Origin and hydrothermal alteration of rare-metal granites in the Al-Hamra area, northeastern Arabian Shield, Saudi Arabia

Abstract The Jabal Hamra (538 Ma) and Jabal Abu ad Dud plutons in northeast Saudi Arabia are epizonal bodies consisting of alkali feldspar granite and alkali feldspar syenite. Fracture-controlled zones of highly altered granites are recorded along the margins of the plutons. The granites intrude metamorphosed volcano-sedimentary successions of the Matran Formation. The rocks of the two plutons are chemically indistinguishable. They are characterized by above-average Th, Nb, Y, Ta, Hf and Zr, very low CaO, TiO2, MgO, FeO and MnO, and by high contents of rare earth elements (REE). Tectonic discrimination diagrams suggest an intra-plate environment, with many geochemical and mineralogical features resembling post-orogenic A-type granites. Numerous local and regional geologic constraints indicate that the plutons were intruded in an extension-related setting following the cessation of Neoproterozoic arc-related magmatism. Geochemical data are consistent with their derivation by partial melting of depleted crust followed by fractional crystallization of feldspars, ferromagnesian minerals and REE-rich accessory phases. The radiogenic isotope data [eNd (T) values are +3.5 to +4.2] indicate that the granite magma was generated from a ‘juvenile’ source, which is typical of the rocks making up most of the Arabian-Nubian Shield. Rare-metal mineralization is associated with the fracture-controlled alteration zones that occur at Jabal Al Hamra and Jabal Abu ad Dud. The altered rocks are characterized by higher TiO2, Fe2O3, SiO2 and lower Al2O3, CaO, Na2O, than the unaltered rocks. They show high and wide range in the total REE contents (804–15579 ppm), Ta (6–194 ppm), Nb (51–3483 ppm), Hf (13–368 ppm), Zr (394–14887 ppm), Th (16–572 ppm) and U (4–143 ppm). Field observations and further petrographic and chemical studies suggest that the altered rocks and the rare metal enrichment are the products of hydrothermal-metasomatic alteration of the quartz alkali feldspar syenite and the alkali feldspar granite. The rare-metal enrichment was explained by orthomagmatic fluid transport of these elements as fluoride complexes, and their subsequent deposition as a result of mixing with externally derived Fe-rich fluids

Inhaled mometasone furoate for the management of refractory oral corticosteroid-dependent asthma: a case report

We report a case study of a 55-year-old white male with severe persistent refractory corticosteroid-dependent asthma receiving inhaled combination therapy with fluticasone propionate 500 μg and salmeterol 50 μg twice-daily in addition to 6-week cycles of oral corticosteroid treatment for the previous 7 months. The patient was switched to high-dose mometasone furoate delivered via a dry powder inhaler (660 μg twice-daily) for 6 weeks

Development of a high pressure compressed natural gas mixer for a 1.5 litre CNG-diesel dual engine

[Abstract]: The Computational Fluid Dynamics (CFD) analysis software was used to study the flow behaviour of compressed natural gas (CNG) and air in a CNG-air mixer to be introduced through the air inlet of a CNG-Diesel dual fuel stationary engine. The results of the simulation show that the Venturi mixer with more holes gives superior engine performance compared to the 4-hole Venturi mixer. Further analysis is done on the different holes mixer to investigate the effect of engine speed on the mass flow rate of CNG and the equivalence ratio Lambda. The second part of the paper represents a comparison results between the performances of a single cylinder research Compression Ignition CI engine fuelled with CNG-diesel system and conventional CI engine fuelled by conventional diesel. The engine was equipped with the simulated Venturi mixer, the result showed significant reduction in the exhaust gas emission compared to the conventional diesel engine. The average power output generated by dual fuel engine was slightly higher than that diesel one at different engine speeds

Brain abscess following rituximab infusion in a patient with pemphigus vulgaris.

