Total Demand Research Articles

The Role of Zakat in Automatic Equilibrium in the Islamic Economy Using the input-output Model

The study aimed to elucidate the role of Zakat in contributing to achieving automatic equilibrium in the economy quantitatively through the use of the input-output model. The study relied on a descriptive approach involving the analysis of quantitative data relevant to the discussion. The study addressed the effectiveness and efficiency of financial instruments of public policy and their role in contributing to achieving automatic equilibrium in both traditional and Islamic economies.
 The study concluded that Zakat has an impact on increasing total demand as measured quantitatively using the input-output model, which works to establish automatic equilibrium in the economy. The study recommended the inclusion of Zakat as a financial tool utilized by the state in its public policies to achieve its economic and social objectives, ensuring the attainment of economic equilibrium. Additionally, it suggested the possibility of employing quantitative methods and mathematical models to study the behavior of economic variables in the Islamic economy.

Analysis of The Need and Availability of Clean Water in The Karo Regency Area

Access to clean water is a fundamental and sustainable necessity for the well-being of human beings, requiring consistent provision. Given the ongoing population growth in Karo Regency, especially in terms of the use of clean water, a significant increase in demand for clean water is anticipated in the coming years. This research aims to understand the demand and availability of clean water required by the community in Karo Regency until the year 2033. The study involves an analysis of the demand for clean water at the PDAM Tirta Malem unit in Karo Regency, using data such as population figures from the last decade, the number of customers over the past ten years, andinformation on the water needs of the population in Karo Regency. The research findings indicate that the projected increase in the number of customers in Karo Regency will result in a demand for 212,644.7 liters per second of clean water in the service area. However, it is anticipated that the existing sources of clean water will be sufficient to meet this demand by the year 2033. This statement is supported by the total demand for clean water based on projectionsfor various types of customers in the service area of Karo Regency in 2033, which is 212,644.7 liters per second, still within the total availability of water that can be produced by the existing springs, which is 373 liters per second.

Macroeconomic effects of a declining wage share: A meta‐analysis of the functional income distribution and aggregate demand

AbstractThis paper reviews the theoretical and empirical literature on the relationship between the functional distribution of income and aggregate demand, which investigates whether declining wage shares increase (“profit‐led”) or decrease (“wage‐led”) demand. It conducts a meta‐regression analysis of 33 studies with 578 estimates for total and domestic demand, covering up to 163 years and 59 countries and regions. Our results suggest that, on average and across all countries, total demand is predominantly profit‐led and domestic demand mainly wage‐led. The effects in the literature range between 0.8 and −0.3 within one standard deviation for domestic demand and between 0.4 and −0.7 for total demand, which are economically significant at the outer bounds. We find mixed evidence for publication selectivity, which may affect the size but not the direction of the results in the literature. If one was to nonetheless correct for this, then total demand would be less profit‐led or statistically insignificant. A set of moderator variables, including publication characteristics, estimation strategies, the covariates included in the studies’ estimation functions, and, in particular, controls for time and space, help explain the variation in the empirical estimates.

Managing the low carbon transition pathways through solid waste electricity

The potential of solid waste as an energy source is clear, owing to its wide availability and renewable properties, which provide a critical answer for energy security. This can be especially effective in reducing the environmental impact of fossil fuels. Countries that rely heavily on coal should examine alternatives such as electricity from solid waste to provide a constant energy supply while also contributing to atmospheric restoration. In this regards, Low Emissions Analysis Platform (LEAP) is used for simulation the entire energy system in Pakistan and forecasted its capital cost and future CO2 emissions in relation to the use of renewable and fossil fuel resources under the different growth rates of solid waste projects like 20%, 30% and 40% for the study period 2023–2053. The results revealed that, 1402.97 TWh units of energy are generated to meet the total energy demand of 1193.93 TWh until 2053. The share of solid waste based electricity in total energy mix is increasing from a mere 0.81% in 2023 to around 9.44% by 2053 under the 20% growth rate, which then increase to 39.67% by 2053 under the 30% growth rate and further increases to 78.33% by 2053 under the 40% growth rate. It is suggested that 40% growth rate for solid waste based electricity projects is suitable for Pakistan until 2053 because under this condition, renewable sources contributes 95.2% and fossil fuels contributed 4.47% in the total energy mix of Pakistan. Hence, CO2 emissions are reduced from 148.26 million metric tons to 35.46 million metric tons until 2053 but capital cost is increased from 13.23 b$ in 2023 to 363.11 b$ by 2053.

