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Comparative study of natural chemical for enhanced oil recovery: Focus on extraction and adsorption at quartz sand surface

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Petroleum 2023年第1期9卷 83-93页

作者： Azza Hashim Abbas Ramzi A.Abd Alsaheb jaafar Kamil abdullah School of Mining and Geosciences Nazarbayev UniversityKazakhstan Al-khwarizmi College of Engineering University of BaghdadIraq Basrah University College of Science and Technology Iraq

In chemical enhanced oil recovery(CEOR),it is very important to utilize the excessive usage of chemicals.A great opportunity lies in adopting natural surfactants,since it is cheaper,ecosystem friendly,and less toxic than their counterpart synthetic *** the availability of natural surfactant sources,it is yet very early to decide on their ***,this research focuses on natural-saponin extracted from different raw materials available in the Middle East and their interaction with quartz-sand.A special focus was given to the adsorption isotherm models to describe the interaction with the reservoir *** raw materials were investigated are fenugreek,sugar beet leaves and *** main extraction method employed was the chemical extraction using the *** study used Uv–vis spectrometer to investigate the micellization behaviour and the consequent adsorption on *** presence of triterpenoid saponin is found dominant in all the sample,the intensity and purity differed according to the raw material *** critical micelle concentration(CMC)was at a close range of 4–5.5 wt%in all the *** highest adsorption was obtained by sugar beet leaves which is 192 g/*** is 25%and 37%higher than the Fenugreek and chickpeas,*** the salinity resulted in adsorption reduction between 2%and 56%.For the adsorption isotherms,it showed good agreement with the Langmuir model *** remarkable finding is that the sugar beet leaves heterogeneous model seems to be valid by Frendluich and Halsey isotherms.

关键词： Natural surfactants Quartz Adsorption isotherm Salinity Fenugreek Sugar beet leaves Chickpeas

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An Optical Based Biosensor for the Determination of Ammonium in Aqueous Environment

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American Journal of Analytical Chemistry 2012年第5期3卷 364-370页

作者： Nur Ellina Azmi jaafar abdullah Musa Ahmad Hamidah Sidek Lee Yook Heng Samsulida Abd Rahman Industrial Biotechnology Research Centre SIRIM Berhad Shah Alam Malaysia Industrial Biotechnology Research Centre SIRIM Berhad Shah Alam Malaysia. School of Chemical Sciences and Food Technology Faculty of Sciences and Technology Universiti Kebangsaan Malaysia Bangi Malaysia. School of Chemical Sciences and Food Technology Faculty of Sciences and Technology Universiti Kebangsaan Malaysia Bangi Malaysia.

A simple and rapid optical biosensor for the determination of ammonium was developed by immobilization of gluta-mate dehydrogenase (GLDH) and diaphorase (Dph) in chitosan film coated on a glass slide employing thiazolyl blue tetrazolium bromide (MTT) as a color indicator. The developed biosensor displays a purple color formation of formazan attributed to the unreacted NADH in the reaction system in the presence of ammonium. The color intensity was found to decrease proportionally with the increase of ammonium concentrations after 10 min exposure. The linearity of the biosensor towards ammonium was in the range of 16.8 – 70 μM (R2 = 0.9955) with detection limit of 11 μM. A good agreement (R2 = 0.9984) with indothymol method was obtained in the measurement of fish pond water samples. The effect of potential interferences such as metals ion has also been evaluated.

