scholarly journals Verification and Optimization of an Ultra-Low Volume (ULV) Sprayer Used for the Inactivation of Indoor Total Bacteria

2021 ◽  
Vol 11 (8) ◽  
pp. 3713
Author(s):  
Yun-Hee Choi ◽  
Da-An Huh ◽  
Ju-Yeon Lee ◽  
Ji Yoon Choi ◽  
Kyong Whan Moon
Keyword(s):  
Cost Effective ◽  
Interactive Effects ◽  
Surface Model ◽  
Chemical Cleaning ◽  
Factors Affecting ◽  
Room Size ◽  
Low Volume ◽  
The Individual ◽  
Physical And Chemical ◽  
Total Bacteria

Physical and chemical cleaning for the removal of indoor microorganisms, which can cause allergic reactions and respiratory diseases, is labor-intensive and time-consuming. An ultra-low volume (ULV) sprayer, a newly introduced device to inactivate pathogenic microorganisms, allows the disinfectant particles to reach hard-to-reach spaces indoors and is more cost-effective than the existing methods. However, few studies have been conducted to verify the efficiency of the ULV sprayer. Here, we verified the disinfection efficiency of the ULV sprayer for inactivating total bacteria present on indoor surfaces, considering the factors affecting bacteria inactivation, and presented the optimal ULV sprayer usage conditions to achieve the highest disinfection efficiency depending on room size. The total bacteria removal efficiency was high (range: 0.56–2.46 log10 reductions), including hard-to-reach spaces. A response surface model was developed to identify the individual and interactive effects of the disinfectant concentration, spray amount, and room size on total bacteria disinfection efficiency. These three variables had interactive effects on the total bacteria disinfection efficiency. The experimental data were fitted to a second-order polynomial model, with high coefficients of determination (R2) for all models (R2 > 0.82). The optimum conditions were a spray amount of 3.08–6.40 L in 160 m3, 3.78–7.22 L in 230 m3, and 5.68–8 L in 300 m3 surface area when using dilution rates of 100 times. These conditions predicted a bacterial disinfection efficiency of >1.10 log10 reductions (92%) on all surfaces. Our results clearly indicate that the ULV sprayer effectively inactivates total bacteria present on indoor surfaces.

scholarly journals Interactive effects between travel behaviour and COVID-19: a questionnaire study

2021 ◽  
Author(s):  
Jinbao Zhang ◽  
Jaeyoung Lee
Keyword(s):  
Early Stage ◽  
Travel Behaviour ◽  
Interactive Effects ◽  
Factors Affecting ◽  
Individual Level ◽  
Passenger Volume ◽  
Spatial Autoregressive ◽  
Railway Passenger ◽  
The Individual ◽  
And Control

Abstract This study has two main objectives: (i) to analyse the effect of travel characteristics on the spreading of disease, and (ii) to determine the effect of COVID-19 on travel behaviour at the individual level. First, the study analyses the effect of passenger volume and the proportions of different modes of travel on the spread of COVID-19 in the early stage. The developed spatial autoregressive model shows that total passenger volume and proportions of air and railway passenger volumes are positively associated with the cumulative confirmed cases. Second, a questionnaire is analysed to determine changes in travel behaviour after COVID-19. The results indicate that the number of total trips considerably decreased. Public transport usage decreased by 20.5%, while private car usage increased by 6.4%. Then the factors affecting the changes in travel behaviour are analysed by logit models. The findings reveal significant factors, including gender, occupation and travel restriction. It is expected that the findings from this study would be helpful for management and control of traffic during a pandemic.

