Span morphing using the GNATSpar wing

Rigid wings usually fly at sub-optimal conditions generating unnecessary aerodynamic loses represented in flight time, fuel consumption, and unfavourable operational characteristics. High aspect ratio wings have good range and fuel efficiency, but lack manoeuvrability. On the other hand, low aspect ratio wings fly faster and are more manoeuvrable, but have poor aerodynamic performance. Span morphing technology allows integrating both features in a single wing design and allows continuously adjusting the wingspan to match the instantaneous flight conditions and mission objectives. This paper develops, a novel span morphing concept, the Gear driveN Autonomous Twin Spar (GNATSpar) for a mini-UAV. The GNATSpar can be used to achieve span extensions up to 100% but for demonstration purposes it is used here to achieve span extensions up to 20% to reduce induced drag and increase flight endurance. The GNATSpar is superior to conventional telescopic and articulated structures as it uses the space available in the opposite sides of the wing instead of relying on overlapping structures and bearings. In addition, it has a self-locking actuation mechanism due to the low lead angle of the driving worm gear. Following the preliminary aero-structural sizing of the concept, a physical prototype is developed and tested in the 7?×5? wind-tunnel at the University of Southampton. Finally, benefits and drawbacks of the design are highlighted and analysed

Span morphing using the compliant spar

This paper develops and models the Compliant Spar concept that allows the wing span to be varied to provide roll control and enhance the operational performance for a medium altitude long endurance (MALE) UAV. The wing semi-span is split into morphing partitions and the concept maybe incorporated in each partition; however only the tip partition is considered here. The Compliant Spar is made of compliant joints arrange in series to allow the partition to be flexible under axial (spanwise) loads but at the same time stiff enough to resist bending loads. Each compliant joint consists of two concentric overlapping AL 2024-T3 tubes joined together using elastomeric material. Under axial (spanwise) loading, the elastomeric material deforms in shear allowing the overlapping distance between the tubes to vary and hence the length (in the spanwise direction) of the joint/spar to vary. High fidelity modelling of the concept is performed. Then, structural optimisation studies are performed to minimise the axial stiffness and the structural mass of the concept for various design constraints. The flexible skin and actuation system to be used are also addressed

The degree of social and educational integration and absorption of Arab Bedouin female students in teacher training institutions in Israel

The issue of the process of integration and absorption of Arab Bedouin female students in teacher training institutions in Israel constitutes a significant yet critical chapter in the course of forming the personal and professional identity of the prospective teacher. The main purpose of this article is to describe the difficulties experienced by Arab Bedouin female students during the process of their social and educational integration and absorption in teacher training institutions. Also, to deal with the differences between Arab and Jewish teacher training institutions. Furthermore, to what extent the cultural encounter is perceived by the students that would enable them to have social and educational integration.The study involved 200 Bedouin Arab female students living in the Negev and learning in four teacher-training colleges in Israel; Kaye College of Education, Achva College, Sakhnin College for teacher training and Al-Qasmi College. The students answered a questionnaire that was written for this study. The findings of the study indicated many difficulties in the process of absorbing and integrating Arab Bedouin students in various teacher-training institutions in the country. Not to mention, language difficulties experienced by them with regard to reading articles and writing papers, not in their native tongue. The multicultural encounter between the different genders also poses a great difficulty in addition to the age difference between Arab and Jewish students. Furthermore, the policy of the Israeli academic institutions does not fully represent the Arab culture and in the interaction between the academic and administrative staff and the Arab Bedouin students

Effects Of Cable Diameter Reduction And Snapping On The Behavior Of Cable-Stayed Bridges

