Improvement Of The Method Of Winter Concreting With The Use Of Heating Wires

2019 ◽  
pp. 51-58
Keyword(s):  
Harmful Effect ◽  
Electric Heating ◽  
Strength Development ◽  
Construction Sites ◽  
Dominant Position ◽  
Heating Wire ◽  
Hands On ◽  
Basic Parameters ◽  
Monolithic Structures

Long-term experience of application of a method of electric heating by heating wires of the monolithic concrete and reinforced concrete structures erected in winter conditions is analyzed. This method, developed by the author of the article, took a dominant position on the construction sites due to the simplicity and efficiency in comparison with the mass applied in those years, the method of electric heating of concrete with steel round and strip electrodes. The data on labor intensity, material and energy costs in comparison with the method of rod electric heating are presented. Step-by-step technological operations on preparatory works and electric heating of monolithic structures with the use of extensive hands-on material, which formed the basis for the development of technological regulations, supplemented by a number of new proposals to improve the technology of works, are concretized. In order to work out the optimal mode of heat treatment, the studies of the concrete thermal conductivity factor in the process of its heating and strength development were carried out. The method for calculation of the basic parameters of concrete electric heating is presented. For simplification of calculations, for a wide contingent of masters, superintendents and technical personnel, the nomogram , making it possible with sufficient accuracy under the construction conditions to calculate the necessary heating parameters, was developed. The necessity of grounding the heating wire remaining in the concrete to reduce the harmful effect of magnetic radiation from various appliances and household appliances on the human body is noted.

scholarly journals Transdisciplinary AI Observatory—Retrospective Analyses and Future-Oriented Contradistinctions

Philosophies ◽  
2021 ◽  
Vol 6 (1) ◽  
pp. 6
Author(s):  
Nadisha-Marie Aliman ◽  
Leon Kester ◽  
Roman Yampolskiy
Keyword(s):  
Ethical Issues ◽  
Descriptive Analysis ◽  
Research Direction ◽  
Short Term ◽  
Safety Critical ◽  
Safety Research ◽  
Hands On ◽  
Near Term ◽  
Ai Safety

In the last years, artificial intelligence (AI) safety gained international recognition in the light of heterogeneous safety-critical and ethical issues that risk overshadowing the broad beneficial impacts of AI. In this context, the implementation of AI observatory endeavors represents one key research direction. This paper motivates the need for an inherently transdisciplinary AI observatory approach integrating diverse retrospective and counterfactual views. We delineate aims and limitations while providing hands-on-advice utilizing concrete practical examples. Distinguishing between unintentionally and intentionally triggered AI risks with diverse socio-psycho-technological impacts, we exemplify a retrospective descriptive analysis followed by a retrospective counterfactual risk analysis. Building on these AI observatory tools, we present near-term transdisciplinary guidelines for AI safety. As further contribution, we discuss differentiated and tailored long-term directions through the lens of two disparate modern AI safety paradigms. For simplicity, we refer to these two different paradigms with the terms artificial stupidity (AS) and eternal creativity (EC) respectively. While both AS and EC acknowledge the need for a hybrid cognitive-affective approach to AI safety and overlap with regard to many short-term considerations, they differ fundamentally in the nature of multiple envisaged long-term solution patterns. By compiling relevant underlying contradistinctions, we aim to provide future-oriented incentives for constructive dialectics in practical and theoretical AI safety research.

scholarly journals Mechanical Properties of Cement-Treated Soil Mixed with Cellulose Nanofibre

2021 ◽  
Vol 11 (14) ◽  
pp. 6425
Author(s):  
Hidenori Takahashi ◽  
Shinya Omori ◽  
Hideyuki Asada ◽  
Hirofumi Fukawa ◽  
Yusuke Gotoh ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Geotechnical Engineering ◽  
Strength Development ◽  
Soft Ground ◽  
Wood Cellulose ◽  
Treated Soil ◽  
Made In ◽  
Cement Treatment

