bluuebunny/crossref_metadata_2025_split huggingface dataset:
An important source of preanalytical error in medical laboratories: centrifugation
Authors: Sonmez Cigdem , Gümüş Alper , Senes Mehmet , Aykal Guzin , Taneli Fatma , Aksungar Fehime , Avci Esin , Coskun Cihan , Çınaroğlu İpek , Colak Ayfer , Eker Pinar , Güçel Funda , Haklıgor Aylin , Bercik Inal Berrin , Orhan Bagnu , Yılmaz Canan 
Published: February 2021

Abstract
Centrifugation separates particles within the specimen according to their shape, dimensions, and density and basically can be defined as a separation method. The centrifuge is an essential device in medical laboratories to prepare the serum, plasma, and urine samples for analysis. It is basically an electric device composed of the stationary (motor) and the motile (rotor) part. The centrifugation depends on two main variables: relative centrifugal force (RCF) and centrifugation time. The physical impact separating the specimen into its components in the centrifuge known as RCF is expressed as the multiples of gravitational acceleration (×g). RPM, defined as the number of rotations of the centrifuge per minute, shows the speed of the centrifuge. RCF value can be calculated by using RPM, and the centrifuge radius. Because models and sizes of centrifuges vary considerably, the use of gravity (g) forces instead of RPM is suggested. The centrifuges can be classified according to their usage, speed, technical specifications, and rotor type. An accurate and precise centrifugation process is essential to prevent errors in the preanalytical phase. The purpose of this document is to ensure the standardization of a good, precise protocol for the centrifugation process among the medical laboratories.
The Ignition of Two Phase Detonation by a Branching Detonation Tube
Authors: Xiong Cha , Qiu Hua , Lu Qinwei 
Published: February 2021

Abstract
A branching tube is available to deliver sufficient energy to directly initiate a detonation wave. But sustaining the detonation wave through a branching tube is a challenge. In this study, a preliminary exploration about a branching pulsed detonation engine with a gas-liquid mixture was carried out to evaluate filling conditions on detonation initiation. Two detonation tubes were connected by three different schemes, such as Tail-Tail, Tail-Mid, and Tail-Head. Experimental results showed only end-head connected tubes can be ignited by the branching tube, which is quite different from the results using gas fuels or pre-evaporated liquid fuel. Liquid fuel distribution is crucial for successful detonation traveling through the branching tube.
Biblical Jubilee Laws in Light of Neo-Babylonian and Achaemenid Period Contracts
Authors: Russell Stephen C. 
Published: February 2021

Zusammenfassung:
Wissenschaftler, die die biblischen Bestimmungen zum Sabbat- und Jobeljahr in Levitikus 25 behandeln, konnten zeigen, wie das Kapitel gesetzliche Traditionen, die sich jetzt in den Büchern Exodus und Deuteronomium befinden – Sabbatjahr und Freilassung – und gesetzliche Konzepte aus dem altorientalischen Kontext – besonders der Schuldenerlass, aber auch grundlegende Vorstellungen von Eigentum – weiterentwickelte, um eine beeindruckend originelle Vision einer nachhaltigen landwirtschaftlich geprägten Gesellschaft zu schaffen, die sich auf der Idee der Verwandtschaft gründet. Ich führe diese unsichere Entwicklungslinie in diesem Artikel fort, indem ich ein landwirtschaftliches Konzept untersuche, das in Levitikus 25 und in Verträgen der neu-babylonischen und achämenidischen Zeit auftaucht: langfristige, landwirtschaftliche Anleihen, die durch die Schulden eines Grundbesitzers erforderlich wurden. Nach rechtlichen und administrativen Aufzeichnungen entstand dieses Konzept im Rahmen des Vertragsrechts als Antwort auf Verschiebungen des Landbesitzes im 6.–4. Jhd. v. u. Z. In früheren Epochen hatte es sich noch nicht voll ausgeprägt. Auf diese Weise bestätigen die Analogien mit dem Alten Orient, die ich hier darlege, die Ansicht, dass Levitikus 25 ein später, nachexilischer Text ist. Ich unterbreite weiter, dass ein Teil der Genialität von Levitikus 25 darin liegt, wie der Text ein Konzept aus dem Vertragsrecht nahm und es zu Rechtsordnungen weiterentwickelte.
Structural systematics of RSn(S 2CN
R′ R″) 2Cl
compounds
Authors: Abdul Muthalib Amirah Faizah , Baba Ibrahim , Khaledi Hamid , Mohd Ali Hapipah , Tiekink Edward R. T. 
Published: February 2021

