Academic literature on the topic 'CMCase. eng'
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Journal articles on the topic "CMCase. eng"
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Klunklin, Warinporn, Kittisak Jantanasakulwong, Yuthana Phimolsiripol, Noppol Leksawasdi, Phisit Seesuriyachan, Thanongsak Chaiyaso, Chayatip Insomphun, et al. "Synthesis, Characterization, and Application of Carboxymethyl Cellulose from Asparagus Stalk End." Polymers 13, no. 1 (December 28, 2020): 81. http://dx.doi.org/10.3390/polym13010081.
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Cellulose from Asparagus officinalis stalk end was extracted and synthesized to carboxymethyl cellulose (CMCas) using monochloroacetic acid (MCA) via carboxymethylation reaction with various sodium hydroxide (NaOH) concentrations starting from 20% to 60%. The cellulose and CMCas were characterized by the physical properties, Fourier Transform Infrared spectroscopy (FTIR), Differential scanning calorimetry (DSC), Scanning electron microscopy (SEM) and X-ray diffraction (XRD). In addition, mechanical properties of CMCas films were also investigated. The optimum condition for producing CMCas was found to be 30% of NaOH concentration for the carboxymethylation reaction, which provided the highest percent yield of CMCas at 44.04% with the highest degree of substitution (DS) at 0.98. The melting point of CMCas decreased with increasing NaOH concentrations. Crystallinity of CMCas was significantly deformed (p < 0.05) after synthesis at a high concentration. The L* value of the CMCas was significantly lower at a high NaOH concentration compared to the cellulose. The highest tensile strength (44.59 MPa) was found in CMCas film synthesized with 40% of NaOH concentration and the highest percent elongation at break (24.99%) was obtained in CMCas film treated with 30% of NaOH concentration. The applications of asparagus stalk end are as biomaterials in drug delivery system, tissue engineering, coating, and food packaging.
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Rizvi, Rubina, Courtney VanHouten, Tiffani J. Bright, Mollie M. McKillop, Shira Alevy, David Brotman, Megan Sands-Lincoln, et al. "The Perceived Impact and Usability of a Care Management and Coordination System in Delivering Services to Vulnerable Populations: Mixed Methods Study." Journal of Medical Internet Research 23, no. 3 (March 12, 2021): e24122. http://dx.doi.org/10.2196/24122.
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Background People with complex needs, such as those experiencing homelessness, require concurrent, seamless support from multiple social service agencies. Sonoma County, California has one of the nation’s largest homeless populations among largely suburban communities. To support client-centered care, the county deployed a Care Management and Coordination System (CMCS). This system comprised the Watson Care Manager (WCM), a front-end system, and Connect 360, which is an integrated data hub that aggregates information from various systems into a single client record. Objective The aim of this study is to evaluate the perceived impact and usability of WCM in delivering services to the homeless population in Sonoma County. Methods A mixed methods study was conducted to identify ways in which WCM helps to coordinate care. Interviews, observations, and surveys were conducted, and transcripts and field notes were thematically analyzed and directed by a grounded theory approach. Responses to the Technology Acceptance Model survey were analyzed. Results A total of 16 participants were interviewed, including WCM users (n=8) and department leadership members (n=8). In total, 3 interdisciplinary team meetings were observed, and 8 WCM users were surveyed. WCM provided a central shared platform where client-related, up-to-date, comprehensive, and reliable information from participating agencies was consolidated. Factors that facilitated WCM use were users’ enthusiasm regarding the tool functionalities, scalability, and agency collaboration. Constraining factors included the suboptimal awareness of care delivery goals and functionality of the system among the community, sensitivities about data sharing and legal requirements, and constrained funding from government and nongovernment organizations. Overall, users found WCM to be a useful tool that was easy to use and helped to enhance performance. Conclusions WCM supports the delivery of care to individuals with complex needs. Integration of data and information in a CMCS can facilitate coordinated care. Future research should examine WCM and similar CMCSs in diverse populations and settings.
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Draganova, D., I. Valcheva, Y. Kuzmanova, and M. Naydenov. "Effect of wheat straw and cellulose degrading fungi of genus Trichoderma on soil respiration and cellulase, betaglucosidase and soil carbon content." Agricultural Science and Technology 10, no. 4 (2018): 349–53. http://dx.doi.org/10.15547/10.15547/ast.2018.04.064.
