557 research outputs found
A conceptual model for loess in England: Principles and applications
PTD, an acronym for Provenance - Transport - Deposition, is a multilayer geomorphotechnical system, the combination of geomorphology, Quaternary Sciences, and geotechnical consequences of its implementation in groundworks and other crosscutting disciplines. Embedded in its three layers are geographical, geochemical, geophysical, mineralogy, dating, lithological and geotechnical inputs. In this state-of-the-art review contribution and for Loess in England, Syngenetic and Epigenetic mechanisms are drawn out and used to generate the three constitutive layers for three conceptual PTD models and the interrelationships among them. The developed models are then deployed to inform earthworks design for three HS2 embankments in Chiltern Hills
Stabilisation of peat with colloidal nano and micro silica
Peat occurs abundantly in wetlands across Iran, particularly around the disappearing Urmia Lake. Conventional chemical stabilisation has been widely used to tackle the high compressibility and shrinkage potential of peat. Whilst effective, this generally reduces the carbon storage capacity of peat. Exotic stabilisers such as nano-silica (NS) have been shown to be relatively less harmful and without any direct environmental risk. NS has proved effective in improving the mechanical properties (to some extent) and pH-dependent natural structure of peat, but is commercially nonviable. This article presents findings from an experimental study of Urmia Lake peat stabilised with composites of NS and cheaper micro-silica (MS). Unconfined compressive strength (UCS) and California Bearing Ratio (CBR) tests were conducted on untreated and treated compacted natural peat soil samples after 7, 14 and 28 days of curing. Nano-silica was varied from 3 % to 9 % (by dry mass) in 3 % increments and micro-silica was varied from 6 % to 24 % (by dry mass) in 6 % increments. The observations are explained in terms of micro-scale events using XRF spectroscopy and SEM imaging. The findings suggest that the UCS of peat can be increased by administration of NS-MS composites, and the effectiveness is dependent on the relative content and particle size of NS and MS. The UCS and elasticity modulus increase with curing time. As manifested in the CBR results, administration of the composites improves the bearing capacity of peat and transforms it into a sub-base with suitable engineering functions whilst safeguarding its ecosystem service provisions
بررسی میزان Øضور دانشمندان پراستناد Øوزه پزشکی بالینی کشور های اسلامی در شبکه های اجتماعی دانشگاهی
Can social media predict soccer clubs' stock prices?: The case of Turkish teams
Finance literature in sports focuses on three main methods of stock price prediction in soccer: based on match results, pre-match expectations or match importance. For pre-match expectations, betting odds is commonly used as the indicator of investors' sentiments. We propose to include Twitter data as another indicator of this variable, and analyze the links between soccer match results, sentiments, and stock returns of the four major Turkish soccer teams. Our results show that social media can be a strong indicator of pre-match expectations and investors’ sentiments in stock price prediction
Investigating the presence rate of clinical medicine highly cited scientists of islamic countries in the academic social networks
Convolutional Drift Networks for Video Classification
Analyzing spatio-temporal data like video is a challenging task that requires
processing visual and temporal information effectively. Convolutional Neural
Networks have shown promise as baseline fixed feature extractors through
transfer learning, a technique that helps minimize the training cost on visual
information. Temporal information is often handled using hand-crafted features
or Recurrent Neural Networks, but this can be overly specific or prohibitively
complex. Building a fully trainable system that can efficiently analyze
spatio-temporal data without hand-crafted features or complex training is an
open challenge. We present a new neural network architecture to address this
challenge, the Convolutional Drift Network (CDN). Our CDN architecture combines
the visual feature extraction power of deep Convolutional Neural Networks with
the intrinsically efficient temporal processing provided by Reservoir
Computing. In this introductory paper on the CDN, we provide a very simple
baseline implementation tested on two egocentric (first-person) video activity
datasets.We achieve video-level activity classification results on-par with
state-of-the art methods. Notably, performance on this complex spatio-temporal
task was produced by only training a single feed-forward layer in the CDN.Comment: Published in IEEE Rebooting Computin
Co-creation and consumer’s purchasing intentions, any value in B2B activities?
