Single seed sorting technology and its interaction with processing for food, malt, feed and industrial markets

Non-Peer Reviewe

Longitudinal Associations Between Cognitive Functioning and Depressive Symptoms Among Couples in the Mexican Health and Aging Study

OBJECTIVE: To examine the bidirectional associations between older adult spouses\u27 cognitive functioning and depressive symptoms over time and replicate previous findings from the United States (US) in Mexico. DESIGN: Longitudinal, dyadic path analysis with the actor-partner interdependence model. SETTING: Data were from the three most recent interview waves (2012, 2015, and 2018) of the Mexican Health and Aging Study (MHAS), a longitudinal national study of adults aged 50+ years in Mexico. PARTICIPANTS: Husbands and wives from 905 community-dwelling married couples (N = 1,810). MEASUREMENTS: The MHAS cognitive battery measured cognitive function. Depressive symptoms were assessed using a modified nine-item Center for Epidemiologic Studies Depression Scale. Baseline covariates included age, education, number of children, limitation with any activity of daily living, limitation with any instrumental activity of daily living, and pain. RESULTS: As hypothesized, there were significant within-individual associations in which one person\u27s own cognitive functioning and own depressive symptoms predicted their own follow-up cognitive functioning and depressive symptoms, respectively. In addition, a person\u27s own cognitive functioning predicted their own depressive symptoms, and a person\u27s own depressive symptoms predicted their own cognitive functioning over time. As hypothesized, there was a significant partner association such that one person\u27s depressive symptoms predicted more depressive symptoms in the partner. CONCLUSION: Findings from this study of older Mexican couples replicates findings from studies of older couples in the US, showing that depressive symptoms in one partner predict depressive symptoms in the other partner over time; however, there was no evidence for cognition-depression partner associations over time

Calibration of the Johnson-Cook Material Model for Additively Manufactured 304L SS Parts: Modeling and Experiments

Selective laser melting (SLM) is a type of additive manufacturing technique which uses a powder bed to form complex metal parts in a layer-by-layer process. This study aims to understand the material flow of parts manufactured by SLM process using 304L stainless steel powder, which is widely used in numerous applications. The tensile specimens were manufactured using 304LSS powder through SLM process. Low strain-rates, high temperature tensile tests were carried out to calibrate the parameters of the constitutive Johnson-Cook strength model. To conduct the tensile tests, different temperatures (25 oC, 150 oC and 250 oC) and strain-rates (0.1 s-1, 0.01 s-1 and 0.001 s-1) were used. The material model developed was used in numerical simulation of the tensile tests and compared with the experimental results.Mechanical Engineerin

An experimental study of the dual-fuel performance of a small compression ignition diesel engine operating with three gaseous fuels

A dual-fuel engine is a compression ignition (CI) engine where the primary gaseous fuel source is premixed with air as it enters the combustion chamber. This homogenous mixture is ignited by a small quantity of diesel, the ‘pilot’, that is injected towards the end of the compression stroke. In the present study, a direct-injection CI engine, was fuelled with three different gaseous fuels: methane, propane, and butane. The engine performance at various gaseous concentrations was recorded at 1500 r/min and quarter, half, and three-quarters relative to full a load of 18.7 kW. In order to investigate the combustion performance, a novel three-zone heat release rate analysis was applied to the data. The resulting heat release rate data are used to aid understanding of the performance characteristics of the engine in dual-fuel mode. Data are presented for the heat release rates, effects of engine load and speed, brake specific energy consumption of the engine, and combustion phasing of the three different primary gaseous fuels. Methane permitted the maximum energy substitution, relative to diesel, and yielded the most significant reductions in CO2. However, propane also had significant reductions in CO2 but had an increased diffusional combustion stage which may lend itself to the modern high-speed direct-injection engine

Compressive and Bending Performance of Selectively Laser Melted AlSi10Mg Structures

