bluuebunny/crossref_metadata_2025 huggingface dataset:
The Hotel Industry’s Summer of 2006
Authors: Sherwyn David , Eigen Zev , Wagner Paul
Published: October 2006

Neutrality agreements allow labor unions to organize workers in hotels and other industries without the trouble of a secret-ballot election. UNITE HERE, which represents hotel employees in several major markets, attempted in summer 2006 to extend its reach into the industry via neutrality agreements. The union contracts expired in several markets, which meant that the hotel chains were faced with the possibility of labor strife in their major cities. In exchange for labor peace, the chains agreed to a moderate extension of organizing by neutrality agreement, but not to the extent that the union might have wished.
Connecting with Culture
Authors: Stipanuk David
Published: October 2006

Community-tourism initiatives such as those described in the “VillageLife” case are one hoped-for way of getting more of the financial benefits of tourism to flow toward local people. They potentially provide a much better chance of connecting tourists with local communities than “enclave” tourism can hope to do. However, as the case illustrates, achieving all of the goals of community tourism can be a daunting task because of the complexity of tourism—including transportation, lodging, food and beverage, attractions, and retail. This means fulfilling all the requirements of being in these businesses, which can be a challenge for those operating with just a profit motive, and an even greater challenge for an operator who wants to mix sustainable tourism with revenue. Achieving a sustainable triple bottom line of economic, social, and environmental success is not easy.
A Commentary on Effective Responses to Tourism Disasters
Authors: Plog Stanley C.
Published: October 2006

Hong Kong’s response to the severe acute respiratory syndrome (SARS) epidemic contrasts to the response of Thai hoteliers and officials to the deadly December 2004 tsunami. Whereas Hong Kong took assertive actions to offset the negative effects of the SARS publicity, efforts in Thailand have been minimal, at best. As explained in this commentary, Hong Kong targeted long-haul travelers, rather than regional markets, and conducted research studies to determine how to win back those travelers’ business. Thai officials, by contrast, have offered promotions that lack a research basis.
A Comparison of Mechanical Properties of Natural Fiber Filled Biodegradable and Polyolefin Polymers
Authors: Taha I. , Ziegmann G.
Published: October 2006

A great value is nowadays being given to light-weight structures and durable light-weight materials and composites. In this respect, fiber reinforced plastics (FRP) are given more importance and are becoming one of the most distinguishing material categories next to metals. This research provides some results of mechanical properties of natural fiber reinforced polyolefins (PP, PE) in comparison to some biodegradable polymers, combined without any bonding enhancements, such as bonding agents or surface modifications. It is for this reason that the composites in this study do not show significant improvement in the mechanical properties of polymers; however they can be used as reference values for the mere natural fiber reinforcement. A comparison of polyolefins and biodegradable polymers shows that some biodegradable polymers eventually provide higher mechanical properties, mainly depending on the initial properties of the neat material.
Wear Behavior of Functionalized Multi-walled Carbon Nanotube Reinforced Epoxy Matrix Composites
Authors: Sulong Abu Bakar , Park Joohyuk , Lee Naesung , Goak Jeungchoon
Published: October 2006

This article studies the tribological behavior of functionalized multi-walled carbon nanotubes (MWNTs) reinforced epoxy matrix composites. MWNTs reinforced epoxy composites are fabricated by an injection molding process. The effects on the tribological properties of different loading concentrations and different functional groups of MWNTs are investigated by using a linear reciprocal wear tester. As increasing the concentration of MWNTs reduces wear loss, better tribological property was attained on functionalized MWNTs than as-produced MWNTs. The changes in worn surface morphology are observed in order to investigate the wear behavior. The MWNTs in the epoxy matrix near the surface are exposed and became a lubricating working film on the worn surface. The dispersion and interfacial bonding of MWNTs in the epoxy matrix are investigated from the fracture surface. The existence of MWNT at the wear surface is verified by a Raman spectrometer.
Applying the Analytical Hierarchy Process (AHP) Approach to Convention Site Selection
Authors: Chen Ching-Fu
Published: October 2006

The convention sector is one of the fastest growing and most lucrative areas of the tourism industry. Solving for the most salient determinants in selecting or organizing a destination for conventions and seeing out their success is an important research topic. This study proposes the analytical hierarchy process (AHP) approach, a decision-making method based on pairwise comparisons between criteria, to construct an evaluation structure with criteria and associated weights of convention site selection for meeting planners. A case study with a three-level evaluation structure is constructed and tested. The findings indicate that the AHP approach is a useful tool to help support a decision in convention site selection.
Forecasting Short Time-Series Tourism Demand with Artificial Intelligence Models
Authors: Yu Gongmei , Schwartz Zvi
Published: October 2006

This study examines the forecast accuracy of fuzzy time series and grey theory in predicting annual U.S. tourist arrivals. The performance of the two artificial intelligence (AI) models is compared to that of two simple methods—double moving average and double exponential smoothing. The rigorous testing approach includes a large sample stratified to adequately represent four generic trend patterns: a rolling short-term forecast, a large holdout sample, models fitting with both equal number of years and optimal number of years, and tests of statistical significance using Wilcoxon’s signed-ranks nonparametric test. This study’s findings indicate, in contrast to recent findings, that the complicated models are not likely to generate a more accurate forecast than the simple traditional models. Given the notable cost associated with these AI forecasting methods, our finding of no significant accuracy advantage suggests that tourism forecasters should not rush to adopt these two methods without careful consideration.
Effects of calcium hydroxide and calcium chloride addition to bentonite in iron ore pelletization
Authors: Tugrul Nurcan , Derun Emek Moroydor , Piskin Mehmet
Published: October 2006

