bluuebunny/crossref_metadata_2025 huggingface dataset:
Ionic liquid pretreatment at high solids loading: A clean approach for fabrication of renewable resource based particulate composites
Authors: Mahmood Hamayoun , Moniruzzaman Muhammad , Yusup Suzana , Akil Hazizan Md.
Published: July 2016

Recently, the concept of high solids loading in ionic liquid (IL) based pretreatment of lignocellulosic biomass has gained numerous attention due to significant economic, environmental, and sustainability benefits. The objective of the present work was to investigate the impact of ILs pretreatment of lignocellulosic oil palm frond (OPF) biomass at high solids loading on the mechanical and thermal properties of the composite panels. The process combines the pretreatment of OPF particles with ILs [bmim][Cl] (1‐butyl‐3‐methylimidazolium chloride) and [emim][OAc] (1‐ethyl‐3‐methylimidazolium acetate) followed by IL recovery by rinsing with acetone‐water mixture prior to mixing of OPF particles with polymer binder to fabricate compression‐molded composite panels. Untreated and treated OPF particles were characterized by scanning electron microscopy, X‐ray diffraction, thermogravimetric analysis, and chemical composition analysis. Further, the effect of ILs pretreatment on kinetics of thermal degradation of biocomposites was evaluated by activation energy approach. Maximal flexural strength, modulus, and strain energy density (SED) of 25 MPa, 1,928 MPa, and 0.48 MJ/m3, respectively, were found for IL [emim][OAc] treated composite. Besides, thermal properties of IL treated composites were also improved. Present study could be a significant step toward practical IL pretreatment strategies for manufacturing of lignocellulosic based composite materials. POLYM. COMPOS., 39:1994–2003, 2018. © 2016 Society of Plastics Engineers
Biophysical characterization of the domain association between cytosolic A and B domains of the mannitol transporter enzymes IIMtl in the presence and absence of a connecting linker
Authors: Lee Ko On , Kim Eun‐Hee , Kim Gowoon , Jung Jea Yeon , Katayama Shigeru , Nakamura Soichiro , Suh Jeong‐Yong
Published: July 2016

The mannitol transporter enzyme IIMtl of the bacterial phosphotransferase system is a multi‐domain protein that catalyzes mannitol uptake and phosphorylation. Here we investigated the domain association between cytosolic A and B domains of enzyme IIMtl, which are natively connected in Escherichia coli, but separated in Thermoanaerobacter tengcongensis. NMR backbone assignment and residual dipolar couplings indicated that backbone folds were well conserved between the homologous domains. The equilibrium binding of separately expressed domains, however, exhibited ∼28‐fold higher affinity compared to the natively linked ones. Phosphorylation of the active site loop significantly contributed to the binding by reducing conformational dynamics at the binding interface, and a few key mutations at the interface were critical to further stabilize the complex by hydrogen bonding and hydrophobic interactions. The affinity increase implicated that domain associations in cell could be maintained at an optimal level regardless of the linker.
Preparation of pulsed DC magnetron deposited Fe‐doped SnO2 coatings
Authors: Kormunda Martin , Fischer Daniel , Hertwig Andreas , Beck Uwe , Sebik Matej , Esser Norbert
Published: July 2016

Iron‐doped SnO2 coatings were deposited in a 50 kHz DC‐pulsed magnetron sputtering discharge. The pulses had a duration of 4 μs in selected gas mixtures from pure argon up to 60% of oxygen at a constant total pressure of 0.2 Pa. A single target of SnO2 with Fe inset was used. The mass spectrometry study detected the gas‐related ions Ar+, O2+ and O+, where the last one becomes the dominant positive ion at higher oxygen contents. Atomic oxygen ions had a higher energy as it resulted from the collision‐caused dissociation on the target surface. The tin‐related species were detected as Sn+ and SnO+. SnO2+ species were not detected. The deposition rate decreased by using gas mixtures with oxygen as well as the corresponding amount of Sn‐related species in the plasma. The increase of oxygen also increased significantly the sheet resistance of the films. The XPS study showed that the iron concentration decreased by using additional oxygen. But the O/Sn ratio in the coatings was constant, contrary to the increased FeO/Fe ratio in the films. An additional analysis of the coatings by spectroscopic ellipsometry has shown a dependence of the polarizability and the permittivity on the amount of oxygen used during the deposition. In contrast, the study has found no such dependence for the absorption of the layers.
Estimation of the functional form of subgrid‐scale parametrizations using ensemble‐based data assimilation: a simple model experiment
Authors: Pulido M. , Scheffler G. , Ruiz J. J. , Lucini M. M. , Tandeo P.
Published: July 2016

Oceanic and atmospheric global numerical models represent explicitly the large‐scale dynamics while the smaller‐scale processes are not resolved, so that their effects in the large‐scale dynamics are included through subgrid‐scale parametrizations. These parametrizations represent small‐scale effects as a function of the resolved variables. In this work, data assimilation principles are used not only to estimate the parameters of subgrid‐scale parametrizations but also to uncover the functional dependencies of subgrid‐scale processes as a function of large‐scale variables. Two data assimilation methods based on the ensemble transform Kalman filter (ETKF) are evaluated in the two‐scale Lorenz '96 system scenario. The first method is an online estimation which uses the ETKF with an augmented space state composed of the model large‐scale variables and a set of unknown global parameters from the parametrization. The second method is an offline estimation which uses the ETKF to estimate an augmented space state composed of the large‐scale variables and by a space‐dependent model error term. Then a polynomial regression is used to fit the estimated model error as a function of the large‐scale model variables in order to develop a parametrization of small‐scale dynamics. The online estimation shows a good performance when the parameter‐state relationship is assumed to be a quadratic polynomial function. The offline estimation captures better some of the highly nonlinear functional dependencies found in the subgrid‐scale processes. The nonlinear and non‐local dependence found in an experiment with shear‐generated small‐scale dynamics is also recovered by the offline estimation method. Therefore, the combination of these two methods could be a useful tool for the estimation of the functional form of subgrid‐scale parametrizations.
Framing program comprehension as fault localization
Authors: Perez Alexandre , Abreu Rui
Published: July 2016

