bluuebunny/crossref_metadata_2025_split huggingface dataset:
Optimizing an Industrial Scale Naphtha Catalytic Reforming Plant Using a Hybrid Artificial Neural Network and Genetic Algorithm Technique
Authors: Sadighi Sepehr , Mohaddecy Reza Seif , Norouzian Ali 
Published: July 2015

In this paper, a hybrid model for estimating the activity of a commercial Pt-Re/Al2O3 catalyst in an industrial scale heavy naphtha catalytic-reforming unit (CRU) is presented. This model is also capable of predicting research octane number (RON) and yield of gasoline. In the proposed model, called DANN, the decay function of heterogeneous catalysts is combined with a recurrent-layer artificial neural network. During a life cycle (919 days), fifty-eight points are selected for building and training the DANN (60%), nineteen data points for testing (20%), and the remained ones for validating steps. Results show that DANN can acceptably estimate the activity of catalyst during its life in consideration of all process variables. Moreover, it is confirmed that the proposed model is capable of predicting RON and yield of gasoline for unseen (validating) data with AAD% (average absolute deviation) of 0.272% and 0.755%, respectively. After validating the model, the octane barrel level (OCB) of the plant is maximized by manipulating the inlet temperature of reactors, and hydrogen to hydrocarbon molar ratio whilst all process limitations are taken into account. During a complete life cycle results show that the decision variables, generated by the optimization program, can increase the RON, process yield and OCB of CRU to about 1.15%, 3.21%, and 4.56%, respectively. © 2015 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0)
Time, Temperature and Amount of Distilled Water Effects on the Purity and Yield of Bis(2-hydroxyethyl) Terephthalate Purification System
Authors: Goh H. W. , Salmiaton A. , Abdullah N. , Idris A. 
Published: July 2015

Polyethylene terephthalate (PET) bottle is one of the common plastic wastes existed in the municipal solid waste in Malaysia. One alternative to solve the abundant of PET wastes is chemical recycling of the wastes to produce a value added product. This technology not only can decrease the PET wastes in landfill sites but also can produce many useful recycled PET products. Bis(2-hydroxyethyl) terephthalate (BHET) obtained from glycolysis reaction of PET waste was purified using crystallization process. The hot distilled water was added to glycolysis product followed by cooling and filtration to extract BHET in white solid form from the product. The effect of three operating conditions namely crystallization time, crystallization temperatures and amount of distilled water used to the yield of crystallization process were investigated. The purity of crystallization products were analyzed using HPLC and DSC. The optimum conditions of 3 hours crystallization time, 2 °C crystallization temperature and 5:1 mass ratio of distilled water used to glycolize solid gave the highest yield and purity of the crystallization process. © 2015 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0)
Experimental Study and Kinetic Modeling of Decoking of Pacol Process Dehydrogenation Catalyst
Authors: Toghyani M. , Rahimi A. , Mamanpoush M. , Kazemian R. , Harandizadeh A. H. 
Published: July 2015

The Pt/γ-Al2O3 catalyst life time was limited by the formation of coke on the external and internal surfaces of catalyst in dehydrogenation reactors. The kinetics of decoking of dehydrogenation catalyst was studied in a pilot scale fixed bed reactor experimentally. The effects of temperature, oxygen concentration and other operating conditions on decoking process were investigated. A kinetic model was deve-loped to describe the decoking of mentioned catalyst. An objective function was defined as the sum of squares of the deviations among the calculated and plant data. Accordingly the appropriate values were found in order to minimize this function. It was concluded that there was a good agreement between simulation results and experimental data. © 2015 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0)
Facile Oxidative Desulfurisation of Benzothiophene Using Polyoxometalate H4[α-SiW12O40]/Zr Catalyst
Authors: Aldes Lesbani Aldes Lesbani , Agnes Agnes , Saragih Randi O. , Verawaty Marieska , Mohadi Risfidian , Zulkifli Hilda 
Published: July 2015

