Engineering Commons^™

3d Printing In Low Resource Healthcare Settings: Analysis Of Potential Implementations, Alenna Beroza

Dissertations, Master's Theses and Master's Reports

3D printing has gained significant momentum in the past ten years, and its unique advantages make it especially ideal for use in low resource healthcare settings, where many designs have already been successfully implemented. Yet, little has been studied on how 3D printing can be sustainably and functionally implemented in low resource healthcare systems as a manufacturing practice. In this report, three business models are proposed for this implementation: In-House Operator, Independent Operator, and Print Farm. These models were then tested over four months in Kisumu county, Kenya, at two workshops and seven public hospitals. I worked with local medical …

Improving Base Metal Electrowinning, Charles Ebenezer Abbey

Doctoral Dissertations

"In zinc electrowinning, Mn oxidizes to form MnO₂ on Pb-Ag anodes, cell walls and pipes. MnO₂ reduces anode corrosion but also leads to short circuits and maintenance issues. MnO₂ is thought to interact with chloride ions and produce oxidized chlorine species. The interactions between Mn and Cl are not well understood. Bench scale experiments were conducted to investigate the effects of the manganese to chloride ratio on anode corrosion rate and electrolyte chemistry using rolled Pb-Ag anodes. Increasing the average Mn/Cl^- ratio from ~7:1 to ~11:1 reduced the anode corrosion rate. Anode scales produced with Mn/Cl …

Plenum-To-Plenum Heat Transfer Characteristics Under Natural Circulation In A Scaled-Down Prismatic Modular Reactor, Salman Mohammed Alshehri

Doctoral Dissertations

“Gas-cooled reactor (GCR) is being developed under the Next Generation Nuclear Plant Program (NGNP) in nuclear engineering studies. As the world searches for an energy source with high energy density, clean, abundant, and storable nature to avoid global warming issues, GCR seems to be a promising solution, particularly the possibility of producing hydrogen. Studying and developing the safety analysis and GCR technologies are required for the optimum design and safety of GCR system. Multiphase Reactors Engineering and Applications Laboratory (mReal) at Missouri University of Science and Technology (S&T) has developed a natural convection heat transfer test facility with one riser …

Utilizing User-Generated Content To Analyze Tours And Activities In Bangkok: A Tripadvisor Case Study, Naina Chugh

Chulalongkorn University Theses and Dissertations (Chula ETD)

The overarching goal of this paper is to gain visibility on tourist preferences and whether or not the needs of tourists are being met. With the Travel and Tourism (T&T) sector being the backbone to the global economy and the sector becoming more saturated and competitive, insights on T&T are vital now, more than ever. The rise of social media and user-generated content has effectuated the opportunity for a systematic analysis of tourist preferences via user-generated content. This paper is focused on gaining insights into tourism in Bangkok, Thailand through user-generated content scraped from TripAdvisor’s online reviews of tours and …

Rice Granules As Natural Carrier To Encapsulate Drug And Aromatic Oils, Xue Liu

Chulalongkorn University Theses and Dissertations (Chula ETD)

Rice granules as major energy supply to humanity worldwide are utilized in many fields, such as food, medical, printing and plastic industries. In this thesis work, rice starch/granule is applied as hydrophilic drug (vancomycin) carrier to achieve the release. By confirmation on the stability of rice granules against to various treatments like alkali, acid and heating, as well as a-amylase, trypsin, and lipase, it is possible to use rice granules as 100% natural source to be the capsule and matrix getting the non-core-shell structure of the formation. The success of encapsulation is confirmed by the observations on crystalline, thermal properties …

การคำนวณหาดัชนีความแห้งแล้งและพืชพรรณจากอุณหภูมิพื้นผิวของข้อมูลดาวเทียมแลนด์แซท 8 และเปรียบเทียบกับผลผลิตข้าวในจังหวัดอุบลราชธานี, ธีรภัทร์ ถิระพล

Chulalongkorn University Theses and Dissertations (Chula ETD)

