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2018

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Articles 571 - 600 of 8951

Full-Text Articles in Engineering

Cubesat Docking And Resource Sharing Mechanism, Shingo Kunito Dec 2018

Cubesat Docking And Resource Sharing Mechanism, Shingo Kunito

Theses and Dissertations

This thesis addresses the design concept of a CubeSat docking and resource sharing mechanism that allows to transfer propellant that is pressurized gas, data, and power. In docking and capture design, the interface is equipped with two air cylinders that are rated up to 20.68 MPa internal pressure generating the ideal force of 1218.4 N each. With the designed air cylinder and mounted configuration, the maximum capture distance between the target and the chaser CubeSat is 40.30 mm. Since air cylinder and body frame are designed specifically for this interface, structural analysis was conducted in ANSYS where results show a …

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An Analytical Model Of Material Deformation In Rotary Friction Welding Of Thin-Walled Tubes, Caleb James Brown Dec 2018

An Analytical Model Of Material Deformation In Rotary Friction Welding Of Thin-Walled Tubes, Caleb James Brown

Theses and Dissertations

A new model of the material flow in rotary friction welding of tubes is proposed. The material flow proposed is based on 3D scans of welds performed with tungsten tracers. The tracers indicate a bifurcation of flow into two deformation paths. A different analysis is performed on each path.The material in Path 1 interacts with the weld interface and exhibits large amounts of azimuthal flow. Previous analytical investigations that have analytically modelled the weld interface as a non-Newtonian fluid are used to calculate the strain rate in this zone.The material in Path 2 transitions from axial to primarily radial flow. …

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Engineering Cell-Free Biosystems For On-Site Production And Rapid Design Of Next-Generation Therapeutics, Kristen Michelle Wilding Dec 2018

Engineering Cell-Free Biosystems For On-Site Production And Rapid Design Of Next-Generation Therapeutics, Kristen Michelle Wilding

Theses and Dissertations

While protein therapeutics are indispensable in the treatment of a variety of diseases, including cancer, rheumatoid arthritis, and diabetes, key limitations including short half-lives, high immunogenicity, protein instability, and centralized production complicate long-term use and on-demand production. Site-specific polymer conjugation provides a method for mitigating these challenges while minimizing negative impacts on protein activity. However, the location-dependent effects of polymer conjugation are not well understood. Cell-free protein synthesis provides direct access to the synthesis environment and rapid synthesis times, enabling rapid evaluation of multiple conjugation sites on a target protein. Here, work is presented towards developing cell-free protein synthesis as …

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Conceptual Design Of A Pilot-Scale Pressurized Coal-Feed System, Taylor L. Schroedter Dec 2018

Conceptual Design Of A Pilot-Scale Pressurized Coal-Feed System, Taylor L. Schroedter

Theses and Dissertations

This thesis discusses the results and insights gained from developing a CFD model of a pilot-scale pressurized dry coal-feed system using the Barracuda CFD software and modeling various design concepts and operating conditions. The feed system was required to transport approximately 0.00378 kg/s (30 lb/hr) of pulverized coal from a vertical hopper to a 2.07 MPa (20.4 atm or 300 psi) reactor with a CO2-to-coal mass flow ratio of 1-2. Two feed system concepts were developed and tested for coal mass flow, CO2-to-coal mass ratio, steadiness, and uniformity. Piping system components also were evaluated for pressure drop and coal roping.With …

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Large-Scale Testing Of Low-Strength Cellular Concrete For Skewed Bridge Abutments, Rebecca Eileen Black Dec 2018

Large-Scale Testing Of Low-Strength Cellular Concrete For Skewed Bridge Abutments, Rebecca Eileen Black

Theses and Dissertations

Low-strength cellular concrete is a type of controlled low-strength material (CLSM) which is increasingly being used for various modern construction applications. Benefits of the material include its ease of placement due to the ability of cellular concrete to self-level and self-compact. It is also extremely lightweight compared to traditional concrete, enabling the concrete to be used in fill applications as a compacted soil would customarily be used. Testing of this material is not extensive, especially in the form of large-scale tests. Additionally, effects of skew on passive force resistance help to understand performance of a material when it is used …

