Pre Filter Research Articles

The Application of Ergonomics in the Design of Air Filtering Devices Through Software Engineering

Air is a part of an important element in life, with the aim that all living things can move optimally. From this everything needs to get quality air, so that the inhaled air feels healthy and fresh. Lately, air problems are very much discussed, especially in urban areas that produce many pollution from various sources produced. Air pollution is one of the activities that produce air quality inappropriate as it should, and is contaminated with hazardous substances for living things. This research has the aim of applying ergonomics in the design of air filtering devices through software repair. In this study, applying analyze, design, development, implement, and evaluate (ADDIE) model. Each of them focuses on the design of the tools carried out: Analyze identifies the problems that occur, especially in the air quality which lately is widely discussed. Design of designing tools that have stages: vacuum cleaner, washable pre filter, activated carbon deodorization filter, dust collecting filter, and internet hardware of things. Development carried out the development that will be carried out, which is integrated with the Internet of Things (IoT) in the form of application. Implement in the application of air filtering equipment, namely in the housing, shopping, and places of dismissal sectors. Evaluate conducts testing that will be known to the strength of the tool, by paying attention to several previous references. The results of this study will produce an air screening tool through software engineering, namely Sketchup software. Some literature studies show air filtering with some tools used will make the dirty air clean air. Some categories and range of standard levels of Particle Metter (PM) 2.5 and Standard Air Freight Index (ISPU): Good (1-50), Medium (51-100), Unhealthy (101-200), Very Unhealthy (201-300 ), and dangerous (301-500). The conclusion in this study results in a design of air filtering tools that can be applied on the roof of the house, shop, and others. This has the goal so that the results of dirty air above will be filtering and producing clean air. So that the air inhaled around the building with the tool will feel healthy and fresh.

Implementation of Gyro Accelerometer Sensor for Measuring Respiration Rate Based on Inhale and Exhale Using Kalman Filter

Respiratory rate is a fundamental vital sign that is sensitive to different pathological conditions including heart, lung, emotional stress, the influence of body temperature and activity fatigue. The respiratory rate in humans is measured by counting the number of breaths for one minute by monitoring and counting the number of times the chest rises and falls during the inhale and exhale process. Various methods for measuring respiratory rate that are commonly used including pneumograph, impedance and capnography are applied in patient monitoring. This study aims to examine and analyze the application of the kalman filter on the output of the gyro accelerometer sensor to increase the results of the detection of respiratory rates using the gyro accelerometer sensor. This study test was carried out using a patient simulator in Surabaya Ministry of Health Polytechnic nursing laboratory. This simulator patient can simulate respiration with a mechanical work system up and down the chest and abdomen, uses an Arduino Nano microcontroller to filter the output of the gyro accelerometer sensor and the results will be compared before and after the filter. The independent variable in this study is the respiration value, while the dependent variable is the sensor output before being filtered. In the relaxed condition of the respondent The most effective use of the kalman filter is found in the parameters R = 10, Q = 0.1 because in the use of these parameters, the value after being filtered has a value that tends to be stable. The highest error value in the application of the gyro accelerometer sensor occurs at sensor position 1 with R = 1 Q = 10 value of 2,6%. This study shows the effect of differences in respiration values before and after using a kalman filter. This study has limited differences in values that are far between the pre filter and after being filtered in several data collections.

Pre-filtration followed by slow double-layered filtration: Media clogging effects on hydraulic aspects and water quality.

This study evaluated clogging effects on head loss and water quality in sand prefiltration columns, followed by innovative double-layered slow-filter filtration technology using anthracite coal and sand. The study was divided into two phases. Phase 1 (filtration rate 11 m3 /m2 ·d) had a layout of a pre-filter (PF) system followed by a slow filter (SF). In Phase 2 (filtration rates of 5.5 and 11 m3 /m2 ·d), two PF systems (PF1 and PF2) followed by SFs (SF1 and SF2) were monitored, be differed only by filtration rate. Phase 1 presents a mean turbidity removal of 45.6% in PF and 23.9% in SF. PF presented a lower head loss in the superficial layers of the filter media, whereas SF presented a more important contribution in the deeper layers of the bed. In Phase 2, the mean results obtained for turbidity removal in PF1 and SF1 were 84.7% and 22.4%, in that order. PF2 and SF2 promoted mean reductions of 84.5% and 22.0%, respectively. Greater clogging is observed in the PF's surface layers, whereas the SFs dissipate greater clogging with depth. Filtration rates and water quality were similar in filter media of different compositions. PRACTITIONER POINTS: Double-layer filters show better use of the porous media in depth. Different materials produce different forms of clogging. Higher filtration rates increase the number of pre-filter and slow filter runs.