Pyrite ash is created as waste from the roasting of pyrite ores during the production of sulphuric acid. These processes generate great amounts of pyrite ash waste that is generally land filled. This creates serious environmental pollution due to the release of acids and toxic substances. Pyrite ash waste can be utilized in the iron production industry as a blast furnace feed to process this waste and prevent environmental pollution. The essential parameters affecting the pelletization process of pyrite ash were studied using bentonite as a binder. Experiments were then carried out using bentonite and a mixture of bentonite with calcium hydroxide and calcium chloride in order to make the bentonite more effective. The metallurgical properties of pyrite ash, bentonite, calcium hydroxide, calcium chloride, a mixture of these and sintered pellets were studied using X-ray analysis. The crushing strength tests were carried out to investigate the strength of pyrite ash waste pellets. The results of these analyses showed that pyrite ash can be agglomerated to pellets and used in the iron production industry as a blast furnace feed. The crushing strength of the pellets containing calcium hydroxide and calcium chloride in addition to bentonite was better than the strength of pellets prepared using only bentonite binder.
Generation amount prediction and material flow analysis of electronic waste: a case study in Beijing, China
Authors: Liu Xianbing , Tanaka Masaru , Matsui Yasuhiro
Published: October 2006

The draft legislation on e-waste prepared by the Chinese national government assigns management responsibility to local governments. It is an urgent task for the municipal government to plan an effective system as soon as possible to divert the e-waste flow from the existing informal e-waste recycling processes. This paper presents a case study implemented in Beijing, the capital city of China, with the purpose of predicting the amount of obsolete equipment for five main kinds of electronic appliances from urban households and to analyse the flow after the end of their useful phase. The amount to be handled was 885 354 units in 2005 and is predicted to double by 2010. Due to consumption growth and the expansion of urbanization it is estimated that the amount will increase to approximate 2 820 000 units by 2020: 70% of the obsolete appliances will be awaiting collection for possible recycling, 7% will be stored at the owner’s home for 1 year on average and 4% will be discarded directly and enter the municipal solid waste collecting system. The remaining items will be reused for about 3 years on average after the change of ownership. The results of this study will assist the waste management authorities of Beijing to plan the collecting system and facilities needed for management of e-waste generated in the near future.
Completing Substance Abuse Treatment in Child Welfare: The Role of Co-Occurring Problems and Primary Drug of Choice
Authors: Choi Sam , Ryan Joseph P.
Published: October 2006

A significant number of substance-abusing parents in the child welfare system do not complete substance abuse treatments. Consequently, their children experience longer stays in substitute care settings, and the risk of the termination of parental rights is increased. This study identifies and determines the specific factors that explain the completion of substance abuse treatment for substance-abusing caregivers in child welfare. The sample includes 871 caregivers enrolled in the Illinois Alcohol and Other Drug Abuse waiver demonstration. Approximately 22% of these caregivers successfully completed all required levels of substance abuse treatment. The multivariate models indicate that age, employment status, and legal involvement were significantly associated with the likelihood of completing substance abuse treatment. Heroin users were significantly less likely to complete treatment as compared with alcohol, cocaine, and marijuana users. The findings are discussed in terms of policy and practice implications for public child welfare systems.
Maria Ossowska
Authors: Zdrenka Marcin T.
Published: October 2006

Maria Ossowska (1896–1974) was focused on the problem of a sociology of morality. At the time she was writing, a sociology of morals was not generally considered proper subject matter for moral philosophers. Yet ethics was already showing its weakness and calling out for a new reformulation. Maria Ossowska formulated a new project for moral philosophy involving a sociological perspective which not only understood ‘morality’ as a social phenomenon which could be researched with sociological methods, but which also understood itself as remaining inextricably related to philosophical reflection. She divided her new ‘moral science’ into three parts: (1) an analysis of moral evaluations and norms; (2) a psychology of morality; and (3) a sociology of morality. In developing this program, Ossowska worked upon various themes or areas, including the moral thought of the British Enlightenment, the chivalrous ethos and bourgeois morality. She introduced and newly reformulated the term ‘ethos’, intending it both as a term of sociology and as related to normative ethics, which is part of moral philosophy. Ossowska%'s most general achievement was to widen awareness in both philosophy and sociology of a new necessary complexity and depth to any moral studies.
Cloning, expression and functional activity of deoxyhypusine synthase from Plasmodium vivax
Authors: Njuguna James T , Nassar Marwa , Hoerauf Achim , Kaiser Annette E
Published: October 2006

Background

Plasmodium vivax is the most widespread human malaria parasite. However, genetic information about its pathogenesis is limited at present, due to the lack of a reproducible in vitro cultivation method. Sequencing of the Plasmodium vivax genome suggested the presence of a homolog of deoxyhypusine synthase (DHS) from P. falciparum, the key regulatory enzyme in the first committed step of hypusine biosynthesis. DHS is involved in cell proliferation, and thus a valuable drug target for the human malaria parasite P. falciparum. A comparison of the enzymatic properties of the DHS enzymes between the benign and severe Plasmodium species should contribute to our understanding of the differences in pathogenicity and phylogeny of both malaria parasites.

Results

We describe the cloning of a 1368 bp putative deoxyhypusine synthase gene (dhs) sequence from genomic DNA of P. vivax PEST strain Salvador I (Accession number AJ549098) after touchdown PCR. The corresponding protein was expressed and functionally characterized as deoxyhypusine synthase by determination of its specific activity and cross-reactivity to human DHS on a Western blot.

The putative DHS protein from P. vivax displays a FASTA score of 75 relative to DHS from rodent malaria parasite, P. yoelii, and 74 relative to that from the human parasite, P. falciparum strain 3D7. The ORF encoding 456 amino acids was expressed under control of IPTG-inducible T7 promoter, and expressed as a protein of approximately 50 kDa (theoretically 52.7 kDa) in E. coli BL21 DE3 cells. The N-terminal histidine-tagged protein was purified by Nickel-chelate affinity chromatography under denaturing conditions. DHS with a theoretical pI of 6.0 was present in both eluate fractions. The specific enzymatic activity of DHS was determined as 1268 U/mg protein. The inhibitor, N-guanyl-1, 7-diaminoheptane (GC7), suppressed specific activity by 36-fold. Western blot analysis performed with a polyclonal anti-human DHS antibody revealed cross-reactivity to DHS from P. vivax, despite an amino acid identity of 44% between the proteins.

