bluuebunny/crossref_metadata_2025 huggingface dataset:
Hybrid artificial neural network system for short-term load forecasting
Authors: Ilic Slobodan , Vukmirovic Srdjan , Erdeljan Aleksandar , Kulic Filip
Published: April 2012

This paper presents a novel hybrid method for Short-Term Load Forecasting
(STLF). The system comprises of two Artificial Neural Networks (ANN),
assembled in a hierarchical order. The first ANN is a Multilayer Perceptron
(MLP) which functions as integrated load predictor (ILP) for the forecasting
day. The output of the ILP is then fed to another, more complex MLP, which
acts as an hourly load predictor (HLP) for a forecasting day. By using a
separate ANN that predicts the integral of the load (ILP), additional
information is presented to the actual forecasting ANN (HLP), while keeping
its input space relatively small. This property enables online training and
adaptation, as new data become available, because of the short training time.
Different sizes of training sets have been tested, and the optimum of 30 day
sliding time-window has been determined. The system has been verified on
recorded data from Serbian electrical utility company. The results
demonstrate better efficiency of the proposed method in comparison to
non-hybrid methods because it produces better forecasts and yields smaller
mean average percentage error (MAPE).
Assessment of boiler’s operating performance in different energy sectors in the province of Vojvodina
Authors: Kljajic Miroslav , Gvozdenac Dusan
Published: April 2012

Creating database enables the wide range of possibilities for implementing
energy management approach and for critical evaluation of accepted practices
in the field of energy efficiency. This paper contains besides the existing
database also measurements in the group of randomly selected boilers. The
sample formed in such a way covers approximately 25% of all boilers in the
Province of Vojvodina. This provides reliability and relevance of obtained
results. With reference to users, it can be the indicator of a need to
undertake concrete activities for the purpose of increasing energy efficiency
of plants and improving observed situation. The last section concerns
relevant authorities responsible for developing and amending the energy
policy.
The Effect of Ex Ante Management Forecast Accuracy on the Post-Earnings-Announcement Drift
Authors: Zhang Li
Published: April 2012

I examine the effect of ex ante management forecast accuracy on the post-earnings-announcement drift when management forecasts about next quarter's earnings are bundled with current quarter's earnings announcements. I build a composite measure of ex ante management forecast accuracy that takes into account forecast ability, forecast difficulty, and forecast environment. The results show that the bundled forecasts with higher ex ante accuracy mitigate investors' under-reaction to current earnings and reduce the magnitude of the post-earnings-announcement drift.

Data Availability: The data used in this paper are available from the sources listed in the text.
An Alternative Technique to Evaluate Crack Propagation Path in Hyperelastic Materials
Authors: Ozelo R. R. M. , Sollero P. , Costa A. L. A.
Published: April 2012

REFERENCE: R. R. M. Ozelo, P. Sollero, and A. L. A. Costa, “An Alternative Technique to Evaluate Crack Propagation Path in Hyperelastic Materials,” Tire Science and Technology, TSTCA, Vol. 40, No. 1, January–March 2012, pp. 42–58.

ABSTRACT: The analysis of crack propagation in tires aims to provide safety and reliable life prediction. Tire materials are usually nonlinear and present a hyperelastic behavior. Therefore, the use of nonlinear fracture mechanics theory and a hyperelastic material constitutive model are necessary. The material constitutive model used in this work is the Mooney–Rivlin. There are many techniques available to evaluate the crack propagation path in linear elastic materials and estimate the growth direction. However, most of these techniques are not applicable to hyperelastic materials. This paper presents an alternative technique for modeling crack propagation in hyperelastic materials, based in the J-Integral, to evaluate the crack path. The J-Integral is an energy-based parameter and is applicable to nonlinear materials. The technique was applied using abaqus software and compared to experimental tests.
Nonprogrammable and programmable cerebrospinal fluid shunt valves: a 5-year study
Authors: Hatlen Timothy J. , Shurtleff David B. , Loeser John D. , Ojemann Jeffrey G. , Avellino Anthony M. , Ellenbogen Richard G.
Published: April 2012

Object

Programmable valves (PVs) for shunting CSF have increasingly replaced nonprogrammable valves (NPVs). There have been only a few longer-term studies (≥ 5 years) conducted that have compared the effectiveness of NPVs with that of PVs for children with hydrocephalus, and only 1 study has reported NPVs as being favorable over PVs. The objective of this retrospective study was to compare the long-term survival of these 2 types of shunt valves.

Methods

The authors collected data for all patients who underwent CSF shunt insertion or revision between January 1, 2000, and December 31, 2008. Patients underwent follow-up for a minimum of 2 years postoperatively. Statistical analyses were done using chi-square, Kaplan-Meier survival curve, and multivariate analyses.

Results

A total of 616 valves were implanted, of which 313 were PVs and 303 were NPVs. Of these, 253 were original shunt implantations and 363 were revisions. The proportion of 5-year survival for NPVs (45.8%) was significantly higher than that for PVs (19.8%) (p = 0.0005, log-rank). The NPVs that survived longer than 6 months also survived through the 5th year better than the PVs (p = 0.0001).

