Seismic designs and numerical analyses required fundamental parameters such as damping ratio and shear modulus. In this study, large-scale triaxial cyclic tests were used to investigate the dynamic properties of limestone BALLAST and electric arc furnace (EAF) slag BALLAST. The term ‘shear stiffness’ is typically reported in a normalized form using shear modulus. As the laboratory test results showed, an increase in confining pressure, loading frequency and anisotropy raises the shear modulus of materials. Shear modulus and damping ratio values do not appear to be significantly affected by an increase in loading cycles. Loading frequency plays the most significant role in changing damping ratio values. An adaptive neuro-fuzzy inference system (ANFIS) was also used to predict the normalized shear modulus and the damping ratio in this study. The results of the developed model were consistent with those of the laboratory tests. Moreover, the relations among the dynamic properties were estimatedly determined using the nonlinear regression method.

Post-Cyclic Monotonic Behavior of Steel Slags Materials Modified By Geogrid and Tire Chips As Railway BALLAST and Sub BALLAST

In the present study utilizing large scale direct shear test, the effect of BALLAST encasing with geogrid has been investigated. In this mater two BALLAST grading of 1 and 4 have been considered in conjunction with three types of geogrids GP35/35, GP40/20 and GP60/20. All direct shear test have been carried out under the vertical surcharges of50, 100 and 150 kPa with shear deformation rate of 1mm/min. The outcomes of the results reveals that in absence of geogrid encasing, the shear strength of BALLAST depends on the maximum particle size, uniformity coefficient and the vertical surcharge value. In the case of geogrid encasing of the BALLAST has promoted the shear strength behavior whereas for the grade 1 gradation of the BALLAST, the maximum friction angle corresponding to 50 and 150 kPa surcharges have been 74.5 and 68.96 degrees while the maximum reduction percentage in dilation angle has been 32.22. On the other hand for BALLAST grading 4, the mentioned variations have been correspondingly obtained as 30.12, 14.67 and 27.86 percentages.

Application of sunscreens is one of the most important ways for skin PROTECTION against sunburn, early skin aging and skin cancer.Due to variety of sunscreen products, it is necessary to assure their PROTECTION ability against the suns damages. Performance assessment of sunscreens against UVB expressed by sun PROTECTION factor. Due to great cost of determination methods of this factor in foreign countries, developing a comprehensive protocol for in vivo SPF determination in Iran would have distinct benefits.In this study four international standards have been reviewed and compared for Sun PROTECTION Factor (SPF) determination including ISO24444, FDA2011, AS/NZS 2604: 2012 and CEN 2006. The general process of in vivo SPF determination is similar in these protocols but there are some obvious differences in details that leading to advantages and disadvantages for each of them.In this study a complete document were collected, then regarding to available facilities and with cooperation of Iran food and drug organization a comprehensive in vivo SPF determination protocol will be developed.

Background: Invasion by different kinds of BALLAST water microorganisms is one of the most important marine environment problems around the world; therefore preventing the invasion of these unwanted and harmful stowaways is one of the main strategies of responsible agencies. Some of these methods such as ocean exchange, heating, filtration, hydro cyclones, UV irradiation and chemical treatment, have various problems such as technical deficiency, high costs, lack of safety and environmental side effects. Materials and Methods: A novel system of treatment by Gamma irradiation is designed to irradiate the blast water uniformly and effectively. To determine the dose distribution as a function of distance from the irradiation source, the MNCP code was used. The systems used for source implant in this simulation were Paterson-Parker, Paris and Network systems. In each system, Sivert-integral and inverse square law were used in MATLAB program to determine the dose distribution. Results: Results of initial laboratory tests on offshore water samples of Siri Island indicated that the appropriate dose for deactivation of organisms of water samples is approximately one kGy. It has been demonstrated that the dose can be provided by twenty five 100,000 Ci line sources of 60Co in a triangle implant arranged in a 1x1 x1 m3 cubic shape water pipe. In order to increase efficiency and radiation safety, water passed from two other coaxial and bigger cubes, after passing from the first cube. A one meter thick wall of concrete around the cubes was adequate to shield the system completely. Conclusion: The main advantages of this system such as high efficiency, safety, reliability, minimum environmental adverse effects, prove that this novel method not only can be used for BALLAST water treatment, but is also effective for drinking water purification.

