High Active Co/Mg1-xCex3+O Catalyst: Effects of Metal-Support Promoter Interactions on CO2 Reforming of CH4 Reaction

Co/Mg1−XCe3+XO (x = 0, 0.03, 0.07, 0.15; 1 wt% cobalt each) catalysts for the dry reforming of methane (DRM) reaction were prepared using the co-precipitation method with K2CO3 as precipitant. Characterization of the catalysts was achieved by X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XRF), X-ray photoelectron spectroscopy (XPS), temperature programmed reduction (H2-TPR), Brunauer–Emmett–Teller (BET), transmission electron microscopy (TEM), and thermal gravimetric analysis (TGA). The role of several reactant and catalyst concentrations, and reaction temperatures (700–900 °C) on the catalytic performance of the DRM reaction was measured in a tubular fixed-bed reactor under atmospheric pressure at various CH4/CO2 concentration ratios (1:1 to 2:1). Using X-ray diffraction, a surface area of 19.2 m2.g−1 was exhibited by the Co/Mg0.85Ce3+0.15O catalyst and MgO phase (average crystallite size of 61.4 nm) was detected on the surface of the catalyst. H2 temperature programmed reaction revealed a reduction of CoO particles to metallic Co0 phase. The catalytic stability of the Co/Mg0.85Ce3+0.15O catalyst was achieved for 200 h on-stream at 900 °C for the 1:1 CH4:CO2 ratio with an H2/CO ratio of 1.0 and a CH4, CO2 conversions of 75% and 86%, respectively. In the present study, the conversion of CH4 was improved (75%–84%) when conducting the experiment at a lower flow of oxygen (1.25%). Finally, the deposition of carbon on the spent catalysts was analyzed using TEM and Temperature programmed oxidation-mass spectroscopy (TPO-MS) following 200 h under an oxygen stream. Better anti-coking activity of the reduced catalyst was observed by both, TEM, and TPO-MS analysis. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA   License (https://creativecommons.org/licenses/by-sa/4.0).

How international SME's vicarious learning may improve their performance? The role of absorptive capacity, strength of ties with local SMEs, and their prior success experiences

This study investigates whether inter-firm relationships can raise innovation and overall performance during SME internationalization, focusing on how SMEs learn from firms in transnational markets and the nature of such relationships. It contributes to research by proposing the role of vicarious learning from networked firms in the host country to improve their absorptive capacity (ACAP), innovation, and overall performance. In particular, this study proposes the moderating roles of the strength of ties with and prior success experience of SMEs in the host country market for enhancing international SMEs' vicarious learning to improve their ACAP, innovation, and overall performance. Structural equation modeling was applied to a sample of 163 valid responses received from international SMEs operating in various industrial sectors in Saudi Arabia. The obtained results support the significantly positive role of international SMEs' vicarious learning from local firms in developing their ACAP and enhancing their innovation and overall performance. However, international SMEs must have strong ties with local firms and learn from such firms' prior success experiences to derive these benefits fully

Green HRM practices and corporate sustainability performance

Purpose: The existing literature indicates that the ultimate purpose of green human resource management (GHRM) practices is to enhance sustainable corporate performance by shaping employees’ green behaviors. In this vein, we argue that green organizational culture and employee existing pro-environmental behaviors are the important factors or channels through which GHRM practices shape green employee behaviors for sustainable corporate performance. Consequently, we draw on the ability, motivation, and opportunity (AMO) framework to examine how firms’ GHRM practices indirectly shape employee green behavior for sustainable corporate performance by cultivating and reinforcing green organizational culture under the boundary condition of high employee pro-environmental behavior. Design/methodology/approach: This study uses multi-source, dyadic, and time-lagged data collected from green HR managers and employees in 242 ISO-14001-certified green firms in the Kingdom of Saudi Arabia. The study applies structural equation modeling through LISREL 12 software for testing of hypotheses. Findings: The findings support the postulation that GHRM practices, directly and indirectly, shape employee green behaviors for sustainable performance. GHRM practices indirectly enhance employee green behaviors for sustainable performance by cultivating and fostering the green organizational culture in the presence of high pro-environmental behavior. Practical implications: This study outlines theoretical and practical implications on how HRM managers require an established green organizational culture and employee pro-environmental behaviors to effectively direct GHRM for enhanced sustainable corporate performance. HRM managers should make use of appropriate interventions, including but not limited to GHRM practices, to foster a green organizational culture and employee pro-environmental behaviors. Originality/value: This is an original study that outlines the importance of alignment between Green HRM practices and employee pro-environmental behaviors towards shaping green organizational culture and employee behaviors for corporate sustainability. The study demonstrates how GHRM practices enhance sustainable corporate performance through sequential mediations of green organizational culture and employee green behaviors, and under the boundary condition of pro-environmental behavior

