Narrow Strip Research Articles

Sweet Division Problems: From Chocolate Bars to Honeycomb Strips

Sweet Division Problems: From Chocolate Bars to Honeycomb Strips

A Compact Planar MIMO Inverted‐F Antenna (PIFA) for Sub‐6 GHz 5G Communication and IoT Wireless Networks Applications

ABSTRACTA compact eight‐port MIMO structure containing planar inverted‐F antennas (PIFAs) as radiating elements is designed for 5G cellular communication applications within the sub‐6 GHz band. The proposed antenna consists of four radiating elements that are placed at four corners on the same plane of geometry. The overall dimension of the ground plane is considered to be 59 mm × 120 mm to make it convenient for modern smart mobile handsets. Each radiating element has 2‐feeding plates, which are situated perpendicular to each other in orientation to make the arrangement cross‐polarized, which in turn exploits polarization diversity as well as spatial diversity among the combination of different radiating elements. The patches are structured by embedding rectangular slots in a meandered shape, and the ground plane is configured by introducing rectangular slots and narrow metallic strips. The prototype of the prescribed MIMO PIFA model has been fabricated and experimentally tested. It shows multi‐band operations (3.27–3.37, 4.16–4.35, 4.93–5.06, and 5.47–5.68 GHz) within the sub‐6 GHz spectrum. The isolation among various patches is observed within the range of −35 dB to −42 dB. The peak gain reaches around 8.1 dBi. The designed MIMO PIFA exhibits superior diversity performance by producing ECC ≤ 0.0006, DG ≈ 10 dB, CCL < 0.20 bits/Hz/s, and MEG ≤ −3 dB. Furthermore, the specific absorption rate (SAR) is evaluated according to the standard values of fat, skin, and muscle at 3.3 GHz. The prescribed model maintains acceptable SAR values for 1‐g and 10‐g tissues, which makes it suitable for smartphone applications.

Soil-climatic conditions of the vineyard and biochemical characteristics of the red dry wine ‘Kara-Koysu’ (Republic of Dagestan, Russian Federation)

ABSTRACT The article provides additional information that emphasizes the growing international interest in the impact of climate (temperature, humidity, precipitation, solar activity) on grape yields and the quality of terroir wine. The study deals with the climate gradient of the terroir of the Derbent region of the Republic of Dagestan (Russia), located on the terraced accumulative-coastal plain of the Caspian lowland, stretching for 160 km from north to south in a narrow strip between the coast of the Caspian Sea and the foothills. The influence of soil and climatic conditions on the biochemical characteristics of red dry wines ‘Kara-Koysu’ from Cabernet Sauvignon wingrapes of the 2019–2021 harvest was studied. The growing season occurred in dry, moderately humid conditions in 2019; hot, with a lot of precipitation in 2020 and more extreme conditions in 2021. The conditions of recent years have contributed to the change of almost all the studied indicators of tested wines. Studies have found that the climatic conditions of 2020–2021 were more favorable for obtaining a rich harvest, high-quality wines due to more UV light exposure and precipitation.

Suppression of magnetic vortex losses in submicron NbN coplanar waveguide resonators

We present a method for improving the performance of microwave coplanar resonators in magnetic fields, by using narrow superconducting strips of width close to the London penetration depth. In a range of low fields, the narrow strips inhibit the presence of magnetic vortices, thus preventing the generation of losses caused by their motion, leading to enhanced resistance to magnetic fields. Our method provides a more straightforward solution compared to previously proposed techniques designed to restrict vortex motion, holding potential for the development of improved devices based on microwave resonators.

Playing to Survive: Children and Innovation During the Little Ice Age in Greenland

Greenland is the world's largest island, but only a narrow strip of land between the Inland Ice and the sea is inhabitable. Yet, the Norse chose to settle here around ad 986. During the eleventh century ad, precontact Inuit people moved into Greenland from northern Alaska via Canada. Although the two cultures faced the same climatic changes during the Little Ice Age, the Inuit thrived, while the Norse did not, for multiple causes. The authors focus on one of these causes, the hitherto overlooked contribution of young children's learning strategies to societal adaptation. The detailed analysis of a large corpus of play objects reveals striking differences between the children's material culture in the two cultures: rich and diverse in the precontact Inuit material and more limited and normative in the Norse. Drawing on insights from developmental psychology, the authors discuss possible effects of play objects on children's future adaptability in variable climatic conditions.

Impact of Aggregation Pheromone Traps on Spatial Distribution of Halyomorpha halys Damage in Apple Orchards.

