Department of Agricultural Engineering

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    Agricultural Tractor Fuel Consumption Estimation By Computer Programming
    (University of Khartoum, 2015-06-16) Tarig Hassab Allah Talha ; Mohmmed Hassan Dahab ; Department of Agricultural Engineering
    A computer model was developed to estimate fuel consumption rate in liter per hour, for tractor only and tractor with implement under different soil conditions The program enables the user to insert the input data through the screen , and obtain the output easily The validity of the model was tested using data from private agricultural company in sudan , for two types of heavy disc harrow (AH280,BH360), (H56,CH65C) with challerger tractors, seeder, and ridger.it was also tested by data form Sennar center for agricultural services using heavy disc harrow + 4WD tractor . The sensitivity analysis showed that the change in any input parameter eg., Speed, unit draft, engine power ,soil transmission coefficient and soil conditions affected the fuel consumption rate estimation. Accordingly, the computer program run and performed very well in estimating fuel consumption for proper machinery performance. This model can be used as a good help to the farm in machinery management and decision making
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    Asimulation Model for Designing and Testing A solid set Sprinkler Irrigation System
    (University of Khartoum, 2015-06-16) Elnijomy, Mohammed Abdelrahman M. ; Amir Bakheit Saeed ; Agricultural Engineering
    Magnetic water treatment devices consist of one or more magnets which are clamped onto or installed inside the incoming residential water supply line. Some of its additional claims is to decrease the water effective hardness therefore softening water and improving plant growth. A wide variety of magnetic water treatment devices are available but most consist of one or more permanent magnets affixed either inside or to the exterior surface of the incoming water pipe. The water is exposed to the magnetic field as it flows through the pipe between the magnets.
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    Aspects of Guar Mechanical Harvesting
    (University of Khartoum, 2015-06-25) Mohamed El Hafiz Adam Mohamed ; Abd El Moneim El Amin Mohamed ; Agricultural Engineering
    A set of experiments was conducted under rainfed conditions, at the Sudanese- Canadian Project, 160 km South of Gedarif during 1992/93 and 1993/94 growing seasons to study planting and harvesting methods of guar. HFG-53 cultivar was used to investigate two mechanical harvest methods as alternative approaches towards alleviating the many problems and difficulties associated with the traditional hand harvesting, and hence new production prospectives. Two mechanical harvest methods, viz. direct combining (D.C) arid windrow combining (W.C), were tested against five seeding rates, viz. 2.5, 5.0, 7.5, 10.0 and 12.5 kg/fed to determine the best combination that would help attaining the maximum total and net yields. A John Deere press drill was used to sow the crop on a seedbed that had been post-harvest tilled by an offset disc harrow and further treated by a Frigstad chiesel plough as a secondary tillage operation. A conventional header was used for direct combining, while a digger -shaker- windrower, with subsequent windrow combining using a pickup header attachment were the relevant stages of the second harvest method (window combining). A Massey Ferguson 760 self-propelled combine was used for threshing. A split-plot design experiment was conducted with harvest methods as main plot factor and seeding rates as sub-plot factor. Yield components and relevant harvest losses as well as total and net yields were the major observations that emphasized during the study. Yields and losses were considered as dependant variables, while harvest methods and seeding rates as independent variables. Statistical analysis revealed that, harvest method has a significant effect on shoe, walker, total discharge, gathering and total losses in both seasons except for shoe and total discharge. On the other hand, seeding rates have significant effect on cylinder and gathering losses in both seasons ,but on total discharge(processing) 1osses in first season, while its effect on pre-harvest and total losses was in the second season. Both harvest methods and seeding rates have a significant effect on net yield at (P≤0.05 and p≤0.01) respectively) in both seasons. While total yield was significantly affected by seeding rates (P≤0.01) in both seasons, but only in the first season that it was found to be affected by harvest method (P≤0.05). Gathering losses represented the major component of total losses. Mean values obtained during direct combining were 6-10.5% of total yield compared to 35-47.5% for windrow combining. Total losses were about 6.4-15% and 37.7-54.8% for direct and windrow cornicing respectively. Total discharge losses did not reach 1% of total yield. Impurities were 4.2-5.7% for direct combining compared to 31.9-43% for windrow combining. The highest total yield was 427.53 kg/fed. and obtained at 10.0 Kg/fed. seeding rate in the first season, compared to 393.83 kg/fed. in the second season at the seeding rate of 12.5 kg/fed. The highest net yield was 484.8 and 491.4 kg/fed. from direct combining compared to 180.0 and 200.9 kg/fed. for windrow combining in both seasons. It was evident that, direct combining resulted in the highest total and net yields at the seeding rate of 10.0 kg/fed., while windrow combining reduced both quantity and quality (up to 43% impurities).
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    Aspects of Sprinker - Irrigation Application in the Sudan
    (University of Khartoum, ) Konda, Khamies Kajo ; Tafwig F.Demian ; Agricultural Engineering
    Aspects of Sprinker - Irrigation Application in the Sudan
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    Assembling And Performance Evaluation of Centre Pivot Irrigation System New Hamdab Irrigation Project Northern State, Sudan
    (University of khartoum, 2015-06-16) Zuhair Abdalmalik Elhassan ; Amir Bakheit Saeed ; Agricultural Engineering
    This study was conducted at new Hamdab agricultural project, one of the newly established resettlement projects associated with the implementation of Merowi Dam. The project lies on the western bank of the River Nile in the Northern state about 300 km north of Omdurman. Following the innovation technologies in the irrigation systems world wide, this study has come to make a comparison between modern irrigation systems and traditional ones in aspects of operation costs, irrigation water requirement and expected yield. The study comprised an updated comprehensive survey on the centre pivot systems introduced in Sudan; then assembling five Zimmatic centre pivot systems on predetermined locations on the sandy area (high terrace) of new Hamdab project. The systems were then evaluated for hydraulic performance namely, uniformity coefficient (Cu), distribution uniformity (Du) and application efficiency (Ea). The centre pivot system was then compared with surface irrigated field plots (pilot farm) while considering the traditional method (tenant field) as a control and wheat as an indicator crop. The centre pivot system wwhen run at two speeds (40% and 100%) respectively gave the following results: 1- Uniformity coefficient (Cu) 75% and 85%. 2- Distribution uniformity (Du) 60% and 76%. 3- Application efficiency (Ea) 53% and 47%. . With respect to wheat growth parameters and yield attributes, the centre pivot irrigation system showed highly significant difference over the pilot farm and the tenant farms, the average productivities of wheat per feddan were respectively: 1532 kg, 464kg, 159 kg for center pivot, pilot farm and tenant farm. On the other hand records of water consumed per feddan per season were 5344 m3 for the centre pivot and 9306 m3 for either one of pilot farm and tenant’s farm. The study clearly shows that center pivot irrigation system has gave prospects particularly in the high terrace soils in north Sudan.
