bluuebunny/crossref_metadata_2025_split huggingface dataset:
Approximations to Optimal k‐Unit Cycles for Single‐Gripper and Dual‐Gripper Robotic Cells
Authors: Geismar H. Neil , Chan Lap Mui Ann , Dawande Milind , Sriskandarajah Chelliah 
Published: December 2008

We consider the problem of scheduling operations in bufferless robotic cells that produce identical parts using either single‐gripper or dual‐gripper robots. The objective is to find a cyclic sequence of robot moves that minimizes the long‐run average time to produce a part or, equivalently, maximizes the throughput. Obtaining an efficient algorithm for an optimum k‐unit cyclic solution ( k ≥ 1) has been a longstanding open problem. For both single‐gripper and dual‐gripper cells, the approximation algorithms in this paper provide the best‐known performance guarantees (obtainable in polynomial time) for an optimal cyclic solution. We provide two algorithms that have a running time linear in the number of machines: for single‐gripper cells (respectively, dual‐gripper cells), the performance guarantee is 9/7 (respectively, 3/2). The domain considered is free‐pickup cells with constant intermachine travel time. Our structural analysis is an important step toward resolving the complexity status of finding an optimal cyclic solution in either a single‐gripper or a dual‐gripper cell. We also identify optimal cyclic solutions for a variety of special cases. Our analysis provides production managers valuable insights into the schedules that maximize productivity for both single‐gripper and dual‐gripper cells for any combination of processing requirements and physical parameters.
Pom Forum: Operations Management's Next Source of Galvanizing Energy?
Authors: Hayes Robert H. 
Published: December 2008

I am concerned that the field of production and operations management is losing direction and cohesion, as well as the battle for the best new faculty, student enrollments, and research funding. This problem is not due to a lack of interesting initiatives but because our several active subfields are pulling us in different directions and causing our common ground to shrink. This is at a time when firms around the globe are facing perplexing operating problems that are apparently not resolvable through existing theories and techniques. Other academic fields have experienced similar strains at certain points, and they tend to get to that point following a progression like those that production and operations management has witnessed three times in the past 50 years. After briefly describing these past histories, I propose that we are near the end of one cycle and need a new jolt of energy to begin another. The problems of coordinating the complex collaborations among networked organizations (the Coordination of Operations across Multiple Organizations) are becoming increasingly important in today's economy. I suggest that intensive multiteam studies of such networks could provide new insights into these pressing problems, stimulate creativity, and help reunify our field.
Crystal Engineering Approach To Design Colorimetric Indicator Array To Discriminate Positional Isomers of Aromatic Organic Molecules
Authors: Trivedi Darshak R. , Fujiki Yuzo , Fujita Norifumi , Shinkai Seiji , Sada Kazuki 
Published: December 2008

AbstractDiscriminating by color: A 2D colorimetric indicator array has been designed by a crystal engineering approach (N⋅⋅⋅HO hydrogen bonding and charge‐transfer complexation) involving solid‐state co‐grinding for the visual discrimination of positional isomers of dihydroxynaphthalene. Factors governing the close packing of π planes, and hence color of the complex, were determined by single‐crystal X‐ray analysis, allowing fine tuning by crystal engineering.magnified imageA 2D colorimetric indicator array to discriminate isomers of dihydroxynaphthalene has been designed by using a crystal engineering concept combined with solid‐state co‐grinding and charge‐transfer complexation. The N⋅⋅⋅HO supramolecular synthon between the pyridyl N atom of the probe and hydroxy group of the analyte has been observed in all reported single‐crystal X‐ray structures of resultant CT complexes. Solid‐state co‐grinding with aromatic solids easily provided the highly concentrated solvent‐free conditions required to promote the formation of charge‐transfer complexes with brighter color changes. Probe D (N,N′‐bis‐(4‐pyridyl)pyromellitic diimide) showed an excellent ability to discriminate eight isomers of dihydroxynaphthalene with a wide variety of colors of the resultant CT complexes.
Stimulating personality: Ethical criteria for deep brain stimulation in psychiatric patients and for enhancement purposes
Authors: Synofzik Matthis , Schlaepfer Thomas E. 
Published: December 2008

