Recent studies on decentralized wetland governance in Uganda have focused mainly on the relationship between central and local governments. Less attention has been given to the relationship between agricultural system...Recent studies on decentralized wetland governance in Uganda have focused mainly on the relationship between central and local governments. Less attention has been given to the relationship between agricultural systems, local governments, and water bodies. This study aims at assessing decentralized wetlands governance in the upper river Rwizi and Iguluibi micro catchments, Lake Victoria Basin Uganda, in relation to farming practices. Qualitative and quantitative methods were used to provide a comprehensive understanding of the contribution of decentralized governance to the management of wetlands resources. Quantitative survey data were analyzed using descriptive summary statistics with the help of Statistical package for Social Sciences (SPSS) soft ware. Qualitative data analysis involved the categorization of verbal and behavioral data for purposes of classification with the use of Nvivo soft ware. Data were analyzed at two levels: the descriptive level of analysis which is the account of the data in terms of what was said, documented or observed with nothing assumed about it. The second level of analysis was interpretive, where data is transformed into what is meant by the responses and conclusions are drawn. All recorded interviews were transcribed into a written report. Findings revealed that decentralized wetlands governance has brought ecosystem services nearer to communities in form of community-based management planning. However, results indicated inadequate institutional capacity, knowledge gaps of existing legal frameworks, limited political support and accountability for local leaders, lack of cooperation and coordination, and inadequate funding. In all, the policy has not fully realized its intended outcomes.展开更多
Mountainous rangelands play a pivotal role in providing forage resources for livestock, particularly in summer, and maintaining ecological balance. This study aimed to identify environmental variables affecting range ...Mountainous rangelands play a pivotal role in providing forage resources for livestock, particularly in summer, and maintaining ecological balance. This study aimed to identify environmental variables affecting range plant species distribution, ecological analysis of the relationship between these variables and the distribution of plants, and to model and map the plant habitats suitability by the Random Forest Method(RFM) in rangelands of the Taftan Mountain, Sistan and Baluchestan Province, southeastern Iran. In order to determine the environmental variables and estimate the potential distribution of plant species, the presence points of plants were recorded by using systematic random sampling method(90 points of presence) and soils were sampled in 5 habitats by random method in 0–30 and 30–60 cm depths. The layers of environmental variables were prepared using the Kriging interpolation method and Geographic Information System facilities. The distribution of the plant habitats was finally modelled and mapped by the RFM. Continuous maps of the habitat suitability were converted to binary maps using Youden Index(?) in order to evaluate the accuracy of the RFM in estimation of the distribution of species potentialhabitat. Based on the values of the area under curve(AUC) statistics, accuracy of predictive models of all habitats was in good level. Investigating the agreement between the predicted map, generated by each model, and actual maps, generated from fieldmeasured data, of the plant habitats, was at a high level for all habitats, except for Amygdalus scoparia habitat. This study concluded that the RFM is a robust model to analyze the relationships between the distribution of plant species and environmental variables as well as to prepare potential distribution maps of plant habitats that are of higher priority for conservation on the local scale in arid mountainous rangelands.展开更多
Global climate change poses a new challenge for species and can even push some species toward an extinction vortex. The most affected organisms are those with narrow tolerance to the climatic factors but many large ma...Global climate change poses a new challenge for species and can even push some species toward an extinction vortex. The most affected organisms are those with narrow tolerance to the climatic factors but many large mammals such as ungulates with a wider ecological niche are also being affected indirectly. Our research mainly used wild sheep in central Iran as a model species to explore how the suitable habitats will change under different climatic scenarios and to determine if current borders of protected areas will adequately protect habitat requirements. To create habitat models we used animal-vehicle collision points as an input for species presence data. We ran habitat models using Max Ent modeling approach under different climatic scenarios of the past, present and future(under the climatic scenarios for minimum(RCP2.6) and maximum(RCP8.5) CO2 concentration trajectories). We tried to estimate the overlap and the width of the ecological niche using relevant metrics. In order to analyze the effectiveness of the protected areas, suitable maps were concerted to binary maps using True Skill Statistic(TSS) threshold and measured the similarity of the binary maps for each scenario using Kappa index. In order to assess the competence of the present protected areas boundary in covering the distribution of species, two different scenarios were employed, which are ensemble scenario 1: an ensemble of the binary maps of the species distribution in Mid-Holocene, present, and RCP2.6;and ensemble scenario 2: an ensemble of binary suitability maps in Mid-Holocene, present, and RCP8.5. Then, the borders of modeled habitats with the boundaries of 23 existing protected areas in two central provinces in Iran were compared. The predicted species distribution under scenario 1(RCP2.6) was mostly similar to its current distribution(Kappa = 0.53) while the output model under scenario 2(RCP8.5) indicated a decline in the species distribution range. Under the first ensemble scenario, current borders of the protected areas in Hamedan province showed better efficiency to cover the model species distribution range. Analyzing Max Ent spatial models under the second climatic scenario suggested that protected areas in both Markazi and Hamedan provinces will not cover "high suitability" areas in the future. Modeling the efficiency of the current protected areas under predicted future climatic scenarios can help the related authorities to plan conservation activities more efficiently.展开更多
In this study,we reported on the concept and practical use of cation exchange resin(CER)for removing anions in water via pretreating the CER with metal salts.The cation exchange resinsupported iron and magnesium oxide...In this study,we reported on the concept and practical use of cation exchange resin(CER)for removing anions in water via pretreating the CER with metal salts.The cation exchange resinsupported iron and magnesium oxides/hydroxides composite(FeMg/CER)was synthesized and introduced as a new and potential adsorbent for selective removal of nitrate ion in the water environment.Characteristics of FeMg/CER were determined by techniques such as Fouriertransform infrared spectroscopy,scanning electron microscopy,and Xray diffraction.The results showed that FeMg/CER material had a high nitrate adsorption capacity of 200 mg NO_(3)^()·g^(1)with a fast equilibrium adsorption time of 30 min at pH 5.In addition,it had good durability of at least 10 times of regeneration,which could be applied to practical water and wastewater treatment.展开更多
