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An Experimental Investigation Of Printing Speed, Layer Thickness, And Nozzle Temperature On The Mechanical Properties Of Silk-Pla Printed Specimens
Get PDFFused Deposition Modeling (FDM) is a popular 3D printing technique used across various industries. Choosing the right printing parameters is essential for ensuring the overall quality and integrity of 3D-printed products. These parameters greatly affect the quality and strength of 3D-printed items. The focus of this study was the influence of printing parameters such as layer thickness, nozzle temperature, and printing speed on the mechanical behavior of 3D-printed silk polylactic acid (PLA). Tensile tests were conducted on a universal testing machine to analyze the mechanical behavior of the printed materials. Moreover, Digital Image Correlation (DIC) analyses were utilized on the tested specimens to determine the displacement and strain across the entire surface area. The test specimens were printed with layer thicknesses of 0.1mm, 0.15mm, and 0.2 mm. The temperatures of the nozzle used during printing varied from 200°C, 210°C, and 220°C, whereas print speeds of 100 mm/s, 120 mm/s, and 140 mm/s were considered. The other printing parameters were kept consistent for all specimens. The tensile specimen, adhering to ASTM D638 standards, was designed using SolidWorks CAD software. In this study, the maximum UTS was observed at 40.68 MPa at 0.2mm layer thickness, 220°C nozzle temperature, and 120mm/s print speed, whereas a layer thickness of 0.2mm, nozzle temperature of 200°C, and print speed of 120mm/s demonstrated the lowest tensile stress, measuring 25.79 MPa. The analysis of variance (ANOVA) indicated that the interaction between layer thickness, nozzle temperature, and printing speed significantly affected the tensile strength and Young\u27s modulus of Silk-PLA. This study revealed that nozzle temperature was the most critical parameter regarding the ultimate tensile strength and Young\u27s modulus, providing crucial insights for optimizing 3D printing parameters, whereas DIC results showed comprehensive insights into the deformation and full field strain distribution of the 3D-printed materials.
Index Terms- Additive manufacturing, FDM, mechanical properties, Silk-PLA, DIC
Sorgoleone (Lipophilic Benzoquinones) Levels In The Root Exudates Of Elite Sorghum [Sorghum Bicolor (L.) Moench] Cultivars
Get PDFNitrogen loss from cropping systems is significant and is estimated at more than 50% of the amounts applied. Root exudates of certain plant species including sorghum [Sorghum bicolor (L.) Moench] contain sorgoleone which can reduce nitrification and nitrogen loss through biological nitrification inhibition (BNI). Therefore, the goal of this study was to screen selected elite sorghum germplasm comprising hybrids and parents to determine the best sorgoleone secreting cultivars. The hypothesis was that nitrogen loss from croplands could be curbed through exploring sorghum BNI traits. Screening of the cultivars selected was done using an established sorghum culture and extraction pipeline that quantifies sorgoleone, the principal BNI compound in sorghum root hairs.
The procedure involved growing the sorghum cultivars in three replicates, harvesting 6-18 roots per cultivar, and then extracting the sorgoleone with solvents and vacuum centrifuging. Freshly harvested roots were washed with 5 mL of dichloromethane (DCM) to extract the sorgoleone. The roots were dried in parchment bags at 65oC for two days to obtain root dry weights. Next, the DCM was evaporated overnight at room temperature to dry the sorgoleone. The dried out sorgoleone was re-extracted with 500 μL methanol and dried down using speed vacuuming followed by a second extraction with 400 μL methanol. The sorgoleone extract was then dissolved in HPLC-grade acetonitrile for HPLC analysis. The sorgoleone extract was separated using a Schimadzu reverse phase C18 column using isocratic elution. The mobile phase comprised 65% acetonitrile and 35% acidified water (0.5% formic acid). Sorgoleone was detected at 260 nm using a Shimadzu diode-array-detector. Concentrations were determined by comparing the peak area with pure sorgoleone samples with known concentrations.