Profiling wastewater characteristics in intra-urban catchments using online monitoring stations.

This study aims to investigate the differences in intra-urban catchments with different characteristics through real-time wastewater monitoring. Monitoring stations were installed in three neighbourhoods of Barcelona to measure flow, total chemical oxygen demand (COD), pH, conductivity, temperature, and bisulfide (HS-) for 1 year. Typical wastewater profiles were obtained for weekdays, weekends, and holidays in the summer and winter seasons. The results reveal differences in waking up times and evening routines, commuting behaviour during weekends and holidays, and water consumption. The pollutant profiles contribute to a better understanding of pollution generation in households and catchment activities. Flows and COD correlate well at all stations, but there are differences in conductivity and HS- at the station level. The article concludes by discussing the operational experience of the monitoring stations.

The effect of aeration mode (intermittent vs. continuous) on nutrient removal and greenhouse gas emissions in the wastewater treatment plant of Corleone (Italy)

The paper reports the results of an experimental study aimed at comparing two configurations of a full-scale wastewater treatment plant (WWTP): conventional activated sludge (CAS) and oxic-settling-anaerobic process (OSA) with intermittent aeration (IA). A comprehensive monitoring campaign was carried out to assess multiple parameters for comparing the two configurations: carbon and nutrient removal, greenhouse gas emissions, respirometric analysis, and sludge production. A holistic approach has been adopted in the study with the novelty of including the carbon footprint (CF) contribution (as direct, indirect and derivative emissions) in comparing the two configurations. Results showed that the OSA-IA configuration performed better in total chemical oxygen demand (TCOD) and ortho-phosphate (PO4-P) removal. CAS performed better for Total Suspended Solids (TSS) removal showing a worsening of settling properties for OSA-IA. The heterotrophic yield coefficient and maximum growth rate decreased, suggesting a shift to sludge reduction metabolism in the OSA-IA configuration. Autotrophic biomass showed a reduced yield coefficient and maximum growth yield due to the negative effects of the sludge holding tank in the OSA-IA configuration on nitrification. The OSA-IA configuration had higher indirect emissions (30.5 % vs 21.3 % in CAS) from additional energy consumption due to additional mixers and sludge recirculation pumps. The CF value was lower for OSA-IA than for CAS configuration (0.36 kgCO2/m3 vs 0.39 kgCO2/m3 in CAS).

Cost Focus versus Comfort Focus: Evidence from a Discrete Choice Experiment with Swiss Residential Electricity Customers

Based on a discrete choice experiment with 582 households in Switzerland, we find, that about 30% of the customers focus on price risks (cost focus) when they choose an electricity tariff, while 70% of the customers are more worried about volume risks (comfort focus). Customers with a cost focus, prefer contracts with low price risks and automatic load control, even when these contracts increased their volume risks and may lead to discomfort, while customers with a comfort focus are unlikely to choose a contract that exposes them to either price or volume risks. All customers prefer direct load control of individual appliances to capacity subscriptions or other demand response approaches which limit their total electricity demand. While customers with a cost focus likely accept direct load control even if this reduces their comfort, enrolling customers with a comfort focus will require further efforts and contracts avoiding comfort loss.

An innovative fuzzy logic frequency regulation strategy for two-area power systems

Modern environmentally friendly power system designs offer several application benefits, but they also generate losses. In order for this structured power system to operate reliably, the total generation, total load demand, and system losses must be balanced. Changes in load demand disrupt both the real and reactive power balances. As a result, the system frequency and tie-line interchange power differ from their planned values. A large variance in system frequency can cause the system to crash. Multiple connected area systems use clever load frequency control techniques in this scenario to deliver dependable and high-quality frequency and tie-line power delivery. In this case, a freestanding hybrid power system is considered, with generated power and frequency intelligently managed. In addition to the unpredictability of the wind, frequent changes in the load profile can result in significant and damaging power variations. The output power of such renewable sources may fluctuate to the point where major frequency and voltage variations occur in the system. The fuzzy logic PID controller (FLPIDC) is an intelligent approach recently proposed to address the load frequency control (LFC) issue of an interconnected power system. Standard proportional integral derivative (PID) controllers operate each section of the system.

