Total Amount Of Energy Research Articles

ENERGY EFFICIENT REHABILITATION OF A HISTORIC BUILDING IN TUCSON, ARIZONA: INVESTIGATING THE POTENTIAL FOR ENERGY CONSERVATION WHILE PRESERVING THE BUILDING’S HISTORICAL INTEGRITY

The focus of this study was to investigate the feasibility of transforming historically significant buildings with high energy requirements into high-performance constructions. The researcher suggested adaptive reuse for the case study, recommending that the building be converted from a warehouse into a café and art studio, which would be in line with the surrounding art district in Tucson, Arizona. As a result of the change in design, everything from the floor plans to the building facades and the mechanical systems were modified. During the visit to the location, the researcher was able to identify the primary factors that led to the low energy efficiency. The study was conducted using the real-life energy simulation that the DOE-2 simulation engine provides. During the process of redesigning the building, the researcher utilized both passive and active design strategies to evaluate how these techniques impacted the amount of energy consumed by the structure. The total amount of energy that was saved from all of the implemented solutions was compared to the total amount of energy that was consumed by the base case (the existing condition). The findings indicated that the chosen case study had a significant potential for reducing energy consumption, with savings amounting to more than 50 percent of the total energy usages.

Observations of Magnetic Reconnection and Particle Acceleration Locations in Solar Coronal Jets

We present a multiwavelength analysis of two flare-related jets on 2014 November 13, using data from the Solar Dynamics Observatory/Atmospheric Imaging Assembly (SDO/AIA), the Reuven High Energy Solar Spectroscopic Imager (RHESSI), the Hinode/X-ray Telescope (XRT), and the Interface Region Imaging Spectrograph (IRIS). Unlike most coronal jets, where hard X-ray (HXR) emissions are usually observed near the jet base, in these events HXR emissions are found at several locations, including in the corona. We carry out the first differential emission measure analysis that combines both AIA (and XRT, when available) bandpass filter data and RHESSI HXR measurements for coronal jets, and obtain self-consistent results across a wide temperature range and into nonthermal energies. In both events, hot plasma first appears at the jet base, but as the base plasma gradually cools, hot plasma also appears near the jet top. Moreover, nonthermal electrons, while only mildly energetic, are found in multiple HXR locations and contain large amounts of total energy. In particular, the energetic electrons that produce the HXR sources at the jet top are accelerated near the top location, rather than traveling from a reconnection site at the jet base. This means that there is more than one particle acceleration site in each event. Jet velocities are consistent with previous studies, including the upward and downward velocities around ∼200 km s−1 and ∼100 km s−1, respectively, and fast outflows of 400–700 km s−1. We also examine the energy partition in the later event, and find that the nonthermal energy in the accelerated electrons is most significant compared to the other energy forms considered. We discuss the interpretations and provide constraints on the mechanisms for coronal jet formation.

Use of Renewable Energy in Agriculture in Terms of Sustainability: Hatay/Turkey Example

The aim of this study was to investigate the use of renewable energy in agriculture and environmental sustainability. Data was obtained with a face to face survey from 120 farmers whom selected randomly from the districts of Hatay province. The Kolmogorov-Smirnov test was used to analyze whether the numerical variables fit the normal distribution or not. Kruskal-Wallis test was used for nonparametric data. The variables found to be significant in the Kruskal- Wallis test were interpreted by using the Mann-Whitney U test. It is found out that age, education level, farm size, total energy cost and income of farmers had a significant relation between groups. Also, differences were identified between farmers' opinions about the use of renewable energy sources and their agricultural practices. Energy is one of the most expensive inputs in agricultural production (especially in irrigation) in the region. The annual total energy amount of the farmers was ₺48.991,60. The total cost of energy affects farmers' information resources. Big farms have a high level of technology use. As a result, the importance of agriculture, energy, environmental protection and sustainability has been evaluated and related recommendations were developed for the region.

