Peak Component Research Articles

Baseline correction for infrared spectra using relative absorbance-based independent component analysis

Infrared spectroscopy has important applications in fields such as materials analysis and chemical detection, while baseline correction is a key step in ensuring the accurate interpretation of spectral data. Uncorrected baselines can lead to deviations in absorption peaks, which affects the accuracy of both quantitative and qualitative analysis. When the absorption peaks of various components in a mixed gas overlap, the lack of reference baseline information in the continuous absorption band can result in significant errors during the baseline correction process. In this paper, we propose a relative absorbance-based independent component analysis (RA-ICA) algorithm to address this challenge. The algorithm first calculates the relative absorbance spectrum that excludes baseline information. Subsequently, based on the Beer-Lambert law and independent component analysis, it extracts independent components containing the absorption peak information of the components, allowing for fitting spectra that require baseline correction. Finally, a baseline model that combines polynomial curves and residuals is used to reconstruct the hidden baseline of the absorption band. Simulation and experimental results demonstrate that the baseline reconstructed using the RA-ICA method exhibits a significantly lower error compared to five other commonly used baseline correction methods and accurately preserves the detailed characteristics of the baseline.

Comparison of experimental and simulated separation performance in capillary tube-in-manifold devices

A metal tube-in-manifold packed bed capillary column device, designed to overcome common limitations associated with capillary LC separations, is described. Experimental results of initial packing tests with sub-3 μm core-shell particles demonstrated efficiencies greater than 47,000 plates/m for a separation performed using the column device. Computational fluid dynamics (CFD) modeling of the multicomponent separation used for this work was validated against experimental LC results and the optimized model was able to effectively predict component peak retention times. However, the accuracy of predicted efficiencies requires further refinement. The tube-in-manifold design demonstrates that packed capillary columns with cylindrical cross-sectional channel geometry and ultrahigh pressure, low dead volume fluidic connections are achievable.

Valorizing Arthrospira cell residues into polysaccharides: Characterization and application in yogurt

This study aimed to extract and characterize polysaccharides from Arthrospira cell residue and evaluate their application in yogurt. Four Arthrospira polysaccharides (APP-50, APP-60, APP-70, and APP-80) were obtained by different ethanol concentrations. With the increase in ethanol concentration, the component peaks of polysaccharide became less and the components were simpler. The results showed that APP-60 had the highest neutral sugar content and the densest spherical structure. APP-50 had the highest protein content, the strongest antioxidant capacity, the porous structure, and the structure was incomplete. The addition of polysaccharides increased the viscosity, storage modulus, loss modulus, and particle size of yogurt, and improved the stability of yogurt during long-term storage. The microstructure of yogurt with added polysaccharides was tighter and more orderly than that of the control yogurt. This study demonstrated that Arthrospira polysaccharides could be used as functional ingredients to enhance the quality and nutritional value of yogurt.

Fluorescent EEM-PARAFAC considerations of Aldrich humic acid salt as an aquatic or terrestrial organic matter surrogate

The fluorescence of “long dead” terrestrially sourced organic carbon (Aldrich humic acid salt) was compared to “recently dead or excreted” aquatically sourced organic carbon (ornamental pond). This research eliminated the “living” (biologically active) category of organic carbon (by azide treatment and filtration) which prevented organic matter continuing to metabolize due to microbial activity during storage and analysis. The focus in this context is on the diagenetic (fulvic and humic) substances, which are considered the most recalcitrant organic carbon forms in water treatment. The purposes of this research were to investigate (a) what excitation-emission matrix (EEM) spectroscopy and PARAllel FACtor (PARAFAC) analysis (EEM-PARAFAC) modeling reveals about the limitations to the use of terrestrially derived Aldrich Humic Acid as an aquatic organic matter surrogate, (b) potential flaws observed in EEM spectra and incorrect PARAFAC component assignments gathered in contemporaneous studies, and (c) how EEM-PARAFAC modeling can be used to illustrate the continuum in organic matter aging or maturity. Additionally, to expand the analysis, data were compared to previously published PARAFAC models derived from other freshwater sources. An important result of this research was discovery of a PARAFAC component peak observed at the emission (EM) wavelength at 540 nm in Aldrich Humic Acid which has been rarely noted in the literature, and not previously recognized for its potential importance. This research implies that Aldrich humic acid should only be used as an aquatic surrogate with caution, and that it can be a surrogate for terrestrial soil or ore samples.