Conclusions

The authors' data suggest that NPVs survive longer than PVs in children, but there is a need for prospective, case-control studies to confirm these data.
Possible differentiation of cerebral glioblastoma into pleomorphic xanthoastrocytoma: an unusual case in an infant
Authors: Yang Michael M. H. , Singhal Ash , Rassekh Shahrad Rod , Yip Stephen , Eydoux Patrice , Dunham Christopher
Published: April 2012

The authors describe an infant girl who, at 10 months of age, presented with a large right parietooccipital tumor causing increased intracranial pressure, mass effect, and midline shift. The tumor was completely resected, and the entirety of the histology was consistent with glioblastoma. She was subsequently placed on adjuvant high-dose chemotherapy consisting of carboplatin, vincristine, and temozolomide, according to Head Start III, Regimen C. Three months after the complete resection, tumor recurrence was noted on MR imaging, during the third cycle of chemotherapy, and biopsy revealed malignant astrocytoma. Given the recurrence and the patient's intolerance to chemotherapy, a palliative course was pursued. Unexpectedly, the patient was alive and had made significant developmental improvements 18 months into palliation. Subsequently, however, signs of increased intracranial pressure developed and imaging demonstrated a very large new tumor growth at the site of prior resection. The recurrence was again fully resected, but microscopy surprisingly revealed pleomorphic xanthoastrocytoma throughout. The clinicopathological and genetic features of this girl's unusual neoplasm are detailed and potential pathogenic hypotheses are explored in this report.
Clinicopathological analysis of nonfunctioning pituitary adenomas in patients younger than 25 years of age
Authors: Yamaguchi-Okada Mitsuo , Inoshita Naoko , Nishioka Hiroshi , Fukuhara Noriaki , Yamada Shozo
Published: April 2012

Object

The authors evaluated the pathological and clinical characteristics of young patients with clinically nonfunctioning pituitary adenomas (NFPAs).

Methods

Twenty-one patients (13 males and 8 females) with NFPAs who were 25 years of age or younger (mean 20 years, range 13–25 years) were retrospectively investigated. The following factors were examined: results of conventional light microscopy, immunohistochemistry, and electron microscopy; clinical symptoms; tumor size and invasion on MRI; and clinical course after therapeutic procedures such as surgery and adjuvant radiotherapy.

Results

Two major significant findings in young patients with NFPAs were noted. First, silent subtype 3 adenomas were common, whereas silent gonadotroph adenomas were rare. Second, silent subtype 3 adenomas in young patients tended to be clinically and radiologically aggressive.

Conclusions

To correct the morphological diagnosis, NFPAs in young patients should be examined by immunohistochemical analysis and electron microscopy, as well as by light microscopy. The authors' results provide information that will be useful when making decisions regarding the treatment of young patients with NFPAs.
Follow-up imaging to detect recurrence of surgically treated pediatric arteriovenous malformations
Authors: Lang Shih-Shan , Beslow Lauren A. , Bailey Robert L. , Vossough Arastoo , Ekstrom Joanna , Heuer Gregory G. , Storm Phillip B.
Published: April 2012

Object

The true postoperative incidence of arteriovenous malformation (AVM) recurrence in the pediatric population remains largely unreported. Some literature suggests that delayed imaging studies should be obtained at 6 months to 1 year after negative findings on a postoperative angiogram. The aim of this study was to describe the timing of AVM recurrences after resection and the neuroimaging modalities on which the recurrences were detected.

Methods

This study was performed in a retrospective cohort of all pediatric patients treated surgically for AVM resection by a single neurosurgeon between 2005 and 2010. Patients were followed after resection with MR angiography (MRA) or conventional angiography, when possible, at various time points. A visual scale for compactness of the initial AVM nidus was used, and the score was correlated with probability of recurrence after surgery.

Results

A total of 28 patients (13 female, 15 male) underwent an AVM resection. In 18 patients (64.3%) an intraoperative angiogram was obtained. In 4 cases the intraoperative angiogram revealed residual AVM, and repeat resections were performed immediately. Recurrent AVMs were found in 4 children (14.3%) at 50, 51, 56, and 60 weeks after the initial resection. Recurrence risk was 0.08 per person-year. No patient with normal results on an angiogram obtained at 1 year developed a recurrence on either a 5-year angiogram or one obtained at 18 years of age. All patients with recurrence had a compactness score of 1 (diffuse AVM); a lower compactness score was associated with recurrence (p = 0.0003).

Conclusions

All recurrences in this cohort occurred less than 15 months from the initial resection. The authors recommend intraoperative angiography to help ensure complete resection at the time of the surgery. Follow-up vascular imaging is crucial for detecting recurrent AVMs, and conventional angiography is preferred because MRA can miss smaller AVMs. One-year follow-up imaging detected these recurrences, and no one who had negative results on an angiogram obtained at 1 year had a late recurrence. However, not all of the patients have been followed for 5 years or until 18 years of age, so longer follow-up is required for these patients. A lower compactness score predicted recurrent AVM in this cohort.
Micro Reactors, Flow Reactors and Continuous Flow Synthesis
Authors: Watts Paul , Wiles Charlotte
Published: April 2012

Dr Paul Watts is a reader in organic chemistry at The University of Hull and since graduating from the University of Bristol, where he completed a PhD in bio-organic natural product synthesis, he has led the Micro Reactor Group at Hull. In this role, he has published 90 papers, and he regularly contributes to the field by way of invited book chapters, review articles, and keynote lecturers on the subject of micro reaction technology in organic synthesis.

