Retarding Effect Research Articles

Endocrine Disrupting Effects of Flame Retardants on Thyroid System

Accumulating scientific evidence shows that thyroid hormone synthesis and signaling are now recognized as one of the important targets of environmental chemicals, especially chemicals called endocrine disruptors. Endocrine disrupting chemicals (EDCs) are man-made chemicals and consist of different types of molecules, for instance some pesticides, plasticizers, flame retardants (FRs), surfactants, many of which can interfere with thyroid hormone synthesis or their actions. FRs, important members of endocrine disruptors, share similarities in their chemical structures when compared with thyroid hormones, and there is accumulating scientific findings pointing out that they may take part in the dysfunction of thyroid hormone homeostasis. The primary aim of using FRs is to minimize the risk of fire and prevention of its spreading. The potential effects of exposure to FRs on the thyroid and thyroid hormones have gained importance since they may easily migrate into the surrounding environment and are especially found in house dust. Within the framework of the results of some experimental animal and in vitro studies, as well as limited human studies researching the consequences of FRs on the thyroid system, this paper aims to make a general assessment of whether these chemicals have a role in some thyroid diseases. Although the information that FRs with endocrine disrupting properties may have an effect on thyroid hormone levels and cause disruption in the thyroid system is still in its infancy, there is emerging evidence that some members of FRs may have thyroid disrupting properties.

Dynamics of comparative analysis of Reynold’s and Vogel’s models (variable viscosity) in a wire coating process filled with magnetized porous

In this paper, we investigate the analysis of Oldroyd 8-constant fluid flow with nanoparticle suspension via a porous media during the coating of wire is carried out. A constant magnetic field and electrically conducting fluid are considered. The governing equations thus obtained for the present model are converted to nonlinear differential equations using variables in dimensionless form. These equations are analytically solved. The influence of some parameters, like magnetic field parameter, porosity parameter, dilatant constant, pseudo-plastic constant and Brinkman number on velocity and temperature distributions are discussed graphically. For fluctuating viscosity, two models, Reynold’s and Vogel’s are considered. It is observed that the magnetic parameter and the Brinkman number increase, both temperature and velocity profiles show a retarding effect in both Reynold’s and Vogel’s models.

Macroscopic Mechanical Properties and Microstructure Characteristics of Solid Waste Base Capillary Retarded Field Covering Material

In the practical operation of traditional landfills, compaction clay often experiences cracking, while the HDPE geomembrane may tear and bulge, resulting in a compromised performance of the landfill covering system. To address this issue, a capillary retarding covering material for landfill sites is proposed by utilizing municipal sludge and construction waste particles as substrates and incorporating a small quantity of calcium bentonite. The mechanical characteristics of the covering material were investigated using a standard consolidation test and a triaxial compression test. A permeability test and a soil water characteristic curve (SWCC) test were conducted to examine the permeability and capillary retarding effect of the covering material. Microscopic tests including SEM scanning, laser particle size analysis, and T2 NMR analysis were performed to investigate the connection mode, particle size composition, and pore structure characteristics of the covered particles. Based on the aforementioned research, the following conclusions can be drawn: The cohesion of the covering material ranged from 50 to 150 kPa, while the internal friction angle ranged from 24.23° to 31°. The cohesion was directly proportional to the content of construction waste, whereas the internal friction angle was inversely proportional to calcium bentonite content. The permeability coefficient ranged from 5.04 × 10−6 cm/s to 7.34 × 10−5 cm/s, indicating a certain level of impermeability. Both the sludge and the calcium bentonite contents jointly influenced the final permeability coefficient in a negative correlation manner, with a notable hydraulic hysteresis phenomenon observed. A higher content of construction waste leads to a more pronounced supporting force exerted by the formed skeleton structures within a load pressure range between 0 and 1600 kPa. When considering a mass ratio of municipal sludge: construction waste: calcium bentonite as 30:60:7, respectively, only a decrease in the pore ratio by approximately 13.20% was observed. This study provides valuable data support for designing and applying capillary retarding cover barrier systems in landfills.

