Influence Of Meteorological Parameters Research Articles

Influence of Meteorological Parameters on Explosive Charge and Stemming Length Predictions in Clay Soil during Blasting Using Artificial Neural Networks

The influence of the meteorological parameters (precipitation and air temperature) during blasting in clay has a direct impact on the success of blasting. In the case of large amounts of precipitation (rain and snow) recorded in the subject area, blasting in clays cannot be carried out due to the grain of the clay and the inability to access the subject area. Moreover, the air temperature in the subject area affects the blasting performance. The most ideal temperature for blasting in clays is between 15 and 25 °C because then the clay has the best geotechnical characteristics. The research was conducted on the exploitation field Cukavec II, which is located near the city of Varaždin in the Republic of Croatia. Amount of precipitation and air temperature were considered to obtain the best blasting effect. Influence of meteorological parameters on the amount of the explosive charge and stemming length when blasting in clays was demonstrated via models based on Artificial Neural Networks (ANN). The ANN model network consists of a Long Short-term Memory (LSTM) part to process time dependent meteorological data, and fully connected layers to process blasting input data. Two types of explosive charges were compared, Pakaex and Permonex V19.

Study of aerosol optical properties at two urban areas in the north of Vietnam with the implication for biomass burning impacts.

The spatiotemporal distribution and characterization of aerosol optical properties in the north of Vietnam were investigated extensively using the long-term measurements obtained from Moderate Resolution Imaging Spectroradiometer (MODIS) (from 2010 to 2019) and two Aerosol Robotic Network (AERONET) stations (Nghia Do, Hanoi City, from 2010 to 2019 and Son La from 2012 to 2019) located in fast-developing urban areas. This study also analyzed the tendency of AOD over different wavelengths as well as the influences of meteorological parameters and boundary layer height (BLH) on AOD and Ångström exponent (AE). The annual mean AOD500 at Nghia Do and Son La stations were 0.81 and 0.78, respectively. Our results revealed the existence of particles emitted from anthropogenic activities in Hanoi and Son La with the dominance of fine particles (more than 90% of the AE440-870 were larger than 1). Besides, a high percentage of AE440-870 larger than or approximately 1.5 during the dry and transition months in Son La indicated the existence of biomass-burning aerosol particles due to forest fires and burning of agriculture residuals. The classification results for aerosol types showed the presence of both biomass burning and urban/industrial aerosol types at Nghia Do and Son La sites. Among the investigated meteorological parameters, surface solar radiation expressed a significant correlation with AE440-870 in all three seasons at the two sites due to the secondary formation of fine particles induced by the high solar radiation condition. The impacts of meteorological parameters and BLH on AOD were not observed simultaneously during three seasons at Nghia Do and Son La stations.

One-Year Real-Time Measurement of Black Carbon in the Rural Area of Qingdao, Northeastern China: Seasonal Variations, Meteorological Effects, and the COVID-19 Case Analysis

In this paper, we report the results obtained from one year of real-time measurement (i.e., from December 2019 to November 2020) of atmospheric black carbon (BC) under a rural environment in Qingdao of Northeastern China. The annual average concentration of BC was 1.92 ± 1.89 μg m−3. The highest average concentration of BC was observed in winter (3.65 ± 2.66 μg m−3), followed by fall (1.73 ± 1.33 μg m−3), spring (1.53 ± 1.33 μg m−3), and summer (0.83 ± 0.56 μg m−3). A clear weekend effect was observed in winter, which was characterized by higher BC concentration (4.60 ± 2.86 μg m−3) during the weekend rather than that (3.22 ± 2.45 μg m−3) during weekdays. The influence of meteorological parameters, including surface horizontal wind speed, boundary layer height (BLH), and precipitation, on BC, was investigated. In particular, such BLH influence presented evidently seasonal dependence, while there was no significant seasonality for horizontal wind speed. These may reflect different roles of atmospheric vertical dilution on affecting BC in different seasons. The △BC/△CO ratio decreased with the increase of precipitation, indicative of the influence of below-cloud wet removal of BC, especially during summertime where rainfall events more frequently occurred than any of other seasons. The bivariate-polar-plot analysis showed that the high BC concentrations were mainly associated with low wind speed in all seasons, highlighting an important BC source originated from local emissions. By using concentration-weighted trajectory analysis, it was found that regional transports, especially from northeastern in winter, could not be negligible for contributing to BC pollution in rural Qingdao. In the coronavirus disease 2019 (COVID−19) case analysis, we observed an obvious increase in the BC/NO2 ratio during the COVID-19 lockdown, supporting the significant non-traffic source sector (such as residential coal combustion) for BC in rural Qingdao.

