Uncertainty quantification of an effective heat transfer coefficient within a numerical model of a bubbling fluidized bed with immersed horizontal tubes

This study investigates sources of steady state computational uncertainty in an effective heat transfer coefficient (HTC) within a non-reacting bubbling fluidized bed with immersed horizontal heat-conducting tubes. The methodical evaluation of this variation, or Uncertainty Quantification (UQ), is a critical step in the experimental analysis process, and is particularly important when the values of input physical parameters are unknown or experimental data is sparse. While the concept applies broadly to all studies, this application investigates a 2D unit cell analogue of a bubbling fluidized bed designed for large-scale carbon capture applications. Without adequate characterization of simulation uncertainties in the HTC, bed operating characteristics, including the thermal efficiency, carbon capture efficiency, and sorbent half-life cannot be well understood. We focus on three primary parameters, solid-solid coefficient of restitution, solid-wall coefficient of restitution, and turbulence model, and consider how their influences vary at different bed solid fractions. This is accomplished via sensitivity analysis and the Bayesian Spline Smoothing (BSS) Analysis of Variance (ANOVA) framework. Results indicate that uncertainties approach 20% at high gas fractions, with the turbulence model accounting for 80% of this variation and the solid-solid coefficient of restitution accounting for the additional 20%

The Monetary Theories of Milton Friedman and J. M. Keynes: A Comparison

For two decades, Milton Friedman has contended that the monetary theory of John Maynard Keynes is highly special, applicable only to conditions of deep depression. He continues to cite Keynes\u27 dependence on a condition of absolute liquidity preference, commonly called the liquidity trap, as the theoretical basis for Keynes\u27 unemployment equilibrium. Friedman believes that Keynes\u27 The General Theory was based on this underlying premise, so that its results are correct only in this special circumstance. Therefore, Friedman contends that Keynes regarded monetary policy as ineffective. Additionally, Friedman criticizes all economists in the Keynesian tradition because they adopt a narrow credit view of monetary policy while his theory is based on a broad monetary view. This study investigates Friedman\u27s charges in reference to Keynes\u27 The General Theory, and in the process a study is made of Keynes\u27 and Friedman\u27s monetary theories. The result is a presentation of the fundamental differences of the two monetary theories. Additionally, Keynes\u27 monetary policy prescriptions from The General Theory are discussed to investigate further any possible basis for Friedman\u27s criticisms

Psychiatric Illness in the Next-of-Kin of Intensive Care Unit Patients

The prevalence of psychiatric symptoms in next-of-kin (NOK) of intensive care unit (ICU) patients has been reported at higher than 70% when screening is performed using the Hospital Anxiety and Depression Scale (HADS). The primary purpose of this study was to assess the ability of the HADS to predict psychiatric illness, diagnosed with the aide of a validated tool, the Structured Clinical Interview for DSM-IV (SCID). In addition, we asked NOK to rate aspects of the ICU experience to determine possible associations with psychiatric diagnosis. Thirty-four NOK were enrolled in this study from July 2006 to November 2006. Subjects were interviewed to gather demographic information, their perception of the ICU experience, and to administer the SCID and the HADS. At least 6 months later, subjects were contacted by telephone to determine presence of psychiatric morbidity after the ICU experience. Fifty-six percent of all NOK experienced symptoms of either anxiety or depression during the ICU admission and 24% had psychiatric illness. The HADS had 100% sensitivity and 58% specificity when used as a screening tool for psychiatric diagnosis. Those with any SCID diagnosis were more likely to be a spouse (50% vs. 9%, p = 0.013) or a primary caregiver (60% vs. 8%, p = 0.003). Most NOK identified the healthcare team as supportive, though a subgroup of NOK who slept in the ICU reported that they found the healthcare team less supportive. This small study suggests the HADS is able to predict psychiatric illness in NOK of ICU patients. The ability to implement this tool as part of clinical practice to better meet the needs of families in the ICU warrants further investigation

Early signs of disease in type 1 diabetes

As a severe chronic disease with long-term complications, type 1 diabetes (T1D) is a burden to the patients and their families as well as a challenge to the health care system. T1D is a heterogeneous disease with a variety of etiologies and a wide range in the rate of progression to the disease. In order to prevent and treat T1D it would be important to identify measures that could be used to predict and monitor disease progression, as well as to further understand the molecular mechanisms involved. During the past 20 yr since its initiation, the Finnish Diabetes Prediction and Prevention Project (DIPP) has collected longitudinal biological samples from children with a human leukocyte antigen gene-conferred risk of T1D. This large sample collection has provided detailed sample series that enable studies to map the progression from health to disease, as well as the healthy maturation of risk-matched children. The DIPP samples have been used in a large body of research to elucidate the factors involved in the development of T1D. Interestingly, results from recent studies exploiting omics platforms have revealed that signs of the disease process can be detected very early on, even prior to appearance of the first T1D-associated antibodies, which are currently considered the earliest indications of the emerging disease. Identification and validation of multi-modal molecular markers will we hope provide a means to subgroup the heterogeneous group of T1D patients and enable prediction, diagnosis, and monitoring of T1D. Discovery of such markers is important in the design and testing of prevention and therapies for T1D</p

Thermal Stability of Self-Assembled Monolayers of n-Hexanethiol on Au(111)-(1 × 1) and Au(001)-(1 × 1)

Thermal desorption in an ultrahigh vacuum of n-hexanethiol (C6T) self-assembled monolayers (SAMs) prepared from ethanolic solutions on Au(111) and Au(001) unreconstructed surfaces was investigated by X-ray photoelectron spectroscopy. The SAMs desorption was performed from room temperature (RT) to 380 K. We report that the hexanethiolate surface saturation coverage is bigger (∼0.4 ML) for the SAM on Au(001) than on Au(111) (∼0.33 ML). We identified a greater stability for C6T SAMs on Au(001). Large amounts of physisorbed species were found on preferred oriented (111) polycrystalline Au at the low coverage regime at RT, while the SAM on the Au(001) single crystal at this conditions desorbs at a steady pace. At 340 K, both SAMs remain stable at the coverage expected for the lying-down phases that maximizes the van der Waals interactions. We observe that at higher temperatures the carbon alpha-sulfur bond breaks, producing free S on both gold surfaces.Fil: Cristina, Lucila Josefina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Física del Litoral. Universidad Nacional del Litoral. Instituto de Física del Litoral; ArgentinaFil: Ruano Sandoval, Gustavo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Física del Litoral. Universidad Nacional del Litoral. Instituto de Física del Litoral; ArgentinaFil: Salvarezza, Roberto Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Ferron, Julio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Física del Litoral. Universidad Nacional del Litoral. Instituto de Física del Litoral; Argentina. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Departamento de Materiales; Argentin