208 research outputs found
Erratum: Piezoelastic PVDF/TPU nanofibrous composite membrane: Fabrication and characterization [Polymers, 11(10), 2019 (1634)] DOI: 10.3390/polym11101634
No full textThe authors wish to make a change to the published paper [1]. Regarding the author name Ahmed H. Hassanain, the last name Hassanain should be spelled Hassanin. The authors apologize for any inconvenience caused. The change does not affect the scientific results. The manuscript will be updated, and the original will remain online on the article webpage https://www.mdpi.com/2073-4360/11/9/1474. 2020 by the authors.Scopu
AEC/FM performance in adaptive reuse projects: investigation of challenges and development of practical guidelines
No full textPurpose: This paper aims to provide architecture, engineering, construction and facilities management (AEC/FM) practitioners with a guiding tool for overcoming the challenges affecting their performance in adaptive reuse project. Design/methodology/approach: Literature review was conducted to comprehend the challenges affecting the AEC/FM performance during the implementation of adaptive reuse projects. A case study was conducted on an adaptively reused building, located in Saudi Arabia. The case study building was converted from a bookstore into an amusement center. Document review of the as-built drawings, and a structured interview with the project manager were conducted. The study concluded with the development of AEC/FM practical guidelines, pertaining to the different involved domains. Findings: This study indicated that the potential challenges are interrelated among the three domains. These challenges pertained to the spatial, legislative, technical, administrative and operational aspects. The findings emphasized the vital role of the integration among the AEC/FM domains, at the early project planning phases. Based on the findings, three sets of AEC/FM guidelines were developed. Research limitations/implications: Theoretically, to the best of the authors’ knowledge, this is the first study that provides a case-specific investigation of the challenges affecting the AEC/FM performance in adaptive reuse projects. Practical implications: The developed practical guidelines could potentially enhance the AEC/FM performance in future adaptive reuse projects. Originality/value: This study contributes to the practice of adaptive reuse projects through providing practical guidelines for mitigating the challenges that affect the AEC/FM performance in these projects.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Real Estate Managemen
String-stable automated steering in cooperative driving applications
No full textThe ever-increasing road transport demand in the developing and the developed world has resulted in road-traffic networks nearing maximum capacity. Traditional approaches to this problem, such as increasing road capacity, do not offer long-term solutions. Combined with rising environmental concerns, the demand for smarter solutions has never been higher. One such solution, which has gained significant ground in the past decades, is automated vehicle platooning. A vehicle platoon is an interconnected dynamical system consisting of automated vehicles driving in close proximity, coordinating their movement through measurements and sometimes inter-vehicular communication. By allowing driving in close proximity, platoons have the potential to increase road capacity, whilst reducing fuel consumption. Platoons are subject to safety and performance requirements. In order to meet these requirements the vehicle platoon needs be string stable, such that effects of disturbances are not amplified in the upstream direction of the string of vehicles. String-stable platoons also help preventing ghost traffic jams, typically caused by human driver behaviour. Advancements in vehicle platooning research have mostly been concerned with longitudinal automation, and consequently with longitudinal string stability. However, driving at small inter-vehicular gaps also requires lateral automation. Naturally, this means that string stability in the lateral sense is required.Therefore, the objective of this MSc thesis is to develop a lateral control method for automated vehicle platoons that yield string-stable behaviour. In the first part, an error model based on a vehicle-following control strategy, which uses vehicle path following, is derived. This model is then used to describe the path-following problem within a platoon. In the second part, a control strategy is proposed using the H∞ framework, such that path following and lateral string stability are guaranteed a-priori. The robustness properties and the performance of the designed controller are analysed by means of frequency-domain analysis and time-domain simulations. Finally, path following and the string-stability properties of the controller have been validated experimentally. The experiments performed confirm the theoretical analysis, thereby showing that lateral string stability is obtainable using the proposed method. <br/
Potassium aluminium sulphate (Alum) inhibits growth of human axillary malodor-producing skin flora in vitro / Hassanain Al-Talib … [et al.]
No full textIntroduction: Axillary malodor is caused by microbial biotransformation of non-smelling molecules present in apocrine secretions, into volatile odorous molecules. This study aimed to determine the antimicrobial activities of potassium aluminium salts (alum) against four malodor-producing axillary bacterial flora, as an alternative natural product for reducing axillary malodor. Methods: The antimicrobial activity of alum against axillary bacterial flora [Micrococcus luteus (ATCC 49732) (M. luteus), Staphylococcus epidermidis (ATCC 14990) (S. epidermidis), Corynebacterium xerosis (ATCC BAA-1293) C. xerosis and Bacilus subtilis (ATCC 19659) (B. subtilis)], was tested in vitro using broth dilution method for different concentrations (0.937 – 20mg/mL) on Luria-Bertani broth. Subculture was done to determine colony-forming units (CFUs) and the minimum inhibitory concentrations (MICs). Results: Alum showed excellent inhibitory effects on all tested bacteria. The lowest MIC of alum was against C. xerosis, at 1.88 mg/mL. M. luteus, B. subtilis and S.epidermidis showed a higher MIC of 3.75, 5.00 and 7.50 mg/mL, respectively. All of the tested bacteria were completely inhibited at a concentration of 7.50 mg/mL. Conclusions: This study revealed that alum has excellent antimicrobial effects against axillary malodor -producing bacteria and is recommended to be used either directly by topical application or as an active ingredient in deodorants and antiperspirants
Validation of a Moving Base Driving Simulator for Motion Sickness Research