Impact and Integration of Electric vehicles on renewable energy based Microgrid: Frequency profile improvement by a-SCA optimized FO-Fuzzy PSS approach

The modelling of an electric vehicle along with its integration and impact over a renewable energy based microgrid topology is well addressed in this manuscript. The frequent charging and discharging of the electric vehicle makes an oscillation over grid frequency. The performance especially frequency of an islanded AC microgrid is also affected seriously under the actions of different uncertainties like load dynamics, wind fluctuation in wind plant, solar intensity variation of PV plant etc. In order to maintain standard frequency, this research work aims to regulate the net power generation of the system in response to total demand. To monitor net generation, this work has intended a fractional order fuzzy power system stabilizer (FO-Fuzzy PSS) control scheme in several dynamic situations. The proposed FO-Fuzzy PSS control scheme acts as most potential candidate to pertain stability in system frequency in above discussed disturbances. The controller gains are tuned optimally with suggesting an advanced- Sine Cosine Algorithm (a-SCA) under different conditions. The performance of the optimal FO- Fuzzy PSS controller is compared over standard fuzzy controller and PID controller in regard to frequency regulation of microgrid system. It is observed that proposed FO-Fuzzy PSS control scheme has the credential to reduce settling time of ΔF1 (area1 microgrid frequency) by 98.60% and 250.82% over fuzzy controller & PID controller correspondingly. Further, the dynamic optimal performance of the proposed a-SCA is compared over original SCA and PSO techniques to justify its superiority.

Imported Inputs, Balance of Payments and Economic Growth: a model and a test on the case of Turkey

Several countries rely heavily on imported intermediate inputs for the manufacturing of their exported goods. Understanding the implications of this reliance on a country's growth performance is vital. To address this issue, we conducted an in-depth analysis using the multi-sectoral balance-of-payments constrained growth model with data from Turkey spanning 1970 to 2019. We used the autoregressive distributed lag method to estimate sectoral export, final import, intermediate goods import, and total import demand functions for five technology-based sectors. Subsequently, we calculated growth rates using the multi-sectoral balance of payments constrained growth models, factoring in the estimated income and price elasticities, as well as the respective sectoral shares in total exports, total imports, total final imports, and total intermediate goods imports. Our results demonstrate that the multi-sectoral balance of payments constrained growth model, which incorporates the impact of imported intermediate goods, successfully predicts Turkey's growth path. The findings indicate that structural changes in the production process and the use of imported intermediate inputs have a positive impact on exports. However, Turkey's significant dependence on imported intermediate goods during the production process leads to a decrease in the multi-sectoral balance of payments constrained growth rate.

Analysing direct air capture for enabling negative emissions in Germany: an assessment of the resource requirements and costs of a potential rollout in 2045

Direct air capture (DAC) combined with subsequent storage (DACCS) is discussed as one promising carbon dioxide removal option. The aim of this paper is to analyse and comparatively classify the resource consumption (land use, renewable energy and water) and costs of possible DAC implementation pathways for Germany. The paths are based on a selected, existing climate neutrality scenario that requires the removal of 20 Mt of carbon dioxide (CO2) per year by DACCS from 2045. The analysis focuses on the so-called “low-temperature” DAC process, which might be more advantageous for Germany than the “high-temperature” one. In four case studies, we examine potential sites in northern, central and southern Germany, thereby using the most suitable renewable energies for electricity and heat generation. We show that the deployment of DAC results in large-scale land use and high energy needs. The land use in the range of 167–353 km2 results mainly from the area required for renewable energy generation. The total electrical energy demand of 14.4 TWh per year, of which 46% is needed to operate heat pumps to supply the heat demand of the DAC process, corresponds to around 1.4% of Germany's envisaged electricity demand in 2045. 20 Mt of water are provided yearly, corresponding to 40% of the city of Cologne‘s water demand (1.1 million inhabitants). The capture of CO2 (DAC) incurs levelised costs of 125–138 EUR per tonne of CO2, whereby the provision of the required energy via photovoltaics in southern Germany represents the lowest value of the four case studies. This does not include the costs associated with balancing its volatility. Taking into account transporting the CO2 via pipeline to the port of Wilhelmshaven, followed by transporting and sequestering the CO2 in geological storage sites in the Norwegian North Sea (DACCS), the levelised costs increase to 161–176 EUR/tCO2. Due to the longer transport distances from southern and central Germany, a northern German site using wind turbines would be the most favourable.