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Two-Phase Interactions On Superhydrophobic Surfaces, Kimberly Ann Stevens Dec 2018

Two-Phase Interactions On Superhydrophobic Surfaces, Kimberly Ann Stevens

Theses and Dissertations

Superhydrophobic surfaces have gained attention as a potential mechanism for increasing condensation heat transfer rates. Various aspects related to condensation heat transfer are explored. Adiabatic, air-water mixtures are used to explore the influence of hydrophobicity on two-phase flows and the hydrodynamics which might be present in flow condensation environments. Pressure drop measurements in a rectangular channel with one superhydrophobic wall (cross-section approximately 0.37 X 10 mm) are obtained, revealing a reduction in the pressure drop for two-phase flow compared to a control scenario. The observed reduction is approximately 10% greater than the reduction that is observed for single-phase flow (relative …

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Repopulation And Stimulation Of Porcine Cardiac Extracellular Matrix To Create Engineered Heart Patches, Silvia Juliana Moncada Diaz Dec 2018

Repopulation And Stimulation Of Porcine Cardiac Extracellular Matrix To Create Engineered Heart Patches, Silvia Juliana Moncada Diaz

Theses and Dissertations

Heart failure is the main cause of death for both men and women in the United States. The only proven treatment for patients with heart failure is heart transplantation. The goal of this research is to create patches of tissue that could mimic the function of the native heart to repair the damaged portions of the heart. In this study, whole porcine hearts were decellularized to create a 3D construct that was recellularized with cardiomyocytes (CM) differentiated from human induced pluripotent stem (IPS) cells. At day 4 of differentiation, IPS-derived CMs were implanted onto cardiac extracellular matrix (cECM) and ten …

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Characterization Of Pyrolysis Products From Fast Pyrolysis Of Live And Dead Vegetation, Mohammad Saeed Safdari Dec 2018

Characterization Of Pyrolysis Products From Fast Pyrolysis Of Live And Dead Vegetation, Mohammad Saeed Safdari

Theses and Dissertations

Wildland fire, which includes both planned (prescribed fire) and unplanned (wildfire) fires, is an important component of many ecosystems. Prescribed burning (controlled burning) is used as an effective tool in managing a variety of ecosystems in the United States to reduce accumulation of hazardous fuels, manage wildlife habitats, mimic natural fire occurrence, manage traditional native foods, and provide other ecological and societal benefits. During wildland fires, both live and dead (biomass) plants undergo a two-step thermal degradation process (pyrolysis and combustion) when exposed to high temperatures. Pyrolysis is the thermal decomposition of organic material, which does not require the presence …

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Relationship Between Compressive Strength Of Different Shape And Thickness Specimens Of Type S Mortar, Theodore James Moffett Dec 2018

Relationship Between Compressive Strength Of Different Shape And Thickness Specimens Of Type S Mortar, Theodore James Moffett

Theses and Dissertations

Mortar is the cementitious binding material placed between masonry blocks to create a composite system. The American Society of Testing and Materials (ASTM), along with other organizations, have established the testing of prismatic mortar specimens for evaluating mechanical properties, like compressive strength. Mortar joints, however, possess vastly different characteristics compared to prismatic specimens, especially in terms of geometry and water content. These differences prevent a direct comparison of compressive strength between prismatic specimens and actual mortar joints in the assembly. The objective of this study was to analyze Type S mortar joints, with particular emphasis on specimen shape and water …

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Experimental Evaluation Of Replaceable Shear Fuse Moment Connections, Shannon Shun Oh Dec 2018

Experimental Evaluation Of Replaceable Shear Fuse Moment Connections, Shannon Shun Oh

