scholarly journals Evaluation of the Bioaerosol Inactivation Ability of Chitosan-Coated Antimicrobial Filters

2021 ◽  
Vol 18 (13) ◽  
pp. 7183
Author(s):  
Ying-Fang Hsu ◽  
Chi-Yu Chuang ◽  
Shinhao Yang
Keyword(s):  
Relative Humidity ◽  
Negative Influence ◽  
Positive Influence ◽  
E Coli ◽  
Air Cleaning ◽  
Fibrous Filters ◽  
Cleaning Device ◽  
The Face ◽  
Face Velocity ◽  
Experimental Findings

This work considers the enhancement of indoor bioaerosol removal efficiency by liquid coating of the antimicrobial agent chitosan onto polypropylene fibrous filters (CCFs). Escherichia coli (E. coli) and Bacillus subtilis (B. subtilis) were chosen as the tested bioaerosols. The results revealed that 2.5% (w/w) of CCFs have significantly higher bioaerosol survival capability (23% and 34% of E. coli and B. subtilis, respectively), compared to an untreated filter (65% and 64% for E. coli and B. subtilis, respectively). Increasing face velocity and relative humidity during operating CCFs could reduce the bioaerosol removal capability. The regression analysis of the experimental findings demonstrated that the higher coating concentration of chitosan had the most positive influence on bioaerosol removal, while the face velocity and relative humidity had a negative influence, but a milder effect was observed (R2 = 0.83 and 0.81 for E. coli and B. subtilis bioaerosols, respectively). A CCF-loaded air-cleaning device was tested in a real indoor environment and resulted in 80.1% bioaerosol removal within 3 h of operating, which suggests that the chitosan-coated filter has the potential for further application in improving indoor air quality in the future.

Removal Virus Bioaerosols by Filters Pretreated with Chitosan/Surfactant

2011 ◽  
Vol 214 ◽  
pp. 163-167
Author(s):  
Yi Chin Huang ◽  
Shin Hao Yang ◽  
Chin Hsiang Luo
Keyword(s):  
Relative Humidity ◽  
Sodium Dodecyl Sulfate ◽  
Sodium Dodecyl ◽  
Chitosan Solution ◽  
Fibrous Filter ◽  
Inactivation Mechanism ◽  
The Face ◽  
Face Velocity ◽  
Experimental Findings ◽  
Inactivation Effect

This work considers the effects of using the chitosan/sodium dodecyl sulfate (SDS) pretreated filters (CSPFs) as the antiseptic filters on the bioaerosol penetration. Three concentrations of chitosan solutions and chitosan/SDS mixing solutions were used to pretreat the polypropylene fibrous filter to make them antiseptic. The λ virus bioaerosol was generated using a Collison nebulizer, as the challenged bioaerosol. The effects of various factors, including the face velocity and the relative humidity on the bioaerosol collection characteristics were evaluated. Experimental results suggested the pretreatment of chitosan/SDS did have an antiseptic effect on virus bioaerosol and increase the inactivation mechanism. Experimental findings also revealed that the addition pretreatment of SDS did raise the inactivation effect of the chitosan. When adding SDS in the chitosan solution, the ammonium groups could appear and present the antiseptic benefit more obviously. Moreover, the antiseptic of the pretreated filter decreased with face velocity and RH.

scholarly journals Analysis of Environmental Factors’ Impact on Donkeys’ Colostrum Quality

2018 ◽  
Author(s):  
Zamfir Marchiș ◽  
Antonia Odagiu ◽  
Aurelia Coroian ◽  
Ioan Oroian ◽  
Manuela Mîrza ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Environmental Factors ◽  
Protein Content ◽  
Wind Velocity ◽  
Experimental Period ◽  
Negative Influence ◽  
Positive Influence ◽  
Human Colostrum ◽  
Positive Correlations ◽  
Complex Influence

