118 research outputs found
Factors influencing the emigration of juvenile Bonga from the Cross River estuary
Studies were conducted to identify and quantify the proximate factors responsible for the emigration of juvenile bonga Ethmalosa fimbriata (Bowdich, 1825) from the Cross River estuary. A time series of bonga cpue, salinity, turbidity and plankton abundance was undertaken, juvenile bonga was abundant in the estuary when salinities ranged between 1 and 9ppt. at salinities outside this range, they were absent. We conclude that salinity is the proximate factor that initiates the emigration of juvenile bonga from the estuar
Reproductive efficiency as a function of age in estuarine catfish, Chrysichthys nigrodigitatus of the Cross River, Nigeria
Study was conducted on the reproductive efficiency of Chrysichthys nigrodigitatus of the Cross River. The objective was to determine the influence of age on eggs size and fecundity. Forty four females of Chrysichthys nigrodigitatus were sampled from April, 2011 to March, 2012. Fecundity and eggs size were measured in relation to fish size. The relationship between egg size and fish size produced a parabolic curve. This implies that younger fish and older fish were less efficient in terms of eggs size and quality while the middle aged fishes were more efficient in terms of eggs size and quality. Similarly, there was an inverse curvilinear relationship between number of eggs per unit weight and somatic weight of the fish. Younger fish are less efficient because of the physiology of growth, while the older fishes are less efficient because of reproductive senescence. Management strategy for the stock therefore requires the conservation of the middle aged individuals for increase in reproduction. Also in aquaculture the middle aged class should be used as broodstock for excellent results
Reproductive Effeciency of an Indigenous Irabian Goat ( Capra Hircus)
Goats (Capra hircus) are economical animal in livestock production especially in rural areas. It is well known that goat can tolerate harsh conditions; however there are little information about its reproduction functions such as testis histomorphometry and efficiency of sertoli cells. This study aimed to estimate germ cell types and number per sertoli cell of an indigenous Iranian goat (Lori goat). Semen was collected from five Lori goats by means of an artificial vagina. Semen volume, concentration, normality and motility of spermatozoa were determined. After removing both testes, tissue paraffin section (5Ό thickness) were prepared and stained using Haematoxylin and Eosin method. Mean weight of testis was 114.40 ±27.00 grams. Means of seminiferous tubule diameter and tubule length per gram testis were 197.20 ± 1.80 Όm and 9956.00 ± 93.00 m, respectively. The mean number of spermatids per each tubule, spermatogonia and spermatocytes at stage I were 163.00 ± 99.9, 140.30 ± 28.60 and 146.40 ± 19.80, respectively. From this study it can be concluded that the Lori goat has high reproductive potentials probably due to high number of sertoli cell per germ cells.Keywords: Lori goat, Testis, Sertoli cell, Seminiferous tubule, Spermatocytes, Spermatogonia, Spermatozoa, Seme
Aqueous extract of Echlum amoenum elevate CSF serotonin and dopamine level in depression rat
Based on a traditional belief, Echlum amoenum (Boraginaceae) dried flowers are used In Iran as an anxiolytic remedy and also as a mood enhancer. But Interfering mechanisms unknown, In this study, efficacy of an aqueous extract of E.amoenum in depressive rat was evaluated, using measurement the changes level CSF serotonin and dopamine as indicator mood. Four groups of male wistar rats each group of seven rats were enrolled in this study. Depressive induced with intraperitoneal injection of reserpine (5mg/kg) and assessment depression by swimming test, the next two weeks of oral performing aqueous extract Echlum amoenum, CSF serotonin and dopamine concentration of rats were measured using ELISA kit. Our finding indicated, performing aqueous extract Echlum amoenum increased CSF serotonin and dopamine concentration in depression rats. The level of CSF serotonin enhanced in control group receiving Echlum amoenum compared control group alone. These results showed the serious changes of neurotransmitters due to Echlum amoenum which can be translated as mood enhancer. It can be concluded, Echlum amoenum induce antidepressant effective In part by increasing level CSF serotonin and dopamine