Energy consumption optimization in wastewater treatment plants: Machine learning for monitoring incineration of sewage sludge

Biomass management in terms of energy consumption optimization has become a recent challenge for developed countries. Nevertheless, the multiplicity of materials and operating parameters controlling energy consumption in wastewater treatment plants necessitates the need for sophisticated well-organized disciplines in order to minimize energy consumption and dissipation. Sewage sludge (SS) disposal management is the key stage of this process, such that incineration due to the high costs of drying remains a matter of concern. Thus, a combination of experimental investigations and data analysis is required for an efficient plant design. Herein, we propose an intelligent tool based on Machine Learning (ML) algorithms (A: Parallel, B: Artificial Neural Network (ANN), and C: Chained, ML models) by employing SciKit-Learn library in Python, followed by hyper-parameter tuning and the k-fold cross-validation implementation. The optimizer receives simulation data from ASPEN PLUS software, and imitates the behavior of system outputs (namely, Yi: fluidized bed temperature, steam heat transfer rate, and dryer residence time in the SS) to yield optimal changing variables (namely, Xi: feed temperature, air temperature, fume temperature, steam flow rate, moisture content in the feedstock, and steam inlet temperature to dryer). The authenticity and precision of our intelligent optimizer was validated in terms of optimum heat transfer amount (the higher the better) and dryer residence time (the lower the better) by data collected from wastewater treatment plant in Gdynia (Poland), demonstrating excellent predictability of the algorithm. The R2 values for A, B, and C ML models were 0.85, 0.94, and 0.91, respectively. The B model, though slightly revealed better prediction than the C model, estimated the outputs in much lower time than the former. Thus, C model was selected as the computational tool for the optimization purpose. Overall, we claim that the methodology developed herein takes the advantage of ca. 6% saving in the total amount of energy required for incineration unit of SS disposal plant, which is well justified considering the energy crisis raised by the geopolitical issues in the area and also the high cost of energy worldwide.

The Impact of Degradation on a Building’s Energy Performance in Hot-Humid Climates

To date, energy consumption in buildings accounts for a significant part of the total amount of energy consumed worldwide. The effect of ageing and degradation of various building components is one of the least studied reasons for the possible increase in energy consumed in buildings over time. In addition, there is a clear lack of practical guidelines that would help specialists take this factor into account. In this paper, an attempt is made to assess a possible change in the energy performance of buildings due to the degradation of their various components (insulated glass units, thermal insulation, airtightness, solar reflectivity of the building envelope, and photovoltaic modules). Detached and apartment buildings in hot-humid climates with reference to the United Arab Emirates (UAE) were considered. The study was based on simulation research using EnergyPlus, in which the initially collected data on the possible deterioration of the properties of various building components was used for dynamic thermal simulation of selected buildings. The results showed an increase in energy consumption for cooling in detached houses might reach up to 9.53–38.4% over 25 years for more airtight and insulated buildings and 12.28–34.93% for less airtight and insulated buildings. As a result, certain patterns of changes in energy consumption for cooling buildings were established, based on which a set of guidelines was developed. These guidelines can help specialists in various fields better understand the trends in the energy performance of buildings under the influence of degradation processes and take appropriate measures.

Development of waste heat recovery technology from steel slag

The temperature of molten steel slag produced by the steelmaking process is 1500°c~1700°c, and the total amount of energy contained is considerable. Therefore, the efficient recovery and utilization of sensible heat of steel slag has always been the focus of attention of the metallurgical field all over the world. However, at present, the average recovery rate of waste heat resources per ton of steel in China's iron and steel industry is less than 26%, while the sensible heat recovery rate of various molten slag (including steel slag) is only 1.6%. There are huge room and a broad market for improvement.

Sustainable Energy: reproductive aspects

The article draws attention to the reproductive aspects of household participation in the implementation of a sustainable economy and sustainable energy, which have been actively studied in recent years. The author examined the main ways households can participate in the development of sustainable energy. It has been established that household participation in sustainable energy depends on many factors, which are classified into exogenous (main and secondary) and endogenous (main and auxiliary). Indicators are proposed to measure the total amount of energy generated in a household and the secondary (re)consumption of generated energy. According to the author, the creation of technological infrastructure within the framework of nature-like technologies will increase the share of households’ contribution to ensuring the reproduction of sustainable energy energy.

