COVID-Safe Spatial Occupancy Monitoring Using OFDM-Based Features and Passive WiFi Samples

During the COVID-19 pandemic, authorities have been asking for social distancing to prevent transmission of the virus. However, enforcing such distancing has been challenging in tight spaces such as elevators and unmonitored commercial settings such as offices. This article addresses this gap by proposing a low-cost and non-intrusive method for monitoring social distancing within a given space, using Channel State Information (CSI) from passive WiFi sensing. By exploiting the frequency selective behavior of CSI with a Support Vector Machine (SVM) classifier, we achieve an improvement in accuracy over existing crowd counting works. Our system counts the number of occupants with a 93% accuracy rate in an elevator setting and predicts whether the COVID-Safe limit is breached with a 97% accuracy rate. We also demonstrate the occupant counting capability of the system in a commercial office setting, achieving 97% accuracy. Our proposed occupancy monitoring outperforms existing methods by at least 7%. Overall, the proposed framework is inexpensive, requiring only one device that passively collects data and a lightweight supervised learning algorithm for prediction. Our lightweight model and accuracy improvements are necessary contributions for WiFi-based counting to be suitable for COVID-specific applications.

Modeling Radiation Exposure from Normal Release of 137Cs Radionuclide to Groundwater for Post-Closure Assessment of Serpong Near Surface Disposal Demo Facility

Near-surface disposal (NSD) has been applied in several countries to dispose of low-level radioactive waste. The demo plant of this disposal type is planned to be constructed in Serpong Nuclear Area, Banten. An assessment of radiation exposure is necessary to ensure the safety requirement of the facility in order to support this program. This study aims to estimate radionuclide migration from the proposed NSD demo facility to the environment and the corresponding total human dose using AMBER mathematical modeling. The representative radionuclide,137Cs, was selected because of its high mobility in the environment and the relatively long half-life in the low-level waste inventory. The scenario considered in the modeling was the normal release to the environment through groundwater. Parameters such as initial radionuclide concentration, soil physical parameters of the study site, and disposal design were entered into AMBER software to be calculated using mathematical formulas. The results show that the radionuclide concentration value in the environment is below the safe limit recommended by the Environmental Supervisory Agency. Likewise, the maximum dose received by the community around the facility is 7.40×10-11 mSv/y, 550 years after the post-closure of the facility, which is also below the regulatory limit of 1 mSv/y for the public.

Lead Bioaccumulation and Translocation in Herbaceous Plants Grown in Urban and Peri-Urban Soil and the Potential Human Health Risk

Lead (Pb) contamination risks to crops grown in urban and peri-urban soils is a great concern that should be better evaluated to define the Pb maximum levels in soils for safe cultivation and to identify suitable strategies to remediate Pb polluted urban soils. The objective of this work was to evaluate the potential risk for human health from the ingestion of the edible portions of barley, castor bean, common bean, Indian mustard, sorghum, spinach, and tomato grown in an unpolluted soil (initial Pb content 32.6 mg kg−1) spiked with 0, 300, 650, 1000 mg Pb kg−1, respectively. The potential possibility of using these plants to phyto-remediate the soil of Pb was also assessed. Pot trials were conducted for two years (2008 and 2009). Results highlighted that all the investigated species were able to attain growth to maturity in high Pb spiked soil, although Pb influenced dry matter accumulation. Even in soils with low Pb concentrations, Pb accumulated the edible parts. Noteworthy, even in untreated control soils, all tested species revealed a Pb concentration in the edible parts that was higher than the safe limit set by FAO/WHO. None of the investigated species were considered Pb hyperaccumulators, but all were shown to be potentially suitable for phyto-stabilization.

