HEIDELBERG RADIOCARBON LAB – ESTABLISHING A NEW CARBON DIOXIDE EXTRACTION LINE FOR CARBONATE SAMPLES

ABSTRACT To achieve high-precision and reproducible results from radiocarbon (14C) dating of carbonate samples in paleoclimate research, a new CO2 extraction line was designed, constructed, and characterized at the Heidelberg Radiocarbon Lab of the Institute of Environmental Physics, Heidelberg. The setup includes a circular glass-tube design, which is operated at vacuum pressure levels of the order of 10–5 mbar. The efficiency of the extraction process was assessed, showing significantly favorable conditions for solid piece samples (99.58 ± 4.69)% over powdered samples (88.28 ± 10.03)%. Process blank values are below 0.2 pMC apparent 14C activity. Repeated measurements of IAEA C2 standards with an average value of (41.09 ± 0.23) pMC attest high accuracy and reproducibility of the instrument. Six consecutive samples of 6 to 12 mg carbonate mass can be processed in one run of roughly 2.5 hours. Thus, the new setup contributes to time-efficient and reproducible radiocarbon dating results for paleoclimate research at the Institute of Environmental Physics. In a first application, Dead Carbon Fraction (DCF) values of a Holocene alpine stalagmite from Schratten Cave are presented, revealing extraordinarily high offsets between atmospheric and stalagmite 14C with DCF values between (49.4 ± 0.4)% and (61.6 ± 0.4)%.

Pars pro toto—Remote Sensing Data for the Reconstruction of a Rounded Chalcolithic Site from NE Romania: The Case of Ripiceni–Holm Settlement (Cucuteni Culture)

Prehistoric sites in NE Romania are facing major threats more than ever, both from natural and human-induced hazards. One of the main reasons are the climate change determined natural disasters, but human-induced activities should also not be neglected. The situation is critical for Chalcolithic sites, with a very high density in the region and minimal traces at the surface, that are greatly affected by one or more natural hazards and/or anthropic interventions. The case study, Ripiceni–Holm, belonging to Cucuteni culture, is one of the most important Chalcolithic discoveries in the region. It is also the first evidence from Romania of a concentric arrangement of buildings in the proto-urban mega-sites tradition in Cucuteni-Trypillia cultural complex, and a solid piece of evidence in terms of irreversible natural and anthropic destruction. Using archival cartographic material, alongside non-destructive and high-resolution airborne sensing and ground-based geophysical techniques (LiDAR, total field and vertical gradient magnetometry), we managed to detect diachronic erosion processes for 31 years, to identify a complex internal spatial organization of the actual site and to outline a possible layout of the initial extent of the settlement. The erosion was determined with the help of the DSAS tool and highlighted an average erosion rate of 0.96 m/year. The main results argue a high percent of site destruction (approximately 45%) and the presence of an active shoreline affecting the integrity of the cultural layer.

Efficacy of diced cartilage graft in dorsal augmentation rhinoplasty and comparison with solid block cartilage

<p class="abstract"><strong>Background:</strong> The aim of the study is to compare the results of dorsal augmentation rhinoplasty using diced cartilage graft wrapped in temporalis fascia and bare, solid block of cartilage.</p><p class="abstract"><strong>Methods:</strong> This is a prospective study of a group of 25 patients who presented to ENT OPD from January 2011 to January 2016 with saddle nose deformity. All the patients underwent external septorhinoplasty with dorsal augmentation using either diced cartilage wrapped in temporalis fascia or solid piece of cartilage harvested from septum or concha. </p><p class="abstract"><strong>Results:</strong> The patients were followed up for 18 months post-operatively and the results were recorded in terms of patient’s satisfaction. Complications, if any were also recorded.</p><p class="abstract"><strong>Conclusions:</strong> Comparison between the two groups yielded equal success rate with no evidence of graft resorption, infection or extrusion in either of the group.</p>