Charge-density response in layered metals: Retardation effects, generalized plasma waves, and their spectroscopic signatures

Charge-density response in layered metals: Retardation effects, generalized plasma waves, and their spectroscopic signatures

Study on the multi‐scale online fatigue crack deformation and growth behaviors under overload in Q&P steel

AbstractThe multi‐scale online fatigue crack deformation and growth behaviors under single overload (SOL) and periodic overload (POL) case in Quenching and Partitioning (Q&P) steel were studied using two micro cameras and sub‐image stitching and matching digital image correlation (DIC) method. Firstly, the microscopic crack tip speckle images and crack images on both sides of the compact tension (CT) specimen during the fatigue crack growth (FCG) process were collected under different overload parameters. Then, the FCG overload retardation, crack tip closing and blunting behaviors, and the crack tip strain distribution and evolution, overload retardation mechanism were analyzed. In addition, the corresponding multi‐scale FCG morphological characteristics and material microstructure under overload case were observed. The results indicate that the overload ratio and interval affect the overload retardation effect of Q&P steel seriously; the overload crack tip blunting and plastic zone are the major factors inducing the overload retardation effect in Q&P steel.

Hydration characteristics and pollutant solidification mechanism of full solid waste electrolytic manganese residue super sulfate cement

In this study, electrolytic manganese residue (EMR) rich in soluble manganese, ammonia nitrogen, and sulfate was combined with carbide slag (CS) and granulated blast furnace slag (GBFS) to produce Full Solid Waste Electrolytic Manganese Residue Super Sulfate Cement (FWS-EMR-SSC). The compressive strength, hydration mechanism, microstructure, hydration kinetics, and pollutant solidification mechanism of FWS-EMR-SSC were investigated. The study revealed that the optimal ratio was 4% carbide slag, 40% EMR, and 56% GBFS, achieving a compressive strength of 38.34 MPa at 28 days. This was due to the release of OH- from carbide slag, causing EMR to dissolve large amounts of SO42- and Ca2+, while GBFS accelerated the release of Ca2+, Si2+, Al3+, leading to the formation of abundant AFt and C-(A)-S-H gel, providing strength to FWS-EMR-SSC. The heat release rate and cumulative heat of the FWS-EMR-SSC system were lower than Ordinary Portland Cement (OPC). Additionally, compared to OPC, the second exothermic peak rate was significantly reduced and delayed in the FWS-EMR-SSC system due to the exothermic release of gypsum, retarding effects, and pronounced generation of AFt. The simulation of FWS-EMR-SSC hydration kinetics using the Krstulović-Dabić model revealed that FWS-EMR-SSC underwent the NG-I-D process. Gypsum retarded the nucleation and crystal growth stages of NG, while AFt had a significant impact on the D diffusion stage. The C-(A)-S-H, AFt gel, and iron-manganese compounds (Fe2Mn(PO4)2(OH)2·(H2O)8, MnFe2O4) generated in the FWS-EMR-SSC system could undergo ion exchange and chemical precipitation with Mn2+. Meanwhile, NH3-N transformed into NH3 release, ensuring that the leaching toxicity of FWS-EMR-SSC met the Chinese standard limits of GB8978-1996 for wastewater discharge.

