Low Price Research Articles

Investigation of the impurity effect on the kinetics of thermal decomposition of natural gypsum at high temperatures

Natural gypsum is the most common sulfate on our planet, which is widely used in construction due to its excellent astringent properties, environmental friendliness, thermal and fire resistance, accessibility in nature and low price. Currently, the influence of modifiers, impurities and additives that can improve the strength, acoustic and thermal insulation characteristics of gypsum, which is so important in modern architecture, construction and reducing power consumption, is being increasingly studied. However, additives and impurities, controlled and uncontrolled, as in natural gypsum, can unpredictably affect the thermal stability and fire resistance of gypsum. The purpose of our work is to study the thermal characteristics of gypsum from various deposits in a wide temperature range. Our work shows that the temperature and rate of dissociation of gypsum directly depends on impurities that can change the process of its decomposition. As a result of the decomposition of natural gypsum with impurities, new phases are formed.It has been experimentally shown that the process of thermal destruction of gypsum with impurities has a complex multistage character, which is described by successive reactions of the nth order of the Avrami-Erofeev equation. It can be assumed that the reaction mechanism consists in the rapid formation of numerous nucleation centers on the surface of solid anhydrite. Kinetic parameters of thermal decomposition of gypsum of complex composition and phase formation at high temperatures are calculated. This experimental study shows the dependence of thermal stability on the amount and grade of impurities in gypsum. The results obtained contribute to the improvement of the basic concepts of the mechanism of decomposition of gypsum, as well as the explanation of some high-temperature phase formation processes in nature.

Examining the drivers of the imbalance price: Insights from the balancing mechanism in the United Kingdom

The increasing integration of renewable energy sources in the UK electricity sector has posed challenges to the stability of the system, leading to a sharp rise in the costs of balancing services. This study analyses half-hourly data from January 2017 to December 2023 to examine the factors determining the imbalance price in the UK's balancing mechanism, with particular focus on the sharp price increases in 2021-2022. Employing a Generalised Additive Model (GAM) to account for non-linear relationships, the analysis finds that the imbalance price is positively affected by the net imbalance volume (demand-side factor) and negatively impacted by the de-rated margin (supply-side factor). The wholesale electricity price, however, is identified as the dominant factor driving both the mean and volatility of the imbalance price during 2021-2022. These findings suggest that the balancing mechanism is functioning effectively and that a reduction in the wholesale price would lead to a lower imbalance price and thus lower costs of balancing services.

Effects of competition law on consumer welfare-evidence from Zambia

This study examined the effects of competition (antitrust) law on consumer welfare in Zambia, with a focus on market practices, pricing, and consumer protection. Aimed at promoting fair competition, competition law seeks to benefit consumers through lower prices, improved quality, innovation, and diverse choices. The research, organized around four key objectives, revealed mixed outcomes in Zambia. High market concentration often led to elevated prices and limited choices, reducing consumer welfare. While Zambia's regulatory framework aims to curb anti-competitive practices, resource constraints hinder enforcement, allowing such practices to persist. Merger controls generally preserved market competition, yet inconsistent application weakened these gains. Consumer awareness emerged as a significant factor, with informed consumers enhancing regulatory effectiveness. The findings emphasized the need for robust enforcement, an improved legal framework, and increased consumer education to maximize the benefits of competition law, better protect consumer interests, and foster competitive markets in Zambia.

A Mini Review on the Synthesis of Mesoporous Silica and its Application in Antibiotic Removal

AbstractIn recent years, antibiotics have been widely used in multiple fields such as agriculture, forestry, animal husbandry as well as human health due to their high efficiency and low price in treating bacterial infections. However, the misuse of antibiotics has posed a serious threat to both ecological environment and human health, resulting in the antibiotic contamination as a global issue. Therefore, the development of novel materials and technologies to remove antibiotics from water has become a research frontier and hotspot. Meanwhile, mesoporous silica materials have been gradually used in the removal of antibiotics via adsorption and degradation due to their controllable structure, tunable pore size as well as diverse sources. This mini review focuses on the research progress of mesoporous silica in removing antibiotics from aquatic environments. The main types and controllable synthesis procedures of mesoporous silica is introduced first, followed by their application in antibiotics removal via both adsorption and catalytic degradation. Furthermore, it proposes the future directions of this field, providing insights for the use of mesoporous silica materials in water pollution control.

