bluuebunny/crossref_metadata_2025 huggingface dataset:
Ethnocultural Empathy Among Frontline Hospitality and Tourism Employees
Authors: Sharifi-Tehrani Mohammad , Sanayei Ali , Kazemi Ali , Rezaie Dolat Abadi Hoseein
Published: March 2019

The current study outlines the measurement of frontline employees' guest-directed ethnocultural empathy abilities in the context of Islamic hospitality in Iran. To this end, nine 4-and 5-star hotels located in three of the country's main cities were sampled for examining their frontline
employees by a modified version of Scale of Ethnocultural Empathy. To test this scale and analyze the data, the variance-based technique of partial least squares structural equation modeling was selected. Out of the scale's dimensions, Empathic Feeling and Expression exerted the strongest
influence on the ethnocultural empathy levels, followed by Empathic Perspective Taking, Acceptance of Cultural Differences, and Empathic Awareness. These underlying four dimensions accounted for more than two thirds of the total variance of ethnocultural empathy. This, along with the substantiation
of convergent validity, discriminant validity, high reliability, and satisfactory model indices, indicates a high contribution of the above dimensions and their modified items to the quantitatively measurement of frontline employees' competencies to empathize with guests of other racial or
ethnic groups. Hotel managers can take advantage of this scale to identify any likely weaknesses with such competencies in order to improve them based on the priorities that various guest segments seek.
The Dynamic Role of Augmented Reality in Tourism
Authors: Maaiah Bashar , Al-Shorman Abdalla , Alananzeh Omar , Al-Badarneh Mohammad
Published: March 2019

The increasing ubiquity of the smart phone has undoubtedly paved the way for the utilizing of technological intermediation in tourism, notably in the case of augmented reality (AR). The current study seeks the opinions and perceptions of AR users about how such technologies impact their
decisionmaking. The study seeks an enhanced understanding of contemporary tourist consumption practices, drawing upon the relationship between code and space using LAYAR AR applications. The research methods that have been deployed in this study involve the conduct of qualitative interviews
with consumers and producers with an interest in AR applications using a snowball sampling approach. The results show that using AR produces the augmented construction of reality that is multidimensional and consists of the owner, site, and tourism agency. It has also been shown that AR is
a secondary tool, where user awareness and sense of the physical environment decreases. It is concluded that integrating technologies into the tourist experience can enhance the enjoyment of the experience and improve expertise and skills in the context of tourist operations and attractions.
CONVERGENCE ORDER OF ONE REGULARIZATION METHOD
Authors: Guseinov S.
Published: March 2019

The multiscale solution of the Klein‐Gordon equations in the linear theory of (two‐phase) materials with microstructure is defined by using a family of wavelets based on the harmonic wavelets. The connection coefficients are explicitly computed and characterized by a set of differential equations. Thus the propagation is considered as a superposition of wavelets at different scale of approximation, depending both on the physical parameters and on the connection coefficients of each scale. The coarse level concerns with the basic harmonic trend while the small details, arising at more refined levels, describe small oscillations around the harmonic zero‐scale approximation.
CONVERGENCE ACCELERATION AND LINEAR METHODS
Authors: Tammeraid I.
Published: March 2019

Two λ‐convergence propositions for linear methods A = (Ank ), while Ank are linear bounded operators from Banach space X into Banach space Y, are presented. These results are applied to study convergence acceleration of linear methods.
Asymmetric Distribution of Weak Photospheric Magnetic Field Values
Authors: Getachew Tibebu , Virtanen Ilpo , Mursula Kalevi
Published: March 2019

We use the synoptic maps of the photospheric magnetic field observed at Wilcox Solar Observatory, Mount Wilson Observatory, Kitt Peak, SOHO/MDI, SOLIS/VSM, and SDO/HMI to study the distribution of weak photospheric magnetic field values in 1974–2018. We fit the histogram distribution of weak field values for each synoptic map of the six data sets separately with a parameterized Gaussian function in order to calculate the possible shift (to be called here the weak-field asymmetry) of the maximum of the Gaussian distribution from zero. We estimate the statistical significance of the weak-field asymmetry for each rotation. We also calculate several versions of lower-resolution synoptic maps from the high-resolution maps and calculate their rotational weak-field asymmetries. We find that the weak-field asymmetries increase with decreasing map resolution. A very large fraction of weak-field asymmetries are statistically significant, with the fraction of significant weak-field asymmetries increasing with decreasing resolution. Significant weak-field asymmetries of high- and low-resolution maps mainly occur at the same times and have the same sign. Weak-field asymmetries for the different data sets and resolutions vary quite similarly in time, and their mutual correlations are very high, especially for low-resolution maps. These results give strong evidence for weak-field asymmetries reflecting a real feature of weak field values, which is best seen in medium- and low-resolution synoptic maps and is most likely related to the supergranulation scale of the photospheric field.
Oxygen Atom Reactions with C2H6, C2H4, and C2H2 in Ices
Authors: Bergner Jennifer B. , Öberg Karin I. , Rajappan Mahesh
Published: March 2019

