ESTIMATION OF GPS DISPERSIVE AND NON-DISPERSIVE NETWORK CORRECTION FOR ISKANDARnet NETWORK-BASED REAL-TIME KINEMATIC (N-RTK) POSITIONING SYSTEM

The concept of N-RTK positioning has been extensively developed in order to better model the distance-dependent errors of GPS carrier-phase measurements. These errors can be separated into a frequency-dependent or dispersive component (i.e., the ionospheric delay) and a non-dispersive component (i.e., the tropospheric delay and orbit biases) to express the network correction in order to attain better modelling of GPS distance dependent errors. However, the N-RTK performance may degrades due to severe atmospheric irregularities that would seriously affect the modelling of the GPS distance-dependent errors, thus affecting the quality of network correction generation. The development of integrity monitoring for network correction would be great idea to identify the quality and reliability of network correction data dissemination. Therefore, this paper aims to estimates the trend of GPS dispersive and non-dispersive network correction to supports future development of integrity monitoring for network correction of ISKANDARnet N-RTK positioning system. The first part of this paper is to extract the GPS dispersive and non-dispersive network residual components. This part includes the double-differencing technique, ambiguity resolution and carrier-phased linear combination in the process. The LIM then are applied for user network coefficient value computation purpose in the second part. Finally, the GPS dispersive and non-dispersive network correction can be generated with GF and IF network correction algorithm respectively. The trend of GPS dispersive and non-dispersive network correction is expected to aid the estimation and realization of threshold limit value for development of integrity monitoring for network correction of ISKANDARnet N-RTK positioning system.

Benzene Exposure on Rig X from Drilling Fluid and Effectiveness of Local Exhaust Ventilation

Introduction: Benzene is a carcinogenic compound commonly found in drilling fluid, a chemical used in oil and gas drilling operations. Benzene exposure to workers is known to cause acute and/or chronic disease. Adequate control measures shall be identified and implemented to prevent the adverse health effects of benzene from the utilization of drilling fluid. Methods: This study measured benzene concentrations at several locations, above the drilling rig, which has the potential risk of benzene vapor exposure. From the measurement results, if the threshold limit value was exceeded, LEV was proposed to be installed and the effectiveness of LEV at each location would be assessed. A two-tailed t-test was used with a confidence level of 95% (α=0.05) to measure the effectiveness of LEV. Results: In several areas, benzene concentration exceeded TLV-TWA, and LEV was installed in those areas as control measures. In this study, it was found that LEV was not always effective in reducing the concentration of benzene in some areas. Conclusion: Drilling fluid was essential for drilling activity, and this could cause benzene vapor to contaminate the working area. The installation of the LEV shall consider the type of containment through which the drilling fluid flows to ensure the mitigation measures are effective to reduce the concentration of benzene in the air that may be exposed to workers.Keywords: benzene, drilling fluid, exhaust ventilation

Study of toxic elements in propolis

There is a threat of heavy metals and toxic elements entering the beekeeping products in relation to the deterioration of the ecological situation. In this regard, a study of one of the most popular beekeeping products, propolis, from the territory of two regions of Russia (Ryazan Oblast and Krasnodar Krai) for the level of Pb, Cd, Sr and the toxic element As was undertaken. The studies were made from 2004 to 2019. The amount of elements was determined spectrophotometrically with an atomic absorption spectrophotometer Spectr AA 220FS. Lead, cadmium and strontium levels were determined using an air-acetylene flame on a gas atomizer. The level of arsenic was determined on a graphite oven of a spectrophotometer using a palladium modifier made by “Mersk”. The lead level in propolis was from 0 to 0.19 mg/kg that exceeds the threshold limit value by a factor of 1.2-12.3. The concentration of cadmium, strontium, arsenic in the studied propolis samples does not exceed the threshold limit value: 0-0.164 mg/kg, 2.1-21.01 mg/kg, 0-1.04 μm/kg, respectively. The accumulated experimental data indicate the need to adjust the threshold limit value (SanPiN 2.3.2. 1078-01) of lead level in propolis. The dynamics of propolis pollution with toxic elements was evaluated in the course of the research. The results of this evaluation confirmed the possibility of using propolis as a bioindicator of environmental pollution with heavy metals and toxic elements. It is necessary to monitor the propolis safety to determine its level of contamination with heavy metals and toxic elements, when using it as a source of biologically active compounds and as a raw material for Pharmacy (making extracts, tablets, ointments, syrups, suppositories, plasters).

