Microcomputer Aided Selection Of Robot Manipulators

This paper presents two programs for microcomputer aided assessment of the performance of robot manipulators. The first program automatically generates robot models based on user-supplied kinematic parameters. The program also derives a kinematic model that relates the motion of manipulator end-effector to the motion of the joints using the inverse kinematic approach. The approach uses a robust inversion technique that can handle singular conditions as well as joint redundancy. A user can optionally select evaluation of kinematic capabilities of the robot manipulator, such as the ability of the end-effector to reach a specified position and orientation in space or the evaluation of the work space. The second program generates dynamic variables, such as forces and torques, based on user-supplied dynamic parameters and equations of motion of the various joints. Both programs are written for implementation on personal computers. Several runs were carried out to demonstrate the capability and execution times of the two program

Trade, Urban Systems, and Labor Markets

This paper investigates the impacts of free trade on the structure of urban systems, skill distribution, and income disparities. The paper proposes a model that integrates international trade theory and the theory of urban system. This is done in a two sector, spatial general equilibrium model of a North-South trade. Each country is populated with a continuum of unskilled workers with heterogeneous potential ability. Through differential training costs, workers with different potential ability can achieve the same productivity. Workers can acquire a skill by investing in training. Thus, skill distribution in both countries is determined endogenously in the model through self-selection. The economy produces a final good with the use of a high-tech intermediate input and unskilled workers. Horizontally differentiated skilled workers produce the high-tech intermediate input. Cities are formed in this model as a result of investment in setup cost, i.e., public infrastructures. I characterize two different types of spatial equilibria: a closed-economy equilibrium, in which each country consists of a system of cities without trade, and a free-trade equilibrium, in which we allow for trade between cities and countries

The city network paradigm: new frontiers;

This chapter provides a survey of recent developments of positive as well as normative theories of city systems. Static theory of city system emphasizes the factors that result in the formation of cities through the interaction between two opposing forces: i) agglomeration economy; ii) agglomeration diseconomy. Furthermore, the theory examines the interaction between cities within the national economy through intercity trade and migration, which shape the internal population composition and industrial structure of cities within the system. New development of this theory has been influenced by industrial organization and economic growth together with the new urban economic paradigm. This chapter focuses on the following questions: What are the factors that lead to the formation of cities? When do cities specialize in production and when do they diversify? When do both specialized cities and diversified cities coexist? What determines the number and sizes of cities of different types in an economy? What are the factors that determine skill distribution and income disparities among different types of cities? What are the impacts of income inequalities on welfare? What are the tax and or subsidy scheme that would result in a Pareto-efficient allocation of resources in a system of cities? Do we need the intervention of federal government in order to achieve a Pareto-efficient allocation of resources in a system of cities? These questions are addressed in a spatial general equilibrium model of a closed economy consisting of a system of monocentric cities

The city network paradigm: new frontiers;

This chapter provides a survey of recent developments of positive as well as normative theories of city systems. Static theory of city system emphasizes the factors that result in the formation of cities through the interaction between two opposing forces: i) agglomeration economy; ii) agglomeration diseconomy. Furthermore, the theory examines the interaction between cities within the national economy through intercity trade and migration, which shape the internal population composition and industrial structure of cities within the system. New development of this theory has been influenced by industrial organization and economic growth together with the new urban economic paradigm. This chapter focuses on the following questions: What are the factors that lead to the formation of cities? When do cities specialize in production and when do they diversify? When do both specialized cities and diversified cities coexist? What determines the number and sizes of cities of different types in an economy? What are the factors that determine skill distribution and income disparities among different types of cities? What are the impacts of income inequalities on welfare? What are the tax and or subsidy scheme that would result in a Pareto-efficient allocation of resources in a system of cities? Do we need the intervention of federal government in order to achieve a Pareto-efficient allocation of resources in a system of cities? These questions are addressed in a spatial general equilibrium model of a closed economy consisting of a system of monocentric cities

FOOD CONSUMPTION AND UTILISATION OF THE GRASSHOPPER CHROTOGONUS LUGUBRIS BLANCHARD (ORTHOPTERA, ACRIDOIDEA, PYRGOMORPHIDAE) AND ITS EFFECT ON THE EGG DEPOSITION

The grasshopper is found all the year round. It is considered as a pest for seedlings. The consumption index differed significantly between groups fed on different diets. Mated females consume more food than virgin females or virgin males. The highest values were recorded for the bean seedlings fed groups indicating some inadequacy in the nutritional value of bean. The growth rate was the highest in clover fed groups. Insects were able to digest bean and clover more efficiently than either wheat seedlings or cotton leaves. The growth rate was accompanied with a higher C.I. in bean, wheat, and cotton indicating that most of these food was excreted. The ECD and ECI were significantly higher in clover fed groups. This indicated that clover was utilised efficiently than the other groups. The different food stuff affected the egg production which could be attributed to the nutritional efficiencies of these diets. The preovipositional period and number of egg-pods were also affected. The number of abnormal egg-pods was the highest in the bean seedlings fed groups

