bluuebunny/crossref_metadata_2025 huggingface dataset:
Do Ethical Leaders Get Ahead? Exploring Ethical Leadership and Promotability
Authors: Rubin Robert S. , Dierdorff Erich C. , Brown Michael E.
Published: July 2012

Despite sustained attention to ethical leadership in organizations, scholarship remains largely descriptive. This study employs an empirical approach to examine the consequences of ethical leadership on leader promotability. From a sample of ninety-six managers from two independent organizations, we found that ethical leaders were increasingly likely to be rated by their superior as exhibiting potential to reach senior leadership positions. However, leaders who displayed increased ethical leadership were no more likely to be viewed as promotable in the near-term compared to those who displayed less ethical leadership. Our findings also show ethical culture and pressure to achieve results are important contextual factors that moderate the relationships between ethical leadership and leader promotability to senior leadership roles.
Transnational Corporations and the Duty to Respect Basic Human Rights
Authors: Arnold Denis G.
Published: July 2012

In a series of reports the United Nations Special Representative on the issue of Human Rights and Transnational Corporations has emphasized a tripartite framework regarding business and human rights that includes the state “duty to protect,” the TNC “responsibility to respect,” and “appropriate remedies” for human rights violations. This article examines the recent history of UN initiatives regarding business and human rights and places the tripartite framework in historical context. Three approaches to human rights are distinguished: moral, political, and legal. It is argued that the tripartite framework’s grounding of the responsibility of TNCs to respect human rights is properly understood as moral and not merely as a political or legal duty. A moral account of the duty of TNCs to respect basic human rights is defended and contrasted with a merely strategic approach. The main conclusion of the article is that only a moral account of the basic human rights duties of TNCs provides a sufficiently deep justification of “the corporate responsibility to respect human rights” feature of the tripartite framework.
Business Ethics and (or as) Political Philosophy
Authors: Heath Joseph , Moriarty Jeffrey , Norman Wayne
Published: July 2012

There is considerable overlap between the interests of business ethicists and those of political philosophers. Questions about the moral justifiability of the capitalist system, the basis of property rights, and the problem of inequality in the distribution of income have been of central importance in both fields. However, political philosophers have developed, especially over the past four decades, a set of tools and concepts for addressing these questions that are in many ways quite distinctive. Most business ethicists, on the other hand, consider their field to be primarily a domain of applied ethics, and so adopt methods and conceptual frameworks developed by moral philosophers. In this paper, we discuss some of the salient differences between these two approaches, and suggest some ways in which business ethicists could benefit from taking a more “political philosophy” approach to these questions. Throughout, we underline the importance of seeking greater compatibility among the principles used in normative theorizing about markets, regulations, corporate governance, and business practices.
Ethics and Network Organizations
Authors: Phillips Robert A.
Published: July 2012

As value chains become longer with increases in outsourcing and subcontracting, the challenges of fixing responsibility become more difficult. Using concepts from the literature on social networks, this paper considers issues of diffusion of responsibility and plausible deniability in such relationships. Specifically, this paper isolates three sources of denial of – or defense against – attributions of responsibility: connection, control and knowledge. It goes on to consider the effects on network density and actor centrality as third parties (tertius illuminans) alter the structure of these networks. Finally, preliminary conclusions are considered including suggestions for addressing these new challenges as well as the potential for conceptual cross-fertilization between network analysis and organizational ethics.
Unmet Duties in Managing Financial Safety Nets
Authors: Kane Edward J.
Published: July 2012

Officials must understand why and how the public lost confidence in the federal government’s ability to manage financial turmoil. Officials outsourced to private parties responsibility for monitoring and policing the safety-net exposures that were bound to be generated by weaknesses in the securitization process. When the adverse consequences of this imprudent arrangement first emerged, officials claimed for months that the difficulties that short-funded, highly leveraged firms were facing in rolling over debt reflected only a shortage of aggregate liquidity and not individual-firm shortages of economic capital. Then, in September 2008, the president and other officials created an unwise sense of urgency that delays in implementation show to have been greatly exaggerated.

That authorities and financiers violated common-law duties of loyalty, competence, and care they owe to taxpayers indicates a massive incentive breakdown in industry and government. Taxpayers deserve a thorough-going reorientation of: (1) how regulatory agencies report on their regulatory performance and back-room interactions with Congress and the Treasury, and (2) the contract structures and performance measures used by the financial industry and its government overseers.
Where Is the Accountability in International Accountability Standards?: A Decoupling Perspective
Authors: Behnam Michael , MacLean Tammy L.
Published: July 2012

A common complaint by academics and practitioners is that the application of international accountability standards (IAS) does not lead to significant improvements in an organization’s social responsibility. When organizations espouse their commitment to IAS but do not put forth the effort necessary to operationally enact that commitment, a “credibility cover” is created that perpetuates business as usual. In other words, the legitimacy that organizations gain by formally adopting the standards may shield the organization from closer scrutiny, thus enabling rather than constraining the types of activities the standards were designed to discourage.

