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Author(s):  
Thomas Deckert ◽  
Jonas Allerbeck ◽  
Takayuki Kurihara ◽  
Daniele Brida

Abstract Energetic correlations and their dynamics govern the fundamental properties of condensed matter materials. Ultrafast multidimensional spectroscopy in the mid infrared is an advanced technique to study such coherent low-energy dynamics. The intrinsic many-body phenomena in functional solid-state materials, in particular few-layer samples, remain widely unexplored to this date, because complex and weak sample responses demand versatile and sensitive detection. Here, we present a novel setup for ultrafast multidimensional spectroscopy with noncollinear geometry and complete field resolution in the 15-40 THz range. Electric fields up to few-100 kV cm-1 drive coherent dynamics in a perturbative regime, and an advanced modulation scheme allows to detect nonlinear signals down to a few tens of V cm-1 entirely background-free with high sensitivity and full control over the geometric phase-matching conditions. Our system aims at the investigation of correlations and many-body interactions in condensed matter systems at low energy. Benchmark measurements on bulk indium antimonide (InSb) reveal a strong six-wave mixing signal and map ultrafast changes of the band structure with access to amplitude and phase information. Our results pave the way towards the investigation of functional thin film materials and few-layer samples.


2022 ◽  
Author(s):  
Domenico Accardo ◽  
Giorgio de Alteriis ◽  
Claudia Conte ◽  
Giancarlo Rufino ◽  
Rosario Schiano Lo Moriello ◽  
...  

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Abir Hadriche ◽  
Ichrak Behy ◽  
Amal Necibi ◽  
Abdennaceur Kachouri ◽  
Chokri Ben Amar ◽  
...  

Characterizing epileptogenic zones EZ (sources responsible of excessive discharges) would assist a neurologist during epilepsy diagnosis. Locating efficiently these abnormal sources among magnetoencephalography (MEG) biomarker is obtained by several inverse problem techniques. These techniques present different assumptions and particular epileptic network connectivity. Here, we proposed to evaluate performances of distributed inverse problem in defining EZ. First, we applied an advanced technique based on Singular Value Decomposition (SVD) to recover only pure transitory activities (interictal epileptiform discharges). We evaluated our technique’s robustness in separation between transitory and ripples versus frequency range, transitory shapes, and signal to noise ratio on simulated data (depicting both epileptic biomarkers and respecting time series and spectral properties of realistic data). We validated our technique on MEG signal using detector precision on 5 patients. Then, we applied four methods of inverse problem to define cortical areas and neural generators of excessive discharges. We computed network connectivity of each technique. Then, we confronted obtained noninvasive networks to intracerebral EEG transitory network connectivity using nodes in common, connection strength, distance metrics between concordant nodes of MEG and IEEG, and average propagation delay. Coherent Maximum Entropy on the Mean (cMEM) proved a high matching between MEG network connectivity and IEEG based on distance between active sources, followed by Exact low-resolution brain electromagnetic tomography (eLORETA), Dynamical Statistical Parametric Mapping (dSPM), and Minimum norm estimation (MNE). Clinical performance was interesting for entire methods providing in an average of 73.5% of active sources detected in depth and seen in MEG, and vice versa, about 77.15% of active sources were detected from MEG and seen in IEEG. Investigated problem techniques succeed at least in finding one part of seizure onset zone. dSPM and eLORETA depict the highest connection strength among all techniques. Propagation delay varies in this range [18, 25]ms, knowing that eLORETA ensures the lowest propagation delay (18 ms) and the closet one to IEEG propagation delay.


