bluuebunny/crossref_metadata_2025 huggingface dataset:
Do Managers Withhold Good News from Labor Unions?
Authors: Chung Richard , Lee Bryan Byung-Hee , Lee Woo-Jong , Sohn Byungcherl Charlie
Published: February 2015

With scarce empirical support, prior literature argues that managers tend to withhold good news and promote bad news to preserve their bargaining power against labor unions. This paper provides empirical evidence of this rarely supported argument. Using comprehensive firm-level data from South Korea, where labor unions have a long tradition of making credible threats, we find that overall disclosure frequency is negatively related to labor union strength, and that this relation is more pronounced in firms with good news. We also find that firms with strong labor unions withhold good news during the labor negotiation period and release it in a gradual fashion afterward and that this pattern is more prominent than that of firms with weak or no unions, implying that managers time news disclosures according to bargaining schedules to achieve better outcomes in labor negotiations. These results are robust to various sensitivity tests.

Data, as supplemental material, are available at http://dx.doi.org/10.1287/mnsc.2014.2075 .

This paper was accepted by Mary Barth, accounting.
Inventory Control in a Spare Parts Distribution System with Emergency Stocks and Pipeline Information
Authors: Howard Christian , Marklund Johan , Tan Tarkan , Reijnen Ingrid
Published: February 2015

Motivated by collaboration with a global spare parts service provider, we consider a two-echelon inventory system with multiple local warehouses, a so-called support warehouse, and a central warehouse with ample capacity. In case of stock-outs, the local warehouses can receive emergency shipments from the support warehouse or the central warehouse at an extra cost. Our focus is on using information on orders in the replenishment pipeline, i.e., pipeline information, to achieve cost-efficient policies for requesting emergency shipments. We introduce a policy where the request for an emergency shipment is based on the time until an outstanding order will reach the stock point considered. The goal is to determine how long one should wait for stock in the replenishment pipeline before requesting an emergency shipment, and the cost effects of using pipeline information in this manner. The analysis utilizes results from queuing theory and provides a decomposition technique for optimizing the policy parameters that reduces the complex multiechelon problem to more manageable single-echelon problems. The performance of our policy indicates that there can be a significant benefit in using pipeline information.
Production Smoothing and the Bullwhip Effect
Authors: Bray Robert L. , Mendelson Haim
Published: February 2015

The bullwhip effect and production smoothing appear antithetical because their empirical tests oppose one another: production variability exceeding sales variability for bullwhip, and vice versa for smoothing. But this is a false dichotomy. We distinguish between the phenomena with a new production smoothing measure, which estimates how much more variable production would be absent production volatility costs. We apply our metric to an automotive manufacturing sample comprising 162 car models and find 75% smooth production by at least 5%, despite the fact that 99% exhibit the bullwhip effect. Indeed, we estimate both a strong bullwhip (on average, production is 220% as variable as sales) and robust smoothing (on average, production would be 22% more variable without deliberate stabilization). We find firms smooth both production variability and production uncertainty. We measure production smoothing with a structural econometric production scheduling model, based on the generalized order-up-to policy.
Women and men's awareness of obstetric fistula in facilities in Kisii and Nyamira Counties, Kenya
Authors: Omari Jerusa , Wakasiaka Sabina , Khisa Weston , Omoni Grace , Lavender Tina
Published: February 2015

Background:

Obstetric fistula has been defined as an ‘abnormal communication’ between the vagina and the bladder or rectum of a woman which results in continuous leakage of urine and/or faeces. The most common cause of obstetric fistula is obstetric trauma. Obstetric fistula is a highly stigmatising condition; often the women are neglected and or ostracised.

Aim:

To establish the knowledge and awareness of fistula among men and women living in an area where fistula prevalence is rising.

Methods:

In this cross-sectional study, women and their partners were recruited purposefully in two counties Kenya: Nyamira and Kisii and interviewed using structured interviews. Data were cleaned and entered into Excel. SPSS was used for descriptive data analysis. Chi2 test was conducted to compare responses according to gender and level of education.

Results:

Three hundred participants (253 women and 47 men) were interviewed over a 3-month period. Responses from women and men were similar. Few (32%) participants reported having seen a woman with fistula in their community. Just over half (53%) said that they knew what causes fistula, of which 89% said they knew that fistula could be treated. Only 27% said that the health care provider mentioned fistula during health education talks. Participants educated to a level above secondary school were more knowledgeable about fistula.

Conclusion:

Fistula information is lacking among community members. There is a need to scale up training and community awareness campaigns to help eradicate fistula from Kenya.
An observational study of midwives' practices to prevent peripartum sepsis in Zimbabwe
Authors: Danda Grace , Dube Kushupika , Dube Peggy , Mudokwenyu-Rawdon Christina , Bedwell Carol
Published: February 2015

This study investigated the availability of infection control policies and/or guidelines while observing midwives' practices in relation to peripartum sepsis prevention. A participant observational study collected data, in May and June 2014, by means of checklists from 37 purposively selected midwives working in the labour and postnatal wards of two central hospitals in Zimbabwe. Descriptive statistics and SPSS version 20 were used during data analysis. The results indicate lack of resources necessary for good midwifery practice and poor standards of infection control among midwives. Strengthening infection control policies and practices, ensuring resource equitable distribution and training of midwives in peripartum sepsis prevention are essential interventions.
A Delphi survey to determine midwifery research priorities among midwives in sub-Saharan Africa
Authors: Maimbolwa Margaret , Omoni Grace , Mwebaza Enid , Chimwaza Angela , Laisser Rose , Mudokwenyu-Rawdon Christina , Bedwell Carol , Smyth Rebecca , Wakasiaka Sabina , Lavender Tina
Published: February 2015

Objective:

In sub-Saharan Africa, midwifery input into the generation of important research questions is limited. The authors aimed to address this issue by enabling midwives to set their own research priorities with the intention of developing a research strategy to conduct studies relevant to clinical practice.