Conclusion

We identify a novel DHS protein in the more benign malaria parasite,P. vivax, on the basis of specific enzymatic activity, cross-reactivity with a polyclonal antibody against human DHS, and amino acid identity with DHS homologs from the rodent malaria parasite, P. yoelii, and human P. falciparum strains.
Expression and loss of alleles in cultured mouse embryonic fibroblasts and stem cells carrying allelic fluorescent protein genes
Authors: Larson Jon S , Yin Moying , Fischer Jared M , Stringer Saundra L , Stringer James R
Published: October 2006

Background

Loss of heterozygosity (LOH) contributes to many cancers, but the rate at which these events occur in normal cells of the body is not clear. LOH would be detectable in diverse cell types in the body if this event were to confer an obvious cellular phenotype. Mice that carry two different fluorescent protein genes as alleles of a locus would seem to be a useful tool for addressing this issue because LOH would change a cell's phenotype from dichromatic to monochromatic. In addition, LOH caused by mitotic crossing over might be discernable in tissues because this event produces a pair of neighboring monochromatic cells that are different colors.

Results

As a step in assessing the utility of this approach, we derived primary embryonic fibroblast populations and embryonic stem cell lines from mice that carried two different fluorescent protein genes as alleles at the chromosome 6 locus, ROSA26. Fluorescence activated cell sorting (FACS) showed that the vast majority of cells in each line expressed the two marker proteins at similar levels, and that populations exhibited expression noise similar to that seen in bacteria and yeast. Cells with a monochromatic phenotype were present at frequencies on the order of 10-4 and appeared to be produced at a rate of approximately 10-5 variant cells per mitosis. 45 of 45 stably monochromatic ES cell clones exhibited loss of the expected allele at the ROSA26 locus. More than half of these clones retained heterozygosity at a locus between ROSA26 and the centromere. Other clones exhibited LOH near the centromere, but were disomic for chromosome 6.

Conclusion

Allelic fluorescent markers allowed LOH at the ROSA26 locus to be detected by FACS. LOH at this locus was usually not accompanied by LOH near the centromere, suggesting that mitotic recombination was the major cause of ROSA26 LOH. Dichromatic mouse embryonic cells provide a novel system for studying genetic/karyotypic stability and factors influencing expression from allelic genes. Similar approaches will allow these phenomena to be studied in tissues.
C-reactive protein in aortic valve disease
Authors: Sanchez Pedro L , Mazzone Anna Maria
Published: October 2006

Aortic Valve Disease, includes a range of disorder severity from mild leaflet thickening without valve obstruction, "aortic sclerosis", to severe calcified aortic stenosis. It is a slowly progressive active process of valve modification similar atherosclerosis for cardiovascular risk factors, lipoprotein deposition, chronic inflammation, and calcification. Systemic signs of inflammation, as wall and serum CRP, similar to those found in atherosclerosis, are present in patients with degenerative aortic valve stenosis and may be expression of a common disease, useful in monitoring of stenosis progression.
Manifestations of pott's disease in the head and neck
Authors: Neal Steven L. , Kearns Michael J. , Harris Jeffrey P. , Seelig John M.
Published: October 2006

Tuberculosis (TB) of the spine, or Pott's disease, is a rarely encountered clinical disorder in the United States today. However, Pott's disease should be strongly suspected in a person who presents with a destructive lesion of the spine involving adjacent vertebrae or a retropharyngeal mass which extends across the midline. The most common presenting signs and symptoms are pain and spinal deformity. The PPD skin test is usually positive, but unlike TB of the larynx, the chest roentgenogrom is almost always negative. Diagnosis may be confirmed by needle aspiration or incisional biopsy and culture.

The otolaryngologic literature has not previously addressed this clinical entity, thus, our experience with a patient with a retropharyngeal mass and quadraplegia diagnosed as Pott's disease will be presented. Subsequent medical therapy, stabilization, and odontoidectomy resulted in resolution of his neurological deficit. The incidence, pathogenesis, clinical features, and management of Pott's disease will be discussed.
Vagal body tumors: diagnosis and treatment
Authors: Moore Grant , Yarington C. T. , Mangham Charles A.
Published: October 2006

This presentation includes a report of four vagal body tumors bringing the total number in the English literature to approximately 80. The diagnosis and treatment of this lesion, its familial incidence and the propensity for multiple secreting or nonsecreting chemodectomas, and appropriate clinical and pathologic studies required will be reviewed in some detail. Appropriate differential diagnostic features will be illustrated by comparison of these tumors with other primary vagal tumors from our experience such as neurofibromas, neurilemomas, and cystic degeneration of neurilemomas.
Clinical implications of orbital cellulitis
Authors: Jackson Keith , Baker Shan R.
Published: October 2006

Periorbital and orbital cellulitis are clearly two distinct disorders with different etiologies. Periorbital cellulitis is well‐documented as a more common infectious process limited to the eyelids in the preseptal region. In contrast, orbital cellulitis represents a more severe, but less common, infection of the orbit posterior to the septum with or without subperiosteal abscess, orbital abscess, or cavernous sinus thrombosis. A retrospective review of the clinical and laboratory data of 137 cases of orbital and periorbital cellulitis was performed. Periorbital cellulitis was documented in 98 cases (71%), in contrast to orbital cellulitis which was noted in 39 (28%) patients. All patients with orbital cellulitis received intravenous antibiotics, however, surgical therapy was necessary for progression of orbital cellulitis in 49% of patients. The majority of patients underwent incision and drainage of an abscess in the orbit. Complications as a result of orbital cellulitis occurred in nine (23%) of the patients. A distinction is made between the clinical entity of periorbital cellulitis and orbital cellulitis. Separating these clinical entities on the basis of physical examination and radiographic studies is important because the medical and surgical management of these two disease processes is different.
The early signs and symptoms of neurotologic complications of chronic suppurative otitis media
Authors: Schwaber Mitchell K. , Pensak Myles L. , Bartels Loren J.
Published: October 2006

The delay in the diagnosis of neurotologic complications of chronic suppurative otitis media has been explained in a number of ways, including antibiotic suppression, surgical drainage, and a lowered index of clinical suspicion because the problem is relatively rare today.