Rapid climate change has provided the opportunity for many species to learn to adapt fast enough to modify their range distribution.The positive and negative responses of the species in terms of distribution are relat...Rapid climate change has provided the opportunity for many species to learn to adapt fast enough to modify their range distribution.The positive and negative responses of the species in terms of distribution are related to parameters such as kind of species,degree of specialization,size and movement skills,and such factors.Moving to high elevations and transitions to higher latitudes are among the strategies proposed as a solution to the negative effects of climate change.Therefore,predicting how different species respond to climate change can help predict the conservation program for them.Species distribution models(SDMs)are widely used to predict the geographical distribution of habitat suitability and species occurrence.Rhinopoma muscatellum is one of the three mousetailed bats(Rhinopomatidae)inhabiting the southeastern,southern,and southwestern parts of Iran and its distribution range to the interior and northern parts of Iran has been limited by the Elburz and Zagros Mountain.To study the effect of climate change on this species,range shifts and coverage of protected regions,74 presence points and environmental variables(climate,topography,anthropogenic,and vegetation)in MaxEnt software were used.Before the implementation of the model,the autocorrelation of the presence points was reduced and the selection of pseudo absent points was limited by using the bias grid.Climate variables were prepared for Mid-Holocene,Current,Climate Current,and Future scenarios in 2070(RCP2.6,RCP4.5,RCP6,and RCP8.5).In order to evaluate the overlap of ecological niche,the Schoener’s D and I statistic metrics were used.Also,to measure the breadth of the niches,B1(inverse concentration)and B2(uncertainty)metrics in ENMTOOLS software were employed.TSS statistics were used as a threshold.Species distribution trend changes in climatic scenarios were performed by the Mann Kendall(MK)test.Based on the results,the AUC values for current and future climate models were calculated to be 0.89 and 0.85,respectively.The distance from settlement,soil organic carbon,and altitude variables have the greatest impact on the current distribution of the species;and among the climatic variables,Isothermality(Bio3),Temperature Seasonality(Bio4),and Max Temperature of Warmest Month(Bio5)had the greatest impact on species distribution.The results showed that in climate change scenarios by 2070,the distribution range and breadth of climatic niche of Rhinopoma muscatellum will be significantly increased(P-value<0.05),habitat fragmentation will be reduced,and in RCP8.5 scenario it will reach the maximum distribution(39.38%of total Iran).This increase will cover the Elburz and Zagros mountain ranges,and a large part of the country will be suitable for the species.In response to current climate change,migration to higher latitudes was identified in this study.Among the main different classes of protected regions in Iran(National parks,Wildlife refuges,and Protected areas),protected areas in all scenarios had the most coverage of the suitable species habitat.展开更多
Petrographic, mineralogical and geochemical investigations were carried out on representative?samples from the Mudawwara-Quwayra Dike (MQD) in southernJordan. The MQD intruded Paleozoic and Cretaceous rocks as sub-ver...Petrographic, mineralogical and geochemical investigations were carried out on representative?samples from the Mudawwara-Quwayra Dike (MQD) in southernJordan. The MQD intruded Paleozoic and Cretaceous rocks as sub-vertical basaltic plugs, striking NW-SE along a fault zone and extending for more than 100 km. The MQD forms irregularly positive features, and is represented by symmetrical, elliptical, elongated or circular hills. It comprises thin basaltic layers intercalated?with pyroclastics and inclusions of different size and lithology, including limestone, sandstone, phosphate, quartzite, and marble. Petrographically, the rock exhibits phyric, porphyritic, vitrophyric and locally glomerophyritic textures manifested by plagioclase, clinopyroxene and rare?olivine and set in a matrix of plagioclase, pyroxene, brown glass and opaque phases. Clinopyroxene?and olivine phenocyrsts show disequilibrium textures such as reaction/resorbed rims in the?forms of corroded ends. The paragenetic sequence shows that olivine is the first phase to be crystallized and coexisting with pyroxene at sometime, while pyroxene continues crystallization. Plagioclase might have crystallized in contemporaneous later than the pyroxene. The MQD rocks are classified?as basalt and exhibit a narrow range of silica with a unique subalkaline affinity. This is most?probably attributed to assimilation of the abundant siliciclastic inclusions by the ascending magma. Emplacement of the MQD is attributed to regional phase of magmatism in Jordan and Saudi Arabia, which is probably the peripheral extension of a large magmatic event widely exposed in the Red Sea realm.展开更多
This study evaluated the performance of rooftop catchment systems in securing non-potable water supply in Birjand, located in an arid area in southeastern Iran. The rooftop catchment systems at seven study sites of di...This study evaluated the performance of rooftop catchment systems in securing non-potable water supply in Birjand, located in an arid area in southeastern Iran. The rooftop catchment systems at seven study sites of different residential buildings were simulated for dry, normal, and wet water years, using 31-year rainfall records. The trial and error approach and mass diagram method were employed to optimize the volume of reservoirs in five different operation scenarios. Results showed that, during the dry water year from 2000 to 2001, for reservoirs with volumes of 200-20000 L, the proportion of days that could be secured for non-portable water supply was on average computed to be 16.4%-32.6% across all study sites. During the normal water year from 2009 to 2010 and the wet water year from 1995 to 1996, for reservoirs with volumes of 200-20000 L, the proportions were 20.8%-69.6% and 26.8%-80.3%, respectively. Therefore, a rooftop catchment system showed a high potential to meet a significant portion of non-potable water demand in the Birjand climatic region. Reservoir volume optimization using the mass diagram method produced results consistent with those obtained with the trial and error approach, except at sites #1, #2, and #5. At these sites, the trial and error approach performed better than the mass diagram method due to relatively high water consumption. It is concluded that the rooftop catchment system is applicable under the same climatic conditions as the study area, and it can be used as a drought mitigation strategy as well.展开更多
The major objective of this study was to evaluate the effects of sand mining disturbances on the diversity of arbuscular mycorrhizal fungi(AMF). In addition, the proportional changes in the diversity of AMF to the dis...The major objective of this study was to evaluate the effects of sand mining disturbances on the diversity of arbuscular mycorrhizal fungi(AMF). In addition, the proportional changes in the diversity of AMF to the distances from riverbanks were assessed. For this purpose, the riparian forest of the Maroon River, Iran was divided into three locations with a 200-meter wide zone in between. Thus, the locations studied were named Distance I(riverbank), Distance II(intermediate), and Distance III(farthest from riverbank). In each of these distances, 10 Tamarix arceuthoides and Populus euphratica of each species were randomly selected. At the same time, soil and root samples were collected from the rhizosphere of the tree species studied. Results indicated that totally 13 AMF species were observed in T. arceuthoides and 19 AMF species were recorded in P. euphratica rhizosphere belonging to 6 genera and 6 families. In these AMF species, Glomus segmentatum, G. geosporum, G. rubiforme, G. nanolumen, G. spinuliferum, Claroideoglomus drummondii, Gigaspora gigantea and Acaulospora paulinae appeared only in P. euphratica rhizosphere, while G. multiforum and Claroideoglomus claroideum were observed only in T. arceuthoides rhizosphere. Moreover, Distance II had the least AMF species both in T. arceuthoides and in P. euphratica rhizospheres, and also the least spore density and root colonization rate. Our results are important in that they provide a list of resistant AMF species that could be used in the conservation of biodiversity.展开更多
