bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Amendments on Physicochemical and Biological Properties of Sodic Soil and Yield of Rice CO 52 (Oryza sativa L.) Grown in a Subtropical Region
Authors: R Vinothini. , Bose. K Subash Chandra , Baskar M.
Published: July 2024

Sodic soils are low in available nutrients, organic carbon, microbial population and enzyme activities. Amendments application not only used to improve soil physico-chemical properties and also increase soil organic carbon and biological activity of sodic soil. Field experiment was conducted in sodic soil using rice (CO 52) as a test crop with various amendments viz., gypsum+ green manure (G+GM), green leaf manure (GLM) and press mud (PM). The influence of amendments on reclamation as well as availability of plant nutrients and biological activity were studied. The microbial population viz., bacteria, fungi and actinomycetes and enzyme activity viz dehydrogenase, phosphatase and urease were increased on reclamation over control. Higher microbial population and greatest enzyme activities were observed in the gypsum+ green manure (G+GM) applied treatments followed by green leaf manure (GLM) and press mud (PM) applied plots. Sodic soil reclamation using various amendments resulted in enhanced crop yield, physicochemical and biological properties of soil.
Hydrocarbon Degradation and Biodegraders in Oil Spillage Sites in Port Harcourt
Authors: Ikpeama Roseanne Adah , Konne Joel Burabari , Ezeh Golda Lugesi , Nyenke Clement Ugochukwu , Okolonkwo Benjamin Nnamdi , Obe Olube Emmanuel , Jaja David , Achi Godspower Ikechi
Published: July 2024

Information on remediation of soils polluted from the activities of artisanal crude oil refining is lacking. The functional capability of the indigenous microbial community and prospects for recovery of important bio-resources has also not been explored. The aim of this study was to identify the hydrocarbon biodegrader present in oil spillage sites in Port Harcourt. Samples were taken from various sites (labelled ss1, ss2, ss3 and controls) in Port Harcourt and the samples were transported to the lab for bacteriological assessment. The samples were cultured in Nutrient agar and Basal Salt Medium (BSM). The total heterotrophic bacteria counts were enumerated by serially diluting the fluid sample. Microbial characterization was done based on morphological, physiological and biochemical tests. From the results, Pseudomonas species and Bacillus species were the probable isolated from the culture of hydrocarbon contaminated environment. The results also revealed increased compared to the control organism that maintained the same growth level throughout the 5 days of incubation, the isolated bacteria (Pseudomonas species and Bacillus species) had steady bacterial growth. This study has shown that Bacillus species and Pseudomonas aeroginosa are potential agents of bioremediation of environmental hydrocarbon pollution.
Advances in Gibberellic Acid Application in Cropping
Authors: Sharma Vastavik , Gantait Aishmita , Kapil Deeksha
Published: July 2024

For plants to thrive, phytohormones play a key role in their development and growth. A total of five different phytohormones have been identified here: auxin, gibberellins, cytokinin, ethylene and abscisic acid. The growth-promoting and dormancy-breaking effects of gibberellin make it a crucial phytohormone. Japan was the site of its discovery around the end of the nineteenth century. The most often utilized type of gibberellic acid is GA3, which is a metabolite. Tobacco and lettuce, require bright light to germinate, and may be grown with the aid of gibberellic acid even in the dark. Internode elongation, like in the case of pea or maize suffering from dwarfism, is another benefit of GA. It aids in the development of seedless tomato and grape types. During germination, gibberellins in the aleurone layer of the endosperm of cereal grains release particular enzymes like amylase, which hydrolyzes starch to form simple sugars. These sugars are then transferred to the developing embryo to be used as a source of energy. Gibberellin plays a crucial role in fruit setting, and it also aids fruit development and increases fruit size, making it one of the most significant growth regulators.
Role of Potash and Other Organic as Vital Nutrient for Qualitative and Quantitative Yield of Banana (Musa pardisicsica L.) in Bihar, India
Authors: Kumari Mamta
Published: July 2024

One of the most significant fruit crops is the banana (Musa paradiscica L.). In the Bihar district of Bhagalpur, it comes in second place behind mangos as a major fruit crop. It may be grown in a variety of climates across the world, including temperate, tropical, and subtropical areas. Because bananas are highly nutritious and have therapeutic qualities, they are produced primarily for their commercial worth. Because of their superior qualities and abundant nutritional content, bananas hold a prominent position in society. In literal word we can say that potash is  highly significant for banana cultivation as shown by the result if potash is higher in dose farmer cultivate banana in qualitatively and quantitatively too. In case of T1 i.e Urea 400g+DAP 150g +700g MOP+2.5 kg  vermicompost +20 g PSB  per pseudostem at 30 DAT, 75 DAT, 135 DAT, 170 DAT,225 DAT & 270 DAT that yields 1234.5 quintal /ha followed by  T2 Urea 400g +DAP 100g+300g MOP+ 2.5kg vermicompost + 25g PSB followed same DAT yields 954.5 quintal per ha. Same result was found by found and advocated the role of potash in banana and booh was published by the name Potassium management in Banana S. Sathiamoorthy and K.J. Jeyabhaskaran published by NRC Banana Trichy, Tamilnadu.  Given its significant commercial value and vast cultivated area, an on-farm experiment was developed to determine the contribution of various nutrient fertilisers to the quality and yield of bananas. This experiment was carried out in the banana growing seasons of 2014–15, 2015–16, and 2016–17. Treatment T1 had given the best result with 1234.5 quintal per hectare with 3.30 BC ratio.
Molecular Mechanism of Cell Signaling Pathways of Cancer Cells in Forward and Reverse Mutation: A Perspective Review
Authors: Hoque Naeema Salatia , Hossain Md. Sakhawat , Rahaman Md. Ashikur , Chowdhury Rifaia Sultana , Alam Md. Ashraful , Hossain Md. Imran , Tama Rahima Tanbin
Published: July 2024

