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Articles 57541 - 57570 of 197988

Full-Text Articles in Engineering

Identification Of Microscopy Cell Images By Using Convolutional Neural Network Application, Ajis Norfatin Farisya Jul 2020

Identification Of Microscopy Cell Images By Using Convolutional Neural Network Application, Ajis Norfatin Farisya

Student Works (2020-2029)

Breast cancer has been the major factor of cancer death and the second main cause of women’s deaths in the world. The false positive results of this cancer cell detection during the screening test leads to false treatment and emotional disturbance of the patients. Thus, breast cancer cell lines (MCF7) is used as the microscopy image samples together with the Human Bone Osteosarcoma Epithelial Cells (U2OS), and Human Hepatocyte as control to study the effectiveness of convolutional neural network (CNN) as a method of image recognition. The objectives of this study are to determine the ability of convolutional neural network …

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Improving Client-Consultant-Contractor Communication In Construction Industry Through Whatsapp Application, Muhammad Hafizul Taib Jul 2020

Improving Client-Consultant-Contractor Communication In Construction Industry Through Whatsapp Application, Muhammad Hafizul Taib

Student Works (2020-2029)

A Smooth and effective communication is very important in construction industry to prevent iteration and rework which will cause money. Since there are a lot of parties involve in construction,it is important to have a good communication platform. In the current world, people are using the technology advancement to enhance the effectiveness of communication amongst people who work in construction industry. Though there are a lot of mobile application designed for construction purpose, WhatsApp is the most commonly used by all. However, there are no studies done to identify the effectiveness of it. This thesis will gather respond from client, …

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Preventing Delayed Cracks In Sus304 Deep Drawn Cups Using Extreme Blank Holding Forces Aided By Nanolubrication, Ibrahim Muhammad Shafiq Jul 2020

Preventing Delayed Cracks In Sus304 Deep Drawn Cups Using Extreme Blank Holding Forces Aided By Nanolubrication, Ibrahim Muhammad Shafiq

Student Works (2020-2029)

This study was to investigate the formation and reformation of delayed cracks of SUS304 cylindrical drawn cups under elevated blank holding force (BHF) from 8~32 kN with 1~3 wt% SiO2 nanolubricants concentrations. The widest crack-free BHF range i.e. from 29 ~ 31 kN was determined for 2 wt% of SiO2 in the experiment. Delayed cracks were also observed below and beyond this BHF range. There was an increment of frictional force at the cup flange region when entering the crack-free BHF range, as proven by the rebound in sidewall thickness, relative intensity of α′-martensite, elongated height and drawing force beyond …

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An Improved Bone Age Assessment Using Advanced Image Processing And Deep Learning Approach, Kim Meng Liang Jul 2020

An Improved Bone Age Assessment Using Advanced Image Processing And Deep Learning Approach, Kim Meng Liang

Student Works (2020-2029)

Pediatricians often apply bone age assessment to measure the skeletal maturity of children and to predict the future height. These discrepancies are good indicators for diagnosing growth disorders. Normally, left hand skeletal is employed in this assessment. The low quality of ossification sites of carpals deteriorates the pediatrician’s visibility in inspecting the pertinent radiographic manifestations. This in turn affects the bone age assessment. Therefore, we have to enhance the quality before assessing them. Histogram equalization is one of the contrast enhancement techniques that suit this type of enhancement. Existing histogram equalizations, however, are confronting with problems in preserving the brightness …

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Challenges In E-Tendering Implementation In Ministry Of Youth And Sports Malaysia, Azis Ahmad Zamie Jul 2020

Challenges In E-Tendering Implementation In Ministry Of Youth And Sports Malaysia, Azis Ahmad Zamie

Student Works (2020-2029)

The Ministry of Youth and Sport, like most ministries in Malaysia, tenders its projects through the traditional paper-based tendering process, which has many weaknesses, including bureaucracy and lack of transparency. In 2008, e-Tender was one of government incentive under e-Government application was introduced to replace manual tendering system in public agencies to systematic procurement which using internet as platform of transaction. Like any other transition project, implementation of e-tender in Ministry of Youth and Sport, is associated with several challenges. This research aims to explore the challenges facing the implementation of the e-tender system in the Ministry of Youth and …

