78 research outputs found

    Exhaust waste heat recovery from a heavy-duty truck engine: Experiments and simulations

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    Waste heat recovery using an (organic) Rankine cycle is an important and promising technology for improving engine efficiency and thereby reducing the CO2 emissions due to heavy-duty transport. Experiments were performed using a Rankine cycle with water for waste heat recovery from the exhaust gases of a heavy-duty Diesel engine. The experimental results were used to calibrate and validate steady-state models of the main components in the cycle: the pump, pump bypass valve, evaporator, expander, and condenser. Simulations were performed to evaluate the cycle performance over a wide range of engine operating conditions using three working fluids: water, cyclopentane, and ethanol. Additionally, cycle simulations were performed for these working fluids over a typical long haul truck driving cycle. The predicted net power output with water as the working fluid varied between 0.5 and 5.7 kW, where the optimal expander speed was dependent on the engine operating point. The net power output for simulations with cyclopentane was between 1.8 and 9.6 kW and that for ethanol was between 1.0 and 7.8 kW. Over the driving cycle, the total recovered energy was 11.2, 8.2, and 5.2 MJ for cyclopentane, ethanol, and water, respectively. These values correspond to energy recoveries of 3.4, 2.5, and 1.6%, respectively, relative to the total energy requirement of the engine. The main contribution of this paper is the presentation of experimental data on a complete Rankine cycle-based WHR system coupled to a heavy-duty engine. These results were used to validate component models for simulations, allowing for a realistic estimation of the steady-state performance under a wide range of operating conditions for this type of system

    Performance Analysis of a Reciprocating Piston Expander and a Plate Type Exhaust Gas Recirculation Boiler in a Water-Based Rankine Cycle for Heat Recovery from a Heavy Duty Diesel Engine

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    The exhaust gas in an internal combustion engine provides favorable conditions for a waste-heat recovery (WHR) system. The highest potential is achieved by the Rankine cycle as a heat recovery technology. There are only few experimental studies that investigate full-scale systems using water-based working fluids and their effects on the performance and operation of a Rankine cycle heat recovery system. This paper discusses experimental results and practical challenges with a WHR system when utilizing heat from the exhaust gas recirculation system of a truck engine. The results showed that the boiler’s pinch point necessitated trade-offs between maintaining adequate boiling pressure while achieving acceptable cooling of the EGR and superheating of the water. The expander used in the system had a geometric compression ratio of 21 together with a steam outlet timing that caused high re-compression. Inlet pressures of up to 30 bar were therefore required for a stable expander power output. Such high pressures increased the pump power, and reduced the EGR cooling in the boiler because of pinch-point effects. Simulations indicated that reducing the expander’s compression ratio from 21 to 13 would allow 30% lower steam supply pressures without adversely affecting the expander’s power output

    An inverse association between plasma benzoxazinoid metabolites and PSA after rye intake in men with prostate cancer revealed with a new method

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    Prostate cancer (PC) is a common cancer among men, and preventive strategies are warranted. Benzoxazinoids (BXs) in rye have shown potential against PC in vitro but human studies are lacking. The aim was to establish a quantitative method for analysis of BXs and investigate their plasma levels after a whole grain/bran rye vs refined wheat intervention, as well as exploring their association with PSA, in men with PC. A quantitative method for analysis of 22 BXs, including novel metabolites identified by mass spectrometry and NMR, was established, and applied to plasma samples from a randomized crossover study where patients with indolent PC (n = 17) consumed 485 g whole grain rye/rye bran or fiber supplemented refined wheat daily for 6 wk. Most BXs were significantly higher in plasma after rye (0.3-19.4 nmol/L in plasma) vs. refined wheat (0.05-2.9 nmol/L) intake. HBOA-glc, 2-HHPAA, HBOA-glcA, 2-HPAA-glcA were inversely correlated to PSA in plasma (p < 0.04). To conclude, BXs in plasma, including metabolites not previously analyzed, were quantified. BX metabolites were significantly higher after rye vs refined wheat consumption. Four BX-related metabolites were inversely associated with PSA, which merits further investigation

    The SNARE Protein SNAP23 and the SNARE-Interacting Protein Munc18c in Human Skeletal Muscle Are Implicated in Insulin Resistance/Type 2 Diabetes

