197,971 research outputs found
Strain based finite fracture mechanics for fatigue life prediction of additively manufactured samples
No full textA novel failure criterion, named Strain-based Finite Fracture Mechanics, is proposed to predict the fatigue life of additively manufactured notched components under uniaxial loading conditions. The model relies on the simultaneous fulfillment of two conditions: a non-local strain requirement and the discrete energy balance. The inputs of the model are strain and the stress intensity factor at failure, which depend on the number of cycles according to power law equations. The inputs can be obtained based on strain-life and stress intensity factor-life data from plain and notched specimens. The present approach is comprehensively validated against experimental datasets on additively manufactured samples from the literature for different materials, raster angles, notch geometries and loading conditions. Predictions by other approaches, such as Finite Fracture Mechanics (in its original stress formulation) and the Theory of Critical Distances, are also considered, for the sake of completeness. Results show that, in general, the proposed strain-based model is more accurate and provides consistently precise predictions across different cases.This work was funded by HORIZON EUROPE Marie Sklodowska-Curie Actions, 861061International Journal of Fractur
Describing variation in rump P8 fat depth of crossbred cattle from birth to slaughter
No full textH.R. Mirzaei, M.P.B. Deland, W.S. Pitchfor
Dynamic long-term expansion planning of electric vehicle parking lots considering lost opportunity cost and energy saving
No full textIn this paper, a practical approach is presented to long-term expansion planning of electric vehicle (EV) parking lots which aims to maximize the parking lot operator's profit. The optimal number, location, capacity, and time for construction or expansion of EV parking lots have also been determined. Moreover, a method based on drivers’ travel patterns is proposed to estimate the number of EVs referring to each area, in which the unscented transformation method (UTM) is used to calculate the annual growth rate of EVs. An innovative and real-time method for optimal charge and discharge scheduling of EVs is also provided, which can calculate the parking lots’ demand at different times. The most important advantages of this method are its independence from iterative-based optimization algorithms and from modeling some input parameters such as the initial state of charge (SOC) and the arrival time of EVs into the parking lot as uncertain parameters. Also, a Lagrange interpolation-based method is proposed to minimize the energy consumption required for EVs to reach a parking lot. In addition, in order to prevent the reduction of parking lot operator's profit in case of non-fulfillment of the obligations of the EV owners, an approach based on paying the lost opportunity cost (LOC) is presented. Real-world data has been used for numerical studies. The results show that based on travel patterns and estimating the number of EVs available in each municipal district and using the proposed real-time scheduling method, parking lot's demand can be calculated as the main prerequisite for parking lots expansion planning. Also, the proposed method for parking selection compared to two other methods will save energy by 26.6% and 8.33%, respectively. Moreover, the proposed approach increases the total parking lot operator's profit by 4.23%
An Application of Image Analysis to Hypersonic Flows
No full textImage-based measurement methods are becoming increasingly common in fluid dynamics and are seen in applications ranging from low subsonic to hypersonic flows. This work is focused on the use of image processing methods for investigations of hypersonic jet flows, visualized through the electron beam technique. Indications about the jets propagation and their resulting morphologies are obtained by means of several techniques carried out on fluorescent images. The main topics presented are an improved measurement technique for moving structures velocities, an image processing method for denoising and reconstruction of jet images and an optical technique for measurements of the jet spreading angles
Mylonchulus kermaniensis Shokoohi, Mehrabi-Nasab, Mirzaei & Peneva, 2013, sp.n.
