A hydrodynamic model for biomass gasification in a circulating fluidized bed riser

This study presents a three-dimensional Computational Fluid Dynamic (CFD) model and experimental measurements of the hydrodynamics in the riser section of a Circulating Fluidized Bed (CFB) biomass gasifier consisting of a binary mixture of polydisperse particles. The model is based on multi-fluid (Eulerian-Eulerian) approach with constitutive equations adopted from the Kinetic Theory of Granular Flow (KTGF). The study first presents an assessment of the various options of the constitutive and closure equations for a binary mixture followed by sensitivity analysis of the model to the solution time step, cell size, turbulence and the alternative formulations of the granular energy equation. Accordingly, a robust and reliable hydrodynamic model is recommended and validated using conventional pressure measurements and Positron Emission Particle Tracking (PEPT) technique. Furthermore, the model predictions and experiments revealed evidence of the particle re-circulation within the lower part of the riser, which is an important feature contributing to rapid mass and heat transfer in a CFB gasifier. The present hydrodynamic model can be further developed; by incorporating appropriate reactions and heat transfer equations, in order to fully predict the performance and products of a CFB biomass gasifier

Effects of dried sugar beet root based concentrates level on wholesale cuts and eye muscle characteristics in Nubian goat male kids

    High meat demand and prices in the Sudan highlighted the needs to improve goat exploitation due to high population and meat high nutritive value and health attributes. However, goats are mainly raised in traditional systems with low inputs and outputs. Nubian is the main goat dairy breed and culled males are used for meat production. Nutrition is among the main constraints for goat production and cconcentrates are not commonly fed. Sugar beet is introduced into the Gezira State and is a valuable feed. There is no information on the effects of dried sugar beet roots (DSBR) based concentrates level on Nubian goat male kids performance and carcass characteristics. Twelve Nubian  goat male kids at 6 month old were housed individually, divided into 3 groups and allocated at random to feeds in 2016. They were fed upgraded Seewa (UPS) ad lib. at 8 am and 4 pm. They were fed DSBP based concentrates (70% DSBP,15% groundnut cakes and 15% sunflower cakes) at 0 (control), 250 g and 500 g in two meals before UPS. They were fed for 8 weeks in addition to a two week preliminary period. They were slaughtered and the left side was divided into wholesale cuts, weighed and dissected. The rib section (10th – 12th) was removed and characteristics and meat composition were determined. All wholesale cuts weight increased with concentrates level. Supplementing upgraded Seewa improved Nubian male kids performance and carcass characteristics. Eye muscle characteristics were affected with concentrates level, but not significantly different.  Concentrates level significantly (P<0.05) affected meat DM, CP and ash. Animals fed 500 g had the highest DM, EE and ash. Animals fed 250 g concentrates had the highest CP. It was concluded that DSBP based concentrates level had improved wholesale cuts weight and meat composition. It was recommended to use DSBR based concentrates and upgraded Seewa in fattening Nubian goat  male kids.                 تمثل الماعز النوبي سلالة الألبان الرئيسة وتستخدم الذكور المستبعدة من القطيع  لإنتاج اللحوم. تعتبر التغذية معوقا رئيسيا لانتاج الماعز ولا تستخدم عادة علائقا مركزة . تم مؤخرا إدخال زراعة  بنجرالسكر في ولاية الجزيرة وهو مصدر علفي قيم. ولا تتوفر معلومات عن استخدام عليقة ترتكز على جذور بنجر السكر المجففة على الأداء وصفات الذبيحة في جديان  ذكور للماعز النوبي. وضع 12 ذكرا من الماعز النوبي بعمر سته أشهر في حظائر مفردة ووزعت لثلاثة مجموعات ووزعت المجموعات لثلاثة أعلاف بصورة عشوائية كاملة في عام 2016م. غذيت الحيوانات على مخلفات قناديل الذرة المحسنة  حسب الرغبة عند الساعه الثامنة صباحا  والرابعة مساءا. كما غذيت الحيوانات على عليقة مركزة ترتكز على جذور  بنجر السكر المجفف ( 70% جذور بنجر السكر المجففة,15% أمباز الفول السوداني و15% أمباز بذرة زهرة الشمس) عند صفر           ( الشاهد) 250 جرام و500 جرام في وجبتين قبل مخلفات قناديل الذرة  المحسنة. غذيت الحيوانات لمدة ثمانية أسابيع مع أسبوعين كفترة تمهيدية. تم ذبح الحيوانات وقسم الجانب الأيسر للقطع الاجماليه ووزنت وشٌرٍحت. اخذ جزء الأضلع ( من العاشرة الى الثانية عشر) وقيست صفات العضلة العينية وتركيب اللحم. جميع القطع الاجماليه  زاد وزنها مع مستوي العليقة المركزة وزادت نسبتهم المئوية مع مستوي العليقة المركزة حتى 250 جراما ثم انخفضت عند500 جرام عليقة مركزة .تأثرت صفات  العضلة العينية بمستوي العليقة المركزة بشكل غيرمعنوي. أثر مستوي العليقة المركزة بشكل معنوي علي المادة الجافة ونسبة البروتين الخام  والرماد  في اللحم. كانت نسب المادة الجافة والمستخلص الأثيري والرماد أعلي في الحيوانات التي غذيت على 500جرام عليقة مركزة. كانت نسبة البروتين الخام أعلي في الحيوانات التي غذيت على 250جرام من العليقة المركزة.كانت الخلاصة من الدراسة ان استخدام مستويات مختلفة من عليقة مركزة ترتكز على جذور بنجر السكر المجففة حسن وزن القطع الاجمالية للذبيحة وتركيب اللحوم. لذلك يوصي بإستخدام جذور بنجر السكر المجفف بمستويات مختلفه مع قناديل الذرة  المحسنة في تسمين ذكور الماعز النوبي .                                                          &nbsp

