Incubation rate and larvae size of Persian sturgeon (Acipenser persicus Borodin 1897) in relation to sperm restripping     

Hadiseh Dadras  Hossein Khara  Shahrouz Baradaran Noveiri 《Aquaculture Research》2014,45(10):1727-1732

In this study, 11 wild male brood fish were used and their mean ages were 15.08 ± 1.66. The luteinizing hormone‐releasing hormone analogue (LH‐RH‐A₂) was used to stimulate twice in few days interval (3–7 days) and then semen samples were stripped. The results showed that there was significant difference among the percentage of motile spermatozoa, sperm density and spermatocrit during two strippings (P < 0.05). The duration of sperm motility in first and second stripping was 315/83 ± 162.16 and 212.5 ± 110.53 s respectively. Also, sperm pH was 8.41 ± 0.53 and 8.05 ± 0.33 in first and second stripping respectively. There was significant differences between hatching rate, as well as larvae size significantly changed in both hatching and initiation of active feeding (P < 0.05).  相似文献   

Effect of weed interference on Zea mays: Growth analysis     

Hossein Ghanizadeh  Shapoor Lorzadeh  Nazer Aryannia 《Weed Biology and Management》2014,14(2):133-137

In order to investigate the effect of weed competition on corn, growth trials were conducted in Shushtar, Iran, using a comparative growth analysis. In this study, two sets of treatments were imposed, based on the phenological stages of corn development, using a randomized complete block design with three replicates. The results showed that barnyardgrass and redroot pigweed were the most dominant weeds in these trials. Increasing the duration of weed interference reduced the corn leaf area index gradually. The reduction in the corn leaf area index led to a decline in the crop growth rate as a result of a reduction in the ability of corn to capture light and its photosynthetic ability. The total dry matter and relative growth rate of corn were decreased when the weeds were removed later as a result of a reduction in the leaf area index. According to these results, the leaf area index has a critical role in weed–crop competition.  相似文献   

Determination of annual reproductive cycle in male sterlet,Acipenser ruthenus using histology and ultrasound imaging     

Golpour  Amin  Broquard  Coralie  Milla  Sylvain  Dadras  Hadiseh  Baloch  Abdul Rasheed  Saito  Taiju  Pšenička  Martin 《Fish physiology and biochemistry》2021,47(3):703-711

Fish Physiology and Biochemistry - The aim of this study was to evaluate seasonal testicular development in the cultured sterlet, Acipenser ruthenus. During annual sexual cycle of male sterlet,...  相似文献   

High performance fibers production process using Taguchi experimental design     

Hossein Ahmadi Danesh Ashtiani  Reza Eslami Farsani 《Fibers and Polymers》2011,12(8):1054-1061

In this research, results of an experimental interaction effect of operating parameters on tensile strength carbon fibers from a commercial PAN-based precursor are investigated. Ten parameters at two and four levels (L₃₂=2¹×4⁹) were investigated: stabilization temperature at first stage (STFIS), stabilization duration time at first stage (SDTFIS), stabilization temperature at second stage (STSS), stabilization duration time at second stage (SDTSS), stabilization temperature at third stage (STTS), stabilization duration time at third stage (SDTTS), stabilization temperature at fourth stage (STFOS), stabilization duration time at fourth stage (SDTFOS), carbonization temperature (CT), and carbonization duration time (CDT). In this study, Taguchi method was used initially to plan a minimum number of experiments. Statistical analysis, analysis of variance (ANOVA), was also employed to determine the relationship between experimental conditions and yield levels. ANOVA was applied to calculate sum of square, variance, ratio of factor variance to error variance and contribution percentage of each factor on response. The results show that increasing all of parameters improves tensile strength performance. The optimum levels of influential factors, determined for tensile strength are STFIS 200 °C, SDTFIS 120 min, STSS 225 °C, SDTSS 120 min, STTS 240 °C, SDTTS 120 min, STFOS 260 °C, SDTFOS 60 min, CT 1400 °C and CDT 10 min. The results showed that CT and ODTFIS are the most and the less effective factors on response, respectively.  相似文献   