No full textMylonchulus kermaniensis sp.n. (Figs. 3 & 4) Material examined. Six females, in good preservation. Measurements. See Table 2. Description Female: Body almost cylindrical, ventrally curved after fixation. Cuticle smooth under LM, 3 µm wide at mid body. Head region continuous with neck, having six lips bearing 6 + 4 papillae. Amphid openings oval, aperture 4–5 µm wide, located 9–12 µm from anterior end. Buccal cavity large, goblet -shaped, about 1.5–1.6 times as long as wide, with thick, cuticularised vertical walls, 2 µm diameter. Dorsal wall bearing a sharp, 8–10 µm long and 4–5 µm wide dorsal tooth, directed forward, located in the anterior half of buccal cavity at 56–60 % from its base; two foramina present at the base of buccal cavity lying close to each other, 4–6 µm long. Six transverse rows of rasplike denticles on subventral walls posterior to the dorsal tooth, the sixth row consisting of four denticles. Nerve ring at 40–47 % of neck length. Excretory pore opening not visible. Cardia conoid, surrounded by intestinal tissue. Reproductive system amphidelphic. Ovaries more or less straight, reflexed and with one row of oocytes. Oviduct long, 99–108 µm long, 1.6–1.9 times corresponding body diameter. Uterus 74–89 µm long, 2.1–2.3 corresponding body diameter. Vagina with parallel walls, less than half of corresponding body diameter, pars refringens vaginae with two drop-like sclerotised pieces. Vulva a transverse slit with, protruding, located posterior to mid part of body. One prevulval papilla, located 11 µm anterior to vulva and one postvulval papilla, located 26–30 µm posterior to vulva present, observed in two specimens. Eggs 1.6–2.4 times the corresponding body diameter. Rectum 0.7–0.9 times the anal body diameter. Tail slightly sigmoid, sharply bent ventrad with digitate posterior portion slightly but clearly bent dorsad. Caudal pores not observed. Caudal glands grouped, spinneret bearing terminal opening. Male. Not found. Diagnosis. Mylonchulus kermaniensis sp. nov. is characterized by its body 1.3–1.5 mm long, head region continuous, buccal capsule of medium size (24– 27 x 15–18 µm), six rows of rasp-like denticles, the sixth line of rasp-like denticles consisting of four denticles, amphidelphic reproductive system, female tail 37–49 μm long (c= 27.9–38.9, c'= 1.2–1.7), slightly sigmoid, sharply bent ventrad with digitate posterior portion slightly but clearly bent dorsad, terminal opening of spinneret. M. cf. hawaiiensis M. kermaniensis sp. n. M. truncatus Locality Jiroft Kerman Dalfard Kerman Province Kerman Kerman Soil Habitat Palm date 6 Ƥ Soil sediment N 10 Ƥ 2 Ƥ Character - Holotype Paratype - Tail length as % of total body length 4.4 ± 0.6 (3–5) 2.9 3.1 ± 0.4 (2.6–3.6) 12.4 – 11.8 Relationship. According to key of the genus Mylonchulus provided by Andrássy (1992) and modified by Ahmad and Jairajpuri (2010), the species M. sigmaturus Cobb, 1917, M. sigmaturellus Mulvey, 1961, M. agilis Doucet, 1980, M. paitensis Yeates, 1992, M. dentatus Jairajpuri, 1970 and M. sessus Jairajpuri, 1982 (considered as a synonym of M. sygmaturus by Andrássy, 1993) form a group characterized by a sigmoid tail, strongly bend ventrad with a digitate posterior portion slightly inclining dorsad and terminal opening of spinneret. Mylonchulus kermaniensis sp. n. is the most similar to M. paitensis described from New Caledonia but can be differentiated from it by different number of rasp-like denticles (6 vs 5 rows), narrower (22–25 vs 25–29 µm) and differently shaped (continuous vs wider than adjacent body) lip region, shorter buccal capsule (24–27 vs 28–29 µm), elevated vulval region (vs not elevated), presence of advulval papillae vs absent and differently shaped tail (digitate portion dorsaly bent vs straight). Tabassum et al., (2001) and Farahmand et al., (2009 a) reported as M. paitensis some specimens from Pakistan and Iran, which are morphologically similar to the studied material, however, they are different in tail morphology, absence of vulval papillae and grouped caudal glands (vs in tandem). Further, the new species can be differentiated from the closely related M. sigmaturus by its differently shaped lip region (continuous vs set off), rasp-like denticles (six vs 7–8 rows), sixth line of rasp-like denticles (bearing four denticles vs bearing more four denticles), submedian teeth (small vs large), digitate portion of tail without caudal pores vs digitate portion of tail bearing caudal pores, higher c’ values (c’= 1.3–1.7 vs 0.8 –1.0) and presence of advulval papillae vs absent; from M. sigmaturellus by its shorter body (1.3–1.5 vs 1.6–2.6 mm) and tail (37–49 vs 55–80 µm), lower c’ values (c’= 1.3–1.7 vs c’= 2–2.5) and differently shaped lip region (continuous vs offset); from M. agilis the new species differs in shorter body (L= 1.3–1.5 vs 1.6 –2.00 mm), number of rows of rasp-like denticles (6 vs 6–9 rows, sixth rows