Cable–stayed bridges are usually constructed in coastal area in which the surrounding atmospheric is considered as severe environmental condition. This atmosphere helps in building up quickly the corrosion of steel cables with time. Visual inspection of cable-stayed bridges built up worldwide shows that the bridge cables suffer from serious corrosion although the cables are protected using different techniques. There is a considerable reduction in cable diameter due to corrosion, which depends on the severity of the environmental condition. There is no sufficient information regarding the effect of reduction in cable diameter on the structural response of cable-stayed bridge. Furthermore, snapping of cables due to accidental and /or corrosion is another important issue which affecting the structural response and safety of cable stayed bridges and need to be addressed for safe design.In this research, the effect of reducing cables diameter, cables layout and snapping of individual cables on the structural behavior and safety of cable-stayed bridge are presented. Three cable layouts are analyzed in this study i.e. harp, semi harp and fan layouts. In each layout, five different reductions in cables diameters are considered i.e 12.50%, 25.00%, 37.50%, and 50.00%. To address snapping of cable, harp bridge layout is considered and the structural behavior of the bridge due to snapping individual cables in the bridge are presented and discussed. The analysis starts with initial shape analysis to stress the cables to minimize the deformation under self-weight of the structure. The analysis was carried out using stiffness method considering the geometrical nonlinearities. The results of initial shape analysis show that in all bridge layouts reflect comparable behavior. The cable forces were found to be the lowest in fan layout cable bridge compared to harp and semi harp layouts. Reducing cables diameter will lead to a redistribution of forces and moment in different components of the bridge and alter the structural behavior in a nonlinear fashion. Reducing cables diameter by 25% will compromise the bridge safety as the stresses in cables, deformation, and bending moment will be increased significantly. The bridge cable layouts have little effect on the structure response of the cable-stayed bridge with reduced cables diameter. The fan layout shows better structural response compared to harp and semi harp layout, especially in term of cable forces and deformation profile. Notwithstanding this fact, 25% of cables reduction diameter will significantly affect the moment in girder of fan bridge layout compared to other layouts of cables Snapping the individual cable in the bridge has a significant effect on the cable force and bending moment distribution in the girder, tower and will cause bridge failure

Synthesis of Phosphonate Analogues of the Antibiotic Moenomycin A12

SUMMARY The moenomycin-type compounds are known to inhibit selectively the enzyme penicillin binding protein 1b (PBP 1b) that catalyses the transglycosylation reaction in the biosynthesis of bacterial cell wall peptidoglycan. The moenomycins (see moenomycin A12) have been shown to interfere with this biosynthetic step interacting with the enzyme(s). The moenomycins do not induce resistance readily. A weak point in this respect may, however, be the phosphate bond to unit F. Its cleavage by a yet poorly characterized enzyme is the only enzymatic degradation reaction of the moenomycins that is known to-date. With this in mind we started a programme aimed at synthesizing trisaccharide analogues of moenomycin A12 in which the phosphate oxygen at C-1 of unit F is replaced by a CH2 group. It seemed important to retain all other functional groups in ring F as present in moenomycin since they are known to be of major importance as far as antibiotic activity is concerned. It appeared that the commercially available and cheap b-D-galactose-pentaacetate 30 would be an interesting starting material for this synthesis. In this work, the synthesis began with the introduction of the C-glycoside appendage at position 1 according to Giannis et al., thus forming the allyl C-galactopyranoside 34, a substance that represents the first C-glycosyl backbone for the synthesis of the glycosyl acceptors. The total synthesis of the glycosyl acceptors is shown in Scheme 6.1. We wanted to convert the C-allyl glycoside 34 into its propenyl analogue. Attempts to achieve this with singlet oxygen and palladium-mediated reaction proved fruitless. On the other hand, ene reaction of 34 with 4-phenyltriazolin-3,5-dione in CH2Cl2 provided 56 in 83 % yield. Ozonolysis of this alkene (-70 °C, MeOH-CH2Cl2) and subsequent quenching with dimethyl sulfide, followed by reduction of the crude aldehyde with sodium acetoxyborohydride (prepared from NaBH4 and AcOH in THF) furnished the primary alcohol 35 (85 %). This alcohol was converted into the mesylate 60 (60 %), and this in turn into the bromide 61 (80 %) by heating it at 80 °C with tetrabutylammonium bromide in toluene. The acetate groups were hydrolysed using Zemplén conditions to furnish 62 quantitatively. The primary hydroxyl group in 62 was protected as a tBuPh2Si ether 63 (85 %) on reaction with TBDPSCl in DMF at 0 °C, and as a tBuMe2Si ether 94 (87 %) on reaction with TBDMSCl in DMF at 0 °C in the presence of imidazole. PTScatalysed isopropylidenation of the 3,4-diols 63 and 94 with 2,2-dimethoxypropane in dry acetone gave the 3,4-O-acetonide derivatives 53 (88 %) and 95 (90 %), respectively. On the other hand, the glycosyl acceptor 53 was converted into the glycosyl acceptor 92. The free hydroxyl group in compound 53 was protected as an acetate group on reaction with acetic anhydride in pyridine in the presence of DMAP giving 89 (88 %). The silyl ether in 89 was cleaved with a molar solution of TBAF in THF affording compound 90 in 87 % yield. The free hydroxyl group in 90 was then subjected to an oxidation using the TEMPO method affording the aldehyde which was in turn oxidised with sodium chlorite to the corresponding acid. The acid was converted to the amide 91, making use of Staab''s method, in which the acid was activated with CDI in dichloromethane to give the imidazolide, which upon reaction with ammonia furnished the amide 91 in an overall yield of 95 %. The required glycosyl acceptor 92 was obtained in quantitative yield by cleavage of the ester bond at position 5 under Zemplén conditions. Disaccharide formation was achieved employing the Jacquinet and Blatter method, which involves the use of glycosyl donor 67 and TMSOTf. No reaction was observed between this donor and acceptor 92, which may reflect the low nucleophilicity of the acceptor. On the contrary, glycosylation with acceptor 53 gave 68 (79 %). Deprotection of the silyl group in the disaccharide 68 was easily accomplished on treatment with a molar solution of TBAF in THF at RT affording 71 (89 %). Synthesis of the uronamide 72 was achieved after three major steps, in an overall yield of 98 %. Oxidation of the primary hydroxyl group in unit F to the corresponding aldehyde was accomplished with sodium hypochlorite and TEMPO. Oxidation of the crude aldehyde to the carboxylic acid with sodium chlorite followed by amide formation according to Staab gave 72. Removal of the isopropylidene group from 72 with trifluoroacetic acid (TFA) at RT furnished the diol 73 (89 %). Introduction of the carbamoyl group at C-4F position was achieved in two steps. Conversion of the diol 73 into the cyclic carbonate 76 with CDI in CH2Cl2 (84 %) and subsequent ring opening of this carbonate by bubbling a stream of gaseous ammonia into the CH2Cl2 solution at 0 °C gave 74 (62 %) as well as its isomer 77 (21 %). Dehalogenation of the N-trichloroacetyl group was intensively studied, but interactions of other functional groups in the studied substances could not be avoided. The base-labile carbonate in 76 and the carbamoyl group in urethane 74 were cleaved under the reaction conditions. Hydrolysis of 76 with 0.5 M LiOH in MeOH-THF (1:1) followed by acetylation gave 80 (73 %), while its reduction with NaBH4 in ethanol followed by acetylation gave 82 (60 °C, 85 %; RT, 83 %). On the other hand, reduction of 74 with NaBH4 in ethanol at 60 °C followed by acetylation gave 82 (78 %), while performing the reduction step at 5 °C (THF-MeOH 4:1) or at RT (ethanol or isopropanol) gave 80 in an average yield of 65 %. In a non reproducible reaction (NaBH4, EtOH, RT, then Ac2O, pyridine, RT), the desired compound 83 (42 %) was obtained accompanied by 82 (46 %) The reaction between the N-trichloroacetyl group and NaBH3CN was also fruitless. The phosphonate grouping was installed making use of Arbuzov reaction furnishing 85 (70 %). Trisaccharides could not be obtained from the oxazoline donor 42 (prepared from chitobiose octaacetate 86) through its reaction with acceptor 53. There was also no coupling product between the recently synthesized donor 88 and the acceptor 92. However, in this work, trisaccharide formation was achieved through the glycosylation reaction of donor 88 and acceptor 95 in 50 % yield (-30 °C, 1,2-dichloroethane, 3 Å, TMSOTf-TEA). Selective deprotection of the TBDMS group in compound 96 was accomplished at -10 °C with 1 eq of a molar solution of TBAF in THF. The free hydroxyl group of 97 was subjected to an oxidation using the TEMPO method affording the aldehyde. After oxidation of the aldehyde with sodium chlorite, the resulting carboxylic acid was converted according to Staab''s method into the amide 93 in an overall yield of 95 % (based on 96). There were difficulties in converting the N-phthalimido group in 93 to the N-acetyl group which is necessary for biological activity of moenomycin-type compounds, since the reactions were accompanied by elimination of HBr. In conclusion, the synthetic methods employed in this work allow to prepare the di- and trisaccharides C-phosphonate analogues of moenomycin A12.Synthese von Phosphonat-Analoga des Antibiotikums Moenomycin A12 Universität Leipzig, Dissertation Diese Arbeit enthält 130 Seiten, 73 Abbildungen, 1 Tabelle, 156 Literaturangaben Referat: Im Rahmen der vorliegenden Arbeit wurden C-Glycosid-Di- und Trisaccharid-Bausteine des Antibiotikums Moenomycin A12 ausgehend von b-D-Galactose-pentaacetat hergestellt. Das Ausgangmaterial wurde in D-Galactoheptonamid übergeführt. Die Einheit F des Disaccharidbausteins hat alle Substituenten, die die Einheit F des Moenomycins A12 hat. Der ausgearbeitete Syntheseweg sollte zur Synthese anderer Analoga geeignet sein

