Zigzag Lines Research Articles

Macrozoobenthos Diversity as an Indicator of the Water Quality of the Salusu River in Ogomatanang Village, Central Sulawesi and Its Use as a Learning Media

The diversity of macrozoobenthos plays an important role as an indicator of water quality. The purpose of this study was to describe the level of macrozoobenthos diversity in the waters of the Salusu River, Ogomatanang Village, Central Sulawesi as an indicator of pollution levels and to produce suitable learning media. The type of research is descriptive. The sampling technique used systematic random and used a subber net using a zig-zag transect line and analyzed the diversity index value. The results of the study found 9 species, divided into 8 families including Baetis sp., Alloperla sp., Parathelphusa convexa, Heptagenia solitaria, Orthetrum sabina, Nemoura sp., Tylomelania arabica, Tylomelania sp., Planaria sp. The diversity index (H') was consecutively at station III (upstream) which was 2.14 with a light level of pollution, the H 'index at station II (ecotone) was 1.91 and the H 'index at station I (downstream) was 1.28 with a moderate level of pollution. The research results obtained were used as validated learning media by a team of content experts by 80%, design 78.6%, media 80%, large group student group trials 85.5% and small group 89.0%. Learning media is very feasible to use with a result of 82.62%.

Relationships between Anthropogenic Activities and Distribution of Medium to Large Mammal Species Assemblage in Madi Wildlife Corridor: Implication for Biodiversity Conservation in Uganda

Wildlife corridors between protected areas increase connectivity by integrating populations into single demographic units, thereby increasing gene flows within populations and thus probability of survival. This study assessed the relationship between anthropogenic activities and mammal species assemblage within and around Madi wildlife corridor. The study adopted recce walks along a zig-zag line transect and straight line transect methods of game tracking. Global Position System (GPS) was used to map locations of direct mammal sightings, vocalizations, tracks, dung/droppings, diggings, carcasses, and skeletal remains of mammal species. Similarly, anthropogenic activities such as hunting using bow and arrows, rifles, trapping, tree cutting, charcoal burning, bush burning, cultivation, and settlements that seemed to influence assemblage of the mammals in the area of study were mapped. The result showed that the Madi wildlife corridor still contained diverse mammal species including but not limited to; the African Elephants (Loxodonta Africana sp.), Buffaloes (Syncerus caffer) Leopards (Panthera pardus), Spotted Hyena (Crocuta Crocuta), Northern Giraffe (Giraffa Camelopardalis), Uganda kob (Kobus kob thomasi), Hartebeest (Alcelaphus buselaphus) and Reedbuck (Redunca arundinum), which were comparable to that of the adjacent Murchison Falls National Park (MFNP). The relationship between anthropogenic activities and species assemblage showed a negatively skewed distribution of some of the large mammal species specifically Elephants, Giraffes, and Hippopotamus. The study recommends gazettement of a wildlife corridor between MFNP and East Madi Wildlife Reserve to promote wildlife connectivity between two adjacent ecosystem-protected areas in northern Uganda. As a long-term strategy for wildlife conservation, it is crucial to undertake a systematic assessment and prioritization and demarcation of wildlife corridors and development of a comprehensive action plan for securing them. We further recommend development of a national Wildlife Corridor Regulations to provide a framework for the sustainable conservation of biodiversity

Dances with Zigzags in Toro Muerto, Peru: Geometric Petroglyphs as (Possible) Embodiments of Songs

Southern Peru is home to one of the richest sites with rock art in South America—Toro Muerto. A unique aspect of the iconography of the petroglyphs of the site is the figures of dancing humans, the so-called danzantes, which are additionally frequently associated with geometric motifs, mostly variants of zigzag lines. Drawing upon intriguing data recorded during Reichel-Dolmatoff's research in Colombia related to the meaning of analogous motifs in Tukano art, as well as broader exploration of the sonic sphere in South American cultures and the thesis that Amazonian animism was a more archaic ontology over a broader area of South America, this paper suggests that the geometric patterns at Toro Muerto, with which the figures of danzantes are juxtaposed, may have been representations of songs. An extension of this hypothesis is the suggestion that some of the more complex compositions consisting of danzantes and linear geometric motifs were graphic metaphors of transfer to the other world.

