Energy Science and Engineering

There is an unmet need to develop high performance energy storage systems (ESS), capable of storing energy from both renewable and nonrenewable sources to meet the current energy crisis and depletion of non-renewable sources. Amongst many available ESS, supercapacitors (ECs) are the most promising because they exhibit a high charge/discharge rate and power density, along with a long cycle life. A novel use of atomically thin carbon allotropes like graphene, carbon nanotubes (CNTs) and electrically conducting polymers (ECPs) such as polypyrrole (PPy) have been studied as high performance conducting electrodes in supercapacitor application. A novel templated sustainable nanocomposite electrode has been fabricated using cellulose extracted from Cladophora c. aegagropila algae as a component of the assembled supercapacitor device which later has been transitioned to a unique template-less freestanding nanocomposite supercapacitor electrode [1]. The specific capacitance of polypyrrole-graphene-cellulose nanocomposite as calculated from the cyclic voltammetry curve is 91.5 F g -1 at the scan rate 50 m Vs -1 in the presence of 1M NaCl electrolyte. The open circuit voltage of the device with polypyrrole -graphene-cellulose electrode was found to be around 225 m V and that of the polypyrrole -cellulose device is only 53 m V without the presence of graphene in the nanocomposite electrode. Understanding the fundamentals by fabricating template nanocomposite electrode led to developing a unique nanocomposite templateless freestanding film which comprises of polypyrrole-graphene-CNT hybrid [2]. Various experiments have been performed using different electrolytes such ascorbic acid, sodium sulfate and sulfuric acid in different scan rates. The specific capacitance of polypyrrole-graphene-CNT nanocomposite with 0.1 wt% of graphene-CNT, as calculated from cyclic voltammetry curve is 450 F g -1 at the scan rate 5 m V s -1 . For the first time a nanofibrous membrane has been developed as a separator which acts as an electrolyte reservoir and ionic diffusion membrane. The performance of the fabricated supercapacitor device has been analyzed using a multimeter and compared with a conventional alkaline (1.5 V) battery. Lighting up of 2.2 V light emitting diode has been demonstrated using the fabricated supercapacitor.

The study delves into the aerosolization process of fuel flow in combustion engines with the aim of adjusting the droplet size distribution to optimize combustion. While smaller droplets offer advantages in better evaporation and combustion, the research nullifies their benefits in enclosed engine environments. Simulating the consecutive processes of fuel injection, droplet formation and breakup, combustion, and pollutants' production and motion within a Reactivity Controlled Compression Ignition (RCCI) engine highlights that the production of excessively fine droplets (below 25 µm Sauter mean diameter) requires a sudden increase in injection pressure, raising the risk of some high-momentum droplets escaping combustion and adhering to engine surfaces. Moreover, the combustion initiates earlier while injection is still in progress, and upstream droplets combust at larger sizes without sufficient time to fragment. These phenomena diminish engine efficiency, escalate emissions of volatile organic compounds, and yield economic detriments. In light of these findings, the study postulates that neither excessively fine nor large droplets are ideal for combustion, and uniformity in fuel droplet size distribution is the key in efficient combustion. Regarding this, to generate more homogeneous and sufficiently small droplets, the study reveals two pivotal characteristics for injection pressure function: a continuous increase combined with specific number of vibrations, leading to an increasing oscillatory function. This discovery is evaluated through a comprehensive framework encompassing energy, exergy, environmental impact, and economic considerations. Not only does it enhance power efficiency and reduce VOC emissions, but it also yields more irreversibility, opening opportunities for more waste heat recovery. These advantages can lead to significant improvements in overall engine performance and efficiency.

Biomass briquetting is a process which converts agro residue and saw dust materials with low bulk density into a uniform size and more convenient households or industrial fuel product. The major advantages offered by biomass densification are related to handling improvement and increasing calorific value per unit volume. In general this process offers energy generation opportunity from any biomass residue. Maichew Particle Board Factory generates a huge amount of dust particles from its different lines which recovered using different cyclones. But this recovered waste doesn't use as a fuel for boiler or dryer and also not yet convert to any valuable product. It is simply disposed to the environment. Therefore, the objective of the project was to study an integrated briquetting plant for Maichew Particle Board Factory which converts the waste dust particle in to valuable product. This case study involved the overall energy review of Ethiopia and briquetting process in detail. According to the selection of appropriate technology which converts the eucalyptus dust to high quality briquette fuel screw press extruder with a pre heater and heated die coils has been chosen. In addition the amount of energy required to convert the dust particle to briquettes is also evaluated. Based on the results of this study, the economic evaluation of the integrated briquetting plant for Maichew Particle Board is feasible besides to its socio environmental benefits. It is an investment which can recover its capital with almost two years.

Production of biogas utilizing agricultural wastes is one of the most demanding technologies for generating energy in sustainable manner considering environmental concerns. However, though the agricultural wastes are available in abundance, the technologies used for the production of biogas such as biological and thermochemical processes are not very efficient. In the present article, we describe a process for the production of biogas from coffee pulp utilizing Cu/TiO 2 as an efficient photocatalyst in its solar photocatalytic pretreatment, producing biogas of high caloric value at enhanced rate. The pretreatment process enhances the coffee pulp-cattle manure codigestion, producing increased amounts of methane, propane, and other combustible components of biogas. The photocatalytic pretreatment was performed using 10%Cu/TiO 2 as photocatalyst, bubbling air as oxidizing agent, and solar radiation as light source. The process enhances the degradation rate of lignocellulosic components of coffee pulp, consequently increasing the biogas production through anaerobic codigestion. The mechanism of photocatalytic degradation of lignocelluloses has been discussed. The results presented in this work indicate the photocatalytic pretreatment is a useful process to increase biogas generation from lignocelluloses-rich natural wastes.

