On the astronomical origin of the Hallstatt oscillation found in radiocarbon and climate records throughout the Holocene

An oscillation with a period of about 2100-2500 years, the Hallstatt cycle, is found in cosmogenic radioisotopes (C-14 and Be-10) and in paleoclimate records throughout the Holocene. Herein we demonstrate the astronomical origin of this cycle. Namely, this oscillation is coherent to the major stable resonance involving the four Jovian planets - Jupiter, Saturn, Uranus and Neptune - whose period is p=2318 yr. The Hallstatt cycle could derive from the rhythmic variation of the circularity of the solar system disk assuming that this dynamics could eventually modulate the solar wind and, consequently, the incoming cosmic ray flux and/or the interplanetary/cosmic dust concentration around the Earth-Moon system. The orbit of the planetary mass center (PMC) relative to the Sun is used as a proxy. We analyzed how the instantaneous eccentricity vector of this virtual orbit varies from 13,000 B. C. to 17,000 A. D.. We found that it undergoes kind of pulsations as it clearly presents rhythmic contraction and expansion patterns with a 2318 yr period together with a number of already known faster oscillations associated to the planetary orbital stable resonances. We found that a fast expansion of the Sun-PMC orbit followed by a slow contraction appears to prevent cosmic rays to enter within the system inner region while a slow expansion followed by a fast contraction favors it. Similarly, the same dynamics could modulate the amount of interplanetary/cosmic dust falling on Earth. These would then cause both the radionucleotide production and climate change by means of a cloud/albedo modulation. Other stable orbital resonance frequencies (e.g. at periods of 20 yr, 45 yr, 60 yr, 85 yr, 159-171-185 yr, etc.) are found in radionucleotide, solar, aurora and climate records, as determined in the scientific literature. Thus, the result supports a planetary theory of solar and/or climate variation.Comment: 36 pages, 14 figures, 1 tabl

Parameters affecting the workability of container glass Part 2. Influence of dissolved gases and of other parameters

The hypotheses associated with variations of dissolved gases, structure, macroinhomogeneity (or cordiness), surface composition gradients and radiant heat transfer properties are presented in some detail in the second part of the review. While each of the physicochemical parameters considered was shown to be potentially influential by laboratory experiments, there is still no general agreement on the factors which are most relevant in practice. The most popular candidates are microstructure formation and variations of the content of dissolved gases; however, so far no conclusive evidence has been obtained. The influence of such parameters on stress-induced viscosity variations is also not well clarified. In order to decide what should be improved in the melting practice to achieve a better control of the forming behaviour, it is essential to solve the alternative with suitable experiments on carefully selected production samples

Parameters affecting the workability of container glass Part 1. Description of the problem - Melting history, rheology and influence of microstructure

Poor workability designates sporadic cases in which the forming behaviour of container glass varies unpredictably, impairing quality, productivity and sometimes strength. The literature offers several plausible suggestions to explain such a poor reproducibility of the rheological behaviour, generally associated with physicochemical parameters of the glass which are not routinely analyzed and which are supposed to vary with "melting history" (temperatures, raw materials, melting atmospheres) and to influence viscosity by altering the structure of "flow units", while the analytical composition remains unchanged. Alternative hypotheses are based on various not properly controlled process parameters, such as gob temperature distribution or plunger and mould condition including lubrication. Moreover, recent advances in rheology show that during the most critical stages of the forming process viscosity may change drastically with the deformation rate, providing a further plausible explanation for the observed irregular forming behaviour. One of the most promising physicochemical parameters is the possible presence of microstructure (phase separation, clustering, microcrystals). While in model glasses the correlation between microstructure and rheology is well-established, both at equilibrium and at high shear rates, there is still a lack of conclusive evidence about the presence of microstructure in industrial multicomponent glass

Thermal conductivity of float glass at room temperature

When the heat transfer coefficient of multiple glazings is to be determined, it is important to know the exact thermal conductivity value of the glasses used for building purposes. The values given for flat glass lie between 0.8 and 1.15 W/(m K ) . The thermal conductivity of 11 float glass samples of 4 different colours, manufactured in 5 European countries, has been determined in the temperature range between 10 and 90 °C with an uncertainty of less than 1.5 %. At 10 °C, the mean value of all glasses investigated amounts to 1.022 W/ (m K); the individual values vary between 1.033 and 1.017 W/(m K) . On the basis of the composition, the basicity and the density, the measurement results could be well interpreted by known theoretical considerations. The slight variation of the thermal conductivity values obtained by measurement is in agreement with the values calculated from the composition and the density and can be explained by the fact that all float glasses are of nearly the same composition. By interpolation of the measurement data, coefficients could be determined to calculate the thermal conductivity from the oxide composition. The investigation has shown that - at 10 °C - a value of 1.02 W/(m K) can be applied for the thermal conductivity of flat glasses used for building purposes, independent of their colour or manufacturer

