440 research outputs found

    System analysis of the bio-based economy in Colombia: A bottom-up energy system model and scenario analysis

    Get PDF
    The transition to a sustainable bio‐based economy is perceived as a valid path towards low‐carbon development for emerging economies that have rich biomass resources. In the case of Colombia, the role of biomass has been tackled through qualitative roadmaps and regional climate policy assessments. However, neither of these approaches has addressed the complexity of the bio‐based economy systematically in the wider context of emission mitigation and energy and chemicals supply. In response to this limitation, we extended a bottom‐up energy system optimization model by adding a comprehensive database of novel bio‐based value chains. We included advanced road and aviation biofuels, (bio)chemicals, bioenergy with carbon capture and storage (BECCS), and integrated biorefinery configurations. A scenario analysis was conducted for the period 2015–2050, which reflected uncertainties in the capacity for technological learning, climate policy ambitions, and land availability for energy crops. Our results indicate that biomass can play an important, even if variable, role in supplying 315–760 PJ/y of modern bio‐based products. In pursuit of a deep decarbonization trajectory, the large‐scale mobilization of biomass resources can reduce the cost of the energy system by up to 11 billion $/year, the marginal abatement cost by 62%, and the potential reliance on imports of oil and chemicals in the future. The mitigation potential of BECCS can reach 24–29% of the cumulative avoided emissions between 2015 and 2050. The proposed system analysis framework can provide detailed quantitative information on the role of biomass in low carbon development of emerging economies

    Modeling and Simulation of PV Panel Under Different Internal and Environmental Conditions with Non-constant Load

    Get PDF
    This paper focuses on PV power conversion under different internal and environmental conditions with non-constant load, connected to a smart grid system. Due to environmental conditions, the PV system is a non-linear system and difficult to predict the power conversion. In the aspect of internal variables, it includes the five parameters of the single diode solar cell model identify their sensitivity through error function. It also identifies the relation between environmental conditions, mainly: irradiance, temperature and wind speed. The modeling and computational simulation with laboratory work identify the effects of internal and environmental effect on the system. The model gives details about the sensitivity of each environmental condition using error function. The work includes the decrease of energy conversion by the solar panel as a function of time due to the shadow effect that affects its performance. Besides these, a smart system is introduced as a DAQ system in laboratory environment to get in real time the power conversion value with the P-V and I-V characteristics of the PV panel

    Impact of an interatrial shunt device on survival and heart failure hospitalization in patients with preserved ejection fraction

    Get PDF
    Aims: Impaired left ventricular diastolic function leading to elevated left atrial pressures, particularly during exertion, is a key driver of symptoms and outcomes in heart failure with preserved ejection fraction (HFpEF). Insertion of an interatrial shunt device (IASD) to reduce left atrial pressure in HFpEF has been shown to be associated with short‐term haemodynamic and symptomatic benefit. We aimed to investigate the potential effects of IASD placement on HFpEF survival and heart failure hospitalization (HFH). Methods and results: Heart failure with preserved ejection fraction patients participating in the Reduce Elevated Left Atrial Pressure in Patients with Heart Failure study (Corvia Medical) of an IASD were followed for a median duration of 739 days. The theoretical impact of IASD implantation on HFpEF mortality was investigated by comparing the observed survival of the study cohort with the survival predicted from baseline data using the Meta‐analysis Global Group in Chronic Heart Failure heart failure risk survival score. Baseline and post‐IASD implant parameters associated with HFH were also investigated. Based upon the individual baseline demographic and cardiovascular profile of the study cohort, the Meta‐analysis Global Group in Chronic Heart Failure score‐predicted mortality was 10.2/100 pt years. The observed mortality rate of the IASD‐treated cohort was 3.4/100 pt years, representing a 33% lower rate (P = 0.02). By Kaplan–Meier analysis, the observed survival in IASD patients was greater than predicted (P = 0.014). Baseline parameters were not predictive of future HFH events; however, poorer exercise tolerance and a higher workload‐corrected exercise pulmonary capillary wedge pressure at the 6 months post‐IASD study were associated with HFH. Conclusions: The current study suggests IASD implantation may be associated with a reduction in mortality in HFpEF. Large‐scale ongoing randomized studies are required to confirm the potential benefit of this therapy

    Detrital chrome spinel evidence for a Neotethyan intra-oceanic island arc collision with India in the Paleocene