The influence of main quality tests on the overall quality of railway BALLAST materials is assessed in this study. The need to integrate all acceptance tests in a unified manner for precise evaluation of BALLAST quality is identified, and a technique of performing this is proposed. Using this approach, a new BALLAST quality index (BQI) is defined in which, the main acceptance tests including abrasive strength, abrasive hardness, fragmentation strength under external loads and weathering resistance, are considered. For the development of the new BQI, all tests results are combined, assigning justified coefficients to each test value according to its contribution on overall quality. Moreover, the comparison of the new index versus the Abrasion Number (AN) as a proposed approach of the Canadian Pacific Railroad for BALLAST selection is investigated. A practical use of the new index is finally presented with regard to the laboratory investigations on different BALLAST rocks, to indicate its capability and applicability.

BALLAST is a layer between sleeper and sub-BALLAST that is composed of broken stones. Since BALLAST bears heavy loads, its high quality is important. If the BALLAST is gradually crushed and fines are generated, stone permeability and drainage property will be damaged and finally, instability will be resulted. If the above problems occur at BALLAST, its substitution is necessary that has high costs. For BALLAST quality control several tests has been suggested in 301 railway magazine that after the test on BALLAST, the results are compared with allowable values and BALLAST quality was controlled. BALLAST grains subjected to train loads, contain numerous cracks. From the fracture mechanic point of view, when stress intensity factor at the crack tip reaches the mixed-mode fracture toughness, crack growth begins and BALLAST grains crush. BALLAST crushing and abrasion are the main reasons for BALLAST contamination which is the main source of various defects, particularly geometric defects in the railway. Since disc-type specimens are among favorite test samples for determining mode I and mixed mode fracture toughness in brittle materials like rocks, Therefore it is suggested to add the determination of the mixed-mode fracture toughness I and II with the semi-circular bend specimens subjected to three-point-bend loading to the BALLAST quality control in 301 railway magazine. In this research, discussed the importance of fracture toughness in extraction, crushing and operation of BALLAST, then the finite element method and experimental is used to analyze a semi-circular disc specimens under bending load and the fracture toughness of two BALLAST mine, Anjilavand and Gaduk was determined. Anjilavand and Gaduk mine is two BALLAST mines in Iran that using them for BALLAST layers in railway substructure. The crack parameters KI, KII and T are calculated for different mixed-mode from pure mode I to pure mode II. YI, YII, and T* are the non-dimensional forms of KI, KII, and T, respectively. These parameters are functions of the crack length ratio, the crack angle and also the location of loading supports in the semi-circular bend specimen. The curves of YI, YII, and T* extracted for various combinations of modes I and II. Since the results for mixed mode fracture resistance of brittle materials are usually presented in a normalized form as KII/KIc versus KI/KIc, where KIc is a material constant called the pure mode I fracture toughness, using the mixed-mode fracture criteria, capped failure modes I and II for both BALLAST rocks were extracted and compared. Fracture toughness of Anjilacvand specimen is greater than Gaduk specimen that shows the Anjilavand BALLAST for operation in railway is better than Gaduk BALLAST.

The concrete sleeper that is one of the major part of BALLAST railway tracks are installed on BALLAST and subgrade to transfer any train wheel loads to the ground support subgrade in operation period that a wide range of loading conditions has been observed. In most of the cases, train wheel impact loads due to asymmetrical cause voids and pockets in contact interface of sleeper and BALLAST. When the BALLAST was damaged, the stiffness in BALLAST supporting of the sleeper will reduce.