Oxygen atom addition and insertion reactions may provide a pathway to chemical complexity in ices that are too cold for radicals to diffuse and react. We have studied the ice-phase reactions of photoproduced oxygen atoms with C2 hydrocarbons under ISM-like conditions. The main products of oxygen atom reactions with ethane are ethanol and acetaldehyde; with ethylene are ethylene oxide and acetaldehyde; and with acetylene is ketene. The derived branching ratio from ethane to ethanol is ∼0.74 and from ethylene to ethylene oxide is ∼0.47. For all three hydrocarbons, there is evidence of an effectively barrierless reaction with O(1D) to form oxygen-bearing organic products; in the case of ethylene, there may be an additional barriered contribution of the ground-state O(3P) atom. Thus, oxygen atom reactions with saturated and unsaturated hydrocarbons are a promising pathway to chemical complexity even at very low temperatures where the diffusion of radical species is thermally inaccessible.
Predicting the Structure of the Solar Corona and Inner Heliosphere during Parker Solar Probe's First Perihelion Pass
Authors: Riley Pete , Downs Cooper , Linker Jon A. , Mikic Zoran , Lionello Roberto , Caplan Ronald M.
Published: March 2019

NASA’s Parker Solar Probe (PSP) spacecraft reached its first perihelion of 35.7 solar radii on 2018 November 5. To aid in mission planning, and in anticipation of the unprecedented measurements to be returned, in late October, we developed a three-dimensional magnetohydrodynamic (MHD) solution for the solar corona and inner heliosphere, driven by the then available observations of the Sun’s photospheric magnetic field. Our model incorporates a wave-turbulence-driven model to heat the corona. Here, we present our predictions for the structure of the solar corona and the likely in situ measurements that PSP will be returning over the next few months. We infer that, in the days prior to first encounter, PSP was immersed in wind emanating from a well-established, positive-polarity northern polar coronal hole. During the encounter, however, field lines from the spacecraft mapped to a negative-polarity equatorial coronal hole, within which it remained for the entire encounter, before becoming magnetically connected to a positive-polarity equatorial coronal hole. When the PSP data become available, these model results can be used to assist in their calibration and interpretation, and, additionally, provide a global context for interpreting the localized in situ measurements. In particular, we can identify what types of solar wind PSP encountered, what the underlying magnetic structure was, and how complexities in the orbital trajectory can be interpreted within a global, inertial frame. Ultimately, the measurements returned by PSP can be used to constrain current theories for heating the solar corona and accelerating the solar wind.
Epitypification of the Central African Cantharellus densifolius and C. luteopunctatus allows for the recognition of two additional species
Authors: Buyck Bart , Henkel Terry W. , Hofstetter Valérie
Published: March 2019

CantharellusdensifoliusandC.luteopunctatusare epitypified on the basis of recently collected specimens from the Central African rain forest that correspond in every way to their respective original descriptions. Sequences obtained from these new collections demonstrate that both epitypes represent distinct species that belong in different subclades of Cantharellussubg.Rubrinus. Previously, the nameC.densifoliushas been consistently misapplied to more or less similar species from the African woodland area, includingC.densilamellatussp. nov.which is described here, In addition,C.tomentosoidessp. nov., a rain forest species that is easily confused withC.densifolius, is described.
Pleiotropic effects of Erythropoietin. Influence of Erythropoietin on processes of mesenchymal stem cells differentiation
Authors: Zubareva Ekaterina V. , Nadezhdin Sergey V. , Burda Yuriy E. , Nadezhdina Natalia A. , Gashevskaya Anastasia S.
Published: March 2019

Structure and synthesis of Erythropoietin: Erythropoietin (EPO) is a glycoprotein hormone.
Recombinant Erythropoietin (Epoetin): Human recombinant erythropoietin is characterised as a factor which stimu-lates differentiation and proliferation of erythroid precursor cells, and as a tissue protective factor.
Anti-ischemic effects of recombinant Erythropoietin: Erythropoietin is one of the most perspective humoral agents which are involved in the preconditioning phenomenon.
Erythropoietin receptors and signal transduction pathways: Erythropoietin effects on cells through their inter-connection with erythropoietin receptors, which triggers complex intracellular signal cascades, such as JAK2/STAT signaling pathway, phosphatidylinositol 3-kinase (PI3K), protein kinase C, mitogen-activated protein kinase (MAPK), and nuclear factor (NF)-κB signaling pathways.
Mechanisms of the effect of Erythropoietin on hematopoietic and non-hematopoietic cells and tissues: In addition to regulation of haemopoiesis, erythropoietin mediates bone formation as it has an effect on hematopoietic stem cells
and osteoblastic niche, and this illustrates connection between the processes of haematopoiesis and osteopoiesis which take place in the red bone marrow.
The effect of Erythropoietin on mesenchymal stem cells and process of bone tissue formation: Erythropoietin promotes mesenchymal stem cells proliferation, migration and differentiation in osteogenic direction. The evidence of which is expression of bone phenotype by cells under the influence of EPO, including activation of bone specific transcription factors Runx2, osteocalcin and bone sialoprotein.
Conclusion: Erythropoietin has a pleiotropic effect on various types of cells and tissues. But the mechanisms which are involved in the process of bone tissue restoration via erythropoietin are still poorly understood.
Hepatoprotective effect of opioid peptides in stress
Authors: Solin Alexey V. , Lyashev Yuri D. , Tsygan Nikolay V.
Published: March 2019

Introduction: Influence of the endogenous opioid system on the liver has not been studied enough. To understand the damaging effects of stress on the liver and the hepatoprotective effects of opioids, a study was performed on stress-re- sistant and stress-susceptible animals.