Investigation of the engineering and environmental properties of cement mortars incorporating ladle furnace steel slag

While the use of ladle steel slag in concrete offers several potential advantages, there are significant research gaps that need to be addressed to promote its safe and effective utilization in the construction industry, e.g. the variations in slag properties, such as chemical composition and physical characteristics, can influence concrete performance. Moreover, even there is some research on the mechanical properties of concrete containing ladle steel slag, more in-depth studies are needed to assess the long-term durability of such concrete and the research should focus more on evaluating the environmental impact of using ladle steel slag in concrete. The paper reports the fundamental findings of a research study focused on the treatment of ladle slag to be applied as a cement substitute in the manufacturing of cement products. The research aimed to determine the optimal proportion of admixture based on treated ladle slag and evaluate the environmental properties of the resulting cement composites. The treatment process involved mechanical activation, specifically grinding the ladle slag fraction of 0/8 mm using a vibrating mill (Coarse slag) and a ball mill (Fine slag). The treated ladle slag, as an admixture, was examined in conjunction with four types of cement (CEM I, CEM II, CEM III, and CEM V). The research findings revealed that the incorporation of coarse ladle slag enhanced the workability of fresh cement paste across all tested formulations. Moreover, the utilization of treated ladle slag as an admixture in cement paste (substituting cement) exhibited a retarding effect on the setting time. As the age of the test specimens progressed (90 to180 days), the strength properties of the samples with ladle slag admixture approached those of the cement composites prepared using natural aggregates. The climate change impact of cement mortars per strength unit spanned from 0.82 to 2.75 kg CO2eq/MPa for composites incorporating finely-ground slag, and from 0.9 to 3.1 kg CO2eq/MPa for composites utilizing coarse slag. The grinding of ladle slag, even up to 30 wt% cement replacement, did not significantly impact the overall global warming potential and climate change, considering the average mill energy consumption of 50 kWh per 1 t of material.

MTRR gene rs1801394 polymorphism is associated with neonatal birth weight in pregnant women with fetal growth retardation

Aim: to assess associations between folate cycle gene polymorphism and neonatal birth weight in pregnant women with fetal growth retardation (FGR) and related functional effects in population of the Central Black Earth Region.Materials and Methods. 98 cases of women with FGR were enrolled to a retrospective molecular and genetic screening to assess prevalence 5 SNPs (single nucleotide polymorphisms) in genes involved in folic acid cycle and methionine metabolism (rs699517 TYMS, rs2790 TYMS, rs1979277 SHMT1, rs1805087 MTR, rs1801394 MTRR).Results. It was found out that allele A of the rs1801394 MTRR was associated with a lower neonatal birth weight (recessive model: β = –0.34 ± 0.13; p = 0.009). This polymorphic locus exerts crucial functional effects by determining the amino acid substitution in methionine synthase reductase (Ile22Met) localized in the region of modified histones, which mark enhancers and promoters in ectoderm, endoderm and mesoderm cell cultures, primary osteoblast cells, brain, fat nuclei, skeletal muscles, etc. In addition, rs1801394 MTRR is found DNA sites (motifs) responsible for sensitivity to transcription factors STAT and TBX5 being also related to MTRR gene mRNA expression level in subcutaneous and visceral adipose tissue, thyroid gland, fibroblast cell culture as well as various brain regions.Conclusion. Thus, the allele A of the rs1801394 polymorphism in MTRR gene is a risk factor for a lower neonatal birth weight.

In situ construction of epoxy crosslinked Si-Al zeolite-like catalytic structure in wood to achieve high flame retardancy

As green renewable resources, wood and its composites are widely used in the construction field, which puts forward higher requirements for their flame-retardant performance. In this study, a high-temperature hydrothermal crystallization method for in situ constructing an epoxy crosslinked Si–Al zeolite-like structural wood composite (WZLC) was reported. Under the action of amine guiding agents and epoxy resin, the zeolite-like catalytic structure constructed in poplar wood comprised negative electrocatalytic sites, which can efficiently catalyze the formation of the carbon layer and endow WZLC with excellent flame retardant, smoke-suppression, and self-extinguishing properties. Compared with the untreated wood (WN), the thermal stability of the treated wood (WZLC) was greatly improved, and the amount of volatile organic compounds released during the decomposition process was significantly reduced. The heat release rate, total heat release, smoke production rate, and total smoke production of WZLC1 decreased by 50.23%, 44.14%, 45.21%, and 28.46%, respectively. Particularly, CO and CO2 yields of WZLC significantly decreased by 92.26% and 92.02%, respectively, indicating that the Si–Al zeolite-like catalytic structure displayed excellent catalytic flame retardant properties, which can effectively decrease the thermal decomposition rate and combustion risk of the WZLC. This method uses less flame retardants to achieve a good flame retardant and smoke suppression effect, thereby reducing the risk of environmental pollution caused by too many flame retardants.