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The Study On The Use Of Project Success Framework Among Project Personnel, Suring Joshua Jul 2020

The Study On The Use Of Project Success Framework Among Project Personnel, Suring Joshua

Student Works (2020-2029)

Projects, programs and portfolios are essential for human endeavors since time immemorial. However, project success rates in various sectors are dismal and not up to expectations. This research aims to investigate the use of a multilevel project success framework among project personnel in various sectors to identify essential success levels and criteria and determine any weaknesses and gaps for enhancing the framework. This is a qualitative study during which a conceptual framework was developed and tested with data gathered using a questionnaire survey with open-ended questions which was distributed to project personnel based on snowball sampling. A total of 52 …

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Project Risk Management In Malaysian Oil And Gas Industry: Implementation By Epc Local Contractor, Che Rosli Zaim Aiman Jul 2020

Project Risk Management In Malaysian Oil And Gas Industry: Implementation By Epc Local Contractor, Che Rosli Zaim Aiman

Student Works (2020-2029)

The megaproject in Downstream Sector of Oil and Gas Industry only achieve 50% success rate which warrants attention by researchers. The Owners and Contractors are not fully aware on the full range of project risks and only few have demonstrated the knowledge and expertise in managing risk effectively. The common understanding had by the EPC Contractor is they are having the full flexibility and freedom in performing execution work by maximizing profit while still complying towards client’s requirement as the contract price has been fixed during award stage. However, there is a hidden risk which seldomly being placed attention by …

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The Critical Success Factors Of Cloud Based Application Implementation In Construction Management, Sukiman Mohd Asfahani Jul 2020

The Critical Success Factors Of Cloud Based Application Implementation In Construction Management, Sukiman Mohd Asfahani

Student Works (2020-2029)

Design and construction are information intensive activities, involving a great number of people collaborating to produce complex, one-off developments. Whilst historically, information may have been managed and communicated using paper-based systems and verbal instructions, the integration of the supply chain, the introduction of computer aided design (CAD) and building information modelling (BIM) and the development of cloud computing application means that information communications technology (ICT) is becoming a fundamental part, not just of the design office, but also of the construction site. Cloud computing is a relatively new phenomenon in the construction industry. It allows the delivery over the 'cloud' …

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A Multicriteria Aware Optimal Routing Approach For Enhancing Quality Of Service In Device To Device Communication, Tilwari Valmik Jul 2020

A Multicriteria Aware Optimal Routing Approach For Enhancing Quality Of Service In Device To Device Communication, Tilwari Valmik

Student Works (2020-2029)

As the world is moving towards the digitalization era, increasing demands of higher data rates, energy effiffifficiency, and seamless connectivity are skyrocketing. Device-to-Device (D2D) communication is one of the key technologies for future Fifth Generation (5G) network. D2D communication technology enhances network coverage, boosts spectral efficiency, has low latency, and enables the devices to communicate with each other, with partial or none involvement of network infrastructure. Therefore, factors of such nature make D2D communication a promising medium guarantying reliability to several telecommunications scenarios. D2D caters to all the needs of it’s users, from the high demand of peer-to-peer users for …

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Microstructural Characteristics And Mechanical Properties Of Sn-Ag-Cu Solders With Minor Additions Of Al And Zn, Yee Mei Leong Jul 2020

Microstructural Characteristics And Mechanical Properties Of Sn-Ag-Cu Solders With Minor Additions Of Al And Zn, Yee Mei Leong

Student Works (2020-2029)

Driven by the recent trend towards miniaturization of lead free electronic products, researchers are putting immense efforts to improve the properties and reliability of Sn based solders. Recently, much interest has been shown on low silver (Ag) content solder SAC 105 (Sn-1.0Ag-0.5Cu) solder because of economic reasons and improvement of impact resistance as compared to SAC387(Sn-3.8Ag-0.7Ag). The present work investigates the effect of minor (0.1-0.5wt.%) Aluminium (Al) and Zinc (Zn) addition to SAC105 on the bulk and interfacial structure between solder and copper substrate during reflow and after thermal aging , the mechanical properties of the solder joint and the …

