EFFECT OF DESIGN CHANGING OF RING CLASP ON ITS RETENTIVE FORCE: EFEK PERUBAHAN DESAIN RING CLASP TERHADAP KEKUATAN RETENSI

Different designs of ring clasp were indicated in short or long span bounded saddle. However, few researches have been done to calculate their retentive absolute forces. The purpose of this in-vitro study was to measure the retentive force of four different ring clasp designs. A test model was made from maxillary plastic replica. Second molar was seated in silicone mould then poured with dental stone. 24 cobalt-chromium ring clasp designs were fabricated to engage 0.5mm undercut using standard casting technique. They were examined radiographically for any casting defects. The dislodging force was measured for each clasp using universal testing machine. The results showed that ring clasp design 2 produced the highest retentive force, while, clasp 4 was the lowest among the other clasps. In addition, significant difference regarding the mean retentive force was estimated among designs 1, 2 and 4. The means of retentive force of ring 1, 2, 3, and 4 were equal to 17.40 ±2.97, 17.52 ±3.05, 12.35±0 .98, and 11.15±2.15 N, respectively. Modifying the ring clasp design by adding extra rest or fortification will change its retentive force using the same undercut depth. Each ring design provides definite retentive force. As conclusion, each ring clasps design offered specific retentive force in dry environ-ment. However design 2 presented the highest force rate while design 4 was the least retentive

STR-832: ULTIMATE FLEXURAL STRENGTH AND LONG-TERM CREEP DEFLECTION FOR STRUCTURAL INSULATED FOAM-TIMBER SANDWICH PANELS

The structural insulated panel (SIP) is a sandwich structured composite that is prefabricated by attaching a lightweight thick core made of Expanded Polystyrene (EPS) foam laminated between two thin, and stiff face skins made of Oriented Strand Board (OSB). The use of sandwich panels provides key benefits over conventional materials including: very low weight; high stiffness; durability and; production and construction cost savings. The facing skins of the sandwich panel can be considered as the flanges for the I-beam carrying bending stresses in which one face skin is subjected to tension, and the other is in compression. The core resists the shear loads and stabilizes the skin faces together giving uniformly stiffened panel. OSB is wood product that shrinks when dry and swells when adsorb moisture either due to liquid or vapor from the surrounding atmosphere. The relative combination of relative humidity and temperature is introduced into the equilibrium moisture content (EMC) that increases with the increase of the relative humidity and with decreasing temperature. Experimental test matrix includes testing 2.44 m (8’) and 4.88 m (16’) long SIPs for 5 years under different sustained loads and weather resistive barriers (WRBs), recording creep deflection, relative humidity and temperature. After creep recovery, the SIPs are loaded to-collapse to determine their flexural strength

Stability and Mechanism of Degradation of Some Brominated Copolymers

The non-flammability properties of halogenated polymeric materials has been given a great deal of attention in the last few years, their thermal decomposition and thermal stability properties having been of particular interest

Medical Treatment of Cystoid Macular Edema with Topical Steroids and Topical Non-Steroidal Anti-Inflammatory Drugs

