The Golden Gate Bridge, known as one of the most beautiful bridges in the world, serves 110,000 vehicles per day, connecting San Francisco to inland as a segment of Highway 101 in California. The average peak hour volume over 6,500 vehicles per hour exceeds the traffic capacity of three lanes on each direction. Due to unique function of the bridge as a gateway of San Francisco, the peak directions in the morning and afternoon were explicitly distinguished. Recurrent traffic delay on the peak direction deteriorated level of service during the commute periods and caused user’s inconvenience and traffic accidents. The workers previously used to move plastic delineators to change lane configuration (4-2, 3-3, and 2-4) in several times a day. Neither did it provide prevention nor physical protection from the head-on collision on the bridge section. In January 2015, the Golden Gate Bridge was completely closed for two days to install the moveable median barrier (MMB) system, Road Zipper®, for more effective and safer variable lane management than the previous operation. One-meter section with 30.48 cm wide of highly reinforced concrete barriers are linked to form a continuous barrier wall and the machine lifts and passes the barriers through a conveyor system at a seeds up to 16 km/h. The MMB enables to quickly reverse lane configuration without traffic closure, providing more lanes to the peak direction as well as eliminating head-on collision on the bridge deck by presence of a physical structure. The traffic monitoring study result shows the significant improvement of average speed during peak hours and the regional traffic accident records shows improvement of safety after implementing the MMB on the Golden Gate Bridge. According to the traffic accident records, 13 injuries occurred in five accidents of vehicle collision in two-directions from 2007 to 2014 but no two-way accident has been reported since the operation of the Road Zipper® began. Furthermore, the MMB would be effectively implemented on construction work zones, managed lanes, variable lane management and other traffic operation to improve traffic safety and maximize utilization of roadway facilities.
In this study, eye movements of drivers on expressway ramps were comprehensively investigated using raw data from driving simulator and eye tracker(MyGaze) deducted though the previous study. Based on the literature review, several parameters including number of fixations, fixation time, horizontal & vertical eye movements, and gaze position were selected. With them, eye movements of older drivers and young drivers were compared and investigated. Average fixation time of older drivers is shorter and tend to focus more on the inside road edge for both left and right turning ramps comparing young drivers. Also, they tend to look wider at right turning ramp. All driver’s fixation points were spread along the inside road edge for both left and right turning ramps. Currently, road delineating facilities are installed on the side where centrifugal force is applied. However, considering the result, it should be installed where centripetal force is applied. In addition, road line marking management should be more taken care of. For future study, vehicle’s speed is also in need of consideration with eye movement.
Recently in Construction field, It has been the big issues to produce an Eco-friendly Construction material and to solve problems about the First grade–Aggregates’ supply&demand. While the Eco-friendly Construction materials which are refurbished and reproduced from construction wastes and industrial by-products have a great deal of effectiveness such as cost or CO2 emission reduction, there is an additional logistical cost due to go through with some processes for recycle such as Intermediary treatments or management and collection of materials. Furthermore, Demand of the First grade-Aggregates is rising and spreading all over the nation for the improvement of Road driving performance, But there is also an additional logistical cost for supply&demand due to the cost of transport growth by sites of construction. In this study, the process and methodology of the new material supply and demand route routings using the Arc Gis Program and the calculation of the available distance through economic analysis are presented. After examining the cost status of construction materials and logistics costs by examining the literature review and related industry, economic feasibility was obtained by comparing the price of general construction materials with the total cost of comparable materials and logistics costs. After an economic analysis, ArcGis3.0 was used to visualize the materials’ supply&demand route and As a result, We can observe the economically secured route from the construction materials’ production plant to where the domestic transportable route and nodes mapped. Throughout the study, the pre-groundwork for an efficient use of the construction materials is able to be prepared and It will be helpful to invigorate supply&demand. In addition to the economic analysis in the future, If the real-time traffic information (traffic volume, speed, environment, etc.) and the performance (structure, functionality, etc.) of each construction materials are reflected, It will be possible to build a decision system for selecting construction materials which meet consumers’ various needs.