Theses and Dissertations

Steel special moment frames (SMFs) are known to be highly ductile seismic force- resisting systems. The performance of an SMF relies on the ability of the connections to accommodate large inelastic deformations. After the brittle failure of some steel moment frame connections during the 1994 Northridge Earthquake, experimental tests were used to investigate the ductility and strength of these connections. An experimental study was performed to investigate the seismic performance a new connection called the Replaceable Shear Fuse (RSF) connection. The RSF connection uses shear-yielding fuse plates to prevent beam and column yielding. A total of 7 test specimens with …

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Internal Deformation Measurements And Optimization Of Synthetic Vocal Fold Models, Cassandra Jeanne Taylor Dec 2018

Internal Deformation Measurements And Optimization Of Synthetic Vocal Fold Models, Cassandra Jeanne Taylor

Theses and Dissertations

Developing lifelike vocal fold models is challenging due to various associatedbiomechanical complexities. Nevertheless, the development and analysis of improved vocal foldmodels is worthwhile since they are valuable tools for gaining insight into human vocal foldvibratory, aerodynamic, and acoustic response characteristics. This thesis seeks to contribute tothe development of computational and physical vocal fold modeling in two ways. First is byintroducing a method of obtaining internal deformation fields within vibrating synthetic vocal foldmodels; second is by presenting an optimization algorithm coupled with a computational vocalfold model to optimize geometry and stiffness of a synthetic vocal fold model to achieve morerealistic vibration …

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The Effects Of Haptics On Rhythm Dance Game Performance And Enjoyment, Bridger Scott Hodges Dec 2018

The Effects Of Haptics On Rhythm Dance Game Performance And Enjoyment, Bridger Scott Hodges

Theses and Dissertations

Haptics are an exciting, ever-expanding field, particularly in relation to video games. Though haptics found their way rather quickly into conventional games through devices like handheld controllers, music and rhythm titles have hardly seen such attention. Little research has been done to examine the effects of haptics on rhythm dance games from a quantitative and qualitative standpoint for the player. StepMania is an open-source dance game which closely mimics the popular title Dance Dance Revolution. This research investigates the effects of haptics on a sample size of fifty individuals. Each completed three songs in the game with varying conditions: the …

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Large-Scale Non-Linear Dynamic Optimization For Combining Applications Of Optimal Scheduling And Control, Logan Daniel Beal Dec 2018

Large-Scale Non-Linear Dynamic Optimization For Combining Applications Of Optimal Scheduling And Control, Logan Daniel Beal

Theses and Dissertations

Optimization has enabled automated applications in chemical manufacturing such as advanced control and scheduling. These applications have demonstrated enormous benefit over the last few decades and continue to be researched and refined. However, these applications have been developed separately with uncoordinated objectives. This dissertation investigates the unification of scheduling and control optimization schemes. The current practice is compared to early-concept, light integrations, and deeper integrations. This quantitative comparison of economic impacts encourages further investigation and tighter integration. A novel approach combines scheduling and control into a single application that can be used online. This approach implements the discrete-time paradigm from …

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Origami-Based Design Of Fold States And Stability, Alex Avila Dec 2018

Origami-Based Design Of Fold States And Stability, Alex Avila

Theses and Dissertations

Origami is a potentially elegant and powerful source of inspiration for many engineering designs. The viable shapes (fold states) of a single device allow it to perform multiple, seemingly contradictory, functions. The fold state is a large factor in the device's performance, but there are challenges in selecting and maintaining those fold states. In this thesis we analyze existing concepts for overcoming these challenges. Those concepts are compared with those that occur in origami-based devices. From this analysis fundamental gaps were identified, specifically, shortcoming in the terminology used to refer to (1) non-flat origami states and (2) sets of facets …

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Examining The Mechanics Responsible For Strain Delocalization In Metallic Glass Matrix Composites, Casey Owen Messick Dec 2018

Examining The Mechanics Responsible For Strain Delocalization In Metallic Glass Matrix Composites, Casey Owen Messick