One of the most dreaded diseases is cancer whose biological process has long been the focus of scientific inquiry. Changes to normal cellular pathways that result in uncontrolled cell growth and proliferation are widely accepted as the primary cause of cancer. It is known as cancer cells' forward mutation, unchecked proliferation and few pathways contribute to cancer development. Including PI3K-Akt pathway EGFR, PI3K/AKT/mTOR, Notch, NF-κB, Ras/MAPK and Wnt/β-catenin are essential for cancer development. Certain cancer forms' genesis and progression are attributed to several cell signaling pathways including the Ras/MAPK and PI3K/AKT/mTOR pathways. In breast, prostate, colorectal, lung and ovarian cancers, the PI3K/AKT/mTOR pathway is often activated, promoting cell survival, proliferation and metastasis. Lung, colorectal, thyroid, and pancreatic cancers often exhibit activation of the Ras/MAPK pathway, which controls cell proliferation, differentiation and survival. It is extremely uncommon but under some circumstances, cancer cells can undergo reverse mutation which returns the mutant gene to its normal phase. It has been observed that despite notable advancements in the field of cancer biology, the intricate relationship between forward and reverse mutations in the formation of cancer is still poorly understood with no prior study having thoroughly investigated their combined processes. This article aimed to provide an investigation of the primary biological processes behind both reverse and forward mutation upon examining the molecular mechanisms underlying both forward and reverse mutation.
Enhancing Mungbean Resistance to Yellow Mosaic Virus: Insights from Biochemical Studies
Authors: Shilpa M. , Manjunath B. , Sunil C.M. , Devaraja  , Gayathri  , Nagaraju N.
Published: July 2024

Mungbean is one among the important and major pulse crop for supplementation of protein in subtropical zones of the world. Apart from providing protein in the diet, it also has the appreciable quality of helping the symbiotic root rhizobia by contributing to fix atmospheric nitrogen enriches the fertility of soil. Among the biotic factors, Mungbean yellow mosaic virus (MYMV) is the major bottleneck for pulse producers. The current study is aimed at estimation of biochemical enzymes like peroxidase, polyphenol oxidase, catalase, phenols and sugars contributing for resistance in mungbean genotypes. Fourteen Mungban genotypes including one susceptible check MYB-11 and KKM-3 (UASB released variety) were screened during kharif 2022 and summer 2023. To determine MYMV induced biochemical changes in mungbean, the infected leaf samples were collected from resistant, moderately resistant, moderately susceptible and susceptible genotypes. The varied level of different defense inducing enzymes from all the 14 mungbean genotypes was estimated. The biochemical constituents such as total sugar, total phenol content and enzyme activity of Peroxidase (PO), Polyphenol oxidase (PPO) and catalase activity were estimated. The present study indicated that the defence inducing enzymes, i.e, peroxidase, polyphenol oxidase, catalase, phenols and sugars, showed comparatively higher level of resistance in genotypes viz., MYB- 6, 7, 8 and 9 when compared to the susceptible check (MYB-11).
Postlaunch calibration and bias characterization of AMSU‐A upper air sounding channels using GPS RO Data
Authors: Chen X. , Zou X.
Published: March 2014

While the calibration accuracy of Advanced Microwave Sounding Unit‐A (AMSU‐A) was well characterized during its prelaunch period, its on‐orbit performance remains important after the launch of each satellite. In this study, Global Positioning System (GPS) radio occultation (RO) data are used to carry out a postlaunch calibration to obtain an estimate of the accuracy of brightness temperatures measured by an AMSU‐A instrument. At each scan angle, the mean difference and a linear regression relationship between AMSU‐A observations and GPS RO brightness temperature simulations can first be derived using data in clear‐sky conditions over ocean. The AMSU‐A upper air sounding channels are then calibrated to GPS RO brightness temperature simulations using either the mean difference or the linear regression relationship. The effect of the above two calibration methods on the biases of AMSU‐A data with respect to National Centers for Environmental Prediction global forecast system (NCEP GFS) 6 h forecast fields is finally examined. It is found that the magnitude and sign of biases vary with channels. After GPS RO calibration, biases are negative and of the same magnitude for all AMSU‐A upper air sounding channels. The negative biases of AMSU‐A brightness temperature are associated with a small warm bias in the physical temperature of NCEP GFS 6 h forecasts compared with GPS RO temperature retrieval above the low troposphere.
Insights into factors affecting nitrate in PM2.5 in a polluted high NOx environment through hourly observations and size distribution measurements
Authors: Xue Jian , Yuan Zibing , Lau Alexis K. H. , Yu Jian Zhen
Published: March 2014

Nitrate, a major PM2.5 component in polluted environments, could be greatly elevated during pollution episodes. In this study, nitrate and other inorganic ions on PM2.5 were measured half hourly at a residential location in Hong Kong in December 2009. Hourly nitrate concentrations in PM2.5 varied from 0.8 to 40.5 µg m−3. In an episode during which hourly visibility was down to 3.7 ± 1.0 km and NO2 was 80.7 ± 14.4 ppb, PM2.5 NO3− reached 27.8 ± 8.0 µg m−3, ~6 times the level during the normal hours. Nitrate was fully balanced by NH4+, indicating abundant presence of NH3. Size‐segregated measurements showed 84% of nitrate was in the fine mode during the episode and also suggested that less acidic fine particles and less abundant sea‐salt particles were the contributing factors to the dominant presence in the fine mode. An observation‐based model for secondary inorganic aerosols was applied to investigate the relative importance of homogeneous and heterogeneous reactions to production of NO3− potential (sum of HNO3 (g) and aerosol nitrate). The modeling analysis shows that both formation pathways were significantly more active during the episode. Gas phase production of HNO3 through reaction of NO2 + OH dominated during the initial rapid buildup of nitrate around noon time, but the heterogeneous N2O5 hydrolysis pathway made a sizable contribution in the subsequent few hours due to sustained high‐NO2 concentrations combined with reduced photolysis loss of N2O5. This case study illustrates the important role of NH3 and NO2 in elevating PM2.5 in a high‐NOx environment through the formation of nitrate.
Graphene Wrapped TiO2 Based Catalysts with Enhanced Photocatalytic Activity
Authors: Wang Chao , Meng Dongli , Sun Jinhua , Memon Jamil , Huang Yong , Geng Jianxin
Published: March 2014