RF energy harvesting schemes for intelligent reflecting surface-aided cognitive radio sensor networks

Energy harvesting (EH) is a potential solution to enhance the node sustainability and prolong the network lifetime of cognitive radio sensor networks (CRSNs). However, CRSNs nodes can only harvest energy from the direct link with energy sources, and severe path loss results in low energy utilization ratio. To solve the above problem, intelligent reflecting surface (IRS) is introduced, and a shared reflection coefficient matrix-based EH scheme is proposed for IRS-aided CRSNs in this paper. An optimization problem with the objective of maximizing the total amount of energy harvested by all CRSNs nodes is formulated, and by optimally adjusting the IRS reflection coefficient, CRSNs nodes can harvest energy from both the direct link and the cascaded reflection link via IRS, which increases the amount of harvested energy. In addition, a subsurface partition-based EH scheme is proposed to reduce the additional computational complexity brought by increasing IRS elements or CRSNs nodes. Simulation results show that the proposed schemes can both dramatically improve energy utilization ratio, and the subsurface partition-based EH scheme will bring in less than 1 percent performance loss when compared with the other scheme, i.e., reasonable subsurface partition can achieve a balance between harvested energy and computational complexity.

Experimental Research of the Impact of Ship’s Rolling on the Performance of PV Panels

Abstract The aim of the International Maritime Organization (IMO) to reduce by half the amount of greenhouse gases emitted by marine ships by 2050, and its vision of the fastest total decarbonisation in the maritime shipping industry within the present century, calls for implementation with various means of decarbonisation. The IMO approaches the process of decarbonisation in two phases. Firstly, short-term, compact projects are to be considered, next, more complex, medium- and long-term solutions should be aimed at. The preferred arrangements to be applied are photovoltaic systems. Their performance depends to a high degree on the solar incidence angle. In the case of a ship swinging as a result of its course in relation to the wave and incidence direction, the incidence angle undergoes significant periodic changes with a significant effect on the power generated by the PV panels. As a result, the total amount of energy produced by the PV panels diminishes. The paper presents experimental research results obtained on the stand that allowed the investigation of PV panels in simulated marine conditions. Two characteristic positions of a PV panel’s rotation axis in relation to the solar rays’ incidence direction were investigated. It was proved for both variants that the rolling period and solar incidence angle affected the power generated by the PV panel.

Experimental Investigation of the Power Storage System for Savonius Turbines in Wind and Water

The Savonius turbine is practical in generating off-grid electrical power for hydrokinetic applications due to its simple design, particularly for small rivers in rural areas. However, despite many studies on methods to improve turbine performance, the electrical aspect of the turbine system is rarely discussed. Therefore, the present study aims to evaluate the performance of a simple and affordable power storage system using a conventional 2-bladed Savonius turbine. The experiment was conducted in a wind tunnel and a water channel with flow speeds of 6 m/s and 0.33 m/s, respectively, corresponding to a Reynolds number of 62700. A power coefficient of 0.09 was discovered for the wind experiment and 0.11 for the water. The total amount of energy extracted from the water was 60% less than from the wind due to the lower available power. It was observed that the tip speed ratio decreases over the charging period due to the constant current and voltage of the Lithium-Ion batteries. This will allow for a fluctuation in the amount of required current and consequently affect the torque needed to spin the generator. The findings confirmed the functionality of the electrical storage system and contributed to the low manufacturing and maintenance cost of the hydrokinetic turbines.

Study of Influence of IT-Technologies on Indicators of the Energy Sector of the Economy

Introduction. Energy is an essential branch of the economy, which needs not only reconstruction but effective, innovative solutions, one of which is the wide implementation of digital technologies. It is important to investigate possible cross-industry changes to adjust macroeconomic scenarios of industry development. The purpose of the study is to assess the degree of influence of the introduced 'smart' technologies in the energy industry on the level of inter-industry relationships according to the developed algorithms of the econometric and static Input-Output models. Results. The main consequence of calculations according to the proposed methodology is the possibility of assessing the impact of the introduction of 'smart' technologies on structural dynamics in the energy sector. However, the statistical data for the selected time interval is not enough for analysis by types of renewable energy. Since the share of 'green' energy in the total amount of energy produced remains insignificant, its influence on the accumulation of 'smart' technologies is insufficient. Conclusions. The analysis of statistical calculations allows us to state that the increase in 'smart' technologies implementation in the energy industry of Ukraine has a direct functional impact, albeit insignificant, and demonstrates the positive dynamics in the IT services inter-industry use. The negligible impact is caused by reduced allocations for the renewal of fixed assets in traditional energy sectors. There is a certain use of the latest technologies in the field of renewable energy sources, but their share in the energy structure is insignificant, although it has positive dynamics. Calculating the macroeconomic scenarios of the industry development according to the direct and inverse Input-Output models, which are promising for developing economic equalization measures in the energy sector, remains relevant. Keywords: econometric model of Input-Output tables, direct and dual problems of the IO model, inter-industry flows, types of economic activity, regression analysis.

