scholarly journals Confinement of Masonry Columns with the FRCM-System: Theoretical and Experimental Investigation

2020 ◽  
Vol 5 (11) ◽  
pp. 101
Author(s):  
Maria Antonietta Aiello ◽  
Alessio Cascardi ◽  
Luciano Ombres ◽  
Salvatore Verre
Keyword(s):  
Experimental Investigation ◽  
Stress Transfer ◽  
Experimental Results ◽  
The Other ◽  
Analytical Models ◽  
Small Scale ◽  
Structural Element ◽  
Technical Literature ◽  
Number Of Layers ◽  
Other Hand

Fabric Reinforced Cementitious Matrix (FRCM) systems are promising solutions for the confinement of masonry columns because they demonstrate strengthening effectiveness and, at the same time, compatibility with historical substrates. Nevertheless, the matrix is responsible for the stress-transfer from the structural element to the fabric-reinforcement. Therefore, in the case of poor-quality mortar, the effectiveness of the strengthening can be limited or even compromised. On the other hand, the low content of fibers utilized for FRCM systems generally involves the need to apply more layers in order to accomplish design requirements and a continuous configuration of the reinforcement is more often addressed. Few experimental and theoretical investigations have been targeted to the before mentioned aspects in the recent past, namely the influence of the kind of mortar, the number of layers, and the strengthening configuration (continuous, discontinuous) on the effectiveness of confinement. The present paper refers to the results of an experimental investigation on FRCM confined clay brick masonry. A series of small-scale masonry columns were tested under monotonic centered load until collapse. The varied parameters were the number of confining layers (i.e., 1, 2, and 3) and the confinement configuration (i.e., continuous and discontinuous). The performed research aims to contribute in strengthening to the knowledge in the field of FRCM-confinement, mainly focusing on some of the mentioned unexplored aspects (number of layers, strengthening configuration) that could be considered for validation/improvement of analytical design-oriented formulas. In particular, some analytical models, available in the technical literature, were adopted for predicting the herein reported experimental results. Even if based on few experimental results, the outcomes showed that the number of FRCM-layers and the confinement configuration were crucial parameters affecting the confining effectiveness. The compressive strength was satisfactorily predicted in all cases by the two available utilized models. On the other hand, an improvement in the utilized AOM model is suggested in order to include the stress–strain curves of the hardening type.

scholarly journals Analysis of Operational Efficiencies and Costs for Extracting Thinned Woods in Small-Scale Forestry, Nasunogahara Area, Tochigi Prefecture, Japan

2020 ◽  
Vol 3 (1) ◽  
pp. 61
Author(s):  
Kazuhiro Aruga
Keyword(s):  
Transportation Costs ◽  
The Other ◽  
Small Scale ◽  
Light Truck ◽  
Operation Costs ◽  
Other Hand ◽  
Light Trucks ◽  
The Cost ◽  
Manual Extraction ◽  
Truck Transportation

In this study, two operational methodologies to extract thinned woods were investigated in the Nasunogahara area, Tochigi Prefecture, Japan. Methodology one included manual extraction and light truck transportation. Methodology two included mini-forwarder forwarding and four-ton truck transportation. Furthermore, a newly introduced chipper was investigated. As a result, costs of manual extractions within 10 m and 20 m were JPY942/m3 and JPY1040/m3, respectively. On the other hand, the forwarding cost of the mini-forwarder was JPY499/m3, which was significantly lower than the cost of manual extractions. Transportation costs with light trucks and four-ton trucks were JPY7224/m3 and JPY1298/m3, respectively, with 28 km transportation distances. Chipping operation costs were JPY1036/m3 and JPY1160/m3 with three and two persons, respectively. Finally, the total costs of methodologies one and two from extraction within 20 m to chipping were estimated as JPY9300/m3 and JPY2833/m3, respectively, with 28 km transportation distances and three-person chipping operations (EUR1 = JPY126, as of 12 August 2020).

