Damage localization and quantification of composite stratified beam structures using residual force method

10.1088/1742-6596/842/1/012028Journal of Physics: Conference Series84211202

Damage detection and quantification in composite beam structure using strain energy and vibration data

10.1088/1742-6596/842/1/012027Journal of Physics: Conference Series84211202

Identification of Endangered Range Plant Species and Change in Ground Cover in North Kordofan State, Sudan

This study was conducted in North Kordofan State. With the objectives of identifying change in ground cover, other range attributes and the endangered plant species. The primary source of data was mainly from previous studies, while secondary data were obtained from field work using loop and transect method, personal interviews, rapid rural appraisal technique and direct observation, SPSS software was used in statistical analysis. The results indicate that there were notable changes in range composition. Percentage live plants and decreased by 17.5, while litter and rock increased by 17.9% and 0.30%. Some of the species still exist, with higher percentage such as Eragrositis termula (Banu,), Aristida sp (Gaw) and Cenchrus ciliaris (Haskaneet,) other species found in very low percentage (endangered) Chrozophora brochianna (Argassy), Aristida seibrana (Bayad), Echinocloa colonum (Difra), and Indigofra spinosa (Singid). Low rainfall savannah zone has higher percentage in live plants and lower percentage in bare soil compared to Semi-desert zone. In Semi-Desert zone the five most dominant species include: Aristida mutablis (Gaw) Eragrositis termula (Banu,), Cenchrus biflorus (Haskaneet Khishin) and Fimbristylis dichtomo (Um fisysat) they represent 70.9% of species composition. In Low-Rainfall Savannah zone the five most dominant species include: Zornia glochidiata (Shilini) Eragrositis termula (Banu,) Aristida mutablis (Gaw), Fimbristylis dichtomo (Um fisysat) and Cenchrus biflorus (Haskaneet Khishin) they represent 69%% of species composition. The important palatable endangered range species include grasses such as Blepharis linarifolia (Bugheil) Monsomia sp (Garin) Oldenlandia senegalensis (Garajob) Vigna sun-hum (Tagtaga) and Chloris gayana (kloris). Change in range attributed was clearly noticed and some important plants are being endangered, therefore the study recommends a strategy for rangeland rehabilitation to be adopted in concentration to important palatable and endangered plant species

3D Simulation of Fin Geometry Influence on Corner Effect in Multifin Dual and Tri-Gate SOI-Finfets

In this work the corner effect sensitivity to fin geometry variation in multifin dual and tri-gate SOI-FinFETs is studied through a commercial, three-dimensional numerical simulator ATLAS from Silvaco International. These devices are compatible with conventional silicon integrated circuit processing, but offer superior performance as the device is scaled into the nanometer range. This study aims wider to use multiple fins between the source and drain regions. The results indicate that for both multifin double and triple gate FinFETs, the corner effect does not lead to an additional leakage current and therefore does not deteriorate the SOI-FinFET performance