Validation of Point Source Models for Determining Industrial Pollution and Integrating with IOT for vulnerability management

Awareness in Environmental pollution which was restricted to water and wastewater pollution has now been extended to air pollution. In Indian Scenario, the popularity of air pollution is gaining momentum day by day and all metro cities are facing this problem due to increase in traffic and industries located in the vicinity. The major contribution to air pollution is from traffic though there are other sources like smoke from factories and burning of any material. Monitoring stations are not provided in many places as it is a costly investment. Though there are very few monitoring stations in metro cities, the other areas still do not have any means to monitor the quality of air we breathe in. This work deals with validating point source models to predict the pollution due to thermal power plant emissions in Ennore, Chennai. The details of wind speed, wind direction, temperature and humidity play a major role in dispersing the air pollutants. Particulate air pollutant PM2.5, PM10 and SO2 were monitored and the variation of air pollutants during summer and winter were studied. The influence of meteorological parameters in the concentration of these pollutants were analysed by this study. AERMOD software was used to model the data and further predictions with the help of advanced technology are discussed in this paper. Deployment of a system using advanced sensors and systems has enabled us to assess the air quality by integrating IOT with sensors which could facilitate continuous monitoring of the pollutants.

Pine radial growth in the Trans-Baikalian steppe and taiga zones as a reflection of the climatic parameters and lake hydrological regime dynamics

The paper presents the results of the annual rings width research of the trunk test core sampled from standing common pines. The purpose of the research is the analysis of the ability to use the radial recruitment changes of the trees growing in different natural zones for further reconstruction and prognosis of the climatic variables and lake hydrological regime. It was revealed that the dynamics of annual rings width in the steppe zone is characterized by the maximum values of the standard deviation and sensitivity to environmental factors in comparison with taiga zone trees. The radial growth of trees in the steppe zone shows a significant positive reaction to atmospheric precipitation and a negative reaction to air temperature from May to October. The influence of meteorological parameters on the annual growth of pine in the taiga zone is less considerable. The analysis of the synchronicity of changes in pine increments in the steppe zone with interannual fluctuations in the water level of Lake Barun-Torey due to the climatic conditions dynamics showed the significant correlation; therefore, the maximum correlation is observed with lake reaction lag for 4-5 years. Dendrochronological analysis of trees in the taiga zone (Baikal-Stanovoye Upland) revealed only a weak correlation with the average annual level of Lake Bount in the current year. Thus, the tree-ring chronology based on pines of steppe zone can be used for retrodiction of the hydrometeorologic elements.

Numerical study of heat and mass evaporation-based transfers in a large dimension reservoir: the influence of meteorological parameters and rayleigh number

Numerical study of heat and mass evaporation-based transfers in a large dimension reservoir: the influence of meteorological parameters and rayleigh number

Influence of Meteorological Parameters on Occurrence and Composition of Fungal Spores in Guava Orchard at Nasik