Determination of Primordial and Anthropogenic Radionuclide Concentrations in Agricultural Soil Of The United Arab Emirates Using Gamma-Ray Spectrometry

The United Arab Emirates (UAE) has initiated the first civilian nuclear power plant, and it will be operating four reactors between (2018-2020). The establishment of Barakah Nuclear Power Plant, which will employ the nuclear power to generate clean energy, is a significant step forward minimizing the UAE carbon footprint. Before the construction of any regulated nuclear facility, it is essential to investigate the environmental background radiation level in the country. Such an investigation is critical for providing the background data for the environmental impact assessment of the nuclear facility. The present study represents the first research effort in the (UAE) to build a database of agricultural topsoil radioactivity concentrations established using standard sampling and analytical procedures. This study determines the primordial radionuclides concentrations obtained from 145 soil samples collected from multiple agriculture farms in the United Arab Emirates. Collected soil samples were analyzed to establish radioactivity concentration levels associated with 226Ra, 232Th and 40K. High-resolution gamma-ray spectrometry measured the activity concentrations. The results indicate that the mean specific activity concentrations (in BqKg-1) were 15.34 ± 2.8, 4.18 ± 1.4 and 310.74 ± 63.9 for 226Ra, 232Th, and 40K, respectively. Besides, the study determines the anthropogenic radionuclides concentration. Cesium-137 was detected in a little number of samples with a specific activity of 0.75 ± 0.01 BqKg-1. All study collected sample activities and radiation parameters were found to be below maximal admissible values established in various international recommendations and standards. Also, the present study represents the first documented baseline concentration of the UAE soil minerals, trace, and heavy metals contents. The mean values (mg Kg-1) were: Al - 8,539.7, As - 2.17, B - 47.68, Ca - 86,264.5, Cd - 0.35, Co - 10.30, Cr - 111.20, Cu - 14.32, Fe - 9,839.80, K - 2,026.80, Mg - 26,688.30, Mn - 237.40, Mo - 0.02, Na - 470.40, Ni - 60.90, P - 450.60, Pb - 4.25, S - 2,393.50, Si - 795.68, Sr - 593.70, V - 20.90 and Zn - 24.90. Further, study results were compared against international recommended levels. Also, we provided recommendations to the UAE concerned entities regarding regulating the concentrations of these elements found in the agricultural soil. Future research recommendations include extending the study scope to cover all the agricultural farms in the UAE including organic farms. The study results supported radioactivity concentration and mineral mapping of the UAE soils using the Geographic Information System (GI

The role of local municipal branches in planning, developing and managing urban growth in Saudi Arabian cities :a case study of the city of Jeddah

PhD ThesisThe impacts of urbanization are becoming increasingly recognized and severe both on national and international levels. The demands of growing populations in cities cause major economic, social and environmental problems. These problems can relate to inadequate infrastructure and lack of access to essential services. The rising awareness and challenges of rapid urbanization has led to urban governance and growth management becoming major research themes in the academic literature as good development principles are sought for effective planning management in urban and surrounding areas. This study focuses on cities in Saudi Arabia, in particular the Jeddah Municipality, which shows some classic problems and issues relating to urbanization. The main research aim was to determine to what extent the current organizational structure of Jeddah is appropriate to address the problems of urban areas. Furthermore, this study has looked at establishing an analytical framework that can contribute to improving management and organization of urban development in the city of Jeddah, by investigating the role of the Jeddah Municipality and Municipal branches to improve the management of urban areas and address their impact on city planning both economically and socially. Primary data was collected through questionnaires and interviews with officials and citizens in the city of Jeddah. It was found that the city of Jeddah grew rapidly and significant activity in terms of physical changes and economic and population growth created a number of problems including inadequate provision of municipal services and public facilities to the citizens; reliance on central administration to conduct affairs and do decision-making without taking into account requests and needs of citizens and their desires to participate in the urban development of the city. A number of recommendations are made to promote change in the organizational structure of the Jeddah Municipality and the municipal branches, as the study showed that the current structure lacks integrity with regard to urban planning, development and management of growth. These include improving the existing organizational structure and making it more efficient and improving in the ability to iv manage changes informed by citizen needs. It is hoped that these recommendations will be effective not only in Saudi cities but also in other cities worldwide

