bluuebunny/crossref_metadata_2025_split huggingface dataset:
Numerical Study of Laminar Forced Convection of Water/Al2o3 Nanofluid in an Annulus with Constant Wall Temperature
Authors: Kashani Amin , Jalali-vahid Davood , Hossainpour Siamak 
Published: October 2018

Laminar forced convection of a nanofluid consisting of water and Al2O3 in a horizontal annulus has been studied numerically. Two-phase mixture model has been used to investigate thermal behaviors of the nanofluid over constant temperature thermal boundary condition and with different volume concentration of nanoparticles. Comparisons with previously published experimental and analytical works on flow behavior in horizontal annulus show good agreements between the results as volume fraction is zero. In general convective heat transfer coefficient increases with nanoparticle concentration.Â ABSTRAK: Kertaskerja ini mengkaji secara numerik olakan paksa bendalir lamina yang menganduangi air dan Al2O3 didalam anulus mendatar. Model campuran dua fasa digunakan bagi mengkaji tingkah laku haba bendalir nano pada keadaan suhu malar dengan kepekatan nanopartikel berbeza. Perbandingan dengan karya eksperimen dan analitikal yang telah diterbitkan menunjukkan bahawa kelakuan aliran didalm anulus mendatar adalah baik apabila pecahan isipadu adalah sifar. Pada amnya, pekali pemindahan haba olakan meningkat dengan kepekatan nanopartikel.Â KEYWORDS: nanofluid; volume concentration; heat transfer enhancement; laminar flow convection; annulus
A Technique for Designing Variation Resilient Subthreshold Sram Cell
Authors: Islam Aminul 
Published: October 2018

This paper presents a technique for designing a variability aware subthreshold SRAM cell. The architecture of the proposed cell is similar to the standard read-decoupled 8-transistor (RD8T) SRAM cell with the exception that the access FETS are replaced with transmission gates (TGs). In this work, various design metrics are assessed and compared with RD8T SRAM cell. The proposed design offers 2.14× and 1.75× improvement in TRA (read access time) and TWA (write access time) respectively compared with RD8T. It proves its robustness against process variations by featuring narrower spread in TRA distribution (2.35×) and TWA distribution (3.79×) compared with RD8T. The proposed bitcell offers 1.16× higher read current (IREAD) and 1.64× lower bitline leakage current (ILEAK) respectively compared with RD8T. It also shows its robustness by offering 1.34× (1.58×) tighter spread in IREAD (ILEAK) compared with RD8T. It exhibits 1.42× larger IREAD to ILEAK ratio. It shows 2.2× higher frequency @ 250 mV with read bitline capacitance of 10 fF. Besides, the proposed bitcell achieves same read stability and write-ability as that of RD8T at the cost of 3 extra transistors. The leakage power of the proposed design is close to that of RD8T. ABSTRAK: Kertas kerja ini membentangkan teknik merekabentuk sel bawah ambang SRAM yang bolehubah. Senibina sel yang dicadangkan adalah sama dengan sel SRAM 8-transistor (RD8T) “pisahan-bacaan” piawai kecuali FET akses digantikan dengan sel pintu transmisi (TGs). Di dalam kajian ini, beberapa metrik rekabentuk dinilai dan dibandingkan dengan sel RD8T SRAM. Rekabentuk yang dicadangkan menawarkan peningkatan 2.14× dan 1.75× dalam TRA (masa akses baca) dan TWA (masa akses tulis) berbanding dengan RD8T. Ia membuktikan kekukuhan variasi proses dengan menampilkan tebaran yang lebih sempit dalam pengagihan TRA (2.35 ×) dan pengagihan TWA (3.79 ×) berbanding dengan RD8T. Sel-Bit yang dicadangkan mempunyai arus baca 1.16 × lebih tinggi (IREAD) dan arus bocor bitline 1.64 × lebih rendah (ILEAK) berbanding dengan RD8T. Ia juga membuktikan kekukuhan dengan menawarkan 1.34 × (1.58 ×) penyebaran sempit di IREAD (ILEAK) berbanding dengan RD8T dan nisbah IREAD / ILEAK 1.42 × lebih besar. Ia menunjukkan kekerapan 2.2 × lebih tinggi pada 250 mV dengan kemuatan membaca bitline sebanyak 10 fF. Selain itu, sel bit yang dicadangkan mencapai kestabilan membaca dan keupayaan menulis yang sama seperti RD8T dengan kos tambahan 3 transistor. Kebocoran kuasa rekabentuk yang dicadangkan hampir sama dengan RD8T. KEYWORDS: variability; robust, subthreshold; random dopant fluctuation (RDF); read static noise margin (RSNM); write static noise margin (WSNM).
INVESTIGATION OF GEOTECHNICAL SPECIFICATIONS OF SAND DUNE SOIL: A CASE STUDY AROUND BAIJI IN IRAQ
Authors: Al-Taie Abbas J. , Al-Shakarchi Yousif J. , Mohammed Ali A 
Published: October 2018