The New Lithotripsy Index predicts success of shock wave lithotripsy.

The aim of this study is to evaluate the factors affecting treatment success in patients who underwent Shock wave lithotripsy (SWL) and to investigate the effect of the Storz Medical Lithotripsy Index (SMLI) on treatment effectiveness. Prospective data were collected on patients undergoing SWL treatment for kidney stones between January 2013 and May 2021. Stone location, number and size were determined with non-contrast CT (NCCT) for all patients. All patients underwent SWL with a Storz Modulith SLK lithotripsy machine without anaesthesia. The total amount of energy applied to the stone was calculated using the SMLI. All patients were evaluated for stone-free status by X-ray at least 2weeks after treatment. The success of the procedure was defined as the patient being completely stone free or the detection of residual fragments < 4mm that did not require further treatment. A total of 1230 patients with kidney stones were included in the study. The mean age of the patients was 42.33 ± 11.78 (18-75), and the mean BMI was 28.47 ± 8.78 (19.25-38.52). During SWL, 75.6% of patients demonstrated excellent pain tolerance (930/1230). A total of 116 patients could not tolerate the pain during SWL (9.4%). Treatment success was associated with fewer treatment sessions (2.34 ± 1.75 vs. 2.90 ± 2.04; p < 0.001), smaller stone size (7.52 ± 3.29 vs 8.60 ± 3.93; p < 0.001) and higher SMLI/stone size (25.11 ± 13.63 vs. 22.27 ± 14.50; p < 0.001). In the univariate and multivariate regression analysis, the factors affecting the success of the treatment were the number of sessions (OR 1.170), stone size (OR 1.142), number of shocks (OR 1.005), SMLI/stone size (OR 1.024) and pain tolerance (OR 0.692). In the treatment of kidney stones with SWL, stone site, stone size, SMLI/stone size, and pain tolerance are the factors affecting success. SMLI per stone size is a statistically significant factor for predicting SWL success.

Insulating foamed lightweight cementitious composite with co-addition of micro-sized aerogel and hydrogen peroxide

Noise pollution and thermal discomfort are major concerns in urban areas these days. The building sector consumes a large amount of total energy to fulfill the thermal comfort demands, which are rapidly increasing with modern advancements. The overwhelming energy demand and noise pollution prevalent in the building sector can be controlled using insulating cementitious composites. Therefore, this research investigates the properties of foamed lightweight cementitious composite (FLCC) which incorporates the co-addition of micro-sized aerogel and hydrogen peroxide. Different contents of aerogel (0.5%, 1%, and 1.5% by weight of cement) were used as additives along with various dosages of hydrogen peroxide (1%, 2%, and 3% by weight of cement) to produce the FLCC. The optimum content of the FLCC comprising 1% aerogel and 3% hydrogen peroxide, has a low oven-dry density of 380 kg/m3 with an adequate compressive strength (about 3 MPa) for application as an insulating cementitious composite. The high porosity characteristic (up to 76%) of the FLCC improved sound absorption and thermal conductivity (reduction by 88%). Overall, the results highlighted the promising role of aerogel and hydrogen peroxide incorporated FLCC as a useful insulating construction material.

