A Leaky Wave Antenna Design Based on Half-mode Substrate Integrated Waveguide Technology for X Band Applications

A new type of leaky-wave antenna (LWA) using half-mode substrate integrated waveguide (HMSIW) as the base structure is proposed in this paper. The structure consists of an array of slot, antenna designed to operate in X band applications from 8 to 12 GHz. HMSIW preserves nearly all the advantages of SIW whereas its size is nearly reduced by half. The antenna radiates one main beam that can be steered from the backward to the forward direction by changing frequency

Partial Closure Report for the Area 514 Treatment and Storage Facility

The purpose of this partial closure report is to inform the Department of Toxic Substances Control (DTSC) of the status of final closure of the Area 514 Treatment and Storage Facility (Area 514) and fulfill the DTSC requirements to proceed with the implementation of the interim action. Area 514 is located at the Livermore main site of Lawrence Livermore National Laboratory (LLNL). LLNL is owned by the U.S. Department of Energy (DOE) and operated jointly by DOE and the University of California. LLNL received its permit to operate hazardous waste facilities from DTSC in 1997. The hazardous waste treatment and storage operations of Area 514 were transferred to a newly constructed complex, the Decontamination and Waste Treatment Facility (DWTF), in 2003. Once the DWTF was operational, the final closure of Area 514 began in accordance with the DTSC-approved closure plan in June 2004. Abri Environmental Engineering, Inc., was retained by LLNL to observe the A514 closure process and prepare this partial closure report and certification. Prior to closure, the configuration of the Area 514 Treatment and Storage Facility consisted of Building 514, the Area 514-1 Container Storage and Treatment unit, the Area 514-2 Container Storage Unit (CSU), the Area 514-3 CSU, Building 513, the Wastewater Treatment Tank Farm unit, and the associated Area 514 yard area. The fenced area of Area 514 included approximately 27,350 ft2 on the LLNL Livermore site. To date, except for the 514-3 CSU, all of the other Area 514 structures have been demolished; and sampling and analysis have taken place. The non-hazardous wastes have been disposed of. At the time of writing this report, the hazardous, mixed, and low-level radioactive wastes are in the process of profiling for final disposition. Once the disposition of all wastes has been finalized, the implementation of the approved closure plan will be completed. As a part of the closure process, LLNL is required to submit a closure report and a certification by a qualified independent engineer within 60 days of closure completion. As a result of the sampling and analysis process, contamination was found at Area 514. The results for the concrete and structural samples have been used for characterization of the wastes that were generated for disposal purposes. No soils have been removed, except for the incidental removal of the soil immediately under the concrete and asphalt pavement, and the results for soil samples have been used to characterize the site and conduct fate and transport modeling. The entire LLNL Livermore site is a CERCLA site; however, the levels of soil contamination found at Area 514 are relatively low, and fate and transport modeling shows that the existing contamination will not impact ground water for hundreds of years. Consequently, LLNL has decided to leave the contamination in place. LLNL is currently conducting a comprehensive risk assessment to possibly attain a risk-based clean-closure determination. LLNL has identified paving the area with asphalt as an interim action to stabilize the site, prevent the surface contamination from becoming airborne, and minimize the movement of the contaminants in soil. This partial closure report is submitted based on DTSC's request

Design of Robust Digital Pole Placer for Car Active Suspension with Input Constraint

This chapter deals with the problem of state feedback control for an active quarter-car suspension system with control input constraint. The dynamics of the suspension system is first formed in terms of the control objectives: ride comfort, suspension deflection, and maximum actuator control force. The control task is formulated as robustly placing the closed poles in a desired region against different passenger load. Since digital computers are widely used in the vehicle industry, a new saturated controller design method is presented for regional pole-placement of uncertain discrete time systems. The constraint of control input saturation is considered in the design phase. The desired dynamic performance for uncertain discrete-time systems is represented by the settling time and damping ratio. A sufficient condition is derived to place the poles in a desired region. The design is formulated in terms of linear matrix inequality optimization. The effectiveness of the proposed design is illustrated by applying it to a quarter?car active suspension system. Different road tests for the proposed controller are carried out: step and bump disturbances. The proposed design achieves the desired oscillation damping due to road disturbances in addition to passenger comfort. The results are compared with the passive suspension system