Hydraulic transients for a pipe line network of treated effluent rising main using SAP 2R

Hydraulic transients occur as a direct result of rapid variations of flow field in pressurized systems. The change in velocity from valve closures or pump operations causes pressure surges that are propagated away from the source throughout the pipeline. The associated pressure changes during a transient period are quite large and occur quickly (within a few seconds). It should also be noted that when the maximum pressures exceed the bar ratings (mechanical strength) of the piping material, failure can occur. Similarly, if the minimum pressure drops below the vapour pressure of the fluid, cavitation can occur. The purpose of the present study is to model and simulate the hydraulic transients in a pipeline network system of treated effluent rising main of Mpophomeni sanitation scheme using SAP 2R. A total of five scenarios were simulated using different combinations. The simulation results show that the transient pressures in the pipeline exceeded the bar rating of the pipe where the bursts or cavitation may occur for the simulated scenario, but transient pressures were reduced to a safe limit after providing water hammer protection devices.

Smart Industry Monitoring and Controlling System Using IoT

Air pollution in an ecosystem has proliferated industrial automation. This dissertation concentrates more on industrial automation and has design an embedded device with sensors to monitor and control the toxic gases in industries. This entire prototype is an excellent result for observing the toxic gases in industry and generates information by using data acquisition and transmission of data. “Internet of Things (IoT)” is a important technology behind this and it provide platform to bring together all the devices in the world to the internet. In this dissertation, the parameters monitored are temperature, humidity and gas leakages in industries. The sensor senses the parameters and uploads these data to the cloud with the help of NodeMCU. If observed gas level is above the threshold which is the safety limit of operation, the first alert is intimated from the Google cloud and the controlling action carried out (ie) automatically close gas leakage valves and then industry will take immediate step to control pollution. Or else, the second alert message is sent through Electronic mail (e-mail) to restore the safe limit, as government play role to power outage in the industries. Cloud is used to store the sensed data, which is then transmitted and processed.

A Dynamic Simulation Assessment for Relocating Flare System into Separated Platform Utilizing Idle Subsea Main Oil line

KLB is an offshore platform that consists of production wells and two train gas lift compressors. During well intervention, the KLB operation team must turn off the flaring system due to potential flare radiation of more than 500 BTU/hr-ft2at the working area and gas dispersion more than 50 %-LEL at the flare tip. The relocation of the KLB flaring system to the nearest platform keeps the KLB gas lift compressor operating during this activity. The relocation scenario can maintain the KLB platform production of 700 BOPD. KLA Flowstation is the nearest platform to the KLB. It is separated one kilometer, connected by an idle subsea oil pipeline, but there are no pigging facilities due to limited space at the KLB platform. Therefore, the comprehensive assessment to relocate the KLB flaring system is a) Flare system study using Flare Network software to simulate backpressure and Mach Number at tailpipe in the KLA and KLB flaring system; b). Dynamic transient simulation using Flow Assurance Software to calculate backpressure, liquid hold up, and slugging condition in the flare KO drum; and c). Flare radiation and dispersion study. The initial condition of the idle subsea oil pipeline was full of liquid as the preservation for a pipeline to prevent a further oil spill in case of a leak during the idle condition. The dewatering process for the idle subsea pipeline has been conducted by purging the pipeline utilizes 0.7 MMscfd gas lift with a pressure of 100 psig to displace liquid content to 20 bbl. The transient simulation for gas swapping was conducted at a gas rate of 4.1 MMscfd as the train compressor's flaring condition. The calculated backpressure at the KLB safety valve is 12.3 psig below the required maximum of 30 psig. The calculated liquid surge volume in the Flare KO drum during flaring is 17 bbl and can be handled by surge volume inside the KO drum. The predicted condensation inside the subsea pipeline shows that the maximum operation of the flaring system is limited to 30 days. The radiation and gas dispersion to the nearest facility is within a safe limit. The KLB teams successfully conducted the relocation of the flaring system from the KLB platform to the KLA platform. The result was no interruption of production, no risk of radiation, and no potential explosion during a well intervention. Experience in the last two activities has confirmed that this method can prevent revenue loss of 19 billion rupiahs. This study has initiated a new engineering standard and best practice for flaring systems as opposed to the current practice which states that the flare location shall be at the same location as the production facilities with no pocket piping in between. This study and field experience have proved that the flaring system can be located on a different platform by conducting engineering assessments to ensure process and process safety criteria are within Company and International Standard.