As the mesoscale eddies in oceans and semi-enclosed seas are significant in horizontal dispersion of pollutants,we investigate the seasonal variations of these eddies in the Persian Gulf(PG)that are usually generated ...As the mesoscale eddies in oceans and semi-enclosed seas are significant in horizontal dispersion of pollutants,we investigate the seasonal variations of these eddies in the Persian Gulf(PG)that are usually generated due to seasonal winds and baroclinic instability.The sea surface height(SSH)data from 2010 to 2014 of AVISO are used to identify and track eddies,using the SSH-based method.Then seasonal horizontal dispersion coefficients are estimated for the PG,using the properties of eddies.The results show an annual mean of 78 eddies with a minimum lifetime of one week.Most of the eddies are predominantly cyclonic(59.1%)and have longer lifetimes and higher diffusion coefficients than the anti-cyclonic eddies.The eddy activity is higher in warm seasons,compared to that of cold seasons.As locations with high eddy diffusion coefficients are high-risk areas by using maps of horizontal eddy diffusion coefficients,perilous times and locations of the release of pollutants are specified to be within the longitude from 51.38°E to 55.28°E.The mentioned areas are located from the Strait of Hormuz towards the northeast of the PG,closer to Iranian coast.Moreover,July can be considered as the most dangerous time of pollution release.展开更多
Plants have always been exploited worldwide for food, medicines, shelter, and other purposes because they are readily available, affordable and acceptable to a large populace of the world. The study was conducted to g...Plants have always been exploited worldwide for food, medicines, shelter, and other purposes because they are readily available, affordable and acceptable to a large populace of the world. The study was conducted to gather information on the proximate composition of fresh and dry leaves of Pterocarpus erinaceus. The proximate composition of the leaf samples was determined using the standard methods of analysis of the Association of Official Analytical Chemists (AOAC). Proximate analysis of the fresh leaf samples of the plant shows a higher moisture content compared to the dry leaf samples. The total fat and total ash contents of the fresh leaf samples were however lower compared to values recorded for the dry leaf samples. The dry matter content of fresh leaf samples was also lower compared to that of the dry leaf samples. Fresh leaf samples again recorded the least crude protein content compared to dry leaf samples. Carbohydrates content in fresh leaf samples was higher compared to dry leaf samples. Generally, higher proximate values were recorded for dry leaf samples than for fresh leaves. Dry matter and moisture contents were detected in high quantities in both fresh and dry leaf samples of P. erinaceus. These results could be a justification for the multiple uses of the plant leaves across Sub-Saharan Africa. Further research should be carried out on the mineral, phytochemical and vitamin composition between the fresh and dry leaves of the plant.展开更多
Shea tree is a major economic plant contributing to household income through the sale of edible fruits, kernels and shea butter. Shea butter is used industrially in the production of cosmetic products, chocolates and ...Shea tree is a major economic plant contributing to household income through the sale of edible fruits, kernels and shea butter. Shea butter is used industrially in the production of cosmetic products, chocolates and margarines. Fruits are used by human and also by birds. This study aimed to explore strategies for the improvement of shea yield through pollination. Two types of pollination (manual and natural pollination) were applied for the comparison of fruits set and their ripening. The fruits set and ripening index as well as average weight of ripe fruits and kernels were estimated. The results showed a significant difference between the fruits set Index of manual pollination and natural pollination (H(1) = 33.437, p = 7.361 × 10<sup>-9</sup>). Similarly, there was a significant difference between the ripening Index of manual pollination and natural pollination (H(1) = 4.5113, p = 0.03367). However, the mode of pollination did not influence the weight of ripe fruits and kernels. Therefore, the manual pollination enhances pollen supply to receptive stigmas for fertilization and improved fruit yield in Vitellaria paradoxa.展开更多
Data processing and climate characterisation to study its impact is becoming difficult due to insufficient and unavailable data,especially in developing countries.Understanding climate’s impact on burnt areas in Ghan...Data processing and climate characterisation to study its impact is becoming difficult due to insufficient and unavailable data,especially in developing countries.Understanding climate’s impact on burnt areas in Ghana(Guinea-savannah(GSZ)and Forest-savannah Mosaic zones(FSZ))leads us to opt for machine learning.Through Google Earth Engine(GEE),rainfall(PR),maximum temperature(Tmax),minimum temperature(Tmin),average temperature(Tmean),Palmer Drought Severity Index(PDSI),relative humidity(RH),wind speed(WS),soil moisture(SM),actual evapotranspiration(ETA)and reference evapotranspiration(ETR)have been acquired through CHIRPS(Climate Hazards group Infrared Precipitation with Stations),FLDAS dataset(Famine Early Warning Systems Network(FEWS NET)Land Data Assimilation System)and TerraClimate platform from 1991 to 2021.The objective is to analyse the link and the contribution of climatic and environmental parameters on wildfire spread in GSZ and FSZ in Ghana.Variables were analysed(area burnt and the number of activefires)through Spearman correlation and the cross-correlation function(CCF)(2001 to 2021).The tests(Mann-Kendall and Sens’s slope trend test,Pettitt test and the Lee and Heghinian test)showed the overall decrease in rainfall and increase in temperature respectively(-0.1 mm;+0.8℃)in GSZ and(-0.9 mm;+0.3℃)in FSZ.In terms of impact,PR,ETR,FDI,Tmean,Tmax,Tmin,RH,ETA and SM contribute tofire spread.Through the codes developed,researchers and decision-makers could update them at different times easily to monitor climate variability and its impact onfires.展开更多
Relying on the conceptual DPSIR framework and MODFLOW analysis,this study used a mixed approach to produce groundwater resource management solutions for the Najafabad area in central Iran.According to DPSIR results,ag...Relying on the conceptual DPSIR framework and MODFLOW analysis,this study used a mixed approach to produce groundwater resource management solutions for the Najafabad area in central Iran.According to DPSIR results,agricultural activities put the highest pressure on groundwater resources in this region.The results showed the effectiveness of reducing waterwithdrawal over 30 years in maintaining the aquifer in a state of equilibrium.The best scenario consisted of cutting down extraction by 10%over the said period.Output maps of the water table rise at the Najafabad aquifer clearly showed that the groundwater management scenario involving a 10%reduction ofwater withdrawal was the most effective solution,as itwould raise thewater level by 6.7 m.Regarding other scenarios,reducing cultivated area by 20%was found to raise the water table by 5.03 m on average,while cutting down water withdrawal by 5%increased the water table by 3.6 m,and a 10%reduction of the cultivated area resulted in a 1.85mrise.The combinedmodel proposed here can be used for similar aquifers and can aid decision-makers and managers.展开更多