收割机前部扩充配件对降低油菜收获损失的作用（摘选）     

M.Amin Asoodar  Y. Izadinia 《农业工程》2012,2(9):79-81

如今,伊朗油菜种植已经在其国内各地发展起来。然而,在整地、种植和收获过程中仍然存在一些问题。因此,需要采用新技术进行机械化收获。目前,谷物联合收获机生产公司除了生产常用设备,也生产一些安装在割台上的扩充配件。机械化收获系统尤其是常用的收获割台存在有相当大的损耗,同时熟练程度和需要特殊的油菜收获配套设备也是造成损失的原因之一。该试验研究一种割台和两种割台扩充配件对油菜收获损失的影响,从而确定损失量以及造成损失的原因。试验中涉及到一种常见割台,以及伊朗制造的采用机械侧刀切割器的Hamed割台扩充配件和采用液压侧刀切割器的Bizo割台扩充配件。试验采用随机完全区组设计,设6次重复。利用安置的托盘测定收获损失量。结果表明,随着割台运禾螺杆与切割器间距离的加大,割台扩充配件能降低损失量。因此,从总损失量考虑,常用割台与其他两种扩充配件相比差异显著。普通割台损失量为599 kghm2,而采用侧面垂直切割可以减少71 kghm2。此外,使用液压系统替代机械系统以及使用双层切割器替代单层刀杆都有助于降低损失量。试验结果显示,破损种子量为39.6 kghm2,占总产量的1.12%。试验结果是令人满意的,同时改善了联合收获机的性能。通过使用割台扩充配件有利于降低收获中的损耗。   相似文献   

A REVIEW OF PRODUCTION FRONTIER RESEARCH IN AQUACULTURE (2001–2011)     

Abdullahi Iliyasu  Zainal Abidin Mohamed  Mohd Mansor Ismail  Amin Mahir Abdullah  Salleh Mohamed Kamarudin  Hashim Mazuki 《Aquaculture Economics & Management (Blackwell Science)》2013,17(3):221-247

Most research works on the production frontier in aquaculture focus on efficiency measurement using either Stochastic Production Frontier (SPF) or Data Envelopment Analysis (DEA). The studies on productivity growth in aquaculture were limited, perhaps due to lack of time-series data. Nevertheless, total factor productivity analysis (TFP) in fish farms has started gaining popularity in recent years. In addition, the majority of the efficiency studies have centered on technical efficiency analysis but substantial increases in the output levels can be fully realized through improving overall economic efficiency. Therefore, this review suggests that future research should estimate all three efficiency indices (i.e., technical, allocative and economic efficiencies).  相似文献   

Optimization of an artificial neural network topology using coupled response surface methodology and genetic algorithm for fluidized bed drying     

Tayyeb NazghelichiMortaza Aghbashlo  Mohammad Hossein Kianmehr 《Computers and Electronics in Agriculture》2011,75(1):84-91

In this study, an integrated response surface methodology (RSM) and genetic algorithm (GA) are recommended for developing artificial neural networks (ANNs) with great chances to be an optimal one. A multi-layer feed forward (MLFF) ANN was applied to correlate the outputs (energy and exergy) to the four exogenous inputs (drying time, drying air temperature, carrot cubes size, and bed depth). The RSM was used to build the relationship between the input parameters and output responses, and used as the fitness function to measure the fitness value of the GA approach. In the relationship building, five variables were used (number of neurons, momentum coefficient and step size in the hidden layer, number of epochs and number of training times). A polynomial model was developed from training results to mean square error (MSE) of 50 developed ANNs to generate 3D response surfaces and contour plots. Finally, GA was applied to find the optimal topology of ANN. The ANN topology had minimum MSE when the number of neurons in the hidden layer, momentum coefficient, step size, number of training epochs and training times were 28, 0.66, 0.35, 2877 and 3, respectively. The energy and exergy of carrot cubes during fluidized bed drying were predicted with R² values of greater than 0.97 using optimal ANN topology.  相似文献   