Halyomorpha halys (Stål) (Hemiptera: Pentatomidae) is an invasive pest causing significant damage to tree crops. Our study examined the impact of newly designed aggregation pheromone-baited 'mini-sailboat' (MSB) traps for controlling H. halys and its effect on the spatial distribution of fruit damage. Four replicates of four traps, with a total of 16 MSB traps, were placed along a 1.3 km border of apple orchards, concentrating the traps on one side of the orchards. A fruit damage assessment for incidence and severity was conducted at increasing distances from the orchard border where the traps were placed, encompassing 107 assessment points. Our study showed that deploying MSB traps along the orchard border significantly increased fruit damage within the first 45 m compared to control plots without traps. However, beyond the first 45 m from the border, there was a significant reduction in damage incidence. In the treated plots, 50% of the damage occurred within 26 m of the traps, while in control plots, within 85 m. Shifting the fruit damage pattern means restricting the pests lingering in a narrow strip near the MSB traps, which paves the way for improved techniques to restructure the crop perimeter.

Epigaeic spiders (Araneae) from three habitats at Stryn, Nordfjord, Western Norway

One year of pitfall sampling in (A) a narrow strip of vegetation (junipers, Rosa sp., small pines) close to a river bank, (B) a cultivated medium humid meadow and (C) a humid deciduous forest (Alnus) with some grass on the ground collected a total of 25, 48 and 32 species, respectively (in total 67 species). Shannon indices of general diversity (ln e) were 1.8, 2.1 and 3.1, respectively. The three sites shared only 9 species, 57% of all species were found in only one locality. Similarity indices were low, especially between loc. A and C. Linyphiidae and Lycosidae were dominant. The latter were scarce in loc. B and C but common at loc. A (Pardosa palustris and P. amentata together comprising 43.5% of total) and net building species more scarce. The local distribution, co-existence, ecological and habitat preferences, seasonal activity and body size of some common species are briefly discussed. For some species, aspects of geographical distribution are discussed.

The Hedendoa and half-weaving

The Hedendoa of Sudan produce goat-hair blankets, called shamlas, for nuptial ceremonies employing an extremely rare and labour-intensive half-weaving technique that is completely unrelated to the narrow braided sewn strips used to produce palm leaf mats that cover their tents. I hypothesize that this technique exemplifies technological transfer resultant from casual encounters and incomplete observations of the weaving techniques of the Bedouin pastoral nomads of the region.

ТРИ САРМАТСКИХ ПОГРЕБАЛЬНЫХ КОМПЛЕКСА ИЗ СТЕПНОГО КРЫМА

The work analyzes three recently discovered burial monuments of the 1st century BC – mid (?) 1st century AD in the Steppe Crimea. Their distinctive features are the use of an older kurgan for burial, the predominant orientation of the deceased to the northern sector, the insignificant depth of the burial, the paucity of grave goods, etc. – typical for early Sarmatian burials of the Northern Black Sea region. Therefore, the complexes under consideration should be correlated specifically with this cultural group. It is important to emphasize that, although large-scale field research in recent years has covered a significant part of the steppe space of the Crimean Peninsula, passing through it in a wide strip from east to west, Sarmatian monuments have not been identified in most of this territory. The newly opened complexes are located on the Kerch Peninsula and near it, i.e. in those areas in which Sarmatian burials were previously known. This only confirms the conclusion already made about the location of Sarmatian burials in the Steppe Crimea only in a narrow strip along the northern and north-eastern borders of the region, along the coast of the Black Sea and Sivash. This location, apparently, marks the path of the ancient nomads from the Dnieper region – one of the main areas of their settlement – to the ancient centers of the Crimean Peninsula, in particular Panticapaeum, to carry out trade and other relationships.

Study on the influence of reduction on mechanical properties and the structure of C1 lead narrow strips during cold rolling

Study on the influence of reduction on mechanical properties and the structure of C1 lead narrow strips during cold rolling

ИССЛЕДОВАНИЕ ПАРАМЕТРОВ ПОСТОЯННОЙ ТЕХНОЛОГИЧЕСКОЙ КОЛЕИ, ПРЕДНАЗНЧЕННОЙ ДЛЯ УХОДА ЗА ПОСЕВАМИ СЕЛЬСКОХОЗЯЙСТВЕННЫХ КУЛЬТУР В ЦЕНТРАЛЬНОМ ЧЕРНОЗЕМЬЕ

