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This paper presents a feasibility study of a hybrid compost waste heat to power/Concentrating Solar Panel (CSP) green energy Organic Rankine Cycle (ORC). The power plant is baselined to operate with a duty of 24/7 on compost waste heat and utilize solar thermal energy to boost power output during the day. This paper discusses the design of the power plant, the design of a compost driven heat exchanger/boiler, compost pile thermal analysis, CSP analysis, and simulated power plant output analysis The selection of isobutane as ORC working fluid is justified herein. A Levelized Cost of Energy (LCOE) analysis was performed to ensure that the energy produced by this hybrid power plant would come at a reasonable and competitive cost. The results herein show that the hybrid power plant affords an LCOE of 4 ¢/kWh for compost operation alone and an LCOE of 10.7 ¢/kWh for compost and CSP solar energy operation. The hybrid compost/ORC power plant presented herein affords an average energy conversion efficiency of 4.3%. Centric to the operation of the compost waste heat to power plant presented herein is the correct design and selection of the heat exchanger which interfaces the compost waste heat stream to the isobutane ORC. The design and analysis of this heat exchanger as well as commercially off-the-shelf hardware to meet the specifications is given in detail herein

This paper presents the research conducted for an industry partner with the goal of developing a waste heat driven, fully renewable and green, power plant. The industry partner was desirous of a compost waste heat driven power plant with the possibility of supplemental solar thermal energy boost, but with the main energy source being compost. The goal is for the plant to operate with a duty of 24/7 on compost waste heat and utilize solar thermal energy to boost power output during the day. This paper discusses the design of a suitable Organic Rankine Cycle (ORC) power plant, the design of a compost driven heat exchanger/boiler, compost pile thermal analysis, Concentrated Solar Power (CSP) hybrid plant analysis, and expected power output analysis for this concept. Furthermore, the selection of isobutane as the baseline refrigerant for this ORC plant will be justified. Analysis was conducted and a feasibility study was carried out in order to determine if the concept is feasible and competitive in the open market. As such, a Levelized Cost of Energy (LCOE) analysis was also performed to ensure that the energy produced at this plant would come at a reasonable, competitive cost. The results shown herein for a hybrid CSP / compost waste to heat isobutane driven ORC powerplant afford an LCOE on the order of 4 ¢/kWh for compost alone and 10.7 ¢/kWh for compost and CSP solar. These are in comparison to the average LCOE for solar stations of approximately 10 ¢/kWh. Paramount to the operation of the compost waste heat to power plant presented herein is the correct design and selection of the heat exchanger which interfaces the compost waste heat stream to the isobutane ORC. The design and analysis of this heat exchanger is given in detail herein.

This paper presents a comparison between traditional flat plate solar thermal collector systems and solar photovoltaic (PV) heat pump systems. The purpose of this analysis was to determine whether or not heat pump technology has matured to the point that a solar PV system paired with a heat pump could outperform a traditional solar thermal flat plate collector system. To this end, two systems with identical panel footprints of 7.6 m2 (82 ft2) were modelled and analyzed at four different locations being Los Angeles CA, Phoenix AZ, Seattle WA, and Denver CO. The expected energy production and Levelized Cost of Energy (LCOE) for both systems at these locations were determined. The solar fraction for the solar thermal collector systems and PV heat pump systems at the four locations studied were found to be f = 0.44 and f = 0.99 in Los Angeles, f = 0.44 and f = 1.00 in Phoenix, f = 0.21 and f = 0.62 in Seattle, and f = 0.34 and f = 0.90 in Denver. As such, it is evident that the solar PV heat pump systems produced more thermal energy than the solar thermal collectors at all locations tested. The LCOE for the solar thermal collector systems and solar PV heat pump systems at each location were found to be 48.42 ¢/kWh and 36.57 ¢/kWh at Los Angeles, 55.37 ¢/kWh and 36.13 ¢/kWh at Phoenix, 81.47 ¢/kWh and 97.29 ¢/kWh at Seattle, and 52.27 ¢/kWh and 67.50 ¢/kWh at Denver. From these values, it can be seen that the solar PV heat pump systems have a lower LCOE in the warmer climates where ground source heat pumps are not needed but have slightly higher LCOE values in cooler climates where they are. As such, this study has found that solar PV heat pump systems have matured enough to outperform solar thermal flat plate collectors in most situations.

This paper presents results of Computational Fluid Dynamics (CFD) modeling and experimental wind tunnel testing to predict the drag coefficient for a Human Powered Vehicle (HPV) entered in the World Human Powered Speed Challenge (WHPSC). Herein, a comparison of CFD to wind tunnel test data is presented for ten different HPV designs. The current study reveals that streamlining the nose cone, tail cone, and wheel housing allows for a reduction of drag forces in critical areas, and a reduced drag coefficient. This allows for a selection to be made during the design phase, prior to manufacturing. Drag coefficients were found to be in the range of 0.133 < CD < 0.273, depending on the type of HPV considered. Wind tunnel testing was performed on scale models of the HPV showing agreement to the CFD results on average to within 16%. The wind tunnel testing showed a 7.7% decrease in drag coefficient from the baseline HPV of 2019 to the baseline HPV of 2020. Thus, the wind tunnel data supported by CFD analysis was used to assist in the design of the HPV.

