Environmental Study of Some Water Characteristics at Um-Al-Naaj Marsh, South of Iraq.

Um-Al-Naaj region in Al-Hawiezah Marsh, Southern Iraq was chosen to study the environmental variations of some water characteristics during 2008, seasonally. The results showed clear seasonal changes in values of some environmental variables (temperature, depth, light penetration, turbidity, total suspended solids, pH, dissolved oxygen, reactive phosphate, reactive nitrite, and reactive nitrate), while there were no clear seasonal changes in electrical conductivity and salinity values. In addition, high nutrients concentrations and light penetration were noted. Statistical analysis showed significant positive relationship between air and water temperature; electrical conductivity and salinity. Water turbidity was significantly affected by total suspended solids. On the other hand, some of the studied variables had significant negative effects (relative relationships) to each other, when water pH and dissolved oxygen were affected by temperature; total suspended solids and turbidity affected also light penetration

Physical and Chemical Properties of Cow's Milk Yogurt Added Whey Protein Concentrate (WPC)

The purpose of this research was to examine the physical and chemical characteristics of cow's milk yogurt with the addition of WPC. The physical characteristics observed included color (L*, a*, b*, whiteness index, hue, chroma), texture (firmness, work of penetration, resistance to probe withdrawal), while the chemical characteristics observed included water content, total solids, and titratable acidity. The main research materials are fresh cow's milk, Whey Protein Concentrate (WPC), and starter yogurt. The study was conducted using a Completely Randomized Design (CRD) with 5 treatments and 4 replications. The treatments consisted of control (P0), adding WPC as much as 2% (P1), 4% (P2), 6% (P3), and 8% (P4) of the amount of milk. Data were analysed using analysis of variance and post-hoc orthogonal polynomial test. The results showed that the addition of WPC up to 8% caused a very significant difference to the water content, total solids, titratable acidity, firmness, and work of penetration of yogurt. However, the addition of WPC up to 8% did not cause a significant difference in the color characteristics of yogurt. Total solids of yogurt increased from 12.08% (control) to 17.74% along with the addition of WPC up to 8%. Based on the results of the research, it can be concluded that the addition of WPC up to 8% can decrease the water content, firmness, and work of penetration of yogurt, as well as increase the total solids and titratable acidity of yogurt. However, it did not cause a noticeable change in the color characteristics of yogurt. However, it did not cause a significant change in the color characteristics of yogurt

Revisiting the problem of a crack impinging on an interface: A modeling framework for the interaction between the phase field approach for brittle fracture and the interface cohesive zone model

Artículo Open Access en el sitio web del editor. Pago por publicar en abierto.The problem of a crack impinging on an interface has been thoroughly investigated in the last three decades due to its important role in the mechanics and physics of solids. In the current investigation, this problem is revisited in view of the recent progresses on the phase field approach of brittle fracture. In this concern, a novel formulation combining the phase field approach for modeling brittle fracture in the bulk and a cohesive zone model for pre-existing adhesive interfaces is herein proposed to investigate the competition between crack penetration and deflection at an interface. The model, implemented within the finite element method framework using a monolithic fully implicit solution strategy, is applied to provide a further insight into the understanding of the role of model parameters on the above competition. In particular, in this study, the role of the fracture toughness ratio between the interface and the adjoining bulks and of the characteristic fracture-length scales of the dissipative models is analyzed. In the case of a brittle interface, the asymptotic predictions based on linear elastic fracture mechanics criteria for crack penetration, single deflection or double deflection are fully captured by the present method. Moreover, by increasing the size of the process zone along the interface, or by varying the internal length scale of the phase field model, new complex phenomena are emerging, such as simultaneous crack penetration and deflection and the transition from single crack penetration to deflection and penetration with subsequent branching into the bulk. The obtained computational trends are in very good agreement with previous experimental observations and the theoretical considerations on the competition and interplay between both fracture mechanics models open new research perspectives for the simulation and understanding of complex fracture patterns.Unión Europea FP/2007-2013/ERC 306622Ministerio de Economía y Competitividad DPI2012-37187, MAT2015-71036-P y MAT2015-71309-PJunta de Andalucía P11-TEP-7093 y P12-TEP- 105