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Abstract. Due to the intensive soil exploitation and increased mineral fertilization, the degradation of plant residues in the soil is becoming more difficult and slower over the years. This disturbs the structure of the soil and the nutritional balance and leads to a reduction in soil fertility. To solve the problem, microorganisms capable of degrading plant residues in the soil can be used. The purpose of this study was to investigate the effect of fungi of genus Trichoderma on the biodegradation of wheat straw in the soil by observation of the change in cellulase enzyme activity in the soil and the increase in soil biological activity. The highest basal soil respiration was noted at T2TUR (65.76 µgCO2) and T6 (53.69 µgCO2). During the entire straw degradation period, the highest endoglucanase activity was observed at T4 (285.0 μgGlu) and T6 (275.56 μgGlu), whereas the highest β-glucosidase was noted at T6 (5220.3 μgPNP/g/h) and T1UKR (5020.0 μgPNP/g/h). The presence of cellulose-degrading fungi positively affected the increase in the total amount of microbial biomass at the end of the study period, whereas the amount of Corg was increased in all straw amended variants. At the beginning of the process, CMCase correlated with the microbial carbon (r=0.896 for Cmic) and β-glucosidase activity was closely connected with both soil organic carbon and microbial carbon (r=0.819 for Corg and r=0.866 for Cmic). At the end of the investigated period a stronger correlation with Corg was observed.
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Silvestre, J., N. Silvestre, and J. de Brito. "An Overview on the Improvement of Mechanical Properties of Ceramics Nanocomposites." Journal of Nanomaterials 2015 (2015): 1–13. http://dx.doi.org/10.1155/2015/106494.
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Due to their prominent properties (mechanical, stiffness, strength, thermal stability), ceramic composite materials (CMC) have been widely applied in automotive, industrial and aerospace engineering, as well as in biomedical and electronic devices. Because monolithic ceramics exhibit brittle behaviour and low electrical conductivity, CMCs have been greatly improved in the last decade. CMCs are produced from ceramic fibres embedded in a ceramic matrix, for which several ceramic materials (oxide or non-oxide) are used for the fibres and the matrix. Due to the large diversity of available fibres, the properties of CMCs can be adapted to achieve structural targets. They are especially valuable for structural components with demanding mechanical and thermal requirements. However, with the advent of nanoparticles in this century, the research interests in CMCs are now changing from classical reinforcement (e.g., microscale fibres) to new types of reinforcement at nanoscale. This review paper presents the current state of knowledge on processing and mechanical properties of a new generation of CMCs: Ceramics Nanocomposites (CNCs).
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Bache, Martin R., Christopher D. Newton, John Paul Jones, Stephen Pattison, Louise Gale, Pascual Ian Nicholson, and Eleri Weston. "Advances in Damage Monitoring Techniques for the Detection of Failure in SiCf/SiC Ceramic Matrix Composites." Ceramics 2, no. 2 (May 15, 2019): 347–71. http://dx.doi.org/10.3390/ceramics2020028.
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From a disruptive perspective, silicon carbide (SiC)-based ceramic matrix composites (CMCs) provide a considerable temperature and weight advantage over existing material systems and are increasingly finding application in aerospace, power generation and high-end automotive industries. The complex structural architecture and inherent processing artefacts within CMCs combine to induce inhomogeneous deformation and damage prior to ultimate failure. Sophisticated mechanical characterisation is vital in support of a fundamental understanding of deformation in CMCs. On the component scale, “damage tolerant” design and lifing philosophies depend upon laboratory assessments of macro-scale specimens, incorporating typical fibre architectures and matrix under representative stress-strain states. This is important if CMCs are to be utilised to their full potential within industrial applications. Bulk measurements of strain via extensometry or even localised strain gauging would fail to characterise the ensuing inhomogeneity when performing conventional mechanical testing on laboratory scaled coupons. The current research has, therefore, applied digital image correlation (DIC), electrical resistance monitoring and acoustic emission techniques to the room and high-temperature assessment of ceramic matrix composites under axial tensile and fatigue loading, with particular attention afforded to a silicon carbide fibre-reinforced silicon carbide composite (SiCf/SiC) variant. Data from these separate monitoring techniques plus ancillary use of X-ray computed tomography, in-situ scanning electron microscopy and optical inspection were correlated to monitor the onset and progression of damage during mechanical loading. The benefits of employing a concurrent, multi-technique approach to monitoring damage in CMCs are demonstrated.