Natural Vulcanization Accelerators in Hevea Latex

1948 ◽  
Vol 21 (4) ◽  
pp. 853-859
Author(s):  
R. F. A. Altman
Keyword(s):  
Amino Acids ◽  
Experimental Results ◽  
The Other ◽  
Active Nitrogen ◽  
Nitrogen Bases ◽  
Other Hand ◽  
Decomposition Processes ◽  
Volatile Products ◽  
Nitrogenous Substances ◽  
The One

Abstract As numerous investigators have shown, some of the nonrubber components of Hevea latex have a decided accelerating action on the process of vulcanization. A survey of the literature on this subject points to the validity of certain general facts. 1. Among the nonrubber components of latex which have been investigated, certain nitrogenous bases appear to be most important for accelerating the rate of vulcanization. 2. These nitrogen bases apparently occur partly naturally in fresh latex, and partly as the result of putrefaction, heating, and other decomposition processes. 3. The nitrogen bases naturally present in fresh latex at later stages have been identified by Altman to be trigonelline, stachhydrine, betonicine, choline, methylamine, trimethylamine, and ammonia. These bases are markedly active in vulcanization, as will be seen in the section on experimental results. 4. The nitrogenous substances formed by the decomposition processes have only partly been identified, on the one hand as tetra- and pentamethylene diamine and some amino acids, on the other hand as alkaloids, proline, diamino acids, etc. 5. It has been generally accepted that these nitrogenous substances are derived from the proteins of the latex. 6. Decomposition appears to be connected with the formation of a considerable amount of acids. 7. The production of volatile nitrogen bases as a rule accompanies the decomposition processes. These volatile products have not been identified. 8. The active nitrogen bases, either already formed or derived from complex nitrogenous substances, seem to be soluble in water but only slightly soluble in acetone.

scholarly journals Comparison of the Fungicidal Properties of Different Humectants in a Tobacco Blend / Vergleich der fungistatischen Wirkung verschiedener Feuchthaltemittel bei einer ungesoßten Tabakmischung

1966 ◽  
Vol 3 (7) ◽  
Author(s):  
H. van Nooy
Keyword(s):  
Experimental Results ◽  
The Other ◽  
Other Hand ◽  
Tobacco Treatment

AbstractThe experimental results indicated in the present paper reveal that among all humectants admitted 1,3-butyleneglycol alone has marked fungicidal properties satisfying the requirements of practical tobacco treatment, and that, on the other hand, diethyleneglycol and glycerine practically do not have such qualities

scholarly journals Elastic Properties of Magnetorheological Elastomers in a Heterogeneous Uniaxial Magnetic Field

2018 ◽  
Vol 19 (10) ◽  
pp. 3045 ◽  
Author(s):  
Takehito Kikuchi ◽  
Yusuke Kobayashi ◽  
Mika Kawai ◽  
Tetsu Mitsumata
Keyword(s):  
Magnetic Field ◽  
Elastic Properties ◽  
Uniform Magnetic Field ◽  
Large Strain ◽  
Small Strain ◽  
Experimental Results ◽  
The Other ◽  
Magnetorheological Elastomers ◽  
Other Hand ◽  
Strain Model

Magnetorheological elastomers (MREs) are stimulus-responsive soft materials that consist of polymeric matrices and magnetic particles. In this study, large-strain response of MREs with 5 vol % of carbonyl iron (CI) particles is experimentally characterized for two different conditions: (1) shear deformation in a uniform magnetic field; and (2), compression in a heterogeneous uniaxial magnetic field. For condition (1), dynamic viscoelastic measurements were performed using a rheometer with a rotor disc and an electric magnet that generated a uniform magnetic field on disc-like material samples. For condition (2), on the other hand, three permanent magnets with different surface flux densities were used to generate a heterogeneous uniaxial magnetic field under cylindrical material samples. The experimental results were mathematically modeled, and the relationship between them was investigated. We also used finite-element method (FEM) software to estimate the uniaxial distributions of the magnetic field in the analyzed MREs for condition (2), and developed mathematical models to describe these phenomena. By using these practicable techniques, we established a simple macroscale model of the elastic properties of MREs under simple compression. We estimated the elastic properties of MREs in the small-strain regime (neo–Hookean model) and in the large-strain regime (Mooney–Rivlin model). The small-strain model explains the experimental results for strains under 5%. On the other hand, the large-strain model explains the experimental results for strains above 10%.

