Systematic Synthesis Procedure Research Articles

Synthesis and Application of Eco-Friendly Adsorbent for Treatment of Congo Red and KMnO4 Dye Aqueous Solution

The use of natural resources as environmentally acceptable adsorbents for wastewater treatment was investigated in two research. The first concentrated on using bamboo leaves as an inexpensive adsorbent to remove the dye KMnO4. Bamboo leaves were carefully synthesised, spectrophotometrically analysed, and showed different adsorption capabilities according to unit adsorbent concentration. The second study used a systematic synthesis procedure and spectrophotometric characterization to remove Congo red dye from mango leaves. The Mangifera indica adsorbent demonstrated a noteworthy 88.27% adsorption peak at a dye concentration of 50 mg/L. Both programmes emphasised the potential of renewable resources and focused on low-cost, environmentally friendly methods to address the problem of water contamination. The research emphasised the adaptability and effectiveness of natural adsorbents, underscoring the significance of sustainable approaches in the treatment of wastewater. These findings contribute significantly to developing green solutions, showcasing the feasibility of utilizing bamboo and mango leaves in addressing diverse dye contaminants. Further optimization and mechanistic understanding are crucial for enhancing the efficiency of these eco-friendly adsorbents, paving the way for environmentally conscious water treatment practices.

Elevating patient care through Human Resources (HR) excellence in healthcare organizations

This paper delves into the critical role of Human Resources (HR) in enhancing patient care within healthcare organizations. The study's purpose was to meticulously analyze the interplay between HR practices and patient care quality, and how strategic HR management contributes to the overall efficacy of healthcare services. By employing a rigorous literature review methodology, the paper synthesizes a wide range of academic sources, focusing on the evolution of HR practices in healthcare, the impact of these practices on staff and patient satisfaction, and the theoretical frameworks guiding them. The research method involved a strategic literature search, adhering to specific inclusion and exclusion criteria, and a systematic procedure for data collection and synthesis. This approach facilitated a comprehensive understanding of the multifaceted nature of HR in healthcare settings. The main findings highlight the significant influence of HR on patient outcomes, emphasizing the correlation between staff well-being and patient care quality. Effective HR management was found to be pivotal in fostering a positive healthcare environment, enhancing staff capabilities, and ultimately improving patient satisfaction. The study concludes that healthcare organizations must prioritize strategic HR management to elevate patient care quality. Recommendations include focusing on employee engagement, continuous professional development, and cultivating a positive organizational culture. The paper suggests that future research should explore the integration of technological advancements in HR practices and adapt to the changing dynamics of the healthcare workforce. This paper offers a classical and engaging perspective on the indispensable role of HR in healthcare, providing valuable insights for healthcare administrators, HR professionals, and policymakers.

Integration of engineering into K-12 education: a systematic review of teacher professional development programs

ABSTRACT Background: Teachers play a prominent role in facilitating the integration of engineering into school instruction. There is an extensive body of literature that has addressed the delivery of engineering teacher professional development programs. A few studies have summarized the features of engineering teacher professional development programs, but none have followed systematic synthesis procedures. Purpose: The study aimed to synthesize the literature on teacher professional development programs focused on the integration of engineering into K-12 education. The purpose of the study was to provide a systematic overview of the general characteristics and key features of PD programs. Design and Method: The systematic review involved three phases, search, selection, and synthesis, and included the application of exclusion criteria, inclusion criteria, and a checklist created by the investigators. Based on an extensive database and journal search, as well as the three review phases mentioned above, 29 articles previously published in peer-reviewed academic journals were included in this systematic review. Results: Results were organized according to six codes: (a) teacher profiles, (b) organizational features, (c) impacts of the professional development programs, (d) factors that promote professional development program effectiveness, (e) assessment of teacher improvement, and (f) addressed limitations. The majority of programs included face-to face workshops combined with field trips to engineering workplaces and follow-ups. Factors that contributed to the effectiveness of the programs included: real-world-focused activities, the promotion of collaboration and interaction with peers and outside experts, development and refinement of plans for classroom implementation, and observation of student interest and progress. Conclusions: This systematic review can provide a conceptual basis for research and practice in engineering-focused teacher professional development, with the assistance of research-based guidelines presented. Future research can investigate the possible long-term effects of the guidelines provided for teachers and their students.