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    Assessment of the Performance of a Landscape Drip Irrigation Systems-Khartoum State
    (University of khartoum, 2015-06-17) Asia Osman Mohammed Ahmed ; Abdel Moniem Elamin Mohamed ; Agricultural Engineering
    The study was conducted during the period from October 2007 to May 2008. The objective of the study was to evaluate the performance of some landscape drip irrigation systems in Khartoum city. The variables which were tested included the hydraulics, management and operation of the systems. The hydraulic parameters of the systems studied were the assessment of the variations in the operating pressure in the different hydro zones and at the heads and tails of laterals. The discharge variations in hydro zones and laterals were also determined. Efficiency indices determined were the coefficient of uniformity, uniformity of distribution and scheduling efficiency. The experimental design adopted was the complete randomized block design with four replications of each treatment. The emitters used had a rated discharge of 1.8l/h. Variations of pressure along the laterals were found to be negligible. The variation in discharge ranged between 1 to 13% for all laterals. The variation was within the accepted values for good design (for lateral A). The uniformity of distribution (Du) was found to be 89% and the coefficient of uniformity determined was found to be 90%. These results were in the range of the recommendations for good drip irrigation system design.
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    Assessment of the Suitability of Raised Bed – Furrow Irrigation Technique in Saving Water for Wheat Production in New Halfa Area, Sudan
    (University of khartoum, ) Mohamed Yousif Daffalla Ebdelrahman ; Abdelmoneim Elamin Mohamed
    Three separate experiments were conducted through the period 2013-2016 in the Agricultural Research Station farm in New Halfa, eastern Sudan. The objectives of the study were to assess the suitability of raised bed planting for wheat crop production, as a technique to save irrigation water and increase water productivity (water use efficiency) and to determine the suitable raised bed dimensions and number of crop rows per bed. In the first experiment four sowing methods (Raised bed planting BP, Seed drilling SD, Broad Casting BC and Wide Level Disc WLD), four quantities of irrigation water (3000 W3, 4000 W4,5000 W5 and 6000 m³/ha W6 ), two wheat varieties (Bohain and Imam) (120kg/ha) and two weed control treatments ( herbicides treated and untreated) were examined . In the second experiment the four sowing methods, four seeding rates (SR84, SR96, SR120 and SR144 kg/ha), two wheat varieties (Bohain and Imam) and two weed control (herbicides treated and untreated) were compared. The two experiments were laid in split- split plot design with three replications. GenStat12.1 program was used for data analysis. In the third experiment Raised beds of different bed widths (80, 100 and 120cm), furrow depths (15cm and 25cm), furrow widths (30 and 40 cm) were compared with the conventionally used seed drilling on flat surface. The experimental design adopted was the Randomized Complete Block Design (RCBD) with three replications. Data was statistically analyzed using Statistix 10 program. The Duncan’s Multiple Range Test (DMRT) was used for the separation of means in all the experiments. Results showed that raised bed planting technique, herbicides treated, for the two varieties gave higher grain yield of wheat crop than the other sowing methods. Using less volume of irrigation water (4000 m³/ha), raised bed planting technique gave the same or higher yield than what was given by the other sowing methods using more volume of irrigation water (5000 - 6000 m³/ha), thus saved 20 - 33% of irrigation water. Using less seeding rate raised bed planting technique gave the same or higher yield than what was given by the other sowing methods by more seeding rate ,thus saved 20- 33% of seeds. Raised bed planting technique gave higher water productivity and less irrigation water irrespective of bed width and furrow dimensions, than seed drill on flat land. The 120 cm bed width used less irrigation water, higher water saving percentage but lower grain yield and lower water productivity than the 80 cm bed width due to the poor wetting pattern at the middle rows resulting from the too wide bed width. The combination 80 cm bed width, 25 cm furrow depth, 40 cm furrow width with 3 crop rows gave grain yield more than that given by seed drills by 42%, high water productivity (1.3 kg/m³) and less irrigation water by 13%. While seed drill sowing method with basin irrigation resulted in high applied water, intensive weed infestation, low grain yield, low water productivity and more irrigation water by 17%. Raised bed planting system had no negative impact on soil salinity or on the main soil nutrients (NPK). The study recommended use of raised bed of 80 cm bed width, 25 cm furrow depth, 40 cm furrow width with 3 crop rows for wheat production in New Halfa area as a water saving technique and high water use efficiency. تم اجراء ثلاثه تجارب منفصله خلال الفتره 2013- 2016 في مزرعة محطة البحوث الزراعية بحلفا الجديده، شرق السودان بغرض معرفة مدى ملاءمة نظام الزراعه على المساطب العالية لانتاج القمح و كتقنية لتوفير مياه الري و رفع كفاءة انتاجية الماء (كفاءة استخدامها). كذلك بغرض تحديد الابعاد