In this study, several approaches in evaluating moisture sensitivity of asphalt mixtures were investigated and compared. To evaluate the moisture damage resistance, twenty types of asphalt mixtures with and without anti stripping additives were tested in the laboratory. Uniaxial compressive strength (UCS) and indirect tensile (IDT) testing were performed to determine the Tensile Strength Ratio (TSR) and Cohesion Strength Ratio (CSR). Stone Mastic Asphalt (SMA) mixtures were found to provide good moisture damage resistance compared to other mixtures. It also does not require anti stripping additives to improve its moisture resistance. Moreover, the correlation coefficient between the TSR test and CSR tests is 0.99 with an average error of 1.5%, which indicates that the TSR test following AASHTO T-283 is still the most reasonable criteria in evaluating the moisture damage of AC mixtures. Marshall Stability Ratio (MSR) and Marshall Stability to Flow Ratio (MSFR) were conducted and were compared to TSR test results. It was found that MSFR value may be used to evaluate the moisture damage resistance of AC mixtures instead of TSR test. Finally, Dynamic Immersion (DI) test was performed to evaluate moisture resistance for loose asphalt mixtures. The DI results showed good correlation also when evaluating moisture resistance compared to TSR. When using DI testing in evaluating moisture resistance, it is recommended to test after 48 hours since it showed higher correlation with the TSR values. Further study is recommended to improve current testing evaluating moisture susceptibility of asphalt mixtures to properly associate it with TSR values.
The aged asphalt binder included in RAP due to the oxidative aging, repeated vehicle load, climate process affects to the recycled asphalt mixture property and performance (stripping, port hole and premature cracking initiation) after paving. The rejuvenator commonly is used to recover the aged binder in hot mix asphalt (HMA) containing RAP; the effect of rejuvenator in HMA had been proven according to many studies for over the past several decades. Also, there are many methods for using RAP in asphalt mixture in aspects of HMA, cold asphalt mixture (CMA) and worm mix asphalt mixture (WMA), and a foamed asphalt mixture is one of them. Employing the foamed asphalt manufacturing technology, the content of RAP in recycled asphalt mixture can be increased more. The objectives of this study are to evaluate of rejuvenator influence on foamed asphalt mixture using 100% RAP based on strength change of test sample and stiffness change of recovered binder from RAP and specimen. As the results, when rejuvenator was added to make foamed asphalt mixture, MS and ITS values decreased clearly as compared with the foamed asphalt mixture without rejuvenator use. The use of rejuvenator up to 6% showed a tendency of the decrease of strength and stability remarkably. The use of rejuvenator over 6% did not decrease the strength and stability. DSR test results, the use of rejuvenator in making a foamed asphalt mixture using 100% RAP showed a recovery effect of the foamed asphalt mixture. And recovered binder from the specimen that was made adding the 6, 12 and 18% rejuvenator showed lower stiffness obviously compared to the recovered binder from RAP adding same dosage of rejuvenator.
When there is a significant stripping in asphalt pavement, it is common practice to use a hydrated lime (HL) as an anti-stripping additive (ASA). However, since many asphalt plants do not have facilities for weighing and casting HL, they prefer to use of a liquid-type ASA (LA). Therefore, various brands of LAs which show proper anti-stripping function are currently developed, imported, and marketed in Korea. In addition to the anti-stripping effect, the HL has been known to give a significant age-retarding effect on paved asphalt in the field. Therefore, there was a question about whether or not the LA provides the same anti-aging effect as The HL. This study investigated anti-aging effect of the asphalt mixes which were prepared using both ASAs and short-term aged and long-term aged in the laboratory. The absolute viscosity was measured as an aging index from the binder recovered from the mixes after short-term aging (STA) and long-term aging (LTA) processes. The results showed that there was a significant higher aging found from the LA-added mix than the normal mix without any ASA. On the other hands, the mix with HL showed significantly lower ageing level than the LA-added mix and normal mix. The retardation of age-hardening by using HL was more effectively observed when the STA condition was stronger.
