190 resultados para CCT


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Este estudio identifica los principales factores que inciden en la determinación de la CCT de los senderos El Cráter, El Puma y El Cafetal de la Reserva Natural Volcán Mombacho. La Capacidad de carga turística se consideró tal y como propone Cifuentes en su metodología, en tres niveles: Capacidad de Carga Física (CCF), Capacidad de Carga Real (CCR) y Capacidad de Carga Efectiva (CCE) (Cifuentes, M. 1999). Se estimó la Capacidad de Manejo (CM) de la RNVM, en 74.24%, obteniendo en el sendero El Cráter una CCE de 442 visitas/día, en el sendero El Puma de 93 visitas/día, y en el sendero El Cafetal de 753 visitas/día. Si se lograse un incremento de la CM en un 80%; el sendero El Cráter in crementaría su CCE a 476 visitas/día; el sendero El Puma a 101 visitas/día; y el sendero El Cafetal a 811 visitas/día. Este escenario está calculado para visitantes con propósitos eco turísticos. Debido a que las visitas de estudiantes de colegio, muestran un comportamiento diferente, se realizó el cálculo considerando dichos elementos en los factores de corrección para los Sendero El Cráter y El Cafetal (El Puma no es frecuentado por estudiantes de colegio). La CCE para estudiantes en el sendero El Cráter fue de 236 visitas/día, con una CM del 74.24%, y para un escenario del 80% de CM se calcula en 255 visitas/día; para el sendero El Cafetal se calculó en 403 visitas/día a un 74.24% de CM y 434 visitas/día a una CM del 80%. Las visitas máximas reportadas para el año 2003 fueron en los meses de Enero y Junio, con 298 y 305 visitas/día; en el año 2002 se reportan los meses de Marzo y Mayo con 366 y 298 visitas/día; la visitación al Sendero El Cráter no excede aún la CCE calculada, no así si los visitantes fueran estudian tes de colegio. Si la tendencia de la visitación continua incrementándose con los años, se requerirá que la administración de la RNVM restringa el número de visitas en los períodos picos de las mismas.

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Aborda a aprovação de outorgas e renovações de rádio e tv pelo Senado Federal. Investiga relatórios de comissões e da Presidência do Senado, no período de 1999 a 2008, para quantificar a aprovação de projetos de decreto legislativo sobre o assunto. Analisa os partidos políticos mais beneficiados, as regiões e os Estados mais contemplados, as categorias de outorgas e renovações mais aprovadas e o fluxo dessas matérias em períodos eleitorais. Verifica a relação entre os projetos de radiodifusão que tramitaram no Senado, no período pesquisado, e a localidade da emissora.

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Designers who want to manufacture a hardenable steel component need to select both the steel and its heat treatment. This project aims to develop a selection methodology for steels and process routes as an aid to designers. Three studies were conducted: - production of software to calculate the "equivalent diameter" and "equivalent Jominy distance" for simple shapes of a steel component; - prediction of semi-empirical Jominy curves (as-cooled) using CCT diagrams and process modelling methods, which were validated by experiment on plain carbon steels; - investigation of tempering of Jominy bars to explore the potential for semi-empirical models for the hardness after tempering.

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This article presents results from conventional creep tests (CCT) and two accelerated test methods (the stepped isothermal method (SIM) and the stepped isostress method (SSM)) to determine the creep and creep-rupture behavior of two different aramid fibers, Kevlar 49 and Technora. CCT are regarded as the true behavior of the yarn, but they are impractical for long-term use where failures are expected only after many years. All the tests were carried out on the same batches of yarns, and using the same clamping arrangements, so the tests should be directly comparable. For both materials, SIM testing gives good agreement with CCT and gave stress-rupture lifetimes that followed the same trend. However, there was significant variation for SSM testing, especially when testing Technora fibers. The results indicate that Kevlar has a creep strain capacity that is almost independent of stress, whereas Technora shows a creep strain capacity that depends on stress. Its creep strain capacity is approximately two to three times that of Kevlar 49. The accelerated test methods give indirect estimates for the activation energy and the activation volume of the fibers. The activation energy for Technora is about 20% higher than that for Kevlar, meaning that it is less sensitive to the effects of increasing temperature. The activation volume for both materials was similar, and in both cases, stress dependent. Copyright © 2012 Wiley Periodicals, Inc.