Optimization and Spectrum-Effect Analysis of Ultrasonically Extracted Antioxidant Flavonoids from Persicae Ramulus.

The objectives of this study were to optimize the ultrasonic-assisted flavonoid extraction process from PR and to establish fingerprints in order to analyze the spectrum-effect relationship of antioxidant activity. The ultrasonic-assisted flavonoid extraction process from PR was optimized using RSM, and the fingerprints of twenty-eight batches of flavonoids from PR were established using UHPLC. Meanwhile, the in vitro antioxidant activity of PR was evaluated in DPPH and ABTS free radical-scavenging experiments. Then, the peaks of the effective antioxidant components were screened using the spectrum-effect relationships. The results show that the optimal extraction yield of flavonoids from PR was 3.24 ± 0.01 mg/g when using 53% ethanol, a 1:26 (g/mL) solid-liquid ratio, and 60 min of ultrasonic extraction. Additionally, the clearance of two antioxidant indices by the flavonoids extracted from PR had different degrees of correlation and showed concentration dependence. Simultaneously, the similarity of the UHPLC fingerprints of twenty-eight batches of PR samples ranged from 0.801 to 0.949, and four characteristic peaks, namely peaks 4, 12, 21, and 24, were screened as the peaks of the components responsible for the antioxidant effect of PR using a GRA, a Pearson correlation analysis, and a PLS-DA. In this study, characteristic peaks of the antioxidant effects of PR were screened in an investigation of the spectrum-effect relationship to provide a scientific basis for the study of pharmacodynamic substances and the elucidation of the mechanism of action of the antioxidant effect of PR.

Insights into the characteristics of changes in dissolved organic matter fluorescence components on the natural attenuation process of toluene

Natural attenuation (NA) is of great significance for the remediation of contaminated groundwater, and how to identify NA patterns of toluene in aquifers more quickly and effectively poses an urgent challenge. In this study, the NA of toluene in two typical soils was conducted by means of soil column experiment. Based on column experiments, dissolved organic matter (DOM) was rapidly identified using fluorescence spectroscopy, and the relationship between DOM and the NA of toluene was established through structural equation modeling analysis. The adsorption rates of toluene in clay and sandy soil were 39 % and 26 %, respectively. The adsorption capacity and total NA capacity of silty clay were large. The occurrence of fluorescence peaks of protein-like components and specific products indicated the occurrence of biodegradation. Arenimonas, Acidovorax and Brevundimonas were the main degrading bacteria identified in Column A, while Pseudomonas, Azotobacter and Mycobacterium were the main ones identified in Column B. The pH, ORP, and Fe(II) were the most important factors affecting the composition of microbial communities, which in turn affected the NA of toluene. These results provide a new way to quickly identify NA of toluene.

Frequency-Dependent Variability of Pulse Wave Transit Time: Pilot Study.

The dynamics of the pulse wave (PW) associated with the PW transit time variability (PWTTV) determines the peripheral pulse rate variability, which is used as a surrogate for heart rate variability (HRV). The aim of the work is to analyze the frequency-dependent dynamics of PWTTV and to identify the possible frequency-phase modulation of PW velocity oscillations on the transit from the heart to the soft tissues of the distal parts of the upper extremities. RR-interval recordings and synchronous records of photoplethysmograms of 12 conditionally healthy subjects from the PhysioNet open database were used in this work. Using the Hilbert-Huang transform 3 spectral components of PWTTV and HRV were identified. It was shown that the amplitudes of PWTTV oscillations were many times (up to 8.4 times) smaller than the amplitudes of HRV, and the peaks of PWTTV spectral components were shifted towards higher frequencies than those of HRV. Functional relations between PWTTV and HRV, which can determine the phase modulation of periodic changes in the PW propagation velocity, were revealed.

Unbalanced Distribution Network Cross-Country Fault Diagnosis Method with Emphasis on High-Impedance Fault Syndrome

Unusual fault scenarios can occur on the utility grid in a power system network. Cross-Country Faults (CCFs) connected to the High-Impedance Fault (HIF) syndrome are more prone to occur in forested areas due to thunderstorms, cyclones, and improper vegetation management and tree pruning. Finding and categorizing CCFs associated with HIF syndrome is a great challenge. This study employed the cross-correlation method to reconstruct the signals produced by CCFs with HIF, which were shown to be complicated, aperiodic, asymmetric, and nonlinear. A decreased sensitivity to random noise means that a given modification might not affect equally all component peaks. This allows for more precise signal recovery. The maximum voltage cross-correlation coefficients were carefully evaluated as distinguishing elements in the development of a suggested fault detection technique. The proposed concept was evaluated on a modified imbalanced IEEE 240 bus system under different case studies. These case studies cover a wide range of scenarios, such as the switching of a capacitor bank, feeder energization, and the effects of nonlinear loads under noisy conditions.