Impact Of Construction And Reclamation Activities On The Water Quality Of The Thane Creek, Central-West Coast Of India

Degradation of natural resources is a major environmental issue the world is currently facing. Estuaries, creeks and coastal water ecosystems are such natural resources that are important as breeding and feeding grounds for fishes and crustaceans. Human activities and alterations made by reclamation have had an adverse effect on their ecology. Due to this, water quality management in these ecosystems has become a necessity. Regular studies of the hydrological parameters are essential for this purpose, as they can assess the status of pollution and help in deciding the mitigation strategy. Water quality of 26 km stretch of Thane creek, central-west coast of India was analyzed in 5 regions of the creek from May 1999 to April 2000. The study revealed spatial and temporal patterns. Heavy suspended solid load (avg. 5.736 gm/L), frequent hypoxia (DO<2.5 mg/L) coupled with excess nutrients like Phosphate-Phosphorus (avg. 0.26 mg/L) and Nitrate-Nitrogen (avg. 0.96 mg/L) were the main features of the creek. The Thane city region showed more deterioration of water quality compared to the other regions in the creek. In this region the suspended solid load showed an increase of 713.69% and dissolved oxygen decreased by 21.55% compared to the data of 1992-93. This can be attributed to the severe onslaught of activities in this region like solid waste dumping, construction of 3 new bridges, etc. since 1993, thereby affecting the flushing characteristic. Hence in order to protect and preserve such ecosystems, alterations to the environment should be meticulously planned

Experimental studies of the resultant contact forces in drillbit-rock interaction

Peer reviewedPostprin

Comparison of fibre optical measurements and discrete element simulations for the study of granulation in a spout fluidized bed

Spout fluidized beds are frequently used for the production of granules or particles through granulation. The products find application in a large variety of applications, for example detergents, fertilizers, pharmaceuticals and food. Spout fluidized beds have a number of advantageous properties, such as a high mobility of the particles, which prevents undesired agglomeration and yields excellent heat transfer properties. The particle growth mechanism in a spout fluidized bed as function of particle-droplet interaction has a profound influence on the particle morphology and thus on the product quality. Nevertheless, little is known about the details of the granulation process. This is mainly due to the fact that the granulation process is not visually accessible. In this work we use fundamental, deterministic models to enable the detailed investigation of granulation behaviour in a spout fluidized bed. A discrete element model is used describing the dynamics of the continuous gas-phase and the discrete droplets and particles. For each element momentum balances are solved. The momentum transfer among each of the three phases is described in detail at the level of individual elements. The results from the discrete element model simulations are compared with local measurements of particle volume fractions as well as particle velocities by using a novel fibre optical probe in a fluidized bed of 400 mm I.D. Simulations and experiments were carried out for three different cases using Geldart B type aluminium oxide particles: a freely bubbling fluidized bed; a spout fluidized bed without the presence of droplets and a spout fluidized bed with the presence of droplets. It is demonstrated how the discrete element model can be used to obtain information about the interaction of the discrete phases, i.e. the growth zone in a spout fluidized bed. Eventually this kind of information can be used to obtain closure information required in more coarse grained models

The Effects of Base Sheet Moisture Content on Size Penetration Characteristics

This thesis was designed to determine the effects of moisture on the penetration of size solution into a paper sample. The experiment involved use of laboratory equipment and procedures to accomplish the objectives of this experiment. Handsheets were conditioned, sized, cut, stained, and viewed under a laboratory microscope to obtain the desired results. The results from this procedure determined that the area of size deposition was dependant upon the moisture content of the paper sheet. As the moisture content of the samples increased, the size was retained more on the sample\u27s surface as opposed to penetration into the paper web. If the results obtained in this study can be reproduced on the machine scale, extensive capital benefits will be realized by the particular mill. The benefits will be in the form of increased production as well as a reduction in steam consumption. However, benefits obtained from this increase in moisture should be weighed against effects on strength as well as other problems associated with high moisture content utilization, such as moisture profile