Structural synthesis of Assur groups with up to 12 links and creation of their classified databases

The present study proposes a systematic method for synthesizing a complete set of Assur groups with different links. Moreover, the corresponding databases, including all classified topological structures of synthesized Assur groups, are created. In this regard, the structural correlation and the topological representation of Baranov trusses and Assur groups are initially reviewed. Then, the primary and the secondary vertex-classified sets are introduced to reduce the times of isomorphism identification in the Assur group synthesis. Based on the vertex-symmetry codes used for the isomorphism identification, the systematic synthesis procedure is proposed to achieve all non-isomorphic Assur groups derived from the corresponding Baranov trusses. Finally, a complete set of Assur groups with 2, 4, 6, 8, 10 and 12 links is obtained and three corresponding databases of all synthesized Assur groups are established in accordance with their classified structural characteristics.

Task-oriented type synthesis of the lower-mobility parallel mechanisms with a common platform

A systematic procedure for the task-oriented type synthesis of parallel mechanisms (PMs) with a common platform is proposed in this study. The method is composed of two stages. In the first stage, constraint wrenches that are compatible to specific task-oriented output motions of the PM is distributed to several limbs. In the second stage, the geometric conditions and admissible joint structures of PM limbs are identified by employing the concept of reciprocal screw. Then desired symmetric or asymmetric PMs are constructed with the proper combinations of those admissible limbs. Lastly, the suggested synthesis method is verified by identifying various forms of lowermobility PMs, such as planar 1T-type PMs, spatial 2T-type PMs and spatial 1T2R-type PMs.

Systematic procedure and framework for synthesis and evaluation of bioethanol production processes from lignocellulosic biomass

Bioethanol from lignocellulosic feedstock rises as a promising alternative to replace liquid fossil fuels in the energy market for the next years. However, the variety of available biomass combined with the necessity of possible pretreatments and their particular features make it difficult to clearly identify the favorable process routes. In this study a systematic approach consisting of seven steps was proposed to obtain possible and feasible alternatives for the conversion of lignocellulosic biomass into bioethanol. The method was exemplified with the aid of a general case study, from the biomass selection to possible by-products generation. The case study resulted in a corn stover based process to produce bioethanol through ammonia fiber explosion pretreatment. Following the systematic approach different alternatives were proposed to finally obtain the optimal flowsheet with a minimum ethanol selling price of 0.43$/kg of ethanol, 35.4% lower than the initial process.

Functional observer-based fuzzy controller design for continuous nonlinear systems

ABSTRACTThis paper presents a novel method of synthesising controllers for nonlinear systems represented by Takagi--Sugeno fuzzy model using functional observer. The proposed method uses minimum order observer for estimating the control input of each rule as a function of states. Existence conditions of the functional observer-based controller are provided in the form of rank equality conditions. The stability conditions of the observer are obtained using quadratic Lyapunov function, and the conditions are presented in the form of linear matrix inequalities. Observer parameters can be obtained by solving these inequalities. Finally, systematic synthesis procedures for constructing the observer are presented. Examples with simulation output are given to demonstrate this method and to compare its performance with a conventional full-state observer-based controller.

Synthesis Procedure of Configurable Building Block-Based Linear and Nonlinear Analog Circuits

Synthesis and design methodology suitable for computer-aided design tools are now emerging as major challenge for analog system designers. This paper proposes a systematic synthesis procedure which provides reusability and programmability, for linear and nonlinear analog circuits using configurable building block (CBB) and analog cell (AC). Operational transconductance amplifier-based ACs are synthesized in terms of CBBs. Reusability and programmability of the synthesis methodology have been demonstrated by realizing different types of linear and nonlinear circuits and mapping those circuits in field programmable analog array. Finally, the proposed methodology has been integrated as an electronic design automation tool AnaSyn1.0. Performance of all the proposed circuits has been verified by SPICE simulation.