Given the increasing competitive nature of global markets, consumers are able to choose from an ever- increasing quality of products and services with constant declining prices. Hence, better understanding of B2B value co-creation activities that governs suppliers’ relationship with a direct impact on consumer is of great importance. The general purpose behind the study is that customers are willing to buy products only if consumers are in demand of the manufactured products, and therefore, the marketing efforts should target the ultimate consumer as opposed to the buyer. The purpose of this study is to investigate the impact of B2B value co-creation on consumers in South East Asia’s manufacturing industry. The research questions of this study are as following; what is the impact of B2B value co-creation on consumer satisfaction? What is the effect of value co-creation behavior on repurchase Intention? What is the effect of value co-creation behavior on willingness to pay premium? Available literature that deals with B2B co-creation in South-East Asia is primarily concerned with examining the concept of value co-creation behavior and its impact within organizational settings, with little consideration given to B2B value co-creation from consumer standpoint. Hence, an approach that attempts to assess B2B value co-creation impact on the ultimate consumer provides a new insights and a greater understanding of B2B value co-creation relationship within this important geographical part of the Asian market. Findings show that B2B value co-creation activities have a positive impact on consumer satisfaction in SE-Asian manufacturing sector. Findings also reveal that B2B value co-creation activities have a positive effect on ultimate consumer repurchase intentions. This suggests that B2B activities involving value co-creation have a positive effect on ultimate product consumer repurchase intention
Anisotropy in Sand–Fibre Composites and Undrained Stress–Strain Implications
Among the plethora of studies on anisotropy in fibre-reinforced sands, there exist conflicting views on effects on the steady-state deformations of initial packing. These conflicting views are further confused by strictly limited experimental evidence on flow in complex loading environments where the principal stresses rotate whereby shearing and torsional stresses combine, and when extension in soil relieves the compressive stresses. In the heuristic of intrinsically anisotropic nature of the soil and in recognition of the inability of placement methods to overcome such anisotropy, this paper aims to use the orientation of principal stress and soil initial packing state combined as proxy parameters to further the knowledge of plastic behaviour in fibre-reinforced sands. This study furthers the knowledge of the dependency of steady states on anisotropy in composite geomaterials. In doing so, the direction of principal stress orientation is varied from 15° to 60° (from vertical axis), taking an intermediate principal stress ratio of 0.5 and 1.0 and two initial confining pressures. Twenty-four undrained torsional shear tests are conducted using a hollow cylindrical torsional shear apparatus. Under compression and plain strain conditions, torsional stresses limit the improvements in soils’ undrained shear strength upon fibre reinforcement. Extension in soil remarkably increases fibres’ contribution to betterment of undrained strength. Fibres are least effective under low isotropic confining pressures and also for certain ranges of torsional stresses
Stabilisation of peat with colloidal nanosilica
Colloidal nanosilica hydrosols are electrochemically stabilised polymerised amorphous silica in low viscosity suspensions. They have no known adverse impact on soil health and ecosystem service functions, thereby having a scope for use in groundworks as an alternative low-viscose stabilising material. Six grades of colloidal nanosilica are synthesised through an in-house procedure and introduced to a natural peat soil. The peak and residual compressive strength of compacted and modified soils are measured immediately after treatment and in four strain levels post treatment. Findings suggest that, despite the direct correlation between the nanosilica content and compressive strength, an increase in nanosilica content does not necessarily offer stability at larger strains. This is a major limitation. The particle-level kinematics in modified peat is discussed to gain a new insight into the role played by silica flocs on the build-up of macro-mechanical quantities such as peak and critical state strength. Overall, modification of peat with nanosilica leads to improvements in strength and formation of composites with generally more dilative behaviour. When used as a single stabiliser, a design 15 % to 20 % grade nanosilica solution yields a reasonably high strength although precautions against excessive straining of modified peat soils need to be taken in the first seven days post treatment. At this optimum grade, the loss of strength on further straining is capped to 9 % at plastic strains 1.5 times the peak strain
Compacted Expansive Elastic Silt and Tyre Powder Waste
Building on/with expansive soils with no treatment brings complications. Compacted expansive soils specifically fall short in satisfying the minimum requirements for transport embankment infrastructures, requiring the adoption of hauled virgin mineral aggregates or a sustainable alternative. Use of hauled aggregates comes at a high carbon and economical cost. On average, every 9m high embankment built with quarried/hauled soils cost 12600 MJ.m-2 Embodied Energy (EE). A prospect of using mixed cutting-arising expansive soils with industrial/domestic wastes can reduce the carbon cost and ease the pressure on landfills. The widespread use of recycled materials has been extensively limited due to concerns over their long-term performance, generally low shear strength and stiffness. In this contribution, hydromechanical properties of a waste tyre sand-sized rubber (a mixture of polybutadiene, polyisoprene, elastomers, and styrene-butadiene) and expansive silt is studied, allowing the short- and long-term behaviour of optimum compacted composites to be better established. The inclusion of tyre shred substantially decreased the swelling potential/pressure and modestly lowered the compression index. Silt-Tyre powder replacement lowered the bulk density, allowing construction of lighter reinforced earth structures. The shear strength and stiffness decreased on addition of tyre powder, yet the contribution of matric suction to the shear strength remained constant for tyre shred contents up to 20%. Reinforced soils adopted a ductile post-peak plastic behaviour with enhanced failure strain, offering the opportunity to build more flexible subgrades as recommended for expansive soils. Residual water content and tyre shred content are directly correlated; tyre-reinforced silt showed a greater capacity of water storage (than natural silts) and hence a sustainable solution to waterlogging and surficial flooding particularly in urban settings. Crushed fine tyre shred mixed with expansive silts/sands at 15 to 20 wt% appear to offer the maximum reduction in swelling-shrinking properties at minimum cracking, strength loss and enhanced compressibility expenses
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