In this paper, the wind data for Plateau North Central Nigeria was collected at 10m height for seven years (2000)(2001)(2002)(2003)(2004)(2005)(2006) at meteorological station Abuja. The assessment for the site is gaining importance for the installation of an appropriate wind turbine at the location. The highest wind speed for this location was found to be 15.4m/s in January and the lowest wind speed is 8.7m/s in August within the period of years considered. The study was carried out using the Weibull parameters scale (c m/s) and shape (k) factors and result obtained for these parameters have an average value of 10.76m/s and 7.47 respectively. These values indicate that the wind would be useful for power generation over a longer period. The power density for this location varies between 368 and 1056W/m 2 , this also shows that Plateau is a good location for wind power generation.

CREA ve GEM: Çin’de temiz enerji büyürken, kömür yatırımları devam ediyor
Coal is losing ground but not letting go: Structural inertia and the struggle to shift coalʼs role in Chinaʼs power system
25 August 2025
Centre for Research on Energy and Clean Air (CREA) ve Global Energy Monitor (GEM), 2025 yılı ilk yarısına ait Çin’in kömürlü enerji projelerine dair yarı yıllık raporunu yayımladı. Rapor, kömürlü enerji yatırımlarının hız kesmeden devam ettiğini ve yeni projelerin onaylanma oranlarının yüksek seyrini sürdürdüğünü ortaya koyuyor.

https://energyandcleanair.org/wp/wp-content/uploads/2025/08/CREA_GEM_China_Coal-power_H1-2025.pdf

With the continuous expansion of the high-purity hydrogen application range, the performance degradation of hydrogen storage alloy (HSA) caused by impurities has attracted widespread attention in producing pure hydrogen from biomass. In this study, the lanthanum-rich mischmetal alloy's purification ability on hydrogen sulfide impurities and cycling performance were studied. The hydrogen with different concentrations of hydrogen sulfide was used to investigate the purification performance, which assumes the gas derived from biomass. Besides, a cycling experiment was designed to analyze cycling performance. The results show that the HSA could remove high concentrations of hydrogen sulfide entirely. It was also found that impurities of 1 ppm hydrogen sulfide had little effect on the HSA. With hydrogen sulfide concentrations of 100 ppm, the hydrogen storage capacity, absorption rate, and release rate were reduced, but they became a stable state from the second cycle. The performance degradation mechanism was analyzed by Energy Dispersive X-Ray Spectroscopy (EDS) and X-ray Photoelectron Spectroscopy (XPS ).

This paper presents an artificial approach for optimizing parameters of the proportional-integral (PI) controller in a reactive power control loop of voltage source converters high-voltage direct current (VSC-HVDC) transmission systems. The control strategy is based on a PI controller due to its simple structure and strong robustness. The Sharaf algorithm particle swarm optimization (SAPSO) is a heuristic optimization method that is used in this paper to get optimal values of PI parameters. This modification based on the inertia weight parameter to speed up the convergence towards the optimal values. SAPSO has many merits, such as easiness in control its parameters and its simple implementation compared to other artificial approaches. VSC-HVDC system is established in MATLAB/Simulink to apply the SAPSO. This system is exposed to different disturbances to evaluate its dynamic response. The objective function is minimizing the error between the measured and reference value of reactive power to get a better dynamic response. The obtained results showed that there is a significant improvement in reactive power dynamic response in a system with optimized parameters.

This paper presents an artificial approach for optimizing parameters of the proportional-integral (PI) controller in a reactive power control loop of voltage source converters high-voltage direct current (VSC-HVDC) transmission systems. The control strategy is based on a PI controller due to its simple structure and strong robustness. The Sharaf algorithm particle swarm optimization (SAPSO) is a heuristic optimization method that is used in this paper to get optimal values of PI parameters. This modification based on the inertia weight parameter to speed up the convergence towards the optimal values. SAPSO has many merits, such as easiness in control its parameters and its simple implementation compared to other artificial approaches. VSC-HVDC system is established in MATLAB/Simulink to apply the SAPSO. This system is exposed to different disturbances to evaluate its dynamic response. The objective function is minimizing the error between the measured and reference value of reactive...

with the acceleration of 0.69ms -2 , the optimum opened-circuit voltage, V OC produced for TENG is 3.97V while for the EMG is 1.85V. The hybrid nanogenerator produced 2.071mW of power with a resistance of 1kΩ. The power density obtained from the prototype is 2.6059Wm -3 which is enough to power up the low power sensor node.

Recent years have seen significant progress in short-term prediction methods, largely driven by the proliferation of data-driven approaches. In this vein, a novel model called the Spatial Feature Attention-based LSTM (Long Short-Term Memory) has emerged, with the goal of improving the accuracy and dependability of shortterm forecasts. Deep learning methodologies have ushered in a new era across multiple fields, and one particularly notable domain benefiting from these advancements is time series forecasting. Weather prediction stands out as a critical area, with implications spanning agriculture, transportation, and disaster management. The precision of short-term weather forecasts holds immense importance, directly influencing decision-making processes and strategic planning efforts.

