Using artificial neural networks with graphical user interface to predict the strength of carded cotton yarns

Artificial neural networks (ANNs) are used in prediction fields. Yarn strength is one of the most important properties, because it reflects the quality of the yarn. The prediction process of yarn strength is very important from the technology side because many of generated forces in the spun yarns could be given by yarn strength. Data were collected from the United Commercial Industrial Company, Damascus, Syria. Then, artificial neural network algorithm was architected. Several neural networks were architected one of these has been chosen, which contained acceptable network error rate. To deal easily with ANN, a simple graphical user interface has been created. This ANN has been tested on a new sample. Results were compared with the actual results as well as the relationship of Solovev which is allocated to predict the strength cotton yarn. ANN has given more acceptable results than Solovev’s relationship.     

Effective thermal conductivity of vacuum insulation panels

Vacuum insulation panels (VIPs) with evacuated fumed silica as the core material and different barrier envelopes were subjected to a series of tests in a guarded hot plate apparatus. The process was conducted to determine thermal conductivity at the centre-of-panel and the edge effect, i.e. the linear thermal transmittance due to the thermal conductivity of the barrier envelope, which is many orders of magnitude higher than that of the evacuated fumed silica. Numerical simulations using a two-dimensional model were carried out in parallel and compared with measured results. In a further step, the influences of different parameters such as panel size, metal layers in the barrier envelope and the shape of the joint between two adjacent VIPs were quantified. Based on these findings, an effective thermal conductivity can be attributed to a system of VIPs. Investigations were performed within the framework of an international research programme of the IEA, Annex 39 'High Performance Thermal Insulation in Buildings and Building Systems', Subtask B.     

Design of a transport triggered vector processor for turbo decoding

In order to meet the requirement of high data rates for next generation wireless systems, efficient implementations of receiver algorithms are essential. On the other hand, faster time-to-market motivates the investigation of programmable implementations. This paper presents a novel design of a programmable turbo decoder as an application-specific instruction-set processor (ASIP) using transport triggered architecture (TTA). The processor architecture is designed in such a manner that it can be programmed with high level language to support different suboptimal maximum a posteriori (MAP) algorithms in a single TTA processor. The design enables the designer to change the algorithms according to the frame error rate performance requirement. A quadratic polynomial permutation interleaver is used for contention-free memory access and to make the processor 3GPP LTE compliant. Several optimization techniques to enable real time processing on programmable platforms are introduced. The essential parts of the turbo decoding algorithm are designed with vector function units. Unlike most other turbo decoder ASIPs, high level language is used to program the processor to meet the time-to-market requirements. With a single iteration, 68.35 Mbps decoding speed is achieved for the max-log-MAP algorithm at a clock frequency of 210 MHz on 90 nm technology.     

Recovery of flared gas through crude oil stabilization by a multi-staged separation with intermediate feeds: A case study

Since the birth of the oil industry, flaring has been used upstream to depressurize eruptive wells and downstream to burn excess gases in refining and petrochemical plants and also in associated and natural gas treatment plants. Unfortunately, flaring produces a great number of harmful by-products such as dangerous particles, volatile organic compounds, polycyclic aromatic and many other compounds just as harmful. The separation of gas and oil phases remains the most important stage in the so-called surface production. Given the high gas oil ratio (GOR) of Algerian crude oil, the separation of this gas is carried out in three or four stages. However, the choice of the optimal number of stages of separation and intermediate values of pressure requires a rigorous computation wherein the use of a simulator is more than necessary to make possible the optimization of the separation process. The present work was performed on a new separation and compression unit in an area where all the associated gas production is being flared despite the new environmental laws. Our approach consists of first simulating the separation process with the most appropriate thermo dynamical model. The intermediate separation pressure values can be determined by empirical correlations such as the method of equal pressure ratio. In our computations we have opted for a graphical method, specifically the method of minimum compression energy, that requires rigorous calculations entailing therefore the use of the Hysis simulator. This treated gas may be valorized as a raw material for the petrochemical industry or compressed and re-injected into the reservoir in order to maintain the rate of oil production. It remains that one important way of valorizing this associated gas is to transform it into liquid through a process known as gas to liquid (GTL) technology.     

Modification and validation of the natural heat convection and subcooled void formation models in the code PARET

Two new modifications have been included in the current PARET code that is widely applied in the dynamic and safety analysis of research reactors. A new model was implemented for the simulation of void formation in the subcooled boiling regime, the other modification dealt with the implementation of a new approach to improve the prediction of heat transfer coefficient under natural circulation condition.     

Design of augmented fuzzy logic power system stabilizers to enhancepower systems stability

This paper presents an augmented fuzzy logic power system stabilizer (PSS) for stability enhancement of multimachine power systems. In order to accomplish a satisfactory damping characteristic over a wide range of operating points, speed deviation (Δω) and acceleration (Δω) of a synchronous generator were taken as the input signals to the fuzzy controller. It is well known that these variables have significant effects on damping the generators' shaft mechanical oscillations. A modification of the terminal voltage feedback signal to the excitation system as a function of the accelerating power on the unit, is also used to enhance the stability of the system. The stabilizing signals are computed using the standard fuzzy membership function depending on these variables. The performance of the proposed augmented fuzzy controller is compared to an optimal controller and its effectiveness is demonstrated by a detailed digital computer simulation of a single machine infinite bus and a multimachine power systems     

Ethnic origin, local labour markets and self-employment in Sweden: a multilevel approach

We investigate the importance of ethnic origin and local labour markets conditions for self-employment propensities in Sweden. In line with previous research, we find differences in the self-employment rate between different immigrant groups as well as between different immigrant cohorts. We use a multilevel regression approach in order to quantify the role of ethnic background, point of time for immigration and local market conditions in order to further understand differences in self-employment rates between different ethnic groups. We arrive at the following: The self-employment decision is to a major extent guided by factors unobservable in register data. Such factors might be, that is, individual entrepreneurial ability and access to financial capital. The individual’s ethnic background and point of time for immigration play a smaller role for the self-employment decision but are more important than local labour market conditions.     

Über die Auflösung von suspendierten Oxydteilchen in flüssigem Eisen

Grundsätzliche Betrachtung über die Abscheidung und Auflösung suspendierter Oxyde. Versuche zur Kinetik der Auflösung von Chromoxyd und Siliziumdioxyd in kohlenstoffhaltigen Eisenschmelzen. Deutung der Versuchsergebnisse. Auflösung von Oxyden unter betrieblichen Bedingungen durch Vakuumbehandlung. Versuchsmä$sZige Überprüfung der theoretischen Vorstellungen.     

Potentialities of the solar-operated rankine engine

Small-capacity solar Rankine engines can operate at low and medium temperature ranges. The performance of this engine depends basically on the collector subsystem, the working fluid and the type of expander. The problems and potentialities of different alternatives of these items are discussed. Three working fluids, toluene, Fluorinol-85 and steam, were selected to examine the performance of the Rankine engine and its potentiality in the medium temperature range (150–350°C). Four types of parabolic trough solar collectors, available in the international market, were considered in this analysis. It was concluded that steam provides the best option while FL-85 still has good advantages. Extensive efforts are needed to find the most suitable expander for this system.