There is a lack of research on why certain types of IAS are more prone than others to being decoupled from organizational practices. Applying a neo-institutional perspective to IAS, we theorize that the structural dimensions of the types of standards themselves can increase the likelihood of organizations adopting IAS standards in form but not in function.
Decoupling of Standard Implementation from Certification: Does Quality of ISO 14001 Implementation Affect Facilities’ Environmental Performance?
Authors: Aravind Deepa , Christmann Petra
Published: July 2012

The literature on certifiable management standards has not paid sufficient attention to implementation of standard requirements in certified firms. Firms that obtain standard certification to achieve the legitimacy benefits of certification may not implement standard requirements sufficiently to realize the standard’s intended performance outcomes. We argue that such decoupling of implementation from certification threatens the effectiveness of certifiable standards as governance mechanisms for firms’ environmental conduct because standard certification may not accurately signal firms’ superior environmental performance to external stakeholders. Empirical findings based on the ISO 14001 standard at the facility level support this view: Quality of standard implementation affects facilities’ environmental performance, and environmental performance of certified and non-certified facilities does not differ significantly for the overall sample and low-quality implementers, while high-quality implementers have better environmental performance than their non-certified counterparts. We provide recommendations for increasing the effectiveness of governance systems for firm conduct based on certifiable standards.
An Institutional Perspective on the Diffusion of International Management System Standards: The Case of the Environmental Management Standard ISO 14001
Authors: Delmas Magali A. , Montes-Sancho Maria J.
Published: July 2012

This paper analyzes how national institutional factors affect the adoption of the international environmental management standard ISO 14001, using a panel of 139 countries from 1996 to 2006. The analysis emphasizes that during the emerging phase of the standard, the potential lack of consensus within the constituents of the national institutional environment concerning the value of a new standard could send mixed signals to firms about the standard. The results show that in the early phase of adoption, regulative and normative forces within the institutional environment can work against each other. Results also show that regulative or coercive forces play a relatively more important role in the early phase of adoption of the standard than in the subsequent phases of diffusion. In the later phases of diffusion of ISO 14001, normative forces, such as the diffusion of other management standards, as well as factors related to trade, play a more important role. Because of the similarities between environmental management standards and corporate social responsibility standards, this study can help identify some of the challenges for diffusion of ISO management standards in the area of social responsibility.
Comments onBEQ’s Twentieth Anniversary Forum on New Directions for Business Ethics Research
Authors: Crane Andrew , Gilbert Dirk Ulrich , Goodpaster Kenneth E. , Miceli Marcia P. , Moore Geoff , Reynolds Scott J. , Schminke Marshall , Waddock Sandra , Weaver Gary R. , Wicks Andrew C.
Published: July 2012

In 2010,Business Ethics Quarterlypublished ten articles that considered the potential contributions to business ethics research arising from recent scholarship in a variety of philosophical and social scientific fields (strategic management, political philosophy, restorative justice, international business, legal studies, ethical theory, ethical leadership studies, organization theory, marketing, and corporate governance and finance). Here we offer short responses to those articles by members ofBusiness Ethics Quarterly’s editorial board and editorial team.
The Ethics of Price Discrimination
Authors: Elegido Juan M.
Published: July 2012

Price discrimination is the practice of charging different customers different prices for the same product. Many people consider price discrimination unfair, but economists argue that in many cases price discrimination is more likely to lead to greater welfare than is the uniform pricing alternative—sometimes for every party in the transaction. This article shows i) that there are many situations in which it is necessary to engage in differential pricing in order to make the provision of a product possible; and ii) that in many such situations, the seller does not obtain an above-average rate of return. It concludes that price discrimination is not inherently unfair. The article also contends that even when conditions i) and/or ii) do not obtain, price discrimination is not necessarily unethical. In itself, the fact that some people get an even better deal than do others does not entail that the latter are wronged.
Dialogue: CEO Compensation
Authors: Kolb Robert , Moriarty Jeffrey
Published: July 2012

In this journal, Jeffrey Moriarty argued that CEOs must refuse to accept compensation above the minimum compensation that will induce them to accept and perform their jobs. Acting otherwise, he maintains, violates the CEO’s fiduciary duty, even for a CEO new to the firm. I argue that Moriarty’s conclusion rests on a failure to adequately distinguish when a person acts as a fiduciary from when she acts on her own account as a person. Further, Moriarty’s argument assumes that the CEO knows this minimum level of compensation. However, we learn the suitability of compensation only through the market process of wage negotiation, not through some process of introspection. I conclude that a CEO who abstains from interfering with the board of directors and its compensation committee is morally free to negotiate for the highest wage available.
Distinct Molecular Motions in a Switchable Chromophore Dielectric 4‐N,N‐Dimethylamino‐4′‐N′‐methylstilbazolium Trifluoromethanesulfonate
Authors: Sun Zhihua , Luo Junhua , Chen Tianliang , Li Lina , Xiong Ren‐Gen , Tong Ming‐Liang , Hong Maochun
Published: July 2012

Molecular motion associated with rotational and orientational phase transitions is one of the prominent structural strategies for assembling the functional materials such as artificial motors and tunable molecular dielectrics. Here, a new organic chromophore molecule, 4‐N,N‐dimethylamino‐4′‐N′‐methylstilbazolium trifluoromethanesulfonate (complex 1), which undergoes an exceptional order‐disorder phase transition at 322 K, is successfully synthesized. The single crystal X‐ray diffraction analysis, thermal analysis, and dielectric measurements are used to characterize its dielectric dynamic behaviors. The results reveal that 1 behaves as a molecular rotator with the obviously distorted bipyramidal geometry of trifluoromethanesulfonate anions. In addition to its disorderings, two very distinct motions of the anionic moieties are confirmed, namely the “earth rotation” of partial units and the “earth revolution” of the whole molecule. Such unique molecular motions are found to be mainly responsible for the order–disorder phase transition together with the abrupt dielectric anomaly and anisotropy. The charge‐transfer cationic parts enhance the molecular motions behaving as the stator and give rise to its excellent third‐order nonlinearities. The concept may allow for the remote control of molecular events to explore functional materials in organic chromophores.
Well‐Defined Degradable Cationic Polylactide as Nanocarrier for the Delivery of siRNA to Silence Angiogenesis in Prostate Cancer
Authors: Chen Chih‐Kuang , Law Wing‐Cheung , Aalinkeel Ravikumar , Nair Bindukumar , Kopwitthaya Atcha , Mahajan Supriya D. , Reynolds Jessica L. , Zou Jiong , Schwartz Stanley A. , Prasad Paras N. , Cheng Chong
Published: July 2012