Improving Patient Confidentiality Systems in Libya using UK Experience

Patient confidentiality has received much attention in recent years because of the rise in the number of confidentiality breach incidents and the need to improve the provision of health services in general. Patient confidentiality is defined as the patients‟ right to the protection of their personal medical information within health institutions under normal conditions. While literature on the protection of patient confidentiality exists, there is little or no attempt made to use a theoretical model to represent this, and hence, with which to appraise the practice of patient confidentiality in health care systems. The main aim of this research study is to contribute to the development of a model for the protection of patient confidentiality in Libya, using experience and evidence from elsewhere, and also to suggest means to improve confidentiality through the application of lessons from the UK health service. The standpoint taken is a pragmatic one, as the focus is on the utility of the proposed model. There are two principal strands to the research: one concerns the views of experts as to factors that influence patient confidentiality. The second major one is the development of a System Dynamics Model to present the flow of patient data and the places where breaches of confidentiality are likely to occur. These two strands are then considered jointly to provide a basis for conclusions and recommendations of particular relevance in Libya (and perhaps more generally). The data used to identify the main factors that affect the practice of patient confidentiality were collected using two stages: literature review and expert surveys. The first iteration requesting views was sent to experts from Libya, Europe and elsewhere in the field of patient confidentiality, to establish a set of factors that might influence the practice of patient confidentiality. A second iteration followed with selected respondents to rank the relative importance of elements of contributing to two factors, trust and ethics, that were identified in the first expert letter survey. The results from the expert letters indicated that the main factors that influence the practice of patient confidentiality, especially in Libya, were trust, ethics, regulation and technology. The results from the interviews and the focus group showed that the findings of the current research had ecological validity. This is based on the Libyan participants‟ views, which strongly supported the research results as having the potential to improve Libyan patient confidentiality systems by learning from the UK experience. The responses were used to inform the insights obtained from the UK NHS model of patient confidentiality of 2003, which was developed into an innovative simulation using Systems Dynamics Modelling (SDM). Quantitative data to populate the model was drawn from NHS statistics. The model was „validated‟ through personal interviews and a focus group with individuals who had experience in the practice of patient confidentiality in the Libyan health service. The results of the running of the SDM model were also compared to known data to provide a check on validity. The proposed SDM model of patient confidentiality was shown to have ecological validity though the views of medical staff and medical records managers in two major general UK hospitals. The premise was that breaches of patient confidentiality could occur either from (i) human error when dealing with patient medical data within the national health services by staff such as frontline medical staff, doctors and nurses, or (ii) at locations of safe-keeping of patient notes, where medical records managers and others store patient medical data on IT systems, with varying dynamics and volume. The results obtained from the developed model of patient confidentiality are encouraging; they may assist health service managers to minimize breaches of patient confidentiality occurrences. Therefore, the current study proposes a framework and recommendations that can help to improve the protection of patient confidentiality systems in the Libyan health service and assist in delivering a good quality of health care

EXTRACTION OF URANIUM (VI) FROM NITRIC ACID AND NITRATE SOLUTIONS BY TRIBUTYLPHOSPHATE/KEROSENE

The extraction of nitric acid and hexavalent uranium from nitric acid and nitric acid containing uranium (VI) media by tributyl phosphate (TBP)/kerosene has been studied, and all factors affecting the extraction process (time of mixing, uranium concentration, nitric acid concentration, TBP concentration, temperature) have been investigated. The equilibrium constant of the extraction reaction of uranium by TBP: UO22 + + 2 NO3- + 2 TBP \leftrightarrows UO2(NO3)2 . 2TBP was found to be 102.464, 102.668 L4/mol4 at 25 \ oC, and the enthalpy was -16.47, -23.07 kJ/mol for 0.5 M and 1 M nitric acid concentrations, respectively. The purification of the yellow cake produced at the pilot plant of uranium extraction from the Syrian wet phosphoric acid was investigated using TBP/kerosene

Primary Antiphospholipid Syndrome Unusual Presentation in a Seventy Two Year Old Man

A 72 year old man with a history of TIAs and stroke with unexplained moderately raised ESR presented a year later with rapid deterioration of vision in his left eye because of central retinal vein occlusion. Primary antiphospholipid syndrome is found in patients with history of arterial or venous thromboembolism, thrombocytopenia and recurrent fetal loss without features of SLE