Since incorrect site selection has sometimes led to the failure of artificial recharge projects,it is necessary to increase the effectiveness of such projects and minimize their failure by employing new techniques.The...Since incorrect site selection has sometimes led to the failure of artificial recharge projects,it is necessary to increase the effectiveness of such projects and minimize their failure by employing new techniques.Therefore,the present research used a combination of decision-making models,numerical groundwater modeling and clustering technique to determine suitable sites for implementation of an artificial recharge project.This hybrid approach was employed for the Yasouj aquifer located in southwestern Iran.In the first stage,by employing an AHP decision-making model,hydraulic conductivity,specific yield,slope,land use,depth to groundwater,and aquifer thickness were selected from 21 criteria used in previous research.The selected criteria were then entered as input into the classical k-means clustering model.Using the output,aquifer was divided into seven different regions or clusters.These clusters were then matched with the land use map,and some of the abandoned land areas were selected as the final option for implementing the artificial recharge project.Finally,the MODFLOW code in the GMS software was used to simulate the groundwater level and cluster the sites selected,with regards to increase in groundwater level.Results indicated that the most significant increases in groundwater level(43 and 27 cm)were those of Clusters 2 and 6 in the northern and western parts of the aquifer,respectively.Therefore,this approach can be used in other similar aquifers in arid and semi-arid regions to select the best sites for artificial recharge and to prevent loss of floodwaters.展开更多
The importance of groundwater portability and the possible sources of anthropogenic contamination have led to the development of intrinsic groundwater vulnerability mapping. In this study, groundwater vulnerability ma...The importance of groundwater portability and the possible sources of anthropogenic contamination have led to the development of intrinsic groundwater vulnerability mapping. In this study, groundwater vulnerability map for Amman Zarqa Basin (AZB) has been generated based on information derived and calculated from processed remote sensing information and laboratory analysis. The database was prepared from soil hydro geological and hydrological data, Digital Elevation Model (DEM), and geological maps. For assessment of groundwater vulnerability, the method proposed by the state geological surveys of Germany (GLA-method) has been adapted and applied. The vulnerability map shows about 77% which is about 2919 Km2 of the AZB is classified as very low to low which could be corresponding to the pollution sources due to the absence of potential hazards and also due to low vulnerabilities. These areas could consequently be interesting for future development as they set preferable in view of ground water protection. In addition, about 14% (530 km2) is classified within the moderate vulnerability zone. About 5% (around 19 km2) of the study area lies under the area of high vulnerability zone. Only 4% can be classified as very high risk areas. Groundwater quality results revealed that water leach ate from point source is the main cause for groundwater contaminations in highly vulnerable karstic limestone aquifer (Amman Wadi Es Sir Aquifer-B2/A7). On the other hand, the Kurnub Sandstone aquifer (K) is generally well protected in the central and eastern part of the AZB due to its thick cover of partly marly sequences. However, the Kurnub aquifer might have a potential risk from the recharged infiltrating surface water from the Zarqa River, which is highly polluted due to industrial activities located along the river.展开更多
Aims Species composition and diversity of the mountainous rangelands are results of interactions between environmental severities,het-erogeneous topography and facilitative effects by nurse plants.This research was ai...Aims Species composition and diversity of the mountainous rangelands are results of interactions between environmental severities,het-erogeneous topography and facilitative effects by nurse plants.This research was aimed to compare relative effects of these three envi-ronmental variables on the natural vegetation of a mountainous rangeland.For a more detailed understanding,effects of four dif-ferent nurse species were separately compared on the various plant growth forms and on two community plant responses(diversity and abundance).Methods A mountainous semiarid rangeland was selected in Baharkish,Quchan,Northeast of Iran.Density and canopy cover of all plant species were recorded under the canopy of four different shrubs and in open areas,in north and south-facing aspects,and in a normal and a drought year.Shannon diversity,total abundance(%cover)and the abundance of different growth forms were used as crite-ria for assessing effects of the environmental variables.Data were arranged in a factorial combination and analyzed by three-way analysis of variance using a GLM analysis.Important Findings(i)Drought,aspect and canopy created niche differentiation:annual forbs and shrubs were more affected by drought,whereas geophytes and grasses were more responsive to slope aspects.Effects of drought and slope aspect were more profound on species diversity,whereas that of canopy facilitation was stronger on plant abundance.(ii)Canopy facili-tation was dependent on severity of the abiotic factors and life history of interacting species.Canopy facilitation allowed for the persistence of only annual forbs,but it was disadvantaged during the drought year.Plant community responses to abiotic factors(slope and drought)were more dependent on the plant growth form,while responses to canopy facilitation were more dependent on the morphology and/or ecology of nurse shrubs.(iii)Effect of shrubs was dependent on their morphology and ecology:shrubs with larger canopy area and nitrogen fixation capa-bility increased,but those with allelopathic effects or a dense canopy structure decreased the diversity of the understory species.展开更多
Today,analyzing of sound pressure level and frequency is considered as an important index in human society.Sound experts believe that analyzing of these parameters can help us to better understanding of work environme...Today,analyzing of sound pressure level and frequency is considered as an important index in human society.Sound experts believe that analyzing of these parameters can help us to better understanding of work environments.Sound measurements and frequency analysis did to fix the harmful frequency in all sections in Shiraz gas power plant with sound analyzer model BSWA 308.The sound pressure levels(LP)and the one and one-third octave band were continuously measured in A and C weighting networks and slow mode for time response.Excel 2013 and Minitab 18.1 software used for statistical calculations.Results analyzed by Minitab 18.1 software.The highest harmful frequency in Shiraz Gas Power Plant(SGPP)was 50 Hz with 115 dB.The sound pressure level(SPL)ranged from 45 dB to 120 dB in one-third octave band and weighting network C.The maximum sound pressure level was in Craft electricity generator with 105.3 dB and 67 Hz.Sound pressure level in surrounded environment was 120 dB.According to the results,in this industry the sound pressure level exceeded the Occupational Exposure Level of Iran(OEL).The value of sound pressure level were higher than the Standard of occupational health.SGPP consumes 47000 cubic meters of natural gas per hour to produce 100 MW(Mega Watt)of electricity.It is very high and it is not economical and cost effective.These numbers indicate that the power plant’s efficiency is low.It could be concluded that the noise pollution is an important issue in these industries.Moreover,SGPP produce noise with loss energy.Frequencies rotation at high sound pressure levels toward low frequencies were happened.展开更多