ABSTRACT:Â While more than half the land surface of Iraq consists of deserts covered mainly with sand dunes, little research has taken place to study the characteristics and the behavior of dune soils. This paper directed toward studying the geotechnical properties of dune sands taken from Baiji city (northwest of Iraq). A vast laboratory testing program was carried out to achieve the purpose of this paper. The physical tests, chemical tests, X-ray diffraction analysis, permeability test, compaction characteristics, compressibility and collapsibility tests; and shear strength tests were included in this program. The results indicate that soil of Baiji sand dune exhibits prefer engineering properties according to their state. As such, this soil is considered suitable for use in geotechnical constructions.Â ABSTRAK: Walaupun lebih separuh daripada bumi Iraq terdiri daripada gurun yang dipenuhi dengan bukit-bukit pasir, tidak banyak penyelidikan dijalankan untuk mengkaji sifat-sifat dan ciri-ciri tanah pasirÂ tersebut. Kertas kerja ini menyelidik sifat geoteknikal bukit pasir yang diambil dari pekan Baiji (di bahagian barat utara Iraq).Â Program penyelidikan makmal yang menyeluruh telahÂ dijalankan bagi mencapai objektif kajian ini. Ujian fizikal, ujian kimia, analisis belauan sinar-x, ujian kebolehtelapan, ciri pemadatan, faktor ketermampatan, ujian keruntuhan dan ujian kekuatan ricih diambilkira dalam program ini. Keputusan menunjukkan bahawa tanih bukit pasir Baiji mengutamakan ciri kejuruteraan berdasarkan keadaannya. Oleh itu, tanah ini dianggap sesuai untuk kegunaan pembinaan geoteknikal.
BLANKET REPRESENTATION AND EXPEDIENT OF DISINFECTING WATER USING PULSING ELECTROMAGNETIC FIELD
Authors: Ozoda Ibragimova , Abdulhak Khalikov 
Published: October 2018

ABSTRACT:Â Â The paper deals with comparative analysis of existing expedients and devices of disinfecting water, spots ways of the solution and a new method ofÂ water purification using electromagnetic field applied in a cross wise direction.Â ABSTRAK: Dalam operasi, analisis perbandingan dijalankan bagi menentukanÂ kesesuaian yang sedia ada dan alatan untuk menyahjangkit air. Dengan mengaplikasikan medan magnet lintang, penyelesaian masalah dikenal pasti dengan meningkatkan kemagnetan terhadap medan elektromagnet ke atas air.
REVIEW OF PASSIVE DRAG REDUCTION TECHNIQUES FOR BLUFF ROAD VEHICLES
Authors: Altaf Alaman , Omar Ashraf A. , Asrar Waqar 
Published: October 2018

ABSTRACT:This paper presents a review of the techniques used to reduce aerodynamic drag over bluff bodies such as cylinders, spheres, 2D bodies with blunt backs and their application to commercial road vehicles.Â The recent research carried out on the drag reduction is presented and categorised. A new classification of the techniques is introduced and major contributions under them are shown. It can be concluded that there is not much work done with realistic 3D bluff bodies, especially using passive methods.ABSTRAK: Kertas kerja ini membentangkan kaji selidik semula teknik yang digunakan untuk mengurangkan seret aerodinamik ke atas jasad tubir seperti silinder, sfera, jasad 2D dengan belakang tumpul dan aplikasinya terhadap kenderaan jalan raya komersial. Pengurangan seretan dibentangkan dan dikategorikan dengan kajian terkini. Klasifikasi teknik terkini diperkenalkan dan sumbangan utamanya diperbentangkan.Â Secara kesimpulannya terdapat banyak tugasan yang tidak yang dapat dijalankan dengan menggunakan jasad tubir 3D sebenar, terutamanya dengan penggunaan kaedah pasif.
INVESTIGATION OF GLASS PLATE FAILURE MECHANISM SUBJECTED TO COPPER AND STEEL PROJECTILE IMPACTS
Authors: Shah Qasim H. , Aung Kyaw M. 
Published: October 2018

