Chlorine dioxide gas is a relatively new sanitizer in the food industry and has more accessibility than its aqueous form. Depending on the generation method of ClO2, there can be byproducts like chlorite and chlorate ions that can decrease the disinfectant efficacy and purity of ClO2. Recently, a new technology has been developed that generates chlorine dioxide without using chlorine gas. This new electrochemical method generates gaseous chlorine dioxide from aqueous sodium chlorite (NaClO2). Unlike earlier methods, there is reduced generation of byproducts, including chlorite and chlorate. Additionally, the purity of ClO2 obtained by this method can be as high as 98%.
The aim of this study was to evaluate the effect of ClO2 gas, generated by the electrochemical method, against the foodborne microorganisms occurring on slaughter equipment and livestock carcasses. Using AISI 304 stainless steel in livestock processing equipment, the disinfectant effect of chlorine dioxide gas, in presence of organic matter such as yeast extract and feces, on E. coli and S. typhimurium contamination, was examined. Both E. coli and S. typhimurium counts were reduced by more than 5 log cycles in presence of 2.5% and 5% feces. When beef, pork skin, and chicken wings were treated with chlorine dioxide gas, despite significant differences in comparison with the control group, the microbial count was reduced by less than 2 log cycles.
Overall, our results confirmed the applicability of gaseous chlorine dioxide as a disinfectant in livestock processing equipment and livestock products.
The challenges faced by the Malaysian shipyard industry had led to the failure of local shipyards in catering to the demand of ship owners. The shipyard industry had recorded the least contribution (1.0%) to the world shipbuilding order book and had caused inconsistencies in the Malaysian shipbuilding ship repair (SBSR) industry’s demand and supply market. The objectives of this study had been to identify the factors that had contributed to the challenges faced by the shipyard industry in Malaysia, and to rank them according to their priorities. The factors of these challenges had been identified by using the cause-and-effect analysis method and were further illustrated in the form of an Ishikawa diagram. Subsequently, an analytic hierarchy process (AHP) method was applied to determine the weightage of the priorities. The results had shown that ‘Market’ (41.66%) had been the most challenging aspect faced by the shipyard industry in Malaysia from all the five factors studied. As such, this research would help shipyard organisations to effectively prioritise these challenging factors as a way of sustaining their businesses and affecting the economic contribution from the shipyard industry.
Cumulative effects are defined as the joint and aggregated effects of many factors and processes. Their consideration in landscape and environmental assessments are integral at both the project and strategic level, and they can help to bridge the different spatial and temporal scales. The primary challenge of conducting cumulative effect assessments (CEAs) is the difficulty in understanding the complicated nature of cumulative effects. We used three criteria for a systematic understanding of the barriers to addressing cumulative effects that are critical for improving knowledge systems for sustainable development and environmental assessment: salience, credibility, and legitimacy, and analyzed three cases through a variety of studies and resources: the Middle Humber in the U.K., the Transboundary Crown of the Continent in the U.S. and Canada, and the Great Sandhills in Canada, to understand how CEAs have been applied and obstructed in terms of the three criteria. In addition, a series of focus group interviews with experts and practitioners were performed to illuminate the critical barriers based on the criteria for addressing CEA in the context of South Korea. Based on the lessons, we suggest several key strategies such as securing a cooperative consulting process, and active and transparent partnerships; using a strategic environmental assessment as a framework; understanding and incorporating stakeholder knowledge; using advanced computer modeling and simulation techniques including effective visualization tools; and preparing a simple model design and understandable scientific information.
Many are crying foul over the Trump Administration’s use of steel and aluminum tariffs, claiming that imports are not a threat to the US national security. Rather, it has been argued that the tariffs are a pretext to gain strategic advantage in unrelated trade negotiations. Members of the Trump administration have hailed subsequent trade concessions as proof that the tariffs have been successful, which, if proven, could raise a credible question as to whether the President exceeded the scope of his authority. Domestic and international challenges have already begun with the US courts being a more effective forum to the challenge the legality of the tariffs than the WTO.