A study of the parameters of the created and formed permanent tramline intended for the passage of agricultural machinery when caring for crops in the Central Black Earth Region has been completed. It has been established that the width of the lanes used for the passage of agricultural machinery propulsion depends on the type of crops cultivated and the sprayers used, as well as on the location of the tramline on the agricultural field. The average width of the lanes on straight sections when forming a constant tramline for crops, which are sown in a narrow strip method, with a self-propelled sprayer on straight sections was 500 mm, and on turning sections - 900 mm; using a trailed sprayer working in tandem with a tractor, the average stripe width on straight sections was 650 mm, and on turning sections – 900 mm. When creating a constant tramline for sugar beet crops, regardless of the type of agricultural machinery used, the average width of the stripes on straight and turning sections was 900 mm. The length of permanent tramline strips for an agricultural field having a rectangular shape was calculated, and it was found that it depends not only on the geometric shape of the field, but also on the operating parameters of the agricultural machinery used and the nature of the location of straight and turning sections. Based on the data obtained, a calculation was made of the percentage of the allocated area of the agricultural field for its creation or formation. When caring for agricultural crops that are sown in a narrow stripe method using a self-propelled sprayer, the percentage of the allocated field area under a constant tramline is 4.7, and when using a trailed sprayer working in tandem with a tractor, the percentage of the allocated area is 5.9. The percentage of the field area allocated for a constant tramline when cultivating sugar beets is 4.7 and does not depend on the type of agricultural machinery used.

Derivation of Coastal Erosion Susceptibility and Socio-Economic Vulnerability Models for Sustainable Coastal Management in Senegal

Coastal erosion has posed significant challenges to sustainability and socio-economic stability along Senegal’s coastline, leading to substantial infrastructure losses. Using GIS multi-criteria decision analysis (MCDA), two sub-indices were derived for Senegal’s coastal departments: the physical susceptibility (PSI) and the social-economic vulnerability (SVI) to coastal erosion. The integrated coastal erosion vulnerability (ICER) model was derived by their aggregation. A total of 26 criteria were used, 18 for PSI and 8 for SVI. The criteria weighting coefficients of the sub-indices were determined using the analytic hierarchy process (AHP). Validation of the model accuracy was performed using receiver operating characteristic (ROC) curves that were calculated based on a created coastal erosion cadaster and true positive (TP) sites and manually acquired true negative (TN) sites. The accuracy assessment confirmed the consistency of the physical susceptibility model (PSI) and proved that existing coastal erosion sites are within (5) very high susceptibility areas. Through the generated ICER, the coastal departments were divided into areas of (1) very low, (2) low, (3) medium, (4) high and (5) very high vulnerability to coastal erosion. Very high (5) and high (4) classes cover around 31% of the coastal departments, mostly encompassing a narrow coastal strip and low river valleys and mouths. The presented coastal susceptibility and vulnerability maps, with a spatial resolution of 30 m, identified problematic areas in Senegal’s coastal departments and can help decision-makers in the construction of effective coastal zone management and sustainable development.

Assessment of Minimally Invasive Surgical Techniques for Sagittal Craniosynostosis: A Multi-Center Time Series Study.

Minimally invasive strip craniectomy is a well-established treatment for sagittal craniosynostosis, however the temporality of change in head shape has not been assessed. In this study, we perform head shape analysis to compare time-series-based clinical outcomes between three different surgical techniques across three academic centers for the treatment of sagittal craniosynostosis. Retrospective, longitudinal 3D images were collected from patients who underwent surgery for the correction of sagittal craniosynostosis for up to 5 years post-operation. The surgical methods studied include spring-assisted craniectomy, narrow-strip craniectomy plus orthotic helmet therapy, and wide-strip craniectomy with biparietal and bitemporal barrel stave wedge osteotomies plus orthotic helmet therapy. Postoperative 3D images were binned into six age groups. Cranial index measurements were calculated on 3D images. 3D whole-head composite images were generated for each procedure to visually represent longitudinal outcomes. The median with interquartile range (IQR) CI measurements at 3-5 years postoperative follow up were 75.9 [73.1-78.6] for spring-assisted, 75.9 [75.4-78.5] for narrow-strip, and 79.4 [76.4-81.9] for wide-strip. The wide-strip CI was significanly different from the spring-assissted and narrow strip groups (p < 0.001). Concerning 3D analysis, spring-assisted patients showed normalization of frontal bossing and skull height compared to age-matched controls, while wide-strip patients showed greater correction of occipital bulleting. Narrow-strip patients had intermediate results between these outcomes. There was no statistically significant regression in longitudinal CI measurements across the three techniques aimed at treating sagittal craniosynostosis. Longitudinal comparison of 3D head shape outcome demonstrated satisfactory correction of scaphocephalic deformity across all three surgical groups.

