Donaldson, Laura MD, PhD; Nicholson, Patrick MD; Hendriks, Eef J. MD; Simons, Martin BS; Margolin, Edward MDEditor(s): Ko, Melissa W. MD; Cestari, Dean M. MD; Quiros, Peter MD; Winges, Kimberly M. MD Author Information
The material recycling of complex waste streams such as external thermal insulation composite systems (ETICS) is challenging, which is why their recycling in the sense of a circular economy is currently hardly established. Therefore, the combined mechanical and thermochemical recycling of ETICS based on expanded polystyrene (EPS) is investigated experimentally and by simulating full process chains in order to evaluate circular economy opportunities. Model ETICS as example for building and construction waste is pretreated mechanically, followed by either pyrolysis and / or gasification steps, and full mass and energy balances are derived. By the combined recycling, inorganic compounds can be separated to a large extent allowing a pre-concentrate generation. The plastic-rich pre-concentrate is converted into either pyrolysis oil with a high styrene monomer content of 51 wt% or to synthesis gas in the subsequent thermochemical conversions. The holistic approach enables a high carbon recycling rate between 53 and 68 wt%. In addition, the investigation reveals technology limitations and op-portunities to be further developed and optimized.
Expanded Polystyrene (EPS) used in External Thermal Insulation Composite Systems (ETICS) is mainly disposed of in waste incineration plants. However, alternative recycling options need to be identified as capacities for this waste treatment are limited and the amount of EPS-based ETICS waste is expected to increase. Herein, it is necessary to quantify the future waste masses with regard to regional distribution as EPS-based ETICS waste is generated decentrally. Furthermore, consistent information on alternative treatment options for EPS-based ETICS waste is lacking. First, we estimate the amount of upcoming EPS waste from ETICS in Germany with a high spatial resolution. Second, we evaluate state-of-the-art waste management options regarding economic, legal and environmental aspects. We find that waste masses will increase from 3 to 33 kt (2020-2040) with large spatial deviations. We conclude that solvent-based recycling seems promising, but more sophisticated analyses are required, i.e. planning of the future waste treatment infrastructures.
This paper presents the results of recent experiments on the recyclability of the textile components in textile reinforced concrete (TRC). TRC as a multi-component system often contains organic ingredients such as carbon fibres and polymer impregnations. Consequently, the recycling of TRC is not trivial and has not yet been sufficiently clarified until now. In this study, an impregnated, bi-axially reinforced, and warp-knitted textiles made of carbon fibres was used in combination with a fine grained concrete. Flexural tests on TRC specimens containing recycled epoxy-impregnated carbon reinforcement were performed, whereby the recycling was simulated by a pre-treatment of the carbon fibre material in a jaw crusher. The results showed a pronounced decrease in flexural strength compared to untreated carbon reinforcement. Moreover, three different crushing methods were investigated with respect to their influence on the recovery of styrene-butadiene-rubber impregnated carbon textiles. Besides jaw crushing and impact milling, crushing with a hammer mill showed the best degree of purity but also caused the highest mechanical damage to the textile. The impact of material, structure of the composite and crushing methods on the separation behaviour could be deduced from the experiments.
Accidental intraventricular placement of a pericardiocentesis catheter is a rare but well-recognized complication. Failure to achieve adequate hemostasis in the ventricular wall on removal of the catheter can potentially result in fatal consequences. Here we describe a case in which a chest drain (10.2F) accidentally entered into the right ventricle while attempting to drain pleural fluid, and the entry site was sealed using an Amplatzer VSD occluder device (St. Jude Medical, St. Paul, MN).
Increased submesothelial collagen deposition, loss of mesothelial cells and increased peritoneal vascularization of peritoneal membrane with vasculopathy leads to peritoneal fibrosis in a patient on long-term peritoneal dialysis (PD). This vascular proliferation within the peritoneum is associated with an increased expression of vascular endothelial growth factor (VEGF), which in turn leads to functional loss or deterioration of the peritoneal membrane over time. Vascular endothelial growth factor inhibitors may slow or even prevent vascular proliferation and subsequent loss of membrane function in peritoneal dialysis patient. We have observed the anti-VGEF effects of a tyrosine kinase inhibitor, sunitinib maleate, in a patient who was on this medication for renal cell carcinoma with extensive abdominal metastasis. The patient had also been on PD for 26 months at the time of the study. In this patient, the tyrosine kinase inhibitor helped to stabilize the abdominal metastasis as well as the thickness of the peritoneal membrane. The D/P creatinine ratio also remained stable. These observations suggest that this tyrosine kinase inhibitor may have prevented peritoneal membrane angiogenesis. We also observed that the patient did not have any further episode of peritonitis from gut-derived organisms, suggesting that stabilization of the intestinal metastasis prevented the transmural migration of bacteria from the gut, thereby preventing peritonitis.