Well‐defined tertiary amine‐functionalized cationic polylactides (CPLAs) are synthesized by thiol‐ene click functionalization of an allyl‐functionalized polylactide, and utilized for the delivery of interleukin‐8 (IL‐8) siRNA via CPLA‐IL‐8 siRNA nanoplexes. The CPLAs possess remarkable hydrolytic degradability, and their cytotoxicity is relatively low. The CPLA‐IL‐8 siRNA nanoplexes can be readily taken up by prostate cancer cells, resulting in significant IL‐8 gene silencing. It is found that the degradability and cytotoxicity of CPLAs, as well as the transfection efficiency of the CPLA‐IL‐8 siRNA nanoplexes, positively correlate with the amine mol% of CPLAs.
Graphene Multilayer Supported Gold Nanoparticles for Efficient Electrocatalysts Toward Methanol Oxidation
Authors: Choi Yuri , Gu Minsu , Park Jongnam , Song Hyun‐Kon , Kim Byeong‐Su
Published: July 2012

This study reports a simple method of integrating electroactive gold nanoparticles (Au NPs) with graphene oxide (GO) nanosheet support by layer‐by‐layer (LbL) assembly for the creation of 3‐dimensional electrocatalytic thin films that are active toward methanol oxidation. This approach involves the alternating assembly of two oppositely charged suspensions of Au NPs with GO nanosheets based on electrostatic interactions. The GO nanosheets not only serve as structural components of the multilayer thin film, but also potentially improve the utilization and dispersion of Au NPs by taking advantages of the high catalytic surface area and the electronic conduction of graphene nanosheets. Furthermore, it is found that the electrocatalytic activity of the multilayer thin films of Au NPs with graphene nanosheet is highly tunable with respect to the number of bilayers and thermal treatment, benefiting from the advantageous features of LbL assembly. Because of the highly versatile and tunable properties of LbL assembled thin films coupled with electrocatalytic NPs, we anticipate that the general concept presented here will offer new types of electroactive catalysts for direct methanol fuel cells.
Palladium nanoparticles supported on SiO2by chemical vapor deposition (CVD) technique as efficient catalyst for Suzuki–Miyaura coupling of aryl bromides and iodides: selective coupling of halophenols
Authors: Iranpoor Nasser , Firouzabadi Habib , Safavi Afsaneh , Motevalli Somayeh , Doroodmand Mohammad M.
Published: July 2012

Nanoparticles of palladium were supported on SiO2by chemical vapor deposition technique. The obtained Pd nanocatalyst was characterized by various techniques. This catalyst was found to be very efficient for the selective cross‐coupling of hydroxyl‐substituted aryl iodides and bromide with arylboronic acids in water at room temperature to produce the corresponding hydroxyl‐substituted biaryls. Coupling of phenylboronic acid with aryl iodides and bromides carrying substituents other than hydroxy group was also performed efficiently in refluxing ethanol. Copyright © 2012 John Wiley & Sons, Ltd.
Oxidation of CoO Studied with the Perturbed Angular Correlation Method
Authors: Wegner D. , Inglot Z. , Lieb K. P.
Published: July 2012

The substages of the oxidation of CoO have been investigated with the PAC method during isochronal and isothermal annealings at low oxygen activity (10−9 atm). The successive trapping of cation vacancies at the 111In probe atoms up to the formation of spinel‐like microclusters has been observed. The results of the PAC experiments are compared with those of X‐ray diffraction and RBS analyses and confirmed by a PAC experiment for 111In in Co3O4. A quantitative analysis of the oxidation kinetics in terms of first order rate equations yields an activation enthalpy of ΔH = 0.27(4) eV. It is found that the absorption of oxygen and the formation of vacancies at the surface are the rate controlling processes in this experiment.
A Study of the Photochromic and Electrochromic Properties of MoO3 Thin Films
Authors: Yao J. N. , Loo B. H. , Fujishima A.
Published: July 2012

The photochromic and electrochromic responses of MoO3 thin films subjecting to UV irradiation were investigated in different environments. It was found that photochromic responses were different in different chemical environments. The presence of oxygen had a detrimental effect on the photochromic responses of the films. Additionally, the irradiated MoO3 films, after biased negatively in 0.1 M LiClO4/propylene carbonate solution, showed enhancement in electrochromism when compared to the non‐irradiated samples treated in a similar fashion. The MoO3 and WO3 thin films showed significant differences in photochromic responses in HCOOH and C2H5OH vapors.
Cyclic Voltammetry for Electron Transfer Reactions at Liquid/Liquid Interfaces
Authors: Stewart A. A. , Campbell J. A. , Girault H. H. , Edddowes M.
Published: July 2012

A theory for cyclic voltammetry at liquid/liquid interfaces for electron transfer is proposed, and the numerical solution of the resulting integral equation is evaluated. This theory has been used to show how the cyclic voltammograms, for electron transfer at ITIES, vary when different ratios of reactants and products, in both phases, are used, and how these voltammograms differ from classical cyclic voltammograms.
Molar Fraction Dependence of Excitation Energy Transfer in Mixed Monolayer Assemblies of 11‐(9‐Carbazolyl)undecanoic Acid and Long‐chain Fatty Acids
Authors: Nagamura Toshihiko , Kamata Shigenobu , Toyozawa Kenji , Ogawa Teiichiro
Published: July 2012