ABSTRACT: A glass plate was subjected to impact by spherical copper and steel projectiles at low velocities. The glass failure features consisted of a central Hertzian cone made up of comminuted glass and a spider web like cracking pattern around the cone with circumferential and radial cracks. The objective of the investigation was to determine if the damage caused by copper projectile impact compared to steel projectile impact was higher for the same kinetic energy (K.E.) projectiles and the reason for this phenomenon. For the constant K.E. impact, copper projectile apparently caused higher damage in glass plate. Higher damage was attributed to projectile contact duration and the contact area between the projectile and the glass plate. Finite element analysis using LS-DYNA based upon maximum principal strain failure criterion for laminated glass model was able to predict the failed material under the impact location and the cracking pattern in the glass plate for a biased meshing scheme. Radial cracks in glass target were reported to be 15% higher for copper projectile impact than the steel projectile impact. ABSTRAK: Kepingan kaca dikenakan impak oleh projektil kuprum dan keluli berbentuk sfera pada halaju rendah. Ciri-ciri kegagalan kaca terdiri daripada kon berpusat Hertzian yang melibatkan kaca yang hancur dan corak pecahan berbentuk sesawang lelabah pada keliling kon dengan retakan lilitan dan jejarian. Tujuan penyelidikan adalah untuk menentukan sebab bagaimanaÂ dengan projektil tenaga kinetik yang sama, kerosakan yang diakibatkan oleh impak projektil kuprum berbanding dengan impak projektil keluli adalah lebih tinggi. Untuk impak tenaga kinetik yang malar, projektil kuprum didapati menyebabkan kerosakan yang lebih ke atas kepingan kaca. Kerosakan lebih disebabkan oleh tempoh sentuhan projektil dan kawasan sentuhan di antara projektil dan kepingan kaca. Analisis unsur terhingga menggunakan LS-DYNA berdasarkan kriteria kegagalan terikan utama maksima untuk model kaca berlamina.Â Kaedah ini berupaya menjangkakan kegagalan objek pada lokasi impak dan corak retakan pada kepingan kaca untuk skim berjejaring terpincang.Â Retakan berjejari pada sasaran kaca didapati 15% lebih tinggi untuk impak projektil kuprum berbandingkanÂ dengan impak projektil keluli.
COUETTE FLOW PROBLEM FOR AN UNSTEADY MHD THIRD-GRADE FLUID WITH HALL CURRENTS
Authors: Azram Muhammad , Zaman Haider 
Published: October 2018

ABSTRACT: In this work, we analyze Coutte flow problem for an unsteady mangneto-hydrodynamic (MHD) third-grade fluid in the presence of a pressure gradient and Hall currnts. Existing literature on the topic shows that the effecs of Hall current on Coutte flow of an unsteady MHD third-grade fluid with a prssure gradient has not yet been investigated. The arising non-linear problem is solved by the homotopy analysis method (HAM) and the convergence of the obtained complex series solution is carefully analyzed. The effects of pressure number, Hartmann number and Hall parameter on unsteady velocity are discussed via analysis of plots. ABSTRAK: Kajian dijalan untuk menganalisa masalah aliran Coutte bagi bendalir MHD gred ketiga dan arus Hall. Bagi topik ini kesan arus Hall terhadap aliran Couette dalam bendalir MHD gred ketiga tak mantap dengan kecerunan tekanan, belum pernah dikaji selidik.Â Masalah tak linear berbangkit diselesaikan dengan kaedah analisis homotopi (HAM) dan ketumpuan solusi rangkaian kompleks dianalisa dengan teliti. Kesan nilai tekanan, nombor Hartmann dan parameter Hall terhadap halaju tak mantap diperbincangkan melalui plot yang dianalisis.KEYWORDS: Cuette; flow; hall currents; unsteady; third-grade fluid; HAMÂ
NANO-BATTERY TECHNOLOGY FOR EV-HEV PANEL: A PIONEERING STUDY
Authors: Rahman Ataur , Rashid M. , Mohiuddin A. K. M. , Hawlader M. N. A. 
Published: October 2018