APPLICATION OF THE FORECASTING METHOD TO THE DEMAND FOR PRINTING RECEIPTS WITH GTO 46 ENGINE

Forecasting is an important part of every business organization and for every very significant management decision. The purpose of forecasting is to reduce the risk or uncertainty faced by a company in making short-term operational decisions and in planning for long-term growth. The company that is the object of this research is a company operating in the printing sector. Focus on observing receipt products because receipt orders are the highest every month. In the implementation of the production process, there are often shortages of raw materials such as NCR paper or non-carbon required paper so that delivery times are late to reach consumers. The effort used to eliminate/reduce the gap between production and sales is to use a forecasting method which aims to determine product quantity adjustments and when they are needed. Based on data processing using cyclical and linear methods, the method used in calculating the next month's forecast is the Linear method. The linear method has the smallest error values, namely SEE = 1100.57, MAD = 871 and MAPE = 26.34. The total forecast demand for receipt products in November is 4839 pieces

Impact of wastewaters on groundwater quality of Bani Al-Hareth and Arhab areas in northern Sana’a city, Yemen

The purpose of this research is to determine the impacts of wastewater effluents on groundwater quality of the northern su­­burbs of Sana’a city. Fourteen duplicate groundwater and wastewater samples were collected from the study area and analyzed. The groundwater samples were analyzed for major elements, and anionic and cationic groups using Atomic Absorption Spectrophotometer (AAS). The wastewater samples were analyzed for Total Coliform (TC), Fecal Coliform (FC), and oxygen demands. For characterizing the groundwater and wastewater qualities of the study area, analysis results were tabulated, statistically treated, and elements and ionic groups were graphically plotted on diagrams and on the Piper well known diagram. The analysis results had shown that some groundwater samples were chemically and biologically contaminated. Moreover, the effluent wastewater samples had shown that all samples contain greater Fecal Coliform (FC) bacteria count and high ammonia content. In addition, the effluent wastewaters are featured with high COD and BOD, reflecting low quality wastewater effluent for the WWTP. Sludge and wastewaters used by farmers, containing high pathogens and parasites, have created or will create significant environmental and health hazards. Similarly, land resources, infrastructure and groundwater quality of the areas are highly, if not already, jeopardized or polluted. Such findings require further detailed studies for monitoring development of pollution in the area.

Enhancing climate resilience in buildings using Collective Intelligence: A pilot study on a Norwegian elderly care center

The combined challenge of climate change and population aging requires novel solutions that enhance the resilience of building energy systems and secure indoor comfort for vulnerable occupants in extreme weather conditions. This research investigates the performance of a newly developed Energy Management (EM) system based on Collective Intelligence (CI) and Reinforcement Learning (RL), called CIRLEM, managing the energy performance of an urban complex in Ålesund, Norway, including an elderly care center with decentralized PV generation, EV charging and storage, while connected to a main electricity grid. CIRLEM controls multiple flexibility assets including independent thermal zones (the demand-side agents) and Electric Vehicle (EV) charging stations (the local storage). In a novel approach, CIRLEM coordinates the distributed storage and generation together with the demand side to control energy systems and react collaboratively to environmental variations. Under extreme weather conditions, without applying CIRLEM, the demand can be more than double that of typical weather conditions. The implementation of the double-layer CIRLEM can reduce the total demand by 35 % over a month. Furthermore, the inclusion of photovoltaic (PV) systems allows the system to be independent from the grid for almost 40 % of its operational hours, while adding EV storage can increase it to around 70 %. Finally, the application of CIRLEM reduced overheating hours from 17 h ∙°C to 2 h ∙°C under extreme conditions, while maintaining comfortable conditions even during temperature ramps.

