Elevated Vertical-Flow Constructed Wetlands for Light Greywater Treatment

Integrated planning of urban blue–green infrastructures is crucial to strengthen urban environmental quality and mitigate negative climate change-associated effects. It implies, however, increased water demand for irrigation, wherefore greywater (wastewater excluding wastewater from toilets and urinals) can be used, yet it requires handling for safe reuse. One treatment option is the use of constructed wetlands (CW), which have thus far not been broadly applied in inner-city districts due to large area requirements. This work investigates a novel bipartite container-based vertical-flow constructed wetland (VFCW) for the treatment of light greywater (from showers and hand wash basins) and its use as irrigation water for urban facade greenery. The VFCW consists of two compartments with 2.5 m2 filter area each, filled with 75 cm zeolite-containing lava sand (0–4 mm) and 75 cm Rhine sand (0–2 mm), respectively. In short, screening has proven to be well suitable for coarse solids removal, so there is no further need to settle light greywater, which reduces overall treatment area and benefits urban application. Treated greywater complied with irrigation standards at all times, yet mixing with rainwater can help reduce salt contents, if applicable. The modular/elevated lava sand VFCW exhibited extensive nitrification, even at extremely low water temperatures, as well as mean effluent concentrations of 6.3 mg/L COD and <0.05 mg/L Ptot, which makes it a very promising treatment option for greywater. All in all, the modular/elevated design promotes urban application of VFCW as a multifunctional blue–green system that can help increase urban resilience.

Frequency Synthesizers Based on Fast-Locking Bang-Bang PLL for Cellular Applications

The fractional-N frequency synthesis based on Digital Phase Locked Loop (DPLLs) has become a conventional design approach for the new radio wireless applications. The advantage of the digitally-intensive design style is the possibility to implement low-power and very accurate digital calibration techniques. Most of these algorithms run in the background tracking PVT variations and either relax or, in some cases, completely remove the performance limitations due to analog impairments. Moreover, the digital loop filter area is practically negligible with respect to the one in analog PLLs. These benefits become even more relevant in the scaled CMOS technology nodes. This chapter identifies the design parameters of a standard DPLL architecture and proposes a novel locking scheme to overcome the intrinsic limitations of the digital frequency synthesizers approach. To prove this new scheme a sub-6 GHz fractional-N synthesizer has been implemented in 65 nm CMOS. The synthesizer has an output frequency from 3.59 GHz to 4.05 GHz. The integrated output jitter is 182fs and the power consumption of 5.28 mW from 1.2 V power supply leads to a FoM of −247.5 dB. This topology exploits a novel locking technique that guarantee a locking time of 5.6 s, for a frequency step of 364 MHz, despite the use of a single bit phase detector.

Procedure and Installation for Determining the Filtering Capacity

The paper presents a method and an installation for determining the filtration capacity of filters made of composite materials with ceramic matrices. Applicable to fluid media (liquid, gaseous) the process is based on generating a pressure gradient in the filter area. The pressure difference between the two sides of the filter determines the passage of the fluid through the filter and its retention of the suspended particles. The process allows the testing of filters with a great diversity regarding the nature of the materials from which they are made, respectively their geometry and dimensions. In the present experiment, filters made of ceramic composite materials based on bentonite reinforced with SiC type ceramic powders and Al type metal powders were tested. From these materials were made cylindrical filters (diameters of 16 mm and length of 15 mm), which, after sintering at a temperature of 1250°C, were tested on the installation, for filtering rainwater samples. The determinations made highlighted a good ability of the filter to retain suspended particles in the water.