Greek loanwords in Serbian vernaculars on the territory of Vojvodina

This paper presents a pilot version of a more comprehensive study on Greek loanwords in Serbian vernaculars which will deal with their identification, distribution, periodisation, and adaptation. The materials excerpted from the presently existing dialectal dictionaries will be compared with the data from three classical sources on the topic: VASMER, POPOVIC 1953-1955, and SKOK. In this phase our goal was to find out whether there is any point in proceeding with the study of Greek loanwords in Serbian, after the results that have been reached by the three abovementioned authors. Our choice for the pilot analysis is Recnik srpskih govora Vojvodine (RSGV) because of its size, representativeness and actuality: it is the largest single dictionary (ten volumes comprising over 2,000 pages), it has covered the vastests continual territory (at the same time most distant from the line of contact with Greek, and also beyond the borders of the Balkan linguistic unity), it falls in the number of the most up-to-date ones (published in the period 2001 to 2011). The paper offers not just a linear inventory of Grecisms from RSGV, but a classification of types of divergencies from the standard body of Grecisms. It features primarily novelties - be they represented by new words (ponomarh ?cleric?, mironisati ?to pray in the church?, parasnik ?unruly person?), by new semantics (buklijas ?horse ridden by the man who carries buklija?, Grk ?shopkeeper?, katarka ?long pole onto which knife for cutting the fishing-net is poised?, kolaba ?structure for drying meat in the attic?, kondir ?bucket for cattle; mode of cutting wine?, krevet ?laundry; chair; the lower layer of sheaves in a stook?, liman ?underwater source?, mira ?extract produced by cooking large amounts of fish in little water, used as an additon to fish-stew?, paripa ?horse farm?), by new formation (krevetnjaca ?a solid piece of wood fencing a straw-mattress?, limaniti ?to make a whirlpool?, talasnjaca ?rigging (on the boat)?, sulundariti se ?to precipitate?), by new phonetics (ararh : jerarh, bukrijas : buklijas, kolaba : koliba, mengule : mengele, raoma/revoma/reoma /roma : reuma, tridofla /trndofl/trndofli/trandofil : trandafil, celerak : ciler), as well as certain archaisms (disage ?saddlebags?, koram ?belly?, trpan ?sickle, pruning hook?; parasiti (se) ?to give up, stop doing something?, komat ?piece of bread?, pironj ?big nail?; dgunja ?quince?, sektembar ?September?), and some semantic rarities (kutlaca ?cooking spoon?, litanija ?scolding?, mengule ?troubles?, psaltirac ?pupil who studies psaltir?, trpeznik ?tablecloth?). Since the body of some two hundred Grecisms in RSGV contains not only a number of them with considerable phonetic, formative and semantic shifts, but also some rarely or nowhere registered words or meanings, it can be expected that in more Southern parts of the Serbian language territory such finds will be even more abundant. Therefore, it can be concluded that it certainly does make sense to proceed with studying Greek loanwords in Serbian vernaculars in future.

Using CAD-CAM Technology for the Full-Mouth, Fixed, Retrievable Implant Restoration: A Clinical Report

Computer-assisted design (CAD) and computer-assisted manufacture (CAM) are technologic advancements used in dentistry today. These technologies have been developed to fabricate a complete arch substructure from a solid piece of titanium for a fixed, screw-retained implant-supported prosthesis. This clinical report demonstrates a treatment approach which uses CAD-CAM technology to incorporate a milled, titanium framework with retrievable metal ceramic crowns.

Field decrystallization and structural modifications of highly doped silicon in a 2.45-GHz microwave single-mode cavity

Highly doped n-type silicon powder responds aggressively to a 2.45-GHz microwave E-field, whereas it remains unperturbed in the H-field. In the E-field, after about 30 s of treatment, the silicon powder attained submelting temperatures and thus coagulated to a bulk solid piece. X-ray diffraction analysis of the surface and the cross section of this solid material failed to show any detectable peaks, ascertaining the fact that the material had decrystallized. The Raman spectra of the material had broad and shallow peaks quite different from the thin, sharp lines exhibited by Si wafer. It appears that the E-field treatment has considerably distorted the lattice structure creating lattice strains throughout the sample. These lattice strains were relieved by grinding (recrystallized).