Improving partial discharges location under dispersion and multi-path propagation

Dispersion and multi-path propagation distort partial discharge (PD) pulses that travel along power cables. Two new techniques to improve the location accuracy using double-ended methods are proposed: the inclusion of a pre-filter (PF), that increases the signal to noise ratio by properly selecting the filter bandwidth and the center frequency, and an echo suppression (ES) technique, that reduces the peak value of the interfering echoes.Two location algorithms (based on cross-correlation and the energy criterion function) are combined with the proposed techniques and their performances against noise, dispersion, and multi-path propagation are evaluated. Simulation results show that the proposed PF technique improves the location accuracy, even for high dispersion conditions, where the location error can be reduced down to half a meter. In addition, the proposed ES technique reduces the number of false detections in those cases where the first PD echo is close to the original PD. Experimental results confirm the benefits of the proposed PF technique, showing that, even under adverse conditions, the location error can be smaller than 1m in a 300m long cable.

Impact of anion exchange adsorbents on regional citrate anticoagulation.

Introduction:Heparin and citrate are commonly used anticoagulants in membrane/adsorption based extracorporeal liver support systems. However, anion exchange resins employed for the removal of negatively charged target molecules including bilirubin may also deplete these anticoagulants due to their negative charge. The aim of this study was to evaluate the adsorption of citrate by anion exchange resins and the impact on extracorporeal Ca2+ concentrations.Methods:Liver support treatments were simulated in vitro. Citrate and Ca2+ concentrations were measured pre and post albumin filter as well as pre and post adsorbents. In addition, batch experiments were performed to quantify citrate adsorption.Results:Pre albumin filter target Ca2+ concentrations were reached well with only minor deviations. Citrate was adsorbed by anion exchange resins, resulting in a higher Ca2+ concentration downstream of the adsorbent cartridges during the first hour of treatment.Conclusions:The anion exchange resin depletes citrate, leading to an increased Ca2+ concentration in the extracorporeal circuit, which may cause an increased risk of clotting during the first hour of treatment. An increase of citrate infusion during the first hour of treatment should therefore be considered to compensate for the adsorption of citrate.

Design of MIMO QFT fractional control based on intelligent fractional PI<SUP align=right>α</SUP>D<SUP align=right>μ</SUP> controller combined with decentralised and centralised FBLFD pre-filter: application to SCARA robot

The aim of this paper is to propose new robust controls for multivariable parametric uncertain systems and to validate their efficiency in robots path tracking. An automated fractional multivariable Quantitative Feedback Theory is developed. The principle is to obtain desired performances on the basis of controllers and pre filters without using loop shaping process. The proposed approach has benefited from the robustness of fractional control. Indeed, the method is based on a combination of intelligent fractional PIαDμ controller with both diagonal and non-diagonal Frequency Band Limited Fractional Differentiator. A bi-objective optimisation based on genetic algorithm is utilised to find the controller parameters. The developed methodologies are applied to a SCARA robot model and the findings highlight the robustness of the designed controller and the success of the diagonal pre-filter to eliminate loop interactions.

An Insight Framework for Content based Medical Image Retrieval using Deep Convolutional Neural Network

Content Based Image Retrieval system is essentially proven techniques for retrieving the DICOM based images. DICOM format is use to acquire, store and shared medical images. Typically, retrieval of image under query upon the medical image databases is performed by fusing the low-level and high-level descriptors along with DCNN features. In this paper, DICOM image meta data are extracted by using dicom function and create the local database for reserve the information. To accomplish the initial search and retrieve the images by using extraction of Semantic information. The DICOM tags are extracted from the DICOM images and use DCNN feature to build a feature vector database. Subsequently prediction is done based on the by leveraging the convolution layers based on the meta data along with DCNN image features. This paper attempts to implement pre filter method to all DICOM images which further decrease the searching no of images, searching time and ultimately gives fast processing. DCNN based prediction model was constructed and finest results are accomplished. Average accuracy of precision and recall up to0.80 and 0.87 respectively is achieved based on precision value which would be suitable for high quality image retrieval based on semantic information confined in the image.

