bluuebunny/crossref_metadata_2025_split huggingface dataset:
Kinetic analysis for the esterification of high free fatty acid feedstocks with a structural identifiability approach
Authors: Aguilar‐Garnica Efrén , Silva‐Romero Yadira E. , Hernández‐Montelongo Rosaura , García‐Sandoval Juan Paulo , Aceves‐Lara César‐Arturo 
Published: June 2014

Esterification is the first step in the biodiesel production process from low cost feedstock, which is typically characterized by its high content (>5%) of free fatty acids (FFAs). Although multiple attempts have been made to describe the kinetics of the esterification process for this feedstock, there is no consensus regarding which model is the most suitable. In this paper, two models were evaluated as candidates to describe the esterification of grease trap wastes, a synthetic mixture of tallow fat and canola oil, and oleic acid, which all have a high degree of acidity. The first model considers a pseudo‐first order reaction, whereas the second model considers the reversibility of the reaction. All parameters involved in these models are structurally identifiable and are estimated with the Levenberg–Marquardt method. A statistical analysis based on Akaike's weights show that the reversible model provides the best fit for all experimental runs compared to the first order model. This result was obtained from variations in catalyst loading and moisture content.Practical applications: The design and implementation of monitoring algorithms or robust control laws for a process carried out in a continuous stirred tank reactor (CSTR) require the knowledge of its dynamical mathematical model that contains a kinetic term. In the particular case of the esterification reactions for feedstock with high content of FFAs developed in the presence of homogeneous acid catalyst, there exists a discrepancy on the mathematical structure of such kinetic term. In this study we perform some batch experiments, considering industrial reagent grade alcohols, to deduce which model (among the two simplest kinetic models) better describes the esterification of oleic acid, grease trap wastes and a mixture of tallow fat and canola oil. Then, the results obtained from this basic research could be applied if monitoring‐regulation tasks are required for the esterification of the feedstock considered herein when such esterification be carried out in a CSTR under industrial conditions.Low cost feedstock has been esterified under variations in catalyst loading and initial moisture content. Two kinetic models were used to fit experimental data and a structural identifiability analysis has been conducted for each parameter contained in these models. According with Akaike's weights, the kinetic model that considers the reversibility of the esterification reaction provides the best fit for all experimental runs.
Understanding the glycerol market
Authors: Ciriminna Rosaria , Pina Cristina Della , Rossi Michele , Pagliaro Mario 
Published: June 2014

As a result of the booming biodiesel and oleochemicals manufacturing taking place worldwide since more than a decade, 2 million tonnes of glycerol consistently reach the market every year, even though after a decade of growth the total glycerol supply is expected to slightly decrease in 2014. Today the supply of glycerol is entirely independent of its demand, as there is as much glycerol as the amount of vegetable oils and animal fats are hydrolyzed to make oleochemicals, or transesterified to produce biodiesel. This unique situation has led to consistently low glycerol prices, which initiated both the market penetration of glycerol in countries where it was not used due to traditional high price, as well as new uses of glycerol as raw material for the production of value added chemicals. This article sheds light on the market of this uniquely versatile chemical whose number of applications is unique amid all existing chemicals.About 2 million tonnes of glycerol consistently reach the market every year, even though after a decade of growth the total glycerol supply is expected to slightly decrease in 2014. Today the supply of glycerol is entirely independent of its demand, as there is as much glycerol as the amount of vegetable oils and animal fats are hydrolyzed to make oleochemicals, or transesterified to produce biodiesel. This article sheds light on the market of this uniquely versatile chemical whose number of applications is unique amid all existing chemicals.
Seismic design and testing of the bottom vertical boundary elements in steel plate shear walls. Part 1: design methodology
Authors: Tsai Keh‐Chyuan , Li Chao‐Hsien , Lee Hung‐Chi 
Published: June 2014