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Synthesis Of Polyurethane Incorporated By Calcium Oxide And Magnesium Oxide For Heavy Metal Removal From Water, Fard Mohsen Vafaei Jul 2020

Synthesis Of Polyurethane Incorporated By Calcium Oxide And Magnesium Oxide For Heavy Metal Removal From Water, Fard Mohsen Vafaei

Student Works (2020-2029)

Water contaminated by heavy metals such as copper, lead, nickel, and cadmium has significant adverse impacts on receiving water. In recent years, various methods, such as adsorption, chemical precipitation, and ion exchange, have been extensively studied for the elimination of heavy metals. Adsorption is one of the numerously and diversely reported mechanisms of removing heavy metals due to its simplicity and costeffectiveness. In this study, highly permeable rigid polyurethanes (PU) incorporating calcium oxide (CaO) (PU/CaO) composite materials were prepared via a facile and economic one-pot synthesis method and characterized for remediation of heavy metal from water. To investigate the effect …

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Suspended Carbon Nanowire Biosensor For Rapid And Label-Free Salmonella Detection, Thiha Aung Jul 2020

Suspended Carbon Nanowire Biosensor For Rapid And Label-Free Salmonella Detection, Thiha Aung

Student Works (2020-2029)

Carbon, the building block life, is rapidly becoming the building block of nextgeneration electronics and sensor materials. Of many ways to handle nanocarbon materials, Carbon Microelectromechanical Systems (C-MEMS) emerges as a unique way for top-down fabrication of three-dimensional carbon micro to nanostructures. In this work, the use of C-MEMS techniques in nanowire biosensor fabrication is explored. Two main hindrances in the use of C-MEMS carbon structures for biosensing lie in miniaturization to nanoscale sensor material and inertness of as-fabricated carbon. This dissertation presents ways to overcome these limitations. First, miniaturization to patterned sub-100 nm carbon nanowires was achieved by optimization …

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Multimode-Interference Based Optical Fiber Sensor For Civil Structures Monitoring, Sue Ping Chew Jul 2020

Multimode-Interference Based Optical Fiber Sensor For Civil Structures Monitoring, Sue Ping Chew

Student Works (2020-2029)

The thesis describes the experimental investigations on the multimode interferencebased fiber sensors using single mode multimode single mode (SMS) and multimode single mode multimode (MSM) structures as a sensing device for structural health monitoring (SHM) applications. Both sensor structures were fabricated, characterized and tested for detecting strain and vibration in civil infrastructures. The proposed SMS structure comprises of a short segment of multimode fiber (MMF), which were fusionspliced by two single mode fibers (SMFs) at both terminals. On the other hand, MSM was fabricated by splicing SMF with MMF at both ends. A new packaging technique for the SMS structure …

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Syntheses, Characterisations And Electrochemical Studies Of Nickel(Ii) And Cobalt(Ii)-Ligand Assisted Cooperative Complexes, Subramaniam Jeevithra Dewi Jul 2020

Syntheses, Characterisations And Electrochemical Studies Of Nickel(Ii) And Cobalt(Ii)-Ligand Assisted Cooperative Complexes, Subramaniam Jeevithra Dewi

Student Works (2020-2029)

A newly designed tetradentate ligand L1 (L1 = 3,6-bis(pyrazol-1-yl)-pyridazine) which offers multinucleation sites on its moiety structure has been prepared. The reaction of L1 with different molar ratio of nickel and cobalt salts lead to the formation of di- and tetranuclear complexes [NiII 2(L1)2(CH3CN)4](PF6)4 (1), [NiII 4(L1)4(μ-OH)4](ClO4)4 (2) and [CoII/III(L1)4(μ-CH3O)2(μ-O)2](PF6)3(NO3) (3), which served as the attempt to design of catalysts based on cheap and earth-abundant metals for carbon dioxide reduction. The presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) as the base controls the nuclearity of the complex formation. In the absence of DBU, complex 1 was formed in dinuclear fashion whereas complex 2 …