Reduced graphene oxide (RGO) wrapped titanium dioxide nanocrystals (TiO2 NCs@RGO) with oxygen vacancies (Vo) and Ti3+ defects have been synthesized by electrostatically wrapping GO around TiO2 NCs followed by thermal annealing at 400 °C. Transmission electron microscope observations have shown that TiO2 NCs@RGO has a unique crystalline core/crystalline shell structure, which is different from the original amorphous TiO2 covered TiO2 NCs. Raman spectroscopy, X‐ray photoelectron spectroscopy, and electron paramagnetic resonance have demonstrated that Vo‐Ti3+ species are more readily formed in TiO2 NCs@RGO than in TiO2 NCs. As a result, TiO2 NCs@RGO exhibits enhanced optical absorption in a wide wavelength range from visible light to near IR and red‐shifted absorption edge. In the photocatalytic degradation reaction of methyl orange, the photodegradation rate constant for TiO2 NCs@RGO is 2.4 times higher than that of TiO2 NCs. The enhanced photocatalytic performance can be attributed to the improved charge separation at the interface of TiO2 NCs and RGO layer and the enhanced optical absorption in visible light region due to the donor levels of the defects such as Vo‐Ti3+ species. This work establishes a new method for preparing Vo defect contained TiO2 catalysts.
High‐Temperature Shape Memory Effect in Ti‐Ta Thin Films Sputter Deposited at Room Temperature
Authors: Motemani Y. , Buenconsejo P. J. S. , Craciunescu C. , Ludwig A.
Published: March 2014

Ti‐Ta based alloys are potential high‐temperature shape memory materials with operation temperatures above 100 °C. In this study, the room temperature fabrication of Ti‐Ta thin films showing a reversible martensitic transformation and a high temperature shape memory effect above 200 °C is reported. In contrast to other shape memory thin films, no further heat treatment is necessary to obtain the functional properties. A disordered α″ martensite (orthorhombic) phase is formed in the as‐deposited co‐sputtered Ti70Ta30, Ti68Ta32 and Ti67Ta33 films, independent of the substrate. A Ti70Ta30 free‐standing film shows a reversible martensitic transformation, as confirmed by temperature–dependent XRD measurements during thermal cycling between 125 °C to 275 °C. Furthermore, a one‐way shape memory effect is qualitatively confirmed in this film. The observed properties of the Ti‐Ta thin films make them promising for applications on polymer substrates and especially in microsystem technologies.
Encephalocele—radial, cardiac, gastrointestinal, anal/renal anomalies: Novel evidence for a new condition?
Authors: Valdez Carolina M. , Altmayer Stephan P.L. , Barrow McArthur A. , Telles Jorge A.B. , Betat Rosilene da S. , Zen Paulo R.G. , Rosa Rafael F.M.
Published: March 2014

The association between encephalocele and radial defects is considered uncommon. These features have been occasionally described separately in certain recurrent conditions such as VACTERL association, oculo‐auriculo‐vertebral spectrum and Edwards syndrome (trisomy 18). DK‐phocomelia is a rare syndrome characterized by both findings. However, Froster‐Iskenius and Meinecke [1992, Clin Dysmorphol 1: 37–41] and Kunze et al. [1992, Eur J Pediatr 151: 467–468] reported patients presenting similar malformations. We proposed, through the description of an additional case, that these last patients present the same condition and thus represent a new syndrome. The fetus presented a cranial vault deformity associated with an exuberant herniation of brain content, compatible with occipital encephalocele. Other uncommon features were also identified: microtia of the left ear with atresia of the external auditory canal; radial defect with aplasia of left radius and thumb; findings suggestive of a congenital heart defect and esophageal atresia; hypoplastic lungs and adrenals; thoracolumbar scoliosis; atrophic right kidney; and single umbilical artery. Thus, based on our review, we believe that these patients represent a new condition characterized by encephalocele and radial defects associated with multiple malformations. We propose, that the name “Encephalocele–radial, cardiac, gastrointestinal, anal/renal anomalies,” as suggested by the London Medical Database, or even the name, “Froster‐Iskenius and Meinecke syndrome” should be used to indicate these cases. © 2014 Wiley Periodicals, Inc.
Report of a newly indentified patient with mutations in BMP1 and underlying pathogenetic aspects
Authors: Valencia María , Caparrós‐Martin Jose A. , Sirerol‐Piquer María Salomé , García‐Verdugo José Manuel , Martínez‐Glez Víctor , Lapunzina Pablo , Temtamy Samia , Aglan Mona , Lund Allan M. , Nikkels Peter G. J. , Ruiz‐Perez Victor L. , Ostergaard Elsebet
Published: March 2014

Osteogenesis imperfecta is a genetic condition characterized by bone fragility and recurrent fractures, which in the large majority of patients are caused by defects in the production of type I collagen. Mutations in the gene encoding bone morphogenetic protein 1 (BMP1, also known as procollagen C‐endopeptidase) have been associated with osteogenesis imperfecta in two sib pairs. In this report, we describe an additional patient with osteogenesis imperfecta with normal bone density and a recurrent, homozygous c.34G>C mutation in BMP1. Western blot analysis of dermal fibroblasts from this patient showed decreased protein levels of the two alternatively spliced products of BMP1 and abnormal cleavage of the C‐terminal propeptide of type I procollagen. In addition, fluorescence and electron microscopy showed impaired assembly of type I collagen fibrils in the extracellular matrix of cultured fibroblasts derived from two patients: the patient described here and a previously reported patient with a homozygous BMP1 c.747C>G mutation. We conclude that BMP1 is essential for human type I collagen fibrilogenesis. © 2014 Wiley Periodicals, Inc.
Maternal complex chromosomal rearrangement leads to TCF12 microdeletion in a patient presenting with coronal craniosynostosis and intellectual disability
Authors: Le Tanno Pauline , Poreau Brice , Devillard Francoise , Vieville Gaëlle , Amblard Florence , Jouk Pierre‐Simon , Satre Véronique , Coutton Charles
Published: March 2014

