Irrigation and drainage in the new millennium

Presented at the 2000 USCID international conference, Challenges facing irrigation and drainage in the new millennium on June 20-24 in Fort Collins, Colorado.Includes bibliographical references.A field study was conducted at Mashtul Pilot Area MPA (260 feddans' 1 feddan = 4200 m2) situated at north Zagazig to evaluate the performance of the long term constructed subsurface drainage system. The evaluation of grades, alignment and clogging of drain lines can give an indication of the system performance and efficiency. Three drainage units served by the same collector were selected. Four 30 m interval PVC lateral pipes were installed at different depths. The results revealed that, the collector drain slopes were either steep or flat while the overall slope of the collector drain was considered steep for about 45.50% of the sections and flat for the rest. On the other hand, some sections showed an inverse slope which can cause a decrease in the discharge rate. The regularity was classified as good for about 82% of the sections and moderate for the rest. The slope of the lateral drains was correct for 41.7% of those under study (12 lateral drains), steep for 16.60%, and flat for the rest, and the regularity was classified as poor except lateral number 71 which had moderate regularity in the first approach while, in the second approach 41.67% had moderate regularity and poor for the rest. Also the deviation of the drain pipes from the straight line was generally larger than pipe diameter. Consequently, air entrapment and sedimentation resulted. The results also indicated that, the average height of sedimentation inside lateral drains was 12.70 mm (618.30 gm/m drain length) while for collector drains, sediment was in 22.88% of pipe diameter. The average reduction in discharge capacity due to sedimentation for laterals and collectors upstream and downstream parts were 17.17%, 32.80% and 17.60% respectively. Also using Manning, Visser and Wesseling equations leads to different safety factors

FARMERS’ BEHAVIORAL INTENTIONS TO USE MOBILE EXTENSION IN ASSIUT GOVERNORATE

Sixteen flax genotypes {13 promising lines This study aimed at: (1) knowing about farmers’ views about advantages, disadvantages of mobile extension service and their suggestions to make this prospective initiative succeed; (2) discovering farmers’ behavioral intentions to use mobile extension service in Assiut governorate; (3) determining the kind of information that farmers will need by using mobile extension service; (4) examining the effect of the six antecedents proposed by Nysveen et al(2005a) on farmers’ behavioral intentions to use mobile extension service. Data were collected by questionnaire from 233 farmers randomly selected from two villages in Assiut governorate. The results showed the advantages, disadvantages of mobile extension service from the viewpoint of the respondents and their suggestions to make this prospective initiative succeed. It came out that the respondents have positive intentions to use mobile extension, and their prospective behavior proceeds to use mobile extension service if it comes into existence. It cleared up that the information needs of farmers by using mobile extension were related to market information (prices, and demand indicators) and know-how information (what to plant and which seed varieties to use). It became clear that the model of Nysveen et al (2005a) was overall significant and the six antecedents of behavioral intentions significantly explains 71% of variance in farmers’ behavioral intentions to use mobile extension service. Finally, based on the results of this study, major recommendations are derived for the potential producers when developing the prospective mobile extension servic

REFORMING AGRICULTURAL EXTENSION IN EGYPT FROM THE VIEWPOINT OF CENTRAL LEVEL EXTENSION EMPLOYEES

This study explored the opinions of central level extension employees about whether the Egyptian agricultural extension system needs to be reformed or not, and the alternatives they consider to be the best-fit options for extension in Egypt. The study covered 98 extension employees at the central level; findings show that all aspects of the Egyptian extension system are good candidates for reform and possible restructuring. These aspects could be ranked as financing, policy & organizational structure, staffing, and field operations as reported by 100%, 95%, 91%, and 68% of the respondents, respectively. Concerning the overall extension system, about 91% of the respondents reported that the Egyptian extension system is a good candidate for reform and possible restructuring. Findings also show that devolution, deconcentration, and delegation were the appropriate arrangements for extension decentralization as mentioned by 85%, 82%, and 55% of the respondents, respectively. Moreover, alternatives of providing and financing extension services were suggested and prioritized