The use of ejector cycles for increased performance and efficiency is becoming more prevalent in industry. The goal of this study is to evaluate an ejector using Computational Fluid Dynamics (CFD) to evaluate flow patterns, perform trade studies varying the type of refrigerant, and determine the entrainment ratio for each working fluid, over a range of boundary condition pressures, set at points along the ejector’s flow path. The 2012 Toyota Prius V is one of the first automobiles using an ejector cycle in their internal cabin refrigeration system. The DENSO Corporation ejector hardware was used as the basis for the creation of geometry for the CFD mode of the ejector. Three working fluids were simulated, R-134a, R-245fa, and R-1235yf. The primary findings of this study were as follows. The CFD study here indicates that R-245fa performs the best out of the three working fluids, when examining their entrainment ratios (ratio of secondary to primary flow rates in the ejector). For all three working fluids, the entrainment ratio was seen to peak performance at an ejector inlet pressure of 1.75 × 105 Pa. The ejector mixing chamber pressure and ejector outlet pressure boundary conditions also witnessed a rise in entrainment ratios, during an increase of their respective pressure values.

Twin wire arc spraying (TWAS) is a plasma spraying process that offers low workpiece heating and high deposition rates at a lower cost. Variations in TWAS process conditions cause the substrate temperature to fluctuate and even melt. Therefore, the motivation of this project was to simulate the heat transfer from the TWAS torch to the substrate during spraying and layer formation of a coating. Simulations using ANSYS FLUENT Computational Fluid Dynamics (CFD) software were used to model the heat transfer in a TWAS system. The results of this paper are meant to augment and improve the database of TWAS technology. A CFD numerical heat transfer model is presented that was used to investigate the substrate surface temperature during the TWAS process. The results for the different pressure models showed that for a 3 second simulation, substrate surface temperatures increased as nozzle inlet pressure was decreased. For the upper and lower bound pressures of 75 psia and 29 psia, substrate surface temperature resulted in 946 °C and 1010 °C, respectively.

This paper presents the results of a thermodynamic analysis of a two-stage cascaded vapor compression refrigeration cycle developed for high-temperature high-pressure applications, such as the one ...

The drive for continuously improving the performance and increasing the efficiencies of marine transportation has resulted in the development of a new alloy, Mercalloy A362™. This alloy was designed to lighten Mercury Marine’s lower transmission gearcase while also improving the alloy’s recyclability. The new prototype gearcase was subjected to Mercury Marine’s standard service conditions, which resulted in the premature failure of the prototype. A previous study revealed that a large accumulation of unwanted residual stress (~120 MPa) was present in the gearcase following the high pressure die casting process. Fortunately, the T5 heat treatment reduced the magnitude of stress by approximately 50%. However, the effects that the T5 heat treatment had on the microstructure and mechanical properties of the alloy were not discussed. Thus, this research article characterizes the effects that the T5 heat treatment has on the volume fraction and morphology of the intermetallics, as well as the tensile performance of the alloy. It was found that the T5 heat treatment led to only minor increases in the volume fraction of Fe-bearing intermetallics, leading to similar tensile properties in both the as-cast and T5 condition. These results suggest that the T5 heat treatment can alleviate residual stress without significantly altering the mechanical properties of the alloy. The results from the previous stress analysis and the current study were used to optimize the manufacturing process which led to the successful introduction of the gearcase into the competitive marine industry.

This paper presents the use of private industry based projects to augment the teaching of a senior level thermal design Heating Ventilation Air Conditioning and Refrigeration (HVAC/R) technical elective. The projects describe herein are used to augment the laboratory portion of the course, and act a synthesizing agents allowing students to experience real-world problem solving first hand. The industry based projects are solicited form local industry representatives, whereby mentors from the engineering company are assigned to direct a team of students to complete a given set of action items during the duration of a semester concluding in an end of semester customer design review. The key to this type of learn-by-doing is the active engagement and willingness on behalf of the industry mentors to take time to guide the students via biweekly face to face or web based tag up meetings. This type of experience is invaluable for the students, since it demonstrates the importance of establishing a network of mentors in order to foster life-long learning in the students chosen field of study.

This paper presents examples of teaching Mechanical Design using a pragmatic approach. The pedagogy used herein embeds real-world experience and projects into the curriculum by taking representative case studies from industry and creating course projects. The approach focuses on using sanity checks using free-body diagrams and hand-calculations, materials specification and proliferate used of commercial off the shelf parts supplier catalog data. Case studies from course projects are presented demonstrating the above skill set reinforcement. The assessment of the student work is presented as it is related to the ABET learning outcomes of the mechanical design curriculum track.