Methods:

A survey was carried out in six countries (Kenya, Malawi, Uganda, Zambia, Zimbabwe and Tanzania). The Delphi method was used with six panels of midwives (n=118) to attain a convergence of opinion on midwifery research priorities. Consensus-building was achieved by using a series of questionnaires delivered using multiple iterations to collect data. Data were analysed using ranked means and proportions.

Findings:

Consensus was reached on 11 research questions which were considered regional priorities. These covered three key areas: midwifery training, clinical care and organisational issues. Conclusions: Midwives prioritised areas of research that had direct applicability to their own practice. All questions were at the applied end of the research spectrum. Priorities tended to cover broad areas within reproductive health, as opposed to being disease-focused. This is likely to reflect the desire to provide quality care that embraces the social aspects of health. Some of these research priorities are being taken forward by midwives in the group.
Recognition, diagnosis, and management of gastro-oesophageal reflux disease in children and young people
Authors: Russell Rachel
Published: February 2015

The recent draft National Institute for Health and Care Excellence (NICE) guidelines in this area have prompted health professionals to look at current management strategies and ensure that best practice, based on current evidence, is being followed. This article distinguishes between gastro-oesophageal reflux (GOR) and gastro-oesophageal reflux disease (GORD), and discusses the symptoms, identifiable risk factors, and management strategies. The importance of reaching a diagnosis after a comprehensive history and physical assessment is considered, and the need for appropriate investigations on the basis of the findings of the evaluation is assessed. Treatment strategies are discussed and key priority areas for implementation from the guideline and key recommendations for future research are presented.
Noncompetitive Immunoassay Detection System for Haptens on the Basis of Antimetatype Antibodies
Authors: Omi Kazuya , Ando Tsuyoshi , Sakyu Takuya , Shirakawa Takashi , Uchida Yoshiaki , Oka Asako , Ise Nobuyuki , Aoyagi Katsumi , Goishi Katsutoshi
Published: February 2015

BACKGROUND

Small molecules classified as haptens are generally measured by competitive immunoassay, which is theoretically inferior to noncompetitive sandwich immunoassay in terms of sensitivity and specificity. We created a method for developing sandwich immunoassays to measure haptens on the basis of antimetatype antibodies.

METHODS

We generated antimetatype monoclonal antibodies against a hapten–antibody immunocomplex using an ex vivo antibody development system, the Autonomously Diversifying Library (ADLib) system. We selected 2 haptens, estradiol (E2) and 25-hydroxyvitamin D [25(OH)D], as analytes. Sandwich immunoassays for these 2 haptens were developed by use of a 96-well microtiter plate and a fully automated chemiluminescence analyzer, and the performances of these immunoassays were investigated.

RESULTS

The developed assays exhibited sensitivity high enough to detect target haptens in serum samples. The limit of detection of the ELISA for E2 was 3.13 pg/mL, and that of the fully automated chemiluminescent enzyme immunoassay (CLEIA) system was 2.1 ng/mL for 25(OH)D. The cross-reactivity with immunoreactive derivatives was effectively improved compared with the competitive assay. The CVs for the sandwich ELISA for E2 were 4.2%–12.6% (intraassay) and 6.2%–21.8% (total imprecision). The CVs for the sandwich CLEIA for 25(OH)D were 1.0%–2.3% (intraassay) and 1.9%–3.5% (total imprecision). In particular, the sandwich CLEIA for 25(OH)D showed correlations of r = 0.99 with both LC-MS/MS and a commercially available 125I RIA.

CONCLUSIONS

Our method represents a potentially simple and practical approach for routine assays of haptens, including vitamins, hormones, drugs, and toxins.
Online-consultation “scientific publication system”: documentation and main results
Authors: Taubert Niels , Schön Kevin
Published: February 2015

This short report provides a description of an online-consultation on the scientific publication system. German-speaking scientists from all disciplines were invited to articulate their perspectives on principles and current problems in scientific publishing in the dialogical procedure. 697 participants addressed their opinion in two areas of consultation (a) Consultation area “evaluate principles”: the goal in this section was to find out whether there is a general consensus throughout academia of what constitutes a good publication system. For this purpose, principles of a good scientific publication system could be commented on and evaluated with positive or negative votes. (b) Consultation area “name problems”: this section aimed at obtaining the perspective of the participants on current challenges and problems of the publication system. The contributions of the participants focus on eight topics: (1) printed vs. digital publication, (2) business models of large publishing houses, (3) open access, (4) publication-based performance indicators, (5) authorship, (6) peer review, (7) publication bias, and (8) research data.
Bandwidth and gain enhancement of RMPA using â€˜câ€™ shaped metamaterial at THz
Authors: Dawar Parul , De Asok
Published: February 2015

This paper elucidates antenna parameter optimization using C shaped metamaterial embedded in antenna substrate at high frequency (THz). Ansoft HFSS version 13 has been used to design and analyse the RMPA (Rectangular Microstrip Patch Antenna ) with design frequency 2.75 THz and operating range of 2.15 THzÂ  to 3.35 THz having FR4 (Îµr = 4.4) as substrate material . Nicolson Ross Wier (NRW) method has been used to retrieve the material parameters from transmission and reflection coefficient. . Results were compared with MATLAB programming based on CAD formulas using equivalent circuit analysis of patch antenna. Finally, antenna parameters such as gain, bandwidth, and radiation pattern are investigated and presented in tables and response-graphs. The unique shape proposed in this paper, gives remarkable enhancement in bandwidth and antenna gain.
Solving optimization problems using black hole algorithm
Authors: Farahmandian Masoum , Hatamlou Abdolreza
Published: February 2015