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A Computational Study Of Water Mobility On Smooth Surface, Cavities And Porous Structure With Hydrophilic And Hydrophobic Coatings, Kok Wee Yong Jul 2020

A Computational Study Of Water Mobility On Smooth Surface, Cavities And Porous Structure With Hydrophilic And Hydrophobic Coatings, Kok Wee Yong

Student Works (2020-2029)

This research focus on water mobility and discovers a new phenomenon where droplet accelerates on a hydrophilic cavity surface when sliding down from a hydrophobic surface. The kinetic energy of droplet increases six (6) times higher than before sliding into the first cavity. This finding is useful for creating an effective way of filling liquids into cavities for passive microfluidics related devices. The work consists of validating cases using Computational Fluid Dynamics (CFD) software. The first part of the research reviews the literature regarding CFD modelling of a water droplet (i) sliding down on a surface, (ii) detachment in a …

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Modeling Of Heavy Vehicle Braking Related To Accident Reconstruction For A Range Of Vehicle And Road Characteristics, Zamzamzadeh Mahdieh Jul 2020

Modeling Of Heavy Vehicle Braking Related To Accident Reconstruction For A Range Of Vehicle And Road Characteristics, Zamzamzadeh Mahdieh

Student Works (2020-2029)

In today's heavy-vehicle accidents, one of the major contributors is emergency braking, particularly for vehicles without an anti-lock braking system (ABS), which is dominant in developing countries like Malaysia. As the heavy vehicle driver applies emergency braking, there is a high chance of wheel lock-up, at which point the vehicle will skid along the road, creating braking marks from the tires. These braking marks are often used in crash reconstructions. Braking marks are mainly used by investigators to examine the vehicle's pre-impact velocity. There are many models and formulations based on kinetic energy that show the effect of some parameters. …

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Engineering Properties And Microstructural Characteristics Of Cement And Geopolymer Based Mortars Using Nontraditional Supplementary Cementitious Materials, Mathialagan Sumesh Jul 2020

Engineering Properties And Microstructural Characteristics Of Cement And Geopolymer Based Mortars Using Nontraditional Supplementary Cementitious Materials, Mathialagan Sumesh

Student Works (2020-2029)

The concrete repair and rehabilitation industry grows rapidly due to deterioration, damage and defects in concrete structures. For various reasons, the concrete construction industry is not sustainable; because it consumes huge quantities of virgin materials, the usage of Portland cement as prime binder. The production of cement is a major contributor to greenhouse gas emissions. In addition, the high cost of commercial repair material. Therefore, it is necessary to develop cost-effective alternative repair materials for concrete repairs. There have been many standard repair materials available in the market, which are costly and not affordable to common people. However, research works …

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Optimal Network Reconfiguration And Distributed Generation Sizing With Consideration Of Protection System, Abdul Rahim Mohamad Norshahrani Jul 2020

Optimal Network Reconfiguration And Distributed Generation Sizing With Consideration Of Protection System, Abdul Rahim Mohamad Norshahrani

Student Works (2020-2029)

Research on network reconfiguration (NR) considering distributed generation (DG) commonly focus on the issues of power loss, voltage deviation, DG sizing and its placement. These works are important and required in the planning stage of the distribution networks. In most of the past works, the protection system is neglected in this stage although it is essential to prevent the network from damages during operation. Without proper consideration of protection system settings and coordination during NR, the protection system may operate inaccurately. This happens due to changes in current flow and fault level when the network changes its configuration. As a …

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Development Of Nano Carbon And Conducting Polymers Based Ternary Composites For Supercapattery, Iqbal Javed Jul 2020

Development Of Nano Carbon And Conducting Polymers Based Ternary Composites For Supercapattery, Iqbal Javed

Student Works (2020-2029)

