Abstract

Hexapod robot is a flexible mechanical robot with six legs. It has the ability to walk over terrain. The hexapod robot look likes the insect so it has the same gaits. These gaits are tripod, wave and ripple gaits. Hexapod robot needs to stay statically stable at all the times during each gait in order not to fall with three or more legs continuously contacts with the ground. The safety static stability walking is called (the stability margin). In this paper, the forward and inverse kinematics are derived for each hexapod’s leg in order to simulate the hexapod robot model walking using MATLAB R2010a for all gaits and the geometry in order to derive the equations of the sub-constraint workspaces for each

The presented work shows a preliminary analytic method for estimation of load and pressure distributions on low speed wings with flow separation and wake rollup phenomena’s. A higher order vortex panel method is coupled with the numerical lifting line theory by means of iterative procedure including models of separation and wake rollup. The computer programs are written in FORTRAN which are stable and efficient.

      The capability of the present method is investigated through a number of test cases with different types of wing sections (NACA 0012 and GA(W)-1) for different aspect ratios and angles of attack, the results include the lift and drag curves, lift and pressure distributions along the wing s

Binary mixtures of three, heavy oil-stocks was subjected to density measurements at temperatures of 30, 35 and 40 °C. and precise data was acquired on the volumetric behavior of these systems. The results are reported in terms of equations for excess specific volumes of mixtures. The heavy oil-stocks used were of good varity, namely 40 stock, 60 stock, and 150 stock. The lightest one is 40 stock with °API gravity 33.69 while 60 stock is a middle type and 150 stock is a heavy one, with °API gravity 27.74 and 23.79 respectively. Temperatures in the range of 30-40 °C have a minor effect on excess volume of heavy oil-stock binary mixture thus, insignificant expansion or shrinkage is observed by increasing the temperature this effect beco

In this study many specimen s were prepared from 2024-T3 Aluminum alloy for corrosion test by the dimensions of (15*15*3) mm according to ASTM G71-31 and then subjected to shot peening process at different time (15, 30, 45) minutes using steel ball having a diameter of 2.75 mm and Rockwell Hardness of 55R_C to induce compressive residual stress which were measured using X-Ray diffraction method, surface roughness and   hardness were tested before and after peening. Electrochemical corrosion test by Tafel extrapolation method was carried out in an environment of 3 .5% NaCl solutions (sea water) where Corrosion rate calculated using Tafle equation.

The obtained results show a favorable influence of SP treatment

This study is an approach to assign the land area of  Kirkuk city [ a city located in the northern of Iraq, 236 kilometers north of  Baghdad  and 83 kilometers  south of  Erbil [ Climatic atlas of  Iraq, 1941-1970  ]  into different  multi zones by using Satellite image and Arc Map10.3,  zones of different traffic noise pollutions. Land zonings process like what achieved in this paper will help and of it’s of a high interest point for the future of Kirkuk city especially urban

Abstract

    This work deals with a numerical investigation to evaluate the utilization of a water pipe buried inside a roof to reduce the heat gain and minimize the transmission of heat energy inside the conditioning space in summer season.     The numerical results of this paper showed that the reduction in heat gain and energy saving could be occurred with specific values of parameters, like the number of pipes per square meter, the ratio of pipe diameter to the roof thickness, and the pipe inlet water temperature. Comparing with a normal roof (without pipes), the results indicated a significant reduction in energy heat gain which is about 37.8% when the number of pipes per m

This study investigates the potential of spent tea leaf-derived activated carbon (STLAC) as an adsorbent for phenol removal from simulated wastewater using a packed-bed adsorber. STLAC was prepared via chemical activation through impregnation with potassium hydroxide, followed by carbonization under controlled conditions. The physicochemical characterization of the prepared activated carbon has been confirmed. Response surface methodology (RSM) with central composite design (CCD) was utilized to optimize four operating parameters: flow rate, initial phenol concentration, bed height, and pH. A quadratic mathematical model was developed to describe the relationship between these parameters and removal efficiency. Results demonstrate the hi

Efforts to combat the recent spread of infectious diseases require innovative solutions for characterizing their transmission. This study introduces a system for helping people maintain safe distances from one another, thereby decreasing the transmission of infectious diseases in crowded public spaces. Real-time video footage from surveillance cameras was processed by the cutting-edge “You Only Look Once” ver. 8 (YOLOv8) computer vision model, which can detect and segment individuals in images. YOLOv8 was combined with an embedded system that includes an Atmel 8-bit AVR microcontroller and an Arduino Uno board, a buzzer, and an LCD. This proposed system can generate alerts when people breach the set social distancing limit of 0.5 m.