Design and Accomplishment of Fir Filters for High Accuracy Reconfigurable Applications

The top function of the job is to establish transpose style Finite Impulse Response filters. That is pipelined along with furthermore constantly aids a variety of regular Entertainments come close to that cause conserving of calculation. Change kind of filter arrangement does say goodbye to straight support the block taking care of process. The MCM is instead much safer in Transpose variety when the normal operand is a couple of with the celebration of routine coefficients that diminish the computational hold-up. The execution of MCM approach is much less complicated out of commission coefficient Transpose design FIR filter however centre in reconfigurable coefficients. In arranged coefficients change FIR filter, area equally as great as hold-up is decreased by making use of MCM strategy. The low-complexity kind utilizing the MCM system is made an application for dealt with coefficients change design FIR filters like multiplier-established design is benefited from for reconfigurable transpose kind FIR filter. Critiques of the end results obtained guidance that efficiency metrics of the recommended execution is considerably harmonies with academic presumptions. Moreover, the recommended FPGA energy lies to include substantially so much less discipline-delay complexity on the other hand with the controlling DA-established implementations of FIR filter. For the actually the very same filter measurement similar to the similar block measurement, the advertised constitution needs thirteen% a lot less ADP as well as also 12.8% a lot less EPS than that of the present direct-from obstructs FIR structure. Based on these findings, we provide a scheme for the selection of direct-type and also transpose-kind company based on the filter dimensions and also block-length for obtaining subject-extend as well as furthermore power superior block FIR frameworks.

Performance Analysis and Testing of Aftermarket Filters

Aftermarket segment is one of the promising and growing section in automobile industry. The popularity of this section is due to the low cost and high replacement rate. Best filters among many will survive in the market. Different Filter manufacturers develop filters for same purpose but varies in their construction. There are a wide variety of aftermarket performance filters for the same type of OEMs. They vary in their brand name, filter area, filter medium, price, service life and method of install. The presence of increased number of aftermarket performance filters has prompted automotive enthusiasts to replace the OEM filter for the same purpose available in lower cost. The paper discusses about the testing procedures to be done to compare the performances both the brands (OEM and Aftermarket filters). All the experiments were conducted at PSG institute of science & Technology Coimbatore. This study shows how much an aftermarket filter varies from that of OEM. The performance of both OEMs (BOSCH and FLEETGUARD) and Aftermarket filter(UCAP) are evaluated by pressure drop, filter efficiency, media strength, porosity tests.

MEMBRANE FOULING IN ANOXIC-OXIC MBR SYSTEM OPERATED AT LOW DISSOLVED OXYGEN

Membrane fouling in a lab-scale anoxic-oxic MBR operated at low dissolved oxygen (DO) was investigated in this study. The system includes an anoxic, an oxic and a membrane basin with the working volumes of 73 L, 124 L, and 68 L, respectively. A hollow fibre membrane module with a pore size of 0.2 µm and with total filter area of 1.44 m2 was submerged in the membrane basin. The system was operated at various low DO concentrations of 2.0; 1.5; 1.0; and 0.5 mg/L. The results shown that at DO higher than 1.0 mg/L, COD and TN removal efficiencies were higher than 90 % and 60 %, respectively. However, low DO (less than 1.0 mg/L) lead to poor sludge flocculation which deteriorate the membrane filterability. The TMP increased dramatically at different DO levels. There was a significant increase of TMP during first 15-days experiment at DO 2.0 mg/L. After that the TMP was increased slowly and lower than 16 kPa to until 30-days. In contrast, when DO was reduced to 1.5, 1.0, and 0.5, the TMP was increased sharply almost from 1 to over 20 kPa within about 15 days.

Modeling Airborne Virus Concentrations in Filtered Swine Barns with Negative-Pressure Ventilating Systems