Various meta-heuristic optimization approaches have been recently created and applied in different areas. Many of these approaches are inspired by swarm behaviors in the nature. This paper studies the solving optimization problems using Black Hole Algorithm (BHA) which is a population-based algorithm. Since the performance of this algorithm was not tested in mathematical functions, we have studied this issue using some standard functions. The results of the BHA are compared with the results of GA and PSO algorithms which indicate that the performance of BHA is better than the other two mentioned algorithms.
The use of Titan yellow dye as a metal ion binding marker for studies on the formation of specific complexes by supramolecular Congo red
Authors: Chłopaś Katarzyna , Jagusiak Anna , Konieczny Leszek , Piekarska Barbara , Roterman Irena , Rybarska Janina , Stopa Barbara , Zemanek Grzegorz , Bielańska Elżbieta , Piwowar Piotr , Sadlik Krystyna
Published: February 2015

Congo red (CR) and other self-assembling compounds creating supramolecular structures of rod- or ribbon-like architecture form specific complexes with cellulose and also with many proteins, including antibodies bound to the antigen and amyloids in particular. The mechanism of complexation and structure of these complexes are still poorly recognized despite the importance of the problem for medicine. This work proposes the progress in electron microscopy studies of amyloid-dye complexes by labeling supramolecular ligand CR with silver ions as a marker. Silver ions are introduced to CR carried by the strongly binding silver dye Titan yellow, which in addition form comicellar structures with CR. Silver carried by self-assembled dye molecules forms in the resulting metal nanoparticles, making the specific amyloid ligand CR perceptible in EM studies.
Effects of Fatherhood on Male Wage and Labor Supply in Japan
Authors: Yukawa Shiho
Published: February 2015

Using data from the Japanese Panel Survey of Consumers (JPSC) for the period 1994–2007, I examine the effect of childbirth on fathers’ wage rates and labor supply in Japan. I also compare the effects of fatherhood between different cohorts by dividing the JPSC sample into two birth-year cohorts (those born in or before 1960 and those born after 1960). The results show that the birth of children significantly increases hourly wage rates by 2.3% and annual work by 69 hours. Comparing these results to those of studies based in the United States and Germany shows that while the effect of childbirth on the Japanese male labor supply is large, it is relatively small on wage rates. The study also shows that childbirth has different impacts on labor market outcomes for the two cohorts. In the early cohort, the birth of children significantly increases wage rates, but has no significant effect on the labor supply. On the contrary, for the later cohort, the birth of children does not increase wage rates and there is a significant increase in the labor supply. Finally, I examine how the gender difference of children impacts labor market outcomes. Although its impact is not so large, the birth of sons has a larger effect than the birth of daughters.
Life Insurance and Suicide: Asymmetric Information Revisited
Authors: Choi Yun Jeong , Chen Joe , Sawada Yasuyuki
Published: February 2015

This paper investigates the nexus between life insurance and suicide behavior by applying semiparametric instrumental variable regressions to OECD cross-country data from 1980 to 2002. The novelty of our analysis lies in the use of cross-country variations in the lengths of the suicide exemption period in policies and foreign market shares in life insurance industries as identifying instruments for life insurance demand. We find that, for the majority of observations, there exists a positive causality from life insurance demand to suicide. This result suggests the existence of adverse selection and moral hazards in life insurance markets in OECD countries.
Application of a point of care creatinine device for trend monitoring in kidney transplant patients: fit for purpose?
Authors: van Lint Céline L. , van der Boog Paul J.M. , Romijn Fred P.H.T.M. , Schenk Paul W. , van Dijk Sandra , Rövekamp Ton J.M. , Kessler Anja , Siekmann Lothar , Rabelink Ton J. , Cobbaert Christa M.
Published: February 2015

The StatSensor

Accuracy of the StatSensor

The StatSensor

Capillary blood testing with the StatSensor
Mono- and double carbonylation of iodobenzene in the presence of reusable supported palladium catalysts
Authors: Papp Máté , Urbán Béla , Drotár Eszter , Skoda-Földes Rita
Published: February 2015

Various silica-supported palladium catalysts were prepared and tested in the carbonylation of aryl iodides in the presence of aliphatic amines and aniline. In the former reaction, the main products are the α-ketoamides, whereas monocarbonylation is favoured with aniline. Small modification of the support, of the palladium precursor, or of the conditions of immobilisation were found to affect considerably the outcome of the reactions and recyclability of the catalysts. Under optimum conditions, the phosphine-free palladium catalysts can be reused six to ten times without considerable loss of activity. By the proper selection of the solvent, the leaching of palladium into the reaction mixtures can be reduced considerably.
Carboxylation of hydroxyarens with metal alkyl carbonates
Authors: Suerbaev Khakim A. , Aldabergenov Mayliby K. , Kudaibergenov Nurbolat Zh.
Published: February 2015