Materials and methods: The investigation was performed on 725 Wistar male-rats. Various types of stress were mod- eled: acute immobilization stress of various duration (3, 6 and 12 hours), chronic stress of limited mobility, swimming stress and traumatic stress (resection of 70% of the liver). Agonists of various types of opioid receptors in equimolar doses were injected to stressed animals at equimolar doses: DAGO – a mu-receptor agonist – at a dose of 6.3 mcg/kg, DSLET – a delta-receptor agonist – at a dose of 10 mcg/kg, and kappa receptor agonist dynorphin A (1-13) – at a dose of 20.1 mcg/kg.

Results and discussion: The stress-limiting action of the studied opioids is characterized by the reduced hepatocyte dystrophy, microcirculation correction, a decreased concentration of lipid peroxidation metabolites, a suppressed cy-tolytic syndrome, a stimulated synthetic ability of the liver, and is more pronounced in stress- susceptible animals.

The greatest stress-protective effect is shown after administering dynorphin A (1-13) in immobilization stress, and DAGO – in swimming stress. Dynorphin A (1-13) and DAGO manifested the most pronounced effect on the liver regeneration after resection. A preliminary stress simulation accelerates liver regeneration at the initial stage after re- section.

Conclusion: The hepatoprotective effect of opioids in stress depends on the typological peculiarities of animals. The results obtained offer a challenge of synthesizing new hepatoprotectors.
Lung segmentation in chest radiographs using fully convolutional networks
Authors: HOODA RAHUL , MITTAL AJAY , SOFAT SANJEEV
Published: March 2019

Automated segmentation of medical images that aims at extracting anatomical boundaries is a fundamental step in any computer-aided diagnosis (CAD) system. Chest radiographic CAD systems, which are used to detect pulmonary diseases, first segment the lung field to precisely define the region-of-interest from which radiographic patterns are sought. In this paper, a deep learning-based method for segmenting lung fields from chest radiographs has been proposed. Several modifications in the fully convolutional network, which is used for segmenting natural images to date, have been attempted and evaluated to finally evolve a network fine-tuned for segmenting lung fields. The testing accuracy and overlap of the evolved network are 98.75% and 96.10%, respectively, which exceeds the state-of-the-art results.
Multiscanning mode laser scanning confocal microscopy system
Authors: AKTÜRK MERT , GÜMÜŞ GÖKHAN , SARIOĞLU BAYKAL , GÖKDEL YİĞİT DAĞHAN
Published: March 2019

In this paper, a table-top, reflective mode, laser scanning confocal microscopy system that is capable of scanning the target specimen alternately through various scanning devices and methods is proposed. We have developed a laser scanning confocal microscopy system to utilize combinations of various scanning devices and methods and to be able to characterize the optical performance of different scanners and micromirrors that are frequently used in scanning microscopy systems such as multiphoton microscopy, optical coherence tomography, or confocal microscopy. By integrating the scanner to be characterized on the same optical path with a galvanometric scan mirror, which is the conventional benchmarking scanning unit in a typical scanning microscope, we obtain two major advantages: (1) microscopy images are automatically acquired from the same location on the target specimen without having any time- consuming alignment problem and accordingly provide a high-quality optical comparison opportunity, and (2) it totally eliminates the utilization of a second scanning microscopy to benchmark the performance of the scanner-based system and considerably reduces the time spent for imaging, which is a crucial factor for a freshly excised tissue, especially under a fluorescence microscope. The system is composed of a 658 nm laser source, collimation optics, a 2D galvanometer, a 2D polymer micro-scanner, an objective lens with a numerical aperture of 0.40, a 100 μm pinhole, a PMT, a DAQ card and peripheral electronics as well as a Matlab software that simultaneously controls the system through a personal computer. Prototype of the proposed flexible LSCM system is first optically characterized using a USAF resolution target. Subsequently, we provided images of red blood and bacteria cells to demonstrate the systems’ capability for clinical diagnostics. It is reported that maximum FOV and lateral resolution of the proposed LSCM are measured to be 420 μm x 360 μm and 1 μm with galvanometer and, and 117 μm x 117 μm and 3.2 μm with the polymer scanner unit, respectively.
Cache pressure-aware caching scheme for content-centric networking
Authors: LUO XI , AN YING
Published: March 2019

Content centric networking (CCN) is a new networking paradigm to meet the growing demand for content access in the future. Because of its important role in accelerating content retrieval and reducing network transmission load, in-network caching has become one of the core technologies in CCN and has attracted wide attention. The existing caching schemes often lack sufficient consideration of node cache status and the temporal validity of user requests, and thus the cache efficiency of the network is greatly reduced. In this paper, a cache pressure-aware caching scheme is proposed, which comprehensively takes into account various factors such as content popularity, cache occupancy rate, cache replacement rate, and the validity period of the Interest packet to achieve reasonable cache placement and replacement. Simulation results show that the proposed scheme effectively improves the cache hit rate and the resource utilization while decreasing the average response hops.
La labor del académico Ignacio Tomás en Écija, su disputa con los arquitectos sevillanos y la construcción de la parroquia mayor de Santa Cruz
Authors: Ruiz Carrasco Jesús María
Published: March 2019

Ignacio Tomás, máximo exponente de la difusión de los preceptos arquitectónicos academicistas en los reinos de Córdoba y Sevilla, intervino decisivamente en la proyección y construcción de varios edificios relevantes de Écija. Sin embargo, su labor contó con la oposición del Cabildo catedralicio, el Arzobispado y los arquitectos de Sevilla, ante quienes tuvo que defender su posición como académico. Esta disputa se manifestó singularmente en torno a la construcción de la parroquia mayor de Santa Cruz, cuyas circunstancias representan paradigmáticamente un periodo conflictivo y heterogéneo de la Arquitectura española.
Invertir en arte: la colección de pintura reunida por el comerciante estadounidense Richard Worsan Meade en Cádiz entre 1804 y 1820
Authors: Carrasco Guadalupe
Published: March 2019