Dr Charlotte Wiles is the Chief Technology Officer at Chemtrix BV, and has been actively researching within the area of micro reaction technology for 10 years, starting with a PhD entitled Micro reactors in organic chemistry, which she obtained from The University of Hull in 2003. In the past decade, she has authored many scientific papers and review articles, recently co-authoring a book on the subject of micro reaction technology in organic synthesis. More recently, she has tailored her experience to the development and evaluation of commercially available continuous flow reactors, systems and peripheral equipment.

This review article explains the advantages of micro reactors and flow reactors as tools for conducting organic synthesis and describes how the technology may be used in research and development as well as production. A selection of examples is taken from the literature to illustrate how micro reactors enables chemists to perform their reactions more efficiently than when using batch processes.
Structural Determination of 3β,11β-Dihydroxyfriedelane from Maytenus Robusta (Celastraceae) by 1D and 2D NMR
Authors: Sousa Grasiely F. , Ferreira Fernanda L. , Duarte Lucienir P. , Silva Grácia D.F. , Messias Maria C.T.B. , Filho Sidney A. Vieira
Published: April 2012

A new pentacyclic triterpene, 3 β,11 β-dihydroxyfriedelane was isolated from leaves of Maytenus robusta Reissek (Celastraceae) together with other four known compounds: 3-oxofriedelane (friedelin), 3 β-hydroxyfriedelane, 3-oxo-29-hydroxyfriedelane and 3-oxo-11 β-hydroxyfriedelane. The structure and chemical conformation of the new friedelane triterpene were established by 1H and 13C NMR, including the 2D experiments, HSQC, HMBC, COSY and NOESY.
Ultrasound Promoted One-Pot Three-Component Synthesis of Novel 7-Aryl-8H-Benzo[h]Indeno[1,2-b]Quinolin-8-Ones Under Solvent-Free Conditions
Authors: Mamaghani Manouchehr , Larghani Tahere Hosseyni
Published: April 2012

A series of novel derivatives of 7-phenyl-8 H-benzo[h]indeno[1,2-b]quinolin-8-ones were synthesised directly by one-pot three-component reaction of indanedione, α-naphthylamine and various substituted arylaldehydes under solvent-free conditions using ultrasonic irradiation as a clean source of energy. This fast method provided the products in high yields (70–93%) and low reaction times (10–75 min).
An Efficient Synthesis of Novel Bis-1,3,4-Thiadiazolyl-Carbamate Derivatives based on Deoxycholic Acid under Microwave Irradiation
Authors: Zhao Zhigang , Li Lin , Liu Min , Mei Qinggang
Published: April 2012

An easy and efficient method for the synthesis of novel deoxycholic acid bis-1,3,4-thiadiazol-carbamate derivatives under microwave irradiation has been developed. Twelve new methyl 3α,12α-bis-[(5-aryl-1,3,4-thiadiazol-2-yl) carbamoyloxy]-cholan-24-oates were obtained in better yield (78–91%) and shorter time (15–22 min). Their structures were identified by 1H NMR, IR, MS spectra and elemental analyses.
Synthesis of Furocoumarins and Biscoumarins by an Isocyanide-Induced Multicomponent Reaction: Isocyanide as a Masked Amine
Authors: Panja Suman Kalyan , Ghosh Jaydip , Maiti Sourav , Bandyopadhyay Chandrakanta
Published: April 2012

The three-component reaction involving chromone-3-carbaldehyde, 4-hydroxycoumarin and cyclohexyl isocyanide produces furocoumarin and biscoumarin derivatives. Formation of the latter compound seems to involve cyclohexylamine. Cyclohexyl isocyanide was found to act as a masked source of cyclohexylamine.
Synthesis and Characterisation of 4-Aminophthalimido-N-Alkyl-Calix[4]Azacrown Derivatives
Authors: Shi Zhi-Qiang , Feng Ya-Qing , Meng Shu-Xian , Chu Wen-Ya
Published: April 2012

Two 4-amino-N-bromoalkylphthalimide derivatives were prepared by the reduction of 4-nitro-N-bromoalkylphthal-imides and SnCl2 and reacted with calix[4]azacrown to give two new 4-aminophthalimido-N-alkyl-calix[4]azacrown derivatives. They were characterised by IR, 1H NMR, 13C NMR and HRMS and shown to adopt a cone conformation, 4-aminophthalimido-N-alkyl-calix[4]azacrown may provide a potential fluorescent probe for Cu2+.
Microwave-Assisted Solvent-Free Synthesis of (E)-Stilbenes
Authors: Wang Liu-chang , Li Jiang , Zhang Xi-quan , Gu Hong-mei , Li Bao-lin
Published: April 2012

An efficient synthesis of a series of stilbenes is reported using 4-nitrotoluene and substituted arylaldehydes as starting materials in the presence of Cs2CO3 and polyethylene glycol under solvent-free microwave irradiation. Compared with conventional method, this strategy exhibited higher stereoselectivity, shorter reaction times and has a lower environmental impact.
The Synthesis of a 2-Deoxy-2-Acetonyl Sugar from its Corresponding Natural Saccharide
Authors: Zhang Ying , Liu Yang , Wang Zhijun , Wang Zhongfu , Huang Linjuan
Published: April 2012