Cellulose nanofibre (CNF), a material composed of ultrafine fibres of wood cellulose fibrillated to nano-order level, is expected to be widely used because of its excellent properties. However, in the field of geotechnical engineering, almost no progress has been made in the development of techniques for using CNFs. The authors have focused on the use of CNF as an additive in cement treatment for soft ground, where cement is added to solidify the ground, because CNF can reduce the problems associated with cement-treated soil. This paper presents the results of a study on the method of mixing CNF, the strength and its variation obtained by adding CNF, and the change in permeability. CNF had the effect of mixing the cement evenly and reducing the variation in the strength of the treated soil. The CNF mixture increased the strength at the initial age but reduced the strength development in the long term. The addition of CNF also increased the flexural strength, although it hardly changed the permeability.

scholarly journals Long-term mechanical and shrinkage properties of cementitious grouts for structural repair

2019 ◽  
Vol 4 ◽  
pp. 9-15
Author(s):  
Md Shamsuddoha ◽  
Götz Hüsken ◽  
Wolfram Schmidt ◽  
Hans-Carsten Kühne ◽  
Matthias Baeßler
Keyword(s):  
Fly Ash ◽  
Flexural Strength ◽  
Cementitious Materials ◽  
Response Surfaces ◽  
Supplementary Cementitious Materials ◽  
Strength Development ◽  
Structural Repair ◽  
Positive Effects ◽  
Micro Silica

Grouts have numerous applications in construction industry such as joint sealing, structural repair, and connections in precast elements. They are particularly favoured in rehabilitation of structures due to penetrability and convenience of application. Grouts for repair applications typically require high-performance properties such as rapid strength development and superior shrinkage characteristics. Sometimes industrial by-products referred as supplementary cementitious materials (SCM) are used with neat cement due to their capabilities to provide binding properties at delayed stage. Micro silica, fly ash and metakaolin are such SCMs, those can modify and improve properties of cement products. This study aims at investigating long-term mass loss and linear shrinkage along with long-term compressive and flexural strength for grouts produced from ultrafine cement and SCMs. A series of mixtures were formulated to observe the effect of SCMs on these grout properties. Properties were determined after 365 days of curing at 23oC and 55% relative humidity. The effect of SCMs on the properties are characterised by statistical models. Response surfaces were constructed to quantify these properties in relation to SCMs replacement. The results suggested that shrinkage was reduced by metakaolin, while micro silica and fly ash had positive effects on compressive and flexural strength, respectively.

scholarly journals A Sample Book Of Late 20th And Early 21st Century Expired Silver Gelatin Photographic Papers

2021 ◽  
Author(s):  
Joanne R. Guillemette
Keyword(s):  
21St Century ◽  
Specific Information ◽  
Educational Tool ◽  
Web Based ◽  
Early 21St Century ◽  
Visual Identification ◽  
Hands On ◽  
Long Term Preservation

In this applied thesis project, a sample booklet of various expired silver gelatin papers is created. Specific information on the use of expired photographic papers by contemporary photographers is discussed as well as insights from collection caretakers (collection managers/archivists/conservators) on the possible implications that printing with expired silver gelatin papers may have for the long-term preservation of photographic works. The major contribution of this thesis is to create and gain a better understanding of tools that can be used in the characterisation and identification of expired silver gelatin papers. It is also to demonstrate that a tactile tool such as the sample booklet can assist in identifying various deterioration events. I feel that it is important to have a hands-on source that can be used independently or collectively with other sources such as web-based visual identification tools. The booklet will be useful as an educational tool for students, collection care takers, as well as professionals in the photographic field.

scholarly journals INSTIGATION ON MECHANISM OF LONG-TERM STRENGTH DEVELOPMENT OF CARBONATED CEMENT-TREATED SAND

2014 ◽  
Vol 68 (1) ◽  
pp. 523-528
Author(s):  
Makoto SHOJI ◽  
Minoru MORIOKA ◽  
Tomomi YOSHIDA ◽  
Kenichiro NAKARAI
Keyword(s):  
Strength Development ◽  
Term Strength

scholarly journals Long-term time-course of strength adaptation to minimal dose resistance training: Retrospective longitudinal growth modelling of a large cohort through training records