Although significant efforts have been devoted on the development of energy storage systems such as batteries and fuel cells in the past decades, the low power density, short cyclic life and high maintenance cost have kept them away from many applications. Alternatively, supercapattery which has the characteristic features of batteries as well as supercapacitors has gained much attention because of its rapid charge/discharge mechanism, long life cycle, and high power density. However, supercapattery generally suffers from poor energy density. This research aims to develop carbon and conducting polymers based ternary nanocomposites for high performance supercapattery. Pristine metal oxide nanostructures suffer …

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Performance Of A New Passive Damper For Seismic Protection Of Structures, Ghaedi Khaled Jul 2020

Performance Of A New Passive Damper For Seismic Protection Of Structures, Ghaedi Khaled

Student Works (2020-2029)

Passive energy dissipation devices have been successfully implemented in buildings around the world to reduce structural responses primarily to earthquakes, wind and other dynamic loads. Unlike active and semi-active control systems, passive systems make use of control devices that serve secondary functions. They are connected to structural members to increase structural damping without the use of external forces. The aim of this research is to introduce and investigate the performance of a new passive damper device called bar damper (BD), which is made of a number of solid bars sandwiched between two plates. The concept, placement and material properties of …

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Dynamic Modeling And Optimal Design For Net Zero Energy Houses Including Hybrid Electric And Thermal Energy Storage, Huangjie Gong, Vandana Rallabandi, Dan M. Ionel, Donald Colliver, Shaun Duerr, Cristinel Ababei Jul 2020

Dynamic Modeling And Optimal Design For Net Zero Energy Houses Including Hybrid Electric And Thermal Energy Storage, Huangjie Gong, Vandana Rallabandi, Dan M. Ionel, Donald Colliver, Shaun Duerr, Cristinel Ababei

Electrical and Computer Engineering Faculty Research and Publications

Net zero energy (NZE) houses purchase zero net metered electricity from the grid over a year. Technical challenges brought forth by NZE homes are related to the intermittent nature of solar generation, and are due to the fact that peak solar generation and load are not coincident. This leads to a large rate of change of load, and in case of high PV penetration communities, often requires the installation of gas power plants to service this variability. This article proposes a hybrid energy storage system including batteries and a variable power electric water heater which enables the NZE homes to …

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Hybrid Nanocellulose-Copper (Ii) Oxide As Engine Oil Additives For Tribological Behavior Improvement, Sakinah Hisham, Kumaran Kadirgama, Hussein A. Mohammed, Amit Kumar, Devarajan Ramasamy, Mahendran Samykano, Saidur Rahman Jul 2020

Hybrid Nanocellulose-Copper (Ii) Oxide As Engine Oil Additives For Tribological Behavior Improvement, Sakinah Hisham, Kumaran Kadirgama, Hussein A. Mohammed, Amit Kumar, Devarajan Ramasamy, Mahendran Samykano, Saidur Rahman

Research outputs 2014 to 2021

© 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/). Friction and wear are the main factors in the failure of the piston in automobile engines. The objective of this work was to improve the tribological behaviour and lubricant properties using hybrid Cellulose Nanocrystal (CNC) and Copper (II) oxide nanoparticles blended with SAE 40 as a base fluid. The two-step method was used in the hybrid nanofluid preparation. Three different concentrations were prepared in a range of 0.1% to …

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Three-Event Energy Detection With Adaptive Threshold For Spectrum Sensing In Cognitive Radio Systems, Alexandru Martian, Mahmood Jalal Ahmad Al Sammarraie, Calin Vladeanu, Dimitrie Popescu Jul 2020

Three-Event Energy Detection With Adaptive Threshold For Spectrum Sensing In Cognitive Radio Systems, Alexandru Martian, Mahmood Jalal Ahmad Al Sammarraie, Calin Vladeanu, Dimitrie Popescu