We report on a young child with intellectual disability and unilateral coronal craniosynostosis leading to craniofacial malformations. Standard karyotype showed an apparently balanced translocation between chromosomes 2 and 15 [t(2;15)(q21;q21.3)], inherited from his mother. Interestingly, array‐CGH 180K showed a 3.64 Mb de novo deletion on chromosome 15 in the region 15q21.3q22.2, close to the chromosome 15 translocation breakpoints. This deletion leads to haploinsufficiency of TCF12 gene that can explain the coronal craniosynostosis described in the patient. Additional FISH analyses showed a complex balanced maternal chromosomal rearrangement combining the reciprocal translocation t(2;15)(q21;q21.3), and an insertion of the 15q22.1 segment into the telomeric region of the translocated 15q fragment. The genomic imbalance in the patient is likely caused by a crossing‐over that occurs in the recombination loop formed during the maternal meiosis resulting in the deletion of the inserted fragment. This original case of a genomic microdeletion of TCF12 exemplifies the importance of array‐CGH in the clinical investigation of apparently balanced rearrangements but also the importance of FISH analysis to identify the chromosomal mechanism causing the genomic imbalance. © 2014 Wiley Periodicals, Inc.
Comparability of multiple data types from the bering strait region: Cranial and dental metrics and nonmetrics, mtDNA, and Y‐chromosome DNA
Authors: Herrera Brianne , Hanihara Tsunehiko , Godde Kanya
Published: March 2014

Different data types have previously been shown to have the same microevolutionary patterns in worldwide data sets. However, peopling of the New World studies have shown a difference in migration paths and timings using multiple types of data, spurring research to understand why this is the case. This study was designed to test the degree of similarity in evolutionary patterns by using cranial and dental metric and nonmetric data, along with Y‐chromosome DNA and mtDNA. The populations used included Inuits from Alaska, Canada, Siberia, Greenland, and the Aleutian Islands. For comparability, the populations used for the cranial and molecular data were from similar geographic regions or had a shared population history. Distance, R and kinship matrices were generated for use in running Mantel tests, PROTEST analyses, and Procrustes analyses. A clear patterning was seen, with the craniometric data being most highly correlated to the mtDNA data and the cranial nonmetric data being most highly correlated with the Y‐chromosome data, while the phenotypic data were also linked. This patterning is suggestive of a possible male or female inheritance, or the correlated data types are affected by the same or similar evolutionary forces. The results of this study indicate cranial traits have some degree of heritability. Moreover, combining data types leads to a richer knowledge of biological affinity. This understanding is important for bioarchaeological contexts, in particular, peopling of the New World studies where focusing on reconciling the results from comparing multiple data types is necessary to move forward. Am J Phys Anthropol 154:334–348, 2014. © 2014 Wiley Periodicals, Inc.
In Situ Three‐Dimensional Synchrotron X‐Ray Nanotomography of the (De)lithiation Processes in Tin Anodes
Authors: Wang Jiajun , Chen‐Wiegart Yu‐chen Karen , Wang Jun
Published: March 2014

The three‐dimensional quantitative analysis and nanometer‐scale visualization of the microstructural evolutions of a tin electrode in a lithium‐ion battery during cycling is described. Newly developed synchrotron X‐ray nanotomography provided an invaluable tool. Severe microstructural changes occur during the first delithiation and the subsequent second lithiation, after which the particles reach a structural equilibrium with no further significant morphological changes. This reveals that initial delithiation and subsequent lithiation play a dominant role in the structural instability that yields mechanical degradation. This in situ 3D quantitative analysis and visualization of the microstructural evolution on the nanometer scale by synchrotron X‐ray nanotomography should contribute to our understanding of energy materials and improve their synthetic processing.
Elektrische Leitfähigkeit flüssigen und gasförmigen Cäsiums bis 2000 °C und 1000 bar
Authors: Renkert H. , Hensel F. , Franck E. U.
Published: March 2014

Zwischen 60°C und 2000°C, bei unter‐ und überkritischen Temperaturen, wurde die elektrische Leitfähigkeit des Cäsiums bis zu Drücken von 1000 bar gemessen. Dazu wurde ein Autoklav mit Innenheizung entwickelt, in den Meßzellen aus Molybdän und Wolfram eingebaut wurden. Der Autoklav war mit reinem Argon gefüllt, dessen Druck dem Cäsiumdruck im Inneren der Meßzellen die Waage hielt.

Zunächst wurde die Dampfdruckkurve bis zum kritischen Punkt bestimmt, für den Tc = 1750°C und pc = 110 bar gefunden wurde.