Indirect adaptive fuzzy finite time synergetic control for power systems

Introduction. Budget constraints in a world ravenous for electrical power have led utility companies to operate generating stations with full power and sometimes at the limit of stability. In such drastic conditions the occurrence of any contingency or disturbance may lead to a critical situation starting with poorly damped oscillations followed by loss of synchronism and power system instability. In the past decades, the utilization of supplementary excitation control signals for improving power system stability has received much attention. Power system stabilizers (PSS) are used to generate supplementary control signals for the excitation system in order to damp low-frequency oscillations caused by load disturbances or short-circuit faults. Problem. Adaptive power system stabilizers have been proposed to adequately deal with a wide range of operating conditions, but they suffer from the major drawback of requiring parameter model identification, state observation and on-line feedback gain computation. Power systems are nonlinear systems, with configurations and parameters that fluctuate with time that which require a fully nonlinear model and an adaptive control scheme for a practical operating environment. A new nonlinear adaptive fuzzy approach based on synergetic control theory which has been developed for nonlinear power system stabilizers to overcome above mentioned problems. Aim. Synergetic control theory has been successfully applied in the design of power system stabilizers is a most promising robust control technique relying on the same principle of invariance found in sliding mode control, but without its chattering drawback. In most of its applications, synergetic control law was designed based on an asymptotic stability analysis and the system trajectories evolve to a specified attractor reaching the equilibrium in an infinite time. In this paper an indirect finite time adaptive fuzzy synergetic power system stabilizer for damping local and inter-area modes of oscillations for power systems is presented. Methodology. The proposed controller design is based on an adaptive fuzzy control combining a synergetic control theory with a finite-time attractor and Lyapunov synthesis. Enhancing existing adaptive fuzzy synergetic power system stabilizer, where fuzzy systems are used to approximate unknown system dynamics and robust synergetic control for only providing asymptotic stability of the closed-loop system, the proposed technique procures finite time convergence property in the derivation of the continuous synergetic control law. Analytical proofs for finite time convergence are presented confirming that the proposed adaptive scheme can guarantee that system signals are bounded and finite time stability obtained. Results. The performance of the proposed stabilizer is evaluated for a single machine infinite bus system and for a multi machine power system under different type of disturbances. Simulation results are compared to those obtained with a conventional adaptive fuzzy synergetic controller.Вступ. Бюджетні обмеження у світі, жадібному до електроенергії, змушують комунальні підприємства експлуатувати станції, що генерують, на повну потужність, а іноді і на межі стабільності. У таких різких умовах виникнення будь-якої позаштатної ситуації або збурення може призвести до виникнення критичної ситуації, що починається з погано згасаючих коливань з подальшою втратою синхронізму та нестійкістю енергосистеми. В останні десятиліття велика увага приділялася використанню додаткових сигналів, керуючих збудження, для підвищення стійкості енергосистеми. Стабілізатори енергосистеми (СЕС) служать для вироблення додаткових сигналів керування системою збудження з метою гасіння низькочастотних коливань, спричинених збуреннями навантаження або короткими замиканнями. Проблема. Адаптивні стабілізатори енергосистем були запропоновані для того, щоб адекватно справлятися з широким діапазоном робочих умов, але вони страждають від основного недоліку, що полягає в необхідності ідентифікації моделі параметрів, спостереження за станом та обчислення коефіцієнта посилення зворотного зв'язку в режимі реального часу. Енергетичні системи є нелінійними системами з конфігураціями та параметрами, які змінюються з часом, що потребує повністю нелінійної моделі та схеми адаптивного управління для практичного операційного середовища. Новий нелінійний адаптивно-нечіткий підхід, заснований на синергетичній теорії управління, розроблений для нелінійних стабілізаторів енергосистем для подолання вищезазначених проблем. Мета. Теорія синергетичного управління успішно застосовувалася під час проєктування стабілізаторів енергосистем. Це найбільш перспективний надійний метод управління, заснований на тому ж принципі інваріантності, що і в ковзному режимі управління, але без його недоліку, пов'язаного з вібрацією. У більшості своїх програм синергетичний закон управління був розроблений на основі аналізу асимптотичної стійкості, і траєкторії системи еволюціонують до заданого атрактора, що досягає рівноваги за нескінченний час. У статті подано непрямий адаптивний нечіткий синергетичний стабілізатор енергосистеми з кінцевим часом для гасіння локальних та міжзонових мод коливань енергосистем. Методологія. Пропонована конструкція регулятора заснована на адаптивному нечіткому управлінні, що поєднує синергетичну теорію управління з атрактором кінцевого часу та синтезом Ляпунова. Удосконалюючи існуючий стабілізатор адаптивної нечіткої синергетичної енергосистеми, де нечіткі системи використовуються для апроксимації динаміки невідомої системи та надійного синергетичного управління тільки для забезпечення асимптотичної стійкості замкнутої системи, запропонований метод забезпечує властивість збіжності за кінцевий час при виведенні безперервного синергетичного закону керування. Наведено аналітичні докази збіжності за кінцевий час, що підтверджують, що запропонована адаптивна схема може гарантувати обмеженість сигналів системи та отримання стійкості за кінцевий час. Результати. Працездатність пропонованого стабілізатора оцінюється для одномашинної системи з нескінченними шинами і багатомашинної енергосистеми при різних типах збурень. Результати моделювання порівнюються з результатами, отриманими за допомогою звичайного нечіткого адаптивного синергетичного регулятора

Pendugaan Umur Simpan Jagung Manis Berdasarkan Kandungan Total Padatan Terlarut Dengan Model Arrhenius

Sweet corn has short shelf life at room temperature storage in the tropical countries (28-33°C). The quality deterioration of sweet corn can be determined by the decrease of its sugar content. The study aimed to estimate the shelf life of sweet corn based on the reduction of its total soluble solid (TSS) by using Arrhenius model. The samples were prepared from fresh harvested corn stored for 10 days at 3 different temperatures of 5, 15 and 28 °C. Total soluble solid (TSS) were analyzed every day by using abbe refractrometer. Organoleptic analysis was used by using hedonic scales from 1 to 7. The analysis was conducted until respondents had graded the samples at score 5 (dislike slightly), 6 (dislike) and approaches can be used to calculate the shelf life of sweet corn. The acceleration factor for the TSS degradation at null approach, it was estimated that if the sweet corn were stored at temperature of 30, 25, 20, 15, 10 and 5°C, the shelf temperatures, the shelf life of sweet corn would be 3.7, 4.5, 5.6, 6.8, 8.4, and 10.3 days. In conclusion, the shelf life predictions of sweet corn were valid well with the experimental results

Environmental Impacts of the liquid waste from Assalaya Sugar Factory in Rabek Locality, White Nile State, Sudan

