First principles study of structural, electronic and optical properties of half-heusler alloys LIMGN, NaMGN and KMGN

In this study, we performed our calculations using the full-potential linearized-augmented plane wave (FP-LAPW) method as implemented in the WIEN2k code based on DFT. The generalized gradient functional with the Wu-Cohen (WC) parameterization was used to evaluate the structural, electronic, optical and thermoelectric properties of the materials under this study. We have calculated the structural parameters and our obtained results are in good agreement with available experimental and previous theory calculations. The density of states and band structure figures have been calculated and analyzed. The optical properties that covered by dielectric function, absorption coefficient, refractive index, extinction coefficient, reflectivity and energy-loss function have been calculated and analyzed in a range energy from 0eV to 30eV

Thermal process, technical review and performance improvement for operational of ultra-supercritical coal fired power plant

In most Asian, a country such as China, India, Indonesia and Malaysia, thermal coal plant plays the roles in providing electric power. As reported in International Energy Agency (IEA) 2018, is forecasting until year 40 percent of energy supply until the year 2040. In fact, look up at the energy security and sustainability of the energy supply, majorities of the countries still operating the coal thermal power plant as baseload. Realizing the importance and criticality, there is a need to maintain and sustain the operational process of a thermal coal plant. Therefore, this research is studying the technical process, mechanism, operation procedure, machine technologies, issues, and challenges faced at one of the supercritical coal plants located in Asia country. Thermal operational process monitored and observed in six-month performances; two-pass ultra-supercritical, pulverized fuel, steam generator, and one double flow intermediate-pressure and two double-flow low-pressure turbines. Operator log sheet, parameters performing, and recording were recorded during the observation period. The management tools, SWOT was applied in scrutinizing and analyzing the input from this study. The study categorizes the barriers based on four elements which are Resources and Management, Material and Machine Technologies, Process Methodology and Environment Work Culture. Besides, this study recommends the strategy to enhance the operational excellent on optimizing the power plant performance

Il medico del lavoro nei Paesi industrializzati: confronto tra modelli professionali ed organizzativi diversi

Diversamente dalla maggior parte delle altre attivit\ue0 mediche, quella del medico del lavoro risente profondamente del tessuto socio-culturale, delle istanze del mondo produttivo e sindacale, del contesto normativo proprio dei singoli Stati. Anche nell'ambito dell'Unione Europea, pur in presenza di una normativa comunitaria ampia, particolareggiata e cogente, la concreta attivit\ue0 quotidiana dei medici del lavoro si svolge con modalit\ue0 molto varie. Questo studio si propone di offrire una panoramica sulla figura del medico del lavoro utile, oltre che ai professionisti desiderosi di svolgere esperienze lavorative all'estero, ad orientare gli auspicati aggiornamenti dei corsi di studio professionalizzanti e della normativa nazionale in materia. Partendo dal Medico Competente e dal Medico del lavoro dei Servizi disegnati dalla legislazione italiana, gli Autori hanno esaminato il modello organizzativo e professionale della medicina del lavoro nei principali Paesi del mondo industrializzato, costruendo una serie di "schede" che ne illustrano le principali caratteristiche. Da questo esame emergono rilevanti differenze nella figura del medico del lavoro sotto molteplici aspetti, ai cui estremi troviamo ad esempio: - ruolo pubblico/privato; - organizzazione prevalentemente individuale-professionale/prevalentemente societaria-dipendente; - discrezionalit\ue0 professionale/contesto di regole; - attivit\ue0 prevalentemente clinico-sanitaria/prevalentemente igienistico-industriale e consulenziale; - regime sanzionatorio specifico (illeciti amministrativi, reati di pericolo)/generico (reati di danno). Nel presente lavoro vengono illustrati alcuni esempi emblematici

The Efficiency Analysis of Medical Records Departments of Tehran University of Medical Sciences Hospitals with Data Envelopment Analysis (2007-2009)

Background and Aim: Analysis of efficiency in hospitals, as the most expensive operating unit of the health system, is very important. This costly unit has several departments that one of them is medical records. This study is trying to analyze the efficiency of medical records department for the enhancement of using medical records facilities.Materials and Methods: In this study, technical, scale and managerial efficiency of medical records department has been studied by data envelopment analysis method, and assuming the scale efficiency variable and the input axis. Information used in this study was the input variables (number of technician personnel and lower and Master of Science personnel and higher), output variables (number of emergency and outpatient and inpatient medical records and the number of filing unit visitors to respond) during 2007-2009.Results: The average technical efficiency of medical records departments is 84 percent, that indicates there is at least 16 percent capacity for an increase in performance. Average of management and scale Performance in units during the 3 years of study are 95 and 89 percent respectively. Most input surplus is relevant to technician and lower personnel. The average performance of these units in general hospitals is 80 percent and in specialized activities is 92 percent.Discussion and Conclusion: Relationship between studied indicators in this study with performance medical records departments showed that using such as employee personnel with undergraduate degrees and higher and educated in medical records filed, the use of managers with enough experience in this department and more use of computer systems for unit activities can fill 16 percent capacity of performance improvement in these units

New Design of a CNG-H2-AIR Mixer for Internal Combustion Engines: An Experimental and Numerical Study