No full textHigher levels of automation in driving may allow drivers to engage in other activities, but may also increase the likelihood of Motion Sickness (MS). The exact causes of MS are not well understood, and various susceptibility factors(e.g. age, gender, ethnicity) can cause large individual differences. To better understand and predict MS, it is ideally studied in a safe and controlled environment, such as a driving simulator. However, the validity of driving simulator studies on MS as a proxy for on-road studies with real vehicles has not been properly evaluated. We conducted an experiment where the temporal aspects and symptom profiles of MS in a real-road driving scenario are compared to Simulator Sickness (SS) in a reproduction of this scenario in a motion-base driving simulator. A cohort of 25 participants was exposed to both the car and the simulator conditions. The scenarios consisted of sections of provocative(slaloming, stop-and-go) and normal driving. Sickening stimuli of the simulator were similar to the car accelerations in design (r = 0.51) but different in outcome (r = 0.27) as a result of motion cueing. MIsery Scale (MISC) scores on a 30 s interval, post-experiment Motion Sickness Assessment Questionnaire (MSAQ) scores, Galvanic Skin Response(GSR) and Electrogastrography (EGG) data were collected. Results showed significant correlations between the car and simulator conditions for 3 out of 4 MSAQ symptom categories (0.48 < r < 0.73, p < 0.02) and a relation (r = 0.57,p = 0.004) for individual sensitivity to sickness. Sickness onset times did not differ between the car and the simulator[F(1,308) = 4.80, p = 0.029], after Bonferroni corrections had been applied. Both MS and SS increased and decreased as a result of the driving style, with the effect being larger in the car condition, than in the simulator (for MISC [F(1,248)= 19.15, p = 0.000] and for GSR [F(1,230) = 5.55, p = 0.019]). Results from all four measures indicate that the severity of sickness was higher in the car as compared to in the simulator. EEG responses did not fully show expected outcomes. However, the signal quality was limited and dedicated EGG equipment may yield different results. Because individual sensitivity and temporal aspects of SS and MS were similar between the car and simulator but different in magnitude, we conclude relative validity for the simulator. As the human vestibular system, a prominent contributor in causing sickness, is solely sensitive to accelerations, we attribute the difference in magnitude due to downscaling of the vehicle motion in the simulator. In order to obtain absolute validity, either extensive training or considerable technological advances may be necessary.Mechanical Engineerin
Interface modification of clay and graphene platelets reinforced epoxy nanocomposites: a comparative study
No full textThe interface between the matrix phase and dispersed phase of a composite plays a critical role in influencing its properties. However, the intricate mecha-nisms of interface are not fully understood, and polymer nanocomposites are no exception. This study compares the fabrication, morphology, and mechanical and thermal properties of epoxy nanocomposites tuned by clay layers (denoted as m-clay) and graphene platelets (denoted as m-GP). It was found that a chemical modification, layer expansion and dispersion of filler within the epoxy matrix resulted in an improved interface between the filler mate-rial and epoxy matrix. This was confirmed by Fourier transform infrared spectroscopy and transmission electron microscope. The enhanced interface led to improved mechanical properties (i.e. stiffness modulus, fracture toughness) and higher glass transition temperatures (Tg) compared with neat epoxy. At 4 wt% m-GP, the critical strain energy release rate G1c of neat epoxy improved by 240 % from 179.1 to 608.6 J/m2 and Tg increased from 93.7 to 106.4 �C. In contrast to m-clay, which at 4 wt%, only improved the G1c by 45 % and Tg by 7.1 %. The higher level of improvement offered by m-GP is attributed to the strong interaction of graphene sheets with epoxy because the covalent bonds between the carbon atoms of graphene sheets are much stronger than silicon-based clay
A Review of Object Oriented CAD Potential for Building Information Modeling and Life Cycle Management
No full textIn many countries, the Architecture/Engineering/Consulting (AEC) industry is characterised by poor performance reflected in project delays and cost overruns. A contributor to the problem is the traditional approach to handling building information and its communication in life cycle management (LCM). Recent developments in Object Oriented Computer Aided Architectural Design (OO CAD) have provided the opportunity for improving building information modelling and its communication for more effective LCM. The aim of the paper is to review the potentials of OO CAD for building information modelling (BIM) and LCM. The paper reviews building information in the life cycle process, identifying the various actors and activities and the need for communication and information flow to support life cycle management. The paper also reviews the concept of OO CAD, highlighting its potential to improve building information and its flow and communication in life cycle management. The paper then goes on to review the potentials and limitations of OO CAD implementation in the AEC industry. The paper concludes by pointing out that the widespread adoption of OO CAD and the anticipated associated improvement in life cycle management will only be encouraged when the building industry is able to agree on a widely acceptable, interoperable standard for encoding building objects
AN INVESTIGATION OF α-PARTICLES ELASTIC SCATTERING ON <sup>24</sup><font>Mg</font> AND <sup>28</sup><font>Si</font> BY USING CLUSTER FOLDING MODEL
No full text Using the α-like cluster and uncluster nucleonic structure of 24 Mg and 28 Si nuclei, α-nucleus single-folding cluster optical potentials have been generated based upon effective α–α and α-nucleon (N) interactions. Angular distributions of the differential cross-section of α elastic scattering by 24 Mg , and 28 Si nuclei have been analyzed over a wide range of incident energies, Eα = 21.9-175.5 MeV , where anomaly in large angle scattering and rainbow scattering features have been investigated. We successfully reproduce the elastic scattering differential cross-section for energy range Eα = 22.2-172.5 MeV for 24 Mg target and 21.9-166 MeV for 28 Si target without renormalization except a few cases at low energies. The energy dependence of the extracted real and imaginary volume integrals and total reaction cross-section has been investigated. </jats:p
Nutritional and chemotactic signals inactivate the expression of a growth-specific gene early in development in Dictyostelium discoideum
No full textThesis (Ph. D.)--Michigan State University. Dept of Zoology, 1990Includes bibliographical references (pages 125-141
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