Polymers ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 9
Author(s):  
Paul Sotta ◽  
Pierre-Antoine Albouy ◽  
Mohammad Abou Taha ◽  
Benoit Moreaux ◽  
Caroline Fayolle

We present a combination of independent techniques in order to characterize crosslinked elastomers. We combine well-established macroscopic methods, such as rheological and mechanical experiments and equilibrium swelling measurements, a more advanced technique such as proton multiple-quantum NMR, and a new method to measure stress-induced segmental orientation by in situ tensile X-ray scattering. All of these techniques give access to the response of the elastomer network in relation to the crosslinking of the systems. Based on entropic elasticity theory, all these quantities are related to segmental orientation effects through the so-called stress-optical law. By means of the combination of these techniques, we investigate a set of unfilled sulfur-vulcanized styrene butadiene rubber elastomers with different levels of crosslinking. We validate that the results of all methods correlate very well. The relevance of this approach is that it can be applied in any elastomer materials, including materials representative of various industrial application, without prerequisite as regards, e.g., optical transparency or simplified formulation. Moreover, the approach may be used to study reinforcement effects in filled elastomers with nanoparticles.


Genes ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 2004
Author(s):  
Bo Yoon Choi ◽  
Munsoo Han ◽  
Ji Won Kwak ◽  
Tae Hoon Kim

The pathogenesis of allergic rhinitis is associated with genetic, environmental, and epigenetic factors. Genotyping of single nucleotide polymorphisms (SNPs) is an advanced technique in the field of molecular genetics that is closely correlated with genome-wide association studies (GWASs) in large population groups with allergic diseases. Many recent studies have paid attention to the role of epigenetics, including alteration of DNA methylation, histone acetylation, and miRNA levels in the pathogenesis of allergic rhinitis. In this review article, genetics and epigenetics of allergic rhinitis, including information regarding functions and significance of previously known and newly-discovered genes, are summarized. Directions for future genetic and epigenetic studies of allergic rhinitis are also proposed.


2021 ◽  
Vol 5 (1) ◽  
pp. 38-53
Author(s):  
Vera Magria ◽  
Asridayani Asridayani ◽  
Rosa Winda Sari

This research analyzes about word formation process of slang word used by gamers in the game online “Mobile Legend”. The purposes of this research are to classify and to analyze the types of word formation processes of slang words used by gamers  using theory word formation process by  Yule (2010) and  Katamba (2005) and to describe the meaning of slang words used by gamers. The method used in this research is descriptive qualitative. The data is formed of slang word in chat feature by gamers. In collecting the data, the researcher used  participant observational method (SLC). Then, the analysis in this research, the researcher used agih method (distributional method) and used Segmenting Immediate Constituents Techniques (Teknik Bagi Unsur langsung/BUL) as the basic technique and delition technique (teknik lesap) as an advanced technique. The results of this research are stated as follows. Firstly, six types of word formation process  in slang word used by gamers; abbreviation, acronym, borrowing, compounding, multiple process, and clipping. Then, the researcher found twelve slang words that utterances by gamer. While for word formation process, the type that dominant is compounding. In the meaning of slang word, the researcher only finds two from seven types of meaning by Leech (1981), they are: firstly social meaning and secondly connotative meaning.


Coatings ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1496
Author(s):  
Essam B. Moustafa ◽  
Waheed Sami Abushanab ◽  
Ammar Melaibari ◽  
Anastasia V. Mikhaylovskaya ◽  
Mohamed Shaaban Abdel-Wahab ◽  
...  

In the present work, an advanced technique was applied to coat an Al 2024 alloy with a surface composite layer reinforced with various nanoparticles. The surface of Al 2024 aluminum alloy was modified with Ta2C, Al2O3 and multi wall carbon nanotubes MWCNTs nanoparticles by friction stir process (FSP). An improvement in the surface of the fabricated nanocomposite due to the refinement of the microstructure grains was achieved. In addition, a significant improvement in the hardness and wear behavior was observed. The reinforcement particles were incorporated into double and triple hybrid composite particles to determine the most effective combination for the controlled properties. The results showed that for the composite reinforced with a double hybrid of Al2O3 and MWCNTs, the microstructure grains of the fabricated nanocomposite surface were refined by 40 times. The hardness was significantly improved, i.e., it was increased by 48% by incorporating the triple reinforcement (Ta2C, Al2O3, and MWCNTs) into the surface of Al 2024 aluminum alloy. The results of wear properties were in agreement with the results of hardness; the maximum wear resistance was obtained for Al 2024-Ta2C + Al2O3 + MWCNTs, and the wear rate was reduced by 11 times.