المناسبه للمسطبه و بطن المسطبه بالاضافه لتحديد عدد صفوف المحصول علي ظهر المسطبه. في التجربة الأولى تمت المقارنة بين أربعة طرق لزراعة القمح وهي طريقة الزراعة على المساطب العالية، طريقة الزراعه بالسطارة، طريقة النثر ثم التسريب وطريقة الزراعة بالقرص العريض وبين أربع كميات من مياه الري وهي 3000 ، 4000 ، 5000 و6000 متر3/فدان و صنفين مجازين من القمح هما بوهين وإمام بمعدل بذر120 كجم/هكتار وطريقتين لمكافحة الحشائش هما الرش بالمبيدات وعدم الرش. التجربة الثانية تضمنت نفس معاملات التجربة الأولى الا ان كميات مياه الري في التجربة الأولى قد استبدلت بأربع معدلات تقاوي هي 84 ، 96 ، 120 و144 كجم/هكتار. المعاملات في التجربتين قد وضعت في تصميم القطع المنشقة في ثلاثة مكررات، تم تحليل البيانات بواسطة برنامج GenStat12.1. في التجربة الثالثة تمت المقارنة بين ثلاثة أبعاد لعرض المسطبة وهي 80 ، 100 و120 سم وبين عمقين لبطن المسطبة هما 15 و25 سم وبين عرضين لبطن المسطبة هما 30 و40 سم والزراعه بواسطة السطارة تم وضع المعاملات في تصميم القطاعات العشوائية الكاملة في ثلاث مكررات. وتمت زراعه صنف واحد هوالصنف بوهين بمعدل بذر120 كجم/هكتار. تم تحليل البيانات بواسطة برنامج Statistix 10 كما تم استخدام اختبار دنكن لتحديد اقل فرق معنوى بين المتوسطات في كل التجارب. اظهرت النتائج ان نظام الزراعة في المساطب العالية ، المعامل بمبيدات الحشائش، أعطى نفس الانتاجيه او اعلي بالنسبة لوحدة المساحة و وحدة المياه في الصنفين باستعمال كمية مياه أقل (4000 متر3/هكتار) من التي تم تحقيقها بالطرق الأخرى بكميات مياه أعلى (5000- 6000 متر3/هكتار ) مما أدى الى توفير 20-33 % من مياه الري. اوضحت النتائج كذلك ان الزراعة بنظام المساطب العالية قد اعطت نفس الانتاجيه أو اكثرباستعمال معدل بذر أقل من التي تم تحقيقها بالطرق الاخرى بمعدلات بذر أعلى مما أدى الى توفير 20-33 % من البذور. كذلك أشارت النتائج بان طريقة الزراعة على المساطب العالية بغض النظر عن أبعاد المسطبة وبطن المسطبة قد نتج عنها كفاءة أعلي لاستخدام مياه الري و استهلاك مياه أقل مقارنة بالزراعة بالتسطير على السطح و الري بالغمر. المسطبة بعرض 120 سم نتج عنها اقل استهلاك لمياه الري و بالتالي نسبة توفير لمياه الري أعلى مقارنة بالمساطب بابعاد 80 و100 سم ولكنها أعطت إنتاجية أقل بالنسبة لوحدة المساحة و وحدة المياه وذلك لضعف البلل في منطقة وسط المسطبة بسبب العرض غير المناسب للمسطبة. التركيبة مسطبة بعرض 80 سم، بطن مسطبة بعمق 25سم و عرض 40 سم و ثلاثه خطوط محصول علي ظهر المسطبة قد اعطت أنتاجية أعلي بحوالي 42% مقارنة بالزراعة بالتسطير و الري بالغمر. و أعلى إنتاجية بالنسبة لوحدة مياه الري 1.3 كجم/م3، و كمية أقل من مياه الري بنسبة 13%. في حين ادت طريقة الزراعة بالتسطير و الري بالغمر الي استهلاك حجم أكبر من مياه الري بنسبة 17% ,مما أدي إلى تدني الإنتاجية بسبب كثافة نمو الحشائش. اشارت النتائج الي ان طريقة الزراعة علي المساطب العالية لم تؤدي الي اي تغيير سلبي في ملوحة التربة أو في العناصر الرئيسية (النيتروجين،الفوسفور و البوتاسيوم). توصي الدراسة باستخدام نظام الزراعة بالمساطب العالية بالتركيبة: مسطبة بعرض 80 سم، بطن مسطبة بعمق 25سم و عرض 40 سم و ثلاثه خطوط محصول علي ظهر المسطبة لزراعة محصول القمح في منطقة حلفا الجديدة كوسيلة لتوفير مياه الري و رفع كفاءة استخدامها.
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    Biomimentic Computer Simulation Design of Moldboard Plough Surface and Application for Three Types of Soil In Kordofan Area
    (University of Khartoum, 2015-11-03) Abden Eldi Salim Ahemed ; Mohamed Hassan Dahab Ahmed ; Agricultural Engineering
    The present study was conducted at Elobied, North Kordofan State, during the period 2011-2013 in three locations; namely, Aldago, Khor Taggat and Algambali near Eobied town. The objectives of the study were to (i) examine the geometrical structure on the body surface of mole cricket as a soil burrowing insect, (ii) determine the physical and mechanical properties of the soil (iii) modify moldboard surface biomimetically in ANSYS program by modeling the structures found on the body surface of mole cricket on inner surface of the implement, and (iv) conduct a computer simulation for conventional smooth surface moldboard and biomimentically non smooth surface moldboard using the Finite Element Method (FEM) with ANSYS program to study stresses distribution on the two implement surfaces. A field experiment was carried out to compare the conventional smooth and modified non smooth surface moldboard by measuring the performance parameters, such as implement draft force, pressure on tool surface, tractor rear wheel slippage, and fuel consumption rate on the three types of soil. The body surface of mole cricket was examined under microscope and found to be composed of convex domes and stepped ridges structures. The cylinder test method of soil showed that the values of soil bulk density were 1.9 g/cm3, 1.5 g/cm3 and 1.3 g/cm3 for Aldago, Khor Taggat and Algambali location, respectively, while the triaxial compression test of soil samples demonstrated that the values of soil cohesion were 15.3 kPa, 10 kPa and 7 kPa for same location in sequence, and the values of internal angle of soil friction were 200 for Aladgo, 310 for Khor Taggat and 340 for Algambali. The soil test indicated that the soil types are clay, gardud (clayey sand) and sand for Aldago, Khor Taggat and Agambali location, respectively. The physical and mechanical properties were used to model the convex domes on the implement surface similar to those structures found on body surface of mole cricket as input. The computer simulation was then conducted to study stresses distribution on two moldboard surfaces. The simulation results showed that the equivalent stress values in case of conventional smooth surface moldboard were 10.20 kPa, 10.25 kPa and 8.72 kPa