Twelve cases of neurotologic complications of chronic suppurative otitis media were reviewed to determine the early and late findings that should raise the physician's index of suspicion. Purulent, malodorous drainage, headache, and fever were the significant early findings. Altered mental status was a late finding, and usually indicated established intracranial infection. By drawing attention to the early findings, we hope to lower the morbidity and mortality associated with these complications.
Dynamics of the nitrogen transformation in a shallow stream and possible interventions
Authors: Kabelkova-Jancarkova I.
Published: October 2006

This paper presents the assessment of the efficiency of the main biological nitrogen transformation processes in a shallow well-oxygenated river and conditions under which they are active and stabilise. The process dynamics was studied with the help of mathematical modelling of 2 years on-line data series measured in a reach of the Toess River, Switzerland. The algal nitrogen uptake was very stable and unaffected by most but frequent flood events. Daylight photosynthetic nitrogen uptake stabilised at 6 mgN m−2streambed h−1 (15 °C), dark uptake on storage products at rates of 0.5–2.5 mgN m−2streambed h−1. Nitrogen uptake by heterotrophic bacteria in the hyporheic zone was relatively constant at a level of 1.5–3.5 mgN m−2streambed h−1. Streambed nitrification could establish only during periods with average an daily concentration of at least 0.3 gNH4-N m−3 in river water for several weeks. The maximum nitrification rate was 35 mgN m−2streambed h−1 for 3 gNH4-N m−3. The effects of reduced nitrification in the WWTP and of river banks shading on a sudden ammonium peak were simulated. A river reach endangered by ammonium spills should be kept open to sun to favour ammonium uptake by algae. In-stream nitrification reduces ammonium peaks efficiently but leads to toxic nitrite concentrations.
Design of a retention tank: comparison of stormwater quality models with various levels of complexity
Authors: Mourad M. , Bertrand-Krajewski J.-L. , Chebbo G.
Published: October 2006

Stormwater quality simulation models are useful tools for the design and management of sewer systems. Modelling results are highly sensitive to experimental data used for calibration. This sensitivity is examined for three modelling approaches of various complexities (site mean concentration approach, event mean concentration approach and build-up, washoff and transport modelling approach) applied to a typical case study (design of a dry detention tank), accounting for the variability of calibration data and their effect on simulation results. Calibrated models with different calibration data sets were used to simulate 3 years of rainfall with different retention tank specific volumes. Annual pollutant load interception efficiencies were determined. Simulations results revealed i) that there is no advantage in using the EMC model compared to the SMC model and ii) that the BWT model resulted in higher design ratios than those given by the SMC/hydraulic approach. For both EMC and BWT models, using an increasing number n of events for calibration leads to narrower confidence intervals for the design ratios. It is crucial for design ratios to account for successive storm events in chronological order and to account for the maximum allowable flow to be transferred to the downstream WWTP.
Matching the critical portion of the flow duration curve to minimise changes in modelled excess shear
Authors: Rohrer C.A. , Roesner L.A.
Published: October 2006

Hydrologic and hydraulic modeling in the USEPA Stormwater Management Model (SWMM) were used to examine the effectiveness of typical stormwater management practices in reducing the potential for stream erosion. Fifty-year continuous simulations were used to produce flow duration curves and stream erosion rates for a variety of critical shear stress values representative of both cohesive and non-cohesive sediments. An excess shear stress erosion potential index was used to evaluate changes in erosion between undeveloped conditions of a 10 hectare watershed and four variations of post-development stormwater control. Evaluation of flow duration curves showed that when development takes place, the duration of mid- to low-range discharges increase significantly, especially when detention practices are applied. In channels with low entrainment thresholds for bed and bank materials, e.g. sands and highly erodible clays, the significant increase of the duration of mid- to low-range discharges results in erosion potential index values greater than two regardless of the detention practices used. Overcontrol detention resulted in erosion potential index values of less than one, indicating a loss of erosion potential for bed materials such as most gravels (ds >6 mm) and resistant clays that have critical shear stress values greater than four Pa.
From point to areal rainfall: linking the different approaches for the frequency characterisation of rainfalls in urban areas
Authors: Ramos M.H. , Leblois E. , Creutin J.-D.
Published: October 2006

In urban water design and management, many hydrologic problems involve the frequency characterisation of rainfalls. Hydrologists are commonly asked to evaluate rainfall intensities for given recurrence frequencies or to indicate how rare an observed event is by estimating its return period. This study aims to improve the characterisation of rainfall hazard over a city by linking point to areal rainfall frequency analysis. We use a stochastic rainfall field generator based on the turning-bands method directly to assess areal rainfall distributions and to illustrate the link between different approaches. The simulating algorithm is applied to rainfall data from the city of Marseilles. The frequency analysis of simulated fields provides the elements to deal with the notions of return period and severity of observed storm events. The study concludes on the importance of a unified approach to assess rainfall better.
Colloidal speciation of heavy metals in runoff and interstitial waters of a retention/infiltration pond
Authors: Béchet B. , Durin B. , Legret M. , Le Cloirec P.
Published: October 2006

The thickness of non-saturated zone and physico-chemical conditions are important parameters to assess the impact of infiltration ponds on water resources with respect to heavy metals transfer. As changes in physico-chemical parameters of solutions have a strong impact on the mobility of colloidal phases in sediments and soils, the colloidal facilitated transfer of heavy metals has to be investigated. Therefore, this study focuses on the characterization of runoff, surface and interstitial waters in a retention/infiltration pond collecting runoff waters of a bridge near Nantes. Physico-chemical parameters and chemical analyses were performed on the waters during about one year. The separation of dissolved and colloidal fractions was carried out by filtration and ultrafiltration for one sample of surface and interstitial waters. Until now, the runoff waters were only filtered at 0.45 μm. The comparison of physico-chemical data shows that the minor variations of runoff water parameters are mitigated in basin and in soils but strong variations impact the composition of interstitial waters. High concentrations of zinc, copper and still of lead are measured in runoff. Lead and cadmium seem to be associated to colloidal and particulate fractions while zinc, copper, nickel and chromium are distributed in all fractions.
Hitting the Mark
Authors: Grieve K.
Published: October 2006