The efficient energy transfer from 11‐(9‐carbazolyl)undecanoic acid to a very small fraction (470 ppm) of benzocarbazolyl derivatives in mixed monolayer assemblies with long‐chain fatty acids was observed when the molar fraction of chromophore‐containing amphiphiles (fc) was higher than about 0.05. The fluorescence intensity ratio of acceptors and donors increased with the molar fraction. It tended to saturate when fc is larger than about 0.2. Such fraction dependence was not explained by the Förster energy transfer among randomly distributed chromophores, but was analyzed by the exciton migration model. Our results show that aggregation of chromophores in mixed monolayer assemblies does occur depending on the molar fraction fc.
Correlation Field, Two‐Dimensional First Order Phase Transition and Heats of Adsorption in CO2on the NaCl(100) Cleavage Plane
Authors: Heidberg J. , Kampshoff E. , Schönekäs O. , Stein H. , Weiss H.
Published: July 2012

Infrared spectra of13C16O2adsorbed on the NaCl(100) cleavage plane from zero to monolayer coverage θ and the corresponding adsorption isotherms have been measured. At 0.3 θm≲ θ ≲ θm,θmbeing the CO2monolayer coverage, thev3vibrational band of adsorbed CO2shows a doublet structure due to a correlation field, whereas at θ ≲ 0.3 θma single band is observed. — The coverage and polarization dependence of the spectra as well as the shape of the isotherms between 80 and 95 K adsorbate temperature reveal a two‐dimensional (2D) first order phase transition from a 2D low density phase into a 2D island‐like solid. The isosteric heats of adsorption have been determined to be 28.5 kJ mol−1and 24 kJ mol−1(‐10% and +25% error) for θ = 0.08 θmand θ = 0.96 θm,respectively. — In the 2D solid there are two CO2molecules per unit cell with a (2 × 1) herringbone structure and two‐dimensional space group pg. The angle between the linear CO2molecule and the NaCl(100) plane is (27 & 5)°. In the 2D low density phase a parallel orientation of the CO2molecules with respect to the surface and a site symmetry C2vhas been found.
Time‐reversible Molecular Motion and Macroscopic Irreversibility
Authors: Posch Harald A. , Hoover William G. , Holian Brad Lee
Published: July 2012

The thermodynamic irreversibility of molecular processes involving heat transfer is established by incorporating time‐reversible dynamical thermostats in the equations of motion. It is then possible to understand why nonequilibrium steady states must obey the Second Law of Thermodynamics, not just with high probability, but with probability one. This is because nonequilibrium states are so rare, relative to equilibrium ones, as to occupy a zero‐volume multifractal part of equilibrium phase space. These conclusions are generally valid. We illustrate them here by studying equilibrium manybody systems, both solid and fluid, as well as a simple one‐body chaotic nonequilibrium steady state. In all these cases we follow the motion of an orthonormal set of comoving vectors {δ}, determining the time‐averaged “Lyapunov Spectrum” of dynamic instability rates, as well as the vectors “Rotation Spectrum”, and relating these spectra to the irreversible nature of nonequilibrium flows described above.
Short‐Wavelength Collective Dynamics in Metastable Water A Molecular Dynamics Simulation Study
Authors: Kowall Th. , Mausbach P. , Geiger A.
Published: July 2012

Motivated by a controversial discussion of the short‐wavelength collective dynamics in water, we calculate the coherent dynamic structure factor from the oxygen motion in low‐density water. In accord with early results of Rahman and Stillinger, we detect at the lowest accessible wavevectors the simultaneous existence of two Brillouin lines. Whereas the low‐frequency mode is strongly damped and is considered to be a remnant of the ordinary sound, the high‐frequency mode can be attributed to collective excitations, propagating within the hydrogen‐bond network. Consequently, a density decrease lowers the weak damping of this mode even more, due to the increasing rigidity of the hydrogen‐bond network. For comparison, we also discuss the temperature and density dependence of a related single particle property, the frequency spectrum of the velocity autocorrelation function.
The Molecular Dynamics of Adsorbed Hydrocarbons
Authors: Leggetter S. , Tildesley D. J.
Published: July 2012

The molecular dynamics simulation technique has been used to study the adsorption of hydrocarbons on a structured graphite surface. Simulations were performed on a united atom model of butane at 282 K and surface coverages of 22.3 Å2/molecule and 32 Å2/molecule. One simulation of decane was performed at 291 K and a surface coverage of 85.6 Å2/molecule. We report in‐plane and out‐of‐plane velocity autocorrelation functions and the surface diffusion coefficients, angular velocity and the reorientational correlation functions and the time correlation functions associated with the conformational dynamics of these flexible molecules.
Computer Simulation of Liquid Methyl Iodide
Authors: Crone‐Münzebrock H. , Döge G.
Published: July 2012

A simple intermolecular potential — with five Lennard‐Jones‐centers and five point charges at the atoms of the molecule — has been used for a molecular dynamic simulation of liquid CH3I at 298 K and 213 K. Structural and dynamical data like radial distribution functions, reorientational correlation times and diffusion coefficients have been calculated and are in good agreement with experimental data. The distributions of some angular functions have been studied to obtain the most probable pair configuration. Particular the Wertheim D(12)‐function has been compared with results of Raman studies of intermolecular vibrational coupling.
High‐Pressure NMR Spectroscopy of the Dynamic Processes in Complex Liquids
Authors: Jonas J.
Published: July 2012