The present study deals with an aeromycological sampling, monitoring and analysis of fungal spore incidence over selected guava orchard in Nasik city. It involved monitoring on occurrence of some important air borne fungal spores, and their changing composition due to fluctuating weather conditions. The study was conducted by using volumetric Tilak air sampler during a period of January 2018 to December 2018; on Guava (Psidium guajava Linn.) fruit plant to trace pathogenic fungal mycoflora associated with the changing climatic conditions; responsible for different diseases. The meteorological parameters like temperature, relative humidity, wind speed and precipitation, in that order of importance, significantly influence the composition of airborne fungal spores. Variations and daily fluctuations in these weather conditions may provide a stimulus to the sporadic outbreaks of certain pathogenic airborne fungal spores that further cause a plant disease. An attempt was made to assess airborne fungal spore distribution patterns in relation to meteorological variables during the period of study. Also, it was observed that, the occurrence of fungal spores was in correlation with the weather changes, field operation, plant growth and disease incidence on the crop. The major diseases caused due to an outbreak of fungal spores on guava orchard were found to be stimulated by moderate precipitation and rapid fluctuations associated with high percentage of humidity.

Temporal variations of ambient air pollutants and meteorological influences on their concentrations in Tehran during 2012\u20132017

We investigated temporal variations of ambient air pollutants and the influences of meteorological parameters on their concentrations using a robust method; convergent cross mapping; in Tehran (2012–2017). Tehran citizens were consistently exposed to annual PM2.5, PM10 and NO2 approximately 3.0–4.5, 3.5–4.5 and 1.5–2.5 times higher than the World Health Organization air quality guideline levels during the period. Except for O3, all air pollutants demonstrated the lowest and highest concentrations in summertime and wintertime, respectively. The highest O3 concentrations were found on weekend (weekend effect), whereas other ambient air pollutants had statistically significant (P < 0.05) daily variations in which higher concentrations were observed on weekdays compared to weekend (holiday effect). Hourly O3 concentration reached its peak at 3.00 p.m., though other air pollutants displayed two peaks; morning and late night. Approximately 45% to 65% of AQI values were in the subcategory of unhealthy for sensitive groups and PM2.5 was the responsible air pollutant in Tehran. Amongst meteorological factors, temperature was the key influencing factor for PM2.5 and PM10 concentrations, while nebulosity and solar radiation exerted major influences on ambient SO2 and O3 concentrations. Additionally, there is a moderate coupling between wind speed and NO2 and CO concentrations.

Pollen season trends in winter flowering trees in South Spain

The present work has studied the trends in pollen seasons of winter flowering trees (Alnus, Cupressaceae, Fraxinus, Populus and Ulmus) in Cordoba, Granada and Malaga (Andalusia, Spain) over the years 1994–2017. The influence of meteorological parameters on the seasonal airborne pollen has been also analyzed. Pollen concentrations were recorded using Hirst-type volumetric spore traps, following the standardized methodology of the Spanish Aerobiology Network and the European Aerobiology Society. The nonparametric Mann–Kendall test and the nonparametric Sen’s method have been used to study linear trends for pollen season timing and intensity, and for temperature and rainfall. Significance was determined using the F-test. Spearman analyses were applied to test for correlations between pollen season parameters and weather-related factors before and over the pollen season. The results obtained suggest that flowering has delayed over recent years, especially for trees with a bloom closer to spring (poplar and elm). Earlier flowering species are more influenced by the meteorological parameters before the flowering. However, species blooming later are more influenced by the meteorological parameters during the pollen season. Meteorological parameters affect more the interior cities than the coastal city.

Effects of Meteorological and Site Parameters on the Health Status of Beech (Fagus sylvatica L.) Forests in Hungary

The influence of meteorological parameters on the health status of beech (Fagus sylvatica L.) was analyzed using long term datasets (1989-2010) collected in 15 sample plots located in Hungary’s main beech regions. Leaf loss values were correlated with different meteorological parameters as explanatory variables. Analysis was performed by the CReMIT (Cyclic Reverse Moving Intervals Techniques) method. Weather, stand, and site parameters were also examined with PCA for comparison. Leaf loss levels showed stronger correlations with maximum monthly temperatures than with monthly precipitation sums. The monthly number of summer days and monthly number of hot days displayed a similar correlation to leaf loss as the maximum monthly temperature did. The correlations were regularly stronger and more frequent on more arid sites where the climate is less favorable for beech. Temperature affected leaf loss more than precipitation did. Our results show that beech forests may suffer heavy damage if climate change continues as projected.

