54 research outputs found

    An AHP Framework to Evaluate Barriers and Potential Tensions to Green Supply Chain Management in the Food and Beverage Industry

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    With an increasing awareness of climate change and the need for sustainable processes, a growing number of studies have addressed green supply chain management (GSCM), its drivers, barriers, and implementation frameworks. However, despite the importance of environmental practices, industries are reluctant to implement GSCM activities, as many obstacles can arise while initiating GSCM in traditional supply chain management (TSCM). The previous literature review indicated substantial research on the barriers that hinder the adoption of green activities. To the best of our knowledge, no previous research has assessed the tensions and conflicts that may arise among collaborating actors, which can also hinder the adoption of environmental business practices. In particular, there is a notable gap in research that investigates the green- supply-chain issues in the Egyptian food and beverage manufacturing sector. In this paper, we went a step ahead to investigate these issues and to explore how GSCM barriers cause tensions among collaborating actors. Hence, the purpose of this paper is to investigate the barriers and tensions that impede the implementation of GSCM in the Egyptian food and beverage industry (FBI).  In our methodology, we targeted three large food and beverage multinational companies located in Egypt. Barriers and types of tensions were identified through the literature review. Data collection consisted of three phases. For the primary source of data, a qualitative method was utilized for semi-structured interviews, followed by a questionnaire survey. Furthermore, a decision group was formed to collect and validate the data. Using the analytic hierarchy process (AHP), this study categorised the identified barriers based on the relevant type of tension and explored how such barriers can create tension among various stakeholders. Thirty-nine barriers and 11 types of tension were identified through the literature review and discussion with experts. Of the total number of identified barriers, 18 were identified as common. Based on the AHP results, the category of economic tensions had the most importance. The barrier related to inflation and the currency exchange rate was the most significant among the 18 barriers and was the main driver of economic tensions. Our findings suggest that the economic instability of countries can affect the implementation of GSCM.  This is the first study that combines barriers and tensions among stakeholders as impediments toward adopting green environmental practices. This study provides a new approach to the literature, giving insight into the tensions that could delay or prevent the adoption of green business activities, an approach that could be a scientific breakthrough for upcoming studies. Finally, this study can help the Egyptian FBI to identify the main issues that could hinder the transition from TSCM to GSCM. Keywords: Green supply chain management; analytical hierarchy process; barrier analysis; tensions; food and beverage industry DOI: 10.7176/EJBM/13-6-01 Publication date:March 31st 202

    Controlling the Microstructure and Properties of Titanium Dioxide for Efficient Solar Cells

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    In this chapter, we review the controlling of the microstructures, the properties, and the different methods to obtain titanium dioxide and the application of these materials on solar cells. We will concentrate on the application of efficient solar cells including dye-sensitized solar cells (DSSCs). In the first section, we provide a background on energy, including its sources—photovoltaics and titanium dioxide—and the advantages of their application in solar cells. The second section outlines the different methods to obtain TiO2 nanoparticles. The shapes of titanium dioxide are explored in the third section. In the fourth section, we discuss the use and effect of the titanium dioxide in the efficient dye-sensitized solar cells, and the last section is a summary of the current state of the art and perspectives of titanium dioxide for efficient solar cells

    Mitigating the Bullwhip Effect and Enhancing Supply Chain Performance through Demand Information Sharing: An ARENA Simulation Study

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    The supply chain is a network of organizations that collaborate and leverage their resources to deliver products or services to end-customers. In today's globalized and competitive market, organizations must specialize and form partnerships to gain a competitive edge. To thrive in their respective industries, organizations need to prioritize supply chain coordination, as it is integral to their business processes.   Supply chain management focuses on the collaboration of organizations within the supply chain. However, when each echelon member optimizes their goals without considering the network's impact, it leads to suboptimal performance and inefficiencies. This phenomenon is known as the Bullwhip effect, where order variability increases as it moves upstream in the supply chain. The lack of coordination, unincorporated material and information flows, and absence of ordering rules contribute to poor supply chain dynamics. To improve supply chain performance, it is crucial to align organizational activities. Previous research has proposed solutions to mitigate the Bullwhip effect, which has been a topic of intense study for many decades. This research aims to investigate the causes and mitigations of the Bullwhip effect based on existing research. Additionally, the paper utilizes ARENA simulation to examine the impact of sharing end-customer demand information. As far as we are aware, no study has been conducted to deeply simulate the bullwhip effect using the ARENA simulation. Previous studies have investigated this phenomenon, but without delving into its intricacies. The simulation results offer potential strategies to mitigate the Bullwhip effect through demand information sharing. Keywords: Supply Chain Management, Bullwhip effect, Inventory management, ARENA simulation, Information sharing, forecasting technique, Demand variability. DOI: 10.7176/JESD/14-14-07 Publication date:August 31st 202

    Silver-Doped Cadmium Selenide/Graphene Oxide-Filled Cellulose Acetate Nanocomposites for Photocatalytic Degradation of Malachite Green toward Wastewater Treatment

