Civil and Environmental Engineering Commons^™

Influence Of Nh4f In Dextran Based Biopolymer Electrolytes: Conductivity And Electrical Analysis, Muhamad Hafiz Hamsan, Mohd Fakhrul Zamani Kadir, Shujahadeen Bakar Aziz, Muhammad Amirul Solihin Azha, Saifful Kamaluddin Muzakir

Makara Journal of Technology

Dextran polymer host was doped with different concentrations of ammonium fluoride (NH4F) via casting technique. In this present work, dextran-NH4F film has been employed to investigate the ionic conductivity using electrochemical impedance spectroscopy from 50 to 5 MHz. The highest room temperature conductivity is achieved at (2.33 ± 0.76) × 10-3 S cm-1 with 40 wt.% NH4F. The electrolyte is found to obey Arrhenius rule at high temperature with activation energy of 0.21 eV. Dielectric analysis has been performed to obtain better understanding on the conductivity pattern. The dielectric parameters e.g. ɛreal, ɛimag, Mreal, and Mimag have been tested as …

Acute Toxicitystudy Of Choline Based Ionic Liquids Towards Danio Rerio Fish And The Aggregation Behavior Of Their Binary Mixtures, Mansoor Ul Hassan Shah, Nasruddin Nasruddin, Suzana Bt Yusup, Muhammad Moniruzzaman

Makara Journal of Technology

Marine oil spills are effectively controlled by chemical dispersants. However, the toxicity associated with it reduce its employment in marine environment. To overcome this limitation, the acute toxicity of choline based ionic liquids was evaluated as a potential low toxic variant for oil spill remediation. Further, the aggregation behavior of the individual as well as their binary mixtures was also evaluated by employing tensiometry technique. The half-lethal concentration, LC50on zebrafish (Danio rerio) of three choline based ionic liquids showed that the studied ionic liquids (ILs) fall in the range of “practically nontoxic” ( 100-1000 mg L-1).Various micellar properties showed that …

Neutron Diffraction Study Of Multiferroic 0.6nife2o4/0.4batio3 Composite, Engkir Sukirman, Yosef Sarwanto, Syahfandi Ahda, Andon Insani

Makara Journal of Technology

Neutron diffraction study on the 0.6NiFe2O4/0.4BaTiO3 multiferroic composite has been carried out. The 0.6NiFe2O4/0.4BaTiO3 multiferroic composites have been synthesized by solid reaction method. In this study, 20 g of BaTiO3 (BTO) and 20 g of NiFe2O4 (NFO) compounds were prepared from the powder raw materials of BaO3 and TiO2 for BTO, and NiO and Fe2O3 for NFO. Furthermore, both BTO and NFO were each crushed for 5 hours using High Energy Milling (HEM). Then the BTO and NFO were calcined in the furnace at 950 °C/5 hours and 900 °C/5 hours, respectively. Both NFO and BTO precursors were manually mixed …

Multiscale Modeling Of Fracture In Quasi-Brittle Materials Using Bifurcation Analysis And Element Elimination Method, Keyvan Zare Rami

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Analyzing the fracture of heterogeneous materials is a complex problem, due to the fact that the mechanical behavior of a heterogeneous material is strongly dependent on a variety of factors, such as its microstructure, the properties of each constituent, and interactions between them. Therefore, these factors must be effectively taken into account for accurate analysis, for which the multiscale method has been widely used. In this scheme, the computational homogenization method is used to obtain the effective macroscopic properties of a heterogeneous material based on the response of a Representative Volume Element (RVE). The growth of damage in an RVE …

Optimizing On-Street Parking Supply With Analytical Models, Chawalit Tipagornwong

Dissertations and Theses

Commercial vehicles are crucial for the urban economy, but they generate negative impacts as well. This leads to restrictions such as a reduction in the number of loading zones. The result is that commercial drivers spend a significant amount of time searching for available loading zones. To avoid searching for parking, some commercial drivers double park, which causes traffic congestion. Therefore, the number of loading zones should be set properly. Since a curb is allocated between both loading zones and parking spaces, both parking types have to be considered. Many on-street parking management strategies have been implemented, including pricing meter …

