“The PaakShooy”: A Robotics Cell for Washing and Preparation of a Corpse for an Islamic Burial

A. Meghdari,K. G. Osgouie,E. Nasiri,A. R. Nemati,A. M. Mortazavi 제어로봇시스템학회 2011 제어로봇시스템학회 국제학술대회 논문집 Vol.2011 No.10

Washing the body and dressing the corpse prior to burial is an act of love and necessity in many religions. Applying robotics and automation technologies for washing and preparation of a deceased Moslem in accordance to the Islamic Shari’a laws has been the challenging foundation of this research. With increasing annual population growth and as a result an increase in number of deaths (historically and/or immediately after a national disaster), automating part of this procedure to increase speed of operation, reducing the health risks to the personnel of washing rooms “Ghassalkhaneh” at the cemeteries and enhancing their quality of life has been the utmost objective of this project. We have named and patented this semi-automated corpse preparation machine as the “PaakShooy” or “ ??? ??? ” in Persian (Farsi) which means purifying the deceased. The whole process is composed of three operational units lined up in series; the automatic washing chamber, drying cell, and the semi-automatic shrouding table. This paper covers an introductory concept of the subject in Islam, a conceptual design of various machines and mechanism to automate the important tasks in accordance to Islamic laws, and the final detailed design, simulation, and animation of the PaakShooy machine. In doing so, consultation with Islamic scholars has been a priority from the beginning of the project to the end.

Comprehensive Evaluation of Fast-Response, Reynolds-Averaged Navier-Stokes, and Large-Eddy Simulation Methods Against High-Spatial-Resolution Wind-Tunnel Data in Step-Down Street Canyons

Hayati, Arash Nemati,Stoll, Rob,Kim, J. J.,Harman, Todd,Nelson, Matthew A.,Brown, Michael J.,Pardyjak, Eric R. Springer-Verlag 2017 Boundary-layer meteorology Vol.164 No.2

<P>Three computational fluid dynamics (CFD) methods with different levels of flow-physics modelling are comprehensively evaluated against high-spatial-resolution wind-tunnel velocity data from step-down street canyons (i.e., a short building downwind of a tall building). The first method is a semi-empirical fast-response approach using the Quick Urban Industrial Complex (QUIC-URB) model. The second method solves the Reynolds-averaged Navier-Stokes (RANS) equations, and the third one utilizes a fully-coupled fluid-structure interaction large-eddy simulation (LES) model with a grid-turbulence inflow generator. Unlike typical point-by-point evaluation comparisons, here the entire two-dimensional wind-tunnel dataset is used to evaluate the dynamics of dominant flow topological features in the street canyon. Each CFD method is scrutinized for several geometric configurations by varying the downwind-to-upwind building-height ratio () and street canyon-width to building-width aspect ratio (S / W) for inflow winds perpendicular to the upwind building front face. Disparities between the numerical results and experimental data are quantified in terms of their ability to capture flow topological features for different geometric configurations. Overall, all three methods qualitatively predict the primary flow topological features, including a saddle point and a primary vortex. However, the secondary flow topological features, namely an in-canyon separation point and secondary vortices, are only well represented by the LES method despite its failure for taller downwind building cases. Misrepresentation of flow-regime transitions, exaggeration of the coherence of recirculation zones and wake fields, and overestimation of downwards vertical velocity into the canyon are the main defects in QUIC-URB, RANS and LES results, respectively. All three methods underestimate the updrafts and, surprisingly, QUIC-URB outperforms RANS for the streamwise velocity component, while RANS is superior to QUIC-URB for the vertical velocity component in the street canyon.</P>

The effect of additives on the properties of HAp-Al2O3 nano-composite powders

S. Tayebi,F. Mirjalili,H. Samadi,A. Nemati 한양대학교 세라믹연구소 2016 Journal of Ceramic Processing Research Vol.17 No.10

Hydroxyapatite is the most important bio ceramic, due to its structure and chemical composition which is similar to bone. Since feeble fracture toughness, brittleness and low tensile strength have restricted their use, for overcoming this problem, theywere often used as a secondary component. HAp-Al2O3 nano-composite powder combined the benefits of biocompatibility ofHAp and high strength of Al2O3. When HAp-Al2O3nano-composite powders were sintered at a higher temperature than 1100-1200 oC, HAp was decomposed and converted to the second phase of TCP, due to the formation of calcium aluminateincreasing decomposition speed of HAp to TCP at higher degree than 1100-1200 oC temperatures; therefore, with the additionof additives to the powders, the decomposition reaction of HAp could be inhibited and the properties could be improved. Inthis study the effects of alumina as reinforcement, pH, surfactant and different additives were investigated. At first,hydroxyapatite powder was synthesized. Then, the effect of different percentage of alumina (15, 20, 25), different pHs (9, 10,11), different surfactants and different additives on HAp-Al2O3 nano-composite powder were studied. The results showed thatthe addition of different additives resulted in increase of the thermal stability and properties of HAp-Al2O3nano compositepowder. By replacement of Cl− and F−ions with OHinHAp structure, decomposition of HAp decreased and stability of HApat higher temperatures was increased. Owing to the decomposition of HAp, the reaction between CaO and Al2O3 reduced;therefore, the amount of calcium alumina phases decreased something which resulted in Al2O3 phase. Moreover, replacementof Cl−and F−ions in the apatite structure limited the growth of the grains and decreased the crystallinity that led to a bettersolubility and bioactivity behavior of nano composite powder.