A highly active catalyst H4[α-SiW12O40]/Zr based polyoxometalete Keggin type was prepared by wet impregnation method and was characterized by FTIR spectroscopy, X-ray diffractometer, surface textural property by SEM, and analysis of porosity by BET method. H4[α-SiW12O40]/Zr was successfully synthesized and showed uniform properties with block solid structure which was applied as heterogeneous stable catalyst for oxidative desulfurization of benzothiophene under simple and mild condition using H2O2 as oxidant. Facile conversion of benzothiophene to sulfone by using heterogeneus H4[α-SiW12O40]/Zr catalyst up to 99% was observed to show the active catalytically. Keggin H4[α-SiW12O40]/Zr cage structure after reaction was different from fresh catalyst which was indicated by the instability of H4[α-SiW12O40]/Zr under reaction condition. © 2015 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0)
Catalytic Hydrogenation of Levulinic Acid in Water into g-Valerolactone over Bulk Structure of Inexpensive Intermetallic Ni-Sn Alloy Catalysts
Authors: Rodiansono Rodiansono , Astuti Maria Dewi , Ghofur Abdul , Sembiring Kiky C. 
Published: July 2015

A bulk structure of inexpensive intermetallic nickel-tin (Ni-Sn) alloys catalysts demonstrated highly selective in the hydrogenation of levulinic acid in water into g-valerolactone. The intermetallic Ni-Sn catalysts were synthesized via a very simple thermochemical method from non-organometallic precursor at low temperature followed by hydrogen treatment at 673 K for 90 min. The molar ratio of nickel salt and tin salt was varied to obtain the corresponding Ni/Sn ratio of 4.0, 3.0, 2.0, 1.5, and 0.75. The formation of Ni-Sn alloy species was mainly depended on the composition and temperature of H2 treatment. Intermetallics Ni-Sn that contain Ni3Sn, Ni3Sn2, and Ni3Sn4 alloy phases are known to be effective heterogeneous catalysts for levulinic acid hydrogenation giving very excellence g-valerolactone yield of >99% at 433 K, initial H2 pressure of 4.0 MPa within 6 h. The effective hydrogenation was obtained in H2O without the formation of by-product. Intermetallic Ni-Sn(1.5) that contains Ni3Sn2 alloy species demonstrated very stable and reusable catalyst without any significant loss of its selectivity. © 2015 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0)
Very low latitude (L = 1.08) whistlers and correlation with lightning activity
Authors: Gokani Sneha A. , Singh Rajesh , Cohen Morris B. , Kumar Sushil , Venkatesham K. , Maurya Ajeet K. , Selvakumaran R. , Lichtenberger J. 
Published: July 2015

AbstractWe present analysis of more than 2000 lightning‐generated whistlers recorded at a low‐latitude station, located at Allahabad (geographic latitude, 25.40°N; geographic longitude, 81.93°E; L = 1.081), India, during December 2010 to November 2011. The main focus of this work is on the correlation between observed low‐latitude whistlers and lightning activity detected by the World‐Wide Lightning Location Network near the conjugate point (geography 9.87°S, 83.59°E) of Allahabad. Whistler occurrence is higher in the postmidnight period as compared to the premidnight period. Whistlers were observed in the daytime only on 2 days that too before 8:30 LT (morning). Seasonally, occurrence is maximum during winter months, which is due to more lightning activity in the conjugate region and favorable ionospheric conditions. About 63% of whistlers were correlated with lightning strokes in the vicinity of the conjugate point within spatial extent of 1000 km (conjugate area). Most (about 53%) whistlers were found to be associated with lightning strokes that were offset to the southeast of the conjugate point. The results indicate that an energy range of 7.5–17.5 kJ of lightning strokes generate most of whistlers at this station. The L shell calculations show that propagation paths of the observed whistlers were embedded in the topside ionosphere. Based on these results we suggest a possibility of ducted mode of propagation even for such very low latitude whistlers.
THEMIS two‐point measurements of the cross‐tail current density: A thick bifurcated current sheet in the near‐Earth plasma sheet
Authors: Saito Miho 
Published: July 2015