Climatological and geological site classification intended for Earth-Air Heat Exchanger Technology (EAHE) is an important factor in the design, implementation and optimal operation of such system. In this context, this paper presents an investigation on the heating performance and operating feasibility of two EAHEs in three different geo-climatic regions in Algeria. First, the performances of the EAHEs were experimentally studied in the temperate Oran climate and the corresponding results were used for validation of the numerical part. The experiment allowed to analyze the effect of the pipe material on the performance of the two EAHEs that are made of different materials (PVC and Zinc). After validation of the numerical part, the study was extended to three different climates including a temperate climate for Oran, an arid climate for Bechar and a steppe climate for El-Bayadh cities. For these climates, the heating study is rarely considered in this context. Furthermore, a sensitivity analysis was conducted in order to evaluate the operating feasibility of the EAHEs in the considered regions. The results revealed that the Zinc EAHE is more efficient in a temperate climate with a COP of 9.5 than in an arid or steppe climate with a COP of 8.2 or 8.1, respectively. However, the PVC EAHE is much better in an arid climate with a COP of 9.4 than in a temperate or steppe climate with a COP of 7.6 or 8.4, respectively. Otherwise, both EAHEs exhibited similar behavior in a steppe climate. The results show that the thermal performance of EAHE mainly depends on geo-climatic conditions and the type of pipe material.

The needs for improving observability of medium and low voltage distribution networks has been significantly increased, in recent year. In this paper, we focus on practical approaches for placement of affordable Measurement Devices (MDs), which are providing three phases voltage, current, and power measurements with certain level of precision. The placement procedure is composed of a state-estimation algorithm and of a greedy placement scheme. The proposed state-estimation algorithm is based on the Distflow model, enhanced to consider the shunt elements (e.g., cable capacitances) of the network, which are not negligible in low voltage networks with underground cables. The greedy placement scheme is formulated such that it finds the location of minimum required number of MDs while certain grid observability limits are satisfied. These limits are defined as the accuracy of state-estimation results in terms of voltage magnitudes and line currents over all nodes and lines, respectively. The effectiveness of the proposed placement procedure has been validated on a realistic test grid of 10 medium voltage nodes and 75 low voltage nodes, whose topology and parameters were made available from the Distribution System Operator (DSO) of the city of Geneva, Switzerland.

This study utilized a full factorial design with three factors at two levels each: thermal conductivity, pipe length, and air velocity. We aimed to identify optimal EAHE configurations for both summer cooling (maximum air temperature reduction) and winter heating (maximum temperature increase). Distinct optimal conditions emerged for each season. For summer cooling and winter heating, optimal configurations involved high thermal conductivity, moderate pipe length, and minimal air velocity. Statistical analysis revealed pipe length as the most influential factor on temperature in both seasons, explaining over 59% of the variability in winter and 49.43% in summer. Air velocity exerted a significant impact, while thermal conductivity had a smaller but still important influence. These findings showcase the effectiveness of full factorial design in unraveling complex interactions and pinpointing key parameters for EAHE optimization.

Leucaena leucocephala or locally known in Malaysia as 'petai belalang' was studied as an alternative material to produce sugar from cellulose. Analyses of the dried samples contain about 25% lignin, 50% cellulose and 17% hemicellulose. This dried sample was pulverised, mixed with water (10% w/v) and pre-treated by autoclaving. The resulting liquid and solid fractions were enzymatically hydrolysed and analysed for sugars, with a yield of 30% and 17%, respectively. Further analyses revealed that the sugars consisted mostly of glucose at 30% from the liquid and 40% from the solid fractions, clearly exhibiting higher content of glucose in the solid fraction. Accordingly, 1kg of fresh petai belalang biomass (84% dry matter) produces 395g of raw sugar, almost 50% of the total fresh weight. In a circular economy, this exhibits the potential of using waste biomass from petai belalang that can be utilised to produce raw sugar. Other sugars were traces of arabinose at 2% and cellulobiose at 1%. Purification of this raw sugar by filtration on PAC actually removed about 80% of the sugar, with a remaining amount of 87g (22%) purified glucose, at 55g and 32g from the liquid and solid portions.

Thunderstorm and lightning are the burning issues in present. Raising temperature badly affects on the environmental balance. We have collected data and studied the temperature variation and the temperature effect on the environment and on the people of Rangpur (divisional city of Bangladesh) region. Increase of monthly maximum temperature is 0.60°C, monthly minimum temp is 1.39°C and monthly mean temperature of Bangladesh is 0.79°C per 100 years where in last 29 years the temperature of Rangpur station is increased almost 1.2°C. [2] Thunderstorm and lightning occur for this increased temperature. We also analyzed the number of occurrences of thunderstorm in last ten years. We tried to find out some way to reduce the temperature increase and to safe the people. We constructed earthen in five multi-stored buildings and observed the lightening effect on and around of these buildings in last ten years.

The present era is said to be an era of information and the period of digitization. The digital information is generated in terabytes daily through various sources like smart phones, social networks, sensors, user generated content. This digitization has raised several issues with respect to data storage on cloud. In the future era of Internet, this explosion of raw data and dependence on data services will grow by four-fold due to storage proliferation of data intensive services and the digital convergence of telecommunication, media and Information Communication Technology (ICT). The next generation data models for storage delivery would migrate to cloud-based infrastructure for storage which will be based on data objects with rich, extensible metadata and elaborated access methods. Such infrastructures will face several research challenges which need to be addressed in order to overcome limitations related to issues like storage access, mobility, cost, energy, security, interoper...