Mn2C MXene functionalized by oxygen is a semiconducting antiferromagnet and an efficient visible light absorber.

Manganese-based MXenes are promising two-dimensional materials due to the broad palette of their magnetic phases and the possibility of experimental preparation because the corresponding MAX phase was already prepared. Here, we systematically investigated geometrical conformers and spin solutions of oxygen-terminated Mn2C MXene and performed subsequent many-body calculations to obtain reliable electronic and optical properties. Allowing energy-lowering using the correct spin ordering via supercell magnetic motifs is essential for the Mn2CO2 system. The stable ground-state Mn2CO2 conformation is antiferromagnetic (AFM) with zigzag lines of up and down spins on Mn atoms. The AFM nature is consistent with the parent MAX phase and even the clean depleted Mn2C sheet. Other magnetic states and geometrical conformations are energetically very close, providing state-switching possibilities in the material. Subsequent many-body GW and Bethe-Salpeter equation (BSE) calculations provide indirect semiconductor characteristics of AFM Mn2CO2 with a fundamental gap of 2.1 eV (and a direct gap of 2.4 eV), the first bright optical transition at 1.3 eV and extremely strongly bound (1.1 eV) first bright exciton. Mn2CO2 absorbs efficiently the whole visible light range and near ultraviolet range (between 10 and 20%).

Isolated Traumatic Sutural Diastasis in a Young Adult: A Case Report

The bony calvarium protects the most vital organ of our body.The skull is composed of various bones united by a zigzag line called sutures.The fusion of these sutures creates the protective calvarium of the brain.In addition to protection, this suture line helps during parturition. When the anterior and posterior fontanelle attaches via a fibrous sheet, it has a favorable shape during vaginal delivery and helps in the development of the brain.The suture fuses with the adjacent bones at certain ages and creates a protective calvarium.During this period, suture diastasis occurs due to various causes, such as RTA, falls, and increased intracranial pressure.It is usually associated with an additional fracture line; however, under

Baroque Iconostases of Eastern Podillya: the Main Structural Types

The iconostases of Eastern Podillya remain a little-known phenomenon that has been ignored by researchers of sacred art, with the exception of Oleh Sydor. The purpose of the article is to analyze and systematize the Eastern Podillya Baroque iconostases (based on the material of Vinnytsia region) by the types of constructions. The analysis of the preserved sacral ensembles and photographs of the lost ones gave reasons to identify four main groups of architectural structures. The monuments of the first group had a strictly horizontal layout of tiers, and the central vertical division was accentuated by larger elements and richer wooden carvings. In the second group, a gradual scale increase toward the centre is observed, starting, as a rule, from the Festival tier. For this purpose several methods were used: cornice bending above the deacon’s doors; placing above the nave row (between the deacon’s doors) an additional tier, mostly of Pentecost Sunday, or a decorative carved or painted panel, etc. Characteristic of the next type is the arched arrangement of the icons of the upper tiers of the middle part, starting from the Festival row. Finally, the fourth group comprises iconostases with creases symmetrical to the central axis, with the tiers in such ensembles being arranged on the same level or in stepwise order. The iconostases of the first three types had a straight line in the plan (alternatively, the side wings were wrapped around the log cabin walls), while the monuments of the fourth type had a broken (zigzag) line. Considering the limited amount of visual material involved, further research prospects depend on the discovery of new sources (iconostases, photographs or sketches), the study of which will allow verifying the conclusions made.

