Search Results (16)

This study conducts a comparative performance analysis of three different low-temperature solar collector systems: flat plate solar collectors (FPCs), heat pipe evacuated tube solar collectors (HPETCs), and heat pipe flat plate solar collectors (HPFPCs). Key performance parameters, such as heat transfer coefficients, useful heat, and thermal efficiency, are analyzed under varying mass flow rate, fluid temperature, and antifreeze concentration. The objective is to evaluate the thermal performance of these systems using different heat transfer fluids, specifically water, and mixtures of 30% and 50% ethylene glycol and propylene glycol. The performance data indicate that the heat transfer coefficient in the HPFPC diminishes by 28% and 41% when antifreeze is employed at concentrations of 30% and 50%, respectively. Furthermore, the integration of heat pipes with water in a flat plate solar collector results in efficiency enhancements, with respect to FPCs, of up to 13% at a fluid temperature of 30 °C, and up to 21% at 80 °C. At the elevated fluid temperature of 80 °C, an efficiency increase of 13% is observed with a 30% ethylene glycol concentration. The incorporation of heat pipes leads to an efficiency improvement of up to 6.5% in comparison to traditional flat plate solar collectors. This study highlights the significant impact of fluid properties, affecting the convective heat transfer coefficient, on the overall efficiency of solar collectors, emphasizing the importance of optimizing fluid composition and operating conditions for enhanced thermal performance. Full article

The plant-based meat alternative (PBMA) market and consumer base on the island of Ireland (IOI) has grown rapidly in recent years. Therefore, this study compared the changes in PBMAs available on the IOI over time and the nutritional profiles of PBMAs with meat counterparts. Three online audits of PBMAs available in Tesco’s and Sainsbury’s in 2021/2022, 2022/2023 and 2023/2024 were conducted. All on-pack information was extracted and analysed using descriptive statistics to identify trends over time. The nutritional content of selected categories of PBMAs identified in the 2023/2024 audit was compared to similar categories of meat using independent samples t-tests or Mann–Whitney-U tests. The number of PBMAs available on the IOI has increased over time (n = 350, n = 321 and n = 398), with a trend in slight improvements in A-scores observed for most categories. Compared to meat, PBMAs had significantly lower total and saturated fat contents and higher carbohydrate, fibre and sugar contents across most categories. The increase in PBMAs over time suggests that the development of new products is ongoing. However, the higher salt contents of PBMAs compared to meat in some categories and only slight improvements in A-scores suggest that focus should be redirected to product reformulation and refinement to improve the nutritional quality of PBMAs. Full article

In this work, we present the construction and control of a four-degrees-of-freedom (DOF) manipulator aimed at addressing one of the key challenges faced by the Academy-Industry Cooperation Center (CCAI): the need for mechatronic equipment to support and facilitate the development of advanced robotic cells. We begin by designing the robot’s structure and components using SolidWorks software for computer-aided design (CAD) modeling. This ensures that all the links and parts fit together properly without collisions. The robot links are then manufactured using 3D printing. Additionally, we performed kinematic modeling, dynamic analysis, and PI-V control, along with control using a trigonometric function (hyperbolic tangent). To evaluate the robot’s movement, we simulate these processes using Matlab R2019a/Simulink software, focusing on key parameters such as position, velocity, and acceleration, which inform the design of PI-V control for each link. We also present the electrical and electronic designs, followed by system implementation. The kinematics of the robot play a crucial role in the dynamics and controller design. We validate the kinematics using Peter Corke’s libraries based on the Denavit–Hartenberg parameters. The results show that the controller based on the trigonometric function improves the response time, particularly enhancing the performance of axes 2 and 3. Full article

A comprehensive analysis of the volatile components of 11 different cherry tomato pastes (Tesco Extra, Orange, Zebra, Yellow, Round Netherland, Mini San Marzano, Spar truss, Tesco Sunstream, Paprikakertész, Mc Dreamy, and Tesco Eat Fresh) commercially available in Hungary was performed. In order to ensure the reliability and accuracy of the measurement, the optimal measurement conditions were first determined. SPME (solid-phase microextraction) fiber coating, cherry tomato paste treatment, and SPME sampling time and temperature were optimized. CAR/PDMS (carboxen/polydimethylsiloxane) fiber coating with a film thickness of 85 µm is suggested at a 60 °C sampling temperature and 30 min extraction time. A total of 64 common compounds was found in the prepared, mashed cherry tomato samples, in which 59 compounds were successfully identified. Besides the already published compounds, new, cherry tomato-related compounds were found, such as 3 methyl 2 butenal, heptenal, Z-4-heptenal, E-2-heptenal, E-carveol, verbenol, limonene oxide, 2-decen-1-ol, Z-4-decen-1-al, caryophyllene oxide, and E,E-2,4-dodecadienal. Supervised and unsupervised classification methods have been used to classify the tomato varieties based on their volatiles, which identified 16 key components that enable the discrimination of the samples with a high accuracy. Full article

