Development of Single Phase Induction Motor Adjustable Speed Control Using M68HC11E9 Micro controller

Variable speed control of a single-phase induction motor could be obtained through voltage control method using semiconductor power devices. These methods suffer from the large harmonics that result from the switching operation. Besides that it has a limited speed control range. Pulse Width Modulation (PWM) technique is considered as one solution for harmonic reduction and increasing the motor efficiency. The advances in domestic and commercial applications in modern life raised the urgent needs to use low power single-phase induction motor. As a consequence, the single-phase induction motor has become the most widely used type of low power ac motors for those applications where regulating speed is of essence and three- phase power source are not available. This work investigates the performance of a closed-loop adjustable speed drive for single-phase induction motor using voltage amplitude control. A microcontroller M68HCl lE-9 has been used to implement such techniques. The microcontroller senses the speed's feedback signal and consequently provides the (PWM) signal that sets the gate voltage of the chopper, which in turn provides the required voltage for the desired speed. A Buck type chopper has been used to control the input voltage of a fully controlled single phase Isolated Gate Bipolar Transistor (IGBT) bridge inverter. The proposed drive system is simulated using Matlab / Simulink, its results were compared with the hardware experimental results. The simulation and laboratory results proved that the drive system could be used for the speed control of a singlephase induction motor with wide speed range

Optimal Cooperative Cognitive Relaying and Spectrum Access for an Energy Harvesting Cognitive Radio: Reinforcement Learning Approach

In this paper, we consider a cognitive setting under the context of cooperative communications, where the cognitive radio (CR) user is assumed to be a self-organized relay for the network. The CR user and the PU are assumed to be energy harvesters. The CR user cooperatively relays some of the undelivered packets of the primary user (PU). Specifically, the CR user stores a fraction of the undelivered primary packets in a relaying queue (buffer). It manages the flow of the undelivered primary packets to its relaying queue using the appropriate actions over time slots. Moreover, it has the decision of choosing the used queue for channel accessing at idle time slots (slots where the PU's queue is empty). It is assumed that one data packet transmission dissipates one energy packet. The optimal policy changes according to the primary and CR users arrival rates to the data and energy queues as well as the channels connectivity. The CR user saves energy for the PU by taking the responsibility of relaying the undelivered primary packets. It optimally organizes its own energy packets to maximize its payoff as time progresses

Image encryption under spatial domain based on modify 2D LSCM chaotic map via dynamic substitution-permutation network

Image encryption has become an important application aspect of information security. Most attempts are focused on increasing the security aspect, the quality of the resulting image, and the time consumed. On the other hand, dealing with the color image under the spatial domain in this filed is considered as another challenge added to the proposed method that make it sensitivity and difficulty. The proposed method aims to encode a color image by dealing with the main color components of the red (R), green (G), and blue (B) components of a color image to strengthen the dependence of each component by modifying a two dimensional logistic- sine coupling map (2D- LSCM). This is to satisfy the statistical features and reduce time-consumption, and benefit from a mixing step of the second of advanced encryption standard (AES) candidates (serpent block cipher) and modified it to achieve in addition of confusion and diffusion processes. The experimental results showed that our proposed method had the ability to resist against statistical attacks and differential attacks. It also had a uniform histogram, a large key space, complex and faster, closer Shannon entropy to 8, and low correlation values between two adjacent pixels compared with other methods

Evaluation of Retinol Level Among Preschool Children, Pregnant and Lactating Women Attending Primary Health Care Centres in Baghdad

Background: Vitamin A deficiency (VAD) is a major public health nutrition problem in the developing world. There have been no studies on this topic in Iraq. This study was designed to evaluate the serum retinol levels of preschool children, pregnant and lactating women. Objectives: The present study is an attempt to estimate the prevalence of vitamin A deficiency among preschool children, pregnant and lactating women attending primary health care centers in Baghdad, in addition to figure out the relation between vitamin A deficiency with some demographical, clinical, variables. Subjects and Methods: The study was conducted during the period from October to December 2009. The sample was comprised of 490 subjects, Lactating women pregnant women and under 6 year's old children attending ten primary health care centers in Baghdad. The data were collected through direct interview; blood samples were taken and analyze for serum retinol (SR) by HPLC analysis and hemoglobin (Hb) level, anthropometric measurement were obtained for the study sample. Results: The study showed that the prevalence of vitamin A deficiency in preschool aged children (below 6 years) was (38.3 %); and that for lactating women and pregnant women were (7.1 %) and (25 %) respectively. Forty percent of pregnant women, (25.8 %) of lactating women and a total of (58.6 %) preschool children were anemic, A correlation coefficient between SR and Hb concentrations was significant (N=490, r=0.533, P<0.0001). Conclusion: Vitamin A deficiency is a public health problem, this study shows that subjects in the 3 groups (preschool children, pregnant and lactating women) are at risk of VAD and anemia; nearly half of them had the co-occurrence of VAD and anemia. A close association between vitamin A deficiency and anemia with a correlation coefficient between SR and Hb concentrations was significant