Die Leitfähigkeit des flüssigen Cäsiums ist nur wenig druckabhängig. Bei 1200°C nimmt sie bei einer Drucksteigerung von 100 bar auf 1000 bar nur um einen Faktor 1,7 zu. Bei der überkritischen Temperatur von 1800°C dagegen wächst sie von 20 Ohm−1 cm−1 auf 2 · 103 Ohm−1 cm−1, wenn der Druck von 100 bar auf 500 bar steigt. Diese Änderung ist ein Beispiel für einen Übergang vom nichtmetallischen zum metallischen Zustand. Sie wird entsprechend diskutiert.
Ostwald Ripening of a Narrow Precipitate Size Distribution
Authors: Markworth Alan J.
Published: March 2014

An analytical study is presented of the Ostwald‐ripening kinetics of a narrow size distribution of precipitate particles. It is shown that, as long as the distribution remains narrow, the temporal evolution of various of its gross properties can be quantitatively described without requiring detailed knowledge of its actual shape. In particular, it is shown that the standard deviation of a narrow distribution of particle radii increases exponentially with time, a result which is consistent with that of another investigation in which the evolution of an initially Gaussian distribution was evaluated.
Die Oxidation von Kohlenmonoxid an Platin im sauren Elektrolyten
Authors: Hamann Carl H.
Published: March 2014

Mit Hilfe potentiodynamischer Messungen konnte der Mechanismus

für die Oxidation von Kohlenmonoxid an Platin in schwefelsauren Lösungen wahrscheinlich gemacht werden. Dieser Mechanismus bezieht sich auf die Oxidation von direkt auf der Platinoberfläche adsorbiertem CO. Darüber hinaus konnte festgestellt werden, daß locker — in Form einer zweiten Adsorptionsschicht — an der Elektrode gebundenes Kohlenmonoxid leichter oxidiert wird als das in der ersten Adsorptionsschicht auf der Elektrode befindliche CO.
A Contribution to a Method for Determining the Mobilities of Natural Charge Carriers in Highly Insulating Organic Liquids
Authors: v. Löhneysen H. , Kleinheins G.
Published: March 2014

A method for measuring the mobilities of natural charge carriers in organic liquids with poor conductivity, which was first presented by Lewa [1], is discussed in detail for the case of several kinds of charge carriers in the liquid. It will be shown that the determination of the sign of the charge carriers is possible, not only for injected carriers [2] but also for natural ones.
Protonen‐Spin‐Gitter‐Relaxationsrate des 1,2‐Dibromäthan‐Moleküls in 1,2‐Dibromäthan‐d4und Benzol‐d6‐Lösungen
Authors: Chatterjee N. , Czubryt J. J. , Bock E. , Tomchuk E.
Published: March 2014

Die Protonenrelaxationsrate des 1.2‐Dibromäthan‐Moleküls sowie ihre Temperaturabhängigkeit wurde in 1,2‐Dibromäthan‐d4und Benzol‐d6‐Lösungen bestimmt. Die molekulare Umorientierungszeit des 1,2‐Dibromäthan‐Moleküls in flüssigem 1,2‐Dibromäthan‐d4, berechnet aus dem intramolekularen Anteil der Spin‐Gitter‐Relaxationsrate bei 25°C, 14,5 · 10−12sec, stimmt gut mit der dielektrischen Relaxationszeit, 11,6 · 10−12sec bei 25°C überein. Die Aktivierungsenergie der intramolekularen bzw. intermolekularen Relaxationsrate beträgt 2,0 kcal/mol bzw. 2,6 kcal/mol und die der Viskosität 2,7 kcal/mol.
Reactive Matrices; Metal Atom Chemistry and Surface Chemistry: Dinickel Monethylene, Ni2(C2H4)
Authors: Ozin Geoffrey A. , Power William J.
Published: March 2014

Using cryochemical manipulation of Ni atom reactions with ethylene‐argon mixtures at 15–20K and from examination of the vibrational and electronic spectra we have identified Ni2(C2H4)m (where m = 1,2) in the presence of Ni(C2H4)m (where m = 1,2,3). These results suggest strongly that the ethylene moiety is complexed to the chemical site in a π‐complexed manner, probably in association with only one of the Ni atoms. Some evidence for the formation of Nix(C2H4)y with x > 3 is presented. – To further characterize the Ni2(C2H4) complex GVB and CI calculations were carried out on Ni(C2H4) and Ni2(C2H4) in π‐coordinate geometry. For both complexes the ethylene geometry is found to be only weakly perturbed, with R(CC) = 1.32 Å and R(NiC) = 2.07 Å. The CH bonds are found to bend only 2° out of the ethylene molecular plane. There is a slight increase in ethylene‐Ni binding energy upon coordination of the second Ni atom, from 14.2 kcal for Ni(C2H4) to 16.8 kcal for Ni2(C2H4). The experimental and theoretical results are discussed with reference to the problem of chemisorption of ethylene on bulk nickel.
Photochemical Oxidation of Iodosilane in Solid Argon
Authors: Ogilvie J. F. , Salares V. R. , Newlands M. J.
Published: March 2014

The photochemical decomposition of iodosilane, alone or in the presence of oxygen, in argon matrices at 4 – 8 K has been studied by methods similar to those used previously for iodomethane (Canad. J. Chem., 53, 269 (1975)). Vibrational absorption spectroscopy has been used to detect the formation of iodosilyl radicals and oxygenated iodosilane derivatives. The use of deuterated iodosilane and oxygen‐18 has permitted identification of structures of likely products. Attribution of absorption lines to the various species has been possible through the use of high‐ and low‐pressure mercury lamps which produce different sets of line intensities. The effect of the relative concentration of oxygen also aids in product identification. The formation of ozone and the production of photochemical explosions with silane/ozone mixtures at 4 K will be discussed.
Charge‐Transfer Reactions on Membrane‐Type Polymer Coated Electrodes under Conditions of Diffusion and Migration of the Redox‐Ions
Authors: Lange Rainer , Doblhofer Karl
Published: March 2014