Raising Adaptive Capacity to Climate Change in Energy and Food Sectors of Egypt

It's highly probable that climate change will impact food security on a global, regional, and local scale. Climate change can disrupt food availability, reduce access to food, and affect food quality. Accordingly, climate change’s impacts on both the agricultural sector reflected on food security and pose a serious threat to sustainable development. Furthermore, the total energy demand of Egypt is marked by an exponential growth of demand on electricity, at a pace much faster than that of GDP, of primary energy consumption and of population mainly due to a doubling up of the consumptions of Egypt. The expected development of the industrial sector, the accelerated access to electricity, and the improvement of standards of living (directly connected with the consumption of the residential sector) are the reasons for these consumption upsurges. The different components of climatic change such as projected increases in temperatures, changes in precipitation patterns, changes in extreme weather events, and reductions in water availability may all result in reduced agricultural productivity and may cause energy consumption upsurges. The main problem pertaining to climatic change and climatic variability in Egypt and even in some parts of the Mediterranean Basin is that systematic climate observation programs are, at present, inadequate to permit reliable assessment, quantification and prediction of climatic conditions and their impacts. A more accurate assessments of regional climate variability and change and their related environmental and socio-economic impacts are highly needed.

Water Demand and Availability in the Tarutung District, North Tapanuli Regency, Indonesia

This comprehensive study addresses the intricate dynamics of population growth, water demand, and availability in the Tarutung District. Employing a geometric approach, we projected the population growth from 2018 to 2032, estimating a 0.74% annual increase. Subsequently, a meticulous water demand analysis encompassed domestic sectors, including household connections and public hydrants, and non-domestic sectors such as educational, religious, market, health, and commercial facilities. The calculated total water demand, encompassing both domestic and non-domestic needs, reached 6,034,026.38 liters per hour and 123,552,000 liters per hour, respectively. In parallel, we investigated the water availability through an examination of spring sources and rainfall data, revealing a substantial surplus. As of now, Tarutung District boasts a surplus water availability of 183,326,289.18 cubic meters per year. In conclusion, the findings indicate that, under current conditions, the Tarutung District is well-equipped to manage its water resources until 2032. However, the study underscores the importance of implementing sustainable environmental policies to safeguard water sources and optimize resource management. The proposed recommendations advocate for local government interventions, community awareness initiatives, water use efficiency enhancements, infrastructure improvements, and stringent forest area management. This research contributes valuable insights to water resource management, emphasizing the need for proactive measures to sustain the water abundance in the Tarutung District. The conclusions drawn and recommendations presented serve as a foundation for informed decision-making, aligning with the broader goals of environmental sustainability and community resilience.

Paper: Modeling and scenario analysis of residential building energy conservation in cities of different weather

Building models are used to predict energy consumption and CO2 emissions under current and future conditions and serve as a basis for building design. The most important energy saving potentials in buildings can be achieved by improving the thermal performance of building and the efficiency of the district heating system. This study investigated energy savings in buildings in cold and hot regions of China and Africa and developed a modeling approach for energy savings in heating and cooling of residential buildings. We have provided an overview of long-term scenarios for energy demand and carbon dioxide (CO2) emissions. Using the industry-renowned software RETScreen, parameter simulations and optimizations are performed over the three time periods (currently 2030 and 2050). As a result, it was found that energy consumption has also increased and the comfort level of high-rise houses is about 10–21% higher than that of cold regions. The comfortable temperature range in these different cities is between 20°C and 29°C. We have showed the difference between the observed values and the model simulations (model bias) for HDD and CDD in cold and hot regions of China and Africa. This model represents spatial patterns and scales observed in Harbin, Shenzhen and South Africa. These features are characterized by an increased north-south gradient in eastern China, a topographically dependent distribution in western China and an associated increase in average temperature. The most commonly used types of heating in residential areas are heat pumps (31%) and district heating (21%). This is also the preferred case for condensing boilers (17%). In non-residential areas, heat pumps (32%), district heating (27%) and condensing boilers (11%) are the most commonly used heating systems. The total energy demand in Africa and China will be increased from 2020 to 2050. It is expected that the total demand for primary energy in China will be 8770 Mtoe in 2050, which corresponds to an increase in demand for primary energy of 1.9%, while Africa will see an increase of 2.7%. Final energy consumption in China and Africa will be 5776 Mtoe and 970 Mtoe respectively.