Identifying Soil and Plant Nutrition Factors Affecting Yield in Irrigated Mature Pistachio Orchards     

Isa Esfandiarpour-Borujeni  Seyed Javad Hosseinifard  Hossein Shirani  Maryam Zeinadini  Ali Asghar Besalatpour 《Communications in Soil Science and Plant Analysis》2018,49(12):1474-1490

The main objective of this study was to evaluate the potential use of a hybrid Genetic Algorithm-Artificial Neural Network (GA–ANN) method for predicting pistachio yield and for identifying the determinant factors affecting pistachio yield in Rafsanjan region, Iran. A total of 142 pistachio orchards were selected randomly and soil samples were taken at three depths. Besides, water samples and leaves from branches without fruit were taken in each sampling point. Management information and pistachio yields were achieved by completing a questionnaire. Primarily, 58 variables affecting pistachio yield were measured, and then 26 out of them were selected by minimizing mean square error (MSE) using a feature selection (FS) method. The results showed that the accuracy of the method was acceptable. Furthermore, the sensitivity analysis showed that the main determinant features affecting the pistachio yield were the irrigation water amount, leaf phosphorus, soil soluble magnesium, electrical conductivity (EC), and leaf nitrogen.  相似文献   

Sulfur uptake and translocation in maize (zea mays) grown in a high pH soil treated with elemental sulfur     

Mehdi Karimizarchi  Amin Soltangheisi  Aminuddin Husin  Mohd Khanif Yusop  Radziah Othman 《Journal of plant nutrition》2018,41(14):1798-1806

A glasshouse experiment was conducted to elucidate the influence of elemental sulfur (S) application rates (0, 0.5, 1.0, and 2.0 g S kg^?1 soil) on the release and uptake of S at 0, 20, and 40 days after incubation. Results showed that there was a progressive upward trend in maize leaves, stem, and root S content with application of elemental S. However, maize production followed a nonlinear model. Plants grown in untreated soils suffer from S deficiency and addition of elemental S at a rate of 0.5 g S kg^?1 soil alleviated S deficiency. The decrease in maize performance due to the highest S application rate was not related to S toxicity. The greatest leave, stem, and root productions were obtained at S concentrations of 0.41, 0.58, and 0.2%, respectively. Overall, application of elemental S at a rate of 0.5 g S kg^?1 soil is recommended for maize performance improvement.  相似文献   

The Use of Coal Gangue as a Cultivation Bed Conditioner in Forage Maize Inoculated with Arbuscular Mycorrhizal Fungi     

Babak Motesharezadeh  Elaheh Ahmadiyan  Hossein Ali Alikhani  Hossein Azarnivand 《Communications in Soil Science and Plant Analysis》2017,48(11):1266-1279

A greenhouse pot experiment was conducted to investigate the effect of application of coal gangue (CG) at different rates (0, 5, 10, 20, and 50%) and inoculation with two arbuscular mycorrhizal (AM) fungi Glomus intraradices and Glomus mosseae, as mediating plant adaptation to soil amended with CG, on the nutrient content of forage maize. The results showed CG amendment at all levels and both AM fungi significantly improved the nutrient content of the plant as compared to control. In general, the highest shoot dry weight and nutrient phosphorus, iron, and zinc (P, Fe, and Zn) were obtained with 10% CG and G. intraradice treatments, which were 49.68, 30.49, 16.72, and 75.71% higher than those of the control plants, respectively. Therefore, 10% dose of CG may be considered as a suitable dose for amendment in the corn cultivation bed in terms of providing nutrient contents for this plant as well as AM fungi root colonization.  相似文献