Systematic Computation of Nonlinear Bilateral Dynamical Systems With a Novel Low-Power Log-Domain Circuit

Simulation of large-scale nonlinear dynamical systems on hardware with a high resemblance to their mathematical equivalents has been always a challenge in engineering. This paper presents a novel current-input current-output circuit supporting a systematic synthesis procedure of log-domain circuits capable of computing bilateral dynamical systems with considerably low power consumption and acceptable precision. Here, the application of the method is demonstrated by synthesizing four different case studies: 1) a relatively complex 2-D nonlinear neuron model; 2) a chaotic 3-D nonlinear dynamical system Lorenz attractor having arbitrary solutions for certain parameters; 3) a 2-D nonlinear Hopf oscillator, including bistability phenomenon sensitive to initial values; and 4) three small neurosynaptic networks comprising three FHN neuron models variously coupled with excitatory and inhibitory synapses. The validity of our approach is verified by nominal and Monte Carlo simulated results with realistic process parameters from the commercially available AMS 0.35- $\mu \text{m}$ technology. The resulting continuous-time, continuous-value, and low-power circuits exhibit various bifurcation phenomena, nominal time-domain responses in good agreement with their mathematical counterparts and fairly acceptable process variation results (less than 5% STD).

LMI based robust state feedback control of negative-imaginary systems

The importance of robust feedback control for uncertain negative imaginary system lies in its practical relevance and engineering applications, for example, lightly damped flexible structures with collocated position sensors and force actuators. This article investigates an LMI based robust static state internally stabilizing feedback controller of the negative imaginary system in presence of strictly negative imaginary uncertainties. The paper first presents some basic theory of negative imaginary systems and then, a necessary and sufficient condition is established for the internal stability of the positive feedback interconnections of negative imaginary systems. The paper provides a systematic controller synthesis procedure based on negative imaginary lemma to achieve robustness in the feedback control of negative imaginary systems. To show the effectiveness of controller synthesis method, one design example is considered and a static state-feedback controller is constructed to force the plant to be stable. The simulation results of this article demonstrate the usefulness of the design method and we believe that feedback control of the negative imaginary system can benefit control engineering practitioners in a number of ways.

Band-gap optimization of two-dimensional phononic crystals based on genetic algorithm and FPWE

Phononic crystals (PnCs) with band-gaps can confine the propagation of elastic waves. In many applications, it is desired to have a unit cell with favored band-gaps. Topological distribution of elastic materials within a unit cell has a significant effect on the band-gap properties, which are extremely difficult to determine without an optimization-based systematic synthesis procedure. In this paper, the two-stage design method, based on genetic algorithm conjunction with fast plane wave expansion method, is adopted to carry out the topology optimization of the two-dimensional (2D) PnCs in square lattices configuration with the maximized relative band-gap between two prescribed dispersion branches. Three numerical examples are given to the optimization of 2D steel-epoxy PnCs in one-eighth symmetry for coupled mode, acoustic mode, and mixed mode, respectively. The results show that the developed method provides an effective tool for the design of the 2D PnCs with favorable band-gaps’ properties.