In rechargeable zinc-air batteries (RZABs) use of aqueous electrolytes is prevalent, but this approach introduces several challenges, such as hydrogen evolution, lower electrochemical stability window, corrosion and passivation of the Zn electrodes. In this regard, the suitability of zinc organic electrolytes is explored to resolve the technical challenges associated with the aqueous electrolytes. In order to address the current challenges and research gaps, suitability of the addressed zinc organic electrolytes was investigated through analyzing theirphysicochemical properties and mass transport; compositional analyses (decomposition screening), formed discharge product and reversibility during redox kinetics; corrosion and passivation phenomena of zinc metal as well as the cathodic oxygen reduction reaction (ORR) performance. Notably, this study is the first to investigate the passivation and corrosion phenomena of Zn metal anodes in organic electrolytes, establishing the correlation between cathodic ORR activity and electrolyte medium, and the decomposition process of organic electrolytes in air environment through saturating the electrolyte medium with dissolved oxygen. The study revealed that zinc triflate/DMF (Dimethylformamide) organic electrolyte has excellent reversibility, charge and mass transport, ORR activity, and minimum passivation than the zinc nitrate/DMF and zinc nitrate/DMSO (Dimethylsufoxide) organic electrolytes.

One of the most important renewable energy sources is solar power and its emergence has revolutionized how we retrieve, store, distribute, and consume electrical power. However, tracking mechanisms have not been entirely effective in the past towards maximizing energy storage from solar energy. This project seeks to design, implement, and optimize a Motorized Maximum Power Point Tracking (MPPT) solar system to improve the efficiency of renewable energy generation. The project involved using a smart algorithm to drive a solar panel connected to light dependent resistors (LDRs) linked to a suitable power source. An Arduino microcontroller and other components were added to the MPPT system to guide its movements towards the sun's most intense ray region. A static solar panel was also designed to perform comparison of solar harvest between stationery and movable panels For 10 days each across sunny, partially cloudy, and cloudy weather, both systems were deployed to observe which solar panel would receive and generate more energy overall. The comparisons showed that the motorized MPPT system was more efficient in retrieving energy, with its setup getting as much as 16% more power across conditions deployed in different weather settings. The MPPT system's superior energy-capturing ability makes it a suitable option for implementation. Results obtained showed that the MPPT solar tracker is a financially feasible option in the long term and should be scaled to meet commercial needs for sustainable energy options.

The main objective of this study is to improve the energy quality extracted by variable speed wind turbine based on doubly fed induction generator. First, the dynamic modeling of different parts of the system is presented. The electrical machine is modeled in PARK reference frame. Thereafter, the control technique is detailed. Indirect field-oriented control with fuzzy logic controllers (FLC) is used to control the rotor currents and consequently the real and reactive powers of the stator generator. Then, the design of FLC is detailed by tuning its most significant parameters, which are scaling factor rules base and membership functions. Finally, a simulation using the MATLAB/SIMULINK environment is carried out to prove the validation of the control strategy using a 2 MW wind turbine. The results show a satisfactory performance in terms of rapidity, stability, and precision under variable wind speed conditions. doubly fed induction generator, field-oriented control, fuzzy logic controller, maximum power point tracking, scaling factor, variable speed wind turbine Othmane Zamzoum

In this study, we propose an indium-rich InGaN/GaN p-i-n thin-film solar cell which incorporates a dual nanograting (NG) structure: Ag nanogratings (Ag-NGs) on the backside of the solar cell and gallium nitride nanogratings (GaN-NGs) on the frontside. Finite-difference time-domain (FDTD) simulation results show that the dual NG structure couples the incident sunlight to the plasmonic and photonic modes, thereby increasing the absorption of the solar cell in a broad spectral range. It is observed that the solar cells having the dual nanograting structures have a significant enhancement in light absorption as compared to cells having either no nanogratings or having only the frontside nanogratings or only the backside nanogratings. Analysis of light absorption in solar cells containing the dual NG structures showed that the absorption enhancement of longer wavelengths is mostly due to the Ag-NGs on the backside and of shorter wavelengths is mostly due to the GaN-NGs on frontside of the solar cell. The J sc and power conversion efficiency (PCE) are calculated under AM1.5G solar illumination and are observed to be significantly enhanced due to the presence of optimized dual NG structures. While there is an increase in J sc from 17.88 to 23.19 mA/cm 2 (~30% enhancement), there is an increase in PCE from 15.49% to 20.24% (~31% enhancement) under unpolarized light (average of TM and TE). Moreover, the study of oblique light incidence shows significantly larger J sc of the dual nanograting solar cells compared to the cells with no nanogratings.

Accurate prediction of the financial markets can provide many benefits, of which underlying economic stability is probably the most important. This area has understandably attracted a significant amount of interest from the research community, and has inspired a diverse range of approaches with varying degrees of success. Gold is a particular commodity which has attracted considerable attention since it was first smelted for ornaments and jewellery by the Egyptians in 3600BC. In uncertain economic times it is regularly used as a safe-haven commodity, and is why there is considerable attention given to enhancing the accuracy of gold prices prediction methods. Previous attempts at gold price prediction have used a variety of econometric and machine learning techniques. In particular Long Short-Term Networks (LSTMs) and more recently an ensemble of Convolutional Neural Networks (CNNs) and LSTMs have been found to have had considerable level of success in time series prediction. In this...

Nowadays, transport network of electrical energy operate beyond their thermal limit, due to growing populations, industrialization and modernization needs. To this end, multi-term power lines are erected in order to ensure the transit of the requested energy while ensuring the stability of the electrical network. But when there is loss of one term of these lines for various reasons (short circuits and others), a problem of transit of this energy is posed. Sure, several research works have been the subject of publications in terms of power transit optimization, however the case of the loss of a term of a transmission line is still a challenge. It is clear that when there is a loss of a term of a line, the power transmitted is reduced because of the increase in the impedance of this line. This study proposes an approach that optimizes the transit of electrical energy post-incident. To do this, the use of the third generation FACTS in this case the UPFC allows us to obtain the expected results. The interest of this work is to satisfy even in emergency or post-contingency conditions the demand for electrical energy while ensuring the stability of the system.