for clay, gardud and sandy soil, respectively, while the values recorded by biomimetic non-smooth surface moldboard with convex domes were 10.35 kPa, 10.32 kPa and 13.12 kPa for the same soil type in sequence. The values of shear stress in XZ plane (plane of motion), in case of conventional smooth surface moldboard, were 33.20 kPa, 22.11 kPa and 16.02 kPa in clay, gardud and sandy soil, respectively, while the values recorded by biomimetic non-smooth surface moldboard with convex domes were 24.50 kPa, 18.00 kPa and 11.23 kPa for the same soil type in sequence. The results of field experiment demonstrated that the biomimetic non smooth surface with convex domes reduced the draft force by 0.8 kN, 0.6 kN and 0.9 kN in clay, gardod and sandy soil, respectively, while the values of pressure on bottom surface in case of conventional smooth surface were 20.00 kPa, 14.44 kPa and 10.00 kPa in clay, gardud and sandy soil, respectively, while the values recorded by biomimetic non-smooth surface with convex domes were 15.56 kPa, 11.11 kPa and 5.00 kPa for the same soil types in sequence.The rear wheel slippage in case of non smooth surface with convex domes was reduced by 12.5 %, 3.8 % and 9.7 % in clay, gardud and sandy soil, respectively, as compared with conventional smooth surface. Fuel consumption rate in case of biomimetic non smooth surface with convex domes was reduced by 9.3 L/ha, 6.7 L/ha and 10 L/ha as compared with conventional smooth surface in clay, gardud and sandy soil, respectively. The differences between the two surfaces for all performance parameters were significant at P  0.01. It can be concluded that the biomimetically modified with convex domes moldboard surface reduces the stresses distribution and the field performance parameters. It is recommended that the biomimetic modification of soil engaging components of agricultural machineries should be adopted to improve their performance. Also, the computer simulation technique has to be implemented to investigate the stresses distribution and deformations to which the tool is subjected so as to select the optimum design before conducting the field work. أجريت هذه الدراسة في الابيض ولاية شمال كردفان فى الفترة من 2011 الى 2013م في ثلاثة مواقع هى الداجو وخورطقت والقمبلي بالقرب من مدينة الابيض. هدف البحث إلى دراسة الأشكال الموجودة على سطح حشرة صرصور الغيط الحفار وتعيين الخواص الميكانيكية والفيزيائية للتربة فى المواقع الثلاثة وتحوير سطح محراث مطرحي بتطبيق المحاكاة الحيوية فى برنامجANSYS وذلك بنمذجة الأشكال التى رُصدت على سطح جسم الصرصور على السطح الداخلي لنموذج المحراث، وإجراء محاكاة حاسوبية للمحراث المطرحي ذو السطح التقليدى الأملس والمحور غير الأملس باستخدام طريقة العناصر المنتهية ببرنامج ANSYS لتعيين توزيع الإجهادات على سطحي المحراث، إجريت تجربة حقلية لقياس متغيرات الأداء كقوة الجر والضغط على سطح المحراث وإنزلاق العجل الخلفي للجرار ومعدل استهلاك الوقود لسطح المحراث المطرحي التقليدي الأملس والمحور غير الأملس وتكرار قياس متغيرات الأداء فى أنواع التربة الثلاثة. أُختبر سطح جسم الصرصور تحت المجهر ووجد أنه يحتوي على أشكال قببية محدبة وسرابات مدرجة. أُستخدمت طريقة الأسطوانة لتحديد الكثافة الظاهرية للتربة ووُجد أنها 1.9 g/cm3 و1.5 g/cm3 و1.3 g/cm3 لكل من موقع الداجو وخور طقت والقمبلي على التوالي, بينما أظهر إختبار الضغط ثلاثي المحاور أن قيم تماسك التربة كانت 15.3 kPa و10 kPa و7 kPa لنفس الترتيب للمواقع الثلاثة،وبلغت قيم زاوية الإحتكاك الداخلى 200 فى الداجو و310 فى خورطقت و340 في القمبلي. أشارت الإختبارات الى أن أنواع التربة هي الطينية والرملية الطينية والرملية للداجو وخور طقت والقمبلي على التوالي. اُستخدمت الخواص الفيزيائية والمكانيكية للتربة كمدخلات لنمذجة اشكال قببية محدبة كتلك التي رصدت على سطح جسم الصرصور أظهرت نتائج المحاكاة أن قيم الاجهاد المكافئ لسطح المطرحة التقليدي الأملس كانت 10.20 kPa و10.25 kPa و8.72 kPa للتربة الطينية والقردودية والرملية على التوالي. وبالنسبة لسطح المطرحة المحور غير الأملس فكانت قيم الإجهاد المكافئ 10.35 kPa و10.32kPa و13.12 kPa فى حالة التربة الطينية والقردودية والرملية على التوالي. أما قيم إجهاد القص فى التربة الطينية والقردودية والرملية فى المستوى XZ (مستوى الحركة) فى حالة السطح التقليدي الأملس فكانت 33.20 kPa و22.11 kPa و16.02 kPa على التوالى، أما فى حالة سطح المحراث المحور غير الأملس فكانت القيم 24.50 kPa و18.00 kPa و11.23 kPa لنفس الترتيب لأنواع التربة. بينت نَتائِج التجربة الحقلية أنَّ السطحَ غير الأملس ذو القبب المحدبة خفض قوة الجر بمقدار 0.8 kN و kN 0.6 و0.9 kN فى التربة الطينية والقردودية والرملية على التوالى وأظهرت النتائج ان قيم الضغط للسطح التقليدي الأملس للمحراث كانت 20.00 kPa و14.44 kPa و10.00 kPa للتربة الطينية والقردودية والرملية على التوالي. أما للسطح المحور غير الأملس فكانت15.56 kPa و11.11kPa و5.00 kPa لنفس الترتيب لأنواع التربة. قلل سطح المحراث المحور غير الاملس ذو القبب المحدبة من إنزلاق العجل بمقدار 12.5% و3.8% و9.7% للتربة الطينبة والقردودية والرملية على التوالي بالمقاربة مع السطح التقليدى الأملس, كما قلل المحراث ذو السطح المحور غير الأملس معدل استهلاك الوقود بمقدار9.3 L/ha و6.7 L/ha و10 L/ha مقارنةً بالمحراث التقليدي ذو السطح الأملس وذلك للتربة الطينية والقردودية والرملية على التوالي. هنالك فرق معنوي (P  0.01) بين السطحين الأملس وغير الأملس في قيم متغيرت الأداء الحقلي. يُستنتج من الدراسة أن المحراث ذو السطح المحور غير الأملس يقلل من توزيع الإجهادات وقيم متغيرات الأداء الحقلي. توصي الدراسة بتبني تقنية المحاكاة الحيوية لأجزاء الآلات الزراعية المتعلقة بالتربة لتحسين أداء تلك الأجزاء. علاوة على ذلك, يُوصى بتطبيق تقنية المحاكاة الحاسوبية للتحقق من توزيع الإجهادات والتشوهات التي تتعرض لها الآلة بهدف إختيار التصميم الأمثل قبل إجراء العمل الحقلي .
