63,929 research outputs found
Development of a virtual reality milling machine for knowledge learning and skill training
Get PDFCurrent methods of training personnel on high cost machine tools involve the use of both classroom and hands on practical training. The practical training required the operation of costly equipment and the trainee has to be under close personnel supervision. The main aim of this project is to reduce the amount of practical training and its inherent cost, time, danger, personal injury risk and material requirements by utilising a virtual reality technology.
In this study, an investigation into the use of Virtual reality for training operators and students to use the Milling Machine was carried out. The investigation has been divided into two sections: first the development of Milling Machine in the 3D virtual environment, where the real machine was re-constructed in the virtual space.
This has been carried out by creating objects and assembling them together. The complete Milling machine was then properly modelled and rendered so it could be viewed from all viewpoints.
The second section was to add motion to the virtual world. The machine was made of functions as for the real machine. This was achieved by attaching Superscape Control Language (SCL) to the objects. The developed Milling machine allows the users to choose the material, speed and feed rate. Upon activation, the virtual machine will be simulated to carry out the machining process and instantaneous data on the machined part can be generated.
The results were satisfactory, the Milling Machine was modelled successfully and the machine was able to perform according to task set. Using the developed Virtual Model, the ability for training students and operators to use the Milling Machine has been achieved
Folio
No full textEducation SpecialEditorial. pp. v-vii; Profile-The Principal. pp. 1-2; Anwar M. Barkat-Article-The Goals of Education at F.C. pp. 3-8; Interview with Mr Abdul Hafeez Pirzada. pp. 9-15; Interview with Dr Abdul Khaliq. pp. 16-37; Interview with Dr Mohammad Ajmal. pp. 38-44; Interview with Dr Z. A. Hashmi. pp. 45-50; Interview with Dr (Miss) Kaneez F. Yousus. pp. 51-56; Anwar M. Barkat-Article-Asian University in the Perspective of Development and Modernization. pp. 57-61; Cyprian, Eric-Article-Thoughts on Education in Pakistan Today. pp. 62-63; Schlorholtz, A. A.-Attitude, Latitude, Gratitude. pp. 64-68; Sabeeh ur Rehman-Things I Want to Say. pp. 69-74; Mohammad Ahmed-Article-Need of Physical Education. pp. 75-77; Iqbal, M. Anwar-Teachers are Difficult for Students. pp. 78-80; Irteza Shah-Article-Education and its Place in our Society. pp. 81-83; Kaleem Omer-Poetry-Kashmir Diary. pp.84; Kaleem Omer-Poetry-Naming a Son. pp. 85; Akhar Tahir-Poetry-Fields. pp. 86; Akhar Tahir-Poetry-Album. pp. 87; Alamgir Hashmi-Poetry-Galillee. pp. 88-89; Alamgir Hashmi-Poetry-F.C.C. Bridge. pp. 90-91; Alamgir Hashmi-Poetry-By the F.C.C. Canal. pp. 92; Nasim Akhter-Poetry-A Visit. pp. 93; Naseer Ahmed-Poetry-In the Evening of Behrain. pp. 94; Naseer Ahmed-Poetry-How I Met My Father's Death. pp. 95; Danish Farhad-Poetry-The Misogynist. pp. 96; Irteza Shah-Poetry-My Love. pp. 97; Afsar Jahan-Poetry-For a Change. pp. 98; John Shaffaq-Poetry-Life. pp. 99; Ashtar Ausaf-Poetry-Apples Have Borrowed. pp. 99; Ashtar Ausaf-Poetry-Above the Trees. pp. 100; Agha Zulqarnain-Poetry-She is Dead. pp. 101; Irteza Shah-Story-Five Soldiers. pp. 102-104; Tahir Sarwar-Story-The Slave. pp. 105-110; Nazli Saleem-Story-The Sacrifice. pp. 111-113; Ghazala Anis-Story-Who Never Turned Up. pp. 114-117; Condolence: Dr E. M. Ewing. pp. 118; Condolence: Professor Z. Bede. pp. 119; Condolence: Gen Nasir-ud-Din. pp. 119; A Letter from Dr E. J. Sinclair. pp. 119; Iqbal Mirza-Dr E. J. Sinclair. pp. 120-122; Iqbal Mirza-Professor R. C. Thomas. pp. 123-125; Tahir Sarwar-Essay-A Visit to a Girls College. pp. 126-128; Haroon Omar-Essay-Man at Cross Roads. pp. 129-131; Abdul Mateen Khan-Essay-Food Crisis in Islamic Countries. pp. 132-133; Ghazala Anis-Essay-Human Happiness. pp. 134-136; Shahid Mahmood-Essay-Reverie. pp. 137-140; Shahid Ghafoor-Essay-Students and Politics. pp. 141-142; Professor Iqbal Mirza and Ashtar Ausef-F. C. Round Up. pp. 143-146; Contributors. pp. 147-148; Folio [Urdu] 128 p.Folio Editors. after contents; Dr Anwar M. Barkat, Principal. before page 1; Prof. Z. Bede (Late). after page 118; Dr R. M. Ewing (Late). after page 118; Prof. R. C. Thomas. after page 122; FCC: a survey (Cartoon). after page 146; Mualana Syed Farzand Ali. after page 8 (Urdu section); General Nasir Ali. after page 6 (Urdu section); Bazm-e-Adab 1973-74. before contents (Urdu section
Thermal expansion anomalies of R(Fe, M)(12) (R=Y, Nd; M=Mo and Si)