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Kedward, K. T., and P. W. R. Beaumont. "The treatment of Fatigue and Damage Accumulation in Composite Design." Advanced Composites Letters 1, no. 4 (July 1992): 096369359200100. http://dx.doi.org/10.1177/096369359200100404.
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SUMMARY The process of design has traditionally involved a specialized treatment of damage accumulation and associated fatigue phenomena, e.g. Miners Rule. The treatment of such phenomena for the case of advanced composites tends to be complicated by the existence of a multiplicity of competing failure modes. The subject assumes even greater importance when the ever expanding types of composite systems are considered, i.e. Polymer Matrix Composites (PMC's), Ceramic Matrix Composites (CMC's) and Metal Matrix Composites (MMC's) to name the broader categories. All composite systems are considered herein to comprise continuous fiber reinforcements.
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Palmieri, Giuseppe, Paolo A. Ascierto, Francesco Perrone, Sabrina M. R. Satriano, Alessandro Ottaiano, Antonio Daponte, Maria Napolitano, et al. "Prognostic Value of Circulating Melanoma Cells Detected by Reverse Transcriptase–Polymerase Chain Reaction." Journal of Clinical Oncology 21, no. 5 (March 1, 2003): 767–73. http://dx.doi.org/10.1200/jco.2003.01.128.
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Purpose: Factors that are predictive of prognosis in patients who are diagnosed with malignant melanoma (MM) are widely awaited. Detection of circulating melanoma cells (CMCs) by reverse transcriptase-polymerase chain reaction (RT-PCR) has recently been postulated as a possible negative prognostic factor. Two main questions were addressed: first, whether the presence of CMCs, defined as the patient being positive for any of the three markers, had a prognostic role; and second, what the predictive value of each individual marker was. Patients and Methods: A consecutive series of 200 melanoma patients observed between January 1997 and December 1997, with stage of disease ranging from I to IV, was analyzed by semiquantitative RT-PCR. Tyrosinase, p97, and MelanA/MART1 were used as markers to CMCs on baseline peripheral blood samples. Progression-free survival (PFS) was used as a unique end point and was described by the product limit method. Multivariable analysis was applied to verify whether the auspicated prognostic value of these markers was independent of the stage of disease, and a subgroup analysis was performed that excluded patients with stage IV disease. Results: Overall, 32% (64 of 200) of patients progressed, and a median PFS of 52 months in the whole series was observed. The presence of CMCs and the markers individually or combined was predictive of prognosis in the univariate analysis but did not provide additional prognostic information to the stage of disease in multivariable models. In the subgroup analysis of stage (ie, I–III subgroup), similar results were observed. Conclusion: Detection of CMCs in peripheral blood samples at the time of MM diagnosis by semiquantitative RT-PCR does not add any significant predictive value to the stage of disease. Thus, this approach should not be used in clinical practice, and further studies are required to determine its usefulness.
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Benassi, Vivian Machado, Rosymar Coutinho de Lucas, Michele Michelin, João Atílio Jorge, Héctor Francisco Terenzi, and Maria de Lourdes Teixeira de Moraes Polizeli. "Production and action of an Aspergillus phoenicis enzymatic pool using different carbon sources." Brazilian Journal of Food Technology 15, no. 3 (September 6, 2012): 253–60. http://dx.doi.org/10.1590/s1981-67232012005000019.
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Aspergillus phoenicis is an interesting heat tolerant fungus that can synthesize enzymes with several applications in the food industry due to its great hydrolytic potential. In this work, the fungus produced high enzymatic levels when cultivated on inexpensive culture media consisting of flakes from different origins such as cassava flour, wheat fibre, crushed soybean, agro-industrial wastes, starch, glucose or maltose. Several enzymatic systems were produced from these carbon sources, but amylase was the most evident, followed by pectinase and xylanase. Traces of CMCases, avicelase, lipase, β-xylosidase, β-glucosidase and α-glucosidase activities were also detected. Amylases were produced on rye flakes, starch, oat flakes, corn flakes, cassava flour and wheat fibre. Significant amylolytic levels were produced in the culture medium with glucose or when this sugar was exhausted, suggesting an enzyme in the constitutive form. Cassava flour, rye, oats, barley and corn flakes were also used as substrates in the hydrolytic reactions, aiming to verify the liberation potential of reducing sugars. Corn flakes induced greater liberation of reducing sugars as compared to the others. Thin layer chromatography of the reaction end products showed that the hydrolysis of cassava flour liberated maltooligosaccharides, but cassava flour and corn, rye, oats and barley flakes were hydrolyzed to glucose. These results suggested the presence of glucoamylase and α-amylase as part of the enzymatic pool of A. phoencis.
