Waste heat recovery from adiabatic diesel engines by exhaust-driven Brayton cycles

An evaluation of Bryton Bottoming Systems (BBS) as waste heat recovery devices for future adiabatic diesel engines in heavy duty trucks is presented. Parametric studies were performed to evaluate the influence of external and internal design parameters on BBS performance. Conceptual design and trade-off studies were undertaken to estimate the optimum configuration, size, and cost of major hardware components. The potential annual fuel savings of long-haul trucks equipped with BBS were estimated. The addition of a BBS to a turbocharged, nonaftercooled adiabatic engine would improve fuel economy by as much as 12%. In comparison with an aftercooled, turbocompound engine, the BBS-equipped turbocharged engine would offer a 4.4% fuel economy advantage. If installed in tandem with an aftercooled turbocompound engine, the BBS could effect a 7.2% fuel economy improvement. The cost of a mass-produced 38 Bhp BBS is estimated at about $6460 or 170/Bhp. Technical and economic barriers that hinder the commercial introduction of bottoming systems were identified. Related studies in the area of waste heat recovery from adiabatic diesel engines and NASA-CR-168255 (Steam Rankine) and CR-168256 (Organic Rankine)

Interactive Two-Stage Stochastic fuzzy Rough Programming for Water Resources Management

This paper deals with a fuzzy programming approach for treating an interactive two-stage stochastic rough-interval water resource management. The approach has been developed by incorporating an interactive fuzzy resolution method within a rough two-stage stochastic programming framework. The approach can not only tackle dual rough intervals presented as an inexact boundary intervals that exist in the objective function and the left- and right-hand sides of the constraints that are associated with different levels of economic penalties when the promised policy targets are violated. The results indicate that a set of solutions under different feasibility degrees has been generated for planning the water resources allocation. They can help the decision makers to conduct in depth analysis of tradeoffs between economic efficiency and constraint-violation risk, as well as enable them to identify, in an interactive way, a desired compromise between satisfaction degree of the goal and feasibility of the constraints. A management example in terms of rough-intervals water resources allocation has been treated for the sake of applicability of the proposed approach

Productivity of date palm as affected by irrigation in a sandy soil

A field experiment was conducted on drip irrigated date palm trees (Barhi var.) in a private farm during the 2020 and 2021 seasons to evaluate the effect of five irrigation treatments (120, 100, 80, and 60% ETo and farmer practice) on amounts of applied irrigation water (AIW), consumptive use (CU), date yield and its components, fruit quality, water use efficiency (WUE), water productivity (WP), consumed electric energy, net income, a local date crop coefficient (Kc) and yield response factor (Ky). Results revealed that, average ETo values varied between 1.26 mm/day in December and 9.85 mm/day in July. The 2–year average AIW values were 17 377, 14 546, 11 715, 8 885 and 24 680 m3/ha for the 120, 100, 80 and 60% ETo treatments and farmer practice, respectively. Highest and lowest fruit yields of 39.2 and 15.2 t/ha were recorded for the 120% and 60% ETo treatments, respectively. The WP values of the same treatments were 2.27 and 1.23 kg fruits/m3. Seasonal average Kc value of 0.74 is obtained for the 120% ETo treatment. The Ky value of 1.187 is obtained for the Barhi variety. The lowest consumed energy (64.7%) and highest net income (31.8%) were recorded for 60% and 120% ETo treatments compared with farmer practice.  Keywords: Applied water, water consumption, water use efficiency, water productivity, crop coefficient, yield response factor, energy saving, net incom

ICI and PAPR enhancement in MIMO-OFDM system using RNS coding

The Inter-Carrier-Interference (ICI) is considered a bottleneck in the utilization of Multiple-Input-Multiple-Output Orthogonal Frequency Division Multiplexing (MIMO-OFDM) systems, due to the sensitivity of the OFDM towards frequency offsets which lead to loss of orthogonality, interference and performance degradation. In this paper Residue Numbers as a coding scheme is impeded in MIMO-OFDM systems, where the ICI levels is measured and evaluated with respect to conventional ICI mitigation techniques implemented in MIMO-OFDM. The Carrier-to-Interference Ratio (CIR), the system Bit-Error-Rate (BER) and the Complementary Cumulative Distribution Function (CCDF) for MIMO-OFDM system with Residue Number System (RNS) coding are analyzed and evaluated. The results had demonstrated a performance of transmission model with and without RNS