AbstractWithin the recent development of brain‐machine‐interfaces deep brain stimulation (DBS) has become one of the most promising approaches for neuromodulation. After its introduction more than 20 years ago, it has in clinical routine become a successful tool for treating neurological disorders like Parkinson's disease, essential tremor and dystonia. Recent evidence also demonstrates efficacy in improving emotional and cognitive processing in obsessive‐compulsive disorder and major depression, thus allowing new treatment options for treatment refractory psychiatric diseases, and even indicating future potential to enhance functioning in healthy subjects. We demonstrate here that DBS is neither intrinsically unethical for psychiatric indications nor for enhancement purposes. To gain normative orientation, the concept of “personality” is not useful – even if a naturalistic notion is employed. As an alternative, the common and widely accepted bioethical criteria of beneficence, non‐maleficence, and autonomy allow a clinically applicable, highly differentiated context‐ and case‐sensitive approach. Based on these criteria, an ethical analysis of empirical evidence from both DBS in movement disorders and DBS in psychiatric disease reveals that wide‐spread use of DBS for psychiatric indications is currently not legitimated and that the basis for enhancement purposes is even more questionable. Nevertheless, both applications might serve as ethically legitimate, promising purposes in the future.
Contacting the brain – aspects of a technology assessment of neural implants
Authors: Decker Michael , Fleischer Torsten 
Published: December 2008

AbstractThe public interest in neural implants has grown considerably in recent years. Progress within related research areas in combination with increasing – albeit overly optimistic and indiscriminate – mass media coverage have led to the impression that the possibilities of neural prosthetics have grown enormously. But a closer look reveals that the reasons for the intensified interest are varied and cannot be attributed to technical progress alone. Some neural prostheses that have been under development for many years have not left the clinical development phase despite intensive research activities. Other implants, like cardiac pacemakers and cochlea implants, are mature products that have already been implanted in a large number of patients.From the public perspective and in media reports, progress in the development of neural implants is associated with new achievements in other fields of neuroscience. Communications on new applications of functional magnetic resonance imaging (fMRI) may suggest that a number of cognitive functions are now easily accessible with technological means. The fact that the interpretation of the results of fMRI studies depends on many conditions and is partly disputed also within the scientific community has been discussed in many publications but only very limited, in the general media. Besides this, research results and implementations in the area of electroencephalography and magnetoencephalography have sparked further debate on the question of free will, on determinism and indeterminism, and have attracted a large media response.The purpose of this paper is to discuss some societal and ethical aspects of neural implants from a technology assessment perspective. Technology assessment (TA) aims at providing knowledge about impacts and consequences of (new) technologies as well as about political and societal ways of dealing with them. It reflects about implementation conditions of technology and potential technology conflicts. Over the last years, neural implants became a subject for TA since they have gained a higher attention in both the political arena and the general public. Especially the ethical and social implications of technologies that electrically stimulate the brain and the possibilities of changing personality traits, changing moods, and perhaps enhancing human cognitive capabilities are central issues in related discussions. In this paper, we want to briefly summarize some of the key arguments as well as topics for future discussion and research.
Das Spurenelement Iod. Zu wenig und zu viel schadet dem Organismus
Authors: Anke Manfred , Arnhold Winfried 
Published: December 2008

AbstractIod ist ein lebenswichtiges chemisches Element. Der Iodbedarf Erwachsener beträgt 1 μg/kg Körpergewicht, empfohlen wird die Aufnahme von 2 μg/kg Körpergewicht. Iodmangel führt zu verschiedenen Krankheitsbildern, von denen der so genannte “Kropf” das bekannteste ist. Doch nicht nur Iodmangel ist gefährlich: Bei einem Konsum von > 7 μg/kg können toxische Nebenwirkungen auftreten, die bei einem schnellen Übergang vom Iodmangel zu einer bedarfsbedingten Iodversorgung bei iodsensitiven Personen (häufig sind es ältere Frauen) zu einer Schilddrüsenüberfunktion führen.
Mikroevolution oder Faunenverfälschung?
Authors: Baier Felix 
Published: December 2008

AbstractIn Heidelberg fielen in den vergangenen Jahren vermehrt melanistische – schwarze – Exemplare der Mauereidechse (Podarcis muralis merremius) auf. Haben sich die Umweltbedingungen am Neckar derart verändert, dass eine schwarze Eidechse einen Selektionsvorteil erlangt? Oder kann das Vorkommen der schwarzen Tiere am Neckar gar nicht durch natürliche Faktoren erklärt werden, weil die Tiere einfach ausgesetzt wurden? Teilnehmer des Heidelberger Life‐Science Lab suchten mit molekularbiologischen Methoden nach einer Erklärung für das Phänomen.
Bistable Molecular Switches Based on Linkage Isomerization in Ruthenium Polypyridyl Complexes with a Ligand‐Bound Ambidentate Motif
Authors: Johansson Olof , Johannissen Linus O. , Lomoth Reiner 
Published: December 2008