The objective of this work was to investigate the possibility of using alkali metal salts of ethylcarbonic acid as a carboxylating reagent in phenol (naphthols) carboxylation and developing a new and simple method for the synthesis of hydroxybenzoic and hydroxynaphthoic acids having broad practical application. It was found that sodium ethyl carbonate and potassium ethyl carbonate can be successfully used as carboxylating agents in carboxylation of phenol and naphthols. For the first time, the effects of the gaseous medium (air, carbon dioxide, argon), pressure, temperature and reaction time on the proceedings of the carboxylation reactions were examined. Simple and convenient procedures for the syntheses of o- and p-hydroxybenzoic, p-aminosalicylic, 1-hydroxy-2-naphthoic, 1-hydroxy-4-naphthoic and 2-hydroxy-3-naphthoic acids were developed. New efficient technologies for preparation of drugs salicylic acid (antiseptic activity), p-aminosalicylic acid (antituberculous activity) and p-hydroxybenzoic acid (bactericide activity) based on carboxylation reactions of phenol and m-aminophenol with sodium and potassium salts of ethyl carbonic acid were worked out.
Two-spherical topological Kac–Moody groups are Kazhdan
Authors: Hartnick Tobias , Köhl Ralf
Published: February 2015

In this note, we prove that a two-spherical Kac–Moody group over a local field endowed with the Kac–Peterson topology enjoys Kazhdan's property (T).
Inversions of the windowed ray transform
Authors: Moon Sunghwan
Published: February 2015

The windowed ray transform is the generalization of the “Analytic-Signal Transform” which was developed to extend arbitrary functions from

ℝ
n

${\mathbb{R}^{n}}$

to

ℂ
n

${\mathbb{C}^{n}}$

in a natural way.
The X-ray transform is also a special case of this transform.
Similar to the X-ray transform, the problem of inverting this transform is overdetermined. Hence it is possible to prove the existence of several inversion formulas.
Kaiser obtained one such inversion formula in 1993. We present several inversion formulas here. One of them is similar to that of Kaiser, but it requires a weaker condition. The others are new.
Arrays of Rotating Permanent Magnet Dipoles for Stirring and Pumping of Liquid Metals
Authors: Bojarevičs Andris , Beinerts Toms , Sarma Mārtiņš , Gelfgat Yurii
Published: February 2015

Multiple configurations of synchronously rotating permanent magnet cylinders magnetized across the axes are proposed for liquid metal stirring for homogenization as well as for pumping. Universal analytical model is used for an initial parameter analysis. Then experimental setups were built to perform physical modelling of the industrial applications, e.g. large-scale metallurgical furnaces. Velocity distribution in the liquid metal was measured using different methods: the Ultrasound Doppler anemometry and the potential difference probes. The study shows that the cylindrical permanent magnet setups can achieve up to 10 times higher energy efficiency compared to AC inductors and have potential of wide-range industrial application, e.g. can be used as stirrers for secondary aluminium furnaces with up to 50 cm thick walls.
The Submillimeter-wave Spectrum of the Formaldehyde Isotopomer H2C18O in its Ground Vibrational State
Authors: Müller Holger S. P. , Gendriesch Ralf , Lewen Frank , Winnewisser Gisbert
Published: February 2015

The ground state rotational spectrum of H2C18O has been studied between 485 and 835 GHz with a sample of natural isotopic composition. Additional lines have been recorded around 130 GHz and near 1.85 THz, using a recently developed far-infrared laser-sideband spectrometer. The accurate new line frequencies were fit together with previously published data to obtain greatly improved spectroscopic constants. Both Watson's S and A reduced Hamiltonians have been employed yielding the rotational constants AA = 281 961.215 (82), BA = 36 902.275 51 (36), CA = 32 513.405 89 (36), AA = 281 961.371 (82), BA = 36 904.173 32 (91), and CA = 32 511.524 65 (86) MHz, respectively.
Hyperfine Interactions at Lanthanide Sites in Europium Doped Oxide Glasses
Authors: Concas G. , Congiu F. , Spano G. , Speghini A. , Gatterer K. , Bartl M. H.
Published: February 2015

A series of europium doped Na2O-B2O3-SiO2, PbO-GeO2 and ZnOTeO2 glasses was investi-gated by means of151 Mössbauer spectroscopy. The distortion of the Eu sites has been evaluated in the Na2O-B2O3-SiO2 glasses by means of the quadrupolar interaction parameter and the asym-metry parameter; the disorder has been estimated by the line width. The occupancy of the sites in the borosilicate glasses is discussed. The correlation of the isomer shift with the optical basicity of the glass is discussed in terms of the degree of covalence of the Eu-O bond.
Structure of Clusters in Methanol-Water Binary Solutions Studied by Mass Spectrometry and X-ray Diffraction
Authors: Takamuku Toshiyuki , Yamaguchia Toshio , Asato Masaki , Matsumoto Masaki , Nishi Nobuyuki
Published: February 2015

The structure of clusters in methanol-water solutions in its dependence on the methanol mole fraction xM has been investigated by mass spectrometry on clusters isolated from submicron droplets by adiabatic expansion in vacuum and by X-ray diffraction on the bulk binary solutions. The mass spectra have shown that the average hydration number, (nm), of m-mer methanol clusters decreases with increasing xM , accompanied by two inflection points at xM = ~0.3 and ~0.7. The X-ray diffraction data have revealed a similar change in the number of hydrogen bonds per water and/or methanol oxygen atom at ~2.8 Å. On the basis of both results, most likely models of clusters formed in the binary solutions are proposed: at 0 < xM < 0.3 the tetrahedral-like water cluster is the main species, at 0.3 < xM < 0.7 chain clusters of methanol molecules gradually evolve with increasing methanol content, and finally, at xM > 7 chain clusters of methanol become predominant. The present results are compared with clusters previously found in ethanol-water binary solutions and discussed in relation to anomalies of the heat of mixing of methanol-water binary solutions.
Structure and Phase Transition in (C2H5NH3)3Sb2Cl9 · (C2H5NH3)SbCl4 ; X-ray, DSC and Dielectric Studies
Authors: Bujak Maciej , Zaleski Jacek
Published: February 2015