Program comprehension is a time‐consuming task performed during the process of reusing, reengineering, and enhancing existing systems. There are tools to assist comprehension by means of dynamic analysis, but most cannot identify the topology and the interactions of certain functionality in need of change. We propose an approach, coined Spectrum‐based Feature Comprehension (SFC), that borrows techniques from software‐fault localization that were proven to be effective even when debugging large applications. SFC analyses the program by exploiting run‐time information from test case executions to identify the components that are important for a given feature, helping software engineers to understand how a program is structured and each of the functionality's dependencies are. We present a toolset, coined PANGOLIN, that implements SFC and displays its report to the user using an intuitive visualization. A user study presented demonstrating PANGOLIN's efficiency in locating components that should be inspected when changing a certain functionality. Participants using SFC spent a median of 50 min locating the feature with greater accuracy, whereas participants using coverage tools took 60 min. Finally, we also detail the Participatory Feature Detection approach, where user interactions with the system are captured; removing the hindrance of requiring pre‐existing automated tests. Copyright © 2016 John Wiley & Sons, Ltd.
The Oxidation and Decomposition Behavior of Carbonate Iron Ore
Authors: Tang Yating , Chu Mansheng , Tang Jue , You Lin , Liu Zhenggen
Published: July 2016

With the aim of high‐efficiency utilization of carbonate iron ore, a new beneficiation process of preoxidation‐reduction‐magnetic separation is proposed. This work focuses on the oxidation and decomposition behavior of carbonate iron ore during the preoxidation. Based on the single factor experiment and non‐isothermal analysis results, it shows that with the increasing of oxidation temperature and time, the oxidation degrees of carbonate iron ore increase rapidly. After oxidizing at 773 K for 30 min, the oxidation degrees OX0, D, and y0 reach 97.36%, 99.12%, and 1.475, respectively. Besides, a porous structure forms with a large amount of cracks after oxidation which is beneficial to the gas diffusion. Then both the oxidation and the decomposition of carbonate iron ore are enhanced consequently. And the main phase and structure transformation of carbonate iron ore during the preoxidation is proceeded as follow as FeCO3 (rhombohedral crystal) → Fe3O4 (cubic crystal) → γ‐Fe2O3 (cubic crystal) → α‐Fe2O3 (rhombohedral crystal). Moreover, the nearest mechanism for carbonate iron ore decomposition within 650–950 K is F1 model, which is random nucleation and subsequent growth. And the values of activation energy and pre‐exponential factor are 220.64 kJ mol−1 and 1.510 × 1014 min−1, respectively.
The Proyecto Costa Escondida: Recent interdisciplinary research in search of freshwater along the North Coast of Quintana Roo, Mexico
Authors: Beddows Patricia A. , Glover Jeffrey B. , Rissolo Dominique , Carter Alice M. , Jaijel Roy , Smith Derek M. , Goodman‐Tchernov Beverly
Published: July 2016

Access to potable water has always been a major concern for human settlement, and this is particularly acute in coastal areas where freshwater can be compromised by saline marine waters. The northeast portion of Mexico's Yucatan Peninsula has a massive freshwater aquifer that today supports the international tourist destinations of Cancun and the Riviera Maya. However, access to this aquifer in pre‐Columbian times was restricted to natural features, such as cenotes (limestone sinkholes), aguadas (freshwater ponds), and coastal springs, or cultural features like wells, the viability of which is directly linked to sea level, which has risen over 2 m in the past 3000 years. In addition, ancient Maya inhabitants of the Yucatan collected rainwater in reservoirs, smaller‐scale cisterns called chultunes, or in ceramic pots. At the coastal site of Vista Alegre, located on the north coast of the Peninsula, there is limited evidence of potable water collection strategies, which has led members of the Proyecto Costa Escondida to critically examine how the freshwater access at the site changed over the past three millennia. To do this, the interdisciplinary research team has conducted (1) a physico‐chemical characterization of accessible surface and groundwater using a calibrated multiparameter probe, (2) a multiproxy study (i.e., micropaleontology, oxygen isotopic analysis) from 12 manual push cores taken in the waters surrounding Vista Alegre, and (3) an archaeological investigation. We hope our project serves as a model for future projects that strive to understand the complex and dynamic relationships between past peoples and their coastlines. WIREs Water 2016, 3:749–761. doi: 10.1002/wat2.1161

This article is categorized under:

Engineering Water > Planning Water

Science of Water > Water and Environmental Change

Human Water > Water Governance
On the performance of interference cancelation in D2D‐enabled cellular networks
Authors: Ma Chuan , Wu Weijie , Cui Ying , Wang Xinbing
Published: July 2016

