86 research outputs found

    Improvement of microstructure and mechanical properties of high dense SiC ceramics manufactured by high-speed hot pressing

    No full text
    Non-oxide ceramics possess high physical-mechanical properties, corrosion and radiation resistance, which can be used as a protective materials for radioactive wastes disposal. The aim of the present study was the manufacturing of high density SiC ceramics with advanced physical and mechanical parameters. The high performance on the properties of produced ceramics was determined by the dense and monolithic structure. The densified silicon carbide samples possessed good mechanical strength, with a high Vickers micro hardness up to 28.5 GPa.БСзкиснСві ΠΊΠ΅Ρ€Π°ΠΌΡ–Ρ‡Π½Ρ– ΠΌΠ°Ρ‚Π΅Ρ€Ρ–Π°Π»ΠΈ Π΄Π΅ΠΌΠΎΠ½ΡΡ‚Ρ€ΡƒΡŽΡ‚ΡŒ високі Ρ„Ρ–Π·ΠΈΠΊΠΎ-ΠΌΠ΅Ρ…Π°Π½Ρ–Ρ‡Π½Ρ– властивості, ΠΊΠΎΡ€ΠΎΠ·Ρ–ΠΉΠ½Ρƒ Ρ‚Π° Ρ€Π°Π΄Ρ–Π°Ρ†Ρ–ΠΉΠ½Ρƒ ΡΡ‚Ρ–ΠΉΠΊΡ–ΡΡ‚ΡŒ, Ρ‰ΠΎ Ρ€ΠΎΠ±Π»ΡΡ‚ΡŒ Ρ—Ρ… пСрспСктивними ΠΊΠ°Π½Π΄ΠΈΠ΄Π°Ρ‚Π°ΠΌΠΈ для використання Π² якості Π±Π°Ρ€'Ρ”Ρ€Π½ΠΈΡ… ΠΌΠ°Ρ‚Π΅Ρ€Ρ–Π°Π»Ρ–Π² для захоронСння Ρ€Π°Π΄Ρ–ΠΎΠ°ΠΊΡ‚ΠΈΠ²Π½ΠΈΡ… Π²Ρ–Π΄Ρ…ΠΎΠ΄Ρ–Π². ΠœΠ΅Ρ‚ΠΎΡŽ Ρ†Ρ–Ρ”Ρ— Ρ€ΠΎΠ±ΠΎΡ‚ΠΈ Π±ΡƒΠ»ΠΎ отримання Π²ΠΈΡΠΎΠΊΠΎΡ‰Ρ–Π»ΡŒΠ½ΠΎΡ— SiC-ΠΊΠ΅Ρ€Π°ΠΌΡ–ΠΊΠΈ Π· вдосконалСними Ρ„Ρ–Π·ΠΈΡ‡Π½ΠΈΠΌΠΈ Ρ– ΠΌΠ΅Ρ…Π°Π½Ρ–Ρ‡Π½ΠΈΠΌΠΈ властивостями. Високі ΠΏΠ°Ρ€Π°ΠΌΠ΅Ρ‚Ρ€ΠΈ ΠΎΡ‚Ρ€ΠΈΠΌΠ°Π½ΠΎΡ— ΠΊΠ΅Ρ€Π°ΠΌΡ–ΠΊΠΈ Π²ΠΈΠ·Π½Π°Ρ‡Π°ΡŽΡ‚ΡŒΡΡ формуванням Π²ΠΈΡΠΎΠΊΠΎΡ‰Ρ–Π»ΡŒΠ½ΠΎΡ— Ρ– ΠΌΠΎΠ½ΠΎΠ»Ρ–Ρ‚Π½ΠΎΡ— структури. ΠšΠ΅Ρ€Π°ΠΌΡ–ΠΊΠ° ΠΊΠ°Ρ€Π±Ρ–Π΄Ρƒ ΠΊΡ€Π΅ΠΌΠ½Ρ–ΡŽ ΠΌΠ°Ρ” ΠΏΠΎΠ»Ρ–ΠΏΡˆΠ΅Π½Ρƒ ΠΌΠ΅Ρ…Π°Π½Ρ–Ρ‡Π½Ρƒ ΠΌΡ–Ρ†Π½Ρ–ΡΡ‚ΡŒ Ρ– високу Ρ‚Π²Π΅Ρ€Π΄Ρ–ΡΡ‚ΡŒ ΠΏΠΎ ВіккСрсу порядка 28,5 Π“ΠŸa.БСскислородныС кСрамичСскиС ΠΌΠ°Ρ‚Π΅Ρ€ΠΈΠ°Π»Ρ‹ Π΄Π΅ΠΌΠΎΠ½ΡΡ‚Ρ€ΠΈΡ€ΡƒΡŽΡ‚ высокиС Ρ„ΠΈΠ·ΠΈΠΊΠΎ-мСханичСскиС свойства, ΠΊΠΎΡ€Ρ€ΠΎΠ·ΠΈΠΎΠ½Π½ΡƒΡŽ ΠΈ Ρ€Π°Π΄ΠΈΠ°Ρ†ΠΈΠΎΠ½Π½ΡƒΡŽ ΡΡ‚ΠΎΠΉΠΊΠΎΡΡ‚ΡŒ, Π΄Π΅Π»Π°ΡŽΡ‰ΠΈΠ΅ ΠΈΡ… пСрспСктивными ΠΊΠ°Π½Π΄ΠΈΠ΄Π°Ρ‚Π°ΠΌΠΈ для использования Π² качСствС Π±Π°Ρ€ΡŒΠ΅Ρ€Π½Ρ‹Ρ… ΠΌΠ°Ρ‚Π΅Ρ€ΠΈΠ°Π»ΠΎΠ² для захоронСния Ρ€Π°Π΄ΠΈΠΎΠ°ΠΊΡ‚ΠΈΠ²Π½Ρ‹Ρ… ΠΎΡ‚Ρ…ΠΎΠ΄ΠΎΠ². ЦСлью настоящСй Ρ€Π°Π±ΠΎΡ‚Ρ‹ Π±Ρ‹Π»ΠΎ ΠΏΠΎΠ»ΡƒΡ‡Π΅Π½ΠΈΠ΅ высокоплотной SiC-ΠΊΠ΅Ρ€Π°ΠΌΠΈΠΊΠΈ с ΡƒΡΠΎΠ²Π΅Ρ€ΡˆΠ΅Π½ΡΡ‚Π²ΠΎΠ²Π°Π½Π½Ρ‹ΠΌΠΈ физичСскими ΠΈ мСханичСскими свойствами. ВысокиС ΠΏΠ°Ρ€Π°ΠΌΠ΅Ρ‚Ρ€Ρ‹ ΠΏΠΎΠ»ΡƒΡ‡Π΅Π½Π½ΠΎΠΉ ΠΊΠ΅Ρ€Π°ΠΌΠΈΠΊΠΈ ΠΎΠΏΡ€Π΅Π΄Π΅Π»ΡΡŽΡ‚ΡΡ Ρ„ΠΎΡ€ΠΌΠΈΡ€ΠΎΠ²Π°Π½ΠΈΠ΅ΠΌ высокоплотной ΠΈ ΠΌΠΎΠ½ΠΎΠ»ΠΈΡ‚Π½ΠΎΠΉ структуры. ΠšΠ΅Ρ€Π°ΠΌΠΈΠΊΠ° ΠΊΠ°Ρ€Π±ΠΈΠ΄Π° крСмния ΠΎΠ±Π»Π°Π΄Π°Π΅Ρ‚ ΡƒΠ»ΡƒΡ‡ΡˆΠ΅Π½Π½ΠΎΠΉ мСханичСской ΠΏΡ€ΠΎΡ‡Π½ΠΎΡΡ‚ΡŒΡŽ ΠΈ высокой Ρ‚Π²Π΅Ρ€Π΄ΠΎΡΡ‚ΡŒΡŽ ΠΏΠΎ ВиккСрсу порядка 28,5 Π“ΠŸa