BackgroundImmunocompromised patients are at increased risk for developing meningitis or, rarely, brain abscess with opportunistic organisms like Listeria monocytogenes.Case reportA 52 year-old Saudi Arabian woman who was diagnosed with pemphigus vulgaris and diabetes and had been on prednisolone and azathioprine for about 4 years. She presented with headache, low-grade fever, and left-sided weakness 2 weeks after receiving the second dose of rituximab infusion. Magnetic resonance imaging revealed an enhanced space-occupying lesion with multiple small cyst-like structures and vasogenic edema in the right temporoparietal area. Her blood culture was positive for Listeria monocytogenes, and a brain biopsy showed necrotic tissues with pus and inflammatory cells. She recovered after a 6-week course of antibiotics with ampicillin and gentamycin.ConclusionsBrain abscess due to Listeria monocytogenes is a risk that should be considered when adding rituximab to the regimen of a patient who is already Immunocompromised

Performance of Teaching and Learning Technology Internship Students as Perceived by Their Trainers

The purpose of this descriptive study is to evaluate the performance of teaching and learning technology students of the College of Education, Sultan Qaboos University during their internship experience. Trainers of the interns rated them on 15 items of performance as displayed in the questionnaire of the study. The internal consistency of the questionnaire was significantly high (.96). It was observed that the general level of performance of the interns was high (a mean of 4.40 out of 5) and the ratings of the individual items of performance ranged from 4.04 to 4.59. However, no gender significant differences were observed in the global ratings of males and females. Apart from this, it was found that 2014 cohort interns performed better than earlier cohorts (before 2014).  The study reveals other significant findings such as location of internship (public or private sector) did not affect performance of interns. Similarly, type of institution (educational or non-educational) was not a significant factor of performance, however, interns in non-educational institutions performed better (though not significantly) than interns in educational institutions). Interns with higher GPAs outperformed their colleagues with lower GPAs. Keywords: Internship evaluation, supervisors’ ratings of interns, teaching and learning technolog

Design and development of mild combustion burner

This paper discussed the design and development of the Moderate and Intense Low oxygen Dilution (MILD) combustion burner using Computational Fluid Dynamics (CFD) simulations. The CFD commercial package was used to simulate preliminary designs for the burner before the final design was sent to workshop for the fabrication. The burner is required to be a non-premixed and open burner. To capture and use the exhaust gas, the burner was enclosed within a large circular shaped wall with an opening at the top. An external EGR pipe was used to transport the exhaust gas which was mixed with the fresh oxidant. To control the EGR and exhaust flow, butterfly valves were installed at the top opening as a damper to close the exhaust gas flow at the certain ratio for EGR and exhaust out to atmosphere. High temperature fused silica glass windows were installed to view and capture images of the flame and analyse the flame propagation. The burner simulation shows that MILD combustion was achieved for the oxygen mole fraction between 3-13%. The final design of the burner was fabricated and ready for the experimental validation

An Algorithm for Inferring Big Data Objects Correlation Using Word Net

© 2016 The Authors. The value of big data comes from its variety where data is collected from various sources. One of the key big data challenges is identifying which data objects are relevant or refer to the same logical entity across various data sources. This challenge is traditionally known as schema matching. Due to big data velocity traditional approaches to data matching can no longer be used. In this paper we present an approach for inferring data objects correlation. We present our algorithm that relies on the objects meta-data and it consults the Word Net thesaurus

Inclusion of the Domains of Sustainable Development in Al Hadith Text Books in the Intermediate Stage

This study aims to identify the areas of sustainable development that should be included in the textbooks of Prophetic Sayings (Hadeeth) in the Kingdom of Saudi Arabia, to determine the degree of availability, and to find out if there are statistically significant differences at (α≤0.05) in the degree of availability. The descriptive analytical method was used to analyze the whole study population. Cooper coefficient of stability, frequencies, and percentages were used to analyze the results and measure the degree of availability of these fields. Chi Square equation was also used to measure the differences between the availability of fields among grades. The social field was firstly ranked with a percentage of 78.16%, and a total of 433 frequencies, while the environmental field followed it with a percentage of 6.98% and a total of 37 frequencies. The paper showed that there were statistically significant differences in the inclusion in Chi equation

Phonological Analysis of English Phonotactics: A Case Study of Arab Learners of English

This study aims to analyze the English phonotactics in the English of Arab learners of English as a foreign language to determine the types of pronunciation difficulties they encounter. More specifically, it investigates the types of declusterization processes found in their interlanguage and the sources of such processes. The results of this study demonstrate that Arab learners of English unintentionally insert an anaptyctic vowel in the onset as well as in the coda of certain English syllables. Results also show that the major reason for declusterization processes is the mother tongue influence. In order to overcome such difficulties, this paper suggests a new approach for teaching and learning L2 syllable structure system