Global trends toward CO2 reduction and resource efficiency have significantly increased the importance of lightweight materials for automobile original equipment manufacturers (OEM). CO2 reduction is a fundamental driver for a more lightweight automobile. The introduction of Electrical Vehicles (EVs) is one initiative towards this end. However EVs are currently facing several weaknesses: limited driving range, battery pack heaviness, lack of safety and thermal control, high cost, and overall limited efficiency. This study presents a panel-style nano-battery technology built into an EV with CuO filler solid polymer electrolyte (SPE) sandwiched by carbon fiber (CF) and lithium (Li) plate. In addition to this, an aluminum laminated polypropylene film is used as the electromagnetic compatibility (EMC) shield. The proposed battery body panel of the EV would reduce the car weight by about 20%, with a charge and discharge capacity of 1.5 kWh (10% of car total power requirement), and provide the heat insulation for the car which would save about 10% power consumption of the air conditioning system. Therefore, the EV would be benefited by 30% in terms of energy reduction by using the proposed body. Furthermore, the proposed body is considered environmental-friendly since it is recyclable for use in a new product. However, the main limiting factors of the SPE are its thermal behavior and moderate ionic conductivity at low temperatures. The SPE temperature is maintained by controlling the battery panel charging/discharge rate. It is expected that the proposed panel-style nano-battery use in an EV would save up to 6.00 kWh in battery energy, equivalent to 2.81 liters of petrol and prevent 3.081 kg of CO2 emission for a travel distance of 100 km.Â KEYWORDS:Â epoxy resin; carbon fiber; lithium thin plate; energy generation; solid electrolyte battery
CHAOS CONTROL AND SYNCHRONIZATION USING SYNERGETIC CONTROLLER WITH FRACTIONAL AND LINEAR EXTENDED MANIFOLD
Authors: Pourmehdi Morteza , Ranjbar Noei Abolfazl , Sadati Jalil 
Published: October 2018

In this manuscript, for the first time, a fractional-order manifold in a synergetic approach using a fractional order controller is introduced. Furtheremore, in the synergetic theory a macro variable is expended into a linear combination of state variables. An aim is to increase the convergence rate as well as time response of the whole closed loop system. Quality of the proposed controller is investigated to control and synchronize a nonlinear chaotic Coullet system in comparison with an integer order manifold synergetic controller. The stability of the proposed controller is proven using the Lyapunov method. In this regard stabilizing control effort is yielded. Simulation result confirm convergence of states towards zero. This is achieved through a control effort with fewer oscillations and lower amplitude of signls which confirm feasibility of the control effort in practice.KEYWORDS:Â synergetic control theory; fractional order system; synchronization; nonlinear chaotic Coullet system; chaos control
A REVIEW ON LOWER APPENDICULAR MUSCULOSKELETAL SYSTEM OF HUMAN BODY
Authors: Akhtaruzzaman M. , Shafie A. A. , Khan M. R. 
Published: October 2018

Rehabilitation engineering plays an important role in designing various autonomous robots to provide better therapeutic exercise to disabled patients. Hence it is necessary to study human musculoskeletal system and also needs to be presented in scientific manner in order to describe and analyze the biomechanics of human body motion. This review focuses on lower appendicular musculoskeletal structure of human body to represent joints and links architectures; to identify muscle attachments and functions; and to illustrate muscle groups which are responsible for a particular joint movement. Firstly, human lower skeletal structure, linking systems, joint mechanisms, and their functions are described with a conceptual representation of joint architecture of human skeleton. This section also represents joints and limbs by comparing with mechanical systems. Characteristics of ligaments and their functions to construct skeletal joints are also discussed briefly in this part. Secondly, the study focuses on muscular system of human lower limbs where muscle structure, functions, roles in moving endoskeleton structure, and supporting mechanisms are presented elaborately. Thirdly, muscle groups are tabulated based on functions that provide mobility to different joints of lower limbs. Finally, for a particular movement action of lower extremity, muscles are also grouped and tabulated to have a better understanding on functions of individual muscle. Basically the study presents an overview of the structure of human lower limbs by characterizing and classifying skeletal and muscular systems.KEYWORDS: Â Musculoskeletal system; Human lower limbs; Muscle groups; Joint motion; Biomechatronics; Rehabilitation.
CENTRIFUGAL COMPRESSOR EFFICIENCY CALCULATION WITH HEAT TRANSFER
Authors: Dragan Valeriu 
Published: October 2018