Colostrum is a natural product, issued by both mammals and humans in first week of lactation. Among different species, donkey colostrum is considered as having, besides a valuable composition in nutrients and immune factors, an outstanding similitude with human colostrum. In this context, and taking into account the scarcity of available data concerning the interaction between climate factors and colostrum quality, a trial was conducted aiming to identify the possible influence of environmental factors on donkey colostrum nutritional traits. A stock of 16 jennies from 2 farms located in the County of Cluj, during a 7 days postpartum period was analyzed. During experimental period the daily temperature, humidity, and wind velocity data were collected. Strong positive correlations may be reported between fat and lactose, and fat and protein respectively, while moderate to strong correlation is emphasized between lactose and protein content of donkey colostrum. Testing the influence of environmental temperature, relative humidity, and wind velocity influence upon nutritional content of donkey colostrum, results the neglectable influence of the wind velocity, the negative influence of the heat stress upon all studied colostrum components, and complex influence of relative humidity, which has positive influence on fat and lactose increase when it increases, while its increase has negative influence on protein content of donkey colostrum.

Does Diversity in The Boardroom Add Value to a Firm?

2018 ◽  
Vol 18 (5) ◽  
Keyword(s):  
Firm Performance ◽  
Panel Data ◽  
Firm Size ◽  
Significant Influence ◽  
Negative Influence ◽  
Positive Influence ◽  
Future Research ◽  
Board Composition ◽  
Board Diversity

This study examines whether board diversity affects firm performance. We investigate this study using panel data of a sample of S&P 500 firms during a 12 year period. After controlling for industry, firm size, and other board composition variables, we find that all three board diversity variables of interest – gender, ethnicity, and age have a significant influence on firm performance. While ethnicity and age have a positive influence on firm performance, it was found that gender has a negative influence. Implications for future research are discussed.

scholarly journals Concerns or Desires Post-Pandemic: An Extended MGB Model for Understanding South Korean Residents’ Perceptions and Intentions to Travel to China

2021 ◽  
Vol 18 (5) ◽  
pp. 2542
Author(s):  
Guanghui Qiao ◽  
Xiao-li Zhao ◽  
Luqi Xin ◽  
Seokchool Kim
Keyword(s):  
Mass Media ◽  
Latent Variables ◽  
Structural Equation ◽  
Mainland China ◽  
Negative Influence ◽  
Positive Influence ◽  
Extended Model ◽  
South Korean ◽  
Structural Relationships ◽  
China Post

In this study, we examined South Korean residents’ travel-related behavioural intention for mainland China post-COVID-19 using an extended model of goal-directed behaviour. To do so, we integrated South Korean residents’ perceptions of country image (PCI), mass media, and concerns about travel into the framework of the original model of goal-directed behaviour (MGB). Structural equation modelling was used to identify the structural relationships among the latent variables. The results show that mass media had a positive influence on South Korean residents’ perception of China’s image, a negative influence on residents’ concerns, and a positive influence on residents’ behavioural intentions for travel overseas. Meanwhile, PCI had a positive influence on residents’ attitude towards travel overseas. The theoretical and practical implications of the study are discussed.

scholarly journals Exposure Assessment of Airborne Bacteria Emitted from Swine Manure Composting Plant

Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1283
Author(s):  
Ki-Youn Kim
Keyword(s):  
Relative Humidity ◽  
Environmental Factors ◽  
Swine Manure ◽  
Airborne Bacteria ◽  
Particulate Matters ◽  
Distribution Characteristics ◽  
E Coli ◽  
Enterococcus Spp ◽  
Staphylococcus Spp ◽  
Rotary Type

This study was performed to investigate the distribution characteristics of airborne bacteria emitted from swine manure composting plants. The types of swine manure composting plants selected for the survey in this study were as follows: screw type, rotary type, and natural dry type. Mean levels of airborne bacteria in swine manure composting plants were 7428 (±1024) CFU m−3 for the screw type, 3246 (±1407) CFU m−3 for the rotary type, and 5232 (±1217) CFU m−3 for the natural dry type, respectively. Based on the results obtained from this study, the swine manure composting plant operated by screw type showed the highest concentration of airborne bacteria, followed by the natural dry type and rotary type. The monthly concentration of airborne bacteria was the highest in August and the lowest in November, regardless of the type of swine manure composting plant. The respirable size of airborne bacteria accounted for about 50% of the total. The ratio of respirable to the total quantity of airborne bacteria was 50%. The correlation relationships between airborne bacteria and environmental factors (temperature, relative humidity, particulate matters, and odor) were not found to be significant in the swine manure composting plants. The predominant genera of airborne bacteria identified were Micrococcus spp., Staphylococcus spp., Escherichia(E-coli) spp., Enterococcus spp., and Enterobacteriaceae spp.