Morphometric analysis of lower Enyong creek basin in South Eastern Nigeria; its implications for applied studies
The drainage basin analysis is important in any hydrological investigation such as study of hydrologic processes, management of wetlands, flood, erosion and landslides susceptibility studies, assessment of groundwater potential and groundwater management. Also, existing theories and models such as the laws of drainage composition can be verified. In the light of the foregoing, the present paper describes the drainage characteristics of the lower Enyong Creek, which is underlain by varying geologic formations. viz; Asu River Formations e.g the Abakiliki Anticlinorium to the recent alluvium in the south It involved detailed map-based quantitative analyses of two 4th order sub-catchments in the study area. The drainage pattern is mainly dendritic type. It is observed that the drainage density value is low which indicates the basin is highly permeable subsoil and thick vegetative cover. The elongation ratio value reveals that the basin is strongly elongated and stream abstraction process constrained by heterogeneous geologic materials. This study would help the local people to utilize the resources for sustainable development of the basin area
Householdsâ Decision to Participate in Cooperative Organizations: Evidence from Farmers in Akwa Ibom State, Southern Nigeria
Farmer organizations are effective mechanisms for increasing agricultural production, income and reducing poverty. Regrettably, farmers have not taken advantage of the lofty benefits accruable to those who voluntarily join these organizations. The study estimated the factors influencing householdâs decision to participate in cooperative organizations and also tested the level of agreement among identified constraints linked with participation. Multistage sampling procedure was employed to select 120 farmers for the study. Primary data were obtained using questionnaires. Data were analyzed using Probit model and Kendallâs coefficient of concordance. Results of analyses revealed that the mean age, years of educational attainment household size and years of farming experience were 32, 15, 5 and 7 respectively. Result of probit analysis further indicate that age of the farmer, farm income, household size, participation in meeting, major decision maker, distance of farm to the nearest road and farmers social status were the most critical factors influencing householdâs decision to participate in cooperative organizations. Result of Kendallâs coefficient of concordance revealed that there was 0.42 (moderate agreement) between the ranking of constraints associated with farmers' participation in cooperative organizations. Furthermore, findings showed that the top five factors limiting householdsâ decision to participate in cooperative organizations were inadequate capital accumulation, high embezzlement of funds, poor leadership, recurring internal crises and lack of initiative. Policies to provide good and accessible roads, increase farmers incomes and encourage youths are rational options that will enhance effective participation in cooperative organizations
The current rate of exploitation of Bonga by the purse seine fishery in the Cross River Estuary and adjacent coastal waters, Nigeria
Studies were conducted to assess the current level of exploitation of bonga in Cross River Estuary
and its adjacent coastal waters. Time series of length-frequency distribution of bonga over 18