Italian Expert Consensus on Clinical and Therapeutic Management of Multiple Chemical Sensitivity (MCS)

Multiple chemical sensitivity (MCS) is a multisystem, recurrent, environmental disorder that flares in response to different exposures (i.e., pesticides, solvents, toxic metals and molds) under the threshold limit value (TLV) calculated for age and gender in the general population. MCS is a syndrome characterized by cutaneous, allergic, gastrointestinal, rheumatological, endocrinological, cardiological and neurological signs and symptoms. We performed a systematic review of the literature to summarize the current clinical and therapeutic evidence and then oriented an eDelphi consensus. Four main research domains were identified (diagnosis, treatment, hospitalization and emergency) and discussed by 10 experts and an MCS patient. Thus, the first Italian MCS consensus had the double aim: (a) to improve MCS knowledge among healthcare workers and patients by standardizing the clinical and therapeutic management to MCS patients; and (b) to improve and shed light on MCS misconceptions not supported by evidence-based medicine (EBM).

Metodología para evaluar la exposición ocupacional a contaminantes químicos en altitud

Este artículo examina el actual método para evaluar la exposición a contaminantes químicos en altitud usando los Threshold Limit Value (TLV). Estos valores son establecidos para trabajos a nivel del mar en jornadas de 8 horas diarias y 40 horas semanales. Se analiza este problema aplicándolo a un grupo específico de mineros chilenos que trabaja sobre los 3000 m con jornadas excepcionales de 12 horas diarias. Se comparan dos alternativas para evaluar la exposición a contaminantes químicos: ajustes al TLV en altitud, y el cálculo de la dosis inhalada. Puesto que la ventilación por minuto es el parámetro fisiológico que cambia en altitud se propone y fundamenta como método de evaluación el cálculo de la dosis inhalada del contaminante químico.

COMPARATIVE ANALYSIS OF STATIC AND DYNAMIC MOE OF PANNÓNIA POPLAR TIMBER FROM DIFFERENT PLANTATIONS

The aim of this study has been to investigate the suitability of Pannónia poplar (Populus × euramericana cv. Pannónia) timber for structural purposes. Static and dynamic modulus of elasticity (MOE) has been determined on samples of 4 different Hungarian plantation origins. The results of the dynamic test showed the same range as the static test, showing a good correlation of the two measurements. As result it can be stated that the domestic Hungarian Pannónia poplar species have in average 11000 N.mm-2 modulus of elasticity. This exceeds considerably the threshold limit value (7000 N.mm-2) necessary for structural applications according to Eurocode 5. Therefore Pannonia poplar is suitable for structural applications, and are a good alternative of the widely used coniferous species in construction sector.

Assessment of Occupational Exposure to Indium Dust for Indium-Tin-Oxide Manufacturing Workers

According to recent research, indium nanoparticles (NPs) are more toxic than micro-sized particles. While cases of indium lung disease have been reported worldwide, very little research has been conducted on the occupational exposure to indium NPs. Recently, an indium-related lung disease was reported in Korea, a global powerhouse for display manufacturing. In this study, we conducted an assessment ofoccupational exposure at an indium tin oxide (ITO) powder manufacturing plant, where the first case of indium lung disease in Korea occurred. Airborne dustwas obtained from a worker’s breathing zone, and area sampling in the workplace environment was conducted using real-time monitoring devices. Personal samples were analyzed for the indium concentrations in total dust, respirable dust fraction, and NPs using personal NPs respiratory deposition samplers. The total indium concentration of the personal samples was lower than the threshold limit value recommended by the American Conference of Governmental Industrial Hygienists (ACGIH TLV), which was set as occupational exposure limit (OEL). However, the respirable indium concentration exceeded the recently set ACGIH TLV for the respirable fraction of indium dust. The concentration of indium NPs ranged between 0.003 and 0.010 × 10−2 mg/m3, accounting for only 0.4% of the total and 2.7% of the respirable indium particles. This was attributed to the aggregating of NPs at the µm sub-level. Given the extremely low fraction of indium NPs in the total and respirable dust, the current OEL values, set as the total and respirable indium concentrations, do not holistically represent the occupational exposure to indium NPs or prevent health hazards. Therefore, it is necessary to set separate OEL values for indium NPs. This study covers only the process of handling ITO powder. Therefore, follow-up studies need to be conducted on other ITO sputtering target polishing and milling processes, which typically generate more airborne NPs, to further investigate the effects of indium on workers and facilitate the necessary implementation of indium-reducing technologies.

Review on Occupational Personal Solar UV Exposure Measurements

During leisure time, people can decide if they want to expose themselves to solar ultraviolet (UV) radiation and to what extent. While working, people do not have this choice. Outdoor workers are exposed to solar UV radiation (UVR) on a daily basis. This may pose a certain health risk, which can be estimated when the personal solar UVR exposure (PE) is known. During past decades, a variety of studies were conducted to measure PE of outdoor workers and our knowledge of the PE of outdoor workers has increased remarkably. As shown by this review, studies clearly indicate that PE of most outdoor workers exceeds the internationally proposed threshold limit value, which is comparable to 1.0 to 1.3 standard erythema dose (SED), respectively, to 1.1 to 1.5 UV Index received over one hour. Besides working in a high UVR environ, monotonic workflow (limited movement, nearly static posture) is a risk factor. In such cases, PE can be higher than ambient UVR. In this review, we provide also a list of milestones, depicting the progress and the most important findings in this field during the past 45 years. However, in many respects our knowledge is still rudimentary, for several reasons. Different measuring positions have been used so that measured PE is not comparable. Few studies were designed to enable the extension of measured PE to other locations or dates. Although the importance of a proper calibration of the measuring devices in respect to the changing solar spectrum was pointed out from the beginning, this is often not performed, which leads to high uncertainties in the presented PE levels. At the end of our review, we provide some key points, which can be used to evaluate the quality of a study respectively to support the design of future studies.