 In this study, cefixime (CFX) was removed from aqueous solutions by using activated carbon (AC) made from broad bean peels (BBPs). To evaluate the adsorbent performance, a conventional experimental approach (one factor at a time) was applied to clarify the impact of the most influential variables (i.e., pH, contact time, and adsorbent dosage) and identify the maximum adsorption capacity. The optimization approach of response surface methodology with a Box–Behnken design (BBD) was employed to investigate the synergistic influences of the three independent variables and determine the optimum experimental conditions. Removal efficiency (%) was evaluated at different pH (2–10), contact time (10–150 min), and adsorbent dosage (0.1–2

This work introduces a novel design of a compact broadband metamaterial (MM) absorber with polarization-insensitive, wide-angle reception for ambient electromagnetic (EM) power harvesting applications. The proposed MM unit cell consists of two layers of low-cost FR-4 substrate. The top layer contains a resonator structure and four lumped resistors. A copper sheet, serving as a ground plane, is placed on the backside of the bottom layer to reduce transmission losses. The top and bottom layers are separated by a thin air layer to enhance absorption at operational frequencies. The overall size of the MM unit cell is 12×12×4.57 mm³, with measurements of 0.16λ₀×0.16λ₀×0.06λ₀ at the lowest frequency in the absorption spectrum. Th

على مدى العقود القليلة الماضية، أدى ارتفاع الطلب العالمي على الطاقة إلى نشوء نمو هائل في قطاع الطاقة، وما ترتب على ذلك من عواقب وخيمة على البيئة. ونتيجة لذلك، بدأ الكوكب بأكمله في التحول إلى توليد الطاقة الخضراء، والتي ليس لها أي آثار سلبية على العالم الطبيعي. تتمتع الكهرباء الشمسية بأعلى كفاءة مقارنة بأشكال الطاقة المتجددة الأخرى. تتناول هذه الدراسة أداء الشبكة الشهرية لمنشأة طاقة شمسية افتراضية بقدرة 100 م

في الجيل الخامس (5G) وأنظمة الاتصالات اللاسلكية المستقبلية، يعد التفاعل بين المدخلات والمخرجات المتعددة (MIMO) والموجات المليمترية (mmWaves) أمرًا مهمًا. يتيح عرض النطاق الترددي الموسع لنطاقات mmWave نشر هوائيات متعددة ، مثل تلك الموجودة في الهواتف الذكية أو الخلايا الصغيرة، مما يتيح أنظمة MIMO بترددات أعلى. يعد الجمع بين <

يتسبب المشي في حدوث الصدمات للاقدام البشرية  وعليه ستتولد قوى  متسارعة وذات  قيم عالية نتيجة لتكرار هذا التصادم والتي يتركز  تاثيرها بالدرجة الاساس  على الكاحل .ان تغيير الزخم بين الكتلة المكافئة للطرف لدى ارتطامه بالارض سيولد اقصى قيم للتصادم وكذلك الحال عند توقف  اجزاءه  المتحركة عن الحركة  .ينتج الزخم على القدم من جراء تاثير تبادل الزخم بين مكونات الطرف ومن  جساءة او مرونة كعب الحذا

In this work, manganese and niobium were added to high-chromium white cast iron, from which drilling and grinding tools were made. Two melts with different proportions of manganese and niobium (manganese 2.75% and niobium 0.49%, manganese 3.5% and niobium 1.1%) were used. High-chromium white cast iron is considered one of the most important alloys in heavy-duty applications, and its properties are affected by the added alloying elements and heat treatment. Niobium can increase corrosion resistance and hardness, form carbides, enhance thermal conductivity and improve response to heat treatment. As for manganese, it can increase impact toughness, remove oxygen from iron oxide and reduce flexibility. The heat treatment was carried out in ac

Earth–air heat exchangers (EAHE) hold great promise for reducing typical air conditioning systems’ energy consumption whilst preserving high indoor comfort. The present analyses a 3D model using COMSOL Multiphysics software for a geothermal heat exchanger to examine the thermal behavior along the piping system. The experimental findings of the real EAHE in Baghdad City during January and June are transferred into the nonisothermal pipe flow interface for modeling temperature, velocity and pressure distributions along the piping system. The temperature variation of subsurface soil and the radial temperature distribution around the pipe are modeled into the heat transfer interface.  The magnitude of heat flux is also computed in diffe