ARTEMETHER LOADED ETHYLCELLULOSE NANOSUSPENSIONS: EFFECTS OF FORMULATION VARIABLES, PHYSICAL STABILITY AND DRUG RELEASE PROFILE

Objective: The aim of this study was to explore the individual and joint effects of drug: ethylcellulose ratio, content of tween 80 and chloroform: water volume ratio on particles' size and size distribution of artemether loaded ethyl cellulose nanosuspension formulations, aiming to achieve nanosuspension with desired particles properties, stability and drug release profile.Methods: Mixed levels design was used to generate a series of artemether loaded ethylcellulose nanosuspensions that produced by emulsification-solvent evaporation technique. Formulations were qualified for particle size and size distribution using dynamic light scattering technique. Best ranked formulation was then evaluated for stability and drug release rate and kinetics.Results: Drug: polymer ratio, content of surfactant and organic: water volume ratio were found to exert considerable influences (p<0.05) on particle size of produced nanosuspensions, either individually or as joint variables. Peak intensity property of nanosuspensions was found to be influenced by drug: polymer ratio (p<0.05) whereas the influences of different variables on the polydisperse index property appear inconsequential (p>0.05). Best ranked (optimal) artemether nanosuspension proved stable and capable to improve and maintain the release of loaded drug over 24 h, at least under the setting conditions of this study.Conclusion: Focusing on both the individual and joint influences of formulation variables assist in achieving nanosuspension with desired particles characteristics, stability and drug release profile

Analysis of multicomponent transient signals using MUSIC superresolution technique

The problem of estimating the parameters of transient signals consisting of real decay constants has for long been a subject of study by many researchers. Such signals arise in many problems in Science and Engineering like nuclear magnetic resonance for medical diagnosis, deep-level transient spectroscopy, fluorescence decay analysis, etc. Many techniques have been suggested by researchers to analyse these signals but they often produce mixed results. A new method of analysis using modified MUSIC (multiple signal classification) subspace algorithm is successfully applied to the analysis of this signal. A noisy multiexponential signal is subjected to a preprocessing procedure consisting of Gardenerspsila transformation and inverse filtering. Modified MUSIC algorithm is then applied to the deconvolved data. The parameters of focus in this paper are the number of components and decay constants. It is shown that with this technique parameter estimates do not significantly change with signal to noise ratio. The superiority of this algorithm over conventional MUSIC algorithm is also shown

Effect of sampling on the parameter estimates of multicomponent transients

The need to estimate the parameters of transient multiexponential signals frequently arises in different areas of applied science. A classical technique that has been frequently used with different modifications is the Gardner transform. Gardner transform is used to convert the original data signal into a convolution model. Converting this model into a discrete type for further analysis depends on the selection of correct sampling conditions. Previously, a relationship between the sampling frequency and the weighting factor in the modified Gardner transform was derived. In this paper, the effect of this relationship on the accuracy of parameter estimates is investigated

Characterization of In-Pipe Acoustic Wave for Water Leak Detection

This paper presents experimental observations on the characteristics of the acoustic signal propagation and attenuation inside water-filled pipes. An acoustic source (exciter) is mounted on the internal pipe wall, at a fixed location, and produces a tonal sound to simulate a leak noise with controlled frequency and amplitude, under different flow conditions. A hydrophone is aligned with the pipe centerline and can be re-positioned to capture the acoustic signal at different locations. Results showed that the wave attenuation depends on the source frequency and the line pressure. High frequency signals get attenuated more with increasing distance from the source. The optimum location to place the hydrophone for capturing the acoustic signal is not at the vicinity of source location. The optimum location also depends on the frequency and line pressure. It was also observed that the attenuation of the acoustic waves is higher in more flexible pipes like PVC ones.Center for Clean Water and Clean Energy at MIT and KFUP