Remotely Accessible Laboratory for Teaching and Research on Solar Thermal Collectors

This paper discusses a new test platform for evaluating the performance of solar thermal collectors that was recently designed and constructed on the roof of the Applied Energy Laboratory at Purdue University, located at 40.4 °N and 86.9 °W. The test platform is mainly used for teaching undergraduate students about applications of thermodynamics and renewable energy, but it can also be used for comparative evaluations of solar thermal collector designs according to an established test standard. The entire system is monitored and controlled by a web-based Building Automation System that automatically tracks and trends both weather data and the performance of individual solar collectors. The online data is particularly helpful for undergraduate education because large numbers of students, including international partners, can access real-time data to learn about solar energy applications. The weather at this location varies significantly by season, which has a substantial impact on the performance of the solar thermal collectors. ASHRAE designates this location as climate zone that experiences both hot, humid summers and cold, dry winters. The solar intensity also varies by season, with longer and more sunny days during the summer and shorter and more cloudy days during the winter. Not surprisingly, evaluations of solar collector performance vary seasonally too. Solar collector efficiency, the ratio of thermal energy collected to the solar energy available, varies from 10% to 80%. Solar energy factor, the ratio of thermal energy collected to the source energy (electricity) to circulate the fluid, varies from 10 to 150. Both performance terms (efficiency and energy factor) are needed to get a complete picture of solar collector performance

Design of Net Zero Energy Environmental Engineering Building in Peru

This paper describes a Net Zero Energy Building (NZEB) being constructed on the engineering campus of the Universidad Nacional de San Augustín (UNSA) in Arequipa, Peru. The project is one part of a larger collaboration between UNSA and Purdue University called the Arequipa Nexus Institute for Sustainable Food, Energy, Water and the Environment (The Nexus Institute) that started in March of 2018. As UNSA seeks to become a leader in environmental engineering, there is an increasing need for a new building that has dedicated resources for teaching and research on sustainable design. Solar panels to achieve net zero energy were an important late addition to the building design. The Arequipa region of Peru is particularly well-suited for solar energy because it enjoys an abundance of sunshine throughout the year. The mild climate is also helpful because buildings do not require extensive HVAC systems that can consume significant amounts of energy

Teamwork Makes the Dream Work: Purdue\u27s IMPACT Course Transformation Faculty Learning Community

Describes the collaborative faculty learning community established within a specific IMPACT team from the Spring 2017 Cohort. Describes the IMPACT course redesign program and experiences of the individual faculty fellows working within the team to redesign their courses

Teamwork Makes the Dream Work: Purdue\u27s IMPACT Course Transformation Faculty Learning Community

Describes the collaborative faculty learning community established within a specific IMPACT team from the Spring 2017 Cohort. Describes the IMPACT course redesign program and experiences of the individual faculty fellows working within the team to redesign their courses

HVAD to HeartMate 3 left ventricular assist device exchange: Best practices recommendations

The HeartWare HVAD System (Medtronic) is a durable implantable left ventricular assist device that has been implanted in approximately 20,000 patients worldwide for bridge to transplant and destination therapy indications. In December 2020, Medtronic issued an Urgent Medical Device Communication informing clinicians of a critical device malfunction in which the HVAD may experience a delay or failure to restart after elective or accidental discontinuation of pump operation. Moreover, evolving retrospective comparative effectiveness studies of patients supported with the HVAD demonstrated a significantly higher risk of stroke and all-cause mortality when compared with a newer generation of a commercially available durable left ventricular assist device. Considering the totality of this new information on HVAD performance and the availability of an alternate commercially available device, Medtronic halted the sale and distribution of the HVAD System in June 2021. The decision to remove the HVAD from commercial distribution now requires the use of the HeartMate 3 left ventricular assist system (Abbott, Inc) if a patient previously implanted with an HVAD requires a pump exchange. The goal of this document is to review important differences in the design of the HVAD and HeartMate 3 that are relevant to the medical management of patients supported with these devices, and to assess the technical aspects of an HVAD-to-HeartMate 3 exchange. This document provides the best available evidence that supports best practices

Effectiveness of Carboplatin and Paclitaxel as First- and Second-Line Treatment in 61 Patients with Metastatic Melanoma