A systematic procedure for synthesis of intensified nonsharp distillation systems with fewer columns

Nonsharp separation sequences can intrinsically improve thermodynamic efficiency than that of sharp sequences for a multicomponent distillation. There are much more nonsharp sequences than that of sharp sequences. In this paper, the synthesis of new intensified distillation systems from nonsharp separation sequences is presented. Such intensified distillation systems have fewer columns and have the potential to reduce both energy and capital costs than conventional configurations. First, the representation of any nonsharp sequence with the simple column configuration is found to be the necessary starting point. Then, five strategies are introduced which present different mechanisms to change the structures of the distillation configurations. Third, a systematic procedure is formulated which can achieve the intensified distillation systems with fewer columns systematically. Finally, the systematic method has been applied to different examples of nonsharp separation sequences. It is demonstrated that the method can be used to generate the new intensified distillation systems from any nonsharp separation sequences. The method is easy to use and can explicitly derive all of the intensified distillation systems for the nonsharp separation sequences for a multicomponent distillation.

Directional modulation transmitter radiation pattern considerations

A pattern synthesis approach is applied to a directional modulation (DM) system. A systematic synthesis procedure is suggested which ensures optimal constellation patterns production along pre-specified communication directions, whereas simultaneously conserving energy dispersal in other directions. In this study, the properties of DM systems synthesised from Gaussian magnitude far-field radiation pattern templates are used to illustrate performance benefits with regards to DM bit error rate response compared with those achieved by a conventional steered array.

GENERATION OF THIRD-ORDER QUADRATURE OSCILLATOR CIRCUITS USING NAM EXPANSION

A systematic synthesis procedure for generating third-order grounded passive element quadrature oscillators is given. The synthesis procedure is based on using nodal admittance matrix (NAM) expansion applied to the Y matrix of a recently reported three Op Amp third-order oscillator circuit. Four new circuits using current conveyors (CCII) are reported. In addition four more new circuits using inverting current conveyors (ICCII) are also given. Many more quadrature third-order oscillator circuits using combinations of CCII and ICCII can be obtained. Simulation results demonstrating the practicality of one of the generated circuits are included.

New Synthesis Procedure To Find the Optimal Distillation Sequence with Internal and External Heat Integrations

Recent developments in energy conservation have sought internal heat integration through side heat exchangers as an attractive energy-efficient alternative to reduce the energy consumption in conventional distillation. However, it is difficult to estimate the effect on the reduction of reboiler duty through internal heat integration without executing rigorous simulations. Thus, the stages used for heat exchange have been selected by trial and error or some heuristics. For a fixed design where heat integration between a rectifying section and a stripping section takes place, current research has derived the optimal structure by trial-and-error or systematic approaches. In this work, the combination of superstructure representation, rigorous simulations, and mathematical programming is effectively used to develop a systematic synthesis procedure, which can derive the optimal distillation process structure including the internal and external heat integration. In the proposed procedure, piece-wise linear functions between the amount of internal heat exchange and the reduction of reboiler and condenser heat duties are derived in advance by executing rigorous simulations. Then, for every pair of rectifying and stripping sections of two columns, the optimal structure with internal heat integration is derived by solving an MILP problem. The cost of side heat exchangers, and the condenser and reboiler duties and areas resulted from internal heat integration are used as parameters in the formulation of a synthesis problem which comprises all the possible distillation sequences. By adopting such a procedure, the overall synthesis problem can also be formulated as an MILP problem, and the optimal process structure can be derived by solving it. The result of a case study to separate a ternary mixture shows the effectiveness of the proposed synthesis method.

Nonlinear Lead-Lag Controller Synthesis for Unstable Nonlinear Systems

AbstractA new systematic procedure for synthesis of nonlinear lead-lag controllers for highly nonlinear unstable plants is developed. The procedure is to stabilize the unstable plant followed by generation of sinusoidal-input describing function (SIDF) models at various operating regimes of interest. The unstable plant frequency domain behavior is extracted, and a set of linear lead-lag controllers are designed that would force the open-loop behavior of the system (comprised of the lead-lag controller and the nonlinear plant) and mimic that of desired. Finally, a describing function inversion is used, and the nonlinear functions describing the values of the lead-lag coefficients as a function of the error signal are obtained. Experimental results are presented for verification, and bounded-input bounded-output stability is demonstrated by successful generation of the describing function models of the closed-loop system comprised of the synthesized nonlinear lead-lag controller and the nonlinear plant.