SUMMARYThis research investigates the seismic design method and the cyclic inelastic behavior of the bottom column, also called the vertical boundary element (VBE), in steel plate shear walls (SPSWs). This study consists of two parts. This Part 1 paper discusses the anticipated pushover responses for properly designed SPSWs and the possible inelastic responses of the bottom VBE at various levels of inter‐story drift. Considering both the tension field action of the infill panel and the sway action of the boundary frame, this study develops a simplified method to compute the flexural and shear demands in the bottom VBE. Based on the superposition method, this approach considers various plastic hinge forming locations at different levels of inter‐story drift. One of the key performance‐based design objectives is to ensure that the top ends of the bottom VBEs remain elastic when the SPSWs are subjected to the maximum considered earthquake. This paper presents the comprehensive design procedures for the bottom VBE. Furthermore, this study conducted cyclic performance evaluation tests of three full‐scale two‐story SPSWs at the Taiwan National Center for Research on Earthquake Engineering in 2011 to validate the effectiveness of the proposed design methods. The experimental program, cyclic inelastic responses of the SPSWs and bottom VBEs, and numerical simulations are presented in Part 2. Copyright © 2014 John Wiley & Sons, Ltd.
Physico‐chemical, sensory, and microbiological assessments of wheat‐based biscuit improved with beniseed and unripe plantain
Authors: Agu Helen Obioma , Okoli Ndidiamaka Azuka 
Published: June 2014

AbstractThe consumption of cereal foods such as biscuit has become very popular globally. Partial replacement of wheat flour with beniseed and unripe plantain flours rich in protein, vitamins, and minerals will increase nutrient, diversify utilization of beniseed and unripe plantain, and increase biscuit variety. Wheat composite biscuit was produced from wheat, beniseed, and unripe plantain flours. The composite flour was mixed in the proportion of 100:0:0, 80:10:10, 70:20:10, 60:30:10, and 50:40:10% of wheat, beniseed, and unripe plantain, respectively. The physical, sensory, chemical, and microbial properties of the biscuits were determined. The physical properties ranged from 6.80 g to 8.30 g for weight, spread ratio 6.93–7.38, and break strength 500–690 g. There was no significant difference (P < 0.05) in taste, crispness, flavor and texture of the biscuits while significant differences (P < 0.05) existed in color and overall acceptability. The proximate composition of the biscuits ranged from 1.84% to 2.55% for moisture, protein 8.03–9.26%, fat 30.07–35.81%, ash 2.94–3.68%, crude fiber 0.47–0.80%, carbohydrate 48.74–55.96%, and energy 526.53–554.21 kcal/100 g. The microbial count of the best biscuit after 20 days of storage was 4.0 × 103 cfu/g for bacteria and mould contained 5.0 × 104 cfu/g. This study forms a basis for new product development for the biscuit food industry.
Flexible establishment of functional brain networks supports attentional modulation of unconscious cognition
Authors: Ulrich Martin , Adams Sarah C. , Kiefer Markus 
Published: June 2014

AbstractIn classical theories of attention, unconscious automatic processes are thought to be independent of higher‐level attentional influences. Here, we propose that unconscious processing depends on attentional enhancement of task‐congruent processing pathways implemented by a dynamic modulation of the functional communication between brain regions. Using functional magnetic resonance imaging, we tested our model with a subliminally primed lexical decision task preceded by an induction task preparing either a semantic or a perceptual task set. Subliminal semantic priming was significantly greater after semantic compared to perceptual induction in ventral occipito‐temporal (vOT) and inferior frontal cortex, brain areas known to be involved in semantic processing. The functional connectivity pattern of vOT varied depending on the induction task and successfully predicted the magnitude of behavioral and neural priming. Together, these findings support the proposal that dynamic establishment of functional networks by task sets is an important mechanism in the attentional control of unconscious processing. Hum Brain Mapp 35:5500–5516, 2014. © 2014 Wiley Periodicals, Inc.
The dorsal medial frontal cortex mediates automatic motor inhibition in uncertain contexts: Evidence from combined fMRI and EEG studies
Authors: Albares Marion , Lio Guillaume , Criaud Marion , Anton Jean‐Luc , Desmurget Michel , Boulinguez Philippe 
Published: June 2014