Legume choice and planting configuration influence intercrop nutrient and yield gains through complementarity and selection effects in legume-based wheat intercropping systems

CONTEXTBy exploiting the complementarities between intercrops, cereal/legume intercropping provides an opportunity to increase legume production with sustained cereal yield. However, little is known about how legume choice and spatial configurations affect the performance and economic viability of legume-based wheat intercropping, especially in arid-irrigated conditions. OBJECTIVEWe conducted this study to investigate the complementarity of three different legumes (chickpea, soybean, and pea) with wheat and determine the appropriate strip width for intercrops. METHODSA three-year study (2021−2023) was conducted to evaluate the effects of legume choice and spatial configuration (narrow strips of 0.6 m (NS) and partially wide strips of 1.2 m (pWS) for each intercrop) on wheat/soybean, wheat/pea, and wheat/chickpea intercropping, and results were compared with their sole systems for dry matter, nitrogen (N) and phosphorus (P) uptake, yield, and economic returns. We also quantified the intensity of the net biodiversity effect (NE), complementarity effect (CE), and selection effect (SE) for yield, N (NEN, CEN, and SEN), and P (NEP, CEP, and SEP) gains of legume-based wheat intercropping systems. RESULTS AND CONCLUSIONSOur results show that intercrops achieved the highest dry matter, nutrient uptake, and grain yield with pWS compared to NS. The intercropped chickpea, soybean, and pea achieved 67–71%, 55–62%, and 62–70% of their sole system yield. The intercropped wheat with chickpea, soybean, and pea produced 66–69%, 57–62%, and 62–66% of sole wheat yield, respectively. Results also confirmed a positive NE with both NS and pWS, mainly due to the higher CE, which ranges from 37% to 104% of NE under all intercropping systems. The nutrient uptake gain with NS and pWS ranged from −3.4 kg ha−1 to 101.5 kg ha−1 (NEN) and − 0.2 kg ha−1 to 13.8 kg ha−1 (NEP). On average, maximum LER (1.36), NE (1012 kg ha−1), NEN (86 kg ha−1), and NEP (12 kg ha−1) were obtained with pWS in wheat/chickpea, followed by wheat/pea and wheat/soybean intercropping. Overall, wheat/pea intercropping with pWS generated the highest net profit (2014, 1533, and 1394 USD ha−1 in 2021, 2022, and 2023, respectively), which was primarily linked to the high market price of pea than chickpea and soybean. SIGNIFICANCEThese results imply that legume choice and spatial configurations influenced complementary and facilitation interactions between intercrops, and wheat/chickpea and wheat/pea intercropping with pWS could be adopted as a productive cropping strategy for obtaining higher and diverse crop yields with reduced land and nutrients than the sole wheat system.

Elliptic equations in weak oscillatory thin domains: Beyond periodicity with boundary‐concentrated reaction terms

In this paper, we analyze the limit behavior of a family of solutions of the Laplace operator with homogeneous Neumann boundary conditions, set in a two‐dimensional thin domain that presents weak oscillations on both boundaries and with terms concentrated in a narrow oscillating neighborhood of the top boundary. The aim of this problem is to study the behavior of the solutions as the thin domain presents oscillatory behaviors beyond the classical periodic assumptions,including scenarios such as quasi‐periodic or almost‐periodic oscillations. We then prove that the family of solutions converges to the solution of a one‐dimensional limit equation capturing the geometry and oscillatory behavior of boundary of the domain and the narrow strip where the concentration terms take place. In addition, we include a series of numerical experiments illustrating the theoretical results obtained in the quasi‐periodic context.

From elastic shallow shells to beams with elastic hinges by Γ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\Gamma $$\\end{document}-convergence

In this paper, we study the Γ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\Gamma $$\\end{document}-limit of a properly rescaled family of energies, defined on a narrow strip, as the width of the strip tends to zero. The limit energy is one-dimensional and is able to capture (and penalize) concentrations of the midline curvature. At the best of our knowledge, it is the first paper in the Γ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\Gamma $$\\end{document}-convergence field for dimension reduction that predicts elastic hinges. In particular, starting from a purely elastic shell model with “smooth” solutions, we obtain a beam model where the derivatives of the displacement and/or of the rotation fields may have jump discontinuities. Mechanically speaking, elastic hinges can occur in the beam.

