9 research outputs found

    Environmental impact assessment (EIA) on cultivation of the nile tilapia (Oreochromis niloticus) with brackish water in Dashtestan

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    EIA is a worthy tool for identifying and assessing potential impacts and control them.it compatibles environmental aspects with sustainable development. In order to predict the effects of tilapia culture activities on regional we gathered physical, biological, and social information to quantify the activities effects on them. We addressed 42 impacts consist of 31 positive, and 11 negative. These affect half of social, 33% of physical, and 17 of biological elements. This equivalent with -42, +304, and+36 when puts in the charts.in order to have a good and comprehensive assessment of activities Leopold matrices was employed. Based on summarized values from this we have +380and -82 results +298. This means that this activity has a great positive result especially on socio-economic environment. These kinds of studies are highly recommended for other parts of the Bushehr province e.g Dashtestan county that most of their water resources are brackish and not suitable for agriculture

    Environmental risk assessment of the activity of specific pathogen free shrimp production centers

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    This study is a part of the national and technology master plan entitled "Attain to technical knowledge of specific pathogen free shrimp production and cut off to dependence on foreign products". The goals of this work were to assess and analysis the risk factors of production of specific pathogen free Litopenaeus vannamei shrimp in its all stages (broodstocking, laravl production, shrimp farming, feeding and water quality), determining the pattern of outcomes monitoring, management and control of outcomes from April 2012 to September 2015 in Bandargah research station and Persian Gulf SPF Shrimp research station and their environment, belonging to Shrimp Research Center, located in Bushehr. Identification and screening of risk factors have been done based on Environment Aspect and Effect Analysis method, (EA)2, using a fine statement questionnaire and quantification of risks. The number of identified risk factors in Bandargah research station was 15 while it was 13 in Persian Gulf SPF Shrimp research station. The more number of risk factors in Bandargah station in respect to its number in Persian Gulf station is might due to lower level of biosecurity, physical structure and aging of Bandargah station and existence of two possible source of contamination, the Bushehr nuclear power plant pollutants and Bandargah fishing harbor, near to the station. On the basis of results, the maximum values of APN in Bandargah station was 42 while it was 30 in Persian Gulf station. These results revealed that the level of risk in Bandargah station is lower than that in Persian Gulf station. The most probable risks in both studied research stations are related to transmission of pathogens in shrimp feeding and water intake pollution

    Global, regional, and national burden of colorectal cancer and its risk factors, 1990–2019: a systematic analysis for the Global Burden of Disease Study 2019

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    Funding: F Carvalho and E Fernandes acknowledge support from Fundação para a Ciência e a Tecnologia, I.P. (FCT), in the scope of the project UIDP/04378/2020 and UIDB/04378/2020 of the Research Unit on Applied Molecular Biosciences UCIBIO and the project LA/P/0140/2020 of the Associate Laboratory Institute for Health and Bioeconomy i4HB; FCT/MCTES through the project UIDB/50006/2020. J Conde acknowledges the European Research Council Starting Grant (ERC-StG-2019-848325). V M Costa acknowledges the grant SFRH/BHD/110001/2015, received by Portuguese national funds through Fundação para a Ciência e Tecnologia (FCT), IP, under the Norma Transitória DL57/2016/CP1334/CT0006.proofepub_ahead_of_prin

    Determination of suitable poplar clones in short rotation system in Chamestan

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    For determining of suitable poplar clones for utilizing in cellulose  industries  on the basis of maximum wood  production in hectar ,15 clones of Populus deltoides, P.euramericana and P.nigra were studied in three exploitaion period (2,3 and 4 years) in chamestan of Mazandran province. In order to homogenize the material, all the shoots were cut at the bottom after the first growth year. At the end of each exploitation period, all stems and shoots were cut and weighted two times; 1) wet wood product and 2) dry biomass after six months of drying in the open air. Some parameters such as survival, number  of total coppice stems per collar, number of shoots over 2 m height, mean diameter and mean height of shoots over 2 m height, diameter and height of the highest  stems and resistance to pests and diseases were studied and compared at the end of the project. Results were analized on the basis of randomized complete block design. Results showed that : a) In 2 years short rotation system, P.d. 69/55, P.e. triplo and P.d. 73/51 produced the highest amount of dry biomass of 20.05, 17.52  and 17.19 ton/ha/year,respectively. b) In 3 years short rotation system, P.d.77/51, P.e. triplo and P.d. 69/55 produced the highest amount of dry biomass of 16.70, 15.75 and 14.73 ton/ha/year, respectively. c) In 4 years short rotation system, P.d. 69/55, P.d. 77/51 and P.e. triplo produced the highest amount of dry biomass of 19.00, 17.77 and 16.96 ton/ha/year, respectively. The diffrences between dry biomass production of poplar clones in each rotation system were significant