The preparation of layered double hydroxide wrapped with triazine-based organic framework to enhance the flame retardancy for polypropylene

Layered double hydroxide (LDH) can be used as a flame retardant (FR) for polypropylene (PP) because of its excellent flame retardancy and smoke-suppression effects. However, the agglomeration of LDH seriously affects its dispersity in the PP matrix, thus limiting its application as a FR polymer. This study aimed to enhance the dispersion of LDH in the PP matrix for improving its flame retardancy performance. Herein, a reactive triazine-based organic framework (TOF) was designed and formed by the in situ polymerisation of cyanuric chloride and melamine, and then the LDH surface was covered with TOF to obtain a novel core–shell FR (LDH@TOF), with TOF as the ‘shell’ and LDH as the ‘core’. Subsequently, LDH@TOF was melted into the PP matrix as nanofillers to prepare PP and LDH@TOF composites (PP/LDH@TOF). As expected, the PP/LDH@TOF composites exhibited superior flame-retarding performance (limiting oxygen index of 29.2% and UL-94 V-0 rating) and favourable smoke-suppression performance at 20 wt% of LDH@TOF loading. Moreover, the peak heat release rate, total heat release and total smoke production of PP/LDH@TOF composites decreased by 29.9%, 12.1% and 12.4%, respectively, compared with those of PP and LDH composites. The outstanding flame retardancy properties of the PP/LDH@TOF composites were attributed to the better dispersibility of LDH@TOF in the PP matrix, the synergy of the physical barrier effect of nanosheets and the dense carbonisation acceleration of LDH@TOF. The findings of this study provide a highly efficient approach for functionalising LDH for expanding its application value of PP composites.

A recursive cell multipole method for atomistic electrodynamics models.

For large plasmonic nanoparticles, retardation effects become important once their length becomes comparable to the wavelength of light. However, most models do not incorporate retardation effects due to the high computational cost of solving for the optical properties of large atomistic electrodynamics systems. In this work, we derive and implement a recursive fast multipole method (FMM) in Cartesian coordinates that includes retardation effects. In this method, higher-order electrodynamic interaction tensors used for the FMM are calculated recursively, thus greatly reducing the implementation complexity of the model. This method allows for solving of the optical properties of large atomistic nanoparticles with controlled accuracy; in practice, taking the expansion to the fifth order provides a good balance of accuracy and computational time. Finally, we study the effects retardation has on the near- and far-field properties of large plasmonic nanoparticles with over a million atoms using this method. We specifically focus on nanorods and their dimers, which are known to generate highly confined fields in their junctions. In the future, this method can be applied to simulations in which accurate near-field properties are required, such as surface-enhanced Raman scattering.

Nitrate leaching characteristics of red soils from different parent materials in subtropical China