Relative Rate Observer Self-Tuning of Fuzzy PID Virtual Inertia Control for An Islanded microgrid

Expanding the usage of renewable energy in islanded microgrids leads to a reduction in its total inertia. Low inertia microgrids have difficulties in voltage and frequency control. That affected saving its stability and preventing a blackout. To improve low inertia islanded microgrids\u27 dynamic response and save their stability, this paper presented relative rate observer self-tuning fuzzy PID (RROSTF-PID) based on virtual inertia control (VIC) for an islanded microgrid with a high renewable energy sources (RESs) contribution. RROSTF-PID based on VIC\u27s success in showing remarkable improvement in the microgrid\u27s dynamic response and enhancement of its stability. Moreover, it handles different contingency conditions successfully by giving the desired frequency support. Ant colony optimization (ACO) technique is used to find the optimal values of the RROSTF-PID based on VIC parameters. Furthermore, using MATLAB TM/Simulink, RROSTF-PID based on VIC response is compared to Optimal Fuzzy PID (OF-PID) based VIC, Fuzzy PID (F-PID) based VIC, PID-based VIC, conventional VIC responses, and the microgrid without VIC response under different operation conditions

Evaluation of selective peripheral neurotomies in the treatment of refractory lower limb spasticity in adults

Background: ‘‘Selective peripheral neurotomies” (SPNs) are indicated for the treatment of refractory focal and multifocal spasticity of lower limbs in adults.Objective: To evaluate the surgical results of selective peripheral neurotomies in 20 adult patients who had refractory focal & multifocal spasticity of the lower limbs, follow up period of one year.Patients and Methods: Prospective study included 20 adult patients who had refractory spasticity of the lower limbs. Preoperative evaluation for muscle tone using Modified Ashworth Score (MAS), muscle power using Medical Research Council Scale (MRCS), functional assessment using Oswestry Functional Scale (OFS) and Range Of Motion (ROM) using manual goniometry were done for all patients. All cases underwent surgery in the form of SPN of tibial, obturator, sciatic and/or femoral nerves. Follow up of the patients was done at 10th day, 3, 6 months and one year postoperatively.Results: The mean age of patients was 31.35 ± 12.42 years. There were statistically significant improvement of muscle tone, muscle power, functional assessment and range of motion between preoperative and one year postoperative values. Improvement of the muscle tone was from a preoperative Mean ± SD of 3.60 ± 0.68 on MAS to a postoperative 2.30 ± 0.86 at one year, improvement of muscle power on MRCS was from preoperative Mean ± SD 3.75 ± 1.08 to postoperative 4.08 ± 0.69 at one year, There was a functional improvement from a preoperative Mean ± SD of 3.0 ± 0.73 on OFS to 3.60 ± 0.60 at one year postoperatively. Also, there was a significant improvement between preoperative ROM Mean ± SD 61.25 ± 15.29 and one year postoperatively 72.25 ± 12.19.Conclusions: Selective peripheral neurotomies could effectively improve muscle tone, muscle power, functional performance & range of motion in patients with refractory focal and multifocal spasticity in the lower limbs.Keywords: Selective peripheral neurotomies, Spasticity, Neuroablative surgeries, Functional neurosurger

Effect of Shape, Orientation and Aging of a Plastic Greenhouse Cover on the Degradation Rate of the Optical Properties in Arid Climates