This study evaluated the effect of steel slag and steel wool fibers (SWF) on self-healing performance of asphalt mixture. The microstructure and distribution of SWF in mixture were examined by a computerized tomography scan and image analysis program. Thermal conductivity was investigated using the thermal constant analyser. The heating rate and healing performance were measured by induction heating system. The results showed the uneven distribution and the agglomeration in the mixtures when the content of fibers exceed a certain dosage. It was found that the mix with steel slag had higher heating rate than the mix with normal aggregate; however, its healing performance was slightly lower because of the breaking of weak steel slag. Finally, the mechanical test results indicated that SWF can enhance the resistance and prolong the fatigue life of asphalt mixtures.
If asphalt-aggregate mixture is produced at a high temperature, the mixture will suffer a significant higher shortterm aging (STA) due to the elevated temperature. The binder in that mixture will be oxidized (aged) more than expected during STA due to the highly elevated temperature. The STA at the high-temperature level is one of the reasons why the hot-mix asphalt (HMA) mixture shows many distresses in the early stage of service life. In this respect, adopting warm-mix asphalt (WMA) technology is another advantage in the asphalt pavement industry. In this study, various levels of STA were used to evaluate aging levels of the binder in the mixture before and after STA. A gel-permeation chromatography (GPC) test was performed on the mixture particles without binder recovery to estimate the significance of aging for each case of STA. Statistical analyses were carried out to determine the difference in aging levels among STA temperatures. Statistical test results found that the aging level of the binder after STA was significantly higher than that of binders before STA at an α = 0.05 level. It was also found that the aging level of binders in the WMA mixture was significantly lower than that of binders in HMA after STA at an α = 0.05 level. It was observed that if an HMA mixture was produced at high-temperature STA, its aging level was estimated to be approximately four years in service.
There are some places such as bridges in the heavily industrialized area where the pavement should have a strong resistance against heavy axle loading and waterproof function. In those places, many polymer-modified asphalt (PMA) pavements were applied to protect premature cracking, severe rutting and water intrusion without success. Therefore, a much tougher pavement material with waterproofing function was developed for those places. This study evaluated important properties of the special type asphalt mixture which is highly condensed to be almost void-free condition. A high-quality PMA binder with PG82-34 grade was used for preparing the mixture and the optimum binder content was determined to allow near 0% air void in the mix design. The deformation strength(SD) by Kim Test and rut depth by wheel tracking test were measured at 60℃ as high temperature properties. The flexural strength and fracture toughness was measured at -10℃ as low temperature property. The void-free AC showed the higher performance in all four properties than any other asphalt concretes which were prepared for comparison. Therefore, it was shown that the normal concern about limiting air voids within 3-5% was just an apprehension. The void-free AC can be applied for heavy duty pavement on the bridge where the water-proofing function and higher rutting and cracking resistance are required.
It is well known fact that the filed asphalt mixture is aged in the truck while hauling and queuing for one to four hours before dumping to the hopper of the paver. This aging, which is called short-term aging (STA), affect the physical and mechanical properties of asphalt mixture. For example, the maximum theoretical density of mixture is changed before and after STA. Therefore, when the asphalt mixture specimen is prepared for testing various physical and mechanical properties in laboratory, the mixture should be STA conditioned by a most-likely STA condition of the field. This is the reason why the STA should be performed properly. This study initiated to investigate STA conditioning protocols, set forth many agencies in the world, and to suggest a proper STA protocol which simulates field HMA condition as most likely as possible. According to this study, it was suggested that the blended loose mix for one specimen poured in a canister should be kept in a drying oven (no forced draft) without cap at 163±2℃ and for 70±15 min for normal HMA mix. This protocol was suggested based on that the absolute viscosity level of the recovered binder after STA should be a similar level of the same binder after a standard RTFO run.