Impact of COVID-19 on Agro business in Bangladesh

COVID-19 has become an alarming pandemic for our earth. It has created panic not only in China but also in developing countries like Bangladesh. The COVID-19 pandemic has significant implications, including financial, economic, and social effects. It has caused massive negative impacts, especially in the agricultural sector. In rural areas, the poor farmers, dairy farmers, vegetable producers, poultry farmers are in deep crisis due to lower prices and lockdown issues. In this paper, we have summarized the Impact of COVID-19 on the Agro business in Bangladesh. The effects of the pandemic cannot be mitigated individually, but an integrated effort on the part of the state authority and the part of people from all sectors need to come forward.

Challenges in Sesame Production and Marketing: Insights from Kerala's Onattukara Region, India

Sesame is one of the nine major oilseeds grown in India, with cultivation spread across every state. Although sesame is grown in 11 districts in Kerala, the sesame cultivated in the Onattukara tract has unique characteristics. In Kerala, sesame is cultivated on 326.51 hectares, with a total production of 163.1 tonnes and a productivity rate of 499 kg per hectare. This study aims to analyze the challenges faced by farmers in the production and marketing of sesame in the Onattukara region of Kerala. The districts of Alappuzha, Pathanamthitta, and Kollam were purposively selected for the study, as the Onattukara region is located within these three districts. A total of 163 farmers were included in the sample, comprising eighty farmers each from Kollam and Alappuzha districts and three farmers from Pathanamthitta. Constraints faced by farmers in sesame cultivation were ranked using the Garrett ranking technique. Sesame cultivation in the Onattukara region faces various challenges in both production and marketing, such as inadequate seed availability, high input costs, low yields, labor shortages, low prices, weather-related issues, price fluctuations, delayed payments, low demand for the final product, and the lack of institutional market mechanism. Similarly, sesame processing unit owners also encounter issues in production and marketing, including raw material shortages, a lack of skilled labor, poor raw material quality, costly production methods, lack of support, low product prices, price volatility, inadequate storage facilities, inefficient markets for final products, and limited consumer awareness. A micro-level study on sesame production and marketing would help producers make informed and specific decisions to improve their income. These insights can guide producers in making informed decisions and assist policymakers in implementing corrective measures like resource allocation for inputs, training and capacity building, improving market linkages to enhance sesame production, productivity, and market stability. These interventions, grounded in micro-level data, could substantially support both short-term gains and long-term sustainability in sesame production, demonstrating the practical utility of the research in enhancing both farmers livelihoods and local agricultural policy.

Highs and Lows: A Mixed-Methods Analysis of the Impact of Adult Use Legalization on Medical Cannabis Patients

ABSTRACT Presently, 24 states have legalized adult use (recreational) cannabis, each following medical-only access. Although states that pass adult use laws report substantial declines in the number of registered medical patients, these laws expand the market, potentially enhancing patient benefits. However, research on federal adult use cannabis legislation in Canada suggests that adult use laws negatively impact medical patients. The purpose of this mixed-methods study was to examine medical cannabis patients’ perceptions of the impact of adult use cannabis laws in the US. We conducted an online survey with forced choice and open-ended questions in a convenience sample of 505 medical cannabis patients. Quantitative analysis indicated that adult use laws decreased stress and legal concerns, and that patient perceptions of cannabis product quality and availability were higher, but prices were also higher. Qualitative analysis largely aligned with quantitative findings, however data were somewhat divergent on price and product availability (with some patients reporting lower prices and accessibility issues). Mixed-methods analysis revealed that legalization also reduced patients’ experience of social stigma. Addressing the patient concerns revealed by these data may help to restore or maintain patient access to affordable, medically relevant cannabis products as additional states merge medical cannabis programs into adult use paradigms.