Fatigue performance simulation of reinforced concrete beams externally strengthened with side bonded CFRP sheets

Damaged Reinforced Concrete (RC) beams are commonly strengthened by bonding Carbon Fiber Reinforced Polymer (CFRP) strips to their soffits. However, inaccessible or narrow soffits limit the use of bottom-bonded CFRP strips. The Side Bonded (SB) CFRP technique overcomes this, yet studies on SB-CFRP-reinforced beams' fatigue behavior are limited. This paper presents a Finite Element (FE) model for simulating the fatigue behavior of RC beams externally strengthened with SB-CFRP sheets. The model incorporates cyclic-dependent CFRP-concrete interface degradation. Existing experimental results are utilized to validate its accuracy. Computational analyses are undertaken to explore the effects of CFRP dimensions, load and prestress levels, and end-U-shaped wrapping on fatigue performance. A simple model is proposed to predict fatigue life considering load and prestress levels. The FE model effectively predicts fatigue performance. Parametric studies indicate that narrow CFRP strips are unable to prevent concrete failure under high loads. Fatigue failure modes include rebar ruptures and CFRP delamination. Besides, the end-U-shaped wrapping reduces interface damage, extending fatigue life. The study emphasizes the sensitivity of vibration excitation method to CFRP debonding. The proposed equation efficiently predicts the fatigue life of RC beams with externally bonded CFRP strips on their sides.

Call to action for cross‐border conservation of the critically endangered Lake Chala tilapia (Oreochromis hunteri)

AbstractLake Chala straddles the Kenya–Tanzania border, with a narrow strip of terrestrial habitat around it. The steep rocky shores are bedecked in a backdrop of Kilimanjaro at sunrise, giving the area the aesthetic beauty of an important tourist destination. The lake has important conservation implications ranging from endemic species including a critically endangered and rapidly declining fish to other unique biodiversity. This calls for urgent action to prevent extinction and promote sustainable management, building on previous work and action plans such as a proposed new conservancy, as the best safeguard against the threats.

Machine learning for authentication of black tea from narrow-geographic origins: Combination of PCA and PLS with LDA and SVM classifiers

This study investigates the feasibility of using UV–Vis spectroscopy coupled with machine learning methods to authenticate tea samples based on their geographical origins in a narrow longitudinal strip (200 km). Several preprocessing methods, such as standard normal variate (SNV), auto-scaling, multiplicative scatter correction (MSC), mean centring (MC), first derivative, and their combinations, were applied to eliminate the noninformative information. The partial least squares-linear discriminant analysis (PLS-LDA) model using first derivative spectra represented the following results, including 98.0% sensitivity, 99.5% specificity, and a mean accuracy of 98.0%. The support vector machine (PLS-SVM) classifier using first derivative spectra represented 94.0% sensitivity, 98.6% specificity, and a mean accuracy of 94.0%. The satisfactory results of the models depicted that the chemical components of tea, such as polyphenols, chlorogenic and fatty acids that absorb UV radiation are the chemical markers that can discriminate tea samples based on their geographical origin. Therefore, UV–Vis spectral fingerprinting combined with machine learning methods could be a practical, feasible, and simple method for classifying tea based on their geographical origins in a narrow longitudinal strip.

A flexible dual-band 4 × 4 MIMO antenna for 5G mm-wave 28/38 GHz wearable applications

This paper presents a novel, dual-band, four-port multi-input–multi-output (MIMO) antenna for 28/38 GHz millimeter wave 5G wearable applications. In the proposed work, we have used a novel design approach to get the dual-band behavior from a MIMO design with a small footprint of 18 × 8.5 × 0.25 mm3. For this purpose, each MIMO element is designed as a composite form of a circular and elliptical structure connected with a narrow strip and fed by a tapered feedline. The peak realized gains and total efficiencies of the antenna, evaluated in free space, are 4.15 dBi, 7.73 dBi and 80.13%, 85.44% at 28 GHz and 38 GHz frequencies, respectively. To appraise the thorough behavior of the MIMO antenna, we have evaluated all the parameters of the antenna: Envelope Correlation Coefficient (ECC), Diversity Gain (DG), Mean Effective Gain (MEG), Channel Capacity Loss (CCL), and Total Active Reflection Coefficient (TARC), and found them satisfactory. Channel capacity of the antenna at SNR = 20 dB is found to be 21.61 bps/Hz. For wearable applications, the proposed 4-port MIMO antenna is designed on a flexible Rogers 3003 substrate, and the performance is checked by evaluating bending analysis. The safety of the antenna is verified by analyzing the 1 g/10 g SAR at 28/38 GHz and the corresponding average SAR values are 0.11/0.08 W/kg and 0.05/0.04 W/kg, respectively. All the average SAR values for the proposed MIMO antenna are within the acceptable limits according to FCC/ICNIRP standards.