Skill distribution and income disparity in a north-south trade model;

What are the impacts of free trade agreement on the social welfare of different groups of labor force in a developed country? What is the impact of free trade on a developed country 19s income disparity? What is the effect of free trade on the skill distribution of a developed country? The objective of this paper is to address the above questions in a simple two-sector general-equilibrium North-South trade model in which both countries produce one final good and one high-tech intermediate input. Horizontally differentiated skilled workers produce the high-tech intermediate input. The final good is produced with the use of a high-tech intermediate input and unskilled labor. Each country is populated by a continuum of unskilled workers with differential potential ability. Workers in the North and South can acquire skill by investment in training or education. Thus, skill distribution in the North and South is determined endogenously in the model through a self-selection. I characterize two different types of equilibrium: a closed-economy equilibrium without trade and free trade equilibrium. Then, I investigate the impact of free trade, in the presence of training costs, on the skill distribution within each country, income disparity, and social welfare

Assessing silica and dissolved oxygen effects on copper corrosion control in southern Nevada water treatment and supply system

A pilot plant study was performed to investigate both the effect of silica on the corrosion process in the water system, and the effect of increased oxygen concentration resulting from ozonation on copper corrosion in the water system. The piping system used in the pilot plant resembled a household piping system, and consisted of four loops of copper pipes. Silica was added to the finished water before entering the loops at three different concentrations and corrosion was monitored by measuring copper concentration in first-draw weekly samples taken from the pilot system. Silica addition was monitored on a daily basis. Alkalinity, pH, dissolved oxygen, temperature, and conductivity were also measured, and the corrosivity of each water was calculated; Statistical and thermodynamic chemical analysis were performed to evaluate the results in chapter, and the most effective dosage of silica was determined. An average of 11.3 mg/l applied silica concentration was found the most effective dosage in retarding the corrosion rate. Increased in dissolved oxygen concentration had insignificant effect on dissolved copper concentration; A multiple linear relationship was found to predict copper concentration in loop 1, where no silica was added, as a function of alkalinity and temperature. It was also found that the formation of Cu(OH){dollar}\sb2,{dollar} Cu(CO{dollar}\sb3),{dollar} CuHCO{dollar}\sb3\sp{+1},{dollar} and Cu(CO{dollar}\sb3)\sb2\sp{-2}{dollar} were thermodynamically favored under the experiment conditions in loop 1

Skill distribution and income disparity in a north-south trade model;

What are the impacts of free trade agreement on the social welfare of different groups of labor force in a developed country? What is the impact of free trade on a developed country 19s income disparity? What is the effect of free trade on the skill distribution of a developed country? The objective of this paper is to address the above questions in a simple two-sector general-equilibrium North-South trade model in which both countries produce one final good and one high-tech intermediate input. Horizontally differentiated skilled workers produce the high-tech intermediate input. The final good is produced with the use of a high-tech intermediate input and unskilled labor. Each country is populated by a continuum of unskilled workers with differential potential ability. Workers in the North and South can acquire skill by investment in training or education. Thus, skill distribution in the North and South is determined endogenously in the model through a self-selection. I characterize two different types of equilibrium: a closed-economy equilibrium without trade and free trade equilibrium. Then, I investigate the impact of free trade, in the presence of training costs, on the skill distribution within each country, income disparity, and social welfare

Antimicrobial susceptibility pattern of genital Mycoplasmas among a group of pregnant women

Mycoplasma hominis (MH) and Ureaplasma urealyticum (UU) are important members of genital Mycoplasmas. They are implicated in urogenital infections and complicated pregnancy (chorioamnionitis, preterm delivery, abortion, and preterm birth) as well as bacterial vaginosis and cervicitis. The administration of antimicrobial agents to pregnant women with preterm rupture of the membranes (PROM) may extend the gestation period and decrease the risks of associated complications and neonatal infections. Despite empirical therapy is the rule in cases suspected to have genital infection in Egypt, the surveillance of the susceptibilities of used antibiotics is mandatory to ensure treatment efficacy and good prevention of any possible complications. This study aimed to assess the infection rate of genital Mycoplasmas (MH and UU) among pregnant females and their antimicrobial susceptibility pattern to provide a provisional idea about the effectiveness of antibiotics used empirically to treat cases of genital infections in pregnant women. High vaginal swabs of 50 pregnant females were examined using Mycoplasma IES kit, for identification of UU and MH. The kit also provides the antimicrobial susceptibility results for 12 antimicrobials of five different classes. UU and MH were detected in 26/50 (52%), and 7/50 (14%) of cases respectively, of which 5 cases showed mixed infection with both organisms. UU was most sensitive to quinolones (90–95%), followed by tetracyclines (80–85%). The least sensitivity was detected with chloramphenicol and clindamycin (40% and 30% respectively). The two MH isolates (100%) were sensitive to the three tested quinolones in addition to clindamycin and thiamphenicol. MH showed 100% sensitivity to clindamycin and 75% of UU isolates were sensitive to azithromycin. Further studies are needed to detect any future changes in the susceptibility pattern for these drugs or other antibiotics