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RFID is a technology that enables the automated capture of observations of uniquely identified physical objects as they move through supply chains. Discovery Services provide links to repositories that have traceability information about specific physical objects. Each supply chain party publishes records to a Discovery Service to create such links and also specifies access control policies to restrict who has visibility of link information, since it is commercially sensitive and could reveal inventory levels, flow patterns, trading relationships, etc. The requirement of being able to share information on a need-to-know basis, e.g. within the specific chain of custody of an individual object, poses a particular challenge for authorization and access control, because in many supply chain situations the information owner might not have sufficient knowledge about all the companies who should be authorized to view the information, because the path taken by an individual physical object only emerges over time, rather than being fully pre-determined at the time of manufacture. This led us to consider novel approaches to delegate trust and to control access to information. This paper presents an assessment of visibility restriction mechanisms for Discovery Services capable of handling emergent object paths. We compare three approaches: enumerated access control (EAC), chain-of-communication tokens (CCT), and chain-of-trust assertions (CTA). A cost model was developed to estimate the additional cost of restricting visibility in a baseline traceability system and the estimates were used to compare the approaches and to discuss the trade-offs. © 2012 IEEE.

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本工作对聚丁二烯(PBD)进行了光谱微结构分析,主要考察了三个问题。1、PBD分子链构象对PBD红外光谱的影响本工作对高顺式(c)PBD样品进行了室温和低温(25℃和-150℃)红外光谱测定,发现高顺式PBD在低温下整个光谱吸收峰大部分峰宽变窄,峰强增加,特别是738cm~(-1)峰,在低温下位移至748cm~(-1),峰强增加一倍多。另外还观察到低温结晶态出现802和598cm~(-1)两个吸收峰,在以前文献中未曾有过报导,我们将它们归属为顺式结构结晶峰。通过计算分峰,原来738cm~(-1)峰分成两个位于742和727cm~(-1)的子峰,在低温下,两个子峰分别位移至748和735cm~(-1),与室温时比较,两个子峰半宽都明显变小。748cm~(-1)子峰峰强也大大增加。结构分析表明,顺式结构特征振动CH=CH面外变角与分子链的构象有密切联系,而仅式(T)和1.2(v)结构却不存在这种情况,因而967cm~(-1)(T)和911cm~(-1)(v)两特征峰低温下变化都很小。本工作认为顺式结构738cm~(-1)峰这一变化是由于顺式结构不同分子链构象所造成的。低温和室温下分峰所得的左子峰对应于最稳定构象产生的吸收,右子峰则对应于相对不稳定构象产生的吸收。同时本工作肯定了米晋瑁等人提出的红外光谱定量分析方法在高顺式样品中的适用性。2、PBD分子链序列结构对红外光谱的影响由于在非高顺式样品中存在CCC、CCT、CCV、TCV、TCT、VCV等多种序列形式,通过不同组成的PBD红外光谱分析,发现在乙烯基含量中、高的样品中,原来738cm~(-1)峰已不再存在,峰值出现在733cm~(-1)附近,而且受1.2结构部分吸收的严重影响,顺式结构CH=CH面外变角吸收已不再是顺式结构的特征峰。通过对850至650cm~(-1)光谱区的光谱解析,本工作认为朱晋瑁等人的红外光谱定量分析方法在乙烯含量中、高的样品中已不再适用。3、PBD拉曼光谱的微结构分析本工作对PBD拉曼光谱1600-1700cm~(-1)区进行了光谱测定,选择了1666、1652和1639.5cm~(-1)吸收峰作为T、C和V构型的特征峰,借助于景遐斌老师的计算分峰方法,对PBD样品进行微结构分析,结果表明,各吸收带拟合良好,特征峰峰位稳定,分别在1666±1、1652±1.5和1639.5±1 cm~(-1),半峰宽变化不大,峰与峰之间相互影响很小,也就是说,我们选用的特征峰是合理的。用分峰所得的相对面积,结合~1H-NMR测得的值,建立了拉曼光谱PBD定量分析方法。用这一方法对27个不同微结构组成的PBD样品进行分析,所得结果与~1HNMR(高顺式样品与~(13)C-NMR、IR)比较,绝大部分样品一致性很好,最大偏差小于2%。本工作认为,用1666、1652和1639.5cm~(-1)碳双键伸缩振动吸收峰作为T、C和V构型特征峰进行定量分析,在理论上是合理的,在实际上是可行的。而且本方法直接使用固体样品,不经任何溶解和处理,所有计算处理在微机上即可实现,操作和计算都很方便。