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van Roode, Mark, Jeff Price, Josh Kimmel, Naren Miriyala, Don Leroux, Anthony Fahme, and Kenneth Smith. "Ceramic Matrix Composite Combustor Liners: A Summary of Field Evaluations." Journal of Engineering for Gas Turbines and Power 129, no. 1 (March 1, 2005): 21–30. http://dx.doi.org/10.1115/1.2181182.
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Solar Turbines Incorporated, under U.S. government sponsored programs, has been evaluating ceramic matrix composite combustor liners in test rigs and Solar’s Centaur® 50S gas turbine engines since 1992. The objective is to evaluate and improve the performance and durability of CMCs as high-temperature materials for advanced low emissions combustors. Field testing of CMC combustor liners started in May of 1997 and by the end of 2004, over 67,000 operating hours had been accumulated on SiC∕SiC and oxide∕oxide CMC liners. NOx and CO emissions have been consistently <15ppmv and <10ppmv, respectively. Maximum test durations of 15,144h and 13,937h have been logged for SiC∕SiC liners with protective environmental barrier coatings. An oxide∕oxide CMC liner with a Friable Graded Insulation coating has been tested for 12,582h. EBCs significantly improve SiC∕SiC CMC liner life. The basic three-layer EBC consists of consecutive layers of Si, mullite, and BSAS. The durability of the baseline EBC can be improved by mixing BSAS with mullite in the intermediate coating layer. The efficacy of replacing BSAS with SAS has not been demonstrated yet. Heavy degradation was observed for two-layer Si∕BSAS and Si∕SAS EBCs, indicating that the elimination of the intermediate layer is detrimental to EBC durability. Equivalent performance was observed when the Hi-Nicalon fiber reinforcement was replaced with Tyranno ZM or ZMI fiber. Melt infiltrated SiC∕SiC CMCs have improved durability compared to SiC∕SiC CMCs fabricated by Chemical Vapor Infiltration of the matrix, in the absence of an EBC. However, the presence of an EBC results in roughly equivalent service life for MI and CVI CMCs. Results to date indicate that oxide∕oxide CMCs with protective FGI show minor degradation under Centaur® 50S gas turbine engine operating conditions. The results of, and lessons learned from CMC combustor liner engine field testing, conducted through 2004, have been summarized.
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Balabai, A. A., A. A. Krikunov, P. M. Semeniv, E. V. Rudenko, and V. P. Zakharova. "MORPHOFUNCTIONAL FEATURES OF THE MYOCARDIUM IN ITS DIASTOLIC OVERLOAD." Medical Science of Ukraine (MSU) 17, no. 2 (June 30, 2021): 39–46. http://dx.doi.org/10.32345/2664-4738.2.2021.06.
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Relevance. Adaptation of the heart chambers to their volume overload, which increases with diastolic filling of the left ventricle (LV) or systolic regurgitation in the left atrium (LA) in case of mitral valve insufficiency leads to remodeling of the myocardium of these chambers. Longitudinal hypertrophy of cardiomyocytes (CMCs), realized by building up new sarcomeres at the end of existing myofibrils, is an adaptation mechanism in the early stages, but eventually turns into maladjustment, which leads to heart failure. Hypertrophied CMCs, damaged during decompensation, are replaced by connective tissue due to excessive activation of fibroblasts with deposition of the extracellular matrix, which is also an element of the myocardial remodeling. The progression of heart failure is also associated with a mismatch between blood supply and myocardial oxygen demand, since an increase in the size of the CMCs is accompanied by a rarefaction of the intramural network of microvessels. It is believed that the violation of the ratio of the size of the heart, angiogenesis and cardiac function are the basis for the transition of adaptive compensation of the heart to decompensation with the progression of heart failure.