Influence of Monoculture and Polyculture Planting Patterns on the Intensity of Pest Attacks by Helopeltis sp. on Arabica Coffee of the Sigarar Utang Variety in North Tapanuli Regency

Coffee is one of the leading commodities in the plantation subsector in North Sumatra which has good market opportunities both domestically and abroad. Especially in the Lake Toba area, apart from the PBKo pest, it turns out that attacks by the coffee leaf sucking pest Helopeltis sp. are also felt to be very important by farmers, because the presence of Helopeltis sp. This causes the coffee leaf shoots to develop brown spots, curl and eventually dry out and die (die back). The aim of the research was to study the symptoms of attacks and the intensity of Helopeltis sp. attacks on Arabica coffee plants in the Lake Toba area, North Tapanuli Regency. This research was carried out on people's coffee plantations in North Tapanuli Regency at an altitude of 1,300 meters above sea level, from February to June 2023. On the Sigarar Utang variety Arabica coffee plantation with monoculture and polyculture planting patterns. The sample plants were determined to be 10% of the total plants at each observation location. Sampling of plant samples is determined using a zig zag line. The parameters observed were the intensity of attacks and the percentage of pest attacks. The results obtained by Helopeltis sp. sucking shoot pests have been known to attack coffee plants in North Tapanuli Regency with symptoms of attack. At the start of the attack, leaf spots are visible, brown, curly and eventually dry out, die back, then grow rosettes, namely shoots, new ones that are shortened tightly and do not develop. The intensity of attacks by Helopeltis sp. on smallholder coffee plantations in North Tapanuli Regency is quite varied, from light to heavy attacks with the intensity of shoot attacks ranging from 15.67% to 57.80%. Monoculture coffee plantations with protective plants, but no pruning, are locations with Helopeltis sp. attack levels in the heavy category with shoot attack intensity reaching 56.66%. The intercropping coffee plant cultivation system (polyculture) had a significant influence on the low intensity of Helopeltis sp. attacks, where tcount (8.921) > ttable (2.306).

Improving the properties of TiC steel bonded cemented carbides by optimizing the slurry rheology, printing path and shape design of 3D gel printing

TiC steel bonded cemented carbide was modeled by an extrusion-based 3D gel printing(3DGP) method. The rheological behavior of slurry was studied to control the slurry extrusion and modeling. The effects of printing parameters, printing path and modeling complexity were researched to get a printed sample without defects. The results indicated that the slurry with a solid loading of 50 vol% (85 wt%) was prepared, and its viscosity change is very little during 24 h in case of a higher shear rate like a nozzle. The viscosity of the slurry decreases with increasing the extrusion pressure and nozzle diameter. The skewed pattern of filaments eliminated pores in printed samples in comparison with the rectangular pattern under the condition of straight lines of the printing path. Pores at the corners of a model can be eliminated by changing the printing path from concentric lines to zigzag lines or two sets of slanted parallel lines. The modeling complexity without a support structure can be revealed by printing tilt cylinders with different angles, and the local parts on a model with a tilt angle of <45° can be printed accurately without designing a support structure. Improving the 3DGP procedure based on these experiences, the TiC steel bonded cemented carbide samples had properties similar to those prepared by conventional powder metallurgy methods.

Investigation of zigzag line defects in friction stir welding of SS304 stainless steel

The zigzag line defect (ZLD) formed in the stir zone (SZ) affects the microstructural and mechanical properties of the materials welded by friction stir welding (FSW). In this research, the cause of ZLD formation in the FSW of SS304 steel was analyzed. The results showed that this defect is formed under incomplete penetration conditions. Under such conditions, oxygen enters the SZ from the incomplete penetration site and linearly creates micro- and nano-voids of metal oxides. The formed oxide voids had high hardness, but due to crack nucleation, they showed low fracture toughness.