In case of performing asphalt pavement overlay on existing concrete pavement layer, applying asphalt emulsion tack-coating or spreading prime-coating is considered to improve adhesion between asphalt and concrete layer. After coating work is done a curing process is considered not only for promoting evaporation process in coated (and/or spread) asphalt emulsion, but also for generating a membrane which can act as a bonding agent. Finally, asphalt overlay construction is performed when this curing process is completely done. However, during asphalt overlay construction process remarkable amount of spread tack-coating layer is lost due to asphalt material transfer vehicles (e.g. trucks, approximately 40~50% of total spread tack coating material is lost). In this paper, a new pavement equipment contains simultaneous asphalt emulsion spreading ability and corresponding construction techniques are introduced. Through applying this equipment, non-stop two step sequent working process: spreading asphalt emulsion on to existing concrete pavement layer then paving asphalt material for overlay construction, is available. During pavement working process temperature of asphalt material was kept with ranged between 130ºC and 170ºC. After performing field performance evaluation, it was found that crucial improvement in pavement layer adhesion, crack and rutting resistant ability were observed compared to the conventional paving method.
Mercury is known as harmful element and significant negative effect on human and living creatures. The current study investigates the effective removal of toxic mercury from aqueous solution by reverse osmosis with low pressure. The various operating conditions as concentration, time and pressure used for the rejection study. The rejection study carried out in both terms as adsorption and pore size for long term (48 h) and achieved 99% mercury rejection. Further, the fouling propensity of membranes was studied and the fouling layer formed on the surface of the membranes was analyzed by the AFM imaging and the flux recovery ratio of the membranes was also calculated. The compatibility, thermal stability, hydrophilicity, surface energy, and morphology of the membranes were systematically investigated.
This study explores sustainability education in textile and apparel (T&A) programs in U.S. higher education institutions. Specifically, the researchers study whether more courses with sustainability focus are offered in higher-ranked institutions and explore whether sustainability is taught more in specific T&A related subject fields. Content analysis was conducted for 3,200 courses found in online course catalogs or the course information sites of 69 institutions. Institutions were selected from the 2015 rankings of the top 50 fashion design and top 50 fashion merchandising schools in the US on www.fashion-schools.org. All cases were coded by two coders with a Cohen’s Kappa score of 97.5%, indicating good interrater reliability. Coded data were analyzed through descriptive statistics, correlation analysis, and t-tests. The findings show that sustainability is being integrated into the curricula and across courses of T&A programs in the U.S. Over half of the institution surveyed offered at least one sustainability embedded course. Higher ranked institutions provided more sustainability- related courses than power-ranked institutions. A natural match between the subject field and specific sustainability theme was observed (e.g., cultural diversity in history/culture and social psychology/education; recycle/reuse in textile science; sustainability in fashion design; social responsibility and ethics in industry/consumer). The need to introduce sustainability in courses holistically is discussed, whereby sustainability within the industry supply chain is examined in a connected way.
Aronia is difficult to eat because it has a bitter taste, bitter taste, and sour taste. Because processing is essential for eating, quality information suitable for processing is needed. This experiment was carried out to confirm the step suitable for processing. Four grades of ripening were collected from 3 varieties (Viking, Nero, McKenzie) based on color, and compared with samples stored for 2 weeks after harvesting. Physicochemical properties such as color, hardness, sugar content, pH and acidity, functional components such as total polyphenols and flavonoids, and antioxidative activities such as DPPH and ABTS were investigated. When compared according to varieties, the hardness of the first degree was highest in other degrees, Depending on harvest time, first degree was higher than other degrees and it decreased with harvest time. Varieties was not significant different lightness, redness and yellowness value. compared according to harvest time, redness was the highest in second degree and lightness, yellowness decreased with harvest time. sugar content was highest in Nero and Mckenzie, birx value increased significantly of ripening and increased with harvesting time. pH was found to be highest in Nero, acidity value was the highest in viking. DPPH, ABTS radical scavening were Nero varieties had the highest radial scavening and increased significantly as the ripening degree increased. Total phenol and flavonoid contents were found to be highest in Nero, the highest content was showed at the first degree of harvesting. The most suitable stage for the processing was considered to be the best after post harvest treatments considering brix, hardness and acidity.
Vitamin A, particularly all-trans retinol is excellent for anti-aging but is sensitive to oxygen, heat and light and has low solubility in water. In this study, retinol was encapsulated within oil-in-water (O/W) emulsion, protein-based particle and cycloamylose(CA). And then, it confirms that retinol contained in each delivery system is stable to UV, pH, and temperature and finally measures bioaccessibility.