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    Biscuits from Composite Flour of Wheat and Sorghum
    (University of Khartoum, 2015-05-10) Ibtihag Awad Abdalla Mahmoud ; Paul Lado Bureng ; Agricultural Extension and Rural Development
    The study is designed to assess the effectiveness of perceived benefits from ACORD's smallholders assistance project, in improving the living conditions of the people in the ten studied Villages in Juba Rural Area council of Bahr El Jebel State. The impact is assessed in terms of adoption and diffusion of innovations for the benefits of community affected The conceptual model and the hypothesis of the adoption and diffusion of innovations used in the study involved the Nature of Innovation and its characteristics of perceived risk, cost, perceived complexity, availability and profitability as influencing factors for the innovations to be adopted and diffused into the social system. In the same study a number of Dependable variables were used, which include perceived benefits, diversification of field crops and diversification of horticultural crops, while the casual variables include age, education, farm size, exposure to extension training and innovativeness. Also in the study pathsets and regression analyses were used where age has been used as exogenous variable as well as intercorrilation matrix In the study a number of analytical techniques were used for the testing of hypothesis which included descriptive statistics, tabular analysis (frequency distribution) correlation, regression, t-test and F-test respectively. The descriptive analysis and tabular analysis have been used to describe the different variables in the study. Correlation is to determine the degree of association between variables, while regression analysis is to test the relationship between dependent and independent variables. The t-test of analysis is to show the significance of the differences between male and female group means as well as determining factors affecting the perceived benefits from ACORD's programme, which make up the ultimate measure of the benefit. The area of study included the ten Villages along the East and West banks of the Nile, at about fifteen miles radius around Juba Town. The Villages were selected using a quota basis were in each Village fifteen households were selected systematically (every fourth house was selected regardless of sex of the household member present in the house). Primary data were collected using structured questionnaire and interview scheduled by the author, assisted by a team of five research assistants. The secondary data were collected from ACORD's field office in Juba and Khartoum as well as information collected from various libraries in Juba and Khartoum contributing to the literature review. Major Findings and Recommendations During the data analysis the following emerged as the major finding and the recommendations provided to correct the situation. ACCORD introduced mainly innovations in a very short time ranging from simple to complex innovations. As such the impact on the adoption rate was minimal. It is recommended that your organization introduce few innovations at any one time starting with simple ones, which can provide immediate and profitable results to the community members. The tractor hire service proved to be one of the most successful innovations at the beginning. But it decline later because very few of the tractors were being use in comparison to the farmers demanding their use, as a result, also of breakdown and lack of spare parts as well as qualified mechanics to carry out repair on time. It is recommended that your organization provide enough tractors to cover all the villages and to provide the spare parts immediately when need arises. It should also train enough mechanics to carry out on the sport repairs in case of break down. The few water irrigation pumps introduce to a number of villages proved successful. But shortages of fuel and spare parts to these fuel pumps were a drawback to the success of the innovations. It is recommended that fuel, spar parts, and mechanics be made available by the organization to necessitate continuity of the project. Lack of transportation of the product to the market centres in Juba town limited the production of the food commodities. It is recommended that the organization and state ministry of agriculture provide transport to the farmers such as bicycles or motorboats or even ordinary boats on loan to the farmers as incentives to encourage them to produce more crops for the market. The exchange farmers visits to different villages has helped to bring the farmers together and to learn from each other experiences as well as to share ideas. It is recommended that the organization formalizes and regularizes these visits to include those communities or villages that are not yet exposed to the program. The majority of the community members in the ten villages are illiterate, and this has contributed to the low rate of adoption and subsequent diffusion of the innovations. It is recommended that the state ministry of education in particular the department of adult education intensify on-going literacy campaign program in collaboration with the university of Juba department of adult education, to include in their curriculum functional literacy in all the villages to encourage learning. There are several NGOs working the same villages carrying out the same activities as those of ACCORD. This has created duplication of efforts and confusion among the community members as recipients of the introduced innovations. To avoid this, it is recommended that all the organization concerned come together and spell out what each one is to be involve in a particular innovation and this need the presence of state government as the main stakeholder so as to reduce these anomalies. The ratio of each village extension worker to the number of farming communities is 1:1000. This makes it difficult for the agent to efficiently cover all the farmers in his/her location through interpersonal communication. It is recommended that the state ministry of agriculture and natural resources train enough village level extension worker/agent to reduce the ration to a manageable level for effective performances. ACCORD has spread itself thinly on the ground by involving itself in so many activities (e.g. HIV/AIDS, Relief work, Education, Agriculture, Gender issues, etc.) with limited resources and budgets. As a result, it has little impact on some of these activities. It is therefore recommended that the organization concentrate its efforts on agriculture development as its main area of activities and live the rest of the activities to other agencies. The program has witness and is continuing to have serious disruptions from regular visits and supervisions by the extension agents and management team to the farmers. This due to the delays in issuing movement permits by the security organs and this has affected the rate of adoption and diffusion of the introduced innovations. It is recommended that the national government work hard to bring about a comprehensive and lasting peace to the whole country