scholarly journals SPECIFIC EMISSIONS FROM BIOMASS COMBUSTION

2014 ◽  
Vol 54 (1) ◽  
pp. 74-78 ◽  
Author(s):  
Pavel Skopec ◽  
Jan Hrdlička ◽  
Michal Kaválek
Keyword(s):  
Calorific Value ◽  
Experimental Results ◽  
The Other ◽  
Biomass Combustion ◽  
Small Scale ◽  
Biomass Fuels ◽  
Rape Plant ◽  
Specific Emissions

This paper deals with determining the specific emissions from the combustion of two kinds of biomass fuels in a small-scale boiler. The tested fuels were pellets made of wood and pellets made of rape plant straw. In order to evaluate the specific emissions, several combustion experiments were carried out using a commercial 25 kW pellet-fired boiler. The specific emissions of CO, SO<sub>2</sub> and NO<sub>x</sub> were evaluated in relation to a unit of burned fuel, a unit of calorific value and a unit of produced heat. The specific emissions were compared with some data acquired from the reference literature, with relatively different results. The differences depend mainly on the procedure used for determining the values, and references provide no information about this. Although some of our experimental results may fit with one of the reference sources, they do not fit with the other. The reliability of the references is therefore disputable.

Effect of Manganese Addition on Strength and Fracture Toughness in Mg-6Al-1Zn Alloy

2006 ◽  
Vol 306-308 ◽  
pp. 857-862 ◽  
Author(s):  
Taisuke Sasaki ◽  
Tokuteru Uesugi ◽  
Yorinobu Takigawa ◽  
Kenji Higashi
Keyword(s):  
Fracture Toughness ◽  
Magnesium Alloy ◽  
Yield Strength ◽  
Ductile Fracture ◽  
Manganese Content ◽  
Experimental Results ◽  
The Other ◽  
Excessive Amount ◽  
Void Coalescence ◽  
Other Hand

The effect of manganese on strength and fracture toughness was investigated using five kinds of Mg-6Al-1Zn alloys. From the experimental results, the yield strength increased with increasing in manganese content until manganese content reached 0.14 wt. %. On the other hand, further increase in yield strength was not observed in case larger than 0.14 % of manganese was added. In addition, fracture toughness decreases with increasing manganese content. Fracture of magnesium alloy was ductile fracture by void coalescence. Adding excessive amount of manganese caused the increase in the presence of inclusions. This kind of particle easily became the nucleus of microvoid. As a conclusion, manganese should be added so that coarse manganese-bearing particle is not formed. Thus, 0.14 wt. % of manganese should be added to Mg-6Al-1Zn alloy in order to develop the alloy with well-balanced relationship between strength and fracture toughness.

Effects of Mandarin Cultivar on Quality of Mandarin Juice

2008 ◽  
Vol 14 (4) ◽  
pp. 307-313 ◽  
Author(s):  
F. Beltrán ◽  
A.J. Perez-López ◽  
J.M. López-Nicolás ◽  
A.A. Carbonell-Barrachina
Keyword(s):  
Vitamin C ◽  
Volatile Compounds ◽  
Experimental Results ◽  
The Other ◽  
Total Volatile ◽  
Color Coordinates ◽  
Juice Processing ◽  
Other Hand ◽  
Cielab Color

Eight mandarin cultivars have been analyzed for their content of vitamin C, minerals (Ca, Mg, K, Na, Fe, Cu, Mn, and Zn), CIELab color coordinates (L*, a*, b*, C*, and h ab), total volatile compounds content and sensory aroma intensity of juice. Experimental results proved that no important enough differences were found in the minerals contents to decide which mandarin cultivar was of higher quality. Clemenules provided the darkest juice with the highest vitamin C content and with the most intense mandarin aroma. On the other hand, Nova and Hernandina mandarin could be considered as the worst cultivars for juice production. Finally if Clemenules mandarins were not available for juice processing, Orogrande, Clemenpons, Ellendale, and Marisol could also be good options.

scholarly journals Modeling of Rate-Independent and Symmetric Hysteresis Based on Madelung’s Rules