Abstract
Three new organotin(IV) structures of general formula RSn(S 2CN
R′ R″) 2Cl, where
R′ ≠ R″, namely MeSn
· [S 2CN(Me)(Cy)] 2Cl ( 1), MeSn[S
2CN( i-Pr)(CH 2Ph)] 2Cl (
2) and PhSn[S 2CN(Et)( i-Pr)]
2Cl ( 3) are described. Each structure features tin
in a distorted octahedral geometry defined by a C ClS
4donor set as a result of two chelating dithiocarbamate ligands.
In all cases the tin-bound carbon and chloride atoms are cis.
The shorter Sn–S bond lengths in 3are correlated with the
presence of the relatively more electronegative Sn-bound phenyl substituent. The
new structures conform to the structural motif adopted by all other compounds
with the formula RSn(S 2CN R′
R″) 2Cl, where R′
= R″, suggesting the unsymmetrical substitution pattern
of the dithiocarbamate ligands in the present study does not influence the
adoption of this structural motif. The homogeneity in the structural motif
notwithstanding, non-systematic variations in geometric parameters are found in
these structures indicating an overall influence of crystal packing upon
molecular geometry.
A preliminary orienting procedure for single crystals, using the Weissenberg camera
Authors: Starkky John 
Published: February 2021

Auszug
Ein Verfahren wird beschrieben, mit dem aus einer Weissenberg-Aufnahme ohne Schichtlinienblende die Orientierung eines Kristalls gegenüber dem Goniometerkopf, auf dem der Kristall befestigt ist, bestimmt werden kann. Die Aufnahme wird mittels dafür konstruierter Diagramme gedeutet; die Konstruktion der Diagramme und ihre Anwendung werden diskutiert. Die Kristallorientierung ist in stereographischer Projektion dargestellt; daraus lassen sich die Korrekturen, die nötig sind, um eine beliebige Kristallrichtung in die Kammerachse zu bringen, ablesen.
Das Verfahren ist nur anwendbar, wenn indizierte Weissenberg-Aufnahmen des Materials vorliegen. Es ist besonders nützlich, wenn mehrere Exemplare des gleichen oder ähnlichen Materials untersucht werden.
The crystal and molecular structure of bis(hydrazine)zinc bis(hydrazincarboxylate-N',O)
Authors: Ferrari A. , Braibanti A. , Bigliardi G. , Lanfredi A. M. 
Published: February 2021

Auszug
Die Kristall- und die Molekületruktur von Zn(N2H4)2(H2Nʹ-NH · COO)2 wurde bestimmt. Die Kristalle bestehen aus einzelnen Molekülen, die durch Wasserstoffbindungen miteinander verknüpft sind. Jedes Molekül ist ein oktaedrisches Chelat. Die sechs Ecken des Koordinations-Oktaeders sind besetzt von zwei Stickstoffatomen des Hydrazin-Moleküle sowie von je zwei Stickstoff- und Sauerstoffatomen der Hydrazincarboxyl-Gruppe. Die Abstände der Zinkatome von den sie umgebenden Atomen sind: Zn-O = 2,05 Å, Zn-Ν = 2,25 Å und 2,17 Å. Die Abstände der Stickstoffatome sind 1,46 A im Hydrazin- Molekül und 1,39 A in der Hydrazincarboxyl-Gruppe. Die Atome N, C und beide O der Gruppe -NH · COO- liegen in einer Ebene mit den C-O-Abständen 1,30 Å und 1,25 Å, entsprechend den Abständen in der Carbonsäure und deren Verbindungen.
The unit cell and space group of gadolinium molybdate and of scandium tungstate
Authors: Bernstein J. L. 
Published: February 2021

Auszug
Gd2(MoO4);, hat die Gitterkonstanten a = 10,396 ± 0,006 Å, C = 10,697 ± 0,004 Å. Wahrscheinlichste Raumgruppen sind P4/mbm-D5
4h Ρ4/mbm-C2
4v oder P4b2-D7
2d Sc2(WO4)3 ist rhombisch, pseudotetragonal, mit a = 9,596 ± 0,004, b = 13,330 ± 0,003 und c = 9,512 ± 0,004 Å; Raumgruppe ist Pnca-D14
2h
A phase transition in potassium chromium sulphate alum at low temperature
Authors: Rat Gouri , Ray Siddhartha 
Published: February 2021