Thermodynamic Model Of Co2 Deposition In Cold Climates, Sandra K. S. Boetcher, Ted Von Hippel, Matthew J. Traum

Publications

A thermodynamic model, borrowing ideas from psychrometric principles, of a cryogenic direct-air CO2-capture system utilizing a precooler is used to estimate the optimal CO2 removal fraction to minimize energy input per tonne of CO2. Energy costs to operate the system scale almost linearly with the temperature drop between the ingested air and the cryogenic desublimation temperature of CO2, driving siting to the coldest accessible locations. System performance in three Arctic/Antarctic regions where the proposed system can potentially be located is analyzed. Colder ambient temperatures provide colder system input air temperature yielding lower CO2 removal energy requirements. A case is also …

Carrying Capacity Of Single-Gauge Railways At Introduction Of Speed Motion Of Passenger-Trains, Saidburkhan Tulaganovich Djabbarov

Journal of Tashkent Institute of Railway Engineers

Results over of complex researches of organization of speed and high-speed motion of passenger-trains are brought on existent single-gauge railways, choice and ground of complex of measures on the increase (to maintenance) of freight and throughput capacity, and ensure continuous operation of the infrastructure of operated railways are presented.

Problems Of The State Of The Rolling Surface Of The Rail Head On Speed And High-Speed Railway Sections Of Jsc "Uzbekistan Temir Yollari", Kuvandik Saginovich Lesov, Igor Ivanovich Kuznetsov, Mukhamedali Kazbek Ugli Kenjaliev, Xushnudbek Odilbekovich Samandarov

Journal of Tashkent Institute of Railway Engineers

In the process of train traffic on the rolling surface of the rail head are formed bumps and fatigue defects, constant dynamic loads lead to the frustration the upper structure of the path. In this article the analyzes integral indicators of the rolling surface of the rails (long waves, medium waves, short waves) on the section of speed and high-speed train traffic for assess the condition of rails in transit. Problems with the formation of wave-like irregularities on the surface of the rails are identified, promising directions in solving this problem are indicated.

Improvement Of Efficiency Of “O‘Zbekiston” Series Electric Locomotive Control System, Usan Berdiev, Malika Nabievna Tuychieva

Journal of Tashkent Institute of Railway Engineers

This article examines the work of efficient use of electric locomotives of the “O‘ZBEKISTON” series operated in the railways of Uzbekistan, storage in working parts, provision of reliable and safe operations, as well as reduction of operating costs and extension of the repair period. For this purpose, during operation, it is constantly necessary to analyze and develop the possibility to achieve planned results using effective methods of technical diagnostics system.

Theoretical Foundations For Determining Kinematic Parameters Of A Jet Unit, Kudrat Raximov, A.R. Babaev, Dilbar Abduraimova

Journal of Tashkent Institute of Railway Engineers

This article discusses the theoretical basis of the dependence of the kinematic parameters, in particular the average speed of flow rate in the suction pipeline of the jet apparatus intended for cleaning water bodies from silting, from changes in the pressure in the mixing chamber. In the problem is considered a single-phase flow, that is, the density of the working and the suction fluid are the same.

Increasing The Efficiency Of Work Of Locomotive Electronic Equipment By Using Portable Diagnostic Devices, Nodir Botirovich Adilov, Nurilla Khayrullayevich Ermatov

Journal of Tashkent Institute of Railway Engineers

This article discusses the current trends in the construction of portable and stationary systems for diagnosing electric and electronic components of locomotives built on integrated chips, as well as presents own model of a portable diagnostic stand for testing electronic devices and electric circuits of locomotives

Evaluation Of The Efficiency Of Flat Sunny Solar Air Heaters With Heat Transfer Turbulizers, Yorkin Sodikovich Abbasov, Muyassar Abubakirovna Umurzakova

Journal of Tashkent Institute of Railway Engineers

The article presents methods for assessing the effectiveness of flat solar air heaters with heat transfer turbulators. The experience of world scientific achievements in the field of increasing the efficiency of solar air heaters is analyzed. The analysis of the effectiveness of flat air heaters. According to the results of the study, it was determined that, in addition to the traditional formula efficiency, for evaluating the effectiveness of flat air heaters with heat transfer turbulators collectors use methods developed in heat engineering and based on the Reynolds analogy.