    Comparative study of soil properties, quantitative and qualitative characteristics of mixed and pure afforestation of Poplar and Alder in Chamestan (Mazandaran)

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    Poplars are fast-growing species that were planted pure in the past. Mixed plantations of poplar with nitrogen fixing species have been recommended recently to increase the soil fertility. In this study, American poplar (Populus deltoids 77/51) has been planted with different mixture ratios with Caucasian Alder (Alnus subcordata) in randomized complete blocks with four replications in Chamestan research station, Mazandaran province, northern Iran. For further comparisons, pure stands of poplar and alder were also added to the treatment design. The plantation spacing was 4×4m. Results after 7 years showed that survival rate of poplar were greater than alder, in general. The highest rate of poplar survival was observed in the treatment of 50% poplar + 50% alder. The differences among treatments were statistically significant. The highest diameter increment was measured within poplars in the treatment of 33% poplar + 67% alder and the least in the pure poplar stand. The highest total height was measured within poplars in the treatment of 67% poplar + 33% alder. The highest volume of individuals trees were measured within poplars in the mixture of 33% poplar + 67% alder, while the highest tree volume of alder was obtained within the alder pure stand. The amount of soil nitrogen was significantly higher in the pure alder stand and mixture of 33% poplar + 67% alder, than in the soil of other treatments

    Effects of pure and mixed Caucasian alder (Alnus subcordata C. A. Mey.) and eastern cottonwood (Populus deltoides Marsh.) plantations on carbon sequestration and some physical and chemical soil properties

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    This study investigated effects of pure and mixed plantations of Caucasian alder (Alnus subcordata C. A. Mey.) and eastern cottonwood(Populus deltoides Marsh.) on carbon sequestration and some physical and chemical soil properties. The stands across the test site were planted in 1996 under randomized complete blocks design at four replications and five treatments at Chamestan Forest Station. The treatment consisted of five pure and mixed eastern cottonwoodand Caucasian alder stands (pure eastern cottonwood, pure Caucasian alder, mixed Caucasian alder and eastern cottonwoodstands at three different levels: 50+50 %, 33+67 % and 67+33 %, respectively). Combined soil samples were taken at two depths including 0-15 and 15-30 cm. The results showed no significant difference in carbon sequestration rates amongst the treatments at both soil depths , except for pH which was significantly different at soil surface layer (

    Effect of soil texture on growth and yield of eastern cottonwood (Populus deltoides Bartr. ex Marsh. 77/51) in Noor alluvial plain

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    In recent decades, poplar cultivation as wood farming has been developed up to 50 thousand hectares using the fast growing eastern cottonwood (Populus‌‌ deltoides‌‌ Bartr. ex Marsh. 77/51) has become a common practice in north of Iran. The current study aimed to select appropriate sites for increasing growth and yield of this poplar clone. For this purpose, three different 20 years-old plantations on three different media naming: loam, silt-loam and silt-clay-loam soils of Noor alluvial plain in north of Iran were selected. The measurements were carried out based on 400 m2 plots with four replications. Quantitative and qualitative analysis showed significant differences among poplar trees grown on different soil textures beds. The poplar trees grown on loamy soils displayed the highest annual height increment of 1.27 m and volume of averaged tree of 0.956 m3. Values for average diameter, basal area and volume ha-1 were also highest in trees grown on loamy soil with total 29.1 cm, 32.59 m2 ha-1 and 443 m3 ha-1, respectively. The mean height of the trees in the silt- loam soil (24.47 mm) was significantly greater than that of the silt- clay- loam. Values for diameter increment and basal area of trees were higher in the silt- clay- loam than in silt- loam soil. In order to get an initial understanding of the habitat condition, clone selection and improvement operation, analyzing of soil is essential prior to planting of trees. In this case we can ensure and guarantee the plantation and the investment would be less risky

    Pull-in instability of paddle-type and double-sided NEMS sensors under the accelerating force

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    Paddle-type and double-sided nanostructures are potential for use as accelerometers in flying vehicles and aerospace applications. Herein the pull-in instability of the cantilever paddle-type and double-sided sensors in the Casimir regime are investigated under the acceleration. The D'Alembert principle is employed to transform the accelerating system into an equivalent static system by incorporating the accelerating force. Based on the couple stress theory (CST), the size-dependent constitutive equations of the sensors are derived. The governing nonlinear equations are solved by two approaches, i.e. modified variational iteration method and finite difference method. The influences of the Casimir force, geometrical parameters, acceleration and the size phenomenon on the instability performance have been demonstrated. The obtained results are beneficial to design and fabricate paddle-type and double-sided accelerometers. © 2015 IAA. Published by Elsevier Ltd. All rights reserved
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