101 research outputs found

    Comparing the effectiveness of face to face and computer mediated collaboration in design

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    Construction projects are complex and organisationally characterised by a high degree of fragmentation. This results in a need for clear communication and collaboration between the project participants in order to ensure the success of a project. Advances in communication technologies have enabled construction project members to supplement face to face (FTF) communication with methods based on computer mediated communication (CMC). The latter has reduced the need for travelling and hence results in savings in aspects, such as cost and time. One aspect of this CMC based communication is the emergence of modern design software which, together with other communication tools enables designers to undertake collaborative design while being geographically remote from one another. The research in this thesis compares the effectiveness of FTF and CMC based collaboration for teams of two people at the design stage of a construction project. The comparison deals with many points that have been not addressed in previous studies and the analysis leads to the conclusion that CMC results in a more effective process than FTF in many aspects. For productivity, the results of this research reveal that team productivity for CMC is higher than for FTF and intriguingly further results show that the productivity score of two people collaborating is higher than for a single designer. Better time management has been found to occur with CMC than FTF. This research found a method of measuring degree of collaboration between users in a team, as well as the results prove that the degree of collaboration in CMC better than FTF. In terms of design quality, the results show that the design quality for FTF is nearly equal to that for CMC. Other aspects of this research examine the relationship between non-verbal and verbal communication as well as between non-verbal communication and team productivity plus the impact of emotional factors on productivity and quality is also examined

    DETERMINATION OF PHYSICOCHEMICAL AND GEOMETRICAL PROPERTIES OF SOME CARVEDILOL DEREVITIVES

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    ABSTRACTObjective: Five derivatives of Carvedilol with different activities were studied in order to suggest unprepared derivative of carvedilol and suggestiona general equation to calculate the activity foe any Carvedilol derivative..Methods: GAUSSIAN 03 software employed to calculate physicochemical and geometrical properties of carvedilol derivatives, the calculated quantumchemical parameters are: The energy gap between the highest occupied molecular orbital and lowest unoccupied molecular orbital (HOMO-LUMO),dipole moment (μ), electronegativity (χ), electron affinity (A), global hardness (η), ionization potential (I), and the global electrophilicity (ω). Theresulting properties used in quantitative structure-activity relationship equation to predict activity.Results: Suggested unprepared carvedilol derivative with an activity of 1.99 × 10 mg as well as development of a general equation, two formula forcalculate activity of carvedilol derivatives specifically Log 1/C = −29.5744 + 17.1334 Log p + 19603.97 ∆ HOMO-LUMO + 2.7725 μ – 38902 η by meanof physicochemical properties and Log 1/C = 2828.25 + 15.01 N electron density − 308.016 O electron density + 306.97 H electron density + 0.32477molecular length by mean of geometrical properties.−5Conclusion: This process may be considered the cost- and time-consuming process, according to the ability of suggestions, new structures to besynthesized using computational chemistry methods.Keywords: Quantitative structure-activity relationship, Density functional theory, Highest occupied molecular orbital and lowest unoccupiedmolecular orbital gap, Global hardness, Global electrophilicity

    Odontogenic tumors:a retrospective study in Egyptian population using WHO 2017 classification

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    Odontogenic tumors (OTs) are considered important among oral lesions because of their clinicopathological heterogeneity and variable biological behavior. The purpose of this retrospective cross-sectional study was to evaluate the frequency and distribution of different types of odontogenic tumors based on the current 2017 WHO Classification of Head and Neck Tumors over a period of 5 years. This was achieved by reviewing the records of Cairo's educational hospitals and institutions and comparing the results with findings in the literature. The records of patients diagnosed with odontogenic tumors were obtained from six educational hospitals and a single institute in Cairo which included: Oral and Maxillofacial Pathology Department, Faculty of Dentistry, Cairo University; General Pathology Department, Faculty of Medicine, Cairo University; Oral Pathology Department, Faculty of Dentistry, Ain Shams University; Eldemerdash Hospital, Ain Shams University; El-Sayed Galal Hospital, Al-Azhar University; Ahmed Maher Teaching Hospital and National Cancer Institute. These records were reviewed over a 5-year (2014-2018) period and the odontogenic tumors were investigated for frequency, age, gender and site. The data were recorded, then analyzed using SPSS software. Intraosseous (central) odontogenic tumors constituted 2.56% of all 8974 registered oral and maxillofacial biopsies. A total of 230 cases of OTs were collected and reviewed. Of these, 97.8% were benign and 2.17% were malignant. The mandible was the most commonly affected anatomic location. Ameloblastoma, with a predilection for the posterior mandible, was the most frequent odontogenic tumor (55.65%), followed by cemento-ossifying fibroma (14.78%) and odontoma (9.13%). Females were more commonly affected than males. Most of the patients were in the third and fourth decades of life. There were no peripheral odontogenic tumors diagnosed in this period. Some similarities and differences between our findings and those of previous studies of various populations were witnessed. OTs may greatly diverge according to the version of the classification used and by the sample size of the study. Retrospective analysis of the relative frequency of OTs in different countries will be helpful in enhancing the understanding of OTs, which is important for both oral maxillofacial surgeons and pathologists