Evaluating the value for money in procurement for EU-funded projects: the perspectives of Slovak regional and local authorities

Awarding public contracts using evaluation criteria that consider price and quality (MEAT) rather than the lowest price allows contracting authorities to pursue broader societal goals, thereby maximising the potential of value for money. This potential becomes even more important when procuring contracts funded by European Structural and Investment Funds (ESIF), which aim to promote environmental sustainability, encourage innovations, and support small and medium-sized enterprises. Despite this, there is a limited understanding of how public authorities adopt MEAT award criteria in procurement contracts co-funded by ESIF resources. Therefore, this paper investigates the effect of ESIF on adopting MEAT in the procurement practices of Slovak regional and local authorities. Using a unique dataset of below and above-threshold contracts, we find a positive effect of ESI co-funding on adopting MEAT criteria. However, this positive effect is significant only when projects are procured using more flexible and straightforward below-threshold procurement procedures. Accounting for prior experience and challenges of complying with above-threshold procurement procedures, the findings underline the importance of organisational capacity in navigating through burdensome procurement and ESIF regulations to obtain the best value using taxpayers’ money.

SOME PHYSICAL-CHEMICAL FEATURES THE SOLID PHASES HYDRAULICITY

The most widely used in composite materials industry are concrete installations bonded with different binders. Higher energy consumption and several ecological problems make their manufacture to become more and more expensive. The growing market of construction works and constant extension of real estate property increases the demand for cheap and new materials with desired features. As a result of many years intensive scientific researches there is now a practical possibility to offer an alternative and unique products technology of manufacture based on binding suspension (bricks, wall, heat insulating and refractory materials and other) – all of them of desired size and shape. The experience of the composite materials technology development shows that in comparison with traditional the microhardness of materials with an ultradispersive structure increases several times and the specific surface increases by an order contributing to a decrease in the sintering temperature. The longevity of similar material is essentially increasing provi­ded structure is forming under conditions of the servi­ce site. Thus, building industry will obtain improved service life and performance from binding suspensions as field installations will continue to move toward adopting and utilizing practices based on technology described herein, rather than on cement technology. Relative to conventional composite materials products with mechano-chemical binders will continue to gain in popularity because of the following advantages: low energy consumption and low prices for the products; ecological safety of the manufacture process and of the ready-made products; good mechanical and design properties; moisture and cold proofness; surface need not be fired; no shrinkage of the products after drying; simple to manufacture a variety of different products; ready availability and flexibility in design; absence of manufacture wastes.

Economic determinants of Ethereum transaction fees in the priority fee and proof of stake periods

ABSTRACT We analyse the economic determinants and dynamics of transaction fees in the Ethereum blockchain before and after two significant platform updates. The first is the August 2021 EIP-1559 ‘London’ upgrade, a switch from user-bid gas price (transaction fee per unit of complexity) to a fee model in which the gas price is the sum of an algorithmically determined base fee and an optional priority fee (tip) chosen by the user. The second update (‘the Merge’) is the switch from proof-of-work to proof-of-stake transactions validation in September 2022. We estimate the impact on Ethereum transaction fees of both demand factors (block utilization, transaction type, ETH price in USD) and algorithmic supply-side factors (the block gas limit and base fee). Using data from nearly 900 million blockchain transactions, we find that the gas price is statistically significantly positively associated with the block utilization rate. A larger share of contract call transactions or legacy (user-bid gas price) transactions is linked with higher gas prices on average. On the supply side, a higher block gas limit is statistically significantly associated with lower gas prices.

Influence of Control Strategy on Heat Recovery Efficiencyin a Single-Duct Periodic Ventilation Device

The subject of the research was a single-duct, decentralised periodic ventilation unit, using accumulative heat exchanger for heat recovery (also called single-core fixed-bed regenerator). It can achieve high efficiency of heat recovery but is vulnerable to pressure differences between the interior of the building and the outside. To counter this, two control strategies were proposed: adjustment of the fan speed based on an air flow sensor and adjustment of the working cycle length based on temperature sensors. The strategies were tested experimentally in actual working conditions. Due to the use of cheap and simple sensors, it was possible to retain the low price of the device. Both control strategies proved to be successful in equalising the amount of supplied and removed air in a single cycle. Moreover, the heat recovery efficiency increased by more than 10% compared to the default working mode.