In this paper we present a case study of apparent performance variation ofan optimized centrifugal compressor design when its metal parts are cold - before the conjugated heat transfer between the fluid and parts reaches an energetic equilibrium. The methods used are numerical, using full viscous 3D computational fluid dynamics with heat transfer. Three cases were considered, an adiabatic wall baseline, an all-blade cooling at 293 K and a more realistic stator row cooling at 293 K. Results indicate an apparent yet erroneous isentropic efficiency reading increase beyond 100% - which was to be expected due to the fluid cooling. However the isentropic and polytropic efficiencies could be estimated and were used to more accurately assess the performance of the compressor. Power consumption decreased to approximately 97% of the original load while the pressure ratio was marginally increased. This alone does not, however, explain the non-physical efficiency readings, which are mainly due to the assumptionsand manner under which the efficiency itself is calculated. The paperÂ presents a more robust approach to measuring efficiency, regardless of the heat transfer within the turbomachinery itself. Possible applications of the study may range from cold-start regime simulation to the optimization of inter-cooling setup or even flow angle control without mechanically actuated OGV
Anti-Plane Surface Disturbance
Authors: Azram M. 
Published: October 2018

Solution to a problem of half-space subjected to anti-plane surface disturbance via Cagniard-de Hoop method has been investigated. The solution is very much dependent on the choice of branch cuts, branches, and their behavior along the appropriate selected contour. Investigations show that the contour, which simplifies the inversion integral, may or may not exist in some quadrants of x-plane and is very much dependent on the position of the point x. Consequently, the solution is the Hankel function of first kind . Key Words: Cagniard-de Hoop method. Inversion Integral. Hankel function. Anti-plane Shear. Waves propagation. Fourier Transform.
Wear Behavior of Woven Roving Aramid / Epoxy Composite under Different Conditions
Authors: Khalid Asad A. 
Published: October 2018

Wear behavior studies of aramid woven roving /epoxy composite has been conducted. Sliding the material against smooth steel counter face under dry and lubricated with oil conditions has been investigated. Powder of Silicon carbide has been mixed with the epoxy resin and tested also. The powder was mixed in a volumetric fraction of 10% with the epoxy resin. Four Laminates of six layers were fabricated by hand lay up method. A pin on disc apparatus has been fabricated to conduct the sliding wear tests on specimens of (4 mm 4 mm 12 mm) in size have been cut from the four laminates. The effect of sliding condition including dry, lubricated, dry with additives and lubricated with additives have been studied. Wear rate tests have been conducted at different sliding speeds and loads. Results show that the wear characteristics are influenced by the operating conditions and the construction of the composite material used. It was also found that the wear of aramid /epoxy composite onto the steel counter face were significantly reduced by using lubricant and additives but still took place.Keywords: Wear, Composite materials, Woven roving aramid, Epoxy, Additives, Lubricant.
Designing Framework of a Segmented Rubber Tracked Vehicle for Sepang Peat Terrain in Malaysia
Authors: Desa Ahmad and Wan Ishak Ataur Rahman, Azmi Yahaya, Mohd. Zohadie, 
Published: October 2018

The focus of this paper is to present the designing framework of an off-road special segmented rubber tracked vehicle that may be required to run on low bearing capacity peat terrain. To complete this study: firstly, mechanical properties of the peat terrain were first determined by using different type of apparatus. Direct shear test was performed using a Wykeham Farrance 25402 shear box apparatus to determine the internal friction angle, cohesiveness and shear deformation modulus of the peat sample. Load-sinkage test was performed using a specially made bearing capacity apparatus to determine the stiffness values of surface mat and underlying peat. Secondly, substantiate the validity of the mathematical model and finally design parameters of the special segmented rubber tracked vehicle were optimized by simulation. Keywords: Tracked vehicle, peat terrain, tractive performance.
Natural Convection Heat Transfer in Concentric Horizontal Annuli Containing a Saturated Porous Medi
Authors: R.Y. Sakr Ahmed F. Alfahaid, , Ahmed M. I. 
Published: October 2018

Natural convection in horizontal annular porous media has become a subject receiving increasing attention due to its practical importance in the problem of insulators, such as ducting system in high temperature gas-cooled reactors, heating systems, thermal energy storage systems, under ground cable systems, etc. This paper presents a numerical study for steady state thermal convection in a fully saturated porous media bounded by two horizontal concentric cylinders, the cylinders are impermeable to fluid motion and maintained at different, uniform temperatures. The solution scheme is based on two-dimensional model, which is governed by Darcy-Oberbeck-Boussinesq equations. The finite element method using Galerkin technique is developed and employed to solve the present problem. A numerical simulation is carried out to examine the parametric effects of Rayleigh number and radius ratio on the role played by natural convection heat transfer in the porous annuli. The numerical results obtained from the present model were compared with the available published results and good agreement is observed. The average Nusselt number at the heating surface of the inner cylinder is correlated to Rayleigh number and radius ratio.Keywords: Natural convection, numerical investigation, saturated porous media, finite element method, concentric horizontal annuli.