Undergraduate Research Program to Recycle Composite Waste

With the rapid growth in the manufacturing industry and increased urbanization, higher amounts of composite material waste are being produced, causing severe threats to the environment. These environmental concerns, coupled with the fact that undergraduate students typically have minimal experience in research, have initiated the need at the UAE University to promote research among undergraduate students, leading to the development of a summer undergraduate research program. In this study, a recycling methodology is presented to test lab-fabricated Carbon-Fiber-Reinforced Polymer (CFRP) for potential applications in industrial composite waste. The work was conducted by two groups of undergraduate students at the UAE University. The methodology involved the chemical dissolution of the composite waste, followed by compression molding and adequate heat treatment for rapid curing of CFRP. Subsequently, the CFRP samples were divided into three groups based on their geometrical distinctions. The mechanical properties (i.e., modulus of elasticity and compressive strength) were determined through material testing, and the results were then compared with steel for prompt reference. The results revealed that the values of mechanical properties range from 2 to 4.3 GPa for the modulus of elasticity and from 203.7 to 301.5 MPa for the compressive strength. These values are considered competitive and optimal, and as such, carbon fiber waste can be used as an alternate material for various structural applications. The inconsistencies in the values are due to discrepancies in the procedure as a result of the lack of specialized equipment for handling CFRP waste material. The study concluded that the properties of CFRP composite prepreg scrap tend to be reusable instead of disposable. Despite the meager experimental discrepancies, test values and mechanical properties indicate that CFRP composite can be successfully used as a material for nonstructural applications.

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Avancemos! Building Partnerships Between Academia and Underserved Latinx Communities to Address Health Disparities Through a Faculty-Mentored Undergraduate Research Program

Health Promotion Practice ◽

10.1177/1524839920953782 ◽

2020 ◽

pp. 152483992095378

Author(s):

Ana Cristina Lindsay

Keyword(s):

Health Disparities ◽

Formative Assessment ◽

Undergraduate Students ◽

Research Program ◽

Undergraduate Research ◽

The United States ◽

Culturally Competent ◽

Research Skills ◽

Professional Career ◽

Undergraduate Research Program

Latinx is the largest minority population group in the United States and disproportionately affected by health disparities. Efforts to address such health disparities require a concerted, multipronged approach that should involve training the next generation of Latinx health professionals to become part of a culturally competent workforce. This article describes a formative assessment of a faculty mentored undergraduate research program at the University Massachusetts–Boston, called “ Avancemos!: Advancing Research Skills and Professional Career Opportunities in Health Sciences for Latinx Undergraduate Students” designed to provide mentorship, research training, and professional career development skills for undergraduate Latinx students. We employed a mixed-method approach in the formative assessment of the program. Our results showed that over the course of four academic semesters the program served a majority female, first-generation, immigrant low-income Latinx undergraduate students. Our qualitative assessment of students’ perceived benefits of participation in the program suggests positive effects on a number of areas including the acquisition of concrete and marketable research skills, enhanced understanding and application of knowledge gained in other courses, increased network, enhanced sense of belonging to the academic community, increased professional self-confidence, and enhanced preparedness and plans to pursue graduate studies. Furthermore, our findings suggest that participation in community-engaged research activities offered opportunities for students to realize the role research plays in reducing health disparities. Faculty-mentored undergraduate research programs such as the Avancemos! offer essential opportunities to build partnerships between academia and underserved Latinx communities to address health disparities, while contributing to the development of culturally competent health professions workforce.

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Influence of the surface treatment of tire rubber residues added in mortars

Revista IBRACON de Estruturas e Materiais ◽

10.1590/s1983-41952008000200001 ◽

2008 ◽

Vol 1 (2) ◽

pp. 113-120 ◽

Cited By ~ 11

Author(s):

A. C. Marques ◽

J. L. Akasaki ◽

A. P. M. Trigo ◽

M. L. Marques

Keyword(s):

Mechanical Properties ◽

Aqueous Solution ◽

Tensile Strength ◽

Compressive Strength ◽

Surface Treatment ◽

Water Absorption ◽

Modulus Of Elasticity ◽

Tire Rubber ◽

Flow Test ◽

Made In

In this work it was evaluated the influence tire rubber addition in mortars in order to replace part of the sand (12% by volume). It was also intended to verify if the tire rubber treatment with NaOH saturated aqueous solution causes interference on the mechanical properties of the mixture. Compressive strength, splitting tensile strength, water absorption, modulus of elasticity, and flow test were made in specimens of 5cmx10cm and the tests were carried out to 7, 28, 56, 90, and 180 days. The results show reduction on mechanical properties values after addition of tire rubber and decrease of the workability. It was also observed that the tire rubber treatment does not cause any alteration on the results compared to the rubber without treatment.