A CFD study of biomass pyrolysis in a downer reactor equipped with a novel gas-solid separator-II thermochemical performance and products

A Eulerian-Eulerian CFD model was used to investigate the fast pyrolysis of biomass in a downer reactor equipped with a novel gas-solid separation mechanism. The highly endothermic pyrolysis reaction was assumed to be entirely driven by an inert solid heat carrier (sand). A one-step global pyrolysis reaction, along with the equations describing the biomass drying and heat transfer, was implemented in the hydrodynamic model presented in part I of this study (Fuel Processing Technology, V126, 366-382). The predictions of the gas-solid separation efficiency, temperature distribution, residence time and the pyrolysis product yield are presented and discussed. For the operating conditions considered, the devolatilisation efficiency was found to be above 60% and the yield composition in mass fraction was 56.85% bio-oil, 37.87% bio-char and 5.28% non-condensable gas (NCG). This has been found to agree reasonably well with recent relevant published experimental data. The novel gas-solid separation mechanism allowed achieving greater than 99.9% separation efficiency and < 2 s pyrolysis gas residence time. The model has been found to be robust and fast in terms of computational time, thus has the great potential to aid in future design and optimisation of the biomass fast pyrolysis process

Effects of age at fattening on male Butana camels performance and some blood parameters in the Sudan