Formaldehyde(HCHO)is formed through the oxidation of volatile organic compounds(VOCs)and can cause human cancer.Bismuth oxide and titanium oxide nanoparticles-functionalized nanographene oxide(Bi_(2)O_(3)/TiO_(2)@NGO)...Formaldehyde(HCHO)is formed through the oxidation of volatile organic compounds(VOCs)and can cause human cancer.Bismuth oxide and titanium oxide nanoparticles-functionalized nanographene oxide(Bi_(2)O_(3)/TiO_(2)@NGO)were used to rapidly remove the HCHO from the air by a photocatalytic degradation-adsorption process(PC-DAP).The formaldehyde vapor in pure air was generated in a dynamic system within a chamber,and flowed over Bi_(2)O_(3)/TiO_(2)@NGO adsorbent inside a fixed-bed quartz reactor(FBQR)under UV irradiation at optimized conditions(250C).At atmospheric pressure,the flow rate and gas hourly space velocity(GHSV)were adjusted to 300 mL/min and 100-450 L/h,respectively.The radicals of HCHO and nanographene oxide(NGO)were generated through the UV-photochemical process,enhancing the chemical adsorption through the radicals’interactions.On the other hand,the semi-degradation process by catalytic oxidation process converted some HCHO into raw materials of CO_(2)and H_(2)O,while the unconverted HCHO was physically absorbed by NGO.Finally,the HCHO concentration in the outlet system was measured by gas chromatography with a flame ionization detector(GC-FID)after derivatizing formaldehyde with 2,4-dinitrophenylhydrazine(DNPH)and acetonitrile.Therefore,efficient removal of HCHO from the air,the removal efficiency of more than 95%,was achieved through physical/chemical adsorption and the semi-degradation.The mean removal efficiencies for HCHO with Bi_(2)O_(3)-TiO_(2)@NGO,TiO_(2)@NGO,Bi_(2)O_(3)@NGO,and NGO were 98.7%,73.6%,61.8%,and 11.4%,respectively(n=10,RSD<5%).The methodology was validated by spiking different concentrations of standard HCHO into pure air.展开更多
文摘Recent studies on decentralized wetland governance in Uganda have focused mainly on the relationship between central and local governments. Less attention has been given to the relationship between agricultural systems, local governments, and water bodies. This study aims at assessing decentralized wetlands governance in the upper river Rwizi and Iguluibi micro catchments, Lake Victoria Basin Uganda, in relation to farming practices. Qualitative and quantitative methods were used to provide a comprehensive understanding of the contribution of decentralized governance to the management of wetlands resources. Quantitative survey data were analyzed using descriptive summary statistics with the help of Statistical package for Social Sciences (SPSS) soft ware. Qualitative data analysis involved the categorization of verbal and behavioral data for purposes of classification with the use of Nvivo soft ware. Data were analyzed at two levels: the descriptive level of analysis which is the account of the data in terms of what was said, documented or observed with nothing assumed about it. The second level of analysis was interpretive, where data is transformed into what is meant by the responses and conclusions are drawn. All recorded interviews were transcribed into a written report. Findings revealed that decentralized wetlands governance has brought ecosystem services nearer to communities in form of community-based management planning. However, results indicated inadequate institutional capacity, knowledge gaps of existing legal frameworks, limited political support and accountability for local leaders, lack of cooperation and coordination, and inadequate funding. In all, the policy has not fully realized its intended outcomes.
基金funded by University of Zabol,Iran(Grant No.UOZ-GR-9517-24)the Vice Chancellery for Research and Technology,University of Zabol,for funding this study
文摘Mountainous rangelands play a pivotal role in providing forage resources for livestock, particularly in summer, and maintaining ecological balance. This study aimed to identify environmental variables affecting range plant species distribution, ecological analysis of the relationship between these variables and the distribution of plants, and to model and map the plant habitats suitability by the Random Forest Method(RFM) in rangelands of the Taftan Mountain, Sistan and Baluchestan Province, southeastern Iran. In order to determine the environmental variables and estimate the potential distribution of plant species, the presence points of plants were recorded by using systematic random sampling method(90 points of presence) and soils were sampled in 5 habitats by random method in 0–30 and 30–60 cm depths. The layers of environmental variables were prepared using the Kriging interpolation method and Geographic Information System facilities. The distribution of the plant habitats was finally modelled and mapped by the RFM. Continuous maps of the habitat suitability were converted to binary maps using Youden Index(?) in order to evaluate the accuracy of the RFM in estimation of the distribution of species potentialhabitat. Based on the values of the area under curve(AUC) statistics, accuracy of predictive models of all habitats was in good level. Investigating the agreement between the predicted map, generated by each model, and actual maps, generated from fieldmeasured data, of the plant habitats, was at a high level for all habitats, except for Amygdalus scoparia habitat. This study concluded that the RFM is a robust model to analyze the relationships between the distribution of plant species and environmental variables as well as to prepare potential distribution maps of plant habitats that are of higher priority for conservation on the local scale in arid mountainous rangelands.
文摘Global climate change poses a new challenge for species and can even push some species toward an extinction vortex. The most affected organisms are those with narrow tolerance to the climatic factors but many large mammals such as ungulates with a wider ecological niche are also being affected indirectly. Our research mainly used wild sheep in central Iran as a model species to explore how the suitable habitats will change under different climatic scenarios and to determine if current borders of protected areas will adequately protect habitat requirements. To create habitat models we used animal-vehicle collision points as an input for species presence data. We ran habitat models using Max Ent modeling approach under different climatic scenarios of the past, present and future(under the climatic scenarios for minimum(RCP2.6) and maximum(RCP8.5) CO2 concentration trajectories). We tried to estimate the overlap and the width of the ecological niche using relevant metrics. In order to analyze the effectiveness of the protected areas, suitable maps were concerted to binary maps using True Skill Statistic(TSS) threshold and measured the similarity of the binary maps for each scenario using Kappa index. In order to assess the competence of the present protected areas boundary in covering the distribution of species, two different scenarios were employed, which are ensemble scenario 1: an ensemble of the binary maps of the species distribution in Mid-Holocene, present, and RCP2.6;and ensemble scenario 2: an ensemble of binary suitability maps in Mid-Holocene, present, and RCP8.5. Then, the borders of modeled habitats with the boundaries of 23 existing protected areas in two central provinces in Iran were compared. The predicted species distribution under scenario 1(RCP2.6) was mostly similar to its current distribution(Kappa = 0.53) while the output model under scenario 2(RCP8.5) indicated a decline in the species distribution range. Under the first ensemble scenario, current borders of the protected areas in Hamedan province showed better efficiency to cover the model species distribution range. Analyzing Max Ent spatial models under the second climatic scenario suggested that protected areas in both Markazi and Hamedan provinces will not cover "high suitability" areas in the future. Modeling the efficiency of the current protected areas under predicted future climatic scenarios can help the related authorities to plan conservation activities more efficiently.
基金Vietnam National University-Ho Chi Minh City under grant number A2020-16-01.
文摘In this study,we reported on the concept and practical use of cation exchange resin(CER)for removing anions in water via pretreating the CER with metal salts.The cation exchange resinsupported iron and magnesium oxides/hydroxides composite(FeMg/CER)was synthesized and introduced as a new and potential adsorbent for selective removal of nitrate ion in the water environment.Characteristics of FeMg/CER were determined by techniques such as Fouriertransform infrared spectroscopy,scanning electron microscopy,and Xray diffraction.The results showed that FeMg/CER material had a high nitrate adsorption capacity of 200 mg NO_(3)^()·g^(1)with a fast equilibrium adsorption time of 30 min at pH 5.In addition,it had good durability of at least 10 times of regeneration,which could be applied to practical water and wastewater treatment.