On the Origins of the Récades of the Kings of Dahomey

On the Origins of the <i>Récades</i> of the Kings of Dahomey

Collective-Coupling Enhanced Ultrabroadband Linear Polarization Conversion on Zigzag-Split Metasurfaces

Polarization manipulation plays a pivotal role in integrated multifunctional devices. Various metasurface-based polarization converters successfully demonstrated high efficiency and broad bandwidth. However, new mechanisms to aggressively enhance performance are still in dire need. Herein, theoretical and experimental evidence corroborates an efficient ultra-wideband transmissive polarization converter based on a topological design method. The triple-layer meta-device consists of a layer of anisotropic zigzag-split resonator array amid two orthogonal wire-grating layers. By splitting double zigzag lines into compound 90°V-shaped resonators, the intra-unit cross-coupling extends to strong inter-unit cross-coupling, giving birth to the multi-resonances enhancement and significant bandwidth broadening. This polarization converter can efficiently convert linearly polarized incident waves into 90° cross-polarized transmitted waves, with a conversion efficiency above 80% over 3.98-22.71 GHz, reaching a fractional bandwidth of 140.4%. The proposed meta-device enables strong cross-coupling in mutual transition from intra-unit to inter-unit. From a physical viewpoint, the novel mechanism is elucidated by the surface current and electric field distributions upon constructive interferences stemming from V-shape-resonator combinations and the Fabry-Pérot-like cavity effect. With both spectrum and function extensions, the proposed polarization conversion strategy finds essential applications in polarization-related systematic scenarios, such as 6G communication, radar imaging, anti-interference, chiral sensing, etc.

Algorithm Development for Full Gaps of Landsat 7 Images

Landsat7 of Enhanced thematic mapper plus (ETM+) was launched on April 15, 1999. Four years later, images start degrading due to the scan line corrector (SLC). SLC is a malfunction that results in pixel gaps in images captured by the sensor of Landsat7. The pixel gap regions extend from about one pixel near the image center and reach up to about 14 pixels in width near the image edge. The shape of this loss is like a zigzag line; however, there are different studies about repairing these gaps. The challenge of all studies depends on retrieving inhomogeneous areas because the homogenous area can be retrieved quickly depending on the surrounding area. This research focuses on filling these gaps by utilizing pixels around them gaps. Pixels from different satellites with the same resolution at the approximate equal date and exact location would be utilized. Mean and standard deviation were used in gap pixel predicting. For complete pixels gap predicting, an image registration should be applied for predicted a good result—image registration comprised of geometric and radiometric registration. Translation and rotation was the main effect of geometric registration, while pixel tone was mainly related to radiometric registration. Two images of Landsat8 (before and after) with nearly the date of Landsat 7 were used. The fidelity criteria (mean square error and mean absolute error) were utilized to evaluate the results. The results showed a good prediction of the gap pixels in the Landsat 7 image, considering the geometric and radiometric parts.

Dietary Biotin Deficiency Affects Reproductive Function and Prenatal Development in Hamsters

The effects of maternal dietary biotin deficiency on hamster embryos were examined by adding different amounts of avidin (0, 10, 50, 100 or 1000 mg/kg diet) to a semipurified commercial diet during the entire period of gestation. On d 10 of gestation, reduced dietary biotin resulted in a high incidence of resorbed and dead embryos. In addition, both the crown-rump length and head length of dietary biotin-deficient embryos were lower, and their digit development was retarded. These embryos were characterized by pericardial cavity enlargement (40%) and zig-zag closure line of the neural tube (44%). Some embryos exhibited abnormalities of the craniofacial region and tail. On d 14 of gestation, embryonic growth retardation, morphological abnormalities and skeletal defects were seen in the dietary biotin-deficient group (fed 100 mg avidin/kg diet). The striking abnormalities were cleft palate, micromelia, micrognathia and rib deformities in approximately 10% of the fetuses. Histological examination of the placentae revealed some differences in the spongiotrophoblast and labyrinth layers between the control and dietary biotin-deficient groups. The teratogenic effect of dietary biotin deficiency previously observed in mice was confirmed in hamsters.

Geneze keltských třetin statéru tzv. hmyzího typu

The Origin of the Celtic 1/3-Staters of the So-Called Insect Type The article deals with chonology, provenance, typology and development of the reverse images of 1/3-staters of the so called insect type which had evolved from the late Bohemian issues of the Athena Alkidemos type during the pre-Stradonice Period already, and was subsequently struck simultaneously with the 1/3-staters of the so-called Muschel type with zigzag line.