Sensors ◽  
2019 ◽  
Vol 19 (2) ◽  
pp. 352 ◽  
Author(s):  
Kairui Cao ◽  
Rui Li
Keyword(s):  
Phenomenological Models ◽  
Turning Points ◽  
Modeling Method ◽  
Experimental Results ◽  
The Other ◽  
Other Hand ◽  
The Relationship ◽  
With Memory

Hysteresis is a kind of nonlinearity with memory, which is usually unwanted in practice. Many phenomenological models have been proposed to describe the observed hysteresis. For instance, the Prandtl-Ishlinskii (PI) model, which consists of several backlash operators, is the most widely used. On the other hand, the well-known Madelung’s rules are always used to validate hysteresis models. It is worth pointing out that the PI model obeys Madelung’s rules. In this paper, instead of considering these rules as criteria, we propose a modeling method for symmetric hysteresis by directly constructing the trajectory based on Madelung’s rules. In the proposed method, turning points are recorded and wiped out according to the input value. After the implementation of the recording and wiping-out mechanisms, the curve which the current trajectory moves along can be determined and then the trajectory can be described. Furthermore, the relationship between the proposed method and the PI model is also investigated. The effectiveness of the presented method is validated by simulation and experimental results.

scholarly journals Doppler-Shifted Inertial Oscillations on a β Plane

2005 ◽  
Vol 35 (8) ◽  
pp. 1480-1488 ◽  
Author(s):  
Xiaoming Zhai ◽  
Richard J. Greatbatch ◽  
Jinyu Sheng
Keyword(s):  
Numerical Model ◽  
The Other ◽  
Small Scale ◽  
Nonlinear Interactions ◽  
Inertial Waves ◽  
Background Flow ◽  
Inertial Oscillations ◽  
Other Hand ◽  
Spherical Earth

Abstract On the spherical earth, and in the absence of a background flow, the poleward propagation of near-inertial oscillations is restricted by the turning latitude. A background flow, on the other hand, provides a way to increase the apparent frequency of near-inertial waves through Doppler shifting. In this note, it is shown that near-inertial oscillations can be advected to latitudes higher than their turning latitude. Associated with the poleward advection there is a squeezing of the meridional wavelength. A numerical model is used to verify this result. The squeezed inertial oscillations are vulnerable to nonlinear interactions, which could eventually lead to small-scale dissipation and mixing.

Jan van Gool als kunstcriticus

1983 ◽  
Vol 97 (4) ◽  
pp. 266-283
Author(s):  
Lyckle De Vries
Keyword(s):  
Art History ◽  
The Other ◽  
Reliable Information ◽  
Small Scale ◽  
Art Theory ◽  
Work Of Art ◽  
Dutch Art ◽  
Other Hand ◽  
History Of ◽  
Expression Of Emotions

AbstractIn 1750 and 1751 Jan van Gool published two volumes of artists' biographies entitled De Nieuwe Schouburg (Note 2). This sequel to Houbraken's Groote Schouburgh (.Note I) is an important source for Dutch art history of the period around 1700. The author's opinions are not strictly governed by the rules of art theory, nor is he a convinced Classicist. His main aim is to give complete and reliable information on the lives and works of artists. In so doing he cannot refrain from giving personal opinions. These characterize him as a competent art critic, who seems to have had an eye for style and quality. He despises work by contemporaries who still adhere to the Leiden tradition of fijnschilderen (small-scale, highly-finished painting). In his view the composition of a painting is of prime importance in assessing its quality, for it is mostly there that an artist's inventiveness, or lack of it, is revealed. Another aspect of great importance is the expression of emotions in painted figures through their glances, gestures and attitudes. Van Gool praises not only history painters who prove to have abilities in this field, but also painters of genre scenes and portraits. He pays far more attention to a painter's brushwork than his style of drawing, his predilection being for masters with a 'courageous' brush. Relatively little attention is given to colour and light and to the plasticity of painted figures. Van Gool's ideals seem to be summed up in the word natural. The essential qualities of the subjects painted must be made visible in the work of art. A painstaking realism in the Leiden tradition would endanger this ideal as much as a severe Classicism. The observation of reality should not be carried so far that details become more important than totalities, but on the other hand the overall form should not be idealized to such an extent that reality is forgotten.

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