AbstractElectron‐transfer‐induced linkage isomerization was investigated in a series of bis‐tridentate Ru polypyridyl complexes [Ru(L‐X‐OH)(Y‐tpy)]2+ with ambidentate ligand L‐X‐OH=bpy‐C(R)(OH)‐py (bpy=2,2′‐bipyridine; py=pyridine; R=H, Me, Ph, or tBu) and spectator ligand Y‐tpy (tpy=2,2′:6′,2′′‐terpyridine; Y=p‐tolyl, p‐PhCO2Me, Cl, OEt, N‐pyrrolidine). The ligand‐bound ambidentate motif switches reversibly between N and O coordination in the RuII and RuIII state, respectively. The potentials of the RuIII/II couple differ by about 0.5 V between the isomers, and this results in a bistable electrochemical response of the molecular switches. The effects of structural modifications in form of substituents on the linking carbon atom of the ambidentate ligand and on the central pyridine moiety of the spectator ligand were investigated by electrochemical and computational methods. Differences in isomerization behavior span six orders of magnitude in rate constants and two orders of magnitude in equilibrium constants. The results can be interpreted in terms of steric and electronic substituent effects and their influence on rotational barriers, ligation geometry, and electron deficiency of the metal center.
Molecular Materials with Contrasting Optical Responses from a Single‐Pot Reaction and Fluorescence Switching in a Carbon Acid
Authors: Patra A. , Radhakrishnan T. P. 
Published: December 2008

AbstractThree for the price of one: The reaction of tetracyanoquinodimethane with an aromatic amine is shown to follow an unusual course leading to three products in a single pot. The product molecules form a family of materials with contrasting optical responses, in that they exhibit light emission of different colors and emission switching that is sensitively triggered by acidic/basic environments (see scheme).magnified imageA wide variety of amines are known to react with 7,7,8,8‐tetracyanoquinodimethane (TCNQ) to yield push–pull diaminodicyanoquinodimethanes with a strongly zwitterionic structure and significant optical and nonlinear optical properties. A novel course of reaction is observed now with the amine 2‐methyl‐4‐chloroaniline, which leads to three well‐defined products, A–C, in a single pot. A and B are formed through the replacement of one cyano group in TCNQ by the amine; A is a carbon acid and B is its corresponding salt. C is the conventional product in which two cyano groups in TCNQ are replaced by the amine. The products are characterized structurally and spectroscopic studies reveal contrasting optical responses. A is nonfluorescent, whereas B and C show red and green emission, respectively, in the solution and solid states. The acid/conjugate‐base pair A and B can be interconverted through facile, reversible, and repeated deprotonation/protonation cycles, which are accompanied by instantaneous switching of the fluorescence. The current study illustrates an interesting case of a single‐pot reaction yielding different optical materials with attributes that can be switched through simple approaches such as protonation or tuned through modification of the push–pull characteristics.
Highly Dense Nitranilates‐Containing Nitrogen‐Rich Cations
Authors: Huang Yangen , Gao Haixiang , Twamley Brendan , Shreeve Jean'ne M. 
Published: December 2008

AbstractHigh density energetic salts containing nitrogen‐rich cations and the nitranilic anion were readily synthesized in high yield by metathesis reactions of sodium nitranilate 2 and an appropriate halide. All of the new compounds were fully characterized by elemental, spectral (IR, 1H, 13C NMR), and thermal (DSC) analyses. The structure of hydrazinium nitranilate (4) was also determined by single‐crystal X‐ray analysis. The high symmetry and oxygen content of the anion give these salts extensive hydrogen bonding capability which further results in the high densities, low water solubilities, and high thermal stabilities (Td> 200 °C) of these compounds. Theoretical performance calculations were carried out by using Gaussian 03 and Cheetah 5.0. The calculated detonation pressures (P) for these new salts fall between 17.5 GPa (10) and 31.7 GPa (4), and the detonation velocities (νD) range between 7022 m s−1 (13) and 8638 m s−1 (4).
Computational Investigation of Hydrogen Adsorption by Alkali‐Metal‐Doped Organic Molecules: Role of Aromaticity
Authors: Srinivasu Kancharlapally , Chandrakumar Kuttay R. S. , Ghosh Swapan K. 
Published: December 2008