The data-parallel programming model is currently the most successful model for programming massively parallel computers. Unfortunately, it is, in its present form, restricted to exploiting flat data parallelism, which is not suitable for some classes of algorithms, e.g. those operating on irregular structures. Recently, some effort has been made to implement nested data-parallel programs efficiently by compiling them into equivalent flat programs using a transformation called flattening. However, previous translations of nested into flat data-parallel programs have proved unwieldy when it comes to inventing and specifying optimizations and verifying the translation. This paper presents a new formalization of the flattening transformation in a calculational style. The formalization is easily verified and provides a good starting point for the development of new optimizations. Some optimizations invented on the basis of this new formalism are described. Furthermore, we present practical evidence obtained by experimenting with an implementation of the transformation.
Modern dialects of Fortran enjoy wide use and good support on high-performance computers as performance-oriented programming languages. By providing the ability to express nested data parallelism in Fortran, we enable irregular computations to be incorporated into existing applications with minimal rewriting and without sacrificing performance within the regular portions of the application. Since performance of nested data-parallel computation is unpredictable and often poor using current compilers, we investigate source-to-source transformation techniques that yield Fortran 90 programs with improved performance and performance stability.
Modern dialects of Fortran enjoy wide use and good support on high-performance computers as performance-oriented programming languages. By providing the ability to express nested data parallelism, modern Fortran dialects enable irregular computations to be incorporated into existing applications with minimal rewriting and without sacrificing performance within the regular portions of the application. Since performance of nested data-parallel computation is unpredictable and often poor using current compilers, we investigate threading and flattening, two source-to-source transformation techniques that can improve performance and performance stability. For experimental validation of these techniques, we explore nested data-parallel implementations of the sparse matrix-vector product and the Barnes-Hut $n$-body algorithm by hand-coding thread-based (using OpenMP directives) and flattening-based versions of these algorithms and evaluating their performance on an SGI Origin 2000 and an NEC SX-4, two shared-memory machines.
A molecular dynamics simulation approximates the motion of atoms in a system of molecules over short intervals of simulated time, typically in the order of picoseconds to nanoseconds. Such simulations may run for days or weeks on a computer when used to investigate the dynamic behavior of small proteins in biological systems. By adding additional restraints, a simulation may be steered to observe the possibility of particular behaviors or to eliminate others over shorter timescales. We have developed the steered molecular dynamics (SMD) system to interactively place and observe the effects of restraints in a running dynamics simulation. In this article, we describe an application of SMD to the extraction of small ligands from proteins, and an immersive virtual 3D environment through which the SMD system can be operated. The virtual environment is constructed using the protein interactive theater (PIT) system, a head-tracked stereo workspace for two users.
PURPOSE:Endoluminal ultrasonography (ELUS) is accurate in the assessment of penetration through the rectal wall by carcinoma. Clinical studies were performed to determine the reliability and validity of ELUS.METHODS:The interobserver reliability among four observers with varying experience with ELUS was determined for staging the penetration of rectal cancer through the rectal wall. The ability of ELUS to change the clinical management of the referring clinician (comprehensiveness) was assessed on all referrals over a six-month period.RESULTS:The reliability of ELUS for staging rectal cancer demonstrated only fair to moderate correlation (weighted kappa range, 0.22-0.47). The accuracy of ELUS compared with surgical pathology demonstrated a learning curve proportional to the experience of the observer. In 45 percent of referrals, ELUS changed the clinical management of patients and in 76 percent of referrals the clinician's confidence in the diagnosis and management of patients was altered. ELUS was more likely to change the management of patients with pelvic pouch sepsis (70 percent) and early neoplastic lesions (57 percent) than in more advanced neoplastic lesions (40 percent), perianal Crohn's disease (40 percent), complex noninflammatory bowel disease sepsis (33 percent), and incontinence (31 percent).CONCLUSIONS:ELUS has the ability to change the clinical management of a variety of anorectal conditions. However, for neoplasia the interobserver reliability is only moderate and a learning curve exists.
Jan F. Prins合作论文数Department of Computer Science, University of North Carolina at Chapel Hill;Renaissance Computing Institute, University of North Carolina at Chapel Hill3