Las guerras napoleónicas fueron una oportunidad para algunos comerciantes estadounidenses para comerciar con España. El comerciante estadounidense Richard W. Meade se estableció en Cádiz entre 1804 y 1820. En estos años consiguió acumular una importante fortuna. Su estancia en Cádiz durante la invasión francesa le permitió reunir una valiosa colección de obras de arte, sobre todo pintura barroca española e italiana. A través de los catálogos de subastas de la colección publicados en 1831 y 1853 y de los manifiestos de carga de los barcos llegados a Filadelfia conservados en la Custom House se ha podido conocer casi en su totalidad la colección de pinturas que Richard W. Meade trasladó a Estados Unidos.
El examen de pintor de Blas de Ledesma en Málaga (1587)
Authors: García Cueto David
Published: March 2019

Se presenta el documento del examen que habilitó a Blas de Ledesma como pintor en 1587, aprobado en la ciudad de Málaga, población en la que hasta ahora era desconocida su presencia. Queda a través de ello constatada su relación con los maestros Francisco de Holguín y Juan Cornejo.
Gasification of Municipal Solid Waste Using Tyre Char as Catalyst
Authors: Saharuddin Mizan Qistina , Kadir Sharifah Aishah Syed A. , Alias Rusmi
Published: March 2019

Gasification is raised as the most promising technologies of municipal solid waste (MSW) removal as well as energy recovery. The principal problem related with the gasification process is the high amount of tar released during the gasification process that causes environmental and operational problems. The purpose of this study is to investigate the performance of MSW gasification using tyre char as an alternative option for catalytic gasification to produce tar free clean gas. Catalytic performance of tyre char was compared with performance of MSW gasification alone without the tyre char in a bench scale downdraft reactor. The waste tyre char removed 80% of tars in syngas at 700 °C. Analysis of the syngas compositions indicated that concentration of H2 and CO were significantly increased. Therefore, it was concluded that chars especially tyre char can be an effective and inexpensive catalyst for tar removal and syngas production of MSW gasification.
Morphology Prediction and Dissolution Behavior of α-Succinic Acid in Ethanol Solution Using Molecular Dynamic Simulation
Authors: Othman Muhamad Fitri , Anuar Nornizar , Yusop Siti Nurul'ain , Nik Salwani Md Azmi , Abd Samad Nurul Azreen
Published: March 2019

Succinic acid is a potential co-former to produce co-crystal, thus an understanding of the dissolution behaviour of succinic acid crystal is crucial for designing the co-crystal. In this works, α-succinic acid was chosen as a model compound for this study regardless its attractive crystal chemistry and its diverse surface properties. The aims of this study are to analyse the morphology of succinic acid crystal (form A) and to analyse the dissolution behaviour of succinic acid crystal (form A) in the ethanol solution using molecular dynamic simulation. Prediction of form A succinic acid morphology were conducted with different combination of charge set and potential function i.e ESP and CVFF which produces hexagonal needle-like shape morphology and shows good agreement with the experimental crystal shape. Dissolution of α-succinic acid in ethanol solvent was investigated using dynamic simulation. Visual observation and mobility assessment shows that the molecules at the edge of the crystal tends to dissolve faster compared to the molecules at other position on the facet.
Meal Disturbance Effect on Blood Glucose Control for Type 1 Diabetes Using Improved Hovorka Equations
Authors: Som Ayub Md , binti Mohd Yusof Nur Farhana Mohd , Ali Sherif Abdulbari , Fuzil Nurul Syazana
Published: March 2019

Artificial pancreas (AP) device consists of continuous subcutaneous insulin infusion (CSII)pump, continuous glucose monitoring (CGM) sensor, CGM receiver amd control algorithm which measure and regulate current blood glucose level (BGL) of type 1 diabetes (T1D) patients in automated manner. All components of the AP device are now well-established and readily avaialble in the market; however, its control algorithm is still at infant stage. This sometimes leads to insufficient or excessive amounts of insulin injected into their body causing hyperglycaemia or hypoglycaemia episodes, respectively. Mathematical equations of Hovorka model were widely used in the control algorithm; however, the model had shown somewhat lacking in terms of interaction and interrelation of selected parameters in its glucose-insulin dynamics. An attempt was made by previous workers to modify certain subsytem equations in the Hovorka model involving glucose, plasma insulin and insulin action subsystems by introducing additional parameters which, in turn, resulted in producing so-called improved Hovorka equations. This study aims to develop a computer algorithm in oder to simulate the BGL of T1D patient during their meal intakes using the improved Hovorka equations via MATLAB and model based predictive control (MPC). Resuls showed that different amounts of administered insulin (Ut) namely; 0.0003 U/min and 0.009 U/min were required to maintain the BGL within normal range (4.5 to 6 mmol/L) when the amounts of meals (DG) taken by the patient were at 57g CHO and 86.5g CHO during lunch and dinner times, respectively. However, the BGL was above the normal range, i.e. hyperglycaemia when DG and Ut were at 32g CHO and 0.035 U/min, respectively during breakfast time. In conclusion, this study has proven that the improved Hovorka equations can be used to simulate the meal disturbance effect on BGL for T1D patients.
Isolation of Antimicrobial Peptide from Food Protein Hydrolysates: An Overview
Authors: Farhana Mashuri Nurul , Tan Huey Ling , Lim Ying Pei , Maqsood-Ul-Haque Siti Noor Suzila
Published: March 2019