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基于电感耦合等离子体四极杆质谱仪进行Nd2O3中稀土杂质测定,着重研究了碰撞反应池技术(CCT)用于基体Nd氧化物和氢氧化物干扰离子的消除。研究表明,以10%O2-10%Ar-80%He为碰撞反应气,保持反应气流速为0.1 mL/min,并通过调谐仪器参数,获得159Tb,165Ho,163Dy同位素的175TbO,179DyO和181HoO出现强氧化物峰,通过对这些氧化物离子进行检测而实现Tb,Dy,Ho的定量分析。在优化的条件下,基体导致的氧化物和氢氧化物质谱干扰可降低25~70倍。研究了CCT模式下不同内标元素用于基体效应的校正。结果表明,Re的校正效果最佳。其余La,Ce,Pr,Sm,Eu,Gd,Er,Tm,Yb和Lu等元素采用常规模式测定,其中Pr的测定采用高分辨以消除基体Nd前沿峰干扰。结合干扰系数校正,所建立的方法适用于99.999%Nd2O3的纯度分析,RSD小于5%,加入回收率令人满意。

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The GGA triplet repeats are widely dispersed throughout eukaryotic genomes. (GGA)n or (GGT)n oligonucleotides can interact with double-stranded DNA containing (GGA:CCT)n to form triple-stranded DNA. The effects of 8 divalent metal ions (3 alkaline-earth metals and 5 transition metals) on formation of these purine-rich triple-helix DNA were investigated by electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI-FT-MS). In the absence of metal ions, no triplex but single-strand, duplex, and purine homodimer ions were observed in mass spectra. The triple-helix DNA complexes were observed only in the presence of certain divalent ions. The effects of different divalent cations on the formation of purine-rich triplexes were compared. Transition-metal ions, especially Co2+ and Ni2+, significantly boost the formation of triple-helix DNA, whereas alkaline-earth metal ions have no positive effects on triplex formation. In addition, Ba2+ is notably beneficial to the formation of homodimer instead of triplex.