This lecture reviews recent applications of the high resolution, high‐pressure NMR spectroscopy to the study of the dynamics in complex liquids. After a brief introduction which points out the essential role of pressure as an experimental variable in the studies of the dynamic structure of liquids, three main topics are covered. — First, selected results of the high‐resolution, natural abundance 13C NMR relaxation experiments on complex liquids of 2‐ethylhexyl cyclohexanecarboxylate and 2‐ethylhexyl benzoate are presented. Second, the experimental studies of the dynamical solvent effects on reaction rates in several systems including 1,1‐difluorocyclohexane, N,N‐dimethyltrichloro‐acetamide, and rhodium complexes are briefly discussed. Third, the promising future of the high‐resolution, high‐pressure NMR techniques to investigate the dynamics in biochemical systems is illustrated on several studies currently in progress in our laboratory.
The Microscopic Basis of Self Diffusion — Mutual Diffusion Relationships in Binary Liquid Mixtures
Authors: Weingärtner Hermann
Published: July 2012

The general relation between self and mutual diffusion coefficients in binary liquid mixtures is best described in terms of velocity cross‐correlation integrals fab. In analogy to the definition of the self diffusion coefficient in terms of a time integral over the velocity autocorrelation function, the fab are given as integrals over velocity cross‐correlation functions. As the latter coefficients are measures for the coupling of the diffusive motions between pairs of particles, they may be used for probing intermolecular interactions in liquid mixtures. The approach is illustrated in application by considering diffusion in some thermodynamically ideal systems and in systems with strong positive and negative deviations from Raoult's law.
Polyion Selfdiffusion in Salt‐Free Solutions of Sodium Poly(Styrene Sulfonate)
Authors: Oostwal M. G. , Blees M. H. , De Bleijser J. , Leyte J. C.
Published: July 2012

The selfdiffusion of polyions in semidilute aqueous salt‐free solutions of the linear polyelectrolyte Sodium Poly(Styrene sulfonate) has been studied by use of Pulsed Field Gradient NMR as a function of concentration and degree of polymerization. The diffusion of the polyions was found to be only moderately dependent on polymer concentration over a large concentration range. A possible transition in diffusional behaviour, apparently independent of molecular weight, has been found to occur at a polymer concentration of about 0.05 monomolal. The molecular weight dependence of the diffusion exhibited almost Rouse‐like behaviour over the concentration range under consideration for degrees of polymerization between 87 (Mw = 16000) and 1066 (Mw = 195000) which indicates that entanglements are probably only of minor importance. Both the concentration and molecular weight dependencies are in contrast to the behaviour of neutral polymers in the semidilute regime.
Determination of Binary Diffusion Coefficients in Supercritical Carbon Dioxide with Supercritical Fluid Chromatography (SFC)
Authors: Dahmen Nicolaus , Dülberg Andreas , Schneider Gerhard M.
Published: July 2012

Binary diffusion coefficients D12 in supercritical carbon dioxide were determined in a Supercritical Fluid Chromatography (SFC) apparatus by the peak broadening method (PBM). Some cyclic and linear ketones were investigated as a function of pressure between 9.5 and 18 MPa at about 314 K corresponding to densities from 513 to 820 kg m−3. The resulting D12 values are of the order of 10−8 m2 s−1 and In D12 decreases about linearly with increasing density ϱ of the CO2.
Pressure‐Jump Experiments for the Study of the Kinetics of Phase Separation in the Binary System Ethene/Hexane. II. Measurements of Pressure‐Induced Temperature Changes
Authors: Metz U. , Schneider G. M.
Published: July 2012

In order to study the process of demixing of the binary gas/liquid system ethene/hexane we used a pressure‐jump technique that makes possible to generate differential pressure jumps from 0.05 up to 1 MPa into the miscibility gap. For relating the time‐dependent appearance of a new phase by means of light scattering to the respective maximum supersaturation of the system under test (see Part I), the knowledge of the corresponding adiabatic temperature changes induced by the pressure jumps was necessary. In this paper we report transient temperature measurements at pressures up to 8 MPa and temperatures from 293 to 323 K that were made with a thermocouple in contact with the binary liquid phase. An empirical formula is presented and discussed which relates the adiabatic thermal pressure coefficient to the critical temperatures and the critical pressures of the binary system over pressures and temperatures ranging from 2 MPa and 20 K respectively away from the vicinity of the critical line.
Elementary Processes of CF2(Ā1B1) and CF2(X̄1A1) with Reactive Gases
Authors: Dornhöfer G. , Hack W. , Hoyermann K. , Rohde G.
Published: July 2012

