This paper considers locating congested fast charging stations (FCSs) and deploying chargers in a stochastic environment, while the related studies have predominantly focused on…
Abstract
This paper considers locating congested fast charging stations (FCSs) and deploying chargers in a stochastic environment, while the related studies have predominantly focused on problems in deterministic environments. Reducing the inconvenience caused by congestion at FCSs is an important challenge for FCS service provider. This is the underlying motivation for this study to consider a problem for FCS network design with the congestion restriction in a stochastic environment. We proposed a maximal coverage problem subject to budget constraints and a congestion restriction in order to maximize the demand coverage. With the derivation of the congestion restriction in the considered stochastic environment, the problem is formulated into an integer programming model. A real-life case study is conducted and managerial implications are drawn from its results.
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Xudong He, GuangYi Yang, E. Yang, Moli Zhang, Dan Luo, Jingjian Liu, Chongnan Zhao, Qinhua Chen and Fengying Ran
Based on DNase I and reduced graphene oxide (rGO)-magnetic silicon microspheres (MNPS), a highly sensitive and selective fluorescent probe for the detection of PD-L1 was developed.
Abstract
Purpose
Based on DNase I and reduced graphene oxide (rGO)-magnetic silicon microspheres (MNPS), a highly sensitive and selective fluorescent probe for the detection of PD-L1 was developed.
Design/methodology/approach
Here °C we present a feasibility of biosensor to detection of PD-L1 in lung tumors plasma. In the absence of PD-L1°C the PD-L1 aptamer is absorbed on the surface of graphene oxide modified magnetic nanoparticles °8rGO-MNPS°9 and leading to effective fluorescence quenching. Upon adding PD-L1°C the aptamer sequences could be specifically recognized by PD-L1 and the aptamer/PD-L1 complex is formed°C resulting in the recovery of quenched fluorescence.
Findings
This sensor can detect PD-L1 with a linear range from 100 pg mL−1 to 100 ng mL−1, and a detection limit of 10 pg•m−1 was achieved.
Originality/value
This method provides an easy and sensitive method for the detection of PD-L1 and will be beneficial to the early diagnosis and prognosis of tumors.
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Jing Bill Xu, Pimtong Tavitiyaman, Xinyan Zhang and Mingfang Zhu
This paper aims to explore students’ work-integrated learning experience. Particularly, students’ application of knowledge and improvement of multiple skills in work-integrated…
Abstract
Purpose
This paper aims to explore students’ work-integrated learning experience. Particularly, students’ application of knowledge and improvement of multiple skills in work-integrated learning, their influence on positive industry image change due to the COVID-19 pandemic, and students’ desired career prospect were explored.
Design/methodology/approach
A questionnaire survey with valid responses from 168 undergraduate students in hospitality and tourism management was conducted in four colleges/universities in Guangdong, China in 2021. PLS-SEM method was used to analyze the data.
Findings
It was found that students’ multiple skills had improved through application of knowledge in work-integrated learning. Skill improvement helped form positive industry image change and shape future career prospect. However, such positive industry image change did not impact students’ career prospect directly.
Originality/value
Today, work-integrated learning has become one of the most valuable opportunities for students in hospitality and tourism management to gain industry experience. However, recent literature has largely examined the negative impacts of COVID-19, whereas few studies have examined the positive aspects of work-integrated learning.
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Dimitrios Buhalis, Xi Yu Leung, Daisy Fan, Simon Darcy, Ganghua Chen, Feifei Xu, Garry Wei-Han Tan, Robin Nunkoo and Anna Farmaki
Kanza Abid, Zafar Iqbal Shams, Muhammad Suleman Tahir and Arif Zubair
The presence of heavy metals in milk causes many acute and chronic physiological dysfunctions in human organs. The present study aims to investigate the heavy metals in cow's and…
Abstract
Purpose
The presence of heavy metals in milk causes many acute and chronic physiological dysfunctions in human organs. The present study aims to investigate the heavy metals in cow's and buffalo's milk of two major cities, Karachi and Gujranwala, Pakistan to estimate metal intake by humans from this source.
Design/methodology/approach
In total, 48 milk samples from 2 cities were drawn from animals' udder to avoid contamination. Each sample was digested with nitric acid at 105 oC (degree Celsius) on a pre-heated electric hot plate to investigate the metals by atomic absorption spectroscopy (flame type). Air-acetylene technique analyzed chromium, cadmium and lead, and the hydride method analyzed arsenic in the milk samples.
Findings
The results revealed the highest mean lead concentration (19.65 ± 43.86 ppb) in the milk samples, followed by chromium (2.10 ± 2.33 ppb) and arsenic (0.48 ± 0.73 ppb). Cadmium was not detected in any sample, assuming cadmium's occurrence was below the detection level. The concentrations of all the metals in the samples of the two cities do not differ statistically. Lead concentrations in the buffalo's milk were higher than in cow's milk (p < 0.05). However, the concentrations of arsenic and chromium between buffalo's and cow's milk do not differ statistically. The present study reveals a lower level of metals in the milk than those conducted elsewhere. The mean concentrations of all the metals met the World Health Organization's (WHO) safety guidelines (1993).
Research limitations/implications
Although cadmium causes toxicity in the human body, cadmium could not be measured because cadmium's concentration was below the detection level, which is 1 ppb.
Practical implications
This study will help reduce the toxic metals in our environment, and the sources of heavy metals, particularly from the industrial sector could be identified. The feed and water consumed by the milking animals could be carefully used for feeding them.
Social implications
This study will help reduce the diseases and malfunction of human organs and organ systems since these heavy metals cause toxicity and carcinogenicity in humans. Arsenic and chromium cause cancer while lead causes encephalopathy (a brain disease).
Originality/value
The study reports heavy metal concentrations in the two attributes of four independent variables of raw milk samples that were scarcely reported from Pakistan.