Electrical & Computer Engineering Faculty Publications

Implementation of dynamic spectrum access (DSA) in cognitive radio (CR) systems requires the unlicensed secondary users (SU) to implement spectrum sensing to monitor the activity of the licensed primary users (PU). Energy detection (ED) is one of the most widely used methods for spectrum sensing in CR systems, and in this paper we present a novel ED algorithm with an adaptive sensing threshold. The three-event ED (3EED) algorithm for spectrum sensing is considered for which an accurate approximation of the optimal decision threshold that minimizes the decision error probability (DEP) is found using Newton’s method with forced convergence in one …

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All-Metallic Phase Change Thermal Management Systems For Transient Spacecraft Loads, Carl R. Hartsfield, Travis E. Shelton, Brian O. Palmer, Ryan P. O'Hara Jul 2020

All-Metallic Phase Change Thermal Management Systems For Transient Spacecraft Loads, Carl R. Hartsfield, Travis E. Shelton, Brian O. Palmer, Ryan P. O'Hara

Faculty Publications

In this work, we explore the thermal properties of gallium as an effective phase change material for thermal management applications. Thermal storage and dissipation of gallium manufactured heat sinks were compared to conventional phase change heat sinks. The comparison revealed a 50-fold (80 K versus 1.5 K) potential reduction in temperature during the phase change process due to the high density, thermal conductivity, and latent heat of fusion. The gallium creates shallow thermal gradients when transiently heated, producing a nearly isothermal process. Computational estimates using lumped sum parameters were able to provide simple modeling to predict the results. Gallium based …

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Synthesis And Fabrication Of Self-Sustainable Triboelectric Energy Case For Powering Smart Electronic Devices, Abu Masa Abdullah, Alejandro Flores, Aminur Rashid Chowdhury, Jianzhi Li, Yuanbing Mao, M. Jasim Uddin Jul 2020

Synthesis And Fabrication Of Self-Sustainable Triboelectric Energy Case For Powering Smart Electronic Devices, Abu Masa Abdullah, Alejandro Flores, Aminur Rashid Chowdhury, Jianzhi Li, Yuanbing Mao, M. Jasim Uddin

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

In recent times, Triboelectric Nanogenerators (TENG) have attained the focus of the scientific community due to its potential as a medium to harvest mechanical energy from the ambient environment. Human motion has been attributed as a source of mechanical energy to drive electronic devices and sensors through TENG. Based on the principles of single electrode TENG, we have developed a Triboelectricity based Stepping and Tapping Energy Case (TESTEC) which magnifies the prospect to power touch electronic devices by utilizing finger tapping and stepping motion. This novel case was constructed with two single electrode TENG operating through the triboelectric mechanism between …

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Skin-Mimo: Vibration-Based Mimo Communication Over Human Skin, Dong Ma, Yuezhong Wu, Ming Ding, Mahbub Hassan, Wen Hu Jul 2020

Skin-Mimo: Vibration-Based Mimo Communication Over Human Skin, Dong Ma, Yuezhong Wu, Ming Ding, Mahbub Hassan, Wen Hu

Research Collection School Of Computing and Information Systems

We explore the feasibility of Multiple-Input-Multiple-Output (MIMO) communication through vibrations over human skin. Using off-the-shelf motors and piezo transducers as vibration transmitters and receivers, respectively, we build a 2x2 MIMO testbed to collect and analyze vibration signals from real subjects. Our analysis reveals that there exist multiple independent vibration channels between a pair of transmitter and receiver, confirming the feasibility of MIMO. Unfortunately, the slow ramping of mechanical motors and rapidly changing skin channels make it impractical for conventional channel sounding based channel state information (CSI) acquisition, which is critical for achieving MIMO capacity gains. To solve this problem, we …

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Physical And Chemical Characteristics Of Supramolecular Complexes Of Glycirrizinic Acid With Phytohormones, Djuraev Tulqin, Esanov Rakhmatillo, Gafurov Makhmudjon, Kushiev Khabibjon Jun 2020

Physical And Chemical Characteristics Of Supramolecular Complexes Of Glycirrizinic Acid With Phytohormones, Djuraev Tulqin, Esanov Rakhmatillo, Gafurov Makhmudjon, Kushiev Khabibjon