Elementary reactions of CF2(Ā1B1) and CF2(X̄1A1) were studied in the gas phase at low pressures and room temperature. Microwave discharges, IR‐ and UV‐Laser photolysis were used to produce CF2(X̄) radicals. Single vibronic level (SVL) excitation into the Ā1B1(0, 6, 0) state was performed with a KrF laser, and the fluorescence of that state was used to monitor their decay. Different experimental arrangements have been used. ‐ The rates of collisional removal of CF2(Ā) radicals were directly measured by the time resolved fluorescence in a quasistatic laser photolysis cell. The rates at room temperature were found to be: (CH3)2 C2(CH3)2 (39 ± 5), CH3 OCHCH2 (27 ± 5), CH2O (13 ± 2), SO2 (30 ± 1), NH3 (14 ± 2) H2O (3.5 ± 0.5), CO2 (0.39 ± 0.1) and H2 (0.82 ± 0.1) (in 1013 cm3/mol s units). The contribution of chemical product formation in the reaction CF2(Ā) + H2 CHF(X̄) + HF was deduced from the CHF(X̄) concentration as measured via LIF. ‐ By mass spectrometric studies of the reactions of CF2(Ā) radicals with (CH3)2C2(CH3)2 and (CH3)2C2H2, the removal rates of CF2(Ā) were assigned to physical quenching (> 99%). The rate constants for the reactions of CF2(X̄) with (CH3)2C2(CH3)2 and (CH3)2C2H2 were determined as (3.6 ± 1.5) · 109 and (6.67 ± 3) · 108 cm3/mol s respectively.
The Static Dielectric Constant of Methyl Cyanide to 350°C and 2000 bar
Authors: Hill W. W. , Rosenzweig S. , Franck E. U.
Published: July 2012

The relative static dielectric constant ε of methyl cyanide was measured from 20 to 350°C, from 50 to 2250 bar and for the liquid along the saturation line to 270°C (Tc = 274.7°C). — Equipment and experimental procedure are described. At 20°C and pressures of 50 and 2000 bar ε changes from 37.7 to 42.9. At 100°C the change over the same pressure range is from 26.6 to 32.4 and at 300°C from 2.50 to 18.5. The accuracy of the data is ±0.4% up to 100°C and ±0.6% up to 300°C. Above 300°C and below 200 bar the data may be uncertain within ±1 or ±2%. Diagrams with ε‐values in dependence of density and temperature are given. The Kirkwood correlation factor below a density of 0.4 g cm−3 is slightly above unity. At densities higher than 0.4 g cm−3 ε declines at all temperatures to about 0.8 at 0.8 g cm−3. This may indicate a certain degree of dimerization, which is discussed.
Importance of Metastable RNA Folding in Template‐Replicase Interactions
Authors: Fernández Ariel
Published: July 2012

We consider the autocatalytic synthesis of MDV‐1 RNA by Q beta replicase, which proceeds by template‐instructed replication. We predict the effect of a particular point mutation in the sequence on the overall doubling time and conjecture its role on the recognition step. The mutation considered destabilizes the folding of the internal recognition site. The theoretical analysis is based on the calculation of nonequilibrium re‐folding events which occur in the RNA chains as they are being synthesized. Free‐energy minima are irrelevant. In order to test the theoretical findings, we incubate both the natural template and the mutant simultaneously, in the presence of the replicase. The experiment reveals that the mutation facilitates the enzyme‐template interaction, thus enhancing recognition. However, examining the exponential phase of the replication kinetics, where the enzyme is in large excess with respect to the RNA species, we can conclude that the mutant presents a larger overall doubling time, in good agreement with our theoretical findings.
Structural Study of Liquid Ethylbromide Using Differential Anomalous X‐ray Scattering
Authors: Mager T. , Schultz E. , Bertagnolli H. , Frahm R.
Published: July 2012

Synchrotron radiation was used for a differential anomalous X‐ray scattering (DAS) study of liquid ethylbromide (C2H5Br). Two diffraction experiments were carried out at photon energies of 12500 and 13464 eV. The dispersion corrections were determined from photoabsorption coefficients obtained from an absorption experiment. After an elaborate and involved data evaluation and correction procedure a differential structure factor was obtained. The peak assignation in the differential atom pair correlation function (DAPCF) was verified by comparison with a theoretical intramolecular distribution function calculated from well known data of the intramolecular geometry of ethylbromide. In addition, a peak at 4.1 Å is found in the DAPCF, which may be assigned to an intermolecular Br—Br atom pair suggesting a strong dispersion interaction.
TiO2 and Bi2O3 Thin Film Oxygen Sensor Materials
Authors: Nicoloso N.
Published: July 2012

The electrical conductivity of polycrystalline TiO2 and Bi2O3, deposited on sapphire substrate by various methods, has been determined as a function of the film thickness, the oxygen partial pressure and the temperature. As a rule, TiO2 films with d ≲ 30 nm are incoherent after heat treatment, thereby restricting the miniaturization of the planar sensor device. Larger films essentially behave like bulk material with fully ionized oxygen defects V2•o (or Ti4•i interstitials) as major intrinsic defects. In case of extrinsic p‐type films, the conductivity contribution of the TiO2/sapphire substrate and TiO2/gas phase interfaces is clearly enhanced with respect to the bulk contribution, mainly due to segregation effects. Doubly ionized oxygen vacancies V2•o and M'Ti defects (trivalent acceptor atoms at Ti‐sites) appear to be the main intrinsic and extrinsic defects involved in the segregation process and in the oxygen exchange reaction. In contrast to TiO2, thin films of Bi2O3 react strongly with the substrate ultimately forming a new stable phase, Al4Bi2O9. Along with this structural change, the conductivity decreases by several orders of magnitude, classifying Bi2O3 as an unsuitable material for such thin film sensor devices.
In Situ Measurements of Tropospheric OH Radicals — A Challenge for the Experimentalist
Authors: Armerding W. , Herbert A. , Schindler T. , Spiekermann M. , Comes F. J.
Published: July 2012