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    Silver-doped cadmium selenide/graphene oxide (GO) (Ag-CdSe/GO) nanocomposites have been synthesized, loaded in cellulose acetate (CA) to form Ag-CdSe/GO@CA heterostructure nanofibers, and characterized in terms of structural, morphological, photocatalytic properties, among others. The photocatalytic degradation of malachite green (MG) was estimated using cadmium selenide-filled CA (CdSe@CA), silver-doped cadmium selenide-filled CA (Ag-CdSe@CA), cadmium selenide/GO-filled CA (CdSe/GO@CA), and silver-doped cadmium selenide/GO-filled CA (Ag-CdSe/GO@CA) nanocomposite materials. The Ag-CdSe/GO@CA nanocomposites exhibit and retain an enhanced photocatalytic activity for the degradation of MG dye. This amended performance is associated with the multifunctional supporting impacts of GO, Ag, and CA on the composite structure and properties. The superior photocatalytic activity is related to the fact that both Ag and GO can act as electron acceptors that boost the separation efficiency of photogenerated carriers and the loading of the combined nanocomposite (Ag-CdSe@GO) on CA nanofibers, which can augment the adsorption of electrons and holes and facilitate the movement of carriers. The stability of Ag-CdSe/GO@CA nanocomposite photocatalysts demonstrates suitable results even after five recycles. This study establishes an advanced semiconductor-based hybrid nanocomposite material for efficient photocatalytic degradation of organic dyes.The Academy of Scientific Research and Technology (ASRT), Egypt, Grant No. 6510, supported this project financially

    CO2 concentration measurements inside expansion-compression engine under high EGR conditions using an infrared absorption method

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    The purpose of this study is to measure the high concentrations of CO2 near a spark plug inside an internal combustion engine, and an infrared absorption method is used for the measurement. The spark plug sensor was adapted to a compression-expansion machine, and the CO2 concentration near the spark plug was measured by adding a gas mixture, including CO2 to imitate EGR. Next, the EGR ratio was changed from 10 to 40%, and the CO2 concentration was measured. The effect of the CO2 on the flame propagation was investigated by visualizing the bottom view of the compression-expansion machine. The measurements of CO2 mass concentration are in agreement with those predicted by direct-absorption spectroscopy fundamental theory from the crank angle −60 to −15 deg ATDC. The error was less than 20%, and under the conditions with an EGR ratio of 20–40%.The purpose of this study is to measure the high concentrations of CO2 near a spark plug inside an internal combustion engine, and an infrared absorption method is used for the measurement. The spark..

    Pathways Towards High-Stable, Low-Cost and Efficient Perovskite Solar Cells

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    The power conversion efficiencies (PCEs) of perovskite solar cells (PSCs) have been reached the initial value when they emerged as dye sensitized solar cell (DSSC) in 2012. Immediately, the interests were drawn in this field worldwide. The researchers have improved the efficiency of PSCs up-to 22%, which was originally started from its initial value of 3.8%, just in 7 years. The rendering of long‐term stabilization and effective cost have special importance for PSCs since the instability issue remained idle in spite of those recently increased efficiency values attained by various research groups. In this way, the better improvements of PSC may increase extraordinary exhibitions as compared to alternate solar cells like organic solar cell (OSC) or DSSC devices. This chapter begins with a general discussion on the requirement for an economical clean energy conversion device. In section 2, fundamental properties of PSC are fit together with their device architecture and working mechanism. In section 3 proceeds with a review on fundamental photovoltaic parameters joined by current-voltage hysteresis. Furthermore, the stability and cost issues will be discussed in Sections 4 and 5. In the end of this chapter, we are discussing the challenges and opportunities based on the chapter content

    Azides in the Synthesis of Various Heterocycles

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    In this review, we focus on some interesting and recent examples of various applications of organic azides such as their intermolecular or intramolecular, under thermal, catalyzed, or noncatalyzed reaction conditions. The aforementioned reactions in the aim to prepare basic five-, six-, organometallic heterocyclic-membered systems and/or their fused analogs. This review article also provides a report on the developed methods describing the synthesis of various heterocycles from organic azides, especially those reported in recent papers (till 2020). At the outset, this review groups the synthetic methods of organic azides into different categories. Secondly, the review deals with the functionality of the azido group in chemical reactions. This is followed by a major section on the following: (1) the synthetic tools of various heterocycles from the corresponding organic azides by one-pot domino reaction; (2) the utility of the chosen catalysts in the chemoselectivity favoring C−H and C-N bonds; (3) one-pot procedures (i.e., Ugi four-component reaction); (4) nucleophilic addition, such as Aza-Michael addition; (5) cycloaddition reactions, such as [3+2] cycloaddition; (6) mixed addition/cyclization/oxygen; and (7) insertion reaction of C-H amination. The review also includes the synthetic procedures of fused heterocycles, such as quinazoline derivatives and organometal heterocycles (i.e., phosphorus-, boron- and aluminum-containing heterocycles). Due to many references that have dealt with the reactions of azides in heterocyclic synthesis (currently more than 32,000), we selected according to generality and timeliness. This is considered a recent review that focuses on selected interesting examples of various heterocycles from the mechanistic aspects of organic azides