Brownian Simulation of Matrix Diffusion

ABSTRACTThe commonly used approach in dealing with matrix diffusion is to assign an effective diffusion constant for the radionuclide in the rock matrix. The idea behind this approach is that, on a scale much larger than the pore size, the irregularities tend to cancel out. Although it might look plausible at first sight, this approach has been questioned both for theoretical and experimental reasons.Here, Brownian simulation has been used to investigate the transport of dissolved material in a rock matrix modeled as a system of pores with a wide variability in size and shape. The Boltzmann distribution is used locally, although the system globally is far from equilibrium.The simulation consists of two main parts. First, the model rock is formed by precipitation of irregular mineral grains from a liquid phase. As the grains grow, they tend to form a mostly solid piece of rock.In the second part of the simulation, a dissolved species is introduced at one side of the rock and allowed to diffuse through its pore system. It is found that no apparent diffusion constant, D, can explain the properties of the system. Rather, D is found to be a function of both distance and time.

Floor trusses subjected to a concentrated load

The results of extensive testing of floor joists subjected to a concentrated load are presented. These floor joists are constructed with 2 × 4 (38 × 89 mm) flanges and steel V web members. The load-carrying capacity of these joists when subjected to a uniformly distributed load has been investigated previously. These joists, however, are often subjected to a concentrated load as the result of a floor opening, and this is the subject of this investigation. The use of this floor truss is similar to two 2 × 12 (38 × 286 mm) joists arranged back-to-back.The floor trusses were modified by adding extra material to the joists and by nailing the exposed bottom flange grips of the V web members. Adding the extra material resulted in the formation of a box section over part of the span. Another method, adding a solid piece of lumber inside the truss to form an I section, was also tried. A concentrated load was applied to the reinforced truss and the truss was loaded to failure. A significant improvement in load-carrying capacity was achieved through a simple modification to an ordinary floor truss.

The Investigation of the Enhancement Mechanisms of the Oxide Treatment on Cemented Carbide Tools

The mechanisms responsible for enhancement of the metal cutting properties of cemented carbide tools during oxide treatments are investigated. The reaction of individual phases present in cemented carbide tools with various oxides was analyzed experimentally under temperature-pressure conditions previously employed for the oxide treatment. The change in the surface structure and the formation of new phases were determined by means of X-ray diffraction, oxidation experiments, and thermodynamic analyses. The experimental results show that during the oxide treatment such carbides as TiC and ZrC, which are chemically more stable than WC, form on the surface of WC. It was also found that a small percentage of oxides mixed in the eutectic phase of Co-WC stabilizes the eutectic phase, thus preventing its adhesion to a solid piece of oxides.

Grundtvigs skoleverden ved K. E. Bugge

Grundtvigs skoleverden, i tekster og udkast. Ed. by K. E. Bugge. I—II.Rev. by Søren HolmThis edition is a collection of the most important parts of Grundtvig’s writings on education, and it has been made by a very competent editor. Mr. Bugge knows Grundtvig’s ideas as well as their historical background, the selection is reasonable, and the get-up is very attractive. Grundtvig’s belief in the spoken word was too strong for him to trust a particular method. Methods may be delusions and mistakes, and, like forms of government, they belong to specific periods. In “Lærebog i verdenshistorien for de tvende øverste klasser i Schouboes Institut” ( 1807) (A History of the World for the two Upper Forms in Schouboe’s School), which he dictated to the pupils, his view on examinations is quite sober: they should be kept in mind, but our real aims are higher. In the same period Grundtvig says about country schools that the villager has the same ultimate objectives as other people. He does not have the time to ponder everything, but then he is entitled to demand that other people should make their results accessible to him. He needs geography rather than natural history. But the clergymen, who were to be the pioneers of knowledge, seem to be more interested in farming. Judging from his “Leksjons- og karakterbog for den unge Stensen Leth” (Report on the lessons of young Stensen Leth) from 1806—here published for the first time—Grundtvig appears to have done a solid piece of work for his salary at Egeløkke. - Several of the later essays are concerned with “the school at Sorø”, others with universities, education of the people, citizenship, and general education. Grundtvig’s capacity for work was inconceivable.