A method for monitoring tropospheric OH and other tropospheric trace gases is discribed which makes use of differential absorption spectroscopy and is based on the fast scanning of a narrowband, frequency‐doubled, and power‐stabilized dye laser. Due to the fast scanning and the power stabilization the fluctuations of the atmosphere and the light source are minimized thus a detection limit better than 10−5 can be achieved for atmospheric long‐path absorption measurements. In a first test in the near of Frankfurt/Main tropospheric OH was observed with an averaged concentration of 1 · 106 OH cm−3. The absorption path‐length was 800 m and the acquisition time 5 min.
Temperature Dependence of Molecular Motions in Polymethylmethacrylate Studied by Positron Annihilation Techniques
Authors: Millán S. , Geckle U. , Lévay B. , Ache H. J.
Published: July 2012

Untreated polymethylmethacrylate (PMMA) as well as PMMA into which charges were injected (PMMA‐electret) were studied by positron annihilation techniques (PAT). A comparison of the PAT data with previously reported results obtained via different techniques including thermally stimulated discharge (TSD) shows good agreement and suggests that the observed effects can be explained by the onset of different types of molecular motions in the polymer. It appears that in the case of the PMMA‐electret an additional transition at 130 K can be identified which may be correlated with a different type of molecular motion, presumably with the rotation of the methyl group of the ester side chain.
Photochemistry in Porous Materials I: Fluorescence Quenching of Anthracene Adsorbed on Different Silicagel Preparations
Authors: Wolff Thomas , Akbarian Fatemeh , Von Bünau Günther
Published: July 2012

Fluorescence excitation spectra of anthracene adsorbed on the internal surface of two silicagel preparations (pore diameters of 3.7 and 8.6 nm respectively) were recorded in the wavelength interval 290 to 390 nm in the absence and presence of oxygen and argon. Areas under these curves were taken as relative measures of fluorescence quantum yields. Fluorescence is quenched strongly by oxygen, following Langmuir‐Hinshelwood‐kinetics with respect to oxygen partial pressures. Very little quenching occurs in the presence of argon. Oxygen quenching rates do not depend on pore size.
Subbandgap Photocurrent of a Ru‐Covered n‐GaAs|Acidic‐Electrolyte Junction
Authors: Jung Ch. , Kolb D. M.
Published: July 2012

The subbandgap photocurrent dependence on electrode potential and light energy has been investigated for the n‐GaAs(100) | 1 M HCl junction after surface modification by electroless deposition of ruthenium. A pronounced peak in the photocurrent‐potential curve was found for Ru‐treated electrodes between −0.6 and −0.1 V/SCE. This behaviour is explained in a model simulation for the photocurrent which takes into account the hole generation in a Ru‐induced surface state by absorption of subbandgap light.
KrF Laser Induced Telomerization of Bromides with Olefins. Part 1: Self‐Inhibition and Kinetic Analysis
Authors: Linyang Zhang , Fuß W. , Kompa K. L.
Published: July 2012

The chain reaction of several organic bromides with olefins was induced by a KrF laser. In all cases we found a self‐inhibition, leading to a termination of first order in the radical concentration. There is indirect evidence that it is due to molecular bromine, accumulated during the reaction in spite of the presence of olefins. It has not been noticed previously. We show that kinetic analysis is easy also for pulsed excitation, and the example CF3Br + C2H4 is studied in detail. We found rate constants for CF3 + C2H4 → CF2C2H4 (7.2 · 109 cm3 mol−1 s−1; this is in between two previous values) and for CF3C2H4 + CF3Br → CF3C2H4Br + CF3 (1.2 · 109 cm3 mol−1 s−1) as well as preliminary values for some other reactions.
Solid State Electrochemical Chlorine Gas Sensor
Authors: Schlechtriemen Gerd‐Ludwig , Sohège Jürgen
Published: July 2012

A solid state sensor for monitoring chlorine is presented. The applied method is the potentiometric partial pressure measurement via heterogeneous secondary equilibria using an appropriate solid state galvanic cell. The sensor is a planar double cell mounted on a supporting ceramic carrier. A high impedance converting circuit and a thick film heating structure are integrated. The various fabrication steps are reported. The sensor is working between 430 and 490 K. The sensitivity to chlorine ranges down to the sub‐ppm region. The response behaviour as well as interferences of water vapour and hydrogen sulfide are discussed.
Electrochemical Detection of Organic Gases: The Development of a Formaldehyde Sensor
Authors: Baltruschat H. , Anastasijevic N. A. , Beltowska‐Brzezinska M. , Hambitzer G. , Heitbaum J.
Published: July 2012

Using differential electrochemical mass spectrometry, we determined the amount of H2‐evolution occuring during formaldehyde oxidation as a function in the potential region of the first oxidation wave. In the second wave, the oxidation product is CO2 in pH 8 solution, as opposed to more alcaline solutions where only formiate is formed. Formaldehyde is reduced to methanol at potentials negative of the RHE.—An electrochemical formaldehyde sensor was built with a sensitivity below 1 ppm. Cross sensitivities towards alcohols can be lowered by UPD of Ag or Hg.
Polymer Membranes for Fuel Cells
Authors: Scherer Günther G.
Published: July 2012

A brief description of the ion exchange membrane fuel cell, of important membrane properties and of some earlier membrane development work is given. We describe some results of membrane stability tests in electrolysis cells, which are important for fuel cell application, in context with fluorination degree and morphology of the membrane. These results demonstrate, that fluorinated membranes with “defined” morphology can be applied in these cells. Finally, we give evidence for asymmetric degradation of membranes at the H2‐side.
An FTIR Study of the Catalytic Activity of a 85:15 Pt:Ru Alloy for Methanol Oxidation
Authors: Iwasita T. , Nart F. C. , Vielstich W.
Published: July 2012