Globally, nitrate (NO3−) leaching from agroecosystems has been of major concern. There is evidence that NO3− leaching exhibits intense seasonal variation in subtropical regions. However, influencing factors to the seasonal dynamics remain unclear. In this study, a two-year field lysimeters experiment was conducted with three red soils derived from different parent materials (Quaternary red clay (QR), red sandstone (RS), and basalt (BA)). An N fertilizer (15N-enriched urea, 10 atom% excess) of 200 kg N ha−1 yr−1 was applied for maize. The effect of parent material on NO3− leaching characteristics was examined in surface (0–20 cm) and subsoil (20–100 cm) layers. The results showed due to the weakening of abundant drainage, there was no significant effect of parent materials on NO3− leaching characteristics in surface layers. Environmental factors (precipitation and temperature) and fertilization together led to obvious seasonal characteristics, i.e. abundant NO3− leaching during both crop growth and fallow periods. In subsoil layers, NO3− leaching characteristics were completely different among three soils. The concentrations and δ15N of NO3− in QR and RS soils showed a continuous increase after first year's fertilization, while those in BA soil remained relatively stable after reaching peak levels around harvest in first year. Meanwhile, the NO3− leaching amount in BA soil was significantly lower than in the other two soils. These might be explained by different NO3− adsorption capacities caused by the differences in mineral composition and free iron and aluminium contents. These elucidated in subsoil layers, NO3− leaching characteristics highly depended on parent materials. Meanwhile, adsorption capacity was limited and cannot slow NO3− leaching in the long run. Our results suggest that seasonal variation of NO3− leaching in surface layers and temporary retardant effect from NO3− adsorption capacity in subsoil layers should receive much attention when calculating and predicting NO3− leaching in subtropical regions.

Investigation on the battery thermal management and thermal safety of battery-powered ship with flame-retardant composite phase change materials

Pure battery-powered ships have attracted much attention because of its unique advantages of zero-emission. However, the problems of adaptability to extreme working conditions and thermal safety risks restrict the development of battery-powered ships. In this study, a novel flexible flame-retardant composite phase change materials (CPCM) with paraffin (PA)/EVA grafted on maleic anhydride (EVA-g-MAH)/expanded graphite (EG)/ammonium polyphosphate (APP)/triphenyl phosphate (TPP)/Na2SiO3 has been proposed and utilized in battery module. Among them, the sample ATPCM2 with APP/TPP/Na2SiO3 ratio of 5/10/10 achieved the optimal thermal properties and flame-retardant effect. The designed multifunctional CPCM harmonizes the competition between flame retardancy, mechanical properties and phase change latent heat by the synergistic effect. Besides, the ATPCM2-Module shows a good temperature control performance during charge-discharge cycles, such as the maximum temperature of battery module can be still controlled below 50 °C at 2C discharge rate and the corresponding temperature difference was effectively maintained within 4.1 °C. This is owing to the constructed stable three-dimensional heat conductive skeleton formed by synergistic flame retardancy effect, which could improve the dissipation heat capacity and thermal safety. With these prominent performances, the designed flexible CPCM with desired flame-retardant and thermal management performance can provide insights into the passive thermal management and thermal safety improvement of both battery-powered ships and high-power battery module under extreme conditions.

Study on the synergistic flame-retardancy of phenyl/vinyl siliconesquioxane and aluminum diethyl phosphinate on polyethylene terephthalate

Polyethylene terephthalate (PET), a widely used engineering thermoplastics, is inherently flammable, presenting significant fire risks. Aluminum diethyl phosphinate (ADP) is widely used in PET, while they tend to increase smoke hazards in its flames retardancy. A novel flame-retardant ladder phenyl/vinyl polysilsesquioxane (VPPSQ) acting as both a charring flame retardant and smoke suppressant was introduced into the PET/ADP composites. For PET/ADP6/VPPSQ4, the limiting oxygen index increased to 32.8 % from 23.3 %, and the amount of heat and smoke released was significantly reduced, compared with neat PET. Additionally, the hazard of dripping was eliminated and the UL 94 rating reaches to V-0 level. This work provides a new strategy for eliminating multiple fire hazards of smoke, heat and dripping of PET. The gas phase flame retardancy effect of ADP is primarily present during the initial stages of combustion, with the carbonization action of ADP becoming more crucial during the middle and later stages of burning. However, the char layer formed by PET/ADP is unstable and undergoes further degradation. When VPPSQ is introduced into PET/ADP, the pyrolysis products of VPPSQ, including silicon fragments, SiO2, and graphitized structures, significantly enhance the thermal stability and barrier effect of the char layer.

