Contact Interface Model for Shallow Foundations Subjected to Combined Cyclic Loading

It has been recognized that the ductility demands on a superstructure might be reduced by allowing rocking behavior and mobilization of the ultimate capacity of shallow foundations during seismic loading. However, the absence of practical reliable foundation modeling techniques to accurately design foundations with the desired capacity and energy dissipation characteristics and concerns about permanent deformations have hindered the use of nonlinear soil–foundation–structure interaction as a designed mechanism for improving performance of structural systems. This paper presents a new “contact interface model” that has been developed to provide nonlinear relations between cyclic loads and displacements of the footing–soil system during combined cyclic loading (vertical, shear, and moment). The rigid footing and the soil beneath the footing in the zone of influence, considered as a macroelement, are modeled by keeping track of the geometry of the soil surface beneath the footing, along with the kinematics of the footing–soil system, interaction diagrams in vertical, shear, and moment space, and the introduction of a parameter, critical contact area ratio (A/Ac); the ratio of footing area (A) to the footing contact area required to support vertical and shear loads (Ac). Several contact interface model simulations were carried out and the model simulations are compared with centrifuge model test results. Using only six user-defined model input parameters, the contact interface model is capable of capturing the essential features (load capacities, stiffness degradation, energy dissipation, and deformations) of shallow foundations subjected to combined cyclic loading.     

Modeling the heating value of Municipal Solid Waste

The most common methods currently being practiced to evaluate the heating value of Municipal Solid Waste (MSW) are by using the equation derived by Dulong, or experimentally by using the bomb calorimeter. There have been numerous other mathematical equations, which were created based on data from the physical composition, proximate or elemental analysis of the MSW. Questions have been raised on the size of the samples used for the experiments and on the applicability of these equations in different parts of the globe. This study was initiated to tackle these problems and also to establish a mathematical model that could calculate the Higher Heating Value of Malaysian MSW. Results showed that the correlation from the physical composition gave the best correlation coefficient when compared to the other correlation created based on the proximate or elemental analysis results. The new equations were also tested against other established equations and produced better results in all the different categories.     

Novel Perspectives Regarding the Pathology,Inflammation, and Biomarkers of Acute Respiratory Distress Syndrome

Acute respiratory distress syndrome (ARDS) is an acute inflammation of the lung resulting from damage to the alveolar–capillary membrane, and it is diagnosed using a combination of clinical and physiological variables. ARDS develops in approximately 10% of hospitalised patients with pneumonia and has a mortality rate of approximately 40%. Recent research has identified several biomarkers associated with ARDS pathophysiology, and these may be useful for diagnosing and monitoring ARDS. They may also highlight potential therapeutic targets. This review summarises our current understanding of those clinical biomarkers: (1) biomarkers of alveolar and bronchiolar injury, (2) biomarkers of endothelial damage and coagulation, and (3) biomarkers for treatment responses.     

Modeling the crop transpiration using an optimality-based approach

Evapotranspiration constitutes more than 80% of the long-term water balance in Northern China. In this area, crop transpiration due to large areas of agriculture and irrigation is responsible for the majority of evapotranspiration. A model for crop transpiration is therefore essential for estimating the agricultural water consumption and understanding its feedback to the environment. However, most existing hydrological models usually calculate transpiration by relying on parameter calibration against local observations, and do not take into account crop feedback to the ambient environment. This study presents an optimality-based ecohydrology model that couples an ecological hypothesis, the photosynthetic process, stomatal movement, water balance, root water uptake and crop senescence, with the aim of predicting crop characteristics, CO₂ assimilation and water balance based only on given meteorological data. Field experiments were conducted in the Weishan Irrigation District of Northern China to evaluate performance of the model. Agreement between simulation and measurement was achieved for CO₂ assimilation, evapotranspiration and soil moisture content. The vegetation optimality was proven valid for crops and the model was applicable for both C ₃ and C ₄ plants. Due to the simple scheme of the optimality-based approach as well as its capability for modeling dynamic interactions between crops and the water cycle without prior vegetation information, this methodology is potentially useful to couple with the distributed hydrological model for application at the watershed scale.