In situ Fourier Transform Infrared Spectroscopy is used to study the catalytic properties of a Pt/Ru alloy as compared to pure platinum. Spectra taken at different potentials show the different behaviour of both metals with respect to methanol adsorption and oxidation. In the potential region below 700 mV the presence of Ru atoms increases the electrocatalytic activity of platinum. In the case of the alloy the poisoning adsorbate COad is adsorbed to a less extent and its seems to be weaker bonded to the Pt/Ru than to the Pt surface.
Tungsten Carbide Catalyzed Hydrogen Anodes for Electrochemical Processes
Authors: Möbius A. , Wiesener K.
Published: July 2012

The application of hydrogen diffusion anodes for the substitution of oxygen developing anodes in technical electrolyses for metal winning also in connection with recycling processes as well as the use of hydrogen diffusion anodes in electroplating technology is to be discussed under following aspects:

more effective energy use,

electrolytic generation of metals of higher purity,

generation of alloyed layers in electroplating and electroforming technology with improved properties and

recycling of pickling and etching bathes.
79Br and 127I Nuclear Quadrupole Resonance Study of Para‐Substituted Anilinium Halides, 4‐RC6H4NH⊕3X⊖ with X = Br, I and R = Cl, Br, SCN, and OCH3. Crystal Structure of 4‐Chloro‐ and 4‐Bromoanilinium Bromide Hemihydrate
Authors: Hartmann Jutta , Dou Shi‐Qi , Weiss Alarich
Published: July 2012

The 79Br and 127I nuclear quadrupole resonance spectra of para‐substituted anilinium bromides and iodides 4‐RC6H4NH⊕3X⊖ with X = Br, I and R = Cl, Br, SCN, OCH3 were studied in the temperature range 77 ≤ T/K ≤ 420. 4‐ClC6H4NH⊕3Br⊖ shows a phase transition at Tc = 132 ± 1 K. 4‐ClC6H4NH⊕3Br⊖ as well as 4‐BrC6H4NH⊕3Br⊖ exist as hemihydrates, too. The two hemihydrates are isomorphous, crystallizing monoclinic, C52h ‐ P21/c, Z = 8. 4‐ClC6H4NH⊕3Br⊖·1/2 H2O: a = 1370.9(5) pm, b = 789.1(3) pm, c = 1940.1(7) pm, β = 125.38(1)°; 4‐BrC6H4NH⊕3Br⊖ · 1/2 H2O: a = 1380.1(7) pm, b = 794.8(5) pm, c = 1934.2(9) pm, β = 125.11(1)°. The influence of hydrogen bonds on 79Br NQR is investigated. NQR results and the structures of the studied compounds are discussed in comparison with known bond properties of anilinium halides.
The Membrane Properties of the Electro‐Polymerized Conducting Pyrrole/N‐Sulfopropyl‐Pyrrole Copolymer
Authors: Zhong Chuanjian , Storck Winfried , Doblhofer Karl
Published: July 2012

Electronically conducting polymer films were prepared electrochemically from aqueous electrolytes containing mixtures of pyrrole and N‐(3‐sulfopropyl)pyrrole. The reversible electrochemical oxidation and reduction (redox‐switching) of these coatings have been studied, mainly with the method of cyclic voltammetry. At various electrode potentials the coated electrodes were withdrawn from the solutions to determine the composition of the films gravimetrically and by energy‐dispersive analysis of X‐rays (EDAX). Volta‐potential measurements were conducted to obtain information on the Donnan‐potentials. Thus the membrane properties of the coatings were characterized as a function of the electrode potential and the mole fraction of sulfonate groups fixed in the copolymer matrix. While conventional polypyrrole films constitute anion exchangers in the oxidized state, the copolymers can be either anion‐ or cation‐exchangers, depending on the concentration of the fixed anions. When the polymer matrix contains about one sulfonate group per 10 pyrrole units, the film undergoes, during redox‐switching, a reversible and complete transition between anion‐ and cation‐exchange character.
Current Oscillations in the Anodic Dissolution of Silicon in Fluoride Electrolytes
Authors: Ozanam F. , Chazalviel J.‐N. , Radi A. , Etman M.
Published: July 2012

The oscillations of the current which take place during the anodic dissolution of silicon in fluoride electrolytes have been investigated. These oscillations occur only upon a perturbation in the electrode potential, and are associated with a fluctuation of the thickness of an oxide layer on the electrode surface. In the corresponding potential range, the experimental data strongly support the picture of a surface consisting of a juxtaposition of small self‐oscillating areas. These areas are decorrelated from each other in the steady state, but are synchronized by a potential perturbation, giving rise to macroscopic oscillations.
Boltzmann Transformation of Taylor Dispersion Profiles to Determine Concentration‐Dependent Diffusion Coefficients. Aqueous Cetylpyridinium Chloride near the Critical Micelle Concentration
Authors: Leaist Derek G.
Published: July 2012

The Taylor dispersion technique is modified to measure the concentration‐dependent mutual diffusion coefficient D of cetylpyridinium chloride (CPC) + water at 25°C near the critical micelle concentration. The solution flowing into the dispersion tube is changed from a solution of CPC concentration C− to a solution of concentration C− + ΔC, forming an initially‐sharp moving boundary at the tube inlet. The broadened concentration profile across the eluted boundary is followed by using a flow‐through differential refractometer at the tube outlet. A numerical procedure similar to the Boltzmann‐Matano procedure for the analysis of free diffusion profiles yields the values of D at the concentrations between C− and C− + ΔC, from a single dispersion run. D for aqueous CPC is found to drop very sharply as the concentration is raised through the critical micelle concentration.