An efficient synthesis of a 2-deoxy-2-acetonyl sugar from its corresponding natural sugar by methallylation of the 2–iodo sugar is reported. The simplified procedure eliminated the need to carry out the reaction under strictly controlled conditions, giving an efficient route for the synthesis of 2-deoxy-2-acetonyl sugar under ordinary laboratory conditions.
Art as Abstract Machine: Guattari's Modernist Aesthetics
Authors: Zepke Stephen
Published: April 2012

Felix Guattari was a modernist. He not only liked a lot of modernist artists, but his ‘aesthetic paradigm’ found its generative diagram in modern art. The most important aspect of this diagram was its insistence on the production of the new, the way it produced a utopian projection of a ‘people to come’, and so a politics whose only horizon was the future. Also important for Guattari's diagram of the ‘modern’ were the forces of abstraction, autonomy and immanent critique. Together these elements construct an artwork that is radically singular and separate, composed of a-signifying, a-temporal and invisible forces, sensations that go beyond our human conditions of possibility. In this Guattari's modernism must be understood as being quite different from his co-option by contemporary art theorists influenced by post-Operaist thought. Post-Operaism understands politics as ‘being-against’, a dialectical form of negation that finds its political condition of possibility in what already exists. Because such thought sees modern art as being entirely subsumed by the institutions and markets that contain it, art itself must be negated in order for aesthetic powers to become political. This has lead post-Operaist thought to align itself strongly with the avant-garde positions of institutional-critique and art-into-life, or ‘non-art’. Guattari's modernism takes him in a very different direction, affirming modern art despite its institutional enframing, because art is forever in the process of escaping itself. This makes modern art the model in Guattari's thought for politics itself.
Institutional Schizophasia and the Possibility of the Humanities' ‘Other Scene’: Guattari and the Exigency of Transversality
Authors: Eng Michael
Published: April 2012

Transversality occupies a central place in Guattari's thought, appearing in his early writings on institutional analysis and on through to his final work, Chaosmosis. Transversality is thus particularly pertinent to understanding Guattari's critique of semiocapitalism and his goal of re-imagining forms of institutional subjectivisation as a way to free the unconscious from structures of lack and the desire for punishment, the very structures upon which capitalism relies for its reproduction. If there is one institution that has taken advantage of semiocapitalism's ability to mask its role in the reproduction of capitalist subjectivity, however, it is the contemporary neoliberal University. This essay thus brings transversality to bear upon the question of the University in semiocapitalism, focusing on the discourses that speak in defence of the humanities. Though defences of the humanities are intended to argue for the humanities’ usefulness in contemporary society, transversality exposes such discourses as the speech of a ‘subjugated group’ whose only effect is to reinforce existing structures of lack and punishment.
The Biological Effects of Ivabradine in Cardiovascular Disease
Authors: Speranza Lorenza , Franceschelli Sara , Riccioni Graziano
Published: April 2012

A large number of studies in healthy and asymptomatic subjects, as well as patients with already established cardiovascular disease (CAD) have demonstrated that heart rate (HR) is a very important and major independent cardiovascular risk factor for prognosis. Lowering heart rate reduces cardiac work, thereby diminishing myocardial oxygen demand. Several experimental studies in animals, including dogs and pigs, have clarified the beneficial effects of ivabradine associated with HR lowering. Ivabradine is a selective inhibitor of the hyperpolarisation activated cyclic-nucleotide-gated funny current (If) involved in pacemaker generation and responsiveness of the sino-atrial node (SAN), which result in HR reduction with no other apparent direct cardiovascular effects. Several studies show that ivabradine substantially and significantly reduces major risks associated with heart failure when added to guideline-based and evidence-based treatment. However the biological effect of ivabradine have yet to be studied. This effects can appear directly on myocardium or on a systemic level improving endothelial function and modulating immune cell migration. Indeed ivabradine is an ‘open-channel’ blocker of human hyperpolarization-activated cyclic nucleotide gated channels of type-4 (hHCN4), and a ‘closed-channel’ blocker of mouse HCN1 channels in a dose-dependent manner. At endothelial level ivabradine decreased monocyte chemotactin protein-1 mRNA expression and exerted a potent anti-oxidative effect through reduction of vascular NADPH oxidase activity. Finally, on an immune level, ivabradine inhibits the chemokine-induced migration of CD4-positive lymphocytes. In this review, we discuss the biological effects of ivabradine and highlight its effects on CAD.
A New and Efficient Method for the Synthesis of 3,4-Disubstituted Pyrrolidine-2,5-diones
Authors: Ilieva Eleonora D. , Petkova Nevena I. , Nikolova Rositca D.
Published: April 2012

A newly found reaction for the synthesis of 3,4-disubstituted 1-hydroxy-pyrrolidine-2,5-diones from 3-substituted coumarins and nitromethane has been elaborated. The reaction involved a simple and convenient experimental procedure. The applicability of the rearrangement reaction is determined.
MALDI-TOF MS Analysis of Native and Permethylated or Benzimidazole-Derivatized Polysaccharides
Authors: Hung Wei-Ting , Wang Shwu-Huey , Chen Yi-Ting , Yu Hui-Ming , Chen Chung-Hsuan , Yang Wen-Bin
Published: April 2012