2021 ◽  
Author(s):  
Francesca Del Signore ◽  
Germain Arribarat ◽  
Leonardo Della Salda ◽  
Giovanni Mogicato ◽  
Alexandra Deviers ◽  
...  

AbstractHigh field MRI represents an advanced technique both for diagnostic and research purposes on animal models such as the Beagle dog. The increasing interest in non-invasive neuroscience, aging, and neuropathological research led to a need of reference values (in terms of volumetric assessment) for the typical brain structures involved and, nowadays, several canine brain MRI atlases have been provided. Since no reports are available regarding the measurements reproducibility and few information are available about formalin fixation effect on brain structures when applied to MRI segmentation, we assessed the segmentation variability of selected structures as a function of the operator (two operators segmented the same data) and their intrinsic variability within a sample of 11 Beagle dogs (9 females and 2 males, 1.6 ± 0.2 years). Then, we analyzed for one further Beagle dog (2 years old) the longitudinal changes in the brain segmentations of these structures corresponding four conditions: in vivo, post mortem (after euthanasia), ex vivo (brain extracted and studied after 1 month in formalin and after 11 months); all the MRI images were collected with a 3 T MRI scanner. Our findings suggest that the segmentation procedure can be considered overall reproducible since only slight statistical differences were detected, apart from the ventricles.Furthermore, in the post mortem/ ex vivo comparison, the majority of the structures showed a higher contrast leading to more reproducible segmentations across operators and a net increase of volume of the studied structures; this could be justified by the intrinsic relaxation time changes observed as a consequence of formalin fixation, that led to an improvement of brain structures visualization and then segmentation.To conclude, MRI based segmentation seems to be a useful and accurate tool that allows longitudinal studies, especially when applied to formalin fixed brains.


2021 ◽  
Vol 10 ◽  
pp. 17-32
Author(s):  
Guido Fava ◽  
Việt Anh Đinh

The most advanced technique to evaluate different solutions proposed for a field development plan consists of building a numerical model to simulate the production performance of each alternative. Fields covering hundreds of square kilometres frequently require a large number of wells. There are studies and software concerning optimal planning of vertical wells for the development of a field. However, only few studies cover planning of a large number of horizontal wells seeking full population on a regular pattern. One of the criteria for horizontal well planning is selecting the well positions that have the best reservoir properties and certain standoffs from oil/water contact. The wells are then ranked according to their performances. Other criteria include the geometry and spacing of the wells. Placing hundreds of well individually according to these criteria is highly time consuming and can become impossible under time restraints. A method for planning a large number of horizontal wells in a regular pattern in a simulation model significantly reduces the time required for a reservoir production forecast using simulation software. The proposed method is implemented by a computer script and takes into account not only the aforementioned criteria, but also new well requirements concerning existing wells, development area boundaries, and reservoir geological structure features. Some of the conclusions drawn from a study on this method are (1) the new method saves a significant amount of working hours and avoids human errors, especially when many development scenarios need to be considered; (2) a large reservoir with hundreds of wells may have infinite possible solutions, and this approach has the aim of giving the most significant one; and (3) a horizontal well planning module would be a useful tool for commercial simulation software to ease engineers' tasks.


Author(s):  
Michael Burkert ◽  
Thomas Calderon ◽  
James W Hesford ◽  
Michael James Turner

This case illustrates capital budgeting in a service industry context. Three features should make this case attractive to instructors. First, the firm's rationing of capital means that students must select one investment among competing investment alternatives. Second, the project involves renovation of an existing hotel. Most cases consider a business expansion where analysis involves estimation of a single series of cash flows to generate net present value (i.e., future cash flows or not). In this case, students model cash flows if the project is accepted, comparing those cash flows to a model of cash flows if the hotel continues without renovation. Third, we introduce Monte Carlo analysis, an advanced technique for assessing uncertainty. The extensive data students use in this case is from an actual hotel chain's project database. The case has been used in undergraduate and graduate managerial accounting classes.


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