Refrigerated gases have been used to store energy with limited success. This paper presents the results of an exploratory study of how the behavior of fluids compressed to high pressures can be used to increase the efficiency of refrigeration cycles and one possible application for renewable energy. This research presents the results of thermodynamic modeling and analysis of a novel Carbon Dioxide (CO2) cycle to be used for alternative energy production. The thermodynamic computational simulations are carried out in MATLAB and use the NIST REFPROP database for modeling the high pressure (on the order of 1000 MPa) CO2 state points. Preliminary results show that the maximum energy that can be recovered using the proposed high pressure cycle in on the order of 11,043 J, for each mole of CO2 flowing in the cycle. Thus the Coefficient of Performance is COP = 2.22, and the efficiency of the cycle is estimated as η = 35%. Future work will focus on the development of equipment such as the cryogenic turbo-expander that can operate at the ultra-high pressures studied.

Performance of a micro-scale heat sink with slip boundary condition at walls is evaluated using entropy generation minimization (EGM) approach. Optimum geometrical parameters and working conditions are obtained by applying two different constraints of fixed microchannel height and constant maximum pressure drop. It has been observed that with fixed channel height constraint, the optimum aspect ratio and Reynolds number are 2.5 and 700, respectively. Slip boundary condition has negligible effect on optimum working parameters while it enhances the thermal performance of the heat sink by almost 4% at fixed height constraint. At maximum pressure drop constraint, the optimum working parameters are aspect ratio of 2.25 and Reynolds number of 850. Slip on the microchannel walls reduces pressure drop and enhances the thermal performance of the heat sink by 11%.

Here we present the results of the newly developed Eulerian-Lagrangian model to simulate both the primary and the secondary phases coupled in a transient analysis. A set of two a-dimensional, transient linear shear flow at low Reynolds numbers was considered, and the effect of shearing rate on a suspended buoyant spherical solid particle was analyzed. The rotation and displacement of the solid particle are considered in the model, and the effect of the secondary phase on the primary phase is also evaluated at each time step without any simplification. In order to overcome the existing discontinuity at the interface between secondary and primary phases in this Eulerian-Lagrangian approach, the interface between the solid particle and the fluid phase is replaced by a kernel function creating a smooth profile from the solid into the liquid with a predefined thickness. Several simulations were performed, and the reliability of the developed model was assessed. The global deviation grid convergence index (GCI) approach was employed to perform solution verification. The observed order of accuracy of the primary phase solver approaches 2, consistent with the formal order of accuracy of the applied discretization scheme. The obtained velocity profiles from the computational analyses show excellent agreement with the analytical solution confirming the reliability of the single-phase flow solver. To validate the computational results for the multiphase flow solver, we used the experimental data from our newly developed linear shear flow apparatus with suspended buoyant particles.

This paper presents the analysis and design of a compressor for application to a Fatty Acid Methyl Ester (FAME) Methyl Linoleate (MLL) bio-refrigerant cascade working cycle. This working fluid is being used in the topping cycle of an active electronics payload cooling system design to operate at elevated temperatures and pressures such as those witnessed by a Venus lander. The twin-screw, three-stage compressor operates at escalated temperatures of approximately 520 °C (960 °F). The total compressor power of 143.4 W is shared as 43.5 W, 47.7 W, and 53.3 W over stages 1, 2, and 3, respectively. The screw compressor is baselined with a D = 1 inch diameter rotor and an L/D (stroke/bore) ratio of L/D = 2 per stage. The compression ratio corresponds to a volume ratio of 6.5. The swept volume for a 4+6 rotor configuration is estimated to be 1.13 CFM at 2000 RPM with an asymmetric profile and no leakage. The volumetric efficiency of the compressor is estimated to be on the order of 80% due to the higher molecular weight of the FAME/MLL working fluid. The SCORG turbomachinery software is used to verify the thermodynamics analysis and affords a volumetric displacement of 0.025 L/rev at 2000 RPM and 80% adiabatic efficiency.

This paper presents modeling of the Puna Geothermal Venture as a case study in understanding how the technology of geothermal can by successfully implemented. The paper presents a review of the Puna Geothermal Venture specifications, followed by simulation results carried out using NREL SAM and RETSCREEN analysis tools in order to quantify the pertinent metrics associated with the geothermal powerplant by retrofitting its current capacity of 30 MW to 60 MW. The paper closes with a review of current state-of-the art H2S abatement strategies for geothermal power plants, and presents an outline of how these technologies can be implemented at the Puna Geothermal Venture.