A Novel PWC Spiking Neuron Model: Neuron-Like Bifurcation Scenarios and Responses

A novel electrical circuit spiking neuron model that has a piece-wise-constant vector field with a state-dependent reset is presented. It is shown that the model exhibits six kinds of border-collision bifurcations, where their bifurcation sets are derived and are summarized into two parameter diagrams. Then, using the diagrams, systematic synthesis procedures of the presented model so that it can reproduce four kinds of bifurcation scenarios that are typically observed in standard neuron models are presented. It is shown that the model can reproduce the bifurcation scenarios as well as corresponding nonlinear response characteristics observed in model and biological neurons. Occurrences of typical neuron-like bifurcations are confirmed by experimental measurements.

Novel Dual-Band Decoupling Network for Two-Element Closely Spaced Array Using Synthesized Microstrip Lines

We investigate an innovative decoupling network for dual-band two-element closely spaced arrays in MIMO applications. The new architecture, combining the reactive element decoupling technique and the eigenmode feed network, provides dual-band decoupling with good radiation characteristics and power balance between the modes. The core block of the decoupling network is a dual-mode 180-degree hybrid coupler; it functions as a conventional coupler in one frequency band but can be equivalent to a pair of isolated direct-thru transmission lines in the other band. This unusual dual-mode coupler is realized by synthesized microstrip lines (cells), consisting of line inductors, parallel-plate capacitors, and series LC tanks. A set of design equations, providing a systematic synthesis procedure of the unit cells, is discussed. The scheme of the dual-band decoupling network is illustrated first, followed by the details of the building circuit blocks; the experimental results and discussion are given at the end of the paper.

Accurate and efficient design technique for wideband substrate integrated waveguide directional couplers

In this article, we present an efficient technique for the accurate design of wideband substrate integrate waveguide directional couplers. By tapering the coupling section, the bandwidth of substrate integrated waveguide (SIW) directional couplers can be enlarged. Two design aspects are involved in this approach. First, the even-mode propagation constant in the tapered coupling section is accurately extracted with the help of a numerical thru-reflect-line calibration technique. Then, it is fitted into the model of a uniform dielectric-filled rectangular waveguide and thereafter extrapolated to the operation range of the odd mode. Second, equivalent circuit models of the waveguide bifurcation effects are also presented together with parametric values. Based on the results of extraction, a 90° 3-dB directional coupler is developed to validate the proposed design approach. To achieve the reverse phasing at two output ports, the prototyped 90° 3-dB directional coupler is subsequently integrated with a novel broadband fixed phase shifter developed with the SIW technology, of which a systematic synthesis procedure has been proposed in this article. Measured performance of both 90° and 180° 3-dB couplers confirms the accuracy of our proposed design approach. This kind of wide-band directional coupler can find applications in wideband power dividing/combining circuits within a single-layer platform. © 2011 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2012. © 2012 Wiley Periodicals, Inc.

Synthesis of Oscillators Using Limit Variables and NAM Expansion

A systematic synthesis procedure for generating second-order grounded passive element canonic oscillators is given. The synthesis procedure is based on using nodal admittance matrix (NAM) expansion with the bracket method as well as using the infinity parameters. The resulting derived oscillators include circuits using various types of current conveyors. Two classes of oscillators are considered in this paper, and they have the advantages of having independent control on the condition of oscillation and on the frequency of oscillation by varying two different grounded resistors. The two classes of oscillators considered can be easily compensated for the parasitic element effects introduced by the current conveyors. This paper is considered to be continuation to the recently published paper on oscillators using NAM expansion D. G. Haigh et al. (2006). This is the first paper in the literature which uses limit-variables called infinity-variables D. G. Haigh et al. (2005) in the synthesis of oscillator circuits. Simulation results demonstrating the practicality of some of the generated circuits are included.