Reconciling patent rights and the human right to access to essential medicines: A critical review

Over 80% of the world’s population lives in developing nations, with limited access to medicines like AIDS and malaria. Competition between patented and generic medications can improve access and lower prices, but counterfeit medicines should be avoided. The Doha Declaration, released at the World Trade Organisation Ministerial Conference in 2001, aims to support nations’ rights to safeguard public health and encourage access to medicines. It aims to influence the interpretation and application of the Agreement on Trade-Related Aspects of Intellectual Property Rights (TRIPS Agreement) in a manner that is health-friendly, considering the responsibility of nations to uphold health rights under international law. The Declaration calls for developed nations to encourage practical solutions for poor people in developing countries, emphasizing that trade agreements should be secondary to defending human rights and achieving the best quality of health for all. International human rights treaties protect the universal human right to health, but rigid trade agreements on patents can hinder affordable medication for low-income populations in developing nations. TRIPS, a treaty that protects intellectual property rights and promotes technological innovation, aims to provide inexpensive medications for HIV/AIDS patients through exclusions from patent admissibility, exceptions, parallel importing, and compulsory licensing.

Fishing Gears and Practices in the Bukbhora Oxbow Lake: Implications for Biodiversity Conservation in South-west Bangladesh

Bukbhora ox-bow Lake (baor) is one of the most renowned baors in the south west Bangladesh and supports diverse fisheries communities. The present study was conducted to identify the types of fishing gears and crafts including their mode of operation in fishing in the Bukbhora baor during the period from July 2023 to June 2024. A total of 18 fishing gears and crafts were recorded at different stations of the Bukbhora ox-bow Lake. Fishing gears were categorized as nets (8), traps (3), hooks and lines (3), wounding gears (2) and crafts (2). Among nets, highest mesh size recorded 5-8 cm in fash jal whereas the lowest was thela jal 0.25 cm. The highest fishing effort/day was found for Jhaki Jal (cast net) 13-15 and the lowest was recorded in case of current and punti Jal (01). Highest CPUE (kg/effort) was found in ber jal (15-18) and the lowest was found in Thela jal (1-1.5). Similarly seine net contributed to the highest catch (70.19%) and push net was the lowest (1.00 %). Maximum fishers had pieces of kochal (Seine net) and komar (drag net) 2-5 pieces and those were jointed together (each of 18 fishers groups separately work) during the harvesting period. Fishing (harvesting of carp species) started in November-December and completed on 30th June in each season. Based on the usage, the seine net was found as the most usable gear by the fishermen constituting 78.15% and fewer amount by traps. The highest price of fishing gear was observed in case of ber jal (about 1,00,000 BDT) and the lowest price was for punti jal (250-2500 BDT). Among 16 fishing gears 5 of these were found illegal in this study due to its mesh size and destructive behavior of fish biodiversity. Except some, majority fish species trapped in the recorded fishing traps were Small Indigenous Species, whereas fishing hooks and lines were used to catch carnivorous fish species mainly. Wounding fishing gears were used for wounding large size fishes during heavy flood or when water level becomes low. This study showed that 40.91% fishers had their own fishing craft (dingi nouka) where 59.09% had no craft. It is recommended to strong implementation of all conservation guidelines and acts to prevent illegal fishing, seizing of destructive fishing gears and also protecting potential breeding habitats.

Surveillance and mapping of tribenuron-methyl-resistant weeds in wheat fields

Tribenuron-methyl (TBM) is among the herbicides that are widely used for controlling broadleaf weeds in wheat fields in Iran due to its low mammalian toxicity and environmental risk, use at low doses, the broad spectrum of weed control, and low price compared to other herbicides. However, wheat farmers’ repeated application and dissatisfaction with the optimal and effective control of the TBM herbicide have led to investigating broadleaf weed resistance in Iranian wheat fields. For this purpose, through a national call in 2018, a total of 240 broadleaf weed populations belonging to 13 species and 7 plant families were collected from 153 wheat fields in 72 counties across 14 provinces suspected to be resistant to the TBM herbicide. Then, a screening test was conducted in a completely randomized design with 5 replications of each biotype using the recommended dose of 25 g a.i. ha− 1 of TBM in the greenhouse. Overall, the results indicated that 124 (51.7%) of the screened populations were resisted to TBM. Specifically, 44 populations (81%) of Sinapis arvensis L., 18 populations (45%) of Malva neglecta Wallr., 25 populations (45%) of Silybum marianum (L.) Gaertn, 2 populations (66.6%) of Ammi majus L., 1 population (50%) of Rapistrum rugosum L., 3 populations (21%) of Descurainia Sophia (L.) Webb ex Prantl, 9 populations (36%) of Vaccaria hispanica Mill., 8 populations (48%) of Galium aparine L., 9 populations (75%) of Melilotus indicus L. According to the Adkins and Maas evaluation, 4 populations (100%) of Raphanus raphanistrum L. were classified as resistant to TBM. This study is the first comprehensive investigation of broadleaf weed resistance to TBM across Iranian wheat fields, providing crucial insights for future herbicide management strategies. Given the high incidence of resistance, continued use of TBM in Iranian wheat fields may lead to increased yield loss and environmental pollution. Additionally, it is necessary to investigate cross-resistance in resistant populations to other ALS-inhibiting herbicides.