Development of near-infrared spectroscopy calibration model and monitoring software: For monitoring hexamethylenetetramine concentration in hexamethylenetetramine–acetic acid solution

In recent years, near-infrared spectroscopy has been increasingly used in chemical engineering processes. However, accurately and in real-time monitoring concentrations remains highly challenging. This study presents a method for accurately monitoring the hexamethylenetetramine concentration in hexamethylenetetramine-acetic acid solution by integrating near-infrared spectroscopy with software techniques. Compared to the methods of zero mean standardization (Z-score), standard normal variate (SNV), first derivative (D1), second derivative (D2), and vector normalization (VN), the Savitzky-Golay first derivative (SGFD) method effectively addresses issues related to baseline drift, noise, and other interferences. This results in clearer identification of characteristic absorption peaks of different components and a significant improvement in the accuracy of the analysis. The study combined the uninformative variable elimination (UVE), differential evolution (DE), and moth flame optimization (MFO) algorithms to optimize a feature wavenumber selection method, which reduced the number of variables by 78.74 %, and the values of root mean square error of calibration set (RMSEC) and root mean square error of prediction (RMSEP) by 18.86 % and 30.38 %, respectively. Additionally, the analytical method was integrated with real-time monitoring software, enabling the monitoring of hexamethylenetetramine concentration. This integration supports the improvement of the quality and safety of the manufacturing process. The results demonstrate the potential application of near-infrared spectroscopy in real-time monitoring and automated control of chemical processes in the chemical industry.

Detection of Extragalactic Anomalous Microwave Emission in NGC 2903 Using KVN Single-dish Observations

We present the results of the single-dish observations using the Korean VLBI Network to search for anomalous microwave emission (AME) in nearby galaxies. The targets were selected from ‘Mapping the dense molecular gas in the strongest star-forming galaxies' (MALATANG), a legacy survey project of the James Clerk Maxwell Telescope. The MALATANG galaxies are good representatives of local galaxies with enhanced nuclear activity associated with star formation and/or active galactic nuclei (AGNs), providing IR-bright galaxy samples; thus, they are good candidates for AME hosts. Combining with ancillary data, we investigated the radio–IR spectral energy distribution (SED), while searching for AME signals in five galaxies. The AME in NGC 2903 was well detected at a significant confidence level, whereas that in NGC 2146 and M82 was marginal. NGC 1068 and Arp 299 indicated no significant hints, and we provide upper limits for the AME. The best-fit SED exhibited local peaks of the AME components at higher frequencies and with stronger peak fluxes than those in previous studies. This suggested that AME originates from denser environments such as molecular clouds or photodissociation regions rather than warm neutral/ionized medium as commonly suggested by previous studies. Further, our AME-detected targets were observed to exhibit higher specific star formation rates than the other extragalactic AME hosts. Furthermore, AME favored starburst galaxies among our sample rather than AGN hosts. Consequently, this might imply that AGNs are excessively harsh environments for tiny dust to survive.

Structure, variability, and origin of the low-latitude nightglow continuum between 300 and 1800 nm: evidence for HO2 emission in the near-infrared

Abstract. The Earth's mesopause region between about 75 and 105 km is characterised by chemiluminescent emission from various lines of different molecules and atoms. This emission was and is important for the study of the chemistry and dynamics in this altitude region at nighttime. However, our understanding is still very limited with respect to molecular emissions with low intensities and high line densities that are challenging to resolve. Based on 10 years of data from the astronomical X-shooter echelle spectrograph at Cerro Paranal in Chile, we have characterised in detail this nightglow (pseudo-)continuum in the wavelength range from 300 to 1800 nm. We studied the spectral features, derived continuum components with similar variability, calculated climatologies, studied the response to solar activity, and even estimated the effective emission heights. The results indicate that the nightglow continuum at Cerro Paranal essentially consists of only two components, which exhibit very different properties. The main structures of these components peak at 595 and 1510 nm. While the former was previously identified as the main peak of the FeO “orange arc” bands, the latter is a new discovery. Laboratory data and theory indicate that this feature and other structures between about 800 and at least 1800 nm are caused by emission from the low-lying A′′ and A′ states of HO2. In order to test this assumption, we performed runs with the Whole Atmosphere Community Climate Model (WACCM) with modified chemistry and found that the total intensity, layer profile, and variability indeed support this interpretation, where the excited HO2 radicals are mostly produced from the termolecular recombination of H and O2. The WACCM results for the continuum component that dominates at visual wavelengths show good agreement for FeO from the reaction of Fe and O3. However, the simulated total emission appears to be too low, which would require additional mechanisms where the variability is dominated by O3. A possible (but nevertheless insufficient) process could be the production of excited OFeOH by the reaction of FeOH and O3.