MALDI-TOF MS provides rapid and sensitive analyses of larger biomolecules. However, MS analyses of polysaccharide have been reported to have lower sensitivity compared to peptides and proteins. Here, we investigated some polysaccharides chemically derivatized by permethylation and ortho-phenylene diamine (OPD) tagging. Methylated glycan is obviously able to improve the sensitivity for mass spectrometry detection. Oxidative condensation by UV-activation tagging to saccharides by OPD and peptide-OPD also improve the sensitivity of MALDI-TOF MS analyses. Polysaccharides including dextran, glucomannan, arabinoxylan, arabinogalactan and beta-1,3-glucan, isolated from nutritional supplements of Ganoderma lucidum and Saccharomyces pastorianus were measured using MALDI-TOF MS with 2,5-dihydroxybenzoic acid (2,5-DHB) as the matrix. These glycans were also derivatized to methylated and benzimidazole-tagged glycans by chemical transformation for molecular weight analysis. The derivatized polysaccharides showed excellent MALDI-TOF MS signal enhancement in the molecular weight range from 1 to 5 kDa. Here, we demonstrate an efficient method to give glycan-benzimidazole (glycan-BIM) derivatives for polysaccharide determination in MALDI-TOF MS. Therefore, permethylated or benzimidazole-derivatized polysaccharides provide a new option for polysaccharide analysis using MALDI-TOF MS.
Synthesis and Biological Evaluation of New Ligustrazine Derivatives as Anti-Tumor Agents
Authors: Wang Penglong , She Gaimei , Yang Yanan , Li Qiang , Zhang Honggui , Liu Jie , Cao Yinqiu , Xu Xin , Lei Haimin
Published: April 2012

To discover new anti-cancer agents with multi-effect and low toxicity, a series of ligustrazine derivatives were synthesized using several effective anti-tumor ingredients of Shiquandabu Wan as starting materials. Our idea was enlightened by the “combination principle” in drug discovery. The ligustrazine derivatives’ anti-tumor activities were evaluated on the HCT-8, Bel-7402, BGC-823, A-549 and A2780 human cancer cell lines. In addition the angiogenesis activities were valued by the chick chorioallantoic membrane (CAM) assay. 1,7-bis(4-(3,5,6-Trimethylpyrazin-2-yl)-3-methoxyphenyl)-1,6-heptadiene-3,5-dione (4) and 3 α,12 α-dihydroxy-5β-dholanic acid-3,5,6-trimethylpyrazin-2-methyl ester (5) not only displayed antiproliferative activities on these cancer cells, but also dramatically suppressed normal angiogenesis in CAM. The LD50 value of the compound 5 exceeded 3.0 g/kg by oral administration in mice.
Bioassay-Guided Antidiabetic Study of Phaleria macrocarpa Fruit Extract
Authors: Ali Rabyah B. , Atangwho Item J. , Kaur Navneet , Abraika Omar Saad , Ahmad Mariam , Mahmud Roziahanim , Asmawi Mohd Z.
Published: April 2012

An earlier anti-hyperglycemic study with serial crude extracts of Phaleria macrocarpa (PM) fruit indicated methanol extract (ME) as the most effective. In the present investigation, the methanol extract was further fractionated to obtain chloroform (CF), ethyl acetate (EAF), n-butanol (NBF) and aqueous (AF) fractions, which were tested for antidiabetic activity. The NBF reduced blood glucose (p < 0.05) 15 min after administration, in an intraperitoneal glucose tolerance test (IPGTT) similar to metformin. Moreover, it lowered blood glucose in diabetic rats by 66.67% (p < 0.05), similar to metformin (51.11%), glibenclamide (66.67%) and insulin (71.43%) after a 12-day treatment, hence considered to be the most active fraction. Further fractionation of NBF yielded sub-fractions I (SFI) and II (SFII), and only SFI lowered blood glucose (p < 0.05), in IPGTT similar to glibenclamide. The ME, NBF, and SFI correspondingly lowered plasma insulin (p < 0.05) and dose-dependently inhibited glucose transport across isolated rat jejunum implying an extra-pancreatic mechanism. Phytochemical screening showed the presence of flavonoids, terpenes and tannins, in ME, NBF and SFI, and LC-MS analyses revealed 9.52%, 33.30% and 22.50% mangiferin respectively. PM fruit possesses anti-hyperglycemic effect, exerted probably through extra-pancreatic action. Magniferin, contained therein may be responsible for this reported activity.
Hydrophilic Carotenoids: Recent Progress
Authors: Háda Magdolna , Nagy Veronika , Deli József , Agócs Attila
Published: April 2012

Carotenoids are substantially hydrophobic antioxidants. Hydrophobicity is this context is rather a disadvantage, because their utilization in medicine as antioxidants or in food chemistry as colorants would require some water dispersibility for their effective uptake or use in many other ways. In the past 15 years several attempts were made to synthetize partially hydrophilic carotenoids. This review compiles the recently synthetized hydrophilic carotenoid derivatives.
Hydrogen Gas Sensors Based on Semiconductor Oxide Nanostructures
Authors: Gu Haoshuang , Wang Zhao , Hu Yongming
Published: April 2012