Antimicrobial resistance (AMR) is one of the most serious public health threats that results mostly from the selective pressure exerted by antibiotic use and abuse. AMR has become a major problem with global human deaths due to antibiotic resistant infections predicted to reach 10 million by 2050. Antimicrobial peptides (AMPs) has been discovered to have capabilities to kill microorganisms and can take other roles as an alternative to antibiotics which is favorable to the need of minimizing the usage of antibiotics as they lead to the increasing of AMR. AMP can be found naturally in almost all domains of life as part of the innate immune system to combat virus, bacteria, fungi and even cancer cells. It can also be extracted from food proteins using enzymatic hydrolysis. High antimicrobial properties/activities are depend on the degree of hydrolysis (DH) of peptides, peptide source/origin, and type of enzyme used for the hydrolysis process. There are several other variables that can be manipulated to optimum condition to obtain high DH. Variables such as temperature, pH, enzyme concentration and hydrolysis time have proven to bring impact to the DH of peptides. Other bioactive peptides that have been discovered during the process have great potential to bring benefit in medicinal and nutraceutical areas.
Simulation and Optimisation of Anti-Dengue Nutraceutical Drink Production Plant for Medic IG Biopharma
Authors: So’aib Mohamad Sufian , Salihon Jailani
Published: March 2019

Carica papaya leaf (CPL) and Garcinia mangostana pericarp (GMP) are potential anti-dengue nutraceutical drink. Here, its production plant was modelled and optimised using Superpro Designer® simulation software to achieve an economically viable production scheme. Three production schemes were presented. Scheme 1 yielded low ROI (18.07%) and lengthy payback period (5.54 years). Despite doubling the output in scheme 2, the new ROI (27.09%) and payback period (3.69 years) remained unattractive. Staggered configuration of the bottlenecking process (fermentation) yielded Scheme 3; which turned out the most economically viable as indicated by its ROI (49.96%) and payback period (2.26 years).
Stabilisation of Emulsified Agarwood Oil in an Aqueous System Using Non-Ionic Surfactant
Authors: Tien Boon Yih , Naim Mohd Nazli , Zakaria Rabitah , Bakar Noor Fitrah Abu , Ahmad Noraini , Lenggoro Wuled
Published: March 2019

Owing to the annually increasing market value of pure agarwood oil, the extracted agarwood oil from Aquilaria malaccensis was emulsified in an aqueous solution using non-ionic surfactant (Tween 80). The surfactant concentration of 0.0167% was determined as the critical micelle concentration (CMC) with an interfacial tension value of 0.014 mNm-1. The adsorption of surfactant at the oil/water interface at the CMC value, however, reduced the zeta potential of the emulsified oil from –45 to –43 mV, and increased its size from 85 to 89 nm. Outside of the CMC value, the emulsified oil droplets tended to coalesce, owing to insufficient coverage of the surfactant at oil/water interface and Ostwald ripening. The droplet size distribution and zeta potential value of the emulsified oil droplets produced at the CMC were the most stable over a month of storage. No significant changes in the emulsified droplet size occurred when the pH conditions varied from pH 3 to 10. The emulsified droplets images obtained from transmission electron microscopy analysis showed a reduction in the layer thickness of the surfactant from 30 to 10 nm in acidic condition and 30 to 19 nm in alkaline condition. The agarwood oil emulsification at CMC value enhance the stability of chemically unstable compounds from degradation.
Natural Deep Eutectic Solvent (NADES) as a Greener Alternative for the Extraction of Hydrophilic (Polar) and Lipophilic (Non-Polar) Phytonutrients
Authors: Kua Yin Leng , Gan Suyin
Published: March 2019

Phytonutrients extracted from natural resources are receiving much attention among researchers due to their highly antioxidative characteristics which prevent several degenerative diseases including cardiovascular diseases and cancers. These nutraceutical compounds can be used in food, pharmaceutical and cosmetic products as natural antioxidants, preservatives, colourings and functional foods. Though much works have been reported on the extraction process, there are concerns on the health and safety risks posed by the commonly used organic solvents derived from petrochemical industry. Thus, there is a need to recover the phytonutrients using green, sustainable, efficient and low cost solvents that are safe for human consumption. This work discusses natural deep eutectic solvent (NADES) as a potential solvent to extract both polar and non-polar phytonutrients simultaneously from natural resources. Previous attempts (in the most recent 3 years) to make use of NADES as an extractant to obtain phytonutrients are presented. The synthesis process of NADES and current challenges when employing NADES are also being reviewed.
Concerns on Analytical Results Involving Infrared to Microscopic Data Dealing with Ionic Liquids in Pretreatment of Lignocellulosic Biomass
Authors: Azizan Amizon , Mokti Nawwarah , Zaharudin Salwa , Mohd Safaai Nor Sharliza
Published: March 2019