Radial basis function neural network optimization algorithm based on dynamic inertial weight particle swarm optimization for separating overlapping peaks in ion mobility spectrometry.

Ion mobility spectrometry (IMS), as a promising analytical tool, has been widely employed in the structural characterization of biomolecules. Nevertheless, the inherent limitation in the structural resolution of IMS frequently results in peak overlap during the analysis of isomers exhibiting comparable structures. The radial basis function (RBF) neural network optimization algorithm based on dynamic inertial weight particle swarm optimization (DIWPSO) was proposed for separating overlapping peaks in IMS. The RBF network structure and parameters were optimized using the DIWPSO algorithm. By extensively training using a large dataset, an adaptive model was developed to effectively separate overlapping peaks in IMS data. This approach successfully overcomes issues related to local optima, ensuring efficient and precise separation of overlapping peaks. The method's performance was evaluated using experimental validation and analysis of overlapping peaks in the IMS spectra of two sets of isomers: 3'/6'-sialyllactose; fructose-6-phosphate, glucose-1-phosphate, and glucose-6-phosphate. A comparative analysis was conducted using other algorithms, including the sparrow search algorithm, DIWPSO algorithm, and multi-objective dynamic teaching-learning-based optimization algorithm. The comparison results show that the DIWPSO-RBF algorithm achieved remarkably low maximum relative errors of only 0.42%, 0.092%, and 0.41% for ion height, mobility, and half peak width, respectively. These error rates are significantly lower than those obtained using the other three algorithms. The experimental results convincingly demonstrate that this method can adaptively, rapidly, and accurately separate overlapping peaks of multiple components, improving the structural resolution of IMS.

Exogenous factors impact on bacterial-microalgal growth and chromophoric dissolved organic matter: a case study of Chrysotila dentata and Marinobacter hydrocarbonoclasticus

The relationship between Chrysolia dentata and bacteria that play an important role in the carbon cycle is complex yet closely intertwined. However, there is still limited knowledge about how phytoplankton interacts with heterotrophic bacteria under external influences. The transformation and processing of dissolved organic matter (DOM) by epiphytic bacteria for phytoplankton especially, under vitamin B12 (VB12) and abscisic acid (ABA) introducing have rarely been investigated. In this experiment, Marinobacter hydrocarbonoclasticus (CA6) was cultured with Chrysotila dentata to investigate growth and DOM release and transformation under the influence of VB12 and ABA. Three-dimensional (3D)-EEM, combined with fluorescence regional integration and the peak selecting method, was used to obtain fluorescent peaks (B, T, A, and C) and four indexes for DOM analysis. Our findings indicate that the incubation of CA6 significantly enhances the release of protein-like components (peak T) and humic-like components (peak C) during the incubation period. However, 100 μg/L VB12 or abscisic acid does not promote axenic microalgae growth or release of C. dentata-derived DOM. However, they have different effects on C. dentata-CA6 growth and the derived DOM. Abscisic acid can facilitate steady growth of both C. dentata and CA6 cells while enhancing the amounts of humic-like components. Conversely, VB12 inhibits the growth of CA6 and results in a rapid decrease in protein-like signal, but it does not significantly enhance C. dentata growth or the transformation of DOM. This indicates that ABA can support stable co-grown of microalgal and bacteria in a water environment, while VB12 may hinder CA6 bacterial growth, resulting in a less stable co-cultured environment. This study uncovers and verifies the impact of exogenous factors and heterotrophic bacteria in the growth of microalgae, underlining their role in transforming and generating algae-derived dissolved organic matter (DOM) within laboratory settings.