Understanding the zigzags of multi-echo phase signals by numerical simulations

Understanding the multi-echo phase zigzag signals is instrumental to assuring the quality of MRI phase data acquisition for ensuing phase exploration and exploitation. This paper provides a theoretical and computational mechanism for understanding the zigzag multi-echo phase formation that has been observed in numerical multi-echo gradient-recalled (GRE) simulations of clinical complex-valued brain MRI images. Based on intravoxel dephasing mechanism, we calculated a train of multi-GRE complex-valued voxel signals by simulating field gradient reversals under perturbations in either gradient strength (G±δG) or gradient duration (Δ±δΔ), as well as the simultaneous bi-variable gradient perturbations (δGδΔ). In this theoretical experiment, we observed a zigzag line of one-shot multi-echo phase signals at a voxel with respect to linear stepwise field gradient variations in δG ∝ n and δΔ ∝ n (where n denotes the echo index). However, the multi-echo magnitude signals were invariant to field gradient reversal, i.e. no multi-echo magnitude zigzags. To support our simulations, we analyzed the clinical one-shot multi-echo T2*-weighted MRI phase images and found similar multi-echo phase zigzags. In this way, we provide a theoretical and computational understanding of multi-echo phase zigzag artifacts, specifically for the eddy current effect on one-shot multi-GRE signals in practice.

Macroreentrant scar-mediated atrial tachycardia terminated by a nonpropagated stimulus within a narrow diastolic isthmus: Electroanatomic correlation

A 76-year-old woman with coronary artery disease status post coronary artery bypass grafting and paroxysmal atrial fibrillation and flutter status post cavotricuspid isthmus ablation underwent radiofrequency (RF) ablation of recurrent, symptomatic atrial tachycardia (AT) (cycle length [CL] 378 ms). High-density activation mapping using a Biosense Webster (Diamond Bar, CA) PentaRay® catheter revealed a macroreentrant circuit rotating clockwise (right anterior oblique, caudal view) along the right atrial free wall and conducting slowly through a narrow isthmus (zigzag line) (Figure 1A).

Continuous contour-zigzag hybrid toolpath for large format additive manufacturing

Large format additive manufacturing (LFAM) has witnessed rapid development in recent years and facilitated digital fabrications of geometrically intricate structures. However, there has been limited research on toolpath optimization tailored for LFAM. This paper presents a novel framework to generate a globally continuous toolpath for both solid and partial infill designs in LFAM. For solid infill, outward contour and double offset schemes are used to generate smooth curves as the primary volume-filling paths; the remaining unfilled areas are covered by extending zigzag lines from the closest contours. Subsequently, a contour layer-wise connection is carried out based on the depth-first-search algorithm to formulate a globally continuous path. A post-processing step is also presented to optimize the coverage and curvature of the toolpath design. The concept is extended for partial infill settings by trimming and joining rectangular grid lines. Compared with other state-of-the-art methods in the literature, the proposed algorithm is superior in delivering better print quality, fewer sharp turns, and enhanced fabrication efficiency. Finally, two interesting experiments demonstrate how LFAM of topology optimized structures can benefit from the proposed continuous toolpath: topology optimized table printed from thermoplastic polyurethane (TPU) and topology optimized chair printed from 3D concrete printing (3DCP).