Recently, the hydrogen gas sensing properties of semiconductor oxide (SMO) nanostructures have been widely investigated. In this article, we provide a comprehensive review of the research progress in the last five years concerning hydrogen gas sensors based on SMO thin film and one-dimensional (1D) nanostructures. The hydrogen sensing mechanism of SMO nanostructures and some critical issues are discussed. Doping, noble metal-decoration, heterojunctions and size reduction have been investigated and proved to be effective methods for improving the sensing performance of SMO thin films and 1D nanostructures. The effect on the hydrogen response of SMO thin films and 1D nanostructures of grain boundary and crystal orientation, as well as the sensor architecture, including electrode size and nanojunctions have also been studied. Finally, we also discuss some challenges for the future applications of SMO nanostructured hydrogen sensors.
Palmprint and Face Multi-Modal Biometric Recognition Based on SDA-GSVD and Its Kernelization
Authors: Jing Xiao-Yuan , Li Sheng , Li Wen-Qian , Yao Yong-Fang , Lan Chao , Lu Jia-Sen , Yang Jing-Yu
Published: April 2012

When extracting discriminative features from multimodal data, current methods rarely concern themselves with the data distribution. In this paper, we present an assumption that is consistent with the viewpoint of discrimination, that is, a person’s overall biometric data should be regarded as one class in the input space, and his different biometric data can form different Gaussians distributions, i.e., different subclasses. Hence, we propose a novel multimodal feature extraction and recognition approach based on subclass discriminant analysis (SDA). Specifically, one person’s different bio-data are treated as different subclasses of one class, and a transformed space is calculated, where the difference among subclasses belonging to different persons is maximized, and the difference within each subclass is minimized. Then, the obtained multimodal features are used for classification. Two solutions are presented to overcome the singularity problem encountered in calculation, which are using PCA preprocessing, and employing the generalized singular value decomposition (GSVD) technique, respectively. Further, we provide nonlinear extensions of SDA based multimodal feature extraction, that is, the feature fusion based on KPCA-SDA and KSDA-GSVD. In KPCA-SDA, we first apply Kernel PCA on each single modal before performing SDA. While in KSDA-GSVD, we directly perform Kernel SDA to fuse multimodal data by applying GSVD to avoid the singular problem. For simplicity two typical types of biometric data are considered in this paper, i.e., palmprint data and face data. Compared with several representative multimodal biometrics recognition methods, experimental results show that our approaches outperform related multimodal recognition methods and KSDA-GSVD achieves the best recognition performance.
Tool for Validation Software Projects in Programming Labs
Authors: Sierra Antonio J.
Published: April 2012

<span style="font-size: 10.0pt; font-family: "Times New Roman","serif"; mso-fareast-font-family: "Times New Roman"; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;" lang="EN-US">This work shows a testing tool used in Fundamentals of Programming II laboratory in Telecommunication Technologies Engineering Degree at University of Sevilla to check the student project. This tool allows students to test the proper operation of their project in autonomous way. This is a flexible and useful tool for testing the project because the tool identifies when the student has carried out a project that meet the given specifications of the project. This implies a high rate of success when the student delivers its project.
Short Experimental Ceramic Projects to Incentivise Mechanical Engineering Students
Authors: Alves Jorge Lino , Duarte Teresa Pereira
Published: April 2012
Approche interactionnelle et didactique invisible – Deux concepts pour la conception et la mise en œuvre de tâches sur le web social
Authors: Ollivier Christian
Published: April 2012

Cet article commence par revenir sur ce qu'est la compétence d'action et de communication que nous concevons comme ayant lieu, toutes les deux, sous contrainte relationnelle. Sur cette base est proposée une approche interactionnelle de l'enseignement / apprentissage des langues qui ajoute aux catégories de tâches telles qu'elles sont généralement conçues (notamment par le CECRL) des tâches de la vie réelle à réaliser dans des interactions sociales réelles dépassant le cadre de la classe.Nous abordons ensuite le principe de didactique invisible qui a permis de construire les sites du projet Babelweb (Ollivier et al.) dans le but de créer des espaces d'interaction de type web social sur lesquels les apprenants peuvent se comporter en "acteurs sociaux" à part entière. La comparaison, croisée avec les résultats de recherches antérieures, du comportement langagier des apprenants sur un blogue de Babelweb et de francophones réalisant une tâche très similaire sur le web social permet de faire émerger les convergences et divergences entre le comportement de ces deux groupes et de faire ressortir les limites, mais aussi les avantages de la didactique invisible.
Facebook-ing and the Social Generation: A New Era of Language Learning
Authors: Blattner Geraldine , Lomicka Lara
Published: April 2012

In this paper, we examine the use of Facebook (FB) as a social networking tool in an intermediate French class. After reviewing the available studies on FB in language instruction, we analyze surveys that were administered to students as well as student FB posts. We look at the potential benefits of social media, specifically FB, and discuss its impact on foreign language learning. We aim to address how FB is being used in the language classroom, how students respond to the integration of this social networking site in courses, the attitudes of higher education foreign language learners towards FB, as well as the role of FB in new learning spaces and with today's learners. An analysis of survey data suggests that students respond in a positive manner toward the use of FB in education and highlights some differences in the way FB is used in both personal and academic settings.
Language Learners' "Willingness to Communicate" through Livemocha.com
Authors: Lloyd Elwyn
Published: April 2012