AbstractResponse inhibition is commonly thought to rely on voluntary, reactive, selective, and relatively slow prefrontal mechanisms. In contrast, we suggest here that response inhibition is achieved automatically, nonselectively, within very short delays in uncertain environments. We modified a classical go/nogo protocol to probe context‐dependent inhibitory mechanisms. Because no single neuroimaging method can definitely disentangle neural excitation and inhibition, we combined fMRI and EEG recordings in healthy humans. Any stimulus (go or nogo) presented in an uncertain context requiring action restraint was found to evoke activity changes in the supplementary motor complex (SMC) with respect to a control condition in which no response inhibition was required. These changes included: (1) An increase in event‐related BOLD activity, (2) an attenuation of the early (170 ms) event related potential generated by a single, consistent source isolated by advanced blind source separation, and (3) an increase in the evoked‐EEG Alpha power of this source. Considered together, these results suggest that the BOLD signal evoked by any stimulus in the SMC when the situation is unpredictable can be driven by automatic, nonselective, context‐dependent inhibitory activities. This finding reveals the paradoxical mechanisms by which voluntary control of action may be achieved. The ability to provide controlled responses in unpredictable environments would require setting‐up the automatic self‐inhibitory circuitry within the SMC. Conversely, enabling automatic behavior when the environment becomes predictable would require top‐down control to deactivate anticipatorily and temporarily the inhibitory set. Hum Brain Mapp 35:5517–5531, 2014. © 2014 Wiley Periodicals, Inc.
Official Japanese Version of the International Parkinson and Movement Disorder Society–Unified Parkinson's Disease Rating Scale: Validation Against the Original English Version
Authors: Kashihara Kenichi , Kondo Tomoyoshi , Mizuno Yoshikuni , Kikuchi Seiji , Kuno Sadako , Hasegawa Kazuko , Hattori Nobutaka , Mochizuki Hideki , Mori Hideo , Murata Miho , Nomoto Masahiro , Takahashi Ryosuke , Takeda Atsushi , Tsuboi Yoshio , Ugawa Yoshikazu , Yamanmoto Mitsutoshi , Yokochi Fusako , Yoshii Fumihito , Stebbins Glenn T. , Tilley Barbara C. , Luo Sheng , Wang Lu , LaPelle Nancy R. , Goetz Christopher G. ,   MDS‐UPDRS Japanese Validation Study Group
Published: June 2014

AbstractThe International Parkinson and Movement Disorder Society (MDS)‐sponsored revision of the Unified Parkinson's Disease Rating Scale (MDS‐UPDRS) has been developed and is now available in English. Part of the overall program includes the establishment of official non‐English translations of the MDS‐UPDRS. We present the process for completing the official Japanese translation of the MDS‐UPDRS with clinimetric testing results. In this trial, the MDS‐UPDRS was translated into Japanese, underwent cognitive pretesting, and the translation was modified after taking the results into account. The final translation was approved as the Official Working Draft of the MDS‐UPDRS Japanese version and tested in 365 native‐Japanese–speaking patients with PD. Confirmatory analyses were used to determine whether the factor structure for the English‐language MDS‐UPDRS could be confirmed in data collected using the Official Working Draft of the Japanese translation. As a secondary analysis, we used exploratory factor analyses to examine the underlying factor structure without the constraint of a prespecified factor organization. Confirmatory factor analysis revealed that Comparative Fit Index for all parts of the MDS‐UPDRS exceeded the minimal standard of 0.90, relative to the English version, and therefore the Japanese translation met the prespecified criterion to be designated, called an official MDS translation. Secondary analyses revealed some differences between the English‐language MDS‐UPDRS and the Japanese translation; however, these differences were considered to be within an acceptable range. The Japanese version of the MDS‐UPDRS met the criterion as an Official MDS Translation and is now available for use (www.movementdisorders.org).
Translational applications of hyperpolarized 3He and 129Xe
Authors: Walkup Laura L. , Woods Jason C. 
Published: June 2014