Co-pyrolysis of orange peel and eggshell for oxygenated rich composite: Process optimization with response surface methodology

Co-pyrolysis of orange peel and chicken eggshell was performed for the synthesis of the composite, a co-pyrolysis technique used to promote natural fabrication and to allow the raw material elemental combination effect and the preparatory conditions such as pyrolysis temperature, residence time, and eggshell/orange peel mixing ratio, to be optimized with the response surface methodology through Box-Behnken Design(BBD). BBD involved a randomized series of 17 experimental runs, and the best optimal conditions were found with a pyrolysis temperature of 300 °C, a residence time of 1 h, and 0.5 as the mixing ratio. These conditions gave a maximum adsorption capacity of 167 mg/g for removal of the modal pollutant methylene blue. FTIR spectra of the composite showed new functional peaks of oxygenated groups, at two different bands. XRD confirmed an amorphous surface with inorganic component peaks, while SEM-EDS revealed rich defects sites along with an enhanced percentage of oxygen elements on the surface; the surface area was enhanced from 1 m2 with unmodified peel to 64 m2 with composite. The adsorption behavior of the composite was studied for dye removal and the adsorption behavior was well explained by the Langmuir isotherm model.

Hepatoprotective activity of Patrinia scabiosaefolia Fisch and quality evaluation based on UPLC fingerprint and multi-component analysis

To establish a quality evaluation method for Patrinia scabiosaefolia Fisch (PS), as well as to study the anti-inflammatory and hepatoprotective effects of the aqueous extract of Patrinia scabiosaefolia Fisch (APS). We used ultra performance liquid chromatography (UPLC) to establish fingerprint and content determination method for PS. The alcoholic liver injury model was prepared by feeding Lieber-DeCarli alcohol liquid feed to mice. We determined the levels of ALT, AST, TC, TG in serum, as well as GSH, MDA in the liver. The mRNA relative expression levels of TNF-α, IL-6, IL-1β, INOS and COX-2 were detected by qRT-PCR, and liver tissues were taken for pathological examination. The fingerprints of 16 batches of PS were established, and 3 component peaks were identified, which were chlorogenic acid (CA), isochlorogenic acid A (ICAA) and isochlorogenic acid C (ICAC). The similarity of the 6 common peaks was between 0.924 and 1.000. A mice model of alcoholic liver injury was successfully made by mixing alcohol liquid feed. The levels of ALT, AST, TC and TG in serum and MDA, TNF-α, IL-1β, LL-6, COX-2 and INOS mRNA in liver were effectively reduced in the drug administration group. The levels of GSH in mouse liver tissue were increased in the drug administration group. The method has good repeatability, stability and feasibility, and it meets the requirements for Quality evaluation. APS exhibits a protective effect against alcoholic liver injury (ALI) in mice.

Cortical Auditory Evoked Potential Testing in Children With Auditory Neuropathy Spectrum Disorder.

In the present report, we reviewed the role of cortical auditory evoked potentials (CAEPs) as an objective measure during the evaluation and management process in children with auditory neuropathy spectrum disorder (ANSD). We reviewed the results of CAEP recordings in 66 patients with ANSD aged between 2 months and 12 years and assessed the relationship between their characteristics (prevalence, morphology, latencies, and amplitudes) and various clinical features, including the mode of medical management. Overall, the CAEPs were present in 85.2% of the ears tested. Factors such as prematurity, medical complexity, neuronal issues, or presence of syndromes did not have an effect on the presence or absence of CAEPs. CAEP latencies were significantly shorter in ears with cochlear nerve deficiency than in ears with a normal caliber nerve. Three different patterns of CAEP responses were observed in patients with bilateral ANSD and present cochlear nerves: (a) responses with normal morphology and presence of both P1-P2complex and N2 components, (b) responses with abnormal morphology and presence of the N2 component but undefined P1-P2complex peak, and (c) entirely absent responses. None of the patients with normal, mild, or moderate degree of hearing loss had a complete absence of CAEP responses. No significant differences were uncovered when comparing the latencies across unaided and aided children and children who later received cochlear implants. The CAEP protocol used in our ANSD program did inform about the presence or absence of central auditory stimulation. Absent responses typically fit into an overall picture of complete auditory deprivation and all of these children were ultimately offered cochlear implants after failing to develop oral language. Present responses, on the other hand, were acknowledged as a sign of some degree of auditory stimulation but always interpreted with caution given that prognostic implications remain unclear.