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Load balancing with shadowing effects handover in Li-Fi and RF hybrid network

Light Fidelity (LiFi) uses light emitting diodes (LEOs) for high speed wireless communications. a hybrid network combining light fidelity (Li-Fi) with a radio frequency (RF) wireless fidelity (Wi-Fi) network is considered. An additional tier of very small Li-Fi attocells which utilise the visible light spectrum offers a significant increase in wireless data throughput in an indoor environment while at the same time providing room illumination. Importantly, there is no interference between Li-Fi and Wi-Fi. A Li-Fi attocell covers a significantly smaller area than a Wi- Fi access point (AP). This means that even with moderate user movement a large number of handover between Li-Fi attocells can occur, and this compromises the system throughput. Dynamic load balancing (LB) can mitigate this issue so that quasi-static users are served by Li-Fi attocells while moving users are served by a Wi-Fi AP. However, due to user movement, local overload situations may occur which prevent handover, leading to a lower throughput. LiFi can significantly alleviate the traffic bottlenecks in high density RF scenarios, typically present in an indoor environment. Hence, a combination of LiFi and RF networks becomes a promising candidate for future indoor wireless communications. In a practical indoor scenario, the optical interference from neighbouring LiFi access points (APs) and the blockages of line-of-sight (LoS) optical channels induced by people and objects are the main factors that cause significant optical channel variations. This research studies LB in a hybrid Li-Fi/Wi-Fi network by taking into account user mobility and handover signalling overheadsl, and also Inthis study, the effect of these two factors on the system throughput of a hybrid LiFilRF network is investigated. Furthermore, a dynamic LB scheme is proposed, where the utility function considers system throughput and fairness. In order to better understand the hand over effect on the LB, the service areas of different APs are studied, and the throughput of each AP by employing the proposed LB scheme is analysed. In order to offer a fair comparison, area data rate, which is defined as the system throughput in a unit area, is used for performance evaluation. The simulation shows that there is an optimal distance between two neighbouring LiFi APs to achieve the highest area data rate. In addition, the area data rate increases with the density of blockages when the blockage density is below a certain threshold

Wireless Technologies for Social Distancing in the Time of COVID-19: Literature Review, Open Issues, and Limitations

This research aims to provide a comprehensive background on social distancing as well as effective technologies that can be used to facilitate the social distancing practice. Scenarios of enabling wireless and emerging technologies are presented, which are especially effective in monitoring and keeping distance amongst people. In addition, detailed taxonomy is proposed summarizing the essential elements such as implementation type, scenarios, and technology being used. This research reviews and analyzes existing social distancing studies that focus on employing different kinds of technologies to fight the Coronavirus disease (COVID-19) pandemic. This study main goal is to identify and discuss the issues, challenges, weaknesses and limitations found in the existing models and/or systems to provide a clear understanding of the area. Articles were systematically collected and filtered based on certain criteria and within ten years span. The findings of this study will support future researchers and developers to solve specific issues and challenges, fill research gaps, and improve social distancing systems to fight pandemics similar to COVID-19

A Novel Social Distancing Approach for Limiting the Number of Vehicles in Smart Buildings Using LiFi Hybrid-Network

The coronavirus (COVID-19) has arisen as one of the most severe problems due to its ongoing mutations as well as the absence of a suitable cure for this virus. The virus primarily spreads and replicates itself throughout huge groups of individuals through daily touch, which regretfully can happen in several unanticipated way. As a result, the sole viable attempts to constrain the spread of this new virus are to preserve social distance, perform contact tracing, utilize suitable safety gear, and enforce quarantine measures. In order to control the virus’s proliferation, scientists and officials are considering using several social distancing models to detect possible diseased individuals as well as extremely risky areas to sustain separation and lockdown procedures. However, models and systems in the existing studies heavily depend on the human factor only and reveal serious privacy vulnerabilities. In addition, no social distancing model/technique was found for monitoring, tracking, and scheduling vehicles for smart buildings as a social distancing approach so far. In this study, a new system design that performs real-time monitoring, tracking, and scheduling of vehicles for smart buildings is proposed for the first time named the social distancing approach for limiting the number of vehicles (SDA-LNV). The proposed model employs LiFi technology as a wireless transmission medium for the first time in the social distance (SD) approach. The proposed work is considered as Vehicle-to-infrastructure (V2I) communication. It might aid authorities in counting the volume of likely affected people. In addition, the proposed system design is expected to help reduce the infection rate inside buildings in areas where traditional social distancing techniques are not used or applicable