Landmark based shortest path detection in alarm system

In this paper, an alarm system for four types of emergency states (explosion, car accident, earthquake and fire) is developed. This system divided in to two parts: transmitted part (Arduino, sensors, GSM, GPS), and emergency part (center site, sub center sites). Center site is included (Android phone, Server), Sub center sites (helping centers) represented the mobile phones of competent authorities like police center or hospital. The alerting in this system as a SMS message is sent by GSM. The system used Haversine formula to determine the nearest sub center from emergency state that receives the SMS alarm message from transmitted part. Also the path is tracked using Google map application

Review of an Accurate System Utilizing GPS Technology

GPS provides precise position and control data anywhere on the planet and in any weather condition. GPS was originally intended for military usage, but in the 1980s, the US Department of Defense made it available for civilian use. The scientific applications of GPS in the military, community, and commercial sectors are expanding on a regular basis. Agriculture, construction, mining, measurement, package delivery, and logistical supply chain management all benefit from GPS technology. Precision GPS time synchronization is critical for big networks, navigation, finance systems, financial markets, and power grids. Wireless services are impossible to imagine without them. In this paper, we will go over the key aspects of GPS technology as well as a discussion of the systems that use it

Effect of Thermal Cycling on Corrosion Rate of Carbon Steel (0.4%C), Water Cooled

The effect of thermal cycling was carried out on steel bars (0.4 %C). A single run was performed at a lower temperature of 320C and an upper temperature of 5000C cooled in water and seawater. For several numbers of cycles up to 30 cycles for an accurate determination of heating and cooling times. The effect of thermal cycling on the corrosion rate was evaluated. The effect of thermal cycling on the following properties was evaluated the corrosion rate. The comparison between the effect of thermal cycling on carbon steel (0.4% C) seawater cooled (previous results, sea-water cooled [1]) and the effect of thermal cycling on carbon steel (0.4 C %) (in this manuscript, water-cooled) has been studied. From the obtained test results (previous and in this paper, it was found that the type of corrosion is uniform, the corrosion rate of the first stage gradually increases with the number of thermal cycling up to 15 cycles, then it takes steady-state up to 30 cycles. It was found that the rate of corrosion (previous results, seawater cooled) is more than (the results in this paper, water-cooled)

Treatment of Anestrous in Iraqi Buffaloes using Ovsynch alone or in Combination with CIDR

The aim of this study was to test the efficacy of the Ovsynch alone or in combination with CIDR treated buffaloes on conception rate of anestrous Iraqi buffaloes. The present study was conducted on 50 anestrous buffaloes suffering from postpartum ovarian inactivity. Buffaloes were randomly assigned to three treatment groups. Buffaloes in Treatment 1 (n=20) received on day 0 GnRH 250 μg and a 25 mg of PGF2α on day 7, two days later a second injection of GnRH (250 μg). Buffaloes in Treatment 2 (n=20) injected on day 0 of the experiment, GnRH 250 μg and a CIDR was placed in the anterior vagina. On day 7, they were injected with 25 mg of PGF2α and on the following day (day 8) the CIDR were removed. On day 9 a second dose of GnRH (250 μg) was injected. Treatment 3 a control group (n=10) received no treatments. Results showed that in treatment 1, 7 out of 20 buffaloes received treatment exhibited estrus within 74.8 ± 6.3 after second GnRH administration. The estrus induction rate was 35%. Total number of buffaloes became pregnant was 1 (5%). In treatment 2 75% of the buffaloes received treatment exhibited estrus within 77.8 ± 5.6 h after CIDR removal. Total number of buffaloes became pregnant was 7 (31.8%). Lower (P <0.05) Pregnancy rate was achieved in buffaloes treated with Ovsynch than other buffaloes treated with Ovsynch plus CIDR. Higher rates of estrus induction (75%; P<0.05) and conception rate (7 buffaloes out of 20) were found in buffaloes treated with Ovsynch plus CIDR. In conclusion, our results indicate that the addition of Ovsynch to a progesterone-based CIDR protocol substantially improves the estrus induction and pregnancy rates in postpartum anestrous buffaloes

Crack Growth Model for Evaluation the Fatigue Life of Aluminum Alloys

The main objective of this study is to experimentally determine the fatigue life of the aluminum alloys AA2014 and AA7075-T651 by measuring the lengths of short and long cracks practically under bending stress with constant amplitude loading and stress ratio (R = -1) at room temperature (RT) 25 C0 by employing Basquin's equation. To determine the fatigue life curve for both alloys at five different levels of constant amplitude stresses, the average failure cycles of three specimens at each stress level were recorded. The surface of specimen was replicated with cellulose paper and liquid acetone. This piece was examined using an optical microscope to record the length of the crack and the number of cycles corresponding to it at a constant stress level. The lengths of the cracks were then measured using the replication approach. A unique mathematical model was created to describe the relationship between crack speed (da/dN) and the length of short and long cracks in order to predict the overall fatigue life of each alloy. When the model's result was contrasted with actual outcomes, the conclusions were reliable and productive