Mark of excellence: Advanced Functional Materials has enjoyed another remarkable year, with all critical indicators pointing to ever‐improving quality and importance. In this Editorial, the Deputy Editor outlines the factors that allow the journal to continue to hit its target of publishing in‐depth reports on the highest‐quality materials science.
Deposition and aggregation of Brownian particles in trickle‐bed reactors
Authors: Iliuta Ion , Larachi Faïçal
Published: October 2006

When dilute liquid suspensions contaminated with Brownian fine solids are treated in catalytic trickle‐bed reactors, bed plugging develops and increases the resistance to two‐phase flow until ultimate unit shutdown for bed substitution with pristine catalyst is imposed. One of the important aspects during plugging with Brownian particles is the aggregation of fines and the release of the fine particles and aggregates from pore bodies within the porous bed as a result of the hydrodynamic or colloidal forces. Current physical models linking gas–liquid flow to the filtration process in high‐pressure/temperature trickle beds neglect the possible colloidal particle aggregation and the release of aggregates. This work attempts to fill this gap by developing a Euler–Euler fluid dynamic model based on the volume average mass, momentum, and species balance equations, filtration equations for the Brownian particles and the aggregates, and the discrete population balance equations for the agglomeration of particles. Both monolayer and multilayer depositions were considered for Brownian particles and only the monolayer deposition in the case of the detaching aggregates. The release of fine particles and aggregates from the collector surface was assumed to be induced by the colloidal forces in the case of Brownian particles/aggregates or by the hydrodynamic forces in the case of non‐Brownian aggregates. Brownian particle aggregation was described by the rate at which a certain size aggregate is being formed by smaller aggregates less the rate at which the aggregate combines to form a larger aggregate. © 2006 American Institute of Chemical Engineers AIChE J 2006
Die Acidität von 4‐Äthinylantipyrin im Vergleich zu verschiedenen substituierten Phenylacetylenen
Authors: Schwenker G. , Meyer H.‐J.
Published: October 2006

Das reaktive Verhalten von 4‐Äthinylantipyrin (Reaktionen mit elektrophilem Primärschritt laufen ab, solche mit nucleophilem bleiben aus) wird durch eine erhöhte Elektronendichte am endständigen Acetylen‐C‐Atom erklärt. Eine erhöhte Elektronendichte ließ sich nachweisen durch den Vergleich der Aciditäten von 4‐Äthinylantipyrin und einer Reihe substituierter Phenylacetylene mit bekannten Substituenteneffekten. 4‐Äthinylantipyrin zeigte dabei die geringste spezifische Leitfähigkeit, die schwächsten Donoreigenschaften bei Wasserstoffbrückenbindungen mit Pyridin und den langsamsten Protonen‐Deuteronenaustausch und ist daher unter allen verglichenen Acetylenen die schwächste Säure.
Untersuchungen über das Auftreten von Polyinen in verschiedenen Cirsium‐Arten 18. Mitt.: Mikroanalytik ätherischer Öle
Authors: Block D. , Knütter S. , Pohloudek‐Fabini R.
Published: October 2006

12 Arten der Gattung Cirsium, Tribus Cyrareae aus der Familie Asteraceae, wurden auf das Vorkommen von Polyinen untersucht. Neben den in mehreren Cirsium‐Arten nachgewiesenen bereits bekannten Verbindungen Tridecadien (1,11)‐tetrain(3,5,7,9) (I) und Tridecaen(1)‐pentain(3,5,7,9,11) (II) konnte aus Cirsium eriophorum ein neues Polyin isoliert und als Undecaen (1)diin(3,5)‐ol(7) (III) identifiziert werden.
Zur Keto‐Enol‐Tautomerie bei heterocyclischen β‐Ketocarbonsäureestern 3. Mitt.: Konfiguration und Konformation 2,6‐dialkylsubstituierter β‐Ketodicarbonsäureester
Authors: Hänsel W. , Haller R.
Published: October 2006

An Hand der 1H‐NMR‐Spektren wurde die Konfiguration und Konformation von 1‐Aza‐, 1‐Oxa‐, 1‐Thia‐ und 1‐Selenacyclohexanondicarbonsäureestern untersucht. In den Ketoformen dieser Verbindungen weisen die Substituenten an C‐2, ‐3, ‐5 und ‐6 die relative Konfiguration 2,6‐/3,5‐cis, 2,3‐/5,6‐trans auf. Die bevorzugte Konformation ist die Sesselform mit äquatorialer Stellung aller Substituenten.
Die kernresonanzspektrographische Untersuchung der Assoziation von Coffein mit Natriumbenzoat und einigen anderen Verbindungen
Authors: Stamm H.
Published: October 2006

Die Protonenresonanzsignale der drei Methylgruppen des Coffeins werden in wäßriger Lösung durch zugesetztes Natriumbenzoat stark verschoben. Die Abhängigkeit der chemischen Verschiebungen vom Benzoatzusatz ergibt s‐förmige Kurven, die auf das Zusammenwirken zweier magnetisch entgegengesetzt wirksamer Effekte hinweisen. Die beiden Effekte werden in der Fremdassoziation und in der Depolymerisation des Coffeins gesehen. Da in Chloroform Coffein keine Selbstassoziation eingeht und demnach auch nicht depolymerisieren kann, führt eine Fremdassoziation in Chloroform zu einer monotonen, nicht‐s‐förmigen Wanderung der Coffeinsignale. Dies läßt sich am Beispiel Coffein/Procainhydrochlorid/Wasser und Coffein/Procainbase/Chloroform zeigen.
Über das Vorkommen von Strophanthidolglykosiden in Corchorus capsularis L. und C. olitorius L
Authors: Schmersahl P.
Published: October 2006

Durch Reduktion des 19‐Oxocardenolids Corchorosid A mit Aluminiumisopropylat oder Natriumborhydrid wurde eine bisher nicht beschriebene Verbindung isoliert, die auf Grund ihrer chemisch‐physikalischen Konstanten sowie ihrer hydrolytischen Abbauprodukte als das 19‐Carbinolderivat charakterisiert werden konnte. Diese Verbindung, die als Corchorosol A bezeichnet wurde, kommt in geringen Mengen im fermentierten Samen von Corchorus capsularis und C. olitorius vor.
Potentielle Cytostatika durch Aminomethylierung NH‐acider Hypnotika
Authors: Werner W. , Fritzsche H.
Published: October 2006