Aim: To provide knowledge that topical steroids and topical non-steroidal antiinflammatory drugs "NSAIDs";can cure cystoid macular edema "CME"; which iscurrently mostly treated by invasive procedures "i.e. intravitreal steroids and antiVEGF, laser and vitrectomy".Introduction: Through many years ever since the CME has been discovered by Irvin,invasive interventions were regarded as the most effective curative modalities oftreatment. Recently it was proved that there is an inflammatory reaction in the processof CME formation, based on that evidence many studies started aiming at evaluating therole of anti-inflammatory agents in the treatment of CME.Case presentation: A 60 years old gentleman presented with deterioration of vision inhis right eye over 45 days, he is on antiglaucoma medications and has undergone aglaucoma surgery two years back, there were no any associated systemic symptoms ordiseases. On examination: the left eye was diagnosed as end stage glaucoma and so itwas excluded from the examination; on examination of the right eye: best correctedvisual acuity was 6/36; intra ocular pressure "IOP" 10 mmHg, dilated fundusexamination: Optic disc: glaucomatous atrophy, Vessels: attenuated arterial system andcongested venous system, Macula: dull with irregular slit lamp light appearanceindicating microcysts formation; and Periphery: was non informative, Ocular CoherentTomography "OCT": showed marked increased thickness of the retinal layers with cystsformation at the macular area. Accordingly the patient was diagnosed as cystoid macularedema and hence the plan was to put him on topical steroids and topical NSAIDs eyedrops qid, a regular follow up and measurement of IOP.Results: OCT repeated after a month and there were no obvious changes, four monthslater OCT showed a remarkable improvement; i.e. the thickness is much lesser, anotherOCT after a further month showed complete resolution of the edema, and best correctedvisual acuity was 6/24.Discussion and Conclusion: CME is in part an inflammatory condition; so it couldpossibly be treated with anti-inflammatory agents, such as topical steroids and NSAIDs,as it is evident in this case CME can be totally cured without the need of invasiveprocedures

Nonlinear estimation of coupling and directionality between signals: Application to uterine EMG propagation.

International audienceUnderstanding the direction and quantity of information flowing in a complex system is a fundamental task in signal processing. Several measures have been proposed to detect the quantity of synchronization and the directionality between time series and in physiological data. In this paper we use two methods that are widely used in synchronization and directionality analysis: Nonlinear correlation coefficient (h(2)) and the general synchronization (H). The performances of both methods were tested on four dimensional coupled synthetic nonlinear Rössler models. They were then applied to a single real labor contraction uterine EMG burst with the aim of using them to detect synchronization and to plot the map of direction of information flow between the whole signal channels. The results on synthetic signal show a slight superiority of H over h(2). The results obtained on a single contraction are encouraging for the future use of these tools for resolving the open question of the directionality of uterine contractions and may provide a way of finding their source loci

Enhancing the Performance of Power System under Abnormal Conditions Using Three Different FACTS Devices

In this paper, a comparison between Flexible Alternating Current Transmission System (FACTS) devices including Static Synchronous Compensator (STATCOM), Static Synchronous Series Compensator (SSSC) and Unified Power Flow Controller (UPFC) for providing a better adaptation to changing operating conditions and improving the usage of current systems. The power system using FACTS devices is presented under different conditions such as single phase fault and three phase fault. A digital simulation using Matlab/Simulink software package is carried out to demonstrate the better performance including the voltage and the current of the presented system using FACTS that located between buses B1 and B2 under different faults types. The results obtained investigate that the presented system gives better response with FACTS as compared to not using them under abnormal conditions besides, the UPFC gives better performance of power system under several faults as compared to STATCOM or SSSC as It can absorb reactive power in a manner which significantly reduced the fault current. It is demonstrated that UPFC can reduce the peak fault current at bus B1 ‎to 63.85% of its value without ‎using FACTS devices under line to ground fault and 79.18% under three line to ‎ground fault whereas STATCOM and SSSC reduce it ‎to (75.21, 94.35%) and (75.40, 94.68%), respectively