Installation of flat solar collectors (FSCs) has been increasing due to the zero cost of renewable energy. However, the performance of this equipment is limited by the area, the material and the thermophysical properties of the working fluid. To improve the properties of the fluid, metal and metal oxide nanoparticles have mainly been used. This paper presents the performance assessment of the FSCs using simple and hybrid carbon nanofluids of low thermal capacity. Energy and mass balance modeling was performed for this study. A parametric analysis was conducted to examine the impact of key variables on the performance of the solar collectors using simple graphite and fullerene nanofluids, as well as hybrid metal–oxide–carbon nanofluids. From the results of heat transfer in FSCs, using graphite and fullerene nanofluids, it can be concluded that adding these nanoparticles improves the convection coefficient by 40% and 30%, respectively, with 10% nanoparticles. The graphite and fullerene nanoparticles can enhance the efficiency of FSCs by 2% and 1.5% more than base fluid. As the decrease in efficiency using fullerene with magnesium oxide is less than 0.2%, fullerene hybrid nanofluids could still be used in FSCs. Full article

In this work, issues of water separation and purification are addressed, where, in order to achieve the desired results, it is necessary to use several disciplines such as classical physics, biotechnology, automatic control, automation, and applications of industry 4.0. Further, the need for comprehensive and automated solutions for rainwater treatment in the agricultural sector is addressed. This research focuses on designing and implementing a system adapted to these needs using Siemens technologies. The methodology ranges from the design of the Piping and Instrumentation Diagram (P&ID) to the implementation of the interface, incorporating Siemens technologies for data acquisition, electrical connections, treatment programming, and PID controller design. The results show significant advances in the development of the system, highlighting the effectiveness of automation and the HMI-PLC human–machine interface in process monitoring and control. These findings support the viability of a comprehensive rainwater treatment system for the agricultural sector, with important implications for water efficiency, environmental preservation, and increased productivity in agricultural and livestock activities. The contribution of this work is the relationship between engineering and research focused on industrial processes. The scientific contribution is to obtain the dynamic models and apply two strategies to obtain the gains of the PID controller. The first method is performed through the proposal of a Hurwitz polynomial, and the second is performed through genetic algorithms (GA), where they are implemented in a controller that is commonly used in the industry. The technological part includes the integration of work (schemes, programming, and communications) so that the result is as close to what was expected. Full article

Knowledge of micronutrient content of commercial plant-based meat alternatives (PBMAs) is limited. This study aimed to identify changes in micronutrient content of PBMAs over time, as well as how micronutrient levels of PBMAs compare to similar meat products using product audit data. An online audit of PBMAs in Tesco and Sainsbury’s was conducted in 2021 and 2023. On-pack information was extracted and inputted into Excel. Products were categorised, with categories containing on-pack micronutrient content for ≥2 products compared with similar meat products using data from Nutritics software and descriptive statistics applied. Nutrient claim thresholds were used to determine how many PBMAs were eligible to make a ‘source of’ or ‘high in’ claim for vitamin B12 (≥0.38 μg and ≥0.75 μg/100 g, respectively) and iron (≥2.1 mg and ≥4.2 mg/100 g, respectively). Results: Around 7% of products (n = 23/351 in 2021 and n = 22/324 in 2023) reported vitamin B12 content on-pack and 8% of products reported iron content on-pack (n = 28/351 for 2021 and n = 25/324 for 2023). All products contained levels adequate to make a ‘source of’ claim, with around 22% (2021) and 41% (2023) of these products eligible to make a ‘high in vitamin B12’ claim and 14% (2021) and 28% (2023) eligible to make a ‘high in iron’ claim. Median vitamin B12 and iron content/100 g was higher in 2023 products for 5/6 and 4/5 categories, respectively, with no change in the other category. For 2023 data, PBMAs had lower mean vitamin B12 contents/100 g in 4/6 categories compared to meat products (0.6–1.8 μg for PBMAs vs. 0.0–3.0 μg for meat products). For all six categories (burgers, mince, beef, pork, chicken, and lamb), PBMAs had higher mean iron contents/100 g than comparable meat categories (2.8–6.8 mg for PBMAs vs. 0.4–2.7 mg for meat products). Magnesium, zinc, calcium, vitamin A, and folic acid contents were listed on ≤1 product per category. Discussion: Vitamin B12 and iron contents of the PBMAs included in these audits appear to be increasing over time, however, levels of vitamin B12 need to increase to equate to those of red meat. Further fortification represents an option for improving the micronutrient profile of PBMAs to reflect levels in comparable meat products. Full article

