Development of Algorithms to Represent Intermediate Layers for Machining Sculptured Surfaces

The objective aim of this research is to develop an algorithm for design and manufacture sculptured surfaces that are common in a wide variety of products such as dies, automobile, and aircrafts components. In the design stage Bezier technique has been used to represent the desire surface. In rough-machining stage, the number of intermediate layers depend on the geometry of the desired surface and on the maximum allowable depth of cut, an algorithm has been proposed to represent these layers, whereas another efficient algorithm has been proposed to represent the semifinished layer depends on the tangents and normal vectors along all the points of the desired surface to create the offset surface. The desired surface generated points using Bezier technique are used as cutter location points for the finish machining tool path. Flat end mill (φ 12mm) has been used for the intermediate stages machining (roughing), while (φ 12mm) ball end mill have been used for both semi-finish and finish machining. The developed algorithm have been tested by several designed sculptured surfaces, its proved good flexibility and efficiently in all of its stages, the results have been implemented for machining one of these surfaces [fifteen intermediate layers, semi-finished layer, and finished] using 3-axis vertical CNC machine. The proposed rough machining algorithm reduces the machining time as compared with contour tool path by 15% for case study two and reduces the NC file size 52% for case study three

A Bezier Curve Based Free Collision Path Planning of an Articulated Robot

The main objective of this paper is to find a path for the robot arm from its given start point to its desired goal point in an automated manner without collision with the obstacles. This paper investigates the problem of path planning for a 5 axis robot, operating in environment with obstacles whose boundaries are enveloped by cubic shape. The path planning approach presented is developed in the robot joint space and consists of three steps. The first step is to used Bezier curve technique , the second step is to generate a sufficient number of intermediate points in Cartesian space along Bezier curve and the third step is to convert the coordinate of the generated intermediate points from it's Cartesian space into joint space and move the robot arm along the free collision generated path. This work is not limited to theoretical studies or simulations, experiments have been run with various tests, on a LabVolt R5150 robot to assess the real efficiency and usability of the adopted method. The method applies to robots in a fixed and known environment. A number of experiments were carried out to test the ability of the robot arm to reach it's goal without collision. Experiment results verify the effectiveness of the method developed in this paper

Manufacture of Load Bearing Concrete Masonry Units Using Waste Demolishing Material

The presence of construction wastes such as clay bricks, glass, wood, plastic, and others in large quantities causes serious environmental problems in the world. Where these wastes can be used to preserve the natural resources used in construction and reduce the impact of this problem on the environment, it also works to reduce the problem of high loads of concrete blocks. Clay bricks aggregate (AB) can be recycled as coarse aggregate and replaced with volumetric proportions of coarse aggregate by ( 5% and 10%), as well as the use of clay brick powder (PB) by replacing its weight of cement (5% and 10%) and reduced in the manufacture of concrete blocks (blocks). Four mixtures will be prepared and tested to learn how to reuse the brick coarse aggregate ACB and PB powder brick as substitute materials for producing concrete blocks, use the water spray method to treat concrete building blocks (blocks) and check the Dimensions and compressive strength, and absorption

Automatic Tool Path Generation for Parametric Surfaces

A tool path generation algorithm has been proposed and implemented in the presented work. The aim of the development of tool path algorithm is to machine parametric surface with a given tolerance and scallop height. The algorithm proposes dividing the desired parametric surface to several linear segments depending on the desired accuracy of the parametric surface. The Bspline technique has been used to generate the required data of the parametric surface. After generating the tool path, the cutter movement has been simulated allowing to reduce the cutting time and cost. The tool path is verified on the C-TEK CNC milling machine by machining six models. Various tool path strategies are also discussed and compared with the developed algorithm. The machining performance includes machining time; dimensional accuracy and surface roughness were measured for result evaluation. A measuring method has been proposed and implemented to measure the accuracy of the final 3D models. A Digital 3D-Touch Probe was used. The statistical method of error assessment and similarity factor has been implemented in this work to show the efficiency of the proposed works. The results showed that the similarity factor of the proposed works were (87.6%) for one model, and (85.9%), (89.6%) for other models. Matlab (v.7.1), UG-NX8.5, and VERCUT software have been used in this work for implementation. A comparison between the proposed method and UG-NX8 has been done to present the flexibility of the proposed method

Evaluation of Al-Thagher Wastewater Treatment Plant

This study aims to evaluate the performance of the sewage treatment plant in Al-Thagher city, in the north of Basrah governorate, the southern part of Iraq. The plant’s performance was estimated based on an analysis of influent and effluent wastewater quality data that represented the monthly averages from Feb. 2017 to Dec. 2018. The results show that the values of temperature (T), pH, ammonia (NH3–N), chemical oxygen demand (COD) and biological oxygen demand (BOD) in all collected samples from the effluent of the plant met the Iraqi water quality standard (IWQS), whereas the values of electrical conductivity (EC), total dissolved solids (TDS), total suspended solids (TSS), sulfate (SO4–2), chloride (Cl–1) and phosphate (PO4–P) met the Iraqi water quality standard (IWQS) in some months and did not meet the standard in other months. The average removal efficiencies were in the following order: COD (77.12%) > BOD (77.03%) > TSS (62.26%) > NH3–N (59.99%) > PO4–P (12.42%) > Cl–1 (1.97%). The removal percentages for the remaining parameters had negative values. The Canadian Council of Ministers of the Environment water quality index (CCME WQI) value of the treated water was 51.80 and classified as “marginal.” The coefficients of determination between each parameter in influent or effluent were calculated. Finally, linear regression equations between these parameters were formulated so that the value of one parameter could be used to predict the value of a different parameter