Selective laser melting (SLM) is a widely used additive manufacturing technique that effectively manufactures complex geometries such as cellular structures. However, challenges such as anisotropy and mechanical property variation are commonly found due to process parameters. In a bid to utilize this method for the commercial production of cellular structures, it is important to understand the behavior of a material under different loading conditions. In this work, the behavior of additively manufactured AlSi10Mg under compression, bending, and tension loads was investigated. Vertical and horizontal build directions are compared for each type of loading. Specimens were manufactured using the reduced build volume (RBV) chamber of the Renishaw AM 250 SLM machine

Effect of SLM Build Parameters on the Compressive Properties of 304L Stainless Steel

Selective laser melting (SLM) is well suited for the efficient manufacturing of complex structures because of its manufacturing methodology. The optimized process parameters for each alloy has been a cause for debate in recent years. In this study, the hatch angle and build orientation were investigated. 304L stainless steel samples were manufactured using three hatch angles (0◦, 67◦, and 105◦) in three build orientations (x-, y-, and z-direction) and tested in compression. Analysis of variance and Tukey\u27s test were used to evaluate the obtained results. Results showed that the measured compressive yield strength and plastic flow stress varied when the hatch angle and build orientation changed. Samples built in the y-direction exhibited the highest yield strength irrespective of the hatch angle; although, samples manufactured using a hatch angle of 0◦ exhibited the lowest yield strength. Samples manufactured with a hatch angle of 0◦ flowed at the lowest stress at 35% plastic strain. Samples manufactured with hatch angles of 67◦ and 105◦ flowed at statistically the same flow stress at 35% plastic strain. However, samples manufactured with a 67◦ hatch angle deformed non-uniformly. Therefore, it can be concluded that 304L stainless steel parts manufactured using a hatch angle of 105◦ in the y-direction exhibited the best overall compressive behavior

Performance Evaluation Of Composite Sandwich Structures With Additively Manufactured Aluminum Honeycomb Cores With Increased Bonding Surface Area

Modern aerostructures, including wings and fuselages, increasingly feature sandwich structures due to their high-energy absorption, low weight, and high flexural stiffness. The face sheet of these sandwich structures are typically thin composite laminates with interior honeycombs made of Nomex or aluminum. Standard cores are structurally efficient, but their design cannot be varied throughout the structure. With additive manufacturing (AM) technology, these core geometries can be altered to meet the design requirements that are not met in standard honeycomb cores. This study used a modified aluminum honeycomb core, with increased surface area on the top and bottom, as the core material in sandwich panels. The modified honeycomb core was produced through the laser powder bed fusion method. The behavior of the modified sandwich composite panels was evaluated through three-point bend, edgewise compression, and impact tests, and their performance was compared to that of a conventional honeycomb core sandwich panel. The three-point bend test results indicated that the sandwich structure\u27s ultimate shear strength improved by 12.6% with the modified honeycomb core. Additionally, the displacement at the failure of the structure increased by 11%. The edgewise compression tests showed that the ultimate edgewise compressive strength improved by 19.1% when using the modified core. The impact test results revealed that the peak force increased by 8% and the energy-absorbing capacity of the sandwich structure increased by 20% with the use of the modified honeycomb core

Survival Outcomes of Patients Treated with Hypofractionated Stereotactic Body Radiation Therapy for Parotid Gland Tumors: a Retrospective Analysis

Background: to review a single-institution experience with the management of parotid malignancies treated by fractionated stereotactic body radiosurgery (SBRT). Findings: Between 2003 and 2011, 13 patients diagnosed with parotid malignancies were treated with adjuvant or definitive SBRT to a median dose of 33 Gy (range 25–40 Gy). There were 11 male and two female patients with a median age of 80. Ten patients declined conventional radiation treatment and three patients had received prior unrelated radiation therapy to neighboring structures with unavailable radiation records. Six patients were treated with definitive intent while seven patients were treated adjuvantly for adverse surgical or pathologic features. Five patients had clinical or pathologic evidence of lymph node disease. Conclusion: at a median follow-up of 14 months only one patient failed locally, and four failed distantly. The actuarial 2-year overall survival, progression-free survival, and local-regional control rates were 46, 84, and 47%, respectively. Statistical analysis revealed surgery as a positive predictor of overall survival while presence of gross disease was a negatively correlated factor (p < 0.05)