Clinical magnetic resonance imaging of the lung is technologically challenging, yet over the past two decades hyperpolarized noble gas (3He and 129Xe) imaging has demonstrated the ability to measure multiple pulmonary functional biomarkers. There is a growing need for non‐ionizing, non‐invasive imaging techniques due to increased concern about cancer risk from ionizing radiation, but the translation of hyperpolarized gas imaging to the pulmonary clinic has been stunted by limited access to the technology. New developments may open doors to greater access and more translation to clinical studies.Here we briefly review a few translational applications of hyperpolarized gas MRI in the contexts of ventilation, diffusion, and dissolved‐phase imaging, as well as comparing and contrasting 3He and 129Xe gases for these applications. Simple static ventilation MRI reveals regions of the lung not participating in normal ventilation, and these defects have been observed in many pulmonary diseases. Biomarkers related to airspace size and connectivity can be quantified by apparent diffusion coefficient measurements of hyperpolarized gas, and have been shown to be more sensitive to small changes in lung morphology than standard clinical pulmonary functional tests and have been validated by quantitative histology. Parameters related to gas uptake and exchange and lung tissue density can be determined using 129Xe dissolved‐phase MRI. In most cases functional biomarkers can be determined via MRI of either gas, but for some applications one gas may be preferred, such as 3He for long‐range diffusion measurements and 129Xe for dissolved‐phase imaging.Greater access to hyperpolarized gas imaging coupled with newly developing therapeutics makes pulmonary medicine poised for a potential revolution, further adding to the prospects of personalized medicine already evidenced by advancements in molecular biology. Hyperpolarized gas researchers have the opportunity to contribute to this revolution, particularly if greater clinical application of hyperpolarized gas imaging is realized. Copyright © 2014 John Wiley & Sons, Ltd.
Comparison of measured rain attenuation in the 10.982‐GHz band with predictions and sensitivity analysis
Authors: Abdulrahman Yusuf , Rahman Tharek A. , Islam Rafiqul M. , Olufeagba Benjamin J. , Chebil Jalel 
Published: June 2014

SummaryThe campaign to collect rain attenuation data on terrestrial links had commenced in Malaysian tropical climates for almost two decades. The terrestrial data so far collected have been greatly utilized to derive useful statistics for various microwave applications, such as frequency scaling, rain rate conversion factor, 1‐min rain rate contour maps, wet antenna losses, and fade slope duration analysis. However, there is still severe scarcity of rain attenuation data on earth–space links in Malaysia. The results of the 2‐year measurement (January 2009–December 2010) of rain rates and rain‐induced attenuation in vertically polarized signals propagating at 10.982 GHz have been presented in this paper. The rain attenuation over the link path was measured at Islamic International University Malaysia and compared with ITU‐R P.618‐10 and Crane global models in this paper. The test results show that the two prediction models seem inadequate for predicting rain attenuation in the Ku‐band in Malaysia. Sensitivity analysis performed on measured data also reveals that the sensitivity variables depend on rain rate. Copyright © 2014 John Wiley & Sons, Ltd.
Exploiting cognitive radios for reliable satellite communications
Authors: Abdel‐Rahman Mohammad J. , Krunz Marwan , Erwin Richard 
Published: June 2014

SummarySatellite transmissions are prone to both unintentional and intentional RF interference. Such interference has significant impact on the reliability of packet transmissions. In this paper, we make preliminary steps at exploiting the sensing capabilities of cognitive radios for reliable satellite communications. We propose the use of dynamically adjusted frequency hopping (FH) sequences for satellite transmissions. Such sequences are more robust against targeted interference than fixed FH sequences. In our design, the FH sequence is adjusted according to the outcome of out‐of‐band proactive sensing, carried out by a cognitive radio module that resides in the receiver of the satellite link. Our design, called out‐of‐band sensing‐based dynamic FH, is first analyzed using a discrete‐time Markov chain (DTMC) framework. The transition probabilities of the DTMC are then used to measure the ‘channel stability’, a metric that reflects the freshness of sensed channel interference. Next, out‐of‐band sensing‐based dynamic FH is analyzed following a continuous‐time Markov chain model, and a numerical procedure for determining the ‘optimal’ total sensing time that minimizes the probability of ‘black holes’ is provided. DTMC is appropriate for systems with continuously adjustable power levels; otherwise, continuous‐time Markov chain is the suitable model. We use simulations to study the effects of different system parameters on the performance of our proposed design. Copyright © 2014 John Wiley & Sons, Ltd.
Modeling, conflict detection, and verification of a new virtualization role‐based access control framework
Authors: Luo Yang , Xia Chunhe , Lv Liangshuang , Wei Zhao , Li Yazhuo 
Published: June 2014