Surface Fitting and Representation By Using 2D Least Squares Method in CAD Applications

This paper presents a general method for automatic surface fitting from scattered range data and describes the implementation of three methods for fitting surfaces: linear, quadratic and cubic. It uses a modified 2D least squares method to fitting, reconstructing and modeling several surfaces and statistical criteria to compare the three approaches. The comparison is performed using a mathematically defined data as real data obtained from the proposed models. The method can be used in a variety of applications such as reverse engineering, automatic generating of a CAD model, etc, and it has proven to be effective as demonstrated by a number of examples using real data from mathematical functions ( sine, cosine, exponential and cubic). By applying the proposed surface fitting model the standard deviation was found to be (0.04-0.26), (0.02- 0.07) and (0.0-0.12) mm for linear, quadratic and cubic fitting models respectively

Evaluation the activity of Neuropeptide Y (NPY), Glucagon like peptide-1 and Ghrelin in controlling appetite in obesity in Erbil City

The epidemic of obesity is at previously unheard-of heights. In 2016, it was predicted that 39% and 13% of individuals worldwide were overweight or obese, respectively. Obesity, which is defined as an imbalance between energy intake and expenditure, results from multiple interactions between genetic, environmental, psychological, behavioral, and nutritional variables, making it a difficult condition to study and treat. The present study aimed to approach the understanding of appetite, bodyweight regulation and the causes of obesity through studying gastrointestinal hormones such as (NPY, GLP-1, and ghrelin) hormones and their impact on controlling appetite in obesity. This comparative study included (152) participants (Obese and non-Obese) in the age range (30-66 years), both males and females who visited (The surgical specialty hospital cardiac center, Hawler teaching hospital, and Erbil’s court). A self-administered questionnaire was used for data collection. Fasting serum metabolic parameters and hormones were measured included (S.NPY, S.GLP-1, S.Ghrelin) and (S.Total Cholesterol, S.Triglycerides, S.HDL, S.LDL, and S.VLDL). According to the BMI of participants, there was a significant association (P < 0.001) between NPY, GLP-1 hormones and BMI, and a significant (p = 0.033) association between Ghrelin and BMI. The present study concluded that serum NPY, GLP-1 and Ghrelin hormones significantly impacted controlling appetite in obesity, would be a useful and important marker to evaluation for obesity. And a strong relationship between these hormones and obesity

Robotic rectal cancer surgery in obese patients may lead to better short-term outcomes when compared to laparoscopy: a comparative propensity scored match study

Se identifican en el presente trabajo los elementos fundamentales de la trama urbana de la ciudad de Toledo. La metodología propuesta se aparta de la utilizada tradicionalmente, debido a las peculiaridades que presenta su ubicación física concreta, intentando enfatizar de forma especial el estudio del medio físico. Para ello se parte de un análisis topográfico y climático del cerro toledano, relacionado con la evolución histórica de la forma urbana, sobre todo con el sistema de murallas. Mediante esta metodología llegan a detectarse cinco ejes estructurantes: el formado por las calles del Barco y Pozo Amargo, el de la puerta de San Sebastián, el de Tendillas y Nuncio Nuevo, el de la calle de la Luz y Azacanes y el del barrio de la Antequeruela. Este esquema se completa con vaguadas secundarias y líneas de deslizamiento. También se detecta un gran colector que se encarga de articular toda esta red y que está formado por las calles del Ángel, Santo Tomé, Trinidad, Hombre de Palo y del Comercio, uniendo entre sí las antiguas puertas interiores de Assuica y de la Sangre

Statistical and Visual Analysis of Error In Interpolating Sculptured Surfaces

This paper presents a general method for automatic surface interpolation from range data and describes the implementation of high order 2D langrangian methods for interpolating surfaces from 3rd to 8th order. It uses a modified 2D lagrangian method to interpolating, reconstructing and modeling several surfaces, and due to this interpolation there will be an error between interpolated surface and the original one, this paper present an algorithm to detect, represent and analyze these interpolating errors and statistical criteria to compare the error in representing the sculptured surfaces that interpolated with different order basis functions. The comparison is performed using a mathematically defined data as real data obtained from the proposed models. The system has been implemented for the design of several sculptured surfaces to illustrate the system flexibility. Then the design results have been implemented for manufacturing two of these surfaces using three axis vertical CNC milling machine tool with ball end mill cutter. The method can be used in a variety of CAD/CAM applications and it has proven to be effective as demonstrated by a number of examples using real data from mathematical functions. By applying the proposed surface interpolating models the percent error was found to be ranged between 0.00001% for some model to 3.5% for some other interpolated models with Lagrange method