Theses and Dissertations

Metallic glass matrix composites (MGMCs) have been developed to improve upon the ductility of monolithic metallic glass. These composites utilize a secondary crystalline phase that is grown into an amorphous matrix as isolated dendritic trees. This work seeks to understand the mechanisms underlying strain delocalization in MGMCs in order to better direct efforts for continual progress in this class of material. A mesoscale modelling technique based on shear transformation zone (STZ) dynamics is used to do so. STZ dynamics is a coarse grained technique that can provide insight into the microscopic processes that control macroscopic behavior, but which can be …

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The Design, Construction, And Thermal Diffusivity Measurements Of The Fluorescent Scanning Thermal Microscope (Fstm), Samuel Hunter Hayden Dec 2018

The Design, Construction, And Thermal Diffusivity Measurements Of The Fluorescent Scanning Thermal Microscope (Fstm), Samuel Hunter Hayden

Theses and Dissertations

Over the life of nuclear fuel, inhomogeneous structures develop, negatively impacting thermal properties. New fuels are under development, but require more accurate knowledge of how the properties change to model performance and determine safe operational conditions. Measurement systems capable of small–scale, pointwise thermal property measurements and low cost are necessary to measure these properties and integrate into hot cells where electronics are likely to fail during fuel investigation. This project develops a cheaper, smaller, and easily replaceable Fluorescent Scanning Thermal Microscope (FSTM) using the blue laser and focusing circuitry from an Xbox HD-DVD player. The FSTM also incorporates novel fluorescent …

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Optimization-Based Spatial Positioning And Energy Management For Unmanned Aerial Vehicles, Ronald Abraham Martin Dec 2018

Optimization-Based Spatial Positioning And Energy Management For Unmanned Aerial Vehicles, Ronald Abraham Martin

Theses and Dissertations

This research applies techniques from the field of optimization to spatial positioning and energy management in Unmanned Aerial Vehicles (UAVs). Two specific areas are treated: optimization of UAV view plans for 3D modeling of infrastructure, and trajectory optimization of solar powered high-altitude long-endurance (HALE) UAVs. Structure-from-Motion (SfM) is a computer vision technique for creating 3D models from 2D images. View planning is the process of planning image sets that will effectively model a given scene. First, a genetic algorithm based view planning approach is demonstrated. A novel terrain simulation environment is developed, and the algorithm is tested at multiple sites …

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Macro-/Micro-Controlled 3d Lithium-Ion Batteries Via Additive Manufacturing And Electric Field Processing, Jie Li, Xinhua Liang, Frank W. Liou, Jonghyun Park Dec 2018

Macro-/Micro-Controlled 3d Lithium-Ion Batteries Via Additive Manufacturing And Electric Field Processing, Jie Li, Xinhua Liang, Frank W. Liou, Jonghyun Park

Chemical and Biochemical Engineering Faculty Research & Creative Works

This paper presents a new concept for making battery electrodes that can simultaneously control macro-/micro-structures and help address current energy storage technology gaps and future energy storage requirements. Modern batteries are fabricated in the form of laminated structures that are composed of randomly mixed constituent materials. This randomness in conventional methods can provide a possibility of developing new breakthrough processing techniques to build well-organized structures that can improve battery performance. In the proposed processing, an electric field (EF) controls the microstructures of manganese-based electrodes, while additive manufacturing controls macro-3D structures and the integration of both scales. The synergistic control of …

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Superelastic And Ph-Responsive Degradable Dendrimer Cryogels Prepared By Cryo-Aza-Michael Addition Reaction, Juan Wang, Hu Yang Dec 2018

Superelastic And Ph-Responsive Degradable Dendrimer Cryogels Prepared By Cryo-Aza-Michael Addition Reaction, Juan Wang, Hu Yang