Membrane transport processes involving diffusion and migration of redox‐ions are analyzed. Two‐electron redox‐systems of the type A+/B3+ are considered. At equilibrium the transference number of the electroactive species in the membrane is assumed to be unity. At time t = 0 a potential step is applied to the coated electrode which leads to zero surface concentration of the electroactive species. Time‐dependent electric field, potential and concentration profiles of A and B across the coating are derived from the Nernst‐Planck and continuity equations with a digital simulation technique. The resulting current transients are shown to follow Cottrell's law, however, the observed “effective” diffusion coefficients differ significantly from the diffusion coefficients of the reacting redox ions. — By comparing values of the potential drop across the membrane with the corresponding currents, “effective membrane resistance, RM” values are derived. RM is shown to differ significantly between the forward and back reactions, and it is time dependent. This has important consequences for accurate analyses of current/voltage curves.
Thermodynamic Properties of the RbReO4 — CsReO4 System
Authors: Lukas Wojciech
Published: March 2014

The excess molar Gibbs free energy GE has been determined by mass spectrometric techniques for the solid phase of the system RbReO4 — CsReO4 at 790 K. The liquidus curve of the T—x phase diagram has been determined by thermal analysis. The solidus and the difference between the excess molar Gibbs free energies of the liquid and the solid phases have been calculated.
1H‐NMR Studies of the System Ta1−xTixHy, 0 ≤ x ≤ 0.3, 0 < y ≤ 0.9. Magnetic Susceptibility and Knight Shift
Authors: Richter Karl‐Hermann , Weiss Alarich
Published: March 2014

The magnetic susceptibility χ and the 1H‐Knight shift KH of the b.c.c. system Ta1−xTixHy, (0 ≤ x ≤ 0.3, 0 < y ≤ 0.9) was studied by high resolution 1H nuclear magnetic resonance spectroscopy at T = 160°C. Moreover temperature dependent measurements of these properties were carried out for x = 0.0 and x = 0.1 within a temperature range of about 150 K in the α‐phase of the alloys. The molar magnetic susceptibility χM(x, y) depends only upon the valence electron concentration and the rigid band model is a very satisfying approximation. On the contrary, the 1H‐Knight shift KH(x, y) is strongly influenced by the titanium atoms and the rigid band model fails. The temperature dependence of χ(T) and KH(T) suggest that the Ti‐3d‐wave‐functions produce a negative hyperfine field at the proton sites which differs in sign from that of the Ta‐5d‐wave‐functions. There are pronounced similarities between the systems Ta1−xTixHy, and Nb1−xTixHy.
A Study of the Reaction of CH2(ã1A1) with H2O in the Gas Phase
Authors: Hack W. , Wagner H. Gg. , Wilms A.
Published: March 2014

The reaction:

was investigated in a quasistatic flash photolysis system at room temperature in the pressure range 0.5 ≦ p/mbar < 1.5 with He as the main carrier gas. The concentrations of CH2(ã1A1) produced in laser photolysis of CH2CO at λL = 308 nm, and the absolute concentration of the reaction product OH were monitored by laser induced fluorescence. In addition the population of the rotational states of the initial product OH (X, n̈ = 0, K) was measured. The time delay between photolysis and probe pulse delivered the time resolution. — The overall 1CH2 depletion rate determined from Stern‐Volmer plots is k1 (298 K) = (1.3 ± 0.2) · 1014 cm3/mol s. The channel:

is determined to be the dominant reaction path in the range 0.5 ≦ k1a/k1 ≦ 1.0. The physical deactivation is found to be less than 50% of k1, in agreement with previous measurements. The bearing of these results on the reaction CH3 + OH and on the thermal CH3OH dissociation is briefly discussed.
An Investigation of the Reaction between CH3 Radicals and NO at High Temperatures
Authors: Wolff Th. , Wagner H. Gg.
Published: March 2014

The reaction between CH3 radicals and NO was investigated behind incident shock waves at temperatures between 1800 and 2150 K and total densities near 2 · 10−6 mol cm−3. — The consumption of CH3 was followed by time‐resolved UV‐absorption measurements at λ = 216 nm. — A rate constant of 2·1010 cm3 mol−1 s−1 for the reaction

at temperatures around 1900 K was determined. — An activation energy of about 85 kJ mol−1 is estimate
29Si High Resolution NMR of the Sol‐Gel Chemistry Forming SiO2 — TiO2 — ZrO2 Glasses from Alkoxides
Authors: Wies Ch. , Meise‐Gresch K. , Müller‐Warmuth W. , Beier W. , Göktas A. A. , Frischat G. H.
Published: March 2014

Chemical reaction steps have been monitored by 29Si NMR in the liquid stage of a sol‐gel process during the preparation of glasses in the ternary system 65SiO2—20TiO2—15ZrO2 from the corresponding alkoxides. Most of the recorded signals could be assigned to monomer species and larger building units, and the time evolution of the spectra of the two‐component systems Si/Ti and Si/Zr has been correlated with that of the pure starting material TEOS. No evidence has been found for the formation of ≡Si —O—Ti≡ or ≡ Si —O —Zr≡ bonds in the early polymerization. Quantitative considerations of the 29Si spectra have revealed the main condensation pathways in the Si/Ti system. 29Si MAS NMR yields, as a preliminary result, a higher branching of the network when passing from the dried gel to the annealed gel‐glas
Protonation Study of Biological Bases of DNA
Authors: Garcia Begoña , Palacios Juan C.
Published: March 2014

UV absorption spectra in aqueous perchloric acid media were recorded at 25°C for the biologically important bases of DNA cytosine, thymine, adenine and guanine. The equilibria occurring in the low acidity range are interpreted in terms of ionization ratios and pH. In the high acidity range, results obtained according to the excess acidity method X, the function Mc, or Hammett's acidity function H0 are in good agreement. The similarity of pKBH+ obtained and those reported in the literature using other acid media and different methods, evidence the validity of the log I values calculated and the equations utilize
Dipole Moments and the Direction of the Transition Dipole Moment of Some Intramolecular Exciplexes
Authors: Baumann Wolfram , Frühling J.‐C. , Brittinger C. , Okada T. , Mataga N.
Published: March 2014