Auszug
Die Phasenumwandlung von Kaliumchromalaun wurde bei 192,5° Κ röntgenographisch untersucht. Aus dem Untersuchungsergebnis geht hervor, daß die Umwandlungstemperatur mit der des ferroelektrischen Curie-Punkts übereinstimmt. Unterhalb dieser Temperatur wird die Struktur rhomboedrisch mit α = 88° und fast der gleichen Gitterkonstanten α = 12,2 Å wie bei der kubischen Modifikation.
230Th-234U model ages of some uranium standard reference materials
Authors: Williams R. W. , Gaffney A. M. 
Published: February 2021

Abstract
The “age” of a sample of uranium is an important aspect of a nuclear forensic investigation and of the attribution of the material to a source. The 230Th- 234U chronometer can be used to determine the production date of even very recently-produced material ( 234U half life = 245250 ± 490 years; 230Th half life = 75690 ± 230 years [1]), provided that the 230Th/234U at the time of formation is known, and that there has been no Th-U fractionation in the sample since production. For most samples of uranium, ages determined with this chronometer are “model ages”, because they are based on the assumptions of a) some initial amount of 230Th in the sample, and b) closed-system behavior of the sample since production. The uranium standard reference materials originally prepared and distributed by the former US National Bureau of Standards and now distributed by New Brunswick Laboratory as certified reference materials (NBS SRM = NBL CRM) are good candidates for materials where these assumptions may be tested. The U isotopic standards have known purification and production dates and closed-system behavior in the solid form (U3O8) may be reliably assumed. In addition, these materials are widely available and can serve as informal round-robin inter-laboratory comparison samples. We determined 230Th-234U model ages for seven of these isotopic standards by isotope dilution mass spectrometry using a multi-collector ICP-MS. The standards dated for this study are U005-A, U010, U030-A, U100, U850, U900 and U970. Model ages obtained range from ∼ 30 to ∼ 52 years ago (reference date: 5-May-2009). The model age of U100 is the same as the purification date, within uncertainty. The other six standards analyzed all give model ages older than the purification dates of record. The magnitude of the discrepancy between model age and purification date does not correlate with the model age or the amount of 232Th in the samples. This indicates that excess 230Th in these six standards results from incomplete purification during production.
EXAFS analysis of uranium(IV) and thorium(IV) complexes in concentrated CaCl2 solutions
Authors: Uehara A. , Fujii T. , Matsuura H. , Sato N. , Nagai T. , Minato K. , Yamana H. , Okamoto Y. 
Published: February 2021

Abstract
The coordination of U4+ and Th4+ in concentrated CaCl2 solutions is studied by U and Th L
III edge extended X-ray absorption fine structure (EXAFS) spectroscopy. With the decrease of concentration of CaCl2 from 6.9 to 4 M, the Cl− ion coordination number N
Cl in the U4+ coordination sphere decreases from 3.4 to 1.3, while the hydration number N
O increases from 4.5 to 6.7. The combined coordination number N
O+NCl of U4+ in concentrated Cl− solution (8.0), is lower than that in 1.5 M perchloric acid aqueous solution (9.0). For Th4+, the decrease of concentration from 6.9 to 4 M CaCl2, the coordination number N
Cl in the Th4+ coordination sphere decreased slightly from 1.9 to 1.5, while coordination number N
O increased from 7.6 to 8.8. The N
O+NCl of Th4+ in concentrated Cl− solution (9.0), is similar to that in 1.5 M perchloric acid. The bond distance of U–Cl (2.67 Å), is shorter than that of Th–Cl (2.76 Å), because of low coordination number N
O to U4+. By adding HCl into the system, the U4+ and Th4+ coordination sphere is unchanged. The coordination structures of U4+ and Th4+ in concentrated LiCl is also discussed.
Comparison of IUPAC k
0 values and neutron cross sections to determine a self-consistent set of data for neutron activation analysis
Authors: Firestone R. B. , Révay Zs. 
Published: February 2021

Abstract
Independent databases of nuclear constants for Neutron Activation Analysis (NAA) have been independently maintained by the physics and chemistry communities for many year. They contain thermal neturon cross sections σ
0, standardization values k
0, and transition probabilities P

γ
. Chemistry databases tend to rely upon direct measurements of the nuclear constants k
0 and P

γ
which are often published in chemistry journals while the physics databases typically include evaluated σ
0 and P

γ
data from a variety of experiments published mainly in physics journals. The IAEA/LBNL Evaluated Gamma-ray Activation File (EGAF) also contains prompt and delayed γ-ray cross sections σ