months time scale was carried out. FAO-ICLARM Fish Stock Assessment Tool (FiSAT) was
employed to determine the population and growth parameters. The instantaneous rates of total
mortality,fishing mortality and natural mortality were 6.9 per year, 5.30 per year, and 1_61per year
respectively. The exploitation rate was 0.77. This implies that the stock of Efimbriata of Cross River
Estuary is experiencing excessive fishing pressure. This proposition is accentuated by the
downward trend in bonga abundance throughout the study period. The over fishing is attributed to
the Ghanaian purse seining, which even penetrates into the bonga nursery in the inner Cross River
estuary for destructive fishing. This phenomenon has exerted adverse socio-economic impact on
thelife of the people of lower Cross River basin whose main source of livelihood is bonga fishery. We
propose a ban on the purse seine fishery in Cross River Estuary
Positive emotion regulation strategies as mediators in depression and generalized anxiety disorder symptoms: A Transdiagnostic framework investigation
Positive emotion regulation (ER) strategies may contribute to the development and maintenance of generalized anxiety disorder (GAD) and depression; nonetheless, the underlying and transdiagnostic mechanisms are still unknown. To examine: 1) the mediating role of positive ER strategies in the relationship between ER deficits and experiential avoidance in GAD and depression symptoms; 2) differences in positive ER strategies among participants with elevated symptoms of GAD, depression, depression comorbid with GAD, and a nonclinical sample. 532 Tehran University students completed questionnaires assessing experiential avoidance, deficits in ER, positive ER strategies (dampening, positive rumination), and GAD and depression symptoms. Differences were assessed in four groups: GAD, depression, depression comorbid with GAD, and nonclinical. Data were analysed with path analysis and MANCOVA. Dampening and positive rumination mediated the relationship between deficits in ER and experiential avoidance in participants with depression and GAD symptoms. As for the between groups comparisons, the comorbid group obtained the highest scores on dampening and the nonclinical group the lowest. By contrast, nonclinical participants had the highest scores on positive rumination, whereas the comorbid group had the lowest. Positive ER strategies might be transdiagnostic variables. Dampening was more associated with psychopathology than positive rumination, suggesting that this strategy could be more clearly considered a transdiagnostic factor. Future studies with clinical samples must support this suggestion
Modeling Ultrasonically Assisted Convective Drying of Eggplan
[EN] Modeling constitutes a fundamental tool with which to analyze the influence of ultrasound on mass transfer phenomena during drying. In this work, the study of the effect of power ultrasound application on the drying kinetics of eggplant was addressed by using different models based on theoretical (diffusion) or empirical approaches. Drying kinetics of eggplant cylinders (height 20mm and diameter 24 mm) were carried at 40°C and 1 m/s applying different ultrasonic powers: 0, 6, 12, 19, 25, 31, and 37 kW/m 3. The experiments were carried out at least three times at each different ultrasonic power. Shrinkage and sorption isotherms were also addressed in order to attain an optimal description of eggplant drying. Applying ultrasound sped up the drying kinetics. The ultrasonic power was identified as having a significant (p<0.05) influence on both the effective moisture diffusivity and the mass transfer coefficient, which was well explained by linear relationships. The most complex model, which considered both external resistance and shrinkage to be significant phenomena, provided the best agreement with experimental data, giving percentages of explained variance of over 99.9% and mean relative errors of under 1.2% in every case. According to these results, ultrasound technology could have the potential to improve the convective drying of eggplant at an industrial scale. © 2011 Taylor & Francis Group, LLC.GarcĂa PĂ©rez, JV.; Ozuna LĂłpez, C.; Ortuño Cases, C.; Carcel CarriĂłn, JA.; Mulet Pons, A. (2011). Modeling Ultrasonically Assisted Convective Drying of Eggplan. Drying Technology. 