This paper discusses the recent progress of a multi-year project investigating the concept of an unmanned aerial vehicle (UAV) being partially powered by the natural environment the drone will encounter along its flight path. This UAV flight is achieved using power generation, management, and storage systems. The aircraft's improvement in sustainability, or endurance, is the main benefit of this design as it harvests energy from the environment available to it, and also using the potential of replacing some of the UAV structure with the structure of the power storage devices to reduce parasitic weight. These UAV enhancements could have many beneficial applications for a modern technological society. Applications in defense are numerous, as a highly sustainable aircraft can provide longterm surveillance over essential targets. Also, weather monitoring can benefit immensely from a highly sustainable drone, as these drones will be able to follow weather patterns as they develop over time and achieve real time updates. The power generation comes from three sources: flexible solar panels, thermoelectric generators, and vibration induced power generation motors (installed in power pods or inside the wing) that are excited by either atmospheric gusts or wing flutter. These forms of AC and DC current will be combined into usable energy for the UAV energy storage devices. Utilizing these forms of energy should in theory greatly extend the flight time of the UAV as it will continually cycle through these different forms of energy throughout the day and night. The flexible solar cells will be either attached onto the wing or replace the wing upper skin structure and take in the energy from the sun during the day, outputting straight DC current. The vibration induced power generation devices are comprised of DC motors attached to leaf springs and a gear/rack mechanism that oscillate from the vibrations of the wings to spin the motor shaft and generate AC power. The thermoelectric generators will generate energy from heat flux across the hot and cold plates of the power management system and the solar cells. All these sources are combined into a single power output via the power management system (PWMS). The PWMS is based off a hybrid power design, where the input sources are combined into a single stable DC output in which lithium polymer (LiPo) batteries or graphene supercapacitors can be charged and discharged into the UAV electric motor driven propeller load.

Objectives The eighth edition of the American Joint Committee on Cancer staging manual now stratifies nonmucinous lung adenocarcinomas (nmLACAs) by the size of the invasive component only. This is determined by direct gross or microscopic measurement; however, a calculated invasive size based on the percentage of invasive growth patterns has been proposed as an alternative option. Methods To compare radiologic with different pathologic assessments of invasive tumor size, we retrospectively reviewed a cohort of resected nmLACAs with a part-solid appearance on computed tomography (CT) scan (n = 112). Results The median direct microscopic pathologic invasive measurements were not significantly different from the median calculated pathologic invasive measurements; however, the median CT invasive measurements were 0.26 cm larger than the median direct pathologic measurements (P < .001). Conclusions Our results show that pathologic calculated invasive tumor measurements are comparable to direct microscopic measurements of invasive tumor, thereby supporting the recommendation for use of calculated invasive tumor size by the pathologist if necessary.

This paper presents the analysis and optimization of multistage refrigeration thermal control system for use in cooling electronics payloads on Venus lander missions. The paper outlines the challen...

Rationale and Objectives The objective of this study was to quantify the impact of different rounding methods on size measurements of pulmonary nodules and to determine the number of nodules that change management categories as a result of rounding. Materials and Methods For this retrospective institutional review board-approved study, we included 503 incidental pulmonary nodules (308 solid and 195 subsolid) from a data repository. Long and short axes were measured. Average diameters were calculated using four different rounding methods (method 1: no rounding; method 2: rounding only the average diameter to the closest millimeter; method 3: rounding only short and long axes; and method 4: rounding short and long axes and the average diameter to the closest millimeter). Nodules were classified for each rounding method according to the 2017 Fleischner Society guideline management categories. Measurements were compared among the four rounding methods using analysis of variance. Results Without rounding, the average nodule diameter was 15.67 ± 5.97 mm. This increased between 0.03 and 0.29 mm using rounding methods 2–4 (range: P Conclusions Rounding methods have a small absolute but statically significant effect on nodule size, impacting management category in less than 3% of the nodules. This suggests that, in clinical practice, any rounding method can be used for determining nodule size without substantially biasing individual nodules toward given management categories.

Objectives The aims of this study were to quantify the relationship between computed tomography (CT) size, volume, density, and roundness of lung adenocarcinomas (ACs) manifesting as pure ground-glass nodules (pGGNs) on CT images and to correlate these parameters with histologic features of invasiveness. Methods From 2005 to 2015, 63 ACs manifesting as pGGNs on CT images were surgically resected at our institution. CT size was measured, and roundness, volumes and densities were computed. CT parameters were correlated to age and sex, as well as to size and number of invasive foci and histologic AC subcategories. Correlations were quantified with Spearman rank correlation coefficients. Results Of 63 ACs, 28 (44%) were AC in situ, 25 (40%) were minimally invasive AC, and 10 (16%) were invasive AC. Six of 35 nodules with invasive foci (17%) were smaller than 10 mm. Correlations between age and CT size, volume, density, and roundness were not significant (range r = –0.061 to 0.144, p = 0.285 to 0.902). Correlations between size and number of invasive foci with CT size ( r = 0.417, p r = 0.389, p = 0.003, respectively) were similar to the correlations with volume ( r = 0.401, p = 0.001 and r = 0.350, p = 0.005, respectively) and stronger than the correlation with density ( r = 0.237, p = 0.062 and r = 0.222, p = 0.081, respectively) and roundness ( r = 0.059, p = 0.648 and r = –0.030, p = 0.831, respectively). Conclusions In ACs manifesting as pGGNs on CT images, nodule size is positively related to size and number of histologically invasive foci. However, invasive foci can be found in pGGNs smaller than 10 mm. Measuring volume and density of pGGNs provides no advantage over two-dimensional size measurements, which appear sufficient for risk estimation in clinical practice.