Device‐to‐device (D2D) communication underlaying cellular networks is a promising technology to improve network resource utilization. In D2D‐enabled cellular networks, interference among spectrum‐sharing links is severer than that in traditional cellular networks, which motivates the adoption of interference cancelation (IC) techniques at the receivers. However, to date, how IC can affect the performance of D2D‐enabled cellular networks is still unknown. In this paper, we present an analytical framework for studying the performance of two IC methods, that is, unconditional IC and successive IC, in large‐scale D2D‐enabled cellular networks using the tools from stochastic geometry. To facilitate the interference analysis, we propose an approach of stochastic equivalence of the interference, which converts the two‐tier interference (interference from the cellular tier and D2D tier) to an equivalent single‐tier interference. Based on the proposed stochastic equivalence models, we derive the general expressions for the successful transmission probabilities of both cellular uplinks and D2D links in the networks where unconditional IC and successive IC are respectively applied. We demonstrate how these IC methods affect the network performance using both analytical and numerical results. Copyright © 2016 John Wiley & Sons, Ltd.
Adaptive channel selection and slot length configuration in cognitive radio
Authors: Fan Rongfei , An Jianping , Jiang Hai , Bu Xiangyuan
Published: July 2016

This paper investigates the channel selection and slot time configuration in a cognitive radio network with a number of potential channels. Each channel alternates between ON state (i.e., the primary user is using the channel) and OFF state (i.e., the primary user does not use the channel), and the state evolution process is modeled as a continuous‐time Markov process. The traffic parameters (the transition rates) of the Markov process also evolve with time, modeled as a discrete‐time Markov process. A secondary user adopts a slotted structure with dynamic slot length. At each slot, the secondary user needs to determine which channel to sense and, if the channel is sensed idle, how long the slot length should be. Considering both the amount of data that the secondary user can transmit and the duration when the secondary user interferes with primary activities, a reward definition is given. Based on the reward definition, an adaptive channel selection and slot length configuration method is proposed, which includes a reward maximization procedure to maximize the achieved reward and an update procedure for the channel state belief vector and traffic parameter state belief vector. Numerical results are given to demonstrate the effectiveness and features of the proposed method. Copyright © 2016 John Wiley & Sons, Ltd.
Lipid Composition and Antioxidant Capacity Evaluation in Tilapia Fillets Supplemented with a Blend of Oils and Vitamin E
Authors: Carbonera Fabiana , Montanher Paula Fernandes , Figueiredo Ingrid Lima , Bonafé Elton Guntendorfer , Santos Júnior Oscar Oliveira , Sargi Sheisa Cyléia , Gonçalves Renata Menoci , Matsushita Makoto , Visentainer Jesuí Vergílio
Published: July 2016

Since the nutritional value of farm‐raised fish fillets is directly related to the diet provided, we supplemented the diet of Tilapia (Oreochromis niloticus) with a blend of chia (Salvia hispanicaL.) oil, tung (Aleurites fordii) oil, and conjugated linoleic acid (CLA) to evaluate the effects on the fatty acid composition. Vitamin E was also added to the diet to improve the antioxidant capacity of tilapia fillets. We observed an increase in α‐linolenic acid content (from 6.56 to 19.03 mg g−1of total lipids), as well as the incorporation of CLA and conjugated linolenic acid (CLnA) isomers in the fillets. The addition of vitamin E resulted in the antioxidant capacity improvement of the fillets and higher values were found after 15 feeding days (39.25 µmol TE g−1in the Ferric Reducing Ability Power assay). Supplementation proved to be an excellent tool to improve the nutritional value of fish fillets.
Health-related quality of life of medical students in a Brazilian student loan programme
Authors: Lins Liliane , Carvalho Fernando Martins , Menezes Marta Silva , Porto-Silva Larissa , Damasceno Hannah
Published: July 2016

This study aimed to evaluate the health-related quality of life of medical students participating in a large Brazilian government loan programme for undergraduate students in private schools.

A cross-sectional study in a stratified sample of students from a private medical school in Salvador, Brazil, evaluated their health-related quality of life by using a Brazilian Portuguese version of the 36-item Short Form Health Survey questionnaire (SF-36).

Students supported by the loan programme consistently presented lower mean scores in all SF-36 domains and in the physical and mental component summary scores than those who were not in the programme. Students supported by the loan programme presented systematically lower physical and mental component mean scores, after stratification by age, gender, school year, physical activity, sleepiness, headache, having a car, having a housemaid, living with family, and living in a rented house.

The loan programme has enabled less wealthy undergraduate students to attend private medical schools in Brazil. However, this support is insufficient to improve students’ health-related quality of life during medical school, as compared with students who do not participate in the programme. Because of a poorer health-related quality of life, students supported by the loan programme deserve special attention from private medical schools.
Liquid water storage in snow and ice in 86 Eastern Alpine basins and its changes from 1970–97 to 1998–2006
Authors: Kuhn Michael , Helfricht Kay , Ortner Martin , Landmann Johannes , Gurgiser Wolfgang
Published: July 2016

The retention and release of liquid water in glacierized basins was modelled with a conceptual, semi-distributed model of the water and ice balance designed for long-term averages with monthly resolution for 100 m elevation bands. Here we present the components of the liquid water balance of 86 mostly glacierized basins on either side of the main Alpine divide between 10 and 13°E in the period 1998–2006 and compare them with the records of 30 basins monitored from 1970 to 1997. Basin average of liquid water retention has maxima in excess of 100 mm per month in May, often followed by maximum release when the retaining snow matrix melts. Glacier storage peaks in August partly due to ice melt and the ensuing filling of the englacial reservoirs and partly on account of a precipitation maximum. These two components combined to a common maximum of storage in summer in the first period 1970–97 and developed two distinct maxima in the warmer period 1998–2006. A further maximum of liquid water storage that was often found in October is most likely due to a peak in precipitation in the southern part of the study region.
Arizona Radiocarbon Dates VI
Authors: Haynes C. Vance , Damon Paul E. , Grey Donald C.
Published: July 2016

The C14measurements reported here were made in this laboratory between November 1, 1963 and November 15, 1965. Sample descriptions are classified as follows:

I.