PENGURANGAN RISIKO MUSCULOSKELETAL DISORDERS PADA AREA MESIN LASER PERFORATOR DI PERUSAHAAN ROKOK MENGGUNAKAN OWAS DAN QFD

Di dalam perusahaan produksi rokok ini terdapat sebuah mesin laser perforator. Setelah pemasangan mesin laser perforator 50 timbul masalah yang berhubungan dengan gangguan muskuloskeletal. Saat dilakukan wawancara, operator mengeluhkan adanya nyeri punggung bawah karena penanganan material dilakukan secara manual. Setelah dilakukan analisis dengan metode OWAS pada dua kegiatan bongkar muat ditemukan masalah yang berhubungan dengan gangguan muskuloskeletal. Dari hasil analisis ditemukan bahwa aktivitas pemuatan (loading) dikategorikan sebagai tindakan korektif 3 artinya postur tubuh berpengaruh sangat merugikan pada sistem muskuloskeletal, sedangkan kegiatan pembongkaran (unloading) termasuk tindakan korektif 2 yang tidak berpengaruh nyata terhadap sistem muskuloskeletal. Selain itu, analisis gaya tekan dilakukan hanya untuk aktivitas pembebanan terhadap gaya tekan total yang bekerja pada L5/ S1. Gaya tekan untuk aktivitas pembebanan adalah 7.186,22 Newton atau lebih dari dua kali lipat dari batas aman maksimum 3.400 Newton. Perbaikan dilakukan dengan menggunakan metode QFD. Sebagai solusinya adalah dibuat troli. Troli tersebut mampu mereduksi gaya tekan total pada aktivitas pembebanan menjadi 3.180,52 Newton dan berhasil mengubah menjadi kategori tindakan korektif 1. Abstract[REDUCTION OF MUSCULOSCELETAL DISORDERS RISK ON LASER PERFORATOR MACHINES AREA IN CIGARETTE COMPANIES USING QFD AND OWAS] Inside this cigarette production company, there is a laser perforator machine. After the installation of the laser perforator machine 50, problems related to musculoskeletal disorders arise. During the interview, the operator complained about low back pain due to manual handling of the material. After analyzing the OWAS method on two loading and unloading activities, problems were found related to musculoskeletal disorders. It was found that the loading activity was categorized as 3 meaning that posture had a very detrimental effect on the musculoskeletal system. Meanwhile, unloading activities included category 2 which had no significant effect on the musculoskeletal system. In addition, the biomechanical analysis was carried out only for the loading activity against the total compressive force acting on L5 / S1. The compressive force for loading activity is 7,186.22 Newton or more than twice the maximum safe limit of 3,400 Newton. Repairs were made using the QFD method. The solution is to make the moving trolley. The moving trolley is able to reduce the total compressive force on the loading activity to 3,180.52 Newton and also, reduce the level to category 1.Keywords: biomechanics; musculoskeletal disorders; Ovako Working Posture Analysis System; OWAS; Quality Function Deployment; QFD; Trolley

Baseline levels of radionuclides concentration in the sea of Wakatobi and Kendari

The importance of an information about the baseline value of radionuclides in the sea of Wakatobi and Kendari to see how large the input or contamination of radionuclides in the area. This contamination can come from waste human activities such as industry and nuclear utilization activities that are biased carried by seawater currents and air gusts. Natural and anthropogenic radionuclide concentrations in the Wakatobi and Kendari seas have been measured using a Gamma spectrometer (HPGe).The monitoring results show that both 226Ra, 232Th, 40K and 137Cs indicate that they are in normal condition and do not exceed the safe limit. The data presented in this study will be very important and useful to be used as basic data in mapping the improvement of radionuclide contamination in the area.