Flame retardant, mechanical, and hot air aging properties of ethylene‐propylene‐diene monomer/ammonium polyphosphate/nano‐silic composite rubber

AbstractIn this work, effect of the ratio of nonhalogenated flame retardants (ammonium polyphosphate [APP] and nano‐silica [nano‐SiO2]) on the mechanical, thermal, and flame retardant properties of ethylene‐propylene‐diene monomer (EPDM) composite rubber were investigated. Vulcanization characteristics, high temperature compression permanent deformation, thermal oxygen aging, dynamic thermodynamic analysis, thermal stability, cone calorimetry, limiting oxygen index (LOI), horizontal vertical combustion (UL‐94), and scanning electron microscopy were carried out. The experimental results showed that the mechanical properties of the composite rubber decreased with the addition of APP. However, the addition of nano‐SiO2 was found to significantly improve the mechanical properties of the composite rubber when it was incorporated. In terms of flame retardant properties of EPDM composite rubber, the combination of APP and nano‐SiO2 has a synergistic flame retardant effect in comparison to the use of single APP flame retardant. The heat release rate of EPDM composite rubber decreased by 34%, the total heat release decreased by 19%, the LOI increased by 76%, and the flame retardant grade of EPDM composite rubber reached V‐0. The EPDM composite rubber fabricated in the present study showed excellent fire resistance and desirable mechanical properties, which are of practical significance for further expanding the application ranges of EPDM rubbers.

Bioinspired phosphorus-free and halogen-free biomass coatings for durable flame retardant modification of regenerated cellulose fibers

Inspired by mussel adhesion and intrinsic flame retardant alginate fibers, a biomass flame retardant (PPCA) containing adhesive catechol and sodium carboxylate structure (-COO−Na+) based on biomass amino acids and protocatechualdehyde was designed to prepare flame retardant Lyocell fibers (Lyocell@PPCA@Na). Furthermore, through the substitution and chelation of metal ions by PPCA in the cellulose molecular chain, flame retardant Lyocell fibers chelating copper and iron ions (Lyocell@PPCA@Cu, Lyocell@PPCA@Fe) were prepared. Compared with the original sample, the peak heat release rate (PHRR) and total heat release (THR) for modified Lyocell fibers were significantly reduced. In addition, the modified sample exhibited a certain flame retardant durability. TG-FTIR analysis showed that the release of flammable gaseous substances was inhibited. The introduction of Schiff bases and aromatic structures in PPCA, as well as the decomposition of carboxylic metal salts were beneficial for the formation of char residue containing metal carbonates and metal oxides to play the condensed phase flame retardant effect. This work develops a new idea for the preparation of eco-friendly flame retardant Lyocell fibers without the traditional flame retardant elements such as P, Cl, and Br.

Surface Modification of Okara Cellulose Crystals with Phenolic Acids to Prepare Multifunction Emulsifier with Antioxidant Capacity and Lipolysis Retardation Effect.

Emulsion-based foods are widely consumed, and their characteristics involving colloidal and oxidative stabilities should be considered. The fabrication of the interfaces by selecting the emulsifier may improve stability and trigger lipolysis, thereby reducing energy uptake from the emulsified food. The present work aimed to develop Okara cellulose crystals (OCs) as a multifunction emulsifier to preserve the physical and chemical stability of a Pickering emulsion via surface modification with phenolic acids. The modification of OC was performed by grafting with the selected phenolics to produce OC-gallic acid (OC-G) and OC-tannic acid (OC-T) complexes. There was a higher phenolic loading efficiency when the OC reacted with gallic acid (ca. 70%) than with tannic acid (ca. 50%). This trend was concomitant with better antioxidant activity of the OC-G than OC-T. Surface modification based on grafting with phenolic acids improved capability of the OC to enhance both the colloidal and oxidative stability of the emulsion. In addition, the cellulosic materials had a retardation effect on the in vitro lipolysis compared to a protein-stabilized emulsion. Surface modification by grafting with phenolic acids successfully provided OC as an innovative emulsifier to promote physico-chemical stability and lower lipolysis of the emulsion.

