438 research outputs found

    Seasonal changes in the abundance and biomass of zooplankton from shallow mudflat river-estuarine system in Persian Gulf

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    The present study was designed to investigate the seasonal changes in the abundance and biomass of zooplankton and their relationships with water quality parameters in mudflat shallow estuary, Helleh River, Persian Gulf (Iran). The zooplankton consisted of Acartia sp., Euterpina sp., Oithona spp., Oncaea sp., Paracalanus sp., Corycaeus sp., Labidocera sp., Macrosetella sp., Microsetella sp., Temora sp., copepod copepodid, copepod nauplii, Barnacle, Polychaeta, Conchoecia sp. (Ostracoda), Hyperid, Decapoda (zoea and megalopa), Actinula, Echinopluteus, Mollusca, Tintinnopsis sp., Ctenophora (Boliopsis sp.), Protozoa (Discorbis sp.), cumacea (Diastylis sp.), Cnidaria (Siphonophora and Phialidium), Nematoda (Pratylenchus spp.), Urocordata (Oikopleura spp.), fish eggs and fish larvae. The maximum biomass was estimated at estuary mouth in all seasons, the highest values in autumn (97.8-255.6 mg/m3) and the lowest in winter (5.5-68.2 mg/m3). The seasonal abundance (density) of zooplankton was 21237±2419, 45739±6053, 5242±648, and 12905±1867 ind./m3 in summer, autumn, winter and spring, respectively. There was a significant correlation (P<0.01) between zooplankton abundance as well as biomass with salinity, dissolved oxygen and chlorophyll a. Based on PCA (Principal Component Analysis), the most important factors in mudflat shallow river–estuarine system that could describe most changes of biomass and abundance of zooplankton were salinity, chlorophyll a, temperature and pH,  respectively.The present study was designed to investigate the seasonal changes in the abundance and biomass of zooplankton and their relationships with water quality parameters in mudflat shallow estuary, Helleh River, Persian Gulf (Iran). The zooplankton consisted of Acartia sp., Euterpina sp., Oithona spp., Oncaea sp., Paracalanus sp., Corycaeus sp., Labidocera sp., Macrosetella sp., Microsetella sp., Temora sp., copepod copepodid, copepod nauplii, Barnacle, Polychaeta, Conchoecia sp. (Ostracoda), Hyperid, Decapoda (zoea and megalopa), Actinula, Echinopluteus, Mollusca, Tintinnopsis sp., Ctenophora (Boliopsis sp.), Protozoa (Discorbis sp.), cumacea (Diastylis sp.), Cnidaria (Siphonophora and Phialidium), Nematoda (Pratylenchus spp.), Urocordata (Oikopleura spp.), fish eggs and fish larvae. The maximum biomass was estimated at estuary mouth in all seasons, the highest values in autumn (97.8-255.6 mg/m3) and the lowest in winter (5.5-68.2 mg/m3). The seasonal abundance (density) of zooplankton was 21237±2419, 45739±6053, 5242±648, and 12905±1867 ind./m3 in summer, autumn, winter and spring, respectively. There was a significant correlation (P<0.01) between zooplankton abundance as well as biomass with salinity, dissolved oxygen and chlorophyll a. Based on PCA (Principal Component Analysis), the most important factors in mudflat shallow river–estuarine system that could describe most changes of biomass and abundance of zooplankton were salinity, chlorophyll a, temperature and pH,  respectively

    The study of effectiveness of descriptive evaluation in 1st and 2nd grade of primary schools in region 3 of Tehran

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    AbstractBasic purpose of this study is investigating effects of evaluation on educational performance of primary school children in region 3 of Tehran. 164 teachers from simple random sampling is chosen .This study is applicable purposely and in “Descriptive” method is navigating. The tool was used in this study is researcher-based questionnaire. In this presumptive method,“K square” examination and independent sample t test and levene‟s test has used for continuous measuring. Data analysis indicated: -descriptive evaluation decreases students‟ stress. -descriptive evaluation increases educational performance. -descriptive evaluation increases teachers‟ satisfaction

    Designing and Psychometric Assessment of the Questionnaire for Artificial Airway Patients’ Satisfaction with Nurse's Non-verbal Communication during Nursing Cares

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    Background & Aim: Verbal communication disorder is one of the most important problems of mechanically ventilated patients which can lead to anxiety and decrease satisfaction. The purpose of this study is designing and psychometric assessment of the questionnaire for artificial airway patients’ satisfaction with nurses nonverbal communication during nursing cares. Materials & Methods: This is a methodological study which was performed using Waltz 2010 method in 4 steps, namely conceptual model definition, determination of goals and tools design, compiling initial plan, and determining reliability and validity in 2016. The study population includes all patients with artificial airway in 3 hospitals under the supervision of Shiraz University of Medical Sciences. Totally, 240 patients were selected for the study, using convenience sampling. The questionnaire validity was evaluated using face, construct, and content validities. Pearson correlation coefficient and Cronbach's alpha were used to evaluate the external and internal reliabilities. SPSS Software V.19 was used for data analysis. Results: The initial version of questionnaire was designed with 27 items. After face and content validation process, the second version was designed in 24 items. The maximum score for all items was 1.5. The values of CVI and CVR were obtained at 0.89 and 0.88, respectively. For construct validity, the items were reduced to 12, based on explanatory factor analysis. The final questionnaire was obtained in 3 satisfaction dimensions namely providing physiologic, social, and emotional-psychological needs with predictive power of 47.706. The Cronbach's alpha value was calculated at 0.67. Pearson correlation coefficient was calculated at 0.67, which suggests the validity and reliability of the questionnaire. Conclusion: Considering the limitation of data availability for evaluating the satisfaction of artificial airway patients with nursing communication, the questionnaire can be an efficient tool for detecting the patient-nurse communicational challenges and patients’ needs in different areas as well as improving care services quality

    Dynamic simulation and optimization of an industrial-scale absorption tower for CO2 capturing from ethane gas

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    AbstractThis article considers a process technology based on absorption for CO2 capturing of ethane gas in phase 9 and 10 of south pars in Iran using diethanolamine (DEA) as absorbent solvent. This CO2 capture plant was designed to achieve 85% CO2 recovery and obtain 19 ppm the CO2 concentration in the outlet of absorber. ASPEN–HYSYS software was used for the dynamic simulation of a commercial-scale CO2 capture plant and amine Pkg equation was chosen from the fluid property package for calculating the thermodynamic properties of the process. A static approach for optimization was used to evaluate the optimum conditions. This research revealed that pressure variation does not have any considerable changes in the absorption process, while both amine inlet temperature and volumetric flow rate increment enhance the absorption tower efficiency. The effect of temperature was very significant as shown in the dynamic study plots. The optimum condition for CO2 absorption from a stream of ethane gas with molar flow rate of 2118 kg mol h−1 was obtained 75 m3  h−1 of amine at 53 °C and 24 bar. This optimized condition is acceptable from economical, safe as well as feasible point of view
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