The structure of (C2H5NH3)3Sb2Cl9 • (C2H5NH3)SbCl4 at 295 K has been determined. The crystals are orthorhombic, space group Pna21 (a -16.925(3), b = 24.703(5), c = 7.956(2) Å, V = 3326.4(12) Å3 , Z = 4, dc= 2.018, dm= 2.01(1) Mg m-3). They consist of an anionic sublattice composed of two different polymeric zig-zag chains. One is built of Sb2Cl9
3- units (corner sharing octahedra) and the other one is made of corner sharing SbCl5
2-square pyramids. In the cavites between the polyanionic chains four non-equivalent ethylammonium cations are located. Three of them are disordered. The cations are connected to the anions by weak N-H...Cl hydrogen bonds. A first order phase transition of the order-disorder type was found at 274 K. It was studied by DSC, dielectric and X-ray diffraction methods. The mechanism of the phase transition is attributed to the ordering of at least one of the ethylammonium cations
Thermochromic Shifts of Absorption and Fluorescence Spectra and Excited State Dipole Moment of PRODAN
Authors: Kawski A. , Kukliński B. , Bojarski P.
Published: February 2015

Using the thermochromic shift method of absorption and fluorescence spectra, the dipole moments in the ground, µg, and excited. µe , state are simultaneously determined for PRODAN in ethyl acetate. The obtained values for µg and µe are compared with those previously determined by the solvatochromic method for two different Onsager radii, and a satisfactory agreement has been obtained
Correlation between the 35CI NQR Parameters of Chloro-containing Organic and Organometallic Compounds and the Results of ab initio Calculations
Authors: Feshin Valentin P. , Feshina Elena V.
Published: February 2015

The results of comparison of experimental 35C1 NQR parameters for a great number of organic and organometallic compounds and estimated ones using ab initio calculations at the RHF/6-31G(d) level were systematized. The NQR frequency changes on going from one compound to another depend, in general, on the changes of populations of the CI atom po-orbitals in these compounds and, first of all, of populations of their less diffuse parts
A Molecular Dynamics Simulation of the Molten Ternary System (Li, K, Cs)Cl
Authors: Matsumiya Masahiko , Takagi Ryuzo
Published: February 2015

The self-exchange velocity (SEV) of neighboring unlike ions, has been evaluated by molecular dynamics simulations of molten CsCl, (Li, K)C1 and (Li, K, Cs)Cl at 673 K. From the increase of the SEV's in the same order as the internal mobilities it is conjectured that there is a strong correlation between these two properties. The pair correlation functions, and the self-diffusion coefficients and the SEV's of Li+, K+, and Cs+ with reference to Cl- have also been calculated. The results allow to conclude that the self-exchange velocity of the cations become vCs < vK < vLi at xCs =0.1 and vLi < vK < vCs at xCs > 0.4. The sequence of the self-diffusion coefficients agrees with that of the SEV's. The results enable to conclude that it is possible to enrich Cs at up to xCs ~ 0.3 - 0.4 in the molten LiCl-KCl eutectic system.
Ionic Interactions in Lanthanide Halides
Authors: Akdeniz Z. , Çiçek Z. , Tosia M. P.
Published: February 2015

We determine a model of the ionic interactions in RX3 compounds (where R is a metal in the rare-earth series from La to Lu and X = CI, Br or I) by an analysis of data on the static and dynamic structure of their molecular monomers. The potential energy function that we adopt is patterned after earlier work on Aluminium trichloride [Z. Akdeniz and M. P. Tosi, Z. Naturforsch. 54a, 180 (1999)], but includes as an essential element the electric polarizability of the trivalent metal ion to account for a pyramidal shape of RX3 molecules. From data referring mostly to trihalides of elements at the ends and in the middle of the rare-earth series (/. e. LaX3, GdX3 and LuX3), we propose systematic variations for the effective valence, ionic radius and electric polarizability of the metal ions across the series. As a first application of our results we predict the structure of the Dy2Cl6 and Dy2Br6 molecular dimers and demonstrate by comparison with electron diffraction data that lanthanide-ion polarizability plays a quantitative role also in this state of tetrahedral-like coordination.
EPR Studies of Cu2+ Doped Zinc Saccharin, [Zn(sac)2·(H20)4 ]·2H20 Single Crystals
Authors: Kartal İ. , Karabulut B. , Köksal F. , İçbudak H.
Published: February 2015

The EPR spectra of Cu2+ in zinc saccharin crystalline powder and single crystals have been recorded at room temperature. The angular variation of the spectra indicates the substitution of the host Zn2+ with Cu2+. Two magnetically inequivalent sites for Cu2+ have been observed. The spectra were fitted with a rhombic spin-Hamiltonian, and the ground state wave function of the complex has been constructed.
Ferroelectricity and Phase Transitions in Pyridinium Periodate Single Crystal
Authors: Czapla Z. , Dacko S. , Kosturek B.
Published: February 2015

Single crystals of pyridinium periodate were grown, and their physical properties were studied. Anomalies of the electric permittivity and birefringence were observed at TC1 = 321 K and TC2 = 211 K. These observations gave evidences for the existence of three phases denoted as I, II, and III. Hysteresis loops were observed both in phase II and III. Pyroelectric measurements showed two anomalies at TC1 and TC2 . The anomaly at TC1 is related to the transition between a para-and ferroelectric phase, and the anomaly at T cl to the transition between two ferroelectric phases.
Phase Diagram, Caesium-133 NMR Spectra and Electrical Conductivity of the Binary System Caesium and Zinc Butyrates
Authors: Mirnaya T. A. , Trachevski V. V. , Dradrakh V. S. , Bylina D. V.
Published: February 2015