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Mechanical Properties of Concrete with Various Water-Cement Ratio After High Temperature Exposure

Jurnal Teknik Sipil ◽

10.28932/jts.v2i2.1262 ◽

2019 ◽

Vol 2 (2) ◽

pp. 126-136

Author(s):

M.I Retno Susilorini ◽

Budi Eko Afrianto ◽

Ary Suryo Wibowo

Keyword(s):

Mechanical Properties ◽

Compressive Strength ◽

High Temperature ◽

Modulus Of Elasticity ◽

Building Materials ◽

Heating Process ◽

High Temperature Exposure ◽

Cement Ratio ◽

Water Cement Ratio ◽

Temperature Exposure

Concrete building safety of fire is better than other building materials such as wood, plastic, and steel,because it is incombustible and emitting no toxic fumes during high temperature exposure. However,the deterioration of concrete because of high temperature exposure will reduce the concrete strength.Mechanical properties such as compressive strength and modulus of elasticity are absolutely corruptedduring and after the heating process. This paper aims to investigate mechanical properties of concrete(especially compressive strength and modulus of elasticity) with various water-cement ratio afterconcrete suffered by high temperature exposure of 500oC.This research conducted experimental method and analytical method. The experimental methodproduced concrete specimens with specifications: (1) specimen’s dimension is 150 mm x 300 mmconcrete cylinder; (2) compressive strength design, f’c = 22.5 MPa; (3) water-cement ratio variation =0.4, 0.5, and 0.6. All specimens are cured in water for 28 days. Some specimens were heated for 1hour with high temperature of 500oC in huge furnace, and the others that become specimen-controlwere unheated. All specimens, heated and unheated, were evaluated by compressive test.Experimental data was analyzed to get compressive strength and modulus of elasticity values. Theanalytical method aims to calculate modulus of elasticity of concrete from some codes and to verifythe experimental results. The modulus elasticity of concrete is calculated by 3 expressions: (1) SNI03-2847-1992 (which is the same as ACI 318-99 section 8.5.1), (2) ACI 318-95 section 8.5.1, and (3)CEB-FIP Model Code 1990 Section 2.1.4.2.The experimental and analytical results found that: (1) The unheated specimens with water-cementratio of 0.4 have the greatest value of compressive strength, while the unheated specimens with watercementratio of 0.5 gets the greatest value of modulus of elasticity. The greatest value of compressivestrength of heated specimens provided by specimens with water-cement ratio of 0.5, while the heatedspecimens with water-cement ratio of 0.4 gets the greatest value of modulus of elasticity, (2) Allheated specimens lose their strength at high temperature of 500oC, (3) The analytical result shows thatmodulus of elasticity calculated by expression III has greater values compares to expression I and II,but there is only little difference value among those expressions, and (4)The variation of water-cementratio of 0.5 becomes the optimum value.

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Mechanical Behavior of 2D C/SiC Composites at Elevated Temperatures under Uniaxial Compression

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.462-463.1 ◽

2011 ◽

Vol 462-463 ◽

pp. 1-6 ◽

Cited By ~ 1

Author(s):

Tao Suo ◽

Yu Long Li ◽

Ming Shuang Liu

Keyword(s):

Compressive Strength ◽

High Temperature ◽

Carbon Fiber ◽

Mechanical Behavior ◽

Uniaxial Compression ◽

Room Temperature ◽

Elevated Temperatures ◽

Carbon Matrix ◽

Structural Applications ◽

Sic Composites

As Carbon-fiber-reinforced SiC-matrix (C/SiC) composites are widely used in high-temperature structural applications, its mechanical behavior at high temperature is important for the reliability of structures. In this paper, mechanical behavior of a kind of 2D C/SiC composite was investigated at temperatures ranging from room temperature (20C) to 600C under quasi-static and dynamic uniaxial compression. The results show the composite has excellent high temperature mechanical properties at the tested temperature range. Catastrophic brittle failure is not observed for the specimens tested at different strain rates. The compressive strength of the composite deceases only 10% at 600C if compared with that at room temperature. It is proposed that the decrease of compressive strength of the 2D C/SiC composite at high temperature is influenced mainly by release of thermal residual stresses in the reinforced carbon fiber and silicon carbon matrix and oxidation of the composite in high temperature atmosphere.