Chemical and Biochemical Engineering Faculty Research & Creative Works

Dendrimers exhibit super atomistic features by virtue of their well-defined discrete quantized nanoscale structures. Here, we show that hyperbranched amine-terminated polyamidoamine (PAMAM) dendrimer G4.0 reacts with linear polyethylene glycol (PEG) diacrylate (575 g/mol) via the aza-Michael addition reaction at a subzero temperature (-20 °C), namely cryo-aza-Michael addition, to form a macroporous superelastic network, i.e., dendrimer cryogel. Dendrimer cryogels exhibit biologically relevant Young's modulus, high compression elasticity and super resilience at ambient temperature. Furthermore, the dendrimer cryogels exhibit excellent rebound performance and do not show significant stress relaxation under cyclic deformation over a wide temperature range (-80 to 100 °C). The …

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Experimental Study On The Influence Of Slickwater On Shale Permeability, Zhonghua Liu, Baojun Bai, Zheyu Zhang, Jing Tang, Shunpeng Zeng, Xiaogang Li Dec 2018

Experimental Study On The Influence Of Slickwater On Shale Permeability, Zhonghua Liu, Baojun Bai, Zheyu Zhang, Jing Tang, Shunpeng Zeng, Xiaogang Li

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

There are two diametrically opposite views of the influence of slickwater on shale permeability among scholars at home and abroad. We used the shale outcrops rock samples from the Lower Silurian Longmaxi Formation in Sichuan Basin. The permeability of these dry samples before and after immersion in different solution systems were tested by pulse attenuation method. The experimental results show that the impregnation of different slickwater components and standard salt solution can promote the increase of the permeability of shale samples. The stress sensitivity of shale samples after liquid immersion is medium weak to weak. The sample stress sensitivity is …

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A Note Of Thanks To John Halloran, William Fahrenholtz Dec 2018

A Note Of Thanks To John Halloran, William Fahrenholtz

Materials Science and Engineering Faculty Research & Creative Works

No abstract provided.

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Bridging The Gap: 3d Modeling To Hands On Learning, Tyler J. Hecht Dec 2018

Bridging The Gap: 3d Modeling To Hands On Learning, Tyler J. Hecht

Construction Management

This project is a rework of Cal Poly Construction Management Building Information Modeling class, Revit Activity. The goal of the assignment is to teach the fundamentals and concepts of Autodesk Revit, and the tools that can be used within the construction industry. The model itself is based upon a hands-on lab that the Commercial Construction class builds. The modeling exercise allows students to model several key elements of a building, following a construction sequence. Following the modeling, the students will be able to create sheets and create their own plan set that was modeled. On those plan sets they will …

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Hard Hat Safety By California Contractors, Jonathan G. Hernandez Dec 2018

Hard Hat Safety By California Contractors, Jonathan G. Hernandez

Construction Management

The hard hat is the quintessential item of PPE, and yet it often gets overlooked when ensuring safety standards are being met. We all expect our hard hat to protect us, but many never inspect it to ensure that it is properly fulfilling its purpose. This disregard to inspection and maintenance can lead to serious injury or death in the event of an accident. While organizations such as OSHA and the hard hat manufacturers themselves post information on this topic, it is unclear if this information is actually being received by the people involved in a construction project. This research …

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Improving Ductility Of Slender Reinforced Concrete, Luke M. Ostrom Dec 2018

Improving Ductility Of Slender Reinforced Concrete, Luke M. Ostrom

Construction Management

The Sylmar earthquake of 1971 caused significant damage to slender, non-ductile reinforced concrete (RC) shear wall buildings in California. A later survey by the Concrete Coalition in 2011, under the guidance of members of the Earthquake Engineering Research Institute (EERI), indicated that there are over 3000 vulnerable concrete buildings in California [8]. This led to City of Los Angeles (LA) Ordinance 193893 enacted in 2015, which requires mandatory upgrades to these concrete buildings by 2035. Current practice to meet the requirements of this ordinance, with respect to RC wall buildings, involves adding new shear walls to the building plan or …

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Virtual Reality And Its Applications In The Mockup Process: A Case Study, David B. Friend Dec 2018