Objective: to study morphological changes in the myocardium of the LV and LA in patients with mitral valve insufficiency.
Materials and methods. Macroscopically, the condition of the myocardium was studied on the material of 14 autopsies of patients who died of NdMK insufficiency. History of NdMK – from 3 months. up to 2.4±1.1 years. As a control, the hearts of 3 deaths without cardiopathology were studied. The material for light microscopy was pieces of myocardium from different segments of the left ventricle, as well as from the walls of the left ventricle, obtained during autopsy.Morphological (macroscopic, histological and electron microscopic), morphometric and statistical research methods were used.
Results. With LV dilatation associated with chronic mitral valve insufficiency, lengthening of each CMCs provides an increase in the area of the myocardial walls, and, accordingly, the size of the cavity of the corresponding chamber of the heart, which compensates to some extent for the increase in diastolic blood volume in the LV and systolic blood volume in the LA. However, the factor limiting this compensation mechanism is the deficiency of the myocardial microvasculature associated with limited capillary growth. The contradiction between the need for the myocardium to lengthen the CMCs and the inability of capillaries to provide them with oxygen leads to a breakdown in compensation with an increase in fibrotic changes. This is a factor limiting the further increase in the volume of the cavity.
Conclusions. Overloading of the myocardium with volume leads to an increase in the length of the CMCs, on average, from 57.3±9.1 µm to 93.7±12.4 µm. The increase in the length of the CMCs is due to the increase in the number of sarcomeres from 43.7±8.4 to 62.5±14.5. The diameter of the CMCs in this case does not increase reliably. Overloading of the heart cavities with volume is often accompanied by desynchronization of the CMCs contraction, which leads to disruption of the integrity of the myocytic "working syncytium" and pronounced interstitial fibrosis.
Dissertations / Theses on the topic "CMCase. eng"
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Zanelato, Alex Izuka. "Produção de enzimas celulolíticas por fermentação em estado sólido em bioreator de leito fixo /." São José do Rio Preto : [s.n.], 2011. http://hdl.handle.net/11449/90759.
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Orientador: João Claudio ThoméoBanca: Roger Darros Barbosa
Banca: Ranulfo Monte Alegre
Resumo: Este trabalho teve como objetivo produzir enzimas celulolíticas por fermentação em estado sólido (FES), em um bioreator de leito fixo, empregando-se o fungo termofílico Myceliophthora sp. e utilizando-se como substratos bagaço de cana-de-açúcar e farelo de trigo. Os testes foram realizados inicialmente em sacos de polipropileno apresentando uma boa produção de CMCase (550U/g) no período de 96 horas de fermentação. As variáveis controladas foram a temperatura de fermentação (40, 45 e 50ºC), umidade inicial (75, 80 e 85% b.u.) e proporção do substrato de bagaço de cana e farelo de trigo (1:1, 3:7 e 1:9 peso). Os estimadores estatísticos não indicaram diferença significativa da produção de celulase com as variações da proporção de bagaço de cana e de farelo de trigo, com a temperatura e com a umidade inicial do substrato, contudo, os melhores resultados foram obtidos para a proporção de 70% de bagaço de cana e 30% de farelo de trigo, temperatura de 50oC e umidade inicial do substrato de 80%. Nos testes em escala de bioreator, foi empregado um leito fixo de 7cm de diâmetro e 50cm de comprimento, encamisado, operado nas condições experimentais de melhor resultados obtidos na escala de sacos, sendo a temperatura da camisa e vazão de ar as variáveis de interesse. O fungo apresentou um bom desenvolvimento no reator, tendo uma produtividade enzimática semelhante à encontrada em escala de saco. Foi observado um gradiente de umidade no interior do leito, sendo este crescente do fundo para o topo do bioreator, comportamento inverso ao da atividade enzimática. As vazões variaram entre 80 e 120 L/h e não afetaram estatisticamente a fermentação, possuindo pouca influência sobre as distribuições longitudinais de umidade e de atividade enzimática. Já os ensaios para as temperaturas de 45 e 50oC mostraram-se distintos, sendo a maior produção de enzimas após 96h... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: This work aimed to produce celullolytic enzymes through solid state fermentation in a fixed bed bioreactor, using the fungus Myceliophtora sp. and wheat bran and sugar cane bagasse as substrate. Initial tests were performed in polypropylene plastic bags, and satisfactory production of CMCase (550U/g.d.s.) was observed at 96h of fermentation. The controlled variables were the temperature (40, 45, and 50o C), the initial moisture content (75, 80, and 85%, w.b.), and wheat bran to sugar cane bagasse proportion (1:1, 3:7, and 1:9, weight). The experimental results did not differ statistically for any experimental condition adopted, even though the best results were obtained using the proportion 3:7 wheat bran/sugar cane bagasse 3:7, 50o C temperature, and 80% initial moisture content. A jacketed fixed bed bioreactor 7.62cm ID and 50cm long was used for scaling-up, and temperature, solid initial moisture content, and air flow rate were used as variables. The fungus adapted well to the bioreactor and to the experimental conditions, and the production of enzymes was similar to the tests performed in the plastic bags. It was observed a longitudinal gradient of moisture, increasing from the bottom to the top of the reactor, opposite effect observed for the enzyme production. The air flow rate was varied from 80 to 120L/h and did not affect neither the moisture nor the enzyme distributions. However, the experiments carried out at 45 and 50o C were statistically distinct, and the enzyme production at 50o C at 96h was larger than at 45o C. At 144h of fermentation, the results at 45o C were similar to those observed at 50o C and 96h. It was observed temperature peaks, the higher one at 18h of fermentation, which was 6o C above the temperature fixed through the jacket and the air at the entrance, for 45o C temperature and 80L/h air flow rate
Mestre
Book chapters on the topic "CMCase. eng"
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Wilson, E. Vance, and Joline P. Morrison. "A Measuring of Task-Technology Fit for Computer-Mediated Communication." In Human Centered Methods in Information Systems, 145–58. IGI Global, 2000. http://dx.doi.org/10.4018/978-1-878289-64-3.ch010.
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A key determinant in the success of computer-mediated communication systems (CMCS) and group support systems (GSS) is the task they are used for (Huber, 1984; DeSanctis & Gallupe, 1987). Task models and theories exist in the domain of non-mediated groups (e.g., McGrath, 1984; Wood, 1986) but application of these to GSS and CMCS has been spotty and the results equivocal (Zigurs & Buckland, 1998). Although research findings repeatedly suggest that the fit between task and computer-mediated communication technology is important, researchers have not yet been able to comprehensively describe or measure the dimensions of appropriate fit. This chapter describes the development and initial testing of an instrument to measure the perceived effectiveness of CMCS based on task type (hereafter PE measure). The PE measure extends prior research in several ways. First, it operationalizes the four major dimensions of McGrath’s task circumplex (McGrath, 1984; McGrath & Hollingshead, 1994), a model which frequently is used as a conceptual framework for studying GSS and CMCS (Dennis & Gallupe, 1993). Thus, it will be straightforward to integrate findings from studies that use the PE measure into the existing literature. Second, all four task types are incorporated into the PE measure, where prior research has focused primarily on generation tasks and, to a lesser extent, choice tasks. This comprehensive view of the overall task construct should benefit the process of theory-building as well as prediction in practical applications. Third, the PE measure has been tested successfully within heterogeneous task domains, suggesting that the instrument has validity and is relatively robust.
Conference papers on the topic "CMCase. eng"
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Presby, Michael J., K. Manigandan, Gregory N. Morscher, Cody Godines, Amir Eftekharian, Jalees Ahmad, Frank Abdi, and Sung R. Choi. "An Investigation of the End-Notched Flexure and End-Loaded Split Tests Applied to the Mode II Interlaminar Fracture of a SiC/SiC Ceramic Matrix Composite." In ASME Turbo Expo 2019: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/gt2019-90031.