    Get PDF
    Models that support a single collision scenario for India and Eurasia are incompatible with the evidence that an intra-oceanic island arc (IOIA) existed within the Neotethyan Ocean. Understanding the spatial and temporal extent of any IOIA is crucial for India-Eurasia collision studies as the entire ocean, including any intra-oceanic features, must have been consumed or emplaced prior to continental collision. Here, we review what is known about the Neotethyan IOIA and report evidence from sedimentary successions in NW India and southern Tibet to constrain when and where it was emplaced. We use detrital mineral geochemistry and supporting provenance and age data to identify the source of the sediments and compare the timing of erosion of IOIA-derived material in both regions. Detrital chrome spinels, extracted from distinct sedimentary horizons in southern Tibet (Sangdanlin) and NW India (Ladakh), exhibit similar average geochemical values (TiO\ua0=\ua00.09 and 0.24%, Cr#\ua0=\ua00.66 and 0.68 and Mg#\ua0=\ua00.45 and 0.53, respectively) and supra-subduction zone (SSZ), forearc peridotite signatures. Furthermore, they overlap with in-situ chrome spinels reported from the Spongtang Ophiolite in NW India and the Sangsang Ophiolite in southern Tibet. As with many of the ophiolitic remnants that crop out in and adjacent to the Yarlung-Tsangpo and Indus suture zones (YTSZ and ISZ respectively), the Spongtang and Sangsang ophiolites formed in an IOIA setting. Linking the source of the detrital chrome spinels to those analysed from remnant IOIA massifs in the YTSZ and ISZ is strong evidence for the emplacement of the IOIA onto the Indian margin. The timing of the IOIA collision with India is constrained by the depositional ages of the chrome spinel-bearing sediments to the end of the Paleocene (Thanetian) in southern Tibet and the Early Eocene in NW India. This indirectly provides a maximum age constraint of Late Paleocene-Early Eocene for intercontinental collision between India and Eurasia. Additionally, this study highlights the importance of targeting distinct sedimentary horizons in collision zones to find evidence for discrete tectonic events that may be obfuscated by later collisions

    Wearable Patient and Health Worker Monitoring: Opportunities for Improved Outcomes and Open Source Sensing

    Get PDF
    Wearable multi-modal monitoring systems, capable of robust real-world recording during the activities of daily life, have the potential to provide rich objective experiential and well-being accounts. Sensing systems have wide clinical application in rehabilitation, pre- and post-surgical assessment, monitoring of the acute medical patient [1] and management of chronic conditions [2] [3], among others. They also provide new opportunities for insights into the workplace activities, processes and stressors of clinical staff and health workers [4] [5]. In prior work [6] of The Quantified Outpatient Project (http://quantifiedoutpatient.com), a prototype 24-hour wearable and ambient monitoring system was developed, and opportunities and challenges identified. A new and evolved “Sense247” design is now presented that addresses data and usability challenges identified in interview feedback and participant assessments. The underpinning vision is for a generic and expandable “core” sensing system to provide objective sensed recordings that supplement, not supplant, subjective reports. To this end, continuously-sensed physiological, environmental and actigraphy recordings are combined with quantified subjective reports

    Benefits and harms of oral anticoagulant therapy in chronic kidney disease: a systematic review and meta-analysis

    Get PDF
    Background: Effects of oral anticoagulation in chronic kidney disease (CKD) are uncertain. Purpose: To evaluate the benefits and harms of vitamin K antagonists (VKAs) and non–vitamin K oral anticoagulants (NOACs) in adults with CKD stages 3 to 5, including those with dialysis-dependent end-stage kidney disease (ESKD). Data Sources: English-language searches of MEDLINE, EMBASE, and Cochrane databases (inception to February 2019); review bibliographies; and ClinicalTrials.gov (25 February 2019). Study Selection: Randomized controlled trials evaluating VKAs or NOACs for any indication in patients with CKD that reported efficacy or bleeding outcomes. Data Extraction: Two authors independently extracted data, assessed risk of bias, and rated certainty of evidence. Data Synthesis: Forty-five trials involving 34 082 participants who received anticoagulation for atrial fibrillation (AF) (11 trials), venous thromboembolism (VTE) (11 trials), thromboprophylaxis (6 trials), prevention of dialysis access thrombosis (8 trials), and cardiovascular disease other than AF (9 trials) were included. All but the 8 trials involving patients with ESKD excluded participants with creatinine clearance less than 20 mL/min or estimated glomerular filtration rate less than 15 mL/min/1.73 m2. In AF, compared with VKAs, NOACs reduced risks for stroke or systemic embolism (risk ratio [RR], 0.79 [95% CI, 0.66 to 0.93]; high-certainty evidence) and hemorrhagic stroke (RR, 0.48 [CI, 0.30 to 0.76]; moderate-certainty evidence). Compared with VKAs, the effects of NOACs on recurrent VTE or VTE-related death were uncertain (RR, 0.72 [CI, 0.44 to 1.17]; low-certainty evidence). In all trials combined, NOACs seemingly reduced major bleeding risk compared with VKAs (RR, 0.75 [CI, 0.56 to 1.01]; low-certainty evidence). Limitation: Scant evidence for advanced CKD or ESKD; data mostly from subgroups of large trials. Conclusion: In early-stage CKD, NOACs had a benefit–risk profile superior to that of VKAs. For advanced CKD or ESKD, there was insufficient evidence to establish benefits or harms of VKAs or NOACs. Primary Funding Source: None. (PROSPERO: CRD42017079709

    Routes for breaching and protecting genetic privacy

    Full text link
    We are entering the era of ubiquitous genetic information for research, clinical care, and personal curiosity. Sharing these datasets is vital for rapid progress in understanding the genetic basis of human diseases. However, one growing concern is the ability to protect the genetic privacy of the data originators. Here, we technically map threats to genetic privacy and discuss potential mitigation strategies for privacy-preserving dissemination of genetic data.Comment: Draft for comment
    corecore