Rationale and Objectives This study aimed to compare long-axis diameter to average computed tomography (CT) diameter measurements of lung adenocarcinomas manifesting as solid lung nodules ≤30 mm on CT, as referenced to pathologic measurements, and to determine the impact of the two CT measurement approaches on tumor (T)-staging of nodules. Materials and Methods This institutional review board-approved study included all 274 radiologic solid adenocarcinomas resected at our institution over 10 years. Two observers measured long- and short-axis diameters on pre-resection chest CT in lung and mediastinal windows. T-stages were determined. CT measurements and T-stages were compared to pathology measurements and T-stages using Wilcoxon signed rank test and McNemar test. Inter- and intraobserver variability was determined with intraclass correlation coefficients (ICC) and Bland-Altman plots. Results For lung and mediastinal windows, nodule size was significantly larger using long-axis diameter rather than average diameter (16.93 vs. 14.92 mm, P .001; and 14.02 vs. 12.17 mm, P .001, respectively). The correlation of CT with pathologic measurements was stronger with long-axis than with average diameter (ICC 0.808 vs. 0.730; and 0.731 vs. 0.621, respectively). Lung window measurements correlated stronger with pathology than mediastinal window measurements. CT T-stages differed from pathology T-stages in more than 20% of nodules ( P .001). Inter- and intraobserver variability was small with long-axis and average diameter (ICC range 0.96–0.991, and 0.970–0.993, respectively), but long-axis diameter showed wider scatter on Bland-Altman plots. Conclusions Long-axis CT diameter is preferable for T-staging because it better reflects the pathology T-stage. Average CT diameter might be used for longitudinal nodule follow-up because it shows less measurement variability and is more conservative in size assessment.

Objectives The eighth edition of the AJCC Cancer Staging Manual now stratifies the T descriptor for lung cancers by each increasing 1.0 cm increment, up to 5.0 cm, with an additional category for tumor greater than 7.0 cm. Bias in pathologic versus radiologic measurements may impact tumor staging. Methods The gross pathologic measurements of 493 resected lung adenocarcinomas were compared with presurgical computed tomography radiologic measurements. Also, pathologic tumor measurement data from the Surveillance, Epidemiology, and End Results (SEER) program database were examined. Results The distribution of pathologic measurements showed clustering at 0.5-cm increments, with 43.0% of pathologic measurements falling on 0.5-cm increments compared to only 20.3% of radiologic measurements. This pathologic measurement clustering was also observed for both 591,691 resected lung cancers and 3,597,685 tumors of any type from the SEER database. Conclusions Compared to radiologic measurements, gross pathologic measurements cluster around whole- and half-cm values. This measurement bias could lead to incorrect pathologic tumor staging and influence clinical treatment plans.

This paper presents the results of using laboratory facilities in conjunction with computer aided data acquisition in order to enhance the teaching and learning experiences of the air conditioning and measurements/instrumentation courses in an engineering program. The paper discusses the use of educational technology in the form of a laboratory experiment developed for support of Science Technology Engineering and Math (STEM) education in an engineering curriculum. The experimental apparatus discussed in the paper is a heat pump demonstration unit with LabView data collection and visualization software. The use of modern technology in the classroom is illustrated in this paper by using a heat pump demonstration unit to illustrate the physical principles of air conditioning and heating. Data collection and acquisition/instrumentation, data reduction curriculum is addressed by using an automated data collection system to gather data for the heating and cooling processes. The main objectives of the study were to i) expose STEM students to LabView based data collection, ii) enhance the curriculum of air conditioning and measurements science by using hands-on facilities, iii) develop technical report writing and data reduction skill sets. The experiment is conducted in small teams of 3 to 4 students in order to make the experiential learning a more intimate process. The heat pump hardware is used to illustrate real world working system. The experiment is composed of a compressor, an evaporator, a condenser and throttling valve. The unit allows for operation as both a heat pump and a refrigeration unit. Thus illustrating the concept of Coefficient of Performance (COP) and Energy Efficiency Ratio (ERR) for both the heat pump and the refrigeration mode are enabled. The unit works on R134A and water as the working fluids. The unit is instrumented with a control thermostat allowing the set-point of the device to be changed. Thermocouples, pressure transducers and flow rate meters are used to collect live data which is fed to the LabView based data-acquisition platform. By using such equipment in the teaching of the Air Conditioning curriculum, it allows the students

Plasma spraying is used in various industries for additive manufacturing applications to apply materials onto a workpiece. Such applications could be for the purpose of repair, protection against corrosion, wear-resistance, or enhancing surface properties. One plasma spraying method is the twin wire arc spraying (TWAS) process that utilizes two electrically conductive wires, across which an electric arc is generated at their meeting point. The molten droplets that are created are propelled by an atomizing gas towards a substrate on which the coating is deposited. The TWAS process offers low workpiece heating and high deposition rates at a lower cost compared to other plasma spraying techniques. As the spray angle for this technique is relatively large (15 degree half angle), particles are lost in the process, lowering the yield of deposited material. The motivation of this project was to constrict the particle flow and reduce the loss of particles that are ejected by the spraying torch. Torch nozzles were designed to help the particle trajectory match the axial flow direction of the atomizing gas flow. Simulations using ANSYS FLUENT Computational Fluid Dynamics (CFD) software was utilized to model both the atomizing gas flow and particle flow for a TWAS system. Various nozzle configurations with arc jet angles between 30–75 degrees showed only small effects on gas flow velocity and shape, with no significant variations in particle flow. These results indicate that nozzle configurations are only one factor in determining particle trajectory, and that phase changes and heat transfer need to be considered as well.