Comparative Analysis Of Modern Electric Centralization Systems, Asadulla Raximovich Azizov, Elnara Kuandikovna Ametova

Journal of Tashkent Institute of Railway Engineers

This article discusses a comparative analysis of modern electrical centralization systems. The possibilities of developing computer centralizations and centralizations implemented on blocks manufactured using microprocessors are discussed

To The Calculation Of Solid-State Cargo Attachment Under The Influence Of Longitudinal Forces, Khabibulla Turanov, Yadgor Ruzmetov, Jamol Shihnazarov

Journal of Tashkent Institute of Railway Engineers

The article is devoted to the calculation of cargo fastening using the current method. It is proved that according to the existing method, the force in all elastic cargo mounts of both one and the other direction under the influence of longitudinal forces has the same value, regardless of the different location of the geometric parameters of the mounts in space. Calculations of forces in elastic elements of fastening by the specified method are given. The results of the comparative analysis showed that the forces in all wire fasteners, in contrast to the existing method of calculation, have different values. …

Analysis Of Sensors Of The Electronic System For Counting Axles (Eacs) And Firm Altpro Frausсher In The Organization Of Train Traffic, Sunnatillo Tuymurodovich Boltaev, Jonibek Fayzullaevich Kurbonov, Aziz Azimovich Saitov

Journal of Tashkent Institute of Railway Engineers

In this scientific work, the sensors of the electronic system for counting axles of various firms used in level crossings, trunk and station railways of the Republic of Uzbekistan are investigated. Based on the analysis, the parameters of the EACS accounting system are determined. The parameters that led to system crashes were defined in the electronic system for calculating the axes of the EACS. The parameters of the components of the EACS accounting system are determined, which are the main element in determining free loaded roads, reference points, points and sections of arrows. The conditions for using the sensor parameter …

The Role Of Intra-Production Accounting In The Management System Of Enterprises Of Jsc " Uzbekistan Temir Yullari», Aijan Baxtiyarovna Djumanova, Shohruh Vosiljon O’G’Li Ergashev

Journal of Tashkent Institute of Railway Engineers

This article discusses the essence, content and tasks of internal accounting and its role in the management system of enterprises of JSC “Uzbekistan temir yullari”. In order to effectively manage the activities of enterprises need to assess the contribution of each farm unit in the final result of the enterprise activity, the mechanism of which are internal accounting, reporting and analysis of their activity. Managers of enterprises for the development and adoption of management decisions need both General information on the enterprise as a whole, and detailed information on intra – production segments of activity-responsibility centers.

To The Question Of The Mathematical Model Of Rational Planning Of Technological Sections Of The Warehouse, Daurenbek Ihtiyarovich Ilesaliev, Jamol Alisherovich Shixnazarov, Avaz Mirsultanovich Merganov

Journal of Tashkent Institute of Railway Engineers

Modern railway warehouses have an important place in the supply chain.The main task of the railway warehouses is to convert incoming cargo flows with large quantities into outgoing flows.This article discusses the structure of the functioning of a standard railway warehouse.Based on the coating method and methods of V.P. Sityaev developed a rational version of the layout of the railway warehouse, taking into account the cost criteria, representing the amount of logistics costs.Based on the results of the study, three options of non-traditional warehouse planning schemes were obtained and recommended.