This case study is based on an investigation into the use that a group of language learners made of Livemocha.com, a Social Networking Site through which language exchange is enabled via social media applications. The learners created profiles in the website and proceeded to interact with speakers of their target languages, reporting back on their experiences over a 10-week period. As communication between language partners can take place through several different channels, and can be asynchronous or synchronous, written or spoken, it was considered that the preferences of learners with different personality types (as indicated by responses to a Myers-Briggs Type Indicator questionnaire) might be accommodated.Several studies have suggested that the anxiety that some language learners feel when communicating in L2, especially when speaking, is reduced in online environments. Under the premise that a reduction in anxiety may lead to an increased "willingness to communicate" (MacIntyre et al., 1998), the principal objective of this project was to examine the type and frequency of online interactions that the participants engaged in with other speakers of their target languages in the Livemocha language learning community.
An Integrated Approach Towards Well Control of a HPHT Well
Authors: Shrivastav Piyush
Published: April 2012

Rising demand for energy has pushed the oil & gas exploration andproduction operations to harsher environments. High pressure and hightemperature (HPHT) is one of such challenging areas. HPHT developments presentchallenges at every stage. HPHT wells are defined as well having pressure above10,000 psi and temperature above 300°F. However the threshold is now pushing20,000 psi at 450°F. Many techniques that are applied to normal pressured wellmust be reexamined before its application in HPHT well else might result inconsiderable financial loss.

High pressure and high temperature impact mud properties in a dynamic way andcan have major effect on well control. This paper presents an integratedapproach on impact of high pressure and high temperature on mud rheology andthermo physical properties. It also discusses mechanism of thermaldisintegration of different types of mud i.e. bentonite mud, polymer mud andoil based mud, and measures to extend their temperature limits. This paper alsodiscusses various symptoms and remedial action to improve mud properties.

Preventing and controlling influxes of reservoir fluid into the well calledkicks are always central to drilling safety, but in HPHT wells the dangers froma kick are amplified. The three issues of HPHT drilling safety are kickprevention, kick detection and well control. This paper gives an overview aboutdetection of kick in a HPHT well, measures to prevent kick and well controlmeasures in case of a kick.

Introduction

The drilling of HPHT wells pose special challenges compared to standardwells:–High pressures and temperatures impact mud properties in a dynamic way, andcan have effects on well control–Increase in mechanical and fluid friction with well depth.–The majority of mud treatment chemicals derived from natural products beginto degrade at temperatures between250 and 275°F.–The volume of a HTHP gas kick remains virtually unchanged as it rises in theannulus from 14,000 to 10,000 ft [4265 to 3050 m]. From 10,000 to 2000 ft [610m] its volume triples. But from 2000 ft to the surface, there is a hundred-foldexpansion.–Put simply, a gas influx of 10 barrels at 14,000 psi becomes 4000 barrelsunder atmospheric conditions.–As reservoir fluid rapidly expands, it forces mud out of the well unloadingreducing mud in the well, cutting hydrostatic pressure at the formation, allowing additional reservoir fluids to enter, and ultimately causing ablowout.

Drilling Mud Composition

Drilling mud is a mixture of many components with different properties. Thevarious components react differently to pressure (p) and temperature (T). Thegas solubility and mixture properties of more complex hydrocarbon influxes varysignificantly. The most common components are base oil, water and weightmaterials (solids). Other components are chemically active, mix or dissolveinto the primary components of the mud for certain time periods during specificoperations on the well.
High-Resolution Seismic Imaging and Reservoir Characterization for Drilling Risk and Production Management
Authors: Yu Jen H. , Smith Mike
Published: April 2012

Often well planning, formation evaluation, reservoir engineering, andproduction management can ultimately be condensed to analyze and utilize thenature and spatial distribution of reservoirs and fluid properties. Thisobservation provides the motivation for this paper's objectives to:reviewthe impact of seismic resolution in imaging the reservoir, andexamine thechallenges and benefits of characterizing the reservoirs and fluid propertiesby integrating seismic, well, and engineering data at different measuringscales (resolutions) and sampling densities.

Two real case studies for sand andcarbonate reservoirs are used to illustrate how a new high resolution techniqueaffects seismic image and elevates reservoir characterization beyond thetraditional resolution enhancement methods.

Introduction

The use of resolution enhancement techniques to improve the seismic image hasbeen part of the seismic industry almost since the origin of seismic signalprocessing. Geophysicists have used statistical deconvolution, signaturedeconvolution, spectral whitening, log-bases blueing, and log-based waveletshaping to better improve the seismic resolution, image the subtle geologicalfeatures, and evaluate the prospects.

This paper begins with the theory of a novel resolution enhancement techniquein the continuous wavelet transform domain and its implementation methodology. Then it introduces a rigorous workflow to improve signal-to-noise ratio (SNR), velocity analysis, resolution, and anisotropic migration for better flattenedPSTM gathers, image, and prestack inversion. Finally, presents real casestudies for conventional and unconventional play types to illustrate how highresolution (HR) in seismic imaging and inversion improves the subsurface imagefor detailed stratigraphical and structural interrelation, reservoircharacterization, and production management. The two case studies are:complex Yegua sands with various thickness and spatial distribution fromlowstand deltas and slope fans in a shelf margin environment, andlowporosity Edward carbonate reservoirs from distal slope wackestones, reef andbank complexes, and back reef lagoonal deposits in a progradational sequence.