A new algorithm for optimal process parameters based on minimum building time in additive manufacturing

BackgroundAdditive manufacturing method is used for manufacturing of solid three-dimensional parts. It requires less human efforts and manufacturing time for parts is less. Different process parameters such as layer thickness, building orientation, infill type, and infill percentage affect the building time, model cost, mechanical properties, and surface roughness. The presented paper develops an algorithm for adapting layers and generating tool-paths. This algorithm can improve the fabrication efficiency and geometrical accuracy in the additive manufacturing (AM) of complex models. The proposed algorithm consists of three modules that identify the optimal process parameters, named as part building orientation, layer thickness, strategy type for internal filling, and slope of the tool-path.ResultsThe input is the PTS file that contains the points of the layers contour of the computer-aided design (CAD) model. All the modules for the proposed algorithm were implemented using the MATLAB R2019a programming language software. The main finding results showed that the fabrication with an adaptive layer thickness was more time-efficient. The build time was reduced up to 47.3%. The developed tool-path generation strategies (contour offset and zigzag line tool-path) can effectively balance the AM surface quality and fabrication efficiency requirements.ConclusionIn this research, the AM users can benefit by saving the cost and time. The parts were fabricated with a high degree of accuracy, and the surface finish was suitable for determining the optimal process parameter.

Important Features Selection and Classification of Adult and Child from Handwriting Using Machine Learning Methods

The classification of different age groups, such as adult and child, based on handwriting is very important due to its various applications in many different fields. In forensics, handwriting classification helps investigators focus on a certain category of writers. This paper aimed to propose a machine-learning (ML)-based approach for automatically classifying people as adults or children based on their handwritten data. This study utilized two types of handwritten databases: handwritten text and handwritten pattern, which were collected using a pen tablet. The handwritten text database had 57 subjects (adult: 26 vs. child: 31). Each subject (adult or child) wrote the same 30 words using Japanese hiragana characters. The handwritten pattern database had 81 subjects (adult: 42 and child: 39). Each subject (adult or child) drew four different lines as zigzag lines (trace condition and predict condition), and periodic lines (trace condition and predict condition) and repeated these line tasks three times. Handwriting classification of adult and child is performed in three steps: (i) feature extraction; (ii) feature selection; and (iii) classification. We extracted 30 features from both handwritten text and handwritten pattern datasets. The most efficient features were selected using sequential forward floating selection (SFFS) method and the optimal parameters were selected. Then two ML-based approaches, namely, support vector machine (SVM) and random forest (RF) were applied to classify adult and child. Our findings showed that RF produced up to 93.5% accuracy for handwritten text and 89.8% accuracy for handwritten pattern databases. We hope that this study will provide the evidence of the possibility of classifying adult and child based on handwriting text and handwriting pattern data.

Zig-Zag Monofilar Spiral Shaped CRLH TL Based Compact Lowpass mono-/duo-/tri-/quad-bandpass Filter

ABSTRACT Planar compact lowpass mono-/duo-/tri-/quad-bandpass filters design based on CRLH TL are presented. Filters are designed by cascading two unit-cells composed of Zig-Zag monofilar spiral lines (ZZMSL) and Zig-Zag open ring (ZZOR) loaded on the main transmission line. Only the length of ZZMSL which is housed within the fixed length of ZZOR is utilized to generate the multiple passbands, so all of the filters are of the same size. At the lowpass (LP) band of the filter’s −3 dB cut-off frequency of 0.71 GHz, the filter’s footprint area (excluding the feed line), is 0.083 λg × 0.034 λ g . The LP band's measured −3 dB cut-off frequency is 0.71 GHz, with a minimal in-band insertion loss of 0.22 dB and a return loss better than 20 dB from DC to 0.46 GHz. The measured center frequencies for four bandpass passbands are 1.3, 2.08, 3.37, and 4.6 GHz, with a −3 dB FBW of 76.15%, 10.57%, 8.6%, and 7.8%, respectively. The minimal insertion losses within the BPs are 0.26, 0.26, 0.39, and 0.4 dB, respectively, whereas the return losses are 33, 36, 19, and 37 dB. Lower in-band insertion loss, good band-to-band isolation, the controllable center frequency with good out-of-band skirts, higher compactness, and lower circuit complexity are all advantages of the proposed lowpass quad-bandpass filter. The Lowpass quad-bandpass filter is finally manufactured. A good agreement between electromagnetic simulation, circuit model simulation, and experimental measurement results validates the design process and filter performance.