ความแห้งแล้งเป็นปัญหาที่สำคัญต่อเกษตรกรรมของประเทศไทย เมื่อความแห้งแล้งเกิดขึ้นรุนแรงทำให้ผลผลิตของพืชผลทางการเกษตรเสียหายมากขึ้นด้วย ดังนั้นปัญหานี้ควรได้รับการติดตาม วางแผน และแก้ไขอย่างใกล้ชิด งานวิจัยนี้จึงมีจุดประสงค์เพื่อคำนวณหาดัชนีความแห้งแล้ง อุณหภูมิพื้นผิว และหาความสัมพันธ์กับผลผลิตข้าว โดยใช้ข้อมูลจากภาพถ่ายจากดาวเทียม Landsat 8 ระบบ OLI และ TIRS ที่ครอบคลุมพื้นที่จังหวัดอุบลราชธานีในปี พ.ศ. 2556 - 2561 นำมาคำนวณหาค่าอุณหภูมิพื้นผิว (LST) ด้วยวิธี Radiative Transfer Equation-Based Method (RTE) และคำนวณหาดัชนีที่เกี่ยวข้องกับความแห้งแล้งคือ ดัชนีผลต่างความแห้งแล้ง (NDDI) และดัชนีความสมบูรณ์พืชพรรณ (VHI) จากนั้นนำมาหาความสัมพันธ์กับผลผลิตข้าว ซึ่งผลที่ได้พบว่า ดัชนีความแห้งแล้งและอุณหภูมิพื้นผิว ที่คำนวณได้สอดคล้องกับสภาพภูมิอากาศของพื้นที่และรายงานของหน่วยงานราชการ ผลการหาความสัมพันธ์พบว่าเมื่ออุณหภูมิพื้นผิวมีค่าสูงขึ้นทำให้ผลผลิตข้าวน้อยลง ในทางตรงกันข้าม เมื่ออุณหภูมิพื้นผิวมีค่าต่ำลงผลผลิตข้าวก็มากขึ้นเช่นกัน ส่วนดัชนีความสมบูรณ์พืชพรรณและดัชนีผลต่างความแห้งแล้งมีแนวโน้มไปในทิศทางเดียวกับผลผลิตข้าวคือ เมื่อดัชนีทั้งสองมีค่าต่ำลงผลผลิตข้าวก็ต่ำลงและเมื่อดัชนีทั้งสองมีค่าสูงขึ้นผลผลิตข้าวมากขึ้น

Efficiency On Extending The Shelf-Life Of Ripened Mango (Cv. Golden Nam Dokmai) Using Bioplastic Bags From Laboratory Scale And Industrial Scale, Tanudkid Butweangphant

Chulalongkorn University Theses and Dissertations (Chula ETD)

Efficiency in extending the shelf-life of ripened Golden Nam Dokmai by using bioplastic bags from laboratory scale and industrial scale production was tested. Polylactic acid (PLA) pellets and various fillers were mixed via twin screw extruder before being blown into film via extruder attached to blown film die in laboratory scale and industrial scale equipment. Oxygen and water vapor permeability of both kinds of bioplastic bags were evaluated for used as modified atmosphere packaging, for extend shelf-life of ripened mango. The oxygen permeability of films was 1,635.59±87.75 and 1,250.64±96.42 cc/m2-day and their water vapor permeability was 165.26±5.74 and 240.45±57.76 g/m2-day …

Grid-Friendly Dispatch Strategy Of Pv Generation System With Battery Energy Storage, Sarute Srisontisuk

Chulalongkorn University Theses and Dissertations (Chula ETD)

High PV penetration reduces stability tolerance due to the lower of system inertia and system ramp capability. To handle higher PV penetration issues, the system operator and PV owners should consider the operation improvement. For the system operator, critical system ramp capability with respect to PV penetration ratio can be useful to determine the lower bound of system ramp capability for handling N-1 contingency and expected disturbances. In the case study, test results reveal that the system can operate securely with PV penetration ratio up to 40%, in which it will require system ramp capability in the range of 0.05-0.09 …

Social Impacts Of Climate Change And Occupational Heat Stress And Adaptation Strategies Of Mining Workers In Ghana, Victor Fannam Nunfam

Theses: Doctorates and Masters

Excessive heat exposure due to rising temperatures associated with climate change adversely affects workers’ health, safety, productivity, and psychosocial well-being in occupational settings. In the hot and tropical regions of developing countries, long hours of physically demanding work, coupled with inadequate adaptation policies to climate change, increases the occurrence of heat-related illnesses and injuries, and contributes to the loss of productive capacity, poor decision making, and other negative effects on the social well-being of workers.

Based on the theories of social impact assessment, risk assessment, adaptation and resilience planning, this study assesses the social impacts of climate change and occupational …