The sorghum genotypes evaluated showed varied levels of germination. Root biomass produced also varied among genotypes as did sorgoleone. Sorgoleone amounts quantified ranged from 1.8 to 19.1 mg/g of sorgoleone/dry root weight for the sorghum genotypes evaluated. In terms of sorgoleone production, the top genotypes in order of magnitude were PI482903 \u3e R.Tx430 \u3e SC372 \u3e SC265 \u3e SC1345 \u3e B.Tx623 \u3eP898012.
Keywords: Sorgoleone, Sorghum, Sorgoleone, Nitrogen, Biological Nitrification Inhibition, HPL
Artificial intelligence to investigate predictors and prognostic impact of time to surgery in colon cancer
No full textBackground and Objectives: The role of time to surgery (TTS) for long-term outcomes in colon cancer (CC) remains ill-defined. We sought to utilize artificial intelligence (AI) to characterize the drivers of TTS and its prognostic impact. Methods: The National Cancer Database was utilized to identify patients diagnosed with non-metastatic CC between 2004 and 2018. AI models were employed to rank the importance of several sociodemographic, facility, and tumor characteristics in determining TTS, and postoperative survival. Results: Among 518 983 patients, 137 902 (26.6%) received intraoperative diagnosis of CC (TTS = 0), while 381 081 (74.4%) underwent elective surgery (TTS \u3e 0) with median TTS of 19.0 days (interquartile range [IQR]: 7.0−33.0). An AI model, identified tumor stage, receipt of adequate lymphadenectomy, histologic grade, lymphovascular invasion, and insurance status as the most important variables associated with TTS = 0. Conversely, the type and location of treating facility and receipt of adjuvant therapy were among the most important variables for TTS \u3e 0. Notably, TTS was among the most important variables associated with survival, and TTS \u3e 3 weeks was associated with an incremental increase in mortality risk. Conclusions: The identification of factors associated with TTS can help stratify patients most likely to suffer poor outcomes due to prolonged TTS, as well as guide quality improvement initiatives related to timely surgical care
(R1957) Some Types of Continuous Function Via N-Neutrosophic Crisp Topological Spaces
Get PDFThe aim of this article is to introduced a new type of continuous functions such as N-neutrosophic crisp gamma continuous and weakly N-neutrosophic crisp gamma continuous functions in a N-neutrosophic crisp topological space and also discuss a relation between them in a N-neutrosophic crisp topological spaces. We also investigate some of their properties in N-neutrosophic crisp gamma continuous function via N-neutrosophic crisp topological spaces. Further, a contra part of continuity called N-neutrosophic crisp gamma-contra continuous map in a N-neutrosophic crisp topology is also initiated. Finally, an application based on neutrosophic score function of medical diagnosis is examined with graphical representation
Reducing Library Anxiety in the Information Seeking Behavior Of First Year College Students
Get PDFThis study explored the use of interactive technology to reduce library anxiety in the information seeking behavior of first year students enrolled in a historically Black college or university. Based on the research focus, the following questions were formulated: What are the determinants for reducing library anxiety in first year college students’ information seeking behavior? Related questions were formatted to test the hypotheses and for data collection:
(1) Can interactive applications included as part of the information retrieval process decrease library anxiety?
(2) Can familiarity, as measured by a pre and post survey, decrease library anxiety? Interactive applications may include virtual and augmented reality, online chat, games and artificial intelligence technology. These are relatively new forms of technology used in education, and research indicates that these technologies promote immersive experiences that can contribute to learning. The research hypothesized that these technologies may also increase familiarity of the library and the related resources, which may reduce library anxiety. This research may provide vital information to higher education administrators and librarians to ensure that all students receive adequate resources to find information needed for their classes and that barriers that prevent progress in student’s education are removed.
Keywords: information seeking behavior, library anxiety, virtual reality, augmented realit
Bourbon Street Breakdown
No full texthttps://digitalcommons.pvamu.edu/brass-ensembles/1008/thumbnail.jp
Saxophone Quartet, Opus 10
No full texthttps://digitalcommons.pvamu.edu/woodwind-ensembles/1000/thumbnail.jp