Geochemical Samples

II.

Geologic-Paleoclimatic Samples

III.

Early Man-Alluvial Stratigraphy Samples

IV.

Archaeologic Samples
Bern Radiocarbon Dates V
Authors: Oeschger H. , Riesen T.
Published: July 2016

This list includes about half of the samples measured during the last year. Many studies need further investigation and the results will be published later when additional information will make better interpretations possible.

The equipment and the technique is essentially the same as described earlier (Bern IV).

Reliable results on CO2 samples extracted out of ice are obtained with the small counter mentioned in Bern IV.

Our laboratory is financed by the Schweizerischer Nationalfonds. The authors wish to thank H. Loosli and P. Horisberger for their assistance in the measurements of part of the samples. They also thank M. Welten and H.-G. Bandi for their help in selecting and discussing the samples.
Gakushuin Natural Radiocarbon Measurements V
Authors: Kigoshi Kunihiko , Kobayashi Hiromi
Published: July 2016

This list includes many of the datings done from September 1964 to October 1965. The instruments and techniques used for this work are essentially the same as those used previously (Gakushuin III). Bone samples were dated on the organic materials obtained by the following procedure. After washing with distilled water the powdered bone samples were boiled with 10% H2SO4 solution 10 to 40 hours. The extract, a clear solution, was exaporated to almost dryness, and, after concentrated H2SO4 was added, heating was continued until most of the organic compounds became insoluble carbonized or polymerized material. The black residue was washed in water and treated as the usual charcoal sample for dating.
Monaco Radiocarbon Measurements II
Authors: Thommeret J. , Thommeret Y.
Published: July 2016

This series reports some of the measurements made since publication of the previous list. Chemical preparation of samples is basically the same as described in Monaco I.

The counting electronics of the proportional counter has been entirely rebuilt by J. Galliot and P. Albertinoli of C.S.M. The new device is transistorized and battery-operated. At regular intervals of time, usually 10 min, the count (anti-coincidence channel) is printed in tape. Large deviations from the mean are easily visible and can lead to rejection of the measurement if the distribution is not normal, i.e. does not fit a straight line on Gaussian paper.
National Physical Laboratory Radiocarbon Measurements IV
Authors: Callow W. J. , Baker M. J. , Hassall Geraldine I.
Published: July 2016

The following list comprises measurements made since those reported in NPL III and is complete to the end of November 1965.

Ages are relative to A.D. 1950 and are calculated using a half-life of 5568 yr. The measurements, corrected for fractionation (quoted δC13values are relative to the P.D.B. standard), are referred to 0.950 times the activity of the NBS oxalic acid as contemporary reference standard. The quoted uncertainty is one standard deviation derived from a proper combination of the parameter variances as described in detail in NPL III. These variances are those of the standard and background measurements over a rolling twenty week period, of the sample δC14and δC13measurements and of the de Vries effect (assumed to add an additional uncertainty equivalent to a standard deviation of 80 yr). Any uncertainty in the half-life has been excluded so that relative C14ages may be correctly compared. Absolute age assessments, however, should be made using the accepted best value for the half-life and the appropriate uncertainty then included. If the net sample count rate is less than 4 times the standard error of the difference between the sample and background count rates, a lower limit to the age is reported corresponding to a net sample count rate of 4 times the standard error of this difference.
Rhodesian Radiocarbon Measurements II
Authors: Sheppard J. G. , Swart E. R.
Published: July 2016

The following is a list of dates which has been obtained since the compilation of List I in December 1963. Owing to an irreparable leak in our original counter, it became necessary to replace it with a new counter of similar design using the same shield as before. The new counter has been operated both at 500 mm Hg pressure, where it has a background of 1.7 counts/min and an NBS oxalic count of 11.4 counts/min, and at 1000 mm Hg pressure, where it has a background of 2.5 counts/min and an NBS oxalic count of 22 counts/min.
University of Texas Radiocarbon Dates IV
Authors: Pearson F. J. , Davis E. Mott , Tamers M. A.
Published: July 2016

This list reports routine measurements made at this laboratory since the preparation of the last list (Texas III). It also includes measurements made on bone samples earlier as part of a study of the suitability of bone for C14 dating (Tamers and Pearson, 1965). In the absence of the laboratory director, M. A. Tamers, who has been on leave at the Caracas (IVIC) laboratory since October, 1963, laboratory operation and the selection and description of geologic samples have been handled by Pearson, and laboratory administration and archaeologic samples by Davis.
Florida State University Radiocarbon Dates II
Authors: Knauer G. A. , Martin J. R. , Goodell H. G. , Phelps D. S.
Published: July 2016

This list is a compilation of samples dated since September, 1965. It includes a continuation of several series begun in FSU I as well as new series undertaken since that time.
Geological Survey of Canada Radiocarbon Dates VI
Authors: Lowdon J. A. , Fyles J. G. , Blake W.
Published: July 2016