Effect of BN whisker-like additive on the flexural strength of Si3N4 ceramics prepared by gel casting method

M. Vaseghi,S. Baghshahi,M. Mashhadi,A. Nemati 한양대학교 세라믹연구소 2019 Journal of Ceramic Processing Research Vol.20 No.2

The gel casting method was used for the production of Si3N4 porous ceramics with 25 vol% solid loading, and the effect ofadding 1 and 3 wt.% of BN whisker-like (synthesized in the laboratory) on the flexural strength of the composites wasinvestigated. The gel-cast samples were prepared using an AM-MBAM monomer system and deionized water solvent. The gelcast bodies were dried at ambient temperature and humidity for 48hrs. The burnout process was carried out at 600 oC for14hrs in the air. The samples were then subjected to heat treatment at 1650 oC for 2 hrs in a bed of 50% Si3N4-50% BN. Resultsshowed that BN whisker-like were agglomerated in deionized water. To solve this problem and to properly disperse thewhisker-like in the slurry, active surface agent groups were employed. Adding BN whisker-like to ceramic bodies, increasedthe porosity from 33% in samples without BN to 46% in samples containing 3 wt% BN whisker-like, resulting in a decreasein the density from 1.8 g/cm3 to about1.61 g/cm3. Since the Si3N4 ceramics require aids for the sintering, SiO2 and Y2O3additives were used with a ratio of 1 to 2, respectively, which led to the formation of Si2N2O phase. Si2N2O is similar to theSi3N4 phase in terms of the thermal expansion coefficient and chemical properties. Because of its rod shaped morphology, ithas a similar function to β-Si3N4 phase in improving the mechanical properties of the ceramic. Although porosity in theceramics containing 3 wt.% BN whisker-like was higher than those containing 1 wt.%, the porosity created vacant spaces forfurther growth of Si2N2O-rod shaped grains and in spite of higher porosity, better flexural strength was achieved for bodieswith 3 wt.% BN whisker-like. Also, in bodies without BN whisker-like, the flexural strength was 88 MPa, due to the lowporosity and the presence of stretched Si2N2O grains.

탄소 강화 코팅의 트라이볼로지적 특성에 관한 연구

안르 우(A. Yu),메티 카뎀(M. Khadem),나르게스 네마티(N. Nemati),올릭세이 펜코브(O. V. Penkov),김창래(C. L. Kim),김대은(D. E. Kim) 한국트라이볼로지학회 2015 한국트라이볼로지학회 학술대회 Vol.2015 No.4

Effects of rod-like BN on dielectric and mechanical properties of Si3N4 porous composite prepared via gelcasting method

M. Vaseghi,S. Baghshahi,M. Mashhadi,A. Nemati 한양대학교 세라믹연구소 2019 Journal of Ceramic Processing Research Vol.20 No.5

Gel-casting is an appropriate method for manufacturing porous parts with complicated forms, which has also been used in shaping Si3N4 bodies. In the present study, porous bulk Si3N4 samples were fabricated using gel-casting. To this aim Si3N4 slurries were prepared with solid loading of 35 vol%. To the slurry was added 1 and 3 wt% rod-like BN to enhance the mechanical properties. BN was selected to further reduce the dielectric constant and loss of the prepared porous Si3N4 samples. The findings suggested that employing rod-like BN increased the porosity from 38 % to 41 %, reducing the flexural strength from 77 MPa in the part without BN to 56 MPa in the part containing 3 wt% BN. On the other hand, dielectric properties reduced in the parts with BN compared with the part without BN.

Trading off between dynamic strain aging and substructure evolution in κ-carbide-free lightweight steel at room temperature

Abedi, H.R.,Zarei Hanzaki, A.,Nemati, N.,Kim, Dae-Eun Elsevier 2018 Scripta materialia Vol.157 No.-

<P><B>Abstract</B></P> <P>The previous proposed models to describe the room temperature dynamic strain aging of twinning-induced-plasticity steels appear to be theoretically invalid in the case of lightweight grades. The proposed theory in the present work accentuates the high capability of the experimented dilute solid solution in progressive formation and refinement of the cell structures. The higher dislocation population in the cell-walls in comparison to that of cell-interiors is viable enough to increase the stress assisted drift and stimulate the sub-boundaries preferred sites to accommodate the solutes. The short-range dislocation core diffusion enables the cell-walls to assist the strain aging to occur.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>