Transformer based day-ahead cooling load forecasting of hub airport air-conditioning systems with thermal energy storage

The air conditioning system constitutes more than half of the total energy demand in hub airport buildings. To enhance the energy efficiency and to enable intelligent energy management, it is vital to build an accurate cooling load prediction model. However, the current models face challenges in dealing with dispersed load patterns and lack interpretability when black box approaches are adopted. To tackle these challenges, we propose a novel k-means-Temporal Fusion Transformer (TFT) based hybrid load prediction model. Specifically, the daily load patterns are grouped using an improved k-means clustering method that considers both input feature weights and dynamic time warping (DTW) distances. Additionally, the statistical features of the clustering output are inputted into the TFT. By further incorporating context information, the integration of data between different schema categories is achieved, thus reducing errors that may occur during the transition process. As a result, the prediction performance and interpretability are significantly improved. The Chongqing Jiangbei Airport T3A terminal is used as a case study, and experiments are conducted using cooling data from the No.1 energy station, as well as the airport traffic data and the meteorological station data. Results are compared with other mainstream models, confirming that the proposed day-ahead load forecasting model achieves improvements in several performance indicators, including MAE, MAPE, CV-RMSE, and R2, which are 384 kW, 3%, 5%, and 0.058 respectively.

Effect of salinity on denitrification, membrane fouling and bacterial community in a fixed-bed biofilm membrane reactor.

In this study, a fixed-bed biofilm membrane bioreactor was used to assess denitrification and carbon removal performance, membrane fouling, composition, and the dynamics of microbial communities across 10 salinity levels. As salinity levels increased (from 0 to 30 g/L), the removal efficiency of total nitrogen and chemical oxygen demand decreased from 98 and 86% in Phase I to 25 and 45% in Phase X, respectively. Beyond a salinity level of 10 g/L, membrane fouling accelerated considerably. The analysis of fouling resistance distribution suggested that soluble microbial products (SMPs) were the primary cause of this phenomenon. The irregularity in microbial community succession reflected the varying adaptability of different bacteria to different salinity levels. The relative abundance of Sulfuritalea, Lentimircobium, Thauera, and Pseudomonas increased from 20.2 to 47.7% as the experiments progressed. Extracellular polymeric substances-related analysis suggested that Azospirillum plays a positive role in preserving the structural integrity of the biofilm carrier. The SMP-related analysis showed a positive correlation between Lentimircobium, Thauera, Pseudomonas, and the SMP content. These results suggested that these three bacterial genera significantly promoted the release of SMP under salt stress, which in turn led to severe membrane fouling.

Will wind power be cost-effective for decarbonizing the city of Tabriz-Iran, whose economy is oil-based, and how?

This paper investigates the decarbonization of Tabriz-City focusing on its wind power for electrification. Statistical, quantitative, comparative, and simulation-research-methods used to analyze the existing and future total energy consumption, demand, and cost in the city according to carbon-based and wind-based electricity. The Monte Carlo Simulation Method has been used to estimate the probability of the Levelized Cost of Electricity. Tabriz thermal power plant generates 1kWh electricity that costs 0.15 US$/kW without subsidies and produces 575 g.CO2/kW.h overall while it will plunge to 0.05US$/kWh producing 7 g.CO2/kWh using wind. The NPV and IRR (32%) analysis show that that investment in wind-based electricity is three times cheaper than thermal power electricity in Tabriz. It is shown that the electrification of an oil-based economy with wind-based power plants is an economical investment for the city. Besides the hub-height and rotor sweep area, the capacity factor is the most decisive in the productivity of the alternative turbines.