Both the 2-L counter, described in GSC I, and the 5-L counter (GSC IV) were operated routinely during the past year. Approximately half of the determinations reported here were obtained from each counter. The 5-L counter was operated mainly at 1 atm.
Instituto Venezolano de Investigaciones Cientificas Natural Radiocarbon Measurements III
Authors: Tamers M. A.
Published: July 2016

The dates reported here represent a portion of those determined in 1966, The Radiocarbon Dating Laboratory of the Instituto Venezolano de Investigaciones Científicas carries out a synthesis of benzene for each sample and detects the activity with a liquid scintillation spectrometer. For routine measurements, 3 cc synthesized benzene and 1 cc commercial toluene, with PPO and dimethyl-POPOP scintillators, are used in a special small counting vial. The modern standard is 95% of the NBS oxalic acid, which gives a net modern count rate of 23.9 cpm. The background is now 8.5 cpm.
Smithsonian Institution Radiocarbon Measurements IV
Authors: Long Austin , Mielke James E.
Published: July 2016

Most of these analyses we obtained during 1966 with equipment and techniques previously employed. Methane from the higher numbered samples was produced in a bomb reactor at pressures up to 1000 psi. Also, many smaller samples were counted in a 700-ml vol counter at 2 atm pressure, which has a background of 1.76 = .02 counts/min.
Stockholm Natural Radiocarbon Measurements VII
Authors: Engstrand Lars G.
Published: July 2016

This paper is a direct continuation of Stockholm VI. The bone samples analyzed and published in this list are treated according to a method, modified (Sellstedt, Engstrand and Gejvall, 1966) and described by Berger, Horney and Libby (1964).
University of Wisconsin Radiocarbon Dates III
Authors: Bender Margaret M. , Bryson Reid A. , Baerreis David A.
Published: July 2016

This report summarizes the radiocarbon dates obtained at the University of Wisconsin since November, 1965; the procedures followed and equipment used have been described previously (Wisconsin II).

The dates reported have been calculated on the assumption of a half-life of 5568 yr for C14, 1950 as the reference year. Samples have normally been run at 3 atm pressure for a minimum of 15,000 counts. The standard deviation quoted includes only the 1σ of the counting statistics of background, sample, and standard counts.
Radiocarbon, Ltd. Natural Radiocarbon Measurements I
Authors: Tucek Charles S.
Published: July 2016

Radiocarbon, Ltd. is a privately owned laboratory designed to provide quality service to the archaeologic and geologic communities. Operations began in 1969 using standard techniques for preparation, conversion to CO2, and purification of samples prior to counting. A sample is counted as CO2 in each of two identical proportional counters of volume 2.2 L, built on the design of östlund and Engstrand (1963); each counter has its own multi-anode guard ring, and is housed in a common shield of iron 8 in. thick.
Algiers Radiocarbon Measurements II
Authors: Rahmouni O. , Roussillot C. , Armanet F.
Published: July 2016

The following series of dates contains most of the measurements obtained since our last list. Procedures of measurements and calculation are as previously described (R., 1970, v. 12, p. 353–357).
University of Bonn Natural Radiocarbon Measurements VI
Authors: Scharpenseel H. W. , Pietig F.
Published: July 2016

Continuation of radiocarbon measurements, mainly on ground water, soil, and subhydric sediment samples. Sample preparation was described earlier (Scharpenseel and Pietig, 1969).
Smithsonian Institution Radiocarbon Measurements VIII
Authors: Stuckenrath Robert , Mielke James E.
Published: July 2016

This list includes samples completed to July, 1972. All samples are counted for at least 2500 min., and X2 analyses are made on 100-min. print-outs. Errors quoted are 1σ, derived from sample, background, and NBS oxalic acid standard measurements, adjusted where appropriate for small-sample dilution.
Gif Natural Radiocarbon Measurements VIII
Authors: Delibrias G , Guillier M T , Labeyrie J
Published: July 2016

The following date list consists of samples prepared mainly during 1970 and 1971. Some old measurements, not included in previous lists are added. Ages reported here are calculated using the conventional half-life of 14C: 5568 years and NBS oxalic acid as recent standard.
University of Georgia Radiocarbon Dates III
Authors: Noakes John E , Brandau Betty Lee
Published: July 2016

The following list of dates is of archaeologic samples submitted in 1971–2, using the counting equipment described in R, 1971, v 13, p 468. Ages are quoted with a 1σ counting error which includes statistical variation of the sample, background, and standard count. The reference year is ad 1950 and 0.95% NBS oxalic acid for 14C dating is the standard. The half-life used is 5570 years.
Scottish Universities Research and Reactor Centre Radiocarbon Measurements II
Authors: Harkness D D , Wilson H W
Published: July 2016

Preparation of samples, operation of counting systems, and calculation of results remain as described previously (Harkness and Wilson, 1973).
University of Cambridge Natural Radiocarbon Measurements XIII
Authors: Switsur V R , West R G
Published: July 2016

The dates presented here were calculated from measurements made at the University Radiocarbon Dating Research Laboratory mostly during 1973–74. The radioactivity of the samples was counted in gas proportional detectors, either silica lined (de Vrieset al, 1959) or of pure copper, filled to 2 atmospheres pressure with pure carbon dioxide. The detectors were fixed in, and completely surrounded by, a plastic scintillator anticoincidence shield mounted inside a massive lead shield to protect against environmental radiation (Switsur, Hall and West, 1970). Modern sample gas was obtained from the combustion of ad 1845 to 1855 rings of an oak tree grown near Cambridge and felled in 1950. Background samples were prepared from Welsh anthracite. The contemporary sample was frequently compared with the activity of the NBS oxalic acid international standard. Age calculations were based on the14C half-life of 5568 years and the uncertainty stated as one standard deviation calculated from the statistical analyses of sample and standards counting rates.
Antwerp University Radiocarbon Dates I
Authors: Vanhoorne R , Van Dongen W
Published: July 2016