Analyzing Supply Chain Uncertainty to Deliver Sustainable Operational Performance: Symmetrical and Asymmetrical Modeling Approaches

The purpose of this study is to analyze different types of supply chain uncertainties and suggest strategies to deal with unexpected contingencies to deliver superior operational performance (OP) using symmetrical and asymmetrical modeling approaches. The data were collected through a survey given to 146 supply chain managers within the fast moving consumer goods industry in Thailand. Symmetrical modeling is applied via partial least squares structural equation modeling (PLS-SEM) in order to assess the theoretical relationships among the latent variables, while asymmetrical modeling is applied via fuzzy set qualitative comparative analysis (fsQCA) to emphasize their combinatory causal relation. The empirical results support the theory by highlighting the mediating effect of supply chain strategy (SCS) in the relation between supply chain uncertainty (SCU) and firms’ OP and, hence, deliver business sustainability for the firms, demonstrating that the choice of SCS should not be an “either-or” decision. This research contributes by providing an illustration of a PLS-SEM and fsQCA based estimation for the rapidly emerging field of sustainable supply chain management. This study provides empirical support for resource dependence theory (RDT) in explaining the relation between SCU and SCS, which leads to sustainable OP. From a methodological standpoint, this study also illustrates predictive validation testing of models using holdout samples and testing for causal asymmetry

مستوى هورمون الغدة الجاردرقية بعد زرعها في حالات استئصال الغدة الدرقية المصابة بالسرطان وكذا مستوى الكالسيوم والفوسفور في نفس المرضى

The success of parathyroid autotransplantation was indicated by the postoperative assay of serum parathormone in thirteen out of fourteen patients to whom total thyroidectomy was carried out because of thyroid cancer during the past three years. Four glands were autotransplanted in four patients and froam two to three glamds were trasplanted in the remaineng nime patients. All patients were followed up with daily calcium and phosphate determinations. Patients with low ca"1"1" level and with hypocalcemic manifestations were given oral and i.v. ca^. supplementation. Postoperatively, seven patients developed hypocalcemia (x 5.7 ± 1.12 mg.%) All patients were successively tapered from all supplementation within one to two monthes from thyroidectomy. The parathormone reached the normal value within 45 days. All have a normal level of serum calcium (x 9.4 ± 1.40 mg.%), phoshorus (x 3.6 l±0.93 mg.%) and parathormone (x 0.23 ± 0.04 ng^ml)-من أربعة عشرة حالة استئصال للغدة الدرقية المصابة بالسرطان . تم بنجاح زراعة الغدد الجاردرقية المأخوذة من نفس المرضى في غدد ثلاثة عشرة حالة من المرضى المترددين على معهد الأورام القومي في خلال الثلاث سنوات الماضية . في عدد أربع حالات تم زراعة أربعة غدد جاردوقية ، وفي باقي الحالات تم زراعة من اثنين إلى ثلاث غدد . وتم متابعة جميع الحالات يوميا بقياس مستوى الكالسيوم والفوسفور وتم تعويض المرضى الذين أصابهم نقص في مستوى الكالسيوم ، بإعطائهم حقن كالسيوم أو كالسيوم عن طريق الفم . وفي خلال ٤٥ ‏يوم بعد العملية وصلت نسبة هرمون الباراثورمون في الدم إلى النسبة الطبيعية (0.05‏-0.3نج/مل) . وفي نهاية الشهرين بعد العملية كان متوسط مستوى هرمون الباراثورمون (0.23±0.04نج/مل) والكالسيوم (9.40±‏1.10 مج%) والفوسفور (3.61±0.93 مج%) وهذه كلها نسب طبيعية . ‏وهذا إن دل انما يدل على نجاح عملية الزرع وأن الغدد الجاردرقية المزروعة قد بدأت في أداء وظيفتها