Transparency in financial reporting is crucial for maintaining trust in financial markets, yet fraudulent financial statements remain challenging to detect and prevent. This study introduces a novel approach to detecting financial statement fraud by applying sentiment analysis to analyse the textual data within financial reports. This research aims to identify patterns and anomalies that might indicate fraudulent activities by examining the language and sentiment expressed across multiple fiscal years. The study focuses on three companies known for financial statement fraud: Wirecard, Tesco, and Under Armour. Utilising Natural Language Processing (NLP) techniques, the research analyses polarity (positive or negative sentiment) and subjectivity (degree of personal opinion) within the financial statements, revealing intriguing patterns. Wirecard showed a consistent tone with a slight decrease in 2018, Tesco exhibited marked changes in the fraud year, and Under Armour presented subtler shifts during the fraud years. While the findings present promising trends, the study emphasises that sentiment analysis alone cannot definitively detect financial statement fraud. It provides insights into the tone and mood of the text but cannot reveal intentional deception or financial discrepancies. The results serve as supplementary information, enriching traditional financial analysis methods. This research contributes to the field by exploring the potential of sentiment analysis in financial fraud detection, offering a unique perspective that complements quantitative methods. It opens new avenues for investigation and underscores the need for an integrated, multidimensional approach to fraud detection. Full article

Sustainability-Linked Bonds (SLBs) are a new type of general corporate purpose bond in which payments are tied to an issuer’s sustainability key performance indicators (KPIs) with respect to the environmental, social, and governance (ESG) criteria. The structure is complementary to green bonds. The Tesco SLBs are linked to the firm’s ability to cut its greenhouse gas emissions by 60%. The priority is to reduce its reliance on nonrenewable grid electricity, which contributed 65% of Tesco’s global carbon emissions footprint. Tesco accounts for 1% of electricity demand in the UK. Failure to meet the goals will result in a coupon step-up by 25 basis points on the last three coupons. The aim of our study is to investigate the presence of, how we call it ‘ESG spread’, marked by negative yield difference between SLB and regular bonds. It is something similar to ‘greenium’, that is, a premium paid by bondholders for green bonds when compared to nongreen bonds. We compare the bid and ask yields of SLBs with the interpolated yields, calculated for the yields of Tesco and Carrefour notes. Then, we look into the SLB yields in coupon step-up scenario to answer the question if the issuer’s failure to keep up with KPIs results in changing of ESG spread from negative to positive. Full article

Many still rightly wonder whether accounting numbers affect business value. Basic questions are “why?” and “how?” We aim at promoting an objective choice on how optimizing the most suitable valuation methods under a “value-based management” framework through some performance measurement systems. First, we present a comprehensive review of valuation methods. Three valuations methods, (i) Free Cash Flow Valuation Model (FCFVM), (ii) Residual Earning Valuation Model (REVM) and (iii) Abnormal Earning Growth Model (AEGM), are presented. We point out advantages and limitations. As applications, the proofs of our findings are illustrated on three study cases: Marks & Spencer’s (M&S’s) business pattern (size and growth prospect), which had a recently advertised valuation “problem”, and two comparable companies, Tesco and Sainsbury’s, all three chosen for multiple-based valuation. For the purpose, two value drivers are chosen, EnV/EBIT (entity value/earnings before interests and taxes) and the corresponding EnV/Sales. Thus, the question whether accounting numbers through models based on mathematical economics truly affect business value has an answer: “Maybe, yes”. Full article

