Optimization of Off-Centre bracing system using Genetic Algorithm

In this paper, a method based on genetic algorithm is proposed for determining the optimum connection point with the highest lateral buckling load in the Off-Centre bracing system. This type of bracing system is mostly used in seismic areas and it allows architects to have more openings in the panel area. In this system, the non-straight diagonal member introduces eccentricity to the system and is connected to the corner of the frame by a third member. In designing this system, designers often use “trial and error” to locate the connection point of the brace elements considering various parameters affecting the design such as opening and frame dimensions, cross sectional areas of brace elements and the location of the brace element connection. Hence, finding the best connection point with maximum lateral buckling load can be problematic by the conventional methods. To demonstrate the effectiveness of the proposed GA method, examples with different frame specifications were presented.     

Integrated Fuzzy DEA-ANFIS to Measure the Success Effect of Human Resource Spirituality

Workplace spirituality has gained attention as it is proven to be a contributor to organizational performance improvement. This paper aims to assess the impact of human resource spirituality on the success of organizational strategic change projects. The success of the projects is measured by the well-known criterion of deviation from the planned budget cost. Data collection is based on a questionnaire survey of 252 personnel in 36 large and medium-scale organizational change projects in power industry. The paper proposes an integrated algorithm of fuzzy data envelopment analysis (FDEA) and adaptive network-based fuzzy inference system (ANFIS) for measuring the pure effect of human resource spirituality on the success of organizational change projects in the power industry. It also achieves a verified tool capable of addressing complexity, nonlinearity, ambiguity, and fuzziness for measuring spirituality of human resources in the projects. Results show that spirituality of the project team has a significant effect on project success.     

Calcium: A comprehensive review on quantification,interaction with milk proteins and implications for processing of dairy products

Calcium (Ca) is a key micronutrient of high relevance for human nutrition that also influences the texture and taste of dairy products and their processability. In bovine milk, Ca is presented in several speciation forms, such as complexed with other milk components or free as ionic calcium while being distributed between colloidal and serum phases of milk. Partitioning of Ca between these phases is highly dynamic and influenced by factors, such as temperature, ionic strength, pH, and milk composition. Processing steps used during the manufacture of dairy products, such as preconditioning, concentration, acidification, salting, cooling, and heating, all contribute to modify Ca speciation and partition, thereby influencing product functionality, product yield, and fouling of equipment. This review aims to provide a comprehensive understanding of the influence of Ca partition on dairy products properties to support the development of kinetics models to reduce product losses and develop added-value products with improved functionality. To achieve this objective, approaches to separate milk phases, analytical approaches to determine Ca partition and speciation, the role of Ca on protein–protein interactions, and their influence on processing of dairy products are discussed.     

Sensing and identification of carbon monoxide using carbon films fabricated by methane arc discharge decomposition technique

Carbonaceous materials have recently received attention in electronic applications and measurement systems. In this work, we demonstrate the electrical behavior of carbon films fabricated by methane arc discharge decomposition technique. The current-voltage (I-V) characteristics of carbon films are investigated in the presence and absence of gas. The experiment reveals that the current passing through the carbon films increases when the concentration of CO₂ gas is increased from 200 to 800 ppm. This phenomenon which is a result of conductance changes can be employed in sensing applications such as gas sensors.     

Rehabilitation of Urban Drainage Systems Using a Resilience-Based Approach

Highly efficient methods are needed to mitigate negative impacts of urban storms such as flooded roads and damage to properties and infrastructures. A rehabilitation approach based on resiliency is proposed in this paper for urban drainage systems using structural improvement of bottlenecks. The resilience-based approach enhances system capability to act very flexible against exceptional loads such as bridge/culvert blockage during the floods. The approach integrates a multi-objective evolutionary algorithm (MOEA) and EPA-SWMM simulation model to find cost-effective rehabilitation measures under structural failure of critical elements in the network. It is applied to the western part of Tehran Stormwater Drainage System (TSDS) to attain optimal measures by minimizing the costs and flood volumes. The approach outperforms the conventional methods (particularly compared to a previous rehabilitation proposal for the study area) when the system encounters unexpected blockage conditions. Results show that the optimal design obtained by the proposed approach can decrease network flooding from 3.5 × 10⁶ m³ to near zero with at most 23% lower investment costs relative to the traditional design.     

An efficient and direct method for out-of-plane buckling analysis of Y-braced steel frames

Dimensionless design-oriented charts are introduced for customising a new and efficient method of computing the out-of-plane critical buckling load of Y-braced steel frame systems. These charts are derived from extensive parametric studies on the basis of an “exact solution”, within the limits of the Eulerian theory, stability analysis, using a wide array of geometric characteristics of practical interest. Demonstrated with numerical examples, these calculations are shown to yield, in a very efficient way, accurate critical load values of these systems. The charts can be used for practical design of Y-brace elements.     

The Application of Bow-Tie Method in Hydrogen Sulfide Risk Management Using Layer of Protection Analysis (LOPA)

Safety systems need to be used in strong and stable ways to achieve the objectives and goals of organizations. The main role of safety systems is highlighted ever than before in maintaining personnel health, environmental protection and improves the reputation of the organizations. Proper functioning of safety system depends on the reliability and the failure probability of the system, which determines the integrated system safety. In this regard, this study aimed to H₂S risk management using bow-tie model with an emphasis on Layer of Protection Analysis (LOPA). An oil processing and gas injection plant is selected as a case of study with considering the high concentration of H₂S (130,000 ppm) as well as very high pressure of gas injection (410 bars). This work commences when hazardous regions is categorized according to H₂S gas leakage resources which followed by H₂S risk assessment (bow-tie model). In the following stage, intelligent safety systems were investigated as one of the LOPAs. Thus, the elements of intelligent safety systems are specified. Based upon the software-defined logic, block diagrams were determined. Then, Probability of Failure on Demand (PFD) and Safety Integrity Level (SIL) were attained. PFD of block diagrams was calculated, and corresponding SIL was obtained using Reliability Block Diagram and the relationships between PFD and reliability. As a result, each of elements or block diagrams was considered the weak points. Accordingly, solutions were proposed to reduce the adverse effects and promote SIL to improve safety performance of plant.     

Analysis and Optimization of Current-Driven Passive Mixers in Narrowband Direct-Conversion Receivers

Properties of the current-driven passive mixer are explored to maximize its performance in a zero-IF receiver. Since there is no reverse isolation between the RF and baseband sides of the mixer, the mixer reflects the baseband impedance to the RF and vice versa through simple frequency shifting. It is also shown that in an IQ down-conversion system the lack of reverse isolation causes a mutual interaction between the two quadrature mixers, which results in different high- and low-side conversion gains, and unexpected IIP2 and IIP3 values. With a thorough and accurate mathematical analysis it is shown how to design this mixer and its current buffer, and how to size components to get the best linearity, conversion gain and noise figure while alleviating the IQ cross-talk problem.