Lignocellulosic biomass containing cellulose, hemicelluloses and lignin is significantly analyzed via methods from infrared to microscopy. These methods help researchers to explore the organic or inorganic functional groups and physical surface impacts microscopically on the particles of the pretreated biomass. Some concerns arise in understanding the data results. An investigation with the presence of ionic liquids on Leucaena Leucocephala (Petai Belalang), Acacia Auriculiformis and Melastoma Malabathricum (Senduduk) are reported via the results of Fourier Transform Infrared Spectrum (FTIR) and Scanning Electron Microscopy (SEM). The model ionic liquids as green solvents used are 1-Ethyl-3-methylimidazolium Acetate (EMIMAc) and 1-Ethyl-3-methylimidazolium Chloride (EMIMCl). This work is very essential to sustain preliminary reliable understanding on the chemical and physical effects on lignocellulosic biomass during pretreatment with solvents.
Characteristic and Erosion Study of Uncoated Sand Proppant Using Impingement Test
Authors: Jarni Husna Hayati , Zin Rohani Mohd , Bakar Noor Fitrah Abu , Rahman Norazah Bt Abdul , Shaari Norin Zamiah Kassim , Othman Nur Hidayati
Published: March 2019

The characterization and properties of sand from beaches in Malaysia that has potential to be used as proppant in hydraulic fracturing was investigated through impingement tests. Eight sand samples were obtained from eight different locations in Malaysia; three samples from West Coastal beaches (Selangor) and five from East Coastal beaches (Kelantan). These impingement tests were conducted by varying several parameters i.e. size ranges of sand, type of targeted metal and distance of nozzle standoff from target. In these tests, air was fed through an acrylic pipe with inner diameter of 8 mm and 4 m length at gas velocity of 100 m/s and flow rate of 200 l/min. 250 g of sand samples were fed in compressed air stream and the samples were projected toward targeted metal i.e. mild steel and aluminium with a 90° of impingement angle. These tests were conducted at different separation distance of 0.5, 2.5 and 5.0 inches of nozzle and target. The results were analysed by measuring the mass loss of the metals after impingement and the images of the impinged metals were captured using camera. The highest metal loss was obtained when the targeted metal was impacted with the largest size range of sand samples. The mass loss of mild steel ranged from 0.03 to 0.16 g and 0.10 to 0.22 g for aluminium, at a variable distance between the nozzle and metal target due to higher hardness of mild steel than aluminium. The mass loss reduced when the distance between nozzle and metal target increased due to energy loss because of the inter particle collision.
Interaction on Standard and Modified Adhesive (Albipox) with Water Using Molecular Modelling
Authors: Sharudin Rahida Wati , Nik Salwani Md Azmi , Zakiah Ahmad
Published: March 2019

Molecular modelling method has been extensively used by process simulators to forecast the expected outcome of certain processes. The objective of this study is to predict the behavior of standard and modified epoxy resins with water using molecular dynamic technique. An arbitrary cell containing adhesive and water molecules was built using the Amorphous Cell Module and dynamic simulation was conducted using Forcite module at two different temperatures; 20 and 50°C for both standard and modified adhesive. From the analysis, the mean square displacement (MSD) for water molecules in a standard adhesive system was higher than Albipox which leads to a higher value of diffusion coefficient. Higher MSD for water in the system with standard adhesive means that it is easier for water molecules to move in the system. It moves to a wider or larger area compared to the water with Albipox in the system. This also shows that the usage of Albipox was successful to control the moisture uptake of water. The predicted diffusion coefficient of water also follows the trend of the experimental data where it increased when the temperature increased for both systems. Based on the result presented in this paper, it has been concluded that molecular modelling was able to predict the interaction of standard and modified adhesive with water.
The Effect of Carboxymethyl Cellulose as Bio Filler on Ionic Conductivity and Physical Property of Waste Cooking Oil Based Polyurethane Composite Polymer Electrolyte
Authors: Tahir Syuhada Mohd , Alias Norhatikah
Published: March 2019

Waste cooking oil (WCO) is an under-utilized, highly abundant raw material from food industry. In this study, WCO was used to prepare solid polymer electrolyte (SPE) films via solvent-free method. WCO was first pretreated and converted into polyol using epoxidation and hydroxylation reaction. Then, WCO-based polyol was combined with diisocyanate, LiCF3SO3 and carboxymethyl cellulose (CMC) to obtain polyurethane SPE films. CMC was added to SPE as bio-filler to observe the effect on ionic conductivity and mechanical properties of SPE. SPE films were characterized using Fourier transformed infrared spectroscopy, electrochemical impedance spectroscopy, x-ray diffraction spectrometer (XRD), differential scanning calorimetry and tensile strength. Addition of CMC resulted in increase of ionic conductivity up to 1.19 x 10-5 S/cm for 15% CMC. The ionic conductivity supported with reduced crystalline peaks intensity in XRD to show that the amorphous nature of SPE increased as more CMC added. Tensile strength also increased with addition of CMC and peaked at 10% CMC (34.17 MPa) due to effective hydrogen bond interaction between CMC and PU or salt. However, increased CMC amount further to 15% reduced tensile strength due to agglomeration of CMC particles. As a conclusion, addition of CMC is a viable method to improve both ionic conductivity and mechanical property of SPE.
Biodegradation Characteristics of Tacca leontopetaloides Thermoplastic Films under Controlled Composting Conditions
Authors: Amin Ainatul Mardhiah Mohd , Sauid Suhaila Mohd
Published: March 2019