Particle Size Distribution and Population Characteristics of Airborne Bacteria Emitted from a Sanitary Landfill Site

Sanitary landfill is a commonly-used method for solid waste disposal. In the process of landfilling, e. g. dumping, stacking, pushing, and compacting, a large number of bioaerosols with pathogenic bacteria will be generated. That can result in air pollution and significant harm to human health if these pathogens are released into the air. Sampling sites were set up in a domestic waste sanitary landfill in North China to collect airborne bacteria in the air. Airborne bacteria, particle size distributions, and populations were analyzed, and the influence of meteorological parameters (temperature, relative humidity (RH), and wind speed (WS)) on the emission of airborne bacteria was also investigated. Results showed that the concentrations of airborne bacteria in the working area and the coverage area were (5437±572) CFU·m-3 and (2707±396) CFU·m-3, respectively. The emission level in the leachate treatment area was the highest, with an average of 9460 CFU·m-3. The concentration of airborne bacteria showed clear seasonal variation, being was much higher in summer than that in the other seasons. Redundancy analysis (RDA) demonstrated that RH, temperature, and WS affected the number of airborne bacteria in the air. The peaks in the airborne particle size distribution were 2.1-4.7 μm in the working area and 0.65-2.1 μm in the coverage area. Most of the airborne bacteria released from the leachate treatment processes were larger than 4.7 μm. Moraxellaceae, Bacillus aerius, Arcobacter, and Aeromonas were potential or opportunistic pathogens detected from the airborne bacteria samples. Effective measures should be taken to reduce the amount of bacterial aerosol emitted to the air in landfill working areas and in the leachate of treatment areas. Operators of landfill machinery and leachate treatment facilities should consider personal protection measures and should reduce their exposure to microbial aerosols in order to prevent disease.

A study on the anomalous behaviour of Radon in different depths of soil at a tectonic fault and its comparison with time-series data at a distant continuous monitoring station

The present study reports the anomalous behaviour of Radon isotope pairs (222Rn, 220Rn) in different soil depths at Mat fault, Mizoram (India). The measurement was taken for six occasions between November 2017 and April 2018 under dry soil condition in majority of the occasions. The Radon isotope pair’s data were generated in situ online at depths of 5 cm, 50 cm and 1 m from ground surface in nine selected grid locations at Mat fault. At the same time, to identify geophysical phenomena Radon data were generated at Mizoram University (MZU) in a continuous monitoring station (CMS), located about 57 km from Mat fault. A ZnS/Ag scintillation-based continuous Radon monitor (Model: SMARTRnDuo, BARC, India) was deployed for monitoring Radon at Mat fault as well as in MZU. Correlation study shows that 222Rn data at 5 cm and 50 cm depths of Mat fault region vary in the same manner with 222Rn data at the CMS during all geophysical and non-geophysical process as identified by the CMS 222Rn data. However, 222Rn data at 1 m depth in the fault region does not show any definite correlation with CMS data. The variation of 220Rn data at 50 cm depth in Mat fault also match the CMS 220Rn data but deviated from it at 5 cm and 1 m depth. The influence of meteorological parameters on 222Rn and 220Rn data monitor at the CMS and Mat fault was also reported, and comparison was made with observation reported by other authors in the region.