Analysis of Hazard Area of Dispersion Caused by Leakage from Underground Gas-Storage Caverns in Salt Rock

To provide information concerning quantitative risk analysis of gas-storage caverns, it is vital to estimate the hazard area of dispersion caused by accidental leakage. The Gaussian plume model is selected to calculate the hazard area caused by continuous leakage; the method of analysis is validated using wind-tunnel experiments of acetylene. Fluent is used to simulate the hazard area of dispersion caused by instantaneous leakage; the method of numerical simulation is verified by Burro/Coyote trials. Furthermore, a sample underground gas-storage cavern in salt rock is examined with respect to the toxic threshold limit value and the upper and lower flammability limits. In doing so, the factors that influence the hazard range of dispersion from salt cavern are discussed. The results indicate that the hazard area decreases with an increase in wind speed and a decrease in atmospheric stability when the leakage is continuous. However, the hazard area decreases with a decrease in wind speed when leakage is instantaneous.

Increasing the environmental friendliness level of the pulp natural production complex to ensure acceptable discharge rates

Изменение природоохранного законодательства предопределило необходимость развития и создания новой методологии экологотехнологического нормирования допустимого сброса по критериям уровня экологичности производства, как суммы производственных природоемкостей при необходимости их соизмерения с региональным природным потенциалом. Исследованы и предложены решения по отдельным определяющим факторам и количественным значениям сбалансированности природоёмкости для природнопроизводственного комплекса «прибрежная акватория Ладожского озера – совокупность производственно-хозяйственных объектов целлюлозного завода». В соответствии с экологической техноёмкостью обозначенной акватории Ладожского озера определены два этапа расчета норм допустимых сбросов (НДС): по предельно допустимым концентрациям (ПДК) для расчетных показателей целлюлозного завода после очистки на сбросе; с учетом конструкции и характеристик глубинного водовыпуска, а также эффекта струйного и основного разбавления до контрольного створа. Представлены структура и методология оценки фактического уровня экологичности целлюлозного природно-производственного комплекса на примере первого расчетного этапа достижения НДС по ПДК. Предложенные в работе мероприятия поэтапного повышения экологичности до 3,5 и соответствующего уровня по степени очистки сбрасываемых стоков с учетом эффектов струйного и основного разбавления обеспечивают достижение НДС. Выполнен комплекс исследований и статистического анализа, который позволил оценить фактический уровень экологичности основного и вспомогательного производств целлюлозного завода, а также по целевым показателям с учетом специфики щелокосодержащих стоков. Предложен для реализации ряд целевых технологических мероприятий, повышающих уровень экологичности целлюлозного завода и минимизирующих соответственно техногенную нагрузку в пределах экологической техноёмкости водной акватории по рыбохозяйственным стандартам специфических для целлюлозного завода показателям. Changing environmental legislation decreed for the authors, in this paper, the necessity of development and creation of new methodology of ecological-technological regulation of the permissible discharge criteria level of environmentally friendly production, as the sum of the production nature intensity their commensuration with the regional natural potential. The paper investigates and proposes solutions for certain determining factors and quantitative values of the balance of natural resource intensity for the natural production complex «coastal waters of lake Ladoga – a set of production and economic objects of a pulp mill». In accordance with the environmental technology intensity of the designated lake Ladoga water area, two stages of calculating the permissible discharge rates (PDR) were determined: according to the threshold limit value (TLV) for the calculated indicators of a pulp mill after treatment at the discharge; taking into account the design and characteristics of the deep water outlet, as well as the effect of jet and main dilution to the control gate. The structure and methodology of assessing the actual level of environmental friendliness of the cellulose natural production complex is presented on the example of the first calculated stage of achieving PDR under the TLV. The actual security proposed in the work activities gradual increase of ecological compatibility to 3.5 and the appropriate level according to the degree of purification of wastewater taking into account the effects of the jet and the primary dilution to achieve PDR. A set of studies and statistical analysis was performed, which allowed us to assess the actual level of environmental friendliness of the main and auxiliary production of the pulp mill, as well as target indicators, taking into account the specifics of alkali-containing effluents. Proposed to implement aер number of targeted technology events, enhance the level of environmental performance at the pulp mill and minimize, respectively, the anthropogenic load in the range of environmental technology intensity water areas for fisheries management standards specific to pulp mill performance.