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本文根据历年来黄河口及邻近海域的沉积物、悬浮体调查资料(1961年3月-10月、1984年、1989年枯、洪季(笔者参加)等及海岸带调查);1855年以来的海图资料;1975年以来逐年卫片资料及黄河口海域遥感卫片解译分析报告等资料进行了分析、整理。同时,本文进行了如下工作:(1)对黄河口海区悬浮泥沙的光谱特征进行了野外实测、室内分析;分析了黄河河水的光谱特征;(2)野外测量了莱州湾南岸海滩滩面物质光谱反射特征,对典型样品取样,分析其粒径及其与光谱反射的关系;(3)分析了自1975年以来黄河口海域的卫片,运用计算机处理CCT;(4)对1961年、1989年底怪沉积物粒度参数及粘、砂含量作了模糊数学分析;(5)对黄河三角洲古岸线、水深作了对比,并用卫片资料分析岸线(现代)的动态变化;(6)对黄河三角洲岸滩进行了模糊动态分类。本文定量分析悬浮泥沙含量与光谱反射峰值波长的关系,得出在黄河口邻近海域、悬沙含量跨度大的地区,在用卫星资料定量计算悬沙含量时,应用分段式回归方程式:在高含量区,以TM4解译较好,相反则用TM3解译为宜。本文首次在该地区用卫星遥感资料与准同步海上观察资料进行相关分析,两者相关系较高,其中以TM4尤高些。针对大气程辐射对卫星资料的影响,提出了一种简易的大气校正方法,取得较好的结果。同时,结合不同时相的卫片分析,我们对黄河口海域泥沙分布规律及其影响因素作了详细的论叙。对1961年和1989年5月两次表层底质的粒度参数及粘、砂含量等要素进行模糊分类,得出黄河泥沙扩散的主要方向在1961年时,主要向北、西北、西及东北,少量向东、东南方向扩散。1989年黄河泥沙的扩散方向主要为东北、东南、西南及向东,少量泥沙向西北沿三角洲岸滩扩散。不同时期实测泥沙分布,岸线变化及卫片的泥沙分布型式证实了上述结论。本文首次研究了莱州湾潮滩表层沉积物粒径组成与光谱反射率的定量关系,得出其最侍研究波段。对不同时期地形图的岸线,等深线、坡度变化的对比分析,得出不同岸段的变化特征。用卫片对岸线动态的定量分析表明,仅在河口等快速变化的地区以及较长时段的岸线变化情况适用,而在变化较小的岸段以及时段较短时,其计算结果误差较大。本文最后提出一种考虑多因素综合作用、并能突出主导因素的模糊动态分类,分类结果与实际情况较为吻合,它为海岸动态性的研究提出了新方向。

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Neurodegenerative diseases such as Huntington disease are devastating disorders with no therapeutic approaches to ameliorate the underlying protein misfolding defect inherent to poly-glutamine (polyQ) proteins. Given the mounting evidence that elevated levels of protein chaperones suppress polyQ protein misfolding, the master regulator of protein chaperone gene transcription, HSF1, is an attractive target for small molecule intervention. We describe a humanized yeast-based high-throughput screen to identify small molecule activators of human HSF1. This screen is insensitive to previously characterized activators of the heat shock response that have undesirable proteotoxic activity or that inhibit Hsp90, the central chaperone for cellular signaling and proliferation. A molecule identified in this screen, HSF1A, is structurally distinct from other characterized small molecule human HSF1 activators, activates HSF1 in mammalian and fly cells, elevates protein chaperone expression, ameliorates protein misfolding and cell death in polyQ-expressing neuronal precursor cells and protects against cytotoxicity in a fly model of polyQ-mediated neurodegeneration. In addition, we show that HSF1A interacts with components of the TRiC/CCT complex, suggesting a potentially novel regulatory role for this complex in modulating HSF1 activity. These studies describe a novel approach for the identification of new classes of pharmacological interventions for protein misfolding that underlies devastating neurodegenerative disease.

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BACKGROUND: The obesity epidemic has spread to young adults, leading to significant public health implications later in adulthood. Intervention in early adulthood may be an effective public health strategy for reducing the long-term health impact of the epidemic. Few weight loss trials have been conducted in young adults. It is unclear what weight loss strategies are beneficial in this population. PURPOSE: To describe the design and rationale of the NHLBI-sponsored Cell Phone Intervention for You (CITY) study, which is a single center, randomized three-arm trial that compares the impact on weight loss of 1) a behavioral intervention that is delivered almost entirely via cell phone technology (Cell Phone group); and 2) a behavioral intervention delivered mainly through monthly personal coaching calls enhanced by self-monitoring via cell phone (Personal Coaching group), each compared to 3) a usual care, advice-only control condition. METHODS: A total of 365 community-dwelling overweight/obese adults aged 18-35 years were randomized to receive one of these three interventions for 24 months in parallel group design. Study personnel assessing outcomes were blinded to group assignment. The primary outcome is weight change at 24 [corrected] months. We hypothesize that each active intervention will cause more weight loss than the usual care condition. Study completion is anticipated in 2014. CONCLUSIONS: If effective, implementation of the CITY interventions could mitigate the alarming rates of obesity in young adults through promotion of weight loss. ClinicalTrial.gov: NCT01092364.

