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Friction 2019年第3期7卷 227-236页

作者： Dayang nor Fatin MAHMUD Mohd Fadzli Bin ABDOLLAH nor Azmmi Bin MASRIPAN noreffendyTAMALDIN Hilmi AMIRUDDIN Faculty of Mechanical Engineering Universiti Teknikal Malaysia MelakaHang Tuah JayaDurian TunggalMelaka76100Malaysia Centre for Advanced Research on Energy Universiti Teknikal Malaysia MelakaHang Tuah JayaDurian TunggalMelaka76100Malaysia

The objective of this work is to investigate the influence of contact pressure and sliding speed on the coefficient of friction and wear of an activated carbon-epoxy composite derived from palm kernel under dry sliding conditions.A wear mode map approach was employed to identify the transitions from mild to severe wear of the *** dry sliding test was executed by utilizing a ball-on-disc tribometer at different contact pressures and sliding speeds with a constant sliding distance and operating *** results showed that,regardless of the sliding speed,the friction coefficient and wear rate of the composite increased drastically when a critical limit of contact pressure is *** for the sliding speed,both the friction coefficient and wear rate increased first and thereafter decreased at a higher speed of 500 rpm.A wear mode map is proposed to classify the boundary from mild to severe wear *** predominant wear failures identified include micro-crack,fine grooves,debonding,delamination,debris,broken carbon,and fracture.

关键词： activated carbon agriculture waste palm kernel friction and wear pressure and speed

Role of toll like-receptor 2 in inflammatory activity of macrophage infected with a recombinant BCG expressing the C-terminus of merozoite surface protein-1 of Plasmodium falciparum

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Asian Pacific Journal of Tropical Biomedicine 2018年第7期8卷 333-339页

作者： nor Munirah Zakaria Rapeah Suppian norazmi Mohd nor nor Fazila Che Mat School of Health Sciences Health Campus Universiti Sains Malaysia

Objective: To investigate the role of toll-like receptor 2(TLR2) in inflammatory activity of macrophage infected with the recombinant Mycobacterium bovis bacillus Calmette-Guerin(rBCG). Methods: Mouse macrophage cell line J774 A.1 was infected with Mycobacterium bovis bacillus Calmette-Guerin(BCG) and rBCG cultures for 48 h in the presence or absence of 10 μg/mL of TLR2 inhibitor. Untreated macrophages were used as a negative control while lipopolysaccharide-stimulated macrophages were used as a positive control. The ability of the macrophage to engulf the BCG and rBCG in the absence or presence of TLR2 inhibitor was assessed using a phagocytic assay, while the production of inflammatory cytokines and nitric oxide by the infected macrophages was evaluated using ELISA and Griess reagent method, while the expression of the inducible nitric oxide synthase was determined using Western blot analysis. Results: The results showed that blocking TLR2 function reduced the phagocytic activity, nitric oxide production and proinflammatory cytokine secretion such as TNF-α, IL-1β and IL-12 p40 as well as inducible nitric oxide synthase expression in the infected macrophages. These data showed the importance of TLR2 in the activation of macrophages following BCG and r BCG infections. Conclusions: Through exploring the immunological mechanism which underlies the protection conferred by the candidate vaccine, this study will improve our understanding of the vaccine candidate's mechanism to protect the host from malaria infection.

关键词： Macrophages Mycobacterium bovis bacillus Calmette-Guerin Plasmodium falciparum Proinflammatory cytokine Toll-like receptor 2

Methane to Liquid Hydrocarbons over Tungsten-ZSM-5 and Tungsten Loaded Cu/ZSM-5 Catalysts

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Journal of Natural Gas Chemistry 2006年第4期15卷 340-347页

作者： Didi Dwi Anggoro nor Aishah Saidina Amin Department of Chemical Engineering University of Diponegoro TembalangSemarang 50239Indonesia Faculty of Chemical and Natural Resources Engineering Universiti Teknologi MalaysiaJohor Bahru 81130Malaysia

Metal containing ZSM-5 can produce higher hydrocarbons in methane oxidation. Many researchers have studied the applicability of HZSM-5 and modify ZSM-5 for methane conversion to liquid hydrocarbons, but their research results still lead to low conversion, low selectivity and low heat resistance. The modified HZSM-5, by loading with tungsten （W）, could enhance its heat resistant performance, and the high reaction temperature （800 ℃） did not lead to a loss of the W component by sublimation. The loading of HZSM-5 with tungsten and copper （Cu） resulted in an increment in the methane conversion as well as CO2 and C5＋ selectivities. In contrast, CO, C2-3 and H2O selectivities were reduced. The process of converting methane to liquid hydrocarbons （C5＋） was dependent on the metal surface area and the acidity of the zeolite. High methane conversion and C5＋ selectivity, and low H20 selectivity are obtained over W/3.0Cu/HZSM.