Measurement of ambient dose rates in tantalite mining sites in Oke ̶ Ogun, southwest, Nigeria

The work scenarios involved in the mining of tantalite a radioactive material expose the miners to ionizing radiation from the ore and the surrounding environment. The dose level in the mine air may be higher than the safe limit due to various contributory sources of ionizing radiation such as radionuclides from rocks, effluents, sand, and radon gas that emanates from caves and this can be of health detriment to the miners. Measurements of ambient dose rates in four selected mining sites have been investigated. Gamma absorbed dose rates were measured in air onsite at Komu, Sepenteri, Gbedu, and Eluku mining sites in Oke-Ogun areas of Oyo State, Nigeria using GammaRAE II dosimeter. Radiation dose to risk software was used to estimate the cancer risk for the period the miners spent onsite. The measured mean dose rate at the sites falls within the range of (19-240) nSv/y and the estimated annual dose rate, cumulative dose, and cancer risk fall within the range of (37-314) μSv/y, (4.0 ̶ 11.1) mSv and (0.5 ̶ 4.5) E-04 respectively. The upper limits of the range for the radiological parameters are all above the safe limit. The health implication of that is that increased work activities at these mining sites may over the years have a negative health effect on the miners. The exposure time of workers can be reduced through proper planning of working shifts for the miners.

COMPARATIVE ANALYSIS OF SOME HEAVY METALS LEVELS IN LEAVES, PEELS AND TUBERS OF CASSAVA PLANTED ALONG EAST-WEST ROAD RIVERS STATE

Introduction: Pollution of the environment by heavy metals has caused serious environmental problems, which threatens the existence of various ecological system, agriculture and human health. This study assessed the comparative analysis of some heavy metals levels in leaves, peels and tubers of cassava planted along East-West Road Rivers State. Materials/Methods: Cassava leaves and tubers samples were collected from farmlands along East-West road (SX, SY and SZ communities, in Emohua, Tai, and Ahoada West LGA respectively), Rivers state, Nigeria. The samples were monitored for heavy metals levels to assess the impact of automobiles on cassava peels, leaves and tubers using Solar Thermo Elementary Atomic Absorption Spectrometer, ModelSG 71906. Metals studied were Lead (Pb), Nickel (Ni), Chromium (Cr), Cadmium (Cd), and Arsenic (As). Results: The mean concentration of Ni present in leaf was 2.81±0.104 mg/kg, tubers recorded 2.23±0.073 mg/kg and peels 3.20±0.06 mg/kg. The highest concentration (4.064±0.035 mg/kg) of Ni was observed in peels while the least concentration (1.80±1.023 mg/kg) was recorded in the tubers. The mean values of Pb in leaves, tubers and peels were 2.22±1.023 mg/kg, 1.80±1.023 mg/kg and 2.64±0.32, highest concentration was recorded in tubers. Arsenic values were 0.16±0.020 mg/kg > 0.51±0.021 mg/kg > 0.38±0.203 mg/kg in peels, tubers and leaves respectively. The values of As were above WHO safe limit of 0.1mg/kg. Also, the mean values of cadmium in leaves, tubers and peels were 0.054±0.570 mg/kg, 0.046±0.057 mg/kg and 0.16±0.609 mg/kg respectively. The highest concentration (0.138±0.109 mg/kg) was in the tubers. Finally, chromium was found to be present in all the cassava samples (leaves, peels and tubers). The mean concentration of chromium (Cr) was 3.58±0.023 mg/kg, 2.76±0.005 mg/kg and 3.83±0.203 mg/kg in leaves, tubers and peels respectively. Conclusion: From the findings, heavy metals were found in the samples and thus, crops should be cultivated far away from major roads.