Evaluation of the stiffness of beam and frame elements using system identification techniques

Traditional methods of~ tructural analysis begin usually by the construction of a mathematical model that best represents the prototype structure. Furthermore, the material and geometric properties of the structure appear in the what is known to be either the stiffness matrix or the flexibility matrix, depending on whether the displacement or the force method is used. The subsequent analysis, ie the determination of the response of the system due to any set of loading condition hinges on the availability of such matrices. However, in situations where such information is absent or cannot be accurately computed, the analysis resorts to approximations which undoubtedly lead to erroneous results or to inaccurate ones at best. This is the case with ageing structures that have been in use for long periods of time or when the construction materials have greatly deteriorated. System identification is a method to improve mathematical modelling. Amethod which overcomes the difficulty resulting from the unknown material and geometric properties through a minimization algorithm is known to some applied science disciplines but not widely known to structural engineers. Helou (1)(2) made his presentation limeted to determinate and indeterminate trusses. The present study is an application of the same principles to beam and framed structures, thus the validity of the derived equations would be established and made general to include any structures. 26

Shock wave therapy for spastic plantar flexor muscles in hemiplegic cerebral palsy children

Background: The spastic motor type is the most common form of cerebral palsy (CP). Spastic equines foot is the most frequent deformity in ambulated children with CP. Shock wave therapy on spastic muscles of the upper limb in stroke patients provided a significant reduction in muscle tone.Aim: The present study aimed to investigate the efficiency of shock wave therapy on spastic planter flexor muscles and its relation to the gait in spastic hemiplegic cerebral palsy children.Methods: Thirty spastic hemiplegic cerebral palsy children from both sexes participated in this study. They were divided randomly into two groups of equal number: Group I (control) included 15 children (6 boys and 9 girls), with mean 5.83 ±0.34 years, received the therapeutic exercises program only. Group II (study) included 15 children (6 boys and 9 girls), with mean age 5.75 ± 0.51 years, received the same therapeutic exercises program which was given to the control group, in addition to shock wave therapy for 1 week (3 session/week).Results: Comparing the pre and post treatment mean values of the Hoffman reflex/Motor response (H/M) ratio and gait variables, revealed statistically significant differences in these variables in the study group.Conclusion: The shock wave therapy is effective in the treatment of hypertonic muscles which help those children to become more independent and participate in everyday activities.KEYWORDS: Shock wave therapy; Spasticity; Cerebral palsy; Gait; H/M rati

Cosine-Based Clustering Algorithm Approach

Due to many applications need the management of spatial data; clustering large spatial databases is an important problem which tries to find the densely populated regions in the feature space to be used in data mining, knowledge discovery, or efficient information retrieval. A good clustering approach should be efficient and detect clusters of arbitrary shapes. It must be insensitive to the outliers (noise) and the order of input data. In this paper Cosine Cluster is proposed based on cosine transformation, which satisfies all the above requirements. Using multi-resolution property of cosine transforms, arbitrary shape clusters can be effectively identified at different degrees of accuracy. Cosine Cluster is also approved to be highly efficient in terms of time complexity. Experimental results on very large data sets are presented, which show the efficiency and effectiveness of the proposed approach compared to other recent clustering methods

Genetic variability of camel (Camelus dromedarius) populations in Saudi Arabia based on microsatellites analysis

The genetic diversity and population genetic structure of dromedary camels (Camelus dromedarius) are poorly documented in Saudi Arabia. The present study was conducted to address some of these genetics using four Saudi Arabian camel populations namely; Magaheem (MG), Maghateer (MJ), Sofr (SO) and Shual (SH). Genomic DNA was extracted from the hair roots of 160 camels, 40 individuals from each population. Sixteen microsatellite markers were used to genotype these 160 camels. Out of these 16 markers, only microsatellite VOLP67 did not produce any polymerase chain reaction (PCR) amplicons. There were 139 alleles generated by the 15 microsatellites loci with a mean of 9.27 alleles per locus. Four of the microsatellites loci studied in MG, eight in MJ and six in both SO and SH were found to be deviated from Hardy-Weinberg equilibrium. The fixation genetic indices (Fst) among the four populations were very low, ranging from 0.006 (between SH and SO) to 0.017 (between MG and MJ), indicating low population differentiation among the four Saudi camel populations. No significant heterozygote excess or bottleneck in most nearest past was detected in the four camel populations as indicated by sign, standardized differences and Wilcoxon tests, along with the normal L shaped distribution of mode-shift test. The present study showed that the microsatellite markers are powerful tools in breeding programs, although there is a need for applying more microsatellites in order to be able to discriminate fairly between camel populations of Saudi Arabia.Keywords: Camels, Camelus dromedarius, microsatellite markers, Saudi Arabia, genetic variabilit

Phytochemical Analysis and Antibacterial Screening of Asparagus Flagellaris (Kunth) Bak used in The Traditional Treatment of Sexually Transmitted Diseases and Urinary Infections

The phytochemistry and antimicrobial effect of the stem, bark and leave of Asparagus flagellaris were studied. The phytochemical screening of the stem, bark and leaves showed appreciable amount of flavonoid and moderate amount of carbohydrate, cardiac glycoside and saponin while reducing sugar, ketones and pentose were detected in traces. The ethanol extract inhibited the growth of six organisms viz Escherichia coli, Corynebacteria, Klebsiella, Neiserra gonorrhoeae, Shegiella dysentariae and Candida albicans, at various concentrations, while the aqueous extract were susceptible on five organism namely Corynebacteria, Streptococcus pyogene, Proteus specie, Neiserra gonorrhoeae, and Treponema palladium. Keywords: Asparagus flagellaris, phytochemical, ethanol extract, aqueous extract and antibacterial screening.Ethiopian Journal of Environmental Studies of Management Vol. 1 (2) 2008: pp. 44-4

