Installation of a family drip irrigation system for the improvement of the livelihood of small-scale farmers in comparison with surface irrigation

Drip irrigation is one of the most efficient methods of water use for crop production. Family drip systems are suitable for small land areas ranging from 10-2000 m2 to irrigate horticultural crops. The system is a complete drip irrigation unit. It operates by gravity from a tank placed one meter high. It is a closed pipe-gravity system, and solid seasonal installation, for growing vegetables, flowers and other horticultural crops on flat or minor slope land. This experiment was established to evaluate a family drip system in comparison with surface irrigation for onion production under north Kassala conditions (Talkouk Locality). The results indicated that family drip system saved irrigation water by 67% and 59%, and increased the total yield of onion by 43% and 34% in sites one and two, respectively, as compared to local surface irrigation. The highest irrigation water productivity (2.98 and 2.73 kg/m3) was obtained under family drip system and the lowest values were 1.25 and 1.28 kg/m3 under surface irrigation in sites one and two, respectively. Moreover, the family drip system scored higher net return and benefit cost ratio compared to the surface irrigation system.         الري بالتنقيط هو أكثر الطرق كفاءة في استخدام المياه لإنتاج المحاصيل. نظام الري بالتنقيط العائلي هو نظام يناسب  المساحات الصغيرة التي تتراوح مساحتها بين 10 الي 2000  متر مربع, لري المحاصيل البستانية. النظام هو وحدة ري بالتنقيط  كاملة؛ يعمل بالجاذبية من خزان وضع علي ارتفاع 1 متر. هو نظام ذو انابيب مغلقة للجاذبية ويمكن تركيبة كل موسم بسهولة لزراعة الخضرواتِ والزهور والمحاصيل البستانية الأخرى على الأراضِي المنحدرة والمستويةِ أَو البسيطةِ. تأسست هذه التجربة لتقييم نظام الري بالتنقيط العائلي مقارنة مع الري السطحي المحلي لإنتاج البصل تحت ظروف شمال كسلا محلية تلكوك. اشارت النتائج إلى أن نظام الري بالتنقيط العائلي حفظ مياه الري بنسبة 67٪ و 59٪، وزيادة الانتاجية بنسبة 43٪ و 34٪ في الموقع الاول والثاني على التوالي مقارنة مع الري السطحي المحلي. ايضا تم الحصول على أعلى إنتاجية لمياه الري (2.98 و2.73 كيلوجرام متر مكعب) تحت نظام الري بالتنقيط العائلي وكانت أقل القيم   (1.25 و 1.28 كيلوجرام متر مكعب) تحت الري السطحي في الموقعين الاول والثاني. علاوة على ذلك، سجل نظام الري بالتنقيط العائلي اعلي عائد ومنفعة مقارنة لنظام الري السطحي

A grouping scheme for secure multicasting in mobile IPv6

In any secure multicasting environment, group management becomes an important aspect for achieving privacy and integrity of the multicast session. In this paper, group management strategy has been proposed to address thls objective. The multicast group has been divided into subgroups or hash families, each subgroup contains the nodes that maps to the same hash key that is calculated by a hash function. A 'clue' has been added to facilitate the joidleave mechanism for members in the group

Routing scheme for macro mobility handover in hierarchical mobile IPv6 network

Significant problems in basic mobile IPv6 occur due to its inability to support micro-mobility because of long delay and high packet loss during handover. Hierarchical mobile IPv6 (HMIPv6) as an extension of basic Mobile IPv6 solves the problem by separating the handover management to macromobility and micro-mobility. HMIPv6 introduced a new protocol element called Mobility Anchor Point (MAP) to manage the mobility. HMIPv6 can reduce the delay and the amount of signaling during handover. However the protocol still cannot meet the requirement for traffic that is delay sensitive such as voice especially in macro mobility management. Duplicate address detection and the transmission time for the handover operation could cause high handover delay

Altered cyclooxygenase-1 and enhanced thromboxane receptor activities underlie attenuated endothelial dilatory capacity of omental arteries in obesity