No full textStructural and thermal-expansion anomaly studies on R(Fe,M)(12) (R=Nd and and Y, M=Mo and Si) compounds were performed by x-ray diffraction. Mo atoms occupy the 8i site. While Si atoms occupy the 8f and 8j sites but not the 8i site. Thermal-expansion anomaly shows only in ab plane in the Mo compounds, while becomes very weak and along with only the c axis in the Si compounds. The anomaly was attributed to the contribution of the interactions of short Fe-Fe distances similar to the previous explanation on other R-Fe intermetallics and that of other strongly positive interactions such as 8j-8j. (c) 2005 American Institute of Physics.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000230168300025&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Physics, AppliedSCI(E)EICPCI-S(ISTP)
Investigation into laser re-melting of inconel 625 HVOF coating blended with WC
Get PDFHigh velocity oxy-fuel (HVOF) spraying of Diamalloy 1005 powders mixed with WC particles onto steel (304) is considered and laser re-melting of the resulting coatings is examined. Laser re-melting process is modeled to determine the melt layer thickness while temperature increase is formulated using the Fourier heating law. The morphological and metallurgical analyses prior and post laser re-melting process are carried out using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). X-ray diffraction (XRD) technique is used to determine the residual stress developed in the coating while the analytical formulation is adopted to predict the residual stress levels at the coating base material interface. The indentation tests are carried out to determine the Young’s modulus and fracture toughness of the coating prior to laser re-melting. Corrosion resistance of coating is measured using potentiodynamic polarization technique prior and post laser treatment process. The predictions of the melt layer thickness are in good agreement with experimental results. The presence of WC particles modifies temperature rise and its gradient in the coating while affecting the Young’s modulus, residual stress levels, and fracture toughness of the coating. The differences in the thermal properties of Inconel 625 powders and WC particles result in formation of small size cellular structure through polyphase solidification. WC dissolution in the central region of the large polycrystalline cells is observed due to the loss of carbon through carbonic gas formation. The results of corrosion tests prevail that significant improvement of corrosion resistance can be achieved after laser treatment process
Mechanical and metallurgical properties of two-layered diamalloy 4010 and 2002 HVOF coating
Get PDFDiamalloy 4010, which is iron/molybdenum blend, is resistive to wear and Diamalloy 2002 is resistive to corrosion and wear. However, combination of these powders in layered structure, may offer advantages over the individual powders. In this case, mechanical properties of the resulting layered structure could be improved. Consequently, investigation into mechanical and metallurgical properties of the resulting structure is necessary. High Velocity Oxy-Fuel coating of Diamalloy 2002 [(WC12Co)50,Ni33Cr9Fe3.5Si2B2C0.5] powders and Diamalloy 4010 [Fe68Mo30Cr1.8Mn0.2] powders as well as two-layered coatings consisting of these powders was carried out. In the two-layered structure, Diamalloy 4010 was sprayed at the substrate surface while Diamalloy 2002 was sprayed on the top of Diamalloy 4010 coating. The coating microstructure and morphology were examined using optical microscope, Scanning Electron Microscope (SEM) and Energy Dispersive Spectroscopy (EDS). The indentation tests were carried out to evaluate the microhardness and surface elastic modulus of the resulting coatings. The mechanical properties of the coatings were examined through tensile and three-point bending tests. It was found that the coating produced for Diamalloy 2002 resulted in higher hardness than that corresponding to Diamalloy 4010. The failure mechanism of coating during tensile and three-point bending tests was mainly crack formation and propagation in the coating. The elastic modulus of coating produced from Diamalloy 2002 was higher than that of Diamalloy 4010 coating, which was due to the presence of 12% WC in the coating. The irregularities observed in the elastic limit of the curves indicated the formation of cracks in the coatings, which was particularly true for two layered coating. The shear stress developed at interface of the two-layered coating was responsible for the crack initiation in the coating. The deep cracks were also formed in the coatings after the tensile tests. This was attributed to the local stress centers, which increased the stress intensity under the tensile load
Letter from Thomas R. Bodine, American Friends Service Committee Seattle office, to Mary M. Kimber, May 25, 1942
