scholarly journals Errors in concrete structures

1979 ◽  
Vol 6 (3) ◽  
pp. 465-467 ◽  
Author(s):  
D. E. Allen
Keyword(s):  
Concrete Structures ◽  
The Other ◽  
Other Hand ◽  
Shrinkage And Creep ◽  
Effects Of Temperature

One hundred and eighty-eight cases of error in concrete structures, 29 of which resulted in collapse and 118 in distress, deterioration, excessive cracking, spalling, deflection, or settlement, were collected from consulting engineers and government departments across Canada. The survey indicated that about half the errors originated in the design and the other half were due to faulty construction. Most of the collapses occurred during construction, mainly as a result of inadequate formwork or temporary bracing; some were due to detailing errors in design. Most serviceability failures, on the other hand, occurred during use. Many of those failures were due to lack of consideration in design of deflection or of the effects of temperature, shrinkage, and creep.

scholarly journals Effects of Retting Media Circulation and Temperature on the Fermentation Process in Soft-Texture and Low Cyanogenic Content Cassava Flour Production

2015 ◽  
Vol 14 (2) ◽  
pp. 67
Author(s):  
M.T.A.P. Kresnowati ◽  
Yazid Bindar ◽  
Lienda Aliwarga ◽  
Dianika Lestari ◽  
Nicholaus Prasetya ◽  
...  
Keyword(s):  
Fermentation Process ◽  
Morphological Changes ◽  
The Other ◽  
Small Scale ◽  
Fermentation Performance ◽  
Cassava Flour ◽  
Fermentation Temperature ◽  
Other Hand ◽  
Effects Of Temperature ◽  
Flour Production

A fermentation process to produce soft-texture and low cyanogenic content cassava flour had been studied, in particular the effects of temperature, circulation of the retting media, and scale to the reduction of cyanogenic content and the structure of cassava. Although the effects of retting media circulation and an increase in the fermentation temperature on cyanogenic content reduction were not clearly seen, they led to more damaged cassava structure and thus improving the overall cassava flour production. On the other hand small scale fermentation led to both cyanogenic content reduction and morphological changes, giving better fermentation performance.

scholarly journals Effects of Cassava Chips Fermentation Conditions on The Produced Flour Properties

2016 ◽  
Vol 16 (1) ◽  
pp. 51
Author(s):  
Angina Meitha ◽  
Yazid Bindar ◽  
M.T.A.P. Kresnowati
Keyword(s):  
Fermentation Process ◽  
Amylose Content ◽  
The Other ◽  
Cassava Flour ◽  
Dextrose Equivalent ◽  
Operation Conditions ◽  
Other Hand ◽  
Flour Properties ◽  
Effects Of Temperature ◽  
As Solubility

A fermentation process to produce soft-texture and low cyanogenic content cassava flour had been studied, in particular the effects of temperature, circulation of the fermentation media, and chips size, on fermented cassava flour (fercaf) properties. Fermentation was shown to affect properties of cassava flour: reducing the cyanogenic content, swelling power, as well as solubility, whereas on the other hand increasing the amylose content and correspondingly the measured DE. Further, the properties of the produced flour were affected by the implemented fermentation operation conditions. Fermentation temperature was found to significantly affect amylose content. Media circulation was found to significantly affect the measured Dextrose Equivalent. On the other hand, the size of cassava chips significantly affected the cyanogenic content and solubility of the flour

scholarly journals AVALIAÇÃO DA RESISTÊNCIA DE CONSOLOS DE CONCRETO MOLDADOS EM DUAS ETAPAS COM A UTILIZAÇÃO DE PROTENSÃO NÃO ADERENTE [ Strength assessment of concrete corbels cast in two steps using unbonded post-tensioning ]

2018 ◽  
Vol 15 (1) ◽  
Author(s):  
Luiz Guilherme Mendonça Chagas ◽  
Izadora Ferreira Nogueira ◽  
Luiz Álvaro Oliveira Júnior ◽  
Daniel Lima Araújo
Keyword(s):  
Experimental Research ◽  
Precast Concrete ◽  
Concrete Structures ◽  
The Other ◽  
Strength Assessment ◽  
Other Hand ◽  
Post Tensioning