scholarly journals Filling the void of family leadership: institutional support to business model changes in the Italian Industry 4.0 experience

2021 ◽  
Author(s):  
Marco Cucculelli ◽  
Ivano Dileo ◽  
Marco Pini
Keyword(s):  
Business Model ◽  
Industry 4.0 ◽  
Manufacturing Industry ◽  
Business Models ◽  
Institutional Support ◽  
Negative Influence ◽  
Positive Influence ◽  
External Support ◽  
Family Management ◽  
Family Leadership

AbstractWe examine whether the probability of innovating a company’s business model towards the Industry 4.0 paradigm is affected by external institutional support and family leadership. Industry 4.0 is the information-intensive transformation of global manufacturing enabled by Internet technologies aimed at reinventing products and services from design and engineering to manufacturing. Using a sample of 3000 firms from a corporate survey on the manufacturing industry in Italy, our results showed that family leadership has a significant positive influence on the adoption of Industry 4.0 business models, but only in terms of family ownership. By contrast, family management has a negative influence on the probability of adopting a new business model. However, this negative influence is almost totally offset by the presence of the Triple Helix, i.e. the external support by public institutions and universities, which counterbalances the lower propensity of family managers to adopt Industry 4.0 business models. This supporting role only occurs when institutions and universities act together.

An experimental study of the influence of riblets on transition

1996 ◽  
Vol 315 ◽  
pp. 31-49 ◽  
Author(s):  
G. R. Grek ◽  
V. V. Kozlov ◽  
S. V. Titarenko
Keyword(s):  
Experimental Study ◽  
Three Dimensional ◽  
Negative Influence ◽  
Positive Influence ◽  
Linear Stage ◽  
Turbulent Transition ◽  
Transition Structures ◽  
Stage Transition ◽  
Tollmien Schlichting ◽  
Laminar Turbulent Transition

An experimental study of the effect of riblets on three-dimensional nonlinear structures, the so-called Λ-vortices on laminar-turbulent transition showed that riblets delay the transformation of the Λ-vortices into turbulent spots and shift the point of transition downstream. This result is opposite to the negative influence of such ribbed surfaces on two-dimensional linear Tollmien-Schlichting waves (the linear stage of transition). Thus, the ribbed surface influences laminar-turbulent transition structures differently: a negative influence on the linear-stage transition structures and a positive influence on the nonlinear-stage transition structures. It is demonstrated that transition control by means of riblets requires special attention to be paid to the choice of their location, taking into account the stage of transition.

scholarly journals Lagged Ensembles, Forecast Configuration, and Seasonal Predictions

2013 ◽  
Vol 141 (10) ◽  
pp. 3477-3497 ◽  
Author(s):  
Mingyue Chen ◽  
Wanqiu Wang ◽  
Arun Kumar
Keyword(s):  
Lead Time ◽  
Geographical Location ◽  
Seasonal Prediction ◽  
Skill Score ◽  
Negative Influence ◽  
Positive Influence ◽  
Prediction Skill ◽  
Ensemble Size ◽  
Seasonal Forecasts ◽  
Ensemble Forecasts

Abstract An analysis of lagged ensemble seasonal forecasts from the National Centers for Environmental Prediction (NCEP) Climate Forecast System, version 2 (CFSv2), is presented. The focus of the analysis is on the construction of lagged ensemble forecasts with increasing lead time (thus allowing use of larger ensemble sizes) and its influence on seasonal prediction skill. Predictions of seasonal means of sea surface temperature (SST), 200-hPa height (z200), precipitation, and 2-m air temperature (T2m) over land are analyzed. Measures of prediction skill include deterministic (anomaly correlation and mean square error) and probabilistic [rank probability skill score (RPSS)]. The results show that for a fixed lead time, and as one would expect, the skill of seasonal forecast improves as the ensemble size increases, while for a fixed ensemble size the forecast skill decreases as the lead time becomes longer. However, when a forecast is based on a lagged ensemble, there exists an optimal lagged ensemble time (OLET) when positive influence of increasing ensemble size and negative influence due to an increasing lead time result in a maximum in seasonal prediction skill. The OLET is shown to depend on the geographical location and variable. For precipitation and T2m, OLET is relatively longer and skill gain is larger than that for SST and tropical z200. OLET is also dependent on the skill measure with RPSS having the longest OLET. Results of this analysis will be useful in providing guidelines on the design and understanding relative merits for different configuration of seasonal prediction systems.