Phase equilibria of non-mesogenic caesium- and zinc-butyrate mixtures were studied by differential thermal analysis and hot stage polarization microscopy. Smectic liquid crystals were found in some composition range. Their appearance is explained by the latent mesomorphism of caesium butyrate. |133Cs NMR spectra and the specific electrical conductivity of the molten mixtures at 155°C were employed to investigate the peculiarities of ionic association and interaction in the melts.
Spectroscopic Studies of Dimethylamino Derivatives of Fluorene
Authors: Heldt J. , Heldt J. R. , Redzimski T. , Diehl H. , Schultz P.
Published: February 2015

2-dimethylamino-9-fluorenol and 2-dimethylamino-9(4'dimethylamino)phenyl-9-fiuorenol in polar solvents in the excited state undergo conformation changes in which two fluorescent isomers are created. The isomers (in the local excited (LE) and charge transfer (CT) configuration) possess separate fluorescence bands, one appearing from the S1 (LE) state and the second from the intramolecular charge transfer state S1 (CT) of the neutral, aromatic molecule. Both bands show a solvatochromic effect. Using the method of the solvent induced Stokes shift of the absorption and fluorescence spectra the permanent dipole moment of the excited state of fluorene and its two derivatives have been determined. The dipole moment of the ground state and the Onsager cavity radius of the studied molecules were calculated with the Auestion Model 1 (AM1) program.
Variation in P-O Bonding in Phosphate Glasses -A Neutron Diffraction Study
Authors: Hoppe Uwe , Kranold Rainer , Stachel Dörte , Barz Andrea , Hannonb Alex C.
Published: February 2015

Two different lengths of P-O bonds in the PO4 units of phosphate glasses are found by neutron diffraction experiments of high resolution in real space. The two lengths are related to bonds of the phosphorus atom with the terminal and the bridging oxygen atoms. The mean lengths and widths of both P-0 distance peaks change as a function of the glass composition. In a large range, starting from vitreous P2O5 s up to the pyrophosphate composition, the behavior of the bond lengths is compared with that in the related crystals and with that resulting from ab initio calculations. The bond lengths depend not only on the species of the participating oxygen atoms and on the number of links of the concerning PO4 unit but also on the number of links of the neighboring PO4 unit and on the species of the modifier cation
Isolated versus Condensed Anion Structure VI: X-ray Structure Analysis and 81Br NQR of Guanidinium Pentabromodicadmate(II), [C(NH2)3]Cd2 Br5 , tris-Hydrazinium Pentabromocadmate(II), [H2NNH3]3 CdBr5 , and bis-Hydrazinium Tetrabromocadmate(II)-Tetra Hydrate, [H2NNH3]2CdBr4-4H20
Authors: Ishihara Hideta , Horiuchi Keizo , Krishnan V. G. , Svoboda Ingrid , Fuess Hartmut
Published: February 2015

The structure of the condensed bromocadmate anions in [C(NH2)3]Cd2Br5 (1) and [H2NNH3]3CdBr5 (2) were studied at room temperature by X-ray diffraction. (1) crystallizes with double-chains bridged by Br atoms (orthorhombic, Pmmn, Z= 2, a = 1394.0(5), b = 394.5(1), c = 1086.9(5) pm). This chain structure was not described previously. (1) shows three 81Br NQR lines at temperatures between 77 and 323 K. Structural phase transitions take place at 283 K and at 535 K. (2) crystallizes with Br bridged zigzag-chains (monoclinic, P21, Z=2,a = 943.1(1), b = 778.8(2), c = 942.0(2) pm, β = 102.10(2)°) and shows a first-order phase transition around 304 K with a large thermal hysteresis. Below the transition point five 81Br NQR lines are observed at temperatures between 122 and 304 K, and above the transition point four 81 Br NQR lines at tem-peratures between 288 and 353 K. Two 81Br NQR lines are observed in [H2NNH3]2CdBr4 -4H20 (3) at temperatures between 77 and around 320 K with positive temperature coefficients
High Dimensional Schwartz KP Equations
Authors: Lou Sen-yue
Published: February 2015

The usual (2+1)-dimensional Schwartz Kadomtsev-Petviashvili (KP) equation is extended to (n+1)-dimensions. The extension is Painleve integrable in the sense that it possesses the Painleve property. A (3+1)-dimensional special one is just found when we solve a real (3+1)-dimensional KP equation approximately.
On the Entropy Flow between Parts of Multi-component Systems, Partial Entropies and the Implications for Observations
Authors: Diebner Hans H.
Published: February 2015

The concept of the time dependent instantaneously occupied phase space volume is applied to multi-component systems. It allows for the investigation of entropy flows betweeen the components of the system and the evaluation of partial entropies assigned to the subsystems. We give numerical examples by means of molecular dynamics simulations of a 100-particle gas. Using a symplectic exactly reversible algorithm, a consistent and reliable evalutation of energy and entropy exchanges as well as the intake of work is achieved. The entropy flow which is related to an information flow is linked to an observational situation. This yields a further indication for the necessity of an intrinsic observer for a better understanding of the physical world. In addition, it indicates the Gödelian structure of cognition in a most serious way because only “first-principle” assumptions are made. Thereby, the paradoxical situation which is created by Jaynes’ concept of an “anthropomorphic entropy” can be resolved by putting the anthropomorphic contents of thermodynamics down to an ontological basis. This is a straightforward extension of Szilard’s and Brillouin’s information theoretical treatment of cognition
Covariant Regularization of Nonlinear Spinorfield Quantum Theories and Probability Interpretation
Authors: Stumpf Harald
Published: February 2015