Die Aminomethylierung von Phenobarbital, Cyclobarbital, Benedorm, Bemegride und Thalidomid unter Verwendung von Bis(2‐chloräthyl)‐amin, Morpholin und Piperidin wird beschrieben. Mit Hilfe von IR‐Spektren wird gezeigt, daß 1‐aminomethylierte 5,5‐disubstituierte Barbitursäuren chelatfreie NH‐Gruppen besitzen, die aminomethylierbar sind.
Kernresonanzspektroskopische Untersuchung einiger 2,2‐dimethylsubstituierter Piperidone und Piperidinole
Authors: Haller R. , Ebersberg J.
Published: October 2006

Die Konformation von 2,2‐Dimethyl‐6‐aryl‐piperidonen‐(4) wurde kernresonanzspektroskopisch untersucht. An Hand der 1H‐NMR‐Spektren war auch die Ermittlung der Konfiguration an C‐4 bei den epimeren Reduktionsprodukten möglich. Die bevorzugte Konformation dieser heterocyclischen Ketone und Alkohole ist die Sesselform mit äquatorialer Stellung des Arylsubstituenten an C‐6.
Die Gelstruktur der wasserhaltigen emulgierenden Salbe
Authors: Gstirner F. , Kottenberg D. , Maas A.
Published: October 2006

Die wasserhaltige emulgierende Salbe (etwa 70% H2O) des 3. Nachtrages zum DAB 6 bzw. des DAB 7 und ihre Ausgangsbestandteile wurden elektronenmikroskopisch untersucht. Mittels einer neuen modifizierten Gefrierätzungsmethode konnte das hypothetische Gelgerüst der plastischen wasserhaltigen emulgierenden Salbe elektronenmikroskopisch nachgewiesen und durch Stereoaufnahmen in seinem dreidimensionalen Feinbau analysiert werden.
Zur Analytik von aus Korkmehl isolierter Phloionsäure
Authors: Vogt H. , Seidel J.
Published: October 2006

Es werden Angaben über die Reinheit von aus Korkmehl isolierter Phloionsäure gemacht. Eine hartnäckige Verunreinigung mit der nahe verwandten Phloionolsäure wird nachgewiesen. Die Verunreinigung wirkt sich erst in Mengen von mehr als 10% erkennbar auf den Schmelzpunkt der Phloionsäure aus. Eine klare Unterscheidung von Phloion‐ und Phloionolsäure über ihre IR‐Spektren war erst nach Ausschalten des Einflusses der Carboxylgruppen durch Verestern mit Methanol möglich. Zur Reinheitsprüfung wird ein dünnschichtchromatographisches Trennverfahren ausgearbeitet, das erlaubt, auch geringe Mengen von Verunreinigungen schnell nachzuweisen.
Dimere Austauschprodukte aromatisch substituierter α‐Aminonitrile VII. Mitt. über Umsetzungen von α‐Aminonitrilen
Authors: Thies H. , Schönenberger H. , Qasba P. K.
Published: October 2006

Die bei der Umsetzung von aromatisch substituierten Aminonitrilen mit metallischem Natrium in Toluol neben Wasserstoff‐Austauschprodukten entstehenden dimeren Austauschprodukte sind wenig beständig. Die primär gebildeten Diphenyldiaminderivate zerfallen bei der Aufarbeitung unter Abspaltung von Amin und weiterhin durch Hydrolyse unter Bildung der entsprechenden Desoxybenzoinderivate.
Potentielle Reaktivatoren der Acetylcholinesterase 1. Mitt.: N‐Alkoxy‐pyridiniumcarbaldoxime
Authors: Schnekenburger J.
Published: October 2006

Sowohl die syn‐ als auch die anti‐Isomere von Pyridin‐N‐oxid‐2‐ und ‐4‐carbaldoxim werden mit starken Alkylierungsmitteln zu syn‐N‐Alkoxy‐pyridiniumcarbaldoximen umgesetzt. Letztere Verbindungen sind als potentielle Reaktivatoren der Acetylcholinesterase von Interesse. Die Konfigurationszuordnung wird vor allem auf Grund der NMR‐Spektren gesichert.
Zur Kenntnis der 2‐Amino‐1,3,4‐oxdiazole 31. Mitt.: Darstellung von 1‐Acyl‐5‐alkoxy(aroxy)carbonyl‐diaminoguanidinen durch Ringöffnung von 2‐Amino‐1,3,4‐oxdiazolen mit Carbazinsäureestern
Authors: Gehlen H. , Uteg K.‐H.
Published: October 2006

2‐Amino‐5‐aryl(alkyl)‐1,3,4‐oxdiazole (I) reagieren mit Carbazinsäureestern unter Ringöffnung, wobei 1‐Acyl‐5‐alkoxy(aroxy)carbonyl‐diaminoguanidine (II, III) erhalten werden. Die Hydrolyse von IIa mit 20proz. HCl führt zum Äthoxycarbonyl‐diaminoguanidin (IV), das als Benzylidenverbindung (V) isoliert werden konnte. Die Struktur wird durch das IR‐Spektrum gestützt.
Relative und absolute Konfiguration von Yangambin und Aschantin
Authors: Hänsel R. , Pelter A.
Published: October 2006

Die für Bisepoxylignane früher gefundenen empirischen Regeln zur Korrelation von Konfigurationsbeziehungen aus NMR‐Daten und optischem Drehvermögen werden für den Fall des Yangambins und des Aschantins angewendet. Die beiden Lignane gehören der (+)‐Sesaminreihe an.
Polyacetylene als Inhaltsstoffe von Silybum marianum Gaertn
Authors: Schulte K. E. , Rücker G. , Stigler H.
Published: October 2006

