12,724 research outputs found
aE Journal 2015/2016: aE/INTECTURE innovating architecture
No full textThe graduation studio of Architectural Engineering focuses on the integration of (new) technology in architecture. For this purpose, the name aE/ INTECTURE® was devised, which will be developed further as a brand in the coming years. Students start with a technical fascination and translate this into an architectural concept, finally being able to implement this within the environment in a responsible way. ‘If technology is the answer, what is the question?‘ Under the guidance of a team of enthusiastic (guest) lecturers, students search for the dot on the horizon that is necessary for coming up with solutions that improve the quality of the built environment and make it more sustainable. In addition, either the ‘making‘ (make) or ‘the energy and material flow’ (flow) is used and applied as a basis in different contexts.Architectural Engineerin
Scaling of solar wind e and the AU, AL and AE indices as seen by WIND
No full textWe apply the finite size scaling technique to quantify the statistical properties of fluctuations in AU, AL and AE indices and in the parameter that represents energy input from the solar wind into the magnetosphere. We find that the exponents needed to rescale the probability density functions (PDF) of the fluctuations are the same to within experimental error for all four quantities. This self-similarity persists for time scales up to ~4 hours for AU, AL and and up to ~2 hours for AE. Fluctuations on shorter time scales than these are found to have similar long-tailed (leptokurtic) PDF, consistent with an underlying turbulent process. These quantitative and model-independent results place important constraints on models for the coupled solar wind-magnetosphere system
An investigation on the diagnostics and prognostic capabilities of acoustic emission (AE) on a spur gearbox
No full textThe aim of this research project is to explore a new technique, Acoustic Emission (AE),
on both the diagnostic and prognostic capabilities in monitoring gear teeth degradation
(pitting), and compare with the more widely used techniques such as vibration
monitoring and Spectrometric Oil Analysis (SOA). Furthermore, by employing the
experimental results and past literature, a model in predicting the amount of gear surface
pitting wear using AE activity level was proposed. The successful forinulation of this
proposed model may be able to predict the remaining life of the gear after pitting has
been detected, thereby allowing timely replacement to be carried out without the risk of
catastrophic failure.
A series of experimental tests which include seeded defect simulations, study on the
effect of operating parameters over AE (under isothermal conditions), AE source
determination tests and accelerated gear fatigue tests have been performed to investigate
the diagnostics and prognostics capabilities of AE via a back-to-back gearbox set up. The
experimental results achieved have highlighted some significant findings: (a) The
variation in rotating speeds, change the AE levels in a much significant amount as
compared to the same variation in applied load. (b) The prime source of AE was
postulated to be asperity contact under rolling and sliding of the meshing gear teeth
surfaces. (c) AE technique has a far better degradation (pitting) monitoring capability
compared to vibration and SOA techniques.
These findings have made a vast contribution in condition monitoring of gearbox using
AE technique and the proposed model has also offered opportunity to make AE a
potentially viable and effective tool in diagnosis and prognosis of gearbox or even other
rotating machinery defects
Immunity Gene Knockdown in Aedes Albopictus and Aedes Polynesiensis Using RNA Interference
No full textAedes albopictus and Aedes polynesiensis mosquitoes both serve as vectors for various neglected tropical diseases that contribute to the cycle of disease and poverty and cause high amounts of pain and suffering. Due to the behavior of these two mosquitoes, traditional vector control techniques may not be adequate to curb disease transmission. This project aimed to investigate a potential way to compromise the vector competence of Ae. albopictus and Ae. polynesiensis through the upregulation of their immune systems. It was hypothesized that RNA interference could be used to reduce the gene expression of Cactus and Caspar, proteins that serve as the negative regulators for two major branches of the mosquito innate immune system. dsRNA and siRNA for Cactus and Caspar were synthesized to initiate the endogenous RNAi pathway in two Ae. albopictus cell lines. Here we report the efforts made to trigger the RNAi induced knockdown of Cactus and Caspar and the progress and challenges made in verifying its success
An Investigation of Acoustic Emission Responses of a Self Aligning Spherical Journal Bearing
No full textHigh power industrial machinery such as steam turbines and large pumps use journal bearings as rotor supports because this type of bearing is a high load carrying capacity. However, abnormal operating conditions in the journal bearings will degrade machine performance, shorten life time and increase the risk of operation. Bearing condition monitoring can detect faults at early stage and hence minimise the occurrence of catastrophic failures. Vibration measurement from an accelerometer is an effective method for monitoring journal bearing. However, due to frequency limitation, it cannot give accurate monitoring results when the bearing produces high frequency excitations such as asperity contacts. For overcoming the limits, acoustic emission (AE) is required for detecting early faults in self aligning journal bearings in high frequency ranges. AE source in journal bearings may originate from sliding friction. The friction in sliding bearings depends on lubricated regions which are influenced by load, speed, lubricant viscosity and bearing conditions. When bearing is operated in boundary lubricated region more asperity contact occurs and generates large AE responses. Hydrodynamic lubrication means that the bearing surfaces are completely separated by oil film, almost there is not severity contact and hence creates very small AE signal. Mixed lubrication occurs between boundary and hydrodynamic lubrication range and creates medium of AE value. The result of AE experiment for self-aligning spherical journal bearing indicates that AE can detect bearing fault in high frequency range till 15000 Hz. For addition there is a positive correlation between speed, load and AE RMS value. For lubricant, if the lubricant has higher viscosity, it generates smaller AE amplitude. The AE characteristic also shows that AE RMS value relates to the friction curve
Nauka ekonomii polityczney podług układu Adama Smith /
No full textTyt. z ekranu tytułowego.Dostępny również w formie drukowanej