关键词： methane liquid hydrocarbons HZSM-5 W-ZSM-5 W-Cu/ZSM-5

A Partial Double-Pass S-Band Erbium-Doped Fibre Amplifier

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Chinese Physics Letters 2005年第12期22卷 3080-3082页

作者： Sulaiman Wadi Harun nor Kamilah Saat Harith Ahmad Faculty of Engineering Multimedia University Jalan Multimedia 63100 Cyberjaya Selangor Malaysia Photonics Laboratory Department of Physics University of Malaya 50603 Kuala Lumpur Malaysia

An efficient and low noise short wavelength band erbium-doped fibre amplifier （S-band EDFA） is proposed and demonstrated using double-pass configuration. This amplifier provides a gain of 1500 nm signal as high as 26.9 dB, which is 9.6 dB higher than the two-stage single-pass amplifier. The corresponding noise figure obtained is 7.5 dB, which is of the same level as in the single-pass amplifier and more than 2 dB lower than the previously reported double-pass amplifier [IEIOE Electron. Express 2 （2005） 182]. The gain enhancement is due to the double pass-propagation of the test signal in the second stage, which increases the effective erbium-doped fibre （EDF） length. The low noise is attributed to the optical circulator between EDFs, which prevents the backward amplified spontaneous emission from propagating into the input part of the amplifier. The proposed amplifier is expected to play an important role in the development of a practical S-band EDFA.

关键词： Erbium doped fiber amplifiers

Optimization of Sentiment Analysis Using Teaching-Learning Based Algorithm

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Computers, Materials & Continua 2021年第11期69卷 1783-1799页

作者： Abdullah Muhammad Salwani Abdullah nor Samsiah Sani Center for Artificial Intelligence Technology Faculty of Information Science&TechnologyUniversiti KebangsaanKajang43000Malaysia

Feature selection and sentiment analysis are two common studies that are currently being conducted;consistent with the advancements in computing and growing the use of social *** dimensional or large feature sets is a key issue in sentiment analysis as it can decrease the accuracy of sentiment classification and make it difficult to obtain the optimal subset of the ***,most reviews from social media carry a lot of noise and irrelevant ***,this study proposes a new text-feature selection method that uses a combination of rough set theory(RST)and teaching-learning based optimization(TLBO),which is known as *** framework to develop the proposed RSTLBO includes numerous stages:(1)acquiring the standard datasets(user reviews of six major ***)which are used to validate search result feature selection methods,(2)preprocessing of the dataset using text processing *** involves applying text processing methods from natural language processing techniques,combined with linguistic processing techniques to produce high classification results,(3)employing the RSTLBO method,and(4)using the selected features from the previous process for sentiment classification using the Support Vector Machine(SVM)*** show an improvement in sentiment analysis when combining natural language processing with linguistic processing for text *** importantly,the proposed RSTLBO feature selection algorithm is able to produce an improved sentiment analysis.

关键词： Feature selection sentiment analysis rough set theory teachinglearning optimization algorithms text processing

Beamforming techniques for massive MIMO systems in 5G:overview,classification,and trends for future research

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Frontiers of Information Technology & Electronic Engineering 2017年第6期18卷 753-772页

作者： Ehab ALI Mahamod ISMAIL Rosdiadee norDIN nor Fadzilah ABDULAH Department of Electrical Electronic and System EngineeringUniversiti Kebangsaan Malaysia(UKM)Bangi 43600Malaysia

Massive multiple-input multiple-output(MIMO) systems combined with beamforming antenna array technologies are expected to play a key role in next-generation wireless communication systems(5G), which will be deployed in 2020 and beyond. The main objective of this review paper is to discuss the state-of-the-art research on the most favourable types of beamforming techniques that can be deployed in massive MIMO systems and to clarify the importance of beamforming techniques in massive MIMO systems for eliminating and resolving the many technical hitches that massive MIMO system implementation faces. Classifications of optimal beamforming techniques that are used in wireless communication systems are reviewed in detail to determine which techniques are more suitable for deployment in massive MIMO systems to improve system throughput and reduce intra-and inter-cell interference. To overcome the limitations in the literature, we have suggested an optimal beamforming technique that can provide the highest performance in massive MIMO systems, satisfying the requirements of next-generation wireless communication systems.