    Experimental study to enhance swirl burner against boundary layer flashback

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    In gas turbine systems, operation stability represents the major challenge to any successful device deployment. Climate change combined with fossil fuel pollution has led to the need of considering high hydrogen content fuels, thus putting more pressure to stabilise gas turbines at operation conditions. Flashback is one of the main operation stability problems that represent a real challenge for gas turbine designers when using fast reacting fuels with high hydrogen content. One mechanism that has shown to contribute to flashback considerably is the propagation of the flame through its boundary layer. Although the latter has been studied, there are still several unknowns in its evolution through the system. Thus, boundary layer flashback of a swirling turbulent flame was investigated in a 150 kW tangential swirl burner previously characterised. To produce controlled changes to the boundary layer, the internal side of the burner was covered by woven wire steel mesh to mimic biological skin techniques in flow drag improvement. Two different wire meshes were used to study the effect of the regular roughness size on the boundary flashback. Moreover, the effects of using the wire mesh in such swirling flow with and without central air injection for reduction of other flashback phenomena were studied. The results show good enhancement of the system to boundary layer flashback, and a new map of the combustion stability of the rig has been produced

    Design and performance analysis of a regenerative evaporative cooler for cooling of buildings in arid climates

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    Evaporative cooling has been considered a low energy consumption process that often is associated with displacement ventilation and passive cooling strategies of buildings. While significant energy savings can be accrued from using evaporative cooling, there are many design challenges to improve the processes of heat and mass transfer and reduce design complexities. This paper seeks to advance the design of evaporative cooling through building and testing a novel regenerative evaporative cooler prototype. It proposes a design that integrates heat pipe and porous ceramic tube modules as an alternative to plate heat exchangers. The paper describes design arrangement of the cooler, a mathematical model and laboratory test results. Under controlled laboratory test conditions, the measured performance indices of wet bulb effectiveness, specific cooling capacity and coefficient of performance (COP) were determined as 0.8, 140 W per m2 of wet ceramic surface area and 11.43 respectively. Furthermore, experimental results show that under typical ambient conditions commensurate with that prevailing in arid climates, the cooler air supply temperature was as much as 14 oC below that of the ambient air

    Clinical Utility of Melatonin in Fibromyalgia Diagnosis

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           Fibromyalgia syndrome (FMS) is a chronic disease with an unknown etiology, which is characterized by reduced pain threshold (hyperallgesia) & pain with normally innocuous stimuli (allodynia).This diffuse pain is often disease associated  with wide range of  other symptoms including fatigue, sleep disturbance, stiffness& more.FMS often occur concomitantly  with other rheumatologic disease such as rheumatoid arthritis(RA), systemic lupus erthymatosus(SLE).       The pineal hormone melatonin (MT) exerts a variety of effects on the immune system. MT activates immune cells and enhances inflammatory cytokine and nitric oxide production.Methods: We were studied 75 subjects, 55 of subjects were FMS patients defined by the American Colleague of Rheumatology (ACR 2010) criteria. Patients' mean age was 32.5 ± 13.9 years. They were classified into two groups: Group I of 25  primary FMS patients . Group II of 30 secondary FMS patients with other rheumatologic disease such as RA, SLE. Twenty age and sex matched healthy individuals were included in the study as a control group.Results:Mean Melatonin titers were significantly reduced (p<0.0001) in primary FMs patients compared to the controls (21.32vs. 30.9 pg/ml), but they were significantly elevated (p<0.0001) in secondary FMS compared to controls (138.1vs.30.9 pg/ml). Our data imposed that, in 1ry FMS there were negative correlations of MT titers with tender points (r=-0.848**,p<0.0001), sleep disturbance(r=-0.963**, p< 0.0001**), Fatigue (r= -0.972**, p<0.001**), WPI (r= -0,953 **, p<0.0001) and SS (r=-0.901**, p< 0.0001). Conclusions:In primary FMS patients melatonin level is lower than melatonin level in control, but MT level is high in secondary FMS patients. There was a negative correlation between MT with tender points, sleep disturbance, fatigue, SS & WPI. But there was a positive correlation between MT & cognitive symptoms

    Novel quinazoline-based sulfonamide derivative (3D) induces apoptosis in colorectal cancer by inhibiting JAK2–STAT3 pathway

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    Introduction: Colorectal cancer (CRC) is a major worldwide health problem owing to its high prevalence and mortality rate. Developments in screening, prevention, biomarker, personalized therapies and chemotherapy have improved detection and treatment. However, despite these advances, many patients with advanced metastatic tumors still succumb to the disease. New anticancer agents are needed for treating advanced stage CRC as most of the deaths occur due to cancer metastasis. A recently developed novel sulfonamide derivative 4-((2-(4-(dimethylamino) phenyl)quinazolin-4-yl)amino)benzenesulfonamide (3D) has shown potent antitumor effect; however, the mechanism underlying the antitumor effect remains unknown. Materials and methods: 3D-mediated inhibition on cell viability was evaluated by MTT and real-time cell proliferation was measured by xCelligence RTDP instrument. Western blotting was used to measure pro-apoptotic, anti-apoptotic proteins and JAK2-STAT3 phosphorylation. Flow cytometry was used to measure ROS production and apoptosis. Results: Our study revealed that 3D treatment significantly reduced the viability of human CRC cells HT-29 and SW620. Furthermore, 3D treatment induced the generation of reactive oxygen species (ROS) in human CRC cells. Confirming our observation, N-acetylcysteine significantly inhibited apoptosis. This is further evidenced by the induction of p53 and Bax; release of cytochrome c; activation of caspase-9, caspase-7 and caspase-3; and cleavage of PARP in 3D-treated cells. This compound was found to have a significant effect on the inhibition of antiapoptotic proteins Bcl2 and BclxL. The results further demonstrate that 3D inhibits JAK2–STAT3 pathway by decreasing the constitutive and IL-6-induced phosphorylation of STAT3. 3D also decreases STAT3 target genes such as cyclin D1 and survivin. Furthermore, a combination study of 3D with doxorubicin (Dox) also showed more potent effects than single treatment of Dox in the inhibition of cell viability. Conclusion: Taken together, these findings indicate that 3D induces ROS-mediated apoptosis and inhibits JAK2–STAT3 signaling in CRC
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