Traditional opal mining practice in Ethiopia, challenges and its economic impact on rural households: the case of wollo opal mining

Background The discovery spurred further exploration, leading to the expansion of opal mining into neighboring districts. Numerous cooperative groups, composed of small-scale miners, traditionally explore, develop, and extract significant amounts of rough opal gemstones. This study tries to investigate the challenges and economic impacts of traditional opal mining practice in wollo province of Ethiopia. Methods The study used in this study is primary data collected from rural households, which are living in five districts of north wollo zone, in Amhara regional state. The data was collected using field observation, focus grouped discussion, interview, and questionnaire from sampled households. The study uses both descriptive and econometric methods of data analysis to achieve its objective. Results Among the challenges of traditional opal mining, primitive way of exploring and extraction, limited access to market and low institutional support in terms of training and finance are identified. The probit model reveals that, increased education, access to training, and access to credit positively influence the likelihood of engaging in opal mining. The ESR model shows that, the average treatment effect on the treated (ATT) indicates that participating in opal mining increases monthly income by 31,380 ETB, while the average treatment effect on the untreated (ATU) shows a potential income increase of 31,625 ETB for non-miners if they engaged in mining. Conclusion The study identifies three main categories of challenges faced by traditional opal miners: exploration and extraction issues, market limitations, and regulatory and institutional shortcomings. Exploration and extraction challenges include the lack of modern mining tools and knowledge, as well as difficult terrain, leading to inefficient and hazardous mining practices. Market-related challenges involve limited access to broader markets and lack of value addition, resulting in miners selling raw opals at significantly lower prices compared to polished ones.

An Analysis of Industry Forces Impacting Apple’s Performance: A Study Using Porter’s Five Forces Framework

The main objective of this study was to identify different electronic industry forces that impact the performance of Apple Inc. using Porter’s five forces framework. The study adopted a desktop methodology. The buyers have moderate power as a result of customers' attraction to the brand. Still, also the availability of alternative products at lower prices gives the customers power to negotiate. There is a moderate power of supplies resulting from a wide industry demand and scarcity of the components. There is a low threat of new entrants in the electronic industry due to high capital investment, high research and development costs, economies of scale and strong brand loyalty. The availability of different products of similar functionalities makes the threat of substitutes to be high in the market like tablets and smartphones. The rivalry of existing competitors is high as the industry is characterized by aggressive price strategies. To maintain its strong position in the market, Apple highly invests in research and development to make its products differentiated and maintains its strong brand loyalty. Apple need to consider the consumers of low incomes as the products of Apple Inc. are regarded as expensive for this group and where the competitors are willing to offer substitute products and services at lower prices.

EXPRESS: Impact of Unreliable Supplier on a Supply Chain with Demand-Generating Marketing

A firm often has multiple sourcing options for its product. Some suppliers may have longer lead times but offer lower prices, whereas reliable suppliers with quick response capabilities may have higher prices. Purchasing from a cheaper, less reliable supplier can help a firm lower its inventory cost but will expose itself to potential risks. This paper analyzes a supply chain in which a manufacturer can source from a cheaper, less reliable supplier with a long lead time and/or a reliable quick-response supplier. The manufacturer also has to make demand-generating marketing investments before the selling season. Our analysis shows that if the unreliable supplier’s reliability is low, the reliable supplier will charge a low wholesale price; otherwise, it will choose a high wholesale price. As the unreliable supplier’s reliability improves, the manufacturer is inclined to increase its marketing investment, but there is a drop at some critical threshold. Interestingly, the existence of an unreliable supplier can lead to a win-win outcome for the reliable supplier and the manufacturer. The unreliable supplier’s reliability has non-monotonic effects on the equilibrium profits of the reliable supplier and the manufacturer.