29(13):1499-1509. doi:10.1080/07373937.2011.576321S149915092913Mujumdar, A. S. (2006). An overview of innovation in industrial drying: current status and R&D needs. Transport in Porous Media, 66(1-2), 3-18. doi:10.1007/s11242-006-9018-yChou, S. K., & Chua, K. J. (2001). New hybrid drying technologies for heat sensitive foodstuffs. Trends in Food Science & Technology, 12(10), 359-369. doi:10.1016/s0924-2244(01)00102-9Lewicki, P. P. (2006). Design of hot air drying for better foods. Trends in Food Science & Technology, 17(4), 153-163. doi:10.1016/j.tifs.2005.10.012Santos, P. H. S., & Silva, M. A. (2009). Kinetics ofL-Ascorbic Acid Degradation in Pineapple Drying under Ethanolic Atmosphere. Drying Technology, 27(9), 947-954. doi:10.1080/07373930902901950Suvarnakuta, P., Devahastin, S., & Mujumdar, A. S. (2005). Drying Kinetics and ÎČ-Carotene Degradation in Carrot Undergoing Different Drying Processes. Journal of Food Science, 70(8), s520-s526. doi:10.1111/j.1365-2621.2005.tb11528.xMayor, L., & Sereno, A. M. (2004). Modelling shrinkage during convective drying of food materials: a review. Journal of Food Engineering, 61(3), 373-386. doi:10.1016/s0260-8774(03)00144-4Gallego-Juarez, J. A. (2010). High-power ultrasonic processing: Recent developments and prospective advances. Physics Procedia, 3(1), 35-47. doi:10.1016/j.phpro.2010.01.006De la Fuente-Blanco, S., Riera-Franco de Sarabia, E., Acosta-Aparicio, V. M., Blanco-Blanco, A., & Gallego-JuĂĄrez, J. A. (2006). Food drying process by power ultrasound. Ultrasonics, 44, e523-e527. doi:10.1016/j.ultras.2006.05.181GarcĂa-PĂ©rez, J. V., CĂĄrcel, J. A., Riera, E., & Mulet, A. (2009). Influence of the Applied Acoustic Energy on the Drying of Carrots and Lemon Peel. Drying Technology, 27(2), 281-287. doi:10.1080/07373930802606428GarcĂa-PĂ©rez, J. V., CĂĄrcel, J. A., Clemente, G., & Mulet, A. (2008). Water sorption isotherms for lemon peel at different temperatures and isosteric heats. LWT - Food Science and Technology, 41(1), 18-25. doi:10.1016/j.lwt.2007.02.010Mulet, A. (1994). Drying modelling and water diffusivity in carrots and potatoes. Journal of Food Engineering, 22(1-4), 329-348. doi:10.1016/0260-8774(94)90038-8Cunha, L. M., Oliveira, F. A. R., & Oliveira, J. C. (1998). Optimal experimental design for estimating the kinetic parameters of processes described by the Weibull probability distribution function. Journal of Food Engineering, 37(2), 175-191. doi:10.1016/s0260-8774(98)00085-5Azzouz, S., Guizani, A., Jomaa, W., & Belghith, A. (2002). Moisture diffusivity and drying kinetic equation of convective drying of grapes. Journal of Food Engineering, 55(4), 323-330. doi:10.1016/s0260-8774(02)00109-7Simal, S., Femenia, A., Garau, M. C., & RossellĂł, C. (2005). Use of exponential, Pageâs and diffusional models to simulate the drying kinetics of kiwi fruit. Journal of Food Engineering, 66(3), 323-328. doi:10.1016/j.jfoodeng.2004.03.025Maroulis, Z. B., Saravacos, G. D., Panagiotou, N. M., & Krokida, M. K. (2001). MOISTURE DIFFUSIVITY DATA COMPILATION FOR FOODSTUFFS: EFFECT OF MATERIAL MOISTURE CONTENT AND TEMPERATURE. International Journal of Food Properties, 4(2), 225-237. doi:10.1081/jfp-100105189Simal, S., Femenia, A., Garcia-Pascual, P., & RossellĂł, C. (2003). Simulation of the drying curves of a meat-based product: effect of the external resistance to mass transfer. Journal of Food Engineering, 58(2), 193-199. doi:10.1016/s0260-8774(02)00369-2Queiroz, M. R., & Nebra, S. A. (2001). Theoretical and experimental analysis of the drying kinetics of bananas. Journal of Food Engineering, 47(2), 127-132. doi:10.1016/s0260-8774(00)00108-4Hassini, L., Azzouz, S., Peczalski, R., & Belghith, A. (2007). Estimation