The radiocarbon dating laboratory was set up during 1972 and 1973 with financial support of the FKFO (Fonds voor Kollektief Fundamenteel Onderzoek) Belgium, to enable us to place Upper Pleistocene and Holocene sediments in their correct stratigraphic position. Dating of samples began in the middle of 1974.
Isotopes' Radiocarbon Measurements XI
Authors: Buckley James
Published: July 2016

This date list includes samples dated from 1968 through 1972. The method of analysis is described in R, 1968, v 10, p 246 and 1970, v 12, p 87. The ages are calculated with the 5568 year half-life without application of any corrections. The NBS oxalic acid standard is used as the modern reference. Errors (± 1 σ) include standard deviations for sample counts, background and modern standard.
University of Miami Radiocarbon Dates VI
Authors: Stipp J J , Eldridge K L , Cadwell R
Published: July 2016

The following radiocarbon measurements are a partial list of projects and samples dated since the Spring of 1975. The technique used is liquid scintillation counting of wholly synthesized benzene as indicated in R, v 16, p 402-408. The intermediate chemical step of converting CO2 to Li2C2 has been modified so that the CO2 is reacted with the lithium metal at a temperature of 950° to 1000°C instead of the 600°C as formerly done (Tamers, 1975). This modification has had the effect of reducing occasional variable losses in conversion yields in this step, and reducing the reaction time required from 30 min to 10 min for a typical ¼ mole sample. Dates are calculated using a 14C half-life of 5568 yr and errors are reported as one standard deviation. No other correction factors are applied.
Hamburg University Radiocarbon Dates I
Authors: Scharpenseel H W , Pietig F , Schiffmann H
Published: July 2016

Radiocarbon measurements are carried out mainly on soil samples and soil organic matter fractions. Benzene samples are prepared as described earlier (Scharpenseel and Pietig, 1969; 1970). Radioactivity is measured in a single quartz vial, using a Packard Tri Carb Model 3075 as well as a Berthold Betascint BF 5000. Most equipment has been transferred from Bonn University Radiocarbon Dating Lab to Hamburg, where operation of former Bonn Radiocarbon Lab will be continued.
Queens College Radiocarbon Measurements II
Authors: Pardi R
Published: July 2016

This list contains all analysis completed since the first list (R, 1975 v 18, p 205).
La Jolla Measurements of Radiocarbon in Tree-Ring Dated Wood
Authors: Suess H E
Published: July 2016

In 1969, at the Nobel Symposium on “Radiocarbon Variations and Absolute Chronology” in Uppsala, a curve was presented that illustrated the functional dependence of measured conventional radiocarbon dates on true historical ages of wood samples (Suess, 1971). The curve was derived from the results of La Jolla measurements of radiocarbon in bristlecone pine wood dendrochronologically dated by and obtained from Professor C W Ferguson of the University of Arizona (Ferguson, 1968). The curve was intended to be adequate for deriving calibrated radiocarbon dates and also for allowing fairly reliable estimates of the accuracy of the absolute dates obtained in this manner. The basis for the validity of this calibration is the well known fact that, for all practical purposes, wood samples that had grown at the same time show the same radiocarbon content. However, the reverse is not always true: Wood samples showing the same radiocarbon content do not necessarily have the same age because of the windings and steps of the curve (Stuiver and Suess, 1966).
Lyon Natural Radiocarbon Measurements VII
Authors: Evin J , Marien G , Pachiaudi Ch
Published: July 2016

This list includes most of the measurements made in 1975 and 1976. Results lower than Ly-1000 are old measurements obtained with counters previously described, especially in R, 1973, v 15, p 134, when the laboratory was in the basement of the Nuclear Physics Institute. At the end of 1974 all the apparatus was transferred to a specially designed building with an isolated counting room overlain by 4m non-radioactive earth.
University of Rome Carbon-14 Dates XVI
Authors: Alessio M , Allegri L , Bella F , Improta S , Belluomini G , Calderoni G , Cortesi C , Manfra L , Turi B
Published: July 2016

This list includes dates measured from July 1975 to December 1976 with CO2 proportional counters. All archaeologic and geologic samples except for Turkey and Sistan series come from Italian territory. Laboratory equipment, largely unchanged but expanded and technically improved, has been previously described (Alessio et al, 1970b, 1976).
Arizona Radiocarbon Dates Ix: Carbon Isotope Dating of Packrat Middens
Authors: Mead Jim I , Thompson Robert S , Long Austin
Published: July 2016

The carbon isotope analyses reported here include all radiocarbon dates run on packrat middens in the United States and Mexico by the Arizona radiocarbon laboratory through October 1977. All samples described below report dates by CO2 (0.5 or 2.0L) counting. Age calculations are based on a 14C half-life of 5568 years, using 0.949 NBS oxalic acid as the modern value. Errors, based on counting statistics, are quoted to ± 1δ; infinite ages quoted to — 2δ.
Antwerp University Radiocarbon Dates III
Authors: Vanhoorne R , Van Strydonck M , Dubois A D
Published: July 2016