Virtual Reality And Its Applications In The Mockup Process: A Case Study, David B. Friend

Construction Management

Mockups are an important part of the construction process as they provide numerous benefits in both constructability review and aesthetic approval. Virtual Reality is an emerging technology that could prove to be a valuable addition to the mockup process. Many construction firms are attempting to incorporate virtual reality into any process they can --ranging from impressing owners in order to procure jobs to training employees so they can more adeptly adjust to field conditions. This paper will introduce virtual reality and some of its applications in the construction industry, specifically analyzing virtual reality and its applications in the mockup process …

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A Comparative Analysis Of Regional Productivity Trends, Michael P. Foley Dec 2018

A Comparative Analysis Of Regional Productivity Trends, Michael P. Foley

Construction Management

Throughout recent decades, the construction industry has suffered considerably from its inability to accurately target and measure key aspects of worker output that hinder productivity most. Much research has been conducted to analyze the factors contributing to labor productivity output at the work face, however, this dissertation is primarily focused on discovering key components of the building process that seem to hinder productivity from the perspective of the general contracting team. This paper’s literature review looks to address historical data relating to productivity difficulties specific to the construction industry, laborers’ productivity dilemma at the work face, and the resulting impact …

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Lean Construction Implementation: Case Study, Devin J. Merker Dec 2018

Lean Construction Implementation: Case Study, Devin J. Merker

Construction Management

Lean construction offers a collaborative approach to traditional construction practices and has the primary goal of increasing value to the client. With the proper use of lean construction tools on projects and the adoption of a lean culture, construction companies have recognized real benefits in terms of cost, productivity, and schedule while increasing customer satisfaction. The construction industry has been slow however in adopting the lean construction practices that have proven to be successful. The research in this study will familiarize the reader with the principles of lean construction, and address why the demand for lean construction is rising. In …

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A Study Of Career Path Interest Amongst Cm Students At Cal Poly San Luis Obispo, Travis J. Tollstrup Dec 2018

A Study Of Career Path Interest Amongst Cm Students At Cal Poly San Luis Obispo, Travis J. Tollstrup

Construction Management

With the labor shortage being experienced in the modern construction industry, it is important that office and field management personnel stay balanced to support the gap in skilled labor. However, for the students of Cal Poly San Luis Obispo, there is a trend that students are more interested in pursuing a career path in Office management, specifically that of a Project Manager. This paper determined the lack of interest in field management career path choice, specifically that of a Superintendent, by surveying the Junior and Senior students to gauge their career interests. It is concluded that there is indeed a …

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Osha-30 Lab Topics Course On Construction Safety And Hazard Identification, Patrick Garcia Dec 2018

Osha-30 Lab Topics Course On Construction Safety And Hazard Identification, Patrick Garcia

Construction Management

The end goal of this research-based project is to evaluate whether an OSHA-30 integrated lab course would be beneficial to Cal Poly’s Construction Management (CM) program and how it might also benefit the construction industry. The research conducted will be to interpret whether or not there is a need for this type of class to be included into the Construction Management Curriculum. Along with data research, two separate surveys were conducted, one survey taken by the Cal Poly Construction Management student population and the other survey taken by industry professionals. Additionally, a fellow Construction Management student, Mathew Bramlett, is working …

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Case Study: Environmental Requirements And Its Impacts Upon The Conservation Center For Wildlife Care, Chase Flemmer Dec 2018

Case Study: Environmental Requirements And Its Impacts Upon The Conservation Center For Wildlife Care, Chase Flemmer

Construction Management

As the population of California continues to grow, urban spaces are rapidly being developed into areas considered to be environmentally sensitive. In order to prevent extensive damage to our state’s delicate ecosystems, environmental regulations are often enforced by local organizations during the course of impactful operations such as construction projects. These regulations will often vary from one site to another, depending on a given site’s location and proximity to the environmentally sensitive areas. No two jobs will posses the exact same specifications for dealing with this aspect of construction, and as such some will require more intense regulations than others. …

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