Investigation of paramagnetic response of metallic epoxies

The paramagnetic properties of epoxies which were impregnated with metal ions were examined as the primary task in this research. A major conclusion was that the quality control of the epoxies was insufficient to permit reliable evaluation. Subsequently, a new set of specimens is being prepared. As an additional task, a new method is investigated for estimating heats of combustion for saturated hydrocarbons. The results of that investigation have shown that the empirical approach is a promising method for on-line measurements

On-line measurement of heat of combustion

An experimental method for an on-line measurement of heat of combustion of a gaseous hydrocarbon fuel mixture of unknown composition is developed. It involves combustion of a test gas with a known quantity of air to achieve a predetermined oxygen concentration level in the combustion products. This is accomplished by a feedback controller which maintains the gas volumetric flow rate at a level consistent with the desired oxygen concentration in the products. The heat of combustion is determined from a known correlation with the gas volumetric flow rate. An on-line microcomputer accesses the gas volumetric flow data, and displays the heat of combustion values at desired time intervals

Measurement of viscosity of gaseous mixtures at atmospheric pressure

Coefficients of viscosity of various types of gas mixtures, including simulated natural-gas samples, have been measured at atmospheric pressure and room temperature using a modified capillary tube method. Pressure drops across the straight capillary tube section of a thermal mass flowmeter were measured for small, well-defined, volume flow rates for the test gases and for standard air. In this configuration, the flowmeter provides the volumetric flow rates as well as a well-characterized capillary section for differential pressure measurements across it. The coefficients of viscosity of the test gases were calculated using the reported value of 185.6 micro P for the viscosity of air. The coefficients of viscosity for the test mixtures were also calculated using Wilke's approximation of the Chapman-Enskog (C-E) theory. The experimental and calculated values for binary mixtures are in agreement within the reported accuracy of Wilke's approximation of the C-E theory. However, the agreement for multicomponent mixtures is less satisfactory, possible because of the limitations of Wilkes's approximation of the classical dilute-gas state model

A simplified method for determining heat of combustion of natural gas

A simplified technique for determination of the heat of combustion of natural gas has been developed. It is a variation of the previously developed technique wherein the carrier air, in which the test sample was burnt, was oxygen enriched to adjust the mole fraction of oxygen in the combustion product gases up to that in the carrier air. The new technique eliminates the need for oxygen enrichment of the experimental mixtures and natural gas samples and has been found to predict their heats of combustion to an uncertainty of the order of 1 percent

Feasibility of a nuclear gauge for fuel quantity measurement aboard aircraft

Capacitance fuel gauges have served as the basis for fuel quantity indicating systems in aircraft for several decades. However, there have been persistent reports by the airlines that these gauges often give faulty indications due to microbial growth and other contaminants in the fuel tanks. This report describes the results of a feasibility study of using gamma ray attenuation as the basis for measuring fuel quantity in the tanks. Studies with a weak Am-241 59.5-keV radiation source indicate that it is possible to continuously monitor the fuel quantity in the tanks to an accuracy of better than 1 percent. These measurements also indicate that there are easily measurable differences in the physical properties and resultant attenuation characteristics of JP-4, JP-5, and Jet A fuels. The experimental results, along with a suggested source-detector geometrical configuration are described

Highly Efficient Formylation of Alcohols, Thiols and Aniline Derivatives by a Heterogeneous (HCOOH/SiO2) System under Microwave Irradiation and Solvent-free Conditions

A simple, rapid and efficient microwave-assisted procedure for the formylation of aniline derivatives and alcohols, using a heterogeneous (HCOOH/SiO2) system under solvent-free conditions is reported. The method is applied to a set of amines, alcohols and thiols and short reaction times (<10 min) with high yields are reported. This protocol introduces a practical and viable green technology of solvent-free and catalyst-free reactions.Keywords: Alcohols, anilines, SiO2, HCOOH, microwave irradiation, solvent-free condition

Numerical modeling of polloution distribution in the Nayban bay

In this study COHERENS which is a three-dimensional hydrodynamic model was employed in order to model and survey dispersion of pollution in Nayband bay. In this model Navier-Stokes equation, continunity equation and transport equations of salinity and temperature in 3-D are solved. Cartesian coordinate for the horizontal and sigma coordinate with five layers was used for the vertical profile. Monthly mean atmospheric parameters and 4 major tidal components (M2, S2, O1, and K1) of the bay were used as the inputs of the model. In this model, uniform grid of 79*100 was used. Once the model was adjusted and the data inserted, the model was run for the bay. Then tidal currents were validated with field observation which resulted in prediction of horizontal dispersion of pollution in different layers. The results showed that dispersion is highly affected by tidal currents. These results can be applied to predict dispersion of pollution in Nayband bay

Interactive impacts of meteorological and hydrological conditions on the physical and biogeochemical structure of a coastal system