关键词： Beamforming classifications Massive MIMO Hybrid beamforming Millimetre-wave beamforming

Characterization of bio-coal briquettes blended from low quality coal and biomass waste treated by Garant■bio-activator and its application for fuel combustion

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International Journal of Coal Science & Technology 2020年第4期7卷 796-806页

作者： Anggoro Tri Mursito Widodo Danang nor Arifin Research Centre for Geotechnology Indonesian Institute of Sciences(LIPI)Jl.Sangkuriang Komplek LIPIGd.70Bandung 40135Indonesia Assessment Unit for Mining Engineering Jampang Kulon.Indonesian Institute of Sciences(LIPI) Jl.CihaurSimpenan.SukabumiIndonesia

Experimental research was carried out on the manufacturing of bio-coal briquettes from a blend of two different types of low-quality coal and biomass waste in the absence of coal carbonization,where the third blend of the material was fermented by adding a bio-activator solution before pressurizing the components into *** coal samples from Caringin-Garut Regency(BB-Garut)had a low calorific value and a high sulfur content(6.57 wt%),whereas the coal samples from Bayah-Lebak Regency(BB-Bayah)had a higher calorific value and a lower sulfur content(0.51 wt%).The biomass added to the coal blend is in the form of fermented cow dung(Bio-Kohe),and it had a calorific value of 4192 kcal/kg and a total sulfur content of 1.56 wt%.The main objective of this study is to determine the total decrease in the sulfur content in a blend of coal and biomass in which a fennentation process was carried out using a bio-activator for 24 *** used bio-activator was made from Garant■(1:40)+molasses 1 wt%/vol,and its used amount was 0.2 L/***,the total sulfur content in the blend was 1.00 wt%-1.14 wt%,which fulfills the necessary quality requirements for non-carbonized bio-coal *** pyritic and sulfate content in the raw coal was dominant,and the organic sulfur,when fermented with Garant■,was found to be less in the produced bio-coal briquettes by 38%-58%.

关键词： Coal blending Biomass waste Fermentation Briquettes material Combustion properties

Traumatic optic neuropathy:a review of 24 patients

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International Journal of Ophthalmology(English edition) 2010年第2期3卷 175-178页

作者： Kok Foo Lee nor Idahriani Muhd nor Azhany Yaakub Wan Hazabbah Wan Hitam Department of Ophthalmology School of Medical SciencesUniversiti Sains MalaysiaHealth Campus16150 Kubang KerianKelantanMalaysia

AIMTo evaluate the clinical presentations of traumatic optic neuropathy and to assess the visual outcome of three groups of patients managed differently (conservative, intravenous corticosteroids only and combination ... 详细信息

关键词： traumatic optic neuropathy orbital fractures corticosteroids

Screening of MgO- and CeO_2-Based Catalysts for Carbon Dioxide Oxidative Coupling of Methane to C_(2+) Hydrocarbons

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Journal of Natural Gas Chemistry 2004年第1期13卷 23-35页

作者： Istadi nor Aishah Saidina Amin Chemical Reaction Engineering Group(CREG) Faculty of Chemical and Natural Resources EngineeringUnivevsiti Teknologi MalaysiaUTM SkudaiJohor Bahru81310 Malaysia

The catalyst screening tests for carbon dioxide oxidative coupling of methane (CO2-OCM) have been investigated over ternary and binary metal oxide catalysts. The catalysts are prepared by doping MgO- and CeO2-based solids with oxides from alkali (Li2O), alkaline earth (CaO), and transition metal groups (WO3 or MnO). The presence of the peroxide (O2-2) active sites on the Li2O2, revealed by Raman spectroscopy, may be the key factor in the enhanced performance of some of the Li2O/MgO catalysts. The high reducibility of the CeO2 catalyst, an important factor in the CO2-OCM catalyst activity, may be enhanced by the presence of manganese oxide species. The manganese oxide species increases oxygen mobility and oxygen vacancies in the CeO2 catalyst. Raman and Fourier Transform Infra Red (FT-IR) spectroscopies revealed the presence of lattice vibrations of metal-oxygen bondings and active sites in which the peaks corresponding to the bulk crystalline structures of Li2O, CaO, WO3 and MnO are detected. The performance of 5%MnO/15%CaO/CeO2 catalyst is the most potential among the CeO2-based catalysts, although lower than the 2%Li2O/MgO catalyst. The 2%Li2O/MgO catalyst showed the most promising C2+ hydrocarbons selectivity and yield at 98.0% and 5.7%, respectively.

关键词： catalyst screening carbon dioxide oxidative coupling methane ternary metal oxide binary metal oxide MgO CeO2 C2+ hydrocarbons

Acute paralysis viruses of the honey bee

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Virologica Sinica 2014年第5期29卷 324-326页

作者： Chunsheng Hou nor Chejanovsky Entomology Department Institute of Plant Protection The Volcani Center

The alarming decline of honey bee(Apis mellifera)colonies in the last decade drove the attention and research to several pathogens of the honey bee including *** challenge the development of healthy and robust colonies since they manage to prevail in an asymptomatic mode and reemerge in acute infections following external stresses,as well as they are able to infect new healthy colonies(de Miranda J R,et al.,2010a;de Miranda J R,et al.,2010b;Di Prisco G,et al.,2013;Nazzi F,et al.,2012;Yang X L,et al.,2005).

关键词： honey Miranda mellifera paralysis Apis prevail challenge infect asymptomatic decline