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Investigations into Ti-15Mo-W Alloys Developed for Medical Applications

Materials ◽

10.3390/ma12010147 ◽

2019 ◽

Vol 12 (1) ◽

pp. 147 ◽

Cited By ~ 4

Author(s):

Mihai Buzatu ◽

Victor Geantă ◽

Radu Ştefănoiu ◽

Mihai Buţu ◽

Mircea-Ionuţ Petrescu ◽

...

Keyword(s):

Mechanical Properties ◽

Compressive Strength ◽

Modulus Of Elasticity ◽

Vacuum Arc ◽

Medical Applications ◽

Structural Investigations ◽

Metallic Material ◽

Β Phase ◽

Vacuum Arc Furnace ◽

Hardness Values

The β-Ti alloys have attracted the attention of researchers due to their excellent properties and their remarkable biocompatibility. The present study evaluated the mechanical behavior analysis (hardness, compressive strength, and modulus of elasticity) of the Ti-15Mo-W system. For experimental research, we chose the TiMo15 biocompatible alloy as a starting material. In order to improve the mechanical properties, we added tungsten amounts of 3.88 to 12.20 wt.% and analyzed the results obtained. The successive melting of the samples was done using a vacuum arc furnace in a copper crucible cooled with water. Following micro-structural investigations, we found this alloy possessed a homogeneous structure and showed β-phase predominance. The investigated alloys have good mechanical properties—the mean Vickers micro-hardness values are between 251 to 321 HV, the compressive strength values range from 717 to 921 MPa, and the modulus of elasticity is between 17.86 and 45.35 GPa. These results are compatible to the requirements of a metallic material for medical applications as artificial implant devices.

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Influence of the Method of Polymerization of Composite Material for Teeth Crown Fillings on its Strength Properties

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.240.168 ◽

2015 ◽

Vol 240 ◽

pp. 168-173

Author(s):

Grzegorz Milewski ◽

Tomasz Majewski

Keyword(s):

Mechanical Properties ◽

Compressive Strength ◽

Composite Material ◽

Modulus Of Elasticity ◽

Strength Properties ◽

Dental Practice ◽

Polymerization Shrinkage ◽

Filling Materials

Polymerization shrinkage of composite filling materials still becomes one of the most important features which decreases strength properties of reconstructed teeth crowns. From among various methods to reduce that disadvantageous phenomenon which are used in a dental practice sandwich filling processing of crown cavity seems to be the most effective one. The paper presents the results of the strength examination of the influence of the different ways of layered polymerization processing on the mechanical properties of modern hybrid micro composite material with regards to the following quantities: compressive strength, strain to fracture, modulus of elasticity and work to fracture.

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Evaluation of Mechanical Behavior and Microstructural Characteristics of Photocatalytic Concretes to Be Used as Pavement Blocks

Journal of Engineering Materials and Technology ◽

10.1115/1.4033275 ◽

2016 ◽

Vol 138 (3) ◽

Author(s):

João Victor Staub de Melo ◽

Glicério Trichês

Keyword(s):

Mechanical Properties ◽

Compressive Strength ◽

Mechanical Behavior ◽

Tio2 Nanoparticles ◽

Modulus Of Elasticity ◽

Microstructural Characteristics ◽

State Tests ◽

Fresh State ◽

Hardened State ◽

Microstructural Behavior

This paper reports the results obtained in a study on the effect of the addition of TiO2 nanoparticles on the mechanical properties and microstructural characteristics of photocatalytic concretes. In the hardened state, tests to determine the compressive strength and modulus of elasticity were carried out. Also, microstructural aspects of the samples were investigated. In the fresh state, the influence of the addition of TiO2 on the concrete compaction and conduction calorimetry curves was evaluated. The results obtained indicated a better mechanical and microstructural behavior of concrete with addition of TiO2.

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