2021 ◽  
Author(s):  
James Steele ◽  
James Fisher ◽  
Jürgen Giessing ◽  
Patroklos Androulakis-Korakakis ◽  
Milo Wolf ◽  
...  
Keyword(s):  
Public Health ◽  
Resistance Training ◽  
Fixed Effects ◽  
Time Course ◽  
Small Samples ◽  
Strength Development ◽  
Minimal Growth ◽  
Minimal Effective Dose ◽  
Minimal Dose

Objective: Public health guidelines for resistance training typically emphasize a minimal effective dose approach. The intention for such guidelines is that individuals engage in these behaviors over the long-term. However, relatively few studies have examined the longitudinal time-course of strength adaptations to resistance training and those which have typically utilize small samples and/or athletic populations. Further, no studies have employed approaches to incorporate participant level random factors into modelling. Thus, the aim of this study was to examine the time-course of strength development resulting from continued participation in minimal dose resistance training in a large sample through retrospective training records. Methods: Data was available for analysis from 14,690 participants who had undergone minimal dose resistance training (1x/week, single sets to momentary failure of six exercises) with records ranging up to 352 weeks (~6.8 years) in length. Linear-log growth models examining the development of strength over time were fit allowing random intercepts and slopes by participant. In addition, the interaction of sex and age were examined as fixed effects. Results: All models demonstrated a robust linear-log relationship which on the untransformed time scale clearly demonstrated the presence of a plateau in strength development around ~1 year into training after which strength was essentially maintained with minimal growth. Sex and age had minimal interaction effects. Conclusions: Substantial strength gains are possible with the use of a minimal dose resistance training approach. Though, these begin to plateau after ~1 year of training with little impact from sex or age on the emergence of this plateau. It is unclear if this plateau can be overcome through alternative approaches. Considering this, our results support public health recommendations for minimal dose resistance training to induce and maintain strength adaptations in adults.

scholarly journals Direct Start Preparations of Polish Tennis Representation to Under 16 Team World Championships (Chile, 2001)

2018 ◽  
Vol 1 (60) ◽  
Author(s):  
Marina Jagiello
Keyword(s):  
Training Load ◽  
Time Structure ◽  
Work Volume ◽  
Equal Importance ◽  
Preparation Period ◽  
Basic Parameters ◽  
Level 2

The analysis comprises a 33-day preparation period of the Polish representation in the fi nale of the Team World Championships held in Chile (16 10—22 10 2001). Particular attention was focused on the time structure of ap-plied training — the arrangement and duration of mesocycles and microcycles. The second aspect of the performed analysis, which was of equal importance, was the general volume and proportions of the applied training means. The performed studies and an analysis of data available in literature indicated that rational preparation to the main start in tennis should comprise the following factors: 1) phase of long term preparations and the current acquired fi tness level; 2) nature of preparations (orientation of workouts, type of applied means) as well as the values of basic parameters in training work (volume and intensity) that precede the particular period; 3) regularities connected with processes of restitution after diverse activities, as regards the magnitude (maximum, submaximal, average and small) and character of training load (related to speed, speed and strength, endurance, etc.); 4) the amount of time remaining for preparations to the main start.Keywords: structure of training, training mesocycles, training means.

Ocean Climate: “Off the Shelf”

2013 ◽  
Vol 47 (1) ◽  
pp. 7-18 ◽  
Author(s):  
Rick Cole ◽  
Jeff Kinder ◽  
Weidong Yu
Keyword(s):  
Private Sector ◽  
Academic Research ◽  
Atmospheric Conditions ◽  
Ocean Climate ◽  
Data Output ◽  
Basic Parameters ◽  
Additional Water ◽  
Scientists And Engineers ◽  
Additional Support

AbstractMeasuring ocean physics and atmospheric conditions at the sea-surface has been taking place for decades. The basic parameters measured remain with additional water column characteristics and meteorology added to data streams as technology advances within the community. A transition of this technology to the private sector from government and academic research institutions has occurred with additional support from innovative individual and group efforts in the field of ocean instrumentation. Due to licensing agreements between institutions and corporations along with entrepreneurial patents, scientists and engineers now have the resources available “off the shelf” (private sector purchase) to pursue and enhance the challenging task of measuring our offshore environment. As a result, long-term monitoring of ocean processes and changes has become more accessible to the research community at large. This paper describes one such project where original equipment manufactured instrumentation was integrated together to mirror the data output from government-funded monitoring systems on multinational ocean climate programs. RDSEA International, along with Down East Instrumentation, have developed a hybrid monitoring system using easily accessible off-the-shelf components.