In arid climates, the optical properties of plastic-covered greenhouses deteriorate very quickly. To examine the effect of greenhouse shape and orientation on the degradation rate of cover optical properties, four greenhouse prototypes were constructed in two shapes (duo-pitched roof and tunnel), covered with a 200  m thick low-density polyethylene film. Two types were oriented in the North–South direction, the other two in the East–West direction, and all were exposed for one year to an arid climate. Samples were taken from the different surfaces of each cover for testing. The total transmittance (Ts) and reflectance (Rs) of the samples were measured and averaged to obtain the whole cover properties (T and R). Measurements were carried out periodically every 30 days for the four prototypes. The degradation behavior of the optical properties of each cover surface (Ts, Rs) and the whole cover (T, R) was investigated for the four film covers during the exposure time. Results show that the degradation rate of Ts depends on the surface location and the cover orientation. Among the different surfaces of the four prototype covers, the maximum difference in the Ts value between the E and N surfaces for the tunnel cover oriented in the N–S direction was 15.5%. Although the variation of the Ts value among the different cover surfaces was found, the time dependences of the whole cover transmittance (T) for the four covers tested were almost similar. Accordingly, the shape and orientation of the small size greenhouses did not significantly affect the degradation rate of the cover optical properties. In the four covers tested, the reduction in the global solar radiation transmittance (T) was 27–31% after one-year exposure compared to the new film. Nonlinear correlation was developed to predict the degradation rate of the cover transmittance as a function of the accumulated solar irradiance

Radiometric Characterization, Solar and Thermal Radiation in a Greenhouse as Affected by Shading Configuration in an Arid Climate.

Shading the greenhouses is necessary in summer to reduce the solar radiation load. This however generates a considerable amount of thermal radiation heat load that needs to be removed via cooling systems. This study aimed to evaluate the effect of different shading configurations on the solar and thermal radiation in a greenhouse. Nets at four different locations were employed to shade the roof and side-walls of a polycarbonate, mechanically ventilated greenhouse. The spectral radiative properties of all these plastic materials were measured in short and long wave spectrum bands. The net solar and thermal radiations and air temperature were measured outside and inside two identical shaded and unshaded greenhouses. The results showed that external roof-shading is desirable, as it reduced the generated thermal radiation in the greenhouse by 21% and 15% during the day and night time, respectively and reduced the greenhouse air temperature during the day. The internal shading (roof and side walls) is undesirable, since it drastically increased the generated thermal radiation in the greenhouse by 147% and strongly increased the greenhouse air temperature during the day. Shading the side-walls is not recommended because it significantly reduces the transmitted solar radiation in the morning and afternoon (when the outside irradiance is low) and is useless at around noon when the outside irradiance is extremely high

Sustainable Multi-objective Optimisation in Land-use Planning based on Non-dominated Sorting Genetic Algorithm (NSGA-II): a Case Study in Alexandria, Egypt

Due to urban sprawling, the world’s land-use patterns have rapidly changed, leading to conflict and competition among urban land-uses. This conflict resulted in a range of inefficient land-use patterns. The negative impacts of such patterns suggest the need to improve the efficiency of land-use planning strategies to support better sustainable development. To attain such efficiency, many researchers have adopted algorithmic approaches perceiving land-use planning as a multi-objective optimization problem. These approaches allow encompassment of the numerous variables and constraints that are introduced in the planning process by decision makers and stakeholders. In this regard, a meta-heuristic method; the Nondominated Sorting Genetic Algorithm (NSGA-II), could provide an efficient decision support tool for landuse planning through offering pareto optimal land-use allocation alternatives. This paper aims at adopting NSGA-II to enhance sustainable land-use planning strategies at a neighborhood scale in the city of Alexandria, Egypt. The research suggests the adaptation of the Constrained Multiobjective Optimization of Land-use Allocation model (CoMOLA) for three main objectives: (i) maximizing the value of economic benefit, (ii) spatial compactness, and (iii) land-use compatibility. Several land-use allocation scenarios are investigated through an iterative process which includes the variables of spatial units’ number, population sizes and significance of allocation objectives. The scenarios are then compared to the existing condition of land-use distribution. The results show that the proposed approach using CoMOLA tool exhibits good potential to support interactive land-use planning processes by searching over multiple plans for optimal sets of non-dominated solutions. The optimized results could provide the scientific basis for defining suitable interventions for improving sustainability measures and spatial optimization of landuses at the neighborhood scale