    Magnetometric Studies of Catalyst Refuses in Nanocarbon Materials

    Get PDF
    It is shown that magnetometry can be employed as an effective tool to control the content of a ferromagnetic constituent in nanocarbon materials. We propose a thermochemical treatment protocol to achieve extensive cleaning of the source nanocarbon materials from ferromagnetic refuses

    Effectiveness of electronic guideline-based implementation systems in ambulatory care settings - a systematic review

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Electronic guideline-based decision support systems have been suggested to successfully deliver the knowledge embedded in clinical practice guidelines. A number of studies have already shown positive findings for decision support systems such as drug-dosing systems and computer-generated reminder systems for preventive care services.</p> <p>Methods</p> <p>A systematic literature search (1990 to December 2008) of the English literature indexed in the Medline database, Embase, the Cochrane Central Register of Controlled Trials, and CRD (DARE, HTA and NHS EED databases) was conducted to identify evaluation studies of electronic multi-step guideline implementation systems in ambulatory care settings. Important inclusion criterions were the multidimensionality of the guideline (the guideline needed to consist of several aspects or steps) and real-time interaction with the system during consultation. Clinical decision support systems such as one-time reminders for preventive care for which positive findings were shown in earlier reviews were excluded. Two comparisons were considered: electronic multidimensional guidelines versus usual care (comparison one) and electronic multidimensional guidelines versus other guideline implementation methods (comparison two).</p> <p>Results</p> <p>Twenty-seven publications were selected for analysis in this systematic review. Most designs were cluster randomized controlled trials investigating process outcomes more than patient outcomes. With success defined as at least 50% of the outcome variables being significant, none of the studies were successful in improving patient outcomes. Only seven of seventeen studies that investigated process outcomes showed improvements in process of care variables compared with the usual care group (comparison one). No incremental effect of the electronic implementation over the distribution of paper versions of the guideline was found, neither for the patient outcomes nor for the process outcomes (comparison two).</p> <p>Conclusions</p> <p>There is little evidence at the moment for the effectiveness of an increasingly used and commercialised instrument such as electronic multidimensional guidelines. After more than a decade of development of numerous electronic systems, research on the most effective implementation strategy for this kind of guideline-based decision support systems is still lacking. This conclusion implies a considerable risk towards inappropriate investments in ineffective implementation interventions and in suboptimal care.</p

    Can computerized clinical decision support systems improve practitioners' diagnostic test ordering behavior? A decision-maker-researcher partnership systematic review

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Underuse and overuse of diagnostic tests have important implications for health outcomes and costs. Decision support technology purports to optimize the use of diagnostic tests in clinical practice. The objective of this review was to assess whether computerized clinical decision support systems (CCDSSs) are effective at improving ordering of tests for diagnosis, monitoring of disease, or monitoring of treatment. The outcome of interest was effect on the diagnostic test-ordering behavior of practitioners.</p> <p>Methods</p> <p>We conducted a decision-maker-researcher partnership systematic review. We searched MEDLINE, EMBASE, Ovid's EBM Reviews database, Inspec, and reference lists for eligible articles published up to January 2010. We included randomized controlled trials comparing the use of CCDSSs to usual practice or non-CCDSS controls in clinical care settings. Trials were eligible if at least one component of the CCDSS gave suggestions for ordering or performing a diagnostic procedure. We considered studies 'positive' if they showed a statistically significant improvement in at least 50% of test ordering outcomes.</p> <p>Results</p> <p>Thirty-five studies were identified, with significantly higher methodological quality in those published after the year 2000 (<it>p </it>= 0.002). Thirty-three trials reported evaluable data on diagnostic test ordering, and 55% (18/33) of CCDSSs improved testing behavior overall, including 83% (5/6) for diagnosis, 63% (5/8) for treatment monitoring, 35% (6/17) for disease monitoring, and 100% (3/3) for other purposes. Four of the systems explicitly attempted to reduce test ordering rates and all succeeded. Factors of particular interest to decision makers include costs, user satisfaction, and impact on workflow but were rarely investigated or reported.</p> <p>Conclusions</p> <p>Some CCDSSs can modify practitioner test-ordering behavior. To better inform development and implementation efforts, studies should describe in more detail potentially important factors such as system design, user interface, local context, implementation strategy, and evaluate impact on user satisfaction and workflow, costs, and unintended consequences.</p