RESUMO: Uma das principais vantagens das estruturas de concreto pré-moldado é a rapidez da execução. Essa vantagem pode ser ainda mais evidenciada se peças como pilares com consolos puderem ser produzidas de forma ainda mais ágil. Este artigo apresenta os resultados de uma pesquisa experimental em consolos curtos de concreto pré-moldado. Os consolos são pré-moldados separadamente do pilar e unidos ao mesmo mediante encaixe e protensão não aderente. Para isso, foram confeccionados três modelos formados por um pilar e dois consolos simétricos, todos pré-moldados, sendo que a ruína se deu por fendilhamento do concreto dos consolos. Os resultados também apontaram que a tipologia de consolo proposta apresentou capacidade resistente apenas 5% menor que do consolo monolítico de referência. Por outro lado, a tipologia de consolo proposta neste trabalho proporcionou capacidade resistente consideravelmente superior à encontrada para a tipologia de consolo moldado em duas etapas sem o uso de protensão.ABSTRACT: One of the key advantages of precast concrete structures is the speed of construction. This advantage can be further evidenced if elements like columns with corbels could be produced in an even more agile way. This paper presents the results of an experimental research on short precast concrete corbels. Corbels are precast separately of the column and then joined to it by means of socked and unbonded post-tensioning. For this, three models composed by a column and two symmetric corbels, all of them precast, were produced, being their failure defined by splitting of concrete in corbels. Results also demonstrated that the proposed typology of corbel presented strength merely 5% lower than the reference monolithic corbel. In the other hand, the proposed typology of corbel provided strength significantly greater than that found for corbel cast in two steps without prestressing.

A STUDY OF THE EFFECTS OF TEMPERATURE AND OTHER FACTORS UPON THE GERMINATION OF VEGETABLE CROPS: III. VEGETABLE VINE CROPS

1960 ◽  
Vol 40 (4) ◽  
pp. 596-606
Author(s):  
W. E. Torfason ◽  
I. L. Nonnecke
Keyword(s):  
Seed Germination ◽  
The Other ◽  
Similar Reaction ◽  
Vegetable Crops ◽  
Watermelon Seed ◽  
Fungal Activity ◽  
Other Hand ◽  
Effects Of Temperature

A study was made of the effects of temperature and duration of exposure upon the germination of cucumber, muskmelon, and watermelon seed. Seeds of four varieties of each crop were germinated at controlled temperatures by rolled-towel method. Muskmelon seed germination was significantly reduced as temperature decreased from 60°F. through 55°, 50° and 45°F. On the other hand, germination of cucumber and watermelon seed was not significantly altered by temperature. Prolonging the duration of exposure to 15 or 22 days resulted in significant reductions in the germination of watermelons but not of the other crops. The interaction of temperature with duration of exposure caused significant differences in the germination of the three crops. At 45° and 50°F., germination decreased generally as exposure lengthened to 15 days and then increased sharply at 22 days. It is postulated that this increase was the result of temperature conditioning or some similar reaction. At 55° and 60°F., germination increased slightly as exposure increased to 8 or 15 days, followed by a decrease at 22 days. This effect was most pronounced at 60°F., probably due to greater fungal activity at that temperature.It is concluded that satisfactory germination of the vine crops can be obtained after relatively long exposure to temperatures lower than the previously accepted minima.

A study of cometary eruptions through OH radio-lines

1999 ◽  
Vol 173 ◽  
pp. 249-254
Author(s):  
A.M. Silva ◽  
R.D. Miró
Keyword(s):  
Short Duration ◽  
Growth Curves ◽  
The Other ◽  
Initial Mass ◽  
Radio Lines ◽  
Other Hand ◽  
Sudden Rise

AbstractWe have developed a model for theH2OandOHevolution in a comet outburst, assuming that together with the gas, a distribution of icy grains is ejected. With an initial mass of icy grains of 108kg released, theH2OandOHproductions are increased up to a factor two, and the growth curves change drastically in the first two days. The model is applied to eruptions detected in theOHradio monitorings and fits well with the slow variations in the flux. On the other hand, several events of short duration appear, consisting of a sudden rise ofOHflux, followed by a sudden decay on the second day. These apparent short bursts are frequently found as precursors of a more durable eruption. We suggest that both of them are part of a unique eruption, and that the sudden decay is due to collisions that de-excite theOHmaser, when it reaches the Cometopause region located at 1.35 × 105kmfrom the nucleus.

Closing the GAP—A 5Å Scanning Microscope

1969 ◽  
Vol 27 ◽  
pp. 6-7
Author(s):  
A. V. Crewe
Keyword(s):  
Normal Form ◽  
The Other ◽  
Resolving Power ◽  
Scanning Microscope ◽  
Conventional Microscope ◽  
Other Hand ◽  
Closing The Gap ◽  
Thermal Sources ◽  
Better Than ◽  
Transmission Microscope

We have become accustomed to differentiating between the scanning microscope and the conventional transmission microscope according to the resolving power which the two instruments offer. The conventional microscope is capable of a point resolution of a few angstroms and line resolutions of periodic objects of about 1Å. On the other hand, the scanning microscope, in its normal form, is not ordinarily capable of a point resolution better than 100Å. Upon examining reasons for the 100Å limitation, it becomes clear that this is based more on tradition than reason, and in particular, it is a condition imposed upon the microscope by adherence to thermal sources of electrons.