Nowadays, transport network of electrical energy operate beyond their thermal limit, due to growing populations, industrialization and modernization needs. To this end, multi-term power lines are erected in order to ensure the transit of the requested energy while ensuring the stability of the electrical network. But when there is loss of one term of these lines for various reasons (short circuits and others), a problem of transit of this energy is posed. Sure, several research works have been the subject of publications in terms of power transit optimization, however the case of the loss of a term of a transmission line is still a challenge. It is clear that when there is a loss of a term of a line, the power transmitted is reduced because of the increase in the impedance of this line. This study proposes an approach that optimizes the transit of electrical energy post-incident. To do this, the use of the third generation FACTS in this case the UPFC allows us to obtain the expected results. The interest of this work is to satisfy even in emergency or post-contingency conditions the demand for electrical energy while ensuring the stability of the system.

In this work, we propose a preliminary design of a horizontal-axis wind turbine (HAWT) as a candidate for the Dhofar Wind Farm project, in the southern Omani Governorate "Dhofar", at the southwest part of the Sultanate of Oman. This wind farm (under construction) is considered to be the first commercial, utility-scale (50MW) wind farm in the GCC (Gulf Cooperation Council) area. The proposed wind turbine has an expected electricity generation of 2MW. We studied the wind atlas of Oman and from which we determined the maximum possible mean wind speed in the entire Sultanate and built our design based on that reference value, which is 6m/s (21.6km/h). After this, we applied a set of modeling equations that estimate the power output from the wind turbine rotor and matched the target electric power to the design variables using a MATLAB computer code. We reached a suitable design and we present here the distribution of the blade angle (twist angle), and the power per unit span along the rotor blade. The rotor design has 3 blades with a diameter of 70m and a rotational speed of 24rpm. This rotor gives 2.37MW of output power, which exceeds the target 2MW output, allowing for about 15% of power losses in the gearbox and generator. We utilized some commercial designs of wind turbines from different international manufacturers as references for typical limits or recommended values of some design parameters.

Previous work by the authors has demonstrated a high rate and high yield hydrolysis of sodium borohydride in the presence of a Ni-Ru catalyst synthesized by wet chemistry. The catalyst has been fully characterized and utilized more than 300 times, exhibiting high stability and durability. In this work, the effect of temperature on the reaction rate was studied and the activation energy of the process estimated for temperatures up to 65 ºC. Typical data in the form of an Arrhenius type relationship showed two slope regions suggesting a change of mechanism that lead to a more accentuated role of ruthenium for temperatures higher than 45 ºC. This effect is maintained with increasing Ru doping of the catalyst. The effect of NaOH as a stabilizer was also studied and the role of Ni and Ru in the hydrolysis of sodium borohydride is under study on the basis of data obtained for various Ru concentrations and data for 100% Ni and 100% Ru as catalysts. An increase in the concentration of Ruthenium in the catalyst allowed effective utilization of the catalyst without the need for the stabilizer, minimizing the induction reaction time. Excellent catalytic activity and catalyst minimal deactivation for sodium borohydride hydrolysis are characteristic of the series of Ni-Ru catalyst synthesized by wet chemistry used in this work.

Demand forecasting in supply chains is essential for efficient inventory
management, production planning, and cost optimization. Traditional
time series models, such as Autoregressive Integrated Moving Average
(ARIMA), are effective in modeling linear relationships but often fall
short in handling the nonlinear complexities characteristic of volatile
demand patterns. Conversely, deep learning models like Long Short
Term Memory (LSTM) networks have proven adept at capturing
intricate temporal dependencies, though they are computationally
intensive and require substantial data. This study introduces a hybrid
ARIMA-LSTM framework that leverages the linearity strengths of
ARIMA in conjunction with LSTM’s capacity for learning non
stationary, nonlinear patterns. The hybrid model decomposes the
demand series, modeling linear trends with ARIMA and residual
nonlinear components with LSTM. Empirical evaluations of real-world
supply chain data reveal that this integrated architecture outperforms
standalone ARIMA and LSTM models, achieving superior predictive
accuracy and robustness in handling demand variability. Our findings
underscore the hybrid model's potential as an advanced predictive
solution for dynamic, data-driven supply chain management.

This work focused on the numerical study of the thermal performance of a solar collector in order to improve the indirect solar drying of fruit in an environment with high solar potential. It aims to contribute to the reduction of post-harvest losses observed during periods of high production. From the retained physical model, an equivalent electrical scheme has been established and energy balance was applied to each slice of the model using the nodal method. The obtained different equations were discretized using the implicit method of finite differences, and solved by the iterative Gaussian Pivot method written in FORTRAN program. The obtained results showed that, from April to June (mangoes harvest period in Ngaoundere city) the raining period in Adamawa Region, the solar air collector that length to width ratio is between 2 and 3, is sufficient to carry out indirect solar drying of fruits with forced convection. The outlet air temperature of the solar collector was between 45 and 60°C with an average value of 50°C, and the thermal efficiency was between 65 and 95% with an average value of 80%. Double glazing improves efficiency of the solar air collector for a small footprint.