AIMS: Obesity is a risk factor for endothelial dysfunction, the severity of which is likely to vary depending on extent and impact of adiposity on the vasculature. This study investigates the roles of cyclooxygenase isoforms and thromboxane receptor activities in the differential endothelial dilatory capacities of arteries derived from omental and subcutaneous adipose tissues in obesity. MAIN METHODS: Small arteries were isolated from omental and subcutaneous adipose tissues obtained from consented morbidly obese patients (n = 65, BMI 45 ± 6 kg m-2 [Mean ± SD]) undergoing bariatric surgery. Relaxation to acetylcholine was studied by wire myography in the absence or presence of indomethacin (10 μM, cyclooxygenase inhibitor), FR122047 (1 μM, cyclooxygenase-1 inhibitor), Celecoxib (4 μM, cyclooxygenase-2 inhibitor), Nω-Nitro-L-arginine methyl ester (L-NAME, 100 μM, nitric oxide synthase inhibitor) or combination of apamin (0.5 μM) and charybdotoxin (0.1 μM) that together inhibit endothelium-derived hyperpolarizing factor (EDHF). Contractions to U46619 (thromboxane A2 mimetic) were also studied. KEY FINDINGS: Acetylcholine relaxation was significantly attenuated in omental compared with subcutaneous arteries from same patients (p < 0.01). Indomethacin (p < 0.01) and FR122047 (p < 0.001) but not Celecoxib significantly improved the omental arteriolar relaxation. Cyclooxygenase-1 mRNA and U46619 contractions were both increased in omental compared with subcutaneous arteries (p < 0.05). L-NAME comparably inhibited acetylcholine relaxation in both arteries, while apamin+charybdotoxin were less effective in omental compared with subcutaneous arteries. SIGNIFICANCE: The results show that the depot-specific reduction in endothelial dilatory capacity of omental compared with subcutaneous arteries in obesity is in large part due to altered cyclooxygenase-1 and enhanced thromboxane receptor activities, which cause EDHF deficiency

Chronic elevation of systemic glucagon-like peptide-1 following surgical weight loss: association with nausea and vomiting and effects on adipokines.

We determined whether persistent nausea and vomiting (N/V) symptoms following Roux-en-Y gastric bypass surgery is due to elevated systemic glucagon-like peptide-1 (GLP-1) and leptin in female non-diabetic subjects. Subjects with N/V post-Roux-en-Y gastric bypass (RYGB) surgery had significantly elevated fasting GLP-1 levels compared to that with post-operative asymptomatic subjects and to morbidly obese, obese and lean subjects not undergoing surgery. Weight loss, glycaemia, insulin and post-prandial GLP-1 levels were similar in all post-operative subjects. Despite comparable BMI, leptin was significantly lower in symptomatic subjects. Furthermore, leptin secretion from subcutaneous adipose tissue was inhibited by GLP-1 (0.1-1.0 nM; n = 6). Persistent N/V following RYGB surgery is associated with elevated fasting GLP-1, but lower leptin levels. The latter may be a consequence of the direct GLP-1 inhibition of leptin secretion from adipose tissue

Estimation method for determining surface film conductance during cooling of fish packages.

This paper presents an alternative method for determining the surface film conductance of an infinite fish slab subjected to the cooling process. Many methods have been published, but their solutions have inherent appreciable inaccuracy and limitations. The present authors used the temperature histories of five locations within a slab sample of fish, obtained by the experimental investigation part of this work, along with the inverse heat conduction problem (IHCP) technique to develop a correlation for variable surface film conductance. When the above correlation was used for temperature predictions, the predicted and experimentally measured temperature distribution profiles were compared numerically. Better agreement than that implemented by other investigators was achieved. This revealed the accuracy and superiority of the present method, and the limitations of other methods are overcome in this method

Highly conductive anion exchange membranes based on polymer networks containing imidazolium functionalised side chains

Two novel types of anion exchange membranes (AEMs) having imidazolium-type functionalised nanofibrous substrates were prepared using the facile and potentially scalable method. The membranes’ precursors were prepared by graft copolymerization of vinylbenzyl chloride (VBC) onto syndiotactic polypropylene (syn-PP) and polyamide-66 (PA-66) nanofibrous networks followed by crosslinking with 1,8-octanediamine, thermal treatment and subsequent functionalisation of imidazolium groups. The obtained membranes displayed an ion exchange capacity (IEC) close to 1.9 mmol g–1 and ionic (OH-) conductivity as high as 130 mS cm–1 at 80 °C. This was coupled with a reasonable alkaline stability representing more than 70% of their original conductivity under accelerated degradation test in 1 M KOH at 80 °C for 360 h. The effect of ionomer binder on the performance of the membrane electrode assembly (MEA) in AEM fuel cell was evaluated with the optimum membrane. The MEA showed a power density of as high as 440 mW cm−2 at a current density is 910 mA cm−2 with diamine crosslinked quaternized polysulfone (DAPSF) binder at 80 °C with 90% humidified H2 and O2 gases. Such performance was 2.3 folds higher than the corresponding MEA performance with quaternary ammonium polysulfone (QAPS) binder at the same operating conditions. Overall, the newly developed membrane was found to possess not only an excellent combination of physico-chemical properties and a reasonable stability but also to have a facile preparation procedure and cheap ingredients making it a promising candidate for application in AEM fuel cell