The doctrine that the content of the conclusion of a deductively valid argument is included in the content of its premises, taken jointly, is a familiar one. It has important consequences for the question of what value valid arguments possess, since it indicates the poverty of three traditional answers: that arguments may and should be used as instruments of persuasion, that they may and should be used as instruments of justification; and that they may and should be used to advance knowledge. The truth is, however, that in each of these cases the argument has only a managerial role and, if there is any work done, it is the premises that do it. It will be maintained that this point has little force against the critical rationalist answer, which I shall defend, that the principal purpose of deductive reasoning from an assemblage of premises is the exploration of their content, facilitating their criticism and rejection. That said, the main aim of the present paper is not to promote critical rationalism but to consider some published objections to the doctrine that a statement asserts every statement that is validly deducible from it. The alleged counterexamples to be considered fall roughly into two groups: statements that emerge with time from a rich mathematical or empirical theory, but were originally unformulated and are deducible from the theory only in a non-trivial way (Frederick 2011, 2014; Williamson 2012); and statements, notably disjunctions, that are easily formulated and are deducible from a theory in a trivial way (Schurz & Weingartner 1987; Mura 1990, 2008; Gemes 1994; Yablo 2014). Each of these counterexamples will be evaluated and dismissed.

Measurement of soil water content is important in hydrology, agriculture, and pedology. To this end, use of methods that can measure soil water content in a natural and safe condition with high speed and accuracy is very important. Recently, the use of Time Domain Reflectometry (TDR) has become common for quick measurement of soil salinity and volumetric water content. This study aimed to assess the effect of clay content and soil salinity on dielectric constant (volumetric water content) in saline and non– saline soils. At all five sites, both the topsoil (0–0.3 m depth) and the subsoil (0.3-0.6 m depth) were sampled. These soil samples were poured into 15-20 cylinders (sub-samples) depending on their clay content. Afterwards, pure water was repeatedly added to some sub-samples at the rate of 0.025 m3 m-3, while the others received 0.03m3m-3 saline water (EC of 0.41, 0.81, 1.053, 2.6, 3.49, 4.71 dSm-1) in repeated doses until the water content was close to saturation in each subsample. The samples were then weighed and packed to reach the same bulk density as originally measured in the field. After 24-48 hrs, the TDR measurement was performed. Soil physicochemical parameters, including organic matter, clay, silt, and sand contents and clay mineralogy were determined. The results showed that higher soil salinity increased soil dielectric constant i.e. both the rise time of the reflected signal and the total time delay increased, resulting in overestimation of soil moisture. The bound water in clay soil reduced the time delay because of its lower dielectric constant caused by specific surface area and affected on polarity of water near the particles, resulting in underestimation of soil water content. There is a turning point moisture, at which the effect of bound water is balanced by the effect of soil electrical conductivity. Also results show that only in one point linear model shows an accurate water measurement; below this point, bound water effect dominates and TDR underestimates soil moisture. Above this point, the effect of soil EC dominates and TDR overestimates soil moisture. This turning point moisture decreases as the soil salinity increases. Overall, the results show that for accurate measurement and avoidance of large errors in measurement of volumetric water content with TDR, salinity and mineralogy of clay content must be included in the calibration equation.

Polyethylene terephthalate (PET) bottles are widely used for packaging mineral water or soft drinks. Migration of toxic residual phthalate esters from PET could potentially change the quality of the bottled contents. The main purpose of this study is to control the migration of five different phthalate esters from PET bottles into the water they contained. To achieve this goal, three different types of nano clay particles were added to PET to slow down the migration of the toxic phthalate esters. The concentration of phthalate esters in the water in contact with PET and PET/nano clay was measured by gas chromatography (GC-FID) combined with the directly suspended droplet micro extraction method. Good precision, accuracy and reproducibility over a wide linear range were achieved by the proposed technique under optimal conditions. The experimental results reveal that adding nano clay fillers to the PET decreases the release of the above-mentioned chemicals from PET into the water considerably due to attainment of a tortuous diffusive path. Data also indicate the significant effect of nano clay volume fraction and exfoliated morphology on obtaining efficient barrier properties. Furthermore the effects of parameters such as storage time, temperature, and amount and type of nano clay inclusions were studied on the migration rate, as well.

This paper presents the problem of workover operations in the production wells. Liquid hydrocarbons recovery involves many operations, and production wells workover and servicing are essential parts of this process. Most of the well intervention operations require preliminary well killing that includes generating a hydrostatic back pressure with a column of fluid required density to eliminate any reservoir fluid inflow and gas surges. Preliminary well killing ensures safety of both crew members and production zone. This work focuses on a specialized additive for workover fluids developed by authors aiming to create and stabilize inverse emulsions. The results of conducted research have shown that the application of special additives not only significantly reduces clay swelling (from 25% to 3.1% in the case of a 5% NaCl solution) but also prevents sudden changes in wettability. These findings lead to conclusion that the use of special formulations results in preserving reservoir permeability by maintaining the size of pores and fractures. Simultaneously, it prevents the formation from a water blockage that could impact fluid flow paths. In case of using kill fluids based on inverse emulsions the permeability decreased 1.5 times less than in case of using water-based fluids.