     

Capacity, Settlement, and Energy Dissipation of Shallow Footings Subjected to Rocking

The effectiveness of structural fuse mechanisms used to improve the performance of buildings during seismic loading depends on their capacity, ductility, energy dissipation, isolation, and self-centering characteristics. Although rocking shallow footings could also be designed to possess many of these desirable characteristics, current civil engineering practice often avoids nonlinear behavior of soil in design, due to the lack of confidence and knowledge about cyclic rocking. Several centrifuge experiments were conducted to study the rocking behavior of shallow footings, supported by sand and clay soil stratums, during slow lateral cyclic loading and dynamic shaking. The ratio of the footing area to the footing contact area required to support the applied vertical loads (A/Ac), related to the factor of safety with respect to vertical loading, is correlated with moment capacity, energy dissipation, and permanent settlement measured in centrifuge and 1 g model tests. Results show that a footing with large A/Ac ratio (about 10) possesses a moment capacity that is insensitive to soil properties, does not suffer large permanent settlements, has a self-centering characteristic associated with uplift and gap closure, and dissipates seismic energy that corresponds to about 20% damping ratio. Thus, there is promise to use rocking footings in place of, or in combination with, structural base isolation and energy dissipation devices to improve the performance of the structure during seismic loading.     

The genetic basis of infertility

Infertility is defined as the inability to conceive after one year of regular unprotected intercourse; approximately one in six couples wishing to start a family fall into this category. Although, in many cases, the diagnosis is simply 'unexplained', a variety of reasons including lack of ovulation, mechanical stoppage, sperm deficiencies and parental age have been implicated. It is difficult to assess accurately the overall magnitude of the contribution of genetics to infertility as most, if not all, conditions are likely to have a genetic component, for example susceptibility to infection. Nevertheless, a significant number of infertility phenotypes have been associated with specific genetic anomalies. The genetic causes of infertility are varied and include chromosomal abnormalities, single gene disorders and phenotypes with multifactorial inheritance. Some genetic factors influence males specifically, whereas others affect both males and females. For example, chromosome translocations affect both males and females, whereas Klinefelter syndrome and the subsequent infertility phenotype caused by it are specific to males. This article reviews current research in the genetic basis of infertility; gender-specific disorders and those affecting both sexes are considered.     

Modeling the crop transpiration using an optimality-based approach

Evapotranspiration constitutes more than 80% of the long-term water balance in Northern China. In this area, crop transpiration due to large areas of agriculture and irrigation is responsible for the majority of evapotranspiration. A model for crop transpiration is therefore essential for estimating the agricultural water consumption and understanding its feedback to the environment. However, most existing hydrological models usually calculate transpiration by relying on parameter calibration against local observations, and do not take into account crop feedback to the ambient environment. This study presents an optimality-based ecohydrology model that couples an ecological hypothesis, the photosynthetic process, stomatal movement, water balance, root water uptake and crop senescence, with the aim of predicting crop characteristics, CO₂ assimilation and water balance based only on given meteorological data. Field experiments were conducted in the Weishan Irrigation District of Northern China to evaluate performance of the model. Agreement between simulation and measurement was achieved for CO₂ assimilation, evapotranspiration and soil moisture content. The vegetation optimality was proven valid for crops and the model was applicable for both C ₃ and C ₄ plants. Due to the simple scheme of the optimality-based approach as well as its capability for modeling dynamic interactions between crops and the water cycle without prior vegetation information, this methodology is potentially useful to couple with the distributed hydrological model for application at the watershed scale.     

Normalized Relationships for Depth of Embedment of Sheet Pile Walls and Soldier Pile Walls in Cohesionless Soils

Normalized, non-dimensional relationships for calculating the depths of embedment of sheet pile walls and soldier pile walls embedded in cohesionless soils are presented. Rankine theory for lateral earth pressures in active and passive conditions are used in the analyses. Relationships are presented for cantilever walls and walls propped at crest. The proposed relationships can be used in dry soil conditions and as well as in saturated soil conditions with steady state seepage. The embedment depth relationships are presented in terms of non-dimensional parameters and can be used for a variety of soil conditions, dimensions and spacing of the walls, and depths of excavation. The presented relationships are simple, easy to use, and do not require tedious calculations.     

Sex pheromone of the tea tortrix moth (Homona coffearia Neitner)

Three compounds were isolated from female abdominal tips of the tea tortrix,Homona coffearia Neitner (Lepidoptera: Tortricidae) and identified as 1-dodecanol, 1-dodecyl acetate, and (E)-9-dodecen-1-yl acetate by chemical tests and mass spectrometry. These were the only appreciably active compounds detected in female gland extracts by male electroantennography of gas chromatographic collections. Synthetic (E)-9-dodecenyl acetate was shown to be active in attracting male moths in the field, and this activity was greatly increased by addition of dodecyl acetate and dodecanol. A very active lure for monitoring consists of 1 mg (E)-9-dodecenyl acetate, 3 mg dodecanol, and 1 mg dodecyl acetate in a polyethylene cap.Lepidoptera: Tortricidae