The dipole moments of some intramolecular exciplex systems have been determined from the effect of an electric field on their fluorescence and are compared to those estimated from solvent shift measurements. The charge transfer between the donor and acceptor subunits is between 0.6 and 0.9 of a full charge transfer. The face‐to‐face type exciplexes show considerable deviations from the general behaviour what might be due to some admixture of locally excited configurations to the exciplex wave function, in this way reducing the dipole moment values and changing the direction of the transition dipole moment.
XP‐Spectra, Sputterexperiments and UV‐VIS‐Reflection Spectra of Polyaniline
Authors: Kessel R. , Hansen G. , Schultze J. W.
Published: March 2014

Electrochemically formed polyaniline (PANI) films were studied both in situ and ex situ using XPS and UV/VIS spectroscopy. The samples studied ex situ were removed at given potentials and rinsed with water, with no changes in the oxidation state or concentration of counter ions. PANI‐RED (0.0 V (SHE)) contained no anions and the XP‐spectra showed an emeraldine‐like structure and 0.27 protonated nitrogen atoms/monomer. PANI‐OX (1.0 V (SHE)) contained 0.2 — 0.3 counter ions/monomer throughout the film. UV/VIS spectroscopy shows a two step redox mechanism involving radical cations. The extended conjugation of PANI‐OX was followed by both reflection spectroscopy and XP‐shake‐up peaks accompanying the photoionisation process. At potentials above 1.0 V (SHE) overoxidation occurs with the removal of anions from the bulk fil
Enthalpies of Mixing in the Ternary System Aluminium Chloride — Potassium Chloride — Aluminium Chloride Monoamine
Authors: Hatem G. , Gaune‐Escard M. , Bros J. P. , Østvold T.
Published: March 2014

Quasi binary enthalpy of mixing experiments have been performed in the ternary liquid system AlCl3 —AlCl3NH3 —KCl by mixing AlCl3 + KCl with AlCl3NH3 keeping the ratio XA1Cl3XKCI = 1.125, 1.5 and 2.0, respectively. At XA1Cl3XNH3 = 0.5 and T = 270°C the enthalpies of mixing were ≃ —430 J mol−1 for all the quasi‐binaries studied. The new enthalpy data are not fully consistent with published vapour pressure data and thermodynamic model calculation
Phase Diagrams with Closed Loop Smectic — Nematic Phase Boundaries
Authors: Illian G. , Kneppe H. , Schneider F.
Published: March 2014

A T, x diagram with a closed loop smectic‐nematic phase boundary is observed in mixtures of 4‐n‐heptyloxy‐4′‐cyanobiphenyl and a mixture of 4‐cyanobenzylidene‐4′‐n‐octyloxyaniline and 4‐n‐pentylphenyl 4‐n‐octyloxybenzoate. Application of pressure reduces the smectic phase area and, at a critical pressure of 145 bar, the area is reduced to a point (double critical point) in the T, x diagram. Thermodynamics leads to an appropriate description of the phase boundary.
Far Infrared Absorption and Rotational Motion of CHClF2 to High Pressures and Temperatures
Authors: Bohn M. A. , Franck E. U.
Published: March 2014

FIR‐absorption spectra of monochloro‐difluoro‐methane (CHClF2) has been measured between 10 and 260 cm−1 at temperatures between 25 and 175°C. High pressure PVT‐data permit the discussion of the spectra as functions of density. The density has been varied between 0.1 and 1.4 g cm−3 by pressures up to 722 bar. The critical data of CHClF2 are 96.15°C, 49.9 bar and 0.513 cm−3. The dipole moment is 1.43 D. Measurements were made with a modified Fourier‐transform IR‐spectrometer. An optical absorption cell for use to 1000 bar and 200°C is described. It has quartz or silicon windows and the optical path length can be varied at operating conditions between 100 μm and 5 mm. The molar absorptivity band at 125°C and low density (0.1 g cm−3) has a pronounced maximum near 30 cm−1, indicating hindered rotation. With increasing density this band decreases and a growing absorption around 60 cm−1 develops, which is ascribed to intermolecular libration. Analogous behaviour is observed at other temperatures. A model based on a generalized Langevin‐equation and the Mori‐memory formalism serves to describe the spectra. The mean squared intermolecular torque and time correlation functions have been calculated. Orientation correlation time at 125°C and 1 g cm−3 is τOR1 = 5 · 10−13 s. The spectral fourth moment of the power spectrum shows the frequency ranges of rotation and libration very clearly.
High Frequency Ultrasonic Absorption Spectroscopy on Aqueous Solutions of Zwitterionic and Nonionic Micelles
Authors: Kaatze U. , Berger W. , Lautscham K.
Published: March 2014

The ultrasonic absorption coefficient has been measured as a function of frequency between 10 MHz and 3 GHz for micellar aqueous solutions of zwitterionic and nonionic surfactants. All solutions show Debye‐type relaxation behaviour with a time constant between 130 and 290 ps (25°C, 40°C). Comparison with corresponding dielectric spectra and with acoustic spectra of pure n‐alkanes and of solutions of ionic micelles suggests this relaxation process to be due to rotational isomerization mechanisms in the hydrocarbon chains An additional relaxation process with a time constant of 1.4 ns (25°C) has been found with a 0.1 molar solution of lysolecithin. This process is discussed in terms of orientational head group motions and, alternatively, of limited radial diffusive motions of the molecules in micelles. It is not clear why this latter relaxation does not occur in solutions of the other surfactants.
1H NMR and 35Cl NQR Studies on the Motion of Pyridinium Ions in Crystalline Pyridinium Tetrachloro‐ and Tetrabromoaurate(III): (pyH)AuX4 (X = Cl, Br)
Authors: Ito Yukari , Asaji Tetsuo , Ikeda Ryuichi , Nakamura Daiyu
Published: March 2014