A demand side management approach to increase self-consumption in buildings

There is a growing interest in increasing the presence of renewable energy in the electric network. Photovoltaic production from grid-connected systems is leading this growth in terms of households. Alongside this development, concern about network security has emerged, because excesses of intermittent renewable energy on the grid could exceed voltage limits. Self-consumption, understood as the capacity of the producer to consume his or her own production, can partially solve these problems. Thermostatic controllable loads, such as heating and cooling, represent 50% of the total amount of energy consumed by buildings; the proper allocation of these loads could be a driving force for self-consumption. In this study, a demand side management strategy is proposed based on a building energy model equipped with an inverter heat pump coupled with a photovoltaic plant. The goal is to maximize the use of local energy from the photovoltaic plant (self-consumption), reducing the export and import of energy to and from the grid. This goal is achieved by optimizing the set-points in each room. An array of optimal set-points over six years is presented. The results show the capacity of the methodology to match similar values of self-consumption (70% in winter and 50% in summer) obtained by strategies based on chemical batteries. The findings are shown in an energy matching chart at different levels of detail (yearly and monthly). Color bubbles are added to the matching chart to help visualize the unmatched energy of the system graphically. In comparison with actual model predictive control technologies, this study’s strategy offers great simplicity and a large saving in computational time.

Characterization and optimization of energy sharing performances in energy-sharing communities in Sweden, Canada and Germany

Peer-to-peer (P2P) renewable power sharing within a building community is a promising solution to enhance the community’s self-sufficiency and relieve the grid stress posed by the increased deployment of distributed renewable power. Existing studies have pointed out that the energy sharing potentials of a building community are affected by various factors including location, community scale, renewable energy system (RES) capacity, energy system type, storage integration, etc. However, the impacts of these factors on the energy sharing potentials in a building community are not fully studied. Being unaware of those factors’ impacts could lead to reduced energy sharing potentials and thus limit the associated improvement in energy and economic performances. Thus, this study conducts a comprehensive analysis of various factors’ impacts on the energy sharing performances in building communities. Two performance indicators are first proposed to quantify the energy sharing performances: total amount of energy sharing and energy sharing ratio (ESR). Then, parametric studies are conducted based on real electricity demand data in three countries to reveal how these factors affect the proposed indictors and improvements in self-sufficiency, electricity costs, and energy exchanges with the power grid. Next, a genetic algorithm based design method is developed to optimize the influential parameters to maximize the energy sharing potentials in a community. The study results show that the main influential factors are RES capacity ratio, PV capacity ratio, and energy storage system capacity. A large energy storage capacity can enhance the ESR. To achieve the maximized ESR, the optimal RES capacity ratio should be around 0.4 ∼ 1.1. The maximum energy sharing ratio is usually smaller in high latitude districts such as Sweden. This study characterizes the energy sharing performances and provides a novel perspective to optimize the design of energy systems in energy sharing communities. It can pave the way for the large integration of distributed renewable power in the future.

Simultaneous Cr (VI) reduction and diazinon oxidation with organometallic sludge formation under photolysis: kinetics, degradation pathways, and mechanism.

In this study, simultaneous removal of an organic matter (diazinon, DIZ) and an inorganic substance (chromium, Cr) was used. Breaking down of organic matter by UV irradiation produces various radicals, including sulfides, carboxyl, hydroxyl, hydrated electrons, and various organic radicals that are highly reactive and help us to precipitation inorganic substance (Cr). The optimal condition was 30:1 DIZ:Cr molar ratio, pH 9, and about 100% and 82.3% of DIZ and Cr were obtained in 30min. Cr deposition was very slow at first. After the destruction of the DIZ structure, Cr deposition began, and various types of sludge with disturbed properties were formed. These sledges were analyzed by FTIR analysis and showed that green sludge could be chromium (III) hydroxide; brown sludge due to chromium (III) hydroxide, tiny green crystals from chromium (III) oxide, red brick from chromium (II) acetate chromium trioxide, as well as black sludge caused by chromium oxide were identified. In UV/DIZ/Cr process, kobs and robs range obtained 0.33-0.15 and 16.8-23.4 $ with both Cr and DIZ concentration increased from 50 to 150mg L-1. Also, EEO for Cr precipitation was 24.65 to 5.74 and for DIZ 12.54 to 4.73 (kwh m-3). Depending on the amount of energy consumption, TCS was 37.19 to 10.47 for Cr precipitation and 4.46 to 1.25 $. It is important to note that when both pollutants are exposed to ultraviolet light, more energy and cost are generally required from UV/DIZ process and less than of UV/Cr process. But it should be noted that in fact 50mg L-1 of chromium and 50mg L-1 of DIZ are being removed at the same time. In UV/DIZ and UV/Cr processes that are exposed to ultraviolet radiation alone, only one of them is removed. Also, when these two pollutants are being removed at the same time, the total amount of energy is much less than the total energy consumption of the pollutants one by one.