Atmospheric dispersion of methane emissions from sugarcane burning in Mexico

Methane is a potent greenhouse gas whose atmospheric dispersion may have different implications at distinct scales. One significant contributor to methane emissions is sugarcane farming in tropical areas like in Mexico, which has the sixth highest production level in the world. A consequence of the industrial use of this resource is that sugarcane preharvest burning emits large quantities of methane and other pollutants. The objective of this research is to estimate the methane emissions by sugarcane burning and to analyze their atmospheric dispersion under the influence of meteorological parameters, according to different concentration scenarios generated during a period. The methane emissions were investigated using the methodology of Seiler and Crutzen, based on the stage production during the harvest periods of 2011/2012, 2012/2013 and 2013/2014. Average of total emissions (1.4 × 103 Mg) at the national level was comparable in magnitude to those of other relevant sugarcane-producing countries such as India and Brazil. Satellite images and statistical methods were used to validate the spatial distribution of methane, which was obtained with the WRF model. The results show a dominant wind circulation pattern toward the east in the San Luis Potosi area, to the west in Jalisco, and the north in Tabasco. In the first two areas, wind convergence at a certain height causes a downward flow, preventing methane dispersion. The concentrations in these areas varied from 9.22 × 10−5 to 1.22 × 102 ppmv and 32 × 10−5 to 2.36 × 102 ppmv, respectively. Wind conditions in Tabasco contributed to high dispersion and low concentrations of methane, varying from 8.74 × 105 to 0.33 × 102 ppmv. Methane is a potent greenhouse gas for which it is essential to study and understand their dispersion at different geographic locations and atmospheric conditions.

Atmospheric levels of BPA associated with particulate matter in an urban environment

Bisphenol A (BPA) is an Endocrine disruptor compound (EDC), capable of interfering with hormone related pathways and cause adverse effects, for example, in the reproductive system in wildlife and humans. As it has multiple applications and uses, mainly in the manufacturing of plastic and resin products, increasing amounts are being released into the environment with resulting enhanced exposure pathways. Since negative effects have been demonstrated even at low doses, it has been increasingly studied. However, these investigations have focused on BPA leaching from food cans, drinks and other consumer products as the oral exposure route is believed to be the most important. Consequently, the potential hazards of dermal or inhalation exposure resulting from the current levels of BPA in the atmosphere are poorly understand. Of the few studies reporting BPA occurrence in air, none of these were carried out in South American countries. Thus, the aim the present investigation was to assess BPA current levels in particulate matter in an urban environment (Córdoba, Argentina) and to analyze its spatial-temporal trends and the influence of meteorological parameters using a medium volume air sampler. Our results suggested a spatial trend that decreased according to the distance to emission sources in the order: Industrial area > City Centre > University campus, whose levels were comparable to other urban cities and with the temporal trend showing a higher prevalence of the compound in the colder months. Wind speed (WS), temperature (T), atmospheric pressure (AP) and relative humidity (RL) were the most influenced variables. However daily values are unpredictable and depend mainly on the emission sources and punctual events that release BPA into the atmosphere.No risk factor could be quantified since there is no reference value for this exposure route; Nevertheless, this study represents the first approach and provides data about this emergent pollutant in and Argentinean city, thus contributing to global BPA studies.

Organochlorine pesticides air monitoring near a historical lindane production site in Spain

The landfilling and dumping of persistent organic pollutants (POPs) and other persistent hazardous chemicals, such as hexachlorocyclohexane (HCH) isomers can have significantly adverse environmental consequences and cause contamination in soil, water, and atmosphere systems. Approximately 115,000 t of HCH wastes were generated by INQUINOSA Factory located in Sabiñánigo (Aragón, Spain) from 1975 to 1992, and were mainly dumped at Bailín and Sardas landfills. Under the frame of the project plan approved by the Government of Aragón, remediation and containment measures were implemented at the derelict production facility and landfill sites. To protect and assess the local environment, the concentrations of HCH isomers, pentachlorobenzene (PeCB) and hexachlorobenzene (HCB) in air were periodically monitored in the Sardas landfills and surroundings by passive sampling devices. The influence of meteorological parameters was evaluated, showing positive correlations between temperature and HCH and HCB concentrations. The highest HCH levels were detected in Sardas landfill and INQUINOSA Factory sites. PeCB values were statistically higher in Sardas landfill than in Sabiñánigo urban core, nevertheless, HCB concentrations were similar in both sampling points. Statistically positive correlations were found among HCH isomers in all sampling points, showing a major common source. The chlorobenzenes also correlated positively with each other. The α-/γ-HCH ratios were calculated (1.46 ± 1.25; mean ± S.D.), corroborating that concentrations detected were mainly originated from the historical production, storage and waste disposal of technical HCH.