Infrared spectroscopic analysis of water incorporated in the structure of industrial soda-lime-silica glasses

The paper illustrates a method for the determination of the water content of glasses by infrared transmittance spectroscopy from the exdnctions of the bands due to free and hydrogen-bonded hydroxyl groups dissolved in the glass. The procedure is discussed in detail, highlighting the sources of random and systematic errors and what can be done to improve the interlaboratory reproducibihty. The ratio of the intensities of the two bands at 2.8 and 3.6 µm is investigated accurately for a range of industrial soda-lime-silica glasses. In the case of containers and float glass it is nearly constant, but it varies widely for other products, such as household appliances, car headlamps and hand worked arücles, probably due to differences in the glass formulation. Accordingly, caution should be exerted in using the simplified method based on the measurement of the first band only, implying a constant rado. Finally, evidence of molecular water in the dealkalized surface layers of commercial articles is obtained using infrared reflectance spectroscopy

Spectrophotometric determination of the normal emissivity of coated flat glass Report of the International Commission on Glass Technical Committee 10 "Optical Properties of Glass"

The results of the activity of TC 10 of the International Commission on Glass aimed at assessing the reproducibility and accuracy of the determination of normal emissivity from IR reflectance measurements with commercial spectrophotometers are presented. Eight European and American flat glass producers and two glass institutes participate in the activity. Two intercomparisons of near normal spectral reflectance are performed on 4 samples, representative of the current production. The circulated samples are subsequently calibrated in a metrological laboratory. The results show that even with a free integration procedure and reference mirror a satisfactory reproducibility can be achieved (the maximum discrepancy in computed U values between the participants being within 0.1 W/(m2 K)). The agreement significantly improves by using a common reference mirror, showing the importance of the availability of reference mirrors calibrated by some metrological source. After discussing the effect of the integration procedure on the resulting emissivity, a new 30 selected ordinates method is developed and transmitted to ISO (to be incorporated into the standard for the computation of the U values of double glazings)

Study of the high-temperature spectral behavior of container glass

The spectral absorption coefficients of container glasses in the wavelength region from 0.4 to 4.5 µm and in the temperature range from room temperature to 1400 °C were measured by a single-beam spectrophotometer by means of the transmission method. From the measured absorption coefficients radiative thermal conductivities in the temperature ränge from 600 to 1400 °C were calculated by means of Rosseland's diffusion approximation. The intensity of the band at 2.8 µm due to dissolved hydroxyl groups in glass was also calculated. While most previous measurements were performed on model glasses with a very simple basic composition, molten in laboratory furnaces from pure raw materials, the glasses investigated in this paper are the most frequently used types of container glasses with a complex composition and different chromophores. The influence of different coloring agents and dissolved water on the spectral behavior and radiative thermal conductivity of glass were studied, checking how the spectra change from room temperature to high temperature

Angular emissivity at room temperature and spectral reflectance at near normal incidence of float glass, borosilicate glass and glass-ceramics

An accurate investigation of the emissivity of uncoated flat glass (necessary to calculate the solar factor and the U value of glazing according to standardized procedures) was performed in agreement with Groupement Europeen des Producteurs de Verre Fiat, in support of CEN and ISO standardization activities. The total angular emissivity of a range of uncoated float glass samples was determined between 10 and 80 °C with an uncertainty of 0.5%. Both the normal and the hemispherical emissivity were nearly identical for all the samples investigated. No significant differences between the top and the bottom side were observed. Measurements were also extended to borosilicate glass and glass-ceramic plates used for fire-resistant glazing, determining their thermal conductivity and angular emissivity behaviour. In order to obtain addidonal information, also the spectral reflectance curves at near normal incidence between 2000 and 200 c m ⁻¹ were obtained using a spectroradiometer. The fact that almost identical curves were obtained for a wide range of float glasses (both sides) as well as for the fire-resistant materials confirms the correctness of the close emissivity values found. On the basis of the resuhs obtained, a Standard value of εn = 0.900 and a εh/εn ratio = 0.936 is suggested for both float glass and for the two other materials

A multi-stage GAN for multi-organ chest X-ray image generation and segmentation

Multi-organ segmentation of X-ray images is of fundamental importance for computer aided diagnosis systems. However, the most advanced semantic segmentation methods rely on deep learning and require a huge amount of labeled images, which are rarely available due to both the high cost of human resources and the time required for labeling. In this paper, we present a novel multi-stage generation algorithm based on Generative Adversarial Networks (GANs) that can produce synthetic images along with their semantic labels and can be used for data augmentation. The main feature of the method is that, unlike other approaches, generation occurs in several stages, which simplifies the procedure and allows it to be used on very small datasets. The method has been evaluated on the segmentation of chest radiographic images, showing promising results. The multistage approach achieves state-of-the-art and, when very few images are used to train the GANs, outperforms the corresponding single-stage approach