Several studies have aimed to convert diesel engines to dual- or tri-fuel engines to improve their fuel economy and reduce the emissions from diesel engine, however, most of these studies do not consider enhancing the homogeneity of fuel mixtures inside the engine and accurately controlling the air fuel ratio. In this study, a new air-fuel mixer was designed, manufactured and tested. The proposed air-gaseous fuel mixer design was conceived to be suitable for mixing air with compressed natural gas (CNG) and a blend of hydrogen and compressed natural gas (HCNG) that gives homogenous mixtures with high uniformity index and also to be easily connected with an Electronic Control Unit (ECU) for controlling accurately the air-gaseous fuel ratio for different engine speeds. For optimizing the homogeneity inside the new mixer, fourteen different mixer models were created to investigate the effects of diameter, location, and the number of holes inside the mixer on the homogeneity and distribution of the mixtures. Computational fluid dynamics analysis software was used to check the flow behavior, distribution and homogeneity of mixtures inside the new mixer models. The simulation results revealed that the best uniformity index (UI) values are obtained in model 7 where the UI values are 0.939 and 0.937, respectively, for an air fuel ratio for a blend of hydrogen and compressed natural gas (AFRHCNG) = 51.31 and the air fuel ratio for compressed natural gas (AFRCNG) = 34.15. According to the numerical and experimental results for the new mixer (model 7) under different engine speeds (1000–4000) and air-CNG ratio of 34.15, a meaningful agreement is reached between the experimental and numerical values for AFRCNG (coefficient of determination (R2) = 0.96 and coefficient of variation (CoV) = 0.001494)

Design and implementation of an intelligent fuzzy VLSI chip for traffic control application

This paper describes a functional Fuzzy Traffic Controller (FTC), which utilizes fuzzy logic algorithm to achieve a smart and a flexible knowledge-based system in hardware design while achieving better efficiency in the traffic control and minimizing traffic jam occurrences at interchange on road area. To develop the system, the behavior level of FTC algorithm has developed using VHDL under MAX+PLUS II CAD environment. The designing part of FTC chip into VHDL program eliminates the shortcomings of other custom facilities and conventional controller design available today. The main goal is to overcome the bandwidth of existing systems. The Finite State Machine (FSM) of the FTC has coded in VHDL program for controlling the specific Traffic flow application. Later on, the FPGA Express (Synthesis tool) has used to get a fully gate level synthesis architecture for the whole Fuzzy based VLSI chip and then the optimization step has been applied for minimizing the VLSI chip's timing delay, clock speed, and area to get the correctness of FTC design. The main features of the FTC chip consist of various operational modes, safety features, capability, and robustness enhancement through fuzzy logic algorithm presented in this paper

A Wide-Bandwidth PVT-Reconfigurable CMOS Power Amplifier with an Integrated Tunable-Output Impedance Matching Network.

Peer reviewed: TrueThis paper proposes a wideband CMOS power amplifier (PA) with integrated digitally assisted wideband pre-distorter (DAWPD) and a transformer-integrated tunable-output impedance matching network. As a continuation of our previous research, which focused only on linearization tuning for wideband and PVT, this work emphasized improving the maximum output power, gain and PAE across the PVT variations while maintaining the linearity for a wide frequency bandwidth of 1 GHz. The DAWPD is employed at the driver stage to realize a pre-distorting characteristic for wideband linearization. The addition of the tunable-output impedance matching technique in this work provides stable output power, PAE and gain across the PVT variations, through which it improves the design's robustness, reliability and production yield. Fabricated in CMOS 130 nm with an 8-metal-layer process, the DAWPD-PA with tunable-output impedance matching can achieve an operating frequency bandwidth of 1 GHz from 1.7 to 2.7 GHz. The DAWPD-PA attained a maximum output power of 27 to 28 dBm with a peak PAE of 38.8 to 41.3%. The power gain achieved was 26.9 to 29.7 dB across the targeted frequencies. In addition, when measured with a 20 MHz LTE modulated signal, the DAWPD-PA achieved a linear output power and PAE of 24.0 to 25.1 dBm and 34.5 to 38.8% across the frequency, respectively. On top of that, in this study, the DAWPD-PA is proven to be resilient to process-voltage-temperature (PVT) variations, where it achieves stable performances via the utilization of the proposed tuning mechanisms, mainly contributed by the proposed transformer-integrated tunable-output impedance matching network

A Wide-Bandwidth PVT-Reconfigurable CMOS Power Amplifier with an Integrated Tunable-Output Impedance Matching Network.

This paper proposes a wideband CMOS power amplifier (PA) with integrated digitally assisted wideband pre-distorter (DAWPD) and a transformer-integrated tunable-output impedance matching network. As a continuation of our previous research, which focused only on linearization tuning for wideband and PVT, this work emphasized improving the maximum output power, gain and PAE across the PVT variations while maintaining the linearity for a wide frequency bandwidth of 1 GHz. The DAWPD is employed at the driver stage to realize a pre-distorting characteristic for wideband linearization. The addition of the tunable-output impedance matching technique in this work provides stable output power, PAE and gain across the PVT variations, through which it improves the design's robustness, reliability and production yield. Fabricated in CMOS 130 nm with an 8-metal-layer process, the DAWPD-PA with tunable-output impedance matching can achieve an operating frequency bandwidth of 1 GHz from 1.7 to 2.7 GHz. The DAWPD-PA attained a maximum output power of 27 to 28 dBm with a peak PAE of 38.8 to 41.3%. The power gain achieved was 26.9 to 29.7 dB across the targeted frequencies. In addition, when measured with a 20 MHz LTE modulated signal, the DAWPD-PA achieved a linear output power and PAE of 24.0 to 25.1 dBm and 34.5 to 38.8% across the frequency, respectively. On top of that, in this study, the DAWPD-PA is proven to be resilient to process-voltage-temperature (PVT) variations, where it achieves stable performances via the utilization of the proposed tuning mechanisms, mainly contributed by the proposed transformer-integrated tunable-output impedance matching network