Small Fish, Big Questions: Inquiry Kits for Teaching Evolution

2018 ◽  
Vol 80 (2) ◽  
pp. 124-131 ◽  
Author(s):  
Emily A. Kane ◽  
E. Dale Broder ◽  
Andrew C. Warnock ◽  
Courtney M. Butler ◽  
A. Lynne Judish ◽  
...  
Keyword(s):  
Natural Selection ◽  
Evolution Education ◽  
Small Fish ◽  
Teaching Evolution ◽  
Local Schools ◽  
Broader Impacts ◽  
Hands On ◽  
Education And Outreach ◽  
Evolution By Natural Selection

Evolution education poses unique challenges because students can have preconceptions that bias their learning. Hands-on, inquiry approaches can help overcome preset beliefs held by students, but few such programs exist and teachers typically lack access to these resources. Experiential learning in the form of self-guided kits can allow evolution education programs to maximize their reach while still maintaining a high-quality resource. We created an inquiry-based kit that uses live Trinidadian guppies to teach evolution by natural selection using the VIST (Variation, Inheritance, Selection, Time) framework. Our collaborative team included evolutionary biologists and education specialists, and we were able to combine expertise in evolution research and inquiry-based kit design in the development of this program. By constructing the kits with grant funds slated for broader impacts and maintaining them at our university's Education and Outreach Center, we made these kits freely available to local schools over the long term. Students and teachers have praised how clearly the kits teach evolution by natural selection, and we are excited to share this resource with readers of The American Biology Teacher.

MAXIMIZING RESTORATION SUCCESS WHEN THE GOOD GROUND IS GONE

2017 ◽  
Vol 12 (3) ◽  
pp. 115-123
Author(s):  
Alex Zimmerman
Keyword(s):  
Management Practices ◽  
Soil Conditions ◽  
Construction Sites ◽  
Repeated Cycle ◽  
Restoration Success ◽  
Fundamental Causes ◽  
Essential Nutrient ◽  
Living Organisms ◽  
Construction Schedules

INTRODUCTION “The good ground is gone” often refers to the challenging nature of construction sites these days. Building on steeper slopes and within tighter boundaries while accelerating construction schedules is adding to the challenge of construction managers. Often the revegetation and restoration is unfortunately not planned or timed for successful long-term vegetation success. Site soil conditions are frequently overlooked and the timing necessary for seed germination, expression, and establishment are rarely factors in determining the schedule of seeding applications for optimum results. All too often less than desired results or failure is the accepted outcome. This will increase the future maintenance costs and encourage the repeated “finger pointing” while seeking to blame one cause or another. Typically, this often-repeated process fails to address the fundamental causes and thereby rarely fixes the problems moving forward. In an effort to break out of this all too often repeated cycle, let's break down the principle challenges and explore options for successful restoration of challenging sites. Successful, long-term revegetation starts with the soil. Without quality soil that takes years to accumulate naturally, revegetation efforts regularly fail or the outcomes are less than ideal. During construction, mining, and general land disturbing activities the soil will be degraded even while practicing the best topsoil harvesting and stock-piling management practices. Many areas where vegetation is desired are essentially mineral without any organic matter or biological activity. When available, stockpiled topsoil will also degrade; the environment within the pile will create conditions that microbes, essential for plant health, will be negatively affected. The longer the stripped soils are stockpiled, the more living organisms are lost. Recommendations and even requirements for limiting the depth of the pile to reduce the loss of beneficial microbes is rarely possible given the tight boundaries of project limits facing site operators. When the stockpile depth is able to be minimized, the pile must also be turned regularly to reduce the loss of the essential nutrient cycling microbiome present in healthy soils.

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