By a decomposition theorem a higher order nonlinear spinorfield equation can be transformed into a set of first order nonlinear spinorfield equations, i. e. into an auxiliary field formulation which allows canonical quantization. The quantum dynamics of the auxiliary fields is expressed in algebraic Schrödinger representation and admits only unphysical state spaces with indefinite metric. Regularization of the classical theory is transferred into quantum field theory by a noninvertible map from the corresponding auxiliary field state space into an associated physical state space, the metric of which is positive definite. For the effective dynamics in the physical state space probability current conservation is proved, and for physical states which describe composite particle configurations the existence of the state space is demonstrated
Sub-Doppler Measurements and Rotational Spectrum of 13C18O
Authors: Klapper G. , Lewen F. , Belova S. P. , Winnewisser G.
Published: February 2015

The rotational spectrum of 13C18O has been measured up to 1 THz. The lowest rotational transitions of 13C18O (J =2←1 to J = 6 ← 5) have been measured by saturation-dip spectroscopy with an experimental accuracy of 2 kHz. These five low J rotational transitions cover the frequency range between 209 and 628 GHz. The narrow linewidths of about 20 kHz of the saturation dips allowed to resolve the two main hyperfine components. The splitting is caused by coupling of the 13C nuclear spin with the rotation of the molecule. The appropriate coupling constant C1(13C18O) is 33.90(81) kHz. In addition we have measured in the Doppler limited mode, the line positions of the rotational transitions J = 7 ← 6 , J = 8 ← 7 , and J = 9 ← 8 with accuracies of 5 kHz. We provide a set of improved constants together with frequency predictions up to 4.1 THz (J = 40 ← 39)
Analysis of the Dielectric Anisotropy of Typical Nematics with the Aid of the Maier-Meier Equations
Authors: Urban Stanisław , Kędzierski Jerzy , Dąbrowski Roman
Published: February 2015

Using the experimental data on the dielectric anisotropy, density, polarizability, dipole moment, and order parameter in the nematic phase of seven typical liquid crystalline substances, the applicability of the Maier-Meier theory for the description of the dielectric properties of nematics is checked. Substanc-es with different polarity and different tendency to form associates in the nematic phase were studied. It is found that the Maier-Meier equations describe fairly well the dielectric permittivity components of nematics. The estimated values of the angle β formed by the dipole moment with the long molecular axis are compared with those obtained in other studies
Photorecombination of Electrons in Dense Plasmas
Authors: Jung Young-Dae , Rhee Soo-Yong
Published: February 2015

The plasma screening effect on the photorecombination of free electrons, with ions in a weakly plas-ma is investigated. The recombination cross section is obtained by the principle of detailed balance with the photoionization cross section of the hydrogenic ion including the plasma screening effects on the bound and continuum states of the electron. It is found that the plasma screening effects on the recom-bination cross section are less than 11% when the Debye length (Λ) is greater than ten times of the Bohr radius (az) of the hydrogenic ion with nuclear charge Z
The T, p-Dependence of the Chemical Shift of the Hydroxyl Protons in Deeply Supercooled Methanol and Water
Authors: Chen Liuping , Gross Thomas , Lüdemann Hans-Dietrich
Published: February 2015

The hydroxyl proton chemical shifts δ (H-O) of supercooled methanol (Tmin= 149 K) and water have been determined (Tmin= 183 K), and the pressure dependence of these shifts was measured up to 200 MPa. In both compounds the downfield shift of δ (H-O) continues down to the lowest temperatures reached. This result disagrees with the two state models for the hydrogen bond formation in both liquids. The isotherms δ(H2O) show for T< 273 K an upfield shift that becomes more pronounced with decreasing temperature. For δ ( H-O-CH3), increasing p causes at all temperatures a downshift
Transition from Regular to Stochastic Vibrational Motion in H+
3 Molecule: An ab initio Classical Trajectory Study
Authors: Babinec P. , Jakubíková E. , Leszczynski J.
Published: February 2015

An ab initio classical trajectory study of intramolecular vibrational dynamics in H+
3 molecule revealed a transition from regular quasiperiodic to stochastic motion at an energy slightly higher than the zero point vibrational energy
Shear Viscosity of the Homologous Series of wCHBT (n = 0 ÷ f 12) in the Isotropic and Nematic Phases
Authors: Jadżyn J. , Dąbrowski R. , Glumiak K. , Czechowski G.
Published: February 2015

The paper presents results of shear viscosity measurements performed on nematogenic 4-(trans-4'-n-alkylcyclohexyl)isothiocyanatobenzenes (CnH 2n + 1-CyHx-Ph-N=C=S, /nCHBT) in the isotropic (n = 0 ÷ 12) and nematic (« = 4 ÷ 12) phases. The viscosity measured in the nematic phase is, due to the flow alignment phenomenon, close to the Migsowicz T? 2 viscosity coefficient. An odd-even effect in the n dependence of the viscosity-activation energy is observed both in the nematic and isotropic phases of nCHBT.
The Reason of the Significant Differences in Antiferromagnetic Interactions between Homologous μ-Acetato-Bridged Dicopper(II) Complexes: A Theoretical Study
Authors: Kavlakoglu E. , Elmali A. , Elerman Y.
Published: February 2015

The influence of the overlap interactions between the bridging ligands and the metal d orbitals on the super-exchange coupling constant has been studied by ab-initio Restricted Hartree-Fock molecular orbital calculations. The interaction between the magnetic d orbitals and the HOMOs of the acetate oxygens has been investigated in homologous μ-acetato-bridged dicopper(II) complexes which have significantly different 2 values (the energy seperation between the spin - triplet and spin - singlet states).
Thermodynamics of EuCl3: Experimental Enthalpy of Fusion and Heat Capacity and Estimation of Thermodynamic Functions up to 1300 K
Authors: Rycerz L. , Gaune-Escard M.
Published: February 2015