The following list contains most of the measurements made during 1977, since our last list (R, 1977, v 19, p 383-388). The laboratory procedures used were those outlined in the previous date lists (R, 1976, v 18, p 151-160; R, 1977, op cit). Dates are calculated using 14C half-life of 5568 yr and errors are reported as one-standard deviation. The collagen extraction follows Longin (1970).
Physical Research Laboratory Radiocarbon Date List III
Authors: Agrawal D P , Krishnamurthy R V , Kusumgar Sheela , Pant R K
Published: July 2016

Presented below are dates from some important archaeologic and Quaternary sites. All dates are based on τ ½ = 5568 yr; to convert the radiocarbon dates for archaeologic samples into ad/bc scale, 1950 has been used as base as per the resolution passed at the Ninth International Radiocarbon Conference, San Diego, 1976. The dates are not corrected for 13C fractionation. All the dates older than 10,000 yr have been given with 2σ errors. Due to uncertainty about the contribution of the biogenic carbon in caliche (CaCO3) samples, the dates represent apparent and not true ages.
Design, Construction and Calibration of A High Accuracy Carbon-14 Counting Set up
Authors: Tans P P , Mook W G
Published: July 2016

The construction and performance of a proportional CO2counter system is described by which an over-all accuracy is obtained of 1.3‰ after a two-day counting period.
Sydney University Natural Radiocarbon Measurements V
Authors: Gillespie R , Temple R B
Published: July 2016

Experimental procedures and methods of age calculation are as previously described (Gillespie Sc Temple, 1976), except that bc/ad ages are not reported (resolution of 9th Radiocarbon Conference, 1976).
Vienna Radium Institute Radiocarbon Dates VIII
Authors: Felber Heinz
Published: July 2016

Measurements have continued with the same proportional counter system, pretreatment procedure, methane preparation and measurement, and calculation, as described previously (R, 1970, v 12, p 298-318). Uncertainties quoted are single standard deviations originating from standard, sample, background counting rates and half-life. No 13C/12C ratios were measured.
University of Wisconsin Radiocarbon Dates XVI
Authors: Bender Margaret M , Baerreis David A , Bryson Reid A
Published: July 2016

Procedures and equipment have been described in previous date lists. Except as otherwise indicated, wood, charcoal and peat samples are pretreated with dilute NaOH and dilute H3PO4 before conversion to the counting gas methane; marls and lake cores are treated with acid only. Very calcareous materials are treated with HCl instead of H3PO4.
Institut Royal Du Patrimoine Artistique Radiocarbon Dates VI
Authors: Dauchot-Dehon M , Heylen J
Published: July 2016

This list includes results of measurements made during 1974-1978. When requested, MASCA corrected dates (Ralph et al, 1973) are reported.
University of Texas At Austin Radiocarbon Dates XIII
Authors: Valastro S , Davis E Mott , Varela Alejandra G
Published: July 2016

This list reports certain 14C measurements completed by November 1978; other projects completed by this time will be reported later. Age calculations are based on 14C half-life of 5568yr and modern standard of 95% NBS oxalic acid, supplemented by tree rings of pre-industrial wood from a log cut in the 1850's (Tx-540; R, 1970, v 12, p 249). Deviations reported are based on counting statistics of sample, background and modern, and are ± 1σ, except that when sample count approaches either modern or background, 2σ limits are reported. Unless noted, 12C/13C measurements were not made and results are not corrected for 13C fractionation (assumed ratio = −25‰ WRT PDB). Our laboratory uses liquid scintillation counting of benzene, with Li2C2 and vanadium-activated catalyst in preparation; chemical yields range between 95% and 99%. Three counters are employed; a Packard Tri-Carb Model 3002 and 2 Beckman LS320 spectrometers obtained through a grant from the National Science Foundation.
University of Miami Radiocarbon Dates XVII
Authors: Johnson R , Introne D S , Mattes J , Stipp J J
Published: July 2016

The following radiocarbon dates are a partial list of samples measured for a variety of projects and materials since April 1979. Chemical and counting procedures remain the same as indicated in R, v 20, p 274-282.
British Museum Natural Radiocarbon Measurements XIII
Authors: Burleigh Richard , Matthews Keith
Published: July 2016

The following list consists of dates for archaeologic samples mostly measured from July 1976 to December 1977. The dates were obtained by liquid scintillation counting of benzene using the laboratory procedures outlined in previous lists (see, eg, BM-VIII, R, 1976, v 18, p 16). Dates are expressed in radiocarbon years relative to ad 1950 based on the Libby half-life for 14C of 5570 yr, and are corrected for isotopic fractionation (δ13C values are relative to PDB). No corrections have been made for natural 14C variations (although in some instances approximate calibrated dates taken from the tables of R M Clark (1975) have been given in the comments where this aids interpretation of results). The modern reference standard is NBS oxalic acid (SRM 4990). Errors quoted with the dates are based on counting statistics alone and are equivalent to ± 1 standard deviation (± 1σ), Dates in this and the next list (BM-XIV) reported to submitters or published elsewhere before the introduction of the new guidelines for rounding of computed figures have deliberately been left unrounded. From BM-XV onwards all BM dates will be rounded before publication in conformity with the recently recommended procedures (R, 1977, v 19, p 362). Descriptions, comments, and references to publications are based on information supplied by submitters.
Udine Radiocarbon Laboratory Date List I
Authors: Barbina Valerio , Calligaris Franco , del Fabbro Adriano , Turello Alessandro , Ciuti Piero
Published: July 2016