关键词： Optical Biosensor Glutamate Dehydrogenase Diaphorase Ammonium

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Ampullary carcinoma:Effect of preoperative biliary drainage on surgical outcome

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World Journal of Gastroenterology 2009年第23期15卷 2908-2912页

作者： Sheikh Anwar abdullah Tarun Gupta Khairul Azhar jaafar Yaw Fui Alexander Chung London Lucien Peng Jin Ooi Steven Joseph Mesenas Department of Gastroenterology and Hepatology Singapore General Hospital 169608 Singapore Department of Surgery Singapore General Hospital 169608 Singapore

AIM： To evaluate the influence of preoperative biliary drainage on morbidity and mortality after surgical resection for ampullary carcinoma.METHODS： We analyzed retrospectively data for 82 patients who underwent potentially curative surgery for ampullary carcinoma between September 1993 and July 2007 at the Singapore General Hospital, a tertiary referral hospital. Diagnosis of ampullary carcinoma was confirmed histologically. Thirty-five patients underwent preoperative biliary drainage （PBD group）, and 47 were not drained （non-PBD group）. The mode of biliary drainage was endoscopic retrograde cholanoiopancreatography （n = 33） or percutaneous biliary drainage （n = 2）. The following parameters were analyzed： wound infection, intra-abdominal abscess, intra-abdominal or gastrointestinal bleeding, septicemia, biliary or pancreatic leakage, pancreatitis, gastroparesis, and re-operation rate. Mortality was assessed at 30 d （hospital mortality） and also longterm. The statistical endpoint of this study was patient survival after surgery.RESULTS： The groups were well matched for demographic criteria, clinical presentation and operative characteristics, except for lower hemoglobin in the non- PBD group （10.9 ± 1.6 vs 11.8 ± 1.6 in the PBD group）.Of the parameters assessing postoperative morbidity, incidence of wound infection was significantly less in the PBD than the non-PBD group [1 （2.9%） vs 12 （25.5%）]. However, the rest of the parameters did not differ significantly between the groups, i.e. sepsis [10 （28.6%） vs 14 （29.8%）], intra-abdominal bleeding [1 （2.9%） vs 5 （10.6%）], intra-abdominal abscess [1 （2.9%） vs 8 （17%）], gastrointestinal bleeding [3 （8.6%） vs 5 （10.6%）], pancreatic leakage [2 （5.7%） vs 3 （6.4%）], biliary leakage [2 （5.7%） vs 3 （6.4%）], pancreatitis [2 （5.7%） vs 2 （4.3%）], gastroparesis [6 （17.1%） vs 10 （21.3%）], need for blood transfusion [10 （28.6%） vs 17 （36.2%）] and re-operation rate [1 （2.9%） vs 5 （10.6%）]. There was no early mortality in either gr

关键词： Ampullary carcinoma Preoperative biliarydrainage Postoperative complications

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Eco-friendly method for synthesis of zeolitic imidazolate framework 8 decorated graphene oxide for antibacterial activity enhancement

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Particuology 2020年第2期18卷 24-32页

作者： Nazerah Ahmad Nik Abdul Hadi Md Nordin Juhana jaafar Nik Ahmad Nizam Nik Malek Ahmad Fauzi Ismail Muhammad Nabil Fikri Yahya Siti Aishah Mohd Hanim Mohd Sohaimi abdullah Advanced Membrane Technology Research Centre Universiti Teknologi Malaysia81310 SkudaiJohorMalaysia Malaysian Institute of Chemical Engineering Technology-Universiti Kuala Lumpur Lot 1988Bandar VendorTaboh Naning78000 Alor GajahMelakaMalaysia Chemical Engineering Department Universiti Teknologi PETRONAS32610 Seri IskandarPerakMalaysia Department of Biosciences Faculty of ScienceUniversiti Teknologi Malaysia81310 SkudaiJohorMalaysia Centre for Student Innovation and Technology Entrepreneurship Universiti Teknologi Malaysia81310 SkudaiJohorMalaysia