AbstractHydrogen storage: Simple organic molecular systems (CnHn, n=4, 5, 6, 8) are proposed for hydrogen storage purposes based on the concept of aromaticity. The adsorption of hydrogen is attributed to pronounced charge transfer from the sodium atom (green, see picture) to the organic systems and the electrostatic interaction between the ion and hydrogen molecules.magnified imageTheoretical studies on hydrogen adsorption in small organic molecular systems, such as cyclobutadiene (C4H4), the cyclopentadienyl radical (C5H5), benzene (C6H6), and cyclooctatetraene (C8H8) and their metal‐doped modifications, are carried out. Our results reveal that the simple van der Waals surfaces of pure organic molecules are not good enough for hydrogen adsorption due to the weak interaction between hydrogen molecules and the organic molecular surface. However, doping of alkali‐metal atoms in the above organic molecular systems increases their hydrogen adsorption ability significantly, mainly due to electron transfer from the metal atom to the carbon surface. This charged surface created around the metal atom is found to enhance the hydrogen adsorption capacity of the complex considerably, both in terms of interaction energy and the number of adsorbed hydrogen molecules, with a hydrogen adsorption capacity ranging from 10 to 12 wt %. The role of aromaticity in such molecular systems is important in stabilizing these ionized organo‐alkali‐metal complexes.
Efficient and Selective Telomerization of 1,3‐Butadiene with Diols Catalyzed by Palladium–Carbene Complexes
Authors: Grotevendt Anne , Jackstell Ralf , Michalik Dirk , Gomez Mario , Beller Matthias 
Published: December 2008

AbstractThe selective telomerization of 1,3‐butadiene with seven different linear and cyclic diols proceeds in the presence of in situ generated palladium carbene catalysts. By applying optimized reaction conditions, including very low metal loadings (2–10 ppm), excellent catalyst turnover numbers (>250 000) and good chemoselectivities are observed with respect to the mono‐octadienyl ether derivatives. This protocol allows the efficient preparation of unsaturated alcohols, which are useful for various applications.
Imido and Amido Titanium Complexes that Contain a [OSSO]‐Type Bis(phenolato) Ligand: Synthesis, Structures, and Hydroamination Catalysis
Authors: Lian Bing , Spaniol Thomas P. , Horrillo‐Martínez Patricia , Hultzsch Kai C. , Okuda Jun 
Published: December 2008

AbstractSalt metathesis reaction of the imido complex [Ti(NR)Cl2(NC5H5)3] (R = tBu, C6H3iPr2‐2,6) with 1 equiv. of the lithium salt of the corresponding [OSSO]‐type bis(phenol) [edtbpH2: (HOC6H2‐tBu2‐4,6)2(SCH2CH2S); rac‐(cydtbp)H2: (HOC6H2‐tBu2‐4,6)2(S2C6H10‐1,2)] afforded imido titanium complexes [Ti(edtbp)(NtBu)(NC5H5)] (1), [Ti(edtbp)(NC6H3iPr2‐2,6)(NC5H5)] (2), and [Ti{rac‐(cydtbp)}(NtBu)(NC5H5)] (3). The bis(dimethylamido)titanium complex [Ti(edtbp)(NMe2)2] (4) was synthesized by protonolysis of [Ti(NMe2)4] with bis(phenol) edtbpH2. Reaction of [Ti(NMe2)Cl3] with the lithium salt of the bis(phenol) gave the chloro dimethylamido complex [Ti(edtbp)(NMe2)Cl] (5) in high yield. All complexes were characterized by NMR spectroscopy and elemental analysis. Additionally, complexes 1 and 5 were studied by X‐ray diffraction analysis. Imido titanium complex 1 shows moderate activity in the intramolecular hydroamination reaction of 5‐phenylpent‐4‐ynylamine. Complexes 1–3 catalyze the intramolecular hydroamination of aminoalkenes. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
CE with LED‐based detection: An update
Authors: Xiao Dan , Yan Lei , Yuan Hongyan , Zhao Shulin , Yang Xiupei , Choi Martin M. F. 
Published: December 2008