Twelve male Butana camels at 2,3 and 4 years old (four in each age group) were&nbsp; fattened for two month in Gadarif, Gadarif State, Sudan to study the effects of age at fattening on animals performance and some haematological factors. They were weighed at the beginning of the experiment and then weekly. Each animal was fed sorghum stover ad lib in two equal meals in the morning and afternoon and 2.0 kg concentrates daily. Clean drinking water was offered ad lib. Feeds DM digestibility was measured for seven days in the last week of the experiment. Jugular vein blood samples were collected for determination of some blood parameters. Daily sorghum stover DMI, TDMI and water intake (litres/day) increased with age at fattening and were higher at 4 years old. Dry matter digestibility increased with age at fattening and was highest at 4 years old. Initial and final body weights and mean daily and weekly weight gains increased with age at fattening. Total weight gain increased up to 3 years and then decreased and was affected with age, except between 2 and 4 years old. Feed conversion ratio was highest at 4 years old. Leucocytes count increased with age at fattening and varied between 2 and 4 years old. Red blood cells count, haemoglobin and packed cell volume increased up to three years old and then decreased. Red blood cells count and haemoglobin varied between 2 and 3 years old.&nbsp; &nbsp;&nbsp;&nbsp;&nbsp; تم تسمين 12 من ذكور أبل البطانة&nbsp; بأعمار 2، 3 و4 سنوات(أربعة في كل مجموعة عمرية) لمدة شهرين في القضارف بولاية القضارف في السودان لدراسة أثر عمر التسمين على الأداء وبعض صفات الدم. وزنت الحيوانات عند بدء التجربة ثم أسبوعياً. أعلف كل حيوان يومياً تبن الذرة الرفيعة حسب الرغبة في وجبتين متساويتين صباحاً وبعد الظهر و2 كجم عليقة مركزة وقدم ماء نظيفاً حسب الرغبة. نم فياس هضمية المادة الجافة لمدة سبعة أيام في الأسبوع الأخير للتجربة. جمعت عينات دم من الوريد الودايجي لقياس بعض مكونات الدم.. زاد التبن المأكول والعلف الكلي&nbsp; المأكول وماء الشرب (لتر) يومياً&nbsp; بزيادة عمر التسمين وكانت أعلى بعمر 4 سنوات. زادت هضمية المادة الجافة بزيادة عمر التسمين وكانت اعلى بعمر4 سنوات. زاد الوزن المبدئي والنهائي&nbsp; ومتوسط الوزن المكتسب اليومي والاسبوعي بزيادة عمر التسمين وكانت أقل بعمر عامين.&nbsp; زاد الوزن المكتسب الكلي حتى عمر 3 سنوات ثم انخفض وتأثر بالعمر. إلا بين عامين وأربعة أعوام. كانت كفاءة تحويل العلف أعلى&nbsp; بعمر 4 سنوات. زاد عدد كريات الدم البيضاء بعمر التسمين واختلف بين عمر عامين وأربعة اعوام. زاد عدد&nbsp; كريات الدم الحمراء والهمقلوبين وحجم الخلايا المضغوطة حتى عمر3 سنوات ثم انخفض. تباين عدد كريات الدم الحمراء والهمقلوبين بين عمر عامين وثلاثة أعوام.&nbsp; &nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; &nbsp

Modeling and performance analysis of biomass fast pyrolysis in a solar-thermal reactor

Solar-thermal conversion of biomass through pyrolysis process is an alternative option to store energy in the form of liquid fuel, gas and bio-char. Fast pyrolysis is a highly endothermic process and essentially requires high heating rate and temperature >400 °C. This study presents a theoretical study on biomass fast pyrolysis in a solar-thermal reactor heated by a parabolic trough concentrator. The reactor is part of a novel closed loop pyrolysis-gasification process. A Eulerian-Eulerian flow model, with constitutive closure equation derived from the kinetic theory of granular flow and incorporating heat transfer, drying and pyrolysis reaction equations, was solved using ANSYS Fluent computational fluid dynamics (CFD) software. The highly endothermic pyrolysis was assumed to be satisfied by a constant solar heat flux concentrated on the reactor external wall. At the operating conditions considered, the reactor overall energy efficiency was found equal to 67.8% with the product consisting of 51.5% bio-oil, 43.7% char and 4.8% non-condensable gases. Performance analysis is presented to show the competitiveness of the proposed reactor in terms of thermal conversion efficiency and environmental impact. It is hoped that this study will contribute to the global effort on securing diverse and sustainable energy generation technologies

Les fracture-luxations transolécraniennes

Les fracture-luxations transolécraniennes sont une entité rare des fracture-luxations du coude. Il s'agit d'une lésion complexe qui peut compromettre le pronostic fonctionnel du coude. Dix patients étaient diagnostiqués dans notre service entre janvier 2005 et novembre 2012. Tous nos patients étaient de sexe masculin, l'âge moyen était de 29 ans. Les fractures de l'olécrane étaient complexes et comminutives dans sept cas et simples chez trois patients. Deux cas étaient associés à des fractures de la tête radiale (Mason III) et deux autres à des fractures de l'apophyse coronoïde. Les résultats étaient évalués après un recul moyen de trois ans et demi par le score de BROBERG et MORREY: trois cas étaient excellents, quatre bons, deux moyens et un mauvais. Cette lésion complexe nécessite une bonne reconstruction de la surface articulaire et une réparation des lésions associées pour permettre une rééducation précoce, seul garant d'une bonne  récupération fonctionnelle.Key words: Transolécranienne, fracture–luxation, Coude, olécran