We report a rapid method for synthesis of zeolitic imidazolate framework 8(ZIF-8)-decorated graphene oxide(GO)composites(ZGO)with good antibacterial *** ZGO composites were synthesized at room temperature with low GO to metal salt *** samples were characterized by X-ray diffraction,transmission electron microscopy,Fourier transform infrared spectroscopy,thermal gravimetric analysis,and surface area *** characterization results show that ZIF-8 with a size of approximately 120 nm is successfully decorated on the surface of GO sheets with the host ZIF-8 framework maintained in the synthesized composite,but there is a significant reduction in the Brunauer-Emmett-Teller surface *** antibacterial activities of the samples against Escherichia coli ATCC 11229 and Staphylococcus aureus ATCC 6538 as model strains of gram-negative and-positive bacteria,respectively,were determined by disc diffusion and minimum inhibitory concentration(MIC)***-1.0(1 wt%of ratio of GO to metal salt)shows the highest antibacterial activity with MIC values required to inhibit bacterial growth of *** and *** of 5 times lower than those of pristine *** antibacterial mechanisms are proposed based on field-emission scanning electron microscope images of the two bacteria after contact with the synthesized ***,owing to the simple synthesis,good stability,low chemical usage,and excellent antibacterial activity of the ZGO composites,they show great potential for application in the field of microbial contamination control.

关键词： Graphene oxide Metal-organic framework Hybrid nanocomposite Zeolitic imidazolate framework Antibacterial agent

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Selective metal leaching from technosols based on synthetic root exudate composition

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Journal of Environmental Sciences 2020年第10期32卷 85-92页

作者： Hussein jaafar Kanbar Zeinab Matar Ghina Abed-AlHadi Safa Veronique Kazpard Research and Aralysis Platform for Enuironmental Sciences(PRASE) Doctoral School of Sciences and Techrology(EDST)The Lebanese UniversityP.O.5Rafic Hariri CampusHadatLebanon Department of Chemistry UmeàUniversitySE-90187UmeàSweden Department of Earth and Life Sciences Faculty of SciencesThe Lebanese UniversityRafic Hariri CampusHadatLebanon Laboratory of Georesources Geosciences and Enuironment(1.2GE)Faculty of SciencesThe Lebanese UniversityFanarLebanon

This study focused on metal release from technosols induced by synthetic root exudate(SRE).The effect of SRE composition on metal release was studied using six *** was done by treating the technosols with SRE solutions having varying concentrations of low molecular weight organic acids (LMWOAs),namely oxalic,citric,and malic ***,the physico-chemical parameters (p H and electric conductivity),Ca,Mg,Fe,Zn,and Cu release (by atomic absorption spectroscopy,AAS),chemical changes (by Fourier transform infrared,FT-IR),and organic parameters (by fluorescence) were *** release showed to be dependent on the SRE composition and technosol *** acid selectively released Ca,Mg,Zn,and Cu from technosols in a concentration-dependent manner;oxalic acid showed a significant role in the release of Mg and *** relatively high LMWOA concentrations,particulate organo-mineral complexes ***,technosol weathering was seen by the dissolution of humic substances and ferriallophanes,which in turn caused metal ***,re-precipitation of these phases showed to re-sorb metals,thus underestimating the role of LMWOAs in metal ***,the selective metal leaching was highly dependent on the SRE composition and LMWOA concentrations on one hand,and on the mineral,organic,and organo-mineral components of the technosols on the *** understanding of such processes is crucial for proposing and implementing environmental management strategies to reduce metal leaching or for the beneficial re-usage of metals (e.g.,for agromining) from technosols.

关键词： Technosols Oxalic acid Citric acid Metals Desorption Organo-mineral complexes

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Reduction of Backscattered Radiation in an X-Ray Room by Using Fabricated Iron Steel Grid

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Advances in Materials Physics and Chemistry 2013年第3期3卷 191-193页

作者： abdullah Taher Qaed Naji Mohamad Suhaimi jaafar School of Physics Universiti Sains Malaysia Pulau Pinang Malaysia

This study aims to improve a way for reducing backscattered radiation in an X-ray room. An iron steel grid, capable to absorb a significant portion of the backscattered radiation, was used. X-ray machine as a source for radiation was directed normally on the phantom, and the backscattered radiation was measured by using ion chamber. The measurements were recorded at various applied voltages (60 kvp to 120 kvp) and the fabricated grid was designed from iron steel constructed of perpendicular parallel strips mounted on a base. The results indicated that the use of iron steel grid was very effective in the reduction of backscattered radiation in an X-ray room up to about 46% by using fabricated iron steel grid.