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    Center Pivot Irrigation System Performance and Alfalfa Water Productivity Under Northern State Conditions
    (University of Khartuom, 2015) Ahmed Elmuiz Elkamel Elhassan Mohammed Elidrisi ; Abdel Moneim Elamin Mohammed ; Agricultural Engineering
    This study was conducted at three schemes in the Northern State during the period from November 2014 to May 2015. These schemes are located on the east bank of the River Nile about 32 km north of Dongla town. The objectives of the study were to evaluate the performance of center pivot irrigation systems. The split plot experimental design was adopted and for the analysis of data the Excel method was followed. The parameters studied were application efficiency, uniformity coefficient and uniformity of distribution. The productivity of alfalfa (ton/hectare/cut) and water productivity (kg/m3) under the Northern State soil and climatic conditions for the three schemes were determined. Results were statistically compared with those obtained from farms under traditional surface irrigation systems (basin irrigation).The results showed that the application efficiency of the centre pivot irrigation systems ranged from 50% to 74%. The uniformity coefficient ranged from 63% to 78%, while uniformity of distribution ranged from 46% to 69% for the three centre pivot schemes. The productivity of alfalfa (per cut) on dry weight basis ranged from 1.3 to 2.4 ton/ha/cut under the center pivot irrigation systems. As for the surface irrigation the productivity was found to be 3.6 ton/ha/cut. The water productivity ranged from 1.2 to 2.3 kg/m3/cut, while for the surface irrigation system water productivity was found to be 1.3 kg /m3/cut. The results obtained regarding system efficiencies are very low and regarded as poor. The productivity of alfalfa (on dry mass basis) followed the trend of the efficiencies (very low). The centre pivot irrigation system was found superior in water productivity compared to the traditional irrigation systems. The study indicates that there are problems regarding the performance of these systems. These problems were in the operation of the systems (speed of travel), lack of maintenance, sprinkler nozzle size, nozzle clogging and system operator. For satisfactory performance of centre pivot irrigation systems, proper techniques, periodic evaluation, proper maintenance and correct operating guidelines should be followed and trained persons should be employed. أجريت هذه الدراسة في ثلاثة مشاريع بالولاية الشمالية في الفترة من نوفمبر 2014 الى مايو 2015م. تقع هذه المشاريع في الضفه الشرقية لنهر النيل على بعد حوالي 32 كلم شمال مدينة دنقلا. الهدف من الدراسة هو تقييم أداء نظم الري المحوري. صممت هذه الدراسة بنظام القطاعات المنشقة وحللت البيانات إحصائيا بإستخدام برنامج إكسل. الخصائص التي تمت دراستها كانت كفاءة الإضافه، معامل الانتظام وانتظام التوزيع. قورنت إنتاجية البرسيم (طن/هكتار/قطعة) وكفاءة إنتاجية ماء الري (كجم/م3) تحت ظروف تربة ومناخ الولاية الشمالية للمشاريع الثلاثة مع النتائج المتحصل عليها من المزارع التي تستخدم نظام الري السطحي التقليدي (الري بالاحواض). أظهرت النتائج أن كفاءة الإضافه لنظام الري المحوري تترواح بين 50% و74%. ويتراوح معامل الانتظام بين 63% و78%, بينما يتراوح انتظام التوزيع بين 46% و69%. إنتاجية البرسيم على اساس الوزن الجاف تراوحت من 1.2 الى 2.3 طن/هكتار/قطعة بالنسبة لمشاريع الري المحوري الثلاثة. اما بالنسبة لنظام الري السطحي كانت الانتاجية 3.6 طن/هكتار/قطعة. تراوحت كفاءة إنتاجية الماء في نظام الري المحوري من 1.2 الى 2.3 كجم/م3/قطعة بينما كفاءة إنتاجية الماء في نظام الري السطحي كانت 1.3 كجم/م3/قطعة. اظهرت النتائج المتحصل عليها بخصوص كفاءات النظام انها ضعيفة جداً. إنتاجية البرسيم (على اساس الوزن الجاف) أخذ منحى كفاءات النظام (ضعيفة جداً). بينما وجد أن نظام الري بالرش المحوري هو الأفضل من حيث كفاءة إنتاجية الماء مقارنةً مع نظم الري السطحي التقليدي. لوحظ ان هناك مشاكل متعلقة باداء هذه الانظمة. تتمثل هذه المشاكل في تشغيل الأنظمة (سرعة الحركة) وضعف الصيانة وحجم فتحة الرشاش وإنسداد فوهة الرشاشات وعامل تشغيل النظام. للحصول على أداء مرض لنظام الري المحوري يجب الأخذ فى الإعتبار التقنيات المناسبة والتقييم الدوري للنظام والصيانة الجيدة وإتباع التوجيهات الصحيحة للتشغيل وتوظيف الأشخاص المدربين.
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    Center Pivot Irrigation Systems: Appropriate Selection, Assembling and Nozzle Programming
    (University of Khartoum, ) Omar Abdel Aziz Mohammed Alhassan ; Amir Bakheit Saeed ; Agricultural Engineering
    This study was conducted during the period June 2013 to June 2016 at Hassad farm of the Central Trading Company (CTC) which is located at Km 111north Omdurman 17Km west of Omdurman – Dongola main road. Fifteen Zimmatic center pivot systems were selected of the American Lindsay company. Each system would cover a cultivated area of 120 feddan. Out of these pivots, seven pivots each was composed of seven towers of equal length of 54.6m, but with two different pipe internal diameters, The first four were of pipe diameter 21.91cm (18 5/8") where as the other three had pipe diameter 16.83cm (6 5/8"), An overhang 27m in length and pipe diameter 12.7cm (5"),attached to each one of the pivots The other eight pivots each had eight towers with no overhang and divided in two groups of four having similar specifications as the previous two groups. Regarding the pivot assembling, two different procedures were followed for twelve pivots in which each tower was erected separately, then towed and linked with the other towers. For the other three pivots, the towers of each pivot were linked together on the ground then assembled as one unit without any towing. Thus saving time, labor and money as compared to the first procedure. Similarly in nozzle programming, two procedures were followed. For twelve pivots the conventional manufacturing chart was applied, however in this method, the manufacturing company needs to be contacted directly or indirectly through the dealer in case of failure or checking programming are required, this will cost time and money. Hence to save such substantial costs, another method was followed in situ. The nozzle particulars as provided by the manufacturing company would be inserted in special computer program and when applied on the other three pivots gave very satisfactory results compared to those of the company. Performance evaluations were done for all pivots based on ASAE Standard S436-1 and satisfactory results were obtained for the coefficient of uniformity (Cu) applying Christiansen (1942) and Heerman-Hein (1968) equations and for the distribution of uniformity (Du), the application efficiency (Ea) and the scheduling uniformity (Su). Hence it is recommended to adopt such nozzle programming as it is simple, cheap and can easily be applicable in situ. أجريت هذه الدراسة في الفترة من يونيو 2013 الى يونيو2016 بمشروع حصاد للشركة التجارية الوسطى (سي تي سي) الذي يقع على بعد 111كلم شمال ام درمان وعلى بعد 17كلم غرب الطريق الرئيسي ام درمان – دنقلا . تم اختيار 15 جهاز ري محوري (زيمتك) من شركة لينزي الامريكية ، يغطي كل محور مساحة 120فدان ، سبعة محاور من هذه المحاور تتكون من سبعة أبراج طول كل برج 54,6 متر بقطر داخلي مختلف للمواسير حيث