BACKGROUND: Patients with metastatic melanoma have a very unfavorable prognosis with few therapeutic options. Based on previous promising experiences within a clinical trial involving carboplatin and paclitaxel a series of advanced metastatic melanoma patients were treated with this combination. METHODS: Data of all patients with cutaneous metastatic melanoma treated with carboplatin and paclitaxel (CP) at our institution between October 2005 and December 2007 were retrospectively evaluated. For all patients a once-every-3-weeks dose-intensified regimen was used. Overall and progression free survival were calculated using the method of Kaplan and Meier. Tumour response was evaluated according to RECIST criteria. RESULTS: 61 patients with cutaneous metastatic melanoma were treated with CP. 20 patients (85% M1c) received CP as first-line treatment, 41 patients (90.2% M1c) had received at least one prior systemic therapy for metastatic disease. Main toxicities were myelosuppression, fatigue and peripheral neuropathy. Partial responses were noted in 4.9% of patients, stable disease in 23% of patients. No complete response was observed. Median progression free survival was 10 weeks. Median overall survival was 31 weeks. Response, progression-free and overall survival were equivalent in first- and second-line patients. 60 patients of 61 died after a median follow up of 7 months. Median overall survival differed for patients with controlled disease (PR+SD) (49 weeks) compared to patients with progressive disease (18 weeks). CONCLUSIONS: Among patients with metastatic melanoma a subgroup achieved disease control under CP therapy which may be associated with a survival benefit. This potential advantage has to be weighed against considerable toxicity. Since response rates and survival were not improved in previously untreated patients compared to pretreated patients, CP should thus not be applied as first-line treatment

Trends in Duck Breeding Populations, 1955-2008

This report summarizes information about the status of duck populations and wetland habitats during spring 2008, focusing on areas encompassed by the U.S. Fish and Wildlife (USFWS) and Canadian Wildlife Services\u27 (CWS) Waterfowl Breeding Population and Habitat Survey. This report does not include information from surveys conducted by state or provincial agencies. In the traditional survey area, which includes strata 1-18, 20-50, and 75-77 (Figure 1), the total duck population estimate (excluding scoters [Melanitta spp.], eiders [Somateria and Polysticta spp.], long-tailed ducks [Clangula hyemalis], mergansers [Mergus and Lophodytes spp.], and wood ducks [Aix sponsa]) was 37.3 ± 0.6 [SE] million birds. This estimate represents a 9% decline over last year\u27s estimate of 41.2 ± 0.7 million birds, but remains 11% above the 1955-2007 long-term averagea (Table 1). Estimated mallard (Anas platyrhynchos) abundance was 7.7 ± 0.3 million birds, which was similar to last year\u27s estimate of 8.3 ± 0.3 million birds and the long-term average (Table 2). Blue-winged teal (A. discors) abundance was 6.6 ± 0.3 million birds. This value is similar to last year\u27s estimate of 6.7 ± 0.4 million birds and 45% above the long-term average. Estimated abundances of gadwall (A. strepera; 2.7 ± 0.2 million) and Northern shovelers (A. clypeata; 3.5 ± 0.2 million) were below 2007 estimates (-19% and -23%, respectively) but remain well above their long-term averages (+56% and +56%, respectively). Estimated abundances of green-winged teal (A. crecca; 3.0 ± 0.2 million) and redheads (Aythya americana; 1.1 ± 0.1 million) were similar to last year\u27s and were \u3e50% above their long-term averages. Estimates of canvasbacks (A. valisineria; 0.5 ± 0.05 million) were 44% below the 2007 estimate (0.9 ± 0.09 million) and 14% below the long-term average. The estimate for Northern pintails (Anas acuta) was 2.6 ± 0.1 million, which was 22% below the 2007 estimate of 3.3 ± 0.2 million, and 36% below the long-term average. The scaup estimate (Aythya affinis and A. marila combined; 3.7 ± 0.2 million) was similar to 2007, and remained 27% below the long-term average of 5.1 ± 0.2 million