AbstractThe basic properties of the near‐Earth current sheet from 8 RE to 12 RE were determined based on Time History of Events and Macroscale Interactions during Substorms (THEMIS) observations from 2007 to 2013. Ampere's law was used to estimate the current density when the locations of two spacecraft were suitable for the calculation. A total of 3838 current density observations were obtained to study the vertical profile. For typical solar wind conditions, the current density near (off) the central plane of the current sheet ranged from 1 to 2 nA/m2 (1 to 8 nA/m2). All the high current densities appeared off the central plane of the current sheet, indicating the formation of a bifurcated current sheet structure when the current density increased above 2 nA/m2. The median profile also showed a bifurcated structure, in which the half thickness was about 3 RE. The distance between the peak of the current density and the central plane of the current sheet was 0.5 to 1 RE. High current densities above 4 nA/m2 were observed in some cases that occurred preferentially during substorms, but they also occurred in quiet times. In contrast to the commonly accepted picture, these high current densities can form without a high solar wind dynamic pressure. In addition, these high current densities can appear in two magnetic configurations: tail‐like and dipolar structures. At least two mechanisms, magnetic flux depletion and new current system formation during the expansion phase, other than plasma sheet compression are responsible for the formation of the bifurcated current sheets.
Isotopic Exchange in Porous and Dense Magnesium Borohydride
Authors: Zavorotynska Olena , Deledda Stefano , Li Guanqiao , Matsuo Motoaki , Orimo Shin‐ichi , Hauback Bjørn C. 
Published: July 2015

AbstractMagnesium borohydride (Mg(BH4)2) is one of the most promising complex hydrides presently studied for energy‐related applications. Many of its properties depend on the stability of the BH4− anion. The BH4− stability was investigated with respect to H→D exchange. In situ Raman measurements on high‐surface‐area porous Mg(BH4)2 in 0.3 MPa D2 have shown that the isotopic exchange at appreciable rates occurs already at 373 K. This is the lowest exchange temperature observed in stable borohydrides. Gas–solid isotopic exchange follows the BH4−+D.→BH3D−+H. mechanism at least at the initial reaction steps. Ex situ deuteration of porous Mg(BH4)2 and its dense‐phase polymorph indicates that the intrinsic porosity of the hydride is the key behind the high isotopic exchange rates. It implies that the solid‐state H(D) diffusion is considerably slower than the gas–solid H→D exchange reaction at the surface and it is a rate‐limiting steps for hydrogen desorption and absorption in Mg(BH4)2.
Barrierless Single‐Electron‐Induced cis–trans Isomerization
Authors: Klaiman Shachar , Cederbaum Lorenz S. 
Published: July 2015

AbstractLowering the activation energy of a chemical reaction is an essential part in controlling chemical reactions. By attaching a single electron, a barrierless path for the cis–trans isomerization of maleonitrile on the anionic surface is formed. The anionic activation can be applied in both reaction directions, yielding the desired isomer. We identify the microscopic mechanism that leads to the formation of the barrierless route for the electron‐induced isomerization. The generalization to other chemical reactions is discussed.
A Combined Experimental–Computational Investigation to Uncover the Puzzling (Chiro‐)optical Response of Pyridocyclophanes: One‐ and Two‐Photon Spectra
Authors: Padula Daniele , Lahoz Inmaculada R. , Díaz Carlos , Hernández Florencio E. , Di Bari Lorenzo , Rizzo Antonio , Santoro Fabrizio , Cid M. Magdalena 
Published: July 2015

AbstractA combined experimental–computational analysis of the one‐ and two‐photon absorption (OPA, TPA) and the electronic circular dichroism (ECD) of complex chiral shape‐persistent (2,6)‐pyrido[142]allenoacetylenic cyclophane, (P,P,P,P)‐MC[142] enantiomers, sheds light on the origin of their peculiar spectral signatures. The study on MC[142], which is represented in solution by three possible conformers, indicates that two of them (chair and twist) are the prevalent conformers at room temperature; the population ratio depending on the solvent. The complex shape of the red‐edge of the UV and ECD spectra is qualitatively reproduced by using vibronic calculations and assigned to progressions on the ethynyl stretchings observable only in the chair and twist conformers. The picture arising from the analysis of the linear spectra is confirmed by two‐photon spectroscopies, showing that they constitute valuable tools for the exploration of high‐energy electronic transitions in pyridoallenoacetylenic cyclophanes. Discrepancies among computed and experimental spectra point out that an accurate description of such complex systems with a large delocalized π framework and a dense manifold of electronic excited state remains a challenge for theoretical models.
Synergic Catalysis of PdCu Alloy Nanoparticles within a Macroreticular Basic Resin for Hydrogen Production from Formic Acid
Authors: Mori Kohsuke , Tanaka Hiromasa , Dojo Masahiro , Yoshizawa Kazunari , Yamashita Hiromi 
Published: July 2015