In den Wurzeln der Composite Silybum marianum Gaertn. wurden 12 Polyacetylene und ein Polyen nachgewiesen. Die Struktur konnte von 7 Substanzen ermittelt werden: Tridecadien‐(1,11)‐tetrain‐(3,5,7,9) (I), Tridecen‐(1)‐pentain‐(3,5,7,9,11) (II), Tridecadien‐(1,3,11)‐triin‐(5,7,9) (III), Tridecen‐(12)‐tetrain‐(4,6,8,10)‐al‐(1) (IV), Tridecadien‐(3,5)‐triin‐(7,9,11)ol‐(1)‐acetat (V), Heptadecatrien‐(1,8,15)‐diin‐(11,13) (VI), Heptadecatrien‐(1,8,15)‐diin‐(11,13)‐ol‐(10) (VII). Von 6 Verbindungen (VIII–XIII) ließ sich eine Teilstruktur aufstellen. In den Blütenköpfchen kommen 5 dieser ungesättigten Verbindungen vor (I, II, III, VIII und IX), im Sproß 2 (I und II). Die Früchte enthalten keine Polyacetylene, dagegen ließen sich in den 7 Tage alten Keimlingen 3 (I, II und V) nachweisen.
Die Synthese von Steroid‐2‐amino‐2‐desoxy‐β‐D‐glucosiden Glykoside von Aminozuckern, I
Authors: Zu Reckendorf W. Meyer , Wassiliadou‐Micheli N. , Machleidt H.
Published: October 2006

Mit Hilfe der Koenigs‐Knorr‐Synthese konnten Digitoxigenin, Strophanthidin und Pregnenolon in die 2‐Amino‐2‐desoxy‐β‐D‐glucopyranoside überführt werden, die in kristalliner Form isoliert wurden.
Reaktionen von 4‐Diphenylmethylen‐4H‐pyranen mit Aminen 25. Mitt. über Untersuchungen an 4‐Pyronen
Authors: Eiden F. , Peglow M.
Published: October 2006

4‐Diphenylmethylen‐1,4‐dihydropyridine (6) können durch Reaktion von 4‐Pyridonen (5) mit Diphenylketen oder von 4‐Diphenylmethylen‐4H‐pyranen (3) mit primären Aminen hergestellt werden. Die Pyridiniumsalze 7 bilden sich aus 6 in saurer Lösung oder aus den Pyryliumsalzen 4 durch Einwirkung primärer Amine.

Bei der Reaktion von 3 (R = H) mit Diphenylamin entsteht ein Bis‐Enamin (10), das in saurer Lösung den Polymethinfarbstoff 12 bildet.
Die antibakterielle Wirkung von Phenolen in Anwesenheit von Polyäthylenglykolstearaten und Polyäthylenglykolen Wertmindernde Wechselwirkungen von Desinfektions‐ und Konservierungsmitteln mit nichtionogenen Tensiden. I. Teil
Authors: Thoma K. , Ullmann E. , Fickel O.
Published: October 2006

Die Wertminderung der Phenole durch Polyäthylenglykolstearate ist abhängig von den physikalisch‐chemischen Eigenschaften der Reaktionspartner. Zunehmende Lipophilic der Phenole erhöht die Wertminderung durch Polyäthylenglykolstearate. Für das Ausmaß der Wertminderung kommt den physikalisch‐chemischen Eigenschaften der Phenole wesentlich größere Bedeutung zu, als denen der Polyäthylenglykolstearate.

Die erforderliche Vervielfachung der Konzentration an Phenolen zur Aufrechterhaltung gleicher antibakterieller Aktivität beträgt in 5proz. Polyäthylenglykolstearatlösungen durchschnittlich 2 (Phenol), 4 (Kresol), 8 (o‐Cl‐m‐Kresol), 30 (Thymol), 38 (p‐Cl‐m‐Xylenol) 800 (Hexachlorophen). – Die Polyäthylenglykole wirken sich auf die antibakterielle Aktivität der Phenole praktisch nicht oder nur geringfügig aus.
Zur Kenntnis der 2‐Amino‐1,3,4‐oxdiazole 33. Mitt.: Darstellung und Reaktionen von in 5‐Stellung heterocyclisch substituierten 2‐Amino‐1,3,4‐oxdiazolen
Authors: Gehlen H. , Demin P. , Uteg K.‐H.
Published: October 2006

Hydrazide heterocyclischer Carbonsäuren reagieren mit Bromeyan unter Bildung der entsprechenden 2‐Amino‐1,3,4‐oxdiazole (I). Das reaktive Verhalten von I gegenüber Arylisocyanaten, Acylhydrazinen, Dialkylsulfaten und alkoholischer KOH wird untersucht.
Gewinnung eines gerbstoffarmen Extraktes aus Rhizoma Rhei
Authors: Gstirner F. , Flach G.
Published: October 2006

Aus einem Extractum Rhei werden die Gerbstoffe durch Chromatographie über eine Polyamidsäule entfernt, und die Anthraverbindungen angereichert, so daß ein Wirkstoffkonzentrat mit etwa 50% Anthraverbindungen und etwa 5% Gerbstoffen gewonnen wird. Das ursprüngliche Verhältnis der Anthraverbindungen in der Droge bleibt nach Bestimmung einiger Einzelwirkstoffe größtenteils erhalten.
Mechanismus der Diphenylverknüpfung bei der Biosynthese von Aporphin‐Alkaloiden 3. Mitt.: Untersuchung zur Biosynthese von Alkaloiden
Authors: Blaschke G.
Published: October 2006

In Fütterungsversuchen mit mehrfach markierten Vorstufen wurde der Reaktionsmechanismus der Biosynthese des Aporphin‐Alkaloids Bulbocapnin aus Reticulin untersucht. Das Ergebnis beweist direkte Diphenylverknüpfung des Reticulins zum Aporphingerüst. Dienonzwischenstufen werden nicht durchlaufen.
Mechanismus der Reduktion des Oxazepams an der Hg‐Tropfelektrode
Authors: Oelschläger H. , Volke J. , Lim G. T. , Bremer U.
Published: October 2006