IN VITRO PROPAGATION OF PLECTRANTHUS BARBATUS ANDREWS AS IMPORTANT MEDICINAL PLANT

Plectranthus barbatus Andrew (Coleus forskolii) is one of the important species of the genus Plectranthus (Coleus) belonging to family Lamiaceae, with a many of traditional medicinal uses in India. C. forskolii is only known source of forskolin; a compound with a many uses in pharmaceutical industries. C. forskolii was lack in Egyptian flora. Moreover, there were no previously studies on this plant in Egypt. Therefore, the present study used tool of biotechnology to conserve the stocks of this plant by micropropagation. C. forskolii seedlings came from its native Thailand at June 2013 and were put in the greenhouse in Desert Research Center for creating an efficient micropropagation protocol. The study was carried out on the effect of growth regulators (cytokinins and auxins) on different micropropagation stages of the explants. In multiplication stage, initiated shoots were cultured on MS medium supplemented with various concentrations (0.5, 1.0, 1.5 and 2.0 mg/L) of cytokinins (6-benzylaminopurine (BA), Kinetin ( KIN) and Thidiazuron (TDZ). The mean number of axillary shoots per explant of C. forskolii reached the highest value 6.19 ±0.573 on MS medium containing 2.0mg/L TDZ. Where, the highest value of mean length was 6.44± 0.310 cm on MS medium containing 1.0 mg/L KIN. The mean number of roots / explant of C. forskolii reached the highest value and the mean length were 30.00 ± 0.577 and 11.8±0.860 cm respectively, on 1/2 MS medium containing 0.5mg/L indole-3-butyric acid(IBA). While, the highest value of shoot length was 11.8±0.860 cm on 1/2 MS medium containing  2.0mg/L naphthalene acetic acid (NAA). A percentage of 83% of rooted plantlets were successfully acclimatized after four weeks and grown normally in the greenhouse in sterile soil mixture of garden soil,  vermiculate and sand (2:1:1/v/v/v). The protocol could be cost effective and useful in germplasm conservation and delivery of tissue cultured Coleus plants

MODELLING TECHNIQUES FOR SLAB TRACK SYSTEMS

The railway slab track has replaced the ballast material in the classical ballasted track with reinforced concrete slab or asphalt layer to cope up with the increasing axle loads, train high-speeds, and to reduce overall maintenance cost. This paper aims to investigate the linear and nonlinear behavior of the most common slab track systems (BÖGL, Shinkansen, and RHEDA 2000) using American (AREMA) loads for different soil types to recommend the most suitable analysis type for each component of the slab track systems. Slab track Finite Element models have been built using Midas GTS NX software. The geometric model for each slab track type has been performed according to their standard section. The results of the analysis have indicated that, for BÖGL slab track, the difference of the rail displacement between the linear and nonlinear analysis is 26% meanwhile the differences of replacement layer stresses for BÖGL between linear and nonlinear are about 40 %. Concerning Shinkansen slab track, the difference of the rail deflection between the linear and nonlinear are 31% while the difference of replacement layer stresses for Shinkansen between linear and nonlinear is significantly huge about 65%. Regarding RHEDA 2000, the rail displacement variation between the linear and nonlinear is 16%. Concerning the replacement layer stresses variance for RHEDA 2000 between linear and nonlinear is about 46%. Changing the subgrade soil types has concluded that the nonlinear modelling should be utilized for the slab track substructure for poor, medium, and good soils while the linear modelling can be sufficient for very good soil types (rocks, gravel, etc.). Linear modelling can be enough to represent the analysis of the slab track superstructure to save computational cost. The railway slab track has replaced the ballast material in the classical ballasted track with reinforced concrete slab or asphalt layer to cope up with the increasing axle loads, train high-speeds, and to reduce overall maintenance cost. This paper aims to investigate the linear and nonlinear behavior of the most common slab track systems (BÖGL, Shinkansen, and RHEDA 2000) using American (AREMA) loads for different soil types to recommend the most suitable analysis type for each component of the slab track systems. Slab track Finite Element models have been built using Midas GTS NX software. The geometric model for each slab track type has been performed according to their standard section. The results of the analysis have indicated that, for BÖGL slab track, the difference of the rail displacement between the linear and nonlinear analysis is 26% meanwhile the differences of replacement layer stresses for BÖGL between linear and nonlinear are about 40 %. Concerning Shinkansen slab track, the difference of the rail deflection between the linear and nonlinear are 31% while the difference of replacement layer stresses for Shinkansen between linear and nonlinear is significantly huge about 65%. Regarding RHEDA 2000, the rail displacement variation between the linear and nonlinear is 16%. Concerning the replacement layer stresses variance for RHEDA 2000 between linear and nonlinear is about 46%. Changing the subgrade soil types has concluded that the nonlinear modelling should be utilized for the slab track substructure for poor, medium, and good soils while the linear modelling can be sufficient for very good soil types (rocks, gravel, etc.). Linear modelling can be enough to represent the analysis of the slab track superstructure to save computational cost