基金the Razi University authorities,Kermanshah,for their help and support of this study。
文摘Rapid climate change has provided the opportunity for many species to learn to adapt fast enough to modify their range distribution.The positive and negative responses of the species in terms of distribution are related to parameters such as kind of species,degree of specialization,size and movement skills,and such factors.Moving to high elevations and transitions to higher latitudes are among the strategies proposed as a solution to the negative effects of climate change.Therefore,predicting how different species respond to climate change can help predict the conservation program for them.Species distribution models(SDMs)are widely used to predict the geographical distribution of habitat suitability and species occurrence.Rhinopoma muscatellum is one of the three mousetailed bats(Rhinopomatidae)inhabiting the southeastern,southern,and southwestern parts of Iran and its distribution range to the interior and northern parts of Iran has been limited by the Elburz and Zagros Mountain.To study the effect of climate change on this species,range shifts and coverage of protected regions,74 presence points and environmental variables(climate,topography,anthropogenic,and vegetation)in MaxEnt software were used.Before the implementation of the model,the autocorrelation of the presence points was reduced and the selection of pseudo absent points was limited by using the bias grid.Climate variables were prepared for Mid-Holocene,Current,Climate Current,and Future scenarios in 2070(RCP2.6,RCP4.5,RCP6,and RCP8.5).In order to evaluate the overlap of ecological niche,the Schoener’s D and I statistic metrics were used.Also,to measure the breadth of the niches,B1(inverse concentration)and B2(uncertainty)metrics in ENMTOOLS software were employed.TSS statistics were used as a threshold.Species distribution trend changes in climatic scenarios were performed by the Mann Kendall(MK)test.Based on the results,the AUC values for current and future climate models were calculated to be 0.89 and 0.85,respectively.The distance from settlement,soil organic carbon,and altitude variables have the greatest impact on the current distribution of the species;and among the climatic variables,Isothermality(Bio3),Temperature Seasonality(Bio4),and Max Temperature of Warmest Month(Bio5)had the greatest impact on species distribution.The results showed that in climate change scenarios by 2070,the distribution range and breadth of climatic niche of Rhinopoma muscatellum will be significantly increased(P-value<0.05),habitat fragmentation will be reduced,and in RCP8.5 scenario it will reach the maximum distribution(39.38%of total Iran).This increase will cover the Elburz and Zagros mountain ranges,and a large part of the country will be suitable for the species.In response to current climate change,migration to higher latitudes was identified in this study.Among the main different classes of protected regions in Iran(National parks,Wildlife refuges,and Protected areas),protected areas in all scenarios had the most coverage of the suitable species habitat.
文摘Petrographic, mineralogical and geochemical investigations were carried out on representative?samples from the Mudawwara-Quwayra Dike (MQD) in southernJordan. The MQD intruded Paleozoic and Cretaceous rocks as sub-vertical basaltic plugs, striking NW-SE along a fault zone and extending for more than 100 km. The MQD forms irregularly positive features, and is represented by symmetrical, elliptical, elongated or circular hills. It comprises thin basaltic layers intercalated?with pyroclastics and inclusions of different size and lithology, including limestone, sandstone, phosphate, quartzite, and marble. Petrographically, the rock exhibits phyric, porphyritic, vitrophyric and locally glomerophyritic textures manifested by plagioclase, clinopyroxene and rare?olivine and set in a matrix of plagioclase, pyroxene, brown glass and opaque phases. Clinopyroxene?and olivine phenocyrsts show disequilibrium textures such as reaction/resorbed rims in the?forms of corroded ends. The paragenetic sequence shows that olivine is the first phase to be crystallized and coexisting with pyroxene at sometime, while pyroxene continues crystallization. Plagioclase might have crystallized in contemporaneous later than the pyroxene. The MQD rocks are classified?as basalt and exhibit a narrow range of silica with a unique subalkaline affinity. This is most?probably attributed to assimilation of the abundant siliciclastic inclusions by the ascending magma. Emplacement of the MQD is attributed to regional phase of magmatism in Jordan and Saudi Arabia, which is probably the peripheral extension of a large magmatic event widely exposed in the Red Sea realm.
文摘This study evaluated the performance of rooftop catchment systems in securing non-potable water supply in Birjand, located in an arid area in southeastern Iran. The rooftop catchment systems at seven study sites of different residential buildings were simulated for dry, normal, and wet water years, using 31-year rainfall records. The trial and error approach and mass diagram method were employed to optimize the volume of reservoirs in five different operation scenarios. Results showed that, during the dry water year from 2000 to 2001, for reservoirs with volumes of 200-20000 L, the proportion of days that could be secured for non-portable water supply was on average computed to be 16.4%-32.6% across all study sites. During the normal water year from 2009 to 2010 and the wet water year from 1995 to 1996, for reservoirs with volumes of 200-20000 L, the proportions were 20.8%-69.6% and 26.8%-80.3%, respectively. Therefore, a rooftop catchment system showed a high potential to meet a significant portion of non-potable water demand in the Birjand climatic region. Reservoir volume optimization using the mass diagram method produced results consistent with those obtained with the trial and error approach, except at sites #1, #2, and #5. At these sites, the trial and error approach performed better than the mass diagram method due to relatively high water consumption. It is concluded that the rooftop catchment system is applicable under the same climatic conditions as the study area, and it can be used as a drought mitigation strategy as well.
基金Behbahan Khatam Al-Anbia University of Technology for its support during this study
文摘The major objective of this study was to evaluate the effects of sand mining disturbances on the diversity of arbuscular mycorrhizal fungi(AMF). In addition, the proportional changes in the diversity of AMF to the distances from riverbanks were assessed. For this purpose, the riparian forest of the Maroon River, Iran was divided into three locations with a 200-meter wide zone in between. Thus, the locations studied were named Distance I(riverbank), Distance II(intermediate), and Distance III(farthest from riverbank). In each of these distances, 10 Tamarix arceuthoides and Populus euphratica of each species were randomly selected. At the same time, soil and root samples were collected from the rhizosphere of the tree species studied. Results indicated that totally 13 AMF species were observed in T. arceuthoides and 19 AMF species were recorded in P. euphratica rhizosphere belonging to 6 genera and 6 families. In these AMF species, Glomus segmentatum, G. geosporum, G. rubiforme, G. nanolumen, G. spinuliferum, Claroideoglomus drummondii, Gigaspora gigantea and Acaulospora paulinae appeared only in P. euphratica rhizosphere, while G. multiforum and Claroideoglomus claroideum were observed only in T. arceuthoides rhizosphere. Moreover, Distance II had the least AMF species both in T. arceuthoides and in P. euphratica rhizospheres, and also the least spore density and root colonization rate. Our results are important in that they provide a list of resistant AMF species that could be used in the conservation of biodiversity.