The temperature dependences of 1H spin‐lattice relaxation times T1, at the Larmor frequencies of 10.5, 16.0, 20.0, and 45.5 MHz, and of 1H NMR second moments M2 were determined for (pyH)AuCl4 and (pyH)AuBr4, where pyH+ indicates a pyridinium ion. The small M2 data less than 1 G2 obtained above ca. 380 K indicated that the cations perform reorientational motion rapidly enough about its pseudohexad C′6 axis existing at the center of the cation and perpendicular to its plane. Below 140 K, both complexes yielded rigid lattice M2 values of the cation. It is interesting features for these complexes that motional narrowing for the NMR line occurs over an extremely wide range of temperature, the log T1, vs. T−1 plots are asymmetric about the 1H T1 minimum with a gentler gradient on the low temperature side, and the minima are extraordinarily long. These unusual results were interpreted by assuming the C′6 reorientation of the cations having electric dipoles among nonequivalent in‐plane orientations. Three potential barriers to the C′6 reorientation were determined as 21.8, 17.2, and 13.5 kJ mol−1 for (pyH)AuCl4, and 22.2,17.4, and 13.7 kJ mol−1 for (pyH)AuBr4. The fade‐out phenomenon of 3SCl NQR signals observed for (pyH)AuCl4 at ca. 230 K when the sample temperature was lowered is also discussed, by referring to the motion of the pyridinium cations.
Steady State Photocapacitance Study of Semiconductor/Electrolyte Junctions II. Surface State Distribution and Charge Transfer Mechanisms
Authors: Allongue P.
Published: March 2014

GaAs/electrolyte junctions are characterized by steady state photocapacitance measurements without (single beam experiment) or with added interband illumination (dual beam experiment). This original approach allows to give unambiguously the surface state distribution and to follow its evolution during electrochemical processes: results show the presence of two corrosion related states at EC −0.98 eV and EC −1.14 eV which behave differently under corrosion or photocorrosion conditions. It is shown that surfaces modified by electro‐deposition of discontinuous metal films exhibit metal‐induced surface states responsible for charge transfers.
The Electrical State of an Ion‐Exchange Membrane Surface after Emersion from Liquid Electrolytes
Authors: Cappadonia Marcella , Doblhofer Karl , Jauch Matthias
Published: March 2014

Electrodes are coated with membrane‐type polymer films containing fixed pyridinium groups. The coated electrodes are withdrawn from various electrolytes (“emersion” under potentiostatic control). In the emersed state the work function of the solvated polymer is determined with Kelvin's method of the vibrating capacitor plate. The determined values are compared with the work function of the electrolyte at the same electrode potential. It is concluded that a surface potential χMex ≈ −0.3 V exists at the emersed polymer surface. Its exact value depends on the type of counter ions. Secondly, it is shown that the concentration dependence of the work function is directly related to the equilibrium potential drop across the intact membrane/solution interface which prevailed before emersion (the “Donnan”‐potential). This suggests that such work‐function measurements yield quantitative information on the electrical work term in the description of the ion‐exchange equilibria.
Reactions of Ethynyl Radicals with Alkynes in the System Sodium Vapour/Ethynylbromide/Alkyne
Authors: Brachhold H. , Alkemade U. , Homann K. H.
Published: March 2014

The radicals were generated from the respective halide RX by the reaction Na + RX → R + NaX in a low‐pressure flow reactor fed by a multi‐slit diffusion burner. Test results are reported for the system Na/CH3I givingk(Na + CH3I) = 6.0 · 10−3andk(CH3+ CH3) = 2.8·1013cm3mol−1s−1. The main part deals with the production of C2H in the system Na/C2HBr and its consecutive reactions with C2HBr and added C2H2and C4H2. The rate constantk(Na + C2HBr) was found to be 2.9 · 1013cm3mol−1s−1. The bimolecular rate constants of C2H with the compounds above have been determined to 1.0·1014, 2.3 · 1013and 4.0·1013cm3mol−1s−1, respectively, at a temperature of 603 K. – The main products in this reaction system are polyynes with a minor formation of ethyne and very little hydrogenated polyynes. The formation of an aromatic compound (ethynylbenzene) is negligibly small, a fact which is discussed in its relation to aromates in hydrocarbon flames. The primary reaction Na + C2HBr and its products are discussed as well as the unimolecular decomposition and stabilization of energized adducts formed by C2H.
Structure and Dynamics of Lipid Model Membranes: FT‐IR‐ and 2H‐NMR‐Spectroscopic Studies
Authors: Blume A. , Hübner W. , Müller M. , Bäuerle H. D.
Published: March 2014

FT‐IR and 2H‐NMR‐spectroscopy has been used to study structure and dynamics of specifically labeled phospholipids in model membranes. Three examples for the application of these two spectroscopic techniques are given. 1. 2H‐NMR‐spectroscopy can be used to study the behavior of pure specifically deuterated model compounds of phospholipids with different head groups like phosphatidylcholines (PC**)) and phosphatidylethanolamines (PE). Line shape simulations of powder spectra and of spectra of oriented samples provide information on the mechanism and correlation times of the molecular reorientations. In mixtures of phospholipids with different head groups 2H‐NMR‐spectroscopy can be used to study the mixing behavior of lipids. Evidence for lipid clustering in the liquid‐crystalline phase comes from different splittings observed for the two components. 2. FT‐IR‐spectroscopy of 13C = O labeled phospholipids gives information on the hydration behavior of the glycerol back bone. Because of the vibrational isotope effect both carbonyl bands of the ester groups of the lipid can be observed separately when one of the C = O groups is labeled with 13C. FT‐IR spectra indicate that both ester carbonyl groups of lipids in hydrated membranes are in contact with water. The amount of hydration depends on the phase state and the nature of the lipid head groups. 3. A combination of 2H‐NMR and FT‐IR‐spectroscopy was used to determine structure and dynamics of phospholipids with ω‐cyclohexyl fatty acids. Drastic differences in conformational and dynamical behavior between odd‐ and even‐numbered members of this lipid class could be detected.