Background: The craniocervical flexion (CCF) exercise is one of the effective exercise in correcting forward head posture (FHP). However, some people with FHP achieve CCF with compensatory movements, for example, low cervical flexion using superficial neck flexors such as the sternocleidomastoid (SCM) muscle. No study has yet investigated whether a dualpressure biofeedback unit (D-PBU) method to prevent low cervical flexion would be helpful in performing pure CCF movement. Objects: The purpose of this study was to compare the effects of the CCF using D-PBU method and the traditional CCF method on the cross-sectional area (CSA) of the longus colli muscle (LCM) and the activity of SCM muscle in subjects with FHP. Methods: Twentyfour FHP subjects (male: 16, female: 8) were recruited for this study. All subjects performed CCF using two different methods: The traditional CCF method and the CCF using D-PBU method. The CSA of the LCM was measured via ultrasound, and surface electromyography was used to measure SCM muscle activity. Results: The change in CSA of the LCM was significantly larger during the CCF using D-PBU method (1.28±.09) compared with the traditional CCF method (1.19±.08) (p<.05). The SCM muscle activity using the CCF using D-PBU method (2.01±1.97 %MVIC) was significantly lower than when using the traditional CCF method (2.79±2.32 %MVIC) (p<.05). Conclusion: The CCF using D-PBU method can be recommended for increasing LCM activation and decreasing SCM muscle activity during CCF movement in subjects with FHP.
The purpose of this study is to compare securing of walking roads’ cross section zones in the walking paths by street by street and city by city. The cities involved with this study are Seoul Metropolitan Area and Tokyo Metropolitan Area. The securing of widths are compared based on zone types such as frontage, pedestrian, and furniture zones. The widths are measured directly through on-site surveys. The widths measured are compared the standards given by the present paper. Among 22 sites, the satisfied sites are counted. In terms of frontage zones in Seoul Metropolitan Area, 17 out of 22 sites are counted as satisfied while in Tokyo Metropolitan Area, 18 out of 22 sites are counted as satisfied. In terms of pedestrian zone, in Seoul Metropolitan Area, 13 out of 22 sites are counted as satisfied while in Tokyo Metropolitan Area, 14 out of 22 sites are counted as satisfied. In terms of furniture zone, in Seoul Metropolitan Area, 14 out of 22 sites are counted as satisfied while in Tokyo Metropolitan Area, 11 out of 22 sites are counted as satisfied. In conclusion, although walking roads’ cross section zones such as frontage, pedestrian, and furniture zones are relatively a new standards in Korea and Japan, many sites are founded being satisfied with the standards. However, the rates of satisfaction differs city by city. Especially the rates of satisfaction in furniture zones in Seoul Metropolitan are somewhat higher while the rates of satisfaction in frontage and pedestrian zones are similar between two cities.
Recently, there is an increasing the pavement distresses such as rutting with an increase in heavy vehicles on the road in Mongolia. Rutting is the longitudinal depression in the wheel path in asphalt pavements and it causes a hydroplaning and severe safety concern for users. This study aims to develop paving material that can prevent rutting on the road pavement by improving the durability of the asphalt mixture in Mongolia. Therefore, this study was carried out using the technique of reinforcing the material by adding fibers to conventional asphalt mixture. Fibers have been used to reinforce various materials for many decades in various parts of the world. It is generally understood that asphalt is strong in compression and weak in tension. Adding fibers with high tensile strength can help increase the strength of a mixture[1]. A mixture of glass fibers was used in this study to evaluate the performance characteristics. In coordination with the City of Ulaanbaatar, The test section selected in this study was Peace Avenue in Ulaanbaatar. The test section was a bus lane with severe rutting by heavy vehicles. The designated road test section performed cutting and overlay using five asphalt mixtures: Glass Fiber-reinforced Asphalt, Hot Mix Asphalt(10mm, 19mm), Polymer Modify Asphalt(2 types). The performance survey was conducted after the summer. As a result, No noticeable cracks were observed in glass-reinforced mixture section and the rut-depth of the glass-reinforced mixture is lower than other mixtures[2].
To be better fit for highways, pavement systems are required to provide comfortable and safe driving and be structurally durable. Composite pavements can be an effective option as they are more durable by placing a high functional asphalt overlay on a rigid concrete base layer. In order to apply a composite pavement system to the field, it is necessary not only to develop technologies that prevent reflecting crack and deterioration of the base layer, but also to improve bonding performance of materials and ensure structural performance as a pavement system against traffic loading. In advanced countries like Japan, USA and Europe, high-functional composite pavement systems are being put into practice across new highway networks. In this study, we evaluated structural performance (rutting, reflecting crack, and deflection) by applying traffic loads of actual highways through an accelerated pavement tester (APT) of a composite pavement section made up of a quiet porous surface laid over a water-proofing layer, a continuously reinforced concrete base, and a lean concrete sub-base layer, which was developed with new pavement methods used for each layer prior to field application. The APT specimen was constructed with paving materials and equipment actually used on site in the same dimensions (W3.5m*L14m*H2m) as actual highway sections in Korea, and 3-axle double-wheel heavy load (45ton) cart type KALES(Korean Accelerated Loading and Environmental Simulator) traveling on the specimen in both directions was used to simulate traffic loading. After applying around 8,574,000 ESALs of traffic loads, no reflecting crack occurred on the asphalt surface of the composite pavement, without surface distress except for rutting. In order to examine what causes rutting of pavements, we surveyed thickness of pavements by layer and measured asphalt density.