Performance risk factors in SME strategic planning

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Keyword(s):  
Strategic Planning ◽  
Financial Performance ◽  
Emerging Market ◽  
Negative Influence ◽  
Positive Influence ◽  
Content Type ◽  
Political Ties ◽  
Pertinent Information ◽  
Internal Stakeholders ◽  
Business Ties

Purpose This paper aims to review the latest management developments across the globe and pinpoint practical implications from cutting-edge research and case studies. Design/methodology/approach This briefing is prepared by an independent writer who adds their own impartial comments and places the articles in context. Findings This research paper concentrates on the links between SME financial performance, business ties, and political ties. Business ties were revealed to be the fundamental microfoundations of formal strategic planning (FSP), by significantly boosting firms' financial performance. However, political ties were revealed to be something to avoid, in emerging market like Turkey, due to their distracting negative influence of firm performance. SMEs can overcome some of the disadvantages of their size by involving positive influence external parties in strategic work, to support internal stakeholders. Originality/value The briefing saves busy executives, strategists and researchers hours of reading time by selecting only the very best, most pertinent information and presenting it in a condensed and easy-to-digest format.

Changes in Aerobic Plate and Escherichia coli–Coliform Counts and in Populations of Inoculated Foodborne Pathogens on Inshell Walnuts during Storage

2016 ◽  
Vol 79 (7) ◽  
pp. 1143-1153 ◽  
Author(s):  
JOHN C. FRELKA ◽  
GORDON R. DAVIDSON ◽  
LINDA J. HARRIS
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Relative Humidity ◽  
Low Temperature ◽  
Foodborne Pathogens ◽  
Limit Of Detection ◽  
Sampling Time ◽  
E Coli ◽  
Plate Counts ◽  
Forced Air

ABSTRACT After harvest, inshell walnuts are dried using low-temperature forced air and are then stored in bins or silos for up to 1 year. To better understand the survival of bacteria on inshell walnuts, aerobic plate counts (APCs) and Escherichia coli–coliform counts (ECCs) were evaluated during commercial storage (10 to 12°C and 63 to 65% relative humidity) over 9 months. APCs decreased by 1.4 to 2.0 log CFU per nut during the first 5 months of storage, and ECCs decreased by 1.3 to 2.2 log CFU per nut in the first month of storage. Through the remaining 4 to 8 months of storage, APCs and ECCs remained unchanged (P > 0.05) or decreased by <0.15 log CFU per nut per month. Similar trends were observed on kernels extracted from the inshell walnuts. APCs and ECCs were consistently and often significantly higher on kernels extracted from visibly broken inshell walnuts than on kernels extracted from visibly intact inshell walnuts. Parameters measured in this study were used to determine the survival of five-strain cocktails of E. coli O157:H7, Listeria monocytogenes, and Salmonella inoculated onto freshly hulled inshell walnuts (~8 log CFU/g) after simulated commercial drying (10 to 12 h; 40°C) and simulated commercial storage (12 months at 10°C and 65% relative humidity). Populations declined by 2.86, 5.01, and 4.40 log CFU per nut for E. coli O157:H7, L. monocytogenes, and Salmonella, respectively, after drying and during the first 8 days of storage. Salmonella populations changed at a rate of −0.33 log CFU per nut per month between days 8 and 360, to final levels of 2.83 ± 0.79 log CFU per nut. E. coli and L. monocytogenes populations changed by −0.17 log CFU per nut per month and −0.26 log CFU per nut per month between days 8 and 360, respectively. For some samples, E. coli or L. monocytogenes populations were below the limit of detection by plating (0.60 log CFU per nut) by day 183 or 148, respectively; at least one of the six samples was positive at each subsequent sampling time by either plating or by enrichment.

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