AbstractHighly dispersed PdCu alloy nanoparticles have been successfully prepared within a macroreticular basic resin bearing N(CH3)2 functional groups. This previously unappreciated combination of alloy is first proven to be responsible for the efficient production of high‐purity H2 from formic acid (HCOOH) dehydrogenation for chemical hydrogen storage. By the addition of Cu, the electronically promoted Pd sites show significantly higher catalytic activity as well as a better tolerance towards CO poisoning as compared to their monometallic Pd counterparts. Experimental and DFT calculation studies revealed not only the synergic alloying effect but also cooperative action by the N(CH3)2 groups within the resin play crucial roles in achieving exceptional catalytic performances. In addition to the advantages such as, facile preparation method, free of additives, recyclable without leaching of active component, and suppression of unfavorable CO formation less than 3 ppm, the present catalytic system is cost‐effective because of the superior catalytic activity compared with that of well‐established precious PdAg or PdAu catalysts. The present catalytic system is particularly desirable for an ideal hydrogen vector in terms of potential industrial application for fuel cells.
HMGA2 expression distinguishes between different types of postpubertal testicular germ cell tumour
Authors: Kloth Lars , Gottlieb Andrea , Helmke Burkhard , Wosniok Werner , Löning Thomas , Burchardt Käte , Belge Gazanfer , Günther Kathrin , Bullerdiek Jörn 
Published: July 2015

AbstractThe group of postpubertal testicular germ cell tumours encompasses lesions with highly diverse differentiation – seminomas, embryonal carcinomas, yolk sac tumours, teratomas and choriocarcinomas. Heterogeneous differentiation is often present within individual tumours and the correct identification of the components is of clinical relevance. HMGA2 re‐expression has been reported in many tumours, including testicular germ cell tumours. This is the first study investigating HMGA2 expression in a representative group of testicular germ cell tumours with the highly sensitive method of quantitative real‐time PCR as well as with immunohistochemistry. The expression of HMGA2 and HPRT was measured using quantitative real‐time PCR in 59 postpubertal testicular germ cell tumours. Thirty specimens contained only one type of tumour and 29 were mixed neoplasms. With the exception of choriocarcinomas, at least two pure specimens from each subgroup of testicular germ cell tumour were included. In order to validate the quantitative real‐time PCR data and gather information about the localisation of the protein, additional immunohistochemical analysis with an antibody specific for HMGA2 was performed in 23 cases. Expression of HMGA2 in testicular germ cell tumours depended on the histological differentiation. Seminomas and embryonal carcinomas showed no or very little expression, whereas yolk sac tumours strongly expressed HMGA2 at the transcriptome as well as the protein level. In teratomas, the expression varied and in choriocarcinomas the expression was moderate. In part, these results contradict data from previous studies but HMGA2 seems to represent a novel marker to assist pathological subtyping of testicular germ cell tumours. The results indicate a critical role in yolk sac tumours and some forms of teratoma.
Sequence variability is correlated with weak immunogenicity in Streptococcus pyogenes M protein
Authors: Lannergård Jonas , Kristensen Bodil M. , Gustafsson Mattias C. U. , Persson Jenny J. , Norrby‐Teglund Anna , Stålhammar‐Carlemalm Margaretha , Lindahl Gunnar 
Published: July 2015