Renewable energy resources like solar energy, wind energy, hydro energy, photovoltaic etc. are gaining much importance due to the day by day depletion of conventional resources. Owing to the lower efficiencies of renewable energy resources, much attention has been paid to improving them. The concept of utilizing phase change materials (PCMs) has attracted wide attention in recent years. This is due to their ability to extract thermal energy when used in collaboration with photovoltaic (PV), thus improving the photoelectric conversion efficiency. In this paper, the objective is to design and fabricate a novel thermal energy storage system using phase change material. An investigation on the characteristics of Potash Alum as a phase change material due to its low cost, easy availability and its usage as an energy storage for the indoor purposes are taken into account. The use of a latent heat storage system using phase change materials (PCMs) is an effective way of storing thermal energy and has the advantage of high-energy storage density and the isothermal nature of the storage process. In the current study, potash alum was identified as a phase change material combined with renewable energy sources, that can be efficiently and effectively used in storing thermal energy at compartively lower temperatures that can later be used in daily life heating requirements.A parabolic dish which acts of a heat collector is used to track and reflects solar radiation at a single point on a receiver tank. Heat transfer from the solar collector to the storage tank is done by using a circulating heat transfer fluid with the help of a pump. The experimental results show that this system is capable of successfully storing and utilizing thermal energy on indoor scale such as cooking, heating and those applications where temperature is below 92 °C. Full article

Many of the foreign companies operating in China have claimed that they have failed and are constantly deciding on a strategic withdrawal from the Chinese market. We intend to conduct an empirical analysis of Chinese consumers in order to determine the cause of Tesco’s management failure in China. The survey was conducted on those in their 20s or older who had experience shopping at both Tesco and RT-Mart. As a result, a total of 650 copies were distributed to obtain an effective sample of 607 copies, which was used for the analysis. This paper conducted a comparative analysis on Chinese consumers who visited both Tesco and its rival company RT-Mart in China. We found through comparative analysis that Tesco was destined to fail in many areas. It was estimated that RT-Mart was more satisfactory in all factors, including product, location, brand recognition, and employee service. Full article

Thin-walled composite box beam structural configuration is representative of a specific high aspect ratio wing structure. The optimal design procedure and lay-up definition including appropriate coupling necessary for aerospace applications has been identified by means of “ad hoc” analytical formulation and by application of commercial code. The overall equivalent bending, torsional and coupled stiffness are derived and the accuracy of the simplified beam model is demonstrated by the application of Altair Optistruct. A simple case of a coupled cantilevered beam with load at one end is introduced to demonstrate that stiffness and torsion angle distribution does not always correspond to the trends that one would intuitively expect. The maximum of torsional stiffness is not obtained with fibers arranged at 45° and, at the maximum torsional stiffness, there is no minimum rotation angle. This observation becomes essential in any design process of composite structures where the constraints impose structural couplings. Furthermore, the presented theory is also extended to cases in which it is necessary to include composite/stiffened hybrid configurations. Good agreement has been found between the theoretical simplified beam model and numerical analysis. Finally, the selected composite configuration was compared to an experimental test case. The numerical and experimental validation is presented and discussed. A good correlation was found confirming the validity of the overall optimization for the optimal lay-up selection and structural configuration. Full article

To contribute to global sustainability, many manufacturers are starting to implement green product development and trying to provide environmentally friendly products. Although green products are environmentally beneficial to our society, the performance of green product development remains poor because of cannibalization from traditional alternatives at lower prices. This is particularly the case in the current unforgiving marketing reality in which many brand retailers, such as Wal-Mart, Tesco, and Carrefour, offer their own store brands as traditional alternatives. Although a large stream of research has studied the effects of competition on manufacturers’ green design, to the best of our knowledge, there is a dearth of research on the effects of competition from retailers’ store brands on manufacturers’ green design. To fill this gap, we present two models in which the manufacturer has an incentive to design for the environment, and the retailer has the flexibility to sell store brands (Model S), or it does not (Model N). Surprisingly, our analysis indicates that the presence of store brands may stimulate the manufacturer to release a new greener version of the national brand. Moreover, we find that although the presence of store brands is beneficial to the retailer and industry, it always hurts the manufacturer’s profitability. To incentivize the manufacturer to support Model S, we propose a two-part tariff contract. Full article

Next year, 2014, it will be 30 years since the first Business-to-Customer online shopping occurred (i.e., Michael Aldrich teleshopping; Gateshead SIS/Tesco as merchant and Mrs. Snowball as the first online home shopper; (Site 1), and 20 years since the first web-based online ordering service was launched. […] Full article