Asphalt pavement overlay method is one of widely chosen construction methods for remodelling existing aged concrete pavement layer. However, in this case reflective cracking is a challenging issue due to movement of transverse joints: built in existing concrete pavement layer with constant interval length. In this paper, collecting field data: collection of displacement and temperature data on existing concrete pavement layer for further complicated pavement performance analysis, was performed. To fulfil this objective, various types of thermometer were embedded into concrete layer with different depth level. Then, movement of existing concrete layer was measured numerically. Each Displacement Measuring Gauge (DMG) along with thermometer was embedded with depth of 3cm and 15cm, respectively. Additional thermometers were embedded at the middle depth of overlaid asphalt pavement layer for further extensive analysis and data collection. Total four testing sites were considered based on different asphalt mixture type and construction method. The 1st site was constructed with conventional construction approach, the 2nd site was constructed with a new pavement equipment contains simultaneous tack-coating function, the 3rd site was similar to 1st site but Guss-asphalt was constructed as a binder course, and in 4th site Noise-Reduction Porous Asphalt (NRPA) was constructed as a surface course and regular Dense Grade Asphalt (DGA) was constructed as a binder course. A field asphalt pavement layer sample coring works: along with basic material property tests, were also performed to acquire not only overlaid asphalt but also existing concrete pavement materials. This gauge measuring work in this study is an initial step therefore, long-term movement data of each pavement layer was not able to be collected, unfortunately. However through collecting and analysing initial data on each test site, two crucial findings were acquired. First, in all four tested site highest temperature variations were observed at the upper asphalt pavement layer and the variation trends decreased with increase of pavement depth (in case of concrete pavement layer, temperature and movement variations also decreased with increase of pavement depth). Secondly, when Guss-asphalt was applied as a binder course temperature variations of existing concrete pavement layer was crucially smaller than those of other comparison cases. These current findings and collected data set can provide successful input information for further pavement structure analysis such as 2D (and/or 3D) Finite Element Method (FEM) analysis as a future study.
Generally, remarkable amount of Reclaimed Asphalt Pavement (RAP) is produced annually by pavement surface cutting: due to early distress on asphalt pavement layer and remodelling construction work on existing aged-asphalt pavement layer. In South Korea, various types of research on proper and optimized RAP material development and field application (including evaluation process) are performed because of increase of existing road maintenance budget and technology. The major material of RAP is recycled aggregate coated with aged asphalt binder. The advantages of application of RAP on asphalt pavement are recyclable material proportion can be increased due to re-using of existing aggregate and eco-friendly characteristics. However, more amount of specific additives (and/or agent) needs to be implemented during production with increase amount (and/or proportion) of RAP on virgin asphalt material inevitably. This action is highly needed because of recovery of penetration grade and absolute viscosity of final production. The required amount of additives tends to be vary based on different aging level of RAP, amount of RAP and types of virgin asphalt binder. But it is well known that required amount of additives tends to be increased with increase of RAP proportion compared to virgin asphalt mixture. Moreover, it also should be known that mere increase of additives on RAP asphalt can provide negative effect on its quality and mechanical performance. In this study, high penetration grade asphalt binder: contains between 200 and 300 level of penetration grade, was used for producing RAP asphalt mixture with small amount of required additive application. After the sample preparation, various characteristics of RAP asphalt were analysed with extensive experimental work.
Recently, Cambodia has been investing a lot of money in the construction and maintenance of roads, which are social infrastructures. However, damage to the existing pavement is accelerating due to the old age of the road pavement, poor drainage facilities and increase in heavy traffic. To solve this problem, a fundamental solution such as a high-performance asphalt mixture is required to extend the life of road pavement. In this study, a high performance glass fiber reinforced asphalt mixture developed in Korea was applied to Cambodia. Prior to field application, Marshall stability tests were performed on glass fiber reinforced asphalt mixtures, SBS modified asphalt mixtures and asphalt mixtures commonly used in Cambodia. The Marshall stability test showed that the glass fiber reinforced asphalt mixture and the SBS modified asphalt mixture had the same strength (about 1.3 times higher strength than the usual asphalt mixture). In addition, the test construction was carried out on the National Highway 2 of Cambodia for the evaluation of the performance of the three mixtures. In the future, the long-term performance evaluation of each mixture will be conducted through follow-up survey of the test construction area.