Results Of Application Of The Methods “Sologub” And Combinator Sorting In The Process Of Forming Multi-Group Trains At The Sorting Station, Sakijan Kabildjanovich Khudayberganov, Shinpolat Mansuraliyevich Suyunbayev, Sherzod Bakhrom Ugli Jumayev

Journal of Tashkent Institute of Railway Engineers

At present, the formation of multi-group freight trains in accordance with the established procedure at all marshalling yards of JSC Uzbek Railways is based on the experience of the relevant personnel. Therefore, one of the urgent tasks is to improve the process of forming such trains based on the introduction of modern technologies. This article presents the results of applying the Sologub methods and combinatorial sorting in the process of forming multi-group trains at the sorting station of JSC Uzbek Railways. The regularity of the dependence of the number of groups in a multi-group train on the required paths was …

Asynchronous Phase Rotor Generators For Power Planes Operating Parallel With A Network, Sharafiddin Kamaliddinovich Alimhodzhaev, Odil Umirzakovich Zakhidov, Mirzohid Hurramovich Taniev

Journal of Tashkent Institute of Railway Engineers

The article presents the results of studies of asynchronous generators of wind power plants and small hydroelectric power stations operating in parallel with the electric network. The parameters of the equivalent circuit are specified, on the basis of which the analytical dependence of the electromagnetic moment of the generator is found. It is proposed to take into account the revealed features of the mechanical characteristics of the generators that differ from the characteristics determined by the generally accepted analytical method

Comparative Analysis Of Functional Diagnostic Methods Of Traction Asynchronous Motors, Zhavkharbek Sulton Ugli Fayzullaev

Journal of Tashkent Institute of Railway Engineers

The article provides a comparative analysis of the methods of functional diagnostics of traction induction motors and justifies that of them the most promising are thermal, electric, vibroacoustic and magnetic methods. To obtain the most reliable information in diagnosing the technical condition of traction induction motors, it is recommended that the methods considered be used in conjunction with the simultaneous improvement of their technical means.

The Research Of Transient Processes In Current Transformers By The Operator's Method, Sultan Fayzullayevich Amirov, Shavkat Mukhsimov, Otabek Tashmuhammatovich Boltayev

Journal of Tashkent Institute of Railway Engineers

In the article the transient processes occurring in current transformers are investigated and the values of the magnetization current are determined by the operator method using the primary current source. Using the obtained results, the regularities of the magnetization current change in time are analyzed. For the investigated wide-range current transformer with a closed and open core, that is, at different values of T', a comparative analysis of the laws of change in time of the aperiodic components of the magnetic current was carried out. It is determined that current transformers with air gap are effective in all cases when …

On The Dynamics Of The Movement Carriage In The Accelerating Grable The Marshalling Yard, Shukhrat Umarkhodjaevich Saidivaliev, Zakhro Valijanovna Ergasheva

Journal of Tashkent Institute of Railway Engineers

The article presents the results of studies of the movement of the carriage on the slope hump (including brake position) when exposed to the forces of wind. Maintaining acceptable speed impacts and screening the Park can be achieved by changing the profiles of individual sections of the drain side hump or application of additional wagon retarders.

Incorporating Geophysical Data In Slope Stability Modeling For Two Slopes In Arkansas, Vanessa Lebow

Graduate Theses and Dissertations

Slope failures in the United States alone cause millions of dollars in damage to infrastructure, threaten national monuments, create environmental hazards, and take an average of 25-50 lives a year. With the inevitable construction that occurs on slopes, it is imperative that the slopes be properly designed which requires a thorough understanding of slope grade, subsurface soil conditions, soil strength parameters, water table locations, and depth to bedrock across the entire site. The preferred method of data collection would be to use borings and other in-situ methods; however, sometimes due to cost constraints or site accessibility only a very limited …

Evaluation Of Concrete Deck Curing Regimens Using Capillary Pressure Sensing System, Samuel Spann

Graduate Theses and Dissertations

Early-age plastic shrinkage cracking is a common problem with the construction of concrete bridge decks due to the high surface area-to-volume ratio and exposure to potentially detrimental environmental effects. Curing regimens are utilized to mitigate cracking risk during the plastic stage of the concrete; the curing regimens evaluated for this study were wet burlap-polyethylene sheeting, two acrylic curing compounds, and one lithium compound. Capillary pressure in the water filled pores has been shown to correlate to the plastic shrinkage cracking risk of concrete. A new portable system has been developed to measure the capillary pressure that could potentially be used …