Retardation effect of the pozzolanic reaction of low-calcium supplementary cementitious materials on clinker hydration at later age: Effects of pore solution, foreign ions, and pH

Clinker hydration at later age in blended cement pastes was found to be retarded by the pozzolanic reaction of low-calcium supplementary cementitious materials (SCMs). Various mechanisms were explored, including the consumption of pore solution, the presence of foreign ions, and pH-related effects. Experimental results indicated that the dissolution of the foreign ions from SCMs was a secondary effect. The primary cause of the retardation effect was the reduction in pH caused by the pozzolanic reaction. Aqueous precipitation tests yielded the following findings related to pH: (1) At lower pH levels, the precipitation of aluminium-incorporated calcium silicate hydrate(C–A–S–H) gel was reduced due to the decreased nano-adhesion force. (2) The morphology of C–A–S–H gel consisted of small spherical particles at lower pH levels, resulting in a denser capillary pore structure. The latter led to increased water retention within the fine gel pores but a reduced amount of pore solution available in the capillary pores for cement hydration.

Effect of Compounded Aluminum Hydroxide Flame Retardants on the Flammability and Smoke Suppression Performance of Asphalt Binders.

Compounded aluminum hydroxide (ATH) flame retardants have been widely used for their low cost and environmentally friendly characteristics. However, previous research lacks a systematic and comprehensive comparison. In addition, the combustion characteristics and phase characterization of asphalt binders are not taken into account either. In this work, flame retardants, for instance, APP, Sb2O3, ZB, and LDHs, were compounded with ATH. The flame retardant behavior, together with the smoke suppression behavior, of asphalt binders with compounded flame retardants was determined by LOI and CCT. Furthermore, mechanisms on flame retardants were investigated. It was found that ATH compounded with ZB significantly reduced the heat smoke release and suppressed the formation of toxic volatiles during asphalt combustion. This was because ATH/ZB facilitated the formation of polyaromatic structures and improved the resistance of the char layer. ATH compounded with APP showed an antagonistic effect in the limiting oxygen test because the reaction between ATH and APP inhibited and delayed the decomposition of ATH during asphalt combustion with more aluminum phosphate presenting relatively poor barrier properties produced.

Does Petroleum Products Pricing Stimulate Economic Growth in Nigeria? An Empirical Investigation Applying ARDL Approach

The rising prices of petroleum products and energy in Nigeria, coupled with a surge in poverty and a decline in living standards, necessitate an investigation into how the pricing of petroleum products has impacted Nigeria’s economic growth from 1990 – 2022. To achieve the purpose of the study, data on growth rate of gross domestic product, premium motor spirit price, automotive gas oil price, household kerosene price, compressed natural gas price and crude oil price were sourced from the World Bank and Petroleum Product Pricing and Regulatory Agency (PPPRA) and analysed by employing the Auto regressive Distributed lag (ARDL) method. Our results and findings revealed that: Prices of Premium Motor Spirit, automotive gas oil, dual purpose kerosene and crude oil were all negatively and marginally related to economic growth in the long run. Only price of compressed natural gas was positively but marginally related to economic growth. This implies that petroleum products prices had retarding effect on economic growth in Nigeria in the long run. In the short run, premium motor spirit and automotive gas oil had mixed effect on economic growth while price of household kerosene and price of crude oil were positively related to economic growth but price of compressed natural gas were negatively related to economic growth. Petroleum products prices proxied by prices of Premium Motor Spirit, Automotive Gas Oil, Household Kerosene, Compressed Natural Gas and Crude oil had less impact on economic growth in the long but had serious implications on economic growth in the short run in Nigeria over the period of the study. Based on this conclusion, the study recommended Increase investment in compressed natural gas, proper utilization of crude oil revenue and strengthening existing policies in the oil and gas sector as possible measures towards improving economic growth in Nigeria.