Trends in Duck Breeding Populations, 1955-2010

This report summarizes information about the status of duck populations and wetland habitats during spring 2010, focusing on areas encompassed by the U.S. Fish and Wildlife (USFWS) and Canadian Wildlife Services\u27 (CWS) Waterfowl Breeding Population and Habitat Survey. We do not include information from surveys conducted by state or provincial agencies. In the traditional survey area, which includes strata 1-18, 20-50, and 75-77 (Figure 1), the total duck population estimate (excluding scoters [Melanitta spp.], eiders [Somateria spp. and Polysticta stelleri], long-tailed ducks [Clangula hyemalis], mergansers [Mergus spp. and Lophodytes cucullatus], and wood ducks [Aix sponsa]) was 40.9 ± 0.7 [SE] million birds. This estimate was similar to last year\u27s estimate of 42.0 ± 0.7 million birds and was 21% above the long-term averagea (1955{2009; Table 1). Estimated mallard (Anas platyrhynchos) abundance was 8.4 ± 0.3 million birds, which was similar to the 2009 estimate of 8.5 ± 0.2 million birds and 12% above the long-term average (Table 2). Estimated abundance of gadwall (A. strepera; 3.0 ± 0.2 million) was similar to the 2009 estimate and 67% above the long-term average (Table 3). Estimated abundance of American wigeon (A. americana; 2.4 ± 0.1 million) was similar to 2009 and the long-term average (Table 4). The estimated abundance of green-winged teal (A. crecca) was 3.5 ± 0.2 million, which was similar to the 2009 estimate and 78% above their long-term average of 1.9 ± 0.2 million (Table 5). The estimate of blue-winged teal abundance (A. discors) was 6.3 ± 0.4 million, which was 14% below the 2009 estimate and 36% above their long-term average of 4.7 ± 0.4 million (Table 6). The estimate for northern pintails (A. acuta; 3.5 ± 0.2 million) was similar to the 2009 estimate, and 13% below the long-term average of 4.0 ± 0.4 million (Table 7). Estimates of northern shovelers (A. clypeata; 4.1 ± 0.2 million) and redheads (Aythya americana; 1.1 ± 0.1 million) were similar to their 2009 estimates and were 76% and 63% above their long-term averages of 2.3 ± 0.02 million and 0.7 ± 0.01 million, respectively (Tables 8 and 9). The canvasback estimate (A. valisineria; 0.6 ± 0.05 million) was similar the 2009 estimate and to the long-term average (Table 10). The scaup estimate (A. affinis and A. marila combined; 4.2 ± 0.2 million) was similar to that of 2009 and 16% below the long-term average of 5.1 ± 0.05 million (Table 11)

A Signal Transmission Technique for Stability Analysis of Multivariable Non-Linear Control Systems

Among the difficulties associated with multivariable, non-linear control systems is the problem of assessing closed-loop stability. Of particular interest is the class of non-linear systems controlled with on/off actuators, such as spacecraft thrusters or electrical relays. With such systems, standard describing function techniques are typically too conservative, and time-domain simulation analysis is prohibitively extensive, This paper presents an open-loop analysis technique for this class of non-linear systems. The technique is centered around an innovative use of multivariable signal transmission theory to quantify the plant response to worst case control commands. The technique has been applied to assess stability of thruster controlled flexible space structures. Examples are provided for Space Shuttle attitude control with attached flexible payloads

Paediatric aortic valve replacement using decellularized allografts

OBJECTIVES: Options for paediatric aortic valve replacement (AVR) are limited if valve repair is not feasible. Results of paediatric Ross procedures are inferior to adult Ross results, and mechanical AVR imposes constant anticoagulation with the inherent risks. METHODS: The study design was a prospective, multicentre follow-up of all paediatric patients receiving decellularized aortic homografts (DAHs) for AVR in 8 European centres. RESULTS: A total of 106 children (77 boys) were operated (mean age 10.1 ± 4.8 years, DAH diameter 20.5 ± 3.8 mm). A total of 60 (57%) had undergone previous surgical interventions: 34 with 1, 15 with 2 and 11 with ≥3. There was one early death in a 12-year-old girl, who underwent her fourth aortic valve operation, due to intracerebral haemorrhage on extracorporeal membrane oxygenation after coronary reimplantation problems following 3-sinus reconstruction 1 year earlier. One 2-year-old patient died due to sepsis 2 months postoperatively with no evidence for endocarditis. In addition, a single pacemaker implantation was necessary and a 2.5-year-old girl underwent successful HTx due to chronic myocardial failure despite an intact DAH. After a mean follow-up of 3.30 ± 2.45 years, primary efficacy end points mean peak gradient (18.1 ± 20.9 mmHg) and regurgitation (mean 0.61 ± 0.63, grade 0-3) were very good. Freedom from death/explantation/endocarditis/bleeding/stroke at 5 years was 97.8 ± 1.6/85.0 ± 7.4/100/100/100% respectively. Calculated expected adverse events were lower for DAH compared to cryopreserved homograft patients (mean age 8.9 years), lower than in Ross patients (9.4 years) and in the same range as mechanical AVR (12.8 years). CONCLUSIONS: Even though the overall number of paediatric DAH patients and the follow-up time span are still limited, our data suggest that DAHs may present a promising additional option for paediatric AVR.status: publishe