A novel demountable shear connector for precast steel‐concrete composite bridges is presented. The connector uses high‐strength steel bolts, which are fastened to the top flange of the steel beam with the aid of a special locking nut configuration that prevents slip of bolts within their holes. Moreover, the connector promotes accelerated construction and overcomes typical construction tolerances issues of precast structures. Most importantly, the connector allows bridge disassembly, and therefore, can address different bridge deterioration scenarios with minimum disturbance to traffic flow, i.e. (i) precast deck panels can be rapidly uplifted and replaced; (ii) connectors can be rapidly removed and replaced; and (iii) steel beams can be replaced, while precast decks and shear connectors can be reused. A series of push‐out tests are conducted to assess the behavior of the connector and quantify the effect of important parameters. The experimental results show shear resistance, stiffness, and slip capacity significantly higher than those of welded shear studs along with superior stiffness and strength against slab uplift. Identical tests reveal negligible scatter in the shear load – slip displacement behavior. A design equation is proposed to predict the shear resistance with absolute error less than 8%.
In this study, biodiesel was prepared from chicken fat via a transesterification reaction using Mussel shells as a catalyst. Pretreatment of chicken fat was carried out using non‐catalytic esterification to reduce the free fatty acid content from 36.28 to 0.96 mg KOH/g oil using an ethanol/ fat mole ratio equal to 115:1. In the transesterification reaction, the studied variables were methanol: oil mole ratio in the range of (6:1 ‐ 30:1), catalyst loading in the range of (9‐15) wt%, reaction temperature (55‐75 °C), and reaction time (1‐7) h. The heterogeneous alkaline catalyst was greenly synthesized from waste mussel shells throughout a calcin
Background: Nasal obstruction is common in otorhinolaryngology outpatient visitors. The diagnosis of such compliant is by history, clinical examination and diagnostic procedures. Nasal endoscopy and computerized tomography scan are common diagnostic investigations. Nasal obstruction is either anterior or posterior (nasal septal deviations, hypertrophied turbinate pathological cyst, polyps, mass etc), or postnasal obstruction (hypertrophied turbinate, adenoid hypertrophy, nasopharyngeal cyst or nasopharyngeal tumors).
Aim of study: Prospective study to compare endoscopic finding and computerized tomography of nose, paranasal sinuses and postnasal space as diagnostic methods for nasal obstruction and other nose, p
... Show MoreThe aim of this study is to investigate the protective effect of Radish (Raphanus sativus) seed alcoholic extract 70% against oxidative stress induced by sodium nitrite NaNO2 Twenty five adult male rabbits were devided into five groups of (five rabbits in each group) and treated daily for 30 days. Group T1: intubated orally 20 mg/kg NaNO2, Group T2: intubated orally 20 mg/kg NaNO2 + 50 mg/kg of alcoholic extract from Raphanus sativus seeds, Group T3: intubated orally 20 mg/kg NaNO2 + 100 mg/kg of alcoholic extract from Raphanus sativus seeds, Group T4: intubated orally 20 mg/kg NaNO2 + 200 mg/kg of alcoholic extract from Raphanus sativus seed as well as Group C: control intubated orally distilled water. In comparison with normal ra
... Show MoreMultiple eliminations (de-multiple) are one of seismic processing steps to remove their effects and delineate the correct primary refractors. Using normal move out to flatten primaries is the way to eliminate multiples through transforming these data to frequency-wavenumber domain. The flatten primaries are aligned with zero axis of the frequency-wavenumber domain and any other reflection types (multiples and random noise) are distributed elsewhere. Dip-filter is applied to pass the aligned data and reject others will separate primaries from multiple after transforming the data back from frequency-wavenumber domain to time-distance domain. For that, a suggested name for this technique as normal move out- frequency-wavenumber domain
... Show MoreThe radon gas concentration in environmental samples soil and water of selected regions in Al-Najaf governorate was measured by using alpha-emitters registrations which are emitted form radon gas in (CR-39) nuclear track detector. The first part is concerned with the determination of radon gas concentration in soil samples, results of measurements indicate that the highest average radon concentration in soil samples was found in (Al-Moalmen) region which was (100.0±7.0 Bq/m3), while the lowest average radon concentration was found in (Al-Askary) region which was (38.5±4.7 Bq/m3), with an average value of (64.23±14.9 Bq/m3) ,the results show that the radon gas concentrations in soil is below the allowed limit from (ICRP) agency which is (
... Show MoreIn this study, biodiesel was prepared from chicken fat via a transesterification reaction using Mussel shells as a catalyst. Pretreatment of chicken fat was carried out using non‐catalytic esterification to reduce the free fatty acid content from 36.28 to 0.96 mg KOH/g oil using an ethanol/ fat mole ratio equal to 115:1. In the transesterification reaction, the studied variables were methanol: oil mole ratio in the range of (6:1 ‐ 30:1), catalyst loading in the range of (9‐15) wt%, reaction temperature (55‐75 °C), and reaction time (1‐7) h. The heterogeneous alkaline catalyst was greenly synthesized from waste mussel shells throughout a calcin
Le Petit Prince est apparu en 1943 vers la fin de la vie de son auteur. La mondialité qu'a gagnée ce récit le rend un des livres les plus lus et les plus vendus dans le monde. Cette popularité en fait un des classiques de la littérature française.
En effet la littérature française a un impact profond et direct sur la vie intellectuelle et littéraire dans le monde arabe. La circulation des œuvres littéraires écrites en français a bien influencé les lecteurs arabes soit en langue française soit traduites en arabe. Cette réalité est identique lorsqu'on parle de la réception du Petit Prince ; l'œuvre la plus connue dans le monde entier dès son apparition officielle.
Ab
... Show MoreThose interested in the educational process and lesson management sought to invest the information experience with industrial intelligence and technology because of its importance in increasing the effectiveness of lesson management and developing the creative capabilities of the teacher in directing and managing his lesson. Field research for sports educational institutions that are interested in managing the lesson and preparing mathematical teaching cadres is an important issue and necessary means for identifying the most important phenomena that accompany the process of managing the educational process, as the teacher's success in providing the appropriate conditions to provide rich and influencing experiences in managing and directing
... Show More