الاربعة ابراج الاولى بقطر 21,91سم (8/5 8 بوصة) بينما الثلاثة ابراج المتبقية من المحور بقطر 16,83سم (8/5 6 بوصة) . يوجد بكل محور وصلة بطول 27متر وقطر 12.7سم (5 بوصة) . اما الثمانية محاور الاخرى فكل محور منها يتكون من ثمانية أبراج تنقسم الى مجموعتين بكل مجموعة أربعة أبراج بنفس مواصفات المحور السابق دون وجود وصلة . تم تطبيق طريقتين من طرق تركيب المحاور حيث تم تركيب 12 محور باحدى الطرق وفيها يتم تجميع الأبراج منفصلة عن بعضها ثم يتم سحبها وشبكها مع الأبراج الاخرى. أما المحاور الثلاثة المتبقة فقد تم تجميعها بطريقة أخرى حيث تم تجميعها على الارض بصورة متشابكة ثم تم رفعها كوحدة واحدة دون الحاجة لعملية السحب حيث يقل الزمن عدد العمالة و التكلفة لهذه الطريقة مقارنة بالطريقة السابقة . كذلك تم تطبيق طريقتين لبرمجة البخاخات حيث تم تطبيق برمجة الشركة المصنعة على 12 محور ، وتطبيق هذه الطريقة يتطلب التواصل مع الشركة المصنعة بصورة مباشرة أو غير مباشرة عن طريق الوكيل في حالة حدوث خلل أو مراجعة للبرمجة مما يكلف المزيد من الوقت والمال ، ولتقليل تلك التكاليف فقد تم تطبيق طريقة أخرى للبرمجة وهي طريقة خاصة تعمل على تحسين برمجة الشركة المصنعة ويتم اعدادها بواسطة الكمبيوتر , وقد تم تطبيقها على ثلاثة محاور وقد أعطت نتائج مرضية عند المقارنة ببرمجة الشركة المصنعة. كذلك تم تطبيق تقييم الاداء على كل المحاور من خلال دراسة جمعية المهندسين الزراعيين الامريكيين (Standard S436-1ASAE) بتطبيق معادلتي كريستيانسين (1942) وهيرمان– هين (1968) لمعامل الانتظام (Cu%) , وحساب انتظام التوزيع (Du%) ، وكفاءة الاضافة (Ea%) ، ومتوسط قيم انتظام الجدولة (Su) ، وقد تم الحصول على نتائج مقبولة . ولهذا تمت التوصيات بتطبيق البرمجة الخاصة وذلك لأنها تقوم بتوفير بعض التكاليف ولأمكانية اعدادها بالموقع وقد اعطت هذه البرمجة نتائجاً مرضية
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    A Comparative Study between Drip and Furrow Irrigation Systems for Producing Okra (Hibiscus Esculentus)
    (University of Khartoum, 2015-05-12) Khalid Mubasher Mustafa ; Amir Bakheit Saeed ; Agricultural Engineering
    A drip irrigation system was designed and installed in the Demonstration Farm of the Faculty of Agriculture, University of Khartoum. The system was evaluated for it's performance relative to the conventional surface (furrow) irrigation method under the same conditions. An on-farm distribution efficiency as high as 96% was obtained for the drip irrigation system. A split plot experimental design was followed. Okra (Hibiscus Esculentus) was taken as an indicator plant. Two okra varieties (Pussa and Sennar) were tested for their watering requirements and agronomic performance, the parameters measured included leaf number, leaf length, leaf width, plant length, plant diameter and the ultimate crop yield. The okra plant agronomic parameters except plant diameter were significantly (p ≤0.05) affected by the irrigation method (drip and furrow). However there were no significant differences between okra varieties (Pussa and Sennar) in terms of leaf number, plant length, plant diameter and yield but there were significant differences with regard to leaf length and leaf width.
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    A comparative Study Between Furrow Furrow Basin and Border Method of Irrigation
    (university of khartoum, ) Salaheldin Abdelrahman Salih
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    A Computer Model For Farm Machinery Selection
    (University of Khartoum, 2005) Fawzi Hamad Elniel Mas’oud ; Omer Mohamed Eltom Elshami ; Agricultural Engineering
    A Machinery Selection Model (MSM) was developed with the objectives of: - determining the number of workdays available for field work and the probability of occurrence of these days in the Rahad Scheme in Sudan, - determining optimum or near optimum machinery sets for an arable farm, with special reference to the Rahad Scheme. The Model was developed using Turbo-Pascal language, consisting of three segments, namely: a Workday segment (WorkMod), a Physical Selection segment (PhysMod), and an Economical Selection segment (EconMod). The input data for the program were: climatic, soilو crop, operations, and machine data. The output was: - Number of workdays available for field work and the probability of occurrence of these days, - Size and number of tillage implements and tractors required to complete the field operation in a reasonably short time, - Economical selection of other implements, (Minimum-cost width and optimum width) and number of tractors required to perform these operations. The sensitivity test of the Model showed that the Model is dynamic and the validity test also gave positive results. Numerical check was also done using Microsoft Excel spreadsheet. The Model is user friendly, self guiding and can be a good planning aid tool for managers in farm machinery selection.
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    Decision Support System Model for Matching Tractor Power and Implement Size in Irrigated Farming of Sudan
    (University of Khartoum, ) Alfarog Hassan Albasheer Mohamed ; Omer Mohamed Eltom Elshami ; Department of Agricultural Engineering
    A decision support system model was developed to match tractor power and implement size. The program options permit the user select the type of operation and the types of implements available in his farm. The system enables the user to insert the inputs data through file system, and obtain the output easily. The feasibility of the system was tested using data from Arab Investment Corporation -Um doom farm- and it was found that the power used in the farm can match the implement available. Also it was tested by making comparison between the power required for zero tillage and for conventional tillage. The sensitivity analyses showed that changing in some parameters (e.g speed, width and soil factor) affected the power required for the farm. According to the results, the decision support system worked very well in matching tractor power and implements sizes for proper performance. Developing other computer programs to assist farm machinery manager in decision –making to solve the problems will face them in this system can be used to help to the managers in the decision-making for calculating the power required and matching power available and implement required for economical machinery use. تم تطوير انموذج نظام لدعم القرار في عملية اختيار القدرة الملائمة للآله. خيارات الأنموذج تتيح للمستخدم امكانية اختيار العمليات الزراعية ونوع الآلات المتاحه في المزرعة. البرنامج يتيح للمستخدم امكانية ادخال البيانات من خلال نظام الملف والحصول على المخرجات (النتائج) بسهولة. وقد تم اختبار ملاءمة الانموذج (النظام) باستعمال بيانات من الحقل من مزرعة ام دوم - التابعه للهيئه العربية للاستثمار والانماء الزراعي – وكانت النتائج أن المزرعة نموذجية. كما تم اختباره ايضا باجراء مقارنة بين الطاقة المطلوبة في الزراعة بدون حرث والزراعة التقليدية. حساسية التحليل تبين أن أي تغيير في المعاملات مثل (السرعة وعرض الآله ومعامل التربة) يؤثر على الطاقة المطلوبة للمزرعة. وفقاً للنتائج فان برنامج الحاسب الألي يعمل جيدا, يقوم بتوليف حجم الجرار المطلوب للمزرعة مع حجم الآلة للحصول على أفضل أداء. يجب تطوير برامج حاسوبية أخرى لمساعدة متخذي القرار في حل المشاكل التي تواجههم في الدراسات القادمة. ويمكن استخدام هذا النظام من قبل الشركات والمؤسسات واصحاب المزارع الذين يعملون في مجال صنع القرار في المزرعة.