of potato moisture diffusivity from convective drying kinetics with correction for shrinkage. Journal of Food Engineering, 79(1), 47-56. doi:10.1016/j.jfoodeng.2006.01.025HernĂĄndez, J. A., PavĂłn, G., & GarcıÌa, M. A. (2000). Analytical solution of mass transfer equation considering shrinkage for modeling food-drying kinetics. Journal of Food Engineering, 45(1), 1-10. doi:10.1016/s0260-8774(00)00033-9Souma, S., Tagawa, A., & Iimoto, M. (2004). Structural Properties for Fruits and Vegetables during Drying. NIPPON SHOKUHIN KAGAKU KOGAKU KAISHI, 51(11), 577-584. doi:10.3136/nskkk.51.577GarcĂa-PĂ©rez, J. V., CĂĄrcel, J. A., de la Fuente-Blanco, S., & Riera-Franco de Sarabia, E. (2006). Ultrasonic drying of foodstuff in a fluidized bed: Parametric study. Ultrasonics, 44, e539-e543. doi:10.1016/j.ultras.2006.06.059CĂĄrcel, J. A., GarcĂa-PĂ©rez, J. V., Riera, E., & Mulet, A. (2007). Influence of High-Intensity Ultrasound on Drying Kinetics of Persimmon. Drying Technology, 25(1), 185-193. doi:10.1080/07373930601161070Blasco, M., GarcĂa-PĂ©rez, J. V., Bon, J., Carreres, J. E., & Mulet, A. (2006). Effect of Blanching and Air Flow Rate on Turmeric Drying. Food Science and Technology International, 12(4), 315-323. doi:10.1177/1082013206067352Garau, M. C., Simal, S., Femenia, A., & RossellĂł, C. (2006). Drying of orange skin: drying kinetics modelling and functional properties. Journal of Food Engineering, 75(2), 288-295. doi:10.1016/j.jfoodeng.2005.04.017Wu, L., Orikasa, T., Ogawa, Y., & Tagawa, A. (2007). Vacuum drying characteristics of eggplants. Journal of Food Engineering, 83(3), 422-429. doi:10.1016/j.jfoodeng.2007.03.030Chaves , M. ; Sgroppo , S.C. ; Avanza , J.R. CinĂ©ticas de secado de berenjena (Solanum melongenaL.). Comunicaciones CientĂficas y TecnolĂłgicas (Universidad Nacional del Nordeste Corrientes Argentina),2003,Resumen E-060 .Akpinar, E. K., & Bicer, Y. (2005). Modelling of the drying of eggplants in thin-layers. International Journal of Food Science and Technology, 40(3), 273-281. doi:10.1111/j.1365-2621.2004.00886.xDe Lima, A. (2002). Simultaneous moisture transport and shrinkage during drying of solids with ellipsoidal configuration. Chemical Engineering Journal, 86(1-2), 85-93. doi:10.1016/s1385-8947(01)00276-5RAHMAN, N., & KUMAR, S. (2007). INFLUENCE OF SAMPLE SIZE AND SHAPE ON TRANSPORT PARAMETERS DURING DRYING OF SHRINKING BODIES. Journal of Food Process Engineering, 30(2), 186-203. doi:10.1111/j.1745-4530.2007.00104.
High Impedance Fault Detection and Localization Using Fully-Connected Convolutional Neural Network: A Deep Learning Approach
The detection and localization of high impedance faults (HIF) in power systems are challenging due to the low fault current magnitude, which often falls below the detection threshold of conventional devices. HIF events introduce harmonics into the network, posing risks to the safety of connected equipment, including the potential for igniting fire which endangers lives and properties. In this study, Emanuel's HIF model was used to generate HIF signatures resembling real HIF events. Model parameters were adjusted to mimic various contact surface impedances. Two datasets were created: 'no-fault' data, simulating the network without HIF, and 'fault' data, incorporating HIF waveforms by simulating single and multiple lines with the HIF model. The faulted line was divided into five segments along the 33 kV line to capture fault signatures at different locations. The generated data, including current waveforms and magnitudes, were processed and divided into an 80:20 ratio for training, validation, and testing using a deep fully connected Convolutional Neural Network for HIF detection and location. The results showed an impressive accuracy rate of 99.44% and 99.78% for detection and location respectively, representing a significant advancement in HIF detection and location, and offering practical applications for enhancing power line safety
- âŠ