Companies compete greatly with each other today, so they need to focus on innovation to develop their products and make them competitive. Lean product development is the ideal way to develop product, foster innovation, maximize value, and reduce time. Set-Based Concurrent Engineering (SBCE) is an approved lean product improvement mechanism that builds on the creation of a number of alternative designs at the subsystem level. These designs are simultaneously improved and tested, and the weaker choices are removed gradually until the optimum solution is reached finally. SBCE implementations have been extensively performed in the automotive industry and there are a few case studies in the aerospace industry. This research describe the use o

Wireless sensor networks (WSNs) are emerging in various application like military, area monitoring, health monitoring, industry monitoring and many more. The challenges of the successful WSN application are the energy consumption problem. since the small, portable batteries integrated into the sensor chips cannot be re-charged easily from an economical point of view. This work focusses on prolonging the network lifetime of WSNs by reducing and balancing energy consumption during routing process from hop number point of view. In this paper, performance simulation was done between two types of protocols LEACH that uses single hop path and MODLEACH that uses multi hop path by using Intel Care i3 CPU (2.13GHz) laptop with MATLAB (R2014a). Th

This work provides a historical overview of water storage tanks used for solar energy collection, with a focus on the impact of different geometric configurations on thermal performance and energy storage efficiency. The designs of cylindrical, spherical, rectangular and triangular tanks were reviewed to analyse their effects on thermal gradients, heat retention and energy storage capacity. Within the scope of nominal processes, the study primarily aimed to identify the factors influencing the choice of tank shape in terms of size, capacity and aspect ratio. Another key objective was to assess what enhances heat storage in the tank to improve thermal efficiency. Comparing cylindrical shapes to other shapes, such as spherical, rectangular

This study proposes a robust control approach for vehicular dynamic system speed control. The proposed method combines a sliding mode controller with a feedback linearization technique. Considering the high nonlinearity of the vehicle dynamic system model, feedback linearization is used to transform the vehicle dynamic system into a linear system. A Lyapunov theorem is used to approve the stability of the proposed controller. Moreover, a proportional integral derivative (PID) controller with genetic algorithms is used for comparison. The integral absolute error (IAE) is used as the performance comparison index between controllers. Simulation results show that the proposed method can achieve excellent performance with high robustness agai

The steady state performance of the counter rotating floating ring Journal bearing is analyzed with isothermal finite bearing theory. The effect of different parameters affecting the performance of the bearing (namely speed ratio, clearance ratio and radii ratio), have been investigated. The load carrying capacity of the bearing increasing with decreasing the radii ratio (R₂/R₁) of the ring and clearance ratio (c₁/c₂), in the other hand, the coefficient of friction increases with increasing the clearance and radii ratios, while decreases with incre4asing the bearing to journal speed ratio (γ). It is shown during this work that different operating conditions are greatly enhanced the performance

New azo-Schiff base compounds were prepared by different processes using (p-fluorophenyl)-1,3,4-thiadiazoles, and their role as corrosion inhibitors for carbon steel alloy in acidic media such as 0.1 M HCl at 298 K was investigated. Spectroscopic methods such as FT-IR and NMR were used to characterise the compounds, and potentiodynamic polarization curves were employed to evaluate their corrosion inhibition. p-Aminoacetophenone was react withed 2-(5-(4-fluorophenyl)-1,3,4-thiadiazol-2-yl) acetohydrazide (A1) to prepare N ′-(1-(4-aminophenyl) ethylidene)-2-(5-(4-fluorophenyl)-1,3,4-thiadiazol-2-yl) acetohydrazide (A2). Azo-Schiff bases (A3-A6) were synthesised by combining the prepared diazonium salts with different phenols. These compo

The present work presents design and implementation of an automated two-axis solar tracking system using local materials with minimum cost, light weight and reliable structure. The tracking system consists of two parts, mechanical units (fixed and moving parts) and control units (four LDR sensors and Arduino UNO microcontroller to control two DC servomotors). The tracking system was fitted and assembled together with a parabolic trough solar concentrator (PTSC) system to move it according to information come from the sensors so as to keep the PTSC always perpendicular to sun rays. The experimental tests have been done on the PTSC system to investigate its thermal performance in two cases, with tracking system (case 1) and without trackin