Radial Access in Primary PCI for Acute Myocardial Infarction

Transradial approach (TRA) is now considered the standard of care in many centers for elective and primary percutaneous coronary intervention (PCI). The use of the radial approach in ST‐segment elevation myocardial infarction (STEMI) patients has been associated with a significant reduction in major adverse cardiac events. However, it is still unclear if the side of radial access (right vs. left) has impact on safety and effectiveness of TRA in primary PCI. So this chapter was conducted to summarize the benefits of transradial access over transfemoral access based on the most recent studies and to compare between using either right radial or left radial as an access for transradial procedure

Detection of Trypanozoon trypanosomes infections on Glossina fuscipes fuscipes (Diptera: Glossinidae) using polymerase chain reaction (PCR) technique in the Blue Nile State, Sudan

Tsetse flies transmit many species of trypanosomes in Africa, some of which are human and livestock pathogens of major medical and socio-economic impact. Identification of trypanosomes is essential to assess the disease risk imposed by particular tsetse populations. The present study was carried out to determine the trypanosomal infection rate of tsetse flies (Glossina fuscipes fuscipes) in the Blue Nile State of Sudan. A polymerase chain reaction (PCR) assay was used because of the inherent difficulty of speciating trypanosomal parasites in the fly. Our results show that 4.44% (8/180) of the flies were positive for a Trypanosoma brucei group. Three of eight positive flies reacted with primers for Trypanosoma b. rhodesiense. We did not detect flies infected with T. b. gambiense. Thus, the burden of flies harboring T. b. rhodesiense and T. b. brucei trypanosomes were 1.67 and 2.78%, respectively. This is the first evidence of T. b. rhodesiense in the Yabus District. Thus, HAT case-detection active surveillance and tsetse fly control campaigns should be conducted before the establishment of human settlement, investment of natural resources into agricultural and animal husbandry.Key words: Glossina fuscipes fuscipes, Trypanosoma brucei, T. b. gambiense, T. b. rhodesiense, infection rate, PCR technique, Blue Nile State

A Cross-sectional Study on Hepatitis B Immune Status among Vaccinated Healthcare Workers in Khartoum, Sudan

Background: Hepatitis B virus (HBV) infection can lead to chronic hepatitis, liver cirrhosis, and Hepatocellular Carcinoma (HCC). Vaccination against the virus plays an important role in its prevention. Health personnel at risk of infection are recommended to receive the vaccine and to check their immune status thereafterObjective:&nbsp; &nbsp;To determine Hepatitis B Immune status among vaccinated health personnel in Khartoum state, Sudan.A total of 106 health personnel from different hospitals and doctors’mess in Khartoum and from different jobs were surveyed and their HBV surface antibodies levels were determined by HBsAb (Quantitative) ELISA Kits.Methods: Of the 106 participants in this study, the majority were females 72.6%. The mean age of those involved was 27.69 years, and nurses made for more than 50% of those surveyed. About 56.6% (60) of the health personnel involved took three or more doses of HBV vaccine while the rest received one or two doses. The results of the participants who received three or more doses of the vaccine represented immunity by 70%. In general, about 47.2% (50) of the participants in this study did show excellent immune response (&gt; 100 mIU/mL) and 18.9% (20) had weak protective levels (between 10 and 100 mIU/mL)So, we concluded that HBV post-vaccination immunity status of health personnel in Khartoum state is lower than post-vaccination HBV immunity in other parts of the world. There is an urgent need for a national protocol of HBV vaccination to improve the immunization status of health personnel with a regular checkup of HBV immunity and easy access to a good-quality vaccine. Keywords: hepatitis B vaccines; healthcare workers; immune respons