This paper represents the biodegradation characterization of thermoplastic starch (TPS) films derived from Tacca leontopetaloides starch; namely thermoplastic starch with glycerol as plasticizer (TPS/GLY), thermoplastic starch with glycerol added with acetic acid (TPS/ACE) and thermoplastic starch with glycerol added with acetic acid with rice husk biochar reinforcement (TPS/BCRH) after aerobic biodegradation under controlled composting conditions. From the experiments, scanning electron micrograph (SEM) of the films showed homogeneous and even surface before the biodegradation but changed into grainy and uneven after subjecting to 45 days of biodegradation. Mechanical properties of all TPS films reduced significantly as expected. Even so, adding rice husk biochar did offer some strength to the TPS formulation. However, Fourier transform infrared (FT-IR) analysis suggested that 45 days of aerobic biodegradation was not capable to alter the chemical structure of the films as the characteristic peaks of all films are quite similar to before the biodegradation took place. The study also found that Aspegillus sp was the degrading TPS microorganism.
Removal of Copper (II) Ion: Effect of Polysulfone Support Thickness
Authors: Shaari Norin Zamiah Kassim , Sulaiman Nurul Aida , Hamdan Soraya Nanis
Published: March 2019

This study was conducted to characterize the industrial wastewater containing Copper (II) ion and to evaluate the effect of different thickness of polysulfone as the support membrane in the fabrication of thin film composite membrane (TFC), on the removal of Copper (II) ion. From the wastewater analysis, it showed that the concentration of copper (II) ion are out of the acceptable range of Environmental Quality (Industrial Effluent) Regulations 2009. For the TFC, the polysulfone support membrane was prepared at two thicknesses, 60μm and 90μm. For each thickness, two formulations of thin layer were coated on it; i) A polymer blend of Polyvinyl Alcohol and Chitosan, and ii) Hybrid membrane as thin layer. Before undergo the treatment process, the pH of the wastewater sample was altered to 7 as the pre-treatment. The final result shows that composite membrane with hybrid membrane as thin layer with 90μm thickness of polysulfone membrane was the best membrane because it could remove 99.67% of copper (II) ion. Finally, the treated water can be discharged to the groundwater because the concentration of copper ion is less than 1 ppm, which it has fulfilled the Environmental Quality regulations. Keywords— Chitosan, Copper ion, composite membrane, hybrid membrane, industrial wastewater
Evaluation of Renewable Methanol Production Plant Design Using Tri-Pressure Stripper Configuration
Authors: Ahmad Mohd Aizad , Nizam Muhammad Fahmi , Rashid Zulkifli Abdul
Published: March 2019

Over the past years in the industry, the emissions of carbon dioxide (CO2) waste into the atmosphere have been rapidly increasing. The carbon capture technology is used in a few power plants to capture CO2 molecules from the flue gas. Researchers have established method to use CO2 and convert into valuable products. Therefore, this study is aim to simulate the reaction between captured CO2 with hydrogen to produce renewable methanol. In order to achieve objective of designing the renewable methanol plant, the Aspen Hysys is used as modelling and simulation tool to obtain about 50k tonnes per year of renewable methanol production. Then, the amount of CO2 is evaluated based on the amount of CO2 in flue gas, CO2 capture and renewable methanol produced. The results of the simulation that obtained is about 16510 kg/h of captured CO2 and 6049 kg/h of methanol produced from the 17936 kg/h of CO2 contained in flue gas. Three different coal-fired power plant capacities have been studied to evaluate their methanol production capacity. A small 110 MW power plant could produce 12705 kg/h of methanol, while 1400 MW and 2420 MW power plant will achieve 161,703 kg/h and 279515 kg/h respectively.
Effect of Electron Beam Irradiation and Ionic Liquid Combined Pretreatment Method on Various Lignocellulosic Biomass
Authors: Jusri Nur Amira Aida , Azizan Amizon , Zain Zuqhair Sherry Zalman , Rahman Abd Mohd Faizal
Published: March 2019

The objective of this study was to characterize the performance of lignocellulosic biomass (LCB) to assess its use as a potential bioethanol or biofuels through pretreatment process. The pretreatment process was performed to remove crystalline structural of biomasses in order to improve enzymatic hydrolysis process. In this work, combined electron beam irradiation and ionic liquid method was used as the pretreatment process for various LCBs such as Gigantochloa albociliata (GA), Leucaena leucocephala (LL), oil palm frond (OPF), acacia and microcrystalline cellulose (MCC) as reference. Irradiation dose was measured through electron beam accelerator over a range of 100-1000 kGy. Ionic liquid (IL) is known as green solvent that can dissolve cellulose. 50% v/v 1-ethyl-3-methylimidazolium acetate (EMIMAc) IL was employed to enhance the effect of irradiation in pretreatment process. The LCBs was analyzed by using two method; Fourier transform infrared (FTIR) and X-ray diffraction (XRD). FTIR result shows different pattern of spectra and peak for each condition. Lateral order index (LOI) based on Beer’s Law was also calculated to determine the changes in structure order after pretretament. For XRD results, the crystallinity index (CrI) of pretreated LCBs was calculated by using Segal’s Equation in order to determine the pattern based on different conditions. The highest percentage of effectiveness showed by pretreated Acacia as the values of LOI and CrI is the lowest compared to other LCBs which is 41.77% and 25.21%, respectively.
Thermo Distillation and Characterization of Bio Oil from Fast Pyrolysis of Palm Kernel Shell (PKS)
Authors: Qarizada Deana , Mohammadian Erfan , Alis Azil Bahari , Yusuf Suriatie Mat , Dollah Aqilah , Rahimi Humapar Azhar , Nazari Ahmad Shah , Azizi Muzhda
Published: March 2019