Porcine reproductive and respiratory syndrome virus (PRRSV) is an economically significant pathogen in the swine industry that can spread through the air. Many swine gestation and farrowing barns with negative-pressure ventilating systems filter the inlet air to manage airborne PRRSV transmission using MERV 8 pre-filters in series with either MERV 14 or MERV 16 filters. Recent research reported air infiltration rates for a new 3,000-sow gestation/farrowing swine barn at several static pressure levels. The barn infiltration data and supplier-provided airflow versus pressure drop data for the filters, a fan, and an evaporative cooling pad were used to model steady-state virus particle concentrations inside a well-mixed barn. Other model inputs included the inside temperature, design ventilating rate, a fan performance factor, filter area, a filter airflow reduction factor due to particulate matter accumulation, and ambient virus particle concentration distributions. For the conditions used, model results indicated that higher barn virus concentrations were obtained with lower mechanical ventilating rates and higher barn infiltration rates. Improved fan performance reduced the number of fans needed but had little impact on barn virus concentrations. Increasing the filter area reduced the pressure drop that the fans had to overcome at higher ventilating rates and correspondingly reduced the unfiltered infiltration rates and barn virus concentrations. Reduced airflow due to particulate matter accumulation on the filters increased the system pressure drop, increased the number of fans running, and increased the barn virus concentrations. Model results indicated that filter combinations that reduced overall virus penetration reduced barn virus concentrations by 57% to 80% for the conditions modeled. More work is needed to assess the model results and the importance of the adjusted factors for other barn and equipment conditions. Keywords: Biosecurity, Filtered barn, Infiltration, Model, Swine, Ventilation, Virus.

Control of Gas and Odor Levels in Swine Facilities Using Filters with Zinc Oxide Nanoparticles

The effectiveness of zinc oxide (ZnO) nanoparticles as filtering media for controlling the levels of hydrogen sulfide (H2S), ammonia (NH3), and odor in swine facilities was evaluated in this study. Semi-pilot scale tests were done to determine basic operational factors, the results of which showed that the fluidized bed air filtration system (FBAFS), loaded with ZnO nanoparticles at a rate of 0.28 g cm-2 of filter area, and a gas flow rate equivalent to 0.5 m s-1 face velocity achieved significant reduction in target gas levels. The performance of this filter system was further investigated in a room-scale environmental chamber representative of normal swine production conditions. When installed as part of the ventilation air recirculation system of the room, the FBAFS with ZnO nanoparticles achieved about 65% H2S and 42% NH3 reductions in the human-occupied zones but had no significant impact on pig performance as well as odor levels in the chamber. Keywords: Ammonia, Face velocity, Filtration, Hydrogen sulfide, Nanoparticles, Odor, Swine, Ventilation, Zinc oxide.

Internal Flow Study of Diesel Fuel Filter

The size and the number of folds severely affect the performance of the diesel fuel filter. Computational fluid dynamics method was applied to diesel filter internal flow simulation, and flow pressure lost was test to verify the simulation result. CFD result shown that, when the filter paper angle less than 3°, the internal flow resistance of fuel filter grown rapidly. The flow resistance decreased slowly when filter paper angle of greater than 6°. If filter paper angle was less than 3 °, effective filter area of filter decreased sharply, and filtration efficiency was lower than limit. The filter paper dust capacity increased rapidly, when filter paper angle was greater than 4.5 °, which prolonged filter life. In order to ensure the flow resistance, filtration efficiency and service life, the angle of the filter paper should be between 3 ° to 4.5 °.

The Microwave Dielectric Materials of (Zn1-xMgx)TiNb2O8 for Electroceramics Devices Applications

The microwave dielectric properties of ZnTiNb2O8 ( ~34, Qf ~42,500GHz, ~ –52ppm/°C) was reported by Hong et. al. To lower the dielectric loss of ZnTiNb2O8, we studied the systems of (Zn1-xMgx)TiNb2O8 (x=0.02-0.1) ceramics. The manner of equivalent-charge trace substitutions for Zn2+-sites were replaced with Mg2+. In order to achieve more stability, CaTiO3 ( ~ +800ppm/°C) was used to adjust the negative τf of (Zn0.95Mg0.05)TiNb2O8 ( ~ –58ppm/°C). A bandpass filter using coupled microstrip-line resonators have been designd for wireless LAN system such as IEEE 802.11 ( 2.4 or 5 GHz). The response of the implemented filter used 0.8(Zn0.95Mg0.05)TiNb2O8-0.2 CaTiO3 ( ~35.77, Qf ~18,000GHz, ~ +4ppm/°C) dielectric substrates. In this paper, the bandpass filter area designed on 0.8(Zn0.95Mg0.05)TiNb2O8-0.2 CaTiO3 is reduced 88% than FR4 substrates and the near zero τf makes better frequency stability.