Evaluating Factors Affecting Safety at Highway–Railway Grade Crossings

2005 ◽  
Vol 1918 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Young-Jin Park ◽  
Frank F. Saccomanno
Keyword(s):  
Statistical Models ◽  
Statistical Significance ◽  
Cost Effective ◽  
Interactive Effects ◽  
Factors Affecting ◽  
Explanatory Variables ◽  
Grade Crossings ◽  
Complex Relationships ◽  
Four Quadrant ◽  
The Cost

Various countermeasures can be introduced to reduce collisions at highway–railway grade crossings. Existing improvements to crossings include the installation of flashing lights or gates, the addition of extra warning devices such as four-quadrant barriers or wayside horns, and the enforcement of speed limits on the approaching highway. Statistical models are needed to ensure that countermeasures introduced at a given crossing are both cost-effective and practicable. However, in large part because of issues of colinearity, poor statistical significance, and parametric bias, many existing statistical models are simple in structure and feature few statistically significant explanatory variables. Accordingly, they fail to reflect the full gamut of factor inputs that explain variation in collision frequency at individual crossings over a given period of time. Before statistical models can be used to investigate the cost-effectiveness of specific countermeasures, models must be developed that more fully reflect the complex relationships that link a specific countermeasure to collision occurrence. This study presents a sequential modeling approach based on data mining and statistical methods to estimate the main and interactive effects of introducing countermeasures at individual grade crossings. This paper makes use of Canadian inventory and collision data to illustrate the potential merits of the model in decision support.

scholarly journals The Economical Factors Affecting Residential Property Price: The Case of Penang Island

2015 ◽  
Vol 7 (12) ◽  
pp. 200 ◽  
Author(s):  
Gholamreza Zandi ◽  
Mahadevan A/L Supramaniam ◽  
Ayesha Aslam ◽  
Lai Kin Theng
Keyword(s):  
Housing Price ◽  
Secondary Data ◽  
Interactive Effects ◽  
Factors Affecting ◽  
Service Department ◽  
Property Price ◽  
Ministry Of Finance ◽  
The Individual ◽  
The Relationship ◽  
Main Factor

<p>The main purpose of this study is to investigate the economical factors which are effecting on the residence property price in the specific state of Malaysia called “Penang”. For this research, secondary data were collected from Bank Negara Malaysia, Department of Statistic Malaysia, Ministry of Finance Malaysia and Valuation and Property Service Department. All the economical factors are on a yearly basis from 2007 to 2014. The study was directed to verify the relationship between the economical factors and housing price in Penang. Both the individual effects and the interactive effects are analyzed. According to the analysis and calculations, the main factor Base Lending Rate (BLR) and second most effecting factor Gross Domestic Product (GDP) are the strong Factors which affect the property prices in Penang.</p>

scholarly journals Factors Affecting Macrobenthic Invertebrates Distribution in Badagry Creek, South Western Nigeria

2018 ◽  
pp. 1-11
Author(s):  
O. A. Olapoju ◽  
C. A. Edokpayi
Keyword(s):  
Dissolved Oxygen ◽  
Species Abundance ◽  
Individual Species ◽  
Chemical Parameters ◽  
Factors Affecting ◽  
Physico Chemical ◽  
Significant Difference ◽  
The Individual ◽  
Sand And Gravel ◽  
Physical And Chemical

The aim of the paper is to identify macroinvertebrates distribution in response to induced stressors and physico-chemical parameters of water and sediment. The species composition of macrobenthic invertebrates as well as the physico-chemical characteristics of Badagry creek was investigated monthly. Six sampling stations selected based on different levels of human activities along the creeks stretch and samples were collected monthly from September 2006 to February 2007. The fluctuations of some of the physical and chemical parameters such as pH, dissolved oxygen, BOD and total organic carbon appeared to have been influenced by activities along the study stretch. Analysis of variance (ANOVA)  for all parameters showed no significant differences (P > 0.05) in the parameters but  Post hoc tests analysis using Duncan showed that there was a significant difference (P = 0.05) in the mean total of some of the parameters. pH, clay, sand and gravel were significantly correlated with other parameters while canonical correspondence analysis (CCA) model showed that the environmental variables correlated with significant part of the variations in the individual species abundance and it revealed that dominant species were found to be significantly correlated with dissolved oxygen, total dissolved solids, sand and pH.

scholarly journals A novel method for production of peroxidase enzyme from garden radish root source using a spouted bed reactor modeling and optimization approach

2021 ◽  
Author(s):  
Shahrbanoo Hamedi ◽  
M. Mehdi Afsahi ◽  
Ali Riahi-Madvar
Keyword(s):  
Kinetic Parameters ◽  
Cost Effective ◽  
Industrial Applications ◽  
Interactive Effects ◽  
Root Extract ◽  
Optimization Approach ◽  
Spouted Bed ◽  
Radish Root ◽  
Peroxidase Enzyme ◽  
The Individual