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    Design and Evaluation of a Multi Grain Thresher and Groundnut Sheller Machine (Case Study South Dar Fur-Sudan)
    (University of Khartoum, 2015-05-13) Mohamed Salah Eldin Mohamed Abdel Rahaman ; Omer Mohamed Eltom ; Agricultural Engineering
    A multi grain thresher and groundnut sheller machine was designed to work under condition of South Dar Fur State. It was locally constructed in Nyala depending on the skill of the local artisans and the material that is available in the market. The whole machine was constructed from steel, sheets, angle iron, bars and bolts and nuts. The machine is mounted on two 600X15 wheels on a single axle that help the mobility of the machine between fields. And has a rigid drawbar with jack. The machine was provided with two types of drums. Pegs type drum is used for threshing sorghum and millet and the other type is the rasp bar for shelling groundnut. The cleaning system of the machine is achieved by means of a sucking fan with a back curved impeller sucks the chaff and shell from a shaker pan with screen fixed on it. The control of the speed of all revolving parts (Drums, fan and shaker) of the machine is through changing of pulleys. The machine was designed to be drive by 8 to 10 hp diesel or petrol engine that mounted on the main frame. The material is fed to the machine manually through the hopper and the final product is collected under the screen on a collecting pan. The results of test and the economic assessment under condition of South Dar Fur of the machine proved that the machine needs only three persons to operate. And it needs sum of SD 424500 as an investment cost on the machine. Which has annual return of SD 881100 this is more profitable than owning the Turkish thresher (HMT-1200SPX) which is now the only Thresher operating in the area in addition of its capability to thresh not to shell groundnut. On the other hand the results of the test indicated that the machine has a capacity of shelling 16-18 sack of groundnut per hour with shelling efficiency 94-96% and loss of kernel not more than 6.5%. And has threshing output 792 Kg of millet per hour with threshing efficiency 98% and not more than 3.1% grain damage and 4% of grain loss. While in threshing sorghum the results showed that the machine output is 480 Kg of sorghum per hour with threshing efficiency 99.2% and not more than 6.5% of grain loss.
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    Designing and Developing an Automated Sprinkler Irrigation System
    (University of Khartoum, 2006) Abdelrahman Ismail Abdelrahman Adam ; Abdel Moneim Elamin Mohamed ; Agricultural Engineering
    A study of designing and developing an automated sprinkler irrigation system was conducted during 2003-2006 at the Faculty of Agriculture-University of Khartoum-Sudan. The study also included soil characteristics (textural class, bulk density, and infiltration) and physical moisture content determination. A computer model was developed using Microsoft Visual Basic 6.0 (Sp6), to design the permanent sprinkler irrigation system used in the experiments. An electronic controller closed-loop system based on soil moisture content made from the local market available materials was also developed. A soil moisture content sensor and rain shutoff devices were designed and constructed for the purpose of the study. The results of soil moisture sensor calibration for clay soil showed that the upper range for the sensor to turn-off the sprinkler system was 26.3%, and the lower point to turn on the system was 17% (as required), both on weight basis. The results of the evaluation of the designed automated sprinkler irrigation system for one zone (square pattern) and for the whole system were as follows respectively: the distribution uniformity DU was 81% and 82%, the Christiansen coefficient CU was found to be 88% and 89%, the scheduling coefficient was 1.2 for both, the application rate was 10.1 mm/h, and 8.9 mm/h, the application efficiency was 90% and 79%, water losses during sprinkler irrigation testing were 1.2 mm, and 2.4 mm. The rain control device shut-off the system when rain depth reached 6.4 mm.
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    Determination of Equilibrium Moisture Content (EMC) of Gum Arabic Powder
    ( University of Khartoum, 2015-05-11) Babiker Ali Abaker Eshag ; Mohamed A. Ismail ; Agricultural Engineering
    This investigation was conducted at the Pharmaceutical laboratory, Faculty of Pharmacy, University of Khartoum, Sudan. The main objective of the work was to determine the equilibrium moisture content (EMC) and to investigate the effect of the surrounding air Relative humidity (RH) and temperature (T) on the variability of equilibrium moisture content (EMC) for Gum Arabic (Acacia senegal var. senegal) mechanical powder, as one of the key solutions to the trade of Gum Arabic in Sudan. Adsorption and desorption Equilibrium moisture content (EMC) data, were determined at 38°C and 50°C for a relative humidity (RH) range of 28.7%-96%. For both adsorption and desorption data, the isotherms obtained had a sigmoid shape (S-shape), which characterizes most biological products. In general, as the relative humidity (RH) increases equilibrium moisture content (EMC) increases. Results showed that the effect of relative humidity (RH) on equilibrium moisture content (EMC) of Gum Arabic variety senegal mechanical powder was statistically significant, whereas for temperature the effect was statistically insignificant. Comparing the adsorption and desorption isotherms it was observed that there was a reverse hysteresis effect (adsorption values were greater than desorption ones) ranged from 5.44% to 2.06% (d.b) for 50°C and 3.94% to 0.84% (d.b) for 38°C.
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    Determination of Equilibrium Moisture Content of Roselle Caylx
    (University of Khartoum, 2015-05-07) Sahar Gaafar Ahmed Dafa Alla ; Mohamed Ayoub Ismail ; Agricultural Engineering
    An experiment was carried out at the Faculty of Agriculture, University of Khartoum, Shambat Campus for the determination of the EMC of whole and broken roselle calyx. For both particle sizes three adsorption isotherms (10oC, 30oC and 50oC) and two desorption isotherms (30oC and 50oC) were determined. The objective of the study is to study the effect of surrounding air RH, surrounding air temperature and particle size on the EMC variability of roselle calyx. Graphical representation and statistical analysis showed that,a polynomial function exists between RH and EMC for both adsorption and desorption isotherms. In general as RH increases EMC increases. Above 85% RH no EMC values were obtained due to the grown of mould on the tested samples. Temperature in general was found to have a negative relationship with EMC i.e. as temperature increases EMC decreases. No hysteresis effects between adsorption and desorption EMC values was observed. Particle size seemed to have no effect on the variability of EMC
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    Determination of Friction Head Losses in Trickle (Bubbler) and Sprinkler Irrigation Systems
    (University of Khartoum, 2015-05-19) Alawi Mohammed Alawi Alsaqaf ; Amir Bakheit Saeed ; Agricultural Engineering
    Field experiments were conducted at Al-Ain Central District of the General Public Gardens Directorate, Al-Ain Municipality, Abu Dhabi Emirate, United Arab Emirates. The experiments were run to determine the friction head losses along the laterals of the trickle (bubbler) and sprinkler irrigation systems within the automated (computerized) irrigation system of the Central District. The results of the experiments indicated that there were no significant differences between the practically measured head losses and head losses as calculated by using friction head losses equations namely : the Hazen-Williams and Darcy-Weisbach when factor (G), as suggested by Anwar (1999) was used. The average measured head losses for trickle (bubbler) and sprinkler systems were 4.36 m and 4.18m, whereas their respective values as calculated by using Hazen-Williams equation and introducing Anwar's(G) factor were 4.20m and 4.64m. Factor (G) is a sequel to the widely used Christiansen's factor (F). It has the advantages to allow for an outflow at the downstream end of the pipeline beyond the last outlet. It can, therefore, be used for computation of frictional head losses and eventually designing of system such as trickle (bubblers) and sprinklers systems in which the pipelines have multiple diameter sizes and equally spaced outlets.