Sensitive mode investigations of lithium-ion cells with tavorite-type LiVXO4F (X = B, Si) as cathodes with stable cycling in low temperature operations

Li-ion battery cathodes appear to be a significant factor affecting the total amount of energy delivered and the cost of the battery systems. LiVXO4F (X = B, Si), a polyanionic-based tavorite structure, is investigated as a cathode for Li-ion batteries and its capability to endure in sensitive mode operations, i.e., at temperatures of approximately 55 and −10 °C. Due to the near-freezing point at the atomic level and the absence of kinetic energy, a battery system operating at a lower temperature is theoretically expected to perform inferior. On the contrary, Vanadium boron oxyfluoride (VBF) has better electrochemical properties because of its tightly packed covalent bond, which produced structural stability at low temperature activities. This intriguing feature appears to hold promise for its use in advanced rechargeable battery systems in low-temperature areas and cold storage devices. This might pave the path for future energy storage and conversion devices to use neoteric tavorite structured electrodes.

Comparative Analysis for a Solar Tracking Mechanism of Solar PV in Five Different Climatic Locations in South Indian States: A Techno-Economic Feasibility

As the second most populous country in the world, India’s needs related to electricity production are still growing; thus, the country is seeking renewable energy resources as an alternative to conventional resources. Currently, India’s use of renewable energies ranks as fifth worldwide, with approximately 13.22% of the total amount of energy used in the form of solar energy, which is very nominal. Therefore, in the present study, a large-scale 20 MW solar PV power plant was modelled to access the technological and economic performances using the System Advisor Model (SAM) for the selected locations: Vishakhapatnam (VSKP), Hyderabad (HYD), Madurai (MDU), Thiruvananthapuram (TVC), and Bangalore (SBC), where solar radiation is high for South Indian states. In order to carry this out, three solar tracking mechanisms, i.e., fixed tracking (FT), single-axis tracking (SAT), and double-axis tracking (DAT), are taken into consideration at the selected locations. The results from the assessment of the FT mechanism’s yearly energy production show that 31 GWh were produced at TVC and 33 GWh were produced at VSKP, HYD, MDU, and SBC in the first year of the project, with a capacity factor (CF) from 18.5% to 19.5%. Conversely, the SAT mechanism generated an annual amount of energy, ranging from 38 GWh to 42 GWh, with an increase in the CF ranging from 22% to 23%. Furthermore, the DAT mechanism’s annual energy generated 44 GWh to 46 GWh, with the CF ranging between 25% and 26.5%. However, the recorded levelized cost of energy (LCOE) ranges were between 3.25 ¢/kWh to 4.25 ¢/kWh at the selected locations for all three mechanisms. The sensitivity analysis results also suggest that the FT and SAT mechanisms are not economically feasible because of their negative net present values (NPV) in all five locations, whereas the DAT mechanism generated positive results for all of the locations after 20 years. Furthermore, according to the study, we concluded that HYD was identified as the most feasible location in the South Indian region for installing a large-scale solar PV power project.

Experimental comparative analysis of hybrid energy harvesters exposed to flow-induced vibrations