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Obesity has spread to all segments of the U.S. population. Young adults, aged 18-35 years, are rarely represented in clinical weight loss trials. We conducted a qualitative study to identify factors that may facilitate recruitment of young adults into a weight loss intervention trial. Participants were 33 adults aged 18-35 years with BMI ≥25 kg/m(2). Six group discussions were conducted using the nominal group technique. Health, social image, and "self" factors such as emotions, self-esteem, and confidence were reported as reasons to pursue weight loss. Physical activity, dietary intake, social support, medical intervention, and taking control (e.g. being motivated) were perceived as the best weight loss strategies. Incentives, positive outcomes, education, convenience, and social support were endorsed as reasons young adults would consider participating in a weight loss study. Incentives, advertisement, emphasizing benefits, and convenience were endorsed as ways to recruit young adults. These results informed the Cellphone Intervention for You (CITY) marketing and advertising, including message framing and advertising avenues. Implications for recruitment methods are discussed.

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BACKGROUND: The Affordable Care Act encourages healthcare systems to integrate behavioral and medical healthcare, as well as to employ electronic health records (EHRs) for health information exchange and quality improvement. Pragmatic research paradigms that employ EHRs in research are needed to produce clinical evidence in real-world medical settings for informing learning healthcare systems. Adults with comorbid diabetes and substance use disorders (SUDs) tend to use costly inpatient treatments; however, there is a lack of empirical data on implementing behavioral healthcare to reduce health risk in adults with high-risk diabetes. Given the complexity of high-risk patients' medical problems and the cost of conducting randomized trials, a feasibility project is warranted to guide practical study designs. METHODS: We describe the study design, which explores the feasibility of implementing substance use Screening, Brief Intervention, and Referral to Treatment (SBIRT) among adults with high-risk type 2 diabetes mellitus (T2DM) within a home-based primary care setting. Our study includes the development of an integrated EHR datamart to identify eligible patients and collect diabetes healthcare data, and the use of a geographic health information system to understand the social context in patients' communities. Analysis will examine recruitment, proportion of patients receiving brief intervention and/or referrals, substance use, SUD treatment use, diabetes outcomes, and retention. DISCUSSION: By capitalizing on an existing T2DM project that uses home-based primary care, our study results will provide timely clinical information to inform the designs and implementation of future SBIRT studies among adults with multiple medical conditions.

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The relationship between heat-treatment parameters and microstructure in titanium alloys has so far been mainly studied empirically, using characterization techniques such as microscopy. Calculation and modeling of the kinetics of phase transformation have not yet been widely used for these alloys. Differential scanning calorimetry (DSC) has been widely used for the study of a variety of phase transformations. There has been much work done on the calculation and modeling of the kinetics of phase transformations for different systems based on the results from DSC study. In the present work, the kinetics of the transformation in a Ti-6Al-4V titanium alloy were studied using DSC, at continuous cooling conditions with constant cooling rates of 5 °C, 10 °C, 20 °C, 30 °C, 40 °C, and 50 °C/min. The results from calorimetry were then used to trace and model the transformation kinetics in continuous cooling conditions. Based on suitably interpreted DSC results, continuous cooling–transformation (CCT) diagrams were calculated with lines of isotransformed fraction. The kinetics of transformation were modeled using the Johnson–Mehl–Avrami (JMA) theory and by applying the "concept of additivity." The JMA kinetic parameters were derived. Good agreement between the calculated and experimental transformed fractions is demonstrated. Using the derived kinetic parameters, the transformation in a Ti-6Al-4V alloy can be described for any cooling path and condition. An interpretation of the results from the point of view of activation energy for nucleation is also presented.