This work focused on the numerical study of the thermal performance of a solar collector in order to improve the indirect solar drying of fruit in an environment with high solar potential. It aims to contribute to the reduction of post-harvest losses observed during periods of high production. From the retained physical model, an equivalent electrical scheme has been established and energy balance was applied to each slice of the model using the nodal method. The obtained different equations were discretized using the implicit method of finite differences, and solved by the iterative Gaussian Pivot method written in FORTRAN program. The obtained results showed that, from April to June (mangoes harvest period in Ngaoundere city) the raining period in Adamawa Region, the solar air collector that length to width ratio is between 2 and 3, is sufficient to carry out indirect solar drying of fruits with forced convection. The outlet air temperature of the solar collector was between 45 and 60°C with an average value of 50°C, and the thermal efficiency was between 65 and 95% with an average value of 80%. Double glazing improves efficiency of the solar air collector for a small footprint.

Current discourse on the transition to a decarbonized energy system future is dominated by renewable energy solutions. Initial conditions for this transition may vary across different regions and countries. There are, however, also opportunities for innovative solutions that utilize other low‐carbon energy sources and technology mix. Sustainable development is a contested concept and varies with priorities attached to social, economic, and environmental goals. Therefore, the one‐size‐fits‐all type of solution paradigm needs to be broadened, to accelerate action in the short to medium term. Our argument is that natural gas can be an important complementary transition fuel to support renewable energy in the short‐ and medium‐term transition phases. This means that the goal of zero fossil fuel as a short‐ and medium‐term solution needs to be reconsidered. This takes us to the next argument that innovation and upgraded technology in the low‐carbon fossil fuel sector will provide an impo...

Current discourse on the transition to a decarbonized energy system future is dominated by renewable energy solutions. Initial conditions for this transition may vary across different regions and countries. There are, however, also opportunities for innovative solutions that utilize other low‐carbon energy sources and technology mix. Sustainable development is a contested concept and varies with priorities attached to social, economic, and environmental goals. Therefore, the one‐size‐fits‐all type of solution paradigm needs to be broadened, to accelerate action in the short to medium term. Our argument is that natural gas can be an important complementary transition fuel to support renewable energy in the short‐ and medium‐term transition phases. This means that the goal of zero fossil fuel as a short‐ and medium‐term solution needs to be reconsidered. This takes us to the next argument that innovation and upgraded technology in the low‐carbon fossil fuel sector will provide an impo...

In view of the complicated heat transfer calculation for air coolers and the difficulty of directly calculating the exit temperature of natural gas in a compressor station, taking the dry air cooler of model GP12 × 3-6-258-13.0S-S-23.4/DR-Ia configured in the West-East Natural Gas Pipeline II as an example, a three-dimensional simplified model of the air cooler is established. The model is used to simulate a temperature flow field of a dry air cooler-finned tube based on Fluent flow field analysis software. This paper studies the cooling effect of the dry air cooler-finned tube on high-temperature and high-pressure natural gas at compressor outlet. By comparing and analyzing the relationships among natural gas mass flow, inlet air temperature, inlet natural gas temperature, and outlet natural gas temperature for an air cooler, the formula of temperature drop of dry air cooler to natural gas is fitted, and the fitting formula is verified by field operation data. The results show that the average error between the fitting results and the actual data is less than 1.5%, which proves the correctness of the fitting formula and greatly simplifies the heat transfer calculation process for air coolers.

The assessment of heavy metal pollution in leaves and soils is essential in environmental health monitoring. We assessed the effect of anthropogenic activities along an industrial-urban-rural gradient in the roadside soil and tree leaves of Bangladesh based on their metal concentration. The concentrations of Pb, Cr, Ni, and Cd were analysed in leaves of Ficus benghalensis, Swietenia macrophylla, and Polyalthia longifolia and topsoil samples using ICP-OES. We used pollution indices to quantify the impact of contaminants on ecosystems. Our findings indicated that there were higher metal concentrations, especially Cd and Pb, in soil and leaves in close proximity to locations with substantial traffic and industrial activities. Igeo index indicated moderately to strongly polluted areas by Cd. The contamination factor (CF) for Cd indicated a severe contamination, while moderately contamination show by Cr, Pb, and Ni. The value of the ecological risk factor was below 40 for Cr, Ni, and Pb; thus, negligible ecological risks were considered for these elements. But, the ecological risk assessment indices showed that Cd poses high ecological risks in soil and leaves across all study areas. Bioaccumulation analysis indicated substantial heavy metal absorption in tree foliage, with F. benghalensis and P. longifolia exhibiting elevated Pb accumulation in urban environments. The PCA indicated that Cd, Cr, Ni, and Pb mostly derived from anthropogenic sources in leaves and soil samples, too. Our results demonstrated that F. benghalensis, S. macrophylla, and P. longifolia are good indicator to assess the effect of anthropogenic activities on the terrestrial ecosystem. Our results also indicated the critical need for environmental monitoring and mitigation techniques in urban and industrial zones to reduce heavy metal pollution in roadside ecosystems.

Although numerous works have been done, most of the studies in fault diagnosis are limited to single fault type at a time. Majority of the works reported in the literature do not extend the diagnosis of the root cause of the fault for simultaneous faults specifically in the distillation column. However, an industrial system is susceptible to more than one fault at a time, which may or may not be interrelated. These faults not only reduce the diagnosis performance but also increase the computational complexity of the diagnosis algorithm. In this work, therefore, a multiple kernel support vector machine (MK‐SVM) algorithm is proposed to diagnose simultaneous faults in the distillation column. In the developed MK‐SVM algorithm, multilabel approach based on various kernel functions has been utilized for the classification of simultaneous faults. Dynamic simulation of a pilot‐scale distillation column using Aspen Plus® is used for generating data in normal and faulty operation. Eight dif...