The radiocarbon laboratory of the Center of Applied Research and Documentation of Udine (CRAD), became operative early in 1977 and uses a benzene liquid scintillation counting method. Benzene is prepared as outlined by Legers and Tamers (1963), Noakes, Kim, and Akers (1967), Belluomini et al (1978). The procedure of chemical synthesis is detailed in CRAD (1977).
University of Granada Radiocarbon Dates I
Authors: González-Gómez Cecilio , de D López-González Juan , Domingo-García María
Published: July 2016

The Radiocarbon Dating Laboratory of The Granada University was established to support the work of archaeologists and geologists. The method of dating is benzene synthesis and liquid scintillation counting developed by a number of investigators (Polach and Stipp, 1967; Tamers, 1969; Pietig and Scharpenseel, 1966) with sample combustion in pure oxygen (Switsur, 1974).
Vienna Radium Institute Radiocarbon Dates XII
Authors: Felber Heinz
Published: July 2016

Measurements have continued with the same proportional counter system, pretreatment procedure, methane preparation and measurement, and calculation, as described previously (R, 1970, v 12, p 298–318). Uncertainties quoted are single standard deviations originating from standard, sample, and background counting rates. No 13C/12C ratios were measured. Sample descriptions have been prepared in cooperation with submitters.
British Museum Natural Radiocarbon Measurements XVI
Authors: Burleigh Richard , Ambers Janet , Matthews Keith
Published: July 2016

The following list consists of dates for archaeologic and geologic samples mostly measured from June 1981 to June 1982. The dates were obtained by liquid scintillation counting of benzene using the laboratory procedures outlined in previous lists (see, eg, BM-VIII, R, 1976, v 18, p 16). Dates are expressed in radiocarbon years relative to ad 1950 based on the Libby half-life for 14C of 5570 yr, and are corrected for isotopic fractionation (δ13C values are relative to PDB). No corrections have been made for natural 14C variations (although in some instances approximate calibrated dates taken from the tables of R M Clark (1975) have been given in the comments where this aids interpretation of results). The modern reference standard is NBS oxalic acid (SRM 4990). Errors quoted with dates are based on counting statistics alone and are equivalent to ± 1 standard deviation (± 1σ). Descriptions, comments, and references to publications are based on information supplied by submitters.
Short-Term Variations in Radiocarbon Concentration with the 11-Year Solar Cycle
Authors: Povinec Pavel , Burchuladze A A , Pagava S V
Published: July 2016

Previous investigations on short-term 14C variations in tree rings are compared with 14C measurements in wine samples. The comparison is made for 4 solar cycles (1903–1944) with the same method of statistical evaluation of measured results. The average amplitude of Δ14C variations as observed by various authors in tree-ring samples is ca 2 ± 1 ‰; however, wine samples show an average amplitude of 4.3 ± 1.6 ‰. The anticorrelation dependence of Δ14C on Wolf sunspot numbers was observed with a time shift between W maxima and Δ14C minima of 3–5 yr for different solar cycles.
On a 50-Year “Climate-Free” δ13C Record from Juniper Tree Rings
Authors: Leavitt Steven W , Long Austin
Published: July 2016

When used with 14C records, an accurate reconstruction of the 13C/12C changes of atmospheric CO2 may be a key constraint to determining the historic activity of the biosphere as CO2 source or sink. We recently detailed the derivation of an atmospheric δ13C record for 1930–1979 from Arizona juniper tree rings (Leavitt and Long, 1983). Each tree was close to a weather station, allowing us to account for the effects of climate on the tree-ring δ13C records. The resulting atmospheric δ13C trend shows an overall decrease of ca 1.3‰, but instead of decreasing exponentially over the whole 50-year period, the best-fit curve decreases exponentially to ca 1960 and then flattens out. The drop from 1956 to 1978 was ca 0.55‰, still very similar to the measured atmospheric drop over that period of 0.65 ± 0.13‰ (Keeling, Mook, and Tans, 1979).
A Contribution to the Interpretation of 14C Groundwater Ages Considering the Example of a Partially Confined Sandstone Aquifer
Authors: Eichinger Lorenz
Published: July 2016

Previously described models and a new model were compared to determine the initial 14C content of groundwater in a partially-confined and unconfined sandstone aquifer (Fränkisches Albvorland, Germany). Isotope and chemical data were derived from samples of water, soil-CO2, and solid carbonates. The various 14C models lead to important differences in resulting groundwater ages.

From the relationship between 14C and 2H or 18O concentrations of groundwater, it must be assumed that chemical and/or physical carbon isotope exchange between the DIC and the solid carbonate has occurred provided the groundwater with lower 18O and 2H concentrations was generated during the Pleistocene. Groundwater ages deduced from 14C and 39Ar concentrations showed discrepancies which can be explained if carbon isotope exchange between DIC and solid carbonate as well as mixing of recent and fossil waters is considered.
Radiocarbon Profiles of Rocky Islet, Xi-Sha Islands: Evidence of Recent Crustal Movements in the South China Sea
Authors: Yee-Chein Chen , Wen-Qiang Jiao
Published: July 2016

The Xi-Sha Islands comprise 35 coral reefs, cays, and islets lying to the northwest of the South China Sea. Since Miocene time, > 1200m of bioherms developed on slowly subsiding granite-gneiss bed rock. These sediments provide evidence for sea-level changes and crustal movements in the South China Sea.