CHEMISTRY AND CHEMICAL ENGINEERING

The process of formation of supramolecular complexes of glycyrrhizinic acid with some phytohormones (indolylacetic acid, indolylbutyric acid, α-naphthyl acetic acid and kinetin) were studied with the aim of creation the plant growth stimulator. The complexes structure was studied using IR and UV spectroscopy methods. The prepared compounds described by some physicochemical parameters. The stability constants and stoichiometric composition of complexes were determined in an aqueous solution at pH of 7,2 using UV spectrometry method. In result, all complexes have composition as 1:1 ratio, except the kinetin complex which has 2:1 ratio. The stability constants were equal: KGA:IAA=1,86±1×104; KGA:IBA=2,51±1×103; KGA:NAA =2,70±1×103 …

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Study Of The Process For The Removal Of Dyeing Matters Of The Plant Occimum Basilicum L. Lamiaceae, Usmonjonova Khulkar, Atkhamova Saida, Dodaev Kuchkor Jun 2020

Study Of The Process For The Removal Of Dyeing Matters Of The Plant Occimum Basilicum L. Lamiaceae, Usmonjonova Khulkar, Atkhamova Saida, Dodaev Kuchkor

CHEMISTRY AND CHEMICAL ENGINEERING

The aim of the work is dedicated isolation of anthocyanins by ethanol from herbal plant of Occimum basilicum L. Lamiaceae basis. The were studied influencing of temperature, concentration of ethanol to isolation of anthocyanins. There were passed investigations on studying influence level of heating and hydromodule system of rav material-solvent to maximal isolating of anthocyanins. The colors define by fotokolorometrical method at wave length 400-600 nm. There are shown at 540 nm maximal peak of anthocyanins and it is geven as a grapfical diagram. From the obtained depends on content of alcohol in aquatic solution from outlet of colors is …

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The Research Of Conditions For The Formation Of Phenol Formaldehyde Resins Modified With Hydroxyl Containg Polyether Polyol, Magrupov Farkhad, Umarov Sherali, Tohirov Murodjon, Radjabova Zukhra Jun 2020

The Research Of Conditions For The Formation Of Phenol Formaldehyde Resins Modified With Hydroxyl Containg Polyether Polyol, Magrupov Farkhad, Umarov Sherali, Tohirov Murodjon, Radjabova Zukhra

CHEMISTRY AND CHEMICAL ENGINEERING

The aim of the study was to study the conditions of copolycondensation of phenol alcohol with hydroxyl-containing polyether polyol in the presence of maleic anhydride chain extender in order to obtain modified thermoset phenolic-formaldehyde oligomers. Investigation of the dependence of the content of free phenol, formaldehyde and methylol groups on time during the synthesis of the modified phenol-formaldehyde resin with the ratios hydroxyl-containing polyether polyol:phenol alcohol 1:60 mol/mol and 1:100 mol/mol. It was revealed that maleic anhydride, present in the reaction medium as a copolycondensation catalyst, also participates in copolycondensation reactions as a chain extender. Moreover, as the molar fraction …

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Vinylation By 3,6-Dimetyloctin-4-Diol-3,6 Acetylene, Yusupova Lola, Abdukarimova Saida, Rajabov Rustambek, Khalimova Oygul Jun 2020

Vinylation By 3,6-Dimetyloctin-4-Diol-3,6 Acetylene, Yusupova Lola, Abdukarimova Saida, Rajabov Rustambek, Khalimova Oygul

CHEMISTRY AND CHEMICAL ENGINEERING

The aim of the research work elaboration of technology of obtaine of acetylene diols and their vinyl ethers. Reaction of formation mono di vinyl ethers as a result vinyl 3,6-dimetyloktin-4-diol-3,6 by acetylene, and also influence of solvents, the catalyst and its quantity, duration of reaction, temperatures is investigated. Are defined speed of reaction. Recommended vinyl 3,6-dimetyloktin-4-diol-3,6 acetylene in the presence of highly basic systems at atmospheric pressure.

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