Life Beyond 1MeV

1980 ◽  
Vol 38 ◽  
pp. 30-33
Author(s):  
K.H. Westmacott
Keyword(s):  
Electron Microscopy ◽  
Past Experience ◽  
The Other ◽  
Good Case ◽  
Other Hand ◽  
The U.S

Life beyond 1MeV – like life after 40 – is not too different unless one takes advantage of past experience and is receptive to new opportunities. At first glance, the returns on performing electron microscopy at voltages greater than 1MeV diminish rather rapidly as the curves which describe the well-known advantages of HVEM often tend towards saturation. However, in a country with a significant HVEM capability, a good case can be made for investing in instruments with a range of maximum accelerating voltages. In this regard, the 1.5MeV KRATOS HVEM being installed in Berkeley will complement the other 650KeV, 1MeV, and 1.2MeV instruments currently operating in the U.S. One other consideration suggests that 1.5MeV is an optimum voltage machine – Its additional advantages may be purchased for not much more than a 1MeV instrument. On the other hand, the 3MeV HVEM's which seem to be operated at 2MeV maximum, are much more expensive.

Can the Academic Self-Concept be Positive and Realistic?

2005 ◽  
Vol 19 (3) ◽  
pp. 129-132 ◽  
Author(s):  
Reimer Kornmann
Keyword(s):  
Academic Performance ◽  
Opposite Effect ◽  
Self Esteem ◽  
Point Of View ◽  
The Other ◽  
Self Concept ◽  
High Ability ◽  
Self Image ◽  
Other Hand

Summary: My comment is basically restricted to the situation in which less-able students find themselves and refers only to literature in German. From this point of view I am basically able to confirm Marsh's results. It must, however, be said that with less-able pupils the opposite effect can be found: Levels of self-esteem in these pupils are raised, at least temporarily, by separate instruction, academic performance however drops; combined instruction, on the other hand, leads to improved academic performance, while levels of self-esteem drop. Apparently, the positive self-image of less-able pupils who receive separate instruction does not bring about the potential enhancement of academic performance one might expect from high-ability pupils receiving separate instruction. To resolve the dilemma, it is proposed that individual progress in learning be accentuated, and that comparisons with others be dispensed with. This fosters a self-image that can in equal measure be realistic and optimistic.

Stories and the Self

2020 ◽  
Vol 32 (2) ◽  
pp. 47-58 ◽  
Author(s):  
Stefan Krause ◽  
Markus Appel
Keyword(s):  
Meta Analysis ◽  
The Self ◽  
The Other ◽  
Lower Degree ◽  
Contrast Effects ◽  
Self Perception ◽  
Self Perceptions ◽  
Other Hand ◽  
The One ◽  
Implicit And Explicit

Abstract. Two experiments examined the influence of stories on recipients’ self-perceptions. Extending prior theory and research, our focus was on assimilation effects (i.e., changes in self-perception in line with a protagonist’s traits) as well as on contrast effects (i.e., changes in self-perception in contrast to a protagonist’s traits). In Experiment 1 ( N = 113), implicit and explicit conscientiousness were assessed after participants read a story about either a diligent or a negligent student. Moderation analyses showed that highly transported participants and participants with lower counterarguing scores assimilate the depicted traits of a story protagonist, as indicated by explicit, self-reported conscientiousness ratings. Participants, who were more critical toward a story (i.e., higher counterarguing) and with a lower degree of transportation, showed contrast effects. In Experiment 2 ( N = 103), we manipulated transportation and counterarguing, but we could not identify an effect on participants’ self-ascribed level of conscientiousness. A mini meta-analysis across both experiments revealed significant positive overall associations between transportation and counterarguing on the one hand and story-consistent self-reported conscientiousness on the other hand.

Don’t Put Me in This Group

2019 ◽  
Vol 50 (2) ◽  
pp. 80-93
Author(s):  
Jort de Vreeze ◽  
Christina Matschke
Keyword(s):  
Positive Emotions ◽  
Negative Emotions ◽  
Negative Information ◽  
The Self ◽  
The Other ◽  
Other Hand ◽  
Group Memberships

Abstract. Not all group memberships are self-chosen. The current research examines whether assignments to non-preferred groups influence our relationship with the group and our preference for information about the ingroup. It was expected and found that, when people are assigned to non-preferred groups, they perceive the group as different to the self, experience negative emotions about the assignment and in turn disidentify with the group. On the other hand, when people are assigned to preferred groups, they perceive the group as similar to the self, experience positive emotions about the assignment and in turn identify with the group. Finally, disidentification increases a preference for negative information about the ingroup.

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