This paper presents Fluid Structure Interaction modeling of candidate implant materials used in the femoral artery graft medical procedure. Two candidate implant materials, namely Teflon and Dacron are considered and modeled using Computational Fluid Dynamics (CFD) and structural Finite Element Analysis (FEA) to obtain Fluid Structure Interaction (FSI) developed stresses within the candidate materials as a result of non-Newtonian blood flowing in a pulsatile unsteady fashion into the femoral artery implant tube. The pertinent findings for a pulsatile velocity maximum magnitude of 0.3 m/s and period of oscillation of 2.75 sec are as follows. For the biological tissue the wall shear stress is found to be 2.15 × 104 Pa, the hoop stress is found to be 1.6 × 104 Pa. For the Teflon implant material, the wall shear stress is found to be 1.177 × 104 Pa, the hoop stress is found to be 2.2 × 104 Pa. For the Dacron implant material the wall shear stress is found to by 3.9 × 104 Pa, the hoop stress is found to be 2.17 × 104 Pa. Based upon the analysis herein the PTFE material would be recommended.

This paper describes the use of ANSYS ICEPAK software in teaching a senior level capstone thermal systems design course in a Mechanical Engineering curriculum. The use of ANSYS ICEPAK software tools in the thermal design course allows our undergraduates the preparation they need to become competitive and productive in today’s private industry sector. The paradigm of learn-by-doing adopted by the college is used in the thermal design course by exposing students to the use of ANSYS ICEPAK software in order to complete a design project in the thermal design course. The senior level capstone thermal design course is a three-unit semester course. Students are broken into teams and are tasked to solve a variety of thermal-fluid, heat transfer related design problem scenarios. The student teams are tasked to design an electronic systems thermal management system using PCBS, fans, heat sinks, heat pipes, etc. in order to meet a set of pre-defined requirements. In this manner, the use of the ICEPAK projects serves to build the soft skills (report writing and technical presentation) of the students. This paper will include examples of ANSYS ICEPAK based thermal design projects and methods of assessment and illustrations of how the thermal design course addresses the Mechanical Engineering program’s ABET objectives and outcomes related to senior design capstone design courses.

PURPOSE: To analyze the incidence and CT patterns of visceral pleural invasion (VPI) in adenocarcinomas on the basis of their CT presentation as solid or subsolid nodules. MATERIALS AND METHODS: A total of 286 adenocarcinomas in direct contact with a pleural surface, resected at an institution between 2005 and 2016, were included in this retrospective, institutional review board–approved study. CT size and longest contact length with a pleural surface were measured and their ratios computed. Pleural deviation, pleural thickening, spiculations, different pleural tag types, pleural effusion, and the CT appearance of transgression into an adjacent lobe or infiltration of surrounding tissue were evaluated. Fisher exact tests and simple and multiple logistic regression models were used. RESULTS: Of the 286 nodules, 179 of 286 (62.6%) were solid and 107 of 286 (37.4%) were subsolid. VPI was present in 49 of 286 (17.1%) nodules and was significantly more frequent in solid (44 of 179; 24.6%) than in subsolid nodules (five of 107; 4.7%; P < .001). In solid nodules, multiple regression analysis showed an association of higher contact length–to-size ratio (adjusted odds ratio [OR], 1.02; P = .007) and the presence of multiple pleural tag types (adjusted OR, 5.88; P = .002) with VPI. In subsolid nodules, longer pleural contact length of the solid nodular component (adjusted OR, 1.27; P = .017) and the CT appearance of transgression or infiltration (adjusted OR, 10.75; P = .037) were associated with VPI. CONCLUSION: During preoperative evaluation of adenocarcinomas for the likelihood of VPI, whether a tumor manifests as a solid or a subsolid nodule is important to consider because the incidence of VPI is significantly higher in solid than in subsolid nodules. In addition, this study showed that the CT patterns associated with VPI differ between solid and subsolid nodules. © RSNA, 2019 Supplemental material is available for this article. See also the commentary by Elicker in this issue.

In this study 3-D CFD modeling of a cylindrical stack Proton-exchange membrane fuel cell (PEMFC) is provided. The H2O-O2 PEMFC uses a 10.8 mm2 area membrane and Platinum (Pt) catalyst. The paper presents the methodology for the PEMFC commercial software module, the set-up of the Computational Fluid Dynamics (CFD) geometry, mesh and boundary conditions. Results for the current-voltage performance curves and 3-D contour plots of the fluid, heat and species concentrations within the PEMFC are given. Results are presented for a low-temperature fuel cell using NAFION membrane and a high-temperature fuel cell using BZY membrane.