γ
from Prompt Gamma-ray Activation Analysis (PGAA) measurements that can also be used to determine k
0 and σ
0 values. As a result several independent databases of fundamental constants for NAA have evolved containing slightly different and sometimes discrepant results. An IAEA CRP for a Reference Database for Neutron Activation Analysis was established to compare these databases and investigate the possibilitiy of producing a self-consistent set of σ
0, k
0, σ

γ
, and P

γ
values for NAA and other applications. Preliminary results of this IAEA CRP comparison are given in this paper.
Radiocarbon dating of ancient Japanese calligraphy sheets and the discovery of 45 letters of a lost manuscript
Authors: Oda H. , Yasu H. , Ikeda K. , Sakamoto M. , Yoshizawa Y. 
Published: February 2021

Abstract
The Miidera-gire is an ancient paper sheet with different, elegant calligraphy on both sides. One side contains a part of a Buddhist scripture from around the ninth to the twelfth century and written in cursive hand, while the other side contains a part of Monzen (an anthology of Chinese literary works). The paleographical style of this Monzen seems to be older than that of the Buddhist scripture and is similar to some Chinese manuscripts written in the Tang Dynasty (AD 618–907). However, amid these elegant calligraphic writings, there exist many copies and counterfeits that were written several centuries later. We, therefore, measured the radiocarbon age of the Miidera-gire by using accelerator mass spectrometry. The calibrated radiocarbon age indicated 666–776 [cal AD] (2σ error), thus leading to the conclusion that the Monzen was first written on the obverse side, and long afterwards, the Buddhist scripture was written on the reverse side. Since only a few incomplete books of Monzen were written before the ninth century, this calligraphy is one of the oldest of the existing Monzen manuscripts.
Radioactive equilibria and disequilibria of U-series nuclides in the products from Izu arc volcanoes, Japan
Authors: Kurihara Y. , Takahashi M. , Sato J. 
Published: February 2021

Abstract
Activity ratios among 238U-230Th-226Ra in the products from Izu arc volcanoes, Japan, were observed in order to estimate the time scale of magmatic processes and the magma generation for Izu arc volcanism. Activity ratios of 238U/230Th and 226Ra/230Th in the basaltic and andesitic products from Izu arc volcanoes were greater than unity, being enriched in 238U and 226Ra relative to 230Th. The 226Ra/230Th activity ratio versus 238U/230Th activity ratio diagram for these products showed positive correlation, suggesting that the 238U-230Th-226Ra disequilibria occurred during the magma genesis by the additions of U- and Ra-rich fluids derived from the subducting slab by dehydration to the mantle wedge. The 230Th-226Ra radioactive disequilibria observed in the basaltic and andesitic products imply a short period of time (<8000 years) between the magma genesis and the eruption. The majority of rhyolitic products was considered to be almost in equilibrium of 238U=230Th=226Ra. The observation that 238U-230Th-226Ra for the rhyolite are in radioactive equilibrium suggested that the rhyolitic magma from Izu arc was generated in the partial melting of the earth crust heated by the basaltic magma of high temperature.
STRAIN ANALYSIS OF REACTOR TYPE CORE STRUCTURES BY CONSIDERING UNCERTAINTIES OF GRAPHITE’S PROPERTIES
Authors: Susmikanti Mike , Himawan Roziq , Sulistyo Jos Budi , Sulistyo Farisy Yogatama 
Published: March 2021

The power reactor with high-temperature gas-cooled reactor (HTGR) technology uses uranium as the reactor fuel. The energy from fission is converted to electrical energy or used for other needs such as hydrogen production or other research activities at high temperatures of around 700 °C. This operation does not allow the use of metal as the core material for the reactor. The material that fits the requirements as a core structure is graphite. Graphite material has specific characteristics, namely the parameters of the modulus of elasticity, coefficient of thermal expansion, and the volume which changes due to temperature and neutron dose. Because the structure of the reactor core is a vital component in the reactor, this research will develop a method for the design of the reactor core structure with graphite material. The design method is based on Design by Analysis which specifically refers to the strain analysis on each of the reactor core components. The design method developed is based on the finite element method. The object of this research is the side reflector made from the Toyo Tanso IG-110 series graphite. Based on the analysis of heat distribution and heat stress for the material before the effect of neutron exposure, the temperature distribution on the side reflector was found, as well as the displacement and heat stress that occurs. isotropic properties, Young's modulus and Poisson’s ratio values can be verified and estimated. The purpose of this research is to analyze the strain of the reactor core structure by taking into account the uncertainty of the graphite properties.
The Causality Model of Maize Farmers’ Income: Integrating Social Capital, Supply Chain, and Competitive Advantage
Authors: Karim Ikawati , Wulandari Eliana , Arsal Ariady , Mandasari Nur Fitriayu 
Published: February 2021