The study aimed to assess the environmental health impacts of the liquid waste from Assalaya Sugar Factory, the efficiency of the existing Assalaya effluent treatment plant, the dilution factors available in the White Nile to gather with wastewater environmental impacts. A descriptive cross-sectional focused on the Factory and its neighborhoods. Four hundred and thirty two out of 3931 households were statistically determined as the sample size, the individual samples were picked using multi-stage stratified method 432 households selected as sample size. Data were collected by using structured questionnaires, field observations, laboratory analysis and interviewing the concerned and affected persons. The effluent load discharged from the factory into the Al - jassir canal at the White Nile was analyzed for BOD, COD, pH, PO4, TDS, TSS, Turbidity, Color, and flow rate.The Data were processed by using the Statistical Package for Social Science (SPSS) version 16, Chi-square test, test associations and office excel 2007. The study showed that Eighty one percent of the households used the surplus irrigation canal as a source for water supply. 64% of the respondents suffered from diarrhea, vomiting and allergic diseases, the rather low rate of water consumption and the bad quality of water consumed were reflected adversely on hygiene and consequently increased water related diseases. The study concludes that always or sometime 49.5% of the water collectors were children and used animals and plastic containers for water collection and transportation. The conducted laboratory water analysis revealed that the average concentrations of PO4, COD and BOD of the raw wastewater produced by Assalaya Sugar Factory were 4260, 3800 and 1500 mg/l, respectively, these values were above the WHO recommended concentrations for the disposed treated effluent (2, 250 and 30 mg/L respectively). As to physical analysis; the turbidity on the average was higher (540 NTU) and the color was (854 TCU) also high

Customer choice of reliability in spinning reserve procurement and cost allocation using well-being analysis,” Elect

a b s t r a c t A novel pool-based market-clearing algorithm for spinning reserve (SR) procurement and the cost allocation associated with provision of spinning reserve among customers (DisCos) is developed in this paper. Rational buyer market model is used to clear energy and spinning reserve markets in the proposed algorithm. This market model gives DisCos the opportunity to declare their own energy requirement together with their desired reliability levels to the ISO and also they can participate in the SR market as a interruptible load. The DisCos' desired reliability levels are selected from a hybrid deterministic/probabilistic framework designated as the system well-being model. Using the demand of each DisCo and its associated desired reliability level, the overall desired system reliability level is determined. The market operator then purchases spinning reserve commodity from the associated market such that the overall desired system reliability level is satisfied. A methodology is developed in this paper to fairly allocate the cost associated with providing spinning reserve among DisCos based on their demands and desired reliability levels. An algorithm is also presented in this paper for implementing the proposed approach. The effectiveness of the proposed technique is examined using the IEEE-RTS

Indirect adaptive fuzzy finite time synergetic control for power systems

Introduction. Budget constraints in a world ravenous for electrical power have led utility companies to operate generating stations with full power and sometimes at the limit of stability. In such drastic conditions the occurrence of any contingency or disturbance may lead to a critical situation starting with poorly damped oscillations followed by loss of synchronism and power system instability. In the past decades, the utilization of supplementary excitation control signals for improving power system stability has received much attention. Power system stabilizers (PSS) are used to generate supplementary control signals for the excitation system in order to damp low-frequency oscillations caused by load disturbances or short-circuit faults. Problem. Adaptive power system stabilizers have been proposed to adequately deal with a wide range of operating conditions, but they suffer from the major drawback of requiring parameter model identification, state observation and on-line feedback gain computation. Power systems are nonlinear systems, with configurations and parameters that fluctuate with time that which require a fully nonlinear model and an adaptive control scheme for a practical operating environment. A new nonlinear adaptive fuzzy approach based on synergetic control theory which has been developed for nonlinear power system stabilizers to overcome above mentioned problems. Aim. Synergetic control theory has been successfully applied in the design of power system stabilizers is a most promising robust control technique relying on the same principle of invariance found in sliding mode control, but without its chattering drawback. In most of its applications, synergetic control law was designed based on an asymptotic stability analysis and the system trajectories evolve to a specified attractor reaching the equilibrium in an infinite time. In this paper an indirect finite time adaptive fuzzy synergetic power system stabilizer for damping local and inter-area modes of oscillations for power systems is presented. Methodology. The proposed controller design is based on an adaptive fuzzy control combining a synergetic control theory with a finite-time attractor and Lyapunov synthesis. Enhancing existing adaptive fuzzy synergetic power system stabilizer, where fuzzy systems are used to approximate unknown system dynamics and robust synergetic control for only providing asymptotic stability of the closed-loop system, the proposed technique procures finite time convergence property in the derivation of the continuous synergetic control law. Analytical proofs for finite time convergence are presented confirming that the proposed adaptive scheme can guarantee that system signals are bounded and finite time stability obtained. Results. The performance of the proposed stabilizer is evaluated for a single machine infinite bus system and for a multi machine power system under different type of disturbances. Simulation results are compared to those obtained with a conventional adaptive fuzzy synergetic controller