文摘As the mesoscale eddies in oceans and semi-enclosed seas are significant in horizontal dispersion of pollutants,we investigate the seasonal variations of these eddies in the Persian Gulf(PG)that are usually generated due to seasonal winds and baroclinic instability.The sea surface height(SSH)data from 2010 to 2014 of AVISO are used to identify and track eddies,using the SSH-based method.Then seasonal horizontal dispersion coefficients are estimated for the PG,using the properties of eddies.The results show an annual mean of 78 eddies with a minimum lifetime of one week.Most of the eddies are predominantly cyclonic(59.1%)and have longer lifetimes and higher diffusion coefficients than the anti-cyclonic eddies.The eddy activity is higher in warm seasons,compared to that of cold seasons.As locations with high eddy diffusion coefficients are high-risk areas by using maps of horizontal eddy diffusion coefficients,perilous times and locations of the release of pollutants are specified to be within the longitude from 51.38°E to 55.28°E.The mentioned areas are located from the Strait of Hormuz towards the northeast of the PG,closer to Iranian coast.Moreover,July can be considered as the most dangerous time of pollution release.
文摘Plants have always been exploited worldwide for food, medicines, shelter, and other purposes because they are readily available, affordable and acceptable to a large populace of the world. The study was conducted to gather information on the proximate composition of fresh and dry leaves of Pterocarpus erinaceus. The proximate composition of the leaf samples was determined using the standard methods of analysis of the Association of Official Analytical Chemists (AOAC). Proximate analysis of the fresh leaf samples of the plant shows a higher moisture content compared to the dry leaf samples. The total fat and total ash contents of the fresh leaf samples were however lower compared to values recorded for the dry leaf samples. The dry matter content of fresh leaf samples was also lower compared to that of the dry leaf samples. Fresh leaf samples again recorded the least crude protein content compared to dry leaf samples. Carbohydrates content in fresh leaf samples was higher compared to dry leaf samples. Generally, higher proximate values were recorded for dry leaf samples than for fresh leaves. Dry matter and moisture contents were detected in high quantities in both fresh and dry leaf samples of P. erinaceus. These results could be a justification for the multiple uses of the plant leaves across Sub-Saharan Africa. Further research should be carried out on the mineral, phytochemical and vitamin composition between the fresh and dry leaves of the plant.
文摘Shea tree is a major economic plant contributing to household income through the sale of edible fruits, kernels and shea butter. Shea butter is used industrially in the production of cosmetic products, chocolates and margarines. Fruits are used by human and also by birds. This study aimed to explore strategies for the improvement of shea yield through pollination. Two types of pollination (manual and natural pollination) were applied for the comparison of fruits set and their ripening. The fruits set and ripening index as well as average weight of ripe fruits and kernels were estimated. The results showed a significant difference between the fruits set Index of manual pollination and natural pollination (H(1) = 33.437, p = 7.361 × 10<sup>-9</sup>). Similarly, there was a significant difference between the ripening Index of manual pollination and natural pollination (H(1) = 4.5113, p = 0.03367). However, the mode of pollination did not influence the weight of ripe fruits and kernels. Therefore, the manual pollination enhances pollen supply to receptive stigmas for fertilization and improved fruit yield in Vitellaria paradoxa.
文摘Data processing and climate characterisation to study its impact is becoming difficult due to insufficient and unavailable data,especially in developing countries.Understanding climate’s impact on burnt areas in Ghana(Guinea-savannah(GSZ)and Forest-savannah Mosaic zones(FSZ))leads us to opt for machine learning.Through Google Earth Engine(GEE),rainfall(PR),maximum temperature(Tmax),minimum temperature(Tmin),average temperature(Tmean),Palmer Drought Severity Index(PDSI),relative humidity(RH),wind speed(WS),soil moisture(SM),actual evapotranspiration(ETA)and reference evapotranspiration(ETR)have been acquired through CHIRPS(Climate Hazards group Infrared Precipitation with Stations),FLDAS dataset(Famine Early Warning Systems Network(FEWS NET)Land Data Assimilation System)and TerraClimate platform from 1991 to 2021.The objective is to analyse the link and the contribution of climatic and environmental parameters on wildfire spread in GSZ and FSZ in Ghana.Variables were analysed(area burnt and the number of activefires)through Spearman correlation and the cross-correlation function(CCF)(2001 to 2021).The tests(Mann-Kendall and Sens’s slope trend test,Pettitt test and the Lee and Heghinian test)showed the overall decrease in rainfall and increase in temperature respectively(-0.1 mm;+0.8℃)in GSZ and(-0.9 mm;+0.3℃)in FSZ.In terms of impact,PR,ETR,FDI,Tmean,Tmax,Tmin,RH,ETA and SM contribute tofire spread.Through the codes developed,researchers and decision-makers could update them at different times easily to monitor climate variability and its impact onfires.
文摘Relying on the conceptual DPSIR framework and MODFLOW analysis,this study used a mixed approach to produce groundwater resource management solutions for the Najafabad area in central Iran.According to DPSIR results,agricultural activities put the highest pressure on groundwater resources in this region.The results showed the effectiveness of reducing waterwithdrawal over 30 years in maintaining the aquifer in a state of equilibrium.The best scenario consisted of cutting down extraction by 10%over the said period.Output maps of the water table rise at the Najafabad aquifer clearly showed that the groundwater management scenario involving a 10%reduction ofwater withdrawal was the most effective solution,as itwould raise thewater level by 6.7 m.Regarding other scenarios,reducing cultivated area by 20%was found to raise the water table by 5.03 m on average,while cutting down water withdrawal by 5%increased the water table by 3.6 m,and a 10%reduction of the cultivated area resulted in a 1.85mrise.The combinedmodel proposed here can be used for similar aquifers and can aid decision-makers and managers.
文摘Since incorrect site selection has sometimes led to the failure of artificial recharge projects,it is necessary to increase the effectiveness of such projects and minimize their failure by employing new techniques.Therefore,the present research used a combination of decision-making models,numerical groundwater modeling and clustering technique to determine suitable sites for implementation of an artificial recharge project.This hybrid approach was employed for the Yasouj aquifer located in southwestern Iran.In the first stage,by employing an AHP decision-making model,hydraulic conductivity,specific yield,slope,land use,depth to groundwater,and aquifer thickness were selected from 21 criteria used in previous research.The selected criteria were then entered as input into the classical k-means clustering model.Using the output,aquifer was divided into seven different regions or clusters.These clusters were then matched with the land use map,and some of the abandoned land areas were selected as the final option for implementing the artificial recharge project.Finally,the MODFLOW code in the GMS software was used to simulate the groundwater level and cluster the sites selected,with regards to increase in groundwater level.Results indicated that the most significant increases in groundwater level(43 and 27 cm)were those of Clusters 2 and 6 in the northern and western parts of the aquifer,respectively.Therefore,this approach can be used in other similar aquifers in arid and semi-arid regions to select the best sites for artificial recharge and to prevent loss of floodwaters.