Comparative study of commercial home air cleaners

Pollution levels and increasing airborne diseases are today key factors driving the dynamic market of home air cleaners. Numerous air purifiers of varying shapes and sizes are now commercialized, often constituted of passive filters (pre filter, HEPA filter, Activated Carbon filter) and sometimes of active systems (photocatalysis for instance). Manufacturers tend to make bold claims regarding the efficiency of their products, but those claims are not often substantiated by hard evidence. This is especially the case with gaseous pollutants. We present here comparative laboratory tests conducted at CEA and inspired by the American, Chinese and French standards, of six commercial air cleaners suitable for medium-sized rooms. The purpose is to measure and compare their Clean Air Delivery Rates for particulate matter, and filtration efficiencies for Volatile Organic Components. The air cleaners are found to be effective against particulate pollution, but their performance against gaseous pollutants is on the whole disappointing.

5×222 Gb/s PM-16QAM Nyquist-WDM Superchannel

This paper reports terabit Nyquist-wavelength division multiplexing (Nyquist-WDM) superchannel transmission using five subcarriers. Each sub-carrier is 222 Gb/s polarization multiplexed- 16 quadrature amplitude modulation (PM-16QAM) advance modulation format based transmitter. Each subcarrier is Nyquist-spaced using a pre filter of bandwidth 33.33 GHz, which is 1.2 ×symbol rate of the PM-16QAM based transmitter. Performance of the proposed superchannel is realized by means of bit error rate (BER), optical signal to noise ratio (OSNR), transmitted power, optical spectrum of the superchannel and individual filtered subcarrier. The proposed work exhibits reference BER of value 4×10-3 at OSNR 21 dB, which is quite remark-able. The proposed Nyquist-WDM superchannel delivers Terabit transmission capacity of 1.11 Tb/s and excellent spectral efficiency of 6.66 bit/s/Hz. Presence of Nyquist-WDM approach makes the system inter channel interference (ICI) tolerant. Hence, the proposed work is efficient enough for the next generation optical network, ultra long haul transmission and elastic net-work.

A modernistic PLL based on feed forward frequency estimator with selective harmonic pre filter for grid imperfection

This paper describes a synchronisation technique to track phase and frequency of input signal under abnormal grid condition like frequency variation. Proposed control topology consist of a conventional synchronous reference frame phase locked loop (SRF PLL) type-2 along with a feed forward frequency estimator loop with selective harmonic filtering technique. It eliminates phase and frequency error under wide frequency deviation. Phase error is fed into proportional integral regulator which reduces it to zero. It is observed that faster and better dynamic performance is achieved by frequency estimator with higher stability margin. The stability is evaluated by bode plot. An estimated frequency is smooth and close to fundamental frequency as it uses the information from all three phase to estimate a single value for frequency. The feed forward action is implemented with pre filtering stage to improve dynamic performance of system. Simulation results are presented to validate effectiveness of proposed technique.

A modernistic PLL based on feed forward frequency estimator with selective harmonic pre filter for grid imperfection

A modernistic PLL based on feed forward frequency estimator with selective harmonic pre filter for grid imperfection

DISCHARGE LIQUID, VECTOR OF TOTAL SUSPENDED SEDIMENT (TSS) OF MAYO TSANAGA AT MAROUA (FAR NORTH CAMEROON)

Mayo Tsanaga is the Cameroonian part of the Lake Chad Basin ungauged. The knowledge of discharge is essential for the design of hydraulic structures and for hydrological risk prediction. The objective of this study is to evaluate discharge, total suspended sediment and the deduction of the specific sediment yield. The exploration of velocity fields and the differences in the pre and post filtration filter weights were adopted as a methodology. The results revealed that annual discharges of Mayo Tsanaga at Maroua from 2012 to 2014 are respectively 1.94 ± 0.38 m3 /s, 2.18 ± 0.43 m3/s and 0.89 ± 0.17 m3/s. Mayo Tsanaga discharge will be used when sizing the second bridge on this river. Mayo Tsanaga's daily mean concentrations of TSS are respectively 429.384 mg/L ± 12.88 for the year 2013 and 17.45 ± 0.52 mg/L for the year 2014. The corresponding specific sediment yield (SSY) of Mayo Tsanaga are 34.92 t.km-2.year-1 in 2013 and 0.57 t.km-2.year-1 in 2014. The SSY expresses the amount of ground lowering for the whole catchment.

Ecological patterns, diversity and core taxa of microbial communities in groundwater-fed rapid gravity filters.