bearing four vs sixth rows bearing more denticles), narrower lip region (21.5–25 vs 30 µm), lower c values (c= 27.9–38.9 vs 37.9–67.6), buccal cavity shape (broad vs funnel shape) and length (24–27 vs 28–30 µm), vulval papillae (present vs absent) and males absent vs males present. In comparison with the M. dentatus the new species differs in number of rows of rasp-like denticles (6 vs 10–15), submedian teeth (small vs large). Finaly, the new species differs from M. sessus in the number of rows of rasp-like denticles (6 vs 7–8), anterior rows of denticles not prominent (vs prominent), larger submedian teeth (vs smaller), shorter rectum (19–25 vs 29–30 µm) and longer tail (37–49 vs 25–33 µm, c= 27.9–38.9 vs c= 47–55; c’= 1.3–1.7 vs 0.9). Type habitat and locality. The specimens were recovered from soil, Kerman (Kerman province), southeastern Iran (N: 30 ° 16 ʹ 48.97 ʺ; E: 57 °04ʹ0 1.27 ʺ) Type material. Female holotype and four female paratypes deposited in the nematode collection of Plant Protection Department, College of Agriculture, Shahid Bahonar University of Kerman, Iran. One paratype female deposited in the Laboratory of Nematology of University of Jaen (Spain). Etymology. The specific epithet refers to the locality where the species has been recovered.Published as part of Shokoohi, Ebrahim, Mehrabi-Nasab, Abdolrahman, Mirzaei, Mahdieh & Peneva, Vlada, 2013, Study of mononchids from Iran, with description of Mylonchulus kermaniensis sp. n. (Nematoda: Mononchida), pp. 519-534 in Zootaxa 3599 (6) on pages 524-528, DOI: 10.11646/zootaxa.3599.6.2, http://zenodo.org/record/22017
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Flow coupling during three-phase gravity drainage
No full textWe measure the three-phase oil relative permeability k(ro) by conducting unsteady-state drainage experiments in a 0.8 m water-wet sand pack. We find that when starting from capillary-trapped oil, k(ro) shows a strong dependence on both the flow of water and the water saturation and a weak dependence on oil saturation, contrary to most models. The observed flow coupling between water and oil is stronger in three-phase flow than two-phase flow, and cannot be observed in steady-state measurements. The results suggest that the oil is transported through moving gas-oil-water interfaces (form drag) or momentum transport across stationary interfaces (friction drag). We present a simple model of friction drag which compares favorably to the experimental data.University of Texas at AustinCenter for Frontiers of Subsurface Energy SecurityUS Department of Energy, Office of Basic Energy Sciences DE-SC0001114Petroleum and Geosystems Engineerin
An optimal strategy for differential braking to enhance vehicle stability in severe turning maneuvers
No full textInternational Conference on Applications and Design in Mechanical Engineering 2012 (ICADME 2012) organized by School of Mechatronic Engineering, Universiti Malaysia Perlis (UniMAP), 27th - 28th Februari 2012 at Bayview Beach Resort, Penang, Malaysia.In a turning maneuver with high lateral acceleration, the decrease of restoring yaw moment generated by tire lateral force is the basic cause of vehicle unstable motion called spin motion. A practical approach to generate a required external yaw moment, independent of tire lateral forces and steering angle, for recovering the vehicle stability is differential braking. In this paper, a new optimal strategy for differential braking is proposed by considering practical aspects of the problem. To achieve this aim, a control system with two layers is designed. In the upper layer, an optimal yaw moment control law is first developed by using a non-linear 2DOF plane vehicle model. Then, by considering the force capacity of each tire, the calculated external moment is adjusted to an extent that the admissible braking forces are distributed between the left and right wheels of the vehicle in the lower layer. At the end, the simulation studies are carried out to indicate the effectiveness of the proposed strategy to improve the vehicle stability in severe turning maneuvers
Face Recognition
No full textMirzaei, M. E. (2020). Review of six popular method: Face Recognition. Iberian Journal of Applied Sciences and Innovations, 1(1).Simulation of human ability has always been attractive topic for researchers but had often been limited to hardware part. With the advancement of technology and emerge of deep learning and machine learning, hope to simulate human perception increased. Face recognition is one of the most important capability of human perception that use in routine. Many researches have been done that led to proposing different approach and various methods. This paper is a survey of face recognition methods that proposed in past decades and also categorize them in meaningful approachespublishersversionpublishe
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