AbstractCE detectors based on LEDs as light sources are attracting considerable attention and having increasing applications. They show excellent stable output with less energy consumption, have long lifetime, and are low‐cost, small in size, and able to work at various wavelengths. This review updates our last review article published in 2007 (Electrophoresis 2007, 28, 233–242) and focuses on the development and application of CE detectors based on LEDs reported in recent years. It describes the exciting new approaches and improved techniques. Three configurations of absorption and fluorescence detection techniques including right‐angle‐type, collinear‐type, and optical‐fiber fluorescence detector are introduced and compared. Lastly, it also discusses their applications and future perspectives in this field.
Use of near‐ and mid‐infrared spectroscopy to distinguish carbon and nitrogen originating from char and forest‐floor material in soils
Authors: Michel Kerstin , Terhoeven‐Urselmans Thomas , Nitschke Renate , Steffan Phillip , Ludwig Bernard 
Published: December 2008

AbstractThe presence of relatively inert organic materials such as char has to be considered in calibrations of soil C models or when calculating C‐turnover times in soils. Rapid and cheap spectroscopic techniques such as near‐infrared (NIRS) or mid‐infrared spectroscopy (MIRS) may be useful for the determination of the contents of char‐derived C in soils. To test the suitability of both spectroscopic techniques for this purpose, artificial mixtures of C‐free soil, char (lignite, anthracite, charcoal, or a mixture of the three coals) and forest‐floor Oa material were produced. The total C content of these mixtures (432 samples) ranged from 0.5% to 6% with a proportion of char‐derived C amounting to 0%, 20%, 40%, 50%, 60%, or 80%. All samples were scanned in the visible and near‐IR region (400–2500 nm). Cross‐validation equations for total C and N, C and N derived from char (Cchar, Nchar) and Oa material were developed using the whole spectrum (first and second derivative) and a modified partial least‐square regression method. Thirty‐six samples were additionally scanned in the middle‐IR and parts of the near‐IR region (7000–400 cm–1 which is 1430–25,000 nm) in the diffuse‐reflectance mode. All properties investigated were successfully predicted by NIRS as reflected by RSC values (ratio of standard deviation of the laboratory results to standard error of cross‐validation) > 4.3 and modeling efficiencies (EF) ≥ 0.98. Near‐infrared spectroscopy was also able to differentiate between the different coals. This was probably due to structural differences as suggested by wavelength assignment. Mid‐IR spectroscopy in the diffuse‐reflectance mode was also capable to successfully predict the parameters investigated. The EF values were > 0.9 for all constituents. Our results indicated that both spectroscopic techniques applied, NIRS and MIRS, are able to predict C and N derived from different sources in soil, if closed populations are considered.
Characterisation of carbonaceous materials using Raman spectroscopy: a comparison of carbon nanotube filters, single‐ and multi‐walled nanotubes, graphitised porous carbon and graphite
Authors: Heise H. M. , Kuckuk R. , Ojha A. K. , Srivastava A. , Srivastava V. , Asthana B. P. 
Published: December 2008

AbstractMulti‐walled carbon nanotube (MWCNT) filters have been recently synthesised which have specific molecular filtering capabilities and good mechanical strength. Optical and scanning electron microscopy (SEM) reveals the formation of highly aligned arrays of bundles of carbon nanotubes having lengths up to 500 µm. The Raman spectra of this material along with four other carbonaceous materials, commercially available single‐walled carbon nanotubes (SWCNTs) and MWCNTs, graphitised porous carbon (Carbotrap) and graphite have been recorded using two‐excitation wavelengths, 532 and 785 nm, and analysed for band positions and shape with special emphasis paid to the D‐, G‐ and G′‐bands. A major difference between the different MWCNT varieties analysed is that G‐bands in the MWCNT filters exhibit almost no dispersion, whereas the other MWCNTs show a noticeable dispersive behaviour with a change in the excitation wavelength. Spectral features similar to those of the MWCNT filter varieties were observed for the Carbotrap material. From the line shape analysis, the intensity ratio, ID/IG, of the more ordered MWCNT filter material using the integral G‐band turns out to be two times lower than that of the less ordered MWCNT filter product at both excitation wavelengths. This parameter can, therefore, be used as a measure of the degree of MWCNT alignment in filter varieties, which is well supported also by our SEM study. Copyright © 2008 John Wiley & Sons, Ltd.