posttest design was used with a convenience sample of 165 pre-licensure baccalaureate nursing students enrolled in a health promotion course at a private university in the northeast region of the United States. The NLN Jeffries Simulation Theory guided the virtual simulation experience and used simulated participants methodology. RESULTS: All students participated in the simulation experience. Statistically significant increases were noted (p < 0.005) in antibiotic, antibiotic use, and antibiotic resistance knowledge between the pre and post surveys. The most significant changes were in knowledge of antibiotic stewardship nursing practices. CONCLUSION: Integration of virtual, scenario-based simulations provided students an active learning opportunity to practice antibiotic stewardship assessment and practice skills through real life-like situational experiences with simulated participants, resulting in improved antibiotic, antibiotic resistance, and antibiotic stewardship knowledge.

What Is the Most Effective Management of the Primary Tumor in Men with Invasive Penile Cancer: A Systematic Review of the Available Treatment Options and Their Outcomes.

Context: The primary lesion in penile cancer is managed by surgery or radiation. Surgical options include penile-sparing surgery, amputative surgery, laser excision, and Moh's micrographic surgery. Radiation is applied as external beam radiotherapy (EBRT) and brachytherapy. The treatment aims to completely remove the primary lesion and preserve a sufficient functional penile stump. Objective: To assess whether the 5-yr recurrence-free rate and other outcomes, such as sexual function, quality of life, urination, and penile preserving length, vary between various treatment options. Evidence acquisition: The EMBASE, MEDLINE, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials (CENTRAL; Cochrane HTA, DARE, HEED), Google Scholar, and ClinicalTrials.gov were searched for publications from 1990 through May 2021. Randomized controlled trials, nonrandomized comparative studies (NRCSs), and case series (CSs) were included. Evidence synthesis: The systematic review included 88 studies, involving 9578 men from 16 NRCSs and 72 CSs. The cumulative mean 5-yr recurrence-free rates were 82.0% for penile-sparing surgery, 83.9% for amputative surgery, 78.6% for brachytherapy, 55.2% for EBRT, 69.4% for lasers, and 88.2% for Moh's micrographic surgery, as reported from CSs, and 76.7% for penile-sparing surgery and 93.3% for amputative surgery, as reported from NRCSs. Penile surgery affects sexual function, but amputative surgery causes more appearance concerns. After brachytherapy, 25% of patients reported sexual dysfunction. Both penile-sparing surgery and amputative surgery affect all aspects of psychosocial well-being. Conclusions: Despite the poor quality of evidence, data suggest that penile-sparing surgery is not inferior to amputative surgery in terms of recurrence rates in selected patients. Based on the available information, however, broadly applicable recommendations cannot be made; appropriate patient selection accounts for the relative success of all the available methods. Patient summary: We reviewed the evidence of various techniques to treat penile tumor and assessed their effectiveness in oncologic control and their functional outcomes. Penile-sparing as well as amputative surgery is an effective treatment option, but amputative surgery has a negative impact on sexual function. Penile-sparing surgery and radiotherapy are associated with a higher risk of local recurrence, but preserve sexual function and quality of life better. Laser and Moh's micrographic surgery could be used for smaller lesions.

Elastic property prediction of single-walled carbon nanotube buckypaper/polymer nanocomposites: stochastic bulk response modeling.

In this study, we investigated the statistical relationship between nanostructure variations of carbon nanotube buckypaper-polymer (BPP) composites and their resulting elastic properties. A statistical simulation was developed to predict the elastic properties of a single-layer BPP lamina and extrapolated to the resultant bulk composite part. The stochastic characteristics of BPP composite nanostructure were quantified from experimental observations and used to generate the input for each simulation set performed. The Mori-Tanaka method was used to calculate the stiffness tensor within the buckypaper-polymer region, and a Monte-Carlo simulation was applied to generate the probability distribution for the effective stiffness tensor within each BPP lamina. Classical laminate theory was then employed to predict the effective elastic response for a multi-layered BPP composite laminate. The theoretical predictions were compared with experimental data, and the resulting trends for the effective tensile modulus between experimental and theoretical corresponded well with each other.

Evaluation of infection concept and content integration in a baccalaureate nursing program curriculum.

Nursing students must graduate from their programs equipped with evidenced-based knowledge and skills to prevent, detect, control, and stop the spread of infectious agents regardless of setting. This program evaluation sought to determine curricular integration of the concept of infection and infection prevention and control practices.

Improvement in the Quantification of Foreign Object Defects in Carbon Fiber Laminates Using Immersion Pulse-Echo Ultrasound.

This research presents a new technique using pulse echo ultrasound for sizing foreign objects within carbon fiber laminates. Carbon fiber laminates are becoming increasingly popular in a wide variety of industries for their desirable properties. It is not uncommon for manufacturing defects to occur within a carbon fiber laminates, causing waste, either in the discarding of failed parts or the overdesign of the initial part to account for these anticipated and undetected errors. One such manufacturing defect is the occurrence of a foreign object within the laminate. This defect will lead to a localized weakness within the laminate including, but not limited to, stress risers, delamination, and catastrophic failure. This paper presents a method to analyze high-resolution c-scan full waveform captured data to automatically capture the geometry of the foreign object with minimal user inputs without a-priori knowledge of the shape of the defect. This paper analyzes twelve samples, each a twelve-lamina carbon fiber laminate. Foreign objects are made from polytetrafluoroethylene (PTFE) measuring 0.05 mm (0.002 in.) thick and ranging in diameter from 12.7 mm (0.5 in) to 1.588 mm (0.0625 in), are placed within the laminates during fabrication at varying depths. The samples are analyzed with a custom high-resolution c-scan system and smoothing, and edge detection methods are applied to the collected c-scan data. Results are presented on the sizing of the foreign objects with an average error of 6% of the true area, and an average absolute difference in the estimation of the diameter of 0.1 mm (0.004 in), an improvement over recently presented ultrasonic methods by a factor of three.

Characterization and Model Validation for Large Format Chopped Fiber, Foamed, Composite Structures Made from Recycled Olefin Based Polymers.

The purpose of this research is to predict the material performance of large format foamed core composite structures, such as crossties or structural timbers, using only constitutive properties. These structures are fabricated from recycled post-consumer/post-industrial waste composed of High-Density Polyethylene (HDPE) and Glass Filled Polypropylene (GFPP). A technical challenge in predicting the final part performance is the mathematical correlation between the microstructural variations and the macroscopic responses as a function of fiber aspect ratio, cell density, and constitutive properties of the polymer blend. The structures investigated have a dense and consolidated outer shell and a closed cell foamed core. The non-linear shell and the foamed core material properties are analyzed with micromechanics models, and the reference stress of the shell and core is predicted using a modified Rule of Mixtures model. The predicted properties are used as the inputs for a Finite Element Analysis (FEA) model, and the computational results are compared to experimental four-point bend test results for sixteen samples performed on a 120-kip compression stage. The results show that the mean of the characterized deflections from the four-point bend tests did not show any variations for an isotropic and transversely isotropic model using a linear analysis. This model was then extended to a non-linear analysis using the Ramberg-Osgood model to predict the full crosstie four-point bend test behavior. The FEA model results show a deviation of 2.45 kN compared to the experimental variation of 3.58 kN between the samples measured.