Here, we document microbial communities in rapid gravity filtration units, specifically serial rapid sand filters (RSFs), termed prefilters (PFs) and after- filters (AFs), fed with anoxic groundwaters low in organic carbon to prepare potable waters. A comprehensive 16S rRNA-based amplicon sequencing survey revealed a core RSF microbiome comprising few bacterial taxa (29–30 genera) dominated by Nitrospirae, Proteobacteria and Acidobacteria, with a strikingly high abundance (75–87±18%) across five examined waterworks in Denmark. Lineages within the Nitrospira genus consistently comprised the second most and most abundant fraction in PFs (27±23%) and AFs (45.2±23%), respectively, and were far more abundant than typical proteobacterial ammonium-oxidizing bacteria, suggesting a physiology beyond nitrite oxidation for Nitrospira. Within the core taxa, sequences closely related to types with ability to oxidize ammonium, nitrite, iron, manganese and methane as primary growth substrate were identified and dominated in both PFs (73.6±6%) and AFs (61.4±21%), suggesting their functional importance. Surprisingly, operational taxonomic unit richness correlated strongly and positively with sampling location in the drinking water treatment plant (from PFs to AFs), and a weaker negative correlation held for evenness. Significant spatial heterogeneity in microbial community composition was detected in both PFs and AFs, and was higher in the AFs. This is the first comprehensive documentation of microbial community diversity in RSFs treating oligotrophic groundwaters. We have identified patterns of local spatial heterogeneity and dispersal, documented surprising energy–diversity relationships, observed a large and diverse Nitrospira fraction and established a core RSF microbiome.

Stability of citrate and calcium dosing in citrate renal replacement therapy

Citrate is the recommended anticoagulant for continuous renal replacement therapy (RRT)[1], and is thought to confer numerous benefits, including more continuous hours of filtration, fewer total circuits used, less overall cost and maybe improved patient and kidney survival when compared with heparin anticoagulation[2]. Citrate is run pre filter, calcium is infused post filter, the rates of both determined by the filter and patient ionised calcium level respectively. This is monitored by blood tests, which must be sampled frequently. Filter and patient ionised calcium levels, citrate and calcium infusion rates, are recorded as part of clinical practice at RSCH. The target plasma ionised calcium concentration is 1.0 - 1.2mM, the target filter ionised calcium concentration is 0.25 - 0.5mM.

Comparison Analysis of Indirect FOC Induction Motor Drive using PI, Anti-Windup and Pre Filter Schemes

This paper presents the speed performance analysis of indirect Field Oriented Control (FOC) induction motor drive by applying Proportional Integral (PI) controller, PI with Anti-Windup (PIAW) and Pre- Filter (PF). The objective of this experiment is to have quantitative comparison between the controller strategies towards the performance of the motor in term of speed tracking and load rejection capability in low, medium and rated speed operation. In the first part, PI controller is applied to the FOC induction motor drive which the gain is obtained based on determined Induction Motor (IM) motor parameters. Secondly an AWPI strategy is added to the outer loop and finally, PF is added to the system. The Space Vector Pulse Width Modulation (SVPWM) technique is used to control the voltage source inverter and complete vector control scheme of the IM drive is tested by using a DSpace 1103 controller board. The analysis of the results shows that, the PI and AWPI controller schemes produce similar performance at low speed operation. However, for the medium and rated speed operation the AWPI scheme shown significant improvement in reducing the overshoot problem and improving the setting time. The PF scheme on the other hand, produces a slower speed and torque response for all tested speed operation. All schemes show similar performance for load disturbance rejection capability.

사이클론 청소기 내부 유동에 관한 수치해석적 연구

가정용 진공청소기는 기본적으로 집진장치(dust collector), 프리 필터(pre filter), 모터(motor), 배기 필터(exhaust filter)의 구조를 가지며, 흡입된 먼지가 포함된 공기는 이러한 구조를 지나 깨끗한 공기가 되어 대기로 방출된다. 본 연구에서는 실생활에 사용되고 있는 구조가 다른 2개의 사이클론 청소기를 선정하여 사이클론 청소기 내 집진장치의 내부 공기 유동에 대해 전산유체역학을 적용하여 집진성능을 평가하고자 하였다. 사이클론 콘(cyclone cone) 영역에서 공기의 유선(streamline)을 해석한 결과, 사이클론 콘 영역에서 상당한 선회수를 가지는 것을 확인하였다. 특정 형상의 청소기에 대한 전산해석 결과에서 출구에서의 속도 분포가 매우 불균일한 결과를 나타내었고 이로 인해 집진성능에 악영향이 나타남이 파악되었다. 이 문제를 해결하기 위해 집진장치 형상에 추가적으로 배플을 설치하여, 달라진 속도 분포에 의한 속도 RMS (Root Mean Square) 값의 개선을 평가하였다. General household vacuum cleaners consist of dust collector, pre filter, motor and exhaust filter, and the filtered clean air is discharged to the atmosphere. By using the CFD methods, we estimated the internal flow in two types of commercial cyclone vacuum cleaners to evaluate the dust collection performance. From the analysis, it was known that the number of revolution had higher values in cyclone cone region. CFD analysis in a specific showed non-uniform velocity distribution at outlet, which results in the deterioration of particle collection performance. In order to improve flow condition, the installation of baffle was proposed and the values of velocity RMS were estimated.