This paper investigates the effect of moisture content on interface shear strength between offshore clay and steel plate. Although, sensitive and high plasticity offshore clay deposits are widely distributed in Malaysia and many other countries in the world, and steel is a vital construction material for many structures, research works on interaction between offshore clay and steel surface are relatively scarce. This study aims to evaluate interface shear strength of offshore clay with various steel surfaces, namely smooth, rough, and corroded. To achieve such aim, direct shear tests were conducted to assess the effect of moisture content and surface roughness on the interface shear strength. The normal stresses were ranged to be 50, 100, and 150 kPa. It was found that, the interface shear strength of offshore clay with rough steel significantly increased by almost 1.5 folds. It was further discovered that, addition of water content induced a progressive decrease in the interface shear strength. In summary, it has been observed that rough steel surface higher than the smooth and corroded steel surface enables a better interaction with offshore clay, enhancing the interface friction angle. The results developed in this research work can contribute a cost-effective design of structures in offshore clay.

Compressional and shear wave velocities (Vp and Vs respectively) are basic and essential parameters for any geomechanical modelling in deep ground conditions. However, both are complex parameters that are strongly influenced by other rock properties such as porosity, in situ stress, pore filling, clay content, etc. Therefore, detailed information about the contribution of each of these attributes can improve the results obtained in geomechanical models. Especially when the wave velocity in the surface conditions is estimated based on in situ data such as geophysical logs from wells or core samples or drilling chips, the importance of this matter becomes much significant. In this research, experimental data for more than 180 shaly rock samples were analysed. Clearly, porosity was the most critical parameter affecting shear wave velocity. Accordingly, increasing porosity leads to a dramatic decrease in wave velocity. Nevertheless, it was noticed that for a certain porosity value, a relatively wide range of wave velocities may be observed. Further investigation revealed that, clay content was also a significant contributing parameter. Based on explicit statistical analysis, a predictive equation was introduced with which shear wave velocity can be estimated with high certainty. Accordingly, for samples with the same porosity, variation in clay content would result in different wave velocities

Clay minerals are largely available in nature and due to special characteristics of clay, have successfully been used for dam core as a water-tightening material. Taking into consideration the execution necessities and so as to reduce the associated costs, it is required to reassess fundamental of the conventional plastic concrete mix design used for constructing water tightening element of the large dams. In this study the effects of two different types of clay minerals with the intention of evaluating the possibility of changing portion of the clay materials on compressive strength of plastic concrete are investigated. The required samples have been prepared and tested according to a special laboratory program. The results indicate that the type of clay mineral has meaningful effects on the strength of the plastic concrete. The results also have shown that the slump of the new mixture of plastic concrete is dependent on the amount of clay in the mix design. Consequently an empirical equation is derived for estimation of compressive strength based on two parameters of clay content and sample age.

Presence of gypsum particles in soil may cause many problems in such different application as agriculture and construction. Solubility causes the gypsum particles in contact with water, to be gradually dissolved and flow out of the environment. The structures built on these soils can be damaged due to solution of gypsum particles existing in the soil and collapse of the bed. In this research the effects of two factors including; gypsum content and hydraulic gradient were studied on solubility of gypsum containing clay soils. Samples of gypsum containing soils were provided artificially by adding various rates of natural gypsum including 0, 5, 10, 20 and 30 percent by weight of clay soil being prepared. Each gypsum soil sample was leached under five hydraulic gradient levels of: 0. 5, 1, 2, 5 and 10. The results indicated that the rate of Gypsum present in the soil directly affects the rate of solubility in a way that by increasing the percent of Gypsum the rate of solubility was increased. Also the rate of leaching including the rate of derived Gypsum from soil to primary rate of Gypsum is decreased by increasing the rate of Gypsum. In addition, by increasing hydraulic gradient, the speed and volume of drained water through the soil increased in a specified time and thereby more gypsum particles washed out through the soil.

Since lime- stabilization is effective on different soil size ranging from sand and finer, the influence of lime and clay content on CBR strength of these soils is investigated. Lime combines with the clay part of these soils and provides cemented materials, which is similar to concrete. Hence, the variation in clay and lime content will affect the amount of cemented materials and consequently the strength. Providing some lime- stabilized clayey sand samples, the effect of clay and lime content on CBR strength is evaluated. The results show that in a particular range of clay content, the mixes have the maximum strength variations and, the optimum lime content is about 7 to 8 percent.