O/W emulsion was compared according to the type and concentration of emulsifier. UV stability of retinol increased with increasing oil concentration. More than 10 wt% of oil was required to maintain stable retinol (50% residual after 24 hours of irradiation). Using anionic emulsifier, retinol had unstable storage stability regardless of oil concentration and temperature.
Protein based particle was compared according to the type of stabilizer and polysaccharide. UV stability of retinol was highest in pectin-coated particles. However, 20% retinol remains after 6 hours of irradiation and is vulnerable to UV compared to other delivery systems. In pH stability, pectin-coated particles also stably retained retinol.
Inclusion complex of retinol and CA was compared according to the concentration of CA. When CA was used, the residual amount of retinol to UV was high (50% residual after 24 hours of irradiation) regardless of the concentration of the host molecule. In the case of storage stability, retinol remained significantly higher regardless of temperature when cycloamylose was used.
It was finally confirmed bioaccessibility each of retinol delivery system. O/W emulsion was determined by emulsifier type, protein-based particle by coating agent, and inclusion complex by CA concentration. All O / W emulsions retained more than 50% retinol, protein based particles retained more than 80% retinol, and inclusion complex retained more than 70% retinol. The bioaccessibility of pure retinol is about 20%. This study provides important information for designing effective delivery systems for improving the stability of retinol.
Amylose is carbohydrate polymer defined as a linear natural polysaccharide composed of α(1→4) bound glucose units. Due to its abundance, renewable nature, low cost, and biodegradability, this polymer is regarded as a promising green material for producing crystals and particles of different sizes ranging from the nanometer scale to the micrometer scale. Herein, short amylose chains and dextran-coated iron oxide magnetic nanoparticles (Dex@IONPs) were introduced to fabricate well-dispersed starch magnetic microbeads (SMMBs), which have a well-defined spherical shape and a uniform size of about 1 μm. We found that the aggregation of SMMBs can be mediated by the introduced Dex@IONPs in a concentration-dependent manner, indicating that Dex@MNPs, as the seed crystals, play an important role in self-assembly of SMMBSs. By using streptococcal protein G tagged with maltose binding protein (MBP-SPG), specific antibody against Escherichia coli O157:H7 was successfully immobilized on the surface of SMMBs. The Ab-functionalized SMMBs showed a high capture efficiency (>90%) comparable to the commercial immunomagnetic microparticles regardless of suspending agents (1X PBS and milk). Moreover, SMMBs exhibited excellent recyclability, in which the Ab immobilized on the surface of SMMBs can be refreshed by using the maltose elution buffer along with the unchanged capture efficiency. In addition, SMMBSs were assembled into the linear rod-shape microstructure by the introduced magnetic field during the amylose-mediated precipitation process. The convenient self-assembly of SMMBs with the well-defined size and shape, biocompatibility, tolerance to environmental variances, high magnetic response behavior, and excellent recyclability in the functionalization make these magnetic microparticles promising for many potential applications such as bio-sensing, labeling, and smart delivery of active compounds.
The outbreaks of foodborne diseases associated with bacterial contamination are still critical issues all over the world. To ensure food safety, the diagnosis of pathogenic bacteria on site at early state of contamination are required. Escherichia coli O157:H7 (E. Coli O157:H7) is one of the major factor causing foodborne diseases. We introduce a sandwich type colorimetric detection method integrated with chitosan-coated starch magnetic polymer beads(CS@SMBs) that can separate and concentrate bacteria in aqueous environment. For signal amplification, horseradish peroxidase-conjugated antibody (HRP-Antibody) and 3,3',5,5'- tetramethylbenzidine (TMB) were employed as enzyme label and chromogenic substrate, respectively. We demonstrate that CS@SMBs not only show a good magnetic sensitivity, but also can capture a variety of bacteria regardless of Gram-negative and Gram-positive, which offer possibility for separation of the broad range of bacteria from food matrix. Our approach successfully captures E. coli O157:H7 with detection limit of 101 CFU/mL through naked eye, making promise of fast, on-site, and sensitive detection of pathogenic bacteria.