Oxazepam (I) wird an der Quecksilbertropfelektrode in sauren Puffern unter Verbrauch von 4 elektronen zum 7‐Chlor‐5‐phenyl‐1,3,4,5‐tetrahydro‐2H‐1,4‐benzodiazepin‐2‐on reduziert. In alkalischen Puffern entsteht unter Aufnahme von 2 Elektronen zunächst das 4,5‐Dihydroprodukt. Dieses reagiert als instabiler cyclischer Aldehydammoniak weiter. I ist in neutralen und alkalischen Puffern bis pH 10, die Dimethylsulfoxid als Lösungsvermittler enthalten, stabil. Die Bildung des 7‐Chlor‐5‐phenyl‐4,5‐dihydro‐2H‐benzodiazepin‐2,3‐(1H)‐dions (II) und der 6‐Chlor‐3,4‐dihydro‐4‐phenyl‐2‐chinazolin‐carbonsäure (III) konnte mit Sicherheit ausgeschlossen werden.
Synthesen in der Reihe der Azabenz[a]‐anthracene und ‐naphthacene
Authors: Winterfeld K. , Franzke H.
Published: October 2006

Die Synthesen wurden auf zwei verschiedenen Wegen durchgeführt. Weg A ging vom 1‐Methyl‐2,3‐dioxo‐3‐azachinolizidin (1) aus, das mit geeigneten 1,2‐Diaminen (o‐Phenylendiamin, 2,3‐Diaminopyridin und 2,3‐Diaminochinoxalin) anfänglich unter Verwendung von geschmolzener Benzoesäure, später mit besserem Ergebnis unter Verwendung von Polyphosphorsäure zur Reaktion gebracht wurde. Da beide Lösungsmittel nicht nur kondensierend, sondern bei den für die Umsetzung erforderlichen hohen Temperaturen auch dehydrierend wirkten, entstanden außer den Kondensations‐ noch Dehydrierungsprodukte der Kondensate.

Syntheseweg B ging vom 2,3‐Dichlorchinoxalin (11) aus, das mit 2‐Pipecolylmethylamin (12), mit Pipecolylamin (13) und 2,2‐Dipiperidyl (15) in siedendem Tetralin zur Umsetzung gebracht wurde.
Synthesen von Flavon‐2′‐carbonsäuren und Chromono‐(2′,3′‐3,4)‐isocumarin‐derivaten
Authors: Wurm G. , Loth H.
Published: October 2006

Bei dem Versuch, 1,2‐Bischromonylbenzolderivate aus Phthalsäure und o‐Hydroxyacetophenonderivaten durch Baker‐Venkataraman‐Umlagerung darzustellen, erhielten wir in einem Schritt Flavon‐2′‐carbonsäurederivate. Es steht damit ein einfacher Weg zur Verfügung, um Flavon‐2′‐carbonsäuren und Chromonoisocumarine zu synthetisieren.
Potentiometrische Bestimmung der Ionisationskonstanten einiger morpholinoalkyl‐substituierter Barbitursäuren. 1. Mitt
Authors: Michailova D. , Natscheva R. , Gagausov J.
Published: October 2006

Es wurden die Ionisationskonstanten von neuen Morpholinoalkylbarbituraten bestimmt. Die Verbindungen besitzen eine ausgeprägte spasmolytische Wirkung. Einige von ihnen wirkten auch tranquillisierend und antiarrhythmisch. Es wurde die potentiometrische Titration angewandt. Die Berechnungen erfolgten je nach dem Charakter der Titrationskurven direkt nach den Logarithmen von KSäure und KBase oder nach der Methode von Noyes. Auch eine Bestimmung der Ionisationskonstante wurde durchgeführt, bei der das Gleichgewicht Base‐Proton als ein Prozeß der stufenartigen Komplexbildung angesehen wird.
Quantitative Bestimmung von Glycyrrhizinsäure über den Eisen(III)‐Glycyrrhetin‐Hydroxamsäurekomplex
Authors: Brieskorn C. H. , Sax H.
Published: October 2006

Glycyrrhetinsäure wird über ihr Säurechlorid quantitativ in Glycyrrhetin‐hydroxamsäure umgewandelt. Sie gibt mit Fe3+ einen roten Komplex, welcher dem Lambert‐Beerschen Gesetz folgt.
Die Synthese von Apigenin‐5‐methyläther
Authors: Krämer J. M.
Published: October 2006

Die Struktur des vor einiger Zeit beschriebenen Apigenin‐5‐methyläthers wurde durch die Synthese bestätigt.
Über monoterpenoide Valeriana‐Alkaloide
Authors: Gross D. , Edner G. , Schütte H. R.
Published: October 2006

In Valeriana officinalis L. werden dünnschichtchromatographisch 12 Dragendorff‐positive Zonen nachgewiesen, von denen die Hauptzone mit dem von Torssell und Wahlberg aufgefundenen Hauptalkaloid identisch ist. Eine weitere Zone wird (S)‐(‐)‐Actinidin zugeordnet. Biosyntheseversuche geben Hinweise, daß Mevalonsäure als spezifischer Precursor des Actinidins und des Hauptalkaloids fungiert und daß die C6‐C2‐Seitenkette des Hauptalkaloids aus Tyrosin hervorgeht.
Über die Synthese von o‐Acylamino‐β‐dimethylaminopropiophenonen Mitt.: Aminomethylierung von 2‐Nitro‐5‐methoxy‐und 2‐Nitro‐5‐benzyloxyacetophenon
Authors: Back W.
Published: October 2006

Der von Makino und Takahashi sowie Joh als 2‐Nitro‐5‐methoxy‐β‐dimethylamino‐propiophenon bezeichnete Körper wurde als 2‐Nitro‐5‐methoxy‐α‐dimethylaminomethyl‐acrylophenon identifiziert. Nach einer früher beschriebenen Methode zur Darstellung von 2‐Nitro‐β‐dimethylamino‐propiophenon war es möglich, 2‐Nitro‐5‐methoxy‐ und 2‐Nitro‐5‐benzyloxy‐acetophenon normal zu aminomethylieren. –Die Synthese von 2‐Amino‐5‐methoxy‐, 2‐Amino‐5‐benzyloxy‐ und 2‐Amino‐5‐hydroxy‐β‐dimethylamino‐propiophenon sowie ihrer Acetylderivate wird beschrieben.