Health and usage monitoring system for military vehicles

© Cranfield University, 2019The aircraft industry has been able to adopt improved maintenance and logistics planning as a result of the technological advances in Integrated Modular Avionics (IMA) and Equipment Health Monitoring (EHM). Same cannot be said about the land system. In the land environment, military vehicles are well behind in achieving the same abilities and hence, the problem of inefficiency in the maintenance and logistics for land based system needs to be addressed. To address this and assess the viability of integrating HUMS and Autonomic Logistics on military land vehicles, this project was proposed. Three main contributions from this research which adds to the knowledge are: (1) assessment of some real system failure which could lead to a poor operational readiness, (2) evaluation of how HUMS can improve the availability and operational readiness and reduction in maintenance cost that leads to the development of cost model and (3) a use of case studies to evaluate degradation of systems under consideration and how their continuous monitoring can help reduce the maintenance cost. A cost modelling study presented a simple and effective method to analyse the financial implication of integrating HUMS system was proposed for military land vehicles. The model provides logical steps to estimate the yearly repair costs, operational availability and the overall costs to understand the financial implication of HUMS integration over the whole service life. The model was also used to assess the financial viability of integrating HUMS in other military platforms e.g. light armoured vehicle, Piranha and Main Battle Tank, Challenger 2. In both the cases, the analysis showed significant financial savings in the long term. A case study was conducted on two different military vehicles to identify the frequency of different systems and sub-systems failures. The 20 challenger 2 and 40 Piranha were studied over the period of 10 years of service time. Study has found that cooling-, lubrication- and the suspension- system were the mostly affected systems in those particular vehicles. An experimental protocol was developed to study the failure detection techniques for the suspension system. The frequency response function was used to identify the failure of the damper and hence the suspension system. The study has observed the changes in the resonance frequency of the failed suspension system with different excitation magnitudes. Effect of vibration waveform was observed to be negligible. However, the small changes in the resonance frequencies using different magnitudes of base excitation seems to suggest the excitation magnitude has the potential to identify the failure based on the frequency response function.Another experimental protocol was developed to examine the failure detection technique for the cooling system of the military vehicle. When the failure was introduced to the cooling system, the significant variations in the temperature were observed for all the engine running conditions at the lab as well as the test with the vehicle running in the field. The variations observed in the temperature measured in different locations in the cooling system could be used to diagnose an early stage of failure in the cooling system, and it can be used to take a preventive action before the actual failure occurs

Comparison of the effect of cycloplegic versus NSAID eye drops on pain after photorefractive keratectomy

Purpose: To compare the effect of Homatropine and Diclofenac eye drops for reducing pain after photorefractive keratectomy (PRK). Methods: This randomized, double-masked, interventional study included 32 patients (64 eyes) who underwent bilateral PRK. After operation, patients received Homatropine eye drops in one eye and Diclofenac eye drops in the fellow eye for 48 h. The level of pain was evaluated using visual analogue scale (VAS), verbal rating scale (VRS), and pain rating index (PRI) at 0.5, 24, and 48 h after operation. Results: The level of pain was statistically similar between the two eyes half an hour after operation; however, Diclofenac eyes had significantly less pain 24 h after operation (1.7 ± 1.4 vs 5.8 ± 2.1, P < 0.001 for VAS, 0.6 ± 0.6 vs 2.4 ± 1.1, P < 0.001 for VRS, and 3.4 ± 3.4 vs 12.0 ± 6.9, P < 0.001 for PRI, respectively). Also, 48 h after surgery, the pain scores were less in the Diclofenac eyes (1.6 ± 1.8 vs 3.4 ± 2.8, P < 0.001 for VAS, 0.6 ± 0.6 vs 1.2 ± 0.9, P < 0.001 for VRS, and 3.3 ± 3.7 vs 6.5 ± 6.2, P < 0.001 for PRI). No case with delayed epithelial healing in both groups was observed. Conclusion: The effect of Homatropine seems to be lower compared to Diclofenac for reducing pain after photorefractive keratectomy. © 2015 Iranian Society of Ophthalmology

Stable Isotope Composition of Cyclone Mekunu Rainfall, Southern Oman

Cyclone Mekunu hit the southern Arabian Peninsula in late May 2018 and brought rainfall amounts that accounted for up to 6 times the mean annual precipitation. Coming from the Arabian Sea, a quite underdocumented region with regard to cyclones, the storm eye crossed the Omani coast approximately 80 km east of the border to Yemen. Using automatic samplers, rainfall samples were collected during the event at three locations along a transect almost parallel to the storm track. The stable isotope analyses show a wide range of δ values, with minimum and maximum values of −17.01‰ δ18O and −1.77‰ δ18O and −122.2‰ δ2H and −1.6‰ δ2H. On average, rainfall becomes isotopically lighter with elevation, but rather irregularly. In view of high wind speeds probably precluding a gradual rainout of ascending air masses, a “pseudo elevation effect” seems likely. Our measurements expand the known δ value range of local cyclones by about 6‰ for δ18O and by nearly 50‰ for δ2H. The isotopic composition of the annual Indian Summer Monsoon shows values of −0.93‰ δ18O to 2.21‰ δ18O and −2.1‰ δ2H to 23.7‰ δ2H. Thus, there is a clear difference in the dual isotope signatures of the two precipitation systems in the area. Our findings enable an assessment of the impact of cyclones on the hydro(geo)logical system. For the arid Najd area, we demonstrate that the isotopic signatures of groundwater samples fall between those of cyclone and (paleo)monsoon precipitation, suggesting that several rainfall types may have contributed to replenishment

Propofol and Kearns-Sayre Syndrome: An idiographic approach

With the focus on an idiographic approach whereby the observations incorporated the various dimensions of individual functioning ‘top-down’ to ‘bottom-up’, this case report describes the successful management of a 14-year-old girl with Kearns-Sayre syndrome and Dyggve-Melchior-Clausen disease requiring a transvenous permanent pacemaker implantation for complete heart block. The patient presented to a tertiary care centre in Muscat, Oman, in 2023 seeking consultation. The current idiographic approach appears to have a heuristic value for 2 interrelated reasons. Firstly, it is unlikely that even tertiary care units can accrue such rare presentations and scrutinise them under nomothetic approach. Secondly, by employing the idiographic approach that is capable of examining each case in-depth, the aspiration for good health and well-being may come to the forefront. To the best of the authors’ knowledge this is the first published idiographic report in anaesthesia care. Keywords: Intravenous Anaesthetics; Artificial Pacemaker; Kearns-Sayre Syndrome; Propofol; Idiographic Approach; Case Report; Oman