AbstractThe M protein of Streptococcus pyogenes, a major bacterial virulence factor, has an amino‐terminal hypervariable region (HVR) that is a target for type‐specific protective antibodies. Intriguingly, the HVR elicits a weak antibody response, indicating that it escapes host immunity by two mechanisms, sequence variability and weak immunogenicity. However, the properties influencing the immunogenicity of regions in an M protein remain poorly understood. Here, we studied the antibody response to different regions of the classical M1 and M5 proteins, in which not only the HVR but also the adjacent fibrinogen‐binding B repeat region exhibits extensive sequence divergence. Analysis of antisera from S. pyogenes‐infected patients, infected mice, and immunized mice showed that both the HVR and the B repeat region elicited weak antibody responses, while the conserved carboxy‐terminal part was immunodominant. Thus, we identified a correlation between sequence variability and weak immunogenicity for M protein regions. A potential explanation for the weak immunogenicity was provided by the demonstration that protease digestion selectively eliminated the HVR‐B part from whole M protein‐expressing bacteria. These data support a coherent model, in which the entire variable HVR‐B part evades antibody attack, not only by sequence variability but also by weak immunogenicity resulting from protease attack.
Extent of genotypic variation for maize cell wall bioconversion traits across environments and among hybrid combinations
Authors: Torres Andres F. , Noordam-Boot Cornelie M. M. , Dolstra Oene , Vlaswinkel Louis , Visser Richard G. F. , Trindade Luisa M. 
Published: July 2015

AbstractThe utilization of maize stover as a substrate for bioenergy production demands the development of dual-purpose hybrid varieties combining both, optimal grain yield and improved biomass processing amenability. In this study, our objectives were to assess how contrasting environments influence the expression of cell wall composition and bioconversion traits relevant to cellulosic fuel production, and to study how these traits are inherited in hybrid combinations. To this end, a panel of maize double haploid (DH) lines and their corresponding test-cross (TC) offspring were tested under different locations (primarily in the Netherlands) and characterized for a variety of cell wall compositional and bioconversion features relevant to cellulosic fuel production. Overall, the DH and TC sets displayed extensive genotypic diversity in cell wall composition, polymeric ultrastructure and bioconversion characteristics. Heritability for the different traits was generally high (h2 > ~0.60); essentially implying that systematic differences between genotypes remained constant across divergent environmental conditions. Moreover, correlations between the performance of DH lines and related TC hybrids were significant and favorable for most investigated traits. Strong associations (r > ~0.50) were especially prominent for cell wall lignin content, degree of substitution of cell wall glucuronoarabinoxylans and cell wall convertibility following pretreatment and enzymatic hydrolysis. In conclusion, complex cell wall bioconversion traits constitute accessible and reliable selection criteria for incorporation in modern breeding programs seeking to advance bio-based maize hybrid varieties. The high heritability and environmental stability of these traits guarantee high selection efficacy during the development of superior DH/inbred material; and their predominantly additive nature prescribe that preliminary selection at the inbred level will guarantee similar correlated genetic gains in hybrid breeding.
Swedish University Students’ Opinion Regarding Information About Soft Markers
Authors: Roshanai Afsaneh Hayat , Lindgren Peter , Nordin Karin , Ingvoldstad Charlotta 
Published: July 2015

AbstractThe aim of this study was to investigate the opinions of Swedish university students about information regarding soft markers, when observed at second trimester ultrasound screening. A cross‐sectional survey, where 85 Swedish university students completed a study specific questionnaire containing eleven hypothetical scenarios, involving various parameters (disease/syndromes/malformations with different characteristics), and location of the markers. Almost all participants indicated that they would wish to be informed, prior to the ultrasound examination, about the assessment and significance of soft markers. However, the number of respondents who requested information about a potential actual finding was considerably less. Several participants wanted to be informed about detected markers associated to serious conditions but not when the marker indicated an increased risk for a treatable disease. Also, the specific location of the marker was of importance to the participants. The majority of respondents wished to be informed about the soft markers if they were observed in the heart or the brain of the foetus, compared to if they were located in the intestine or the skeleton. The students’ opinion, in this study, implicate the importance of pre‐examination information to enable expectant parents to make informed choice regarding the second trimester ultrasound screening as well as on reciving information of actual findings.