Time series analysis of soil radon in Northern Pakistan: Implications for earthquake forecasting

Time series analysis of soil radon data has previously been proposed as a mechanism for earthquake hazard forecasting, but it is not universally accepted as such. Here we perform time series analysis of soil radon along an active fault zone in North Pakistan, in order to investigate pre-earthquake anomalies for a period of July 24, 2014 to April 30, 2015. The methodology includes geochemical analysis of soil, deterministic analysis (Hurst exponent H), quantification of meteorological influence and abnormalities of soil radon within the context of earthquake forecasting. In particular, for analyzing abnormalities in radon data, we have used residual signal processing techniques to reduce the regular effect of meteorological factors and a statistical criterion (x¯±2σ) at a 95% confidence interval. Results of geochemical analysis suggest that any abnormal enhancement in soil radon concentration is not associated with the presence of key radionuclides such as 226Ra, 232Th and 40K. The deterministic analysis of radon and meteorological parameters reveals that H belongs to the interval 0.5≤H≤1, which indicates a persistent trend with insignificant infrequency and irregularity. Likewise, the influence of meteorological parameters on soil radon is quantified via correlation coefficients suggesting an insignificant impact. Furthermore, temporal variability of residual radon around the time of earthquake activity reveals the presence of six notable anomalous peaks overpassing the statistical criterion during the investigated period. An absence of anomalous residual radon behavior for some earthquake events in the investigated period can be attributed to their low magnitude and high RE/RD value. Finally, our results validate earlier findings and recommend the use of radon as a seismic indicator.

Influences of meteorological parameters on indoor radon concentrations (222Rn) excluding the effects of forced ventilation and radon exhalation from soil and building materials

Elevated indoor radon concentrations (222Rn) in dwellings pose generally a potential health risk to the inhabitants. During the last decades a considerable number of studies discussed both the different sources of indoor radon and the drivers for diurnal and multi day variations of its concentration. While the potential sources are undisputed, controversial opinions exist regarding their individual relevance and regarding the driving influences that control varying radon indoor concentrations. These drivers include (i) cyclic forced ventilation of dwellings, (ii) the temporal variance of the radon exhalation from soil and building materials due to e.g. a varying moisture content and (iii) diurnal and multi day temperature and pressure patterns. The presented study discusses the influences of last-mentioned temporal meteorological parameters by effectively excluding the influences of forced ventilation and undefined radon exhalation. The results reveal the continuous variation of the indoor/outdoor pressure gradient as key driver for a constant “breathing” of any interior space, which affects the indoor radon concentration with both diurnal and multi day patterns. The diurnally recurring variation of the pressure gradient is predominantly triggered by the day/night cycle of the indoor temperature that is associated with an expansion/contraction of the indoor air volume. Multi day patterns, on the other hand, are mainly due to periods of negative air pressure indoors that is triggered by periods of elevated wind speeds as a result of Bernoulli's principle.