Effects of aqueous leaves extract of Ocimum gratissimum on blood glucose levels of streptozocininduced diabetic wistar rats

The hypoglycemic effects of aqueous leaves extract of Ocimum gratisimum was investigated in streptozocin-induced diabetic rats. A single administration of the extract at the doses of 250, 500 and 1000 mg/kg body weight was done. The aqueous extract at the dose of 500 mg/kg significantly lowered blood glucose level (

An investigation into methods for dose optimisation for paediatric AP pelvis projections when considering size variations

PurposeThere is a lack of literature on paediatric x-ray dose optimisation; this is especially true for pelvis radiography using digital systems. Various reasons exist for this including the limited availability of paediatric phantoms on which to conduct optimisation studies and that the paediatric age/size range is broad, unlike the adult. This adds to the complexity of optimisation. The paediatric population presents a further complexity regarding the high potential for radiation damage. This is because they have a longer time left to live and are more radiosensitive.To address the lack of phantoms available for optimisation studies, this thesis presents a novel, low-cost approach for the construction and validation of paediatric X-ray phantoms. Using this approach, three phantoms were produced to answer the research questions posed in this thesis. Using these phantoms, experiments were conducted to optimise dose and image quality. The outcomes of these experiments have value to AP pelvis X-ray imaging in children.MethodConstructed of plaster of Paris and PMMA, the three phantoms were made to represent 1, 5 and 10-year-old paediatric pelvises. Using these phantoms, dose optimisation studies were undertaken combining assessments of image quality (IQ) and radiation dose for each paediatric age. Systematic variations (factorial design) of exposure factors (kVp, mAs, SID and additional filtration) were conducted to acquire AP pelvis X-ray images. Images for the 1 and 5-year-old phantom were acquired with manual exposure control. While the images for the 10-year-old were acquired with automatic exposure control (AEC), including assessing the effects of orientation and chamber configuration. IQ was assessed using SNR and CNR values measured by placing a region of interest (ROI) on the bony anatomies within the pelvic area. Visual IQ was assessed using relative and absolute VGA methods with an IQ scale, combining the sharpness and clarity of the visibility of bony anatomies. The radiation doses were measured by placing a dosimeter on the surface of each phantom. Analyses for optimisation included main effects, correlation and regression.ResultsUsing physical and visual measures, phantom validation demonstrated close similarity to the human paediatric pelvis. Using the phantoms, ‘dose optimised techniques’ for diagnostically acceptable IQ for each paediatric age were as follows: 65 kVp, 2 mAs, 115 cm SID and 1 mm Al + 0.1 mm Cu additional filtration for 1 year-olds; 62 kV,p 8 mAs, 130 cm SID and 1 mm Al + 0.1 mm Cu additional filtration for 5 year-olds; 89 kVp, 130 cm SID and 1 mm Al + 0.1 mm Cu additional filtration (Head Away (HA) from the two other AEC chambers whilst using both of these chambers) for 10 year-olds. The main effect analysis showed a continuous increase/decrease for increasing exposure factors except for kVp. IQ at first increased with kVp until kVp reached a specific point, beyond which IQ decreased. The correlation test showed moderate and strong correlations between mAs and radiation dose, and physical and visual IQ for both imaging modes. kVp showed either a weak or no correlation with radiation dose and IQ for manual imaging. Physical and visual IQ measures showed moderate to strong correlations for manual and AEC. Regression analysis showed that mAs and filtration had the highest impact when undertaking manual imaging. The regression analysis for AEC imaging showed that filtration had the highest impact on radiation dose, while kVp had the highest impact on IQ.ConclusionPaediatric pelvis phantoms that are suitable for dose optimisation studies can be produced at low cost using readily available materials. Using the phantoms, optimal imaging techniques for AP pelvis were identified for 1, 5 and 10 year-olds. Further work is recommended, including developing electronic look-up tables for selecting exposure conditions which give acceptable image quality at low doses

Preliminary antidiarrhoeal activity of methanolic extracts of Securinega virosa (Euphorbiaceae)

Securinega virosa is used as remedy for diarrhoea in tropical Africa, but has not been investigated for its antidiarrhoeal activity. This study was therefore aimed at investigating the methanolic extracts of theleaves, stem bark and root bark for antidirrhoeal activity, using castor oil-induced diarrhoeal model in mice. The effects of these extracts on perfused isolated rabbit jejunum were also evaluated. Themethanolic leaves extract (8 x 10-5 – 1.6 x 10-3 mgml-1) produced a dose-dependent relaxation of the rabbit jejunum, while the methanolic stem bark and root bark extracts (2 x 10-5 – 3.2 x 10-3 mgml-1)produced contraction of the tissue. The methanolic root bark extract produced a dose-dependent protection against the castor oil- induced diarrhoea with the highest protection (100%), obtained at 100mgkg-1 comparable to that of loperamide (5 mgkg-1), the standard agent. The leaves extract also protected the mice but was not dose-dependent. The highest protection (60%) was obtained at thelowest dose (50 mgkg-1). The stem bark extract did not protect the animal against diarrhoea. The preliminary phytochemical analysis revealed that the three extracts contained similar phytochemicalconstituents which include alkaloids, tannins, saponins, flavonoids and cardiac glycosides. However, only the leaves extract contained anthraquinone glycosides. The acute toxicity test revealed the medianlethal dose (LD50) values for the leaves, stem bark and root bark extracts to be 1265, 288.5 and 774.6 mgkg-1 respectively. This suggests that the stem bark extract is relatively the most toxic. These results obtained revealed that the leaves and root bark extracts possess pharmacological activity against diarrhoea and may possibly explain the use of the plant in traditional medicine