    Computerized clinical decision support systems for chronic disease management: A decision-maker-researcher partnership systematic review

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>The use of computerized clinical decision support systems (CCDSSs) may improve chronic disease management, which requires recurrent visits to multiple health professionals, ongoing disease and treatment monitoring, and patient behavior modification. The objective of this review was to determine if CCDSSs improve the processes of chronic care (such as diagnosis, treatment, and monitoring of disease) and associated patient outcomes (such as effects on biomarkers and clinical exacerbations).</p> <p>Methods</p> <p>We conducted a decision-maker-researcher partnership systematic review. We searched MEDLINE, EMBASE, Ovid's EBM Reviews database, Inspec, and reference lists for potentially eligible articles published up to January 2010. We included randomized controlled trials that compared the use of CCDSSs to usual practice or non-CCDSS controls. Trials were eligible if at least one component of the CCDSS was designed to support chronic disease management. We considered studies 'positive' if they showed a statistically significant improvement in at least 50% of relevant outcomes.</p> <p>Results</p> <p>Of 55 included trials, 87% (n = 48) measured system impact on the process of care and 52% (n = 25) of those demonstrated statistically significant improvements. Sixty-five percent (36/55) of trials measured impact on, typically, non-major (surrogate) patient outcomes, and 31% (n = 11) of those demonstrated benefits. Factors of interest to decision makers, such as cost, user satisfaction, system interface and feature sets, unique design and deployment characteristics, and effects on user workflow were rarely investigated or reported.</p> <p>Conclusions</p> <p>A small majority (just over half) of CCDSSs improved care processes in chronic disease management and some improved patient health. Policy makers, healthcare administrators, and practitioners should be aware that the evidence of CCDSS effectiveness is limited, especially with respect to the small number and size of studies measuring patient outcomes.</p

    Severity dependent distribution of impairments in PSP and CBS: Interactive visualizations

    Get PDF
    BACKGROUND: Progressive supranuclear palsy (PSP) -Richardson's Syndrome and Corticobasal Syndrome (CBS) are the two classic clinical syndromes associated with underlying four repeat (4R) tau pathology. The PSP Rating Scale is a commonly used assessment in PSP clinical trials; there is an increasing interest in designing combined 4R tauopathy clinical trials involving both CBS and PSP. OBJECTIVES: To determine contributions of each domain of the PSP Rating Scale to overall severity and characterize the probable sequence of clinical progression of PSP as compared to CBS. METHODS: Multicenter clinical trial and natural history study data were analyzed from 545 patients with PSP and 49 with CBS. Proportional odds models were applied to model normalized cross-sectional PSP Rating Scale, estimating the probability that a patient would experience impairment in each domain using the PSP Rating Scale total score as the index of overall disease severity. RESULTS: The earliest symptom domain to demonstrate impairment in PSP patients was most likely to be Ocular Motor, followed jointly by Gait/Midline and Daily Activities, then Limb Motor and Mentation, and finally Bulbar. For CBS, Limb Motor manifested first and ocular showed less probability of impairment throughout the disease spectrum. An online tool to visualize predicted disease progression was developed to predict relative disability on each subscale per overall disease severity. CONCLUSION: The PSP Rating Scale captures disease severity in both PSP and CBS. Modelling how domains change in relation to one other at varying disease severities may facilitate detection of therapeutic effects in future clinical trials
    • …
    corecore