Combined effects of air pollution and allergens in the city of Rome

Urban green is an important aspect in the quality of life of citizens of modern cities. Nevertheless some ornamental plants cause allergic diseases in sensitive subjects that may be worsened by air pollution.Studies on air quality are usually addressed to the evaluation of single substances and their specific effects: little is known about the cumulative effect that different pollutants may have on human health. Even less is known about possible combined action of traditional air pollutants with pollen and spores that have huge effects, in terms of allergies and asthma, on citizenship of the urban areas.In this work the synergistic effect of PM10, PM2.5, NO2, O3 and airborne pollens (belonging to 4 taxa: Cupressaceae/Taxaceae, Graminaceae, Olea and Urticaceae) was studied in the city of Rome during six years (from 2010 to 2015).For air pollutants, concentration values recorded by air-quality monitoring network of Rome were used. Pollens and spores data were detected by the Aerobiological Monitoring Centre of the University of Rome Tor Vergata. Effects on human health were evaluated on a group of 100 patients (aged between 4 and 18) by the Allergymonitor™ã application that records daily symptoms of hay fever, bronchial asthma and the prescribed therapies.Data collected in the medical record were processed by 2 different Symptom Medication daily Scores and compared with time series of air concentration of mentioned pollutants, pollen and spores.Statistical analysis allowed highlighting when concomitant high levels of allergenic species and air pollution occur, the influence of meteorological parameters, of the flowering calendar, of taking drugs and how these aspects affect symptoms in patients.

Influence of meteorological parameters on the soil radon (Rn222) emanation in Kutch, Gujarat, India

The soil radon (Rn222) and thoron (Rn220) concentrations recorded at Badargadh and Desalpar observatories in the Kutch region of Gujarat, India, have been analyzed to study the sources of the radon emissions, earthquake precursors, and the influence of meteorological parameters on radon emission. Radon and meteorological parameters were recorded using Radon Monitor RMT 1688-2 at these two stations. We used the radon data during February 21, 2011 to June 8, 2011, for Badargadh and March 2, 2011 to May 19, 2011, for the Desalpar station with a sampling interval of 10min. It is observed that the radon concentrations at Desalpar varies between 781 and 4320Bqm-3with an average value of 2499Bqm-3, whereas thoron varies between 191 and 2017Bqm-3with an average value of 1433.69Bqm-3. The radon concentration at Badargadh varies between 264 and 2221Bqm-3with an average value of 1135.4Bqm-3, whereas thoron varies between 97 and 556Bqm-3. To understand how the meteorological parameters influence radon emanation, the radon and other meteorological parameters were correlated with linear regression analysis. Here, it was observed that radon and temperature are negatively correlated whereas radon and other two parameters, i.e., humidity and pressure are positively correlated. The cross correlogram also ascertains similar relationships between radon and other parameters. Further, the ratio between radon and thoron has been analyzed to determine the deep or shallow source of the radon emanation in the study area. These results revealed that the ratio radon/thoron enhanced during this period which indicates the deeper source contribution is prominent. Incidentally, all the local earthquakes occurred with a focal depth of 18-25km at the lower crust in this region. We observed the rise in the concentrations of radon and the ratio radon/thoron at Badargadh station before the occurrence of the local earthquakes on 29th March 2011 (M 3.7) and 17th May 2011 (M 4.2). We clearly observed the radon level crossing the mean + 2*sigma level before the occurrence of these events. We conclude that these enhanced radon emissions are linked with alteration of the crustal stress/strain in this region as this observing station is near the epicenters of the earthquakes. We did not observe considerable variations in radon at the Desalpar station which is far from the earthquake location.

Influence of meteorological parameters on the operation of a grid - connected PV solar plant

Elementary description and information on a grid-connected photovoltaic solar power plant (PV plant) of 2 kWp installed in Niš and the influence of meteorological parameters on its operation are given in this paper. Besides, experimental results of the calculation of the energy efficiency, electrical energy generated and output power of this PV plant operating in the real climate conditions in 2017 are presented. The results regarding climate parameters and characteristic performance parameter of 2 kWp PV plant in Niš in 2017 are discussed and it was found that in 2017 annual energy efficiency of this PV plant was 10.63% and it decreased with the ambient temperature increasing.