Truck Activity Pattern Classification Using Anonymous Mobile Sensor Data, Taslima Akter

Graduate Theses and Dissertations

To construct, operate, and maintain a transportation system that supports the efficient movement of freight, transportation agencies must understand economic drivers of freight flow. This is a challenge since freight movement data available to transportation agencies is typically void of commodity and industry information, factors that tie freight movements to underlying economic conditions. With recent advances in the resolution and availability of big data from Global Positioning Systems (GPS), it may be possible to fill this critical freight data gap. However, there is a need for methodological approaches to enable usage of this data for freight planning and operations.

To …

Study Of Internal Strains Developed In Concrete Decks At Early Ages In Steel Continuous Bridges, Fernando R. Benitez Ortiz

Graduate Theses and Dissertations

The Arkansas Department of Transportation (ARDOT) has identified bridge deck cracking shortly after concrete decks are placed and prior to applying traffic loads. Previous researchers have confirmed improper construction practices and design methods can lead to deck cracking. Currently, many contractors throughout Arkansas are using continuous deck pours. This construction approach may restrict the concrete slab from movement during early age shrinkage, causing tensile stresses to develop. The final stresses at the end of construction must be lower than the concrete tensile strength, if not cracking issues will develop. Eventually, these cracks may enlarge due to service load stresses and …

Cytotoxicity And Mutagenicity Of Disinfection Byproduct Mixtures Formulated Using Free Chlorine And Monochloramine, Yonas Ghebremedhin

Graduate Theses and Dissertations

Bioassays have been used extensively to assess various toxicity endpoints of drinking water disinfection byproducts (DBPs), but an emphasis on single compounds prevails. In this research, DBP mixtures were assessed using a cytotoxicity test with Chinese Hamster Ovary (CHO) cells and an Ames fluctuation test with Salmonella typhimurium TA-98 and TA-100 with and without S9 rat liver homogenate. Seven whole mixture DBP concentrates were formulated using reconstituted natural organic matter (NOM) extracts from the Upper Mississippi River using scaled disinfectant dosing protocols with free chlorine and monochloramine in the presence and absence of added bromide. DBPs were identified by gas …

Weigh-In-Motion Auto-Calibration Using Automatic Vehicle Identification, Fu Ren Zhang Zhang Durandal

Graduate Theses and Dissertations

Weigh-in-Motion (WIM) sensors are installed on mainline lanes at highway locations to record vehicle weights, axle spacing, vehicle class, travel speed, vehicle length, and traffic volume. These data elements support effective transportation planning, infrastructure design, and policy development. Therefore, it is important that WIM sensors supply accurate data. After initial installation and calibration, WIM systems may experience measurement drifts in weight and axle detection. Recalibration takes two general forms: (a) On-site calibration involving running trucks of known weight over WIM scales and (b) Auto-calibration methods involving comparisons to assumed reference weights. Auto-calibration can be more cost and time effective than …

Evaluation Of Fracture Principles In Asphalt Concrete Utilizing The Sc(B) Geometry, Airam Marlee Morales Vega

Graduate Theses and Dissertations

Since cracking is one of the principal distresses to be considered in asphalt concrete, multiple fracture tests and geometries have been used to quantify cracking resistance. One of the most popular geometries that have been used in fracture tests is the Semi-Circular bend (SC(B)). However, for this geometry, most of the fracture test methods use different parameters such as thickness, testing temperatures, and loading rates. Thus, the purpose of this research was first to evaluate fracture energy by performing a ruggedness test based on ASTM E1169. Then, to apply fracture mechanics concepts to evaluate three specimen thicknesses (25, 50, and …

The Bridge Newsletter Winter 2019, Missouri University Of Science And Technology

The Bridge Newsletter

-Dehghani joins S&T
-Life after death of solar panels
-Civil engineering senior studies in Hong Kong
-Planning for future climate changes in the Artic