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Abstract Delamination is a common failure mode observed in ceramic matrix composites (CMCs) and occurs as a result of applied interlaminar tensile and shear stresses exceeding the interlaminar strength. As CMCs are further implemented into aero engines the need to understand their interlaminar failure becomes increasingly important. While significant contributions have been made toward understanding the mode I fracture toughness of CMCs, limited work exists on mode II. Several test methods for measuring the mode II fracture toughness have been proposed in literature, namely the end-notched flexure (ENF) and the end-loaded split (ELS) tests. This work investigates the mode II fracture toughness of a melt-infiltrated SiC/SiC CMC at ambient temperature using the ENF and ELS test methods. Acoustic emission (AE), direct current potential drop (DCPD), and digital image correlation (DIC) are implemented as health monitoring techniques to monitor crack initiation and propagation. Results show reasonable correlation between the two test methods and that the ELS test method is better suited for characterizing R-curve behavior.
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Abdi, Frank, Cody Godines, Michael J. Presby, Amir Eftekharian, Jalees Ahmad, Sung Choi, Gregory N. Morscher, Steve Gonczy, and Jun Shi. "CMC Mode II Crack Growth Resistance Prediction of ASTM Specimen and Test Validation." In ASME Turbo Expo 2019: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/gt2019-90985.
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Abstract The objective of this effort is to predict ceramic matrix composites (CMC) interlaminar Mode II Crack Growth Resistance (CGR), and the design of ASTM test specimen. Currently, there are a number of test standards and American Society for Testing and Materials (ASTM) for CMC’s at both ambient and elevated temperatures; however, there are no standardized test methods for determination of interlaminar shear (Mode II) fracture toughness in CMC’s. Although research work exists on interlaminar Mode II fracture toughness of CMC’s, the test methods applied showed definite drawbacks and limitations. Delamination Crack Growth (CGR) tests of CMC Mode II may exhibit zig-zag pattern, wavy cracks, fiber bridging, and premature specimen failure under bending load. The experimental parameters that may contribute to the difficulty can be summarized as specimen width and thickness, interface coating thickness, mixed mode failure evolution, and interlaminar defects. Modes II crack growth resistances, GII, were analytically and numerically determined at ambient temperature using end notched flexure (ENF) and the end-loaded split (ELS). Finite Element (FE) based. Multi-scale progressive failure analysis (MS-PFA) a combined Micro-mechanical damage and fracture mechanics Virtual Crack Closure Technique (VCCT) algorithms. Modeling of melt-infiltrated SiC/SiC CMC of ENF specimen (Laminate: with initial crack length was accomplished using a MS-PFA and VCCT approach. Test data were compared with MS-PFA prediction: a) Force vs. Crack Opening Displacement; and b) Mode II crack tip energy release rate vs. crack extension length for both edge and center line due to formation of Micro Crack Density Contribution, Crack Tip Stiffness Reduction; and c) zig-zag crack growth behavior (adhesive/cohesive). Next the ASTM Standard Proposed linear SGR equation was developed based on interpretation compliance technique from both MS-PFA Analysis and Test.
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Hung, Mao-Hsiung, Chia-Hung Wang, and Yao He. "A Real-Time Routing Algorithm for End-to-End Communication Networks with QoS Requirements." In 2016 Third International Conference on Computing Measurement Control and Sensor Network (CMCSN). IEEE, 2016. http://dx.doi.org/10.1109/cmcsn.2016.44.
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Chang, Ruei-Jie, Chi-Rung Wu, Ke-Yi He, and Bor-Shyh Lin. "A Flexible and Wearable EEG Device." In 2016 Third International Conference on Computing Measurement Control and Sensor Network (CMCSN). IEEE, 2016. http://dx.doi.org/10.1109/cmcsn.2016.24.
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Choi, Sung R., and Robert W. Kowalik. "Interlaminar Crack Growth Resistances of Various Ceramic Matrix Composites in Mode I and Mode II Loading." In ASME Turbo Expo 2007: Power for Land, Sea, and Air. ASMEDC, 2007. http://dx.doi.org/10.1115/gt2007-27080.
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Interlaminar crack growth resistances were evaluated for five different SiC fiber-reinforced ceramic matrix composites (CMCs) including three gas-turbine grade MI SiC/SiC composites. Modes I and II crack growth resistances, GI and GII, were determined at ambient temperature using double cantilever beam (DCB) and end notched flexure (ENF) methods, respectively. The CMCs exhibited GI = 200–500 J/m2 and GII = 200–900 J/m2. All the composites (except for one SiC/CAS composite) showed rising R-curve behavior either in mode I or in mode II, presumably attributed to fiber bridging (in modes I and II) and frictional constraint (mode II) in the wake region of a propagating crack. A glass fiber-reinforced epoxy polymer matrix composite, used as comparison, showed typically 2-3 and 8 times greater in GI and GII, respectively, compared to the CMCs. Experimental error analysis regarding the effect of the off-the-center of a crack plane on GI and GII was also made.