Abstract The main advantages of the dried enzymes are the lower cost of storage and longer time of preservation for industrial applications. In this study for the first time, the spouted bed reactors were utilized for drying the garden radish (Raphanus sativus L.) root extract as a cost-effective source of the peroxidase enzyme. The response surface methodology (RSM) was used to evaluate the individual and interactive effects of main parameters (the inlet air temperature (T) and the air flow rate (Q)) on the residual enzyme activity (REA). The maximum REA of 38.7% was obtained at the T= 50 °C and Q= 1.4. In order to investigate the drying effect on the catalytic activity, the optimum reaction conditions (pH and temperature), as well as kinetic parameters, were investigated for the fresh and dried enzyme extracts (FEE and DEE). The obtained results showed that optimum pH was decreased about 12.3% while 85.7% increase was observed in optimum temperature of DEE compare to FEE. Moreover, kinetic parameters, thermal-stability, and shelf life of the enzyme were considerably improved after drying by the spouted bed. Overall, the results confirmed that a spouted bed reactor can be used as a promising method for drying heat-sensitive materials such as peroxidase enzyme.

scholarly journals Factors Affecting the Lut Desert Tourism in Iran: Developing an Interpretive-Structural Model

2021 ◽  
Vol 13 (13) ◽  
pp. 7245
Author(s):  
Beniamino Murgante ◽  
Mohammad Eskandari Sani ◽  
Sara Pishgahi ◽  
Moslem Zarghamfard ◽  
Fatemeh Kahaki
Keyword(s):  
Sampling Method ◽  
Structural Model ◽  
Tourism Development ◽  
Cost Effective ◽  
Structural Modeling ◽  
Interpretive Structural Modeling ◽  
Factors Affecting ◽  
Purposive Sampling ◽  
Interpretive Structural Model ◽  
Lut Desert

The Lut desert is one of the largest and most attractive deserts in Iran. The value of desert tourism remains unclear for Iran’s economy and has only recently been taken into consideration by the authorities, although its true national and international value remains unclear. This study was aimed at investigating the factors that influence tourism development in the Lut desert. Data collected through the purposive sampling method was analyzed using Interpretive Structural Modeling and the MICMAC Analysis. According to the results, cost-effective travel expenses, security, and safety provided in the desert, together with appropriate media advertising and illustration of the Lut desert (branding) are the leading factors that influence tourism in the Lut desert in Iran. This paper highlighted the importance of desert tourism, especially in this region.

scholarly journals Physical and chemical imaging of adhesive interfaces with soft X-rays

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Hiroyuki Yamane ◽  
Masaki Oura ◽  
Osamu Takahashi ◽  
Tomoko Ishihara ◽  
Noriko Yamazaki ◽  
...  
Keyword(s):  
Molecular Level ◽  
Covalent Bond ◽  
Chemical Imaging ◽  
Diglycidyl Ether ◽  
X Rays ◽  
X Ray ◽  
Covalent Bond Formation ◽  
Chemical States ◽  
The Individual ◽  
Physical And Chemical

AbstractAdhesion is an interfacial phenomenon that is critical for assembling carbon structural composites for next-generation aircraft and automobiles. However, there is limited understanding of adhesion on the molecular level because of the difficulty in revealing the individual bonding factors. Here, using soft X-ray spectromicroscopy we show the physical and chemical states of an adhesive interface composed of a thermosetting polymer of 4,4’-diaminodiphenylsulfone-cured bisphenol A diglycidyl ether adhered to a thermoplastic polymer of plasma-treated polyetheretherketone. We observe multiscale phenomena in the adhesion mechanisms, including sub-mm complex interface structure, sub-μm distribution of the functional groups, and molecular-level covalent-bond formation. These results provide a benchmark for further research to examine how physical and chemical states correlate with adhesion, and demonstrate that soft X-ray imaging is a promising approach for visualizing the physical and chemical states at adhesive interfaces from the sub-mm level to the molecular level.

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