A rapid localization and analysis method for isoquinoline alkaloids with fluorescence in Coptis chinensis Franch. By fabricating the nano-silver sol as a substrate for surface-enhanced Raman spectroscopy

BackgroundThe quality of traditional Chinese medicines (TCMs) directly impacts their clinical efficacy and drug safety, making standardization a critical component of modern TCMs. Surface-enhanced Raman spectroscopy (SERS) is an effective physical detection method with speed, sensitivity, and suitability for large sample analyses. In this study, a SERS analysis method was developed using a nano-silver sol as the matrix to address the interference of fluorescence components in TCMs and overcome the limitations of traditional detection methods. ResultsThe higher sensitivity and efficiency of SERS was used, enabling detection of a single sample within 30 s. Coptis chinensis Franch. (CCF) was chosen as the model medicine, the nano-silver sol was used as the matrix, and CCF’s fourteen main fluorescent alkaloids were tested as index components. Typical signal peaks of the main components in CCF corresponded to the bending deformation of the nitrogen-containing ring plane outer ring system, methoxy stretching vibration, and isoquinoline ring deformation vibration. Through SERS detection of different parts, the distribution content of the main active components in the cortex of CCF was found to be lower than that in the xylem and phloem. Additionally, rapid quality control analyses indicated that among the nine batches of original medicinal materials purchased from Emei and Guangxi, the main active ingredient showed a higher content. SignificanceA SERS-based method for the rapid localization and analysis of multiple components of TCMs was established. The findings highlight the potential of SERS as a valuable tool for the analysis and quality control of TCMs, especially for fluorescent components.

Extraction and diagnosis of rolling bearing fault signals based on improved wavelet transform

As the continuous growth of the machinery industry, the importance of rolling bearings as key connecting parts in machinery movement is also increasing. However, the extraction and diagnosis of rolling bearing fault signals are difficult, and how to use modern transform analysis methods to raise the extraction efficiency and diagnostic accuracy becomes the focus. For this, a rolling bearing fault signal extraction and diagnosis model is designed based on empirical wavelet transform. The diagnostic model is optimized by using support vector machine and quantum genetic algorithm to design a rolling bearing fault signal extraction and diagnosis model based on improved empirical wavelet transform-support vector machine. The test results show that the research method can obtain four component signals showing different anomalies when generating time domain diagrams. Only five component peaks are generated and one group is extracted as output when generating component peaks. The abnormal amplitude of envelope spectrum basically reaches 0.40×10-6 or above. The judgment accuracy of component diagnosis reaches 98.12%. The above results show that the research method has better fault signal extraction ability and better diagnostic accuracy when performing fault signal diagnosis, which can provide new technical support for rolling bearing fault signal extraction and diagnosis.

Warming-induced contraction of tropical convection delays and reduces tropical cyclone formation

The future risk of tropical cyclones (TCs) strongly depends on changes in TC frequency, but models have persistently produced contrasting projections. A satisfactory explanation of the projected changes also remains elusive. Here we show a warming-induced contraction of tropical convection delays and reduces TC formation. This contraction manifests as stronger equatorial convection and weaker off-equatorial convection. It has been robustly projected by climate models, particularly in the northern hemisphere. This contraction shortens TC seasons by delaying the poleward migration of the intertropical convergence zone. At seasonal peaks of TC activity, the equatorial and off-equatorial components of this contraction are associated with TC-hindering environmental changes. Finally, the convection contraction and associated warming patterns can partly explain the ensemble spread in projecting future TC frequency. This study highlights the role of convection contraction and provides motivation for coordinated research to solidify our confidence in future TC risk projections.

Design and analysis of PM‐assisted synchronous reluctance machine with shifted magnetic poles

AbstractThe authors present a new design of a PM‐assisted synchronous reluctance motor (PM‐SynRM) with uneven air‐gap length to improve the power factor and enhance the torque production capability. The rotor structure is modified to properly shift rotor magnetic poles and therefore (i) increases the back‐EMF and the electromagnetic torque, (ii) allows electromagnetic torque and reluctance torque components peak near the same current phase angle. The proposed solution is simple, does not require changing the arrangement of magnets and/or flux barriers and is applicable to all types of PM‐SynRMs. Sensitivity analysis is carried out to determine the extent of which the proposed magnetic pole shifting may impact the resultant torque profile. To assess the level of success, the electromagnetic characteristics of the proposed design (e.g. torque, power factor, and back‐EMF) are compared against the baseline structure under the same operating conditions. For verification purposes, Finite Element simulation results are validated via a series of analytical calculations and experimental measurements, and supported with detailed theoretical discussion.