The heat capacity of solid EuCl3 was measured by differential scanning calorimetry from 300 K up to the melting temperature, and beyond. These results were compared with literature data and fitted by a polynomial temperature dependence. The enthalpy of EuCl3 fusion was measured. Furthermore, by combination of these results with literature data on the entropy at 298.15 Sm
0 (EuCl3, s, 298.15 K) and the standard molar enthalpy of formation of ∆form H0m (EuCl3, s, 298.15 K), the thermodynamic functions have been calculated up to 1300 K.
Magnetic Susceptibility of the Cluster Compounds Mo6Se8 and Mo6Te8
Authors: Concas G. , Congiu F. , Lehmann A. Geddo , Muntoni C. , Sanna S. , Spano G.
Published: February 2015

The magnetic susceptibility of the cluster compounds Mo6Se8 and Mo6Te8 has been measured at temperatures between 82 and 330 K, using a Faraday balance. The paramagnetic and diamagnetic components of the susceptibility have been analyzed. The Pauli component was evaluated using the density of states at the Fermi level obtained by band structure calculations,while the core component was evaluated using the calculated atomic core diamagnetism. The paramagnetic susceptibility of Mo6Se8 is due mainly to the Pauli contribution, while the Van Vleck contribution is small, in agreement with the metallic feature of the compound. The paramagnetic susceptibility of Mo6Te8 is due mainly to the Van Vleck term,while the Pauli contribution of the conduction electrons is very small. The result points out that the Mo6 clusters in the telluride retain their molecular character, with small intercluster interactions.
An Infrared Study of the CaA Zeolite Reacted with CO2
Authors: Ucun F.
Published: February 2015

An infrared study was made on the CaA zeolite reacted with CO2 gas. It was found that a carbonate ion (CO3
2-) is formed by binding of CO2 to an oxygen, and this carbonate ion coordinates to a Ca2+ cation in the zeolite in the unidentate way.
Quadrupole Coupling in Ammonium Metaperiodate at Low Temperature
Authors: Segel S. L. , Brown R. J. C. , Ylinen E. E. , Ingman L. P. , Bastow T. J.
Published: February 2015

The temperature dependences of the 127I nuclear quadrupole coupling in NH4IO4 and in ND4IO4 are reported. In each salt, the quadrupole coupling decreases to a very small value at low temperatures, and in the case of ND4IO4 passes through zero and changes sign at 87 K.
Sub-Doppler Saturation Spectroscopy of HCN up to 1 THz and Detection of J = 3 —> 2 (4—> 3) Emission from TMC1
Authors: Ahrens Volker , Lewen Frank , Takano Shuro , Winnewisser Gisbert , Urban Štepán , Negirev A. A. , Koroliev A. N.
Published: February 2015

Very high-resolution ( ∼ 30 kHz) and very precise (±2 kHz) saturation dip and crossover dip measurements are reported for HCN. Nine consecutive rotational transitions of the vibrational ground state were recorded, covering the rotational spectrum up to the J = 11 ← 10 transition at 975 GHz. Commencing the saturation dip measurements with the J = 3 ← 2 transition located at 265 886.4 MHz, all rotational transitions were measured up to J = 11 ← 10 (ΔF = 1), positioned at a center frequency of 974 487.2 MHz. It has become possible to resolve the hyperfine structure of every rotational transition to varying degrees. Transitions obeying the selection rules ΔJ = 1, ΔF = 0 are have been resolved, those obeying the selection rules J = 1, F = 1 are only resolved for transitions lower than the J = 6 ← 5 transition.

These new experimental saturation dip data, together with the molecular beam maser emission data of the J = 1 → 0 and J = 2 → 1 transitions reported by De Lucia and Gordy, (Phys. Rev. 187, 58 (1969)), and the recent terahertz measurements performed in this laboratory up to J = 22-21 at 1.946 THz (Maiwald et al., J. Mol. Spectrosc. 202, 166 (2000)), were subjected to a least squares analysis which yielded a highly precise set of molecular constants for the ground state of HCN: B = 44 315.974 970 (156) MHz, D = 0.087 216 35 (169) MHz, H = 0.086 96 (242) Hz; eQq = -4.709 03 (162) MHz, eQqJ = 0.244 (88) Hz, CN = 10.09 (38) kHz, CNJ = -0.0143 (86) mHz.

Two constants, the hydrogen spin-rotation, CH = -4.35 (5) kHz, and the spin-spin interaction between the proton and nitrogen nucleus, SNH = 0.154 (3) kHz, can not be determined from the saturation dip measurements and have been taken from Ebenstein and Muenter, J. Chem. Phys. 80, 3989 (1984). There also a value for the ground state permanent electric dipole moment (in Debye’s) is given, which we quote for completeness: 〈μ〉000 = 2.985 188 (3) D.

We also report the discovery of the J = 3 → 2 and J = 4 → 3 ground state rotational transitions of HCN in the dark, cold molecular cloud TMC1 by using the KOSMA 3m-Submillimeter Telescope located in the central Swiss Alps. For the J = 3 → 2 transition the hyperfine splitting has partly been resolved. The intensities of the hyperfine components are anomalous, and they are not in thermodynamic equilibrium.
Nonlinear Instability of an Electrohydrodynamic Planar Jet
Authors: Lee Doo-Sung
Published: February 2015

The nonlinear breakup of a fluid jet forming a plane sheet stressed at the surface by an electric field is studied. A third-order theory using the method of strained coordinates is applied to study the capillary instability of the jet. The time of breakup of the jet is obtained numerically.