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Abdi, Frank, Harsh Baid, Jalees Ahmad, Steve Gonczy, Gregory N. Morscher, Sung Choi, and Cody Godines. "Ceramic Matrix Composite Interlaminar Fracture Toughness (Mode I-II) Characterization." In ASME Turbo Expo 2015: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/gt2015-44047.
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The objective of this effort is to develop and demonstrate innovative interlaminar Mode I and Mode II fracture toughness analysis and test methods for ceramic matrix composites (CMC). Currently, there are number of American Society for Testing and Materials (ASTM) test standards for CMC’s at both ambient and elevated temperatures, including interlaminar tension and shear strength test methods. However, there are no standardized test methods for determination of interlaminar fracture toughness in CMC’s. Although research work exists on interlaminar Mode I and Mode II fracture toughness of various types of CMC’s, the test methods applied particularly in Mode II fracture toughness testing showed definite drawbacks and limitations. ASTM test standards for CMC’s may exhibit a zig-zag (wavy) crack path pattern, and fiber bridging. The experimental parameters that may contribute to the difficulty can be summarized as: specimen width and thickness, interface coating thickness, mixed mode failure evolution, and interlaminar defects. Modes I and II crack growth resistances, GI and GII, were analytically determined at ambient temperature using double cantilever beam (DCB) and End Notched Flexure (ENF) geometries. Three (3) CMC material systems were analyzed (Sylramic/IBN/MI, SiC/SiC CVI, and SiC/CAS). Several Finite Element (FE) based potential techniques were investigated: a) Multi-scale progressive failure analysis (MS-PFA); b) Virtual Crack Closure Technique (VCCT); and c) Contour Integral (CI). Advantages and disadvantages of each were identified. The final modeling algorithm recommended was an integrated damage and fracture evolution methodology using MS-PFA and VCCT. The analysis results (Fracture energy vs. crack length, Fracture energy vs. load, Fracture energy vs. crack opening displacement) matched the Mode I and Mode II coupon tests and revealed the following key findings. Mode I-DCB specimen: 1) Sylramic/IBN/MI failure mode is due to interlaminar tension (ILT) only in the interface section and a zig-zag pattern observed 2) VCCT crack growth resistance of Sylramic/IBN/MI is well matched to the test data and 3) SiC/SiC CVI failure mode is a mixed mode behavior (ILT to interlaminar shear (ILS). Mode II ENF specimen MS-PFA analysis suggests mixed mode behavior and the zig-zag pattern similar to Mode I coupon tests.
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He, Xialong, Kuo-Kun Tseng, Huang-Nan Huang, Shuo-Tsung Chen, Shu-Yi Tu, Fufu Zeng, and Jeng-Shyang Pan. "Wavelet-Based Quantization Watermarking for ECG Signals." In 2012 International Conference on Computing, Measurement, Control and Sensor Network (CMCS). IEEE, 2012. http://dx.doi.org/10.1109/cmcsn.2012.119.
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Chen, He, Fufu Zeng, Kuo-Kun Tseng, Huang-Nan Huang, Shu-Yi Tu, and Jeng-Shyang Panl. "ECG Human Identification with Statistical Support Vector Machines." In 2012 International Conference on Computing, Measurement, Control and Sensor Network (CMCS). IEEE, 2012. http://dx.doi.org/10.1109/cmcsn.2012.120.
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Guozhong Yao, Jianqun Wang, Zhengshan Li, and Xuejun Ran. "Modulated laser signal front-end processing technology." In 2010 International Conference on Computer, Mechatronics, Control and Electronic Engineering (CMCE 2010). IEEE, 2010. http://dx.doi.org/10.1109/cmce.2010.5610274.
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Jin Wang, Xiaomei Lin, and Kebing Wu. "ECG data compression research based on wavelet neural network." In 2010 International Conference on Computer, Mechatronics, Control and Electronic Engineering (CMCE 2010). IEEE, 2010. http://dx.doi.org/10.1109/cmce.2010.5610512.
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