No full textLetter from Thomas R. Bodine to Mary M. Kimber, asking Kimber to visit individuals from the Puget Sound area incarcerated at Pinedale Assembly Center: Rev. Daisuke Kitigawa, Waichi Oyanagi, Chisako Higuchi, Mutsuo Hasiguchi and Mrs. Matsuoka, Makato Kobukata, the Hirabayashi family, and Violet Yokoyama. A note in pencil at the top of the page: "Burcham." A response letter from Grace and Calvin Coke to Thomas R. Bodine is found in item: chs_ms840_0306.Personal correspondence, organizational records, government documents, publications, and other papers created or collected by Joseph R. Goodman documenting the forced removal and incarceration of Japanese Americans during World War II, as well as organized resistance to incarceration. Included in the collection are records of the Japanese Young Men's Christian Association and the Japanese American Citizens' League in San Francisco, including papers of the Japanese YMCA's executive secretary Lincoln Kanai; Sakai family papers; Goodman's correspondence to and from Japanese American incarcerees, organizations opposing forced removal and incarceration of Japanese Americans, the War Relocation Authority, and others; publications, photographs, and ephemera from the Topaz Relocation Center, where Goodman taught high school; War Relocation Authority records and publications; and newspaper clippings, pamphlets, and reports about forced removal and incarceration created by various government, religious, and civic organizations, in California and nationwide
Bending analysis of switchable frequency selective surface based on flexible composite substrate
Get PDFIn this paper presents a switchable frequency selective surface (FSS) based on composite flexible substrate has been investigated. To make the FSS switchable, various combinations of switches are used. The design is bent E-field and H-field directions over various bending curvatures and the corresponding behavior is analyzed. It is observed that design has less variation when bending is applied along H-field direction. Whereas, slight variations are observed when bending is applied along the E-field direction. It is noted that the design exhibits stop band and pass band characteristics. Furthermore, in pass band it provides single wideband and dual band operations. These characteristics are preserved when bending is applied, thus making it suitable for wearable applications and modern communication systems
Investigation into coatings produced from nanoparticle blended feedstock for rotating equipment repair applications
Get PDFCoating of carbon steel with conventional and nano particle blended feedstock material is considered in relation to repair applications of rotating equipment. Gas Metal Arc Welding (GMAW) and Wire Arc Spray (WAS) processes are used to produce the coatings on carbon steel workpieces. The wire arc sprayed workpieces are heat treated at temperature similar to the operating temperature of hot-path components of power gas turbines. The microstructure and metallurgy of the workpieces are examined using the Scanning Electron Microscope (SEM), Optical Microscope, Energy Dispersive Spectroscopy (EDS), X-ray Diffraction (XRD). The indentation tests are carried out to assess the microhardness variation across the coatings. In the case of coatings produced by GMAW, it is found that fine structures are formed in the coating due to the presence of nano particles and they resulted in increased microhardness of the coatings. In the case of the wire arc sprayed workpieces, the formation of dimples like structure at the surface increases the surface roughness of the coatings. In addition, the microhardness of the resulting coating is significantly higher than that of the base material. The heat treatment does not alter the microstructure and microhardness of the coatings significantly
A 2 h periodic variation in the low-mass X-ray binary Ser X-1
No full textSpectroscopy of the low-mass X-ray binary Ser X-1 using the Gran Telescopio Canarias have revealed a ?2 h periodic variability that is present in the three strongest emission lines. We tentatively interpret this variability as due to orbital motion, making it the first indication of the orbital period of Ser X-1. Together with the fact that the emission lines are remarkably narrow, but still resolved, we show that a main-sequence K dwarf together with a canonical 1.4 M? neutron star gives a good description of the system. In this scenario, the most likely place for the emission lines to arise is the accretion disc, instead of a localized region in the binary (such as the irradiated surface or the stream-impact point), and their narrowness is due instead to the low inclination (?10°) of Ser X-1
Sidelobe Suppression in Resonant Cavity Antennas through Near-field Analysis
No full textThis paper describes an effective approach to reduce the high sidelobe levels (SLLs) in resonant cavity antennas (RCAs) with small footprints. The objective is to first understand the reason behind the high SLL in compact RCAs and than improve its radiation characteristics. For this, a near-field to far-field transformation routine is implemented in MATLAB, which allows to understand the individual effects of near-field amplitude and phase distributions on the SLL in the far-field patterns. This approach resulted in an optimal electric-field distribution, which is realized by a dielectric partially reflecting superstructure (PRS) exhibiting a broadside directivity of 19.5 dBi with significantly low sidelobe levels of -30dB in both the principle planes. It is important to note that the proposed approach can be linked easily with global optimization techniques to fit the radiation patterns within specific pattern masks
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