关键词： Reduction Backscattered Radiation X-Ray Iron Steel Grid

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Microscopy Observations of Habitable Space in Biochar for Colonization by Fungal Hyphae From Soil

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Journal of Integrative Agriculture 2014年第3期13卷 483-490页

作者： Noraini M jaafar Peta L Clode Lynette K Abbott Soil Biology and Molecular Ecology Group School of Earth and Environment and UWA Institute of Agriculture The University of Western Australia Department of Land Management Faculty of Agriculture Universiti Putra Malaysia Centre for Microscopy Characterisation and Analysis The University of Western Australia

Biochar is a potential micro-environment for soil microorganisms but evidence to support this suggestion is limited. We explored imaging techniques to visualize and quantify fungal colonization of habitable spaces in a biochar made from a woody feedstock. In addition to characterization of the biochar, it was necessary to optimize preparation and observation methodologies for examining fungal colonization of the biochar. Biochar surfaces and pores were investigated using several microscopy techniques. Biochar particles were compared in soilless media and after deposition in soil. Scanning electron microscopy （SEM） observations and characterization of the biochar demonstrated structural heterogeneity within and among biochar particles. Fungal colonization in and on biochar particles was observed using light, fluorescence and electron microscopy. Fluorescent brightener RR 2200 was more effective than Calcofluor White as a hyphal stain. Biochar retrieved from soil and observed using fluorescence microscopy exhibited distinct hyphal networks on external biochar surfaces. The extent of hyphal colonization of biochar incubated in soil was much less than for biochar artificially inoculated with fungi in a soilless medium. The location of fungal hyphae was more clearly visible using SEM than with fluorescence microscopy. Observations of biochar particles colonized by hyphae from soil posed a range of difficulties including obstruction by the presence of soil particles on biochar surfaces and inside pores. Extensive hyphal colonization of the surface of the biochar in the soilless medium contrasted with limited hyphal colonization of pores within the biochar. Both visualization and quantification of hyphal colonization of surfaces and pores of biochar were restricted by two-dimensional imaging associated with uneven biochar surfaces and variable biochar pore structure. There was very little colonization ofbiochar from hyphae in the agricultural soil used in this study.

关键词： biochar agriculture fungi soil habitable pore space microscopy

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Cardiovascular Disease Prediction Among the Malaysian Cohort Participants Using Electrocardiogram

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Computers, Materials & Continua 2022年第4期71卷 1111-1132页

作者： Mohd Zubir Suboh Nazrul Anuar Nayan Noraidatulakma abdullah Nurul Ain Mhd Yusof Mariatul Akma Hamid Azwa Shawani Kamalul Arinfin Syakila Mohd Abd Daud Mohd Arman Kamaruddin Rosmina jaafar Rahman Jamal Faculty of Engineering and Built Environment Universiti Kebangsaan MalaysiaBangi43600Malaysia Medical Engineering Technology Section Universiti Kuala Lumpur British Malaysian InstituteGombak53100Malaysia Institut Islam Hadhari Universiti Kebangsaan MalaysiaBangi43600Malaysia UKM Medical Molecular Biology Institute(UMBI) Kuala Lumpur56000Malaysia Faculty of Health Sciences Universiti Kebangsaan MalaysiaBangi43600Malaysia