Thermo distillation of palm kernel shell in a column reactor was studied in this paper. The objective of this research was to characterize the bio oil and bio oil fractions. The maximum yield was around 70 wt% at 120 °C. The bio oil fractions were collected in ten columns at different temperature ranging between 75- 105°C. HHV of bio oil was 26MJ/Kg. The bio oil moisture, volatility, fixed carbon, and ash were determined and found to be around 6.44wt%, 52.72wt%, 24.39wt%, 16.45wt%, respectively. It can be seen that the PKS bio oil can be considered as an alternative fuel. . HHV of bio oil fraction was between 20- 21MJ/Kg, The density of bio oil fraction was 976.54 g/ mL, and pH of bio oil fraction were around of 2.16.
Chlorella sorokiniana: Effect of Nitrate Replete Concentration on Biomass Yield, Cell and Nitrate Concentration
Authors: Zakariah Nor Azalina , Rahman Norazah Bt Abdul , Rahim Noor Amelina Abdul
Published: March 2019

Effect of various nitrate replete concentrations have been investigated in terms of biomass yield, cell and nitrate concentrations. Media used in this study is Bold’s basal medium which contains nitrate that act as nutrient. Its concentrations have been varied for obtaining the high biomass yield. The nitrate concentrations used were 30 mg nitrate/L, 35 mg nitrate/L, 40 mg nitrate/L, 45 mg nitrate/L and 50 mg nitrate/L) with 30 mg nitrate/L as a control. Microalgae Chlorella sp. is cultured and aerated in a Schott bottle with presents of light. Results showed that the best concentration to obtain highest biomass yield was 45 mg nitrate/L. It also gave the highest optical density reading at day 9 with 2.100 ± 0.070 and showed the highest cell concentration with 703 ± 29 x 106 cells/mL. Dry algae produced by this concentration after the end of the cycle was 291 ± 9 mg which was the highest compared to other concentration. It is suggested that as the biomass yield is increased by using 45 mg nitrate/L concentration, other methods to increase lipid content can be paired with nitrate replete method and can be further studied in the future.
Diffusion Coefficient and Interfacial Tension with Addition of Silica Nanoparticles in CO2-Surfactant-Water-Hexane for Enhanced Oil Recovery (EOR) Using Molecular Dynamic Simulation
Authors: Nik Salwani Md Azmi , Rosli Nor Roslina , Tengku Mohd Tengku Amran , Tan Huey Ling , Bakar Noor Fitrah Abu
Published: March 2019

Dynamic simulation for investigating the interactions of molecules that involved carbon dioxide (CO2), sodium dodecyl sulfate (SDS), water (H2O), hexane and silica nanoparticles (SiO2) in terms of diffusion coefficient and interfacial tension (IFT) were conducted at 298 K and 383 K for three different systems which consists of three layers (L1-L2-L3); CO2-water-water/hexane (S1), CO2-water/SDS-water/hexane (S2) and CO2-water/SDS/SiO2-water/hexane (S3). Analyses of the mean square displacement (MSD) showed that higher curve definition was obtained at 383 K than 298 K system, indicates higher mobility of the molecules. The diffusion coefficient of all CO2, SiO2, SDS and hexane molecules in all systems were higher at 383 K than 298 K due to heat supplied that energized the molecules and enhanced their diffusivity at the elevated temperature. The IFT between L1-L2 (I1) and L2-L3 (I2) determined from the pressure tensor data, decreased from 36.3 to 16.13 mN/m and 42.35 to 6.45 mN/m, respectively for S1 with the increment of temperature. Addition of SDS surfactant further decreased the I1 and I2 from 25.67 to 11.83 mN/m and 29.95 to 9.46 mN/m, respectively for S2 when the temperature increased. The IFT reduced significantly from 25.67 to 0.57 mN/m and 29.95 to 1.13 mN/m for I1 and I2, respectively at 298 K with addition of SiO2 into SDS-Water i.e. S3. The addition of SiO2 and SDS further reduced the interfacial tension due to the part taken by SiO2 and SDS in disrupting the closely linked hydrogen bond between water molecules at the interphase.
Investigation on the Impact of an Enhanced Oil Recovery Polymer towards Microbial Growth and Microbial Induced Corrosion Rates
Authors: Hasrizal Abd Rahman , Yaakob Najmiddin
Published: March 2019

Some of the enhanced oil recovery (EOR) techniques involve injection of polymer brine in the formation. Addition of polymer increases the viscosity causing improved sweep efficiency owing to favorable mobility factor. Microbial induced corrosion (MIC) is caused by growth of certain bacterial species in the pipeline system and the reservoir. There is possibility of MIC to occur along the water injection schemes. Sea water is considered bereft of nutrients not allowing much bacterial activity but some sessile consortia may grow on internal line surface and cause corrosion. When the sea water is injected into the formation some anaerobic consortia dominated by sulfate reducing bacteria (SRB) grow in the formation. These bacteria use oxygen present in sulfate for respiration and volatile fatty acids (VFAs) as carbon source. But after some time of water injection the formation may get depleted of VFAs thwarting bacterial growth. This study was taken up to understand impact of EOR polymer on growth of bacterial consortium. A bacterial consortia labelled as consortia II from ATCC which is tough oilfield bacteria consortia was allowed to grow with VFA (lactate or acetate), in absence of VFA and in presence of 1000 ppm of HPAM polymer. Planktonic and sessile counts were monitored over 40 days period. Results from this study showed, microbes utilized the polymer as their secondary nutrient, whenever their preferred nutrient was depleted or insufficient. SRB sessile count which was 102 cells/cm2 in nutrient depleted medium picked up a value of 106 cells/cm2 in presence of polymer. It was observed that the bacteria first utilize the available VFA source, after that a period of lull for about 5 days followed before the growth being picked up.