文摘The importance of groundwater portability and the possible sources of anthropogenic contamination have led to the development of intrinsic groundwater vulnerability mapping. In this study, groundwater vulnerability map for Amman Zarqa Basin (AZB) has been generated based on information derived and calculated from processed remote sensing information and laboratory analysis. The database was prepared from soil hydro geological and hydrological data, Digital Elevation Model (DEM), and geological maps. For assessment of groundwater vulnerability, the method proposed by the state geological surveys of Germany (GLA-method) has been adapted and applied. The vulnerability map shows about 77% which is about 2919 Km2 of the AZB is classified as very low to low which could be corresponding to the pollution sources due to the absence of potential hazards and also due to low vulnerabilities. These areas could consequently be interesting for future development as they set preferable in view of ground water protection. In addition, about 14% (530 km2) is classified within the moderate vulnerability zone. About 5% (around 19 km2) of the study area lies under the area of high vulnerability zone. Only 4% can be classified as very high risk areas. Groundwater quality results revealed that water leach ate from point source is the main cause for groundwater contaminations in highly vulnerable karstic limestone aquifer (Amman Wadi Es Sir Aquifer-B2/A7). On the other hand, the Kurnub Sandstone aquifer (K) is generally well protected in the central and eastern part of the AZB due to its thick cover of partly marly sequences. However, the Kurnub aquifer might have a potential risk from the recharged infiltrating surface water from the Zarqa River, which is highly polluted due to industrial activities located along the river.
文摘Aims Species composition and diversity of the mountainous rangelands are results of interactions between environmental severities,het-erogeneous topography and facilitative effects by nurse plants.This research was aimed to compare relative effects of these three envi-ronmental variables on the natural vegetation of a mountainous rangeland.For a more detailed understanding,effects of four dif-ferent nurse species were separately compared on the various plant growth forms and on two community plant responses(diversity and abundance).Methods A mountainous semiarid rangeland was selected in Baharkish,Quchan,Northeast of Iran.Density and canopy cover of all plant species were recorded under the canopy of four different shrubs and in open areas,in north and south-facing aspects,and in a normal and a drought year.Shannon diversity,total abundance(%cover)and the abundance of different growth forms were used as crite-ria for assessing effects of the environmental variables.Data were arranged in a factorial combination and analyzed by three-way analysis of variance using a GLM analysis.Important Findings(i)Drought,aspect and canopy created niche differentiation:annual forbs and shrubs were more affected by drought,whereas geophytes and grasses were more responsive to slope aspects.Effects of drought and slope aspect were more profound on species diversity,whereas that of canopy facilitation was stronger on plant abundance.(ii)Canopy facili-tation was dependent on severity of the abiotic factors and life history of interacting species.Canopy facilitation allowed for the persistence of only annual forbs,but it was disadvantaged during the drought year.Plant community responses to abiotic factors(slope and drought)were more dependent on the plant growth form,while responses to canopy facilitation were more dependent on the morphology and/or ecology of nurse shrubs.(iii)Effect of shrubs was dependent on their morphology and ecology:shrubs with larger canopy area and nitrogen fixation capa-bility increased,but those with allelopathic effects or a dense canopy structure decreased the diversity of the understory species.
文摘Today,analyzing of sound pressure level and frequency is considered as an important index in human society.Sound experts believe that analyzing of these parameters can help us to better understanding of work environments.Sound measurements and frequency analysis did to fix the harmful frequency in all sections in Shiraz gas power plant with sound analyzer model BSWA 308.The sound pressure levels(LP)and the one and one-third octave band were continuously measured in A and C weighting networks and slow mode for time response.Excel 2013 and Minitab 18.1 software used for statistical calculations.Results analyzed by Minitab 18.1 software.The highest harmful frequency in Shiraz Gas Power Plant(SGPP)was 50 Hz with 115 dB.The sound pressure level(SPL)ranged from 45 dB to 120 dB in one-third octave band and weighting network C.The maximum sound pressure level was in Craft electricity generator with 105.3 dB and 67 Hz.Sound pressure level in surrounded environment was 120 dB.According to the results,in this industry the sound pressure level exceeded the Occupational Exposure Level of Iran(OEL).The value of sound pressure level were higher than the Standard of occupational health.SGPP consumes 47000 cubic meters of natural gas per hour to produce 100 MW(Mega Watt)of electricity.It is very high and it is not economical and cost effective.These numbers indicate that the power plant’s efficiency is low.It could be concluded that the noise pollution is an important issue in these industries.Moreover,SGPP produce noise with loss energy.Frequencies rotation at high sound pressure levels toward low frequencies were happened.
基金the Science and Research Branch,Islamic Azad Universitythe Research Institute of Petroleum Industry(RIPI)for supporting this work
文摘Formaldehyde(HCHO)is formed through the oxidation of volatile organic compounds(VOCs)and can cause human cancer.Bismuth oxide and titanium oxide nanoparticles-functionalized nanographene oxide(Bi_(2)O_(3)/TiO_(2)@NGO)were used to rapidly remove the HCHO from the air by a photocatalytic degradation-adsorption process(PC-DAP).The formaldehyde vapor in pure air was generated in a dynamic system within a chamber,and flowed over Bi_(2)O_(3)/TiO_(2)@NGO adsorbent inside a fixed-bed quartz reactor(FBQR)under UV irradiation at optimized conditions(250C).At atmospheric pressure,the flow rate and gas hourly space velocity(GHSV)were adjusted to 300 mL/min and 100-450 L/h,respectively.The radicals of HCHO and nanographene oxide(NGO)were generated through the UV-photochemical process,enhancing the chemical adsorption through the radicals’interactions.On the other hand,the semi-degradation process by catalytic oxidation process converted some HCHO into raw materials of CO_(2)and H_(2)O,while the unconverted HCHO was physically absorbed by NGO.Finally,the HCHO concentration in the outlet system was measured by gas chromatography with a flame ionization detector(GC-FID)after derivatizing formaldehyde with 2,4-dinitrophenylhydrazine(DNPH)and acetonitrile.Therefore,efficient removal of HCHO from the air,the removal efficiency of more than 95%,was achieved through physical/chemical adsorption and the semi-degradation.The mean removal efficiencies for HCHO with Bi_(2)O_(3)-TiO_(2)@NGO,TiO_(2)@NGO,Bi_(2)O_(3)@NGO,and NGO were 98.7%,73.6%,61.8%,and 11.4%,respectively(n=10,RSD<5%).The methodology was validated by spiking different concentrations of standard HCHO into pure air.