A comprehensive study was conducted to differentiate cardiovascular disease (CVD) subjects from non-CVD subjects using short recording electrocardiogram (ECG) of 244 Malaysian adults in The MalaysianCohort project. An automated peak detection algorithm to detect nine fiducialpoints of electrocardiogram (ECG) was developed. Forty-eight features wereextracted in both time and frequency domains, including statistical featuresobtained from heart rate variability and Poincare plot analysis. These includefive new features derived from spectrum counts of five different frequencyranges. Feature selection was then made based on p-value and correlationmatrix. Selected features were used as input for five classifiers of artificialneural network (ANN), k-nearest neighbors (kNN), support vector machine(SVM), discriminant analysis (DA), and decision tree (DT). Results showedthat six features related to T wave were statistically significant in distinguishingCVD and non-CVD groups. ANN had performed the best with 94.44% specificity and 86.3% accuracy, followed by kNN with 80.56% specificity, 86.49%sensitivity and 83.56% accuracy. The novelties of this study were in providingalternative solutions to detect P-onset, P-offset, T-offset as well as QRS-onsetpoints using discrete wavelet transform method. Additionally, two out of thefive newly proposed spectral features were significant in differentiating bothgroups, at frequency ranges of 1–10 Hz and 5–10 Hz. The prediction outcomeswere also comparable to previous related studies and significantly importantin using ECG to predict cardiac-related events among CVD and non-CVDsubjects in the Malaysian population.

关键词： Cardiovascular disease ECG fiducial point detection electrocardiogram feature extraction machine learning

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Gender-Based Analysis of User Reactions to Facebook Posts

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Big Data Mining and Analytics 2024年第1期7卷 75-86页

作者： Yassine El Moudene jaafar Idrais Rida El Abassi Abderrahim Sabour Mathematical Engineering and Computer Science Laboratory Faculty of SciencesIbn Zohr UniversityAgadir 8706Morocco Department of Computer Science Mathematical−High School of Technology Ibn Zohr UniversityAgadir 8706Morocco

Online Social Networks(OSNs)are based on the sharing of different types of information and on various interactions(comments,reactions,and sharing).One of these important actions is the emotional reaction to the *** diversity of reaction types available on Facebook(namely FB)enables users to express their feelings,and its traceability creates and enriches the users’emotional identity in the virtual *** paper is based on the analysis of 119875012 FB reactions(Like,Love,Haha,Wow,Sad,Angry,Thankful,and Pride)made at multiple levels(publications,comments,and sub-comments)to study and classify the users’emotional behavior,visualize the distribution of different types of reactions,and analyze the gender impact on emotion *** of these can be achieved by addressing these research questions:who reacts the most?Which emotion is the most expressed?

关键词： profiling knowledge extraction data mining emotion mining social media data crawling Facebook reactions gender

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Cost Optimized Non-Contacting Experimental Modal Analysis Using a Smartphone

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Sound & Vibration 2020年第4期54卷 225-236页

作者： jaafar Hallal Mohammad Hammoud Mahmoud Fakih Ali Hallal Mechanical Engineering Department Faculty of EngineeringLebanese UniversityBeirutLebanon SDM Research Group Mechanical Engineering DepartmentInternational University of BeirutBeirutLebanon Mechanical Engineering Department Lebanese International UniversityBekaaLebanon Civil Engineering Department Faculty of EngineeringLebanese UniversityBeirutLebanon

The vibrations behavior analysis is an essential step in the mechanical design *** methods such as analytical modelling,numerical analysis and experimental measurements can be used for this ***,the numerical or analytical models should be validated through experimental measurements,usually *** paper introduces an inexpensive smartphone as an accurate,non-intrusive vibrations’behavior measurement *** experimental measurement procedure based on the video processing method is *** procedure allows the measurement of the natural frequencies and the mode shapes of a vibrating structure,simply by using a smartphone built-in *** experimental results are compared to those obtained using an accurate analytical model,where the natural frequencies error is less than 2.7%and the modal assurance criterion is higher than *** order to highlight the obtained results,a comparison has been done using a high quality and high frame per second(fps)camera-based measurement of material *** the highest recovered natural frequency and its associated mode shape depend on the frame per second rate of the recorded video,this procedure has great potential in low frequencies problems such as for big structures like buildings and *** validated technique re-introduces the personal smartphone as an accurate inexpensive non-contacting vibration measurement tool.

关键词： Experimental measurement motion magnification smartphone vibrations mode shape natural frequency

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