In this study, hybrid energy harvesting based on electromagnetic induction (EM) and piezoelectric transduction (PZT) is experimentally investigated under different conditions of flow-induced vibrations. The energy harvesting performance of the system is examined when the electromagnetic and piezoelectric mechanisms are used both separately and simultaneously. In this regard, firstly, only electromagnetic induction harvesting structure is attached to a beam, and time-dependent voltage and displacement are experimentally investigated. Then, PZT has adhered to the beam, and voltage outputs are measured in both the PZT and EM circuits. The third scenario is based on removing the electromagnetic harvesting structure and only the piezoelectric energy harvesting performance is studied. The mentioned cases are investigated under different excitation circumstances, that is, distinct bluff-body geometries and flow velocities. While the square bluff-body geometry is connected to the structure, both PZT and EM harvested power are determined by considering different electrical load resistances. It is mainly revealed that the total energy amount is higher in the hybrid configuration. After determining the hybrid structure is the most effective, elements with different splitters geometry are attached to the bluff-body geometry of the harvesting structure. Finally, the vibration enhancement potential of these new types of splitters on the harvesting structure is experimentally investigated. For the solo electromagnetic harvester, the maximum power is obtained at an external load resistance value of 10 kΩ, while for the solo PZT harvester, the maximum power is observed at the resistance value of 330 kΩ. Among the three types of splitter geometries examined, the highest voltage was obtained from type-1 as 14.168 V.

The Benefits of Midmorning Snack to Combat Stunting: A Longitudinal Panel Study in the Riau Province of Indonesia

Aim:The aim of this research was to help stunted adolescents improve their nutritional status.Background:Stunting is a leading global nutritional problem, especially in developing countries such as Indonesia. This was a longitudinal panel study in the SMP Negeri 3 Pekanbaru Riau Province Junior High School in Indonesia.Objective:The objective of this study was to determine the impact of calcium and phosphorus supplementation via additional midmorning snacks for adolescents with stunting conditions.Methods:We included 36 participants, aged 12–15 years with a height-for-age Z-score of &lt;-2 standard deviation. They underwent a one-month nutritional intervention during which selected snacks and high-calcium milk were given for midmorning snacks. The midmorning snack menu varied daily and included gado-gado (rice, boiled egg, potato, tempeh, tofu, long beans, cabbage &amp; peanut sauce), fried vermicelli (vermicelli, omelet, cucumber &amp; prawn crackers), batagor (tofu, cassava flour crackers, boiled egg &amp; peanut sauce), lontong medan (rice, boiled egg, vermicelli, french fries, fried anchovy, green bean &amp; carrots curry), sandwich (plain toast, omelet, cucumber, lettuce, tomato &amp; chili sauce), chicken porridge (rice porridge, fried bread, shredded chicken &amp; chicken broth), and fried rice teri (rice, anchovy, prawn crackers, cucumber, chili sauce &amp; soy sauce). The total amount of energy from the meals and milk was 541.8 kcal (30 % of RDARecommended Dietary Allowance), 25 g of protein (50 % of RDA), 90 g of carbohydrate (30 % of RDA), and 600 mg of calcium (35 % of RDA). Meal and milk administration lasted 34 days in total. Data analysis and food intake consumption were conducted using the Pearson Product moments test.Results:The participants’ mean height-for-age Z-score before and after the nutritional intervention was -2.5 ± 0.4 (-3.2 — -2.0) and -2.3 ± 0.4 (-3.2 — -1.2), respectively. After the intervention, the rate of stunting was reduced up to 19.4%; the rate of calcium intake before the nutritional intervention was 50% below the recommended dietary allowance—27.3 ± 27.8 (3.3:100.0) %; the rate of phosphorus intake among the participants was sufficient. The rate of calcium intake after the nutritional intervention was 59.1 ± 19.0 (15.5 — 100.0) % due to which the nutritional quality of food before the intervention was still lacking, namely 52.7 ± 15.5 (28.4 — 86.3) after the nutrition intervention increased to 84.8 ± 20.3 (30.9 — 100.0); (r-value = 0.43; p-value = 0.01).Conclusion:The nutritional intervention increased calcium intake. The outcome of the nutritional intervention led to the improvement of nutritional status from stunting to the normal category.Other:The midmorning snack given to teenagers is a snack meal available in the school canteen that they can buy with pocket money. It is necessary to create awareness about the importance of consuming high calcium midmorning snacks for teenagers. The activity of consuming high-calcium midmorning snacks by adolescents can be continued independently. So far, teenagers do not use pocket money to buy midmorning snacks that are high in calcium, but they buy other types of snacks that are low in calcium, consisting of pastel, noodles, tofu, fritters, pao, tempeh, rice cake, and eclairs. So far, no nutritional intervention has significantly increased the nutritional status of stunted children to normal levels; however, this type of intervention may become a viable option in the future.