Welfare‐Reducing Integration Under Emission Taxes and Endogenous Competition Mode

ABSTRACTThis study examines asymmetric supply chain competition between integrated and non‐integrated supply chains under emission taxes when firms choose competition mode in the final goods market endogenously. We find that higher emission taxes may lead the non‐integrated downstream firm to adopt aggressive pricing to induce its upstream firm to lower prices, leveling competition with an integrated one. When the non‐integrated chain integrates, however, quantity contracts become dominant strategies, which might distort welfare under lower emission taxes if both environmental damage and product substitutability are sufficiently high. Our finding indicates the welfare‐reducing effects of government interventions post‐integration when emission tax policy and endogenous competition mode are relevant.

An Economically Sustainable Glass Recycling Business Model in Puerto Rico: A Conceptual Solution for Regions Without Government Recycling Programs

In Puerto Rico, less than 5% of glass waste is recycled annually compared to a US national average of 25%. In regions like Puerto Rico, where government glass recycling programs are absent, glass presents a challenging waste stream to profitably recycle due to high transportation costs and low market prices, with few scalable models identified in the literature. This study emerged from a multi-year shared action learning partnership between Worcester Polytechnic Institute’s Puerto Rico Project Center and the Corporación del Proyecto ENLACE, a community development NGO serving the Caño Martín Peña communities in San Juan, Puerto Rico. Based on online research and interviews with 16 key stakeholders, we describe an economically sustainable glass recycling business model designed for the Caño Martín Peña communities that offers broader applicability for similar contexts. The business model achieves three goals: (1) it offers a free and convenient glass-collection service for the Caño Martín Peña communities; (2) it generates local employment opportunities in a low-income region; and (3) it operates in an economically sustainable manner. The viability of the glass-recycling business model is premised on strategic partnerships with government agencies, recycling companies, glass-sand markets, and local businesses.

Winter barley productivity in the southern part of the Rostov region when sowing sunflower as a forecrop with different seeding rates

The current study was conducted in the southern part of the Rostov region in the agrotechnical crop rotation of the laboratory for cultivation technology of grain and row crops of the FSBSI Agricultural Research Center “Donskoy” in 2021–2023. The purpose of the study was to determine the effect of seeding rates on productivity of various winter barley varieties sown after sunflower. The conducted study allowed identifying the response of winter barley varieties to different seeding rates. The winter barley variety ‘Marusya’ on average over the years of research formed the mean maximum grain productivity of 6.43 t/ha when sowing with the lowest seeding rate (3 million pcs. of germ. grains per 1 ha). For the varieties ‘Vivat’ and ‘Foks 1’, the optimal seeding rate was 4 million pcs. of germ. seeds per 1 ha, and the obtained productivity was 6.31 and 5.81 t/ha, respectively. The response of the studied winter barley varieties to seeding rates was different through the years, but the effect of this factor was 4.6–10.5 %. Reliable differences in the experiment were obtained only for the variety ‘Vivat’ for all seeding rates. The winter barley productivity was determined by the choice of a variety, and the effect of this factor ranged from 32.5 to 78.1 %. There was determined that when sowing with the lowest seeding rate (3 million pcs. of germ. grains per 1 ha), all winter barley varieties in the trial had the largest number of grains per ear and grain weight per ear with 36.3–43.2 g and 1.62–2.10 g, respectively. There was established that in the variant with this seeding rate, the varieties formed a heavy, large-size grain (nature weight of 637–660 g/l) with ‘1000-grain weight’ of 42.1–43.8 g and 10.8 to 11.3 % of protein in grain. There has been established an economic efficiency of cultivating the varieties ‘Vivat’, ‘Marusya’ and ‘Foks 1’ when sowing them with the lowest seeding rate of 3 million pcs. of germ. grains per 1 ha. With a low cost price of produced grain (5405–6136 rubles/t), in this variant of trial, the varieties obtained the maximum conditional net income (34378–45499 rubles/ha) and production profitability (108–147%).