The German Bight was exposed to record high riverine discharges in June 2013, as a result of flooding of the Elbe and Weser rivers. Several anomalous observations suggested that the hydrodynamical and biogeochemical states of the system were impacted by this event. In this study, we developed a biogeochemical model and coupled it with a previously introduced high-resolution hydrodynamical model of the southern North Sea in order to better characterize these impacts and gain insight into the underlying processes. Performance of the model was assessed using an extensive set of in situ measurements for the period 2011–2014. We first improved the realism of the hydrodynamic model with regard to the representation of cross-shore gradients, mainly through inclusion of flow-dependent horizontal mixing. Among other characteristic features of the system, the coupled model system can reproduce the low salinities, high nutrient concentrations and low oxygen concentrations in the bottom layers observed within the German Bight following the flood event. Through a scenario analysis, we examined the sensitivity of the patterns observed during July 2013 to the hydrological and meteorological forcing in isolation. Within the region of freshwater influence (ROFI) of the Elbe–Weser rivers, the flood event clearly dominated the changes in salinity and nutrient concentrations, as expected. However, our findings point to the relevance of the peculiarities in the meteorological conditions in 2013 as well: a combination of low wind speeds, warm air temperatures and cold bottom-water temperatures resulted in a strong thermal stratification in the outer regions and limited vertical nutrient transport to the surface layers. Within the central region, the thermal and haline dynamics interactively resulted in an intense density stratification. This intense stratification, in turn, led to enhanced primary production within the central region enriched by nutrients due to the flood but led to reduction within the nutrient-limited outer region, and it caused a widespread oxygen depletion in bottom waters. Our results further point to the enhancement of the current velocities at the surface as a result of haline stratification and to intensification of the thermohaline estuarine-like circulation in the Wadden Sea, both driven by the flood event

Effect of vitamin D vaginal suppository on sexual functioning among postmenopausal women: a three-arm randomized controlled clinical trial

Objective: Vaginal atrophy, the second most common complication of menopause, can lead to sexual dysfunction. This study evaluated the effect of a vitamin D vaginal suppository on sexual functioning in postmenopausal women. Methods:This three-arm randomized controlled trial was conducted between August 2019 and August 2020. The sample comprised 105 postmenopausal women who were referred to comprehensive health service centers to receive postmenopausal care. The inclusion criteria were as follows: (i) being menopausal for at least 1 year, (ii) being married, (iii) being sexually active, and (iv) having sexual desire. Participants were randomly assigned to three groups for 8 weeks of treatment: intervention (vaginal suppository containing 1,000 units of vitamin D3), placebo (vaginal suppository placebo), or control (no treatment). The main outcome measure was sexual functioning, which was assessed using the Female Sexual Function Scale (FSFI) 4 times during the study (i.e., 1 month before the intervention, immediately after the intervention, 1 month after the intervention, and 2 months after the intervention). Results: Immediately and 1 month after the trial, the intervention group had the highest FSFI score, followed by the placebo group, both of which were significantly higher than those of the control group (P<0.05). At the 2-month follow-up, the intervention and placebo groups had similar FSFI scores (P=0.08), both of which were significantly higher than those in the control group (P=0.001 and P=0.03, respectively). Conclusion: Vitamin D vaginal suppositories were more effective at improving sexual functioning among postmenopausal women in the short-term and appeared to prevent aging-related sexual functioning decline in the long term

The ICON Earth System Model Version 1.0

This work documents ICON-ESM 1.0, the first version of a coupled model based 19 on the ICON framework 20 • Performance of ICON-ESM is assessed by means of CMIP6 DECK experiments 21 at standard CMIP-type resolution 22 • ICON-ESM reproduces the observed temperature evolution. Biases in clouds, winds, 23 sea-ice, and ocean properties are larger than in MPI-ESM. Abstract 25 This work documents the ICON-Earth System Model (ICON-ESM V1.0), the first cou-26 pled model based on the ICON (ICOsahedral Non-hydrostatic) framework with its un-27 structured, icosahedral grid concept. The ICON-A atmosphere uses a nonhydrostatic dy-28 namical core and the ocean model ICON-O builds on the same ICON infrastructure, but 29 applies the Boussinesq and hydrostatic approximation and includes a sea-ice model. The 30 ICON-Land module provides a new framework for the modelling of land processes and 31 the terrestrial carbon cycle. The oceanic carbon cycle and biogeochemistry are repre-32 sented by the Hamburg Ocean Carbon Cycle module. We describe the tuning and spin-33 up of a base-line version at a resolution typical for models participating in the Coupled 34 Model Intercomparison Project (CMIP). The performance of ICON-ESM is assessed by 35 means of a set of standard CMIP6 simulations. Achievements are well-balanced top-of-36 atmosphere radiation, stable key climate quantities in the control simulation, and a good 37 representation of the historical surface temperature evolution. The model has overall bi-38 ases, which are comparable to those of other CMIP models, but ICON-ESM performs 39 less well than its predecessor, the Max Planck Institute Earth System Model. Problem-40 atic biases are diagnosed in ICON-ESM in the vertical cloud distribution and the mean 41 zonal wind field. In the ocean, sub-surface temperature and salinity biases are of con-42 cern as is a too strong seasonal cycle of the sea-ice cover in both hemispheres. ICON-43 ESM V1.0 serves as a basis for further developments that will take advantage of ICON-44 specific properties such as spatially varying resolution, and configurations at very high 45 resolution. 46 Plain Language Summary 47 ICON-ESM is a completely new coupled climate and earth system model that ap-48 plies novel design principles and numerical techniques. The atmosphere model applies 49 a non-hydrostatic dynamical core, both atmosphere and ocean models apply unstruc-50 tured meshes, and the model is adapted for high-performance computing systems. This 51 article describes how the component models for atmosphere, land, and ocean are cou-52 pled together and how we achieve a stable climate by setting certain tuning parameters 53 and performing sensitivity experiments. We evaluate the performance of our new model 54 by running a set of experiments under pre-industrial and historical climate conditions 55 as well as a set of idealized greenhouse-gas-increase experiments. These experiments were 56 designed by the Coupled Model Intercomparison Project (CMIP) and allow us to com-57 pare the results to those from other CMIP models and the predecessor of our model, the 58 Max Planck Institute for Meteorology Earth System Model. While we diagnose overall 59 satisfactory performance, we find that ICON-ESM features somewhat larger biases in 60 several quantities compared to its predecessor at comparable grid resolution. We empha-61 size that the present configuration serves as a basis from where future development steps 62 will open up new perspectives in earth system modellin