Efficient monitoring of highly complex process industries is essential for better management, safer operations and high-quality production. Timely detection of various faults helps to improve the performance of the complex industries, prevent various unfavorable consequences and reduce the maintenance cost. Fault Detection and Diagnosis (FDD) for process monitoring and control has been an active field of research for the past two decades. Distillation columns are inherently nonlinear, and thus to have an accurate and robust performance, the fault detection methods should be based on nonlinear dynamic methods. The paper presents a robust data-driven fault detection approach for realistic tray upsets in the distillation column. The detection of tray faults in the distillation column is conducted by Nonlinear AutoRegressive with eXogenous Input (NARX) network with Tapped Delay Lines (TDL). Aspen Plus® Dynamic simulation has been used to generate normal and faulty datasets. The study sh...

Early detection of anomalies is crucial to maintain high productivity at a re nery. For this purpose, we propose an anomaly detection system based on adaptive resonance theory (ART) for industrial plants. The feature of the system is that it has several ART systems applied to subsystems of the plant in order to narrow down the cause of the anomalies. This report presents our examination of online anomaly detection tests on whether or not the proposed system is applicable to a distillation tower system. The tests were conducted with experimental equipment of a distillation tower in Universiti Teknologi PETRONAS (UTP). In the tests, we carried out four cases of anomaly operation (e.g., valve sticking and tray upset) that would cause quality or yield losses in the product. By learning normal operation data, the proposed system could detect anomalies in all four cases, and no false positives were observed in normal operation. We also found that the system could narrow down the cause of the anomalies by using the results of each ART system, thereby demonstrating that the system is applicable for the distillation tower system.

Food waste, particularly animal-derived waste, presents a significant challenge globally, prompting the need for sustainable management strategies. In 2022, the amount of food waste per capita reached 131 kg/capita in the EU (European Union), which is why the search for environmentally friendly ways to manage food waste through thermochemical conversion processes has gained momentum in recent years. Animal-derived waste is a good source of organic matter (proteins, lipids, and polysaccharides) and mineral compounds (calcium phosphate, mostly hydroxyapatite). This composition makes animal-derived waste valuable for the extraction of chemical compounds, such as hydroxyapatite (HAp), which constitutes up to 70 wt% of animal bones; keratin; collagen; and hyaluronic acid (HA), to produce pharmaceutical, medical, or industrial byproducts. The thermochemical conversion of chicken bones through pyrolysis and gasification creates a new opportunity to valorize this type of waste by reintroducing valuable by-products into the economy and thus achieving sustainable waste management objectives. The results of this study showcase the multiple applications of the pyrolysis of chicken bone waste products (as adsorbents in aqueous mediums, catalysts, fertilizers, and biomedical applications) and the necessity of a better exploration of the gasification process of chicken bone waste. Therefore, this study explores the properties of animal-derived waste and discusses the pyrolysis and gasification of chicken bone waste, the influence of process conditions on product yields, and the catalytic enhancement of these thermochemical processes.

Supercapacitors proved to be significant power storage devices. Their high storage density, long shelf-life and reduced wear/cycle ratio promise efficient battery technologies soon. Recent advances in material science demonstrate that carbon-based composites enable enhanced performance of supercapacitors. The abundant availability of carbon composites has led a spike in the interest of researchers to take a deep look at their underlying properties that help bring up commercially viable supercapacitor technologies. In addition, the exceptional charge retention capacity and conductivity of the carbon based materials (CNTs and grapheme) trigged the researchers to use these materials in supercapacitors fabrication. In this detailed review, synthesis of carbon-based anode materials and their performance have been considered and relative examination is done. Various carbon-based composites have been analyzed based on existing research for understanding supercapacitors performance in terms of cyclic stability, shelf-life energy storage capacity and applicable to various applications. This detailed review also acknowledges the challenges and constraints in material synthesis and device fabrication.

Le mouvement d'un mobile (M) est donné par les équations suivantes : ‖𝐎𝐌 ⃗⃗⃗⃗⃗⃗⃗ ‖ = ‖𝒓 ⃗ ‖ = { 𝒓(𝜃) = 𝑎 + 𝑏 𝑐𝑜𝑠𝜃 = 𝒂 (1 + 𝑐𝑜𝑠𝜽 ) ; 𝒃 = 𝒂 𝜽(𝑡) = 𝜔. 𝑡 Avec : 𝝎 𝑒𝑡 𝒂 sont des 𝐜𝐨𝐧𝐬𝐭𝐚𝐧𝐭𝐞𝐬 réelles et 𝐩𝐨𝐬𝐢𝐭𝐢𝐯𝐞𝐬 La trajectoire dont l'équation en coordonnées polaires s'écrit : 𝒓(𝜽) = 𝑎(1 + 𝑐𝑜𝑠𝜃) est une courbe fermée appelé cardioïde (forme d'un Coeur) L'axe 𝑶𝑿 est un axe de symétrie, car : 𝒓(𝜃) = 𝒓(-𝜃) ⇔ 𝒄𝒐𝒔(𝜃) = 𝒄𝒐𝒔(-𝜃)

Clean drinking water is one of the biggest issues in the world, and will be the most studied subject along with food in the near future. Some of the fresh water sources are contaminated with Sulfur, Nitrogen, Phosphorous and other organic and inorganic contaminants. Desalination is a solution to this waste water problem, but it is costly and time consuming process. Objective of this study is to develop a cheaper and sustainable process for cleaning lake and other drinking water sources. In this study, algae, clothes, waste papers and fruit wastes, such as date and olive seeds were used to produce activated carbons. These materials were briquetted under high pressure using different amount of molasses as binder. Date and olive seeds were crushed, sieved and dried prior to the briquetting process. Chemical activation of the briquettes and seeds were performed using zinc chloride (ZnCl2) and calcium hydroxide (Ca(OH)2. After the chemical activation, carbonization in inert atmosphere wa...