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    OBJECTIVE-Our previous studies suggest that the SNARE protein synaptosomal-associated protein of 23 kDa (SNAP23) is involved in the link between increased lipid levels and insulin resistance in cardiomyocytes. The objective was to determine whether SNAP23 may also be involved in the known association between lipid accumulation in skeletal muscle and insulin resistance/type 2 diabetes in humans, as well as to identify a potential regulator of SNAP23. RESEARCH DESIGN AND METHODS-We analyzed skeletal muscle biopsies from patients with type 2 diabetes and healthy, insulin-sensitive control subjects for expression (mRNA and protein) and intracellular localization (subcellular fractionation and immunohistochemistry) of SNAP23, and for expression of proteins known to interact with SNARE proteins. Insulin resistance was determined by a euglycemic hyperinsulinemic clamp Potential mechanisms for regulation of SNAP23 were also investigated in the skeletal muscle cell line L6. RESULTS-We showed increased SNAP23 levels in skeletal muscle from patients with type 2 diabetes compared with that from lean control subjects Moreover, SNAP23 was redistributed from the plasma membrane to the microsomal/cytosolic compartment in the patients with the type 2 diabetes Expression of the SNARE-interacting protein Munc18c was higher in skeletal muscle from patients with type 2 diabetes Studies in L6 cells showed that Munc18c promoted the expression of SNAP23. CONCLUSIONS-We have translated our previous in vitro results into humans by showing that there is a change in the distribution of SNAP23 to the interior of the cell in skeletal muscle from patients with type 2 diabetes. We also showed that Munc18c is a potential regulator of SNAP23. Diabetes 59: 1870-1878, 201

    The transition of reported pain in different body regions – a one-year follow-up study

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    BACKGROUND: The course of pain at a specific region such as the lower back has previously been shown as well as for generalized pain. However we have not found any report on the course of pain from various different specific regions. The aim of this investigation was to study the one-year transition of reported pain in different body locations. METHODS: From a general population 14555 men and women, 46–68 years, responded to an extensive health questionnaire including the standardized Nordic questionnaire. The population represented 27% of the total population within the age group in Malmö, Sweden. At the one year follow-up 12607 responded to the questionnaire, yielding a response rate of 87%. The one year prevalence of long-lasting pain and the pattern of pain reporting from different regions were studied for men and women. RESULTS: The one-year prevalence of long-lasting neck pain was 14% (95% CI 13–15) among men and 25% (95% CI 24–26) among women at baseline and 15% (95% CI 14–16) for the men and 23% (95% CI 22–24) for the women at follow-up. Of those reporting neck pain "all the time" at baseline, 48% of the men and 54% of the women also reported neck pain "all the time" at the one-year follow-up. At the follow-up neck pain was reported as present "often" by 43% of the men and 47% of the women who reported neck pain "often" at baseline. Similar transition pattern were found for neck, shoulders, elbow/wrist/hand and lower back symptoms, as well as consistent prevalence rates. CONCLUSION: The one-year transition pattern of reported pain was similar in different body regions and among men and women. Furthermore the prevalence rates of long-lasting pain in the population were consistent at baseline and the follow-up. The findings of similar transition patterns support the interpretation of long-lasting pain as a generalized phenomenon rather than attributed to specific exposure. This may have implications for future pain research

    Psychological and physiological impacts of a fast-track diagnostic workup for men with suspected prostate cancer : Preliminary report from a randomized clinical trial

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    Funding Information: This study was funded by The Swedish Cancer Society (CF2016/795 and 2018/765) and Nyckelfonden, Örebro, Sweden (2015). The funders had no role in the design and conduct of the study, collection, analysis, and interpretation of the data, and writing and approval of the manuscript. Funding Information: This study was funded by The Swedish Cancer Society (CF2016/795 and 2018/765) and Nyckelfonden, ?rebro, Sweden (2015). The funders had no role in the design and conduct of the study, collection, analysis, and interpretation of the data, and writing and approval of the manuscript. This randomized clinical trial was approved by the ethics committee at ?rebro University Hospital and was registered at the ISRCTN registry www.isrctn.com (No. ISRCTN45953686). Written informed consent was obtained from all individual participants included in the study. All authors accept the publication of this work and all patients provided signed inform consent to use their data. The datasets generated and/or analyzed during the current study are not publicly available to protect participant confidentiality but can be partly provided from authors on reasonable request. The authors declare that they have no competing interest. This study was funded by The Swedish Cancer Society (CF2016/795 and 2018/765) and Nyckelfonden, ?rebro, Sweden (2015). The funders had no role in the design and conduct of the study, collection, analysis, and interpretation of the data, and writing and approval of the manuscript. JZ, RC, OA, SOA, UV, FF, and KF conceived of and designed the study; JZ, SD, JC, AME, JF, OA, and SOA contributed to collection of the data; JZ and RC analyzed the data; JZ drafted the manuscript; JZ, RC, SD, JC, AME, JF, OA, SOA, UV, FF, and KF revised the manuscript critically for important intellectual content; All authors read and approved the final manuscript. The authors thank all the subjects who have participated in this clinical trial.Peer reviewe
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