Knockdown of Core Clock Genes in Aedes albopictus and Aedes polynesiensis
No full textNeglected Tropical Diseases (NTDs) are debilitating diseases that affect one-sixth of the global population. Most of them are transmitted by mosquitoes since they are the most prevalent viral and parasitic vectors. Since mosquitoes have a large contribution in the transmission of NTDs, finding effective ways to make them less efficient disease vectors is an important task for disease control. The circadian clock of mosquitoes has a large impact on host-seeking rhythmicity for disease vectors, meaning it is an important aspect in mosquito biology. The circadian rhythm is heavily dependent on clock gene expression levels, which are regulated by a series of transcriptional and translational feedback loops (TTFL). The long-term aim of this study is to use RNA interference to knockdown the expression of core clock genes in Aedes albopictus, also known as Asian tiger mosquito, and Aedes polynesiensis, also known as Polynesian tiger mosquito, to observe changes in their feeding behavior. For my project, two Ae. albopictus cell lines, U4.4 and C6/36, are being transfected to observe changes in clock gene expression levels prior to doing the same in mosquitoes. Both Ae. albopictus and Ae. polynesiensis are diurnal feeders, meaning their peak biting times are during sunrise and sunset. Knocking down positive regulators of the feedback loop will likely affect their normal feeding pattern and aid in lessening the spread of a variety of diseases
Immunity Gene Knockout of Protein Inhibitor of Activated STAT (PIAS) in Aedes albopictus using CRISPR-Cas9
No full textNeglected Tropical Diseases (NTDs) present a considerable public health threat to more than one billion people worldwide – especially to communities with high rates of poverty, little access to medical care, and inadequate waste disposal methods. Aedes albopictus, the Asian tiger mosquito, is one of the main vectors for several diseases – most notably, the dengue, chikungunya, and Zika viruses. Due to the prevalence of Ae. albopictus and other such vectors, methods to control the spread of disease are essential to eliminating the threat of NTDs. This research aims to study the impacts of a CRISPR-Cas9-mediated gene knock-out of the PIAS negative regulator in the JAK-STAT immune pathway. We hypothesize that the knock-out of PIAS will upregulate multiple genes in the immune system and the production of antimicrobial peptides (AMPs). The work presented here reports on the initial efforts to transfect an Ae. albopictus C6/36 cell line with a CRISPR-Cas9 plasmid designed to knock out PIAS, and the preparation to perform RT-qPCR comparative gene analysis on two immune genes hypothesized to be directly impacted by this knock-out. Additionally, this paper describes the challenges encountered and future directions for completing this project
Condition Monitoring of Helical Gears Using Acoustic Emission (AE) Technology
No full textTechniques such as vibration monitoring, thermal analysis and oil analysis are well
established as means to have been used to improve reliability of gearboxes and extend
time-to-failure. In this area Acoustic Emission (AE) technology is still in its infancy but
the attention shown by researchers towards this method has increased dramatically
because several studies have shown the AE offers the important advantage of improved
sensitivity over more conventional monitoring tools for the early detection and
prediction of gear failure.
Helical gear lubrication is critically important for maintaining the integrity of operating
gears and the oil also prevents asperity contact at the gear mesh thereby protecting the
gears from a deterioration process and surface failures. In gear systems, there are three
types of lubrication regimes: Dry Running, Boundary Lubrication (BL), Hydrodynamic
Lubrication (HL) and Elastohydro-dynamic Lubrication (EHL). The last regime is
associated with the normal operating running condition of gears.
Acoustic emissions were acquired from gears and analysed for different lubrication
regimes (dry, BL, HL and EHL regimes at different temperatures), and corresponding
specific film thicknesses (λ) levels. The results showed an inverse relationship between
AE signal levels and specific film thickness (λ) of the oil. This relation was used to
determine the lubrication regime from the measured AE signals. For instance, dry
running had the highest AE levels which were attributed to the metal-to-metal contact of
the gear mesh. The BL regime had relatively high AE levels which also attributed to the
level of asperity contact is greater than the oil film thickness. The HL regime was
characterized by the lowest AE levels due to the lubricant oil completely separating the
teeth during gear meshing. Finally, the EHL regime showed intermediate AE levels
compared to the BL and HL regimes because the oil film was less than for the HL
regime but greater than for the BL regime.
It is shown that the application of advanced signal processing methods is necessary for
monitoring helical gears; Kurtosis and Spectral Kurtosis were used to investigate the
AE signatures and found to be effective in de-noising (spectral kurtosis) acquired
signals. Acoustic Emission proved to be a powerful tool to detect the oil regime for both
defective and non-defective conditions.
It is concluded that the experimental findings of this research programme will provide
the foundations for significant advancement in the application of AE for the
determining the lubrication regime present within a helical gearbox and for the detection
of developing gear faults. This should give a new impetus in the field of maintenance
and prevention of human and material catastrophes.
Several papers presenting the findings of this research have been published in
international journals and given at conferences
aE Journal 2017/2018: aE/Intecture innovating architecture
No full textDriven by the need to think differently about resources, energy, power generation, the choice of materials, and user involvement, we see the built environment in a new perspective. The program, Architectural Engineering, seeks for innovative and inspiring architectural solutions for social and environmental issues throughout all scales.To achieve this, innovation of the architectural challenge is high on our agenda. Innovation is more than just a technical improvement. How do you implement new current issues in modern architecture? We anticipate new energy, materials, and circularity. We also use the current environment of the metropolis and the countryside. We add new buildings, strengthen existing stock, and work on new components of buildings. From high to low tech. From digital to traditional, looking carefully to the context.Architectural Engineerin
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