Evidence for grow-through penetration of 0.2-μm-pore-size filters by Serratia marcescens and Brevundimonas diminuta

We find that both Brevundimonas diminuta and Serratia marcescens can grow through sterilizing grade filter membranes of different membrane polymer compositions. Although this passage does not occur on a consistent basis, generation of "grow-through positive" results indicate that grow-through can occur stochastically at basal levels. This observation argues that the following risk mitigation strategies during pharmaceutical aseptic processing are warranted: minimization of processing times, and monitoring, minimizing and characterizing pre-filter bioburden.

Improved Leakage-Based Precoding with Vector Perturbation for MU-MIMO Systems

In this paper, we present an improved leakage-based transmit precoding scheme that is composed of vector perturbation (VP), pre-filter (PF), and signal-to-leakage-plus-noise ratio (SLNR) precoder for multi-user multi-input multi-output (MU-MIMO) systems. In particular, we propose a new PF capable of greatly improving the system performance by mitigating residual leakage effects caused by VP. Through the bit-error-rate (BER) evaluations, we verify the superiority of the proposed transmit precoding scheme to various conventional block diagonalization (BD)- and SLNR-based precoding schemes exploiting PF and VP.

Reducing particle exposures in a tropical office building using electrostatic precipitators

Epidemiological surveys have shown that indoor fine particle exposures are associated with various health outcomes. Concomitantly, empirical data on the impact of electrostatic precipitation filter use on indoor particles in an office building has not been published. This research reports an intervention study on the impact of various filters within the air-handling unit (AHU) of a tropical office building. The following filtration methods were tested: (1) media filters (MED); (2) electrostatic precipitation filters (EAC); and (3) electrostatic precipitation filters enhanced with a media pre-filter (EAC-PF). The efficiencies of EAC filters were significantly superior to media filters for the removal of fine particles. Enhancement of EAC with media pre-filters (PF) augments the fine particle removal resulting in overall efficiencies comparable to that of HEPA filters. However, there was no difference in the removal efficiencies of coarse particles between MED, EAC and EAC-PF filters. When indoor particle removal effectiveness was evaluated, EAC and EAC-PF filters were more effective than MED filters for submicron particles. Further, effectiveness of EAC-PF was significantly superior to EAC due to effects of PF filtration of large particles, backpressure and lesser re-entrainment of large particles into the supply air stream. Effectiveness of EAC and EAC-PF were lower in occupied compared to non-occupied periods due to the higher particle loadings on collection plates. Using mass balance models, the results showed that effectiveness of electrostatic precipitation filters will improve as recirculation rates increase. These findings suggest that employing electrostatic precipitator filters under high recirculation rates can be an energy efficient strategy to reduce harmful indoor fine particle exposures.

Numerical Methods for Simulation of Guitar Distortion Circuits

Electric guitarists prefer analog distortion effects over many digital implementations. This article suggests reasons for this and proposes that detailed study of the electrical physics of guitar distortion circuits provides insight to design more accurate emulations. This work introduces real- time emula- tion applied to guitar audio amplifi ers in the form of a tutorial about relevant numerical methods and a case study. The results here make a compelling case for simulating musical electronics using numerical methods in real time. Analog guitar distortion effect devices known as solid- state distortion boxes commonly include a diode clipper circuit with an embedded low- pass fi lter. These distortion- effect devices can be mod- eled and accurately simulated as Ordinary Differen- tial Equations (ODEs). A survey and a comparison of the basic numerical integration methods are presented as they apply to simulating circuits for audio processing, with the widely used diode clipper presented as an example. A dedicated simulator for the diode clipper has been developed to compare several numerical integration methods and their real- time feasibility. We found that implicit or semi- implicit solvers are preferred, although the prefi lter / static nonlinearity approximation comes surprisingly close to the actual solution.