AbstractIn the last 10 years, virtualization has become a widespread technique in cloud computing; however, few of the access control models have ever addressed the security issue of multi‐domain and virtualized network management; this paper enhanced the classic role‐based access control model through two concepts: domain and virtual machine. We defined a new model named VRBAC in which authorized users can migrate or copy virtual machines from one domain to another without causing a conflict. Domain users or groups are allowed to share permissions of not only resources like shared files but also virtual machines with others either from the same or a different domain. Three kinds of VRBAC policy conflicts are defined in forms of ontologies, which provide extra access to description logic reasoning and facilitate the policy conflict detection. The experimental results based on Microsoft Active Directory and VMware vSphere suggest that all policy conflicts can be detected effectively and efficiently. Moreover, the generated reports can provide conflict details such as conflict types, positions, and causes, which will serve as guidance for further resolution of the improper authorizations and access violations. Copyright © 2014 John Wiley & Sons, Ltd.
A ciphertext‐policy hidden vector encryption scheme supporting multiuser keyword search
Authors: Zhenhua Liao , Jinmiao Wang , Bo Lang 
Published: June 2014

AbstractIn cloud computing, large amount of data can be effectively stored and managed. People could outsource the encrypted data using searchable encryption (SE) for data security and efficient retrieval. However, most existing SE schemes only support the single‐user access, and multiuser searchable encryption is required in many enterprise applications. From the attribute‐based encryption (ABE), we found that the flexibility and usability of encryption schemes can be greatly improved by embedding attribute‐based access policy in the ciphertext. In this paper, by using the idea of ABE, we propose a ciphertext‐policy hidden vector encryption (CPHVE) scheme to support both encryption and search operations for multiple users. In the scheme, a keyword is encrypted with an attribute‐based access policy, which can be searched when the users' attributes satisfy the policy. The security of CPHVE is also defined and proved in this paper. Moreover, the CPHVE scheme is based on standard complexity assumptions on bilinear groups of prime order, thus it is more efficient than the existing schemes. Copyright © 2014 John Wiley & Sons, Ltd.
Effect of Palm Oil Enzymatic Interesterification on Physicochemical and Structural Properties of Mixed Fat Blends
Authors: Danthine Sabine , Lefébure Emilie , Trinh Hoa Nhu , Blecker Christophe 
Published: June 2014

AbstractThe physicochemical properties of binary and ternary fat systems made of commercial samples of palm oil (PO) blended with anhydrous milk fat (AMF) and/or rapeseed oil (RO) were studied. Physical properties such as solid fat content by pulsed‐Nuclear Magnetic Resonance (p‐NMR), melting profile by differential scanning calorimetry (DSC), and polymorphism of the blends were investigated. Palm oil was then batch enzymatically interesterified for 27 h, using Lipozyme® TL IM as biocatalyst, and further blended with AMF and/or RO in the same way. The objective of the present work was to evaluate the effect of batch enzymatic interesterification (B‐EIE) of palm oil on physical characteristics of the investigated fat blends. For that purpose, iso‐solid diagrams have been constructed from p‐NMR data. It was shown that B‐EIE of palm oil modifies its melting behaviour, but also its polymorphic stability and miscibility with other fats. Under dynamic conditions, after B‐EIE, the non‐ideal behaviour (eutectic) detected at low temperatures in the ternary PO/AMF/RO system disappears in the corresponding EIE‐PO/AMF/RO. After static crystallization followed by a tempering, the hardness of palm oil is increased after B‐EIE, as well as the hardnesses of the blends containing this fat compared to the native one. Polymorphism stability of the binary and ternary fat systems is also modified after B‐EIE compared to the corresponding native systems.