    Novel Pyridinium Based Ionic Liquid Promoter for Aqueous Knoevenagel Condensation: Green and Efficient Synthesis of New Derivatives with Their Anticancer Evaluation

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    Herein, a distinctive dihydroxy ionic liquid ([Py-2OH]OAc) was straightforwardly assembled from the sonication of pyridine with 2-chloropropane-1,3-diol by employing sodium acetate as an ion exchanger. The efficiency of the ([Py-2OH]OAc as a promoter for the sono-synthesis of a novel library of condensed products through DABCO-catalyzed Knoevenagel condensation process of adequate active cyclic methylenes and ninhydrin was next investigated using ultimate greener conditions. All of the reactions studied went cleanly and smoothly, and the resulting Knoevenagel condensation compounds were recovered in high yields without detecting the aldol intermediates in the end products. Compared to traditional strategies, the suggested approach has numerous advantages including mild reaction conditions with no by-products, eco-friendly solvent, outstanding performance in many green metrics, and usability in gram-scale synthesis. The reusability of the ionic liquid was also studied, with an overall retrieved yield of around 97% for seven consecutive runs without any substantial reduction in the performance. The novel obtained compounds were further assessed for their in vitro antitumor potential toward three human tumor cell lines: Colo-205 (colon cancer), MCF-7 (breast cancer), and A549 (lung cancer) by employing the MTT assay, and the findings were evaluated with the reference Doxorubicin. The results demonstrated that the majority of the developed products had potent activities at very low doses. Compounds comprising rhodanine (5) or chromane (12) moieties exhibited the most promising cytotoxic effects toward three cell lines, particularly rhodanine carboxylic acid derivative (5c), showing superior cytotoxic effects against the investigated cell lines compared to the reference drug. Furthermore, automated docking simulation studies were also performed to support the results obtained

    Prognostic model to predict postoperative acute kidney injury in patients undergoing major gastrointestinal surgery based on a national prospective observational cohort study.

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    Background: Acute illness, existing co-morbidities and surgical stress response can all contribute to postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery. The aim of this study was prospectively to develop a pragmatic prognostic model to stratify patients according to risk of developing AKI after major gastrointestinal surgery. Methods: This prospective multicentre cohort study included consecutive adults undergoing elective or emergency gastrointestinal resection, liver resection or stoma reversal in 2-week blocks over a continuous 3-month period. The primary outcome was the rate of AKI within 7 days of surgery. Bootstrap stability was used to select clinically plausible risk factors into the model. Internal model validation was carried out by bootstrap validation. Results: A total of 4544 patients were included across 173 centres in the UK and Ireland. The overall rate of AKI was 14·2 per cent (646 of 4544) and the 30-day mortality rate was 1·8 per cent (84 of 4544). Stage 1 AKI was significantly associated with 30-day mortality (unadjusted odds ratio 7·61, 95 per cent c.i. 4·49 to 12·90; P < 0·001), with increasing odds of death with each AKI stage. Six variables were selected for inclusion in the prognostic model: age, sex, ASA grade, preoperative estimated glomerular filtration rate, planned open surgery and preoperative use of either an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker. Internal validation demonstrated good model discrimination (c-statistic 0·65). Discussion: Following major gastrointestinal surgery, AKI occurred in one in seven patients. This preoperative prognostic model identified patients at high risk of postoperative AKI. Validation in an independent data set is required to ensure generalizability

    Evaluation of appendicitis risk prediction models in adults with suspected appendicitis

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    Background Appendicitis is the most common general surgical emergency worldwide, but its diagnosis remains challenging. The aim of this study was to determine whether existing risk prediction models can reliably identify patients presenting to hospital in the UK with acute right iliac fossa (RIF) pain who are at low risk of appendicitis. Methods A systematic search was completed to identify all existing appendicitis risk prediction models. Models were validated using UK data from an international prospective cohort study that captured consecutive patients aged 16–45 years presenting to hospital with acute RIF in March to June 2017. The main outcome was best achievable model specificity (proportion of patients who did not have appendicitis correctly classified as low risk) whilst maintaining a failure rate below 5 per cent (proportion of patients identified as low risk who actually had appendicitis). Results Some 5345 patients across 154 UK hospitals were identified, of which two‐thirds (3613 of 5345, 67·6 per cent) were women. Women were more than twice as likely to undergo surgery with removal of a histologically normal appendix (272 of 964, 28·2 per cent) than men (120 of 993, 12·1 per cent) (relative risk 2·33, 95 per cent c.i. 1·92 to 2·84; P < 0·001). Of 15 validated risk prediction models, the Adult Appendicitis Score performed best (cut‐off score 8 or less, specificity 63·1 per cent, failure rate 3·7 per cent). The Appendicitis Inflammatory Response Score performed best for men (cut‐off score 2 or less, specificity 24·7 per cent, failure rate 2·4 per cent). Conclusion Women in the UK had a disproportionate risk of admission without surgical intervention and had high rates of normal appendicectomy. Risk prediction models to support shared decision‐making by identifying adults in the UK at low risk of appendicitis were identified
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