Friction stir welding (FSW) is an innovative solid joining operation that has recently been intensively adopted in welding various similar and dissimilar metallic materials, including aluminum, steel, titanium alloys, and others. The success of FSW relies on a set of parameters like rotational speed, travel speed, axial force, tool geometry, etc. The role of tool geometry (involving both pin and shoulder design) is highly important in producing sound and high-strength weld joints. Therefore, this research aims to review the latest published works regarding the performance of different tool geometries. The discussion of the findings of the cited works revealed that each tool pin design has shown different behavior due to the various stirr

This study involves adding nano materials and interaction with cement mortar behavior for several mortar samples under variable curing time with constant water to cement ratio (W/C = 0.5). The effects of adding nano materials on the microstructure of cement mortar were studied by (Scanning Electronic Microscopy (SEM) and X-Ray (for samples at different curing time 28 and 91 days. Small ratio replacements of nano particles (SiO₂ or Al₂O₃) were added to Ordinary Portland Cement (OPC) type (I). The percentage of nano materials additives replacement by weight of ordinary Portland cement includes (1, 2, 3, 4 and 5%) for both types of nano materials with constant (W/C) ratio, also the amount of the fin

Abstract

 One of the major components in an automobile engine is the throttle valve part. It is used to keep up with emissions and fuel efficiency low. Design a control system to the throttle valve is newly common requirement trend in automotive technology. The non-smoothness nonlinearity in throttle valve model are due to the friction model and the nonlinear spring, the uncertainty in system parameters and non-satisfying the matching condition are the main obstacles when designing a throttle plate controller.

In this work, the theory of the Integral Sliding Mode Control (ISMC) is utilized to design a robust controller for the Electronic Throttle Valve (ETV) system. From the first in

In this paper, a compact multiband printed dipole antenna is presented as a candidate for use in wireless communication applications. The proposed fractal antenna design is based on the second level tent transformation. The space-filling property of this fractal geometry permits producing longer lengths in a more compact size. Theoretical performance of this antenna has been calculated using the commercially available software IE3D from Zeland Software Inc. This electromagnetic simulator is based on the method of moments (MoM). The proposed dipole antenna has been found to possess a considerable size reduction compared with the conventional printed or wire dipole antenna designed at the same design frequency and using the same substrate

The reduction of vibration properties for composite material (woven roving E-glass fiber plies in thermosetting polyester matrix) is investigated at the prediction time under varied combined temperatures (60  to -15) using three types of boundary conditions like (CFCF, CCCF, and CFCC). The vibration properties are the amplitude, natural frequency, dynamic elastic moduli (young modulus in x, y directions and shear modulus in 1, 2 plane) and damping factor. The natural frequency of a system is a function of its elastic properties, dimensions, and mass. The woven roving glass fiber has been especially engineered for polymer reinforcement; but the unsaturated thermosetting polyester is widely used, offering a good balance of vibration p

Laser drilling is capable of producing small, precisely positioned holes with high degree of reproductively. In this paper , IR millisecond Nd:YAG single pulsed laser was used to determine the effect of laser parameters on the drilled hole of the glass - fiber reinforced epoxy composite FR-4 sample of 2 mm in thickness . The type of laser source was GSI lumonics JK760TR Series laser 1.064μm system in a CNC cabin. The JK760TR series has a 0.3-50ms pulse length and a maximum repetition rate 500Hz with an average power of 600W. The investigation of single pulse laser drilling in this paper was based on theoretical and experimental solutions. In single pulse technique, the investigation included focal plane position fpp, pulse shap

Abstract

     Travel Time estimation and reliability measurement is an important issues for improving operation efficiency and safety of traffic roads networks. The aim of this research is the estimation of total travel time and distribution analysis for three selected links in Palestine Arterial Street in Baghdad city. Buffer time index results in worse reliability conditions. Link (2) from Bab Al Mutham intersection to Al-Sakara intersection produced a buffer index of about 36%  and 26 % for Link (1) Al-Mawall intersection to Bab Al- Mutham intersection and finally for link (3) which presented a 24% buffer index. These illustrated that the reliability get worst for link

        In this study multi objective optimization is utilized to optimize a turning operation to reveal the appropriate level of process features. The goal of this work is to evaluate the optimal combination of cutting parameters like feed, spindle speed, inclination angle and workpiece material to have a best surface quality Taguchi technique L9 mixed orthogonal array, has been adopted to optimize the roughness of surface. Three rods of length around (200 mm) for the three metals are used for this work. Each rod is divided into three parts with 50 mm length. For brass the optimum parametric mix for minimum Ra is A1, B1 and C3, i.e., at tool inclination angle (5), feedrate of 0.01, spindle speed of 120