Among the many characterization techniques for solar panel testing, two, electroluminescence (EL) and photoluminescence (PL), can provide useful visual information about the presence of different types of cell defects. EL is performed outdoors by night in commercial solar plants due to the very weak luminescence emission compared to sunlight. PL faces the added difficulty of needing to find a large‐area homogeneous light source to excite the modules. Since nighttime work poses many drawbacks and risks, a daylight outdoor EL/PL system would be useful for offering safe inspection of solar plants. We present daylight luminescence techniques based on a bias switching method, in which a pulsed luminescence signal is obtained by alternating the polarization state of the solar panels, synchronizing it with the luminescence image detection by an InGaAs camera. Fast switching and selecting an optimized exposure time are key to achieving high‐quality images. The daylight luminescence method d...

This manuscript presents the development of a functional prototype of a photovoltaic system named sunflower. It employs linear PID controllers to accurately track solar radiation. The design process initiates with the construction of a light sensor comprising three key components: transducer, conditioning, and postprocessing unit. Additionally, two PID controllers are developed to precisely adjust the position of the photovoltaic system to an orthogonal angle relative to the incident solar radiation. The results demonstrate that the sensing system effectively determines the optimal angle for solar radiation collection by the sunflower photovoltaic system. The designed controllers efficiently maximize the incidence of light energy, ensuring a stable response in the face of input changes or external disturbances. This enhancement significantly improves the prototype's accuracy, stability, and speed, even in scenarios involving multiple light energy sources.

This paper is written in response to the paper “How green is blue hydrogen?” by R. W. Howarth and M. Z. Jacobson. It aims at highlighting and discussing the method and assumptions of that paper, and thereby providing a more balanced perspective on blue hydrogen, which is in line with current best available practices and future plant specifications aiming at low CO2 emissions. More specifically, in this paper, we show that: (i) the simplified method that Howarth and Jacobson used to compute the energy balance of blue hydrogen plants leads to significant overestimation of CO2 emissions and natural gas (NG) consumption and (ii) the assumed methane leakage rate is at the high end of the estimated emissions from current NG production in the United States and cannot be considered representative of all‐NG and blue hydrogen value chains globally. By starting from the detailed and rigorously calculated mass and energy balances of two blue hydrogen plants in the literature, we show the impact...

O VI Encontro Nacional de História da Geografia e IV Encontro Nacional de Geografia Histórica foi realizado em Salvador entre os dias 15 e 18 de outubro de 2024, na Reitoria do Instituto Federal de Educação, Ciência e Tecnologia da Bahia (IFBA). O evento foi organizado pela Rede Brasilis – Rede Brasileira de História da Geografia e Geografia Histórica – em parceria com o Departamento de Geografia do IFBA, do campus Salvador, e outras instituições do Brasil e do exterior, contando com financiamento do PAEP/CAPES. Com o tema "Travessias, intercâmbios e circulação do conhecimento" geográfico, a jornada acadêmica buscou fortalecer os debates sobre trajetórias de personagens, instituições e obras responsáveis pelo desenvolvimento da Geografia, além daqueles direcionados ao conhecimento da história dos lugares, seus processos estruturantes e agentes sociais

Methane fermentation is an attractive practice in waste processing, which enables one to both control pollution and recover energy. This kind of anaerobic digestion is exposed to inhibitors, which can retard the process and cause failure. The mechanism causing toxicity of these substances and their impact on the efficiency of the process are already known, but there is still not much information about their influence on methane fermentation microorganisms' activity and the composition of microbiota. In this review, based on 168 articles, we present a summary of the up-to-date research on the inhibition of anaerobic processes by some specific toxicants: ammonia, sulfides, ions of light metals, heavy metals, antibiotics, ethylene and acetylene, chlorophenols, halogen aliphatic hydrocarbons, aliphatic nitro compounds, and longchain fatty acids. This review principally focuses on the impact of these inhibitors on the microorganisms involved in the process. More accurate recognition of methane fermentation inhibition mechanisms, with particular emphasis on the microbiological aspect, can help to improve the efficiency of the process.

The Purpose of this study is to evaluate the role of Natural Gas in attaining sustainable development goals in India. In this study more than 50 published research papers and reports from national and international journals and institutions and their websites, has been reviewed. In this review, it has been found that natural gas significantly contributes in achieving sustainable development Goals (SDGs) and affordable and clean energy (SDG7) in India. The paper also presented the status of the gas economy in India present and future. This study will help to understand the role of natural gas in attaining sustainable goals in India.

Scientific evidences have shown that greenhouse gas (GHG) emissions, caused by fossil fuel-based energy sources, contribute to global warming and climate change. In particular, anthropogenic emissions of GHGs led, over the past 100 years, to a considerable increase in the concentration of these gases in the atmosphere. Indeed, since 1750, the atmospheric concentrations of carbon dioxide (CO 2 ), methane (CH 4 ), and nitrous oxide (N 2 O) have increased approximately 31%, 150%, and 16%, respectively. 1 Population growth will continue to underpin rising energy demand and then GHG emission if the current energy policy scenario does not change. In fact, during the last 40 years, global energy demand increased from 5000 Mtep in 1970 to 12 000 Mtep in 2010 (2.24% of annual growth), and the demand is expected to double in 2050 compared with the 2010 level. Besides, energy prices will continue to have a major impact on future demand and supply patterns. In the New Policies Scenario of the International Energy Agency (IEA), crude oil import