Both studies are presented to show the holistic workflow of prestack dataprocessing, resolution enhancement, petrophysical evaluation, and prestackinversion.

Theory: High Resolution Enhancement with Bandwidth Extension

The bandwidth extension technique described here attempts to recover the lostwavelet characteristics from the available bandwidth in seismic data. Theavailable bandwidth acts as the fundamental frequencies, for which harmonicsand subharmonics are computed from and compared with the data, and then addedback to the wavelet by a convolutional-like process in the CWT domain. Thiseffectively reshapes the wavelet and broadens the seismic bandwidth. Any highharmonic and low subharmonics frequencies that do not match reflectivity in therecorded seismic data will not remain in the final result (Smith et al.,2008).
The Benchmarking of the new ISO for the Site Specific Assessment of Mobile Jack-Up Units
Authors: Stiff John James , Lewis David Roger
Published: April 2012

The paper presents the logic behind, and the results of, a series of comparisonanalyses between a number of jack-up site-specific assessments using both thenew ISO 19905-1 on the site-specific assessment of mobile jack-up units [Ref.1] and the Society of Naval Architects and Marine Engineers Technical &Research Bulletin 5-5A [Ref. 2]. The study shows that the differences in theresults of analyses between those undertaken using 5-5A and ISO 19905-1 aregenerally small, although one area of potentially larger difference, which wasintentionally excluded from the comparison, (the normally lower kinematicsreduction factor in 19905) could lead to lower wave loads in 19905calculations.

ISO 19905 is largely based on 5-5A, however, the ISO development incorporatedsome major changes, including:Enhancements to calculation methodsSignificant changes in the geotechnical calculations, including the method ofcalculating acceptable bearing capacity, incorporation of deep penetrationcases, distinction between backfill and backflow, etc.Changes to enhance compatibility with other ISO documents in the 19900series, particularly ISO 19902 addressing Fixed Offshore Structures [Ref. 3](e.g. the structural code checks for tubular members)Introduction of additional structural member checksRe-structuring of 5-5A into a more logical ISO formatIntroduction of "benign" changes required for ISO compatibility (e.g.introduction of apparent and intrinsic wave periods), although some proved tobe less benign than othersAdditional loadcases for jack-ups operating close to resonance

Given so many changes, there was concern that the ISO may not be useable (e.g.there would be gaps, inconsistencies, and serious transposition errors), andeven if an analysis could be undertaken using it, the analysis results would besignificantly different from a similar assessment using 5-5A.

To ensure the compatibility and acceptability of ISO assessments results, a twopart benchmarking process was undertaken:

Part 1 Contract a single consultant to ensure the complete ISO could be used toproduce an answer. In effect, could an analysts start an analysis using thedocument and arrive at a solution - regardless of whether the solution wascorrect. This work resulted in some important changes.

Part 2 Contract four consultants to assess four jack-up designs, and comparethe results to a comparable series of assessments based on SNAME Bulletin 5-5A. In most cases each jack-up was assessed by two consultants with the analysesaligned at specific points. Alignment allowed differences in ISO interpretationto be identified, and ensured that results did not diverge as they progressed.A detailed sample calculation "Go-By" was also produced.
Production Optimization by Solving the Well Location Problem
Authors: Santana Roberta
Published: April 2012

The paper presents a process for determining optimal subsurface producing wellsand production unit location in a field to improve reservoir performance, recovery and reduce the pipeline total length used, decreasing costs, maximizing the revenue. The process is illustrated by optimizing well locationsusing statistics analysis, after several static reservoir model simulations, under defined parameters. These locations are then optimized with dynamic flowsimulation values' Sensibility Analysis. The response surface methodology isapplied to understand the flow distributing along the pipelines and thendetermine the best production unit location. This method is demonstrated byapplying it to a field scale simulation model considering only producingwells.

1. Introduction

The reservoir simulation is related to the development and management of an oilfield in order to establish a field fluid behavior model, previewing the oilrecovery. It provides enough data to analyze if the project matches theeconomic and safety prospection. During the development of the field, thereservoir simulation model is used as a decision tool to select the bestdevelopment project and also provide for the production of oil, gas and waterfield. Simulators are used in order to receive the characteristics of the rock, fluid and location of the field as well as its faults, creating a realthree-dimensional model of the subsurface reservoir. The location of wells inthe reservoir to be explored is one of the challenging steps in the process ofdecision the best strategy for developing a field that includes severalparameters, such as uncertainties and geological properties of confinedfluids.

Optimum well placement is a crucial step in a field development. The distancesbetween wells and platform are related to their productivity: short distancesperform less pressure drop along pipelines leading to higher production. Thenecessity to obtain maximum recovery with minimum investments can be addressedby reducing the cost of the installations as pipelines and equipments. Thus, the cost of the facilities necessary to maintain a satisfactory production of afield cannot bring enough profit and that field is not economically attractiveand viable. The structure optimization in the allocation of productionfacilities should also consider the economic variables associated[2] with theunderstanding that the scenario that produces more may not be the mostinteresting for the company.