A micromachined thermal flow sensor is presented demonstrating sensing liquid flow rates as low as 2 microliters per minute capable of being used for biomedical applications. These flow sensors rely on the varying electrical resistance of sensors generated by forced convection at different flow rates. The sensor array presented was constructed using microelectromechanical systems (MEMS) techniques including micro-molding, wet etching and dry etching utilizing biocompatible materials. A numerical model was built using COMSOL multi-physics in order to predict and optimize the electrical, thermal and fluid behavior of the sensor, which was verified with experimental data. The construction allowed for multiple thermal flow sensing operational modes. Here, constant current hot film and constant current calorimetric were simulated and tested. A variety of flow sensor geometries were compared to investigate maximum heat transfer to the sensors, thermal insultation, size, sensitivity and range capabilities. The sensor design is such that it is capable of detecting different flow direction and various flow ranges for different fluids. In addition to the performance capabilities outlined, the sensor is relatively inexpensive and should have a long lifetime due to the lack of moving parts.

The numerical modeling of the premixed combustion occurring in the chamber of a polygon engine is presented in this paper. This research is being carried out to support the analysis and design of a lightweight, two-stroke, six-sided, in-plane, polygon engine. Results for average combustion chamber temperature, turbulent flame speed, progress variable, and Damkohler number versus piston position are presented for methane (CH4), diesel (C10H22), and ethanol (C2H50H) fuels, respectively.

This paper presents a discretized enthalpy analysis of a FAME-MLL, NH3 plate-fin heat exchanger (PFHX) with single and two-phase flow. The paper outlines the methodology used to model the PFHX and presents a MATLAB simulation model, which uses the NIST REFPROP database for thermo-physical property evaluation. The paper presents analysis for a staged single-phase, two-phase PFHX architecture. Plots of the heat transfer coefficients, overall heat transfer coefficient, specific enthalpy and heat flux variation over the length of the PFHX are provided. The mass, volume, area, effectiveness-number of transfer units rating for each PFHX are given.

Estimation of Energy Savings from Community Scale Solar Water Heating in Los Angeles County explores the extent to which community scale solar water heating systems, designed for residential structures in Los Angeles County and constructed from currently available technology, can displace natural gas for domestic water heating through a series of case studies. The effects of policy, urban form, and building characteristics on the performance of solar water heating systems, as well as community scale solar water heating’s potential to reduce emissions from the residential housing sector, are discussed herein. Three public and three private residential developments were selected as case studies for community scale solar water heating, with numbers of units and residents ranging from the tens to hundreds. These six cases were draw from the pool of approximately 19,000 “energy communities” in Los Angeles County, i.e. residential developments where the installation and operation of community scale solar water heating systems is broadly feasible. The six properties were also chosen to represent a cross-section housing stock and development patterns common in Los Angeles County, and different levels of suitability for solar water heating. The performance of and energy savings from solar water heating systems on each of these properties is then evaluated using the National Renewable Energy Laboratory’s System Advisor Model (NREL SAM). The results of the system simulations reveal how building characteristics and hot water demand affect the performance of community scale solar water heating systems. The case study sites’ system simulations show that residential developments with community scale solar water heating systems reach an average solar fraction of 50%. The results of the case studies indicate that community scale solar water heating is viable as an emissions reduction technology for the residential building sector in Mediterranean climates. However, side-by-side comparison with solar PV systems and other water heating technologies (such as grid-connected heat pumps) is necessary to determine optimality in terms of cost, emissions reduction, and thermal efficiency) in specific contexts.

Spontaneous cancer regression is a rare event, scarcely reported among gastrointestinal malignancies. Pancreatic adenocarcinoma regression has been documented in five previous cases, none of which included liver metastases, and the mechanism by which this occurs is not known. A 56-year-old woman with history of discoid lupus, homocysteinemia and peripheral vascular disease was diagnosed with stage IV pancreatic ductal adenocarcinoma (PDA) metastatic to the liver. She received palliative chemotherapy with 5-fluorouracil, leucovorin, irinotecan and oxaliplatin (FOLFIRINOX) for 6 months, complicated by mucositis, diarrhoea, vomiting and twoClostridium difficilecolitis episodes. Cancer initially responded to chemotherapy. However, due to substantial toxicities, she decided to discontinue cytotoxic chemotherapy and focus on palliation alone. Thereafter, CT and carbohydrate antigen (CA) 19-9 showed further response and ultimately complete cancer regression that has persisted for 33 months after cessation of chemotherapy. This is the first report in the English literature showing spontaneous regression of a PDA with liver metastases. Two possible mechanisms are proposed: antitumoral autoimmunity and tumour hypoxia related to vascular disease.