Astaxanthin(Ast) is considered a powerful antioxidant. However, the efficacy of Ast is limited due to its poor water solubility and stability. To enhance the properties of Ast, 2-hydroxypropyl-γ-cyclodextrin(HPγ-CyD) can be used through complexation. In this study, we investigated the wound healing ability of Ast/HP-γCyD(Ast/HP-γ-CyD) complex in sacran-based hydrogel. HP-γ-CyD played an important role to increase the elastic modulus of the sacran-based hydrogel with high swelling ability. Unusually, the Ast/HP-γ-CyD complex in sacran-based hydrogel provided the highest wound healing ability in mice. These results suggest that the Ast/HP-γ-CyD complex in sacran-based hydrogel has the potential for use as a new transdermal therapeutic system to promote the wound-healing process
Carnosic acid from rosemary extract is one of the natural phenolic compounds which show the antioxidant and antimicrobial activities. Nevertheless, the use of rosemary extracts in food matrix is highly limited due to the low water solubility and poor chemical stability of active constituents of extract. Therefore, the aim of this study is to investigate the functionality and effect of starch based polymers on rosemary extract in aqueous solution for improving their efficiency of food application.
To manufacture the rosemary-starch polymer complex, starch based polymers (cycloamylose; CA, cyclodextrin; CD, hydroxypropyl-beta-cyclodextrin; HP-b-CD, maltodextrin; MD, clustered dextrin; ClusD) were firstly dispersed in 5mM phosphate buffer (pH7) according to each concentrations. Rosemary extract was then dissolved in solution to react with the polymers. Enhanced water solubility of rosemary extract was measured using a spectrophotometer. Antioxidant (ABTS assay) & antimicrobial activity (MIC test) were also tested.
In aqueous solution containing CD and HP-b-CD, the solubility of rosemary extract increased almost twice or more (189% and 248% respectively). CA, MD, and ClusD solutions also showed the results of increasing the solubility about 126%~129%. As rosemary extract dissolved better, it was also found to have increased antioxidant and antibacterial activity of rosemary-starch polymer complex. Especially, the degree of antioxidant activity has been increased much larger than the increased solubility level. Consequently, more studies are needed to determine why these results are produced. If further studies and experiments are conducted on this, it could be beneficial for food industry interested in utilizing rosemary extract.
A quality of forage under optimal condition needs to be evaluated because an optimal condition for high productivity does not guarantee high quality product. In this study, we aimed at investigating a quality of barley grown under optimal conditions for maximizing productivity by comparing its ingredient contents with those under other conditions in plant factory-type fresh forage growing system. To compare the ingredient in barley grown at 4 conditions, we used multivariate analysis of variance (MANOVA) and Tukey’s post-hoc test. The optimal growth condition (20 and 63% of humidity) was applied to the first group (group 1), while other groups were cultivated under 20 / 90% (group 2), 18 / 63% (group 3), and 23 / 63% (group 4). In the analysis, contents of ingredients in each sample were measured at two parts, i.e., roots and shoots. Result showed that roots included 86.68% of moisture, 1.86% of crude-protein, 0.58% of crude-fat, 2.13% of crude-fiber, 195.78 ppm of minerals, and 231.48 μmol/g of amino acids. For shoots, 92.42% of moisture, 2.52% of crude-protein, 0.16% of crude-fat, 1.86% of crude-fiber, 263.78 ppm of minerals, and 208.34 μmol/g of amino acids were contained. When comparing by groups, moisture, crude-fat, and some minerals (Fe, Na, and P) were not significantly different by groups. In contrast, crude-protein, crude-fiber, and few minerals (Ca and K) were different. Overall, the variation in total amount of ingredient was less than 20% among groups, suggesting quality of barley under optimal conditions for productivity was acceptable. In conclusion, the optimal condition for yielding maximal productivity maintains barley quality, but an operating conditions needs to be changed when emphasizing functional aspect of forage.