Social capital structure, effective supply chain, and competitive advantage have been expected to increase maize farmers’ income. Maize, as a main income, has not been able to prosper farmers yet. Structural Equation Modelling was applied to analyze the effectiveness of social capital, supply chain, and competitive advantage on the maize farmers’ income. This study was conducted with 120 maize farmers as samples in one of Indonesia's maize production centers. Three indicators measure each variable. Social capital indicators are trust, social network, and norm; supply chain is the flow of goods, flow of information, and flow of capital; the competitive advantage is cost leadership, product differentiation, and focus. Furthermore, the indicators of farmers’ income are land area, production, and labor. The study revealed that social capital did not directly impact maize farmers' income by the test variables of social capital, supply chain, and competitive advantage. In this case, in increasing maize farmers’ income, social capital needs to be supported by supply chain and competitive advantage as intervening variables. The study further revealed that social capital significantly affected the supply chain and competitive advantage, in which these two variables significantly influenced maize farmers’ income. Moreover, supply chain and competitive advantage have reinforced social capital to increase maize farmers’ income. From the intervening variables, competitive advantage was more vital to reinforce social capital than supply chain in increasing maize farmers’ income.
Tecnologias, múltiplas linguagens e práticas pedagógicas na formação superior a distância
Authors: Garbin Mônica Cristina , Oliveira Édison Trombeta de 
Published: March 2021

O uso de tecnologias na educação deve considerar as especificidades da área do conhecimento para, então, propor a demanda de seu uso pedagógico (SHULMAN, 1986; 1987; KOEHLER; MISHRA, 2005; 2008; OLIVEIRA; PICONEZ, 2016). Na Educação a Distância (EaD), os processos, metodologias e materiais costumam ser bastante padronizados, por questões de tempo e custos de produção. O presente artigo tem como objetivo identificar as práticas pedagógicas na EaD consideradas adequadas às áreas de conhecimento, considerando a visão de professores, alunos e mediadores. Para tanto, está em desenvolvimento uma pesquisa institucional em uma universidade pública virtual no Estado de São Paulo, que propõe o desenvolvimento de um modelo de oferta de disciplinas considerando as especificidades de cada área do conhecimento, tendo como base a tabela da Capes. Assim, após a organização das disciplinas ofertadas na instituição de acordo com as áreas do conhecimento, foram realizados grupos focais e aplicação de questionários com o público da universidade, para o levantamento das práticas pedagógicas mais adequadas para cada área. Será proposto um conjunto de práticas pedagógicas para cada área e espera-se que uma nova definição de modelo de oferta de disciplinas, com a participação de toda a comunidade acadêmica, gere possibilidades acordadas ao modelo pedagógico adotado pela instituição e que também sirvam de parâmetro inclusive para outras instituições, além de promover a melhoria da organização interna da instituição no processo de aprendizagem dos alunos.
Cortical activity at different time scales: high‐pass filtering separates motor planning and execution
Authors: Eriksson David , Heiland Mona , Schneider Artur , Diester Ilka 
Published: March 2021

Abstract
The smooth conduction of movements requires simultaneous motor planning and execution according to internal goals. So far it is not known how such movement plans can be modified without being distorted by ongoing movements. Previous studies have isolated planning and execution related neuronal activity by separating behavioral planning and movement periods in time by sensory cues1–7. Here, we introduced two novel tasks in which motor planning developed intrinsically. We separated this continuous self-paced motor planning statistically from motor execution by experimentally minimizing the repetitiveness of the movements. Thereby, we found that in the rat sensorimotor cortex, neuronal motor planning processes evolved with slower dynamics than movement related responses both on a sorted unit and population level. The fast evolving neuronal activity preceded skilled forelimb movements while it coincided with movements in a locomotor task. We captured this fast evolving movement related activity via a high-pass filter approach and confirmed the results with optogenetic stimulations. As biological mechanism underlying such a high pass filtering we suggest neuronal adaption. The differences in dynamics combined with a high pass filtering mechanism represents a simple principle for concurrent motor planning and execution in which planning will result in relatively slow dynamics that will not produce movements.