Objectives An intraoperative consultation (IOC) checklist was developed and implemented aimed at standardizing slide labeling and monitoring metrics central to quality and safety in surgical pathology. Design Data were collected for all IOC cases over a 9-month period. Slide labeling defect rates and IOC turnaround time (TAT) were recorded and compared for the pre- and postimplementation periods. Results In total, 839 IOC cases were analyzed. Preintervention slide labeling showed that 85% of cases contained at least one defect (n = 565). Postintervention data revealed that 27% of cases contained at least one defect (n = 274). The improvement was statistically significant (P < .001). Mean TAT was 21.6 minutes preintervention vs 23.2 minutes postintervention, and the change was insignificant (P = .071). Conclusions The implementation of a standardized IOC reduced slide labeling error. This improvement did not affect mean TAT and may have the increased quality of IOC TAT data reporting. Other metrics affecting patient safety and quality were monitored and standardized.

Power overgeneration by renewable sources combined with less dispatchabe conventional power plants introduce the power grid to a new challenge, i.e., instability. The stability of the power grid requires constant balance between generation and demand. A well-known solution to power overgeneration is grid-scale energy storage. Although different energy storage technologies have been tested and demonstrated, reducing the cost of energy storage remains as a challenging goal for researchers, industries, and governments. Compressed Air Energy Storage (CAES) has been utilized for grid-scale energy storage for a few decades. However, conventional diabatic CAES systems are difficult and expensive to construct and maintain due to their high pressure operating condition. Hybrid Compressed Air Energy Storage (HCAES) systems are introduced as a new variant of old CAES technology to reduce the cost of energy storage using compressed air. The HCAES system split the received power from the grid into two subsystems. A portion of the power is used to compress air, as done in conventional CAES systems. The rest of the electric power is converted to heat in a high-temperature Thermal Energy Storage (TES) component using Joule heating. In this study, a solid-state grid-tied TES system is designed to operate with a HCAES system. The storage medium is considered to be high-temperature refractory concrete. The thermal energy is generated inside the concrete block using resistive heaters (wires) that are buried inside a concrete block. A computational approach was adopted to investigate the performance of the proposed TES system during a full charge/storage/discharge cycle. It was shown that the proposed design can be used to receive 200 kW of power from the grid for 6 hours without overheating the resistive heaters. The discharge computations show that the proposed geometry of the TES, along with a control strategy for the flow rate can provide a 74-kW micro-turbine of the HCAES with the minimum required temperature, i.e., 1144K at 0.6 kg/s of air flow rate for 6 hours. The computations were performed in ANSYS/FLUENT and the results were verified and validated using a grid independence study.

We would like to thank the authors of the three editorials (1-3) for their interest in and comments on our article “ Lung Adenocarcinoma Manifesting as Pure Ground-Glass Nodules: Correlating CT Size, Volume, Density, and Roundness with Histopathologic Invasion and Size ” (4).

Lost foam casting is a sand casting process in which the mold consists of an evaporative polystyrene foam pattern embedded in sand. It is especially well suited for making complex parts with convoluted features such as engine blocks, transmission cases, and cylinder heads. This article describes the lost foam casting process and its primary advantages, including the elimination of flash and parting lines, the relative ease of prototyping with foam, and the ability to incorporate multiple metals, whether in sections or layers, through sequential pours. It illustrates an entire process cycle from mold filling to fusion, cooling, and part ejection. The article also provides information on casting quality, discussing dimensional tolerances, fold defects, and porosity.

This paper describes the design of an inflight power generation, management and storage system applicable to Unmanned Air Vehicles (UAV). Emerging UAV, drones and other aircraft can use electrical propulsion systems. To extend battery charge and aircraft range, power can be generated from multiple sources during flight including aero-elastic vibrations from gusts and flutter, and bending movements and sunlight. These sources of "free" energy can be summed and used during flight operation. This research will employ the aero-elastic vibrations of the wing that will be captured using motor generator created devices that uses vibrations to generate electricity. Stress flexing piezoelectric devices will be attached at the root of the wing, where the most bending strain occurs. Flexible solar panels are collocated to the top of UAV wing to enhance energy harvesting. These three sources will be summed together to power the propeller of an aircraft. A Maximum Power Point Tracker (MPPT) board is utilized to adjust the input voltage to harvest power from the wing vibration phenomenon and transform this power to supply the voltage requirements of the battery or graphene super-capacitors under load.

The eighth edition of the American Joint Committee on Cancer staging manual now stratifies nonmucinous lung adenocarcinomas (nmLACAs) by the size of the invasive component only. This is determined by direct gross or microscopic measurement; however, a calculated invasive size based on the percentage of invasive growth patterns has been proposed as an alternative option.To compare radiologic with different pathologic assessments of invasive tumor size, we retrospectively reviewed a cohort of resected nmLACAs with a part-solid appearance on computed tomography (CT) scan (n = 112).The median direct microscopic pathologic invasive measurements were not significantly different from the median calculated pathologic invasive measurements; however, the median CT invasive measurements were 0.26 cm larger than the median direct pathologic measurements (P.001).Our results show that pathologic calculated invasive tumor measurements are comparable to direct microscopic measurements of invasive tumor, thereby supporting the recommendation for use of calculated invasive tumor size by the pathologist if necessary.